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Sample records for noise-equivalent temperature difference

  1. Noise-equivalent sensitivity of photoacoustics

    PubMed Central

    Winkler, Amy M.; Maslov, Konstantin

    2013-01-01

    Abstract. The fundamental limitations of photoacoustic microscopy for detecting optically absorbing molecules are investigated both theoretically and experimentally. We experimentally demonstrate noise-equivalent detection sensitivities of 160,000 methylene blue molecules (270 zeptomol or 2.7×10−19  mol) and 86,000 oxygenated hemoglobin molecules (140 zeptomol) using narrowband continuous-wave photoacoustics. The ultimate sensitivity of photoacoustics is fundamentally limited by thermal noise, which can present in the acoustic detection system as well as in the medium itself. Under the optimized conditions described herein and using commercially available detectors, photoacoustic microscopy can detect as few as 100s of oxygenated hemoglobin molecules. Realizable improvements to the detector may enable single molecule detection of select molecules. PMID:24026425

  2. Determination of noise equivalent sigma(0) using highly correlated repeat-pass SAR images

    NASA Technical Reports Server (NTRS)

    Sun, James; Freeman, Anthony

    1993-01-01

    Noise equivalent sigma(sup 0) is a fundamental parameter in any synthetic aperture radar (SAR) measurement. Knowledge of the noise equivalent sigma(sup 0) allows the radar application scientist to band the error contributions due to noise present in his/her data. In this paper, a novel technique for determining noise equivalent sigma(sup 0) is presented. It has been observed that a pair of images obtained by a SAR over the same area in a nearly repeating orbit can demonstrate a high degree of correlation, depending on the baseline. If noise independence and signal power invariance are assumed, an estimate for the noise equivalent sigma(sup 0) for each image can be determined without any known ground targets. We examine the application of this technique to several images of different backscatter obtained by ERS-1.

  3. Noise equivalent circuit of a semiconductor laser diode

    NASA Technical Reports Server (NTRS)

    Harder, C.; Margalit, S.; Yariv, A.; Katz, J.; Shacham, J.

    1982-01-01

    A small-signal model of a semiconductor laser is extended to include the effects of intrinsic noise by adding current and voltage noise sources. The current noise source represents the shot noise of carrier recombination, while the voltage noise source represents the random process of simulated emission. The usefulness of the noise equivalent circuit is demonstrated by calculating the modulation and noise characteristics of a current-driven diode as a function of bias current and frequency.

  4. Equivalence of optical and electrical noise equivalent power of hybrid NbTiN-Al microwave kinetic inductance detectors

    SciTech Connect

    Janssen, R. M. J.; Endo, A.; Visser, P. J. de; Klapwijk, T. M.; Baselmans, J. J. A.

    2014-11-10

    We have measured and compared the response of hybrid NbTiN-Al Microwave Kinetic Inductance Detectors (MKIDs) to changes in bath temperature and illumination by sub-mm radiation. We show that these two stimulants have an equivalent effect on the resonance feature of hybrid MKIDs. We determine an electrical noise equivalent power (NEP) from the measured temperature responsivity, quasiparticle recombination time, superconducting transition temperature, and noise spectrum, all of which can be measured in a dark environment. For the two hybrid NbTiN-Al MKIDs studied in detail, the electrical NEP is within a factor of two of the optical NEP, which is measured directly using a blackbody source.

  5. Measuring PET scanner sensitivity; Relating count rates to image signal-to-noise ratios using noise equivalent counts

    SciTech Connect

    Strother, S.C. ); Casey, M.E. ); Hoffman, E.J. . Nuclear Medicine Lab.)

    1990-04-01

    Sensitivity parameters derived from a plot of a scanner's true coincidence count (TCC) rates as a function of activity in a 20 cm cylindrical phantom have no direct link to image quality. Noise equivalent count (NEC) rate curves, which incorporate the noise effects of subtracting the randoms and scatter count components provide a direct link between image signal-to-noise ratios and the scatter, randoms and trues coincidence count rates. The authors have measured TCC and NEC curves with a standardized 20 cm diameter nylon cylinder for five different PET scanners with several scanner-collimator combinations. In addition, the authors have compared TCC and NEC curves on one scanner with those from an Alderson brain phantom.

  6. Determination of noise equivalent reflectance for a multispectral scanner: A scanner sensitivity study

    NASA Technical Reports Server (NTRS)

    Gibbons, D. E.; Richard, R. R.

    1979-01-01

    The methods used to calculate the sensitivity parameter noise equivalent reflectance of a remote-sensing scanner are explored, and the results are compared with values measured over calibrated test sites. Data were acquired on four occasions covering a span of 4 years and providing various atmospheric conditions. One of the calculated values was based on assumed atmospheric conditions, whereas two others were based on atmospheric models. Results indicate that the assumed atmospheric conditions provide useful answers adequate for many purposes. A nomograph was developed to indicate sensitivity variations due to geographic location, time of day, and season.

  7. A reconsideration of the noise equivalent power and the data analysis procedure for the infrared imaging video bolometers

    SciTech Connect

    Pandya, Shwetang N. Sano, Ryuichi; Peterson, Byron J.; Kobayashi, Masahiro; Mukai, Kiyofumi; Pandya, Santosh P.

    2014-12-15

    The infrared imaging video bolometer (IRVB) used for measurement of the two-dimensional (2D) radiation profiles from the Large Helical Device has been significantly upgraded recently to improve its signal to noise ratio, sensitivity, and calibration, which ultimately provides quantitative measurements of the radiation from the plasma. The reliability of the quantified data needs to be established by various checks. The noise estimates also need to be revised and more realistic values need to be established. It is shown that the 2D heat diffusion equation can be used for estimating the power falling on the IRVB foil, even with a significant amount of spatial variation in the thermal diffusivity across the area of the platinum foil found experimentally during foil calibration. The equation for the noise equivalent power density (NEPD) is re-derived to include the errors in the measurement of the thermophysical and the optical properties of the IRVB foil. The theoretical value estimated using this newly derived equation matches closely, within 5.5%, with the mean experimental value. The change in the contribution of each error term of the NEPD equation with rising foil temperature is also studied and the blackbody term is found to dominate the other terms at elevated operating temperatures. The IRVB foil is also sensitive to the charge exchange (CX) neutrals escaping from the plasma. The CX neutral contribution is estimated to be marginally higher than the noise equivalent power (NEP) of the IRVB. It is also established that the radiation measured by the IRVB originates from the impurity line radiation from the plasma and not from the heated divertor tiles. The change in the power density due to noise reduction measures such as data smoothing and averaging is found to be comparable to the IRVB NEPD. The precautions that need to be considered during background subtraction are also discussed with experimental illustrations. Finally, the analysis algorithm with all the improvements is validated and found to reproduce the input power well within 10% accuracy. This article answers many fundamental questions relevant to the IRVB and illustrates the care to be exercised while processing the IRVB data.

  8. Limits to the NEP of an intracavity LiNbO3 upconverter. [Noise Equivalent Power

    NASA Technical Reports Server (NTRS)

    See, Y. C.; Guha, S.; Falk, J.

    1980-01-01

    Limits to low noise equivalent power (NEP) operation of a lithium niobate upconverter are investigated. Upconversion is achieved inside the optical cavity of an Ar-ion laser. Limits to NEP are imposed by limits to conversion efficiency and by noise present in the upconversion process. Conversion efficiency is limited by thermal effects in the lithium niobate. Thermally induced wedging, focusing, and aberrations are caused by the lithium niobate absorption at the 514.5-nm argon pump wavelength. The primary component of noise in the upconverter is due to upconversion of thermal radiation from the lithium niobate crystal. The lowest NEP, at a wavelength of 3.4 microns, achieved in this study was 8.9 x 10 to the -14th W/(Hz to the 1/2 power).

  9. Performance limits to the operation of nanoplasmonic chemical sensors: noise-equivalent refractive index and detectivity

    NASA Astrophysics Data System (ADS)

    Jaksic, Zoran; Jaksic, Olga; Matovic, Jovan

    2009-04-01

    We considered figures of merit for chemical and biological sensors based on plasmonic structures and utilizing adsorption/desorption mechanism. The operation of these devices in general is limited by noise determining the minimum detectable refractive-index change. We dedicated our work to the intrinsic noise mechanisms connected with the plasmonic process itself. In contrast, most of the available literature is almost exclusively dedicated to the external noise sources (illumination source and photodetector). Reviewing the refractive-index fluctuations caused by thermal, adsorption-desorption and 1/f noise, we observed a striking analogy between the qualitative behavior of noise in (nano)plasmonic devices and that in semiconductor infrared detectors. The power spectral densities for noise in both of these have an almost identical shape; the adsorption-desorption noise corresponds to generation-recombination processes in detectors, while the other two mechanisms exist in the both types of the devices. Thus the large and mature existing apparatus for infrared detector noise analysis may be applied to the plasmonic sensors. Based on the observed analogy, we formulated the noise-equivalent refractive-index and the specific detectivity as the figures of merit to analyze the ultimate performance of plasmon sensors. The approach is valid for conventional surface plasmon resonance sensors, but also for nanoplasmonic and metamaterial-based devices.

  10. Optimization of noise-equivalent count rates in 3D PET

    NASA Astrophysics Data System (ADS)

    Badawi, R. D.; Marsden, P. K.; Cronin, B. F.; Sutcliffe, J. L.; Maisey, M. N.

    1996-09-01

    We have used noise-equivalent count (NEC) rates to optimize count rate performance for 3D acquisition in PET in a wide range of situations, with particular reference to imaging of the torso. We have also compared NEC performance for 2D and 3D acquisition in order to establish the conditions under which 3D mode offers an improvement over 2D mode. Measurements were performed on four tissue-equivalent phantoms ranging in size from that of an infant's head (13 cm diameter) to that of an obese adult's chest 37 cm by 48 cm. Count rate data were acquired as a function of phantom size, activity in the field of view, lower energy discriminator level (LLD) and acquisition mode, and NEC rates were derived as a function of these variables. The LLD at which the highest NEC rate is obtained shows a dependence both on phantom size and on the activity in the field of view both for 2D and for 3D acquisition. The relative advantage of 3D mode over 2D mode, at the optimum LLD setting, is also strongly dependent both on activity in the field of view (FOV) and on the phantom size. The main limiting factors for 3D NEC rates are detector dead-time for small phantoms and random coincidences for large phantoms. The 3D NEC rate is more than twice as great as the 2D NEC rate when less than 60 MBq is present in the FOV for all phantoms except the largest, in which case a ratio of two is only achieved for activities less than 25 MBq. For the smallest phantom, 3D/2D NEC ratios of greater than 3.5 are obtained when the activity in the FOV falls below 10 MBq.

  11. Characterization of imaging performance in differential phase contrast CT compared with the conventional CT: Spectrum of noise equivalent quanta NEQ(k)

    SciTech Connect

    Tang Xiangyang; Yang Yi; Tang Shaojie

    2012-07-15

    Purpose: Differential phase contrast CT (DPC-CT) is emerging as a new technology to improve the contrast sensitivity of conventional attenuation-based CT. The noise equivalent quanta as a function over spatial frequency, i.e., the spectrum of noise equivalent quanta NEQ(k), is a decisive indicator of the signal and noise transfer properties of an imaging system. In this work, we derive the functional form of NEQ(k) in DPC-CT. Via system modeling, analysis, and computer simulation, we evaluate and verify the derived NEQ(k) and compare it with that of the conventional attenuation-based CT. Methods: The DPC-CT is implemented with x-ray tube and gratings. The x-ray propagation and data acquisition are modeled and simulated through Fresnel and Fourier analysis. A monochromatic x-ray source (30 keV) is assumed to exclude any system imperfection and interference caused by scatter and beam hardening, while a 360 Degree-Sign full scan is carried out in data acquisition to avoid any weighting scheme that may disrupt noise randomness. Adequate upsampling is implemented to simulate the x-ray beam's propagation through the gratings G{sub 1} and G{sub 2} with periods 8 and 4 {mu}m, respectively, while the intergrating distance is 193.6 mm (1/16 of the Talbot distance). The dimensions of the detector cell for data acquisition are 32 Multiplication-Sign 32, 64 Multiplication-Sign 64, 96 Multiplication-Sign 96, and 128 Multiplication-Sign 128 {mu}m{sup 2}, respectively, corresponding to a 40.96 Multiplication-Sign 40.96 mm{sup 2} field of view in data acquisition. An air phantom is employed to obtain the noise power spectrum NPS(k), spectrum of noise equivalent quanta NEQ(k), and detective quantum efficiency DQE(k). A cylindrical water phantom at 5.1 mm diameter and complex refraction coefficient n= 1 -{delta}+i{beta}= 1 -2.5604 Multiplication-Sign 10{sup -7}+i1.2353 Multiplication-Sign 10{sup -10} is placed in air to measure the edge transfer function, line spread function and then modulation transfer function MTF(k), of both DPC-CT and the conventional attenuation-based CT. The x-ray flux is set at 5 Multiplication-Sign 10{sup 6} photon/cm{sup 2} per projection and observes the Poisson distribution, which is consistent with that of a micro-CT for preclinical applications. Approximately 360 regions, each at 128 Multiplication-Sign 128 matrix, are used to calculate the NPS(k) via 2D Fourier transform, in which adequate zero padding is carried out to avoid aliasing in noise. Results: The preliminary data show that the DPC-CT possesses a signal transfer property [MTF(k)] comparable to that of the conventional attenuation-based CT. Meanwhile, though there exists a radical difference in their noise power spectrum NPS(k) (trait 1/|k| in DPC-CT but |k| in the conventional attenuation-based CT) the NEQ(k) and DQE(k) of DPC-CT and the conventional attenuation-based CT are in principle identical. Conclusions: Under the framework of ideal observer study, the joint signal and noise transfer property NEQ(k) and detective quantum efficiency DQE(k) of DPC-CT are essentially the same as those of the conventional attenuation-based CT. The findings reported in this paper may provide insightful guidelines on the research, development, and performance optimization of DPC-CT for extensive preclinical and clinical applications in the future.

  12. Characterization of imaging performance in differential phase contrast CT compared with the conventional CT: Spectrum of noise equivalent quanta NEQ(k)

    PubMed Central

    Tang, Xiangyang; Yang, Yi; Tang, Shaojie

    2012-01-01

    Purpose: Differential phase contrast CT (DPC-CT) is emerging as a new technology to improve the contrast sensitivity of conventional attenuation-based CT. The noise equivalent quanta as a function over spatial frequency, i.e., the spectrum of noise equivalent quanta NEQ(k), is a decisive indicator of the signal and noise transfer properties of an imaging system. In this work, we derive the functional form of NEQ(k) in DPC-CT. Via system modeling, analysis, and computer simulation, we evaluate and verify the derived NEQ(k) and compare it with that of the conventional attenuation-based CT. Methods: The DPC-CT is implemented with x-ray tube and gratings. The x-ray propagation and data acquisition are modeled and simulated through Fresnel and Fourier analysis. A monochromatic x-ray source (30 keV) is assumed to exclude any system imperfection and interference caused by scatter and beam hardening, while a 360 full scan is carried out in data acquisition to avoid any weighting scheme that may disrupt noise randomness. Adequate upsampling is implemented to simulate the x-ray beam's propagation through the gratings G1 and G2 with periods 8 and 4 ?m, respectively, while the intergrating distance is 193.6 mm (1/16 of the Talbot distance). The dimensions of the detector cell for data acquisition are 32 32, 64 64, 96 96, and 128 128 ?m2, respectively, corresponding to a 40.96 40.96 mm2 field of view in data acquisition. An air phantom is employed to obtain the noise power spectrum NPS(k), spectrum of noise equivalent quanta NEQ(k), and detective quantum efficiency DQE(k). A cylindrical water phantom at 5.1 mm diameter and complex refraction coefficient n = 1 ? ? + i? = 1 ?2.5604 10?7 + i1.2353 10?10 is placed in air to measure the edge transfer function, line spread function and then modulation transfer function MTF(k), of both DPC-CT and the conventional attenuation-based CT. The x-ray flux is set at 5 106 photon/cm2 per projection and observes the Poisson distribution, which is consistent with that of a micro-CT for preclinical applications. Approximately 360 regions, each at 128 128 matrix, are used to calculate the NPS(k) via 2D Fourier transform, in which adequate zero padding is carried out to avoid aliasing in noise. Results: The preliminary data show that the DPC-CT possesses a signal transfer property [MTF(k)] comparable to that of the conventional attenuation-based CT. Meanwhile, though there exists a radical difference in their noise power spectrum NPS(k) (trait 1/|k| in DPC-CT but |k| in the conventional attenuation-based CT) the NEQ(k) and DQE(k) of DPC-CT and the conventional attenuation-based CT are in principle identical. Conclusions: Under the framework of ideal observer study, the joint signal and noise transfer property NEQ(k) and detective quantum efficiency DQE(k) of DPC-CT are essentially the same as those of the conventional attenuation-based CT. The findings reported in this paper may provide insightful guidelines on the research, development, and performance optimization of DPC-CT for extensive preclinical and clinical applications in the future. PMID:22830779

  13. Energy from low temperature differences

    NASA Astrophysics Data System (ADS)

    Parsons, B. K.

    1985-05-01

    A number of energy conservation and alternative energy approaches utilize a low temperature heat source. Applications in this category include: solar ponds, ocean thermal energy conversion (OTEC), low temperature solar thermal, geothermal, and waste heat recovery and bottoming cycles. Low temperature power extraction techniques are presented and the differences between closed and open Rankine power cycles are discussed. Specific applications and technical areas of current research in OTEC along with a breakdown of plant operating conditions and a rough cost estimate illustrate how the use of low temperature power conversion technology can be cost effective.

  14. Effective detective quantum efficiency (eDQE) and effective noise equivalent quanta (eNEQ) for system optimization purposes in digital mammography

    NASA Astrophysics Data System (ADS)

    Salvagnini, Elena; Bosmans, Hilde; Struelens, Lara; Marshall, Nicholas W.

    2012-03-01

    Effective detective quantum efficiency (eDQE) and effective noise equivalent quanta (eNEQ) were recently introduced to broaden the notion of DQE and NEQ by including system parameters such as focus blurring and system scatter rejection methods. This work investigates eDQE and eNEQ normalized for mean glandular dose (eNEQMGD) as a means to characterize and select optimal exposure parameters for a digital mammographic system. The eDQE was measured for three anode/filter combinations, with and without anti-scatter grid and for four thicknesses of poly(methylmethacrylate) (PMMA). The modulation transfer function used to calculate eDQE and eNEQ was measured from an edge positioned at 20,40,60,70 mm above the table top without scattering material in the beam. The grid-in eDQE results for all A/F settings were generally larger than those for grid-out. Contrarily, the eNEQMGD results were higher for grid-out than gridin, with a maximum difference of 61% among all A/F combinations and PMMA thicknesses. The W/Rh combination gave the highest eNEQMGD for all PMMA thicknesses compared to the other A/F combinations (for grid-in and grid-out), supporting the results of alternative methods (e.g. the signal difference to noise ratio method). The eNEQMGD was then multiplied with the contrast obtained from a 0.2mm Al square, resulting in a normalized quantity that was higher for the W/Rh combination than for the other A/F combinations. In particular, the results for the W/Rh combination were greater for the grid-in case. Furthermore, these results showed close agreement with a non-prewhitened match filter with eye response model observer (d') normalized for MGD.

  15. Electron temperature differences and double layers

    NASA Technical Reports Server (NTRS)

    Chan, C.; Hershkowitz, N.; Lonngren, K. E.

    1983-01-01

    Electron temperature differences across plasma double layers are studied experimentally. It is shown that the temperature differences across a double layer can be varied and are not a result of thermalization of the bump-on-tail distribution. The implications of these results for electron thermal energy transport in laser-pellet and tandem-mirror experiments are also discussed.

  16. Measuring noise equivalent irradiance of a digital short-wave infrared imaging system using a broadband source to simulate the night spectrum

    NASA Astrophysics Data System (ADS)

    Green, John R.; Robinson, Timothy

    2015-05-01

    There is a growing interest in developing helmet-mounted digital imaging systems (HMDIS) for integration into military aircraft cockpits. This interest stems from the multiple advantages of digital vs. analog imaging such as image fusion from multiple sensors, data processing to enhance the image contrast, superposition of non-imaging data over the image, and sending images to remote location for analysis. There are several properties an HMDIS must have in order to aid the pilot during night operations. In addition to the resolution, image refresh rate, dynamic range, and sensor uniformity over the entire Focal Plane Array (FPA); the imaging system must have the sensitivity to detect the limited night light available filtered through cockpit transparencies. Digital sensor sensitivity is generally measured monochromatically using a laser with a wavelength near the peak detector quantum efficiency, and is generally reported as either the Noise Equivalent Power (NEP) or Noise Equivalent Irradiance (NEI). This paper proposes a test system that measures NEI of Short-Wave Infrared (SWIR) digital imaging systems using a broadband source that simulates the night spectrum. This method has a few advantages over a monochromatic method. Namely, the test conditions provide spectrum closer to what is experienced by the end-user, and the resulting NEI may be compared directly to modeled night glow irradiance calculation. This comparison may be used to assess the Technology Readiness Level of the imaging system for the application. The test system is being developed under a Cooperative Research and Development Agreement (CRADA) with the Air Force Research Laboratory.

  17. Detection of Temperature Difference in Neuronal Cells

    PubMed Central

    Tanimoto, Ryuichi; Hiraiwa, Takumi; Nakai, Yuichiro; Shindo, Yutaka; Oka, Kotaro; Hiroi, Noriko; Funahashi, Akira

    2016-01-01

    For a better understanding of the mechanisms behind cellular functions, quantification of the heterogeneity in an organism or cells is essential. Recently, the importance of quantifying temperature has been highlighted, as it correlates with biochemical reaction rates. Several methods for detecting intracellular temperature have recently been established. Here we develop a novel method for sensing temperature in living cells based on the imaging technique of fluorescence of quantum dots. We apply the method to quantify the temperature difference in a human derived neuronal cell line, SH-SY5Y. Our results show that temperatures in the cell body and neurites are different and thus suggest that inhomogeneous heat production and dissipation happen in a cell. We estimate that heterogeneous heat dissipation results from the characteristic shape of neuronal cells, which consist of several compartments formed with different surface-volume ratios. Inhomogeneous heat production is attributable to the localization of specific organelles as the heat source. PMID:26925874

  18. Temperature sensitivity of different soil carbon sources

    NASA Astrophysics Data System (ADS)

    Thiessen*, S.; Gleixner, G.; Wutzler, T.; Reichstein, M.

    2012-04-01

    Soils contain the largest carbon pool in terrestrial ecosystems and it is widely assumed that even if a small fraction of this pool is mobilized due to global warming, this might affect the CO2 concentration in atmosphere. The effect of temperature and the influence of fresh substrate on soil organic matter decomposition are two key issues, which we need to understand in order to forecast soil carbon dynamics under climate change. The objective of this study was to investigate the temperature sensitivity of freshly added organic matter and bulk soil carbon to test the kinetic assumption of substrate quality. Further we were able to investigate if the addition of fresh organic matter accelerates decomposition of soil organic matter ("priming effect (PE)") and does this effect depends on temperature. We performed a laboratory incubation experiment in a newly developed through-flow soil incubation system and incubated sieved soil samples with and without 13C labeled litter for 199 days. The soils were incubated with two temperature treatments, one with diurnally temperature cycle between 5 and 15 C, the other between 15 and 25 C. Soil CO2 production was continuously monitored with an infrared gas analyzer, while the 13C signal was determined for -1, 2, 15, 42, 70, 93, 135, 158 and 199 days after litter addition. We observed that the instantaneous temperature sensitivity does not differ between the original and the amended soil. However, in the amended treatment the temperature sensitivity increased during the incubation time, along with increasing microbial biomass. Further, we found in both temperature treatments a stimulation of the soil organic matter decomposition by the freshly add organic matter. This relative stimulation was smaller in the warm treatment (46%) and in the cold treatment (54%). Overall we conclude that there is no simple substrate-temperature sensitivity relationship, but complex interactions governing the emergent temperature sensitivity.

  19. Meaning of temperature in different thermostatistical ensembles.

    PubMed

    Hänggi, Peter; Hilbert, Stefan; Dunkel, Jörn

    2016-03-28

    Depending on the exact experimental conditions, the thermodynamic properties of physical systems can be related to one or more thermostatistical ensembles. Here, we survey the notion of thermodynamic temperature in different statistical ensembles, focusing in particular on subtleties that arise when ensembles become non-equivalent. The 'mother' of all ensembles, the microcanonical ensemble, uses entropy and internal energy (the most fundamental, dynamically conserved quantity) to derive temperature as a secondary thermodynamic variable. Over the past century, some confusion has been caused by the fact that several competing microcanonical entropy definitions are used in the literature, most commonly the volume and surface entropies introduced by Gibbs. It can be proved, however, that only the volume entropy satisfies exactly the traditional form of the laws of thermodynamics for a broad class of physical systems, including all standard classical Hamiltonian systems, regardless of their size. This mathematically rigorous fact implies that negative 'absolute' temperatures and Carnot efficiencies more than 1 are not achievable within a standard thermodynamical framework. As an important offspring of microcanonical thermostatistics, we shall briefly consider the canonical ensemble and comment on the validity of the Boltzmann weight factor. We conclude by addressing open mathematical problems that arise for systems with discrete energy spectra. PMID:26903095

  20. Minimum Temperatures, Diurnal Temperature Ranges and Temperature Inversions in Limestone Sinkholes of Different Sizes and Shapes

    SciTech Connect

    Whiteman, Charles D.; Haiden, Thomas S.; Pospichal, Bernhard; Eisenbach, Stefan; Steinacker, Reinhold

    2004-08-01

    Air temperature data from five enclosed limestone sinkholes of various sizes and shapes on the 1300 m MSL Duerrenstein Plateau near Lunz, Austria have been analyzed to determine the effect of sinkhole geometry on temperature minima, diurnal temperature ranges, temperature inversion strengths and vertical temperature gradients. Data were analyzed for a non-snow-covered October night and for a snow-covered December night when the temperature fell as low as -28.5C. Surprisingly, temperatures were similar in two sinkholes with very different drainage areas and depths. A three-layer model was used to show that the sky-view factor is the most important topographic parameter controlling cooling for basins in this size range and that the cooling slows when net longwave radiation at the floor of the sinkhole is nearly balanced by the ground heat flux.

  1. Radically Different Kinetics at Low Temperatures

    NASA Astrophysics Data System (ADS)

    Sims, Ian

    2014-06-01

    The use of the CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme, or Reaction Kinetics in Uniform Supersonic Flow) technique coupled with pulsed laser photochemical kinetics methods has shown that reactions involving radicals can be very rapid at temperatures down to 10 K or below. The results have had a major impact in astrochemistry and planetology, as well as proving an exacting test for theory. The technique has also been applied to the formation of transient complexes of interest both in atmospheric chemistry and combustion. Until now, all of the chemical reactions studied in this way have taken place on attractive potential energy surfaces with no overall barrier to reaction. The F + H2 {→} HF + H reaction does possess a substantial energetic barrier ({\\cong} 800 K), and might therefore be expected to slow to a negligible rate at very low temperatures. In fact, this H-atom abstraction reaction does take place efficiently at low temperatures due entirely to tunneling. I will report direct experimental measurements of the rate of this reaction down to a temperature of 11 K, in remarkable agreement with state-of-the-art quantum reactive scattering calculations by François Lique (Université du Havre) and Millard Alexander (University of Maryland). It is thought that long chain cyanopolyyne molecules H(C2)nCN may play an important role in the formation of the orange haze layer in Titan's atmosphere. The longest carbon chain molecule observed in interstellar space, HC11N, is also a member of this series. I will present new results, obtained in collaboration with Jean-Claude Guillemin (Ecole de Chimie de Rennes) and Stephen Klippenstein (Argonne National Labs), on reactions of C2H, CN and C3N radicals (using a new LIF scheme by Hoshina and Endo which contribute to the low temperature formation of (cyano)polyynes. H. Sabbah, L. Biennier, I. R. Sims, Y. Georgievskii, S. J. Klippenstein, I. W. M. Smith, Science 317, 102 (2007). S. D. Le Picard, M. Tizniti, A. Canosa, I. R. Sims, I. W. M. Smith, Science 328, 1258 (2010). H. Sabbah, L. Biennier, S. J. Klippenstein, I. R. Sims, B. R. Rowe, J. Phys. Chem. Lett. 1, 2962 (2010). M. Tizniti, S. D. Le Picard, F. Lique, C. Berteloite, A. Canosa, M. H. Alexander, I. R. Sims, Nature Chemistry 6, 141 (2014). S. Cheikh Sid Ely, S. B. Morales, J. C. Guillemin, S. J. Klippenstein, I. R. Sims, J. Phys. Chem. A 117, 12155 (2013). K. Hoshina, Y. Endo, J. Chem. Phys. 127, 184304 (2007).

  2. Development of Temperature Sensitive Paints for the Detection of Small Temperature Differences

    NASA Technical Reports Server (NTRS)

    Oglesby, Donald M.; Upchurch, Billy T.; Sealey, Bradley S.; Leighty, Bradley D.; Burkett, Cecil G., Jr.; Jalali, Amir

    1997-01-01

    Temperature sensitive paints (TSP s) have recently been used to detect small temperature differences on aerodynamic model surfaces. These types of applications impose stringent performance requirements on a paint system. The TSP s must operate over a broad temperature range, must be physically robust (cannot chip or peel), must be polishable to at least the smoothness of the model surface, and must have sufficient sensitivity to detect small temperature differences. TSP coatings based on the use of metal complexes in polymer binders were developed at NASA Langley Research Center which meet most of the requirements for detection of small temperature differences under severe environmental conditions.

  3. Mid-infrared laser absorption spectrometers based upon all-diode laser difference frequency generation and a room temperature quantum cascade laser for the detection of CO, N2O and NO

    NASA Astrophysics Data System (ADS)

    Kasyutich, V. L.; Holdsworth, R. J.; Martin, P. A.

    2008-08-01

    We describe the performance of two mid-infrared laser spectrometers for carbon monoxide, nitrous oxide and nitric oxide detection. The first spectrometer for CO and N2O detection around 2203 cm-1 is based upon all-diode laser difference frequency generation (DFG) in a quasi-phase matched periodically-poled lithium niobate (PPLN) crystal using two continuous-wave room-temperature distributed feedback diode lasers at 859 and 1059 nm. We also report on the performance of a mid-infrared spectrometer for NO detection at 1900 cm-1 based upon a thermoelectrically-cooled continuous-wave distributed feedback quantum cascade laser (QCL). Both spectrometers had a single-pass optical cell and a thermoelectrically cooled HgCdZnTe photovoltaic detector. Typical minimum detection limits of 2.8 ppmv for CO, 0.6 ppmv for N2O and 2.7 ppmv for NO have been demonstrated for a 100 averaged spectra acquired within 1.25 s and a cell base length of 21 cm at 100 Torr. Noise-equivalent absorptions of 10-5 and 10-4 Hz-1/2 are typically demonstrated for the QCL and the DFG based spectrometers, respectively.

  4. Ground surface temperature simulation for different land covers

    NASA Astrophysics Data System (ADS)

    Herb, William R.; Janke, Ben; Mohseni, Omid; Stefan, Heinz G.

    2008-07-01

    SummaryA model for predicting temperature time series for dry and wet land surfaces is described, as part of a larger project to assess the impact of urban development on the temperature of surface runoff and coldwater streams. Surface heat transfer processes on impervious and pervious land surfaces were investigated for both dry and wet weather periods. The surface heat transfer equations were combined with a numerical approximation of the 1-D unsteady heat diffusion equation to calculate pavement and soil temperature profiles to a depth of 10 m. Equations to predict the magnitude of the radiative, convective, conductive and evaporative heat fluxes at a dry or wet surface, using standard climate data as input, were developed. A model for the effect of plant canopies on surface heat transfer was included for vegetated land surfaces. Given suitable climate data, the model can simulate the land surface and sub-surface temperatures continuously throughout a six month time period or for a single rainfall event. Land surface temperatures have been successfully simulated for pavements, bare soil, short and tall grass, a forest, and two agricultural crops (corn and soybeans). The simulations were run for three different locations in US, and different years as imposed by the availability of measured soil temperature and climate data. To clarify the effect of land use on surface temperatures, the calibrated coefficients for each land use and the same soil coefficients were used to simulate surface temperatures for a six year climate data set from Albertville, MN. Asphalt and concrete give the highest surface temperatures, as expected, while vegetated surfaces gave the lowest. Bare soil gives surface temperatures that lie between those for pavements and plant-covered surfaces. The soil temperature model predicts hourly surface temperatures of bare soil and pavement with root-mean-square errors (RMSEs) of 1-2 C, and hourly surface temperatures of vegetation-covered surfaces with RMSEs of 1-3 C.

  5. Electron beam irradiated polyamide-6 at different temperatures

    NASA Astrophysics Data System (ADS)

    Burillo, G.; Adem, E.; Muoz, E.; Vsquez, M.

    2013-03-01

    Electron beam irradiation of Polyamide-6 (PA-6) films was carried out over a range of irradiation doses (15-1200 kGy) in air at different temperatures (from room temperature to 80 C), and at a dose rate of 4.48 kGy/min. The effect of temperature on the radiochemical crosslinking, scission yield, and the dose of incipient gel formation of PA-6 were investigated on the basis of solution viscosity, molecular weight and gel content. The crosslinking efficiency increases with increasing irradiation dose and temperature. The crosslinking rates of PA-6 irradiated above the glass transition temperature (Tg), about 50 C, are higher than those samples irradiated at temperatures below Tg. FTIR and electron paramagnetic resonance (EPR) spectroscopy are used to determine modifications in the samples induced by irradiation. EPR was also used to study the decay of the free radicals.

  6. Temperature transport in Lysimeters – comparison of different setups

    NASA Astrophysics Data System (ADS)

    Weller, Ulrich; Weber, Katja; Seyfarth, Manfred; Reth, Sascha

    2015-04-01

    Lysimeter studies are designed to mimick the undisturbed soil for the study of soil processes. Ecological and chemical processes are influenced by temperature and therefore it is mandatory that the temperature regime in the lysimeter follows closely the natural conditions. Unfortunately the lysimeter has a lower boundary that cuts off the natural dampening temperature flux. Also the walls of the vessel can transport temperature in a higher rate than the soil would do. And the exchange with the surrounding air at the installation facility may add a bias to the temperature regime in the lysimeter vessels. To test the influence of the wall and the lower boundary we have set up a lysimeter experiment with three different lysimeters. These are all 1m surface by 2 m depth vessels, identically filled with a sandy loam. All three were instrumented with temperature sensors in 4 depths, and at each depth with 4 sensors, with a distance of 2,5 cm; 5 cm; 10 cm and 15 cm from the wall. In addition, temperature sensors in the surrounding soil and air temperature in the lysimeter containment are available. The three vessels differ in their setup and material. One vessel is a standard stainless steel vessel with seepage boundary, the second is stainless steel with isolation and a controlled lower boundary. This vessel has a tube system at the bottom that circulates water in the vessel and the surrounding soil at the same depth. The control ascertains that the bottom temperature of the lysimeter vessel is always the same as in the surrounding soil. The third vessel is made of PE, in order to minimize temperature transport in the wall material. The data so far shows little difference between the alternative setup. It seems that in a well closed lysimeter containment the temperature regime is sufficiently close to the natural soil. This is especially true for the top soil where most biological and chemical processes occur.

  7. Temperature Rise during Resin Composite Polymerization under Different Ceramic Restorations

    PubMed Central

    Yondem, Isa; Altintas, Subutay Han; Usumez, Aslihan

    2011-01-01

    Objectives: The purpose of this study was to measure temperature increase induced by various light polymerizing units during resin composite polymerization beneath one of three types of ceramic restorations. Methods: The resin composite (Variolink II) was polymerized between one of three different ceramic specimens (zirconium oxide, lithium disilicate, feldspathic) (diameter 5 mm, height 2 mm) and a dentin disc (diameter 5 mm, height 1 mm) with a conventional halogen light, a high intensity halogen light, or an LED unit. The temperature rise was measured under the dentin disc with a J-type thermocouple wire connected to a data logger. Ten measurements were carried out for each group. The difference between the initial and highest temperature readings was taken and the 10 calculated temperature changes were averaged to determine the mean value in temperature rise. Two way analysis of variance (ANOVA) was used to analyze the data (polymerizing unit, ceramic brand) for significant differences. The Tukey HSD test was used to perform multiple comparisons (?=.05). Results: Temperature rise did not vary significantly depending on the light polymerizing unit used (P=.16), however, the type of ceramic system showed a significant effect on temperature increases (P<.01). There were no statistically significant differences between lithium disilicate and feldspathic ceramic systems (P >.05); in comparison, the resin composite polymerized under the zirconium oxide ceramic system induced a significantly lower temperature increase than the other ceramic systems tested (P<.05) Conclusions: The resin composite polymerized beneath zirconium oxide ceramic system induced significantly smaller temperature changes. The maximal temperature increase detected in all groups in this study was not viewed as critical for pulpal health. PMID:21769272

  8. Influence of perfusate temperature on nasal potential difference.

    PubMed

    Bronsveld, Inez; Vermeulen, Franois; Sands, Dorotha; Leal, Teresinha; Leonard, Anissa; Melotti, Paola; Yaakov, Yasmin; de Nooijer, Roel; De Boeck, Kris; Sermet, Isabelle; Wilschanski, Michael; Middleton, Peter G

    2013-08-01

    Nasal potential difference (NPD) quantifies abnormal ion transport in cystic fibrosis. It has gained acceptance as an outcome measure for the investigation of new therapies. To quantify the effect of solution temperature on NPD, we first examined the effect of switching from room temperature (20-25C) to warmed (32-37C) solutions and vice versa during each perfusion step. Secondly, standard protocols were repeated at both temperatures in the same subjects. Changing solution temperature did not alter NPD during perfusion with Ringer's solution (<1 mV) (p>0.1). During perfusion with zero chloride solution, changing from room temperature to warmed solutions tended to decrease absolute NPD (i.e. it became less negative) by 0.9 mV (p>0.1); changing from warmed to room temperature increased NPD by 2.1 mV (p<0.05). During isoprenaline perfusion, changing from room temperature to warmed solutions increased NPD by 1.5 mV (p<0.01) and from warmed to room temperature decreased NPD by 1.4 mV (p<0.05). For full protocols at room temperature or warmed in the same subjects, mean values were similar (n = 24). During warmed perfusion, group results for total chloride response had a larger standard deviation. As this increased variability will probably decrease the power of trials, this study suggests that solutions at room temperature should be recommended for the measurement of NPD. PMID:23100510

  9. Dayside-Nightside Temperature Differences in Hot Jupiter Atmospheres

    NASA Astrophysics Data System (ADS)

    Komacek, Thaddeus D.; Showman, Adam P.

    2015-12-01

    The infrared phase curves of low-eccentricity transiting hot Jupiters show a trend of increasing flux amplitude, or increasing day-night temperature difference, with increasing equilibrium temperature. Here we utilize atmospheric circulation modeling and analytic theory to understand this trend, and the more general question: what processes control heat redistribution in tidally-locked giant planet atmospheres? We performed a wide range of 3D numerical simulations of the atmospheric circulation with simplified forcing, and constructed an analytic theory that explains the day-night temperature differences in these simulations over a wide parameter space. Our analytic theory shows that day-night temperature differences in tidally-locked planet atmospheres are mediated by wave propagation. If planetary-scale waves are free to propagate longitudinally, they will efficiently flatten isentropes and lessen day-night temperature differences. If these waves are damped, the day-night temperature differences will necessarily be larger. We expect that wave propagation in hot Jupiter atmospheres can be damped in two ways: by either radiative cooling or frictional drag. Both of these processes increase in efficacy with increasing equilibrium temperature, as radiative cooling is directly related to the cube of temperature and magnetically-induced (Lorentz) drag becomes stronger with increasing partial ionization and hence temperature. We find that radiative cooling plays the largest role in damping wave propagation and hence plays the biggest role in controlling day-night temperature differences. As a result, day-night temperature differences in hot Jupiter atmospheres decrease with increasing pressure and increase with increasing stellar flux. One can apply this result to phase curve observations of individual hot Jupiters in multiple bandpasses, as varying flux amplitudes between wavelengths implies that different photospheric pressure levels are being probed. Namely, a larger flux amplitude in one waveband than the band-averaged value implies a relatively low photospheric pressure and hence high abundance of the absorber in that waveband. This effect has been seen for both HD 189733b and WASP-14b, where the 3.6 micron flux amplitude is larger than the 4.5 micron flux amplitude, which constrains the relative abundances of methane and carbon monoxide and hence the C/O ratio in these atmospheres.

  10. Simulation of Soil Temperature Dynamics with Models Using Different Concepts

    PubMed Central

    Sndor, Renta; Fodor, Nndor

    2012-01-01

    This paper presents two soil temperature models with empirical and mechanistic concepts. At the test site (calcaric arenosol), meteorological parameters as well as soil moisture content and temperature at 5 different depths were measured in an experiment with 8 parcels realizing the combinations of the fertilized, nonfertilized, irrigated, nonirrigated treatments in two replicates. Leaf area dynamics was also monitored. Soil temperature was calculated with the original and a modified version of CERES as well as with the HYDRUS-1D model. The simulated soil temperature values were compared to the observed ones. The vegetation reduced both the average soil temperature and its diurnal amplitude; therefore, considering the leaf area dynamics is important in modeling. The models underestimated the actual soil temperature and overestimated the temperature oscillation within the winter period. All models failed to account for the insulation effect of snow cover. The modified CERES provided explicitly more accurate soil temperature values than the original one. Though HYDRUS-1D provided more accurate soil temperature estimations, its superiority to CERES is not unequivocal as it requires more detailed inputs. PMID:22792047

  11. Simulation of soil temperature dynamics with models using different concepts.

    PubMed

    Sndor, Renta; Fodor, Nndor

    2012-01-01

    This paper presents two soil temperature models with empirical and mechanistic concepts. At the test site (calcaric arenosol), meteorological parameters as well as soil moisture content and temperature at 5 different depths were measured in an experiment with 8 parcels realizing the combinations of the fertilized, nonfertilized, irrigated, nonirrigated treatments in two replicates. Leaf area dynamics was also monitored. Soil temperature was calculated with the original and a modified version of CERES as well as with the HYDRUS-1D model. The simulated soil temperature values were compared to the observed ones. The vegetation reduced both the average soil temperature and its diurnal amplitude; therefore, considering the leaf area dynamics is important in modeling. The models underestimated the actual soil temperature and overestimated the temperature oscillation within the winter period. All models failed to account for the insulation effect of snow cover. The modified CERES provided explicitly more accurate soil temperature values than the original one. Though HYDRUS-1D provided more accurate soil temperature estimations, its superiority to CERES is not unequivocal as it requires more detailed inputs. PMID:22792047

  12. General properties of the acoustic plate modes at different temperatures.

    PubMed

    Anisimkin, V I; Anisimkin, I V; Voronova, N V; Pu?hkov, Yu V

    2015-09-01

    Using acoustic plate modes with SH-polarization and quartz crystal with Euler angles 0, 132.75, 90, as an example, general properties of the acoustic plate modes at different temperatures are studied theoretically and experimentally in the range from -40 to +80C. It is shown that in addition to well-known parameters responsible for temperature characteristics of acoustic waves the temperature coefficients of the acoustic plate modes depend on the mode order n, plate thickness h/?, and expansion of the plate in direction of its thickness (h - thickness, ? - acoustic wavelength). These properties permit the mode sensitivity to be increased or decreased without replacing plate material and orientation. PMID:26002698

  13. Effect of different healing temperature on self-healing hydrogel

    NASA Astrophysics Data System (ADS)

    Sirajuddin, Najiyyah Abdullah; Jamil, Mohd Suzeren Md; Lazim, Azwan Mat

    2014-09-01

    In this study, hydrogels of poly(2-hydroxyethyl methacrylate) with different healing temperature were studied on healing efficacy of self-healing hydrogel. To identify the optimum healing temperature of healable hydrogel which give the highest healing efficacy, the sample were tested from 45C-65C for 5 hours. The gel being cut will merge together through intermolecular diffusion of dangling chain and/or chain slippage. The results showed that 60C was the optimum healing temperature which provides the highest ultimate tensile strength of healing efficacy. The pictures of durability poly(HEMA) hydrogel were taken and supported the self-healing behavior of hydrogel.

  14. Temperature dependencies of Henry's law constants for different plant sesquiterpenes.

    PubMed

    Copolovici, Lucian; Niinemets, Ülo

    2015-11-01

    Sesquiterpenes are plant-produced hydrocarbons with important ecological functions in plant-to-plant and plant-to-insect communication, but due to their high reactivity they can also play a significant role in atmospheric chemistry. So far, there is little information of gas/liquid phase partition coefficients (Henry's law constants) and their temperature dependencies for sesquiterpenes, but this information is needed for quantitative simulation of the release of sesquiterpenes from plants and modeling atmospheric reactions in different phases. In this study, we estimated Henry's law constants (Hpc) and their temperature responses for 12 key plant sesquiterpenes with varying structure (aliphatic, mono-, bi- and tricyclic sesquiterpenes). At 25 °C, Henry's law constants varied 1.4-fold among different sesquiterpenes, and the values were within the range previously observed for monocyclic monoterpenes. Hpc of sesquiterpenes exhibited a high rate of increase, on average ca. 1.5-fold with a 10 °C increase in temperature (Q10). The values of Q10 varied 1.2-fold among different sesquiterpenes. Overall, these data demonstrate moderately high variation in Hpc values and Hpc temperature responses among different sesquiterpenes. We argue that these variations can importantly alter the emission kinetics of sesquiterpenes from plants. PMID:26291755

  15. Temperature responses of mesophyll conductance differ greatly between species.

    PubMed

    von Caemmerer, Susanne; Evans, John R

    2015-04-01

    The temperature responses of mesophyll conductance (gm ) were investigated for nine species using carbon isotope techniques combining tunable diode laser spectroscopy and gas exchange measurements. Species included the evergreen trees Eucalyptus pauciflora and Quercus engelmannii; the tropical evergreen tree Lophostemon confertus; as well as the herbaceous species Nicotiana tabacum, Oryza sativa, Triticum aestivum, Gossypium hirsutum, Glycine max and Arabidopsis thaliana. Responses varied from a two- to threefold increase in mesophyll conductance between 15 and 40 °C observed for N. tabacum, G. hirsutum, G. max and E. pauciflora to almost no change in L. confertus and T. aestivum. To account for the different temperature responses between species, we suggest that there must be variation in both the activation energy for membrane permeability and the effective pathlength for liquid phase diffusion. Stomatal conductance was relatively independent of increases in leaf temperature and concomitant increases in leaf to air vapour pressure difference. Two exceptions were Eucalyptus and Gossypium, where stomatal conductance increased with temperature up to 35 °C despite increasing leaf to air vapour pressure. For a given species, temperature responses of stomatal and mesophyll conductance were independent of one another. PMID:25224884

  16. Temperature Dependence of Acetylcholine Receptor Channels Activated by Different Agonists

    PubMed Central

    Gupta, Shaweta; Auerbach, Anthony

    2011-01-01

    The temperature dependence of agonist binding and channel gating were measured for wild-type adult neuromuscular acetylcholine receptors activated by acetylcholine, carbamylcholine, or choline. With acetylcholine, temperature changed the gating rate constants (Q10 ? 3.2) but had almost no effect on the equilibrium constant. The enthalpy change associated with gating was agonist-dependent, but for all three ligands it was approximately equal to the corresponding free-energy change. The equilibrium dissociation constant of the resting conformation (Kd), the slope of the rate-equilibrium free-energy relationship (?), and the acetylcholine association and dissociation rate constants were approximately temperature-independent. In the mutant ?G153S, the choline association and dissociation rate constants were temperature-dependent (Q10 ? 7.4) but Kd was not. By combining two independent mutations, we were able to compensate for the catalytic effect of temperature on the decay time constant of a synaptic current. At mouse body temperature, the channel-opening and -closing rate constants are ?400 and 16ms?1. We hypothesize that the agonist dependence of the gating enthalpy change is associated with differences in ligand binding, specifically to the open-channel conformation of the protein. PMID:21320433

  17. Deposition Ice Nuclei Concentration at Different Temperatures and Supersaturations

    NASA Astrophysics Data System (ADS)

    Lpez, M. L.; Avila, E.

    2013-05-01

    Ice formation is one of the main processes involved in the initiation of precipitation. Some aerosols serve to nucleate ice in clouds. They are called ice nuclei (IN) and they are generally solid particles, insoluble in water. At temperatures warmer than about -36C the only means for initiation of the ice phase in the atmosphere involves IN, and temperature and supersaturation required to activate IN are considered as key information for the understanding of primary ice formation in clouds. The objective of this work is to quantify the IN concentration at ground level in Crdoba City, Argentina, under the deposition mode, that is to say that ice deposits on the IN directly from the vapor phase. It happens when the environment is supersaturated with respect to ice and subsaturated with respect to liquid water. Ice nuclei concentrations were measured in a cloud chamber placed in a cold room with temperature control down to -35C. The operating temperature was varied between -15C and -30C. Ice supersaturation was ranged between 2 and 20 %. In order to quantify the number of ice particles produced in each experiment, a dish containing a supercooled solution of cane sugar, water and glycerol was placed on the floor of the cloud chamber. The activated IN grew at the expense of vapor until ice crystals were formed and these then fell down onto the sugar solution. Once there, these crystals could grow enough to be counted easily with a naked eye after a period of about three minutes, when they reach around 2 mm in diameter. In order to compare the present results with previously reported results, the data were grouped in three different ranges of supersaturation: the data with supersaturations between 2 and 8 %, the data with supersaturations between 8 and 14% and the data with supersaturations between 14 and 20 %. In the same way, in order to analize the behavior of IN concentration with supersaturation, the data were grouped for three different temperatures, the data with temperatures between -15C and -20C, the data with temperatures between -20C and -25C and the data with temperatures between -25C and -30C. The results confirm that for each temperature range, the concentration of IN increases at higher supersaturation, and show the tendency of the IN concentration to increase with increasing ice supersaturation. Based on previous parameterizations, a combination of IN concentration in relation with temperature and ice supersaturation is proposed in this work. As far as we know, this is among the first work to measure and parameterize the concentration of deposition ice nuclei in the Southern Hemisphere.

  18. Temperature profiles of different cooling methods in porcine pancreas procurement.

    PubMed

    Weegman, Bradley P; Suszynski, Thomas M; Scott, William E; Ferrer Fbrega, Joana; Avgoustiniatos, Efstathios S; Anazawa, Takayuki; O'Brien, Timothy D; Rizzari, Michael D; Karatzas, Theodore; Jie, Tun; Sutherland, David E R; Hering, Bernhard J; Papas, Klearchos K

    2014-01-01

    Porcine islet xenotransplantation is a promising alternative to human islet allotransplantation. Porcine pancreas cooling needs to be optimized to reduce the warm ischemia time (WIT) following donation after cardiac death, which is associated with poorer islet isolation outcomes. This study examines the effect of four different cooling Methods on core porcine pancreas temperature (n = 24) and histopathology (n = 16). All Methods involved surface cooling with crushed ice and chilled irrigation. Method A, which is the standard for porcine pancreas procurement, used only surface cooling. Method B involved an intravascular flush with cold solution through the pancreas arterial system. Method C involved an intraductal infusion with cold solution through the major pancreatic duct, and Method D combined all three cooling Methods. Surface cooling alone (Method A) gradually decreased core pancreas temperature to <10 C after 30 min. Using an intravascular flush (Method B) improved cooling during the entire duration of procurement, but incorporating an intraductal infusion (Method C) rapidly reduced core temperature 15-20 C within the first 2 min of cooling. Combining all methods (Method D) was the most effective at rapidly reducing temperature and providing sustained cooling throughout the duration of procurement, although the recorded WIT was not different between Methods (P = 0.36). Histological scores were different between the cooling Methods (P = 0.02) and the worst with Method A. There were differences in histological scores between Methods A and C (P = 0.02) and Methods A and D (P = 0.02), but not between Methods C and D (P = 0.95), which may highlight the importance of early cooling using an intraductal infusion. In conclusion, surface cooling alone cannot rapidly cool large (porcine or human) pancreata. Additional cooling with an intravascular flush and intraductal infusion results in improved core porcine pancreas temperature profiles during procurement and histopathology scores. These data may also have implications on human pancreas procurement as use of an intraductal infusion is not common practice. PMID:25040217

  19. Predicting thermal inactivation in media of different pH of Salmonella grown at different temperatures.

    PubMed

    Mañas, Pilar; Pagán, Rafael; Raso, Javier; Condón, Santiago

    2003-10-15

    The influence of the growth temperature and the pH of the heating medium on the heat resistance at different temperatures of Salmonella typhimurium ATCC 13311 was studied and described mathematically. The shift of the growth temperature from 10 to 37 degrees C increased heat resistance of S. typhimurium fourfold. The pH of the heating medium at which heat resistance was maximum was pH 6 for cells grown at 37 degrees C, but changed with growth temperature. The alkalinization of the heating medium from pH 6 to pH 7.7 decreased the heat resistance of cells grown at 37 degrees C by a factor of 3. Neither the growth temperature nor the pH modified the z values significantly (4.9 degrees C). The decimal reduction times at different treatment temperatures, in buffers of different pH of cells of S. typhimurium grown at different temperatures, were accurately described by a mathematical equation (correlation coefficient of 0.97). This equation was also tested for Salmonella senftenberg 775W (ATCC 43845) and Salmonella enteritidis ATCC 13076, strains in which the correlation coefficients between the observed and the theoretically calculated values were 0.91 and 0.98, respectively. PMID:12927706

  20. Clay facial masks: physicochemical stability at different storage temperatures.

    PubMed

    Zague, Vivian; de Almeida Silva, Diego; Baby, Andr Rolim; Kaneko, Telma Mary; Velasco, Maria Valria Robles

    2007-01-01

    Clay facial masks--formulations that contain a high percentage of solids dispersed in a liquid vehicle--have become of special interest due to specific properties presented by clays, such as particle size, cooling index, high adsorption capacity, and plasticity. Although most of the physicochemical properties of clay dispersions have been studied, specific aspects concerning the physicochemical stability of clay mask products remain unclear. This work aimed at investigating the accelerated physicochemical stability of clay mask formulations stored at different temperatures. Formulations were subjected to centrifuge testing and to thermal treatment for 15 days, during which temperature was varied from -5.0 degrees to 45.0 degrees C. The apparent viscosity and visual aspect (homogeneity) of all formulations were affected by temperature variation, whereas color, odor, and pH value remained unaltered. These results, besides the estimation of physicochemical stability under aging, can be useful in determining the best storage conditions for clay-based formulations. PMID:17342267

  1. Effect of different alkaline solutions on crystalline structure of cellulose at different temperatures.

    PubMed

    Keshk, Sherif M A S

    2015-01-22

    Effect of alkaline solutions such as 10% NaOH, NaOH/urea and NaOH/ethylene glycol solutions on crystalline structure of different cellulosic fibers (cotton linter and filter paper) was investigated at room temperature and -4C. The highest dissolution of cotton linter and filter paper was observed in NaOH/ethylene glycol at both temperatures. X-ray patterns of treated cotton linter with different alkaline solutions at low temperature showed only two diffractions at 2?=12.5 and 21.0, which belonged to the crystalline structure of cellulose II. CP/MAS (13)C NMR spectra showed the doublet peaks at 89.2 ppm and 88.3 ppm representing C4 resonance for cellulose I at room temperature, Whereas, at low temperature the doublet peaks were observed at 89.2 ppm and 87.8 ppm representing C4 resonance for cellulose II. Degree of polymerization of cellulose plays an important role in cellulose dissolution in different alkaline solutions and temperatures, where, a low temperature gives high dissolutions percentage with change in crystalline structure from cellulose I to cellulose II forms. PMID:25439945

  2. Refinement of thermal imager minimum resolvable temperature difference calculating method

    NASA Astrophysics Data System (ADS)

    Kolobrodov, V. G.; Mykytenko, V. I.

    2015-11-01

    Calculating methods, which accurately predict minimum resolvable temperature difference (MRTD), are of significant interest for many years. The article deals with improvement the accuracy of determining the thermal imaging system MRTD by elaboration the visual perception model. We suggest MRTD calculating algorithm, which is based on a reliable approximation of the human visual system modulation transfer function (MTF) proposed by N. Nill. There was obtained a new expression for the bandwidth evaluation, which is independent of angular size of the Foucault bar target.

  3. Expression of dehydrins in wheat and barley under different temperatures.

    PubMed

    Kosov, Klra; Vtmvs, Pavel; Pril, Ilja Tom

    2011-01-01

    The review summarizes recent knowledge on the expression of cold-inducible dehydrins with a special attention to Wcs120 and Dhn5 genes in wheat and barley plants under different temperatures. When plants are exposed to cold, dehydrins start accumulating both in freezing-tolerant and freezing-susceptible plants; however, their accumulation correlates with plant acquired frost tolerance (FT). During a long-term cold acclimation (CA), dehydrin accumulation is significantly affected by Vrn1/Fr1 locus and the expression of the major vernalization gene VRN1, respectively. A different dynamics of dehydrin transcripts and proteins during CA is also observed. Transcripts reach their maximum within the first week of CA while proteins gradually accumulate until vernalization. Vernalization is associated with a significant decrease in dehydrin accumulation while the decrease of acquired FT is delayed. Studies carried out on plants grown at moderately cold temperatures (9-20 C) have shown that both dehydrin transcripts and proteins can be detected even at these temperatures and that plants with different FT levels can be distinguished according to dehydrin accumulation without any exposure to severe cold. In conclusion, the potential use of these results in the breeding programmes aimed at the enhancement of wheat and barley FT is discussed. PMID:21421346

  4. The Effects of High Temperature on Gessoes with Different Admixtures

    NASA Astrophysics Data System (ADS)

    Budu, Ana-Maria; Sandu, Ion; Cristache, Raluca Anamaria

    2014-11-01

    This paper presents the effects of temperature on gessoes that have different substances added, usually used in painting or restoration to enhance the flexibility of the ground layer or to create a suitable gesso for the specific painting technique. Five samples of gesso were made and applied on Balsa wood (a dry, stable wood that is used in restoration for completing the missing elements of the panel). After the thermal treatment, the samples were analyzed optical, by microscopy and colorimetry. The results showed small differences in colour, but no cracks of the gessoes

  5. Uncertainties in estimating Normalized Difference Temperature Index from TOA radiances

    NASA Astrophysics Data System (ADS)

    peng, jian; liu, yuanbo; loew, alexander

    2013-04-01

    The widely used surface temperature/vegetation index (Ts/NDVI) triangle method provides an effective way to estimate surface turbulent energy fluxes and soil moisture. This type of method mainly relies on the Normalized Difference Temperature Index (NDTI), which is usually calculated from land surface temperature (LST). However, retrieval of LST from remote sensing data requires atmospheric correction procedures, which are often difficult and troublesome. Our study investigates the feasibility of determining NDTI using top of the atmosphere (TOA) radiances, instead of satellite-derived LST. A thorough assessment of the uncertainties in NDTI estimates for different atmospheric and surface conditions is performed. It is shown that NDTI can be estimated from TOA radiances with an accuracy of 90% if the spatial variabilities of atmospheric parameters (water vapor, effective atmospheric temperature) and surface emissivity are below 10%, 4 K and 0.05, respectively. A test study is performed using Moderate Resolution Imaging Spectroradiometer (MODIS) data over a heterogeneous area of the Poyang Lake basin of China for six consecutive image acquisitions. When the spatial variations of the surface emissivity, effective atmospheric temperature and water vapor are respectively less than 0.01, 1 K and 0.2 g cm-2, the TOA radiance-calculated NDTI value and LST-determined NDTI value are quite close with root mean square deviation (RMSD) values and biases varying from 0.033 to 0.051 and from -0.004 to 0.014. The high coefficient of determination (R2) values, ranging from 0.904 to 0.939, indicated that the use of TOA radiances appears to be adequate for calculating NDTI in these studies. Overall, the proposed algorithm requires less a prior information on the atmospheric state while providing NDTI estimates at a similar level of accuracy than obtained using atmospherically corrected LST data products. It therefore provides a useful alternative for determining NDTI from satellite data.

  6. Piglets Surface Temperature Change at Different Weights at Birth

    PubMed Central

    Caldara, Fabiana Ribeiro; dos Santos, Luan Sousa; Machado, Sivanilza Teixeira; Moi, Marta; de Alencar Ns, Irenilza; Foppa, Luciana; Garcia, Rodrigo Garfallo; de Kssia Silva dos Santos, Rita

    2014-01-01

    The study was carried out in order to verify the effects of piglets weight at birth on their surface temperature change (ST) after birth, and its relationship with ingestion time of colostrum. Piglets from four different sows were weighed at birth and divided into a totally randomized design with three treatments according to birth weight (PBW): T1 - less than 1.00 kg, T2 - 1.00 to 1.39 kg, and T3 - higher than or equal to 1.40 kg. The time spent for the first colostrum ingestion was recorded (TFS). Images of piglets surface by thermal imaging camera were recorded at birth (STB) and 15, 30, 45, 60, and 120 min after birth. The air temperature and relative humidity were recorded every 30 min and the indexes of temperature and humidity (THI) were calculated. A ST drop after 15 min from birth was observed, increasing again after sixty minutes. Positive correlations were found between the PBW and the ST at 30 and 45 min after birth. The PBW was negatively correlated with the TFS. The THI showed high negative correlations (?0.824 and ?0.815) with STB and after 15 min from birth. The piglets surface temperature at birth was positively correlated with temperature thereof to 15 min, influencing therefore the temperatures in the interval of 45 to 120 min. The birth weight contributes significantly to postnatal hypothermia and consequently to the time it takes for piglets ingest colostrum, requiring special attention to those of low birth weight. PMID:25049971

  7. Physical Constraints on Temperature Difference in Some Thermogenic Aroid Inflorescences

    PubMed Central

    GIBERNAU, MARC; BARAB, DENIS; MOISSON, MARC; TROMBE, ALAIN

    2005-01-01

    Backgrounds and Aims Thermogenesis in reproductive organs is known from several plant families, including the Araceae. A study was made of the relationship between temperature increase and spadix size in the subfamily Aroideae in order to determine whether the quantitative variation of heat production among species and inflorescences of different sizes follows a physical law of heat transfer. Methods Spadix temperature was measured in 18 species from eight genera of tropical Araceae from the basal clade of Aroideae, both in French Guiana and in the glasshouses of the Montreal Botanical Garden. Key Results A significant logarithmic relationship was found between the volume of the thermogenic spadix zone and the maximum temperature difference between the spadix and ambient air. Four heat transfer models were applied to the data (conductive heat transfer alone, convective heat transfer alone, radiative heat transfer alone, and convective and radiative heat transfers) to test if physical (geometric and thermic) constraints apply. Which heat transfer model was the most probable was determined by using the criterion of a classical minimization process represented by the least-squares method. Two heat transfer models appeared to fit the data well and were equivalent: conductive heat transfer alone, and convective plus radiative heat transfers. Conclusions The increase in the temperature difference between the spadix and ambient air appears to be physically constrained and corresponds to the value of a thermal model of heat conduction in an insulated cylinder with an internal heat source. In the models, a heat metabolic rate of 29.5?mW g?1 was used, which was an acceptable value for an overall metabolic heat rate in aroid inflorescences. PMID:15883130

  8. Stall cleanliness and stall temperature of two different freestall bases.

    PubMed

    Wadsworth, B A; Stone, A E; Clark, J D; Ray, D L; Bewley, J M

    2015-06-01

    The objective of this study was to describe the differences in freestall cleanliness and stall temperature between a barn with Dual Chamber Cow Waterbeds (DCCW; Advanced Comfort Technology, Reedsburg, WI) and a barn with rubber-filled mattresses at the University of Kentucky Coldstream Dairy Research Farm from January 18, 2012, to May 3, 2013. Stall cleanliness was measured twice weekly (n=134) by the same 2 observers using a 0.91 m×0.91 m wire grid containing 128 equally sized rectangles (10.16 cm×5.08 cm). This grid was centered at the rear portion of the stall; a rectangle that was visibly wet or had any amount of feces present was defined as a dirty rectangle. Weekly stall temperature (n=66) was measured by the same observer during a.m. milkings in the same predetermined stalls. Feces and wet sawdust were removed from the stalls before stall temperatures were acquired. Temperatures were obtained using a handheld thermometer at 30.48 cm above the stall base as determined via dual laser measurements. Stall temperature was measured on the front, middle, and back of the stall first with clean sawdust and then with the sawdust removed from the stall and wiped clean with a towel. Daily temperature-humidity index (THI) was calculated using Kentucky climate data calculated through the University of Kentucky College of Agriculture via a data logger, located 5.63 km from the Coldstream Dairy Farm. Stall cleanliness was not different between the DCCW barn (26.09±0.89 rectangles) and the rubber-filled mattress barn (23.70±0.89 rectangles). Mean THI throughout the study was 64.39±0.82. Stall temperature was different among THI categories. Temperature-humidity index categories 1 (coldest), 2, 3, and 4 (warmest) had THI ranges of 22.94 to 50.77, 50.77 to 64.88, 64.88 to 78.75, and 78.75 to 101.59, respectively. Stall temperatures (°C; least squares means±SE) were 2.26±0.30, 8.86±0.30, 15.52±0.30, and 20.95±0.30 for THI categories 1 to 4, respectively. Stalls with rubber-filled mattresses had a lower temperature (°C) than DCCW with least squares means±SE of 10.52±0.21°C and 13.29±0.21°C, respectively. The DCCW were probably significantly warmer because water holds heat well. The DCCW may have more of a heat-insulating effect compared with rubber-filled mattresses. PMID:25841963

  9. Chlorella Virus Encoded Deoxyuridine triphosphatases Exhibit different Temperature Optima

    SciTech Connect

    Zhang,Y.; Moriyama, H.; Homma, K.; Van Etten, J.

    2005-01-01

    A putative deoxyuridine triphosphatase (dUTPase) gene from chlorella virus PBCV-1 was cloned, and the recombinant protein was expressed in Escherichia coli. The recombinant protein has dUTPase activity and requires Mg{sup 2+} for optimal activity, while it retains some activity in the presence of other divalent cations. Kinetic studies of the enzyme revealed a K{sub m} of 11.7 {mu}M, a turnover k{sub cat} of 6.8 s{sup -1}, and a catalytic efficiency of k{sub cat}/K{sub m} = 5.8 x 105 M{sup -1} s{sup -1}. dUTPase genes were cloned and expressed from two other chlorella viruses IL-3A and SH-6A. The two dUTPases have similar properties to PBCV-1 dUTPase except that IL-3A dUTPase has a lower temperature optimum (37{sup o}C) than PBCV-1 dUTPase (50{sup o}C). The IL-3A dUTPase differs from the PBCV-1 enzyme by nine amino acids, including two amino acid substitutions, Glu81{yields}Ser81 and Thr84{yields}Arg84, in the highly conserved motif III of the proteins. To investigate the difference in temperature optima between the two enzymes, homology modeling and docking simulations were conducted. The results of the simulation and comparisons of amino acid sequence suggest that adjacent amino acids are important in the temperature optima. To confirm this suggestion, three site-directed amino acid substitutions were made in the IL-3A enzyme: Thr84{yields}Arg84, Glu81{yields}Ser81, and Glu81{yields}Ser81 plus Thr84{yields}Arg84. The single substitutions affected the optimal temperature for enzyme activity. The temperature optimum increased from 37 to 55{sup o}C for the enzyme containing the two amino acid substitutions. We postulate that the change in temperature optimum is due to reduction in charge and balkiness in the active cavity that allows more movement of the ligand and protein before the enzyme and substrate complex is formed.

  10. Infrared thermal detector array using Eu(TTA)3-based temperature sensitive paint for optical readable thermal imaging device

    NASA Astrophysics Data System (ADS)

    Wang, Min; Tsukamoto, Takashiro; Tanaka, Shuji

    2015-03-01

    This paper presents the design and fabrication of an infrared (IR) thermal detector array made of Eu(TTA)3-based temperature sensitive paint (TSP). The TSP emits 610?nm visible luminescence depending on temperature, and works as an IR-to-visible converter. An optical readout system was designed to excite and observe the detector array using a 355?nm light-emitting diode (LED) and a charge-coupled-device (CCD) camera, respectively. The temperature coefficient of the TSP was measured to be -1.58%?K-1, and thermal images of a 400?C object were successfully obtained. The noise analysis showed that the noise-equivalent temperature difference (NETD) of the imaging system was about 4.5?K.

  11. High-operating temperature MWIR photon detectors based on Type II InAs/GaSb superlattice

    NASA Astrophysics Data System (ADS)

    Razeghi, Manijeh; Pour, Siamak A.; Huang, Edward; Chen, Guanxi; Haddadi, Abbas; Nguyen, Binh-Minh

    2011-06-01

    Recent efforts have been paid to elevate the operating temperature of Type II superlattice Mid Infrared photon detectors. Using M-structure superlattice, novel device architectures have been developed, resulting in significant improvement of the device performances. In this paper, we will compare different photodetector architectures and discuss the optimization scheme which leads to almost one order of magnitude of improvement to the electrical performance. At 150K, single element detectors exhibit a quantum efficiency above 50%, and a specific detectivity of 1.05x1012 cm.Hz1/2/W. BLIP operation with a 300K background and 2π FOV can be reached with an operating temperature up to 180K. High quality focal plane arrays were demonstrated with a noise equivalent temperature difference (NEDT) of 11mK up to 120K. Human body imaging is achieved at 150K with NEDT of 150mK.

  12. Mechanism of boron uptake by hydrocalumite calcined at different temperatures.

    PubMed

    Qiu, Xinhong; Sasaki, Keiko; Takaki, Yu; Hirajima, Tsuyoshi; Ideta, Keiko; Miyawaki, Jin

    2015-04-28

    Hydrocalumite (Ca-Al-layered double hydroxide (LDH)) was prepared and applied for the removal of borate. The properties of Ca-Al-LDH calcined at different temperatures were diverse, which affected the sorption density and mechanism of boron species. The sorption density increased with increase in calcined temperature and the sample calcined at 900C (Ca-Al-LDH-900) showed the maximum sorption density in this work. The solid residues after sorption were characterized by (11)B NMR, (27)Al NMR, SEM, and XRD to investigate the sorption mechanism. Dissolution-reprecipitation was the main mechanism for sorption of borate in Ca-Al-LDH. For Ca-Al-LDH calcined at 300 and 500C, regeneration occurred in a short time and the newly forming LDHs were decomposed to release Ca(2+) ions and formed ettringite with borate. Two stages occurred in the sorption of boron by Ca-Al-LDH calcined at 900C. In the first stage, boron species adsorbed on the alumina gel resulting from the hydration of calcined products. In this stage, borate was included as an interlayer anion into the newly forming LDHs in the following stage, and then immobilized as HBO3(2-) into the interlayer, most the LDHs. PMID:25661174

  13. Dielectric Behavior of Biomaterials at Different Frequencies on Room Temperature

    NASA Astrophysics Data System (ADS)

    Shrivastava, B. D.; Barde, Ravindra; Mishra, A.; Phadke, S.

    2014-09-01

    Propagation of electromagnetic (EM) waves in radiofrequency (RF) and microwave systems is described mathematically by Maxwell's equations with corresponding boundary conditions. Dielectric properties of lossless and lossy materials influence EM field distribution. For a better understanding of the physical processes associated with various RF and microwave devices, it is necessary to know the dielectric properties of media that interact with EM waves. For telecommunication and radar devices, variations of complex dielectric permittivity (referring to the dielectric property) over a wide frequency range are important. For RF and microwave applicators intended for thermal treatments of different materials at ISM (industrial, scientific, medical) frequencies, one needs to study temperature and moisture content dependencies of the Permittivity of the treated materials. Many techniques have been developed for the measurement of materials. In the present paper authors used Bones and scales of Fish taken from Narmada River (Rajghat Dist. Barwani) as biomaterials. Dielectric properties of Biomaterials with the frequency range from 1Hz to 10 MHz at room temperature with low water content were measured by in-situ performance dielectric kit. Analysis has been done by Alpha high performance impedance analyzer and LCR meters. The experimental work were carried out in Inter University Consortium UGC-DAE, CSR center Indore MP. Measured value indicates the dielectric constant (ɛ') dielectric loss (ɛ") decreases with increasing frequency while conductivity (σ) increases with frequency increased.

  14. Modeling soil temperatures at different depths by using three different neural computing techniques

    NASA Astrophysics Data System (ADS)

    Kisi, Ozgur; Tombul, Mustafa; Kermani, Mohammad Zounemat

    2015-07-01

    This study compares the accuracy of three different neural computing techniques, multi-layer perceptron (MLP), radial basis neural networks (RBNN), and generalized regression neural networks (GRNN), in modeling soil temperatures (ST) at different depths. Climatic data of air temperature, wind speed, solar radiation, and relative humidity from Mersin Station, Turkey, were used as inputs to the models to estimate monthly ST values. In the first part of the study, the effect of each climatic variable on ST was investigated by using GRNN models. Air temperature was found to be the most effective variable in modeling monthly ST. In the second part of the study, the accuracy of GRNN models was compared with MLP, RBNN, and multiple linear regression (MLR) models. RBNN models were found to be better than the GRNN, MLP, and MLR models in estimating monthly ST at the depths of 5 and 10 cm while the MLR and GRNN models gave the best accuracy in the case of 50- and 100-cm depths, respectively. In the third part of the study, the effect of periodicity on the training, validation, and test accuracy of the applied models was investigated. The results indicated that the adding periodicity component significantly increase models' accuracies in estimating monthly ST at different depths. Root mean square errors of the GRNN, MLP, RBNN, and MLR models were decreased by 19, 15, 19, and 15 % using periodicity in estimating monthly ST at 5-cm depth.

  15. Fabrication and parameters calculation of room temperature terahertz detector with micro-bridge structure

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Li, Weizhi; Gou, Jun; Wu, Zhiming; Jiang, Yadong

    2015-01-01

    Room temperature terahertz (THz) detector indicates great potentials in imaging application because of real-time, compact bulk and unique spectral characteristics. Different dimension THz detectors based on micro-bridge structure were designed and simulated to get optimizing microbolometer parameters from the simulation results of membrane temperature changing and THz absorption. Those microbolometers were fabricated with complex semiconductor process and three dimension deformations of micro-bridges were obtained by laser scanning confocal microscope to identify the focal plane array micro-bridge design. The noise equivalent power of THz detector achieves 123 pW/Hz1/2 and average response time of the detector is 6.7 ms, which is suitable for the application of active THz imaging.

  16. Maximum vehicle cabin temperatures under different meteorological conditions

    NASA Astrophysics Data System (ADS)

    Grundstein, Andrew; Meentemeyer, Vernon; Dowd, John

    2009-05-01

    A variety of studies have documented the dangerously high temperatures that may occur within the passenger compartment (cabin) of cars under clear sky conditions, even at relatively low ambient air temperatures. Our study, however, is the first to examine cabin temperatures under variable weather conditions. It uses a unique maximum vehicle cabin temperature dataset in conjunction with directly comparable ambient air temperature, solar radiation, and cloud cover data collected from April through August 2007 in Athens, GA. Maximum cabin temperatures, ranging from 41-76C, varied considerably depending on the weather conditions and the time of year. Clear days had the highest cabin temperatures, with average values of 68C in the summer and 61C in the spring. Cloudy days in both the spring and summer were on average approximately 10C cooler. Our findings indicate that even on cloudy days with lower ambient air temperatures, vehicle cabin temperatures may reach deadly levels. Additionally, two predictive models of maximum daily vehicle cabin temperatures were developed using commonly available meteorological data. One model uses maximum ambient air temperature and average daily solar radiation while the other uses cloud cover percentage as a surrogate for solar radiation. From these models, two maximum vehicle cabin temperature indices were developed to assess the level of danger. The models and indices may be useful for forecasting hazardous conditions, promoting public awareness, and to estimate past cabin temperatures for use in forensic analyses.

