Sample records for noise-equivalent temperature difference

  1. Minimum resolvable temperature difference measurements on undersampled imagers

    Microsoft Academic Search

    Ronald G. Driggers; Van A. Hodgkin; Richard H. Vollmerhausen; Patrick O'Shea

    2003-01-01

    Minimum Resolvable Temperature Difference (MRTD) is the primary measurement of performance for infrared imaging systems. Where Modulation Transfer Function (MTF) is a measurement of resolution and three-dimensional noise (or noise equivalent temperature difference) is a measurement of sensitivity, MRTD combines both measurements into a test of observer visual acuity through the imager. MRTD has been incorrectly applied to undersampled thermal

  2. Noise-equivalent sensitivity of photoacoustics

    PubMed Central

    Winkler, Amy M.; Maslov, Konstantin; Wang, Lihong V.

    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 2.710?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

  3. Measuring PET scanner sensitivity: relating countrates to image signal-to-noise ratios using noise equivalents counts

    Microsoft Academic Search

    S. C. Strother; M. E. Casey; E. J. Hoffman

    1990-01-01

    True coincidence count (TCC) and noise equivalent count (NEC) curves were measured with a standardized 20-cm-diameter nylon cylinder for five different CTI\\/Siemens PET (positron emission tomography) scanners with several scanner-collimator combinations: (1) 831\\/08-12 with 1-mm collimator septa; (2) 933\\/08-12 and 933\\/08-16 with 3?1-mm tapered collimator septa; and (3) 931\\/08-12 with 3?1-mm tapered and a 1-mm collimator septa and the 931\\/08-16

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

    SciTech Connect

    Strother, S.C. (Neurology Dept., Memorial Sloan-Kettering Cancer Center, New York, NY (US)); Casey, M.E. (CTI PET Systems Inc., Knoxville, TN (US)); Hoffman, E.J. (California Univ., Los Angeles, CA (USA). 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.

  5. Noise Equivalent Counts Based Emission Image Reconstruction Algorithm of Tomographic Gamma Scanning

    E-print Network

    Ke Wang; Zheng Li; Wei Feng; Dong Han

    2014-04-17

    Tomographic Gamma Scanning (TGS) is a technique used to assay the nuclide distribution and radioactivity in nuclear waste drums. Both transmission and emission scans are performed in TGS and the transmission image is used for the attenuation correction in emission reconstructions. The error of the transmission image, which is not considered by the existing reconstruction algorithms, negatively affects the final results. An emission reconstruction method based on Noise Equivalent Counts (NEC) is presented. Noises from the attenuation image are concentrated to the projection data to apply the NEC Maximum-Likelihood Expectation-Maximization