  17. Maximum vehicle cabin temperatures under different meteorological conditions.

    PubMed

    Grundstein, Andrew; Meentemeyer, Vernon; Dowd, John

    2009-05-01

    A variety of studies have documented the dangerously high temperatures that may occur within the passenger compartment (cabin) of cars under clear sky conditions, even at relatively low ambient air temperatures. Our study, however, is the first to examine cabin temperatures under variable weather conditions. It uses a unique maximum vehicle cabin temperature dataset in conjunction with directly comparable ambient air temperature, solar radiation, and cloud cover data collected from April through August 2007 in Athens, GA. Maximum cabin temperatures, ranging from 41-76 degrees C, varied considerably depending on the weather conditions and the time of year. Clear days had the highest cabin temperatures, with average values of 68 degrees C in the summer and 61 degrees C in the spring. Cloudy days in both the spring and summer were on average approximately 10 degrees C cooler. Our findings indicate that even on cloudy days with lower ambient air temperatures, vehicle cabin temperatures may reach deadly levels. Additionally, two predictive models of maximum daily vehicle cabin temperatures were developed using commonly available meteorological data. One model uses maximum ambient air temperature and average daily solar radiation while the other uses cloud cover percentage as a surrogate for solar radiation. From these models, two maximum vehicle cabin temperature indices were developed to assess the level of danger. The models and indices may be useful for forecasting hazardous conditions, promoting public awareness, and to estimate past cabin temperatures for use in forensic analyses. PMID:19234721

  18. Measurement of relative permittivity of LTCC ceramic at different temperatures

    NASA Astrophysics Data System (ADS)

    Tan, Qiulin; Kang, Hao; Qin, Li; Xiong, Jijun; Zhou, Zhaoying; Zhang, Wendong; Luo, Tao; Xue, Chenyang; Liu, Jun

    2014-03-01

    Devices based on LTCC (low-temperature co-fired ceramic) technology are more widely applied in high temperature environments, and the temperature-dependent properties of the LTCC material play an important role in measurements of the characteristics of these devices at high temperature. In this paper, the temperature-dependence of the relative permittivity of DuPont 951 LTCC ceramic is studied from room temperature to 500 C. An expression for relative permittivity is obtained, which relates the relative permittivity to the resonant frequency, inductance, parasitic capacitance and electrode capacitance of the LTCC sample. Of these properties, the electrode capacitance is the most strongly temperature-dependent. The LTCC sample resonant frequency, inductance and parasitic capacitance were measured (from room temperature to 500 C) with a high temperature measurement system comprising a muffle furnace and network analyzer. We found that the resonant frequency reduced and the inductance and parasitic capacitance increased slightly as the temperature increases. The relative permittivity can be calculated from experimental frequency, inductance and parasitic capacitance measurements. Calculating results show that the relative permittivity of DuPont 951 LTCC ceramic ceramic increases to 8.21 from room temperature to 500 C.

  19. Considerations for modeling thin cirrus effects via brightness temperature differences

    NASA Technical Reports Server (NTRS)

    Schmidt, E. O.; Arduini, R. F.; Wielicki, B. A.; Stone, R. S.; Tsay, S.-C.

    1995-01-01

    Brightness temperature difference (BTD) values are calculated for selected Geostationary Operational Environmental Satellite (GOES-6) channels (3.9, 12.7 micrometer) and Advanced Very High Resolution Radiometer channels (3.7, 12.0 micrometer). Daytime and nighttime discrimination of particle size information is possible given the infrared cloud extinction optical depth and the BTD value. BTD values are presented and compared for cirrus clouds composed of equivalent ice spheres (volume, surface area) versus randomly oriented hexagonal ice crystals. The effect of the hexagonal ice crystals is to increase the magnitude of the BTD values calculated relative to equivalent ice sphere (volume, surface area) BTDs. Equivalent spheres (volume or surface area) do not do a very good job of modeling hexagonal ice crystal effects on BTDs; however, the use of composite spheres improves the simulation and offers interesting prospects. Careful consideration of the number of Legendre polynomial coefficients used to fit the scattering phase functions is crucial to realistic modeling of cirrus BTDs. Surface and view-angle effects are incorporated to provide more realistic simulation.

  20. Changes in population occupancy of Bradyrhizobia under different temperature regimes.

    PubMed

    Saeki, Yuichi; Ozumi, Satoru; Yamamoto, Akihiro; Umehara, Yosuke; Hayashi, Masaki; Sigua, Gilbert C

    2010-01-01

    To elucidate how temperature affects bradyrhizobial ecology, long-term incubations of Bradyrhizobium japonicum USDA 6(T), 38, and 123 and of Bradyrhizobium elkanii USDA 76(T) were conducted under various temperature conditions. Proliferative traits in liquid culture and population occupancies in soil microcosms were compared. The occupancies of USDA 76(T) and USDA 123 in soil microcosms during long-term incubation changed with the temperature conditions. These results suggest that temperature is an environmental factor affecting the ecology and occupancy of bradyrhizobia in soils. PMID:21576887

  1. Study of calcinations of ammonium diuranate at different temperatures

    NASA Astrophysics Data System (ADS)

    Manna, Subhankar; Karthik, Phani; Mukherjee, Abhishek; Banerjee, Joydipta; Roy, Saswati B.; Joshi, Jyeshtharaj B.

    2012-07-01

    Effect of calcination temperature has been studied on tap density, surface area, porosity, O/U ratio, morphology and crystal phases of uranium oxides. The oxides were produced by calcination of ammonium diuranate (ADU). It has been observed that O/U ratio reduces with an increase in temperature. Surface area and porosity increases with temperature, passes through maxima and then reduces. These observations have been explained using high resolution SEM. The crystal phase analysis has shown that the heating of ADU results in to ?-U3O8 via ?-UO3.

  2. Poplar saplings exposed to recurring temperature shifts of different amplitude exhibit differences in leaf gas exchange and growth despite equal mean temperature

    PubMed Central

    Cerasoli, Sofia; Wertin, Timothy; McGuire, Mary Anne; Rodrigues, Ana; Aubrey, Doug P.; Pereira, Joo Santos; Teskey, Robert O.

    2014-01-01

    Most investigations of plant responses to changes in temperature have focused on a constant increase in mean day/night temperature without considering how differences in temperature cycles can affect physiological processes and growth. To test the effects of changes in growth temperature on foliar carbon balance and plant growth, we repeatedly exposed poplar saplings (Populus deltoides nigra) to temperature cycles consisting of 5 days of a moderate (M, +5 C) or extreme (E, +10 C) increase in temperature followed by 5 days of a moderate (M, ?5 C) or extreme (E, ?10 C) decrease in temperature, with respect to a control treatment (C, 23.4 C). The temperature treatments had the same mean temperature over each warm and cool cycle and over the entire study. Our goal was to examine the influence of recurring temperature shifts on growth. Net photosynthesis (A) was relatively insensitive to changes in growth temperature (from 20 to 35 C), suggesting a broad range of optimum temperature for photosynthesis. Leaf respiration (R) exhibited substantial acclimation to temperature, having nearly the same rate at 13 C as at 33 C. There was no evidence that preconditioning through temperature cycles affected the response of A or R to treatment temperature fluctuations. Averaged across the complete warm/cool temperature cycle, the A : R ratio did not differ among the temperature treatments. While foliar carbon balance was not affected, the temperature treatments significantly affected growth. Whole-plant biomass was 1.5 times greater in the M treatment relative to the C treatment. Carbon allocation was also affected with shoot volume and biomass greater in the M and E treatments than in the C treatment. Our findings indicate that temperature fluctuations can have important effects on growth, though there were few effects on leaf gas exchange, and can help explain differences in growth that are not correlated with mean growth temperature. PMID:24876300

  3. N?O accumulation from denitrification under different temperatures.

    PubMed

    Poh, Leong Soon; Jiang, Xie; Zhang, Zhongbo; Liu, Yu; Ng, Wun Jern; Zhou, Yan

    2015-11-01

    The effects of temperature on nitrous oxide (N2O) accumulation during denitrification and denitritation were investigated. Batch experiments were performed to measure N2O accumulation at 25 and 35 C. More N2O accumulation was observed during denitritation at the higher temperature as compared with full denitrification and low temperature tests. The highest nitrite concentration tested in this study (25 mg/L NO2 (-)N and pH 8.0) did not show inhibitory effect on N2O reduction. It was found that the major cause of more N2O accumulation during denitrification at higher temperature was due to higher N2O production rate and lower N2O solubility. Specific nitrate, nitrite, and N2O reduction rates increased 62, 61, and 41 %, respectively, when temperature rose from 25 to 35 C. The decrease of N2O solubility in mixed liquor at 35 C (when compared to 25 C) resulted in faster diffusing rate of N2O from liquid to gas phase. It was also more difficult for gas phase N2O to be re-dissolved. The diffused N2O was then accumulated in the headspace, which was not available for denitrification by denitrifiers. The results of this study suggest higher temperature may worsen N2O emission from wastewater treatment plants (WWTPs). PMID:26129949

  4. Storage of Steindachneridion parahybae oocytes at different temperatures.

    PubMed

    Sanches, Eduardo Antônio; Okawara, Renan Yoshiharu; Caneppele, Danilo; Neumann, Giovano; Bombardelli, Robie Allan; Romagosa, Elizabeth

    2014-12-30

    The objective of this study was to assess the influence of temperature and time on the storage of fresh Steindachneridion parahybae oocytes. Two experiments were carried out: (1) the fertilization rates of oocytes exposed to temperatures of 5, 15, 28 (room temperature) and 35°C were assessed 15min (control), 115, 235 and 355min after release; (2) the fertilization and hatching rates, as well as the percentage of normal larvae of oocytes exposed to 14, 17 or 20°C, 20min (control) were assessed 50, 80 and 110min after stripping. In the first experiment, the highest fertilization rates (P<0.05) were obtained in the control treatment (15min, 28°C), with 74.34±5.48% oocytes showing loss of viability over time. In the second experiment, there was a reduction (P<0.05) in the fertilization rates at the temperatures and times tested. The artificial fertilization of S. parahybae oocytes is recommended immediately after collection, and if storage is necessary, it should be conducted at temperatures between 17 and 20°C. PMID:25458322

  5. Human local and total heat losses in different temperature.

    PubMed

    Wang, Lijuan; Yin, Hui; Di, Yuhui; Liu, Yanfeng; Liu, Jiaping

    2016-04-01

    This study investigates the effects of operative temperature on the local and total heat losses, and the relationship between the heat loss and thermal sensation. 10 local parts of head, neck, chest, abdomen, upper arm, forearm, hand, thigh, leg and foot are selected. In all these parts, convection, radiation, evaporation, respiration, conduction and diffusion heat losses are analyzed when operative temperature is 23, 28, 33 and 37°C. The local heat losses show that the radiation and convection heat losses are mainly affected by the area of local body, and the heat loss of the thigh is the most in the ten parts. The evaporation heat loss is mainly affected by the distribution of sweat gland, and the heat loss of the chest is the most. The total heat loss of the local body shows that in low temperature, the thigh, leg and chest have much heat loss, while in high temperature, the chest, abdomen, thigh and head have great heat loss, which are useful for clothing design. The heat losses of the whole body show that as the operative temperature increases, the radiation and convection heat losses decrease, the heat losses of conduction, respiration, and diffusion are almost constant, and the evaporation heat loss increases. By comparison, the heat loss ratios of the radiation, convection and sweat evaporation, are in agreement with the previous researches. At last, the formula about the heat loss ratio of convection and radiation is derived. It's useful for thermal comfort evaluation and HVAC (heating, ventilation and air conditioning) design. PMID:26879106

  6. Size distribution of spray droplets at different temperature

    NASA Astrophysics Data System (ADS)

    Kim, Ildoo; Lee, Hyung Ju; Choi, Ho Jin; Hwang, Ki-Young; Air-breathing Engine Division Team

    2013-11-01

    Atomization of a liquid jet through an injection nozzle is not only of fundamental interests but also crucial to many real-life applications like engines, ink-jet printers, flow cytometry. Because of practical importance, there have been many studies on the atomization mechanism such as its dependence on the nozzle shape, ambient air pressure and etc. In this study, we investigate the atomization characteristics focused on its dependence on fluid temperature. We varied the temperature of the fluid from -30 C to 300 C, and it is injected through a nozzle pneumatically. Such cold or hot jet of fluid is atomized in the flow-controlled chamber, and the size distribution of the spray droplets was measured by optical technique.

  7. Influence of temperature difference on surface figure controlling during continuous polishing

    NASA Astrophysics Data System (ADS)

    Hong, Meijuan; Xu, Xueke; Dun, Aihuan; Yang, Minghong; Gao, Wenlan; Wei, Chaoyang; Liu, Shijie; Shao, Jianda; Zhang, Yang

    2015-08-01

    During continuous polishing, temperature is a significant source of processing uncertainty. Three work pieces of different kind material (K9, Nd:glass and ULE) were polished on 2.4m continuous polisher. It turns out that temperature difference has different influence on different material work pieces. It also indicates that temperature difference aggravates the processing uncertainy. The deformation caused by temperature difference is simulated using ANSYS. It shows that, with top-bottom temperature difference of 0.1C, the deformation of Nd:glass, K9 and ULE are 0.444E-6 m (about 0.7025?), 0.249E-6 m (about 0.3925? ), and 0.105E-8 m (about 0.00166?), respectively. With radial temperature difference of 0.1C, the deformation of Nd:glass, K9 and ULE are 0.831E-7 m (about 0.1313?), 0.465E-7 m (about 0.07348?) and 0.196E-9 m (about 3.0973E-4?), respectively. To explore the top-bottom temperature difference and radial temperature difference along the polishing surface, a small aperture Nd:glass and a large aperture Nd:glass in polishing have been measured using thermal infrared imager. The results showed that for 260 mm 26 mm Nd: glass, the radial temperature difference is about 0.1C, while the top-bottom temperature difference is about 0.1C ~ 0.21C. Contrastively, for 810 mm460 mm40 mm Nd:glass, the radial temperature difference have reached 0.4C, while top - bottom temperature difference ranges between 0.1C ~ 0.27C. When element gets larger, it will suffer greater temperature difference. These temperature differences are great enough to cause deformation far beyond the polishing accuracy required. Finally, methods are proposed to diminish the effect of temperature difference.

  8. Benchmark analysis of forecasted seasonal temperature over different climatic areas

    NASA Astrophysics Data System (ADS)

    Giunta, G.; Salerno, R.; Ceppi, A.; Ercolani, G.; Mancini, M.

    2015-12-01

    From a long-term perspective, an improvement of seasonal forecasting, which is often exclusively based on climatology, could provide a new capability for the management of energy resources in a time scale of just a few months. This paper regards a benchmark analysis in relation to long-term temperature forecasts over Italy in the year 2010, comparing the eni-kassandra meteo forecast (e-kmf®) model, the Climate Forecast System-National Centers for Environmental Prediction (CFS-NCEP) model, and the climatological reference (based on 25-year data) with observations. Statistical indexes are used to understand the reliability of the prediction of 2-m monthly air temperatures with a perspective of 12 weeks ahead. The results show how the best performance is achieved by the e-kmf® system which improves the reliability for long-term forecasts compared to climatology and the CFS-NCEP model. By using the reliable high-performance forecast system, it is possible to optimize the natural gas portfolio and management operations, thereby obtaining a competitive advantage in the European energy market.

  9. Shock Initiation of Energetic Materials at Different Initial Temperatures

    SciTech Connect

    Urtiew, P A; Tarver, C M

    2005-01-14

    Shock initiation is one of the most important properties of energetic materials, which must transition to detonation exactly as intended when intentionally shocked and not detonate when accidentally shocked. The development of manganin pressure gauges that are placed inside the explosive charge and record the buildup of pressure upon shock impact has greatly increased the knowledge of these reactive flows. This experimental data, together with similar data from electromagnetic particle velocity gauges, has allowed us to formulate the Ignition and Growth model of shock initiation and detonation in hydrodynamic computer codes for predictions of shock initiation scenarios that cannot be tested experimentally. An important problem in shock initiation of solid explosives is the change in sensitivity that occurs upon heating (or cooling). Experimental manganin pressure gauge records and the corresponding Ignition and Growth model calculations are presented for two solid explosives, LX-17 (92.5 % triaminotrinitrobenzene (TATB) with 7.5 % Kel-F binder) and LX-04 (85 % octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine (HMX) with 15 % Viton binder) at several initial temperatures.

  10. Type-II InAs/GaSb photodiodes and focal plane arrays aimed at high operating temperatures

    NASA Astrophysics Data System (ADS)

    Razeghi, M.; Abdollahi Pour, S.; Huang, E. K.; Chen, G.; Haddadi, A.; Nguyen, B. M.

    2011-09-01

    Recent efforts to improve the performance of type II InAs/GaSb superlattice photodiodes and focal plane arrays (FPA) have been reviewed. The theoretical bandstructure models have been discussed first. A review of recent developments in growth and characterization techniques is given. The efforts to improve the performance of MWIR photodiodes and focal plane arrays (FPAs) have been reviewed and the latest results have been reported. It is shown that these improvements has resulted in background limited performance (BLIP) of single element photodiodes up to 180 K. FPA shows a constant noise equivalent temperature difference (NEDT) of 11 mK up to 120 K and it shows human body imaging up to 170 K.

  11. Temperature-induced plasticity in membrane and storage lipid composition: thermal reaction norms across five different temperatures.

    PubMed

    Van Dooremalen, Coby; Koekkoek, Jacco; Ellers, Jacintha

    2011-02-01

    Temperature is a key environmental factor inducing phenotypic plasticity in a wide range of behavioral, morphological, and life history traits in ectotherms. The strength of temperature-induced responses in fitness-related traits may be determined by plasticity of the underlying physiological or biochemical traits. Lipid composition may be an important trait underlying fitness response to temperature, because it affects membrane fluidity as well as availability of stored energy reserves. Here, we investigate the effect of temperature on lipid composition of the springtail Orchesella cincta by measuring thermal reaction norms across five different temperatures after four weeks of cold or warm acclimation. Fatty acid composition in storage and membrane lipids showed a highly plastic response to temperature, but the responses of single fatty acids revealed deviations from the expectations based on HVA theory. We found an accumulation of C(18:2n6) and C(18:3n3) at higher temperatures and the preservation of C(20:4n6) across temperatures, which is contrary to the expectation of decreased unsaturation at higher temperatures. The thermal response of these fatty acids in O. cincta differed from the findings in other species, and therefore shows there is interspecific variation in how single fatty acids contribute to HVA. Future research should determine the consequences of such variation in terms of costs and benefits for the thermal performance of species. PMID:21115015

  12. Optimum dose variation caused by post exposure bake temperature difference inside photoresist over different sublayers and thickness

    NASA Astrophysics Data System (ADS)

    Kang, Young-Min; An, Ilsin; Kim, Do Wan; Oh, Hye-Keun

    2008-03-01

    In principle, the dose should not be changed to make the same linewidth if a perfect anti-reflection coating (ARC) is used for all the sublayers underneath the resist. However, the optimum dose for different sublayers and thicknesses are different even though perfect ARC is used. The post exposure bake (PEB) process of a chemically amplified resist is one of the key processes to make very small features of semiconductor device. The photo-generated acid makes the deprotection of protected polymer, and this deprotection highly depends on the PEB temperature and time. The diffusion length of acid is also strongly dependent on PEB temperature and time. As the linewidth of the device decreases, smaller diffusion length is required to reduce the roughness of the line edge and width. One of the key factors to determine the deprotection and acid diffusion is the initial temperature rising and the final real temperature inside the resist. The unpredictable temperature rising to the pre-set temperature mainly causes the variation of linewidth and the optimum dose. In order to predict the accurate PEB temperature and time dependency of the linewidth and dose, the heat transfer from the hot plate to the resist on the top of the multiply stacked sublayers over the silicon wafer has to be known since the reaction and diffusion occur inside the resist, not on the top of the bare silicon wafer. We studied heat transfer from the hot plate to the top of the resist including conductivity and thickness of each sublayer. For this purpose, a novel numerical approach incorporated with analytic method was proposed to solve the heat conduction problem. The unknowns for temperature are located only at the interfaces between layers, so that it is fast and efficient. We calculated the time that is consumed for the resist to attain the prescribed PEB temperature for the different multi stacks and thicknesses. Calculation shows that the temperature rising is different and final temperature on top of the resist is also different for various sublayers and thicknesses of theirs including resist itself. Experiment by us and others also clearly show that there is a definite temperature difference between on top of the bare wafer and on top of the resist. The effects for the different layer stacks and thicknesses are investigated to obtain proper dose and linewidth control due to different actual resist PEB temperature.

  13. IMPLICATIONS OF RADIOMETRIC-AERODYNAMIC TEMPERATURE DIFFERENCES FOR HEAT FLUX ESTIMATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the application of radiometric surface temperature observations for heat flux computations in numerical models, it is necessary to consider differences between the so-called aerodynamic temperature, which is the model-derived temperature that relates to the efficiency of heat exchange between t...

  14. Differences between near-surface equivalent temperature and temperature trends for the Eastern United States. Equivalent temperature as an alternative measure of heat content

    USGS Publications Warehouse

    Davey, C.A.; Pielke, R.A., Sr.; Gallo, K.P.

    2006-01-01

    There is currently much attention being given to the observed increase in near-surface air temperatures during the last century. The proper investigation of heating trends, however, requires that we include surface heat content to monitor this aspect of the climate system. Changes in heat content of the Earth's climate are not fully described by temperature alone. Moist enthalpy or, alternatively, equivalent temperature, is more sensitive to surface vegetation properties than is air temperature and therefore more accurately depicts surface heating trends. The microclimates evident at many surface observation sites highlight the influence of land surface characteristics on local surface heating trends. Temperature and equivalent temperature trend differences from 1982-1997 are examined for surface sites in the Eastern U.S. Overall trend differences at the surface indicate equivalent temperature trends are relatively warmer than temperature trends in the Eastern U.S. Seasonally, equivalent temperature trends are relatively warmer than temperature trends in winter and are relatively cooler in the fall. These patterns, however, vary widely from site to site, so local microclimate is very important. ?? 2006 Elsevier B.V. All rights reserved.

  15. Effect of saddle height on skin temperature measured in different days of cycling.

    PubMed

    Priego Quesada, Jose Ignacio; Carpes, Felipe P; Salvador Palmer, Rosario; Pérez-Soriano, Pedro; Cibrián Ortiz de Anda, Rosa M

    2016-01-01

    Infrared thermography can be useful to explore the effects of exercise on neuromuscular function. During cycling, it could be used to investigate the effects of saddle height on thermoregulation. The aim of this study was to examine whether different cycling postures, elicited by different knee flexion angles, could influence skin temperature. Furthermore, we also determined whether the reproducibility of thermal measurements in response to cycling differed in the body regions affected or not affected by saddle height. Sixteen cyclists participated in three tests of 45 min of cycling at their individual 50 % peak power output. Each test was performed in a different knee flexion position on the bicycle (20°, 30°, 40° knee flexion when the pedal crank was at 180°). Different knee angles were obtained by changing saddle height. Skin temperatures were determined by infrared thermography before, immediately after and 10 min after the cycling test, in 16 different regions of interest (ROI) in the trunk and lower limbs. Changes in saddle height did not result in changes in skin temperature in the ROI. However, lower knee flexion elicited higher temperature in popliteus after cycling than higher flexion (p = 0.008 and ES = 0.8), and higher knee flexion elicited lower temperature variation in the tibialis anterior than intermediate knee flexion (p = 0.004 and ES = 0.8). Absolute temperatures obtained good and very good intraday reproducibility in the different measurements (ICCs between 0.44 and 0.85), but temperature variations showed lower reproducibility (ICCs between 0.11 and 0.74). Different postures assumed by the cyclist due to different saddle height did not influence temperature measurements. Skin temperature can be measured on different days with good repeatability, but temperature variations can be more sensitive to the effects of an intervention. PMID:27026901

  16. Improving the Accuracy of Satellite Sea Surface Temperature Measurements by Explicitly Accounting for the Bulk-Skin Temperature Difference

    NASA Technical Reports Server (NTRS)

    Castro, Sandra L.; Emery, William J.

    2002-01-01

    The focus of this research was to determine whether the accuracy of satellite measurements of sea surface temperature (SST) could be improved by explicitly accounting for the complex temperature gradients at the surface of the ocean associated with the cool skin and diurnal warm layers. To achieve this goal, work centered on the development and deployment of low-cost infrared radiometers to enable the direct validation of satellite measurements of skin temperature. During this one year grant, design and construction of an improved infrared radiometer was completed and testing was initiated. In addition, development of an improved parametric model for the bulk-skin temperature difference was completed using data from the previous version of the radiometer. This model will comprise a key component of an improved procedure for estimating the bulk SST from satellites. The results comprised a significant portion of the Ph.D. thesis completed by one graduate student and they are currently being converted into a journal publication.

  17. Different variation behaviors of resistivity for high-temperature-grown and low-temperature-grown p-GaN films

    NASA Astrophysics Data System (ADS)

    Jing, Yang; De-Gang, Zhao; De-Sheng, Jiang; Ping, Chen; Zong-Shun, Liu; Jian-Jun, Zhu; Ling-Cong, Le; Xiao-Jing, Li; Xiao-Guang, He; Li-Qun, Zhang; Hui, Yang

    2016-02-01

    Two series of p-GaN films grown at different temperatures are obtained by metal organic chemical vapor deposition (MOCVD). And the different variation behaviors of resistivity with growth condition for high- temperature(HT)-grown and low-temperature(LT)-grown p-GaN films are investigated. It is found that the resistivity of HT-grown p-GaN film is nearly unchanged when the NH3 flow rate or reactor pressure increases. However, it decreases largely for LT-grown p-GaN film. These different variations may be attributed to the fact that carbon impurities are easy to incorporate into p-GaN film when the growth temperature is low. It results in a relatively high carbon concentration in LT-grown p-GaN film compared with HT-grown one. Therefore, carbon concentration is more sensitive to the growth condition in these samples, ultimately, leading to the different variation behaviors of resistivity for HT- and LT-grown ones. Project supported by the National Natural Science Foundation of China (Grant Nos. 61474110, 61377020, 61376089, 61223005, and 61176126), the National Natural Science Fund for Distinguished Young Scholars, China (Grant No. 60925017), the One Hundred Person Project of the Chinese Academy of Sciences, and the Basic Research Project of Jiangsu Province, China (Grant No. BK20130362).

  18. The effect of imposed temperature difference on thermal conductivity in armchair single-walled carbon nanotube

    NASA Astrophysics Data System (ADS)

    Mehri, Ali; Jamaati, Maryam; Moradi, Moslem

    2015-02-01

    Thermal conductivity of carbon nanotubes depends on various factors. The simulation of heat transport in armchair single-walled carbon nanotube by direct nonequilibrium molecular dynamics (NEMD) method employing Tersoff-Brenner potential indicates that, thermal conductivity decreases with increase in temperature difference between two ends of the tube. Increasing the imposed temperature differential along the tube axis, leads to domination of Umklapp scattering and impacts the heat transport. The applied temperature difference does not influence the behavior of thermal conductivity vs. tube length, diameter and temperature, but changes its value.

  19. Clinical review: Brain-body temperature differences in adults with severe traumatic brain injury.

    PubMed

    Childs, Charmaine; Lunn, Kueh Wern

    2013-01-01

    Surrogate or 'proxy' measures of brain temperature are used in the routine management of patients with brain damage. The prevailing view is that the brain is 'hotter' than the body. The polarity and magnitude of temperature differences between brain and body, however, remains unclear after severe traumatic brain injury (TBI). The focus of this systematic review is on the adult patient admitted to intensive/neurocritical care with a diagnosis of severe TBI (Glasgow Coma Scale score of less than 8). The review considered studies that measured brain temperature and core body temperature. Articles published in English from the years 1980 to 2012 were searched in databases, CINAHL, PubMed, Scopus, Web of Science, Science Direct, Ovid SP, Mednar and ProQuest Dissertations & Theses Database. For the review, publications of randomised controlled trials, non-randomised controlled trials, before and after studies, cohort studies, case-control studies and descriptive studies were considered for inclusion. Of 2,391 records identified via the search strategies, 37 were retrieved for detailed examination (including two via hand searching). Fifteen were reviewed and assessed for methodological quality. Eleven studies were included in the systematic review providing 15 brain-core body temperature comparisons. The direction of mean brain-body temperature differences was positive (brain higher than body temperature) and negative (brain lower than body temperature). Hypothermia is associated with large brain-body temperature differences. Brain temperature cannot be predicted reliably from core body temperature. Concurrent monitoring of brain and body temperature is recommended in patients where risk of temperature-related neuronal damage is a cause for clinical concern and when deliberate induction of below-normal body temperature is instituted. PMID:23680353

  20. Clinical review: Brain-body temperature differences in adults with severe traumatic brain injury

    PubMed Central

    2013-01-01

    Surrogate or 'proxy' measures of brain temperature are used in the routine management of patients with brain damage. The prevailing view is that the brain is 'hotter' than the body. The polarity and magnitude of temperature differences between brain and body, however, remains unclear after severe traumatic brain injury (TBI). The focus of this systematic review is on the adult patient admitted to intensive/neurocritical care with a diagnosis of severe TBI (Glasgow Coma Scale score of less than 8). The review considered studies that measured brain temperature and core body temperature. Articles published in English from the years 1980 to 2012 were searched in databases, CINAHL, PubMed, Scopus, Web of Science, Science Direct, Ovid SP, Mednar and ProQuest Dissertations & Theses Database. For the review, publications of randomised controlled trials, non-randomised controlled trials, before and after studies, cohort studies, case-control studies and descriptive studies were considered for inclusion. Of 2,391 records identified via the search strategies, 37 were retrieved for detailed examination (including two via hand searching). Fifteen were reviewed and assessed for methodological quality. Eleven studies were included in the systematic review providing 15 brain-core body temperature comparisons. The direction of mean brain-body temperature differences was positive (brain higher than body temperature) and negative (brain lower than body temperature). Hypothermia is associated with large brain-body temperature differences. Brain temperature cannot be predicted reliably from core body temperature. Concurrent monitoring of brain and body temperature is recommended in patients where risk of temperature-related neuronal damage is a cause for clinical concern and when deliberate induction of below-normal body temperature is instituted. PMID:23680353

  1. Different mechanisms at different temperatures for the ring-opening polymerization of lactide catalyzed by binuclear magnesium and zinc alkoxides.

    PubMed

    Sun, Yangyang; Cui, Yaqin; Xiong, Jiao; Dai, Zhongran; Tang, Ning; Wu, Jincai

    2015-10-01

    Two binuclear magnesium and zinc alkoxides supported by a bis-salalen type dinucleating heptadentate Schiff base ligand were synthesized and fully characterized. The two complexes are efficient initiators for the ring-opening polymerization (ROP) of L-lactide, affording polymers with narrow polydispersities and desirable molecular weights. Interestingly, the mechanisms for the ROP of lactide are different at different temperatures. At a high temperature of 130 C, a coordination-insertion mechanism is reasonable for the bulk melt polymerization of lactide. At a low temperature, the alkoxide cannot initiate the ROP reaction; however, upon the addition of external benzyl alcohol into the system, the ROP of lactide can smoothly proceed via an "activated monomer" mechanism. In addition, these complexes display slight stereo-selectivity for the ring-opening polymerization of rac-lactide, affording partially isotactic polylactide in toluene with a Pm value of 0.59. PMID:26308730

  2. Each to their own: skeletal muscles of different function use different biochemical strategies during aestivation at high temperature.

    PubMed

    Young, Karen M; Cramp, Rebecca L; Franklin, Craig E

    2013-03-15

    Preservation of muscle morphology depends on a continuing regulatory balance between molecules that protect and molecules that damage muscle structural integrity. Excessive disruption of the biochemical balance that favours reactive oxygen species (ROS) in disused muscles may lead to oxidative stress, which in turn is associated with increased atrophic or apoptotic signalling and/or oxidative damage to the muscle and thus muscle disuse atrophy. Increases in the rate of oxygen consumption likely increase the overall generation of ROS in vivo. Temperature-induced increases in oxygen consumption rate occur in some muscles of ectotherms undergoing prolonged muscular disuse during aestivation. In the green-striped burrowing frog, Cyclorana alboguttata, both large jumping and small non-jumping muscles undergo atrophy seemingly commensurate with their rate of oxygen consumption during aestivation. However, because the extent of atrophy in these muscles is not enhanced at higher temperatures, despite a temperature-sensitive rate of oxygen consumption in the jumping muscle, we proposed that muscles are protected by biochemical means that, when mobilised at higher temperatures, inhibit atrophy. We proposed that the biochemical response to temperature would be muscle-specific. We examined the effect of temperature on the antioxidant and heat shock protein systems and determined the extent of oxidative damage to lipids and proteins in two functionally different skeletal muscles, the gastrocnemius (jumping muscle) and the iliofibularis (non-jumping muscle), by aestivating frogs at 24 and 30C for 6 months. We assayed small molecule antioxidant capacity, mitochondrial and cytosolic superoxide dismutase activities and Hsp70 concentrations to show that protective mechanisms in disused muscles are differentially regulated with respect to both temperature and aestivation. High aestivation temperature results in an antioxidant response in the metabolically temperature-sensitive jumping muscle. We assayed lipid peroxidation and protein oxidation to show that oxidative damage is apparent during aestivation and its pattern is muscle-specific, but unaffected by temperature. Consideration is given to how the complex responses of muscle biochemistry inform the different strategies muscles may use in regulating their oxidative environment during extended disuse and disuse at high temperature. PMID:23197095

  3. Wind effect on PV module temperature: Analysis of different techniques for an accurate estimation.

    NASA Astrophysics Data System (ADS)

    Schwingshackl, Clemens; Petitta, Marcello; Ernst Wagner, Jochen; Belluardo, Giorgio; Moser, David; Castelli, Mariapina; Zebisch, Marc; Tetzlaff, Anke

    2013-04-01

    In this abstract a study on the influence of wind to model the PV module temperature is presented. This study is carried out in the framework of the PV-Alps INTERREG project in which the potential of different photovoltaic technologies is analysed for alpine regions. The PV module temperature depends on different parameters, such as ambient temperature, irradiance, wind speed and PV technology [1]. In most models, a very simple approach is used, where the PV module temperature is calculated from NOCT (nominal operating cell temperature), ambient temperature and irradiance alone [2]. In this study the influence of wind speed on the PV module temperature was investigated. First, different approaches suggested by various authors were tested [1], [2], [3], [4], [5]. For our analysis, temperature, irradiance and wind data from a PV test facility at the airport Bolzano (South Tyrol, Italy) from the EURAC Institute of Renewable Energies were used. The PV module temperature was calculated with different models and compared to the measured PV module temperature at the single panels. The best results were achieved with the approach suggested by Skoplaki et al. [1]. Preliminary results indicate that for all PV technologies which were tested (monocrystalline, amorphous, microcrystalline and polycrystalline silicon and cadmium telluride), modelled and measured PV module temperatures show a higher agreement (RMSE about 3-4 K) compared to standard approaches in which wind is not considered. For further investigation the in-situ measured wind velocities were replaced with wind data from numerical weather forecast models (ECMWF, reanalysis fields). Our results show that the PV module temperature calculated with wind data from ECMWF is still in very good agreement with the measured one (R² > 0.9 for all technologies). Compared to the previous analysis, we find comparable mean values and an increasing standard deviation. These results open a promising approach for PV module temperature estimation using meteorological parameters. References: [1] Skoplaki, E. et al., 2008: A simple correlation for the operating temperature of photovoltaic modules of arbitrary mounting, Solar Energy Materials & Solar Cells 92, 1393-1402 [2] Skoplaki, E. et al., 2008: Operating temperature of photovoltaic modules: A survey of pertinent correlations, Renewable Energy 34, 23-29 [3] Koehl, M. et al., 2011: Modeling of the nominal operating cell temperature based on outdoor weathering, Solar Energy Materials & Solar Cells 95, 1638-1646 [4] Mattei, M. et al., 2005: Calculation of the polycrystalline PV module temperature using a simple method of energy balance, Renewable Energy 31, 553-567 [5] Kurtz, S. et al.: Evaluation of high-temperature exposure of rack-mounted photovoltaic modules

  4. Acclimation and acute temperature effects on population differences in oxidative phosphorylation.

    PubMed

    Baris, Tara Z; Crawford, Douglas L; Oleksiak, Marjorie F

    2016-01-15

    Temperature changes affect metabolism on acute, acclamatory, and evolutionary time scales. To better understand temperature's affect on metabolism at these different time scales, we quantified cardiac oxidative phosphorylation (OxPhos) in three Fundulus taxa acclimated to 12 and 28°C and measured at three acute temperatures (12, 20, and 28°C). The Fundulus taxa (northern Maine and southern Georgia F. heteroclitus, and a sister taxa, F. grandis) were used to identify evolved changes in OxPhos. Cardiac OxPhos metabolism was quantified by measuring six traits: state 3 (ADP and substrate-dependent mitochondrial respiration); E state (uncoupled mitochondrial activity); complex I, II, and IV activities; and LEAK ratio. Acute temperature affected all OxPhos traits. Acclimation only significantly affected state 3 and LEAK ratio. Populations were significantly different for state 3. In addition to direct effects, there were significant interactions between acclimation and population for complex I and between population and acute temperature for state 3. Further analyses suggest that acclimation alters the acute temperature response for state 3, E state, and complexes I and II: at the low acclimation temperature, the acute response was dampened at low assay temperatures, and at the high acclimation temperature, the acute response was dampened at high assay temperatures. Closer examination of the data also suggests that differences in state 3 respiration and complex I activity between populations were greatest between fish acclimated to low temperatures when assayed at high temperatures, suggesting that differences between the populations become more apparent at the edges of their thermal range. PMID:26582639

  5. Measurement of surface temperature and emissivity of different materials by two-colour pyrometry

    NASA Astrophysics Data System (ADS)

    Raj, Vinay C.; Prabhu, S. V.

    2013-12-01

    An experimental investigation is performed to substantiate the capability of a charge coupled device camera to measure local temperature and emissivity of different materials heated to temperatures above 500 °C by two-colour pyrometric technique using colorimetric method. Materials investigated are Inconel 718 with pyromark (high temperature paint), Inconel 718, stainless steel SS 304 and SS 316. Centerline temperature and emissivity distribution is obtained for target plates maintained at constant temperature by AC heating while complete temperature and emissivity distribution is provided for plates heated by flame impingement. The obtained results are compared with a calibrated infrared camera and thermocouples and the temperature distribution is found to be in close agreement. These results pertain to partially oxidized metal alloys covered in this study. Deviation in the measurement of emissivity can be attributed to its dependence on wavelength range, oxidation, and sensitivity of the image detector.

  6. Measurement of surface temperature and emissivity of different materials by two-colour pyrometry.

    PubMed

    Raj, Vinay C; Prabhu, S V

    2013-12-01

    An experimental investigation is performed to substantiate the capability of a charge coupled device camera to measure local temperature and emissivity of different materials heated to temperatures above 500 °C by two-colour pyrometric technique using colorimetric method. Materials investigated are Inconel 718 with pyromark (high temperature paint), Inconel 718, stainless steel SS 304 and SS 316. Centerline temperature and emissivity distribution is obtained for target plates maintained at constant temperature by AC heating while complete temperature and emissivity distribution is provided for plates heated by flame impingement. The obtained results are compared with a calibrated infrared camera and thermocouples and the temperature distribution is found to be in close agreement. These results pertain to partially oxidized metal alloys covered in this study. Deviation in the measurement of emissivity can be attributed to its dependence on wavelength range, oxidation, and sensitivity of the image detector. PMID:24387454

  7. Statistical modeling of urban air temperature distributions under different synoptic conditions

    NASA Astrophysics Data System (ADS)

    Beck, Christoph; Breitner, Susanne; Cyrys, Josef; Hald, Cornelius; Hartz, Uwe; Jacobeit, Jucundus; Richter, Katja; Schneider, Alexandra; Wolf, Kathrin

    2015-04-01

    Within urban areas air temperature may vary distinctly between different locations. These intra-urban air temperature variations partly reach magnitudes that are relevant with respect to human thermal comfort. Therefore and furthermore taking into account potential interrelations with other health related environmental factors (e.g. air quality) it is important to estimate spatial patterns of intra-urban air temperature distributions that may be incorporated into urban planning processes. In this contribution we present an approach to estimate spatial temperature distributions in the urban area of Augsburg (Germany) by means of statistical modeling. At 36 locations in the urban area of Augsburg air temperatures are measured with high temporal resolution (4 min.) since December 2012. These 36 locations represent different typical urban land use characteristics in terms of varying percentage coverages of different land cover categories (e.g. impervious, built-up, vegetated). Percentage coverages of these land cover categories have been extracted from different sources (Open Street Map, European Urban Atlas, Urban Morphological Zones) for regular grids of varying size (50, 100, 200 meter horizonal resolution) for the urban area of Augsburg. It is well known from numerous studies that land use characteristics have a distinct influence on air temperature and as well other climatic variables at a certain location. Therefore air temperatures at the 36 locations are modeled utilizing land use characteristics (percentage coverages of land cover categories) as predictor variables in Stepwise Multiple Regression models and in Random Forest based model approaches. After model evaluation via cross-validation appropriate statistical models are applied to gridded land use data to derive spatial urban air temperature distributions. Varying models are tested and applied for different seasons and times of the day and also for different synoptic conditions (e.g. clear and calm situations, cloudy and windy situations). Based on hourly air temperature data from our measurements in the urban area of Augsburg distinct temperature differences between locations with different urban land use characteristics are revealed. Under clear and calm weather conditions differences between mean hourly air temperatures reach values around 8C. Whereas during cloudy and windy weather maximum differences in mean hourly air temperatures do not exceed 5C. Differences appear usually slightly more pronounced in summer than in winter. First results from the application of statistical modeling approaches reveal promising skill of the models in terms of explained variances reaching up to 60% in leave-one-out cross-validation experiments. The contribution depicts the methodology of our approach and presents and discusses first results.

  8. Effect of ultrasonic treatment of brown rice at different temperatures on cooking properties and quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research aimed at developing quick cooking brown rice by investigating the effect of ultrasonic treatment at different temperatures on cooking time and quality. The medium grain brown rice was ultrasonically treated in water at temperatures of 25C, 40C and 55C for 30 min and then dried by ai...

  9. Comparing different reactor configurations for Partial Nitritation/Anammox at low temperatures.

    PubMed

    Gilbert, Eva M; Agrawal, Shelesh; Schwartz, Thomas; Horn, Harald; Lackner, Susanne

    2015-09-15

    Partial Nitritation/Anammox (PN/A) is a well-established technology for side-stream nitrogen removal from highly concentrated, warm wastewaters. The focus has now shifted to weakly concentrated municipal wastewaters with much lower concentrations and temperatures. The major challenge is the temperature, which ranges from moderate 20C in summer to cold 10C in winter. For this study, the most frequently used configurations for side-stream applications were exposed to a slow temperature reduction from 20C to 10C to simulate a realistic temperature gradient. To evaluate the behavior of the different biomasses based on their properties, four lab reactors were operated in two different configurations. Synthetic wastewater was used to avoid side effects of heterotrophic growth. Differences in the response of the different reactor systems to this temperature gradient clearly indicated, that the geometry of the biomass has a major impact on the overall PN/A performance at low temperatures: While anammox activity in suspended biomass suffered already at 15C, it persevered in granular biomass as well as in biofilms on carriers for temperatures down to <13C. Further, anammox activity in thicker biofilms was less affected than in thinner biofilms and even adaption to low temperatures was observed. PMID:26043375

  10. Eleven years of ground-air temperature tracking over different land cover materials

    NASA Astrophysics Data System (ADS)

    Cermák, Vladimír; Dedecek, Petr; Bodri, Louise; Safanda, Jan; Kresl, Milan

    2015-04-01

    We have analyzed series of air, near surface and shallow ground temperatures under four different land covers, namely bare clayey soil, sand, grass and asphalt, collected between 2002 and 2013, monitored at the Geothermal Climate Change Observatory Sporilov. All obtained temperature series revealed a strong dependence of the subsurface thermal regime on the surface cover material. The ground "skin" temperatures are generally warmer than the surface air temperatures for all monitored surfaces; however they mutually differ significantly reflecting the nature of the land surface. Asphalt shows the highest temperatures, temperatures below the grassy surface are the lowest. A special interest was paid to the assessment of the "temperature offset", the difference between the surface ground temperature and the surface air temperature. Even when its instant value varies dramatically on both, daily and annual scale, by up to 30+ K, on a long time scale it is believed to be generally constant. The characteristic 2003-2013 mean offset values for the individual covers are following: asphalt 4.1 K, sand 1.6 K, clay 1.3 K and grass 0.2-0.3 K. All four surface covers revealed their daily and inter-annual cycles. Incident solar radiation is the primary variable in determining the amount of the temperature offset value and its time changes. A linear relationship between air-ground temperature differences and incident solar radiation was detected. The slope of the linear regression between both variables is clearly surface cover dependent. The greatest value of 3.3 K per 100 W.m-2 was found for asphalt, rates of 1.0 to 1.2 apply for bare soil and sand covers and negative slope of -0.44 K per 100 W.m-2 stands for grass, during the day or year the slope rates may vary extensively reflecting the periodic daily and/or annual cycle as well as the irregular instant deviations in solar radiation.

  11. Optical properties of traditional ceramic with different sintering temperatures in terahertz range

    NASA Astrophysics Data System (ADS)

    Miao, Xin Y.; Yang, Qing N.; Feng, Cheng J.; Bao, Ri M.; Zhao, Kun; Xiao, Li Z.

    2015-11-01

    Terahertz spectroscopy was used to study the sintering process of traditional ceramic by scanning sample with different final temperatures (from 100-1450C). Absorption coefficient (?) and refractive index (n) were obtained with different final temperatures. The sintering process was divided into four stages on the basis of ? and n, which characterized the ceramic sintering process well. The results coincide with the actual situation. Therefore, THz-TDS represents a promising technique to monitor the synthesis process of materials.

  12. Temperature dependence of properties of Mn-doped nanocrystals with different binding symmetry

    NASA Astrophysics Data System (ADS)

    Yang, Boping; Zhao, Qing; Zhang, Jiayu

    2016-02-01

    We report the temperature dependence of photoluminescent properties of Mn-doped nanocrystals (NCs) with different binding symmetry. The photoluminescence peaks of Mn2+ ions shift to shorter wavelength with increasing temperatures, resulting from the reduction of crystal field. Further evidence for temperature-dependent crystal field variety is demonstrated by electronic paramagnetic resonance (EPR) spectra. Additionally, the inflexion temperature of the excited state lifetimes increases from 170 K (Sample I) to 220 K (Sample IV), which is speculated to be resulted from the easily affected wave function overlap due to thermal lattice expansion in more symmetrical binding Mn-doped NCs.

  13. Tailoring biochars from different feedstock and produced at different temperature and time of pyrolysis for their use as soil amendments

    NASA Astrophysics Data System (ADS)

    Zornoza, Raul; Moreno, Fabian; Acosta, Jose A.; Gomez Lopez, Maria Dolores; Faz, Angel

    2015-04-01

    Biochar used as a soil amendment to improve soil quality and fertility and increase soil carbon sequestration has been the focus of much research in the recent past. Unlike most conventional soil organic materials, which are readily decomposed, the recalcitrant nature of biochar increases its potential value as a soil amending material for the longer term. However, many biochars can be hydrophobic, and added to soil can aggravate water availability in areas where water scarcity is a major limiting factor for agriculture or forestry. It has been shown that biochar characteristics are influenced by production variables, especially feedstock, pyrolysis temperature and time of pyrolysis. Although there have been different studies characterizing biochars prepared from different sources, there are few studies comparing different types of biochar produced from domestic residues, manures or crop residues pyrolysis; there are, in addition, fewer studies dealing with the hydrophobic properties of the biochars. The different feedstock can have different properties which would result into different biochars even produced at the same operational factors. The main objective of this experiment was to study the influence of feedstock properties and pyrolysis temperature and time on nutrient contents, heavy metals, recalcitrance, thermal stability and hydrophobicity of biochars from cotton crop residues (CR), pig manure (PM) and domestic waste (DW). Biochars were obtained by pyrolysis under oxygen-limited conditions in a muffle furnace. The temperature was increased at 5°C min-1 to 300°C, 400°C, 500°C and 700°C and then maintained for 1h, 2h, 4 and 5 h at this temperature. All biochar properties were strongly influenced by feedstock source except for pH, the recalcitrance index and hydrophobicity. Nutrient contents were normally higher in the PM biochar, except for Cu and Ca which were higher in the DW biochar and B in the CR biochar. Heavy metal contents were significantly higher in the DW biochar. Biochar yield was higher in the DW biochar owing to the higher content of ashes. The temperature of pyrolysis did not significantly influence the level of nutrients. However, biochar yield decreased with increasing temperature, while pH increased with increasing temperature. All biochars produced at 300°C and 400°C were highly hydrophobic. Hydrophobicity totally disappeared in all biochars produced over 500°C at 2 h. Thermal stability was highly influenced by pyrolysis temperature, increasing with increasing temperature. Biochar produced at 300°C and 400°C showed presence of different pools of labile and recalcitrant pools, while biochar produced over 500°C showed an acute recalcitrant phase, with low content of labile pools. The disappearance of hydrophobicity was associated with the decreased in the labile pools of the biochar and increased thermal stability. No significant influence of the pyrolysis time was observed in any of the properties studied except for hydrophobicity, which tended to decrease with decreasing the time of pyrolysis. Our results showed that biochars can be tailored for different purposes in terms of the needs of specific nutrients, C sequestration, reduction of the content of toxic heavy metals, or absence of hydrophobicity to avoid negative hydrological processes in the soil. Acknowledgements: This work has been funded by the Programme Young Leaders in Research from Fundación Séneca (Agency of Science and Technology of the Region of Murcia, Spain) through the Project 18920/JLI/13.

  14. Temperature difference between the cooled and the noncooled parts of an electrolyte in capillary electrophoresis.

    PubMed

    Musheev, Michael U; Filiptsev, Yuri; Krylov, Sergey N

    2010-10-15

    Joule heating always accompanies electrophoresis and unavoidably leads to a temperature increase of the electrolyte. The elevated temperatures are known to adversely affect the quality of separation and detection. To minimize the temperature increase in capillary electrophoresis (CE), Joule heat is removed by actively cooling the capillary. However, there are always small parts of the capillary, such as its inlet, outlet, and detection window, which are not actively cooled. The noncooled capillary inlet has been recently proven to have an elevated temperature which is high enough to significantly affect CE-based quantitative affinity analyses. The temperature difference between the cooled and noncooled regions has never been determined due to the lack of a suitable method. Here, we report on the first experimental determination of temperature in the cooled part of the capillary and the noncooled inlet region of the capillary. We found that, under typical CE conditions, with a low-conductivity run buffer, the temperature in the noncooled inlet exceeded the temperature in the cooled region by more than 15 C. High-conductivity buffers are anticipated to have even greater temperature differences between the noncooled and cooled capillary parts. Our results strongly suggest the potential effect of the noncooled capillary regions on the quality of CE-based analyses, which cannot be ignored. The simplest way to avoid potential errors is to move the sample to the cooled region by pressure or by applying a low electric field. PMID:20853855

  15. Electrical transport in carbon black-epoxy resin composites at different temperatures

    NASA Astrophysics Data System (ADS)

    Macutkevic, J.; Kuzhir, P.; Paddubskaya, A.; Maksimenko, S.; Banys, J.; Celzard, A.; Fierro, V.; Bistarelli, S.; Cataldo, A.; Micciulla, F.; Bellucci, S.

    2013-07-01

    Results of broadband electric/dielectric properties of different surface areacarbon black/epoxy resin composites above the percolation threshold are reported in a wide temperature range (25-500 K). At higher temperatures (above 400 K), the electrical conductivity of composites is governed by electrical transport in polymer matrix and current carriers tunneling from carbon black clusters to polymer matrix. The activation energy of such processes decreases when the carrier concentration increases, i.e., with the increase of carbon black concentration. At lower temperatures, the electrical conductivity is governed by electron tunneling and hopping. The electrical conductivity and dielectric permittivity of composites strongly decrease after annealing composites at high temperatures (500 K); at the same time potential barrier for carriers tunneling strongly increases. All the observed peculiarities can be used for producing effective low-cost materials on the basis of epoxy resin working at different temperatures for electrical applications.

  16. Differences between radiosonde and dropsonde temperature profiles over the Arctic Ocean

    SciTech Connect

    Skony, S.M.; Kahl, J.D.W.; Zaitseva, N.A.

    1994-10-01

    The boundary layer structure measured by 402 pairs of approximately collocated radiosonde and dropsonde temperature profiles over the Arctic Ocean during the period 1957-1961 is examined. The radiosonde profiles were obtained at the Russian drifting ice camps `North Pole 7` and `North Pole 8,` and the dropsonde profiles were measured during the United States Air Force `Ptarmigan` series of weather reconnaissance flights. The boundary layer structure is characterized by the features of the low-level tropospheric temperature inversion. The results indicate that the dropsonde soundings, although containing relatively few measurement levels, contain sufficient vertical resolution to characterize the temperature inversion. Systematic differences were noted in wintertime inversion features and near-surface temperatures as measured by dropsondes and radiosondes. These differences are attributed to contrasting temperature lag errors accompanying ascending and descending sensors.

  17. Temperature dependent competition between different recombination channels in organic heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Linderl, Theresa; Hörmann, Ulrich; Beratz, Sergej; Gruber, Mark; Grob, Stefan; Hofmann, Alexander; Brütting, Wolfgang

    2016-02-01

    A modification of the Shockley–Queisser theory for organic heterojunctions is presented with a special focus on constellations, where a linear extrapolation of the temperature dependence of the open circuit voltage results in the optical gap of the absorber rather than in the intermolecular charge transfer (CT) gap. We demonstrate that, depending on the electronic coupling strength between donor and acceptor molecules, either singlet or CT recombination is dominant in different temperature regimes. The different regimes are separated by a transition temperature that is usually well above room temperature (RT). However, in the case of small energy level offset and weak electronic coupling, it can be around 300 K or even below. We point out that a linear extrapolation of the open circuit voltage V oc towards 0 K for measured temperatures larger than the transition temperature results in a photovoltaic gap that is close to the optical gap, whereas for values below the transition temperature the CT gap will be extracted. We show that for α-sexithiophene (6T)/diindenoperylene (DIP) solar cells heating the substrate during 6T deposition leads to a molecular configuration at the interface where the coupling between donor and acceptor molecules is strongly reduced. This leads to a transition temperature well below RT which is confirmed by temperature dependent electroluminescence measurements. By comparing the temperature dependent spectra of high temperature and RT grown 6T/DIP solar cells to the spectra of the individual materials, the different contributions from the CT gap and the optical gap are separated.

  18. Evaluation of steam sterilization processes: comparing calculations using temperature data and biointegrator reduction data and calculation of theoretical temperature difference.

    PubMed

    Lundahl, Gunnel

    2007-01-01

    When calculating of the physical F121.1 degrees c-value by the equation F121.1 degrees C = t x 10(T-121.1/z the temperature (T), in combination with the z-value, influences the F121.1 degrees c-value exponentially. Because the z-value for spores of Geobacillus stearothermophilus often varies between 6 and 9, the biological F-value (F(Bio) will not always correspond to the F0-value based on temperature records from the sterilization process calculated with a z-value of 10, even if the calibration of both of them are correct. Consequently an error in calibration of thermocouples and difference in z-values influences the F121.1 degrees c-values logarithmically. The paper describes how results from measurements with different z-values can be compared. The first part describes the mathematics of a calculation program, which makes it easily possible to compare F0-values based on temperature records with the F(BIO)-value based on analysis of bioindicators such as glycerin-water-suspension sensors. For biological measurements, a suitable bioindicator with a high D121-value can be used (such a bioindicator can be manufactured as described in the article "A Method of Increasing Test Range and Accuracy of Bioindicators-Geobacillus stearothermophilus Spores"). By the mathematics and calculations described in this macro program it is possible to calculate for every position the theoretical temperature difference (deltaT(th)) needed to explain the difference in results between the thermocouple and the biointegrator. Since the temperature difference is a linear function and constant all over the process this value is an indication of the magnitude of an error. A graph and table from these calculations gives a picture of the run. The second part deals with product characteristics, the sterilization processes, loading patterns. Appropriate safety margins have to be chosen in the development phase of a sterilization process to achieve acceptable safety limits. Case studies are discussed and experiences are shared. PMID:17390699

  19. Thermal deformation of a large space panel caused by temperature difference between front and rear sides

    NASA Astrophysics Data System (ADS)

    Ichikawa, Naoki; Kurokawa, Haruhisa; Yajima, Nobuyuki; Kokaji, Shigeru; Suzuki, Akio

    This paper describes the development of a ground test system for determining the thermal deformation of large antenna panels to be used in space. The system is designed to measure the deformation occurring as a result of temperature differences between the front and rear surfaces of the panel. In the experimental set-up, a symmetric honeycomb panel was used. The front surface of the panel was heated by IR radiation, and the deformation was determined using a fringe scanning moire system which measured the shape of the rear surface. It was found that the temperature difference realized by the system was of the same order as was estimated on the orbit. The variations in the temperature difference were less than 15 percent of the average value. The effects of temperature distribution on the deformation were evaluated to be negligible by an FEM calculation.

  20. Comparing different protocols of temperature selection in the parallel tempering method

    NASA Astrophysics Data System (ADS)

    Fiore, Carlos E.

    2011-09-01

    Parallel tempering Monte Carlo simulations have been applied to a variety of systems presenting rugged free-energy landscapes. Despite this, its efficiency depends strongly on the temperature set. With this query in mind, we present a comparative study among different temperature selection schemes in three lattice-gas models. We focus our attention in the constant entropy method (CEM), proposed by Sabo et al. In the CEM, the temperature is chosen by the fixed difference of entropy between adjacent replicas. We consider a method to determine the entropy which avoids numerical integrations of the specific heat and other thermodynamic quantities. Different analyses for first- and second-order phase transitions have been undertaken, revealing that the CEM may be an useful criterion for selecting the temperatures in the parallel tempering.

  1. A physics-based algorithm for retrieving land-surface emissivity and temperature from EOS/MODIS data

    SciTech Connect

    Wan, Z.; Li, Z.L.

    1997-07-01

    The authors have developed a physics-based land-surface temperature (LST) algorithm for simultaneously retrieving surface band-averaged emissivities and temperatures from day/night pairs of MODIS (Moderate Resolution Imaging Spectroradiometer) data in seven thermal infrared bands. The set of 14 nonlinear equations in the algorithm is solved with the statistical regression method and the least-squares fit method. This new LST algorithm was tested with simulated MODIS data for 80 sets of band-averaged emissivities calculated from published spectral data of terrestrial materials in wide ranges of atmospheric and surface temperature conditions. Comprehensive sensitivity and error analysis has been made to evaluate the performance of the new LST algorithm and its dependence on variations in surface emissivity and temperature, upon atmospheric conditions, as well as the noise-equivalent temperature difference (NE{Delta}T) and calibration accuracy specifications of the MODIS instrument. In cases with a systematic calibration error of 0.5%, the standard deviations of errors in retrieved surface daytime and nighttime temperatures fall between 0.4--0.5 K over a wide range of surface temperatures for mid-latitude summer conditions. The standard deviations of errors in retrieved emissivities in bands 31 and 32 (in the 10--12.5 {micro}m IR spectral window region) are 0.009, and the maximum error in retrieved LST values falls between 2--3 K.

  2. Ambient temperature influences core body temperature response in rat lines bred for differences in sensitivity to 8-hydroxy-dipropylaminotetralin.

    PubMed

    Nicholas, Andrea C; Seiden, Lewis S

    2003-04-01

    Agonist-induced decrease in core body temperature has commonly been used as a measure of serotonin1A (5-HT(1A)) receptor sensitivity in mood disorder. The thermoregulatory basis for 5-HT(1A) receptor agonist-induced temperature responses in humans and rats remains unclear. Therefore, the influence of ambient temperature on 5-HT(1A) receptor-mediated decreases in core body temperature were measured in rat lines bred for high (HDS) or low (LDS) sensitivity to the selective 5-HT(1A) receptor agonist 8-hydroxy-dipropylaminotetralin (8-OH-DPAT). HDS and LDS rats were injected with either saline, 0.25 or 0.50 mg/kg 8-OH-DPAT at ambient temperatures of 10.5, 24, 30, or 37.5 degrees C, and core temperature was measured by radiotelemetry. For both lines, the thermic response to acute 8-OH-DPAT was greatest at 10.5 degrees C and decreased in magnitude as ambient temperature increased to 30 degrees C, consistent with hypothermia. HDS rats displayed a greater hypothermic response than LDS rats at 10.5, 24, and 30 degrees C. At 37.5 degrees C, LDS rats showed a lethal elevation of temperature in response to 0.50 mg/kg 8-OH-DPAT. All thermic responses to 8-OH-DPAT, including the lethality, were effectively blocked by pretreatment with the 5-HT(1A) receptor antagonist WAY100635, suggesting line differences in thermoregulatory circuits that are influenced by 5-HT(1A) receptor activation. Following repeated injection of 8-OH-DPAT, the magnitude of the hypothermic response decreased in both lines at 10.5 degrees C, but increased in HDS rats treated with 0.50 mg/kg 8-OH-DPAT at 30 and 37.5 degrees C. This pattern was reversed in HDS rats following 8-OH-DPAT challenge at 24 degrees C, suggesting that a compensatory thermoregulatory response accounts for changes in the hypothermic response to chronic 8-OH-DPAT. PMID:12649391

  3. Egg incubation temperature differently affects female and male hatching dynamics and larval fitness in a leafhopper

    PubMed Central

    Chuche, Julien; Thiéry, Denis

    2012-01-01

    Temperature effects on ectotherms are widely studied particularly in insects. However, the life-history effects of temperature experienced during a window of embryonic development, that is egg stage, have rarely been considered. We simulated fluctuating temperatures and examined how this affects the operational sex ratio (OSR) of hatching as well as nymph and adult fitness in a leafhopper, Scaphoideus titanus. Specifically, after a warm or cold incubation we compared males and females hatching dynamics with their consequences on the sex ratio in the course of time, body size, weight, and developmental rate of the two populations, all reared on the same posthatching temperature. Males and females eggs respond differently, with females more sensitive to variation in incubation temperature. The different responses of both sexes have consequences on the sex ratio dynamic of hatchings with a weaker protandry after warm incubation. Temperatures experienced by eggs have more complex consequences on posthatching development. Later nymphal instars that hatched from eggs exposed to warm temperature were larger and bigger but developmental rate of the two populations was not affected. Our study demonstrates how incubation temperature could affect operational sex ratio and posthatching development in an insect and how this may be critical for population growth. PMID:22837822

  4. Alteration of protein patterns in black rock inhabiting fungi as a response to different temperatures

    PubMed Central

    Tesei, Donatella; Marzban, Gorji; Zakharova, Kristina; Isola, Daniela; Selbmann, Laura; Sterflinger, Katja

    2012-01-01

    Rock inhabiting fungi are among the most stress tolerant organisms on Earth. They are able to cope with different stressors determined by the typical conditions of bare rocks in hot and cold extreme environments. In this study first results of a system biological approach based on two-dimensional protein profiles are presented. Protein patterns of extremotolerant black fungi Coniosporium perforans, Exophiala jeanselmei and of the extremophilic fungus Friedmanniomyces endolithicus were compared with the cosmopolitan and mesophilic hyphomycete Penicillium chrysogenum in order to follow and determine changes in the expression pattern under different temperatures. The 2D protein gels indicated a temperature dependent qualitative change in all the tested strains. Whereas the reference strain P. chrysogenum expressed the highest number of proteins at 40C, thus exhibiting real signs of temperature induced reaction, black fungi, when exposed to temperatures far above their growth optimum, decreased the number of proteins indicating a down-regulation of their metabolism. Temperature of 1C led to an increased number of proteins in all of the analysed strains, with the exception of P. chrysogenum. These first results on temperature dependent reactions in rock inhabiting black fungi indicate a rather different strategy to cope with non-optimal temperature than in the mesophilic hyphomycete P.chrysogenum. PMID:22862921

  5. Different effects of increased water temperature on egg production of Calanus finmarchicus and C. glacialis

    NASA Astrophysics Data System (ADS)

    Pasternak, A. F.; Arashkevich, E. G.; Grothe, U.; Nikishina, A. B.; Solovyev, K. A.

    2013-09-01

    Two copepod species, Calanus finmarchicus (a widespread North Atlantic species) and C. glacialis (an Arctic species), are dominant in the zooplankton of Arctic seas. We hypothesized that the anticipated warming in the Arctic might have different effects on the arctic and boreal species. The effect of temperature on egg production rate (EPR) in these species at temperatures of 0, 2.5, 5, 7.5, and 10C under contrasting feeding conditions was assessed in 5-day-long experiments. The EPR of the fed C. finmarchicus increased with temperature over the entire tested range. On the contrary, the EPR of C. glacialis increased only in the range of 0-5C and dropped with further temperature growth. The difference in the influence of temperature on reproduction of these two species is statistically significant. Feeding conditions have a considerable effect on the C. finmarchicus EPR. The EPRs of the female C. glacialis that fed or starved for 5 days displayed no significant difference. These results suggest that the C. finmarchicus EPR increases with temperature under favorable feeding conditions, whereas the C. glacialis EPR decreases at a temperature over 5C independently of the feeding conditions. This allows for prediction of the shift in abundances of these two species in pelagic communities of Arctic seas in the case of a warming scenario.

  6. Alteration of protein patterns in black rock inhabiting fungi as a response to different temperatures.

    PubMed

    Tesei, Donatella; Marzban, Gorji; Zakharova, Kristina; Isola, Daniela; Selbmann, Laura; Sterflinger, Katja

    2012-08-01

    Rock inhabiting fungi are among the most stress tolerant organisms on Earth. They are able to cope with different stressors determined by the typical conditions of bare rocks in hot and cold extreme environments. In this study first results of a system biological approach based on two-dimensional protein profiles are presented. Protein patterns of extremotolerant black fungi -Coniosporium perforans, Exophiala jeanselmei - and of the extremophilic fungus -Friedmanniomyces endolithicus - were compared with the cosmopolitan and mesophilic hyphomycete Penicillium chrysogenum in order to follow and determine changes in the expression pattern under different temperatures. The 2D protein gels indicated a temperature dependent qualitative change in all the tested strains. Whereas the reference strain P. chrysogenum expressed the highest number of proteins at 40C, thus exhibiting real signs of temperature induced reaction, black fungi, when exposed to temperatures far above their growth optimum, decreased the number of proteins indicating a down-regulation of their metabolism. Temperature of 1C led to an increased number of proteins in all of the analysed strains, with the exception of P. chrysogenum. These first results on temperature dependent reactions in rock inhabiting black fungi indicate a rather different strategy to cope with non-optimal temperature than in the mesophilic hyphomycete P.chrysogenum. PMID:22862921

  7. High operating temperature interband cascade focal plane arrays

    SciTech Connect

    Tian, Z.-B.; Godoy, S. E.; Kim, H. S.; Schuler-Sandy, T.; Montoya, J. A.; Krishna, S.

    2014-08-04

    In this paper, we report the initial demonstration of mid-infrared interband cascade (IC) photodetector focal plane arrays with multiple-stage/junction design. The merits of IC photodetectors include low noise and efficient photocarrier extraction, even for zero-bias operation. By adopting enhanced electron barrier design and a total absorber thickness of 0.7 μm, the 5-stage IC detectors show very low dark current (1.10 × 10{sup −7} A/cm{sup 2} at −5 mV and 150 K). Even with un-optimized fabrication and standard commercial (mis-matched) read-out circuit technology, infrared images are obtained by the 320 × 256 IC focal plane array up to 180 K with f/2.3 optics. The minimum noise equivalent temperature difference of 28 mK is obtained at 120 K. These initial results indicate great potential of IC photodetectors, particularly for high operating temperature applications.

  8. Metabolite profiling reveals temperature effects on the VOCs and flavonoids of different plant populations.

    PubMed

    Goh, H-H; Khairudin, K; Sukiran, N A; Normah, M N; Baharum, S N

    2016-01-01

    Temperature is one of the key factors in limiting the distribution of plants and controlling major metabolic processes. A series of simulated reciprocal transplant experiments were performed to investigate the effect of temperature on plant chemical composition. Polygonum minus of different lowland and highland origin were grown under a controlled environment with different temperature regimes to study the effects on secondary metabolites. We applied gas chromatography-mass spectrometry and liquid chromatography time-of-flight mass spectrometry to identify the chemical compounds. A total of 37 volatile organic compounds and 85 flavonoids were detected, with the largest response observed in the compositional changes of aldehydes and terpenes in highland plants under higher temperature treatment. Significantly less anthocyanidin compounds and larger amounts of flavonols were detected under higher temperature treatment. We also studied natural variation in the different plant populations growing under the same environment and identified compounds unique to each population through metabolite fingerprinting. This study shows that the origin of different plant populations influences the effects of temperature on chemical composition. PMID:26417881

  9. Tolerance, oxygen consumption and ammonia excretion of Ophiopholis sarsii vadicola in different temperatures and salinities

    NASA Astrophysics Data System (ADS)

    Fang, Jinghui; Zhang, Jihong; Jiang, Zengjie; Zhao, Xuewei; Jiang, Xu; Du, Meirong; Gao, Yaping; Fang, Jianguang

    2015-06-01

    There are more than 2000 species of brittle stars in the world. For most of them, many scientific questions including basic characteristics of eco-physiology are still unknown. In the present study, Ophiopholis sarsii vadicola acclimated at 15C, salinity 31, were assessed for temperature and salinity tolerance. Its oxygen consumption and ammonia excretion were studied at different temperatures (5, 10, 15, 20, 25C) and salinities (25, 30, 35). O. sarsii vadicola could tolerate 0-24C and no brittle star was dead in the salinity range of 19-48 in the experimental situation. Two-way ANOVA showed that the oxygen consumption and ammonia excretion normalized with both dry mass and wet mass, Q 10, which is used to describe the temperature sensitivity of respiration, and moisture content were significantly affected by temperature and salinity, and the combined effects of the two factors were significant. Stepwise multiple regression analysis revealed that logarithmic oxygen consumption and ammonia excretion showed a significant positive relationship with logarithmic temperature and salinity. The logarithmic moisture content of the brittle stars showed an inverse relationship with logarithmic salinity, but a positive relationship with logarithmic temperature. This suggests that the tolerance of temperature and salinity of brittle stars is closely related to their living environment, and that the effects of temperature on oxygen consumption are more significant at higher salinity, and that the ammonia excretion is less affected by salinity at lower temperatures.

  10. Electron temperature difference between the o-point and x-point of a magnetic island

    SciTech Connect

    Yang Jinhong; Zhu Sizheng; Yu Qingquan; Zhuang, G.

    2009-09-15

    The electron temperature difference between the o-point and the x-point of a magnetic island is studied numerically by solving the two-dimensional energy transport equation. It is found that, even without a localized radio-frequency heating at the island's o-point, there is usually a temperature difference between these two points. This difference depends on the radial profile of the heating power deposition, the ratio between the parallel and the perpendicular heat conductivity and the island width, and it takes a minimum when the island width is about twice the local heat diffusion layer width. The effect of the temperature difference on the island growth is further studied, and the peaked heating power density profile at magnetic axis is found be destabilizing.

  11. Improving the Accuracy of Satellite Sea Surface Temperature Measurements by Explicitly Accounting for the Bulk-Skin Temperature Difference

    NASA Technical Reports Server (NTRS)

    Wick, Gary A.; Emery, William J.; Castro, Sandra L.; Lindstrom, Eric (Technical Monitor)

    2002-01-01

    The focus of this research was to determine whether the accuracy of satellite measurements of sea surface temperature (SST) could be improved by explicitly accounting for the complex temperature gradients at the surface of the ocean associated with the cool skin and diurnal warm layers. To achieve this goal, work was performed in two different major areas. The first centered on the development and deployment of low-cost infrared radiometers to enable the direct validation of satellite measurements of skin temperature. The second involved a modeling and data analysis effort whereby modeled near-surface temperature profiles were integrated into the retrieval of bulk SST estimates from existing satellite data. Under the first work area, two different seagoing infrared radiometers were designed and fabricated and the first of these was deployed on research ships during two major experiments. Analyses of these data contributed significantly to the Ph.D. thesis of one graduate student and these results are currently being converted into a journal publication. The results of the second portion of work demonstrated that, with presently available models and heat flux estimates, accuracy improvements in SST retrievals associated with better physical treatment of the near-surface layer were partially balanced by uncertainties in the models and extra required input data. While no significant accuracy improvement was observed in this experiment, the results are very encouraging for future applications where improved models and coincident environmental data will be available. These results are included in a manuscript undergoing final review with the Journal of Atmospheric and Oceanic Technology.

  12. Cloacal and surface temperatures of tom turkeys exposed to different rearing temperature regimes during the first 12 weeks of growth.

    PubMed

    Mayes, S L; Strawford, M L; Noble, S D; Classen, H L; Crowe, T G

    2015-06-01

    Years of genetic selection have caused an increase in growth rate and market body mass in agricultural poultry species compared to earlier genetic strains, potentially altering their physiological requirements. The objective of this study was to expose Hybrid Converter tom turkeys on a weekly basis to the recommended rearing temperature regime (TCON: control) or 4°C below the recommended standard (TTRT: treatment) to determine their thermal responses. Once per week for 12 weeks, 12 turkeys were individually exposed to either TCON or TTRT for a 2-h period. Surface temperatures of the breast (TBREAST), wing (TWING), drumstick (TDRUM), head (THEAD), and shank (TSHANK) were measured at 20-min intervals using an infrared camera, while a thermal data logger measured the skin surface temperature under the wing (TLOGGER) at 30-s intervals. The cloacal temperature (TCORE) was measured using a medical thermometer at the start and end of the exposure period. Regardless of exposure temperature, the TBREAST (TCON: P<0.001 and TTRT: P<0.001), TWING (TCON: P<0.001 and TTRT: P<0.001), and TDRUM (TCON: P<0.001 and TTRT: P<0.001) decreased from weeks 4 to 6 and remained constant from weeks 1 to 3 and 8 to 12. THEAD was elevated in week 2 (TCON: P<0.001) or week 3 (TTRT: P<0.001), TSHANK increased slightly during week 3 for both TCON (P<0.001) and TTRT (P<0.001), and TLOGGER (TCON: P<0.001 and TTRT: P=0.001) and TCORE (TCON: P<0.001 and TTRT: P<0.001) were lower during the first week. Thereafter, THEAD, TSHANK, TLOGGER, and TCORE remained constant. Exposure to TTRT resulted in lower TBREAST, TWING, and TDRUM compared to TCON. Generally, THEAD, TSHANK, TLOGGER, and TCORE were not affected by the different exposure temperatures. The data demonstrated that the degree of thermal response expressed is dependent on the location of measurement, age, and exposure temperature. PMID:25589083

  13. Effects of inherent alkali and alkaline earth metallic species on biomass pyrolysis at different temperatures.

    PubMed

    Hu, Song; Jiang, Long; Wang, Yi; Su, Sheng; Sun, Lushi; Xu, Boyang; He, Limo; Xiang, Jun

    2015-09-01

    This work aimed to investigate effects of inherent alkali and alkaline earth metallic species (AAEMs) on biomass pyrolysis at different temperatures. The yield of CO, H2 and C2H4 was increased and that of CO2 was suppressed with increasing temperature. Increasing temperature could also promote depolymerization and aromatization reactions of active tars, forming heavier polycyclic aromatic hydrocarbons, leading to decrease of tar yields and species diversity. Diverse performance of inherent AAEMs at different temperatures significantly affected the distribution of pyrolysis products. The presence of inherent AAEMs promoted water-gas shift reaction, and enhanced the yield of H2 and CO2. Additionally, inherent AAEMs not only promoted breakage and decarboxylation/decarbonylation reaction of thermally labile hetero atoms of the tar but also enhanced thermal decomposing of heavier aromatics. Inherent AAEMs could also significantly enhance the decomposition of levoglucosan, and alkaline earth metals showed greater effect than alkali metals. PMID:26005925

  14. Temperature Profiles Along the Root with Gutta-percha Warmed through Different Heat Sources

    PubMed Central

    Simeone, Michele; Santis, Roberto De; Ametrano, Gianluca; Prisco, Davide; Borrelli, Marino; Paduano, Sergio; Riccitiello, Francesco; Spagnuolo, Gianrico

    2014-01-01

    Objectives: To evaluate temperature profiles developing in the root during warm compaction of gutta-percha with the heat sources System B and System MB Obtura (Analityc Technology, Redmond, WA, USA). Thirty extracted human incisor teeth were used. Root canals were cleaned and shaped by means of Protaper rotary files (Dentsply-Maillefer, Belgium), and imaging was performed by micro-CT (Skyscan 1072, Aartselaar, Belgium). Methods: Teeth were instrumented with K-type thermocouples, and the roots were filled with thermoplastic gutta-percha. Vertical compaction was achieved through the heat sources System B and System MB, and temperature profiles were detect-ed by means of NI Dac Interface controlled by the LabView System. With both heat sources, higher temperature levels were recorded in the region of the root far from the apex. When the warm plugger tip was positioned at a distance of 3 mm from the root apex, temperature levels of about 180°C were used to soften gutta-percha, and no statistically significant differences were observed between peak temperatures developed by the two heating sources at the root apex. However, a temperature level higher than 40°C was maintained for a longer time with System MB. Results: Statistically significant differences were observed in peak temperature levels recorded far from the root apex. Thus, with a temperature of about 180°C and the warm plugger positioned at 3 mm from the root apex, both heating sources led to a temperature slightly higher than 40°C at the apex of the root, suggesting that the gutta-percha was properly softened. Significance: A temperature level higher than 40°C was maintained for a longer time with System MB, thus providing an ad-equate time for warm compaction of the gutta-percha. PMID:25614768

  15. The Shift of Thermoneutral Zone in Striped Hamster Acclimated to Different Temperatures

    PubMed Central

    Zhao, Zhi-Jun; Chi, Qing-Sheng; Liu, Quan-Sheng; Zheng, Wei-Hong; Liu, Jin-Song; Wang, De-Hua

    2014-01-01

    Temperature affects all biological functions and will therefore modulate ecologically significant interactions between animals and their environment. Here, we examined the effect of ambient temperature (Ta) on the thermal biology and energy budget in striped hamsters acclimated to cold (5°C), warm (21°C) and hot temperatures (31°C). Thermoneutral zone (TNZ) was 22.5–32.5°C, 25–32.5°C and 30–32.5°C in the cold-, warm- and hot-acclimated hamsters, respectively. The cold acclimation decreased the lower critical temperature and made the TNZ wider, and hot exposure elevated the lower critical temperature, resulting in a narrow TNZ. Within the TNZ, cold-acclimated hamsters showed a significantly higher rate of metabolism and thermogenesis than those acclimated to hot temperature. Digestive enzymes activities, including intestinal sucrase, maltase, L-alanine aminopeptidase-N and leucine aminopeptidase were higher in the cold than in the hot. The changes in metabolic rate and thermogenesis at different temperatures were in parallel with cytochrome c oxidase activity and uncoupling protein 1 gene expression of brown adipose tissue. This suggests that the shift of the lower critical temperature of TNZ is possibly associated with the rate of metabolism and thermogenesis, as well as with the digestive capacity of the gastrointestinal tract at different Ta. The upper critical temperature of TNZ may be independent of the changes in Ta. The changes of lower critical temperature of TNZ are an important strategy in adaption to variations of Ta. PMID:24400087

  16. Unsteady temperature field of turbine disk analyzed by coupled boundary element-finite difference method

    NASA Astrophysics Data System (ADS)

    Du, Shengguang

    1991-10-01

    The unsteady temperature field of a turbine disk is presently computed by means of the Brebbia et al. (1984) coupled boundary element finite-difference method, incorporating an additional boundary condition and occassionally incorporating a thermal-conductivity term. The application of the method to the calculation and analysis of the transient temperature field of a turbine disk is shown to require much less data and computing time, while yielding higher-accuracy results than the simple finite-element method.

  17. Acclimation of Solea senegalensis to different ambient temperatures: implications for thyroidal status and osmoregulation.

    PubMed

    Arjona, Francisco J; Ruiz-Jarabo, Ignacio; Vargas-Chacoff, Luis; Martn Del Ro, Mara P; Flik, Gert; Mancera, Juan M; Klaren, Peter H M

    2010-01-01

    We have investigated the regulation of thyroidal status and osmoregulatory capacities in juveniles from the teleost Solea senegalensis acclimated to different ambient temperatures. Juveniles, raised in seawater at 19C, were acclimated for 3weeks to temperatures of 12, 19 and 26C. Since our preliminary observations showed that at 12C feed intake was suppressed, our experimental design controlled for this factor. The concentration of branchial Na(+),K(+)-ATPase, estimated by measurements of enzyme activity at the optimum temperature of this enzyme (37C), did not change. In contrast, an increase in Na(+),K(+)-ATPase activity (measured at 37C), was observed in the kidney of 12C-acclimated fish. In fish acclimated to 12C, the hepatosomatic index had increased, which correlated with increased plasma levels of triglycerides and non-esterified fatty acids. Plasma cortisol levels did not differ significantly between the experimental groups. In liver and gills, the amount of iodothyronine deiodinases that exhibit thyroid hormone outer ring deiodination was up-regulated only when fish did not feed. When assayed at the acclimation temperature, kidney deiodinase activities were similar, indicating a temperature-compensation strategy. 3,5,3'-triiodothyronine (T3) tissue concentrations in gills and kidney did not differ significantly between experimental groups. However, at 12C, lower T3 tissue levels were measured in plasma and liver. We conclude that S. senegalensis adjusts its osmoregulatory system to compensate for the effects of temperature on electrolyte transport capacity. The organ-specific changes in thyroid hormone metabolism at different temperatures indicate the involvement of thyroid hormones in temperature acclimation. PMID:24391247

  18. Recovery of Pasteurella hemolytica from aerosols at differing temperature and humidity.

    PubMed Central

    Jericho, K W; Langford, E V; Pantekoek, J

    1977-01-01

    A Pasteurella hemolytica suspension with fetal calf serum was aerosolized in a standard system with ambient temperature of 30 or 2 degrees C and relative humidity conditions of 90 or 60%. The number of organisms sprayed in five minutes and the number recovered from one third of the aerosol during these five minutes was determined. Recoveries were influenced by temperature difference between aerosol and collecting fluid. Recoveries ranged between 0.059--0.94%. Images Fig. 1. PMID:861840

  19. Influence trend of temperature distribution in skin tissue generated by different exposure dose pulse laser

    NASA Astrophysics Data System (ADS)

    Shan, Ning; Wang, Zhijing; Liu, Xia

    2014-11-01

    Laser is widely applied in military and medicine fields because of its excellent capability. In order to effectively defend excess damage by laser, the thermal processing theory of skin tissue generated by laser should be carried out. The heating rate and thermal damage area should be studied. The mathematics model of bio-tissue heat transfer that is irradiated by laser is analyzed. And boundary conditions of bio-tissue are discussed. Three layer FEM grid model of bio-tissue is established. The temperature rising inducing by pulse laser in the tissue is modeled numerically by adopting ANSYS software. The changing trend of temperature in the tissue is imitated and studied under the conditions of different exposure dose pulse laser. The results show that temperature rising in the tissue depends on the parameters of pulse laser largely. In the same conditions, the pulse width of laser is smaller and its instant power is higher. And temperature rising effect in the tissue is very clear. On the contrary, temperature rising effect in the tissue is lower. The cooling time inducing by temperature rising effect in the tissue is longer along with pulse separation of laser is bigger. And the temperature difference is bigger in the pulse period.

  20. Lipase-catalyzed interesterification in packed bed reactor using 2 different temperatures.

    PubMed

    Chae, Mi-Hwa; Park, Hye-Kyung; Kwon, Kwang-Il; Kim, Jong-Wook; Hong, Seung In; Kim, Yangha; Kim, Byung Hee; Kim, In-Hwan

    2011-05-01

    Lipase-catalyzed interesterification of high oleic sunflower oil and fully hydrogenated soybean oil (70 : 30, wt/ wt) was carried out in a packed bed reactor using an immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) and the effect of a stepwise temperature protocol involving the 2 different temperatures, 60 and 70 C, was investigated. The melting point of a fat that was incubated at 70 C for 9 min was 57 C, which suggested that it should be to employ a lower reaction temperature of 60 C, after the first 9 min of the reaction. There were no significant differences (P < 0.05) in the conversion degree, triacylglycerol profile, and solid fat content between a constant temperature protocol (70 C) and a stepwise temperature protocol (a combination of 70 and 60 C). After 50 cycles, the overall residual activities of enzymes employed in stepwise temperature protocol were significantly (P < 0.05) higher than those of enzymes employed in constant temperature protocol. PMID:22417335

  1. Temperature measurements with two different IR sensors in a continuous-flow microwave heated system.

    PubMed

    Rydfjord, Jonas; Svensson, Fredrik; Fagrell, Magnus; Svmarker, Jonas; Thulin, Mns; Larhed, Mats

    2013-01-01

    In a continuous-flow system equipped with a nonresonant microwave applicator we have investigated how to best assess the actual temperature of microwave heated organic solvents with different characteristics. This is non-trivial as the electromagnetic field will influence most traditional methods of temperature measurement. Thus, we used a microwave transparent fiber optic probe, capable of measuring the temperature inside the reactor, and investigated two different IR sensors as non-contact alternatives to the internal probe. IR sensor 1 measures the temperature on the outside of the reactor whilst IR sensor 2 is designed to measure the temperature of the fluid through the borosilicate glass that constitutes the reactor wall. We have also, in addition to the characterization of the before mentioned IR sensors, developed statistical models to correlate the IR sensor reading to a correct value of the inner temperature (as determined by the internal fiber optic probe), thereby providing a non-contact, indirect, temperature assessment of the heated solvent. The accuracy achieved with these models lie well within the range desired for most synthetic chemistry applications. PMID:24204419

  2. Momentum and mass fluxes in a gas confined between periodically structured surfaces at different temperatures

    NASA Astrophysics Data System (ADS)

    Donkov, Alexander A.; Tiwari, Sudarshan; Liang, Tengfei; Hardt, Steffen; Klar, Axel; Ye, Wenjing

    2011-07-01

    It is well known that in a gas-filled duct or channel along which a temperature gradient is applied, a thermal creep flow is created. Here we show that a mass and momentum flux can also be induced in a gas confined between two parallel structured surfaces at different temperatures, i.e., orthogonal to the temperature gradient. We use both analytical and numerical methods to compute the resulting fluxes. The momentum flux assumes its maximum value in the free-molecular flow regime, the (normalized) mass flux in the transition flow regime. The discovered phenomena could find applications in methods for energy-conversion and thermal pumping of gases.

  3. Temperature influences on water permeability and chlorpyrifos uptake in aquatic insects with differing respiratory strategies.

    PubMed

    Buchwalter, David B; Jenkins, Jeffrey J; Curtis, Lawrence R

    2003-11-01

    Aquatic insects have evolved diverse respiratory strategies that range from breathing atmospheric air to breathing dissolved oxygen. These strategies result in vast morphological differences among taxa in terms of exchange epithelial surface areas that are in direct contact with the surrounding water that, in turn, affect physiological processes. This paper examines the effects of acute temperature shifts on water permeability and chlorpyrifos uptake in aquatic insects with different respiratory strategies. While considerable differences existed in water permeability among the species tested, acute temperature shifts raised water influx rates similarly in air-breathing and gill-bearing taxa. This contrasts significantly with temperature-shift effects on chlorpyrifos uptake. Temperature shifts of 4.5 degrees C increased 14C-chlorpyrifos accumulation rates in the gill-bearing mayfly Cinygma sp. and in the air-breathing hemipteran Sigara washingtonensis. However, the temperature-induced increase in 14C-chlorpyrifos uptake after 8 h of exposure was 2.75-fold higher in Cinygma than in Sigara. Uptake of 14C-chlorpyrifos was uniformly higher in Cinygma than in Sigara in all experiments. These findings suggest that organisms with relatively large exchange epithelial surface areas are potentially more vulnerable to both osmoregulatory distress as well as contaminant accumulation. Temperature increases appear more likely to impact organisms that have relatively large exchange epithelial surface areas, both as an individual stressor and in combination with additional stressors such as contaminants. PMID:14587925

  4. Temperature influences on water permeability and chlorpyrifos uptake in aquatic insects with differing respiratory strategies

    USGS Publications Warehouse

    Buchwalter, D.B.; Jenkins, J.J.; Curtis, L.R.

    2003-01-01

    Aquatic insects have evolved diverse respiratory strategies that range from breathing atmospheric air to breathing dissolved oxygen. These strategies result in vast morphological differences among taxa in terms of exchange epithelial surface areas that are in direct contact with the surrounding water that, in turn, affect physiological processes. This paper examines the effects of acute temperature shifts on water permeability and chlorpyrifos uptake in aquatic insects with different respiratory strategies. While considerable differences existed in water permeability among the species tested, acute temperature shifts raised water influx rates similarly in air-breathing and gill-bearing taxa. This contrasts significantly with temperature-shift effects on chlorpyrifos uptake. Temperature shifts of 4.5??C increased 14C-chlorpyrifos accumulation rates in the gill-bearing mayfly Cinygma sp. and in the air-breathing hemipteran Sigara washingtonensis. However, the temperature-induced increase in 14C-chlorpyrifos uptake after 8 h of exposure was 2.75-fold higher in Cinygma than in Sigara. Uptake of 14C-chlorpyrifos was uniformly higher in Cinygma than in Sigara in all experiments. These findings suggest that organisms with relatively large exchange epithelial surface areas are potentially more vulnerable to both osmoregulatory distress as well as contaminant accumulation. Temperature increases appear more likely to impact organisms that have relatively large exchange epithelial surface areas, both as an individual stressor and in combination with additional stressors such as contaminants.

  5. Nonlinear optical parameters of nanocrystalline AZO thin film measured at different substrate temperatures

    NASA Astrophysics Data System (ADS)

    Jilani, Asim; Abdel-wahab, M. Sh; Al-ghamdi, Attieh A.; Dahlan, Ammar sadik; Yahia, I. S.

    2016-01-01

    The 2.2 wt% of aluminum (Al)-doped zinc oxide (AZO) transparent and preferential c-axis oriented thin films were prepared by using radio frequency (DC/RF) magnetron sputtering at different substrate temperature ranging from room temperature to 200 °C. For structural analysis, X-ray Diffraction (XRD) and Atomic Force Electron Microscope (AFM) was used for morphological studies. The optical parameters such as, optical energy gap, refractive index, extinction coefficient, dielectric loss, tangent loss, first and third order nonlinear optical properties of transparent films were investigated. High transmittance above 90% and highly homogeneous surface were observed in all samples. The substrate temperature plays an important role to get the best transparent conductive oxide thin films. The substrate temperature at 150 °C showed the growth of highly transparent AZO thin film. Energy gap increased with the increased in substrate temperature of Al doped thin films. Dielectric constant and loss were found to be photon energy dependent with substrate temperature. The change in substrate temperature of Al doped thin films also affect the non-liner optical properties of thin films. The value of χ(3) was found to be changed with the grain size of the thin films that directly affected by the substrate temperature of the pure and Al doped ZnO thin films.

  6. Experimental set up of a magnetoelectric measuring system operating at different temperatures

    NASA Astrophysics Data System (ADS)

    Gil, K.; Gil, J.; Cruz, B.; Ramirez, A.; Medina, M.; Torres, J.

    2016-02-01

    The magnetoelectric effect is the phenomenon whereby through a magnetic stimulation can be produced an electrical response or vice versa. We implement a magnetoelectric voltage measuring device through the dynamic method for a different range of temperatures. The system was split into an electric set and an instrumentation and control set. Design and element selection criteria that the experimenter must take into account are presented, with special emphasis in the design of the sample holder, which is the fundamental component that differentiates the system operating at high temperature and the one operating at room temperature. The experimental equipment consists of an electromagnet with DC magnetic flux density (B) in a range of (0.0 to 1.6) KOe, a Helmholtz coil which operates with a sinusoidal B between (0.0 and 0.016) KOe and a PT100 temperature sensor. A tubular heating resistance, a Checkman temperature control and an SSR 40A were used for controlling the temperature. As an application of the system, the transverse and longitudinal magnetoelectric coefficient was measured for a thin film of BiFeO3 at room temperature and 307K. It was observed that the behaviour of the longitudinal and transverse magnetoelectric coefficient matches the reported value and decreased with increasing temperature.

  7. Temperature Characterization of Different Urban Microhabitats of Aedes albopictus (Diptera Culicidae) in Central-Northern Italy.

    PubMed

    Vallorani, Roberto; Angelini, Paola; Bellini, Romeo; Carrieri, Marco; Crisci, Alfonso; Mascali Zeo, Silvia; Messeri, Gianni; Venturelli, Claudio

    2015-08-01

    Aedes albopictus (Skuse) is an invasive mosquito species that has spread to many countries in temperate regions bordering the Mediterranean basin, where it is becoming a major public health concern. A good knowledge of the thermal features of the most productive breeding sites for Ae. albopictus is crucial for a better estimation of the mosquitoes' life cycle and developmental rates. In this article, we address the problem of predicting air temperature in three microhabitats common in urban and suburban areas and the air and water temperature inside an ordinary catch basin, which is considered the most productive breeding site for Ae. albopictus in Italy. Temperature differences were statistically proven between the three microhabitats and between the catch basin external and internal temperature. The impacts on the developmental rates for each life stage of Ae. albopictus were tested through a parametric function of the temperature, and the aquatic stages resulted as being the most affected using the specific temperature inside a typical catch basin instead of a generic air temperature. The impact of snow cover on the catch basin internal temperature, and consequently on the mortality of diapausing eggs, was also evaluated. These data can be useful to improve epidemiological models for a better prediction of Ae. albopictus seasonal and population dynamics in central-northern Italian urban areas. PMID:26314064

  8. Genetically determined differences in ethanol sensitivity influenced by body temperature during intoxication

    SciTech Connect

    Alkana, R.L.; Finn, D.A.; Bejanian, M.; Crabbe, J.C.

    1988-01-01

    The present study investigated the importance of body temperature during intoxication in mediating differences between five inbred strains of mice (C57BL/6J; BALB/cJ; DBA/2J; A/HeJ; 129/J) in their acute sensitivity to the hypnotic effects of ethanol. Mice exposed to 22/degrees/C after ethanol injection became hypothermic and exhibited statistically significant differences between strains in rectal temperatures at the return of the righting reflex (RORR), duration of loss of the righting reflex (LORR), and blood and brain ethanol concentrations at RORR. Exposure to 34/degrees/C after injection offset ethanol-hypothermia and markedly reduced strain-related differences in rectal temperatures and blood and brain ethanol concentrations at RORR. Brain ethanol concentrations at RORR were significantly lower in C57, BALB, DBA and A/He mice exposed to 34/degrees/C compared to mice exposed to 22/degrees/C during intoxication suggesting that offsetting hypothermia increased ethanol sensitivity in these strains. Taken with previous in vitro studies, these results suggest that genetically determined differences in acute sensitivity to the behavioral effects of ethanol reflect differences in body temperature during intoxication as well as differences in sensitivity to the initial actions of ethanol at the cellular level.

  9. Rheological characterization of novel physically crosslinked terpolymeric hydrogels at different temperatures

    NASA Astrophysics Data System (ADS)

    Malana, Muhammad Aslam; Zohra, Rubab; Khan, Muhammad Saleem

    2012-09-01

    The main objective of this research work is to reveal the detailed and extensive rheological characterization of terpolymeric hydrogel formulations using a variety of monomers having different concentrations of acrylic acid and applying a range of temperatures. The hydrogels with the different concentrations of acrylic acid were prepared in the absence of air using three different monomers, by free radical polymerization, gradually increasing the temperature up to polymerization point, using ethyl alcohol as solvent. Different shear measurements were performed to study rheological properties, temperature dependence, and yield strength of acrylic acid pharmaceutical hydrogels. Various models were applied to analyze the rheological behavior of the gels. The acrylic acid pharmaceutical gels having physical cross links in the gel networks, exhibit remarkable temperature dependence especially with relatively higher concentration of acrylic acid at greater shear rate. Flow curves plotted at various temperatures indicate that these gels exhibit a reasonable pseudoplastic behavior. All these hydrogels require appropriate yield strength to break their network structures. The gel samples exhibit the best fit to the Modified Bingham model, which can explain the overall flow behavior of these topical gels. The rheological analysis indicates that these gels may be used as topical gels for targeted and controlled drug delivery at a specific site.

  10. Effects of Temperature on Solute Transport Parameters in Differently-Textured Soils at Saturated Condition

    NASA Astrophysics Data System (ADS)

    Hamamoto, S.; Arihara, M.; Kawamoto, K.; Nishimura, T.; Komatsu, T.; Moldrup, P.

    2014-12-01

    Subsurface warming driven by global warming, urban heat islands, and increasing use of shallow geothermal heating and cooling systems such as the ground source heat pump, potentially causes changes in subsurface mass transport. Therefore, understanding temperature dependency of the solute transport characteristics is essential to accurately assess environmental risks due to increased subsurface temperature. In this study, one-dimensional solute transport experiments were conducted in soil columns under temperature control to investigate effects of temperature on solute transport parameters, such as solute dispersion and diffusion coefficients, hydraulic conductivity, and retardation factor. Toyoura sand, Kaolin clay, and intact loamy soils were used in the experiments. Intact loamy soils were taken during a deep well boring at the Arakawa Lowland in Saitama Prefecture, Japan. In the transport experiments, the core sample with 5-cm diameter and 4-cm height was first isotropically consolidated, whereafter 0.01M KCl solution was injected to the sample from the bottom. The concentrations of K+ and Cl- in the effluents were analyzed by an ion chromatograph to obtain solute breakthrough curves. The solute transport parameters were calculated from the breakthrough curves. The experiments were conducted under different temperature conditions (15, 25, and 40 oC). The retardation factor for the intact loamy soils decreased with increasing temperature, while water permeability increased due to reduced viscosity of water at higher temperature. Opposite, the effect of temperature on solute dispersivity for the intact loamy soils was insignificant. The effects of soil texture on the temperature dependency of the solute transport characteristics will be further investigated from comparison of results from differently-textured samples.

  11. Evaluation of the improved linear emissivity constraint temperature and emissivity separation method by using the simulated hyperspectral thermal infrared data

    NASA Astrophysics Data System (ADS)

    Wu, Hua; Li, Zhao-Liang; Tang, Bo-Hui; Tang, Rong-Lin

    2015-12-01

    In this study, an improved linear emissivity constraint temperature and emissivity separation (I-LECTES) method was first proposed to overcome the discontinuities problem of the retrieved land surface emissivities (LSEs) in the former linear emissivity constraint temperature and emissivity separation (LECTES) method. Consequently, the hyperspectral thermal infrared data were carefully simulated according to the configuration of Designs & Prototypes microFTIR Model 102, and were used to evaluate the performance of the I-LECTES method. Meanwhile, the I-LECTES method was also compared with the LECTES method. Different the atmosphere and surface circumstances were considered, as well as the different levels of noise equivalent temperature difference (NEΔT). The results showed that the proposed I-LECTES method is of a better accuracy compared with the LECTES method and has the characteristic of keeping the retrieved LSEs continuous, which sounds more reasonable. Because the noises in the ground measured radiance may have more effects on the accuracies of land surface temperature (LST) and LSEs than those in the atmospheric downwelling radiance, the noise in the ground measured radiance should be removed as much as possible to improve the accuracies of retrieved LST and LSEs. Furthermore, taken into account the lower retrieval accuracies for the cold and dry atmosphere, both the I-LECTES method and the LECTES method should be taken a full consideration. The proposed method is regarded to be promising because of its holding continuity and noise-immune.

  12. Handling Temperature Bursts Reaching 464C: Different Microbial Strategies in the Sisters Peak Hydrothermal Chimney

    PubMed Central

    Kurtz, Stefan; LaRoche, Julie

    2014-01-01

    The active venting Sisters Peak (SP) chimney on the Mid-Atlantic Ridge holds the current temperature record for the hottest ever measured hydrothermal fluids (400C, accompanied by sudden temperature bursts reaching 464C). Given the unprecedented temperature regime, we investigated the biome of this chimney with a focus on special microbial adaptations for thermal tolerance. The SP metagenome reveals considerable differences in the taxonomic composition from those of other hydrothermal vent and subsurface samples; these could be better explained by temperature than by other available abiotic parameters. The most common species to which SP genes were assigned were thermophilic Aciduliprofundum sp. strain MAR08-339 (11.8%), Hippea maritima (3.8%), Caldisericum exile (1.5%), and Caminibacter mediatlanticus (1.4%) as well as to the mesophilic Niastella koreensis (2.8%). A statistical analysis of associations between taxonomic and functional gene assignments revealed specific overrepresented functional categories: for Aciduliprofundum, protein biosynthesis, nucleotide metabolism, and energy metabolism genes; for Hippea and Caminibacter, cell motility and/or DNA replication and repair system genes; and for Niastella, cell wall and membrane biogenesis genes. Cultured representatives of these organisms inhabit different thermal niches; i.e., Aciduliprofundum has an optimal growth temperature of 70C, Hippea and Caminibacter have optimal growth temperatures around 55C, and Niastella grows between 10 and 37C. Therefore, we posit that the different enrichment profiles of functional categories reflect distinct microbial strategies to deal with the different impacts of the local sudden temperature bursts in disparate regions of the chimney. PMID:24837379

  13. Thermal fluctuations of haemoglobin from different species: adaptation to temperature via conformational dynamics.

    PubMed

    Stadler, A M; Garvey, C J; Bocahut, A; Sacquin-Mora, S; Digel, I; Schneider, G J; Natali, F; Artmann, G M; Zaccai, G

    2012-11-01

    Thermodynamic stability, configurational motions and internal forces of haemoglobin (Hb) of three endotherms (platypus, Ornithorhynchus anatinus; domestic chicken, Gallus gallus domesticus and human, Homo sapiens) and an ectotherm (salt water crocodile, Crocodylus porosus) were investigated using circular dichroism, incoherent elastic neutron scattering and coarse-grained Brownian dynamics simulations. The experimental results from Hb solutions revealed a direct correlation between protein resilience, melting temperature and average body temperature of the different species on the 0.1 ns time scale. Molecular forces appeared to be adapted to permit conformational fluctuations with a root mean square displacement close to 1.2 at the corresponding average body temperature of the endotherms. Strong forces within crocodile Hb maintain the amplitudes of motion within a narrow limit over the entire temperature range in which the animal lives. In fully hydrated powder samples of human and chicken, Hb mean square displacements and effective force constants on the 1 ns time scale showed no differences over the whole temperature range from 10 to 300 K, in contrast to the solution case. A complementary result of the study, therefore, is that one hydration layer is not sufficient to activate all conformational fluctuations of Hb in the pico- to nanosecond time scale which might be relevant for biological function. Coarse-grained Brownian dynamics simulations permitted to explore residue-specific effects. They indicated that temperature sensing of human and chicken Hb occurs mainly at residues lining internal cavities in the ?-subunits. PMID:22696485

  14. Evolution of microstructural defects with strain effects in germanium nanocrystals synthesized at different annealing temperatures

    SciTech Connect

    Zhang, Minghuan; Cai, Rongsheng; Zhang, Yujuan; Wang, Chao; Wang, Yiqian; Ross, Guy G.; Barba, David

    2014-07-01

    Ge nanocrystals (Ge-ncs) were produced by implantation of {sup 74}Ge{sup +} into a SiO{sub 2} film on (100) Si, followed by high-temperature annealing from 700 °C to 1100 °C. Transmission electron microscopy (TEM) studies show that the average size of Ge-ncs increases with the annealing temperature. High-resolution TEM (HRTEM) investigations reveal the presence of planar and linear defects in the formed Ge-ncs, whose relative concentrations are determined at each annealing temperature. The relative concentration of planar defects is almost independent of the annealing temperature up to 1000 °C. However, from 1000 °C to 1100 °C, its concentration decreases dramatically. For the linear defects, their concentration varies considerably with the annealing temperatures. In addition, by measuring the interplanar spacing of Ge-ncs from the HRTEM images, a strong correlation is found between the dislocation percentage and the stress field intensity. Our results provide fundamental insights regarding both the presence of microstructural defects and the origin of the residual stress field within Ge-ncs, which can shed light on the fabrication of Ge-ncs with quantified crystallinity and appropriate size for the advanced Ge-nc devices. - Highlights: • Growth of Ge nanocrystals at different annealing temperatures was investigated. • Strain field has great effects on the formation of dislocations. • Different mechanisms are proposed to explain growth regimes of Ge nanocrystals.

  15. Effect of temperature on the substrate utilization profiles of microbial communities in different sewer sediments.

    PubMed

    Biggs, Catherine A; Olaleye, Omolara I; Jeanmeure, Laurent F C; Deines, Peter; Jensen, Henriette S; Tait, Simon J; Wright, Phillip C

    2011-01-01

    Sewer systems represent an essential component of modern society. They have a major impact on our quality of life by preventing serious illnesses caused by waterborne diseases, by protecting the environment, and by enabling economic and social development through reducing flood risk. In the UK, systems are normally large and complex and, because of the long lifespan of these assets, their performance and hence their management are influenced by long-term environmental and urban changes. Recent work has focussed on the long-term changes in the hydraulic performance of these systems in response to climate change, e.g. rainfall and economic development. One climate-related driver that has received little attention is temperature, which may in itself have a complex dependence on factors such as rainfall. This study uses Biolog EcoPlates to investigate the effect of different temperatures (4 degrees C, 24 degrees C and 30 degrees C) on the carbon substrate utilization profiles of bacterial communities within sewer sediment deposits. Distinct differences in the metabolic profiles across the different temperatures were observed. Increasing temperature resulted in a shift in biological activity with an increase in the number of different carbon sources that can be utilized. Certain carboxylic and amino acids, however, did not support growth, regardless of temperature. Distinct differences in carbon utilization profiles were also found within sewers that have similar inputs. Therefore, this study has demonstrated that the carbon utilization profile for microbial communities found within sewer sediment deposits is dependent on both temperature and spatial variations. PMID:21473276

  16. Grazing Characteristics and Growth Efficiencies at Two Different Temperatures for Three Nanoflagellates Fed with Vibrio Bacteria at Three Different Concentrations.

    PubMed

    Ishigaki, T.; Sleigh, M.A.

    2001-04-01

    Small inocula of one of the flagellates Paraphysomonas imperforata, Pteridomonas danica, and Cafeteria roenbergensis were added to suspensions of the bacterium Vibrio natriegens at each of three concentrations between 107 and 108 cells ml-1 and incubated at each of the temperatures 10 degrees C and 25 degrees C. Samples were taken at intervals for counting the flagellates and bacteria to determine the timing of the maximum of flagellate numbers and the concentrations at that time. Measurements of the protein concentration of the suspensions during incubation were used to determine the gross growth efficiency (GGE) or yield of flagellate grazing in each experiment. The most effective grazer was Pteridomonas, followed by Paraphysomonas, with Cafeteria being least effective, as judged by the threshold bacterial concentrations at which flagellate multiplication ceased, which were about 2 x 105, 2 x 106, and 2 x 107, respectively, and by the finding that Pteridomonas consumed 99%, Paraphysomonas about 95%, and Cafeteria only 60-70% of the available bacteria in the experiments. Peak concentrations of flagellates were reached later at the lower temperature, but the numbers of flagellates produced and of bacteria eaten were of a similar order at the two temperatures and the GGE was only slightly higher at the lower temperature. The time taken to reach peak flagellate numbers changed little with a threefold increase in bacterial concentrations, but the GGE increased and the numbers of bacteria eaten to produce one flagellate decreased when the bacterial concentration was increased. The three flagellates show clear evidence of niche specialization in differences in thresholds of bacterial prey concentration. PMID:11391464

  17. Influence of Different Temperature Sensors on Measuring Energy Efficiency and Heating-Up Time of Hobs

    NASA Astrophysics Data System (ADS)

    Beges, G.; Drnovsek, J.; Ogorevc, J.; Bojkovski, J.

    2015-03-01

    Measuring performance, mainly temperature dependence, for electric cooking ranges, hobs, ovens, and grills for household use is essential for producers as low power consumption of appliances represents a powerful selling point and also in terms of ecodesign requirements. It is also important from a consumer perspective, as these appliances are responsible for the significant share of households' electricity bills. The aim of the paper was to highlight and clearly define possible ambiguities and weaknesses of standardized procedures for measuring hob performance. Differences between measurement/test results of testing laboratories are possible due to lack of detailed information in the standard, and it is difficult to obtain technical accessories required in the standard. An energy consumption comparison of three different hobs is presented (standard iron electrical hob, radiant-glass ceramic, and induction hob). Various temperature sensors (different types of thermocouples and a platinum resistance thermometer) and technical accessories (e.g., different cookware) were used to research differences or influences on final result of hobs' energy efficiency. Results show that temperature measurements with different sensors have an influence on the time difference in critical points for determination of hob energy efficiency.

  18. Microstructures and properties of titanium nitride films prepared by pulsed laser deposition at different substrate temperatures

    NASA Astrophysics Data System (ADS)

    Guo, Hongjian; Chen, Wenyuan; Shan, Yu; Wang, Wenzhen; Zhang, Zhenyu; Jia, Junhong

    2015-12-01

    The nanostructured titanium nitride (TiN) films were fabricated by pulsed laser deposition (PLD) technique at different substrate temperatures under residual vacuum, and the influence of substrate temperatures on the microstructure, mechanical and tribological properties of TiN films was investigated and discussed. The results shown that the consistent stoichiometric TiN films were obtained and the grain size increased from 10.5 to 38.7 nm with the increasing of substrate temperature. The hardness of films decreased with the substrate temperatures increasing, the highest hardness reached to 30.6 GPa at the substrate temperature of 25 °C, and the critical load increased first and decreased at 500 °C, the highest critical load was 23.8 N at the substrate temperature of 300 °C. The film deposited at the substrate temperature of 25 °C registered the lowest friction coefficient of 0.088 and wear rate of 7.8 × 10-7 mm3/(N m). The excellent tribological performance of the films was attributed to the small grain size, high hardness and smooth surface of the film.

  19. Coffee roasting and aroma formation: application of different time-temperature conditions.

    PubMed

    Baggenstoss, Juerg; Poisson, Luigi; Kaegi, Ruth; Perren, Rainer; Escher, Felix

    2008-07-23

    The impact of time-temperature combinations of roasting processes on the kinetics of aroma formation in coffee was investigated. The development of 16 aroma compounds and the physical properties of coffee beans was followed in a commercial horizontal drum roasting process and in laboratory scale fluidizing-bed roasting processes at high temperature-short time and low temperature-long time conditions. All trials were run to an equal roast end point as defined by the lightness of coffee beans. In addition, the effect of excessive roasting on aroma composition was studied. Compared to low temperature-long time roasting, high temperature-short time roasting resulted in considerable differences in the physical properties and kinetics of aroma formation. Excessive roasting generally led to decreasing or stable amounts of volatile substances, except for hexanal, pyridine, and dimethyl trisulfide, whose concentrations continued to increase during over-roasting. When the drum roaster and the fluidizing bed roaster were operated in the so-called temperature profile mode, that is, along the identical development of coffee bean temperature over roasting time, the kinetics of aroma generation were similar in both processes. PMID:18572953

  20. Compressive strength development of concrete with different curing time and temperature

    SciTech Connect

    Kim, J.K.; Moon, Y.H.; Eo, S.H.

    1998-12-01

    In this experimental and analytic research, the strength development for various curing histories was investigated with particular regard to the influences of curing time points with given temperatures. For this purpose, four different points of curing time were considered with an individual interval of 24 h. Two different temperatures of 5 C and 40 C were applied for the selective intervals, whereas the rest period days were under the reference curing condition of 20 C. A new model for the strength prediction was suggested based on the rate constant model. In this model, the equivalent ages introduced in the Saul and Arrhenius models were modified to show the effects of curing temperature at different ages. Test results show that the concrete subjected to a high temperature at an early age attains higher early-age strength but eventually attains lower later-age strength. The concrete subjected to a low temperature at an early age leads to lower early-age strength but almost the same later-age strength. Moreover, the proposed model showed better agreement with the test results than the existing models.

  1. Carbon turnover and ammonia emissions during composting of biowaste at different temperatures.

    PubMed

    Eklind, Ylva; Sundberg, Cecilia; Smrs, Sven; Steger, Kristin; Sundh, Ingvar; Kirchmann, Holger; Jnsson, Hkan

    2007-01-01

    The effects of different process temperatures (40, 55, and 67 degrees C) during composting of source-separated household waste were studied in a 200 L compost reactor at an oxygen concentration of 16%. The overall decomposition measured as carbon mineralization, decomposition of different carbon constituents, and the dynamics of nitrogen mineralization and the microbial community, are reported. Ammonia emissions at 67 degrees C were more than double those at lower temperatures, and they were lowest at 40 degrees C. The decomposition rate, measured as CO2 emission, was highest at 55 degrees C. Decomposition of crude fat was slower at 40 degrees C than at 55 and 67 degrees C. The peak in microbial biomass was largest in the run at 40 degrees C, where substantial differences were seen in the microbial community structure and succession compared to thermophilic temperatures. Biowaste composting can be optimized to obtain both a high decomposition rate and low ammonia emissions by controlling the process at about 55 degrees C in the initial, high-rate stage. To reduce ammonia emissions it seems worthwhile to reduce the temperature after an initial high-temperature stage. PMID:17766831

  2. Temperature rise during polymerization of different cavity liners and composite resins

    PubMed Central

    Karatas, Ozcan; Turel, Verda; Bayindir, Yusuf Ziya

    2015-01-01

    Objective: The purpose of this study was to evaluate the thermal insulating properties of different light curing cavity liners and composite resins during light emitting diode (LED) curing. Materials and Methods: Sixty-four dentin discs, 1 mm thick and 8 mm in diameter, were prepared. Specimens were divided into four groups. Calcium hydroxide (Ca[OH]2), resin-modified glass ionomer cement, flowable composite and adhesive systems were applied to dentin discs according to the manufacturers’ instructions. The rise in temperature during polymerization with a LED curing unit (LCU) was measured using a K-type thermocouple connected to a data logger. Subsequently, all specimens were randomly divided into one of two groups. A silorane-based composite resin and a methacrylate-based composite resin were applied to the specimens. Temperature rise during polymerization of composite resins with LCU were then measured again. Data were analyzed using one-way ANOVA and post hoc Tukey analyses. Results: There were significant differences in temperature rise among the liners, adhesives, and composite resins (P < 0.05). Silorane-based composite resin exhibited significantly greater temperature rises than methacrylate-based resin (P < 0.05). The smallest temperature rises were observed in Ca(OH)2 specimens. Conclusion: Thermal insulating properties of different restorative materials are important factors in pulp health. Bonding agents alone are not sufficient to protect pulp from thermal stimuli throughout curing. PMID:26751112

  3. Behavior, metabolism and swimming physiology in juvenile Spinibarbus sinensis exposed to PFOS under different temperatures.

    PubMed

    Xia, Ji-Gang; Nie, Li-Juan; Mi, Xia-Mei; Wang, Wei-Zhen; Ma, Yi-Jie; Cao, Zhen-Dong; Fu, Shi-Jian

    2015-10-01

    The harmful effects of perfluorooctane sulfonate (PFOS) are of growing international concern. This paper aimed to gain an integrated understanding of fitness-related ecological end points, such as behavior, metabolism and swimming physiology, in juvenile Spinibarbus sinensis in response to PFOS toxicity at different temperatures. The fish were exposed to a range of PFOS concentrations (0, 0.32, 0.8, 2 and 5mg/L) at different temperatures (18 and 28C) for 30days. The effects on fish behavior, metabolic characteristics and aerobic swimming performance caused by PFOS at different temperatures were investigated. Our results showed that both PFOS and temperature had important influences on spontaneous swimming behavior, social interactions, routine metabolic rate (RMR), net energetic cost of transport (COTnet) and critical swimming speed (U crit) in fish. The lowest observed effect concentration for both U crit and RMR was 5 and 0.8mg/L at 18 and 28C, respectively. We found that PFOS affected various behavioral and social end points and also appeared to affect metabolic rates and reduced U crit, likely as a result of increased COTnet, and that many of these effects also changed with respect to temperature. Our results further the understanding of the metabolic and behavioral toxicity of PFOS to aquatic organisms. PMID:26077224

  4. Metabolic flux and nodes control analysis of brewer's yeasts under different fermentation temperature during beer brewing.

    PubMed

    Yu, Zhimin; Zhao, Haifeng; Zhao, Mouming; Lei, Hongjie; Li, Huiping

    2012-12-01

    The aim of this work was to further investigate the glycolysis performance of lager and ale brewer's yeasts under different fermentation temperature using a combined analysis of metabolic flux, glycolytic enzyme activities, and flux control. The results indicated that the fluxes through glycolytic pathway decreased with the change of the fermentation temperature from 15 °C to 10 °C, which resulted in the prolonged fermentation times. The maximum activities (V (max)) of hexokinase (HK), phosphofructokinase (PFK), and pyruvate kinase (PK) at key nodes of glycolytic pathway decreased with decreasing fermentation temperature, which was estimated to have different control extent (22-84 %) on the glycolytic fluxes in exponential or flocculent phase. Moreover, the decrease of V (max) of PFK or PK displayed the crucial role in down-regulation of flux in flocculent phase. In addition, the metabolic state of ale strain was more sensitive to the variation of temperature than that of lager strain. The results of the metabolic flux and nodes control analysis in brewer's yeasts under different fermentation temperature may provide an alternative approach to regulate glycolytic flux by changing V (max) and improve the production efficiency and beer quality. PMID:23065402

  5. Evaluation of AIRS, MODIS, and HIRS 11 Micron Brightness Temperature Difference Changes from 2002 through 2006

    NASA Technical Reports Server (NTRS)

    Broberg, Steven E.; Aumann, Hartmut H.; Gregorich, David T.; Xiong, X.

    2006-01-01

    In an effort to validate the accuracy and stability of AIRS data at low scene temperatures (200-250 K range), we evaluated brightness temperatures at 11 microns with Aqua MODIS band 31 and HIRS/3 channel 8 for Antarctic granules between September 2002 and May 2006. We found excellent agreement with MODIS (at the 0.2 K level) over the full emperature range in data from early in the Aqua mission. However, in more recent data, starting in April 2005, we found a scene temperature dependence in MODIS-AIRS brightness temperature differences, with a discrepancy of 1- 1.5 K at 200 K. The comparison between AIRS and HIRS/3 (channel 8) on NOAA 16 for the same time period yields excellent agreement. The cause and time dependence of the disagreement with MODIS is under evaluation, but the change was coincident with a change in the MODIS production software from collection 4 to 5.

  6. CREST modelling of PBX 9502 corner turning experiments at different initial temperatures

    NASA Astrophysics Data System (ADS)

    Whitworth, N. J.

    2014-05-01

    Corner turning is an important problem in regard to detonation wave propagation in TATB-based explosives. Experimentally, a sudden change in the direction of the propagating wave, such as turning a sharp corner, can result in dead-zones being left behind in the corner turn region, with the observed behaviour being particularly sensitive to the initial temperature of the explosive. In this paper, the entropy-dependent CREST reactive burn model is used to simulate corner turning experiments on the TATB-based explosive PBX 9502. Calculated results of double cylinder tests at three different initial temperatures (-54C, ~23C, and 75C), and a "hockey puck" experiment at ambient temperature, are compared to the corresponding test measurements. The results show that the model is able to: (i) calculate persistent dead-zones in PBX 9502 without recourse to any shock desensitisation treatment, and (ii) predict changes in corner turning behaviour with initial temperature using one set of coefficients.

  7. CREST Modelling of PBX 9502 Corner Turning Experiments at Different Initial Temperatures

    NASA Astrophysics Data System (ADS)

    Whitworth, Nicholas

    2013-06-01

    Corner turning is an important problem in regard to detonation wave propagation in TATB-based explosives. Experimentally, a sudden change in direction of the propagating wave, such as turning a sharp corner, can result in dead-zones being left behind in the corner turn region, with the observed behaviour being particularly sensitive to the initial temperature of the explosive. In this paper, the entropy-dependent CREST reactive burn model is used to simulate corner turning experiments on the TATB-based explosive PBX 9502. Calculated results of double cylinder tests at three different initial temperatures (-54C, 25C, and 75C), and a ``hockey puck'' experiment at ambient temperature, are compared to the corresponding test measurements. The results show that the model is able to: (i) calculate persistent dead-zones in PBX 9502 without recourse to any shock desensitisation treatment, and (ii) predict changes in corner turning behaviour with initial temperature using one set of coefficients.

  8. Effects of different sitting positions on skin temperature of the lower extremity

    PubMed Central

    Namkoong, Seung; Shim, JeMyung; Kim, SungJoong; Shim, JungMyo

    2015-01-01

    [Purpose] The purpose of this study was to identify the effect of different sitting positions on the skin temperature of the lower extremity. [Subjects] The subjects of this study were 23 healthy university students (8 males, 15 females). [Methods] Normal sitting (NS), upper leg cross (ULC) and ankle on knee (AOK) positions were conducted to measure the changes in skin temperature using digital infrared thermographic imaging (DITI). [Results] ULC upper ankle, NS upper shin, ULC upper shin and NS lower shin showed significant declines in temperature with time. [Conclusion] These finding suggest that the ULC and NS sitting positions cause decline of blood flow volume to the lower extremity resulting in decrease of temperature of the lower extremity. Especially, sitting with the legs crossed interferes with the circulation of blood flowing volume much more than just sitting in a chair. PMID:26355265

  9. Sessile droplet freezing and ice adhesion on aluminum with different surface wettability and surface temperature

    NASA Astrophysics Data System (ADS)

    Ou, JunFei; Shi, QingWen; Wang, ZhiLe; Wang, FaJun; Xue, MingShan; Li, Wen; Yan, GuiLong

    2015-07-01

    This paper focused on the sessile droplet freezing and ice adhesion on aluminum with different wettability (hydrophilic, common hydrophobic, and superhydrophobic surfaces, coded as HIS, CHS, SHS, respectively) over a surface temperature range of -9C to -19C. It was found that SHS could retard the sessile droplet freezing and lower the ice adhesion probably due to the interfacial air pockets (IAPs) on water/SHS interface. However, as surface temperature decreasing, some IAPs were squeezed out and such freezing retarding and adhesion lowering effect for SHS was reduced greatly. For a surface temperature of -19C, ice adhesion on SHS was even greater than that on CHS. To discover the reason for the squeezing out of IAPs, forces applied to the suspended water on IAPs were analyzed and it was found that the stability of IAPs was associated with surface micro-structures and surface temperature. These findings might be helpful to designing of SHS with good anti-icing properties.

  10. Self-diffusion of lignite/water under different temperatures and pressure: A molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Liu, Xinjian; Jin, Yu; Huang, Congliang; He, Jingfeng; Rao, Zhonghao; Zhao, Yuemin

    2016-01-01

    Temperature and pressure have direct and remarkable implications for drying and dewatering effect of low rank coals such as lignite. To understand the microenergy change mechanism of lignite, the molecular dynamics simulation method was performed to study the self-diffusion of lignite/water under different temperatures and pressure. The results showed that high temperature and high pressure can promote the diffusion of lignite/water system, which facilitates the drying and dewatering of lignite. The volume and density of lignite/water system will increase and decrease with temperature increasing, respectively. Though the pressure within simulation range can make lignite density increase, the increasing pressure showed a weak impact on variation of density.

  11. Surface acoustic wave velocity of gold films deposited on silicon substrates at different temperatures

    SciTech Connect

    Salas, E.; Jimenez Rioboo, R. J.; Prieto, C.; Every, A. G.

    2011-07-15

    Au thin films have been deposited by DC magnetron sputtering on Si (001) substrates at different substrate temperatures, ranging from 200 K to 450 K. With increasing temperature, the expected crystallinity and morphology of the Au thin film are clearly improved, as shown by x ray diffraction, atomic force microscopy and scanning electron microscopy experiments. Parallel to this, the surface acoustic wave propagation velocity shows a clear enhancement toward the ideal values obtained from numerical simulations of a Au thin film on Si (001) substrate. Moreover, a very thin and slightly rough interlayer between the Si (001) substrate and the Au thin film is developed for temperatures above 350 K. The composition and nature of this interlayer is not known. This interlayer may be responsible for the steep change in the structural and elastic properties of the Au thin films at the higher temperatures and possibly also for an improvement of the adhesion properties of the Au on the Si (001) substrate.

  12. The forms of alkalis in the biochar produced from crop residues at different temperatures.

    PubMed

    Yuan, Jin-Hua; Xu, Ren-Kou; Zhang, Hong

    2011-02-01

    The forms of alkalis of the biochars produced from the straws of canola, corn, soybean and peanut at different temperatures (300, 500 and 700C) were studied by means of oxygen-limited pyrolysis. The alkalinity and pH of the biochars increased with increased pyrolysis temperature. The X-ray diffraction spectra and the content of carbonates of the biochars suggested that carbonates were the major alkaline components in the biochars generated at the high temperature; they were also responsible for the strong buffer plateau-regions on the acid-base titration curves at 500 and 700C. The data of FTIR-PAS and zeta potentials indicated that the functional groups such as -COO(-) (-COOH) and -O(-) (-OH) contained by the biochars contributed greatly to the alkalinity of the biochar samples tested, especially for those generated at the lower temperature. These functional groups were also responsible for the negative charges of the biochars. PMID:21112777

  13. Land Surface Temperature Measurements form EOS MODIS Data

    NASA Technical Reports Server (NTRS)

    Wan, Zhengming

    1996-01-01

    We have developed a physics-based land-surface temperature (LST) algorithm for simultaneously retrieving surface band-averaged emissivities and temperatures from day/night pairs of MODIS (Moderate Resolution Imaging Spectroradiometer) data in seven thermal infrared bands. The set of 14 nonlinear equations in the algorithm is solved with the statistical regression method and the least-squares fit method. This new LST algorithm was tested with simulated MODIS data for 80 sets of band-averaged emissivities calculated from published spectral data of terrestrial materials in wide ranges of atmospheric and surface temperature conditions. Comprehensive sensitivity and error analysis has been made to evaluate the performance of the new LST algorithm and its dependence on variations in surface emissivity and temperature, upon atmospheric conditions, as well as the noise-equivalent temperature difference (NE(Delta)T) and calibration accuracy specifications of the MODIS instrument. In cases with a systematic calibration error of 0.5%, the standard deviations of errors in retrieved surface daytime and nighttime temperatures fall between 0.4-0.5 K over a wide range of surface temperatures for mid-latitude summer conditions. The standard deviations of errors in retrieved emissivities in bands 31 and 32 (in the 10-12.5 micrometer IR spectral window region) are 0.009, and the maximum error in retrieved LST values falls between 2-3 K. Several issues related to the day/night LST algorithm (uncertainties in the day/night registration and in surface emissivity changes caused by dew occurrence, and the cloud cover) have been investigated. The LST algorithms have been validated with MODIS Airborne Simulator (MAS) dada and ground-based measurement data in two field campaigns conducted in Railroad Valley playa, NV in 1995 and 1996. The MODIS LST version 1 software has been delivered.

  14. Differences in physiological response to increased seawater temperature in nearshore and offshore corals in northern Vietnam.

    PubMed

    Faxneld, Suzanne; Jrgensen, Tove Lund; Nguyen, Ngai D; Nystrm, Magnus; Tedengren, Michael

    2011-04-01

    Effects of elevated seawater temperature show high spatial heterogeneity and variation within and among coral species. The objective of this study was to investigate how two coral species, Porites lutea and Galaxea fascicularis, from two high latitude reefs differently exposed to chronic disturbance, respond to elevated seawater temperatures. Corals were collected from reefs nearshore (i.e. subjected to high sediment load, higher chlorophyll ? concentrations, turbidity etc.) and offshore (i.e. less exposed). The corals were exposed in the lab to gradually increasing temperatures (25.5-33.5C) for 72h after which they were allowed to recover to ambient temperature (25.5C) for 24h. Production and respiration were measured after 24, 48, 72 and 96h. The results show that P. lutea from nearshore reefs suffered an initial decrease in gross primary production/respiration (GP/R) ratio after 24h, after only a moderate temperature increase (+2C, from 25.5 to 27.5C), while there was no difference in GP/R ratio between heat-exposed and controls the other days, indicating that the chronic disturbance in the nearshore reef had no effect on their thermotolerance. Furthermore, P. lutea from the offshore reef showed a decrease in GP/R ratio both after 24h and 72h (33.5C) of exposure. In comparison, G. fascicularis showed a decrease in GP/R ratio after 48h, 72h and 96h of exposure for the nearshore corals. Also, after 72h these corals had withdrawn their polyps. There were no differences between heat-treated and controls for the offshore G. fascicularis. This implies that the chronically disturbed G. fascicularis had lower thermotolerance when exposed to a temperature increase. This study, hence, shows that the response of corals to elevated seawater temperature varies with species and environmental background history. PMID:21324522

  15. Difference method for analysing infrared images in pigs with elevated body temperatures.

    PubMed

    Siewert, Carsten; Dänicke, Sven; Kersten, Susanne; Brosig, Bianca; Rohweder, Dirk; Beyerbach, Martin; Seifert, Hermann

    2014-03-01

    Infrared imaging proves to be a quick and simple method for measuring temperature distribution on the pig's head. The study showed that infrared imaging and analysis with a difference ROI (region of interest) method may be used for early detection of elevated body temperature in pigs (> 39.5°C). A high specificity of approx. 85% and a high sensitivity of 86% existed. The only prerequisite is that there are at least 2 anatomical regions which can be recognised as reproducible in the IR image. Noise suppression is guaranteed by averaging the temperature value within both of these ROI. The subsequent difference imaging extensively reduces the off-set error which varies in every thermal IR-image. PMID:24398117

  16. Growth characteristics of 28 strains of white tide forming coccolithophorids and elementary analysis under different temperatures

    NASA Astrophysics Data System (ADS)

    Watanabe, Y.; Kawachi, M.; Kawahata, H.

    2008-12-01

    With the increase of the CO2 concentration in the atmosphere, global warming and acidification of the oceans are troublesome, influencing the marine organisms and the ecosystem. Coccolithophorids are marine unicellular haptophytes producing minute calcareous scales (coccoliths). Because of the conversion of CO2 to CaCO3 and the sedimentation of coccoliths, coccolithophorids are one of the most important organisms participating to the global biogeochemical cycles. Among the coccolithophorids, Gephyrocapsa oceanica and Emiliania huxleyi distribute widely in both oceanic and coastal environments. They often form massive water bloom called white tide and are known to be the major producer of CaCO3 in the present ocean. Moreover, elementary analysis of coccoliths accumulated in sediments provides valuable information on the analysis of paleoenvironment. Although the growth characteristics and calcification properties are important information to estimate their contribution to the global carbon cycle and paleoenvironment, most of the studies have targeted only few strains. Here, we focused on the effect of the temperature on the growth and elementary component of the coccolith for a variety of strains of G. oceanica and E. huxleyi collected from different environments. This approach would clarify the temperature response to various populations and the importance of the use of coccolith as an environmental indicator. 28 strains (20 of G. oceanica, 8 of E. huxleyi) were originally established as cultures or obtained from culture collection. We measured their growth rate from the chlorophyll fluorescence under different temperatures (10, 15, 20, 25, 30C). We also analysed the oxygen isotope ratio, Sr/Ca, U/Ca, Ba/Ca for 5 selected strains with ICP-MS and ICP-AES. In most strains, the optimal growth temperatures were obtained at 20 and 25C, while the growth rates dropped with temperature decrease. No significant differences between the two species were observed. We noted that one Emiliania strain from Bering Sea kept a high growth rate at the lowest temperature (10C) and one Gephyrocapsa strain from tropical sea showed the highest growth at 30C. Locality differences provide more obvious physiological differences than the species differences, suggesting the existence of diverse ecotypes in those cosmopolitan species. The elementary analysis exhibited a high correlation of the cultivation temperatures with the oxygen isotope ratio (R2=0.97) suggesting a high reliability but less correlation of the temperatures with Sr/Ca, U/Ca and Ba/Ca.

  17. Design of an experimental set up for convective drying: experimental studies at different drying temperature

    NASA Astrophysics Data System (ADS)

    Mohan, V. P. Chandra; Talukdar, Prabal

    2013-01-01

    An experimental setup is designed to investigate the convective drying of moist object experimentally. All the design data, components of setup, materials and specifications are presented. Transient moisture content of a rectangular shaped potato slice (4 2 2 cm) is measured at different air temperatures of 40, 50, 60 and 70 C with an air velocity of 2 m/s. Two different drying rate periods are observed. Results are compared with available results from literature.

  18. Temperature response of photosynthesis in different drug and fiber varieties of Cannabis sativa L.

    PubMed

    Chandra, Suman; Lata, Hemant; Khan, Ikhlas A; Elsohly, Mahmoud A

    2011-07-01

    The temperature response on gas and water vapour exchange characteristics of three medicinal drug type (HP Mexican, MX and W1) and four industrial fiber type (Felinq 34, Kompolty, Zolo 11 and Zolo 15) varieties of Cannabis sativa, originally from different agro-climatic zones worldwide, were studied. Among the drug type varieties, optimum temperature for photosynthesis (Topt) was observed in the range of 30-35C in high potency Mexican HPM whereas, it was in the range of 25-30C in W1. A comparatively lower value (25C) for Topt was observed in MX. Among fiber type varieties, Topt was around 30C in Zolo 11 and Zolo 15 whereas, it was near 25C in Felinq 34 and Kompolty. Varieties having higher maximum photosynthesis (PN max) had higher chlorophyll content as compared to those having lower PN max. Differences in water use efficiency (WUE) were also observed within and among the drug and fiber type plants. However, differences became less pronounced at higher temperatures. Both stomatal and mesophyll components seem to be responsible for the temperature dependence of photosynthesis (PN) in this species, however, their magnitude varied with the variety. In general, a two fold increase in dark respiration with increase in temperature (from 20C to 40C) was observed in all the varieties. However, a greater increase was associated with the variety having higher rate of photosynthesis, indicating a strong association between photosynthetic and respiratory rates. The results provide a valuable indication regarding variations in temperature dependence of PN in different varieties of Cannabis sativa L. PMID:23573022

  19. The Effect of Storage at Three Different Temperatures on the Activity of Lipase Solution.

    ERIC Educational Resources Information Center

    Bradley, Karen; Mathewman, David

    1984-01-01

    Presented are procedures used to assay the activity of lipase during storage at three different temperatures. Since lipase solutions can decay even when refrigerated, it is recommended that the enzyme be freshly prepared prior to laboratory sessions in which they are used. (JN)

  20. [Temperature compensation strategy and implementation for photoelectric modulation interferometer with large optical path difference].

    PubMed

    Wang, Yan-Chao; Wang, Zhi-Bin; Zhang, Ji-Long; Chen, You-Hua

    2013-05-01

    For temperature drift in hypervelocity photoelectric modulation interferometer, a control model of temperature compensation is presented including voltage and phase compensation. First, according to the similar and modeling theory, an equivalent circuit model of mechanical properties of hypervelocity photoelectric modulation interferometer was established, the impact of temperature drift on its resonance frequency was analyzed, a mathematical model was set up, which contains drive voltage, frequency and resonance frequency, and the control method was determined for high optical path difference to get steady. Then, a digital method including voltage and phase compensation is given for optical path difference deviation control, which merges the DPLL and program of voltage and phase compensation. Finally, the control method was tested through experiment system. A test between drive control system including voltage and phase compensation and traditional drive control system was executed, using a laser doppler vibrometer to record the amount of change in optical path difference within 3 hours. Results show that the optical path difference deviation caused by temperature drift in long term is reduced by about 50%. PMID:23905367

  1. Metabolic and Cardiovascular Responses during Aquatic Exercise in Water at Different Temperatures in Older Adults

    ERIC Educational Resources Information Center

    Bergamin, Marco; Ermolao, Andrea; Matten, Sonia; Sieverdes, John C.; Zaccaria, Marco

    2015-01-01

    Purpose: The aim of this study was to investigate the physiological responses during upper-body aquatic exercises in older adults with different pool temperatures. Method: Eleven older men (aged 65 years and older) underwent 2 identical aquatic exercise sessions that consisted of 3 upper-body exercises using progressive intensities (30, 35, and 40…

  2. Open cycle traveling wave thermoacoustics: mean temperature difference at the regenerator interface.

    PubMed

    Weiland, Nathan T; Zinn, Ben T

    2003-11-01

    In an open cycle traveling wave thermoacoustic engine, the hot heat exchanger is replaced by a steady flow of hot gas into the regenerator to provide the thermal energy input to the engine. The steady-state operation of such a device requires that a potentially large mean temperature difference exist between the incoming gas and the solid material at the regenerator's hot side, due in part to isentropic gas oscillations in the open space adjacent to the regenerator. The magnitude of this temperature difference will have a significant effect on the efficiencies of these open cycle devices. To help assess the feasibility of such thermoacoustic engines, a numerical model is developed that predicts the dependence of the mean temperature difference upon the important design and operating parameters of the open cycle thermoacoustic engine, including the acoustic pressure, mean mass flow rate, acoustic phase angles, and conductive heat loss. Using this model, it is also shown that the temperature difference at the regenerator interface is approximately proportional to the sum of the acoustic power output and the conductive heat loss at this location. PMID:14650014

  3. Effect of temperature on the intrinsic viscosity and conformation of different pectins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of temperature on the intrinsic viscosity and on the conformation of different pectins obtained from citrus, apple and sunflower in a 0.17M NaCl solution were studied. The intrinsic viscosity and the flow activation energy of the polymer (Ea) derived from slope of d In [']/ d(l/T) as an ...

  4. Effects of foliage plants on human physiological and psychological responses at different temperatures

    NASA Astrophysics Data System (ADS)

    Jumeno, Desto; Matsumoto, Hiroshi

    2015-02-01

    Escalation of task demands and time pressures tends to make a worker run into work stress, which leads to mental fatigue and depression. The mental fatigue can be reduced when attention capacity is restored. Nature can serve as a source of fascination which can restore the attention capacity. People bring plants indoors so they can experience nature in their workplace. The stress and fatigue are also affected by air temperatures. The increase or decrease of temperatures from the comfort zone may induce the stress and fatigue. The objective of this study is to investigate the intervention of using foliage plants placed inside a building at different air temperature levels. The effects of foliage plants on human stress and fatigue were measured by human physiological responses such as heart rate, amylase level, electroencephalography (EEG), and the secondary task-reaction time. Several different tasks, namely typing, math and logical sequences are included in the investigation of these studies. Fifteen subjects, with the age ranged from 22 to 38 years old have participated in the study using within subject design. From the study, it is revealed that the presence of foliage plants at several temperatures have different effects on meditation, secondary task reaction time and typing accuracy. This study also revealed that the presence of plants on several types of tasks has different effects of attention which are useful for increasing work performance.

  5. Metabolic and Cardiovascular Responses during Aquatic Exercise in Water at Different Temperatures in Older Adults

    ERIC Educational Resources Information Center

    Bergamin, Marco; Ermolao, Andrea; Matten, Sonia; Sieverdes, John C.; Zaccaria, Marco

    2015-01-01

    Purpose: The aim of this study was to investigate the physiological responses during upper-body aquatic exercises in older adults with different pool temperatures. Method: Eleven older men (aged 65 years and older) underwent 2 identical aquatic exercise sessions that consisted of 3 upper-body exercises using progressive intensities (30, 35, and 40

  6. Physiological and antioxidant responses of two accessions of Arabidopsis thaliana in different light and temperature conditions.

    PubMed

    Szymańska, Renata; Nowicka, Beatrycze; Gabruk, Michał; Glińska, Sława; Michlewska, Sylwia; Dłużewska, Jolanta; Sawicka, Anna; Kruk, Jerzy; Laitinen, Roosa

    2015-06-01

    During their lifetime, plants need to adapt to a changing environment, including light and temperature. To understand how these factors influence plant growth, we investigated the physiological and antioxidant responses of two Arabidopsis accessions, Shahdara (Sha) from the Shahdara valley (Tajikistan, Central Asia) in a mountainous area and Lovvik-5 (Lov-5) from northern Sweden to different light and temperature conditions. These accessions originate from different latitudes and have different life strategies, both of which are known to be influenced by light and temperature. We showed that both accessions grew better in high-light and at a lower temperature (16°C) than in low light and at 23°C. Interestingly, Sha had a lower chlorophyll content but more efficient non-photochemical quenching than Lov-5. Sha, also showed a higher expression of vitamin E biosynthetic genes. We did not observe any difference in the antioxidant prenyllipid level under these conditions. Our results suggest that the mechanisms that keep the plastoquinone (PQ)-pool in more oxidized state could play a role in the adaptation of these accessions to their local climatic conditions. PMID:25214438

  7. Seasonally and diurnally different response of surface air temperature to historical urbanization in Sapporo, North Japan

    NASA Astrophysics Data System (ADS)

    Sato, T.; Sugimoto, S.; Sasaki, T.

    2014-12-01

    Anthropogenic landscape changes have dramatically altered near surface climate in many regions of the world. In particular, regional/local-scale land use change is attributed to the long-term change in observed surface air temperature through changes in surface radiation budget and energy partitioning. This study analyses the response of surface air temperature characteristics to the historical urbanization in Sapporo, a snowy city in North Japan. Around Sapporo, natural forest has been cleared and replaced with urban since the late 19th century. Annual mean temperature in Sapporo has increased dramatically, whose rate being approximately twice of that in the station without urbanization. The rate of temperature increase shows asymmetric feature among seasons and dependent on time of the day; a prominent warming in winter daily minimum temperature and no significant trend in summer daily maximum temperature. In order to clarify the seasonal and diurnal dependence of the response to land use change, two 27-year simulations were conducted using WRF-ARW model nudged to reanalysis data during 19872/1983 winter to 2008/2009 winter; a control run uses past land cover and a sensitivity run uses present land cover. The numerical experiments successfully replicate the observed influence of urbanization with higher temperature change in winter nights and smaller temperature change in summer days. An analysis on surface energy balance indicates the changes in Bowen ratio is a primal cause of increasing sensible heat in both summer and winter. However, atmospheric response to the elevated sensible heat flux is very different depending on boundary layer structure between winter and summer or between night and day. This mechanism could clearly explain the asymmetric temperature trend observed worldwide, especially in cold regions where nocturnal inversion develops.

  8. First year growth in the lithodids Lithodes santolla and Paralomis granulosa reared at different temperatures

    NASA Astrophysics Data System (ADS)

    Calcagno, J. A.; Lovrich, G. A.; Thatje, S.; Nettelmann, U.; Anger, K.

    2005-10-01

    The southern king crab, Lithodes santolla Molina, and stone crab, Paralomis granulosa Jacquinot, inhabit the cold-temperate waters of southernmost South America (southern Chile and Argentina), where stocks of both species are endangered by overfishing. Recent investigations have shown that these crabs show life-cycle adaptations to scarcity of food and low temperatures prevailing in subantarctic regions, including complete lecithotrophy of all larval stages and prolonged periods of brooding and longevity. However, growth and development to maturity are slow under conditions of low temperatures, which may explain the particular vulnerability of subpolar lithodids to fisheries. In the present study, juvenile L. santolla and P. granulosa were individually reared in the laboratory at constant temperatures ranging from 3-15 C, and rates of survival and development through successive instars were monitored throughout a period of about nine months from hatching. When the experiments were terminated, L. santolla had maximally reached juvenile instar IV (at 6 C), V (9 C), or VII (15 C). In P. granulosa the maximum crab instar reached was II (at 3 C), V (6 C), V (9 C), or VII (15 C). The intermoult period decreased with increasing temperature, while it increased in successively later instars. In consequence, growth rate showed highly significant differences among temperatures (P<0.001). Growth-at-moult was highest at 9 C. Rates of survival decreased significantly in juvenile P. granulosa with increasing temperature. Only at 15 C in L. santolla, was a significantly enhanced mortality found compared with lower temperatures. Our results indicate that juvenile stages of L. santolla and P. granulosa are well adapted to 5-10C, the range of temperatures typically prevailing in subantarctic marine environments. In spite of causing higher mortality rates, higher rearing temperatures (12-15 C) should accelerate the rates of growth and maturation, which may be favourable for projects aiming at aquaculture or repopulation of overexploited king crab stocks.

  9. Drop Hammer Tests with Three Oleo Strut Models and Three Different Shock Strut Oils at Low Temperatures

    NASA Technical Reports Server (NTRS)

    Kranz, M

    1954-01-01

    Drop hammer tests with different shock strut models and shock strut oils were performed at temperatures ranging to -40 C. The various shock strut models do not differ essentially regarding their springing and damping properties at low temperatures; however, the influence of the different shock strut oils on the springing properties at low temperatures varies greatly.

  10. Nutrient transformation during aerobic composting of pig manure with biochar prepared at different temperatures.

    PubMed

    Li, Ronghua; Wang, Quan; Zhang, Zengqiang; Zhang, Guangjie; Li, Zhonghong; Wang, Li; Zheng, Jianzhong

    2015-01-01

    The effects of the corn stalk charred biomass (CB) prepared at different pyrolysis temperatures as additives on nutrient transformation during aerobic composting of pig manure were investigated. The results showed that the addition of CB carbonized at different temperatures to pig manure compost significantly influenced the compost temperature, moisture, pH, electrical conductivity, organic matter degradation, total nitrogen, [Formula: see text] and NH3 variations during composting. Compared with control and adding CB charred at lower temperature treatments, the addition of CB prepared over 700°C resulted in higher pH (over 9.2) and NH3 emission and lower potherb mustard seed germination index value during the thermophilic phase. Peak temperatures of composts appeared at 7 days for control and 11 days for CB added treatments. During 90 days composting, the organic matter degradation could be increased over 14.8-29.6% after adding of CB in the compost mixture. The introduction of CB in pig manure could prolong the thermophilic phase, inhibit moisture reduce, facilitate the organic matter decomposition, reduce diethylene triamine pentaacetic acid (DTPA) extractable Zn and Cu contents in pig manure composts and increase ryegrass growth. The study indicated that the corn stalk CB prepared around 500°C was a suitable additive in pig manure composting. PMID:25209736

  11. Air pollution, temperature, and regional differences in lung cancer mortality in Japan.

    PubMed

    Choi, K S; Inoue, S; Shinozaki, R

    1997-01-01

    In this study, the authors investigated regional differences in lung cancer mortality in Japan, and, based on data acquired between 1970 and 1990 for 47 Japanese prefectures, estimated the relationship between regional lung cancer mortality and air pollution and/or temperature. Investigators used data for nitrogen dioxide, sulfur dioxide, motor vehicle density, tobacco expenditure, and temperature as independent variables for age-adjusted lung cancer death rates. The age-adjusted lung cancer death rates were higher in the southern geographical block of Japan (i.e., approximately 1.2-fold in males and 1.1-fold in females) and in the northern block (approximately 1.2-fold in males) than in the central block. The regional differences in the age-adjusted lung cancer death rates were explained by nitrogen dioxide and temperature. Temperature caused a greater effect (regression coefficients) of nitrogen dioxide on the age-adjusted lung cancer death rates than did nitrogen dioxide alone in the southern block (i.e., approximately 1.3-fold in males and 1.2-fold in females). These results provide the first evidence of a possible synergistic interaction between air pollution and high temperature on lung cancer mortality. PMID:9169624

  12. Difference in ocular surface temperature by infrared thermography in phakic and pseudophakic patients

    PubMed Central

    Sniegowski, Matthew; Erlanger, Michael; Velez-Montoya, Raul; Olson, Jeffrey L

    2015-01-01

    Purpose To assess the change in ocular surface temperature between healthy phakic and pseudophakic patients. Methods We included patients with no history of ocular disease other than cataract. Patients were divided into three groups: clear lens, cataract, and pseudophakic. All patients had two ocular surface digital thermal scans. An average of five surface points was used as the mean ocular surface temperature. Results were analyzed with a one-way analysis of variance and a Tukey’s least significance difference test. The patients were further divided into phakic and pseudophakic groups. Correlation coefficients between several variables were done in order to assess dependencies. Results Fifty-six eyes (28 cataracts, 12 clear lenses, 16 pseudophakic) were enrolled. The mean ocular surface temperature in the cataract group was 34.14°C±1.51°C; clear lens: 34.43°C±2.27°C; and pseudophakic: 34.97°C±1.57°C. There were no statistical differences among the study groups (P=0.3). There was a nonsignificant negative correlation trend between age and surface temperature in the phakic group. The trend inverted in the pseudophakic group but without statistical significance. Conclusion Although cataract extraction and intraocular lens implantation seem to induce a mild increase in ocular surface temperature, the effect is not clear and not significant. PMID:25834383

  13. In vitro evaluation of temperature rise during different post space preparations

    PubMed Central

    Gokturk, Hakan; Ozkocak, Ismail; Taskan, Mehmet Murat; Aytac, Fatma; Karaarslan, Emine Sirin

    2015-01-01

    Objective: The aim of this study was to evaluate temperature alterations on the outer root surface during post space preparation with six different post drills by using an infrared thermometer. Materials and Methods: Sixty extracted single-rooted human mandibular incisor teeth were used. After root canal obturation, the specimens were divided into six groups (n = 10). During post space preparation, the temperature rises were measured in the middle third of the roots using a noncontact infrared thermometer with a sensitivity of 0.1C. The temperature data were transferred from the thermometer to the computer and were observed graphically. Results: The maximum temperature rise was observed in Snowpost 2 (29.95 10.2C) (P < 0.001), but there were no significant differences among Snowpost 2 (29.95 10.2C), Snowpost 1 (24.6 8.0C), and Relyx 2 (17.68 9.1C) (P > 0.05). Conclusions: Although water coolant used, the critical temperature rise was observed on the outer root surface in all post drill systems. PMID:26929693

  14. Investigation of gender difference in human response to temperature step changes.

    PubMed

    Xiong, Jing; Lian, Zhiwei; Zhou, Xin; You, Jianxiong; Lin, Yanbing

    2015-11-01

    The purpose of this study was to examine gender difference in human response to temperature step changes. A total of three step-change conditions (S5: 32 C-37 C-32 C, S11: 26 C-37 C-26 C, and S15: 22 C-37 C-22 C) were designed and a laboratory experiment with 12 males and 12 females was performed. Results of this study support our hypothesis that females differ from males in human response to sudden temperature changes from the perspectives of psychology, physiology and biomarkers. Females are more prone to show thermal dissatisfaction to cool environments while males are more likely to feel thermal discomfort in warm environments. It is logical that men have a stronger thermoregulation ability than women as male skin temperature change amplitude is smaller while the time to be stable for skin temperature is shorter than that of females after both up-steps and down-steps. In S15, males witnessed a more intensive decrease in RMSSD while females underwent a remarkable instant reduce in oral temperatures after the up-step. Marginal significance was observed in male IL-6 before and after the up-step in S15 while female IL-6 prominently increased after the down-step in S15. PMID:26265493

  15. Physiological and biochemical responses of Ricinus communis seedlings to different temperatures: a metabolomics approach

    PubMed Central

    2014-01-01

    Background Compared with major crops, growth and development of Ricinus communis is still poorly understood. A better understanding of the biochemical and physiological aspects of germination and seedling growth is crucial for the breeding of high yielding varieties adapted to various growing environments. In this context, we analysed the effect of temperature on growth of young R. communis seedlings and we measured primary and secondary metabolites in roots and cotyledons. Three genotypes, recommended to small family farms as cash crop, were used in this study. Results Seedling biomass was strongly affected by the temperature, with the lowest total biomass observed at 20°C. The response in terms of biomass production for the genotype MPA11 was clearly different from the other two genotypes: genotype MPA11 produced heavier seedlings at all temperatures but the root biomass of this genotype decreased with increasing temperature, reaching the lowest value at 35°C. In contrast, root biomass of genotypes MPB01 and IAC80 was not affected by temperature, suggesting that the roots of these genotypes are less sensitive to changes in temperature. In addition, an increasing temperature decreased the root to shoot ratio, which suggests that biomass allocation between below- and above ground parts of the plants was strongly affected by the temperature. Carbohydrate contents were reduced in response to increasing temperature in both roots and cotyledons, whereas amino acids accumulated to higher contents. Our results show that a specific balance between amino acids, carbohydrates and organic acids in the cotyledons and roots seems to be an important trait for faster and more efficient growth of genotype MPA11. Conclusions An increase in temperature triggers the mobilization of carbohydrates to support the preferred growth of the aerial parts, at the expense of the roots. A shift in the carbon-nitrogen metabolism towards the accumulation of nitrogen-containing compounds seems to be the main biochemical response to support growth at higher temperatures. The biochemical changes observed in response to the increasing temperature provide leads into understanding plant adaptation to harsh environmental conditions, which will be very helpful in developing strategies for R. communis crop improvement research. PMID:25109402

  16. Analysing the Effects of Different Land Cover Types on Land Surface Temperature Using Satellite Data

    NASA Astrophysics Data System (ADS)

    Şekertekin, A.; Kutoglu, Ş. H.; Kaya, S.; Marangoz, A. M.

    2015-12-01

    Monitoring Land Surface Temperature (LST) via remote sensing images is one of the most important contributions to climatology. LST is an important parameter governing the energy balance on the Earth and it also helps us to understand the behavior of urban heat islands. There are lots of algorithms to obtain LST by remote sensing techniques. The most commonly used algorithms are split-window algorithm, temperature/emissivity separation method, mono-window algorithm and single channel method. In this research, mono window algorithm was implemented to Landsat 5 TM image acquired on 28.08.2011. Besides, meteorological data such as humidity and temperature are used in the algorithm. Moreover, high resolution Geoeye-1 and Worldview-2 images acquired on 29.08.2011 and 12.07.2013 respectively were used to investigate the relationships between LST and land cover type. As a result of the analyses, area with vegetation cover has approximately 5 ºC lower temperatures than the city center and arid land., LST values change about 10 ºC in the city center because of different surface properties such as reinforced concrete construction, green zones and sandbank. The temperature around some places in thermal power plant region (ÇATES and ZETES) Çatalağzı, is about 5 ºC higher than city center. Sandbank and agricultural areas have highest temperature due to the land cover structure.

  17. [Properties of maize stalk biochar produced under different pyrolysis temperatures and its sorption capability to naphthalene].

    PubMed

    Huang, Hua; Wang, Ya-Xiong; Tang, Jing-Chun; Tang, Jing-Chun; Zhu, Wen-Ying

    2014-05-01

    Biochar was made from maize stalk under three different temperatures of 300, 500 and 700 degreeC. The elemental composition of biochar was measured by elemental analyzer. Scanning electron microscope (SEM) was used to measure the surface morphology. Sorption of naphthalene to biochar was researched by batch sorption experiments. Results showed that, with the increase of temperature, C content increased from 66. 79% to 76. 30% , H and O contents decreased from 4.92% and 19. 25% to 3. 18% and 9.53%, respectively; H/C, O/C, (O + N)/C, aromaticity and hydrophobicity increased, and polarity decreased. SEM results showed that maize stalk biochar was platy particles, and its roughness of surface increased with increasing temperature. The sorption of naphthalene on biochar followed the Lagergren pseudo-second order dynamic sorption model. Initial sorption rate and equilibrium sorption capacity increased as preparation temperatures increased at the same initial concentration of naphthalene. The isotherm sorption behavior can be described by the Freundlich model, which indicated that, as pyrolysis temperature increased, the sorption capacity of biochar increased, and nonlinearity increased first and then decreased. Biochar derived from maize stalk had distinct features when compared with other feedstocks, and its elemental composition, surface features and sorption behaviors were significantly influenced by pyrolysis temperature. PMID:25055682

  18. Pressure-temperature phase diagrams of maize starches with different amylose contents.

    PubMed

    Buckow, Roman; Jankowiak, Lena; Knorr, Dietrich; Versteeg, Cornelis

    2009-12-23

    The amylose/amylopectin ratio in starch granules has a distinct impact on the physicochemical properties of starches. In this study the effects of high pressure and temperature combinations on the gelatinization of four maize starches with different amylose contents were investigated in an excess of water (90% w/w). Microscopy was used to determine the loss of birefringence in starch granules. Experiments were undertaken in the pressure range of 0.1-750 MPa and temperature range of 30-110 degrees C, holding the conditions constant for 5 min. Temperature and pressure stabilities of high amylose starches were found to be significantly higher than those of waxy and normal maize starch. Thermodynamic models are proposed to describe the loss in birefringence as a function of pressure and temperature. From the pressure-temperature phase diagrams constructed it was evident that maize starch gelatinization is not accelerated at pressures below 300-400 MPa. However, at higher pressures the threshold temperature to initiate starch granule hydration and gelatinization is significantly reduced for all starches investigated. This study extends the knowledge of the impact of high pressure on food components and will possibly make the technology more attractive to use as a substitute for or in combination with conventional food-processing methods. PMID:19916500

  19. Sex Differences in Behavioral Outcomes Following Temperature Modulation During Induced Neonatal Hypoxic Ischemic Injury in Rats

    PubMed Central

    Smith, Amanda L.; Garbus, Haley; Rosenkrantz, Ted S.; Fitch, Roslyn Holly

    2015-01-01

    Neonatal hypoxia ischemia (HI; reduced oxygen and/or blood flow to the brain) can cause various degrees of tissue damage, as well as subsequent cognitive/behavioral deficits such as motor, learning/memory, and auditory impairments. These outcomes frequently result from cardiovascular and/or respiratory events observed in premature infants. Data suggests that there is a sex difference in HI outcome, with males being more adversely affected relative to comparably injured females. Brain/body temperature may play a role in modulating the severity of an HI insult, with hypothermia during an insult yielding more favorable anatomical and behavioral outcomes. The current study utilized a postnatal day (P) 7 rodent model of HI injury to assess the effect of temperature modulation during injury in each sex. We hypothesized that female P7 rats would benefit more from lowered body temperatures as compared to male P7 rats. We assessed all subjects on rota-rod, auditory discrimination, and spatial/non-spatial maze tasks. Our results revealed a significant benefit of temperature reduction in HI females as measured by most of the employed behavioral tasks. However, HI males benefitted from temperature reduction as measured on auditory and non-spatial tasks. Our data suggest that temperature reduction protects both sexes from the deleterious effects of HI injury, but task and sex specific patterns of relative efficacy are seen. PMID:26010486

  20. Developmental Biology of Zeugodacus cucurbitae (Diptera: Tephritidae) in Three Cucurbitaceous Hosts at Different Temperature Regimes.

    PubMed

    Mkiga, A M; Mwatawala, M W

    2015-01-01

    Fruit flies are key pests of cucurbits in many parts of the world, including Tanzania. Developmental biology of Zeugodacus cucurbitae (Coquillett) has been determined across temperature regimes in some cucurbitaceous hosts, in limited geographies. This study was conducted to determine duration and survival rates of immature stages of Z. cucurbitae in three cucurbitaceous hosts, at different temperature regimes. It was hypothesized that temperature and cucurbitaceous hosts influence duration and survival of immature stages of Z. cucurbitae. We conducted experiments in the environmental chamber set at 75 ± 10% RH and a photoperiod of 12:12 (L:D) h, at temperatures of 20, 25, and 30°. Our results showed that duration and survival of immature stages of Z. cucurbitae differed significantly among the temperature regimes but not among the hosts. Egg incubation period as well as larval and pupal stages were significantly longer (P < 0.0001) at low temperature in all three hosts Likewise, survival rate of all immature stages were significantly higher (P < 0.0001) at higher than lower temperatures. The three hosts, cucumber (Cucumis sativus), watermelon (Citrullus lanatus (Thunb.) Matsum. and Nakai), and pumpkin (Cucurbita pepo) did not significantly affect duration or survival rates of immature stages of Z. cucurbitae. The low developmental thresholds were estimated at 15.88, 13.44, and 12.62 for egg, larva and pupa, respectively. These results further confirm that Z. cucurbitae is well adapted to warm climate, which dominates many areas of Tanzania. PMID:26589874

  1. [Adsorption of Cd(II) varies with biochars derived at different pyrolysis temperatures].

    PubMed

    Wang, Zhen-Yu; Liu, Guo-Cheng; Monica, Xing; Li, Feng-Min; Zheng, Hao

    2014-12-01

    Ten biochars were prepared at different pyrolysis temperatures (300- 600 degrees C) using peanut shells and Chinese medicine material residue as raw materials, and were characterized. Adsorption behavior of Cd(II) on these biochars at different solution pHs, sorption times, and Cd(II) concentrations was investigated. The C content, surface area, and aromaticity of the biochars increased with increasing pyrolysis temperature, while the amount of oxygen-containing functional groups decreased. In addition, the content of inorganic minerals (e. g., Ca/Mg carbonate or phosphate) was enriched, but their solubility was reduced with increasing pyrolysis temperature. As the solution pHs increased from 2.0 to 6.0, the amount of Cd(II) adsorbed on the biochars gradually increased, and achieved the maximum at pH 6.0. Adsorption processes could be divided into two stages: fast and slow sorption. The rate of Cd(II) adsorption on these biochars was regulated by film and intraparticle diffusion, precipitation and ion exchange. With increasing temperature, the percentage of fast sorption to overall sorption of Cd(II) gradually decreased. Sharp decrease of oxygen-containing functional groups and formation of insoluble crystalline minerals reduced the rate of fast sorption on the high-temperature biochars (> 500 degrees C). For low-temperature biochars (? 400 degrees C), precipitation and ion exchange were the dominant sorption mechanisms. For high-temperature biochars (? 500 degrees C), more integrated ?-conjugated aromatic structures enhanced the contribution of Cd-? interaction to the overall sorption, but the formation of phosphate and carbonate minerals probably weakened the sorption. These results will provide important information on screening biochars as engineered adsorbents to remove or immobilize Cd(II) in contaminated water and soil. PMID:25826948

  2. Effects of Urban Morphology on Intra-Urban Temperature Differences: Two Squares in Glasgow City Centre

    NASA Astrophysics Data System (ADS)

    Drach, P. R. C.; Emmanuel, R.

    2014-12-01

    The perspective of climate change increases the necessity of tackling the urban over heating effects, by developing strategies to mitigate/adapt to changes. Analysing the influence of urban form on intra-urban temperature dynamics could be a helpful way of reducing its negative consequences. Also, it would help untangle the urban effect from the effect caused by atmospheric conditions. The present paper presents the effect of atmospheric conditions as exemplified by atmospheric stability (modified Pasquill-Gifford-Turner classification system) and urban morphology as measured by the Sky View Factor (SVF) on intra-urban variations in air temperature in a cold climate city, in and around the mature urban area of Glasgow, UK (55 51' 57.294"N, 4 15' 0.2628"W). The aim is to highlight their combined importance and to make preliminary investigations on the local warming effect of urban morphology under specific atmospheric stability classes. The present work indicates that the maximum intra-urban temperature differences (i.e. temperature difference between the coolest and the warmest spots in a given urban region) is strongly correlated with atmospheric stability. The spatial patterns in local temperature variations consistently show that water bodies and urban parks have lower temperature variations. Thus, greenery and urban materials could play an important role in influencing the local climate in cold cities. The knowledge of urban morphology's influence on local temperature variations could be an important tool for devising appropriate planning/design strategies to face urban overheating in the coming years as the background climate continues to warm.

  3. Developmental Biology of Zeugodacus cucurbitae (Diptera: Tephritidae) in Three Cucurbitaceous Hosts at Different Temperature Regimes

    PubMed Central

    Mkiga, A. M.; Mwatawala, M. W

    2015-01-01

    Fruit flies are key pests of cucurbits in many parts of the world, including Tanzania. Developmental biology of Zeugodacus cucurbitae (Coquillett) has been determined across temperature regimes in some cucurbitaceous hosts, in limited geographies. This study was conducted to determine duration and survival rates of immature stages of Z. cucurbitae in three cucurbitaceous hosts, at different temperature regimes. It was hypothesized that temperature and cucurbitaceous hosts influence duration and survival of immature stages of Z. cucurbitae. We conducted experiments in the environmental chamber set at 75 ± 10% RH and a photoperiod of 12:12 (L:D) h, at temperatures of 20, 25, and 30°. Our results showed that duration and survival of immature stages of Z. cucurbitae differed significantly among the temperature regimes but not among the hosts. Egg incubation period as well as larval and pupal stages were significantly longer (P < 0.0001) at low temperature in all three hosts Likewise, survival rate of all immature stages were significantly higher (P < 0.0001) at higher than lower temperatures. The three hosts, cucumber (Cucumis sativus), watermelon (Citrullus lanatus (Thunb.) Matsum. and Nakai), and pumpkin (Cucurbita pepo) did not significantly affect duration or survival rates of immature stages of Z. cucurbitae. The low developmental thresholds were estimated at 15.88, 13.44, and 12.62 for egg, larva and pupa, respectively. These results further confirm that Z. cucurbitae is well adapted to warm climate, which dominates many areas of Tanzania. PMID:26589874

  4. Autotrophic Growth of Bacterial and Archaeal Ammonia Oxidizers in Freshwater Sediment Microcosms Incubated at Different Temperatures

    PubMed Central

    Wu, Yucheng; Ke, Xiubin; Hernández, Marcela; Wang, Baozhan; Dumont, Marc G.; Jia, Zhongjun

    2013-01-01

    Both bacteria and archaea potentially contribute to ammonia oxidation, but their roles in freshwater sediments are still poorly understood. Seasonal differences in the relative activities of these groups might exist, since cultivated archaeal ammonia oxidizers have higher temperature optima than their bacterial counterparts. In this study, sediment collected from eutrophic freshwater Lake Taihu (China) was incubated at different temperatures (4°C, 15°C, 25°C, and 37°C) for up to 8 weeks. We examined the active bacterial and archaeal ammonia oxidizers in these sediment microcosms by using combined stable isotope probing (SIP) and molecular community analysis. The results showed that accumulation of nitrate in microcosms correlated negatively with temperature, although ammonium depletion was the same, which might have been related to enhanced activity of other nitrogen transformation processes. Incubation at different temperatures significantly changed the microbial community composition, as revealed by 454 pyrosequencing targeting bacterial 16S rRNA genes. After 8 weeks of incubation, [13C]bicarbonate labeling of bacterial amoA genes, which encode the ammonia monooxygenase subunit A, and an observed increase in copy numbers indicated the activity of ammonia-oxidizing bacteria in all microcosms. Nitrosomonas sp. strain Is79A3 and Nitrosomonas communis lineages dominated the heavy fraction of CsCl gradients at low and high temperatures, respectively, indicating a niche differentiation of active bacterial ammonia oxidizers along the temperature gradient. The 13C labeling of ammonia-oxidizing archaea in microcosms incubated at 4 to 25°C was minor. In contrast, significant 13C labeling of Nitrososphaera-like archaea and changes in the abundance and composition of archaeal amoA genes were observed at 37°C, implicating autotrophic growth of ammonia-oxidizing archaea under warmer conditions. PMID:23455342

  5. Influence of Air Temperature Difference on the Snow Melting Simulation of SWAT Model

    NASA Astrophysics Data System (ADS)

    YAN, Y.; Onishi, T.

    2013-12-01

    The temperature-index models are commonly used to simulate the snowmelt process in mountain areas because of its good performance, low data requirements, and computational simplicity. Widely used distributed hydrological model: Soil and Water Assessment Tool (SWAT) model is also using a temperature-index module. However, the lack of monitoring air temperature data still involves uncertainties and errors in its simulation performance especially in data sparse area. Thus, to evaluate the different air temperature data influence on the snow melt of the SWAT model, five different air temperature data are applied in two different Russia basins (Birobidjan basin and Malinovka basin). The data include the monitoring air temperature data (TM), NCEP reanalysis data (TNCEP), the dataset created by inverse distance weighted interpolation (IDW) method (TIDW), the dataset created by improved IDW method considering the elevation influence (TIDWEle), and the dataset created by using linear regression and MODIS Land Surface Temperature (LST) data (TLST). Among these data, the TLST , the TIDW and TIDWEle data have the higher spatial density, while the TNCEP and TM DATA have the most valid monitoring value for daily scale. The daily simulation results during the snow melting seasons (March, April and May) showed reasonable results in both test basins for all air temperature data. While R2 and NSE in Birobidjan basin are around 0.6, these values in Malinovka basin are over 0.75. Two methods: Generalized Likelihood Uncertainty Estimation (GLUE) and Sequential Uncertainty Fitting, version. 2 (SUFI-2) were used for model calibration and uncertainty analysis. The evolution index is p-factor which means the percentage of measured data bracketed by the 95% Prediction Uncertainty (95PPU). The TLST dataset always obtained the best results in both basins compared with other datasets. On the other hand, the two IDW based method get the worst results among all the scenarios. Totally, the performances of the data created from the MODIS land surface temperature which have a high spatial density are better than other data and can directly improve the snow melting results of SWAT model and reduce the uncertainty to a certain extend.

  6. Co-doped sodium chloride crystals exposed to different irradiation temperature

    SciTech Connect

    Ortiz-Morales, A.; Cruz-Zaragoza, E.; Furetta, C.; Kitis, G.; Flores J, C.; Hernandez A, J.; Murrieta S, H.

    2013-07-03

    Monocrystals of NaCl:XCl{sub 2}:MnCl{sub 2}(X = Ca,Cd) at four different concentrations have been analyzed. The crystals were exposed to different irradiation temperature, such as at room temperature (RT), solid water (SW), dry ice (DI) and liquid nitrogen (LN). The samples were irradiated with photon from {sup 60}Co irradiators. The co-doped sodium chloride crystals show a complex structure of glow curves that can be related to different distribution of traps. The linearity response was analyzed with the F(D) index. The F(D) value was less than unity indicating a sub-linear response was obtained from the TL response on the function of the dose. The glow curves were deconvoluted by using the CGCD program based on the first, second and general order kinetics.

  7. Modelling adult Aedes aegypti and Aedes albopictus survival at different temperatures in laboratory and field settings

    PubMed Central

    2013-01-01

    Background The survival of adult female Aedes mosquitoes is a critical component of their ability to transmit pathogens such as dengue viruses. One of the principal determinants of Aedes survival is temperature, which has been associated with seasonal changes in Aedes populations and limits their geographical distribution. The effects of temperature and other sources of mortality have been studied in the field, often via mark-release-recapture experiments, and under controlled conditions in the laboratory. Survival results differ and reconciling predictions between the two settings has been hindered by variable measurements from different experimental protocols, lack of precision in measuring survival of free-ranging mosquitoes, and uncertainty about the role of age-dependent mortality in the field. Methods Here we apply generalised additive models to data from 351 published adult Ae. aegypti and Ae. albopictus survival experiments in the laboratory to create survival models for each species across their range of viable temperatures. These models are then adjusted to estimate survival at different temperatures in the field using data from 59 Ae. aegypti and Ae. albopictus field survivorship experiments. The uncertainty at each stage of the modelling process is propagated through to provide confidence intervals around our predictions. Results Our results indicate that adult Ae. albopictus has higher survival than Ae. aegypti in the laboratory and field, however, Ae. aegypti can tolerate a wider range of temperatures. A full breakdown of survival by age and temperature is given for both species. The differences between laboratory and field models also give insight into the relative contributions to mortality from temperature, other environmental factors, and senescence and over what ranges these factors can be important. Conclusions Our results support the importance of producing site-specific mosquito survival estimates. By including fluctuating temperature regimes, our models provide insight into seasonal patterns of Ae. aegypti and Ae. albopictus population dynamics that may be relevant to seasonal changes in dengue virus transmission. Our models can be integrated with Aedes and dengue modelling efforts to guide and evaluate vector control, better map the distribution of disease and produce early warning systems for dengue epidemics. PMID:24330720

  8. Effects of different dentin thicknesses and air cooling on pulpal temperature rise during laser welding.

    PubMed

    Secilmis, Asli; Bulbul, Mehmet; Sari, Tugrul; Usumez, Aslihan

    2013-01-01

    The neodymium/yttrium-aluminum-garnet (Nd/YAG) laser has been suggested to repair broken prostheses in the mouth. This study investigated the effects of different dentin thicknesses and air cooling on pulpal temperature rise during laser welding. Three intact human maxillary molars were prepared for full-veneer crown. For each tooth, dentin thicknesses in mesiobuccal cusp was 2, 3, or 4 mm. Twenty dies were duplicated from each of the prepared teeth. For metal copings with 0.5-mm thickness, wax patterns were prepared with dip wax technique directly onto each of dies. All patterns were sprued and invested. The castings were made using a nickel-chromium alloy (Nicromed Premium, Neodontics). A hole with 0.5-mm diameter was prepared on the mesiobuccal cusp of each crown. The Nd/YAG laser (9.85 W; 1 Hz repetition rate; fluence, 1.230 J/cm(2); Fidelis Plus 3, Fotona) was used for welding with or without air cooling (n = 10). The temperature rise was measured in pulpal chamber with a J-type thermocouple wire that was connected to a data logger. Differences between start and highest temperature reading were taken, and temperature rise values were compared using two-way analysis of variance and Tukey's honestly significant difference tests (? = .05). Pulpal temperature rise varied significantly depending on the dentin thickness and air cooling (p < 0.05). The non-air cooling group induced significantly the highest temperature increases. There were no significant differences between 2- and 3-mm dentin thicknesses groups (p > 0.05); however, pulpal temperature rise was the lowest for 4-mm dentin thickness group (p < 0.05). The highest values of thermal increase were found in the pulp chamber (6.8C) when no air cooling was used in 2-mm dentin thickness group. Laser welding on base metal castings with Nd/YAG laser can be applied with air cooling to avoid temperature rises known to adversely affect pulpal health when dentin thickness is 2 or 3 mm. PMID:22562450

  9. Multi-point abnormal-temperature warning sensor system with different thresholds

    NASA Astrophysics Data System (ADS)

    Sun, Q.; Liu, D.; Wang, J.; Liu, H.; Xia, L.; Shum, P.

    2009-09-01

    We propose and experimentally demonstrate a time-division-multiplexing-based (TDM-based) multi-point abnormal-temperature warning sensor system with different thresholds. A multi-channel fiber Bragg grating (FBG) serving as the wavelength selector is employed in the fiber ring laser to generate a multi-wavelength pulsed light source. The sensor array is composed of multiple uniform sensing FBGs at different positions and with different nominal wavelengths. The warning signal is obtained by only monitoring the time slot between the injected pulse and the reflected pulse. The measurement range and resolution are theoretically discussed and experimentally demonstrated.

  10. Room-temperature terahertz detection based on CVD graphene transistor

    NASA Astrophysics Data System (ADS)

    Yang, Xin-Xin; Sun, Jian-Dong; Qin, Hua; Lv, Li; Su, Li-Na; Yan, Bo; Li, Xin-Xing; Zhang, Zhi-Peng; Fang, Jing-Yue

    2015-04-01

    We report the fabrication and characterization of a single-layer graphene field-effect terahertz detector, which is coupled with dipole-like antennas based on the self-mixing detector model. The graphene is grown by chemical vapor deposition and then transferred onto an SiO2/Si substrate. We demonstrate room-temperature detection at 237 GHz. The detector could offer a voltage responsivity of 0.1 V/W and a noise equivalent power of 207 nW/Hz1/2. Our modeling indicates that the observed photovoltage in the p-type gated channel can be well fit by the self-mixing theory. A different photoresponse other than self-mixing may apply for the n-type gated channel. Project supported by the National Natural Science Foundation of China (Grant Nos. 61271157, 61401456, and 11403084), Jiangsu Provincial Planned Projects for Postdoctoral Research Funds (Grant No. 1301054B), the Fund from Suzhou Industry Technology Bureau (Grant No. ZXG2012024), China Postdoctoral Science Foundation (Grant No. 2014M551678), the Graduate Student Innovation Program for Universities of Jiangsu Province (Grant No. CXLX12_0724), the Fundamental Research Funds for the Central Universities (Grant No. JUDCF 12032), and the Fund from National University of Defense Technology (Grant No. JC13-02-14).

  11. Algorithm development for land surface temperature measurement from GOES-R satellite

    NASA Astrophysics Data System (ADS)

    Yu, Yunyue; Tarpley, Dan; Raja, M. K. Rama Varma; Xu, Hui; Privette, Jeffrey L.

    2007-10-01

    The Geostationary Operational Environmental Satellite (GOES) program is developing a new generation sensor, the Advanced Baseline Imager (ABI), to be carried on the GOES-R satellite to be lunched in approximately in 2014. Compared to the current GOES imager, ABI will have significant advantages for measuring land surface temperature as well as to providing qualitative and quantitative data for a wide range of applications. Specifically, spatial resolution of the ABI sensor is 2 km, and the infrared window noise equivalent temperature is 0.1 K, which are very close to the polarorbiting satellite sensors such as AVHRR. Most importantly, ABI observes the full disk every five minutes, which not only provides more cloud-free measurements but also makes daily temperature variation analysis possible. In this study we developed split window algorithms for the LST measurement from the ABI sensor. We generated the ABI sensor data using MODTRAN radiative transfer model and NOAA88 atmospheric profiles and ran regression analyses for the LST algorithm development. The algorithms are developed by optimizing existing split window LST algorithms and adding a path length correction term to minimize the retrieval errors due to difference atmospheric path absorption from nadir view to the edge-of-scan. The algorithm coefficients are stratified for dry and moist atmospheric conditions, as well as for the daytime and nighttime. The algorithm sensitivity to land surface emissivity uncertainty is analyzed to ensure the algorithm performance.

  12. [Regularities of carbon monoxide outgassing from two nonmetallic materials at different temperatures].

    PubMed

    Zhang, X; Wei, Y; Yu, B

    1998-06-01

    To investigate the regularity of carbon monoxide outgassing from nonmetallic materials in air tight cabin, two nonmetallic materials was observed. 30-9304 foam plastics and aluminum-plated polyester adhesive film were sealed in airtight glass ampules, and outgassed for 70 days at four different temperatures. The outgassing CO was determined continuously with transform/gas chromatography. Curve fitting and regression were used in data analysis. The results showed that: (1) when temperature was kept constant, the relation between the outgassed CO and outgassing time appeared to be a "s" shaped or exponented curve; (2) at a fixed time the amount of outgassed CO increased with temperature exponentially; (3) the amount of CO outgassed in 12 h at 100 degrees C from the two materials corresponds those for 45 d at 50 degrees C, there is an iso-effect principle for CO outgassing. PMID:11541422

  13. Archaeal Community Structures in the Solfataric Acidic Hot Springs with Different Temperatures and Elemental Compositions

    PubMed Central

    Watanabe, Keiko; Yamamoto, Hideo; Yamamoto, Shuichi

    2013-01-01

    Archaeal 16S rRNA gene compositions and environmental factors of four distinct solfataric acidic hot springs in Kirishima, Japan were compared. The four ponds were selected by differences of temperature and total dissolved elemental concentration as follows: (1) Pond-A: 93°C and 1679 mg L−1, (2) Pond-B: 66°C and 2248 mg L−1, (3) Pond-C: 88°C and 198 mg L−1, and (4) Pond-D: 67°C and 340 mg L−1. In total, 431 clones of 16S rRNA gene were classified into 26 phylotypes. In Pond-B, the archaeal diversity was the highest among the four, and the members of the order Sulfolobales were dominant. The Pond-D also showed relatively high diversity, and the most frequent group was uncultured thermoacidic spring clone group. In contrast to Pond-B and Pond-D, much less diverse archaeal clones were detected in Pond-A and Pond-C showing higher temperatures. However, dominant groups in these ponds were also different from each other. The members of the order Sulfolobales shared 89% of total clones in Pond-A, and the uncultured crenarchaeal groups shared 99% of total Pond-C clones. Therefore, species compositions and biodiversity were clearly different among the ponds showing different temperatures and dissolved elemental concentrations. PMID:23710131

  14. Prediction of the resolution of capillary columns in different conditions of inlet pressure and temperature.

    PubMed

    Vezzani, S; Moretti, P; Castello, G; Travaini, G

    2004-02-13

    A procedure previously described for the prediction of the plate height of capillary columns operated at different inlet pressure of the carrier gas and at various column temperatures by using few retention data measured under isobaric conditions was modified and improved in order to permit the prediction of the retention times and of the peak widths at various heights. It is therefore possible to calculate the ratio, delta, between the peak width at different heights and the peak width at half height, whose value is used to predict the resolution at different height of two closely eluting peaks. It was found that the delta values do not depend on temperature and inlet pressure and are a characteristic of the used column; they can therefore be used in order to calculate the resolution in any temperature and inlet pressure condition. The method was used to predict the retention time, the peak width and the resolution of polar and non-polar compounds (alkanes, alkenes, chloroalkanes, alcohols, ketones) on capillary columns of different length and polarity by using as the starting data retention and width values measured in three isobaric runs only. PMID:14763748

  15. Concentration of Umami Compounds in Pork Meat and Cooking Juice with Different Cooking Times and Temperatures.

    PubMed

    Rotola-Pukkila, Minna K; Pihlajaviita, Seija T; Kaimainen, Mika T; Hopia, Anu I

    2015-12-01

    This study examined the concentrations of umami compounds in pork loins cooked at 3 different temperatures and 3 different lengths of cooking times. The pork loins were cooked with the sous vide technique. The free amino acids (FAAs), glutamic acid and aspartic acid; the 5'-nucleotides, inosine-5'-monophosphate (IMP) and adenosine-5'-monophosphate (AMP); and corresponding nucleoside inosine of the cooked meat and its released juice were determined by high-performance liquid chromatography. Under the experimental conditions used, the cooking temperature played a more important role than the cooking time in the concentration of the analyzed compounds. The amino acid concentrations in the meat did not remain constant under these experimental conditions. The most notable effect observed was that of the cooking temperature and the higher amino acid concentrations in the released juice of meat cooked at 80 C compared with 60 and 70 C. This is most likely due to the heat induced hydrolysis of proteins and peptides releasing water soluble FAAs from the meat into the cooking juice. In this experiment, the cooking time and temperature had no influence on the IMP concentrations observed. However, the AMP concentrations increased with the increasing temperature and time. This suggests that the choice of time and temperature in sous vide cooking affects the nucleotide concentration of pork meat. The Sous vide technique proved to be a good technique to preserve the cooking juice and the results presented here show that cooking juice is rich in umami compounds, which can be used to provide a savory or brothy taste. PMID:26524113

  16. Bacillus spore inactivation differences after combined mild temperature and high pressure processing using two pressurizing fluids.

    PubMed

    Robertson, Rosalind E; Carroll, Tim; Pearce, Lindsay E

    2008-06-01

    Spores of six species (28 strains) of dairy Bacillus isolates were added to sterile reconstituted skim milk and pressure processed (600 MPa for 60 s at 75 degrees C) using either a water-based pressurizing fluid or silicon oil. Processing temperatures peaked at 88 and 90 degrees C, respectively, for both fluids. For all strains, the log inactivation was consistently higher in the silicon oil than in the water-based fluid. This has potential implications for food safety assessment of combined pressure-temperature processes. High pressure processing causes mild heating during pressurization of both the target sample (i.e., spores) and the pressurizing fluid used for pressure delivery. Primarily, the adiabatic heat of compression of the fluids as well as other heat-transfer properties of the fluids and equipment determines the magnitude of this heating. Pressure cycles run with silicon oil were 7 to 15 degrees C higher in temperature during pressurization than pressure cycles run with the water-based pressurizing fluid, due to the greater adiabatic heat of compression of silicon oil. At and around the target pressure, however, the temperatures of both pressurizing fluids were similar, and they both dropped at the same rate during the holding time at the target pressure. We propose that the increased spore inactivation in the silicon oil system can be attributed to additional heating of the spore preparation when pressurized in oil. This could be explained by the temperature difference between the silicon oil and the aqueous spore preparation established during the pressurization phase of the pressure cycle. These spore-inactivation differences have practical implications because it is common practice to develop inactivation kinetic data on small, jacketed laboratory systems pressurized in oil, with extensive heat loss. However, commercial deployment is invariably on large industrial systems pressurized in water, with limited heat loss. Such effects should be considered in food safety assessments of combined pressure-temperature processes. PMID:18592744

  17. Skin and bulk temperature difference at Lake Tahoe: A case study on lake skin effect

    NASA Astrophysics Data System (ADS)

    Wilson, R. Chris; Hook, Simon J.; Schneider, Philipp; Schladow, S. Geoffrey

    2013-09-01

    water, infrared radiometers on satellites measure radiation leaving from the surface skin layer and therefore the retrieved temperature is representative of the skin layer. This is slightly different from the bulk layer deeper in the water where various floating thermometers take temperature measurements to validate satellite measurements. The difference between the bulk and skin temperature (skin effect) must be understood to properly validate schemes that use surface skin temperature to infer bulk temperatures. Further skin temperatures retrieved over inland waters may show different patterns to those retrieved over oceans due to differences in conditions such as wind speed, aerosols, and elevation. We have analyzed the differences between the skin and bulk temperatures at four permanent monitoring stations (buoys) located on Lake Tahoe since 1999 and compared the results with similar studies over the ocean typically obtained from boat cruises. Skin effect distributions were found to be consistent across the buoys; however, the diurnal behavior of the skin effect was slightly different and shown to be related to wind speed measured at an individual buoy. When wind speed was less than 2 m s-1, the skin temperature osclillated and greatly increased the uncertainty in the skin effect reported over Lake Tahoe. When downwelling sky radiation was increased from clouds or high humidity, this led to nighttime skin temperatures that were warmer than bulk temperatures by as much as 0.5 K. The size of the warm skin effect is larger than other ocean studies that observed warm nighttime skin values around 0.1 K. The nighttime skin effect was seen to be more consistent with a smaller standard deviation compared to the daytime skin effect. The nighttime skin behavior had a mean and standard deviation that ranged between 0.3 and 0.5 K and between 0.3 and 0.4 K, respectively. In contrast, daytime skin effect was strongly influenced by direct solar illumination and typically had a mean of 0.5 K in the morning that decreased to 0.1 K by midday. The standard deviation of the daytime skin effect ranged from 0.3 in the morning to 0.8 by midday. As the solar heating reduces later in the day the skin effect increases to a 0.3 K mean with a standard deviation of 0.4 K. The results for Lake Tahoe clearly demonstrate that validating satellite-derived skin measurements or merging multiple satellites data sets together would be most successful when using nighttime data at wind speeds greater than 2 m s-1 with greater uncertainties expected when using daytime measurements. Further, the assumptions used for the skin effect behavior over oceans may not be appropriate over lakes because of the greater range of environmental conditions that affect lakes.

  18. Antioxidant and oxidative stress responses of sojourners at high altitude in different climatic temperatures.

    PubMed

    Sinha, Sanchari; Singh, Som Nath; Saha, Mantu; Kain, T C; Tyagi, A K

    2010-01-01

    High altitude (HA) is a multi-stressor environment comprising hypobaric hypoxia and cold. Climatic temperature varies with seasonal variation at HA. The present study was undertaken to investigate the effect of ambient temperature on antioxidant profile among sojourners at HA. The study was conducted on sojourners exposed to an altitude of 4,560 m in two different seasons and categorized into two groups (SOJ 1, n=63, ambient temp. at HA: -6 degree to +10degreeC; SOJ 2, n=81, ambient temp. at HA: 3degree-22degreeC). Blood was collected at sea level (SL) and after 4 weeks of HA exposure. Antioxidant enzymes showed significant upregulation in SOJ 2 at HA. In SOJ 1, superoxide dismutase and glutathione peroxidase showed significant upregulation but catalase and glutathione reductase showed significant decrease at HA. Non-enzymatic antioxidants showed significant reduction in SOJ 1 whereas a sustained antioxidant profile was observed in SOJ 2 at HA. Oxidative stress markers showed higher levels in SOJ 1 than SOJ 2 at HA. Differences observed between SOJ 1 and SOJ 2 at HA may be the consequence of different environmental temperatures. Cold stress was higher in SOJ 1 as evidenced from the significantly lower oral temperature in SOJ 1 as compared to SOJ 2. Cold- and hypoxia-induced increase in energy expenditure was significantly high in SOJ 1 than SOJ 2. To conclude, chronic exposure to hypoxia in moderate climatic temperature has a potential preconditioning effect on antioxidant system, but exposure to both cold and hypoxia causes greater oxidative stress due to altered metabolic rate. PMID:20099373

  19. Temperature control during therapeutic hypothermia for newborn encephalopathy using different Blanketrol devices.

    PubMed

    Laptook, Abbot R; Kilbride, Howard; Shepherd, Edward; McDonald, Scott A; Shankaran, Seetha; Truog, William; Das, Abhik; Higgins, Rosemary D

    2014-12-01

    Therapeutic hypothermia improves the survival and neurodevelopmental outcome of infants with newborn encephalopathy of a hypoxic-ischemic origin. The NICHD Neonatal Research Network (NRN) Whole Body Cooling trial used the Cincinnati Sub-Zero Blanketrol II to achieve therapeutic hypothermia. The Blanketrol III is now available and provides additional cooling modes that may result in better temperature control. This report is a retrospective comparison of infants undergoing hypothermia using two different cooling modes of the Blanketrol device. Infants from the NRN trial were cooled with the Blanketrol II using the Automatic control mode (B2 cohort) and were compared with infants from two new NRN centers that adopted the NRN protocol and used the Blanketrol III in a gradient mode (B3 cohort). The primary outcome was the percent time the esophageal temperature stayed between 33C and 34C (target 33.5C) during maintenance of hypothermia. Cohorts had similar birth weight, gestational age, and level of encephalopathy at the initiation of therapy. Baseline esophageal temperature differed between groups (36.6C 1.0C for B2 vs. 33.9C 1.2C for B3, p<0.0001) reflecting the practice of passive cooling during transport prior to initiation of active device cooling in the B3 cohort. This difference prevented comparison of temperatures during induction of hypothermia. During maintenance of hypothermia the mean and standard deviation of the percent time between 33C and 34C was similar for B2 compared to B3 cohorts (94.8% 0.1% vs. 95.8% 0.1%, respectively). Both the automatic and gradient control modes of the Blanketrol devices appear comparable in maintaining esophageal temperature within the target range during maintenance of therapeutic hypothermia. PMID:25285767

  20. Temperature Control During Therapeutic Hypothermia for Newborn Encephalopathy Using Different Blanketrol Devices

    PubMed Central

    Kilbride, Howard; Shepherd, Edward; McDonald, Scott A.; Shankaran, Seetha; Truog, William; Das, Abhik; Higgins, Rosemary D.

    2014-01-01

    Therapeutic hypothermia improves the survival and neurodevelopmental outcome of infants with newborn encephalopathy of a hypoxic-ischemic origin. The NICHD Neonatal Research Network (NRN) Whole Body Cooling trial used the Cincinnati Sub-Zero Blanketrol II to achieve therapeutic hypothermia. The Blanketrol III is now available and provides additional cooling modes that may result in better temperature control. This report is a retrospective comparison of infants undergoing hypothermia using two different cooling modes of the Blanketrol device. Infants from the NRN trial were cooled with the Blanketrol II using the Automatic control mode (B2 cohort) and were compared with infants from two new NRN centers that adopted the NRN protocol and used the Blanketrol III in a gradient mode (B3 cohort). The primary outcome was the percent time the esophageal temperature stayed between 33°C and 34°C (target 33.5°C) during maintenance of hypothermia. Cohorts had similar birth weight, gestational age, and level of encephalopathy at the initiation of therapy. Baseline esophageal temperature differed between groups (36.6°C±1.0°C for B2 vs. 33.9°C±1.2°C for B3, p<0.0001) reflecting the practice of passive cooling during transport prior to initiation of active device cooling in the B3 cohort. This difference prevented comparison of temperatures during induction of hypothermia. During maintenance of hypothermia the mean and standard deviation of the percent time between 33°C and 34°C was similar for B2 compared to B3 cohorts (94.8%±0.1% vs. 95.8%±0.1%, respectively). Both the automatic and gradient control modes of the Blanketrol devices appear comparable in maintaining esophageal temperature within the target range during maintenance of therapeutic hypothermia. PMID:25285767

  1. Effect of four different reflective barriers on black-globe temperatures in calf hutches

    NASA Astrophysics Data System (ADS)

    Friend, T. H.; Haberman, J. A.; Binion, W. R.

    2014-12-01

    Polyethylene hutches are a popular method of housing dairy calves from 0 to 60 or more days of age, although these hutches get hot when in full sun. This study characterized the relative differences in the ability of four different types of radiant barriers to reduce black-globe temperature within these hutches. Treatments included three different types of covers (two types of laminates (Cadpak P and Cadpak ESD) and an aluminized 3.0-mil white low-density polyethylene (LDPE)) and a reflective paint (LO/MIT-1). The reflective covers were 1.8 × 3 m finished size, and covered the top and sides of the hutch down to 0.15 m above the ground, leaving the front and back exposed. The LO/MIT-1 paint covered the entire sides and roof of the hutch. Two 24-h trials 1 week apart were conducted during relatively hot and clear days in early August. Black-globe temperatures were recorded in duplicate and averaged at 20-min intervals using blackened table tennis balls mounted 0.3 m above the floor in the center of each hutch. Ambient temperature (shade) during the hottest 2-h period for both trials averaged 39.9 °C while the uncovered control averaged 41.1 °C, and LO/MIT-1 averaged 39.9 °C; both of which were significantly higher ( P < 0.01) than the Cadpak P (38.9 °C), Cadpak ESD (38.6 °C), and aluminized LDPE (38.7 °C). During periods of high solar radiation, the hutches with covers had lowest black-globe temperatures followed by hutches painted with reflective paint, while control hutches had the highest temperature.

  2. Effect of four different reflective barriers on black-globe temperatures in calf hutches.

    PubMed

    Friend, T H; Haberman, J A; Binion, W R

    2014-12-01

    Polyethylene hutches are a popular method of housing dairy calves from 0 to 60 or more days of age, although these hutches get hot when in full sun. This study characterized the relative differences in the ability of four different types of radiant barriers to reduce black-globe temperature within these hutches. Treatments included three different types of covers (two types of laminates (Cadpak P and Cadpak ESD) and an aluminized 3.0-mil white low-density polyethylene (LDPE)) and a reflective paint (LO/MIT-1). The reflective covers were 1.8 × 3 m finished size, and covered the top and sides of the hutch down to 0.15 m above the ground, leaving the front and back exposed. The LO/MIT-1 paint covered the entire sides and roof of the hutch. Two 24-h trials 1 week apart were conducted during relatively hot and clear days in early August. Black-globe temperatures were recorded in duplicate and averaged at 20-min intervals using blackened table tennis balls mounted 0.3 m above the floor in the center of each hutch. Ambient temperature (shade) during the hottest 2-h period for both trials averaged 39.9 °C while the uncovered control averaged 41.1 °C, and LO/MIT-1 averaged 39.9 °C; both of which were significantly higher (P < 0.01) than the Cadpak P (38.9 °C), Cadpak ESD (38.6 °C), and aluminized LDPE (38.7 °C). During periods of high solar radiation, the hutches with covers had lowest black-globe temperatures followed by hutches painted with reflective paint, while control hutches had the highest temperature. PMID:24619461

  3. Antioxidant and oxidative stress responses of sojourners at high altitude in different climatic temperatures

    NASA Astrophysics Data System (ADS)

    Sinha, Sanchari; Singh, Som Nath; Saha, Mantu; Kain, T. C.; Tyagi, A. K.; Ray, Uday Sankar

    2010-01-01

    High altitude (HA) is a multi-stressor environment comprising hypobaric hypoxia and cold. Climatic temperature varies with seasonal variation at HA. The present study was undertaken to investigate the effect of ambient temperature on antioxidant profile among sojourners at HA. The study was conducted on sojourners exposed to an altitude of 4,560 m in two different seasons and categorized into two groups (SOJ 1, n = 63, ambient temp. at HA: -6 to +10C; SOJ 2, n = 81, ambient temp. at HA: 3-22C). Blood was collected at sea level (SL) and after 4 weeks of HA exposure. Antioxidant enzymes showed significant upregulation in SOJ 2 at HA. In SOJ 1, superoxide dismutase and glutathione peroxidase showed significant upregulation but catalase and glutathione reductase showed significant decrease at HA. Non-enzymatic antioxidants showed significant reduction in SOJ 1 whereas a sustained antioxidant profile was observed in SOJ 2 at HA. Oxidative stress markers showed higher levels in SOJ 1 than SOJ 2 at HA. Differences observed between SOJ 1 and SOJ 2 at HA may be the consequence of different environmental temperatures. Cold stress was higher in SOJ 1 as evidenced from the significantly lower oral temperature in SOJ 1 as compared to SOJ 2. Cold- and hypoxia-induced increase in energy expenditure was significantly high in SOJ 1 than SOJ 2. To conclude, chronic exposure to hypoxia in moderate climatic temperature has a potential preconditioning effect on antioxidant system, but exposure to both cold and hypoxia causes greater oxidative stress due to altered metabolic rate.

  4. Anaerobic biodegradation of 2,4-dichlorophenol in freshwater lake sediments at different temperatures

    SciTech Connect

    Kohring, G.W.; Rogers, J.E.; Wiegel, J.

    1989-01-01

    Anaerobic degradation of 2,4-dichlorophenol (2,4-DCP) between 5 and 72C was investigated. Anaerobic sediment slurries prepared from local freshwater sediments were partitioned into anaerobic tubes or serum vials, which then were incubated separately at the various temperatures. Reductive 2,4-DCP dechlorination occurred only in the temperature range between 5 and 50C, although methane was formed up to 60C. In sediment samples from two sites and at all temperatures from 5 to 50C, 2,4-DCP was transformed to 4-chlorophenol (4-CP). The 4-CP intermediate was subsequently degraded after an extended lag period in the temperature range from 15 to 40C. Adaptation periods for 2,4-DCP transformation decreased between 5 and 25C, were essentially constant between 25 and 35C, and increased in the tubes incubated at temperatures between 35 and 40C. This suggests that at least two different organisms were involved in the transformation of 2,4-DCP to 4-CP.

  5. Intravaginal and in vitro temperature changes with tampons of differing composition and absorbency.

    TOXLINE Toxicology Bibliographic Information

    Hill DR; Davis CC; Osborn TW 3rd

    2010-02-01

    Vaginal tampons are Class II medical devices used by women to manage menstruation. The purpose of this study was to investigate intravaginal temperature changes with simulated and actual menstrual tampon use. Tampons (with varying absorbent compositions) embedded with a thermocouple sensor were used to study temperature effects in vitro in a model of the vagina (condom placed in a hollow glass tube, jacketed in a 37 degrees C water bath, and dosed with human menses to fluid saturation) and clinically during menstrual tampon wear under controlled conditions (up to 8 h in a stationary, supine position). Elevations in the temperature of the tampon core occurred upon menses fluid acquisition both in vitro and clinically. Temperature profile characteristics varied from a transient spike with commercial cotton-rayon blend tampons of two different absorbencies to a small but sustained rise (> or =6 h) with a carboxymethyl cellulose (CMC)-containing prototype. On the basis of the results from this study, fluid absorption by tampons generates an exothermic event whose characteristics vary with tampon design and composition. We speculate the small, sustained increased in tampon temperature noted during this study may enhance the production of a bacterial exotoxin associated with tampons composed of CMC.

  6. Intravaginal and in vitro temperature changes with tampons of differing composition and absorbency.

    PubMed

    Hill, Donna R; Davis, Catherine C; Osborn, Thomas W

    2010-02-01

    Vaginal tampons are Class II medical devices used by women to manage menstruation. The purpose of this study was to investigate intravaginal temperature changes with simulated and actual menstrual tampon use. Tampons (with varying absorbent compositions) embedded with a thermocouple sensor were used to study temperature effects in vitro in a model of the vagina (condom placed in a hollow glass tube, jacketed in a 37 degrees C water bath, and dosed with human menses to fluid saturation) and clinically during menstrual tampon wear under controlled conditions (up to 8 h in a stationary, supine position). Elevations in the temperature of the tampon core occurred upon menses fluid acquisition both in vitro and clinically. Temperature profile characteristics varied from a transient spike with commercial cotton-rayon blend tampons of two different absorbencies to a small but sustained rise (> or =6 h) with a carboxymethyl cellulose (CMC)-containing prototype. On the basis of the results from this study, fluid absorption by tampons generates an exothermic event whose characteristics vary with tampon design and composition. We speculate the small, sustained increased in tampon temperature noted during this study may enhance the production of a bacterial exotoxin associated with tampons composed of CMC. PMID:20024967

  7. Wavelength properties of DCG holograms under the conditions of different temperature and humidity

    NASA Astrophysics Data System (ADS)

    Liu, Yujie; Li, Wenqiang; Ding, Quanxin; Yan, Zhanjun

    2014-12-01

    Holograms recorded in dichromated gelatin (DCG) are usually sealed with a glass plate cemented with an epoxy glue to protect the holograms from moisture in the environment. An investigation of the wavelength properties of sealed DCG holograms had been carried out paying attention to holograms which were exposed to different temperature and humidity environment in this work. The investigation had revealed that (a) exposing the sealed DCG holograms to high relative humidity (RH=98%) environment or immersing them in room-temperature water for 20 hours can not affect the holograms; (b) the sealed DCG holograms can be used at temperature below 50C without showing undue detrimental effects regarding their optical properties; (c) the peak wavelength of sealed DCG holograms can cause blue shift of several nanometers at 70C~85C and the velocity of blue shift is proportional to the environmental temperature; (d) the holograms can be destroyed at 100 or above. The experimental results above will be analyzed and discussed in this paper. A method to improve the stability of sealed DCG holograms is proposed: baking the sealed DCG holograms at proper temperature (e.g., 85C in this study).

  8. Antioxidant activities of orange peel extract in ghee (butter oil) stored at different storage temperatures.

    PubMed

    Asha, A; Manjunatha, M; Rekha, R M; Surendranath, B; Heartwin, P; Rao, J; Magdaline, E; Sinha, Chitranayak

    2015-12-01

    Antioxidant activities of butylatedhydroxyanisole (BHA) and orange peel powder extract in ghee stored at different storage temperatures (T1:6 ± 2 °C; T2: 32 ± 2 °C; T3:60 ± 2 °C) were evaluated during storage period of 21 days. Peroxide value (PV), thiobarbituric acid (TBA), radical scavenging activity (RSA) and free fatty acids (FFA) of ghee samples were analyzed during the study. PV, TBA and FFA of ghee samples increased significantly while radical scavenging activity (RSA) of ghee samples decreased significantly at accelerated temperature (T3) as compared to the temperatures at T1 and T2. Effect of storage temperature on development of peroxides and TBA of ghee samples was significantly higher than the effect of treatment and storage period while treatment had more significant effect on the change in FFA and RSA as compared to storage temperature and storage period. Ghee incorporated with orange peel extract (OPE) showed stronger activity in quenching DPPH radicals and least development of PV, TBA and FFA than ghee incorporated with BHA and control. The study revealed that orange peel could be a good natural source of antioxidants which can be used in fat rich food products like ghee to retard oxidative deterioration. PMID:26604397

  9. Different pressure-temperature behavior of the structured and unstructured regions of titin.

    PubMed

    Somkuti, Judit; Mrtonfalvi, Zsolt; Kellermayer, Mikls S Z; Smeller, Lszl

    2013-01-01

    Contrary to the classical view, according to which all proteins adopt a specific folded conformation necessary for their function, intrinsically unstructured proteins (IUPs) display random-coil-like conformation under physiological conditions. We compared the structured and unstructured domains from titin, a giant protein responsible for striated-muscle elasticity. A 171-residue-long fragment (polyE) of the disordered PEVK domain, and an Ig domain (I27) with ordered structure were investigated. FTIR (Fourier transform infrared) and fluorescence spectroscopy combined with a diamond anvil cell were used for investigation of the secondary structures under wide range of pressure and temperature. PolyE preserves its disordered characteristics across the entire range of investigated pressure (0-16kbar), temperature (0-100C), pD (3-10.5) and different solvent conditions. The detailed temperature-pressure phase diagram of titin I27 was determined. At 30C, increasing pressure unfolds titin I27 in one step at 10.5kbar. Increasing temperature at atmospheric pressure results in two transitions. At 50C the secondary structure is loosened and the protein transforms into a molten-globule state. At 65C the protein completely unfolds. Unfolding is followed by aggregation at ambient pressure. Moderate pressures (>2kbar), however, can prevent the protein from aggregation. Our experiments in wide range of physical parameters revealed four different structures for I27, while the unstructured character of the PEVK fragment is insensitive to these parameters. PMID:23063534

  10. Impact of pH and temperature on phase diagrams of different aqueous biphasic systems.

    PubMed

    Chakraborty, Arabinda; Sen, Kamalika

    2016-02-12

    The phase diagrams of aqueous biphasic systems impart a distinct idea regarding the feasibility of biphase formation by different water soluble substances at their optimum concentrations. Depending on nature of the components viz., the water soluble polymers, surfactants, salts, amino acids or ionic liquids, a general trend of the biphase formation with varying temperature, pH and concentration has been studied over the recent years. This critical review is an endeavor to assess the general trends of these phase forming components to form biphasic systems with varying conditions of temperature and pH in light of the reported phase diagrams. Suitable explanations for the mechanisms of such behavior have been sorted out. The avenue yet to be explored has been addressed as these systems have a tremendous potential to be the future platform to solve different analytical issues. PMID:26795280

  11. Releasing H2 molecules with a partial pressure difference without the use of temperature

    NASA Astrophysics Data System (ADS)

    Lee, Hoonkyung; Huang, Bing; Duan, Wenhui; Ihm, Jisoon

    2010-08-01

    Using the pseudopotential density-functional method as well as equilibrium thermodynamic functions, we explore the process of releasing H2 molecules adsorbed on a transition-metal atom caused by the hydrogen-ammonia partial pressure difference. The H2 molecules bind to a transition-metal atom at H2 pressure- NH3 pressure-temperature 50atm-10-9atm-25C , and they are released at 3atm-10-6atm-25C . This process involves the same mechanism responsible for carbon monoxide poisoning of hemoglobin with the O2-CO partial pressure difference. We show that our findings can be applicable to an approach to induce hydrogen desorption on nanostructured hydrogen-storage materials without the need for increasing temperature.

  12. Influence of Light Intensity at Different Temperatures on Rate of Respiration of Douglas-Fir Seedlings

    PubMed Central

    Brix, Holger

    1968-01-01

    The rate of photorespiration of Douglas-fir seedlings was measured under different light intensities by: (1) extrapolating the curve for CO2 uptake in relation to atmospheric CO2 content to zero CO2 content, and (2) measuring CO2 evolution of the plants into a CO2-free airstream. Different results, obtained from these techniques, were believed to be caused by a severe restriction of the photosynthetic activity when the latter was used. With the first method, CO2 evolution was lower than the dark respiration rate at low light intensity. For all temperatures studied (6, 20, 28) a further increase in light intensity raised the CO2 evolution above dark respiration before it leveled off. The rate of CO2 evolution was stimulated by increase in temperature at all light intensities. With the CO2-free air method, CO2 evolution in the light was less than dark respiration at all light intensities. PMID:16656775

  13. A dual-temperature-difference approach to estimate daytime sensible and latent heat fluxes under advective conditions during BEAREX08

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Dual-Temperature-Difference (DTD) approach uses continuous radiometric surface temperature measurements in a two-source (soil + vegetation) energy balance model to solve for the daytime evolution of the sensible and latent heat fluxes. By using the surface-air temperature difference at two time...

  14. Apparatus for measurement of thermal conductivity of insulation systems subjected to extreme temperature differences

    NASA Technical Reports Server (NTRS)

    Dube, W. P.; Sparks, L. L.; Slifka, A. J.; Bitsy, R. M.

    1990-01-01

    Advanced aerospace designs require thermal insulation systems which are consistent with cryogenic fluids, high thermal loads, and design restrictions such as weight and volume. To evaluate the thermal performance of these insulating systems, an apparatus capable of measuring thermal conductivity using extreme temperature differences (27 to 1100 K) is being developed. This system is described along with estimates of precision and accuracy in selected operating conditions. Preliminary data are presented.

  15. Influence of temperature difference calculation method on the evaluation of Rankine cycle performance

    NASA Astrophysics Data System (ADS)

    Morisaki, Takafumi.; Ikegami, Yasuyuki.

    2014-02-01

    In the new century, energy and environmental problems are becoming more critical, and the development of natural energy is desired. Low-grade Thermal Energy Conversion (LTEC) is refocused as one of the renewable energy methods. The usefulness of LTEC is expected using hot springs and waste heat. In the case of the Rankine cycle using ammonia as the working fluid, the thermal properties of the working fluid changes in the evaporator. The traditional evaluation method of heat exchanger performance is the LMTD (Logarithmic Mean Temperature Difference) method. On the other hand, the GMTD (Generalized Mean Temperature Difference) method allows the variation of thermal properties in the heat exchanger. The aim of this study is to compare the two methods for the calculation of temperature differences and the corresponding influence on the total performance of the Rankine cycle that is operated using ammonia as a working fluid. As a result, the thermal efficiency of the Rankine cycle is greater than that of the LMTD method. Moreover, the computable range of the GMTD calculation method is less than that of the LMTD calculation method.

  16. Avoiding hypothermia in neonatal pigs: effect of duration of floor heating at different room temperatures.

    PubMed

    Pedersen, L J; Malmkvist, J; Kammersgaard, T; Jørgensen, E

    2013-01-01

    The effect of different farrowing room temperatures (15, 20, or 25°C), combined with floor heating (FH) at the birth site, on the postnatal rectal temperature of pigs, use of creep area, and latency to first colostrum uptake was investigated with 61 litters born by loose-housed sows. Pig rectal temperature was measured at birth, as well as at 0.25, 0.5, 1, 1.5, 2, 3, 4, 12, 24, and 48 h after birth. The drop in rectal temperature from birth to 0.5 h postpartum was less (P<0.05) at room temperature of 25°C compared with 20 and 15°C. Minimum rectal temperature was less (P<0.001) at 15°C than either 20 or 25°C, and the time it took for rectal temperature to increase above 37°C was longer (P<0.05) when room temperature was 15°C than 20 and 25°C. Rectal temperatures at 24 (P<0.001) and 48 h (P<0.05) postpartum were also lower at room temperature of 15°C than 20 and 25°C. Duration of FH (12 or 48 h) did not influence (P>0.28) the rectal temperature at 24 or 48 h after birth. More pigs used the creep area 12 to 60 h after birth of the first pig at a room temperature of 15°C with 12 h FH compared with all other treatments. During the latter part of this period, more pigs stayed in the creep area also at 20°C with 12 h FH. After 60 h, more pigs (P<0.01) used the creep area at low compared with high room temperatures (15°C>20°C>25°C). Odds ratio of pigs dying before they had suckled was 6.8 times greater (P=0.03) at 15 than 25°C (95% CI of 1.3 to 35.5), whereas the odds ratio of dying during the first 7 d was 1.6 greater (P=0.05) for 48 vs. 12 h of FH (95% CI of 1.0 to 2.57), mainly due to more pigs being crushed. In conclusion, FH for 48 h was no more favorable than 12 h for pigs because the risk of hypothermia was equal in the 2 treatments, and the risk of dying increased with the longer FH duration. Increasing the room temperature to 25°C reduced hypothermia and the risk of pigs dying before colostrum intake. PMID:23100591

  17. Effect of Different Cooling Regimes on the Mechanical Properties of Cementitious Composites Subjected to High Temperatures

    PubMed Central

    Yu, Jiangtao; Weng, Wenfang; Yu, Kequan

    2014-01-01

    The influence of different cooling regimes (quenching in water and cooling in air) on the residual mechanical properties of engineered cementitious composite (ECC) subjected to high temperature up to 800°C was discussed in this paper. The ECC specimens are exposed to 100, 200, 400, 600, and 800°C with the unheated specimens for reference. Different cooling regimens had a significant influence on the mechanical properties of postfire ECC specimens. The microstructural characterization was examined before and after exposure to fire deterioration by using scanning electron microscopy (SEM). Results from the microtest well explained the mechanical properties variation of postfire specimens. PMID:25161392

  18. Temperature dependence of far-infrared difference reflectivity of YBa2Cu3O7-y

    NASA Astrophysics Data System (ADS)

    Krenn, H.; Bauer, G.; Vogl, G.; Strasser, G.; Gornik, E.

    1989-04-01

    Far-infrared difference reflectivity spectra (50-450 cm-1) below, across and above the transition temperature on polycrystalline single-phase YBa2Cu3O7-y samples were measured. The data are compared with model fits using the explicit temperature dependence of the Mattis-Bardeen conductivity, an effective-medium approach and temperature-dependent phonon oscillator parameters and alternatively a plasma model. For the plasma model we alternatively use a generalized Drude-like expression with a frequency-dependent damping after Thomas et al. [Phys. Rev. B 36, 846 (1987)] or the original model with Orenstein et al. [Phys. Rev. B 36, 729 (1987)] and Sherwin, Richards, and Zettl [Phys. Rev. B 37, 1587 (1988)] with a Drude contribution plus a mid-infrared oscillator, but with constant carrier relaxation rates. The models explain the difference reflectivity data (precision <0.2%) with a fitting accuracy of 1-2 % (Mattis-Bardeen model) or 2-3 % (plasma model) over the full temperature range. In order to investigate their applicability, reflectivity, and conductivity data of a highly oriented YBa2Cu3O7-y sample, as recently published by Bonn et al. [Phys. Rev. Lett. 58, 2249 (1987)], were also fitted with both models. Because of the frequency dependence of the free-carrier damping rates, it was important to fulfill the Kramers-Kronig relations between the real and the imaginary part of the dynamic conductivity in the calculations. For both models the characteristic dependences of the conductivity on frequency and temperature are given. Whereas, naturally, the Mattis-Bardeen model yields a gaplike depression of the conductivity for frequencies below an assumed gap, the plasma model results in somewhat smoother dependences of Re(σ(ω)) and Im(σ(ω)) in the frequency region of interest.

  19. Equivalence of elemental carbon by thermal/optical reflectance and transmittance with different temperature protocols.

    PubMed

    Chow, Judith C; Watson, John G; Chen, L W Antony; Arnott, W Patrick; Moosmller, Hans; Fung, Kochy

    2004-08-15

    Charring of organic carbon (OC) during thermal/optical analysis is monitored by the change in a laser signal either reflected from or transmitted through a filter punch. Elemental carbon (EC) in suspended particulate matter collected on quartz-fiber filters is defined as the carbon that evolves after the detected optical signal attains the value it had prior to commencement of heating, with the rest of the carbon classified as organic carbon (OC). Heretofore, operational definitions of EC were believed to be caused by different temperature protocols rather than by the method of monitoring charring. This work demonstrates that thermal/ optical reflectance (TOR) corrections yield equivalent OC/ EC splits for widely divergent temperature protocols. EC results determined by simultaneous thermal/optical transmittance (TOT) corrections are 30% lower than TOR for the same temperature protocol and 70-80% lower than TOR for a protocol with higher heating temperatures and shorter residence times. This is true for 58 urban samples from Fresno, CA, as well as for 30 samples from the nonurban IMPROVE network that are individually dominated by wildfire, vehicle exhaust, secondary organic aerosol, and calcium carbonate contributions. Visual examination of filter darkening at different temperature stages shows that substantial charring takes place within the filter, possibly due to adsorbed organic gases or diffusion of vaporized particles. The filter transmittance is more influenced by the within-filter char, whereas the filter reflectance is dominated by charring of the near-surface deposit that appears to evolve first when oxygen is added to helium in the analysis atmosphere for these samples. The amounts of charred OC (POC) and EC are also estimated from incremental absorbance. Small amounts of POC are found to dominate the incremental absorbance. EC estimated from absorbance are found to agree better with EC from the reflectance charring correction than with EC from the transmittance charring correction. PMID:15382872

  20. Anaerobic biodegradation of 2,4-dichlorophenol in freshwater lake sediments at different temperatures

    SciTech Connect

    Kohring, G.W.; Rogers, J.E.; Wiegel, J.

    1989-02-01

    Anaerobic degradation of 2,4-dichlorophenol (2,4-DCP) between 5 and 72 degrees C was investigated. Anaerobic sediment slurries prepared from local freshwater pond sediments were partitioned into anaerobic tubes or serum vials, which then were incubated separately at the various temperatures. Reductive 2,4-DCP dechlorination occurred only in the temperature range between 5 and 50/degree/C, although methane was formed up to 60 degrees C. In sediment samples from two sites and at all tested temperatures from 5 to 50 degrees C, 2,4-DCP was transformed to 4-chlorophenol (4-CP). The 4-CP intermediate was subsequently degraded after an extended lag period in the temperature range from 15 to 40/degree/C. Adaptation periods for 2,4-DCP transformation decreased between 5 and 25/degree/C, were essentially constant between 25 and 35/degree/C, and increased in the tubes incubated at temperatures between 35 and 40/degree/C. The degradation rates increased exponentially between 15 and 30/degree/C, had a second peak at 35/degree/C, and decreased to about 5% of the peak activity by 40/degree/C. In tubes from one sediment sample, incubated at temperatures above 40/degree/C, an increase in the degradation rate was observed following the minimum at 40/degree/C. This suggests that at least two different organisms were involved in the transformation of 2,4-DCP to 4-CP. Storage of the original sediment slurries for 2 months at 12/degree/C resulted in increased adaptation times, but did not affect the degradation rates.

  1. Temperature Rise Within the Pulp Chamber During Composite Resin Polymerisation Using Three Different Light Sources

    PubMed Central

    Santini, A; Watterson, C; Miletic, V

    2008-01-01

    The purpose of the study was to compare temperature rise during polymerisation of resin based composites (RBCs) with two LED light curing units (LCUs) compared to a halogen control light. Methods: Forty-five extracted molars, patients aging 11-18 years were used. Thermocouples (TCs) were placed in contact with the roof of the pulp chamber using a split-tooth method. Teeth were placed in a water bath with the temperature of the pulp chamber regulated at 371C. Group 1 (control): Prismatics Lite II (Dentsply Detrey, Konstanz, Germany), a halogen LCU, light intensity 500 mW/cm2. Group 2: Bluephase ( Ivoclar Vivadent, Schaan, Liechtenstein), light intensity 1100 mW/cm2. Group 3:Elipar Freelight2 (3M ESPE, Seefeld, Germany), light intensity 1000 mW/cm2. Temperature changes were continuously recorded with a data logger connected to a PC. Results: Significantly higher temperature rise was recorded during bond curing than RBC curing in all 3 groups. (Halogen; p =0.0003: Bluephase; p=0.0043: Elipar; p=0.0002.). Higher temperatures were recorded during polymerisation of both Bond and RBC with both LED sources than with the halogen control. There was no significant difference between the two LED,LCUs (Bond:p=0.0279: RBC p=0.0562: Mann-Whitney). Conclusion: The potential risk of pulpal injury during RBC polymerisation is increased when using light-curing units with high energy output compared to low energy output light sources. The rise is greatest when curing bonding agent alone and clinicians are advised to be aware of the potential hazard of thermal trauma to the pulp when using high intensity light sources. However the mean temperature rise with all three units was below the limits normally associated with permanent pulp damage. PMID:19444316

  2. Microbiological impact of spray washing broiler carcasses using different chlorine concentrations and water temperatures.

    PubMed

    Northcutt, J K; Smith, D P; Musgrove, M T; Ingram, K D; Hinton, A

    2005-10-01

    A study was conducted to investigate the microbiological impact of spray washing broiler carcasses with chlorinated water (0 or 50 ppm) at different temperatures (21.1, 43.3, or 54.4 degrees C). A whole carcass rinse (WCR) was performed on each carcass before (control) and after spray washing (final). After the control WCR, carcasses were inoculated with 0.1 g of cecal material containing 2 x 10(5) cells per gram of Campylobacter and 2 x 10(5) cells per gram of nalidixic acid-resistant Salmonella. Carcasses were held at room temperature for 12 min before washing in an inside-outside bird washer (80 psi for 5 s). Chlorine level and water temperature had no effect on total aerobic bacteria, Escherichia coli, or Campylobacter numbers recovered from the final WCR. Levels of bacteria found on carcasses before and after washing were 4.6, 3.6, and 3.5 log10 cfu/mL rinse for total aerobic bacteria, E. coli, and Campylobacter, respectively. Average counts for nalidixic acid-resistant Salmonella after washing were 3.1 log10 cfu/ mL rinse irrespective of water temperature or chlorine level (P < 0.05). In addition, chlorine level and water temperature had no effect on the breast skin color, with average values of L* = 66.6; a* = -0.09; b* = -0.05 (P < 0.05). Under the conditions outlined in the present study, adding chlorine and/or elevating the water temperature during spray washing in an inside-outside bird washer did not enhance the removal of bacteria from broiler carcasses and had no effect on carcass skin color. PMID:16335135

  3. Thermal Band Characterization of LANDSAT-4 Thematic Mapper. [Buffalo, New York and water temperature in Lake Erie

    NASA Technical Reports Server (NTRS)

    Lansing, J. C.; Barker, J. L.

    1984-01-01

    A quick look monitor in the spacecraft control center was used to measure the TM Band 6 shutter background and the 34.7 C internal blackbody signal on over 50 dates. Comparison of relative internal gains between the four channels to prelaunch values showed changes over 9 months of up to 5%, while 512 x 512 subsections of the original 10 daytime scenes showed scene counts that ranged from 135 down to 62. A night scene of the Buffalo area was used to determine channel gain relative to the mean and to discern a systematic along scan pattern in a difference between forward and reverse scan counts of up to 0.5. A corrected digital image was produced and individual gains and offsets were calculated for the four channels. At satellite radiance was determine and noise equivalent temperature difference was calculated. The calibration data and the Buffalo scene, with the corrections and estimates of the atmospheric transmission and radiance, were used to make a temperature estimate for an area of Lake Erie of 21 C to 27 C. Local records of the temperature showed 21 C.

  4. Non-equilibrium melting processes of silicate melts with different silica content at low-temperature plasma

    NASA Astrophysics Data System (ADS)

    Vlasov, V.; Volokitin, G.; Skripnikova, N.; Volokitin, O.; Shekhovtsov, V.; Pfuch, A.

    2015-11-01

    This article is devoted to research the possibility of high-temperature silicate melts producing from different silica content at low-temperature plasma taking into account nonequilibrium melting processes.

  5. Aqueous leaching of organic acids and dissolved organic carbon from various biochars prepared at different temperatures.

    PubMed

    Liu, Peng; Ptacek, Carol J; Blowes, David W; Berti, William R; Landis, Richard C

    2015-03-01

    Biochar has been used as a soil amendment, as a water treatment material, and for carbon (C) sequestration. Thirty-six biochars, produced from wood, agricultural residue, and manure feedstocks at different temperatures, were evaluated for the aqueous leaching of different forms of soluble C. The release of inorganic C (alkalinity), organic acids (OAs), and total dissolved organic C (DOC) was highly variable and dependent on the feedstock and pyrolysis temperature. The pH and alkalinity increased for the majority of samples. Higher pH values were associated with high-temperature (high-T) (600 and 700C) biochars. Statistically significant differences in alkalinity were not observed between low-temperature (low-T) (300C) and high-T biochars, whereas alkalinity released from wood-based biochar was significantly lower than from others. Concentrations of OAs and DOC released from low-T biochars were greater than from high-T biochars. The C in the OAs represented 1 to 60% of the total DOC released, indicating the presence of other DOC forms. The C released as DOC represented up to 3% (majority <0.1%) of the total C in the biochar. Scanning electron microscopy with energy dispersive X-ray spectroscopy showed the high-T biochars had a greater proportion of micropores. Fourier transform infrared spectroscopy showed that hydroxyl, aliphatic, and quinone were the predominant functional groups of all biochars and that the abundance of other functional groups was dependent on the feedstock. The release of DOC, especially bioavailable forms such as OAs, may promote growth of organisms and heavy metal complexation and diminish the potential effectiveness of various biochars for C sequestration. PMID:26023986

  6. A comparison of temperature and precipitation responses to different Earth radiation management geoengineering schemes

    NASA Astrophysics Data System (ADS)

    Crook, J. A.; Jackson, L. S.; Osprey, S. M.; Forster, P. M.

    2015-09-01

    Earth radiation management has been suggested as a way to rapidly counteract global warming in the face of a lack of mitigation efforts, buying time and avoiding potentially catastrophic warming. We compare six different radiation management schemes that use surface, troposphere, and stratosphere interventions in a single climate model in which we projected future climate from 2020 to 2099 based on RCP4.5. We analyze the surface air temperature responses to determine how effective the schemes are at returning temperature to its 1986-2005 climatology and analyze precipitation responses to compare side effects. We find crop albedo enhancement is largely ineffective at returning temperature to its 1986-2005 climatology. Desert albedo enhancement causes excessive cooling in the deserts and severe shifts in tropical precipitation. Ocean albedo enhancement, sea-spray geoengineering, cirrus cloud thinning, and stratospheric SO2 injection have the potential to cool more uniformly, but cirrus cloud thinning may not be able to cool by much more than 1 K globally. We find that of the schemes potentially able to return surface air temperature to 1986-2005 climatology under future greenhouse gas warming, none has significantly less severe precipitation side effects than other schemes. Despite different forcing patterns, ocean albedo enhancement, sea-spray geoengineering, cirrus cloud thinning, and stratospheric SO2 injection all result in large scale tropical precipitation responses caused by Hadley cell changes and land precipitation changes largely driven by thermodynamic changes. Widespread regional scale changes in precipitation over land are significantly different from the 1986-2005 climatology and would likely necessitate significant adaptation despite geoengineering.

  7. Comparison of different methods of estimating the mean radiant temperature in outdoor thermal comfort studies

    NASA Astrophysics Data System (ADS)

    Krger, E. L.; Minella, F. O.; Matzarakis, A.

    2014-10-01

    Correlations between outdoor thermal indices and the calculated or measured mean radiant temperature Tmrt are in general of high importance because of the combined effect on human energy balance in outdoor spaces. The most accurate way to determine Tmrt is by means of integral radiation measurements, i.e. measuring the short- and long-wave radiation from six directions using pyranometers and pyrgeometers, an expensive and not always an easily available procedure. Some studies use globe thermometers combined with air temperature and wind speed sensors. An alternative way to determine Tmrt is based on output from the RayMan model from measured data of incoming global radiation and morphological features of the monitoring site in particular sky view factor (SVF) data. The purpose of this paper is to compare different methods to assess the mean radiant temperature Tmrt in terms of differences to a reference condition (Tmrt calculated from field measurements) and to resulting outdoor comfort levels expressed as PET and UTCI values. The Tmrt obtained from field measurements is a combination of air temperature, wind speed and globe temperature data according to the forced ventilation formula of ISO 7726 for data collected in Glasgow, UK. Four different methods were used in the RayMan model for Tmrt calculations: input data consisting exclusively of data measured at urban sites; urban data excluding solar radiation, estimated SVF data and solar radiation data measured at a rural site; urban data excluding solar radiation with SVF data for each site; urban data excluding solar radiation and including solar radiation at the rural site taking no account of SVF information. Results show that all methods overestimate Tmrt when compared to ISO calculations. Correlations were found to be significant for the first method and lower for the other three. Results in terms of comfort (PET, UTCI) suggest that reasonable estimates could be made based on global radiation data measured at the urban site or as a surrogate of missing SR data or globe temperature data recorded at the urban area on global radiation data measured at a rural location.

  8. Comparison of different methods of estimating the mean radiant temperature in outdoor thermal comfort studies.

    PubMed

    Krüger, E L; Minella, F O; Matzarakis, A

    2014-10-01

    Correlations between outdoor thermal indices and the calculated or measured mean radiant temperature T(mrt) are in general of high importance because of the combined effect on human energy balance in outdoor spaces. The most accurate way to determine T(mrt) is by means of integral radiation measurements, i.e. measuring the short- and long-wave radiation from six directions using pyranometers and pyrgeometers, an expensive and not always an easily available procedure. Some studies use globe thermometers combined with air temperature and wind speed sensors. An alternative way to determine T(mrt) is based on output from the RayMan model from measured data of incoming global radiation and morphological features of the monitoring site in particular sky view factor (SVF) data. The purpose of this paper is to compare different methods to assess the mean radiant temperature T(mrt) in terms of differences to a reference condition (T(mrt) calculated from field measurements) and to resulting outdoor comfort levels expressed as PET and UTCI values. The T(mrt) obtained from field measurements is a combination of air temperature, wind speed and globe temperature data according to the forced ventilation formula of ISO 7726 for data collected in Glasgow, UK. Four different methods were used in the RayMan model for T(mrt) calculations: input data consisting exclusively of data measured at urban sites; urban data excluding solar radiation, estimated SVF data and solar radiation data measured at a rural site; urban data excluding solar radiation with SVF data for each site; urban data excluding solar radiation and including solar radiation at the rural site taking no account of SVF information. Results show that all methods overestimate T(mrt) when compared to ISO calculations. Correlations were found to be significant for the first method and lower for the other three. Results in terms of comfort (PET, UTCI) suggest that reasonable estimates could be made based on global radiation data measured at the urban site or as a surrogate of missing SR data or globe temperature data recorded at the urban area on global radiation data measured at a rural location. PMID:24375056

  9. Interface interaction of Co atop Bepp2 with different substrate temperatures

    NASA Astrophysics Data System (ADS)

    Li, Dong; Guo, Xiaobin; Wu, Kai; Cui, Baoshan; Zuo, Yalu; Wang, Jianbo; Xi, Li

    2015-12-01

    The interaction at organic-ferromagnetic interfaces in organic spin-valves has a considerable effect on efficient spin injection or detection. In this work, Al/Co films were deposited on the organic Bepp2 layers at two different substrate temperatures to investigate the interface interaction. The interaction including penetration, interdiffusion and chemical reaction has been studied by the surface morphology measurement, X-ray photoelectron spectroscopy combined with Argon ion etching technique and magnetic properties measurement. It was found that the interfacial penetration and chemical reaction were serious, forming plenty of holes and non-ferromagnetic metallic carbide and oxides owing to the high energy of sputtered Co atoms into the organic Bepp2 layer when depositing Co on Bepp2 layer at the substrate temperature of 24 C. However, this phenomenon weakened when lowering the temperature to -13 C. Our results show that the low substrate temperature can reduce the penetration of the top metal electrode into the organic layer and weaken the chemical reaction between the top electrode and organic layer, which could pave a way for obtaining high-spin injection and extraction efficiency in organic spin-valve devices.

  10. Avian influenza virus H9N2 survival at different temperatures and pHs.

    PubMed

    Davidson, I; Nagar, S; Haddas, R; Ben-Shabat, M; Golender, N; Lapin, E; Altory, A; Simanov, L; Ribshtein, I; Panshin, A; Perk, S

    2010-03-01

    The H9N2 avian influenza virus (AIV) subtype has become endemic in Israel since its introduction in 2000. The disease has been economically damaging to the commercial poultry industry, in part because of the synergistic pathology of coinfection with other viral and/or bacterial pathogens. Avian influenza virus viability in the environment depends on the cumulative effects of chemical and physical factors, such as humidity, temperature, pH, salinity, and organic compounds, as well as differences in the virus itself. We sought to analyze the viability of AIV H9N2 strains at three temperatures (37, 20, and 4 C) and at 2 pHs (5.0 and 7.0). Our findings indicated that at 37 C AIV H9N2 isolate 1525 (subgroup IV) survived for a period of time 18 times shorter at 20 C, and 70 times shorter period at 4 C, as measured by a decrease in titer. In addition, the virus was sensitive to a lower pH (pH 5.0) with no detectable virus after 1 wk incubation at 20 C as compared to virus at pH 7.0, which was viable for at least 3 wk at that temperature. The temperature sensitivity of the virus corresponds to the occurrence of H9N2 outbreaks during the winter, and lower pH can greatly affect the viability of the virus. PMID:20521722

  11. [The use of Charcot's douche with different temperature regimes in the training process of the athletes].

    PubMed

    Iakimenko, S N; Polustruev, A V; Turmanidze, V G; Khodasevich, L S; Poliakova, A V

    2012-01-01

    Thirty six male athletes at the age from 17 to 25 years (masters and candidate masters of sports) were divided into two groups as follows: group 1 (fencing, n=20) and group 2 (badminton, n=16). The athletes used Charcot's douche with a water temperature either 20 degrees C or 38-40 degrees C after each evening training session. Their functional conditions were estimated based on the results of the measurements of the muscular tone and tensodynamometry. The data obtained were supplemented by the assessment of the subjective state of the athletes and pedagogical testing. It was shown that the hydroprocedures using water with a temperature of 20 degrees C produced tonic effect while the application of water with a temperature of 38-40 degrees C had a relaxing action. Taken together, the results of the study indicate that Charcot's douche with different temperature regimes can be recommended as a tool for controlling the adaptive mechanisms in the athletes, enhancing their functional abilities, and improving the efficacy of the training process. PMID:22908471

  12. Sensitivity to chilling temperatures and distribution differ in the mangrove species Kandelia candel and Avicennia marina.

    PubMed

    Kao, Wen-Yuan; Shih, Chen-Ning; Tsai, Tyng-Tyng

    2004-07-01

    We compared the effects of short-term (hours) and long-term (days) exposure to chilling temperatures on the photosynthetic gas exchange, leaf characteristics and chlorophyll a fluorescence of seedlings of the mangrove species Kandelia candel Druce and Avicennia marina (Forsk.) Vierh. Both species occur along the west coast of Taiwan, but K. candel occurs further north than A. marina. We hypothesized that temperature was one of the major environmental factors limiting the northern distribution of A. marina. Avicennia marina was more sensitive to chilling temperatures than K. candel. Leaves of both species showed reductions in light-saturated photosynthetic rates (Amax), stomatal conductance (gs) and quantum yield of photosystem II after a 1-h exposure to 15 degrees C, with A. marina showing significantly greater reductions in Amax and gs than K. candel. No significant differences in Amax, gs and electron transport rate (ETR) were found between leaves of K. candel grown at 15 and 30 degrees C for 10 days. However, leaves of A. marina grown for 10 days at 15 degrees C had significantly lower Amax, gs and ETR than plants grown at 30 degrees C. After 20 days at 15 degrees C, leaf mass per area of both species was increased significantly, whereas area-based chlorophyll concentrations were reduced, with significantly greater changes in A. marina than in K. candel. We concluded that sensitivity to low winter temperatures is a primary limiting factor in the distribution of A. marina along the western coast of Taiwan. PMID:15123458

  13. Chemotactic behavior of Campylobacter spp. in function of different temperatures (37C and 42C).

    PubMed

    Baserisalehi, Majid; Bahador, Nima

    2011-12-01

    The chemotactic behaviour of Campylobacter strains was determined in the presence of different amino acids at two temperatures (37 C and 42 C). Two strains of catalase positive (Campylobacter jejuni) and negative (Campylobacter sputurum) Campylobacter were isolated from river water in Tonekabon, Iran and identified by phenotyping and 16srRNA Gene sequencing methods. Chemotactic responses of the isolates were assessed toward a variety of amino acids viz., L-cystine, L-asparagine, L-histidine, L-aspartic acid, L-serine, L-phenylalanine, L-leucine and L-tryptophan by disc and capillary methods at two temperatures: 37 C and 42 C. C. jejuni showed positive chemotactic response towards L-cystine,L-tryptophan, L-phenylalanine, - L-leucine, L-asparagine and L-Serine at both, 37 C and 42 C however, it was greater at 37 C. C. sputurum showed negative or weak response towards all of the amino acids. In addition, C. jejuni illustrated strong chemotactic response to L-asparagine follow by L-serine and weak chemotaxis response to L-phenylalanine and L-cysteine at 37 C. Overall, C. jejuni showed relatively strong chemotactic response to some amino acids, likewise it was greater at 37 C. Hence, the human body temperature (37 C) in compared to avian body temperature (42 C) probably promotes chemotactic response of C. jejuni, which it might be a reason for causing disease in human being compared to avian. PMID:21757020

  14. An improved method for correction of air temperature measured using different radiation shields

    NASA Astrophysics Data System (ADS)

    Cheng, Xinghong; Su, Debin; Li, Deping; Chen, Lu; Xu, Wenjing; Yang, Meilin; Li, Yongcheng; Yue, Zhizhong; Wang, Zijing

    2014-11-01

    The variation of air temperature measurement errors using two different radiation shields (DTR502B Vaisala, Finland, and HYTFZ01, Huayun Tongda Satcom, China) was studied. Datasets were collected in the field at the Daxing weather station in Beijing from June 2011 to May 2012. Most air temperature values obtained with these two commonly used radiation shields were lower than the reference records obtained with the new Fiber Reinforced Polymers (FRP) Stevenson screen. In most cases, the air temperature errors when using the two devices were smaller on overcast and rainy days than on sunny days; and smaller when using the imported rather than the Chinese shield. The measured errors changed sharply at sunrise and sunset, and reached maxima at noon. Their diurnal variation characteristics were, naturally, related to changes in solar radiation. The relationships between the record errors, global radiation, and wind speed were nonlinear. An improved correction method was proposed based on the approach described by Nakamura and Mahrt (2005) (NM05), in which the impact of the solar zenith angle (SZA) on the temperature error is considered and extreme errors due to changes in SZA can be corrected effectively. Measurement errors were reduced significantly after correction by either method for both shields. The error reduction rate using the improved correction method for the Chinese and imported shields were 3.3% and 40.4% higher than those using the NM05 method, respectively.

  15. Effects of elevated temperatures on different restorative materials: An aid to forensic identification processes

    PubMed Central

    Pol, Chetan A.; Ghige, Suvarna K.; Gosavi, Suchitra R.; Hazarey, Vinay K.

    2015-01-01

    Background: Heat-induced alterations to dental and restorative materials can be of great interest to forensic dentistry. Knowing the specific optical behavior of dental materials can be of high importance as recognition of changes induced by high temperatures can lead to the determination of material which was used in a dental restoration, facilitating identification of burned human remains. Aim: To observe the effects of predetermined temperatures (200°C–400°C–600°C–800°C–1000°C) on unrestored teeth and different restorative materials macroscopically and then examine them under a stereomicroscope for the purpose of identification. Materials and Methods: The study was conducted on 375 extracted teeth which were divided into five groups of 75 teeth each as follows: group 1- unrestored teeth, group 2- teeth restored with all-ceramic crowns, Group 3- with class I silver amalgam filling, group 4- with class I composite restoration, and group 5- with class I glass ionomer cement restoration. Results: Unrestored and restored teeth display a series of specific macroscopic & stereomicroscopic structural changes for each range of temperature. Conclusion: Dental tissues and restorative materials undergo a series of changes which correlate well with the various temperatures to which they were exposed. These changes are a consequence of the nature of the materials and their physicochemical characteristics. PMID:26005305

  16. On the large deformation behaviour of reinforced rubber at different temperatures

    NASA Astrophysics Data System (ADS)

    Lion, Alexander

    1997-11-01

    This essay investigates the temperature dependence of the mechanical properties of a filler-loaded tread compound experimentally and proposes a physically based method to represent this behaviour in the framework of non-linear continuum thermomechanics. To this end, we realise a series of monotonic and cyclic strain controlled tests on cylindrical specimens in tension at different temperature levels. The experimental data show the isothermal mechanical behaviour to be mainly influenced by non-linear elasticity in combination with non-linear rate dependence and weak equilibrium hysteresis. We observe that the rate sensitivity of the material depends strongly on the temperature : at low temperature levels, the rate sensitivity is essentially higher than at high temperatures. The elastic properties of the material depend comparatively less on the temperature. Nevertheless, higher temperature levels lead to higher equilibrium stresses. In order to represent the material behaviour, we start with a multiplicative split of the deformation gradient into a mechanical and a thermal part as proposed by Lu and Pister (1975). Physically, this idea corresponds to a stress-free thermal expansion followed by an isothermal stress-producing deformation. We suppose the thermal part of the deformation gradient to be isotropic. As a consequence of this, the velocity gradient decomposes additively into a pure thermal and a pure mechanical part. By using these elements, we exploit the Clausius Duhem inequality and assume the so-called 'mechanical second Piola Kirchhoff stress tensor' to be a functional of the 'mechanical Green's strain tensor'. In a further step, we define this functional by a system of constitutive equations which are based on a rheological model. The evolution equations for the internal variables are formulated by using the concept of dual variables proposed by Haupt and Tsakmakis (1989, 1996). The rate sensitivity is modelled by a stress and temperature dependent viscosity function. The elastic part of the equilibrium stress is described by entropy elasticity in combination with a modified Mooney Rivlin strain energy function. The equilibrium hysteresis effects are represented by rate independent plasticity in arclength representation as proposed by Valanis (1971). The constitutive model is compatible with the dissipation principle of thermodynamics and describes the general trend of the experimental data fairly well.

  17. Tilted microlens fabrication method using two photoresists with different melting temperatures

    NASA Astrophysics Data System (ADS)

    Hung, Shih-Yu; Chang, Tung-Yu; Shen, Ming-Ho; Yang, Hsiharng

    2014-02-01

    A new fabrication method for a tilted microlens array for light control films was developed to increase the efficiency of a liquid crystal display so that lateral light sources are collected and the dazzling light problem at certain viewing angles is improved. The thermal reflow with two layers of different photoresists is used to fabricate the tilted microlens array in this study. After the lithography process, the round photoresist column with two layers of different photoresists can be obtained. During the thermal reflow processing, the upper photoresist layer (AZ-4620) reaches the glass transition temperature, which is transformed from a glassy state into a rubbery state. Since the glass transition temperature of the lower photoresist layer (AZ-5214E) is higher than the temperature of thermal reflow, the lower photoresist layer is still able to maintain its solid state. The lower layer creates a round base during the thermal reflow process. The experimental results show that the photoresist mold of tilted microlens may be produced under gravity by inverting and tilting the substrate during the thermal reflow process. After the wafer is placed inversely and obliquely, the base can not only restrict the bottom shape of the liquid photoresist to a round shape but also prevent the sliding of liquid photoresist during the thermal reflow process. Compared with the conventional thermal reflow without a base, the photoresist base is relatively reliable and effective in preventing lenses from sliding.

  18. Effects of long-term storage at different temperatures on conidia of Botrytis cinerea Pers.: Fr.

    PubMed

    Gindro, K; Pezet, R

    2001-10-16

    Survival of Botrytis cinerea conidia was studied after storage without pretreatments at different temperatures (-80 degrees C, -20 degrees C, 4 degrees C and 21 degrees C). Germination tests performed during 3 years showed that viability at 21 degrees C was completely lost after 1 month. Conidia stored for 30 months at -80 degrees C, -20 degrees C and 4 degrees C were able to germinate, respectively, at 79%, 8% and 0.2%. Changes in adenylate level, energy charge and respiration (O(2) consumption) made on each set of conidia were correlated to the germination rate. The 30-month-old stored conidia showed differences in pathogenicity tests on apples. While the pathogenic aggressiveness of conidia stored at -80 degrees C was almost the same as for fresh conidia, it decreased with increasing temperature of storage. An ultrastructural study made on conidia stored for 30 months at -80 degrees C has shown the emergence of a new wall layer in a retraction zone of the cytoplasm by comparison to fresh conidia. However, the integrity of the cytoplasmic content was maintained. The effects of low temperature storage, maintenance of cell integrity and pathogenicity of conidia of B. cinerea are discussed. PMID:11682186

  19. Antigenicity and viability of Anisakis larvae infesting hake heated at different time-temperature conditions.

    PubMed

    Vidacek, Sanja; de las Heras, Cristina; Solas, Maria Teresa; Mendizábal, Angel; Rodriguez-Mahillo, Ana I; Tejada, Margarita

    2010-01-01

    Heat treatments (40 to 94 degrees Celsius, 30 s to 60 min) were applied to different batches of Anisakis simplex L3 larvae isolated from hake ovaries and viscera to study the effect of heat on the viability of the larvae measured as mobility, emission of fluorescence under UV light, and changes in color after staining with specific dyes, and on A. simplex antigenic proteins. The aim was to determine the lowest time-temperature conditions needed to kill the larvae to avoid anisakiasis in consumers, and to evaluate whether high temperature modifies the antigenicity of A. simplex extracts. Heating at 60 degrees Celsius for 10 min (recommended by some authors) was considered unsafe, as differences in viability between batches were found, with some larvae presenting spontaneous movements in one batch. At higher temperatures (> or = 70 degrees Celsius for > or = 1 min), no movement of the larvae was observed. Antigenic protein Ani s 4 and A. simplex crude antigens were detected in the larvae heated at 94 + or - 1 degrees Celsius for 3 min. This indicates that allergic symptoms could be provoked in previously sensitized consumers, even if the larvae were killed by heat treatment. PMID:20051205

  20. Cavitation performance simulation of turbine meter under different temperature water condition

    NASA Astrophysics Data System (ADS)

    Huang, Y. Z.; Zhang, B. S.; Chen, G.; Zhu, B. L.

    2015-01-01

    A cavitation thermodynamics model based on phase change, which is suitable for prediction of cavitation with thermal effects is developed. The cavitation characteristic at different temperature and cavitation number is investigated and analyzed. The initial cavitation of turbine flow meter generally occurs in the blade suction side. With the development of cavitation, the cavitation zone will appear on the front and the back end of the conditioner. In order to avoid the gather of cavitation, the design of the optimizing the blade structure should be adapted, and at the same time, the back pressure should be limited on the installation requirements. Expanding the measurement range and preventing cavitation occurs are the goal of the design and installation. The temperature effects on the cavitation of turbine flow meter is quite obvious and the increase of the temperature will delay the occurrence of cavitation. Pressure difference and the impeller torque will change obviously with the decrease of the cavitation number, which will cause the measurement error of the turbine meter.

  1. Monoethanol amine modified zeolite 13X for CO{sub 2} adsorption at different temperatures

    SciTech Connect

    P.D. Jadhav; R.V. Chatti; R.B. Biniwale; N.K. Labhsetwar; S. Devotta; S.S. Rayalu . s_rayalu@neeri.res.in

    2007-12-15

    Zeolite 13X has been modified with monoethanol amine (MEA). MEA loadings of 0.5-25 wt % have been achieved using the impregnation method in different solvents. The mode of incorporation based on methanol with stirring at room temperature appears to be the most feasible. The adsorbent has been characterized for crystallinity, surface area, pore volume, and pore size. The thermal stability of the adsorbent is studied using a thermal analyzer. The CO{sub 2} adsorption capacity of adsorbents is evaluated using the breakthrough adsorption method with a packed column on a 10 g scale. The adsorption capacities of adsorbents are estimated in the temperature range 30-120{sup o}C. The adsorbents show improvement in CO{sub 2} adsorption capacity over the unmodified zeolite by a factor of ca. 1.6 at 30{sup o}C, whereas at 120{sup o}C the efficiency improved by a factor of 3.5. For adsorption at these temperatures, different MEA loading levels were found to be suitable as per the governing adsorption phenomena, that is, physical or chemical. The adsorbent is also studied for CO{sub 2} selectivity over N{sub 2} at 75{sup o}C. The MEA-modified adsorbent shows better CO{sub 2} selectivity, which was improved further in the presence of moisture. 25 refs., 6 figs., 3t abs.

  2. Changes in the Mean Meridional Circulation associated with different condition in the global surface temperature

    NASA Astrophysics Data System (ADS)

    D'Agostino, Roberta; Lionello, Piero

    2014-05-01

    This study focuses on the behavior of the Mean Meridional Circulation (MMC) and its relationship with the precipitation distribution under different conditions of mean surface temperatures at global scale. Modifications in the MMC and in particular in the Hadley and Ferrel Cells, have important implications for subtropical and mid-latitude societies because may lead to profound changes in regional climate. There are still many open questions on the strengthening/weakening and widening/narrowing of the Hadley Cells in occurrence of Global Warming scenarios. Therefore this work aims at highlighting the differences in the MMC according to changes in global surface temperature. Analysis of the differences in the MMC between coldest and warmest years of the 20th - 21th Century is presented using an ensemble of 10 climate model runs of the ERA-20CM Experiment on monthly time scale with 1.5x1.5 horizontal resolution. The meridional mass stream function is computed to study variation in the MMC. It gives some useful information about strength, width and poleward extent of the Hadley and Ferrel Cells, in order to understand how the MMC responds to different conditions in the mean surface temperature field. The relationship between the meridional mass stream function and the monthly total (convective and stratiform) precipitation zonal mean is also investigated in order to find out how the strengthening and weakening of the Hadley and Ferrel cells control the amount of the rainfall in the MMC. During warm years the analysis shows that, in both hemispheres, the Hadley and Ferrel cells are stronger. The intensification of the ascending branch of the Hadley Circulation determines more precipitation in the Tropics. Conversely a stronger subsiding branch implies less precipitation over subtropical areas. Moreover, during warm years the strengthening of the Ferrel Circulation displaces precipitation poleward both in Northern and Southern Hemispheres.

  3. Investigation of temperature and aridity at different elevations of Mt. Ailao, SW China.

    PubMed

    You, Guangyong; Zhang, Yiping; Liu, Yuhong; Schaefer, Douglas; Gong, Hede; Gao, Jinbo; Lu, Zhiyun; Song, Qinghai; Zhao, Junbin; Wu, Chuansheng; Yu, Lei; Xie, Youneng

    2013-05-01

    Our current understanding is that plant species distribution in the subtropical mountain forests of Southwest China is controlled mainly by inadequate warmth. Due to abundant annual precipitation, aridity has been less considered in this context, yet rainfall here is highly seasonal, and the magnitude of drought severity at different elevations has not been examined due to limited access to higher elevations in this area.In this study, short-term micrometeorological variables were measured at 2,480 m and 2,680 m, where different forest types occur. Drought stress was evaluated by combining measurements of water evaporation demand (E p) and soil volumetric water content (VWC). The results showed that: (1) mean temperature decreased 1 C from 2,480 m to 2,680 m and the minimum temperature at 2,680 m was above freezing. (2) Elevation had a significant influence on E p; however, the difference in daily E p between 2,480 m and 2,680 m was not significant, which was possibly due to the small difference in elevation between these two sites. (3) VWC had larger range of annual variation at 2,680 m than at 2,480 m, especially for the surface soil layer.We conclude that the decrease in temperature does not effectively explain the sharp transition between these forest types. During the dry season, plants growing at 2,680 m are likely to experience more drought stress. In seeking to understand the mountain forest distribution, further studies should consider the effects of drought stress alongside those of altitude. PMID:22752399

  4. Temperature and Pressure Evolution during Al Alloy Solidification at Different Squeeze Pressures

    NASA Astrophysics Data System (ADS)

    Li, Junwen; Zhao, Haidong; Chen, Zhenming

    2015-06-01

    Squeeze casting is an advanced and near net-shape casting process, in which external high pressure is applied to solidifying castings. The castings are characterized with fine grains and good mechanical properties. In this study, a series of experiments were carried out to measure the temperature and pressure histories in cavity of Al-Si-Mg direct squeeze castings with different applied solidification pressures of 0.1, 50, 75, and 100 MPa. The evolution of the measured temperatures and pressures was compared and discussed. The effect of pressure change on formation of shrinkage defects was analyzed. Further the friction between the castings and dies during solidification was calculated. It is shown that the applied squeeze pressure has significant influence on the friction at die and casting interfaces, which affects the pressure evolution and transmission. The results could provide some benchmark data for future thermal-mechanics coupled modeling of squeeze castings.

  5. Terahertz absorption spectrum of para and ortho water vapors at different humidities at room temperature

    NASA Astrophysics Data System (ADS)

    Xin, X.; Altan, H.; Saint, A.; Matten, D.; Alfano, R. R.

    2006-11-01

    Terahertz time-domain spectroscopy has been used to measure the absorption of water vapor in 0.2-2.4THz range from low to high humidity at room temperature. The observed absorption lines are due to the water molecular rotations in the ground vibrational state. We find that the absorption strength of para transitions increases as humidity increases, while the absorption strength of ortho transitions increases and then decreases in intensity with increasing humidity. We explain this difference based on the nuclear spin statistics based ratio of ortho to para water monomer populations at room temperature. The preferential adsorption on the solid surfaces of para water leads to an ortho dominated vapor cloud whose monomer rotational absorption intensity decreases due to the effects of dimerization, molecular collisions, clustering, and interactions with liquid droplets at high concentrations.

  6. Experimental investigation of benzoic acid diffusion coefficient in ?-Al2O3 nanofluids at different temperatures

    NASA Astrophysics Data System (ADS)

    Manouchehrian Fard, Manouchehr; Beiki, Hossein

    2015-12-01

    An experimental study was performed to measure benzoic acid diffusion coefficient in water-based ?-Al2O3 nanofluids at different temperatures. Measurements were carried out at 15, 20 and 25 C. ?-Al2O3 nanoparticles with an average diameter of 10-20 nm were added into de-ionized water as the based fluid. Nanoparticles volume fractions used in the based fluid were 0.025, 0.05, 0.1, 0.2, 0.4 and 0.8 %. Measurements showed that the diffusion coefficients was not changed with nanoparticles concentration and no enhancement was found. Dependence of diffusion coefficients on nanoparticles concentration followed the same trend in all temperatures investigated in this work. Nano stirring and nano-obstacles could be regarded as two reasons for mass diffusivity changes in nanofluids.

  7. Studies of Water Absorption Behavior of Plant Fibers at Different Temperatures

    NASA Astrophysics Data System (ADS)

    Saikia, Dip

    2010-05-01

    Moisture absorption of natural fiber plastic composites is one major concern in their outdoor applications. The absorbed moisture has many detrimental effects on the mechanical performance of these composites. A knowledge of the moisture diffusivity, permeability, and solubility is very much essential for the application of natural fibers as an excellent reinforcement in polymers. An effort has been made to study the water absorption behavior of some natural fibers such as bowstring hemp, okra, and betel nut at different temperatures to improve the long-term performance of composites reinforced with these fibers. The gain in moisture content in the fibers due to water absorption was measured as a function of exposure time at temperatures ranging from 300 K to 340 K. The thermodynamic parameters of the sorption process, such as diffusion coefficients and corresponding activation energies, were estimated.

  8. Thermal Diffusivity for III-VI Semiconductor Melts at Different Temperatures

    NASA Technical Reports Server (NTRS)

    Ban, H.; Li, C.; Lin, B.; Emoto, K.; Scripa, R. N.; Su, C.-H.; Lehoczky, S. L.

    2004-01-01

    The change of the thermal properties of semiconductor melts reflects the structural changes inside the melts, and a fundamental understanding of this structural transformation is essential for high quality semiconductor crystal growth process. This paper focused on the technical development and the measurement of thermal properties of III-VI semiconductor melts at high temperatures. Our previous work has improved the laser flash method for the specialized quartz sample cell. In this paper, we reported the results of our recent progress in further improvements of the measurement system by minimizing the free convection of the melt, adding a front IR detector, and placing the sample cell in a vacuum environment. The results for tellurium and selenium based compounds, some of which have never been reported in the literature, were obtained at different temperatures as a function of time. The data were compared with other measured thermophysical properties to shed light on the structural transformations of the melt.

  9. Deformation and failure of bulk metallic glasses under different initial temperatures

    NASA Astrophysics Data System (ADS)

    Li, J. C.; Chen, X. W.; Huang, F. L.

    2015-09-01

    Based on the coupled thermo-mechanical model, a constitutive model for bulk metallic glasses (BMGs), which is generalized to the multi-axial stress state and considers the effects of free volume, heat and hydrostatic stress, has been modified in the present paper. Besides, a failure criterion of critical free volume concentration is introduced based on the coalescence mechanism of free volume. The constitutive model as well as the failure criterion is implemented into the LS-DYNA commercial software by user material subroutine (UMAT). Then FEM simulations for different initial material temperatures are conducted and the evolutions of material parameter as well as corresponding macroscopic mechanical behaviour of material are analyzed. Relative analysis shows that the initial material temperature significantly affects the deformation and failure of material.

  10. The effects of caffeine administered at different temperatures on foetal development.

    PubMed

    Tomaszewski, Marek; Burdan, Franciszek; Olchowik, Grazyna; Tomaszewska, Monika

    2016-03-01

    An easy access to products containing caffeine makes it widely consumed to excess by the general population, including pregnant women. Beverages containing caffeine are consumed at different temperatures (iced, hot, room temperature). Caffeine easily passes through biological membranes, including the blood-brain barrier, the placental barrier, and can also enter the amniotic fluid, breast milk and semen. The aim of this study was to evaluate the relationship between caffeine's developmental toxicity, and the solution's temperature (both low and high) administered to pregnant female rats. Fertilized females were randomly divided into two main groups: an experimental (E) and a control group (C). The experimental groups received caffeine (30mg/day) in 10 (E1), 25 (E2) and 45(o)C (E3). The females in the control group were given water at the same temperature (C1, C2 and C3). On the day 21 of pregnancy, the pregnant females were killed by decapitation, using a specially prepared laboratory guillotine, after which the mothers' internal organs were weighed. Additionally, the offspring were examined using standard teratological methods. The study found that caffeine administered to pregnant females at a dose of 30mg/day and at the temperatures of 10°C, 25°C or 45°C did not produce any teratogenic effects. The only sign of its adverse effect was the appearance of developmental abnormalities in the form of haematomas and saturated bleeding in the internal organs. These changes most frequently occurred in foetuses of females which received caffeine at 10°C or 45°C. PMID:27007534

  11. Analysis of midgut gene expression profiles from different silkworm varieties after exposure to high temperature.

    PubMed

    Li, Qing Rong; Xiao, Yang; Wu, Fu Quan; Ye, Ming Qiang; Luo, Guo Qing; Xing, Dong Xu; Li, Li; Yang, Qiong

    2014-10-01

    The silkworm is a poikilothermic animal, whose growth and development is significantly influenced by environmental temperature. To identify genes and metabolic pathways involved in the heat-stress response, digital gene expression analysis was performed on the midgut of the thermotolerant silkworm variety '932' and thermosensitive variety 'HY' after exposure to high temperature (932T and HYT). Deep sequencing yielded 6,211,484, 5,898,028, 5,870,395 and 6,088,303 reads for the 932, 932T, HY and HYT samples, respectively. The annotated genes associated with these tags numbered 4357, 4378, 4296 and 4658 for the 932, 932T, HY and HYT samples, respectively. In the HY-vs-932, 932-vs-932T, and HY-vs-HYT comparisons, 561, 316 and 281 differentially expressed genes were identified, which could be assigned to 179, 140 and 123 biological pathways, respectively. It was found that some of the biological pathways, which included oxidative phosphorylation, related to glucose and lipid metabolism, are greatly affected by high temperature and may lead to a decrease in the ingestion of fresh mulberry. When subjected to an early period of continuous heat stress, HSP genes, such as HSP19.9, HSP23.7, HSP40-3, HSP70, HSP90 and HSP70 binding protein, are up-regulated but then reduced after 24h and the thermotolerant '932' strain has higher levels of mRNA of some HSPs, except HSP70, than the thermosensitive variety during continuous high temperature treatment. It is suggested that HSPs and the levels of their expression may play important roles in the resistance to high temperature stress among silkworm varieties. This study has generated important reference tools that can be used to further analyze the mechanisms that underlie thermotolerance differences among silkworm varieties. PMID:25046138

  12. Volume changes in the lower leg during quiet standing and cycling exercise at different ambient temperatures.

    PubMed

    Stick, C; Hiedl, U; Witzleb, E

    1993-01-01

    The purpose of this study was to investigate whether ambient temperature influences both the rate of leg swelling during orthostasis and the oedema-preventing effect of the skeletal muscle pump. Using mercury-in-rubber strain gauges, volume changes were measured in the calf (n = 34) and near the ankle (n = 24) in healthy volunteers aged 19-33 years. Measurements were performed during 12 min of motionless standing in an upright posture and during 17 min of cycle exercise at intensities of 50 W and a pedalling rate of 50 rpm. The experiments were done in an air-conditioned chamber at temperatures of 20, 28 and 36 degrees C and 50% relative humidity. The rate of leg swelling, which occurred while standing, did not differ significantly among the three temperatures. The mean increases in calf volume during 10 min (min 2-12) orthostasis were 1.6 (SEM 0.1)%, 1.9 (SEM 0.2)% and 2.0 (SEM 0.2)% at 20, 28 and 36 degrees C respectively. In the ankle region the mean values were 0.9 (SEM 0.1)%, 1.0 (SEM 0.1)%, and 1.0 (SEM 0.1)% at the three temperatures, respectively. Exercising at low temperatures continuously reduced the volume of the leg, but at 36 degrees C the leg volume did not change significantly either at the calf or near the ankle. The mean volume changes measured between min 2 and min 15 were, at the calf, -1.1 (SEM 0.1)%, -0.8 (SEM 0.2)%, and -0.02 (SEM 0.1)% at 20, 28 and 36 degrees C, respectively. Near the ankle the mean changes were -0.7 (SEM 0.1)%, -0.3 (SEM 0.1)%, and +0.2 (SEM 0.1)%.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8330611

  13. The Statistical Differences Between the Gridded Temperature Datasets, and its Implications for Stochastic Modelling

    NASA Astrophysics Data System (ADS)

    Fredriksen, H. B.; Lvsletten, O.; Rypdal, M.; Rypdal, K.

    2014-12-01

    Several research groups around the world collect instrumental temperature data and combine them in different ways to obtain global gridded temperature fields. The three most well known datasets are HadCRUT4 produced by the Climatic Research Unit and the Met Office Hadley Centre in UK, one produced by NASA GISS, and one produced by NOAA. Recently Berkeley Earth has also developed a gridded dataset. All these four will be compared in our analysis. The statistical properties we will focus on are the standard deviation and the Hurst exponent. These two parameters are sufficient to describe the temperatures as long-range memory stochastic processes; the standard deviation describes the general fluctuation level, while the Hurst exponent relates the strength of the long-term variability to the strength of the short-term variability. A higher Hurst exponent means that the slow variations are stronger compared to the fast, and that the autocovariance function will have a stronger tail. Hence the Hurst exponent gives us information about the persistence or memory of the process. We make use of these data to show that data averaged over a larger area exhibit higher Hurst exponents and lower variance than data averaged over a smaller area, which provides information about the relationship between temporal and spatial correlations of the temperature fluctuations. Interpolation in space has some similarities with averaging over space, although interpolation is more weighted towards the measurement locations. We demonstrate that the degree of spatial interpolation used can explain some differences observed between the variances and memory exponents computed from the various datasets.

  14. Mantle heterogeneity and temperatures inferred from magmas from different tectonic settings

    NASA Astrophysics Data System (ADS)

    Green, D. H.

    2003-04-01

    In many earth models, Mid-Ocean Ridge magmatism is attributed to decompression melting of upwelling upper mantle/asthenosphere at normal mantle temperature. By contrast, upwelling of anomalously high temperature deep mantle plumes is invoked as the cause of "hot spots" (Hawaii, Iceland). The compositions of olivine phenocrysts in picritic magmas define both the coexisting magma composition and the temperature of crystallization. Olivine phenocrysts in Mid-Ocean Ridge tholeiitic picrites and in Hawaiian picrites range up to Mg#92.1 and Mg#91.3 respectively. The anhydrous liquidus temperatures (1 bar pressure) of N-MORB picrites average 1335^oC, of E-MORB picrites average 1355^oC and of Hawaiian picrites average 1365^oC. Correction of liquidus temperatures for dissolved volatiles leads to the conclusion that magma temperatures for all types were approximately 1325^oC implying mantle potential temperature Tp1430^oC. The evidence from magmatic temperatures and compositions is that the temperature contrast between the magmatic products of "hot spots" and mid-ocean ridges is <= 20^oC. The study of distinctive primitive magmas from back-arc basins (tholeiitic picrite) and island arcs (boninite, picritic ankaramite), using both the phenocryst phase of the magmas themselves, and experimental studies of picrites and peridotites demonstrate significant roles for volatiles (C-H-O fluids) and for addition of components from the subducted slab into the overlying mantle wedge. Mantle potential temperatures of Tp 1430^oC are also appropriate for these settings. As well as demonstrating consistent mantle potential temperature in upwelling regions of different tectonic settings, the constraints from experimental studies of liquid/residue equilibria require mantle compositional heterogeneity in major elements and mineral phases. Refractory elements (Cr, Mg, Ni) and phase relationships (chromite-bearing harzburgite vs spinel-bearing lherzolite residues) provide signatures for sources ranging from fertile, modern, well-mixed mantle (MORB sources),residual harzburgite re-enriched in asthenosphere (Hawaiian sources), to extremely refractory harzburgite (island arc boninites) or re-fertilized harzburgite (picritic ankaramites). In the intraplate settings, the role of an "incipient melting" field in lherzolite+(C-H-O) at depths of >90 km to ?<200 km creates conditions in which both depletion (N-MORB to D-MORB sources) and enrichment (N-MORB to E-MORB sources) occur by migration of a 1-2% melt fraction. In the island arc settings, relative proportions of Na-Ca-Al in magmas characterized by very magnesian liquidus olivines and Cr-rich spinels (Cr#>75) provide evidence for slab-derived components including hydrous dacitic magma (high Na/Ca, low Ca/Al) and dolomitic carbonatite (high Ca/Al, high CO_2/H_2O).

  15. Microbial biomass and activity in soils with different moisture content heated at high temperatures

    NASA Astrophysics Data System (ADS)

    Barreiro, Ana; Lombao, Alba; Martin, Angela; Cancelo-González, Javier; Carballas, Tarsy; Díaz-Raviña, Montserrat

    2015-04-01

    It is well known that soil properties determining the thermal transmissivity (moisture, texture, organic matter, etc.) and the duration and temperatures reached during soil heating are key factors driving the fire-induced changes in soil microbial communities. However, despite its interest, the information about this topic is scarce. The aim of the present study is to analyze, under laboratory conditions, the impact of the thermal shock (infrared lamps reaching temperatures of 100 °C, 200 °C and 400 °C) on microbial communities of three acid soils under different moisture level (0 %, 25 % and 50 % per soil volume). Soil temperature was measured with thermocouples and the impact of soil heating was evaluated by means of the analysis of the temperature-time curves calculating the maximum temperature reached (Tmax) and the degree-hours (GH) as an estimation of the amount of heat supplied to the samples (fire severity). The bacterial growth (leucine incorporation) and the total microbial biomass (PLFA) were measured immediately after the heating and one month after the incubation of reinoculated soils. The results showed clearly the importance of moisture level in the transmission of heat through the soil and hence in the further direct impact of high temperatures on microorganisms living in soil. In general, the values of microbial parameters analyzed were low, particularly immediately after soil heating at higher temperatures; the bacterial activity measurements (leucine incorporation technique) being more sensitive to detect the thermal shock showed than total biomass measurements (PLFA). After 1 month incubation, soil microbial communities tend to recover due to the proliferation of surviving population using as substrate the dead microorganisms (soil sterilization). Thus, time elapsed after the heating was found to be decisive when examining the relationships between the microbial properties and the soil heating parameters (GH, Tmax). Analysis of results also showed that the measurement of the heat supplied to the soil (GH) rather than Tmax is a useful parameter to interpret microbial changes induced by soil heating. Acknowledgements. This work was supported by Spanish Ministry of Economy and Competitiveness (AGL2012-39686-C02-01) and for the for the MAPFRE foundation. A. Barreiro and A. Lombao are recipients of FPU grant from Spanish Ministry of Education. Keywords: Degree-hour, soil heating, leucine incorporation, total PLFA biomass

  16. Acute toxicity of arsenic under different temperatures and salinity conditions on the white shrimp Litopenaeus vannamei.

    PubMed

    Valentino-lvarez, Jess Alberto; Nez-Nogueira, Gabriel; Fernndez-Bringas, Laura

    2013-06-01

    The aim of this study was to determine acute toxicity in the post larvae of the white shrimp Litopenaeus vannamei after 96h of exposure to dissolved arsenic under three different temperatures and salinity conditions. Recent reports have shown an increase in the presence of this metalloid in coastal waters, estuaries, and lagoons along the Mexican coast. The white shrimp stands out for its adaptability to temperature and salinity changes and for being the main product for many commercial fisheries; it has the highest volume of oceanic capture and production in Mexican shrimp farms. Lethal concentrations (LC50-96h) were obtained at nine different combinations (3??3 combinations in total) of temperature (20, 25, and 30C) and salinity (17, 25, and 33) showing mean LC50-96h values (standard error) of 9.13??0.76, 9.17??0.56, and 6.23??0.57mgAs?L(-1)(at 20C and 17, 25, and 33 salinity); 12.29??2.09, 8.70??0.82, and 8.03??0.59mgAs?L(-1) (at 25C and 17, 25, and 33 salinity); and 7.84??1.30, 8.49??1.40, and 7.54??0.51mgAs?L(-1) (at 30C and 17, 25, and 33 salinity), respectively. No significant differences were observed for the optimal temperature and isosmotic point of maintenance (25C-S 25) for the species, with respect to the other experimental conditions tested, except for at 20C-S 33, which was the most toxic. Toxicity under 20C-S 33 conditions was also higher than 25C-S 17 and 20C (S 17 or 25). The least toxic condition was 25C-S 17. All this suggests that the toxic effect of arsenic is not affected by temperature changes; it depends on the osmoregulatory pattern developed by the shrimp, either hyperosmotic at low salinity or hiposmotic at high salinity, as observed at least on the extreme salinity conditions here tested (17 and 33). However, further studies testing salinities near the isosmotic point (between 20 and 30 salinities) are needed to clarify these mechanisms. PMID:23471636

  17. Fabrication of porous titanium implants by three-dimensional printing and sintering at different temperatures.

    PubMed

    Xiong, Yaoyang; Qian, Chao; Sun, Jian

    2012-01-01

    This study evaluated the feasibility of using three-dimensional printing (3DP) to fabricate porous titanium implants. Titanium powder was blended with a water-soluble binder material. Green, porous, titanium implants fabricated by 3DP were sintered under protective argon atmosphere at 1,200, 1,300, or 1,400C. Sintered implant prototypes had uniform shrinkage and no obvious shape distortion after sintering. Evaluation of their mechanical properties revealed that titanium prototypes sintered at different temperatures had elastic modulus of 5.9-34.8 GPa, porosity of 41.06-65.01%, hardness of 115.2-182.8 VHN, and compressive strength of 81.3-218.6 MPa. There were significant differences in each type of these data among the different sintering temperatures (p<0.01). Results of this study confirmed the feasibility of fabricating porous titanium implants by 3DP: pore size and pore interconnectivity were conducive to bone cell ingrowth for implant stabilization, and the mechanical properties matched well with those of the human bone. PMID:23037845

  18. Response of largemouth bass (Micropterus salmoides) from different thermal environments to increased water temperature.

    PubMed

    Mulhollem, Joshua J; Suski, Cory D; Wahl, David H

    2015-08-01

    Due to concerns of global climate change, additional research is needed to quantify the thermal tolerance of species, and how organisms are able to adapt to changes in thermal regime. We quantified the thermal tolerance and thermal stress response of a temperate sportfish from two different thermal environments. One group of largemouth bass (Micropterus salmoides) inhabited thermally enhanced reservoirs (used for power plant cooling), with water temperatures typically 2-5C warmer than nearby reservoirs. We tested fish for chronic thermal maxima and reaction to an 8C heat shock using three common physiological indices of stress. We observed no evidence of differences between groups in thermal maxima. We observed no differences in thermal maxima between fish from artificially warmed and natural systems. Our results disagree with research, suggesting differences due to adaptation to different thermal environments. We speculate that behavioral modifications, lack of adequate time for genetic divergence, or the robust genetic plasticity of largemouth bass explain the lack of difference between treatment groups. PMID:25869216

  19. Evolutionary force in confamiliar marine vertebrates of different temperature realms: adaptive trends in zoarcid fish transcriptomes

    PubMed Central

    2012-01-01

    Background Studies of temperature-induced adaptation on the basis of genomic sequence data were mainly done in extremophiles. Although the general hypothesis of an increased molecular flexibility in the cold is widely accepted, the results of thermal adaptation are still difficult to detect at proteomic down to the genomic sequence level. Approaches towards a more detailed picture emerge with the advent of new sequencing technologies. Only small changes in primary protein structure have been shown to modify kinetic and thermal properties of enzymes, but likewise for interspecies comparisons a high genetic identity is still essential to specify common principles. The present study uses comprehensive transcriptomic sequence information to uncover general patterns of thermal adaptation on the RNA as well as protein primary structure. Results By comparing orthologous sequences of two closely related zoarcid fish inhabiting different latitudinal zones (Antarctica: Pachycara brachycephalum, temperate zone: Zoarces viviparus) we were able to detect significant differences in the codon usage. In the cold-adapted species a lower GC content in the wobble position prevailed for preserved amino acids. We were able to estimate 40-60% coverage of the functions represented within the two compared zoarcid cDNA-libraries on the basis of a reference genome of the phylogenetically closely related fish Gasterosteus aculeatus. A distinct pattern of amino acid substitutions could be identified for the non-synonymous codon exchanges, with a remarkable surplus of serine and reduction of glutamic acid and asparagine for the Antarctic species. Conclusion Based on the differences between orthologous sequences from confamiliar species, distinguished mainly by the temperature regimes of their habitats, we hypothesize that temperature leaves a signature on the composition of biological macromolecules (RNA, proteins) with implications for the transcription and translation level. As the observed pattern of amino acid substitutions only partly support the flexibility hypothesis further evolutionary forces may be effective at the global transcriptome level. PMID:23051706

  20. Impact of different defects on the kinetics of negative bias temperature instability of hafnium stacks

    NASA Astrophysics Data System (ADS)

    Zhang, J. F.; Zhao, C. Z.; Chang, M. H.; Zahid, M. B.; Peaker, A. R.; Hall, S.; Groeseneken, G.; Pantisano, L.; De Gendt, S.; Heyns, M.

    2008-01-01

    For SiO2 or SiON, negative bias temperature instability (NBTI) generally follows a power law. There is less information available for the NBTI of Hf stacks and it will be studied and compared with that of SiO2 in this work. We found that the power factor for Hf stacks was substantially smaller and the NBTI kinetics has a "flat-then-rise" feature. The flat region at short stress time originates from the preexisting cyclic positive charge in Hf stacks, which is different from the defect responsible for the rising part at longer time and leads to the smaller power factor for Hf stacks.

  1. Electrical resistance of CNT-PEEK composites under compression at different temperatures

    PubMed Central

    2011-01-01

    Electrically conductive polymers reinforced with carbon nanotubes (CNTs) have generated a great deal of scientific and industrial interest in the last few years. Advanced thermoplastic composites made of three different weight percentages (8%, 9%, and 10%) of multiwalled CNTs and polyether ether ketone (PEEK) were prepared by shear mixing process. The temperature- and pressure-dependent electrical resistance of these CNT-PEEK composites have been studied and presented in this paper. It has been found that electrical resistance decreases significantly with the application of heat and pressure. PMID:21711952

  2. Role of different scattering mechanisms on the temperature dependence of transport in graphene

    PubMed Central

    Sarkar, Suman; Amin, Kazi Rafsanjani; Modak, Ranjan; Singh, Amandeep; Mukerjee, Subroto; Bid, Aveek

    2015-01-01

    Detailed experimental and theoretical studies of the temperature dependence of the effect of different scattering mechanisms on electrical transport properties of graphene devices are presented. We find that for high mobility devices the transport properties are mainly governed by completely screened short range impurity scattering. On the other hand, for the low mobility devices transport properties are determined by both types of scattering potentials - long range due to ionized impurities and short range due to completely screened charged impurities. The results could be explained in the framework of Boltzmann transport equations involving the two independent scattering mechanisms. PMID:26608479

  3. Hawking radiation temperatures in non-stationary Kerr black holes with different tortoise coordinate transformations

    NASA Astrophysics Data System (ADS)

    Lan, X. G.; Jiang, Q. Q.; Wei, L. F.

    2012-04-01

    We apply the Damour-Ruffini-Sannan method to study the Hawking radiations of scalar and Dirac particles in non-stationary Kerr black holes under different tortoise coordinate transformations. We found that all the relevant Hawking radiation spectra show still the blackbody ones, while the Hawking temperatures are strongly related to the used tortoise coordinate transformations. The properties of these dependences are discussed analytically and numerically. Our results imply that proper selections of tortoise coordinate transformations should be important in the studies of Hawking radiations and the correct selection would be given by the experimental observations in the future.

  4. Stability and Function at High Temperature. What Makes a Thermophilic GTPase Different from Its Mesophilic Homologue.

    PubMed

    Katava, Marina; Kalimeri, Maria; Stirnemann, Guillaume; Sterpone, Fabio

    2016-03-17

    Comparing homologous enzymes adapted to different thermal environments aids to shed light on their delicate stability/function trade-off. Protein mechanical rigidity was postulated to secure stability and high-temperature functionality of thermophilic proteins. In this work, we challenge the corresponding-state principle for a pair of homologous GTPase domains by performing extensive molecular dynamics simulations, applying conformational and kinetic clustering, as well as exploiting an enhanced sampling technique (REST2). While it was formerly shown that enhanced protein flexibility and high temperature stability can coexist in the apo hyperthermophilic variant, here we focus on the holo states of both homologues by mimicking the enzymatic turnover. We clearly show that the presence of the ligands affects the conformational landscape visited by the proteins, and that the corresponding state principle applies for some functional modes. Namely, in the hyperthermophilic species, the flexibility of the effector region ensuring long-range communication and of the P-loop modulating ligand binding are recovered only at high temperature. PMID:26907829

  5. Metabolic differences between white and brown fat from fasting rabbits at physiological temperature.

    PubMed

    Lpez-Ibarra, Z; Modrego, J; Valero-Muoz, M; Rodrguez-Sierra, P; Zamorano-Len, J J; Gonzlez-Cantalapiedra, A; de Las Heras, N; Ballesteros, S; Lahera, V; Lpez-Farr, A J

    2015-04-01

    It has been suggested that activated brown adipose tissue (BAT) shows increased glucose metabolic activity. However, less is known about metabolic activity of BAT under conditions of fasting and normal temperature. The aim of this study was to compare the possible differences in energetic metabolism between BAT and white adipose tissue (WAT) obtained from rabbits under the conditions of physiological temperature and 24?h after fasting conditions. The study was carried out on New Zealand rabbits (n=10) maintained for a period of 8 weeks at 232?C. Food was removed 24?h before BAT and WAT were obtained. Protein expression levels of the glycolytic-related protein, glyceraldehyde-3-phosphate dehydrogenase, and pyruvate dehydrogenase were higher in WAT than that in BAT. The expression level of carnitine palmitoyltransferase 1 (CPT1) and CPT2, two fatty acid mitochondrial transporters, and the fatty acid ?-oxidation-related enzyme, acyl CoA dehydrogenase, was higher in BAT than in WAT. Cytosolic malate dehydrogenase expression and malate dehydrogenase activity were higher in WAT than in BAT. However, lactate dehydrogenase expression and lactate content were significantly higher in BAT than in WAT. In summary, this study for the first time, to our knowledge, has described how under fasting and normal temperature conditions rabbit BAT seems to use anaerobic metabolism to provide energetic fuel, as opposed to WAT, where the malate-aspartate shuttle and, therefore, the gluconeogenic pathway seem to be potentiated. PMID:25701828

  6. Similar plastic responses to elevated temperature among different-sized brook trout populations.

    PubMed

    Wood, Jacquelyn L A; Fraser, Dylan J

    2015-04-01

    The potential influence of population size on the magnitude of phenotypic plasticity, a key factor in adaptation to environmental change, has rarely been studied. Conventionally, small populations might exhibit consistently lower plasticity than large populations if small population habitats are generally poor in quality and if genetic diversity underpinning plasticity is lost as population size is reduced. Alternatively, small populations might exhibit (1) consistently higher plasticity as a response to the increased environmental variation that can accompany habitat fragment size reduction or (2) greater variability in plasticity, as fragmentation can increase variability in habitat types. We explored these alternatives by investigating plasticity to increasing temperature in a common garden experiment using eight fragmented populations of brook trout varying nearly 50-fold in census size (179-8416) and 10-fold in effective number of breeders (18-135). Across six early-life-history traits and three temperatures, we found almost no evidence for differences in either the magnitude or variability of plasticity in relation to population size, despite that one temperature represented an extreme climate warming scenario. The documentation of similar plastic responses of small and large populations suggests that phenotypic plasticity is not reduced as population size decreases, and that even very small populations of some species might have the ability to respond to climate change. PMID:26230021

  7. Studies on the effect of MDMA (ecstasy') on the body temperature of rats housed at different ambient room temperatures

    PubMed Central

    Green, A Richard; O'Shea, Esther; Saadat, Kathryn S; Elliott, J Martin; Colado, M Isabel

    2005-01-01

    3,4-Methylenedioxymethamphetamine (MDMA, ecstasy') administration to rats produces hyperthermia if they are housed in normal or warm ambient room temperature (Ta) conditions (?20C), but hypothermia when in cool conditions (Ta?17C). We have now investigated some of the mechanisms involved. MDMA (5?mg?kg?1 i.p.) produced a rapid decrease in rectal temperature in rats at Ta 15C. This response was blocked by pretreatment with the dopamine D2 receptor antagonist remoxipride (10?mg?kg?1 i.p.), but unaltered by pretreatment with the D1 antagonist SCH23390 (1.1?mg?kg?1 i.p.). MDMA (5?mg?kg?1) did not alter the tail temperature of rats at Ta 15C, but decreased the tail temperature of rats at Ta 30C. A neurotoxic dose of MDMA (three doses of 5?mg?kg?1 given 3?h apart) decreased cortical and hippocampal 5-HT content by approximately 30% 7 days later. This lesion did not influence the rise in tail temperature when rats were moved from Ta 20C to 30C compared to nonlesioned controls, but did result in a lower tail temperature than that of controls when they were returned to Ta 24C. Acute administration of MDMA (5?mg?kg?1) to MDMA-lesioned rats produced a sustained decrease in tail temperature in rats housed at Ta 30C compared to nonlesioned controls. These data suggest that the thermoregulatory problems previously observed in MDMA-lesioned rats housed at Ta 30C result, partially, from their inability to lose heat by vasodilation of the tail, a major heat-loss organ in this species. PMID:15997230

  8. Impact response characteristics of a cyclotetramethylene tetranitramine based polymer-bonded explosives under different temperatures

    NASA Astrophysics Data System (ADS)

    Xiaogan, Dai; Yushi, Wen; Hui, Huang; Panjun, Zhang; Maoping, Wen

    2013-09-01

    The temperature-impact safety correlation of a cyclotetramethylene tetranitramine (HMX) based polymer-bonded explosive (PBX) was investigated. Matrix of tests was determined by projectile velocities in the range of 160 m/s-370 m/s and five temperature cases of 28 °C (room temperature), 75 °C, 105 °C, 160 °C, and 195 °C. The safety performance under thermal-impact combined environment was evaluated by high speed camera and air over-pressure gauges. The samples before and after impact were compared by the scanning electron microscope. The mechanical performance and thermal decomposition under different temperatures were also studied by mechanics machine and the thermo gravimetric analysis technique. The phase transition of PBX-2 is investigated by XRD spectrograph. The results show that the reaction threshold of unheated explosive is between 263.5 m/s and 269.9 m/s. While heated to 75 °C and 105 °C, the values are increased to 316 m/s-367 m/s and 286 m/s-298.3 m/s, respectively. However, the threshold is less than 176 m/s at 160 °C and the threshold at 195 °C is even lower, which is less than 166.7 m/s. According to the temperature histories, the pictures of wreckages, the over-pressures, the mechanical performance, the thermal decomposition, and phase transition properties, some conclusions can be drawn. First of all, compared with unheated case, the impact safety of PBX-2 is improved at both 75 °C and 105 °C by a softened, easy-flowing, and energy absorbing mechanical properties. Secondly, at 160 °C, the impact safety becomes worse due to the thermal decomposition. Thirdly, when the temperature reaches or exceeds the β → δ phase transition range, the impact safety of PBX-2 becomes significantly worse.

  9. Constructal thermodynamics combined with infrared experiments to evaluate temperature differences in cells.

    PubMed

    Lucia, Umberto; Grazzini, Giuseppe; Montrucchio, Bartolomeo; Grisolia, Giulia; Borchiellini, Romano; Gervino, Gianpiero; Castagnoli, Carlotta; Ponzetto, Antonio; Silvagno, Francesca

    2015-01-01

    The aim of this work was to evaluate differences in energy flows between normal and immortalized cells when these distinct biological systems are exposed to environmental stimulation. These differences were considered using a constructal thermodynamic approach, and were subsequently verified experimentally. The application of constructal law to cell analysis led to the conclusion that temperature differences between cells with distinct behaviour can be amplified by interaction between cells and external fields. Experimental validation of the principle was carried out on two cellular models exposed to electromagnetic fields. By infrared thermography we were able to assess small changes in heat dissipation measured as a variation in cell internal energy. The experimental data thus obtained are in agreement with the theoretical calculation, because they show a different thermal dispersion pattern when normal and immortalized cells are exposed to electromagnetic fields. By using two methods that support and validate each other, we have demonstrated that the cell/environment interaction can be exploited to enhance cell behavior differences, in particular heat dissipation. We propose infrared thermography as a technique effective in discriminating distinct patterns of thermal dispersion and therefore able to distinguish a normal phenotype from a transformed one. PMID:26100383

  10. Constructal thermodynamics combined with infrared experiments to evaluate temperature differences in cells

    PubMed Central

    Lucia, Umberto; Grazzini, Giuseppe; Montrucchio, Bartolomeo; Grisolia, Giulia; Borchiellini, Romano; Gervino, Gianpiero; Castagnoli, Carlotta; Ponzetto, Antonio; Silvagno, Francesca

    2015-01-01

    The aim of this work was to evaluate differences in energy flows between normal and immortalized cells when these distinct biological systems are exposed to environmental stimulation. These differences were considered using a constructal thermodynamic approach, and were subsequently verified experimentally. The application of constructal law to cell analysis led to the conclusion that temperature differences between cells with distinct behaviour can be amplified by interaction between cells and external fields. Experimental validation of the principle was carried out on two cellular models exposed to electromagnetic fields. By infrared thermography we were able to assess small changes in heat dissipation measured as a variation in cell internal energy. The experimental data thus obtained are in agreement with the theoretical calculation, because they show a different thermal dispersion pattern when normal and immortalized cells are exposed to electromagnetic fields. By using two methods that support and validate each other, we have demonstrated that the cell/environment interaction can be exploited to enhance cell behavior differences, in particular heat dissipation. We propose infrared thermography as a technique effective in discriminating distinct patterns of thermal dispersion and therefore able to distinguish a normal phenotype from a transformed one. PMID:26100383

  11. Mathematical modelling of microbial growth in packaged refrigerated beef stored at different temperatures.

    PubMed

    Giannuzzi, L; Pinotti, A; Zaritzky, N

    1998-01-01

    Gompertz and logistic models were fitted to experimental counts of microorganisms growing in beef stored at 0, 4, 7, 9 and 10 degrees C. Samples were packaged in polyethylene (high gaseous permeability) and in EVA/SARAN/EVA (low gaseous permeability) films, being EVA ethyl vinyl acetate and SARAN polyvinyl and polyvinylidene chloride copolymer. Lag phase duration (LPD) and specific growth rate (mu) were obtained as derived parameters for lactic acid bacteria, Enterobacteriaceae, Pseudomonas sp. and psychrotrophic microorganisms. The reciprocal of LPD was fitted to an Arrhenius type equation; LPD of lactic acid bacteria showed a marked dependence on temperature, with activation energy values (ELPD) of 222.2 and 216.9 kJ/mol for polyethylene and ESE respectively. The effect of initial microbial population at different storage temperatures on adaptation period was analyzed. As the initial microbial population increased, adaptation period decreased for all studied microorganisms and for both packaging films. The effect of temperature on specific growth rate was better interpreted by the Arrhenius model than by the linear or the square root equations. Psychrotrophic microorganisms in beef showed the highest activation energy values for specific growth rate (E mu) in both packaging films, being E mu 85.50 and 103.10 KJ/mol for polyethylene and ESE film respectively. In both films, Enterobacteriaceae showed the lowest E mu values, being 15.33 and 59.89 kJ/mol in ESE and polyethylene respectively. The final number of microorganisms (maximum population density) did not show significant changes with storage temperature. PMID:9562882

  12. Developmental and growth temperature regulation of two different microsomal omega-6 desaturase genes in soybeans.

    PubMed

    Heppard, E P; Kinney, A J; Stecca, K L; Miao, G H

    1996-01-01

    The polyunsaturated fatty acid content is one of the major factors influencing the quality of vegetable oils. Edible oils rich in monounsaturated fatty acid provide improved oil stability, flavor, and nutrition for human and animal consumption. In plants, the microsomal omega-6 desaturase-catalyzed pathway is the primary route of production of polyunsaturated lipids. We report the isolation of two different cDNA sequences, FAD2-1 and FAD2-2, encoding microsomal omega-6 desaturase in soybeans and the characterization of their developmental and temperature regulation. The FAD2-1 gene is strongly expressed in developing seeds, whereas the FAD2-2 gene is constitutively expressed in both vegetative tissues and developing seeds. Thus, the FAD2-2 gene-encoded omega-6 desaturase appears to be responsible for production of polyunsaturated fatty acids within membrane lipids in both vegetative tissues and developing seeds. The seed-specifically expressed FAD2-1 gene is likely to play a major role in controlling conversion of oleic acid to linoleic acid within storage lipids during seed development. In both soybean seed and leaf tissues, linoleic acid and linolenic acid levels gradually increase as temperature decreases. However, the levels of transcripts for FAD2-1, FAD2-2, and the plastidial omega-6 desaturase gene (FAD 6) do not increase at low temperature. These results suggest that the elevated polyunsaturated fatty acid levels in developing soybean seeds grown at low temperature are not due to the enhanced expression of omega-6 desaturase genes. PMID:8587990

  13. Effects of different surfaces on the transport and deposition of ruthenium oxides in high temperature air

    NASA Astrophysics Data System (ADS)

    Vr, N.; Matus, L.; Pintr, A.; Osn, J.; Hzer, Z.

    2012-01-01

    In order to understand the behaviour of ruthenium oxides in the reactor coolant system during an air ingress accident, new tests were performed in the frame of the RUSET (RUthenium Separate Effect Test) experimental program. These aimed to ascertain the effects of different surfaces (quartz, stainless steel (SS), zirconium alloy, alumina, oxidised metal, and surfaces with Mo or Cs deposits) on the transport and decomposition of ruthenium oxides in air stream along the temperature gradient zone (1100-100 C). The results demonstrated that the heterogeneous phase decomposition of RuO 3 and RuO 4 to RuO 2 is catalysed more efficiently by the quartz surface than by the SS or alumina surfaces. The presence of MoO 3 layers decreased the RuO x precipitation extent on all investigated surfaces. The trapping effect of Cs deposit on Ru in the temperature gradient zone was proved in the case of the SS surface. On the contrary, presence of Cs precipitate on alumina and especially on quartz surfaces was found to decrease their catalytic effect on the decomposition of ruthenium oxides, and thus increased the RuO 4 concentration in the outlet air. Similarly to the effect observed for Cs deposition, the presence of other fission products in the evaporation area (at 1100 C) decreased the partial pressure of RuO 4 in the outlet air at the SS surface and increased it at quartz and alumina surfaces. When zirconium (E110) cladding material was placed in the temperature gradient zone, no Ru transmittance occurred until the high temperature end of the zirconium tube was completely oxidised. After the intense oxidation of E110, Ru release occurred only in the presence of other fission product species. Pre-oxidation of SS surfaces in steam had no significant effect on the Ru passage.

  14. 2D-PAGE protein analysis of dinoflagellate Alexandrium minutum based on three different temperatures

    NASA Astrophysics Data System (ADS)

    Latib, Norhidayu Abdul; Norshaha, Safida Anira; Usup, Gires; Yusof, Nurul Yuziana Mohd

    2015-09-01

    Harmful algae bloom or red tide seems to be considered as threat to ecosystem, especially to human consumption because of the production of neurotoxin by dinoflagellates species such as Alexandrium minutum which can lead to paralytic shellfish poisoning. The aim of this study is to determine the most suitable method for protein extraction of A. minutum followed by determination of differential protein expression of A. minutum on three different temperatures (15C, 26C and 31.5C). After the optimization, the protein extract was subjected to two-dimensional polyacrylamide gel electrophoresis (2-DE) to compare the intensity and distribution of the protein spots. Based on quantitative and qualitative protein assessment, use of Trizol reagent is the most suitable method to extract protein from A. minutum. 2-DE analysis of the samples results in different distribution and intensity of the protein spots were compared between 15C, 26C and 31.5C.

  15. Changes in exercise and post-exercise core temperature under different clothing conditions

    NASA Astrophysics Data System (ADS)

    Kenny, Glen P.; Reardon, Francis D.; Thoden, Jim S.; Giesbrecht, Gordon G.; Kenny, G.

    This study evaluates the effect of different levels of insulation on esophageal (Tes) and rectal (Tre) temperature responses during and following moderate exercise. Seven subjects completed three 18-min bouts of treadmill exercise (75% VO2max, 22C ambient temperature) followed by 30 min of recovery wearing either: (1) jogging shoes, T-shirt and shorts (athletic clothing); (2) single-knit commercial coveralls worn over the athletic clothing (coveralls); or (3) a Canadian Armed Forces nuclear, bacteriological and chemical warfare protective overgarment with hood, worn over the athletic clothing (NBCW overgarment). Tes was similar at the start of exercise for each condition and baseline Tre was 0.4C higher than Tes. The hourly equivalent rate of increase in Tes during the final 5 min of exercise was 1.8C, 3.0C and 4.2C for athletic clothing, coveralls and NBCW overgarment respectively (P<0.05). End-exercise Tes was significantly different between conditions [37.7C (SEM 0.1C), 38.2C (SEM 0.2C and 38.5C (SEM 0.2C) for athletic clothing, coveralls and NBCW overgarment respectively)] (P<0.05). No comparable difference in the rate of temperature increase for Tre was demonstrated, except that end-exercise Tre for the NBCW overgarment condition was significantly greater (0.5C) than that for the athletic clothing condition. There was a drop in Tes during the initial minutes of recovery to sustained plateaus which were significantly (P<0.05) elevated above pre-exercise resting values by 0.6C, 0.8C and 1.0C, for athletic clothing, coveralls, and NBCW overgarment, respectively. Post-exercise Tre decreased very gradually from end-exercise values during the 30-min recovery. Only the NBCW overgarment condition Tre was significantly elevated (0.3C) above the athletic clothing condition (P<0.05). In conclusion, Tes is far more sensitive in reflecting the heat stress of different levels of insulation during exercise and post-exercise than Tre. Physiological mechanisms are discussed as possible explanations for the differences in response.

  16. The different effects of sea surface temperature and aerosols on climate in East Asia during spring

    NASA Astrophysics Data System (ADS)

    Hu, Haibo; Liu, Chao; Zhang, Yuan; Yang, Xiuqun

    2015-08-01

    In this study, we used the NCAR CAM3.0 model to study the climate effects of both decadal global Sea Surface Temperature (SST) changing and the increasing aerosol concentration in East Asia in boreal spring. In the decadal SST changing experiment, a prominent sea surface cyclone anomaly occurred west of the Northwest Pacific warming SST. The cyclone anomaly is conductive to anomalous rising motion and more rainfall over the Northwest Pacific and southeast coast areas of China, but less rainfall in central China. Caused by the only aerosol concentration increasing, the change of climate in East Asia is totally different from that induced by the regime shift of SST around 1976/77 with the same model. The sulfate and black carbon aerosol concentrations were doubled respectively and synchronously in East Asia (20-50N, 100-150E) to investigate the climate effects of these two major aerosol types in three experiments. The results show that, in all three aerosol concentration changing experiments, the rainfall during boreal spring increases in North China and decreases in central China. It's worth noting that in the DTWO experiment, the rainfall diminishes in central China while it increases in the north and southeast coast areas of China, which is similar to observations. From the vertical profile between 110E and 120E, it is found that sulfate and black carbon aerosols first change the temperature of lower troposphere owing to their direct radiative effect, and then induce secondary meridional circulation anomaly through the different dynamic mechanisms involved, and at last generate precipitation and surface temperature anomalous patterns mentioned above.

  17. Effect of different post mortem temperatures on carcass quality of suckling lamb.

    PubMed

    Rubio, Begoña; Vieira, Ceferina; Martínez, Beatriz; Fernández, Ana M

    2013-08-01

    The effect of post mortem treatment on microbiological lamb carcass quality was studied. Suckling lambs carcasses were assigned to three different post mortem treatments: conventional (2  for 24 h), ultra-rapid (-20  for 3.5 h then 2  until 24 h post mortem) and slow (12   for 7 h then 2  until 24 h post mortem). Carcass pH and temperature were measured at 0, 3.5, 7 and 24 h post slaughter. Lamb carcasses were sampled for total aerobic viable and Enterobacteriaceae counts just after dressing and 24 h post mortem. A significant effect (p < 0.05) of post mortem treatment on carcasses temperature and pH was found corresponding the faster pH fall to slowly chilled muscles. However, no differences were found at 24 h post mortem among treatments in both parameters. Regarding microbiological results, carcasses of ultra-rapid treatment had the lowest total aerobic viable and Enterobacteriaceae counts and those belonging to conventional treatment had the highest total aerobic viable counts. From 0 to 24 h post mortem, an increase of total aerobic viable was observed in conventional and slow treatments whilst Enterobacteriaceae counts remained constant in all cases. From a microbiological point of view, the ultra-rapid treatment was the only one allowed to maintain the hygienic carcasses quality. However, according to pH and temperature results the carcasses subjected to this treatment may be susceptible to cold shortening. PMID:23733807

  18. Effects of high temperature on different restorations in forensic identification: Dental samples and mandible

    PubMed Central

    Patidar, Kalpana A; Parwani, Rajkumar; Wanjari, Sangeeta

    2010-01-01

    Introduction: The forensic odontologist strives to utilize the charred human dentition throughout each stage of dental evaluation, and restorations are as unique as fingerprints and their radiographic morphology as well as the types of filling materials are often the main feature for identification. The knowledge of detecting residual restorative material and composition of unrecovered adjacent restoration is a valuable tool-mark in the presumptive identification of the dentition of a burned victim. Gold, silver amalgam, silicate restoration, and so on, have a different resistance to prolonged high temperature, therefore, the identification of burned bodies can be correlated with adequate qualities and quantities of the traces. Most of the dental examination relies heavily on the presence of the restoration as well as the relationship of one dental structure to another. This greatly narrows the research for the final identification that is based on postmortem data. Aim: The purpose of this study is to examine the resistance of teeth and different restorative materials, and the mandible, to variable temperature and duration, for the purpose of identification. Materials and Methods: The study was conducted on 72 extracted teeth which were divided into six goups of 12 teeth each based on the type of restorative material. (Group 1 - unrestored teeth, group 2 - teeth restored with Zn3(PO4)2, group 3 - with silver amalgam, group 4 with glass ionomer cement, group 5 - Ni-Cr-metal crown, group 6 - metal ceramic crown) and two specimens of the mandible. The effect of incineration at 400C (5 mins, 15 mins, 30 mins) and 1100C (15 mins) was studied. Results: Damage to the teeth subjected to variable temperatures and time can be categorized as intact (no damage), scorched (superficially parched and discolored), charred (reduced to carbon by incomplete combustion) and incinerated (burned to ashes). PMID:21189989

  19. Surface induces different crystal structures in a room temperature switchable spin crossover compound.

    PubMed

    Gentili, Denis; Liscio, Fabiola; Demitri, Nicola; Schfer, Bernhard; Borgatti, Francesco; Torelli, Piero; Gobaut, Benoit; Panaccione, Giancarlo; Rossi, Giorgio; Degli Esposti, Alessandra; Gazzano, Massimo; Milita, Silvia; Bergenti, Ilaria; Ruani, Giampiero; alitro, Ivan; Ruben, Mario; Cavallini, Massimiliano

    2015-12-14

    We investigated the influence of surfaces in the formation of different crystal structures of a spin crossover compound, namely [Fe(L)2] (LH: (2-(pyrazol-1-yl)-6-(1H-tetrazol-5-yl)pyridine), which is a neutral compound thermally switchable around room temperature. We observed that the surface induces the formation of two different crystal structures, which exhibit opposite spin transitions, i.e. on heating them up to the transition temperature, one polymorph switches from high spin to low spin and the second polymorph switches irreversibly from low spin to high spin. We attributed this inversion to the presence of water molecules H-bonded to the complex tetrazolyl moieties in the crystals. Thin deposits were investigated by means of polarized optical microscopy, atomic force microscopy, X-ray diffraction, X-ray absorption spectroscopy and micro Raman spectroscopy; moreover the analysis of the Raman spectra and the interpretation of spin inversion were supported by DFT calculations. PMID:26575005

  20. Dielectrical Properties of CeO2 Nanoparticles at Different Temperatures

    PubMed Central

    Zamiri, Reza; Abbastabar Ahangar, Hossein; Kaushal, Ajay; Zakaria, Azmi; Zamiri, Golnoosh; Tobaldi, David; Ferreira, J. M. F.

    2015-01-01

    A template-free precipitation method was used as a simple and low cost method for preparation of CeO2 nanoparticles. The structure and morphology of the prepared nanoparticle samples were studied in detail using X-ray diffraction, Raman spectroscopy and Scanning Electron Microscopy (SEM) measurements. The whole powder pattern modelling (WPPM) method was applied on XRD data to accurately measure the crystalline domain size and their size distribution. The average crystalline domain diameter was found to be 5.2 nm, with a very narrow size distribution. UV-visible absorbance spectrum was used to calculate the optical energy band gap of the prepared CeO2 nanoparticles. The FT-IR spectrum of prepared CeO2 nanoparticles showed absorption bands at 400 cm-1 to 450 cm-1 regime, which correspond to CeO2 stretching vibration. The dielectric constant (εr) and dielectric loss (tan δ) values of sintered CeO2 compact consolidated from prepared nanoparticles were measured at different temperatures in the range from 298 K (room temperature) to 623 K, and at different frequencies from 1 kHz to 1 MHz. PMID:25910071

  1. Crude oil degradation by bacterial consortia under four different redox and temperature conditions.

    PubMed

    Xiong, Shunzi; Li, Xia; Chen, Jianfa; Zhao, Liping; Zhang, Hui; Zhang, Xiaojun

    2015-02-01

    There is emerging interest in the anaerobic degradation of crude oil. However, there is limited knowledge about the geochemical effects and microbiological activities for it. A mixture of anaerobic sludge and the production water from an oil well was used as an inoculum to construct four consortia, which were incubated under sulfate-reducing or methanogenic conditions at either mesophilic or thermophilic temperatures. Significant degradation of saturated and aromatic hydrocarbons and the changing quantities of some marker compounds, such as pristane, phytane, hopane and norhopane, and their relative quantities, suggested the activity of microorganisms in the consortia. Notably, the redox conditions and temperature strongly affected the diversity and structure of the enriched microbial communities and the oil degradation. Although some specific biomarker showed larger change under methanogenic condition, the degradation efficiencies for total aromatic and saturated hydrocarbon were higher under sulfate-reducing condition. After the 540-day incubation, bacteria of unknown classifications were dominant in the thermophilic methanogenic consortia, whereas Clostridium dominated the mesophilic methanogenic consortia. With the exception of the dominant phylotypes that were shared with the methanogenic consortia, the sulfate-reducing consortia were predominantly composed of Thermotogae, Deltaproteobacteria, Spirochaeta, and Synergistetes phyla. In conclusion, results in this study demonstrated that the different groups of degraders were responsible for degradation in the four constructed crude oil degrading consortia and consequently led to the existence of different amount of marker compounds under these distinct conditions. There might be distinct metabolic mechanism for degrading crude oil under sulfate-reducing and methanogenic conditions. PMID:25216580

  2. Ballistics ordnance gelatine - How different concentrations, temperatures and curing times affect calibration results.

    PubMed

    Maiden, Nicholas R; Fisk, Wesley; Wachsberger, Christian; Byard, Roger W

    2015-08-01

    A study was undertaken to determine whether different concentrations of ordnance gelatine, water types, temperatures and curing times would have an effect on projectile penetration of a gelatine tissue surrogate. Both Federal Bureau of Investigation (FBI) and North Atlantic Treaty Organization (NATO) specified gelatines were compared against the FBI calibration standard. 10% w/w and 20% w/w concentrations of gelatine with Bloom numbers of 250 and 285 were prepared and cured at variable temperatures (3-20°C) for 21 hours-3 weeks. Each block was shot on four occasions on the same range using steel calibre 4.5 mm BBs fired from a Daisy(®) air rifle at the required standard velocity of 180 ± 4.5 m/s, to ascertain the mean penetration depth. The results showed no significant difference in mean penetration depth using the three different water types (p > 0.05). Temperature changes and curing times did affect penetration depth. At 10°C, mean penetration depth with 20% gelatine 285 Bloom for the two water types tested was 49.7 ± 1.5 mm after 21 h curing time, whereas the same formulation at 20°C using two different water types was 79.1 ± 2.1 mm after 100 h curing time (p < 0.001). Neither of the NATO 20% concentrations of gelatine at 10°C or a 20% concentration of 285 Bloom gelatine at 10°C met the same calibration standard as the FBI recommended 10% formulation at 4°C. A 20% concentration of 285 Bloom at 20°C met the same calibration/penetration criteria as a 10% concentration of 250 Bloom at 4 °C after 100 h of curing, therefore matching the FBI calibration standard for a soft tissue simulant for wound ballistics research. These results demonstrate significant variability in simulant properties. Failure to standardise ballistic simulants may invalidate experimental results. PMID:26165674

  3. IAD of oxide coatings at low temperature: a comparison of processes based on different ion sources

    NASA Astrophysics Data System (ADS)

    Niederwald, Hansjoerg S.; Kaiser, Norbert; Schallenberg, Uwe B.; Duparre, Angela; Ristau, Detlev; Kennedy, Michael

    1997-10-01

    A comparative study of different ion and plasma assisted physical vapor deposition processes at low temperature is reported. To work out a clear comparison of the different processes, the object of the study are single layers of different metal oxides like Ta2O5, TiO2, SiO2 and mixed oxides like H4 (Merck) deposited on glass and silicon substrates. Three different types of ion- (or plasma-respectively) sources are used: the cold cathode ion source from Denton (CC 104), the end hall ion source Mark II from CSC and the advanced plasma source from Leybold. Each of these processes is run under conditions concerning process parameters like bias, ion current, ion energy, beam characteristics and gas flow, which were understood to be optimized also to maintain long-term stability as realistic production conditions. The resulting metal oxide single layers are characterized by their optical properties, dispersion curves for NUV and VIS as well as absorption and scatter at discrete wavelengths. Also discussed are mechanical properties like hardness and adherence. A test method is presented which clearly shows the superior behavior of the IAD coatings.

  4. The Effect of Different Water Immersion Temperatures on Post-Exercise Parasympathetic Reactivation

    PubMed Central

    de Oliveira Ottone, Vinícius; de Castro Magalhães, Flávio; de Paula, Fabrício; Avelar, Núbia Carelli Pereira; Aguiar, Paula Fernandes; da Matta Sampaio, Pâmela Fiche; Duarte, Tamiris Campos; Costa, Karine Beatriz; Araújo, Tatiane Líliam; Coimbra, Cândido Celso; Nakamura, Fábio Yuzo; Amorim, Fabiano Trigueiro; Rocha-Vieira, Etel

    2014-01-01

    Purpose We evaluated the effect of different water immersion (WI) temperatures on post-exercise cardiac parasympathetic reactivation. Methods Eight young, physically active men participated in four experimental conditions composed of resting (REST), exercise session (resistance and endurance exercises), post-exercise recovery strategies, including 15 min of WI at 15°C (CWI), 28°C (TWI), 38°C (HWI) or control (CTRL, seated at room temperature), followed by passive resting. The following indices were assessed before and during WI, 30 min post-WI and 4 hours post-exercise: mean R-R (mR-R), the natural logarithm (ln) of the square root of the mean of the sum of the squares of differences between adjacent normal R–R (ln rMSSD) and the ln of instantaneous beat-to-beat variability (ln SD1). Results The results showed that during WI mRR was reduced for CTRL, TWI and HWI versus REST, and ln rMSSD and ln SD1 were reduced for TWI and HWI versus REST. During post-WI, mRR, ln rMSSD and ln SD1 were reduced for HWI versus REST, and mRR values for CWI were higher versus CTRL. Four hours post exercise, mRR was reduced for HWI versus REST, although no difference was observed among conditions. Conclusions We conclude that CWI accelerates, while HWI blunts post-exercise parasympathetic reactivation, but these recovery strategies are short-lasting and not evident 4 hours after the exercise session. PMID:25437181

  5. [Effects of nighttime temperature increase at different growth stages on double season rice grain yield].

    PubMed

    Wei, Jin-Lian; Pan, Xiao-Hua; Deng, Qiang-Hui

    2010-02-01

    Two experimental glass-houses were utilized to study the effects of nighttime temperature increase (NTI) at different growth stages on the grain yield of double season rice. The NTI from the stage of sowing to panicle differentiation (primary branch differentiation) improved the tillering of rice, and increased the effective panicles. An average 1 degrees C rise in the minimum nighttime temperature (MNT) at this stage increased the grain yield of early and late rice by 10.02% - 13.18% and 6.52% - 7.78% (P < 0.01), respectively. The NTI from the stage of panicle differentiation to heading (10% panicle heading from flag leaf sheath) promoted the spikelet abortion, and reduced the number of developed spikelet. An average 1 degrees C rise in MNT at this stage decreased the grain yield of early and late rice by 3.76% - 6.67% and 3.66% - 6.94% (P < 0.01), respectively. NTI from the stage of heading to maturity decreased the filled grain rate of early rice remarkably, but had an opposite effect on late rice. An average 1 degrees C rise in MNT at this stage induced a grain yield loss by 2.07% - 5.61% (P < 0.05) and a grain yield gain by 1.63% - 2.28% (P < 0.05) for early and late rice, respectively. All the results illustrated that there existed obvious differences in the effects of NTI at different growth stages on the grain yield of double season rice. PMID:20462002

  6. Improving the energy efficiency of refrigeration plants by decreasing the temperature difference in air-cooled condensers

    NASA Astrophysics Data System (ADS)

    Shishov, V. V.; Talyzin, M. S.

    2015-09-01

    The electric energy consumption efficiency is estimated in comparing the real refrigeration machine cycle with the theoretical inverse Carnot cycle. The potential for saving electricity in using aircooled condensers with different values of temperature difference is shown. A procedure for calculating a refrigerating system with the evaporation temperature equal to -10°C, which corresponds at this temperature level to the thermal load of a standard supermarket, is described. The calculation was carried out taking into account the annual profile of temperatures in the indicated locality and based on the possibility of adjusting the condenser capacity for maintaining constant condensation temperature. The payback period in case of using condensers with different values of temperature difference is calculated; for example, in using condensers with a temperature difference of less than 15 K, the payback period will be less than one year. Decreasing the temperature difference results, on one hand, in a larger annual consumption of electric energy by the condenser fans, and on the other hand, it results in a lower condensation pressure, which leads to a smaller annual consumption of energy by the compressor unit. As a result, the total amount of energy consumed by the refrigeration system decreases so that despite a higher cost of condensers designed to operate at lower values of temperature difference, it becomes possible to achieve the above-mentioned payback period. Additionally, the payback period in case of using an air-cooled microchannel aluminum condenser was calculated: in case of using such a condenser with a temperature difference of 8 K instead of the condenser with the temperature difference equal to 15 K, the payback period will be less than half a year. Recommendations for designing new refrigeration systems equipped with air-cooled condensers are given.

  7. Absorption, Fluorescence and Emission Anisotropy Spectra of 4-Cyano-N,N-dimethylaniline in Different Media and at Different Temperatures

    NASA Astrophysics Data System (ADS)

    Kawski, A.; Piszczek, G.

    1997-05-01

    The effect of temperature on fluorescence and emission anisotropy spectra of 4-cyano-N,N-dimethylaniline (CDMA) was investigated in viscous (glycerol and paraffin oil) and rigid (polyvinyl alcohol) PVA and polyvinyl chloride) PVC) media. A strong effect of temperature on the intensity of a and b emission bands was observed. It was also found that the emission anisotropy, r, does not vary in the longwave emission band a at a fixed temperature but decreases in the emission band b together with the decreasing wavelength. The latter effect is due to the fact that the transition moment in this band is perpendicular to the long axis of the CDMA molecule. For CDMA in paraffin oil, a normal b band with negative emission anisotropy only occurs. In all other media used, the emission anisotropy has lower values, approaching zero, which results from the considerable covering of band b with a broad emission band a.

  8. Kefir grains as a starter for whey fermentation at different temperatures: chemical and microbiological characterisation.

    PubMed

    Londero, Alejandra; Hamet, Mara F; De Antoni, Graciela L; Garrote, Graciela L; Abraham, Anala G

    2012-08-01

    We report here a comparative analysis of the growth, acidification capacity, and chemical and microbiologic composition between kefir grains after 20 subcultures in whey at 20, 30, and 37C and the original kefir grains coming from milk along with a determination of the microbiological composition of the fermented whey as compared with that of traditional fermented milk. When fermentation was carried out repeatedly at 30 or 37C, kefir grains changed their kefir-like appearance, exhibited reduced growth rates, had a lower diversity of yeasts and water content, and a higher protein-to-polysaccharide ratio compared with the original kefir grains. In contrast, at 20C kefir grains could remain in whey for prolonged periods without altering their acidification capacity, growth rate, macroscopic appearance or chemical and microbiologic composition-with the only difference being a reduction in certain yeast populations after 20 subcultures in whey. At this incubation temperature, the presence of Lactobacillus kefiranofaciens, Lb. kefir, Lb. parakefir, Lactococcus lactis, Kluyveromyces marxianus, Saccharomyces unisporus, and Sac. cerevisiae was detected in kefir grains and in fermented whey by denaturing-gradient-gel electrophoresis (DGGE). In whey fermented at 20C the number of lactic-acid bacteria (LAB) was significantly lower (P<005) and the number of yeast significantly higher (P<005) than in fermented milk. Since the DGGE profiles were similar for both products, at this temperature the microbiologic composition of fermented whey is similar to that of fermented milk. We therefore suggest a temperature of 20C to preserve kefir grains as whey-fermentation starters. PMID:22717048

  9. Muscle fatigue examined at different temperatures in experiments on intact mammalian (rat) muscle fibers

    PubMed Central

    Roots, H.; Ball, G.; Talbot-Ponsonby, J.; King, M.; McBeath, K.; Ranatunga, K. W.

    2009-01-01

    In experiments on small bundles of intact fibers from a rat fast muscle, in vitro, we examined the decline in force in repeated tetanic contractions; the aim was to characterize the effect of shortening and of temperature on the initial phase of muscle fatigue. Short tetanic contractions were elicited at a control repetition rate of 1/60 s, and fatigue was induced by raising the rate to 1/5 s for 23 min, both in isometric mode (no shortening) and in shortening mode, in which each tetanic contraction included a ramp shortening at a standard velocity. In experiments at 20C (n = 12), the force decline during a fatigue run was 25% in the isometric mode but was significantly higher (35%) in the shortening mode. In experiments at different temperatures (1030C, n = 11), the tetanic frequency and duration were adjusted as appropriate, and for shortening mode, the velocity was adjusted for maximum power output. In isometric mode, fatigue of force was significantly less at 30C (?20%) than at 10C (?30%); the power output (force velocity) was >10 higher at 30C than at 10C, and power decline during a fatigue run was less at 30C (?2030%) than at 10C (?50%). The finding that the extent of fatigue is increased with shortening contractions and is lower at higher temperatures is consistent with the view that force depression by inorganic phosphate, which accumulates within fibers during activity, may be a primary cause of initial muscle fatigue. PMID:19057001

  10. The time of day differently influences fatigue and locomotor activity: is body temperature a key factor?

    PubMed

    Machado, Frederico Sander Mansur; Rodovalho, Gisele Vieira; Coimbra, Cndido Celso

    2015-03-01

    The aim of this study was to verify the possible interactions between exercise capacity and spontaneous locomotor activity (SLA) during the oscillation of core body temperature (Tb) that occurs during the light/dark cycle. Wistar rats (n=11) were kept at an animal facility under a light/dark cycle of 14/10h at an ambient temperature of 23C and water and food ad libitum. Initially, in order to characterize the daily oscillation in SLA and Tb of the rats, these parameters were continuously recorded for 24h using an implantable telemetric sensor (G2 E-Mitter). The animals were randomly assigned to two progressive exercise test protocols until fatigue during the beginning of light and dark-phases. Fatigue was defined as the moment rats could not keep pace with the treadmill. We assessed the time to fatigue, workload and Tb changes induced by exercise. Each test was separated by 3days. Our results showed that exercise capacity and heat storage were higher during the light-phase (p<0.05). In contrast, we observed that both SLA and Tb were higher during the dark-phase (p<0.01). Notably, the correlation analysis between the amount of SLA and the running capacity observed at each phase of the daily cycle revealed that, regardless of the time of the day, both types of locomotor physical activity have an important inherent component (r=0.864 and r=0.784, respectively, p<0.01) without a direct relationship between them. This finding provides further support for the existence of specific control mechanisms for each type of physical activity. In conclusion, our data indicate that the relationship between the body temperature and different types of physical activity might be affected by the light/dark cycle. These results mean that, although exercise performance and spontaneous locomotor activity are not directly associated, both are strongly influenced by daily cycles of light and dark. PMID:25479573

  11. Anaerobic oxidation of methane at different temperature regimes in Guaymas Basin hydrothermal sediments.

    PubMed

    Biddle, Jennifer F; Cardman, Zena; Mendlovitz, Howard; Albert, Daniel B; Lloyd, Karen G; Boetius, Antje; Teske, Andreas

    2012-05-01

    Anaerobic oxidation of methane (AOM) was investigated in hydrothermal sediments of Guaymas Basin based on ?(13)C signatures of CH(4), dissolved inorganic carbon and porewater concentration profiles of CH(4) and sulfate. Cool, warm and hot in-situ temperature regimes (15-20?C, 30-35?C and 70-95?C) were selected from hydrothermal locations in Guaymas Basin to compare AOM geochemistry and 16S ribosomal RNA (rRNA), mcrA and dsrAB genes of the microbial communities. 16S rRNA gene clone libraries from the cool and hot AOM cores yielded similar archaeal types such as Miscellaneous Crenarchaeotal Group, Thermoproteales and anaerobic methane-oxidizing archaea (ANME)-1; some of the ANME-1 archaea formed a separate 16S rRNA lineage that at present seems to be limited to Guaymas Basin. Congruent results were obtained by mcrA gene analysis. The warm AOM core, chemically distinct by lower porewater sulfide concentrations, hosted a different archaeal community dominated by the two deep subsurface archaeal lineages Marine Benthic Group D and Marine Benthic Group B, and by members of the Methanosarcinales including ANME-2 archaea. This distinct composition of the methane-cycling archaeal community in the warm AOM core was confirmed by mcrA gene analysis. Functional genes of sulfate-reducing bacteria and archaea, dsrAB, showed more overlap between all cores, regardless of the core temperature. 16S rRNA gene clone libraries with Euryarchaeota-specific primers detected members of the Archaeoglobus clade in the cool and hot cores. A V6-tag high-throughput sequencing survey generally supported the clone library results while providing high-resolution detail on archaeal and bacterial community structure. These results indicate that AOM and the responsible archaeal communities persist over a wide temperature range. PMID:22094346

  12. Correlation of activity and weight in comet goldfish (Carassius auratus) at differing water temperatures.

    PubMed

    Nevitt, J R; Hall, R

    1977-08-01

    Correlations of activity and weight at three water temperatures, 20 degrees, 26 degrees, and 30 degrees C, were examined in the comet goldfish (Carassius auratus). For the 12 subjects general activity scores increased as water temperature increased. Heavier subjects were more active at low temperatures while lighter subjects were more active at higher temperatures. PMID:905098

  13. Differences and Similarities between Summer and Winter Temperatures and Winds during MaCWAVE

    NASA Technical Reports Server (NTRS)

    Schmidlin, F. J.; Goldberg, R. A.

    2008-01-01

    The Mountain and Convective Waves Ascending Vertically Experiment (MaCWAVE) was carried out in two sequences: one during the summer from the Andoya Rocket Range (69N) during July 2002 to examine convective initiation of gravity waves. The second was a winter sequence from ESRANGE (68N) during January 2003 to examine mountain-initiated waves. Inflatable falling spheres released from small meteorological rockets provided significant information about the variation of temperature and wind from 50 km and higher. The small rocket launch activity was restricted to 12-hour periods that inhibited observing a full diurnal cycle, nonetheless, the time-history of the measurements have provided information about tidal motion. During summer, temperature variation was smaller than observed during winter when peak differences reached 15-20 K at 80-85 km. variation in zonal winds varied up to more than 100 mps in summer and winter. Times of wind vs. altitude showed that the peak zonal component occurred approximately two hours ahead of the peak meridional wind. Measurement details and the observed variations are discussed.

  14. Differences and Similarities in MaCWAVE Summer and Winter Temperatures and Winds

    NASA Technical Reports Server (NTRS)

    Schmidlin, F. J.; Goldberg, R. A.

    2008-01-01

    Small meteorological rockets released inflatable falling spheres during the MaCWAVE Campaign. The Mountain and Convective Waves Ascending Vertically Experiment (MaCWAVE) was carried out in two parts, a summer sequence from Andoya Rocket Range (69N) during July 2002 to examine convective initiation of gravity waves and a winter sequence from ESRANGE (68N) during January 2003 to examine mountain-terrain initiated gravity waves. The sphere-tracked data provided significant information about the variation of temperature and wind from 70 km and above. The changes observed may be considered akin to tidal motion; unfortunately the launch activity was restricted to 12-hour periods, thus the observation of a full diurnal cycle was not possible. During summer, temperature variation was smaller than that observed during winter when peak to null differences reached 15-20 K at 80-85 km. Variation in the zonal winds varied up to 100+mps in summer and winter. Examination of the times of peak wind vs altitude showed that the peak zonal wind occurred approximately two hours ahead of the peak meridional wind. We provide details about the measurements and observed variations.

  15. Proteomic responses to hypoxia at different temperatures in the great scallop (Pecten maximus)

    PubMed Central

    Lacroix, Camille; Richard, Joëlle; Flye-Sainte-Marie, Jonathan; Bargelloni, Luca; Pichereau, Vianney

    2015-01-01

    Hypoxia and hyperthermia are two connected consequences of the ongoing global change and constitute major threats for coastal marine organisms. In the present study, we used a proteomic approach to characterize the changes induced by hypoxia in the great scallop, Pecten maximus, subjected to three different temperatures (10 °C, 18 °C and 25 °C). We did not observe any significant change induced by hypoxia in animals acclimated at 10 °C. At 18 °C and 25 °C, 16 and 11 protein spots were differentially accumulated between normoxia and hypoxia, respectively. Moreover, biochemical data (octopine dehydrogenase activity and arginine assays) suggest that animals grown at 25 °C switched their metabolism towards anaerobic metabolism when exposed to both normoxia and hypoxia, suggesting that this temperature is out of the scallops’ optimal thermal window. The 11 proteins identified with high confidence by mass spectrometry are involved in protein modifications and signaling (e.g., CK2, TBK1), energy metabolism (e.g., ENO3) or cytoskeleton (GSN), giving insights into the thermal-dependent response of scallops to hypoxia. PMID:25861557

  16. Gene and Protein Expression in Response to Different Growth Temperatures and Oxygen Availability in Burkholderia thailandensis

    PubMed Central

    Peano, Clelia; Chiaramonte, Fabrizio; Motta, Sara; Pietrelli, Alessandro; Jaillon, Sebastien; Rossi, Elio; Consolandi, Clarissa; Champion, Olivia L.; Michell, Stephen L.; Freddi, Luca; Falciola, Luigi; Basilico, Fabrizio; Garlanda, Cecilia; Mauri, Pierluigi; De Bellis, Gianluca; Landini, Paolo

    2014-01-01

    Burkholderia thailandensis, although normally avirulent for mammals, can infect macrophages in vitro and has occasionally been reported to cause pneumonia in humans. It is therefore used as a model organism for the human pathogen B. pseudomallei, to which it is closely related phylogenetically. We characterized the B. thailandensis clinical isolate CDC2721121 (BtCDC272) at the genome level and studied its response to environmental cues associated with human host colonization, namely, temperature and oxygen limitation. Effects of the different growth conditions on BtCDC272 were studied through whole genome transcription studies and analysis of proteins associated with the bacterial cell surface. We found that growth at 37C, compared to 28C, negatively affected cell motility and flagella production through a mechanism involving regulation of the flagellin-encoding fliC gene at the mRNA stability level. Growth in oxygen-limiting conditions, in contrast, stimulated various processes linked to virulence, such as lipopolysaccharide production and expression of genes encoding protein secretion systems. Consistent with these observations, BtCDC272 grown in oxygen limitation was more resistant to phagocytosis and strongly induced the production of inflammatory cytokines from murine macrophages. Our results suggest that, while temperature sensing is important for regulation of B. thailandensis cell motility, oxygen limitation has a deeper impact on its physiology and constitutes a crucial environmental signal for the production of virulence factors. PMID:24671187

  17. Thermophysical properties and rheological behavior of electro-rheological fluids at different temperatures

    NASA Astrophysics Data System (ADS)

    Korobko, Evguenia V.; Korobko, Yulia O.

    2000-04-01

    Fluid disperse systems, sensitive to the external electric field-electrorheological fluids, are finding increasing use in various areas of industry and technology. Their physicomechanical, electrophysical characteristics determine the valuable specific properties of the materials with assigned structure, obtainable with everwide use of electric fields, which makes it possible to substantially enhance efficiency and productiveness of technological processes and to improve the control of operational regimes of the equipment which employ fluid disperse media. The present investigations has been undertaken with the aim of studying thermophysical properties and rheophysical behavior of low-concentration ER- fluid (diatomite in transformer oil) at different temperatures. It was shown that the electric field, which changes considerably the structure of electrorheological fluid, influences effective thermal conductivity and diffusivity coefficients. Their increase with electric field intensity and the increase of the effective viscosity with temperature are connected with the increase of the conductive component of the overall heat transfer through the contact spots between the solid particles, and with intensification of electric convection in the spaces between the dispersed particles.

  18. Definition of predictor variables for MAP poultry filets stored under different temperature conditions.

    PubMed

    Herbert, Ulrike; Albrecht, Antonia; Kreyenschmidt, Judith

    2015-03-01

    Storage tests under different temperatures (2, 4, 10, and 15C) were conducted to identify the best predictor variable that is most effective to explain the loss of the shelf life and quality of modified atmosphere packed (MAP) poultry, and constitutes the basis for the prediction of the remaining shelf life. The samples were packed in 70% O2 and 30% CO2, which is the common used gas atmosphere for poultry filets in Germany. Typical spoilage microorganisms (Pseudomonas spp., Brochothrix thermosphacta, Enterobacteriaceae, and Lactobacillus spp.) and total viable count (TVC) were enumerated frequently. Additionally, samples were analyzed for sensory changes, pH, and gas concentration. The data extraction and selections by stepwise regression and principle component analysis (PCA) was carried out to identify a variable which has the main influence on shelf life and freshness loss. The results accentuate that the spoilage is caused by a wide range of microorganisms. No specific microorganism could be identified as the dominant originator for the deteriorative changes. Solely TVC showed significant correlations between the development of the sensory decay and the development of the TVC for each single storage temperature. PMID:25638474

  19. Use Of Minimum Resolvable Temperature Difference (MRTD) For The Evaluation And Specification Of Thermal Imaging Systems

    NASA Astrophysics Data System (ADS)

    Newbery, A. R.; McMahon, R.

    1981-10-01

    Minimum Resolvable Temperature Difference (MRTD) is now the most widely used parameter for describing both the temperature sensitivity, and spatial resolution of thermal imaging systems. It can be measured in the laboratory, using fairly simple equipment, it can be calculated from component parameters, and a good correlation has been established between MRTD and the field performance of systems, eg detection and recognition ranges of targets. However, both the strength, and the weakness of MRTD lies in the fact that it is a subjective parameter. It is measured by an observer viewing standard bar targets, and so it combines the spatial resolution and noise characteristics (thermal resolution) in the correct way. It also takes account of the performance degradations due for example to cosmetic defects. On the other hand, being a subjective measurement, there is bound to be some variations in measured values, particularly from one laboratory to another. This causes problems, if only from an administrative point of view, when testing a system against a given specification.

  20. Proteomic responses to hypoxia at different temperatures in the great scallop (Pecten maximus).

    PubMed

    Artigaud, Sbastien; Lacroix, Camille; Richard, Jolle; Flye-Sainte-Marie, Jonathan; Bargelloni, Luca; Pichereau, Vianney

    2015-01-01

    Hypoxia and hyperthermia are two connected consequences of the ongoing global change and constitute major threats for coastal marine organisms. In the present study, we used a proteomic approach to characterize the changes induced by hypoxia in the great scallop, Pecten maximus, subjected to three different temperatures (10 C, 18 C and 25 C). We did not observe any significant change induced by hypoxia in animals acclimated at 10 C. At 18 C and 25 C, 16 and 11 protein spots were differentially accumulated between normoxia and hypoxia, respectively. Moreover, biochemical data (octopine dehydrogenase activity and arginine assays) suggest that animals grown at 25 C switched their metabolism towards anaerobic metabolism when exposed to both normoxia and hypoxia, suggesting that this temperature is out of the scallops' optimal thermal window. The 11 proteins identified with high confidence by mass spectrometry are involved in protein modifications and signaling (e.g., CK2, TBK1), energy metabolism (e.g., ENO3) or cytoskeleton (GSN), giving insights into the thermal-dependent response of scallops to hypoxia. PMID:25861557

  1. Histological features of respiratory epithelium of calves held at differing temperature and humidity.

    PubMed Central

    Jericho, K W; Magwood, S E

    1977-01-01

    The effect of ambient temperature and humidity on the structure of respiratory epithelium of calves was studied. Four calves of each of three experiments were acclimatized to a nonoperational environmental chamber for six days and then exposed to constant extremes of temperatures and relative humidity of one of 30 degrees C --35%, or 27 degrees C--92%, or 5 degrees C--92% respectively in this chamber for eight days each. Five calves (3 and 2) were similarly acclimatized then exposed to 1 degrees C--40%. Nasal swabs were taken from all animals at regular intervals. Swabs of three animals yielded Mycoplasma spp. and one swab yielded the virus of infectious bovine rhinotracheitis. Detailed histological studies of respiratory epithelium of nose, trachea, major bronchus and terminal bronchioli were conducted at four sites. Goblet cells were least in calves held in hot and dry air; calves held in dry air had the least polymorphonuclear cells and the greatest prevalence of hypochromatic cell layers and vacuolation of epithelial cells. Differences between experiments were evident most for sites of trachea and major bronchus. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 1. Fig. 2. Fig. 3. PMID:922554

  2. Investigation of Li in Clay Interlayers at Different Temperatures by NMR

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Lee, J.

    2007-12-01

    We used 6Li and 7Li MAS NMR to investigate the environmental changes of Li in the interlayer of clay minerals at room and high (250C) temperatures. We also checked the usefulness 6Li NMR in studying Li in interlayer. Hectorite, Wyoming-montmorillonite, beidellite, and lepidollite were used for our study. 6Li NMR spectra show narrower peaks than those of 7Li NMR, but S/N ratio is low and there are no noticeable chemical shift changes, which makes it difficult to apply 6Li NMR to get information on Li environment in clay interlayers. 7Li NMR spectra, however, show changes in the peak width and quadrupole pattern, providing information on the Li environment in the interlayer, even though the change in chemical shift is not observed. In montmorillonite, two different environments of Li are observed, one having narrow peak with typical quadrupole pattern, and another having broad peak without that pattern. At high temperature, the broad peak becomes relatively, narrow which was also obserbed in the 7Li NMR spectra obtained from beidellite, but not hectorite. This changes are attributed to the coordination changes in the water molecules around Li which is tightly bonded on the basal oxygen of Si tetrahedra as inner-sphere complexes. The narrow peak in montmorillnoite can be assigned to the Li bonded as outer-sphere complexes.

  3. Influence of orientation on the size effect in BCC pillars with different critical temperatures.

    SciTech Connect

    Arzt, Eduard; Gruber, Patrick A.; Clark, Blythe G.; Frick, Carl P.; Schneider, Andreas S.

    2010-09-01

    The size effect in body-centered cubic metals is comprehensively investigated through micro/nano-compression tests performed on focused ion beam machined tungsten (W), molybdenum (Mo) and niobium (Nb) pillars, with single slip [2 3 5] and multiple slip [0 0 1] orientations. The results demonstrate that the stress-strain response is unaffected by the number of activated slip systems, indicating that dislocation-dislocation interaction is not a dominant mechanism for the observed diameter dependent yield strength and strain hardening. Furthermore, the limited mobility of screw dislocations, which is different for each material at ambient temperature, acts as an additional strengthening mechanism leading to a material dependent size effect. Nominal values and diameter dependence of the flow stress significantly deviate from studies on face-centered cubic metals. This is demonstrated by the correlation of size dependence with the material specific critical temperature. Activation volumes were found to decrease with decreasing pillar diameter further indicating that the influence of the screw dislocations decreases with smaller pillar diameter.

  4. Transcription profiles of the bacterium Mycoplasma pneumoniae grown at different temperatures

    PubMed Central

    Weiner, J.; Zimmerman, C.-U.; Ghlmann, H. W. H.; Herrmann, R.

    2003-01-01

    Applying microarray technology, we have investigated the transcriptome of the small bacterium Mycoplasma pneumoniae grown at three different temperature conditions: 32, 37 and 32C followed by a heat shock for 15 min at 43C, before isolating the RNA. From 688 proposed open-reading frames, 676 were investigated and 564 were found to be expressed (P < 0.001; 606 with P < 0.01) and at least 33 (P < 0.001; 77 at P < 0.01) regulated. By quantitative real-time PCR of selected mRNA species, the expression data could be linked to absolute molecule numbers. We found M.pneumoniae to be regulated at the transcriptional level. Forty-seven genes were found to be significantly up-regulated after heat shock (P < 0.01). Among those were the conserved heat shock genes like dnaK, lonA and clpB, but also several genes coding for ribosomal proteins and 10 genes of unassigned functions. In addition, 30 genes were found to be down-regulated under the applied heat shock conditions. Further more, we have compared different methods of cDNA synthesis (random hexamer versus gene-specific primers, different RNA concentrations) and various normalization strategies of the raw microarray data. PMID:14576319

  5. Thermal preference, thermal resistance, and metabolic rate of juvenile Chinese pond turtles Mauremys reevesii acclimated to different temperatures.

    PubMed

    Xu, Wei; Dang, Wei; Geng, Jun; Lu, Hong-Liang

    2015-10-01

    The thermal acclimatory capacity of a particular species may determine its resilience to environmental change. Evaluating the physiological acclimatory responses of economically important species is useful for determining their optimal culture conditions. Here, juvenile Chinese three-keeled pond turtles (Mauremys reevesii) were acclimated to one of three different temperatures (17, 25 or 33C) for four weeks to assess the effects of thermal acclimation on some physiological traits. Thermal acclimation significantly affected thermal resistance, but not thermal preference, of juvenile M. reevesii. Turtles acclimated to 17C were less resistant to high temperatures than those acclimated to 25C and 33C. However, turtles increased resistance to low temperatures with decreasing acclimation temperature. The acclimation response ratio of the critical thermal minimum (CTMin) was lower than that of the critical thermal maximum (CTMax) for acclimation temperatures between 17 and 25C, but slightly higher between 25 and 33C. The thermal resistance range (i.e., the difference between CTMax and CTMin) was widest in turtles acclimated to the intermediate temperature (25C), and narrowest in those acclimated to low temperature (17C). The standard metabolic rate increased as body temperature and acclimation temperature increased, and the temperature quotient (Q10) between acclimation temperatures 17 and 25C was higher than the Q10 between 25 and 33C. Our results suggest that juvenile M. reevesii may have a greater resistance under mild thermal conditions resembling natural environments, and better physiological performance at relatively warm temperatures. PMID:26590464

  6. Determination of spectrum and different temperature of spontaneous chemiluminescence in rice seeds during early imbibition

    NASA Astrophysics Data System (ADS)

    Chen, WenLi; Xing, Da; Van Wijk, Roeland

    2005-02-01

    With high-sensitivity single-photon counter, spontaneous chemiluminescence (CL) spectrum and different temperature study on rice (Oryza sativa L.) seeds during early imbibition were carried out. The emission spectrum of whole rice seed, rice and coat had a greater proportion of red light during early imbibition. Comparing with spontaneous CL of barley (Hordeum vulgare L.) and soybean (Glycine max L. Merr) seeds, the spontaneous CL of rice seeds had a nonlinear, logarithmic-like increase of intensity in the T range 30-50C, the Van't Hoff coefficient Q10=IT+10/IT is equal to 2, which led us to the conclusion that spontaneous CL of rice seed during early imbibition partly came from enzyme catalyzing chemistry reaction.

  7. Abrupt reduction of the critical temperature difference of a thermoacoustic engine by adding water

    NASA Astrophysics Data System (ADS)

    Tsuda, K.; Ueda, Y.

    2015-09-01

    The critical temperature difference (?Tcri) that causes a thermoacoustic spontaneous oscillation is reduced by the presence of water in the working fluid of a thermoacoustic engine. This letter introduces the effects of two design parameters on the reduction of ?Tcri: one is the mass of water added as the working fluid and the other is the characteristic length of the stack, which is the heart of a thermoacoustic engine. The experimental results show that when the mass of added water exceeds the threshold value, ?Tcri decreases abruptly; however, the decreased ?Tcri changes slightly with further increase in the added mass. Moreover, the characteristic length of the stack was found to have little effect on ?Tcri when water is added. These results provide a design guide for a thermoacoustic engine that includes water as the working fluid.

  8. Rarefied Gas Flows Induced through a Pair of Parallel Meshes with Different Temperatures

    NASA Astrophysics Data System (ADS)

    Sugimoto, H.; Kawakami, S.; Moriuchi, K.

    2008-12-01

    A simple method to form micro-channels that induce a rarefied gas flow by the effect of the temperature field is proposed. A pair of parallel wire meshes, one is heated and the other is unheated, induces a gas flow through the pair of meshes in the direction from unheated mesh to heated mesh. Three test devices with different diameters, 1 mm, 100 μm, and 25 μm, of the wire of the mesh, have been devised and the flow through the device is detected by a thin film or a small windmill for various pressures of the gas. The flow is observed in a range of the pressure where the mean free path of gas molecules is close to the scale of the mesh structure, e.g., the diameter of the wire. It is extended to a wider range of the pressure in the device using combined meshes consisting of coarser and finer mesh.

  9. Terahertz absorption spectrum of water vapor at different humidity at room temperature

    NASA Astrophysics Data System (ADS)

    Xin, Xuying; Altan, Hakan; Matten, David; Saint, Angelamaria; Alfano, Robert

    2006-03-01

    We measured the absorption spectrum of water vapor in 0.2-2.4THz range at different humidity from 17% to 98% at room temperature using Er: doped fiber laser (IMRA America Inc.) based terahertz time-domain spectroscopy. The experiments were performed in a nitrogen-purged cage at atmosphere environment to obtain the reference and water absorption information. The seventeen absorption lines were observed due to water molecular rotations in the ground vibration state. The first three absorption lines at low frequencies increase with humidity, following the Beer-Lambert Law, while some of high frequency lines were found to decrease with humidity. These effects will be discussed. The observed line broadening is due to collisions occurring among water and nitrogen molecules.

  10. Effects of experimental reheating of natural basaltic ash at different temperatures and redox conditions

    NASA Astrophysics Data System (ADS)

    D'Oriano, C.; Pompilio, M.; Bertagnini, A.; Cioni, R.; Pichavant, M.

    2013-05-01

    A set of experiments have been performed on volcanic materials from Etna, Stromboli and Vesuvius in order to evaluate how the exposure to thermal and redox conditions close to that of active craters affects the texture and composition of juvenile pyroclasts. Selected samples were placed within a quartz tube, in presence of air or under vacuum, and kept at T between 700 and 1,130 °C, for variable time (40 min to 12 h). Results show that reheating reactivates the melt, which, through processes of chemical and thermal diffusion, reaches new equilibrium conditions. In all the experiments performed at T = 700-750 °C, a large number of crystal nuclei and spherulites grows in the groundmass, suggesting conditions of high undercooling. This process creates textural heterogeneities at the scale of few microns but only limited changes of groundmass composition, which remains clustered around that of the natural glasses. Reheating at T = 1,000-1,050 °C promotes massive groundmass crystallization, with a different mineral assemblage as a function of the redox conditions. Morphological modifications of clasts, from softening to sintering as temperature increases, occur under these conditions, accompanied by progressive smoothing of external surfaces, and a reduction in size and abundance of vesicles, until the complete obliteration of the pre-existing vesicularity. The transition from sintering to welding, characteristic of high temperature, is influenced by redox conditions. Experiments at T = 1,100-1,130 °C and under vacuum produce groundmass textures and glass compositions similar to that of the respective starting material. Collapse and welding of the clasts cause significant densification of the whole charge. At the same temperature, but in presence of air, experimental products at least result sintered and show holocrystalline groundmass. In all experiments, sublimates grow on the external surfaces of the clasts or form a lining on the bubble walls. Their shape and composition is a function of temperature and fO2 and the abundance of sublimates shows a peak at 1,000 °C. The identification of the features recorded by pyroclasts during complex heating-cooling cycles allows reconstructing the complete clasts history before their final emplacement, during weakly explosive volcanic activity. This has a strong implication on the characterization of primary juvenile material and on the interpretation of eruption dynamics.

  11. The relation between climatic temperature and sudden infant death syndrome differs among communities: results from an ecologic analysis.

    PubMed

    Jones, M E; Ponsonby, A L; Dwyer, T; Gilbert, N

    1994-05-01

    We examined the negative relation between temperature and the sudden infant death syndrome (SIDS) in 22 communities in seven countries. We estimated the percentage increase in SIDS rate for a 1 degree C drop in climatic temperature. The relation differed substantially among communities. In New Zealand and Australia (10 communities), the association was consistently strong; in Europe (seven communities), it varied from strong to weak; and in the USA (five communities), it was moderate or weak. We postulate that low climatic temperature indirectly increases the incidence of SIDS, particularly in countries where outdoor climatic temperature modifies the indoor temperature and clothing habits. PMID:8038248

  12. Amorphization of Zr-Al under mechanical alloying at different temperatures: A re-entrant melting phenomenon

    SciTech Connect

    Sheng, H.W.; Lu, K.; Ma, E.

    1998-12-31

    Zr{sub 100{minus}x}Al{sub x} powder blends have been subjected to ball milling at different temperatures to investigate the amorphization process. At low temperatures the Zr-Al solid solutions amorphized under the polymorphous constraints, whereas at higher temperatures there was an obvious two-phase coexistence region. The Al concentration for the complete amorphization of Zr-Al increased with increasing temperature, suggesting a re-entrant melting behavior. Both of the temperature- and composition-dependent amorphization mechanisms are analyzed in terms of the thermodynamic properties of the phases involved, as well as the dynamic effects brought in by the non-equilibrium milling process.

  13. Response of fish to different simulated rates of water temperature increase

    SciTech Connect

    Wike, L.D.; Tuckfield, R.C.

    1992-08-01

    We initiated this study to define the limits of effluent-temperature rate increases during reactor restart, which will help minimize fish kills. We constructed an apparatus for exposing fish to various temperature-increase regimens and conducted two experiments based on information from system tests and scoping runs. In the rate experiment, we acclimated the fish to 20{degree}C, and then raised the temperature to 40{degree}C at varying rates. Because scoping runs and literature suggested that acclimation temperature may affect temperature-related mortality, we conducted an acclimation experiment. We acclimated the fish to various temperatures, then raised the temperatures to 39--40{degree}C at a rate of 2{degree}C every 12 hours. Based on the analysis of the data, we recommend temperature-increase rates during reactor restart of 2.5{degree}C every nine hours if ambient water temperatures are over 20{degree}C. If water temperatures are at or below 20{degree}C, we recommend temperature-increase rates of 2.5{degree}C every 12 hours. No regulation of temperature is required after effluent temperatures reach 40{degree}C. We recommend further studies, including expanded testing with the simulation system and behavioral and bioenergetic investigations that may further refine acceptable rates of effluent-temperature increases.

  14. Acute effects of ozone on heart rate and body temperature in the unanesthetized, unrestrained rat maintained at different ambient temperatures

    SciTech Connect

    Watkinson, W.P.; Aileru, A.A.; Dowd, S.M.; Doerfler, D.L.; Tepper, J.S.

    1993-01-01

    The present studies were conducted to investigate the concentration-response characteristics of acute ozone (O3) exposure on the cardiovascular and thermoregulatory function of the unanesthetized, unrestrained rat, and to examine the modulating effects produced by changes in ambient temperature (T[sub a]) on the induced toxic response. For all studies, groups of male Fischer 344 rats (n=4-6/group) were implanted with radiotelemetry transmitters and allowed to recover overnight. The transmitters permitted continuous monitoring of electrocardiogram (ECG) and body core temperature (T[sub co]); heart rate (HR) was derived from the ECG signal. Frequency of breathing (f) was obtained in selected experiments by means of a Fenn box. All animals were monitored according to the following protocol: control (filtered air; 0.25 h); exposure (O3; 2 h); recovery (filtered air; 3-18 h). For the concentration-response experiments, O3 concentration was varied from 0.25-1.0 ppm and all exposures were conducted at an T[sub a] of 18-20 C. Significant decreases in HR and T[sub co] were demonstrated at O3 concentrations as low as 0.37 ppm.

  15. Estimates of the difference between thermodynamic temperature and the International Temperature Scale of 1990 in the range 118 K to 303 K.

    PubMed

    Underwood, R; de Podesta, M; Sutton, G; Stanger, L; Rusby, R; Harris, P; Morantz, P; Machin, G

    2016-03-28

    Using exceptionally accurate measurements of the speed of sound in argon, we have made estimates of the difference between thermodynamic temperature, T, and the temperature estimated using the International Temperature Scale of 1990, T90, in the range 118 K to 303 K. Thermodynamic temperature was estimated using the technique of relative primary acoustic thermometry in the NPL-Cranfield combined microwave and acoustic resonator. Our values of (T-T90) agree well with most recent estimates, but because we have taken data at closely spaced temperature intervals, the data reveal previously unseen detail. Most strikingly, we see undulations in (T-T90) below 273.16 K, and the discontinuity in the slope of (T-T90) at 273.16 K appears to have the opposite sign to that previously reported. PMID:26903104

  16. Assessment of acute toxicity of carbofuran in Macrobrachium olfersii (Wiegmann, 1836) at different temperature levels.

    PubMed

    Barbieri, Edison; Moreira, Priscila; Luchini, Luiz Alberto; Ruiz Hidalgo, Karla; Muñoz, Alejandro

    2016-01-01

    Carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate; C12H15NO3) is one of the most toxic carbamate pesticides. For acute toxicity of carbofuran, juveniles of Macrobrachium olfersii were exposed to different concentrations of carbofuran using the static renewal method at different temperature levels (15, 20 and 25°C) at pH 7.0. The main purpose of the present study was to detect the acute toxicity of carbofuran to M. olfersii and investigate its effects on oxygen consumption and ammonium excretion; these tests have not been carried out in this species before. First, the acute toxicity - median lethal concentration - of carbofuran to M. olfersii for 24, 48, 72 and 96 h was examined, which resulted in the following values: 1.64, 1.22, 0.86 and 0.42 mg L(-1), respectively. Furthermore, we also found that carbofuran caused an inhibition in oxygen consumption of 60.6, 65.3 and 66.2% with respect to the control. In addition, after separate exposures to carbofuran, elevations in ammonium excretion were more than 500% with respect to the control. PMID:23847016

  17. Growth and heavy metal removal by Klebsiella aerogenes at different pH and temperature

    SciTech Connect

    Al-Shahwani, M.F.; Jazrawi, S.F.; Al-Rawi, E.H.; Ayar, N.S.

    1984-01-01

    A strain of Klebsiella aerogenes isolated from Rustamiyah Station for treatment of wastewater was examined for its ability to grow in a media supplemented with maximum tolerance concentrations of Pb/sup + +/, Zn/sup + +/, Ni/sup + +/, and Cd/sup + +/, separately, at different temperatures and initial pH. The results indicated that at 28/sup 0/C during the first 24 hr, Pb/sup + +/ and Ni/sup + +/ had no effect on the growth of the bacteria, while the presence of Zn/sup + +/ and Cd/sup + +/ decreased the cell count. The growth reached a maximum level after the second day and started to decrease gradually. The bacterial count at 37/sup 0/C was less than that at 28/sup 0/C. No bacterial multiplication occurred at 44/sup 0/C. There was little difference between heavy metal removal at 28 and 37/sup 0/C. At 44/sup 0/C, little removal took place. In general, slightly acidic or neutral medium was better for both bacterial growth and metal removal.

  18. The influence of internal and skin temperatures on active cutaneous vasodilation under different levels of exercise and ambient temperatures in humans

    NASA Astrophysics Data System (ADS)

    Demachi, Koichi; Yoshida, Tetsuya; Kume, Masashi; Tsuji, Michio; Tsuneoka, Hideyuki

    2013-07-01

    To clarify the influence of internal and skin temperature on the active cutaneous vasodilation during exercise, the body temperature thresholds for the onset of active vasodilation during light or moderate exercise under different ambient temperature conditions were compared. Seven male subjects performed 30 min of a cycling exercise at 20 % or 50 % of peak oxygen uptake in a room maintained at 20, 24, or 28 C. Esophageal (Tes) and mean skin temperature (Tsk) as measured by a thermocouple, deep thigh temperature (Tdt) by the zero-heat-flow (ZHF) method, and forearm skin blood flow by laser-Doppler flowmetry (LDF) were monitored. The mean arterial pressure (MAP) was also monitored non-invasively, and the cutaneous vascular conductance (CVC) was calculated as the LDF/MAP. Throughout the experiment, the Tsk at ambient temperatures of 20, 24, and 28 C were approximately 30, 32, and 34 C, respectively, for both 20 % and 50 % exercise. During 50 % exercise, the Tes or Tdt thresholds for the onset of the increase in CVC were observed to be similar among the 20, 24, and 28 C ambient conditions. During 20 % exercise, the increase in Tes and Tdt was significantly lower than those found at 50 %, and the onset of the increase in CVC was only observed at 28 C. These results suggest that the onset of active vasodilation was affected more strongly by the internal or exercising tissue temperatures than by the skin temperatures during exercise performed at a moderate load in comparison to a light load under Tsk variations ranging from 30 C to 34 C. Therefore, the modification by skin temperature of the central control on cutaneous vasomotor tone during exercise may differ between different exercise loads.

  19. Migration of DEHP and DINP into dust from PVC flooring products at different surface temperature.

    PubMed

    Jeon, Seunghwan; Kim, Ki-Tae; Choi, Kyungho

    2016-03-15

    Phthalates are important endocrine disrupting chemicals that have been linked to various adverse human health effects. Phthalates are ubiquitously present in indoor environment and could enter humans. Vinyl or PVC floorings have been recognized as one of important sources of phthalate release to indoor environment including house dust. In the present study, we estimated the migration of di(2-ethylhexyl)phthalate (DEHP) and di-isononyl phthalate (DINP) from the flooring materials into the dust under different heating conditions. For this purpose, a small chamber specifically designed for the present study and a Field and Laboratory Emission Cell (FLEC) were used, and four major types of PVC flooring samples including two UV curing paint coated, an uncoated residential, and a wax-coated commercial type were tested. Migration of DEHP was observed for an uncoated residential type and a wax-coated commercial type flooring. After 14days of incubation, the levels of DEHP in the dust sample was determined at room temperature on average (standard deviation) at 384±19 and 481±53μg/g, respectively. In contrast, migration of DINP was not observed. The migration of DEHP was strongly influenced by surface characteristics such as UV curing coating. In the residential flooring coated with UV curing paint, migration of DEHP was not observed at room temperature. But under the heated condition, the release of DEHP was observed in the dust in the FLEC. Migration of DEHP from flooring materials increased when the flooring was heated (50°C). In Korea, heated flooring system, or 'ondol', is very common mode of heating in residential setting, therefore the contribution of PVC flooring to the total indoor DEHP exposure among general population is expected to be greater especially during winter season when the floor is heated. PMID:26824397

  20. Small change, big difference: Sea surface temperature distributions for tropical coral reef ecosystems, 1950-2011

    NASA Astrophysics Data System (ADS)

    Lough, J. M.

    2012-09-01

    Changes in tropical sea surface temperature (SST) are examined over the period 1950-2011 during which global average temperature warmed by 0.4C. Average tropical SST is warming about 70% of the global average rate. Spatially, significant warming between the two time periods, 1950-1980 and 1981-2011, has occurred across 65% of the tropical oceans. Coral reef ecosystems occupy 10% of the tropical oceans, typically in regions of warmer (+1.8C) and less variable SST (80% of months within 3.3C range) compared to non-reef areas (80% of months within 7.0C range). SST is a primary controlling factor of coral reef distribution and coral reef organisms have already shown their sensitivity to the relatively small amount of warming observed so far through, for example, more frequent coral bleaching events and outbreaks of coral disease. Experimental evidence is also emerging of possible thermal thresholds in the range 30C-32C for some physiological processes of coral reef organisms. Relatively small changes in SST have already resulted in quite large differences in SST distribution with a maximum hot spot of change in the near-equatorial Indo-Pacific which encompasses both the Indo-Pacific warm pools and the center of coral reef biodiversity. Identification of this hot spot of SST change is not new but this study highlights its significance with respect to tropical coral reef ecosystems. Given the modest amount of warming to date, changes in SST distribution are of particular concern for coral reefs given additional local anthropogenic stresses on many reefs and ongoing ocean acidification likely to increasingly compromise coral reef processes.

  1. Role of temperature differences between surface and deep reservoirs in geyser dynamics: Insights from laboratory experiments

    NASA Astrophysics Data System (ADS)

    Munoz Saez, C.; Shteinberg, A.; Manga, M.

    2012-12-01

    Geysers are springs that produce episodic eruptions of steam, liquid water, and non-condensable gases. Their eruptions are smaller and more frequent than other eruptive processes (volcanic, or hydrothermal eruptions), providing a feasible natural laboratory to understand eruptive processes. Moreover, the fluid dynamics of geysers probe processes that operate in more inaccessible geothermal systems. We developed laboratory experiments to understand the role of the surface temperature on geyser dynamics. For the experimental model, we followed to model developed by Steinberg et al. (1982), which produced periodic eruptions. In this experimental model, eruptions are driven by the ascent of bubbles. The "explosive" ejection of fluid occurs when bubbles reach the surface of the conduit. The eruption of a bubble influences the nucleation on the next bubble through the pressure changes in the conduit. The experimental apparatus consists of a bottom reservoir and a vertical conduit that opens into an upper chamber that collects and returns liquid to the reservoir after the eruption. The reservoir was heated from below at a constant rate. The fluid used was Freon 113, which has a boiling point of 48C. Temperature in the upper part of the tube was varied between 0 to 20C. As we increase the temperature difference between the reservoir and the surface of the tube we find (1) that vapor contained in the upper part of bubble tends condense, impeding its ascent to the surface, (2) an increase the number of bubbles generated during the time between eruptions, (3) that the volume of vapor in the tube remain almost constant during the period between eruptions (4) an increase the frequency of eruptions, (5) an increase the escape speed of fluid from the tube, and (6) an increase in Reynolds number. We interpret these results in terms of heat transport by the rising bubbles. Bubbles transport the heat as latent heat of evaporation. Because the amount of heating was the same in all cases, to transport the same amount of heat with bubbles that tend to condense in the upper conduit, they must be generated more rapidly and hence eruptions occur more frequently. Even though, natural eruptive systems are much more complex that these experiments, our model allows us to study the coupling between bubble nucleation, bubble growth and ascent, and surface eruption. Reference: Steinberg, G.S., Merzhanov, G.S., and Steinberg, A.S. (1982) Geyser process: Theory, modeling, and field experiments. Part 3.Theory of the geyser process, Modern Geology, 8, 67-70.

  2. Understanding Differences in Upper Stratospheric Ozone Response to Changes in Chlorine and Temperature as Computed Using CCMVal Models

    NASA Technical Reports Server (NTRS)

    Douglass, A. R.; Stolarski, R. S.; Strahan, S. E.; Oman, L. D.

    2012-01-01

    Projections of future ozone levels are made using models that couple a general circulation model with a representation of atmospheric photochemical processes, allowing interactions among photochemical processes, radiation, and dynamics. Such models are known as chemistry and climate models (CCMs). Although developed from common principles and subject to the same boundary conditions, simulated ozone time series vary for projections of changes in ozone depleting substances (ODSs) and greenhouse gases. In the upper stratosphere photochemical processes control ozone level, and ozone increases as ODSs decrease and temperature decreases due to greenhouse gas increase. Simulations agree broadly but there are quantitative differences in the sensitivity of ozone to chlorine and to temperature. We obtain insight into these differences in sensitivity by examining the relationship between the upper stratosphere annual cycle of ozone and temperature as produced by a suite of models. All simulations conform to expectation in that ozone is less sensitive to temperature when chlorine levels are highest because chlorine catalyzed loss is nearly independent of temperature. Differences in sensitivity are traced to differences in simulated temperature, ozone and reactive nitrogen when chlorine levels are close to background. This work shows that differences in the importance of specific processes underlie differences in simulated sensitivity of ozone to composition change. This suggests a) the multi-model mean is not a best estimate of the sensitivity of upper ozone to changes in ODSs and temperature; b) the spread of values is not an appropriate measure of uncertainty.

  3. Lattice damage and secondary phase formation in Yttria stabilised zirconia implanted with Fe at different temperatures

    NASA Astrophysics Data System (ADS)

    Zhou, Shengqiang; Shalimov, Artem; Wang, Yugang; Potzger, Kay

    2011-09-01

    In this paper we report on the lattice damage and nanocrystalline secondary phase formation in Fe implanted Yttria stabilised zirconia (YSZ) up to a peak concentration of 10%. The implantation temperature has been varied between room temperature and 1000 C. Samples were characterized using Rutherford backscattering/channeling and X-ray diffraction. We observed that (1) YSZ remains partially crystalline even after Fe implantation at room temperature and the lattice damage can be partially recovered if implantation is performed at elevated temperatures; (2) crystalline bcc-Fe nanoparticles have formed and grown with increasing implantation temperature. The nanoscale Fe precipitates and the YSZ matrix have a crystallographic orientation relationship.

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

    PubMed Central

    Chen, Xiaoying; Song, Fengbin; Liu, Fulai; Tian, Chunjie; Liu, Shengqun; Xu, Hongwen; Zhu, Xiancan

    2014-01-01

    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. PMID:24895680

  5. Low temperatures enhance the toxicity of copper and cadmium to Enchytraeus crypticus through different mechanisms.

    PubMed

    Cedergreen, Nina; Nrhave, Nils Jakob; Nielsen, Kristoffer; Johansson, Hanna K L; Marcussen, Helle; Svendsen, Claus; Spurgeon, David J

    2013-10-01

    Knowledge about how toxicity changes with temperature is important for determining the extent of safety factors required when extrapolating from standard laboratory conditions to variable field scenarios. In the present study, the authors evaluated the toxicity of Cu and Cd to the potworm Enchytraeus crypticus at 6 temperatures in the range of 11 C to 25 C. For both metals, reproductive toxicity decreased approximately 2.5-fold with increasing temperature. This is contrary to what most other studies have found. Measurements of the bioavailable fraction of the metals in the soils and the internal metal concentrations in the worms over time showed that the major cause of change in toxicity with temperature for Cu was the worms' ability to regulate internal concentration at high temperatures. Uptake of Cd increased with time at all temperatures and with higher rates at high temperatures. Hence, the lower toxicity of Cd at high temperatures is proposed to be due to the E. crypticus being more efficient at immobilizing Cd and/or repairing damages at high compared to low temperatures. The present study concludes that no consistent relationship between metal toxicity and temperature across species can be made. The metabolic dependence of the species in terms of regulating metal uptake, excretion, immobilization, damage, and repair processes, will be crucial factors in determining species susceptibility to metals at varying temperatures. PMID:23661382

  6. Moisture and temperature controls on nitrification differ among ammonia oxidizer communities from three alpine soil habitats

    NASA Astrophysics Data System (ADS)

    Osborne, Brooke B.; Baron, Jill S.; Wallenstein, Matthew D.

    2016-03-01

    Climate change is altering the timing and magnitude of biogeochemical fluxes in many highelevation ecosystems. The consequent changes in alpine nitrification rates have the potential to influence ecosystem scale responses. In order to better understand how changing temperature and moisture conditions may influence ammonia oxidizers and nitrification activity, we conducted laboratory incubations on soils collected in a Colorado watershed from three alpine habitats (glacial outwash, talus, and meadow). We found that bacteria, not archaea, dominated all ammonia oxidizer communities. Nitrification increased with moisture in all soils and under all temperature treatments. However, temperature was not correlated with nitrification rates in all soils. Site-specific temperature trends suggest the development of generalist ammonia oxidzer communities in soils with greater in situ temperature fluctuations and specialists in soils with more steady temperature regimes. Rapidly increasing temperatures and changing soil moisture conditions could explain recent observations of increased nitrate production in some alpine soils.

  7. Moisture and temperature controls on nitrification differ among ammonia oxidizer communities from three alpine soil habitats

    USGS Publications Warehouse

    Osborne, Brooke B; Baron, Jill S.; Wallenstein, Matthew D.

    2015-01-01

    Climate change is altering the timing and magnitude of biogeochemical fluxes in many high elevation ecosystems. The consequent changes in alpine nitrification rates have the potential to influence ecosystem scale responses. In order to better understand how changing temperature and moisture conditions may influence ammonia oxidizers and nitrification activity, we conducted laboratory incubations on soils collected in a Colorado watershed from three alpine habitats (glacial outwash, talus, and meadow). We found that bacteria, not archaea, dominated all ammonia oxidizer communities. Nitrification increased with moisture in all soils and under all temperature treatments. However, temperature was not correlated with nitrification rates in all soils. Site-specific temperature trends suggest the development of generalist ammonia oxidizer communities in soils with greater in situ temperature fluctuations and specialists in soils with more steady temperature regimes. Rapidly increasing temperatures and changing soil moisture conditions could explain recent observations of increased nitrate production in some alpine soils.

  8. Moisture and temperature controls on nitrification differ among ammonia oxidizer communities from three alpine soil habitats

    NASA Astrophysics Data System (ADS)

    Osborne, Brooke B.; Baron, Jill S.; Wallenstein, Matthew D.

    2015-11-01

    Climate change is altering the timing and magnitude of biogeochemical fluxes in many highelevation ecosystems. The consequent changes in alpine nitrification rates have the potential to influence ecosystem scale responses. In order to better understand how changing temperature and moisture conditions may influence ammonia oxidizers and nitrification activity, we conducted laboratory incubations on soils collected in a Colorado watershed from three alpine habitats (glacial outwash, talus, and meadow). We found that bacteria, not archaea, dominated all ammonia oxidizer communities. Nitrification increased with moisture in all soils and under all temperature treatments. However, temperature was not correlated with nitrification rates in all soils. Site-specific temperature trends suggest the development of generalist ammonia oxidzer communities in soils with greater in situ temperature fluctuations and specialists in soils with more steady temperature regimes. Rapidly increasing temperatures and changing soil moisture conditions could explain recent observations of increased nitrate production in some alpine soils.

  9. Isotopic ordering in eggshells reflects body temperatures and suggests differing thermophysiology in two Cretaceous dinosaurs

    NASA Astrophysics Data System (ADS)

    Eagle, Robert A.; Enriquez, Marcus; Grellet-Tinner, Gerald; Pérez-Huerta, Alberto; Hu, David; Tütken, Thomas; Montanari, Shaena; Loyd, Sean J.; Ramirez, Pedro; Tripati, Aradhna K.; Kohn, Matthew J.; Cerling, Thure E.; Chiappe, Luis M.; Eiler, John M.

    2015-10-01

    Our understanding of the evolutionary transitions leading to the modern endothermic state of birds and mammals is incomplete, partly because tools available to study the thermophysiology of extinct vertebrates are limited. Here we show that clumped isotope analysis of eggshells can be used to determine body temperatures of females during periods of ovulation. Late Cretaceous titanosaurid eggshells yield temperatures similar to large modern endotherms. In contrast, oviraptorid eggshells yield temperatures lower than most modern endotherms but ~6 °C higher than co-occurring abiogenic carbonates, implying that this taxon did not have thermoregulation comparable to modern birds, but was able to elevate its body temperature above environmental temperatures. Therefore, we observe no strong evidence for end-member ectothermy or endothermy in the species examined. Body temperatures for these two species indicate that variable thermoregulation likely existed among the non-avian dinosaurs and that not all dinosaurs had body temperatures in the range of that seen in modern birds.

  10. Effects of rapid temperature changes on HK, PK and HSP70 of Litopenaeus vannamei in different seasons

    NASA Astrophysics Data System (ADS)

    Guo, Biao; Wang, Fang; Dong, Shuanglin; Hou, Chunqiang

    2010-09-01

    Activities of hexokinase (HK), pyruvate kinase (PK) and levels of HSP70 were measured to evaluate the response of Litopenaeus vannamei to rapid temperature changes under controlled laboratory conditions. Shrimps were subjected to a quick temperature change from 27°C to 17°C for the summer case (Cold temperature treatment), or from 17°C to 27°C for the winter case (Warm temperature treatment). After 0.5, 1, 3, 6, 12, 24, 48, and 72 h of exposure time, shrimps were sampled and prepared for further analysis. The results showed that the effect of acute temperature changes on activities of HK was significant. Patterns of variations of the two glycolytic enzymes suggested that enzymes in the glycolysis cycle could adjust their activities to meet the acute temperature change. The HSP70 level increased in both cold and warm temperature treatments, suggesting that the rapid temperature changes activated the process of body’s self-protection. But the difference in expression peak of HSP70 might be related to the different body size and the higher thermal sensitivity to temperature increase than to temperature decrease of L. vannamei.

  11. Developing a Heatwave Early Warning System for Sweden: Evaluating Sensitivity of Different Epidemiological Modelling Approaches to Forecast Temperatures

    PubMed Central

    strm, Christofer; Ebi, Kristie L.; Langner, Joakim; Forsberg, Bertil

    2014-01-01

    Over the last two decades a number of heatwaves have brought the need for heatwave early warning systems (HEWS) to the attention of many European governments. The HEWS in Europe are operating under the assumption that there is a high correlation between observed and forecasted temperatures. We investigated the sensitivity of different temperature mortality relationships when using forecast temperatures. We modelled mortality in Stockholm using observed temperatures and made predictions using forecast temperatures from the European Centre for Medium-range Weather Forecasts to assess the sensitivity. We found that the forecast will alter the expected future risk differently for different temperature mortality relationships. The more complex models seemed more sensitive to inaccurate forecasts. Despite the difference between models, there was a high agreement between models when identifying risk-days. We find that considerations of the accuracy in temperature forecasts should be part of the design of a HEWS. Currently operating HEWS do evaluate their predictive performance; this information should also be part of the evaluation of the epidemiological models that are the foundation in the HEWS. The most accurate description of the relationship between high temperature and mortality might not be the most suitable or practical when incorporated into a HEWS. PMID:25546283

  12. Tympanic temperature and heart rate changes in firefighters during treadmill runs performed with different fireproof jackets.

    PubMed

    Ftaiti, F; Duflot, J C; Nicol, C; Grlot, L

    2001-04-15

    Six well-trained firefighters performed six treadmill runs at 70% of the velocity at VO2max (Maximal aerobic velocity MAV = 13.2+/-0.3 km h(-1)). A recovery time of 1 week was allowed between trials. The first session was performed by subjects wearing only shorts (i.e. no fire jacket, J0). A similar protocol was applied subsequently to test the physiological effects associated with the wearing of one of five different fire jackets: one leather (J1) and four textile-type jackets: VTN with membrane (J2), VTN without membrane (J3), Vidal with Kermel HTA (Haute Teneur en Aramide i.e. high density in Aramide) (J4); and Rolland with Kermel HTA (J5). All sessions were performed in a randomized order and in laboratory conditions. Exercise with the fireproof jackets resulted in higher tympanic temperature (Tty), heart rate (HR) and body mass loss (BML) changes compared to J0 (p<0.001). The magnitudes of these changes depended on the type of the jacket. Exercise in the leather jacket (J1) resulted in the highest Tty and HR, which differed significantly from values in all other conditions (p<0.001). The exercise-induced increases in Tty wearing jackets J3 and J5 were also significantly (p < 0.05) higher than those observed with jackets J2 and J4. In conclusion, textile jackets induced less HR and Tty stresses than the leather one. The magnitude of the physiological responses induced by textile jackets were correlated to jacket weight. J2 and J4 jackets were more effective in limiting hyperthermia and any potential detrimental effect on the exercise capacity. PMID:11345493

  13. Upgrade of egg quality through different heat-combating systems during high environmental temperature.

    PubMed

    Anjum, Muhammad Safdar; Sandhu, Mansur Abdullah; Mukhtar, Nasir; Rahman, Zia-ur

    2014-10-01

    The aim of the study was to find out the effect of various heat-combating systems (HCS) on the egg quality characteristics of commercial laying hens during high environmental temperature of the year. Three hundred pullets were wing banded and randomly divided into 15 experimental units comprising of 20 pullets each. These units were randomly allotted to five treatment groups, replicated thrice according to four heat-combating systems (desert cooling, water sprinkling, time limit feeding, ascorbic acid supplementation), and the control was maintained under the same housing system. The mean values of egg weight, eggshell thickness, Haugh unit, thick albumen height, yolk height, and yolk diameter were calculated. The layers kept under the influence of desert cooling produced eggs with more weight and thicker shells than those under other systems. Results of the present study did not show any difference in the shell thickness between water sprinkling and ascorbic acid supplementation as compared to the control group. Haugh unit and yolk index values obtained from the layers kept under various HCS did not significantly differ from those of the control group. All HCS significantly reduced the occurrence of blood spots in the eggs as compared to the control. All the treatments in general markedly reduced the incidence of meat spots in the eggs especially with the supplementation of ascorbic acid being the most effective. Among all of the treatments, the desert cooling system proved to be the best for producing better-quality eggs during hot periods of the year with less humidity. PMID:24839898

  14. Investigation of potential waste material insulating properties at different temperature for thermal storage application

    NASA Astrophysics Data System (ADS)

    Ali, T. Z. S.; Rosli, A. B.; Gan, L. M.; Billy, A. S.; Farid, Z.

    2013-12-01

    Thermal energy storage system (TES) is developed to extend the operation of power generation. TES system is a key component in a solar energy power generation plant, but the main issue in designing the TES system is its thermal capacity of storage materials, e.g. insulator. This study is focusing on the potential waste material acts as an insulator for thermal energy storage applications. As the insulator is used to absorb heat, it is needed to find suitable material for energy conversion and at the same time reduce the waste generation. Thus, a small-scale experimental testing of natural cooling process of an insulated tank within a confined room is conducted. The experiment is repeated by changing the insulator from the potential waste material and also by changing the heat transfer fluid (HTF). The analysis presented the relationship between heat loss and the reserved period by the insulator. The results show the percentage of period of the insulated tank withstands compared to tank insulated by foam, e.g. newspaper reserved the period of 84.6% as much as foam insulated tank to withstand the heat transfer of cooking oil to the surrounding. The paper finally justifies the most potential waste material as an insulator for different temperature range of heat transfer fluid.

  15. Detection of significant differences between absorption spectra of neutral helium and low temperature photoionized helium plasmas

    SciTech Connect

    Bartnik, A.; Wachulak, P.; Fiedorowicz, H.; Fok, T.; Jarocki, R.; Szczurek, M.

    2013-11-15

    In this work, spectral investigations of photoionized He plasmas were performed. The photoionized plasmas were created by irradiation of helium stream, with intense pulses from laser-plasma extreme ultraviolet (EUV) source. The EUV source was based on a double-stream Xe/Ne gas-puff target irradiated with 10 ns/10 J Nd:YAG laser pulses. The most intense emission from the source spanned a relatively narrow spectral region below 20 nm, however, spectrally integrated intensity at longer wavelengths was also significant. The EUV radiation was focused onto a gas stream, injected into a vacuum chamber synchronously with the EUV pulse. The long-wavelength part of the EUV radiation was used for backlighting of the photoionized plasmas to obtain absorption spectra. Both emission and absorption spectra in the EUV range were investigated. Significant differences between absorption spectra acquired for neutral helium and low temperature photoionized plasmas were demonstrated for the first time. Strong increase of intensities and spectral widths of absorption lines, together with a red shift of the K-edge, was shown.

  16. CO{sub 2}-gasification reactivity of different carbonaceous materials at elevated temperatures

    SciTech Connect

    Gu, J.; Wu, S.; Wu, Y.; Gao, J.

    2009-07-01

    At the atmospheric pressure and at the temperatures between 1,223 and 1,673 K, the CO{sub 2} gasification reactivity of seven different carbonaceous materials comprising coal tar pitch coke, petroleum coke, natural graphite, carbon black and three coal chars was investigated by using thermogravimetric analysis. Their crystalline structures were analyzed by X-ray diffraction (XRD). It is found that the reactivity of the chars, pitch coke and petroleum coke produced from liquid phase carbonization, is several times poorer than that of the coal chars produced from solid phase carbonization and even lower than that of natural graphite. At the same time, it is obtained that under the condition of the chemical reaction control, the apparent activation energies of the former are in the range of 135.82-174.92 kJ/mol, while those of the latter are between 89.95 kJ/mol and 110.05 kJ/mol. Besides, the reactivity of the sample has a certain correlation with the crystalline structure of the sample, i.e., the larger the fraction of the relatively better crystalline structure is, the poorer the reactivity of the sample is.

  17. Detection of significant differences between absorption spectra of neutral helium and low temperature photoionized helium plasmas

    NASA Astrophysics Data System (ADS)

    Bartnik, A.; Wachulak, P.; Fiedorowicz, H.; Fok, T.; Jarocki, R.; Szczurek, M.

    2013-11-01

    In this work, spectral investigations of photoionized He plasmas were performed. The photoionized plasmas were created by irradiation of helium stream, with intense pulses from laser-plasma extreme ultraviolet (EUV) source. The EUV source was based on a double-stream Xe/Ne gas-puff target irradiated with 10 ns/10 J Nd:YAG laser pulses. The most intense emission from the source spanned a relatively narrow spectral region below 20 nm, however, spectrally integrated intensity at longer wavelengths was also significant. The EUV radiation was focused onto a gas stream, injected into a vacuum chamber synchronously with the EUV pulse. The long-wavelength part of the EUV radiation was used for backlighting of the photoionized plasmas to obtain absorption spectra. Both emission and absorption spectra in the EUV range were investigated. Significant differences between absorption spectra acquired for neutral helium and low temperature photoionized plasmas were demonstrated for the first time. Strong increase of intensities and spectral widths of absorption lines, together with a red shift of the K-edge, was shown.

  18. Novel Low Temperature Co-Fired Ceramic Material System Composed of Dielectrics with Different Dielectric Constants

    NASA Astrophysics Data System (ADS)

    Sakamoto, Sadaaki; Adachi, Hiroshige; Kaneko, Kazuhiro; Sugimoto, Yasutaka; Takada, Takahiro

    2013-09-01

    We found that the co-firing low temperature co-fired ceramic (LTCC) materials of different dielectric constants (ɛr) with Cu wiring is achievable using a novel, original design. It was confirmed that the dielectric characteristics of the dielectrics designed in this study are very suitable for the use of the dielectrics in electronic components such as filters mounted in high-speed radio communication equipment. The dielectric constants of the lower- and higher-dielectric-coefficient materials were 8.1 and 44.5, respectively, which are sufficiently effective for downsizing LTCC components. Observing the co-fired interface, it was confirmed that excellent co-firing conditions resulted in no mechanical defects such as delamination or cracks. On the basis of the results of wavelength dispersive X-ray spectrometry (WDX) and X-ray diffractometry (XRD), it was confirmed that co-firing with minimal interdiffusion was realized using the same glass for both dielectrics. It is concluded that the materials developed are good for co-firing in terms of the mechanical defects and interdiffusion that appear in them.

  19. The role of Coulomb collisions in limiting differential flow and temperature differences in the solar wind

    NASA Technical Reports Server (NTRS)

    Neugebauer, M.

    1976-01-01

    Data obtained by OGO 5 are used to confirm IMP 6 observations of an inverse dependence of the helium-to-hydrogen temperature ratio in the solar wind on the ratio of solar-wind expansion time to the Coulomb-collision equipartition time. The analysis is then extended to determine the relation of the difference between the hydrogen and helium bulk velocities (the differential flow vector) with the ratio between the solar-wind expansion time and the time required for Coulomb collisions to slow down a beam of ions passing through a plasma. It is found that the magnitude of the differential flow vector varies inversely with the time ratio when the latter is small and approaches zero when it is large. These results are shown to suggest a model of continuous preferential heating and acceleration of helium (or cooling and deceleration of hydrogen), which is cancelled or limited by Coulomb collisions by the time the plasma has reached 1 AU. Since the average dependence of the differential flow vector on the time ratio cannot explain all the systematic variations of the vector observed in corotating high-velocity streams, it is concluded that additional helium acceleration probably occurs on the leading edge of such streams.

  20. Establishment of Three Francisella Infections in Zebrafish Embryos at Different Temperatures

    PubMed Central

    Brudal, Espen; Ulanova, Lilia S.; O. Lampe, Elisabeth; Rishovd, Anne-Lise; Winther-Larsen, Hanne C.

    2014-01-01

    Francisella spp. are facultative intracellular pathogens identified in increasingly diverse hosts, including mammals. F. noatunensis subsp. orientalis and F. noatunensis subsp. noatunensis infect fish inhabiting warm and cold waters, respectively, while F. tularensis subsp. novicida is highly infectious for mice and has been widely used as a model for the human pathogen F. tularensis. Here, we established zebrafish embryo infection models of fluorescently labeled F. noatunensis subsp. noatunensis, F. noatunensis subsp. orientalis, and F. tularensis subsp. novicida at 22, 28, and 32°C, respectively. All infections led to significant bacterial growth, as shown by reverse transcription-quantitative PCR (RT-qPCR), and to a robust proinflammatory immune response, dominated by increased transcription of tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β). F. noatunensis subsp. orientalis was the most virulent, F. noatunensis subsp. noatunensis caused chronic infection, and F. tularensis subsp. novicida showed moderate virulence and led to formation of relatively small granuloma-like structures. The use of transgenic zebrafish strains with enhanced green fluorescent protein (EGFP)-labeled immune cells revealed their detailed interactions with Francisella species. All three strains entered preferentially into macrophages, which eventually assembled into granuloma-like structures. Entry into neutrophils was also observed, though the efficiency of this event depended on the route of infection. The results demonstrate the usefulness of the zebrafish embryo model for studying infections caused by different Francisella species at a wide range of temperatures and highlight their interactions with immune cells. PMID:24614659

  1. Chemical spray pyrolysis of ?-In2S3 thin films deposited at different temperatures

    NASA Astrophysics Data System (ADS)

    Sall, Thierno; Mar Soucase, Bernab; Mollar, Miguel; Hartitti, Bouchaib; Fahoume, Mounir

    2015-01-01

    In2S3 thin films were deposited onto indium tin oxide-coated glass substrates by chemical spray pyrolysis while keeping the substrates at different temperatures. The structures of the sprayed In2S3 thin films were characterized by X-ray diffraction (XFD). The quality of the thin films was determined by Raman spectroscopy. Scanning electron microscopy (SEM) and atomic force microscopy were used to explore the surface morphology and topography of the thin films, respectively. The optical band gap was determined based on optical transmission measurements. The indium sulfide phase exhibited a preferential orientation in the (0, 0, 12) crystallographic direction according to the XRD analysis. The phonon vibration modes determined by Raman spectroscopy also confirmed the presence of the In2S3 phase in our samples. According to SEM, the surface morphologies of the films were free of defects. The optical band gap energy varied from 2.82 eV to 2.95 eV.

  2. Evolution of morphology and structure of Pb thin films grown by pulsed laser deposition at different substrate temperatures

    SciTech Connect

    Lorusso, Antonella Maiolo, Berlinda; Perrone, Alessio; Gontad, Francisco; Maruccio, Giuseppe; Tasco, Vittorianna

    2014-03-15

    Pb thin films were prepared by pulsed laser deposition on a Si (100) substrate at different growth temperatures to investigate their morphology and structure. The morphological analysis of the thin metal films showed the formation of spherical submicrometer grains whose average size decreased with temperature. X-ray diffraction measurements confirmed that growth temperature influences the Pb polycrystalline film structure. A preferred orientation of Pb (111) normal to the substrate was achieved at 30?C and became increasingly pronounced along the Pb (200) plane as the substrate temperature increased. These thin films could be used to synthesize innovative materials, such as metallic photocathodes, with improved photoemission performances.

  3. Patterns of surface temperatures in two mole-rats (Bathyergidae) with different social systems as revealed by IR-thermography.

    PubMed

    Sumbera, Radim; Zelov, Jitka; Kunc, Petr; Knzkov, Ivana; Burda, Hynek

    2007-10-22

    Furred subterranean mammals face the problem of dissipating heat to the environment because high humidity and absence of air flow in sealed belowground tunnels constrain heat loss from body by convection and evaporation. In order to detect body areas responsible for heat loss, surface temperatures in two species of African mole-rats were measured at different ambient air temperatures by infrared thermography. Fur characteristics were also evaluated. Thinner pelage of the ventrum, its moderate temperature and large size suggest that ventral side of the body is the main thermal avenue for heat loss in both species. Interspecific differences could be explained by different fur characteristics connected with social thermoregulation. Compared to the social Fukomys mechowii, the solitary Heliophobius argenteocinereus has denser and longer fur on most of its body; its surface temperature was thus lower than in F. mechowii at lowered ambient temperatures. On the other hand, the denser and longer hair cover in H. argenteocinereus impedes heat dissipation at highest ambient temperatures (and probably also during digging activity) resulting in increase of core body temperature. H. argenteocinereus seems to be more sensitive to overheating than F. mechowii. At lower air temperatures, the social species may uses huddling to combat hypothermia. PMID:17544016

  4. Internal neutronics-temperature coupling in Serpent 2 - Reactivity differences resulting from choice of material property correlations

    SciTech Connect

    Valtavirta, V.

    2013-07-01

    This paper describes the unique way of simultaneously solving the power and temperature distributions of a nuclear system with the Monte Carlo neutron transport code Serpent 2. The coupled solution is achieved through the implementation of an internal temperature solver and material property correlations in the code. The program structure is reviewed concerning the temperature solver and the internal correlations as well as the internal coupling between these two and the neutron transport part. To estimate the reactivity differences resulting from correlation choices a simple pin-cell case has been calculated. It is established, that some correlation choices may result in difference in reactivity of approximately 100 pcm. (authors)

  5. Cochliobolus lunatus colonizes potato by adopting different invasion strategies on cultivars: New insights on temperature dependent-virulence.

    PubMed

    Louis, Bengyella; Waikhom, Sayanika D; Jose, Robinson C; Goyari, Sailendra; Talukdar, Narayan C; Roy, Pranab

    2015-10-01

    Extreme temperature fluctuations affect the interaction dynamics of Cochliobolus lunatus through temperature-dependent virulence, virulence differentiation and induced-virulence which poses a major threat to global food security. The relationship between higher temperature and pathogenicity of C. lunatus on reported hosts are poorly understood. In this study, temperature stress was applied on C. lunatus to investigate the correlation among the different types of conidia. Additionally, a comparative dissection of the invasion process, infection structures and conidial germination pattern on four different Solanum tuberosum L. (potato) cultivars were performed. Based on microscopic examination, it was found that C. lunatus adopts different hyphae morphology and septation pattern at different temperature regimes and produce different types of conidia. The study showed that four-celled conidia are overproduced at elevated temperature (>30 °C) than one, two, three and five-celled conidia. Our finding revealed that C. lunatus conidia exhibit bipolar germination (>14.67%, P<0.05), unipolar germination (>35.33%, P<0.05), penetrate subcutaneously via epidermal anticlinal cell wall (>0.33%, P < 0.05) and differentially form appressoria-like structures during colonization of four different potato cultivars. Importantly, it is shown that unipolar germination and bipolar germination in C. lunatus are independently occurring phenomenon irrespective of the host. It is confirmed that C. lunatus adopt different but highly successful strategies on four different potato cultivars to incite brown-to-black leaf spot disease. Altogether, our data showed that increase in temperature enhances C. lunatus virulence on different potato cultivars irrespective of their inherent thermotolerant traits. PMID:26205908

  6. Growth and lipid accumulation in three Chlorella strains from different regions in response to diurnal temperature fluctuations.

    PubMed

    Yang, Weinan; Zou, Shanmei; He, Meilin; Fei, Cong; Luo, Wei; Zheng, Shiyan; Chen, Bo; Wang, Changhai

    2016-02-01

    It was economically feasible to screen strains adaptive to wide temperature fluctuation for outdoor cultivation without temperature control. In this research, three Chlorella strains from arctic glacier, desert soil and temperate native lake were isolated and identified. The growth, biochemical composition, lipid content and fatty acid composition of each strain cultured under the mode of diurnal temperature fluctuations were compared. All the three Chlorella strains showed desirable abilities of accumulating lipid under diurnal temperature fluctuations and their fatty acid profiles were suitable for biodiesel production, although the growth and biochemical composition were seemed to be region-specific. The highest lipid content was at 51.832.49% DW, 42.802.97% DW and 36.132.27% DW under different temperature fluctuation of 11C, 25C, 7C, respectively. The results indicated that the three Chlorella strains could be promising biodiesel feedstock for outdoor cultivation by the cultural mode of diurnal temperature fluctuations. PMID:26700754

  7. How does low temperature coupled with different pressures affect initiation mechanisms and subsequent decompositions in nitramine explosive HMX?

    PubMed

    Wu, Qiong; Xiong, Guolin; Zhu, Weihua; Xiao, Heming

    2015-09-21

    We have performed ab initio molecular dynamics simulations to study coupling effects of temperature (534-873 K) and pressure (1-20 GPa) on the initiation mechanisms and subsequent chemical decompositions of nitramine explosive 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX). A new initiation decomposition mechanism of HMX was found to be the unimolecular C-H bond breaking, and this mechanism was independent of the coupling effects of different temperatures and pressures. The formed hydrogen radicals could promote subsequent decompositions of HMX. Subsequent decompositions were very sensitive to the pressure at low temperatures (534 and 608 K), while the temperature became the foremost factor that affected the decomposition at a high temperature (873 K) instead of the pressure. Our study may provide a new insight into understanding the coupling effects of the temperature and pressure on the initiation decomposition mechanisms of nitramine explosives. PMID:26264421

  8. Temperature effect on proliferation and differentiation of satellite cells from turkeys with different growth rates1.

    PubMed

    Clark, D L; Coy, C S; Strasburg, G M; Reed, K M; Velleman, S G

    2016-04-01

    Poultry selected for growth have an inefficient thermoregulatory system and are more sensitive to temperature extremes. Satellite cells are precursors to skeletal muscle and mediate all posthatch muscle growth. Their physiological functions are affected by temperature. The objective of the current study was to determine how temperature affects satellite cells isolated from the pectoralis major (p. major) muscle (breast muscle) of turkeys selected for increased 16 wk body weight (F line) in comparison to a randombred control line (RBC2) from which the F line originated. Pectoralis major muscle satellite cells were thermally challenged by culturing between 33°C and 43°C to analyze the effects of cold and heat on proliferation and differentiation as compared to control temperature of 38°C. Expression levels of myogenic regulatory factors: myogenic differentiation factor 1 (MYOD1) and myogenin (MYOG) were quantified by quantitative polymerase chain reaction (qPCR). At all sampling times, proliferation increased at a linear rate across temperature in both the RBC2 and F lines. Differentiation also increased at a linear rate across temperature from 33 to 41°C at all sampling times in both the F and RBC2 lines. Satellite cells isolated from F line turkeys were more sensitive to both hot and cold temperatures as proliferation and differentiation increased to a greater extent across temperature (33 to 43°C) when compared with the RBC2 line. Expression ofMYOD1andMYOGincreased as temperatures increased from 33 to 41°C at all sampling times in both the F and RBC2 lines. These results demonstrate that satellite cell function is sensitive to both cold and hot temperatures and p. major muscle satellite cells from F line turkeys are more sensitive to temperature extremes than RBC2 satellite cells. PMID:26769270

  9. Oxidative damage in different tissues of neonatal chicks exposed to low environmental temperature.

    PubMed

    Mujahid, Ahmad; Furuse, Mitsuhiro

    2009-04-01

    Maintenance of body temperature in a cold environment is crucial for survival in homeotherms. However, we have previously reported that on exposure to low environmental temperature, neonatal chicks (Gallus gallus) show hypothermia, decreased behavioral activity, and absence of gene transcript enhancement of putative thermogenic proteins, as well as no change in mitochondrial substrate oxidation enzymes. Various metabolic abnormalities and/or tissue damage may also decline the thermogenic capacity of low-temperature-exposed neonatal chicks. Therefore, to investigate oxidative damage in low-temperature-exposed (20 degrees C for 12 h) neonatal chicks, we studied lipid peroxidation when compared to the control chicks kept at thermoneutral temperature (30 degrees C). Malondialdehyde (MDA), was measured in plasma, brain, heart, liver and skeletal muscle (pectoralis superficialis and gastrocnemius). Weight gain and feed consumption did not change when chicks were exposed to low-temperature as compared to that of control chicks. On low-temperature exposure, body temperature was significantly decreased and plasma non-esterified fatty acid level was 1.3-fold higher than that of control chicks. In low-temperature exposed chicks, brain and heart MDA levels were 2.1- and 1.2-fold higher, respectively, than that of control chicks. This increase in MDA levels was not observed in plasma, liver and muscle of low-temperature-exposed chicks. In conclusion, there is evidence of increased lipid peroxidation in brain and heart of neonatal chicks exposed to low-temperature. We hypothesize that this oxidative damage in brain and heart may contribute to the impaired physiological, behavioral and thermoregulatory responses that potentiate the sensitivity to cold exposure. PMID:19256080

  10. Effect of biochar produced at different pyrolysis temperature on the soil respiration of abandoned mine soil

    NASA Astrophysics Data System (ADS)

    Kim, Yong Seong; Kim, Juhee; Hwang, Wonjae; Hyun, Seunghun

    2015-04-01

    Contaminated soils near an abandoned mine site included the high acidic mine tailing have received great interest due to potential risk to human health, because leachable elements in low pH continuously release from mine site soil with ground water and precipitation event. Biochar, which is the obtained pyrolysis process of biomass, is used as a soil amendments and carbon storage. Especially, many researchers report that the biochar application to soil show increasing soil pH, CEC, adsorption capacity of various elements, as well as, enhanced microbial activity. Therefore, biochar application to contaminated soil near abandoned mine site is expected to have a positive effects on management of these site and soils through the decreased leachability of contaminants. However, effects of biochar application to these site on the soil respiration, as a common measure of soil health, are poorly understood. The objective of this study is to evaluate the effects of biochar application to abandoned mine site soil on the microbial activity with soil respiration test. Biochar was obtained from giant Miscanthus in a slow pyrolysis process (heating rate of 10° C min-1 and N2 gas flow rate of 1.2 L min-1) at the temperature of 400° C (BC4) and 700° C (BC7), respectively. All biochar samples were prepared with grinding and sieving for particle size control (150~500μm). Soil sample was collected from abandoned mine site at Korea (36° 58'N, 128° 10'E). Main contaminants of this soil were As (12.5 g kg-1), Pb (7.3 g kg-1), and Zn (1.1 g kg-1). Biochars were applied (5% by dry weight) to the soil (final mixture weight were 800g), and then moisture contents were adjusted to 100% field capacity (-0.33 bar) in the respirometer with vacuum pump. CO2 efflux of each samples was continuously assessed using continuous aeration system (air flow rate 25 cc min-1) using air cylinder during 130hr (at 20° C and darkness condition). The CO2 emitted from the samples were carried to the infrared gas sensor, and these data were sent to a data logger. During the measuring periods, the cumulative CO2 emission were similar between the control (516.8 mg-CO2 kg-1-soil) and BC4 5% mixture (519.3 mg-CO2 kg-1-soil), while BC7 5% mixture was significantly decreased (356.1 mg-CO2 kg-1-soil) compared to other treatment and control. Because the degradation rate of biochar generally increased with decreasing pyrolysis temperature, this result suggest that the soil respiration rates of biochar amended soils are affected by physico-chemical properties of biochar during early incubation periods (about 1 weeks), For example, surface properties of used biochars, which are related to adsorption of soil organic matter and CO2, have different properties with pyrolysis temperature such as specific surface area (BC4=5.08 m2g-1; BC7=260.75 m2 g-1, respectively), average pore diameter (BC4=4,673 nm; BC7=2,606 nm, respectively), and functional groups of biochar surface. However, there was not clear evidence of biochar-mine soil interaction process, because of the short observation periods. Future work should focus on the adsorption of CO2 and soil organic matter of biochar and soil-biochar interaction with long time periods and various biological test.

  11. Molecular analysis of the microbial community structures in water-flooding petroleum reservoirs with different temperatures

    NASA Astrophysics Data System (ADS)

    Wang, L.-Y.; Duan, R.-Y.; Liu, J.-F.; Yang, S.-Z.; Gu, J.-D.; Mu, B.-Z.

    2012-11-01

    Analyses of microbial communities from six water-flooding petroleum reservoirs at temperatures from 21 to 63 C by 16S rRNA gene clone libraries indicates the presence of physiologically diverse and temperature-dependent microorganisms in these subterrestrial ecosystems. In samples originating from high-temperature petroleum reservoirs, most of the archaeal sequences belong to thermophiles affiliated with members of the genera Thermococcus, Methanothermobacter and the order Thermoplasmatales, whereas bacterial sequences predominantly belong to the phyla Firmicutes, Thermotogae and Thermodesulfobacteria. In contrast to high-temperature petroleum reservoirs, microorganisms belonging to the Proteobacteria, Methanobacteriales and Methanomicrobiales were the most encountered in samples collected from low-temperature petroleum reservoirs. Canonical correspondence analysis (CCA) revealed that temperature, mineralization, ionic type as well as volatile fatty acids showed correlation with the microbial community structures, in particular members of the Firmicutes and the genus Methanothermobacter showed positive correlation with temperature and the concentration of acetate. Overall, these data indicate the large occurrence of hydrogenotrophic methanogens in petroleum reservoirs and imply that acetate metabolism via syntrophic oxidation may represent the main methanogenic pathway in high-temperature petroleum reservoirs.

  12. Densities of mixtures containing n-alkanes with sunflower seed oil at different temperatures

    SciTech Connect

    Gonzalez, C.; Resa, J.M.; Ruiz, A.; Gutierrez, J.I.

    1996-07-01

    Densities for mixtures containing sunflower seed oil with pentane, hexane, heptane, and octane have been determined at various temperatures between 298.15 K and 313.15 K using a vibrating tube densimeter. The derived excess volumes have been correlated by the Redlich-Kister equation. All the systems showed negative deviations from ideality. The excess volumes increased with an increase in temperature.

  13. WHITE SUCKER 'CATOSTOMUS COMMERSONI' EMBRYO DEVELOPMENT, AND EARLY GROWTH AND SURVIVAL AT DIFFERENT TEMPERATURES

    EPA Science Inventory

    White suckers (Catostomus commersoni) were exposed from fertilization through hatching to seven constant temperatures from 6.2 through 24.1C. High percentages of apparently normal larvae hatched at temperatures from 9.0 through 17.2C. Maximum percent hatch occurred at 15.2C, whil...

  14. Critical currents of YBCO tapes and Bi-2212 wires at different temperatures and magnetic fields

    SciTech Connect

    Lombardo, V.; Barzi, e.; Turrioni, D.; Zlobin, A.V.; /Fermilab

    2010-08-01

    Design studies for the cooling channel of a Muon Collider call for straight and helical solenoids generating field well in excess of the critical fields of state of the art Low Temperature Superconductors (LTS) such as Nb{sub 3}Sn or NbTi. Therefore, High Temperature Superconductors (HTS) will need to be used for the manufacturing of all or certain sections of such magnets to be able to generate and withstand the field levels at the cryogenic temperatures required by the new machine. In this work, two major High Temperature Superconductors - Bi2212 round wires and YBCO coated conductor tapes - are investigated to understand how critical current density of such conductors scales as a function of external field and operating temperature. This is vital information to make conductor choices depending on the application and to proceed with the design of such magnets.

  15. Investigation of ZnO:Al thin films sputtered at different deposition temperatures

    NASA Astrophysics Data System (ADS)

    Kim, Deok Kyu; Kim, Hong Bae

    2015-05-01

    ZnO:Al (AZO) thin films were prepared on glass substrates by using RF magnetron sputtering at various deposition temperature, and their properties were investigated. With increasing deposition temperature, the crystallinity was slightly improved, whereas the resistivity continuously deteriorated due to a decrease in the mobility and in the carrier concentration. From an X-ray photoelectron spectroscopy (XPS) analysis, the behaviors of the mobility and the carrier concentration were affected by impurity bonding such as oxygen species on the film surface. The mobility decreased due to an increase in the potential height and was the main factor at a low deposition temperature (200 C). In addition, the carrier concentration decrease due to the trapping of electrons and to the reduction of oxygen vacancy and was dominant factor at a high deposition temperature (400 C). For the deposition of AZO films, if improved electrical properties are to be obtained, the deposition temperature needs to choose so as to minimize the impurity bonding.

  16. Long-term water temperature reconstructions from mountain lakes with different catchment and morphometric features

    PubMed Central

    Luoto, Tomi P.; Nevalainen, Liisa

    2013-01-01

    Long-term water temperature records are necessary for better understanding climate change impacts on freshwaters. We reconstruct summer water temperatures from three climatically sensitive mountain lakes in Austria using paleolimnological methods aiming to examine long-term thermal dynamics and lakes' responses to regional climate variability since the Little Ice Age. Our results indicate divergent trends for the lakes. In two of the lakes, which are located at the sunny southern slope of mountains, water temperature has increased several degrees concurrent with the observed air temperature increase. In contrast, no change is observed in the reconstructed water temperatures of a shaded lake, located at the northern slope, where also the ecological and thermal changes are most subtle. The results indicate the importance of cold water inputs, such as snowmelt and groundwater, on lakes' thermal conditions and suggest that watershed characteristics and lake stratification play a major role in defining the lake-specific thermal regime. PMID:23965988

  17. Variations in vertical temperature profile of extratropical cyclones under different environmental conditions

    NASA Astrophysics Data System (ADS)

    Karakhanyan, A. A.; Molodykh, S. I.

    2015-11-01

    We study variations in the vertical temperature profile in central parts of warm and cold sectors of extratropical cyclones which emerge and evolve in the Northern Hemisphere during solar minimum. Dynamics of the vertical temperature profile during cyclogenesis over the land and ocean under quiet and disturbed geomagnetic conditions is analyzed. The classic cyclolysis occur under quiet geomagnetic conditions; the temperature decreases in the warm sector and increases in the cold one at a level up to 300 hPa. Under disturbed geomagnetic conditions, there is a slow increase in temperature in the cold sector. The warm sector of the cyclone is characterized by a small increase and stabilization of temperature, which perhaps results in slow cyclolysis and in increased lifetime of cyclones.

  18. Changes in Temperature Sensitivity and Activation Energy of Soil Organic Matter Decomposition in Different Qinghai-Tibet Plateau Grasslands

    PubMed Central

    Li, Jie; He, Nianpeng; Wei, Xuehong; Gao, Yang; Zuo, Yao

    2015-01-01

    Qinghai-Tibet Plateau grasslands are unique geographical regions and store substantial soil organic matter (SOM) in the soil surface, which make them very sensitive to global climate change. Here, we focused on three main grassland types (alpine meadow, steppe, and desert) and conducted a soil incubation experiment at five different temperatures (5, 10, 15, 20, and 25°C) to investigate SOM decomposition rates (R), temperature sensitivity (Q10), and activation energy (Ea). The results showed that grassland type and incubation temperature had significant impact on R (P < 0.001), and the values of R were exponential correlated with incubation temperature in three alpine grasslands. At the same temperature, R was in the following order: alpine meadow > alpinesteppe > alpine desert. The Q10 values differed significantly among different grasslands, and the overall trends were as follows: alpine meadow (1.56 ± 0.09) < alpine steppe (1.88 ± 0.23) < alpine desert (2.39 ± 0.32). Moreover, the Ea values differed significantly across different grassland types (P < 0.001) and increased with increasing incubation time. The exponential negative correlations between Ea and R at 20°C across all grassland types (all Ps < 0.001) indicated that the substrate-quality temperature hypothesis is applicable to the alpine grasslands. Our findings provide new insights for understanding the responses of SOM decomposition and storage to warming scenarios in this Plateau. PMID:26176705

  19. Temperature

    NASA Technical Reports Server (NTRS)

    Berenson, P. J.; Robertson, W. G.

    1973-01-01

    The problems in human comfort in heat stress are emphasized, with less emphasis placed upon cold exposure problems. Physiological parameters related to human thermal interactions are discussed, as well as data concerning thermal protective clothing. The energy balance equation, heat transfer equation, thermal comfort, heat stress, and cold stress are also considered. A two node model of human temperature regulation in FORTRAN is appended.

  20. Fungal Communities Associated with the Biodegradation of Polyester Polyurethane Buried under Compost at Different Temperatures

    PubMed Central

    Zafar, Urooj; Houlden, Ashley

    2013-01-01

    Plastics play an essential role in the modern world due to their low cost and durability. However, accumulation of plastic waste in the environment causes wide-scale pollution with long-lasting effects, making plastic waste management expensive and problematic. Polyurethanes (PUs) are heteropolymers that made up ca. 7% of the total plastic production in Europe in 2011. Polyester PUs in particular have been extensively reported as susceptible to microbial biodegradation in the environment, particularly by fungi. In this study, we investigated the impact of composting on PUs, as composting is a microbially rich process that is increasingly being used for the processing of green waste and food waste as an economically viable alternative to landfill disposal. PU coupons were incubated for 12 weeks in fresh compost at 25°C, 45°C, and 50°C to emulate the thermophilic and maturation stages of the composting process. Incubation at all temperatures caused significant physical deterioration of the polyester PU coupons and was associated with extensive fungal colonization. Terminal restriction fragment length polymorphism (TRFLP) analysis and pyrosequencing of the fungal communities on the PU surface and in the surrounding compost revealed that the population on the surface of PU was different from the surrounding compost community, suggesting enrichment and selection. The most dominant fungi identified from the surfaces of PU coupons by pyrosequencing was Fusarium solani at 25°C, while at both 45°C and 50°C, Candida ethanolica was the dominant species. The results of this preliminary study suggest that the composting process has the potential to biodegrade PU waste if optimized further in the future. PMID:24056469

  1. Different temperature adaptation in Arctic and Atlantic heterotrophic bacteria in the Barents Sea Polar Front region

    NASA Astrophysics Data System (ADS)

    Brsheim, Knut Yngve; Drinkwater, Kenneth F.

    2014-02-01

    In the northern Barents Sea, at and around the Polar Front, carbon cycle variables were investigated during 2 weeks in late summer of 2007. Arctic Water primary production in the experimental period averaged 50 mmol C m- 2 day- 1, as estimated from satellite sensed chlorophyll. In Atlantic waters, which appeared to just have passed the culmination of a late summer bloom, primary production was 125 mmol C m- 2 day- 1. Total organic carbon (TOC) averaged 82.4 ?M C in the mixed layer, and the values showed a gradient with highest values to the southeast and lowest to the northwest. The distribution of TOC was not related to the distribution of Atlantic and Arctic waters, although the highest values were found in Atlantic Water. Integrated bacterial production in the mixed layer, as estimated from thymidine incorporation rates, averaged 6.3% of primary production. In Atlantic Water, over the depth of the mixed layer, bacterial production rate averaged 0.40 mmol C m- 3 day- 1, which was 6.6 times the average in Arctic Water and 2.3 times the average in the front regions. Below 30 m depth, bacterial production rates were generally higher in the Arctic Water than in the Atlantic Water. Moreover, when production rates of bacteria were compared according to temperature, the rates in Arctic Water were systematically higher than the rates in Atlantic Water. This difference implies that the heterotrophic bacteria from the Arctic have adapted towards higher growth efficiency than the bacteria in Atlantic Water.

  2. Biofilm formation under different temperature conditions by a single genotype of persistent Listeria monocytogenes strains.

    PubMed

    Ochiai, Yoshitsugu; Yamada, Fumiya; Mochizuki, Mariko; Takano, Takashi; Hondo, Ryo; Ueda, Fukiko

    2014-01-01

    Some Listeria monocytogenes strains, termed persistent strains, originate from the same processing plant and have the ability to survive and grow over extended periods of time at contamination sources. In order to evaluate biofilm formation by such persistent strains, we isolated the pathogen from chicken samples collected from the same retail shop in repeated visits over 6 months. Strains that were of serotype 1/2b and were assigned to the same genotype by multi-virulence-locus sequence typing analysis were isolated on repeated occasions from December 1997 to June 1998 and thus were defined as persistent strains. In the present study, biofilm formation by the persistent strains was evaluated using microplates at 30 and 37C. The biofilm-forming capability was measured after cells attaching to the microplate well were stained with crystal violet. Comparison of biofilm formation at 30C among the persistent strains showed that a significantly higher amount of the stain was obtained from the persistent strains isolated from December to March than from those isolated from April to June. However, no significant difference in biofilm formation at 30C was observed between persistent and nonpersistent groups of L. monocytogenes strains. In contrast, biofilm formation at 37C was consistent among the persistent strains, and they produced significantly more biofilm at 37C than did the nonpersistent strains. The persistent strains were also found to change their biofilm-forming ability in a temperature-dependent manner, which may suggest that the persistent strains alter their biofilm formation in response to changing environmental factors. PMID:24406011

  3. Natural populations of Arabidopsis thaliana differ in seedling responses to high-temperature stress

    PubMed Central

    Zhang, Nana; Belsterling, Brian; Raszewski, Jesse; Tonsor, Stephen J.

    2015-01-01

    Little is known about adaptive within-species variation in thermotolerance in wild plants despite its likely role in both functional adaptation at range limits and in predicting response to climate change. Heat shock protein Hsp101, rapidly heat induced in Arabidopsis thaliana, plays a central role in thermotolerance in laboratory studies, yet little is known about variation in its expression in natural populations. We explored variation in thermotolerance and Hsp101 expression in seedlings from 16 natural populations of A. thaliana sampled along an elevation and climate gradient. We tested both naive controls (maintained at 22 C until heat stress) and thermally pre-acclimated plants (exposed to a 38 C 3-h acclimation treatment). After acclimation, seedlings were exposed to one of two heat stresses: 42 or 45 C. Thermotolerance was measured as post-stress seedling survival and root growth. When stressed at 45 C, both thermotolerance and Hsp101 expression were significantly increased by pre-acclimation. However, thermotolerance did not differ between pre-acclimation and control when followed by a 42 C stress. Immediately after heat stress, pre-acclimated seedlings contained significantly more Hsp101 than control seedlings. At 45 C, Hsp101 expression was positively associated with survival (r2 = 0.37) and post-stress root growth (r2 = 0.15). Importantly, seedling survival, post-stress root growth at 45 C and Hsp101 expression at 42 C were significantly correlated with the home sites' first principal component of climate variation. This climate gradient mainly reflects a temperature and precipitation gradient. Thus, the extent of Hsp101 expression modulation and thermotolerance appear to be interrelated and to evolve adaptively in natural populations of A. thaliana. PMID:26286225

  4. Fungal communities associated with the biodegradation of polyester polyurethane buried under compost at different temperatures.

    PubMed

    Zafar, Urooj; Houlden, Ashley; Robson, Geoffrey D

    2013-12-01

    Plastics play an essential role in the modern world due to their low cost and durability. However, accumulation of plastic waste in the environment causes wide-scale pollution with long-lasting effects, making plastic waste management expensive and problematic. Polyurethanes (PUs) are heteropolymers that made up ca. 7% of the total plastic production in Europe in 2011. Polyester PUs in particular have been extensively reported as susceptible to microbial biodegradation in the environment, particularly by fungi. In this study, we investigated the impact of composting on PUs, as composting is a microbially rich process that is increasingly being used for the processing of green waste and food waste as an economically viable alternative to landfill disposal. PU coupons were incubated for 12 weeks in fresh compost at 25C, 45C, and 50C to emulate the thermophilic and maturation stages of the composting process. Incubation at all temperatures caused significant physical deterioration of the polyester PU coupons and was associated with extensive fungal colonization. Terminal restriction fragment length polymorphism (TRFLP) analysis and pyrosequencing of the fungal communities on the PU surface and in the surrounding compost revealed that the population on the surface of PU was different from the surrounding compost community, suggesting enrichment and selection. The most dominant fungi identified from the surfaces of PU coupons by pyrosequencing was Fusarium solani at 25C, while at both 45C and 50C, Candida ethanolica was the dominant species. The results of this preliminary study suggest that the composting process has the potential to biodegrade PU waste if optimized further in the future. PMID:24056469

  5. Natural populations of Arabidopsis thaliana differ in seedling responses to high-temperature stress.

    PubMed

    Zhang, Nana; Belsterling, Brian; Raszewski, Jesse; Tonsor, Stephen J

    2015-01-01

    Little is known about adaptive within-species variation in thermotolerance in wild plants despite its likely role in both functional adaptation at range limits and in predicting response to climate change. Heat shock protein Hsp101, rapidly heat induced in Arabidopsis thaliana, plays a central role in thermotolerance in laboratory studies, yet little is known about variation in its expression in natural populations. We explored variation in thermotolerance and Hsp101 expression in seedlings from 16 natural populations of A. thaliana sampled along an elevation and climate gradient. We tested both naive controls (maintained at 22 C until heat stress) and thermally pre-acclimated plants (exposed to a 38 C 3-h acclimation treatment). After acclimation, seedlings were exposed to one of two heat stresses: 42 or 45 C. Thermotolerance was measured as post-stress seedling survival and root growth. When stressed at 45 C, both thermotolerance and Hsp101 expression were significantly increased by pre-acclimation. However, thermotolerance did not differ between pre-acclimation and control when followed by a 42 C stress. Immediately after heat stress, pre-acclimated seedlings contained significantly more Hsp101 than control seedlings. At 45 C, Hsp101 expression was positively associated with survival (r(2) = 0.37) and post-stress root growth (r(2) = 0.15). Importantly, seedling survival, post-stress root growth at 45 C and Hsp101 expression at 42 C were significantly correlated with the home sites' first principal component of climate variation. This climate gradient mainly reflects a temperature and precipitation gradient. Thus, the extent of Hsp101 expression modulation and thermotolerance appear to be interrelated and to evolve adaptively in natural populations of A. thaliana. PMID:26286225

  6. A terahertz detector operating at room temperature

    NASA Astrophysics Data System (ADS)

    Lu, X. H.; Kang, L.; Chen, J.; Zhong, Y. Y.; He, N.; Zhang, L. B.; Jin, B. B.; Xu, W. W.; Wu, P. H.; Yao, Q. J.; Shi, S. C.

    2008-12-01

    A detector for terahertz(THz) operating at room temperature for detecting the THz signals is fabricated by using radio frequency (RF) magnetron sputtering and electronic beam lithography. This detector is composed of a planar logarithm periodic antenna of Al film and a microbolometer of Nb5N6 thin film, acting as both a radiation absorber and a temperature sensor, respectively which is fabricated on a high resistivity Si substrate with 100nm thick SiO2 layer. The best attainable responsivity of this device is over 100 volts per watt at 300K at a bias current of 2 mA,and the electrical noise equivalent powers (NEP) is as low as 3.9810-10WHz1/2.These are good enough for many detecting and imaging arrays in THz frequencies.

  7. Energy budget during lactation in striped hamsters at different ambient temperatures.

    PubMed

    Zhao, Zhi-Jun

    2011-03-15

    The combination of two stressors, lactation and cold, is suggested to be an excellent model for testing the factors limiting sustained energy intake (SusEI). Limits to SusEI during peak lactation may be imposed peripherally by the capacity of mammary glands to produce milk or may be driven by the ability of animals to dissipate body heat. To distinguish between the two mechanisms, body mass change, food intake, reproductive output (using litter size and mass) and serum prolactin (PRL) levels were measured in striped hamsters lactating at 23, 30 and 5C. Resting metabolic rate (RMR) during late lactation was also measured. Female hamsters lactating at 5C showed significantly lower change in body mass, but had higher food intake and RMR than females at 23 and 30C. Asymptotic food intake averaged 14.60.4, 14.50.7 and 16.20.5 g d(-1) for females at 23, 30 and 5C, respectively. The females at 5C had 11.4% higher asymptotic food intake than females at 23 and 30C (F(2,51)=3.3, P<0.05, Tukey's HSD, P<0.05). No significant differences in litter size and PRL levels were observed between the three groups; however, litter mass at 5C was lower by 19.7 and 19.8% than litter mass at 23 and 30C on day 19 of lactation (F(2,51)=3.5, P<0.05, Tukey's HSD, P<0.05). Differences in the above parameters between 23 and 30C were not significant. Litter mass was positively correlated with asymptotic food intake (23C, r=0.60, P<0.05; 30C, r=0.94, P<0.01; 5C, r=0.77, P<0.01). These data suggested that females lactating at cold temperatures increased food intake to compensate for additional energy demands for thermogenesis, but they might not be capable of exporting more energy as milk to the pups, indicating a possible consistency with the peripheral hypothesis. However, the present results do not considerably distinguish the peripheral limitation hypothesis from the heat dissipation limits hypothesis. PMID:21346127

  8. Long-term rearing of Arctic charr Salvelinus alpinus under different salinity regimes at constant temperature.

    PubMed

    Arnason, T; Gunnarsson, S; Imsland, A K; Thorarensen, H; Smradttir, H; Steinarsson, A; Gstavsson, A; Johansson, M; Bjrnsson, B Th

    2014-10-01

    Arctic charr Salvelinus alpinus of the Hlar strain (mean s.e. body mass = 1521 31 g) were reared at four different salinity regimes at a constant temperature of 74 C. Two groups were given a three-month acclimation in salinity 18 before the salinity was increased to either 25 or 29 (groups called A25 and A29), and two groups were reared in salinities 25 or 29 over the full experimental period of 409 days (groups called F25 and F29). In the first 3 months, the A25 and A29 groups had the highest growth rates. By October 2011, there were no significant differences (two-way nested ANOVA, P > 005) in the mean body masses among A25, F25 and F29 (c. 1450 g), whereas A29 had a lower mean mass (1282 g). The growth in the last period from October 2011 to January 2012 was reduced by sexual maturation in the highest salinity regimes (A29 and F29), whereas fish in groups A25 and F25 showed high growth throughout the study. Males in all salinity groups had higher growth rates than females for the most part of the study, but the divergence between the sexes was most pronounced in the highest salinity regimes. All salinity groups showed distinct changes in Na(+) , K(+) -ATPase activity, with high activity in spring and summer, and lower activity in the autumn. Plasma sodium (Na(+) ) levels were stable indicating that none of the experimental groups had problems in maintaining hydromineral balance during the study. While plasma leptin levels were not affected by salinity regimes, it was noted that these levels were 13-30% higher in fish with empty guts compared with those having food in their gut at the time of sampling. This suggests a link between leptin levels and food intake, indicating that this hormone may play a role in food intake and energy allocation in fishes. PMID:25053158

  9. Differences between observed and a coupled simulation of North Atlantic sea surface currents and temperature

    NASA Astrophysics Data System (ADS)

    Molinari, Robert L.; Garraffo, Zulema; Snowden, Derrick

    2008-09-01

    North Atlantic sea surface temperature (SST) distributions derived from observations and a coupled model from NOAA's Geophysical Fluid Dynamics Laboratory, CM2.1, are compared to evaluate the model's ability to simulate recent (1900 to the present) oceanic surface characteristics. The North Atlantic focus will limit our analyses to spatial scales less than gyre, scales usually not addressed in previous model-observation comparisons. Identifying model differences from observations at these scales will assist modelers in identifying problems to be considered and remedies to be applied. The properties compared are the mean annual SST, standard deviation, amplitude of the annual and semiannual harmonic, decadal meridional movements of the axis of the Gulf Stream, propagation of SST anomalies along the axis of the Gulf Stream, and 100-year trends in SST records. Because of the dependence of SST on surface currents, observed flow from surface drifters and simulated flow from 15 m fields are also compared. The model simulates the large-scale properties of all the variables compared. However, there are areas of differences in some variables that can be related to inadequacies in the simulated current fields. For example, the model Gulf Stream (GS) axis after separation from the western boundary is located some 100 km north of the observed axis, which contributes to an area of warmer simulated SSTs. The absence of a slope current in the same region that advects colder water from the Labrador Sea in the observations also contributes to this area of higher model SSTs. The model North Atlantic Current (NAC) is located to the east of the observed NAC contributing to a large area of SST discrepancy. The patterns of the amplitude of the annual harmonic are similar with maximum amplitude off the east coast of northern North America. The semiannual harmonic exhibits relatively large amplitudes (>1C) north of about 55N, a signal not found in the observations. In both the model and observations, a region of increased standard deviations encompasses the GS and NAC. The model simulates north-south migrations of the GS core but at a longer period (20 years) than observed. The model does not simulate the SST anomalies that propagate along the observed GS and NAC. The model captures both the spatial and temporal characteristics of the Atlantic Multidecadal Oscillation. Both model and observations exhibit a dipole in trends, with positive trends in the subtropical Atlantic and negative trends in the subpolar gyre. The modeled region of negative trends is limited to the western subpolar Atlantic. The observed trends extend farther to the east.

  10. Thermopreference, tolerance and metabolic rate of early stages juvenile Octopus maya acclimated to different temperatures.

    PubMed

    Noyola, Javier; Caamal-Monsreal, Claudia; Daz, Fernando; Re, Denisse; Snchez, Adolfo; Rosas, Carlos

    2013-01-01

    Thermopreference, tolerance and oxygen consumption rates of early juveniles Octopus maya (O. maya; weight range 0.38-0.78g) were determined after acclimating the octopuses to temperatures (18, 22, 26, and 30C) for 20 days. The results indicated a direct relationship between preferred temperature (PT) and acclimated temperature, the PT was 23.4C. Critical Thermal Maxima, (CTMax; 31.81.2, 32.70.9, 34.81.4 and 36.51.0) and Critical Thermal Minima, (CTMin; 11.60.2, 12.80.6, 13.71.0, 19.000.9) increased significantly (P<0.05) with increasing acclimation temperatures. The endpoint for CTMax was ink release and for CTMin was tentacles curled, respectively. A thermal tolerance polygon over the range of 18-30C resulted in a calculated area of 210.0C(2). The oxygen consumption rate increased significantly ?=0.05 with increasing acclimation temperatures between 18 and 30C. Maximum and minimum temperature quotients (Q10) were observed between 26-30C and 22-26C as 3.03 and 1.71, respectively. These results suggest that O. maya has an increased capability for adapting to moderate temperatures, and suggest increased culture potential in subtropical regions southeast of Mxico. PMID:24229799

  11. Isotopic ordering in eggshells reflects body temperatures and suggests differing thermophysiology in two Cretaceous dinosaurs.

    PubMed

    Eagle, Robert A; Enriquez, Marcus; Grellet-Tinner, Gerald; Pérez-Huerta, Alberto; Hu, David; Tütken, Thomas; Montanari, Shaena; Loyd, Sean J; Ramirez, Pedro; Tripati, Aradhna K; Kohn, Matthew J; Cerling, Thure E; Chiappe, Luis M; Eiler, John M

    2015-01-01

    Our understanding of the evolutionary transitions leading to the modern endothermic state of birds and mammals is incomplete, partly because tools available to study the thermophysiology of extinct vertebrates are limited. Here we show that clumped isotope analysis of eggshells can be used to determine body temperatures of females during periods of ovulation. Late Cretaceous titanosaurid eggshells yield temperatures similar to large modern endotherms. In contrast, oviraptorid eggshells yield temperatures lower than most modern endotherms but ∼ 6 °C higher than co-occurring abiogenic carbonates, implying that this taxon did not have thermoregulation comparable to modern birds, but was able to elevate its body temperature above environmental temperatures. Therefore, we observe no strong evidence for end-member ectothermy or endothermy in the species examined. Body temperatures for these two species indicate that variable thermoregulation likely existed among the non-avian dinosaurs and that not all dinosaurs had body temperatures in the range of that seen in modern birds. PMID:26462135

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

    PubMed

    Khanday, M A; Hussain, Fida

    2015-02-01

    During cold exposure, peripheral tissues undergo vasoconstriction to minimize heat loss to preserve the maintenance of a normal core temperature. However, vasoconstricted tissues exposed to cold temperatures are susceptible to freezing and frostbite-related tissue damage. Therefore, it is imperative to establish a mathematical model for the estimation of tissue necrosis due to cold stress. To this end, an explicit formula of finite difference method has been used to obtain the solution of Pennes' bio-heat equation with appropriate boundary conditions to estimate the temperature profiles of dermal and subdermal layers when exposed to severe cold temperatures. The discrete values of nodal temperature were calculated at the interfaces of skin and subcutaneous tissues with respect to the atmospheric temperatures of 25 C, 20 C, 15 C, 5 C, -5 C and -10 C. The results obtained were used to identify the scenarios under which various degrees of frostbite occur on the surface of skin as well as the dermal and subdermal areas. The explicit formula of finite difference method proposed in this model provides more accurate predictions as compared to other numerical methods. This model of predicting tissue temperatures provides researchers with a more accurate prediction of peripheral tissue temperature and, hence, the susceptibility to frostbite during severe cold exposure. PMID:25660630

  13. Regional differences in the surface temperature of Naked Neck laying hens in a semi-arid environment

    NASA Astrophysics Data System (ADS)

    de Souza, Joo Batista Freire; de Arruda, Alex Martins Varela; Domingos, Hrica Girlane Tertulino; de Macedo Costa, Leonardo Lelis

    2013-05-01

    The aim of this study was to evaluate the regional differences in the surface temperature of Naked Neck hens that were subjected to different temperatures in a semi-arid environment. The surface temperature was measured in four body regions (face, neck, legs and feathered area) of 60 Naked Neck hens. The following environmental variables were measured at the center of the shed: the black globe temperature ( T G ), air temperature ( T A ), wind speed ( U) and relative humidity ( R H ). The T A was divided into three classes: 1 (24.0-26.0 C), 2 (26.1-28.9 C) and 3 (29.0-31.0 C). An analysis of variance was performed by the least squares method and a comparison of the means by the Tukey-Kramer test. The results showed a significant effect of T A class, the body region and the interaction between these two effects on the surface temperature. There was no significant difference between the T A classes for the face and neck. The legs and feathered area showed significant differences between the T A classes. Regarding the effect of body regions within each T A class, there was a significant difference among all regions in the three T A classes. In all T A classes the neck had the highest average followed by the face and legs. The feathered area showed the lowest average of the different T A classes. In conclusion, this study showed that there are regional differences in the surface temperature of Naked Neck hens, with the legs acting as thermal windows.

  14. Foot model for tracking temperature of safety boot insoles: application to different insole materials in firefighter boots.

    PubMed

    Garca-Hernndez, Csar; Snchez-lvarez, Eduardo J; Huertas-Taln, Jos-Luis

    2016-01-01

    This research is based on the development of a human foot model to study the temperature conditions of a foot bottom surface under extreme external conditions. This foot model is made by combining different manufacturing techniques to enable the simulation of bones and tissues, allowing the placement of sensors on its surface to track the temperature values of different points inside a shoe. These sensors let researchers capture valuable data during a defined period of time, making it possible to compare the features of different safety boots, socks or soles, among others. In this case, it has been applied to compare different plantar insole materials, placed into safety boots on a high-temperature surface. PMID:26651242

  15. Low-temperature production of silicon carbide films of different polytypes

    SciTech Connect

    Semenov, A. V. Puzikov, V. M.; Golubova, E. P.; Baumer, V. N.; Dobrotvorskaya, M. V.

    2009-05-15

    The study is concerned with the effect of temperature on the structure of SiC films formed by deposition of the C and Si ions with the energy 120 eV. On the basis of the X-ray structural studies, it is unambiguously established that the structure of the growing polytype is finely dependent on the substrate temperature. In the temperature range from 1080 deg. C to 1510 deg. C, the sequence of films involving the 21R, 51R, 27R, and 6H polytypes is produced for the first time. The effect of temperature on the silicon-carbon atomic content ratio [Si]/[C] in the deposited films is determined. At optimized parameters of deposition the film structured as the 51R rhombohedral polytype is grown.

  16. Growth and biopigment accumulation of cyanobacterium Spirulina platensis at different light intensities and temperature

    PubMed Central

    Kumar, Manoj; Kulshreshtha, Jyoti; Singh, Gajendra Pal

    2011-01-01

    In order to find out optimum culture condition for algal growth, the effect of light irradiance and temperature on growth rate, biomass composition and pigment production of Spirulina platensis were studied in axenic batch cultures. Growth kinetics of cultures showed a wide range of temperature tolerance from 20 C to 40 C. Maximum growth rate, cell production with maximum accumulation of chlorophyll and phycobilliproteins were found at temperature 35 C and 2,000 lux light intensity. But with further increase in temperature and light intensity, reduction in growth rate was observed. Carotenoid content was found maximum at 3,500 lux. Improvement in the carotenoid content with increase in light intensity is an adaptive mechanism of cyanobacterium S.platensis for photoprotection, could be a good basis for the exploitation of microalgae as a source of biopigments. PMID:24031731

  17. Growth and lipid accumulation properties of a freshwater microalga Scenedesmus sp. under different cultivation temperature.

    PubMed

    Li, Xin; Hu, Hong-ying; Zhang, Yu-ping

    2011-02-01

    Microalgal lipid is a promising feedstock for biodiesel production. Effect of cultivation temperature on the growth and lipid accumulation properties of a freshwater microalga Scenedesmus sp. LX1 was studied. Scenedesmus sp. LX1 could grow in a wide range of temperature (10?30C), and the growth activation energy was 49.3 kJmol(-1). The optimal temperature to produce microalgal biomass and lipid was 20C, and after 15 days of batch cultivation the productivities of 313.3 g biomass(g P)(-1), 112 g lipid (g P)(-1) and 14.7 g TAGs(g P)(-1) were obtained. The content of polyunsaturated fatty acids decreased with the increase of cultivation temperature. The reactive oxygen species (ROS) levels at 10C and 20C were higher than that under higher temperature. For the first time the cultivation temperature, ROS level, specific growth rate and lipid content per microalgal biomass were correlated together. PMID:21055924

  18. The interaction between peripheral and central fatigue at different muscle temperatures during sustained isometric contractions.

    PubMed

    Lloyd, Alex; Hodder, Simon; Havenith, George

    2015-08-15

    Changes in central fatigue have been linked to active and passive changes in core temperature, as well as integration of sensory feedback from thermoreceptors in the skin. However, the effects of muscle temperature (Tm), and thereby metaboreceptor and local afferent nerve temperature, on central fatigue (measured using voluntary activation percentage) during sustained, high muscle fatigue exercise remain unexamined. In this study, we investigated Tm across the range of cold to hot, and its effect on voluntary activation percentage during sustained isometric contractions of the knee extensors. The results suggest that contrary to brief contractions, during a sustained fatiguing contraction Tm significantly (P < 0.001) influences force output (-0.7%/C increase) and central fatigue (-0.5%/C increase), showing a negative relationship across the Tm continuum in moderately trained individuals. The negative relationship between voluntary activation percentage and Tm indicates muscle temperature may influence central fatigue during sustained and high muscle fatigue exercise. On the basis of on an integrative analysis between the present data and previous literature, the impact of core and muscle temperature on voluntary muscle activation is estimated to show a ratio of 5.5 to 1, respectively. Accordingly, Tm could assume a secondary or tertiary role in the reduction of voluntary muscle activation when body temperature leaves a thermoneutral range. PMID:26041110

  19. Molecular analysis of the microbial community structures in water-flooding petroleum reservoirs with different temperatures

    NASA Astrophysics Data System (ADS)

    Wang, L.-Y.; Duan, R.-Y.; Liu, J.-F.; Yang, S.-Z.; Gu, J.-D.; Mu, B.-Z.

    2012-04-01

    Temperature is one of the most important environmental factors regulating the activity and determining the composition of the microbial community. Analysis of microbial communities from six water-flooding petroleum reservoirs at temperatures from 20 to 63 C by 16S rRNA gene clone libraries indicates the presence of physiologically diverse and temperature-dependent microorganisms in these subterrestrial ecosystems. In high-temperature petroleum reservoirs, most of the archaeal sequences belong to the thermophilic archaea including the genera Thermococcus, Methanothermobacter and Thermoplasmatales, most of the bacterial sequences belong to the phyla Firmicutes, Thermotogae and Thermodesulfobacteria; in low-temperature petroleum reservoirs, most of the archaeal sequences are affiliated with the genera Methanobacterium, Methanoculleus and Methanocalculus, most of the bacterial sequences to the phyla Proteobacteria, Bacteroidetes and Actinobacteria. Canonical correspondence analysis (CCA) revealed that temperature, mineralization, ionic type as well as volatile fatty acids showed correlation with the microbial community structures. These organisms may be adapted to the environmental conditions of these petroleum reservoirs over geologic time by metabolizing buried organic matter from the original deep subsurface environment and became the common inhabitants in subsurface environments.

  20. Modeling of soil C-dynamics reveals different carbon pool sizes and decomposition rates under varying incubation temperatures

    NASA Astrophysics Data System (ADS)

    Schdel, C.; Luo, Y.; Schuur, E. A.; Zhou, J.

    2011-12-01

    Soils contain about two thirds of all organic carbon that is stored in terrestrial ecosystems. Annual release of soil carbon (C) to the atmosphere currently exceeds the rate of anthropogenic CO2 emissions by a factor of 10 demonstrating that even small changes in soil C cycling are highly relevant to the global C cycle. Total soil organic matter consists of different C pools with intrinsic turnover rates ranging from less than a year to thousands of years. The objectives of this study were to model soil C-dynamics of a long-term incubation study (336 days, Conant et al. 2008) under two different incubation temperatures (25C and 35C) to obtain i) soil CO2-efflux rates, ii) C-dynamics and iii) temperature sensitivities of C-pools with different turnover times. Respiration rates and soil C-dynamics of three different C-pools were modeled by a 1st order differential equation and data assimilation techniques were used to optimize parameter estimation. All C of the most labile pool (fast turnover time) was respired within the first ten days of the incubation study and pool size as well as absolute decline of the labile C-pool did not differ between temperatures. The intermediate C-pool (intermediate turnover time) was initially 70% larger at the higher temperature but as C was respired at a higher rate the intermediate pool was of equal size at both temperatures after 336 days of incubation. The most recalcitrant C-pool (slow turnover time) declined very slowly over time at both temperatures. However, the contribution of the recalcitrant C-pool to the whole CO2-efflux became more important towards the end of the incubation study. A 10K higher incubation temperature resulted in a larger intermediate C-pool and therefore in twice as much C released. This modeling study shows that higher temperatures increase the amount of easily decomposable C and that C-pool sizes vary at different temperatures. These results are of particular interest for high latitude regions as temperatures are predicted to increase more rapidly in arctic ecosystems and strong effects of higher temperatures on permafrost C are to be expected.

  1. Critical Temperature Differences of a Standing Wave Thermoacoustic Prime Mover with Various Helium-Based Binary Mixture Working Gases

    NASA Astrophysics Data System (ADS)

    Setiawan, Ikhsan; Nohtomi, Makoto; Katsuta, Masafumi

    2015-06-01

    Thermoacoustic prime movers are energy conversion devices which convert thermal energy into acoustic work. The devices are environmentally friendly because they do not produce any exhaust gases. In addition, they can utilize clean energy such as solar-thermal energy or waste heat from internal combustion engines as the heat sources. The output mechanical work of thermoacoustic prime movers are usually used to drive a thermoacoustic refrigerator or to generate electricity. A thermoacoustic prime mover with low critical temperature difference is desired when we intend to utilize low quality of heat sources such as waste heat and sun light. The critical temperature difference can be significantly influenced by the kinds of working gases inside the resonator and stack's channels of the device. Generally, helium gas is preferred as the working gas due to its high sound speed which together with high mean pressure will yield high acoustic power per unit volume of the device. Moreover, adding a small amount of a heavy gas to helium gas may improve the efficiency of thermoacoustic devices. This paper presents numerical study and estimation of the critical temperature differences of a standing wave thermoacoustic prime mover with various helium-based binary-mixture working gases. It is found that mixing helium (He) gas with other common gases, namely argon (Ar), nitrogen (N2), oxygen (O2), and carbon dioxide (CO2), at appropriate pressures and molar compositions, reduce the critical temperature differences to lower than those of the individual components of the gas mixtures. In addition, the optimum mole fractions of Hegas which give the minimum critical temperature differences are shifted to larger values as the pressure increases, and tends to be constant at around 0.7 when the pressure increases more than 2 MPa. However, the minimum critical temperature differences slightly increase as the pressure increases to higher than 1.5 MPa. Furthermore, we found that the lowest critical temperature difference for He-Armixture gas is around 66 °C which is achieved in pressure range of 1.5 MPa - 2.0 MPa and mole fractions of helium of 0.55 - 0.65. The He-N2 and He-O2 mixture gases demonstrate almost the same performances, both have the lowest critical temperature difference around 59 °C atpressures of 1.0 MPa - 1.5 MPa and helium's mole fractions of 0.35 - 0.55. For all tested gases, the lowest critical temperature difference of around 51 °C is provided by He-CO2 mixture gas at pressures of 0.5 MPa - 1.0 MPa with helium's mole fractions of 0.15 - 0.40.

  2. Investigation of effective base transit time and current gain modulation of light-emitting transistors under different ambient temperatures

    SciTech Connect

    Yang, Hao-Hsiang; Tu, Wen-Chung; Wang, Hsiao-Lun; Wu, Chao-Hsin

    2014-11-03

    In this report, the modulation of current gain of InGaP/GaAs light-emitting transistors under different ambient temperatures are measured and analyzed using thermionic emission model of quantum well embedded in the transistor base region. Minority carriers captured by quantum wells gain more energy at high temperatures and escape from quantum wells resulting in an increase of current gain and lower optical output, resulting in different I-V characteristics from conventional heterojunction bipolar transistors. The effect of the smaller thermionic lifetime thus reduces the effective base transit time of transistors at high temperatures. The unique current gain enhancement of 27.61% is achieved when operation temperature increase from 28 to 85 °C.

  3. Possibility of passive THz camera using for a temperature difference observing of objects placed inside the human body

    NASA Astrophysics Data System (ADS)

    Trofimov, Vyacheslav A.; Trofimov, Vladislav V.; Kuchik, Igor E.

    2014-06-01

    As it is well-known, application of the passive THz camera for the security problems is very promising way. It allows seeing concealed object without contact with a person and this camera is non-dangerous for a person. We demonstrate new possibility of the passive THz camera using for a temperature difference observing on the human skin if this difference is caused by different temperatures inside the body. We discuss some physical experiments, in which a person drinks hot, and warm, and cold water and he eats. After computer processing of images captured by passive THz camera TS4 we may see the pronounced temperature trace on skin of the human body. For proof of validity of our statement we make the similar physical experiment using the IR camera. Our investigation allows to increase field of the passive THz camera using for the detection of objects concealed in the human body because the difference in temperature between object and parts of human body will be reflected on the human skin. However, modern passive THz cameras have not enough resolution in a temperature to see this difference. That is why, we use computer processing to enhance the camera resolution for this application. We consider images produced by THz passive cameras manufactured by Microsemi Corp., and ThruVision Corp.

  4. Differences in the catalytic mechanisms of mesophilic and thermophilic indole-3-glycerol phosphate synthase enzymes at their adaptive temperatures

    SciTech Connect

    Zaccardi, Margot J.; Mannweiler, Olga; Boehr, David D.

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer Catalytic mechanisms of thermophilic-mesophilic enzymes may differ. Black-Right-Pointing-Pointer Product release is rate-determining for thermophilic IGPS at low temperatures. Black-Right-Pointing-Pointer But at higher temperatures, proton transfer from the general acid is rate-limiting. Black-Right-Pointing-Pointer Rate-determining step is different still for mesophilic IGPS. Black-Right-Pointing-Pointer Both chemical and physical steps of catalysis are important for temperature adaptation. -- Abstract: Thermophilic enzymes tend to be less catalytically-active at lower temperatures relative to their mesophilic counterparts, despite having very similar crystal structures. An often cited hypothesis for this general observation is that thermostable enzymes have evolved a more rigid tertiary structure in order to cope with their more extreme, natural environment, but they are also less flexible at lower temperatures, leading to their lower catalytic activity under mesophilic conditions. An alternative hypothesis, however, is that complementary thermophilic-mesophilic enzyme pairs simply operate through different evolutionary-optimized catalytic mechanisms. In this communication, we present evidence that while the steps of the catalytic mechanisms for mesophilic and thermophilic indole-3-glycerol phosphate synthase (IGPS) enzymes are fundamentally similar, the identity of the rate-determining step changes as a function of temperature. Our findings indicate that while product release is rate-determining at 25 Degree-Sign C for thermophilic IGPS, near its adaptive temperature (75 Degree-Sign C), a proton transfer event, involving a general acid, becomes rate-determining. The rate-determining steps for thermophilic and mesophilic IGPS enzymes are also different at their respective, adaptive temperatures with the mesophilic IGPS-catalyzed reaction being rate-limited before irreversible CO{sub 2} release, and the thermophilic IGPS-catalyzed reaction being rate limited afterwards.

  5. Effect of Different Temperatures on Consumption of Two Spotted Mite, Tetranychus urticae, Eggs by the Predatory Thrips, Scolothrips longicornis

    PubMed Central

    Pakyari, Hajar; Enkegaard, Annie

    2012-01-01

    Environmental variables such as temperature are important factors affecting the efficacy of biological control agents. This study evaluated the predation rate of the predatory thrips Scolothrips longicornis Priesner (Thysanoptera: Thripidae) against the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) under laboratory conditions. Based on daily and total prey consumption of different life stages of S. longicornis on spider mite eggs at temperatures covering the range suitable for development and survival of the predator (15° C to 37° C, 60 ± 10% RH, 16:8 L:D), there was a significant effect of temperature on prey consumption. The number of prey consumed daily by first and second instar larvae increased linearly with increasing temperature from 15 °C to 37 °C, whereas daily consumption of preovipositing and postovipositing females was uninfluenced by temperature. Lower temperature thresholds for consumption by first and second instar larvae of S. longicornis was estimated to be 6.8 ± 0.04° C and 4.6 ± 0.03° C, respectively. The daily consumption of ovipositing females followed a nonlinear pattern, with maximum daily predation estimated at 32.8° C. From the model used to describe consumption of ovipositing females, an upper threshold for consumption of 41.4° C was estimated. The performance of S. longicornis at the different temperatures is discussed in relation to its practical use in integrated pest control programs. PMID:23425212

  6. Effect of different temperatures on consumption of two spotted mite, Tetranychus urticae, eggs by the predatory thrips, Scolothrips longicornis.

    PubMed

    Pakyari, Hajar; Enkegaard, Annie

    2012-01-01

    Environmental variables such as temperature are important factors affecting the efficacy of biological control agents. This study evaluated the predation rate of the predatory thrips Scolothrips longicornis Priesner (Thysanoptera: Thripidae) against the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) under laboratory conditions. Based on daily and total prey consumption of different life stages of S. longicornis on spider mite eggs at temperatures covering the range suitable for development and survival of the predator (15 C to 37 C, 60 10% RH, 16:8 L:D), there was a significant effect of temperature on prey consumption. The number of prey consumed daily by first and second instar larvae increased linearly with increasing temperature from 15 ()C to 37 ()C, whereas daily consumption of preovipositing and postovipositing females was uninfluenced by temperature. Lower temperature thresholds for consumption by first and second instar larvae of S. longicornis was estimated to be 6.8 0.04 C and 4.6 0.03 C, respectively. The daily consumption of ovipositing females followed a nonlinear pattern, with maximum daily predation estimated at 32.8 C. From the model used to describe consumption of ovipositing females, an upper threshold for consumption of 41.4 C was estimated. The performance of S. longicornis at the different temperatures is discussed in relation to its practical use in integrated pest control programs. PMID:23425212

  7. Use of palm mid-fraction in dark chocolate as base filling centre at different storage temperatures.

    PubMed

    Jinap, S; Ali, A A; Man, Y B; Suria, A M

    2000-11-01

    Dark chocolates filled with palm mid-fraction (PMF) were stored at different temperatures to evaluate the physical and chemical changes. Storage at low temperature (18 degrees C) reduces the PMF migration to negligible extent. Higher storage temperatures (30 and 35 degrees C) increased the PMF migration from the filling centre into the chocolate coating. As a consequence of fat migration, fatty acid composition, triglyceride composition, hardness, solid fat content, melting point and polymorphic structure changed, leading to bloom formation, which started by fat migration and was influenced by recrystallization tendency within the chocolate coating. PMID:11271851

  8. Fracture Surface Analysis in HDPE Pipe Material Fatigued at Different Temperatures and Loading Frequencies

    NASA Astrophysics Data System (ADS)

    Khan, Zafarullah

    2012-07-01

    Effect of temperature and loading frequency on the fatigue fracture process in high-density polyethylene (HDPE) pipe material has been investigated in this study via optical and scanning electron microscopy. Fatigue tests were performed using rectangular coupons obtained by slitting and flattening 50-mm-wide ring sections from 4-inch schedule 80 HDPE pipes. The flattening was carried out in a specially designed compression fixture at a temperature of 105 °C. Fatigue tests were conducted at temperatures of 0, 23, and 40 °C and loading frequencies of 0.1, 1, and 50 Hz. Fracture surface examinations reveal that the fatigue crack-growth process at all the test temperatures and loading frequencies involved mechanisms of shear yielding and crazing. Crack growth via crazing was found to be the dominant mechanism at higher temperature of 40 °C, while at 0 °C, a small amount of initial shear yielding precede the crazing process. Filler material particles contained in the HDPE pipe material play an important role of stress concentrators and help in micro-void nucleation, which promotes crack growth via crazing. The fatigue resistance of HDPE may thus be improved by addressing the stress concentration effect of filler particles.

  9. Ambient temperature effect on single-bubble sonoluminescence in different concentrations of sulfuric acid solutions

    NASA Astrophysics Data System (ADS)

    Imani, Kh.; Bemani, F.; Silatani, M.; Sadighi-Bonabi, R.

    2012-01-01

    The effect of ambient temperature on the parameters of the single-bubble sonoluminescence in sulfuric acid (SA) diluted in water is studied. Using a hydrochemical model, three dominant instabilities of shape, Bjerknes, and diffusion are considered. The phase diagrams of the bubble in the (R0 - Pa) space are presented, and the parametric dependence of the light intensity is discussed. In contrast to water, the calculated thermal-bremsstrahlung mechanism of light emission at the fixed degassing condition of high SA concentrations shows that, with increasing the temperature of aqueous SA solutions, the light intensity increases. However, at diluted SA solutions similar to water, the light intensity decreases with increasing the ambient temperature. For 50 wt % SA, it was observed that the emitted light was almost temperature independent. Furthermore, it is found that, at the fixed temperatures of 20 C, 10 C, and 0 C, the aqueous solutions of 65 wt %, 50 wt %, and 45 wt % SA, respectively, have the maximum light emission.

  10. Effect of Te Inclusions in CdZnTe Crystals at Different Temperatures

    SciTech Connect

    A Hossain; A Bolotnikov; G Camarda; R Gul; K Kim; Y Cui; G Yang; L Xu; R James

    2011-12-31

    CdZnTe crystals often exhibit nonuniformities due to the presence of Te inclusions and dislocations. High concentrations of such defects in these crystals generally entail severe charge-trapping, a major problem in ensuring the device's satisfactory performance. In this study, we employed a high-intensity, high-spatial-resolution synchrotron x-ray beam as the ideal tool to generate charges by focusing it over the large Te inclusions, and then observing the carrier's response at room- and at low-temperatures. A high spatial 5-{micro}m resolution raster scan revealed the fine details of the presence of extended defects, like Te inclusions and dislocations in the CdZnTe crystals. A noticeable change was observed in the efficiency of electron charge collection at low temperature (1 C), but it was hardly altered at room-temperature.

  11. HA/Bioglass composite films deposited by pulsed laser with different substrate temperature

    NASA Astrophysics Data System (ADS)

    Wang, D. G.; Chen, C. Z.; Jin, Q. P.; Li, H. C.; Pan, Y. K.

    2013-05-01

    In this experiment, the HA/Bioglass composite films on Ti-6Al-4V were deposited by a pulsed laser at Ar atmosphere, and the influence of substrate temperature on the morphology, phase constitutions, bonding configurations and adhesive strength of the films was studied. The obtained films were characterized by an electron probe microanalyzer (EPMA), scanning electron microscope (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR), scratch apparatus, and so on. The results show that the amount of the droplets, the crystallinity, and the critical load of the deposited films all increase with the increase of the substrate temperature; however, the substrate temperature has little influence on the functional groups of the films.

  12. HA/Bioglass composite films deposited by pulsed laser with different substrate temperature

    NASA Astrophysics Data System (ADS)

    Wang, D. G.; Chen, C. Z.; Jin, Q. P.; Li, H. C.; Pan, Y. K.

    2014-03-01

    In this experiment, the HA/Bioglass composite films on Ti-6Al-4V were deposited by a pulsed laser at Ar atmosphere, and the influence of substrate temperature on the morphology, phase constitutions, bonding configurations and adhesive strength of the films was studied. The obtained films were characterized by an electron probe microanalyzer (EPMA), scanning electron microscope (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR), scratch apparatus, and so on. The results show that the amount of the droplets, the crystallinity, and the critical load of the deposited films all increase with the increase of the substrate temperature; however, the substrate temperature has little influence on the functional groups of the films.

  13. [Study on the vacuum ultraviolet transmittance of barium fluoride crystals at different temperature].

    PubMed

    Peng, Ru-Yi; Fu, Li-Ping; Tao, Ye

    2014-03-01

    Two VUV-grade BaF2 windows with 0.5 mm-thick and 1 mm-thick respectively were selected to study the transmittance variety with the temperature. The results show that the cutoff wavelength of BaF2 crystals will shift towards the long wave with the increase in temperature. In a certain temperature range, BaF2 crystals can depress 130.4 nm radiation well, and also has a high transmittance at 135.6 nm. Compared with the reported method in which SrF2 crystals can be applied to suppress 130.4 nm stray light by heating, BaF2 crystal can inhibit the 130. 4 nm emission line completely, and thus reduce the power consumption of the device at the same time. This indicates that BaF2 crystals can play an important role in the ionosphere optical remote sensing detection. PMID:25208398

  14. Telenomus remus Nixon egg parasitization of three species of Spodoptera under different temperatures.

    PubMed

    Pomari, A F; Bueno, A F; Bueno, R C O F; Menezes, A O

    2013-08-01

    Telenomus remus Nixon is a promising biocontrol agent as an egg parasitoid of Spodoptera spp., but the lack of information on the host-parasitoid interactions in this system precludes its applied use in agriculture. Therefore, we studied the parasitism capacity of T. remus on eggs of Spodoptera cosmioides (Walker), Spodoptera eridania (Cramer), and Spodoptera frugiperda (Smith) in a range of temperatures (19, 22, 25, 28, 31, and 34 ± 1°C) under controlled conditions (70 ± 10% RH and 12 h photophase). Egg masses of Spodoptera spp. were offered to a single-mated T. remus female on a daily basis. More than 80% lifetime parasitism on eggs of S. cosmioides, S. frugiperda, and S. eridania was reached from 1 to 5, 1 to 7, and 1 to 9 days, respectively, at temperatures from 19 to 34°C. More than 80% parasitization was obtained at extreme temperatures for all hosts studied. Lifetime parasitization of S. frugiperda, S. cosmioides, and S. eridania was affected by temperature, with the lowest values for S. frugiperda (34°C) and S. cosmioides (19 and 34°C). Parasitization of S. eridania eggs was reduced around 18% at 28 and 31°C, but dropped more severely at 34°C. Parasitoid longevity was reduced as temperature increased. Thus, our data indicated that T. remus might be suitable as a biocontrol agent against S. eridania, S. cosmioides, and S. frugiperda in geographical areas that fit the temperature range studied here, even though T. remus parasitism was reduced at 34°C. PMID:23949860

  15. [Development and reproduction of Sipha flava (Forbes) (Hemiptera: Aphididae) at different temperatures].

    PubMed

    de Oliveira, Simone A; Souza, Brígida; Auad, Alexander M; da Silva, Daniela M; Souza, Lívia S; Carvalho, Caio A

    2009-01-01

    The aphid Sipha flava (Forbes) is a pest on elephant grass, but little is known about its biology. The objective of this work was to evaluate the temperature effects on the development, survival and reproduction of S. flava fed on Pennisetum purpureum. Twelve-hour-old nymphs were individualized on sections of elephant grass blades and maintained at 12, 16, 20, 24, 28 and 32 degrees C+/-1 degrees C, UR 70+/-10% and 12 h photophase. A total of 150 nymphs were used per treatment divided in 30 replicates, using a totally random design. The lower threshold temperatures (LTT) for first, second, third and fourth instars were 0.83, 1.05, 3.01 and 4.98 degrees C, respectively, indicating a change in thermal requirements as the development progress. The LTT for the whole nymphal stage was 2.08 degrees C, pointing to the tolerance of this species to low temperatures. A significant reduction in survival was observed at high temperatures (28 and 32 degrees C). Although the reproductive periods were longer and insects lived longer at 12 degrees C as compared with those at higher temperatures, the total fecundity was substantially reduced. The overall life cycle duration was almost twice as long at 12 degrees C than at 24 degrees C. The greatest daily production of nymphs and greatest number of nymphs produced overall occurred at 24 degrees C. The temperatures of 20 degrees C and 24 degrees C were more suitable to S. flava development and reproduction. PMID:19618044

  16. The use of a DNA stabilizer in human dental tissues stored under different temperature conditions and time intervals

    PubMed Central

    TERADA, Andrea Sayuri Silveira Dias; da SILVA, Luiz Antonio Ferreira; GALO, Rodrigo; de AZEVEDO, Aline; GERLACH, Raquel Fernanda; da SILVA, Ricardo Henrique Alves

    2014-01-01

    Objective The present study evaluated the use of a reagent to stabilize the DNA extracted from human dental tissues stored under different temperature conditions and time intervals. Material and Methods A total of 161 teeth were divided into two distinct groups: intact teeth and isolated dental pulp tissue. The samples were stored with or without the product at different time intervals and temperature. After storage, DNA extraction and genomic DNA quantification were performed using real-time PCR; the fragments of the 32 samples that represented each possible condition were analyzed to find the four pre-selected markers in STR analysis. Results The results of the quantification showed values ranging from 0.01 to 10,246.88 ng/?L of DNA. The statistical difference in the quantity of DNA was observed when the factors related to the time and temperature of storage were analyzed. In relation to the use of the specific reagent, its use was relevant in the group of intact teeth when they were at room temperature for 30 and 180 days. The analysis of the fragments in the 32 selected samples was possible irrespective of the amount of DNA, confirming that the STR analysis using an automated method yields good results. Conclusions The use of a specific reagent showed a significant difference in stabilizing DNA in samples of intact human teeth stored at room temperature for 30 and 180 days, while the results showed no justification for using the product under the other conditions tested. PMID:25141206

  17. Differential Listeria monocytogenes strain survival and growth in Katiki, a traditional Greek soft cheese, at different storage temperatures.

    PubMed

    Kagkli, Dafni-Maria; Iliopoulos, Vassilios; Stergiou, Virginia; Lazaridou, Anna; Nychas, George-John

    2009-06-01

    Katiki Domokou is a traditional Greek cheese, which has received the Protected Designation of Origin recognition since 1994. Its microfloras have not been studied although its structure and composition may enable (or even favor) the survival and growth of several pathogens, including Listeria monocytogenes. The persistence of L. monocytogenes during storage at different temperatures has been the subject of many studies since temperature abuse of food products is often encountered. In the present study, five strains of L. monocytogenes were aseptically inoculated individually and as a cocktail in Katiki Domokou cheese, which was then stored at 5, 10, 15, and 20 degrees C. Pulsed-field gel electrophoresis was used to monitor strain evolution or persistence during storage at different temperatures in the case of the cocktail inoculum. The results suggested that strain survival of L. monocytogenes was temperature dependent since different strains predominated at different temperatures. Such information is of great importance in risk assessment studies, which typically consider only the presence or absence of the pathogen. PMID:19376914

  18. XMM-Newton and Chandra cross-calibration using HIFLUGCS galaxy clusters . Systematic temperature differences and cosmological impact

    NASA Astrophysics Data System (ADS)

    Schellenberger, G.; Reiprich, T. H.; Lovisari, L.; Nevalainen, J.; David, L.

    2015-03-01

    Context. Robust X-ray temperature measurements of the intracluster medium (ICM) of galaxy clusters require an accurate energy-dependent effective area calibration. Since the hot gas X-ray emission of galaxy clusters does not vary on relevant timescales, they are excellent cross-calibration targets. Moreover, cosmological constraints from clusters rely on accurate gravitational mass estimates, which in X-rays strongly depend on cluster gas temperature measurements. Therefore, systematic calibration differences may result in biased, instrument-dependent cosmological constraints. This is of special interest in light of the tension between the Planck results of the primary temperature anisotropies of the cosmic microwave background (CMB) and Sunyaev-Zel'dovich-plus-X-ray cluster-count analyses. Aims: We quantify in detail the systematics and uncertainties of the cross-calibration of the effective area between five X-ray instruments, EPIC-MOS1/MOS2/PN onboard XMM-Newton and ACIS-I/S onboard Chandra, and the influence on temperature measurements. Furthermore, we assess the impact of the cross-calibration uncertainties on cosmology. Methods: Using the HIFLUGCS sample, consisting of the 64 X-ray brightest galaxy clusters, we constrain the ICM temperatures through spectral fitting in the same, mostly isothermal regions and compare the different instruments. We use the stacked residual ratio method to evaluate the cross-calibration uncertainties between the instruments as a function of energy. Our work is an extension to a previous one using X-ray clusters by the International Astronomical Consortium for High Energy Calibration (IACHEC) and is carried out in the context of IACHEC. Results: Performing spectral fitting in the full energy band, (0.7-7) keV, as is typical of the analysis of cluster spectra, we find that best-fit temperatures determined with XMM-Newton/EPIC are significantly lower than Chandra/ACIS temperatures. This confirms the previous IACHEC results obtained with older calibrations with high precision. The difference increases with temperature, and we quantify this dependence with a fitting formula. For instance, at a cluster temperature of 10 keV, EPIC temperatures are on average 23% lower than ACIS temperatures. We also find systematic differences between the three XMM-Newton/EPIC instruments, with the PN detector typically estimating the lowest temperatures. Testing the cross-calibration of the energy-dependence of the effective areas in the soft and hard energy bands, (0.7-2) keV and (2-7) keV, respectively, we confirm the previously indicated relatively good agreement between all instruments in the hard and the systematic differences in the soft band. We provide scaling relations to convert between the different instruments based on the effective area, gas temperature, and hydrostatic mass. We demonstrate that effects like multitemperature structure and different relative sensitivities of the instruments at certain energy bands cannot explain the observed differences. We conclude that using XMM-Newton/EPIC instead of Chandra/ACIS to derive full energy band temperature profiles for cluster mass determination results in an 8% shift toward lower ?M values and <1% change of ?8 values in a cosmological analysis of a complete sample of galaxy clusters. Such a shift alone is insufficient to significantly alleviate the tension between Planck CMB primary anisotropies and Sunyaev-Zel'dovich-plus-XMM-Newton cosmological constraints. Appendices are available in electronic form at http://www.aanda.org

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

    NASA Astrophysics Data System (ADS)

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

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

  20. Impact of different temperatures on survival and energy metabolism in the Asian citrus psyllid, Diaphorina citri Kuwayama.

    PubMed

    El-Shesheny, Ibrahim; Hijaz, Faraj; El-Hawary, Ibrahim; Mesbah, Ibrahim; Killiny, Nabil

    2016-02-01

    Temperature influences the life history and metabolic parameters of insects. Asian citrus psyllid (ACP), Diaphorina citri is a tropical and subtropical pest. ACP invaded new regions around the world and threatened the citrus industry as a vector for Huanglongbing (HLB) disease. ACP is widely distributed and can survive high (up to 45C) and low temperatures (as low as -6C). The precise mechanism of temperature tolerance in ACP is poorly understood. We investigated adult survival, cellular energy balance, gene expression, and nucleotide and sugar-nucleotide changes under the effect of different temperature regimes (0C to 45C with 5C intervals). The optimum temperatures for survival were 20 and 25C. Low temperatures of 0C and 5C caused 50% mortality after 2 and 4days respectively, while one day at high temperature (40C and 45C) caused more than 95% mortality. The lowest quantity of ATP (3.691.6ng/insect) and the maximum ATPase enzyme activities (57.437.6?U/insect) were observed at 25C. Correlation between ATP quantities and ATPase activity was negative. Gene expression of hsp 70, V-type proton ATPase catalytic subunit A and ATP synthase ? subunit matched these results. Twenty-four nucleotides and sugar-nucleotides were quantified using HPLC in ACP adults maintained at low, high, and optimum temperatures. The nucleotide profiles were different among treatments. The ratios between AMP:ATP and ADP:ATP were significantly decreased and positively correlated to adults survival, whereas the adenylate energy charge was increased in response to low and high temperatures. Exploring energy metabolic regulation in relation with adult survival might help in understanding the physiological basis of how ACP tolerates newly invaded regions. PMID:26603556

  1. Effects of 17α-ethinylestradiol at different water temperatures on zebrafish sex differentiation and gonad development.

    PubMed

    Luzio, Ana; Santos, Dércia; Fontaínhas-Fernandes, António A; Monteiro, Sandra M; Coimbra, Ana M

    2016-05-01

    In the current climate change scenario, studies combining effects of water contaminants with environmental parameters, such as temperature, are essential to predict potentially harmful impacts on aquatic organisms. In zebrafish (Danio rerio), sex determination seems to have a polygenic genetic basis, which can be secondarily influenced by environmental factors, such as temperature and endocrine disrupting chemicals (EDCs). The present study aimed to evaluate the effects of the EDC 17α-ethinylestradiol (EE2), a potent synthetic estrogen, on zebrafish sex differentiation and gonad development at different water temperatures. Therefore, zebrafish raised at three distinct water temperatures (23, 28 or 33±0.5°C), were exposed to 4ng/L of EE2, from 2hours to 60days post-fertilization (dpf). Subsequently, a quantitative (stereological) assessment of zebrafish gonads was performed, at 35 and 60dpf, to identify alterations on gonadal development and differentiation. The results show that low temperature delayed general growth of zebrafish, as well as gonad differentiation and maturation, while high temperature induced an opposite effect. Moreover, sex ratio was skewed toward males when zebrafish were exposed to the high temperature. In general, EE2 exposure promoted gonad maturation in both genders, independently of the temperature. However, at the high temperature condition, exposure to EE2 induced a delay in the male gonad development, with some individuals still showing differentiating gonads at 60dpf. The findings of this study support the notion that zebrafish has a genetic sex determination mechanism highly sensitive to environmental factors and show that it is essential to study the effects of water contaminants at different climate scenarios in order to understand potential future impacts on organisms. PMID:26897088

  2. The effect of temperature on apoptosis and adipogenesis on skeletal muscle satellite cells derived from different muscle types

    PubMed Central

    Harding, Rachel L; Clark, Daniel L; Halevy, Orna; Coy, Cynthia S; Yahav, Shlomo; Velleman, Sandra G

    2015-01-01

    Satellite cells are multipotential stem cells that mediate postnatal muscle growth and respond differently to temperature based upon aerobic versus anaerobic fiber-type origin. The objective of this study was to determine how temperatures below and above the control, 38°C, affect the fate of satellite cells isolated from the anaerobic pectoralis major (p. major) or mixed fiber biceps femoris (b. femoris). At all sampling times, p. major and b. femoris cells accumulated less lipid when incubated at low temperatures and more lipid at elevated temperatures compared to the control. Satellite cells isolated from the p. major were more sensitive to temperature as they accumulated more lipid at elevated temperatures compared to b. femoris cells. Expression of adipogenic genes, CCAAT/enhancer-binding protein β (C/EBPβ) and proliferator-activated receptor gamma (PPARγ) were different within satellite cells isolated from the p. major or b. femoris. At 72 h of proliferation, C/EBPβ expression increased with increasing temperature in both cell types, while PPARγ expression decreased with increasing temperature in p. major satellite cells. At 48 h of differentiation, both C/EBPβ and PPARγ expression increased in the p. major and decreased in the b. femoris, with increasing temperature. Flow cytometry measured apoptotic markers for early apoptosis (Annexin-V-PE) or late apoptosis (7-AAD), showing less than 1% of apoptotic satellite cells throughout all experimental conditions, therefore, apoptosis was considered biologically not significant. The results support that anaerobic p. major satellite cells are more predisposed to adipogenic conversion than aerobic b. femoris cells when thermally challenged. PMID:26341996

  3. Effect of temperature and hydration on protein fluctuations: Molecular dynamics simulation of Cu, Zn superoxide dismutase at six different temperatures. Comparison with neutron scattering data

    NASA Astrophysics Data System (ADS)

    Melchionna, S.; Falconi, M.; Desideri, A.

    1998-04-01

    The equilibrium properties of solvated Cu,Zn superoxide dismutase have been sampled in the isothermal-isobaric ensemble at six different temperatures, namely at T=80, 130, 200, 225, 250, and 300 K. Molecular dynamics simulations covering the same range of temperatures have been also carried out for the protein in vacuo. Evaluation of the Debye-Waller factors as a function of temperature indicates that the "glasslike" transition, experimentally observed at approximately 200 K by neutron scattering experiments, is well reproduced when the protein is simulated in the presence of water solvent whereas the simulations without solvent are not able to reproduce the experimental results. Analysis of anharmonicity and anisotropy of the atomic motions indicates that these parameters are good indicators for the occurrence of the transition. Analysis of the atomic fluctuations of different protein shells, having different degrees of exposure to the solvent, shows that the transition is driven by the protein atoms belonging to the external shell, whose Debye-Waller factors are found to be larger in vacuo than in the solvated system.

  4. ANAEROBIC BIODEGRADATION OF 2,4-DICHLOROPHENOL IN FRESHWATER LAKE SEDIMENTS AT DIFFERENT TEMPERATURES

    EPA Science Inventory

    Anaerobic degradation of 2,4-dichlorophenol (2,4-DCP) between 5 and 72C was investigated. naerobic sediment slurries prepared from local freshwater sediments were partitioned into anaerobic tubes or serum vials, which then were incubated separately at the various temperatures. ed...

  5. RESPONSES OF LARGEMOUTH BASS FROM DIFFERENT LATITUDES TO ELEVATED WATER TEMPERATURES

    EPA Science Inventory

    The effects of elevated temperatures on largemouth bass (Micropterus s. salmoides), from Minnesota and Wisconsin (our northern stock) and from Tennessee (our southern stock), were compared at four first-year life stages. The purpose of these tests was to determine the degree of a...

  6. Effect of Extruder Screw Speed, Temperature, and Enzyme Levels on Sugar Recovery from Different Biomasses

    PubMed Central

    Karunanithy, Chinnadurai; Muthukumarappan, Kasiviswanathan; Gibbons, William R.

    2013-01-01

    Biofuels from biomass have the potential to reduce the dependency on fossil fuels. An efficient pretreatment method is required to accomplish the target of the Energy Act 2005. Extrusion could be a viable continuous pretreatment method to be explored. The objectives of the current study were to investigate the influence of screw speed and barrel temperature on sugar recovery from the selected warm season grasses and to select a suitable enzyme combination and dose for enzymatic hydrolysis. The ground, moisture-balanced biomasses were pretreated using a single screw extruder at various screw speeds (100, 150, and 200?rpm) and barrel temperatures (50, 75, 100, 150, and 200C). Cellulase or multienzyme with ?-glucosidase was varied from 1?:?1 to 1?:?4 during enzymatic hydrolysis to accomplish the second objective. Screw speed, barrel temperature, and their interaction had a significant influence on sugar recovery from the selected biomasses. A maximum of 28.2, 66.2, and 49.2% of combined sugar recoverywasachieved for switchgrass, big bluestem, prairie cord grass when pretreated at a screw speed of 200, 200, and 150?rpm and at a barrel temperature of 75, 150, and 100C, respectively, using cellulase and ?-glucosidase at a ratio of 1?:??4. Extrusion pretreatment of these biomasses used only 2837% of the rated extruder power. PMID:25969784

  7. Small differences in temperature interact with solar radiation to alter anthocyanin in grapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite a century of research, we still lack a concrete, mechanistic understanding of solar radiation and temperature effects on anthocyanin accumulation and composition, crucial for red wine grapes. Our aim was to elucidate the mechanistic response to microclimate of anthocyanin metabolism in Viti...

  8. Photosynthesis and growth response of different switchgrass ecotypes to fluctuating growth temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Switchgrass (Panicum virgatum L.), a warm-season C4 grass that shows good potential as a bioenergy feedstock and conservation crop, is widely adapted throughout North America. However, its productivity tends to decline with increasing latitude. In northern regions where growing season temperatures c...

  9. Temperature Quotients of Ammonia Emission for Different Nitrogen Sources Applied to Four Agricultural Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperature is an important factor influencing ammonia (NH3) emission from nitrogen (N) sources containing ammonium (NH4+) or other N sources transformed into NH4+ form applied to soils. This research was conducted using Biscayne Marl Soil (BMS), Krome Gravelly Loam (KGL) soils from Florida, Quincy ...

  10. Vulnerability of lodging risk to elevated CO2 and increased soil temperature differs between rice cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anthropogenic increases in atmospheric carbon dioxide concentration, [CO2], and subsequent increases in surface temperatures, are likely to impact the growth and yield of cereal crops. One means for yield reduction is for climate parameters to increase the occurrence of lodging. Using an in situ f...

  11. Association of Weekly Suicide Rates with Temperature Anomalies in Two Different Climate Types

    PubMed Central

    Dixon, P. Grady; Sinyor, Mark; Schaffer, Ayal; Levitt, Anthony; Haney, Christa R.; Ellis, Kelsey N.; Sheridan, Scott C.

    2014-01-01

    Annual suicide deaths outnumber the total deaths from homicide and war combined. Suicide is a complex behavioral endpoint, and a simple cause-and-effect model seems highly unlikely, but relationships with weather could yield important insight into the biopsychosocial mechanisms involved in suicide deaths. This study has been designed to test for a relationship between air temperature and suicide frequency that is consistent enough to offer some predictive abilities. Weekly suicide death totals and anomalies from Toronto, Ontario, Canada (19862009) and Jackson, Mississippi, USA (19802006) are analyzed for relationships by using temperature anomaly data and a distributed lag nonlinear model. For both analysis methods, anomalously cool weeks show low probabilities of experiencing high-end suicide totals while warmer weeks are more likely to experience high-end suicide totals. This result is consistent for Toronto and Jackson. Weekly suicide totals demonstrate a sufficient association with temperature anomalies to allow some prediction of weeks with or without increased suicide frequency. While this finding alone is unlikely to have immediate clinical implications, these results are an important step toward clarifying the biopsychosocial mechanisms of suicidal behavior through a more nuanced understanding of the relationship between temperature and suicide. PMID:25402561

  12. Polyamide-6: The effects on mechanical and physicochemical properties by electron beam irradiation at different temperatures

    NASA Astrophysics Data System (ADS)

    Adem, E.; Burillo, G.; del Castillo, L. F.; Vsquez, M.; Avalos-Borja, M.; Marcos-Fernndez, A.

    2014-04-01

    The electron beam irradiation of polyamide-6 (PA-6) films was carried out in air over a range of 50-1000 kGy at varying temperatures and a dose rate of 5.1 kGy min-1. The effects of the irradiation at temperatures above and below the glass transition temperature (Tg) on the thermal and mechanical properties were studied. Melting and crystallization temperatures decreased significantly with the increase in irradiation dose, whereas percent of crystallinity varied only slightly and Tg slightly increased for irradiated samples respect to non irradiated one with no significant effect of the dose. Mechanical properties were affected by irradiation. The material became more rigid with a direct relationship between the mechanical properties and the irradiation dose. The irradiation above Tg led to a larger variation in the thermal and mechanical properties respect to the irradiation below Tg. The changes in properties were related to the crosslinking produced in the amorphous part of the polymer by the electron beam irradiation.

  13. Catalytic activity of beta-amylase from barley in different pressure/temperature domains.

    PubMed

    Heinz, Volker; Buckow, Roman; Knorr, Dietrich

    2005-01-01

    The depolymerization of starch by beta-amylase during exposure to hydrostatic pressure up to 700 MPa and within a temperature range from 20 to 70 degrees C has been investigated. Inactivation of the enzyme as well as alterations in conversion speed in response to combined pressure-temperature treatments were assessed by analyzing the kinetic rate constants. At 200 MPa a significant stabilization of the enzyme against heat inactivation was observed. However, high pressure also impedes the catalytic reaction and a progressive reduction of the conversion rate constants with increasing pressure was found at all temperatures investigated. For the overall reaction of maltose liberation from soluble starch in ACES buffer at pH 5.6 an optimum was identified at 106 MPa and at 63 degrees C, which is approximately 7 degrees C above the local maximum at ambient pressure (0.1 MPa). Gelatinization of nonsoluble starch granules in response to pressure-temperature (p-T) treatment has been inspected by phase-contrast microscopy and yielded circular curves of identical effect in the p-T plane. PMID:16321045

  14. TEMPERATURE QUOTIENTS OF AMMONIA EMISSION OF DIFFERENT NITROGEN SOURCES APPLIED TO FOUR AGRICULTURAL SOILS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emitted ammonia (NH3) is the primary gaseous form of nitrogen (N) loss from N sources applied to soils, which contain instant or transformable ammonium (NH4+). However, our knowledge of NH3 volatilization in relation to temperature is incomplete. This research was conducted using Biscayne Marl Soil ...

  15. CHANGES IN THE RAT EEG SPECTRA AND CORE TEMPERATURE AFTER EXPOSURE TO DIFFERENT DOSES OF CHLORPYRIFOS.

    EPA Science Inventory

    Our previous study showed that single exposure to 25 mg/kg (p.o.) of organophsphate pesticide chlorpyrifos (CHP) led to significant alterations in all EEG frequency bands within 0.1-50 Hz range, reduction in core temperature (Tc) and motor activity (MA). The alterations in EEG pe...

  16. Responses to bleaching herbicides by leaf chloroplasts of maize plants grown at different temperatures.

    PubMed

    Vecchia, F D; Barbato, R; La Rocca, N; Moro, I; Rascio, N

    2001-04-01

    The effects of growth temperature on chloroplast responses to norflurazon and amitrole, two herbicides inhibiting carotenogenesis, at phytoene desaturation and lycopene cyclization, respectively, were studied in leaves of maize plants grown at 20 degrees C and 30 degrees C in light. At the lower temperature both chemicals caused severe photo-oxidative damage to chloroplasts. In organelles of norflurazon-treated leaves neither carotenoids nor chlorophylls were detectable and the thylakoid system was dismantled. In organelles of amitrole-treated leaves lycopene was accumulated, but small quantities of beta-carotene and xanthophylls were also produced. Moreover, some chlorophyll and a few inner membranes still persisted, although these latter were disarranged, lacking essential protein components and devoid of photosynthetic function. The increase in plant growth temperature to 30 degrees C did not change the norflurazon effects on carotenoid synthesis and the photo-oxidative damage suffered by chloroplasts. By contrast, in organelles of amitrole-treated leaves a large increase in photoprotective carotenoid biosynthesis occurred, with a consequent recovery of chlorophyll content, ultrastructural organization and thylakoid composition and functionality. This suggests that thermo-modulated steps could exist in the carotenogenic pathway, between the points inhibited by the two herbicides. Moreover it shows that, unlike C(3) species, C(4) species, such as maize, can express a strong tolerance to herbicides like amitrole, when supplied to plants growing at their optimum temperature conditions. PMID:11413217

  17. Growth of Salmonella and Listeria monocytogenes on fresh-cut cantaloupe under different temperature abuse scenarios

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effective cold chain management is a critical component of food safety practice. In this study, we examined the impact of commonly encountered temperature abuse scenarios on the proliferation of Salmonela enterica and Listeria monocytogenes on fresh-cut cantaloupe. During one week of storage, Salmon...

  18. DIFFERENCES IN THE TEMPERATURE QUOTIENTS OF AMMONIA EMISSION ON THE FERTILIZED SOILS FROM FLORIDA AND WASHINGTON

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperature is a very important factor for ammonia emission but not well understood yet. This research was conducted with Biscayne Marl Soil and Krome Gravelly Loam from Florida and Quincy Fine Sand and Warden Silt Loam from Washington. The soils were weighed (300 g dry weight) and placed in a 500 m...

  19. BIOMASS ACCUMULATION AND PARTITIONING OF EASTERN GAMMAGRASS GROWN UNDER DIFFERENT TEMPERATURE AND CO2 LEVELS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eastern gamagrass has been reported to have one of the highest photosynthetic rates of any C4 species but data on temperature x CO2 interactions are lacking. This study was conducted to determine the potential effects of future increases of atmospheric carbon dioxide on growth, biomass accumulation...

  20. SEASONAL DIFFERENCES IN CLEAR-SKY NIGHTTIME FORAGE TEMPERATURE IN PROXIMITY TO DECIDUOUS TREES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Considerable research has been done on daytime forage shading by silvopasture trees since solar radiation is required for photosynthesis. However, trees also impact nighttime temperature on clear nights when trees also effectively shade forages from cold skies. Appalachia has a temperate climate a...

  1. Clearance of yellow pigments lutein and zeathanxin in channel catfish reared at different water temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to determine clearance time of yellow pigments lutein and zeaxanthin in channel catfish at various temperatures. Fish of initial weight of 13.4 g were stocked into flow-through aquaria and fed once daily with a yellow pigment enhanced diet for 11 weeks when the yellow color be...

  2. Geometric thermal phase diagrams for studying the thermal dynamic stability of hollow gold nanoballs at different temperatures.

    PubMed

    Jiang, Luyun; Sun, Wei; Gao, Yajun; Zhao, Jianwei

    2014-04-14

    Thermal stability is one of the main concerns for the synthesis of hollow nanoparticles. In this work, molecular dynamics simulation gave an insight into the atomic reconstruction and energy evolution during the collapse of hollow gold nanoballs, based on which a mechanism was proposed. The stability was found to depend on temperature, its wall thickness and aspect ratio to a great extent. The relationship among these three factors was revealed in geometric thermal phase diagrams (GTPDs). The GTPDs were studied theoretically, and the boundary between different stability regions can be fitted and calculated. Therefore, the GTPDs at different temperatures can be deduced and used as a guide for hollow structure synthesis. PMID:24569850

  3. Dramatic difference in the responses of phosphoenolpyruvate carboxylase to temperature in leaves of C3 and C4 plants.

    PubMed

    Chinthapalli, Bhaskarrao; Murmu, Jhadeswar; Raghavendra, Agepati S

    2003-02-01

    Temperature caused phenomenal modulation of phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) in leaf discs of Amaranthus hypochondriacus (NAD-ME type C(4) species), compared to the pattern in Pisum sativum (a C(3) plant). The optimal incubation temperature for PEPC in A. hypochondriacus (C(4)) was 45 degrees C compared to 30 degrees C in P. sativum (C(3)). A. hypochondriacus (C(4)) lost nearly 70% of PEPC activity on exposure to a low temperature of 15 degrees C, compared to only about a 35% loss in the case of P. sativum (C(3)). Thus, the C(4) enzyme was less sensitive to supra-optimal temperature and more sensitive to sub-optimal temperature than that of the C(3) species. As the temperature was raised from 15 degrees C to 50 degrees C, there was a sharp decrease in malate sensitivity of PEPC. The extent of such a decrease in C(4) plants (45%) was more than that in C(3) species (30%). The maintenance of high enzyme activity at warm temperatures, together with a sharp decrease in the malate sensitivity of PEPC was also noticed in other C(4) plants. The temperature-induced changes in PEPC of both A. hypochondriacus (C(4)) and P. sativum (C(3)) were reversible to a large extent. There was no difference in the extent of phosphorylation of PEPC in leaves of A. hypochondriacus on exposure to varying temperatures, unlike the marked increase in the phosphorylation of enzyme on illumination of the leaves. These results demonstrate that (i) there are marked differences in the temperature sensitivity of PEPC in C(3) and C(4) plants, (ii) the temperature induced changes are reversible, and (iii) these changes are not related to the phosphorylation state of the enzyme. The inclusion of PEG-6000, during the assay, dampened the modulation by temperature of malate sensitivity of PEPC in A. hypochondriacus. It is suggested that the variation in temperature may cause significant conformational changes in C(4)-PEPC. PMID:12554714

  4. Elevated temperature differently affects foliar nitrogen partitioning in seedlings of diverse Douglas fir provenances.

    PubMed

    Du, Baoguo; Jansen, Kirstin; Junker, Laura Verena; Eiblmeier, Monika; Kreuzwieser, Jürgen; Gessler, Arthur; Ensminger, Ingo; Rennenberg, Heinz

    2014-10-01

    Global climate change causes an increase in ambient air temperature, a major environmental factor influencing plant physiology and growth that already has been perceived at the regional scale and is expected to become even more severe in the future. In the present study, we investigated the effect of elevated ambient air temperature on the nitrogen metabolism of two interior provenances of Douglas fir (Pseudotsuga menziesii var. glauca) originating from contrasting habitats, namely the provenances Monte Creek (MC) from a drier environment and Pend Oreille (PO) from a more humid environment. Three- to four-year-old seedlings of the two provenances were grown for 3 months in controlled environments under either control temperature (day 20 °C, night 15 °C) or high temperature (HT, 30/25 °C) conditions. Total nitrogen (N), soluble protein, chlorophyll and total amino acid (TAA) contents as well as individual amino acid concentrations were determined in both current-year and previous-year needles. Our results show that the foliar total N contents of the two provenances were unaffected by HT. Arginine, lysine, proline, glutamate and glutamine were the most abundant amino acids, which together contributed ∼88% to the TAA pool of current- and previous-year needles. High temperature decreased the contents of most amino acids of the glutamate family (i.e., arginine, proline, ornithine and glutamine) in current-year needles. However, HT did not affect the concentrations of metabolites related to the photorespiratory pathway, such as [Formula: see text], glycine and serine. In general, current-year needles were considerably more sensitive to HT than previous-year needles. Moreover, provenance PO originating from a mesic environment showed stronger responses to HT than provenance MC. Our results indicate provenance-specific plasticity in the response of Douglas fir to growth temperature. Provenance-specific effects of elevated temperature on N-use efficiency suggest that origin might determine the sensitivity and growth potential of Douglas fir trees in a future warmer climate. PMID:25240727

  5. Compressive behavior of bulk metallic glass under different conditions --- Coupled effect of temperature and strain rate

    NASA Astrophysics Data System (ADS)

    Yin, Weihua

    Metallic glass was first reported in 1960 by rapid quenching of Au-Si alloys. But, due to the size limitation, this material did not attract remarkable interest until the development of bulk metallic glasses (BMGs) with specimen sizes in excess of 1 mm. BMGs are considered to be promising engineering materials because of their ultrahigh strength, high elastic limit and wear resistance. However, they usually suer from a strong tendency for localized plastic deformation with catastrophic failure. Many basic questions, such as the origin of shear softening and the strain rate eect remain unclear. In this thesis, the mechanical behavior of the Zr55Al 10Ni5Cu30 bulk metallic glass and a metallic glass composite is investigated. The stress-strain relationship for Zr55Al10Ni 5Cu30 over a wide range of strain rate (5x10 --5 to 2x103 s--1) was investigated in uniaxial compression loading using both MTS servo-hydraulic system (quasi-static) and compression Kolsky bar system (dynamic). The effect of the strain rate on the fracture stress at room temperature was discussed. Based on the experimental results, the strain rate sensitivity of the bulk metallic glass changes from a positive value to a negative value at high strain rate, which is a consequence of the significant adiabatic temperature rise during the dynamic testing. In order to characterize the temperature eect on the mechanical behavior of the metallic glass, a synchronically assembled heating unit was designed to be attached onto the Kolsky bar system to perform high temperature and high strain rate mechanical testing. A transition from inhomogeneous deformation to homogeneous deformation has been observed during the quasi-static compressive experiments at testing temperatures close to the glass transition temperature. However, no transition has been observed at high strain rates at all the testing temperatures. A free volume based model is applied to analyze the stress-strain behavior of the homogeneous deformation. To further examine the inelastic deformation of the Zr-based bulk metallic glasses, instrumented nanoindentation experiments were performed. A transition from discrete plastic deformation to continuous plastic deformation was found when strain rate is increased but still within the quasi-static strain rate region. Motivated by the metal matrix composite material, a tungsten reinforced BMG composite was investigated at quasi-static and dynamic strain rates. The mechanical behavior of the metallic glass matrix was improved significantly by the addition of W particles.

  6. Development, Survival, and Reproduction of Megacopta cribraria (Heteroptera: Plataspidae) at Different Constant Temperatures.

    PubMed

    Shi, Shu-Sen; Cui, Juan; Zang, Lian-Sheng

    2014-12-01

    The plataspid Megacopta cribraria (F.), an economic pest of soybeans, Glycine max (L.) Merrill, in Asia recently invaded North America and has become not only an important pest of soybean but also a nuisance pest. Although much is reported about M. cribraria in its native and invasive range, little information has been documented on the effect of temperatures on its development, longevity, and reproduction. We evaluated the influence of five constant temperatures (17-33C) on the development, survival, fecundity, and population growth of M. cribraria in the laboratory. The developmental time for egg and nymph stages was shortened significantly with increasing temperature. The developmental time from egg to adult emergence was 114.81, 76.26, 44.54, and 38.54 d at 17, 21, 25, and 29C, respectively. The nymphs of M. cribraria could not complete full development at a constant 33C. The developmental threshold temperature estimated for egg to adult was 14.25C, with a thermal constant of 849.56 degree-days. Females had the longest preoviposition period at 21C (54.33 d), and the preoviposition period was shortened significantly as the temperature increased. Females had the longest oviposition period (35.33 d) and the highest fecundity (159.67 eggs per female) at 25C and did not lay any eggs at 17C. Female longevity was found to be shortest (44.0 d) at 29C, and similar (75.67-81.50 d) at 17-25C. The population trend index of M. cribraria was the highest (46.47) at 25C, followed by 29C (10.84) and 21C (6.70). The results will be useful for predicting the phenology and population dynamics of M. cribraria and will provide some biological information on the invasive species in its nonnative range. PMID:26470070

  7. Development and survival of embryos of lake herring at different constant oxygen concentrations and temperatures

    USGS Publications Warehouse

    Brooke, L.T.; Colby, P.J.

    1980-01-01

    Eggs of lake herring (Coregonus artedii) were incubated in a continuous-flow system at four constant water temperatures (2-8A?C) and five dissolved oxygen (DO) concentrations (1-12 mg/L). In comparison with incubation time at 12 mg/L DO, time to median hatch was significantly longer (P < 0.05) at 2 mg/L at 6A?C (no hatch at 1 mg/L), at 3 mg/L or less at 4A?C, and at 4 mg/L or less at 2A?C. The time between hatching of the first and last eggs varied inversely with temperature. Mean total lengths of newly hatched fry were significantly shortened (P < 0.05) at 1 and 2 mg/L DO. At 6 and 8A?C , percent survival through hatching was greater than at 2 and 4A?C at DO of 4 mg/L or more, but fell to zero at 1 mg/L. The percentage of normal fry produced decreased noticeably below 4 mg/L DO. The optimum temperature for highest percentage survival of normal fry decreased directly with the level of dissolved oxygen. The temperatures at which the highest percentages of normal fry hatched from eggs incubated at DO concentrations of 4 or 8, 2, and 1 mg/L, were 6, 4, and 2A?C, respectively - indicating a decreasing DO demand by embryos incubated at the lower temperatures. Our findings supported a previously published hypothesis that DO concentrations below 4 mg/L can be adverse to survival and development of coregonid embryos in nature.

  8. An experimental study of the influence of the temperature difference field uniformity on cross-flow heat exchanger performance

    SciTech Connect

    Lu, B.; Lloyd, J.R.; Guo, Z.Y.; Zhou, S.Q.

    1996-12-31

    An experimental study of heat exchanger performance has been conducted utilizing a basic cross-flow heat exchanger configuration. Six different cross-flow, finned-tube heat exchanger flow configurations were tested in a specially designed wind tunnel system to investigate the importance of the Temperature Difference Uniformity on the effectiveness of heat exchanger performance. The Temperature Difference Field (TDF) and the Temperature Difference Uniformity Factor, {Phi}, were employed as design factors to characterize and evaluate heat exchanger thermal performance. A base heat exchanger configuration was established, and then five modifications on the base configuration were made in a systematic study to enhance the performance. The fluids were air on the outside, and hot water inside the tubes. The basic configurations included either 28 or 56 tubes in the bank. The results of the experiments have clearly demonstrated the importance of flow distribution and how it can be used to control the Temperature Difference Field; which, as a design parameter, is an important component of heat exchanger performance optimization. Heat exchanger effectiveness for the best flow distribution was found to increase by 4.3% over that of the conventional flow distribution with no associated increase in pressure drop. This promotes a new path for them to increase heat exchanger heat transfer effectiveness. Comments on further possible performance enhancement strategies are presented.

  9. Studies on the effect of plasticiser and addition of toluene diisocyanate at different temperatures in composite propellant formulations.

    PubMed

    Jawalkar, S N; Mehilal; Ramesh, K; Radhakrishnan, K K; Bhattacharya, B

    2009-05-30

    Different composite propellant mixtures have been prepared using ammonium perchlorate, aluminium powder and hydroxyl terminated polybutadiene by varying the percentage of plasticiser and addition of toluene diisocyanate at different temperatures, and studied their different properties such as viscosity build-up, mechanical and ballistic properties and sensitivity. The data on different plasticiser level indicate that on decreasing the plasticiser content, there is a significant enhancement in end of mix viscosity, tensile strength and modulus while elongation decreases drastically. The data on sensitivity of the studied mixtures reveal that on decreasing the percentage of plasticiser, the sensitivity increases, accordingly. Further, the data on the effect of addition of TDI at different temperatures (35-60 degrees C) infer that on increasing the addition temperature of TDI there is a decrease in end of mix viscosity i.e. 800Pas at 35 degrees C to 448Pas at 60 degrees C. Moreover, there is no effect on mechanical and ballistic properties on higher temperature addition of TDI was observed. PMID:18835097

  10. Sub-10 pW/Hz0.5 room temperature Ni nano-bolometer

    NASA Astrophysics Data System (ADS)

    Yang, Hyun-Ho; Rebeiz, Gabriel M.

    2016-02-01

    In this letter, we report on room temperature Ni nano-bolometers with a measured electrical noise equivalent power of 8.7 pW/Hz0.5 based on air-suspended and self-aligned nano-stack (SiO2/Ni/SiO2) structures, which is an outstanding electrical performance among uncooled micro/nano-bolometers. This result, together with electrical resistances of 172.6 Ω and modulation frequencies of 15-30 kHz, shows that Ni nano-bolometers can be easily coupled to terahertz antennas and are appropriate for fast passive imaging applications.

  11. Clostridium tyrobutyricum strains show wide variation in growth at different NaCl, pH, and temperature conditions.

    PubMed

    Ruusunen, Marjo; Surakka, Anu; Korkeala, Hannu; Lindstrm, Miia

    2012-10-01

    Outgrowth from Clostridium tyrobutyricum spores in milk can lead to butyric acid fermentation in cheeses, causing spoilage and economical loss to the dairy industry. The aim of this study was to investigate the growth of 10 C. tyrobutyricum strains at different NaCl, pH, and temperature conditions. Up to 7.5-fold differences among the maximum growth rates of different strains in the presence of 2.0% NaCl were observed. Five of 10 strains were able to grow in the presence of 3.0% NaCl, while a NaCl concentration of 3.5% was completely inhibitory to all strains. Seven of 10 strains were able to grow at pH 5.0, and up to 4- and 12.5-fold differences were observed among the maximum growth rates of different strains at pH 5.5 and 7.5, respectively. The maximum growth temperatures varied from 40.2 to 43.3C. The temperature of 10C inhibited the growth of all strains, while 8 of 10 strains grew at 12 and 15C. Despite showing no growth, all strains were able to survive at 10C. In conclusion, wide variation was observed among different C. tyrobutyricum strains in their ability to grow at different stressful conditions. Understanding the physiological diversity among the strains is important when designing food control measures and predictive models for the growth of spoilage organisms in cheese. PMID:23043827

  12. Laser-induced breakdown spectroscopy on metallic samples at very low temperature in different ambient gas pressures

    NASA Astrophysics Data System (ADS)

    El-Saeid, R. H.; Abdelhamid, M.; Harith, M. A.

    2016-02-01

    Analysis of metals at very low temperature adopting laser-induced breakdown spectroscopy (LIBS) is greatly beneficial in space exploration expeditions and in some important industrial applications. In the present work, the effect of very low sample temperature on the spectral emission intensity of laser-induced plasma under both atmospheric pressure and vacuum has been studied for different bronze alloy samples. The sample was cooled down to liquid nitrogen (LN) temperature 77 K in a special vacuum chamber. Laser-induced plasma has been produced onto the sample surface using the fundamental wavelength of Nd:YAG laser. The optical emission from the plasma is collected by an optical fiber and analyzed by an echelle spectrometer combined with an intensified CCD camera. The integrated intensities of certain spectral emission lines of Cu, Pb, Sn, and Zn have been estimated from the obtained LIBS spectra and compared with that measured at room temperature. The laser-induced plasma parameters (electron number density Ne and electron temperature Te) were investigated at room and liquid nitrogen temperatures for both atmospheric pressure and vacuum ambient conditions. The results suggest that reducing the sample temperature leads to decrease in the emission line intensities under both environments. Plasma parameters were found to decrease at atmospheric pressure but increased under vacuum conditions.

  13. Assessing the Total Mortality Caused by Two Species of Trichogramma on Its Natural Host Plutella xylostella (L.) at Different Temperatures.

    PubMed

    Marchioro, C A; Krechemer, F S; Foerster, L A

    2015-06-01

    Trichogramma pretiosum Riley and Trichogramma atopovirilia Oatman & Platner are natural enemies of Plutella xylostella (L.) in Southern Brazil. Laboratory studies to evaluate parasitoids performance under different conditions, such as temperature regimes, are necessary to assess their potential as biocontrol agents of P. xylostella. In most studies involving Trichogramma, parasitism rate is the main parameter used to evaluate parasitoid performance, ignoring that parasitoids can cause egg mortality by feeding on the host content and/or to multiple drilling without laying eggs. This study was conducted to investigate three main issues: how temperature affects T. pretiosum and T.atopovirilia development on eggs of P. xylostella, whether or not these species respond differently to temperature, and how important is the mortality they cause besides parasitism on P. xylostella. Temperature effects (from 10 to 30C) on development, survival, parasitism rate, mortality, and total mortality caused by T. pretiosum and T. atopovirilia on eggs of P. xylostella were evaluated. Temperature affected the development time, female longevity, parasitism rate, mortality not directly related to parasitoid larval development, and total mortality caused on the host. No significant differences were recorded for the estimated thermal requirements for T. pretiosum and T. atopovirilia. However, the higher mortality caused by T. pretiosum indicates that this parasitoid is the most suitable to be used against P. xylostella. Also, the results suggest that the use of parasitism rate as the only parameter to evaluate the performance of T. pretiosum and T. atopovirilia may underestimate the potential of these parasitoids in regulating pest populations. PMID:26013271

  14. Effect of temperature difference between manikin and wet fabric skin surfaces on clothing evaporative resistance: how much error is there?

    NASA Astrophysics Data System (ADS)

    Wang, Faming; Kuklane, Kalev; Gao, Chuansi; Holmr, Ingvar

    2012-01-01

    Clothing evaporative resistance is one of the inherent factors that impede heat exchange by sweating evaporation. It is widely used as a basic input in physiological heat strain models. Previous studies showed a large variability in clothing evaporative resistance both at intra-laboratory and inter-laboratory testing. The errors in evaporative resistance may cause severe problems in the determination of heat stress level of the wearers. In this paper, the effect of temperature difference between the manikin nude surface and wet textile skin surface on clothing evaporative resistance was investigated by both theoretical analysis and thermal manikin measurements. It was found that the temperature difference between the skin surface and the manikin nude surface could lead to an error of up to 35.9% in evaporative resistance of the boundary air layer. Similarly, this temperature difference could also introduce an error of up to 23.7% in the real clothing total evaporative resistance ( R et_real < 0.1287 kPa m2/W). Finally, it is evident that one major error in the calculation of evaporative resistance comes from the use of the manikin surface temperature instead of the wet textile fabric skin temperature.

  15. Different Transcriptional Responses from Slow and Fast Growth Rate Strains of Listeria monocytogenes Adapted to Low Temperature.

    PubMed

    Cordero, Ninoska; Maza, Felipe; Navea-Perez, Helen; Aravena, Andrés; Marquez-Fontt, Bárbara; Navarrete, Paola; Figueroa, Guillermo; González, Mauricio; Latorre, Mauricio; Reyes-Jara, Angélica

    2016-01-01

    Listeria monocytogenes has become one of the principal foodborne pathogens worldwide. The capacity of this bacterium to grow at low temperatures has opened an interesting field of study in terms of the identification and classification of new strains of L. monocytogenes with different growth capacities at low temperatures. We determined the growth rate at 8°C of 110 strains of L. monocytogenes isolated from different food matrices. We identified a group of slow and fast strains according to their growth rate at 8°C and performed a global transcriptomic assay in strains previously adapted to low temperature. We then identified shared and specific transcriptional mechanisms, metabolic and cellular processes of both groups; bacterial motility was the principal process capable of differentiating the adaptation capacity of L. monocytogenes strains with different ranges of tolerance to low temperatures. Strains belonging to the fast group were less motile, which may allow these strains to achieve a greater rate of proliferation at low temperature. PMID:26973610

  16. Different Transcriptional Responses from Slow and Fast Growth Rate Strains of Listeria monocytogenes Adapted to Low Temperature

    PubMed Central

    Cordero, Ninoska; Maza, Felipe; Navea-Perez, Helen; Aravena, Andrés; Marquez-Fontt, Bárbara; Navarrete, Paola; Figueroa, Guillermo; González, Mauricio; Latorre, Mauricio; Reyes-Jara, Angélica

    2016-01-01

    Listeria monocytogenes has become one of the principal foodborne pathogens worldwide. The capacity of this bacterium to grow at low temperatures has opened an interesting field of study in terms of the identification and classification of new strains of L. monocytogenes with different growth capacities at low temperatures. We determined the growth rate at 8°C of 110 strains of L. monocytogenes isolated from different food matrices. We identified a group of slow and fast strains according to their growth rate at 8°C and performed a global transcriptomic assay in strains previously adapted to low temperature. We then identified shared and specific transcriptional mechanisms, metabolic and cellular processes of both groups; bacterial motility was the principal process capable of differentiating the adaptation capacity of L. monocytogenes strains with different ranges of tolerance to low temperatures. Strains belonging to the fast group were less motile, which may allow these strains to achieve a greater rate of proliferation at low temperature. PMID:26973610

  17. Local Piezoelectric Properties and Polarity Distribution of ZnO Films Deposited at Different Substrate Temperatures

    NASA Astrophysics Data System (ADS)

    Li, Cuiping; Dai, Wei; Xu, Sheng; Li, Xiaowei; Gao, Chengyao; Chen, Ximing; Yang, Baohe

    2015-04-01

    In this work we deposited c-axis-oriented ZnO films using radiofrequency magnetron sputtering at substrate temperatures from 200°C to 500°C. We then characterized their local piezoelectric properties and polarity distributions using piezoresponse force microscopy, revealing that these ZnO films contained grains with opposite polarities: O-face and Zn-face. The grains with O-face polarity exhibited larger piezoresponse magnitude than those with Zn-face polarity. As the substrate temperature was increased, the predominant polarization orientation of the films changed from O-face to Zn-face. The film deposited at 300°C showed uniform polarization orientation together with higher piezoresponse magnitude.

  18. Numerical analysis of steady turbulent triple jet flow with temperature difference

    NASA Astrophysics Data System (ADS)

    Nouali, Nassira; Mataoui, Amina

    2016-02-01

    The numerical predictions confirm a new classification of flow patterns of triple jet interaction. The addition of side jets increase the rate of decrease of the centreline velocity for the flow of type A and decreases in the other cases. The effect of various types of flow on the rate of decrease of the velocity, the turbulent kinetic energy and the temperature in the combined region are detailed. Several correlations are proposed.

  19. Molecular and Cellular Effects Induced in Mytilus galloprovincialis Treated with Oxytetracycline at Different Temperatures

    PubMed Central

    Banni, Mohamed; Sforzini, Susanna; Franzellitti, Silvia; Oliveri, Caterina; Viarengo, Aldo; Fabbri, Elena

    2015-01-01

    The present study evaluatedthe interactive effects of temperature (16°C and 24°C) and a 4-day treatment with the antibiotic oxytetracycline (OTC) at 1 and 100μg/L on cellular and molecular parameters in the mussel Mytilus galloprovincialis. Lysosomal membrane stability (LMS), a sensitive biomarker of impaired health status in this organism, was assessed in the digestive glands. In addition, oxidative stress markers and the expression of mRNAs encoding proteins involved in antioxidant defense (catalase (cat) and glutathione-S-transferase (gst)) and the heat shock response (hsp90, hsp70, and hsp27) were evaluated in the gills, the target tissue of soluble chemicals. Finally, cAMP levels, which represent an important cell signaling pathway related to oxidative stress and the response to temperature challenges, were also determined in the gills. Exposure to heat stress as well as to OTC rendered a decrease in LMS and an increase in malonedialdehyde accumulation (MDA). CAT activity was not significantly modified, whereas GST activity decreased at 24°C. Cat and gst expression levels were reduced in animals kept at 24°C compared to 16°C in the presence or absence of OTC. At 16°C, treatment with OTC caused a significant increase in cat and gst transcript levels. Hsp27 mRNA was significantly up-regulated at all conditions compared to controls at 16°C. cAMP levels were increased at 24°C independent of the presence of OTC. PCA analysis showed that 37.21% and 25.89% of the total variance was explained by temperature and OTC treatment, respectively. Interestingly, a clear interaction was observed in animals exposed to both stressors increasing LMS and MDA accumulation and reducing hsp27 gene expression regulation. These interactions may suggest a risk for the organisms due to temperature increases in contaminated seawaters. PMID:26067465

  20. Molecular and Cellular Effects Induced in Mytilus galloprovincialis Treated with Oxytetracycline at Different Temperatures.

    PubMed

    Banni, Mohamed; Sforzini, Susanna; Franzellitti, Silvia; Oliveri, Caterina; Viarengo, Aldo; Fabbri, Elena

    2015-01-01

    The present study evaluated the interactive effects of temperature (16C and 24C) and a 4-day treatment with the antibiotic oxytetracycline (OTC) at 1 and 100 ?g/L on cellular and molecular parameters in the mussel Mytilus galloprovincialis. Lysosomal membrane stability (LMS), a sensitive biomarker of impaired health status in this organism, was assessed in the digestive glands. In addition, oxidative stress markers and the expression of mRNAs encoding proteins involved in antioxidant defense (catalase (cat) and glutathione-S-transferase (gst)) and the heat shock response (hsp90, hsp70, and hsp27) were evaluated in the gills, the target tissue of soluble chemicals. Finally, cAMP levels, which represent an important cell signaling pathway related to oxidative stress and the response to temperature challenges, were also determined in the gills. Exposure to heat stress as well as to OTC rendered a decrease in LMS and an increase in malonedialdehyde accumulation (MDA). CAT activity was not significantly modified, whereas GST activity decreased at 24C. Cat and gst expression levels were reduced in animals kept at 24C compared to 16C in the presence or absence of OTC. At 16C, treatment with OTC caused a significant increase in cat and gst transcript levels. Hsp27 mRNA was significantly up-regulated at all conditions compared to controls at 16C. cAMP levels were increased at 24C independent of the presence of OTC. PCA analysis showed that 37.21% and 25.89% of the total variance was explained by temperature and OTC treatment, respectively. Interestingly, a clear interaction was observed in animals exposed to both stressors increasing LMS and MDA accumulation and reducing hsp27 gene expression regulation. These interactions may suggest a risk for the organisms due to temperature increases in contaminated seawaters. PMID:26067465

  1. GROWTH AND SURVIVAL OF YOUNG-OF-THE-YEAR EMERALD SHINERS ('NOTROPIS ATHERINOIDES') AT DIFFERENT TEMPERATURES

    EPA Science Inventory

    Young-of-the-year emerald shiners (Notropis atherinoides) were exposed to mean constant temperatures of 6.9, 11.9, 16.0, 19.8, 24.0, 26.9, 28.9, 311.0, 32.8, 34.9, and 36.7C for 6 wk. Maximum rates of growth and net biomass gain occurred at 28.9C, but these rates were not statist...

  2. Growth of AlInN films via elemental layers annealing at different temperatures

    NASA Astrophysics Data System (ADS)

    Afzal, Naveed; Devarajan, Mutharasu; Ibrahim, Kamarulazizi

    2015-09-01

    This work investigates the growth of AlInN films on Si (100) substrates through the annealing of Al and InN stacking layers in the temperature range 200∘C to 800∘C. The Al/InN layers were prepared on Si (100) substrates using RF magnetron sputtering technique at 100∘C. The layers were annealed in a quartz tube furnace at 200∘C, 400∘C, 600∘C and 800∘C for six hours. Structural features of the films were examined through XRD whereas the surface morphology and composition of the films were studied through FESEM and EDS, respectively. The FESEM and EDS cross-sectional analyses of the films were also conducted to observe the mixing of Al/InN stacking layers. XRD patterns revealed the formation of polycrystalline AlInN films whereas the FESEM and EDS cross-sectional results indicated that the mixing of Al/InN stacked layers became more prominent with increase of the annealing temperature. Surface roughness of the films studied through AFM also exhibited an increasing trend with increase of the annealing temperature.

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

    NASA Astrophysics Data System (ADS)

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

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

  4. INFLUENCE OF BLOOD FLOW AND MILLIMETER WAVE EXPOSURE ON SKIN TEMPERATURE IN DIFFERENT THERMAL MODELS

    PubMed Central

    Alekseev, S.I.; Ziskin, M.C.

    2008-01-01

    Recently we showed that the Pennes bioheat transfer equation was not adequate to quantify mm wave heating of the skin at high blood flow rates. To do so, it is necessary to incorporate an effective thermal conductivity to obtain a hybrid bioheat equation (HBHE). The main aim of this study was to determine the relationship between non-specific tissue blood flow in a homogeneous unilayer model and dermal blood flow in multilayer models providing that the skin surface temperatures before and following mm wave exposure were the same. This knowledge could be used to develop multilayer models based on the fitting parameters obtained with the homogeneous tissue models. We tested four tissue models consisting of 1 to 4 layers and applied the one-dimensional steady-state HBHE. To understand the role of the epidermis in skin models we added to the one- and three-layer models an external thin epidermal layer with no blood flow. Only the combination of models containing the epidermal layer was appropriate for determination of the relationship between non-specific tissue and dermal blood flows giving the same skin surface temperatures. In this case we obtained a linear relationship between non-specific tissue and dermal blood flows. The presence of the fat layer resulted in the appearance of a significant temperature gradient between the dermis and muscle layer which increased with the fat layer thickness. PMID:18780297

  5. Sorption of antibiotic sulfamethoxazole varies with biochars produced at different temperatures.

    PubMed

    Zheng, Hao; Wang, Zhenyu; Zhao, Jian; Herbert, Stephen; Xing, Baoshan

    2013-10-01

    Sorption of sulfonamides on biochars is poorly understood, thus sulfamethoxazole (SMX) sorption on biochars produced at 300-600 C was determined as a function of pH and SMX concentration, as well as the inorganic fractions in the biochars. Neutral SMX molecules (SMX(0)) were dominant for sorption at pH 1.0-6.0. Above pH 7.0, although biochars surfaces were negatively-charged, anionic SMX species sorption increased with pH and is regulated via charge-assisted H-bonds. SMX(0) sorption at pH 5.0 was nonlinear and adsorption-dominant for all the biochars via hydrophobic interaction, ?-? electron donor-acceptor interaction and pore-filling. The removal of inorganic fraction reduced SMX sorption by low-temperature biochars (e.g., 300 C), but enhanced the sorption by high-temperature biochars (e.g., 600 C) due to the temperature-dependent inorganic fractions in the biochars. These observations are useful for producing designer biochars as engineered sorbents to reduce the bioavailability of antibiotics and/or predict the fate of sulfonamides in biochar-amended soils. PMID:23811180

  6. Growth behavior of titanium dioxide thin films at different precursor temperatures

    PubMed Central

    2012-01-01

    The hydrophilic TiO2 films were successfully deposited on slide glass substrates using titanium tetraisopropoxide as a single precursor without carriers or bubbling gases by a metal-organic chemical vapor deposition method. The TiO2 films were employed by scanning electron microscopy, Fourier transform infrared spectrometry, UV-Visible [UV-Vis] spectroscopy, X-ray diffraction, contact angle measurement, and atomic force microscopy. The temperature of the substrate was 500C, and the temperatures of the precursor were kept at 75C (sample A) and 60C (sample B) during the TiO2 film growth. The TiO2 films were characterized by contact angle measurement and UV-Vis spectroscopy. Sample B has a very low contact angle of almost zero due to a superhydrophilic TiO2 surface, and transmittance is 76.85% at the range of 400 to 700 nm, so this condition is very optimal for hydrophilic TiO2 film deposition. However, when the temperature of the precursor is lower than 50C or higher than 75C, TiO2 could not be deposited on the substrate and a cloudy TiO2 film was formed due to the increase of surface roughness, respectively. PMID:22280933

  7. [Biological efficacy and persistence of biphenthrin sprayed on maize at different grain temperatures].

    PubMed

    Silveira, Rodrigo D; Faroni, Lda R A; Pimentel, Marco A G; Peternelli, Luiz A; Zocolo, Guilherme

    2006-01-01

    The objective of this work was to evaluate the immediate and latent effects of the grain temperature, during the spraying process, on the persistence and biological efficacy of the biphenthrin insecticide against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). For such, biphenthrin was sprayed on the grain at the temperatures: 25, 30, 35, 40 and 45 degrees C. To access the persistence of biphenthrin, insecticide residue analyses were carried out monthly, just after spraying until 90 days of storage. To evaluate the biological efficacy of biphenthrin, 20 adults of each species were placed in petri dishes with sprayed grain, and kept in climate cabinets under 27 degrees C and 55% of RH, during 48h. Evaluations were done every 15 days, starting just after spraying and finishing at 90 days of storage. Both persistence and biological efficacy of biphenthrin reduced as storage time and grain temperatures increased. Additionally, S. zeamais was more tolerant to biphenthrin than T. castaneum. PMID:17348140

  8. Temperature Increase during Different Post Space Preparation Systems: An In Vitro Study

    PubMed Central

    Nazari Moghadam, Kiumars; Shahab, Shahriar; Shirvani, Soghra; Kazemi, Ali

    2011-01-01

    INTRODUCTION: The purpose of this study was to evaluate external root surface temperature rise during post space preparation using LA Axxess bur, Beefill pack System, and Peeso Reamer drill. MATERIALS AND METHODS: The distal canals of forty-five extracted human permanent mandibular first molars were instrumented in crown-apical manner and obturated with lateral condensation technique. Teeth were then randomly divided into three groups according to post space preparation technique including: group 1. LA Axxess bur (Sybronendo Co., CA, USA), group 2 Beefill pack System (VD W Co., Munich, Germany) and group 3 Peeso Reamer drill (Mani Co., Tochigi-ken, Japan). Temperature was measured by means of digital thermometer MT-405 (Comercio Co., Sao Paulo, Brazil) which was installed on the root surfaces. Data was collected and submitted to one-way ANOVA and Post hoc analysis. RESULTS: Root surface temperatures were found to be significantly higher (7.32.7 vs. 4.32.1 and 42.4,) in samples of Beefill pack System compared with the two other groups (P<0.02). CONCLUSION: Using Beefill pack System during post space preparation may be potentially hazardous for periodontal tissues. PMID:24778690

  9. Design and fabrication of a bidimentional microbolometer array for Terahertz detection characterized at different temperatures

    NASA Astrophysics Data System (ADS)

    Ordua-Daz, A.; Castillo-Domnguez, E.; Torres-Jacome, A.; De la Hidalga-Wade, F. J.; Trevio-Palacios, C. G.

    2011-01-01

    We present the design, micromachining and characterization of a bidimentional bolometer array for radiation detection in the 0.7-1.5 THz frequency range. The detector is based on a boron doped amorphous silicon film (a-Si-B:H). The film optimized for sensitivity enhancement was obtained using 500 sccm diborane flow with 95 nm thickness. The sensing layer was deposited using plasma enhanced chemical vapor deposition (PECVD) technique at low frequency on a 0.45 ?m thick silicon nitride membrane sustained by a micromachined frame in crystalline silicon. The design consists of four 5x5 bolometer arrays made by conventional lithography. The bolometer active area is 660 ?m x 420 ?m and the detector will operate as a focal plane array. The current-voltage characteristics present an ohmic behaviour; the temperature coefficient of resistance (TCR) was obtained by measuring the bolometer performance from room temperature down to liquid nitrogen temperature. The responsivity was measured under illumination from a black body radiating at 300, 500, 700, 900 and 1100 C, obtaining a value of R =1.17 x 10-2 A/W with a dark current of 4.43 x 10-9 A

  10. Measurements of Sr/Ca in bones to evaluate differences in temperature

    NASA Astrophysics Data System (ADS)

    Santos, P. R.; Added, N.; Aburaya, J. H.; Rizzutto, M. A.

    2008-04-01

    Analysis of aragonite from sea shells and coral skeletons showed a clear correlation between the strontium and calcium concentrations for these crystals (Sr/Ca ratio) and seawater temperature obtained by satellites and ship readings. In this work we present the results of a study that correlates Sr/Ca ratio with formation temperature of another calcium crystal, the hydroxyapatite (Ca10(PO4)6(OH)2), main mineral compound of teeth and bones from vertebrates. These animals, independent of its thermoregulation pattern (endothermic or ectothermic) have variations of internal temperature along the body. One interesting application of this work is to differentiate warm-blooded animals from cold-blooded ones just by measuring Sr/Ca ratio in their bones. Bones from a crocodile from Caiman yacare species and two dogs, a poodle and a non defined race, were analyzed using PIXE technique and thick target correction. A 1.78 (18) MeV external proton beam was used in LAMFI-USP with an accumulated charge of about 10 μC for probing the samples. Emitted X-rays were collected using Si-PIN detectors (140 keV for Fe). As in coral skeletons, the Sr/Ca ratio of animals is lower in the body's warmer parts and higher in colder parts.

  11. Toxoplasma gondii: virulence of tachyzoites in serum free media at different temperatures.

    PubMed

    Diab, M R; El-Bahy, M M

    2008-01-01

    Highly virulent Toxoplasma gondii tachyzoite multiplication was recorded on the 4th and 5th days post cultivation (dpc) in seven selected cell lines either with or without fetal calf serum (FCS) in the maintenance media. The multiplication rate was slightly lower in the absence of FCS. The cell line mono-layers collapsed dying by the 6th day of infection both in presence or absence of FCS at 37 degrees C. Carcinoma of human larynx (Hep2) and Madian Darby Bovine Kidney (MDBK) cell lines were the most suitable for in vitro multiplication, followed by that of African green monkey kidney cells (VERO), pooled kidney from 1-day-old hamster (BHK), rabbit kidney cells (RK13) and human rhabdomyosarcoma (RDA), while Chicken embryo cells (CER) were the least suitable. In absence of FCS, CER, BHK, Hep2, RDA and MDBK were able to maintain virulent tachyzoites at +4 degrees C for 14 days. The infectivity of the tachyzoites was however lower, killing 40% of the inoculated mice. Tachyzoites survived at room temperature, in the dark, for 14 days in Hep2, RDA and MDBK. However, Hep2 was the only one able to keep virulent tachyzoites until 21 dpc at room temperature and at +4 degrees C. Hep2 propagated tachyzoites were still alive but with low infectivity up to 28 dpc. The cell-lines failed to support the development of tachyzoites after 7 dpc at 37 degrees C and after the 35 dpc at lower temperatures. PMID:17904554

  12. Differential stability of TATA box binding proteins from archaea with different optimal growth temperatures

    NASA Astrophysics Data System (ADS)

    Kopitz, Annette; Soppa, Jörg; Krejtschi, Carsten; Hauser, Karin

    2009-09-01

    The TATA box binding protein (TBP) is involved in promoter recognition, the first step of transcription initiation. TBP is universally conserved and essential in archaea and eukaryotes. In archaea, TBPs have to be stable and to function in species that cover an extremely wide range of optimal growth temperatures (OGTs), from below 0 °C to more than 100 °C. Thus, the archaeal TBP family is ideally suited to study the evolutionary adaptation of proteins to an extremely wide range of temperatures. We characterized the thermostability of one mesophilic and one thermophilic TBP by infrared spectroscopy. Transition temperatures ( Tms) of thermal unfolding have been determined using TBPs from Methanosarcina mazei (OGT 37 °C) and from Methanothermobacter thermautotrophicus (OGT 65 °C). Furthermore, the influence of protein and salt concentration on thermostability has been characterized. Together with previous studies, our results reveal that the Tms of archaeal TBPs are closely correlated with the OGTs of the respective species. Noteworthy, this is also true for the TBP from M. mazei representing the first characterized TBP from a mesophilic archaeon. In contrast, the only characterized eukaryotic TBP of the mesophilic plant Arabidopsis thaliana has a Tm more than 40 °C above the OGT.

  13. Influence of temperature on measurements of the CO2 compensation point: differences between the Laisk and O2-exchange methods.

    PubMed

    Walker, Berkley J; Cousins, Asaph B

    2013-04-01

    The CO2 compensation point in the absence of day respiration (?*) is a key parameter for modelling leaf CO2 exchange. ?* links the kinetics of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) with the stoichiometry of CO2 released per Rubisco oxygenation from photorespiration (?), two essential components of biochemical models of photosynthesis. There are two main gas-exchange methods for measuring ?*: (i) the Laisk method, which requires estimates of mesophyll conductance to CO2 (g m) and (ii) measurements of O2 isotope exchange, which assume constant values of ? and a fixed stoichiometry between O2 uptake and Rubisco oxygenation. In this study, the temperature response of ?* measured using the Laisk and O2-exchange methods was compared under ambient (25 C) and elevated (35 C) temperatures to determine whether both methods yielded similar results. Previously published temperature responses of ?* estimated with the Laisk and O2-exchange methods in Nicotiana tabacum demonstrated that the Laisk-derived model of ?* was more sensitive to temperature compared with the O2-exchange model. Measurements in Arabidopsis thaliana indicated that the Laisk and O2-exchange methods produced similar ?* at 25 C; however, ?* values from O2 exchange were lower at 35 C compared with the Laisk method. Compared with a photorespiratory mutant (pmdh1pmdh2hpr) with increased ?, wild-type (WT) plants had lower Laisk values of ?* at 25 C but were not significantly different at 35 C. These differences between Laisk and O2 exchange values of ?* at 35 C could be explained by temperature sensitivity of ? in WT and/or errors in the assumptions of O2 exchange. The differences between ?* measured using the Laisk and O2-exchange method with temperature demonstrate that assumptions used to measure ?*, and possibly the species-specific validity of these assumptions, need to be considered when modelling the temperature response of photosynthesis. PMID:23630324

  14. Influence of temperature on measurements of the CO2 compensation point: differences between the Laisk and O2-exchange methods

    PubMed Central

    Walker, Berkley J.; Cousins, Asaph B.

    2013-01-01

    The CO2 compensation point in the absence of day respiration (?*) is a key parameter for modelling leaf CO2 exchange. ?* links the kinetics of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) with the stoichiometry of CO2 released per Rubisco oxygenation from photorespiration (?), two essential components of biochemical models of photosynthesis. There are two main gas-exchange methods for measuring ?*: (i) the Laisk method, which requires estimates of mesophyll conductance to CO2 (g m) and (ii) measurements of O2 isotope exchange, which assume constant values of ? and a fixed stoichiometry between O2 uptake and Rubisco oxygenation. In this study, the temperature response of ?* measured using the Laisk and O2-exchange methods was compared under ambient (25 C) and elevated (35 C) temperatures to determine whether both methods yielded similar results. Previously published temperature responses of ?* estimated with the Laisk and O2-exchange methods in Nicotiana tabacum demonstrated that the Laisk-derived model of ?* was more sensitive to temperature compared with the O2-exchange model. Measurements in Arabidopsis thaliana indicated that the Laisk and O2-exchange methods produced similar ?* at 25 C; however, ?* values from O2 exchange were lower at 35 C compared with the Laisk method. Compared with a photorespiratory mutant (pmdh1pmdh2hpr) with increased ?, wild-type (WT) plants had lower Laisk values of ?* at 25 C but were not significantly different at 35 C. These differences between Laisk and O2 exchange values of ?* at 35 C could be explained by temperature sensitivity of ? in WT and/or errors in the assumptions of O2 exchange. The differences between ?* measured using the Laisk and O2-exchange method with temperature demonstrate that assumptions used to measure ?*, and possibly the species-specific validity of these assumptions, need to be considered when modelling the temperature response of photosynthesis. PMID:23630324

  15. Pharmacokinetics of sulphadimidine in carp (Cyprinus carpio L.) and rainbow trout (Salmo gairdneri Richardson) acclimated at two different temperature levels.

    PubMed

    van Ginneken, V J; Nouws, J F; Grondel, J L; Driessens, F; Degen, M

    1991-04-01

    The influence of temperature (10 degrees C and 20 degrees C) on pharmacokinetics and metabolism of sulphadimidine (SDM) in carp and trout was studied. At 20 degrees C a significantly lower level of distribution (Vdarea) and a significantly shorter elimination half-life (T(1/2)beta) was achieved in both species compared to the 10 degrees C level. In carp the body clearance parameter (ClB(SDM)) was significantly higher at 20 degrees C compared to the value at 10 degrees C, whereas for trout this parameter was in the same order of magnitude for both temperatures. N4-acetylsulphadimidine (N4-SDM) was the main metabolite of SDM in both species at the two temperature levels. The relative N4-SDM plasma percentage in carp was significantly higher at 20 degrees C than at 10 degrees C, whereas there was in trout no significant difference. In neither species was the peak plasma concentration of N4-SDM (Cmax(N4-SDM)) significantly different at two temperatures. The corresponding peak time of this metabolite (Tmax(N4-SDM)) was significantly shorter at 20 degrees C compared to 10 degrees C in both carp and trout. In carp at both temperatures, acetylation occurs to a greater extent than hydroxylation. Only the 6-hydroxymethyl-metabolite (SCH2OH) was detected in carp, at a significant different level at the two temperatures. Concentrations of hydroxy metabolites in trout were at the detection level of the HPLC-method (0.02-micrograms/ml). The glucuronide metabolite (SOH-gluc.) was not detected in either species at the two temperatures. PMID:1882494

  16. Antenna noise temperatures of the 34-meter beam-waveguide antenna with horns of different gains installed at F1

    NASA Technical Reports Server (NTRS)

    Otoshi, T. Y.; Lee, P. R.; Franco, M. M.

    1994-01-01

    This article presents a set of theoretical and measured zenith-antenna noise temperatures at 8.45 GHz for the DSS-13 34-m beam-waveguide antenna when horns of different gains are installed at F1. The methodology for calculations is shown in detail. The major differences between calculated and measured values are attributed to changes in subreflector support leg scattering when illuminated by the various horns.

  17. Temperature dependence of APD-based PET scanners

    SciTech Connect

    Keereman, Vincent; Van Holen, Roel; Vandenberghe, Stefaan; Vanhove, Christian

    2013-09-15

    Purpose: Solid state detectors such as avalanche photodiodes (APDs) are increasingly being used in PET detectors. One of the disadvantages of APDs is the strong decrease of their gain factor with increasing ambient temperature. The light yield of most scintillation crystals also decreases when ambient temperature is increased. Both effects lead to considerable temperature dependence of the performance of APD-based PET scanners. In this paper, the authors propose a model for this dependence and the performance of the LabPET8 APD-based small animal PET scanner is evaluated at different temperatures.Methods: The model proposes that the effect of increasing temperature on the energy histogram of an APD-based PET scanner is a compression of the histogram along the energy axis. The energy histogram of the LabPET system was acquired at 21 C and 25 C to verify the validity of this model. Using the proposed model, the effect of temperature on system sensitivity was simulated for different detector temperature coefficients and temperatures. Subsequently, the effect of short term and long term temperature changes on the peak sensitivity of the LabPET system was measured. The axial sensitivity profile was measured at 21 C and 24 C following the NEMA NU 4-2008 standard. System spatial resolution was also evaluated. Furthermore, scatter fraction, count losses and random coincidences were evaluated at different temperatures. Image quality was also investigated.Results: As predicted by the model, the photopeak energy at 25 C is lower than at 21 C with a shift of approximately 6% per C. Simulations showed that this results in an approximately linear decrease of sensitivity when temperature is increased from 21 C to 24 C and energy thresholds are constant. Experimental evaluation of the peak sensitivity at different temperatures showed a strong linear correlation for short term (2.32 kcps/MBq/C = 12%/C, R = ?0.95) and long term (1.92 kcps/MBq/C = 10%/C , R = ?0.96) temperature changes. Count rate evaluation showed that although the total count rate is consistently higher at 21 C than at 24 C for different source activity concentrations, this is mainly due to an increase in scattered and random coincidences. The peak total count rate is 400 kcps at both temperatures but is reached at lower activity at 21 C. The peak true count rate is 138 kcps (at 100 MBq) at 21 C and 180 kcps (at 125 MBq) at 24 C. The peak noise equivalent count rate is also lower at 21 C (70 kcps at 70 MBq) than at 24 C (100 kcps at 100 MBq). At realistic activity levels, the scatter fraction is lower at higher temperatures, but at the cost of a strong decrease in true count rate.Conclusions: A model was proposed for the temperature dependence of APD-based PET scanners and evaluated using the LabPET small animal PET scanner. System sensitivity and count rate performance are strongly dependent on ambient temperature while system resolution is not. The authors results indicate that it is important to assure stable ambient temperature to obtain reproducible results in imaging studies with APD-based PET scanners.

  18. Effect of Different Time/Temperature Roast Combinations on Peanut Flavor-Descriptive Sensory, Electronic Nose and Electronic Eye Characterization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Roasting is of central importance to peanut flavor. Standard industry practice is to roast peanuts to a specific surface color (Hunter L-value) for a given application; however, equivalent surface colors can be generated using different temperature/time roast combinations. To better understand the e...

  19. A two-dimensional finite-difference solution for the temperature distribution in a radial gas turbine guide vane blade

    NASA Technical Reports Server (NTRS)

    Hosny, W. M.; Tabakoff, W.

    1975-01-01

    A two-dimensional finite difference numerical technique is presented to determine the temperature distribution in a solid blade of a radial guide vane. A computer program is written in Fortran IV for IBM 370/165 computer. The computer results obtained from these programs have a similar behavior and trend as those obtained by experimental results.

  20. The effect of temperature on different Salmonella serotypes during warm seasons in a Mediterranean climate city, Adelaide, Australia.

    PubMed

    Milazzo, A; Giles, L C; Zhang, Y; Koehler, A P; Hiller, J E; Bi, P

    2016-04-01

    Changing trends in foodborne disease are influenced by many factors, including temperature. Globally and in Australia, warmer ambient temperatures are projected to rise if climate change continues. Salmonella spp. are a temperature-sensitive pathogen and rising temperature can have a substantial effect on disease burden affecting human health. We examined the relationship between temperature and Salmonella spp. and serotype notifications in Adelaide, Australia. Time-series Poisson regression models were fit to estimate the effect of temperature during warmer months on Salmonella spp. and serotype cases notified from 1990 to 2012. Long-term trends, seasonality, autocorrelation and lagged effects were included in the statistical models. Daily Salmonella spp. counts increased by 1·3% [incidence rate ratio (IRR) 1·013, 95% confidence interval (CI) 1·008-1·019] per 1 °C rise in temperature in the warm season with greater increases observed in specific serotype and phage-type cases ranging from 3·4% (IRR 1·034, 95% CI 1·008-1·061) to 4·4% (IRR 1·044, 95% CI 1·024-1·064). We observed increased cases of S. Typhimurium PT9 and S. Typhimurium PT108 notifications above a threshold of 39 °C. This study has identified the impact of warm season temperature on different Salmonella spp. strains and confirms higher temperature has a greater effect on phage-type notifications. The findings will contribute targeted information for public health policy interventions, including food safety programmes during warmer weather. PMID:26522685

  1. Factors affecting the wettability of different surface materials with vegetable oil at high temperatures and its relation to cleanability

    NASA Astrophysics Data System (ADS)

    Ashokkumar, Saranya; Adler-Nissen, Jens; Møller, Per

    2012-12-01

    The main aim of the work was to investigate the wettability of different surface materials with vegetable oil (olive oil) over the temperature range of 25-200 °C to understand the differences in cleanability of different surfaces exposed to high temperatures in food processes. The different surface materials investigated include stainless steel (reference), PTFE (polytetrafluoroethylene), silicone, quasicrystalline (Al, Fe, Cr) and ceramic coatings: zirconium oxide (ZrO2), zirconium nitride (ZrN) and titanium aluminum nitride (TiAlN). The ceramic coatings were deposited on stainless steel with two different levels of roughness. The cosine of the contact angle of olive oil on different surface materials rises linearly with increasing temperature. Among the materials analyzed, polymers (PTFE, silicone) gave the lowest cos θ values. Studies of the effect of roughness and surface flaws on wettability revealed that the cos θ values increases with increasing roughness and surface flaws. Correlation analysis indicates that the measured contact angle values gave useful information for grouping easy-clean polymer materials from the other materials; for the latter group, there is no direct relation between contact angle and cleanability. In addition to surface wettability with oil many other factors such as roughness and surface defects play an essential role in determining their cleanability.

  2. Patterns of Substrate Utilization During Long-Term Incubations at Different Temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microorganisms play key roles in biogeochemical cycling by facilitating the release of nutrients from organic compounds. In doing so, microbial communities use different organic substrates that yield different amounts of energy for maintenance and growth of the community. Carbon utilization efficien...

  3. Carbon mineralization of flooded boreal soil and vegetation under different temperature and oxygen conditions

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Ullah, S.; Roulet, N.; Moore, T.

    2009-05-01

    Flooding of terrestrial ecosystems significantly alters carbon (C) mineralization rates, which results in increasing emissions of carbon dioxide (CO2) and methane (CH4). To better understand the changes after water impoundment, C mineralization under flooded conditions needs to be investigated. This study investigates CO2 and CH4 fluxes from flooded boreal soil and vegetation, compares them to the fluxes of non- flooded treatment, and examines how environmental factors affect the fluxes. We conducted short-term in vitro experiments using boreal forest soil (FH layer), peat soil (0 to 5 and 5 to 15 cm) layer, and black spruce needles and small twigs, and shrub, sedge, lichen, and moss tissues. Flooded samples were incubated in 1- L Mason jars without light, under three temperatures (5, 12, and 24degC) and 0 and 50 percent of ambient oxygen (O2) concentration, and non-flooded ones were incubated in 1-L plastic containers under same light and temperature conditions to those of flooded samples and ambient oxygen concentration. We collected gas samples after flushing with nitrogen gas and air, and the fluxes of CO2 and CH4 were determined by gas chromatography. The average CO2 and CH4 fluxes in all materials were 200 and 0.8 microgram C/g organic matter/day, with smaller CO2 fluxes and larger CH4 fluxes than the fluxes of non-flooding (CO2 and CH4: 370 and 0.2 microgram C/g organic matter/day). Among the flooded samples, forest and peatland ground vegetation showed much high CO2 fluxes, and peat soils released more CH4 than other materials. Higher temperatures increased emissions of both CO2 and CH4, and the lower O2 concentration increased CH4 emissions. These results suggest the flooded vegetation and peat soil largely contribute to the total C emission in the flooded ecosystem and that spatial and temporal variability in CO2 and CH4 emissions can be related to substrate type, temperature and O2 concentration.

  4. Lower stratospheric temperature differences between meteorological analyses in two cold Arctic winters and their impact on polar processing studies

    NASA Astrophysics Data System (ADS)

    Manney, Gloria L.; Sabutis, Joseph L.; Pawson, Steven; Santee, Michelle L.; Naujokat, Barbara; Swinbank, Richard; Gelman, Melvyn E.; Ebisuzaki, Wesley

    2003-03-01</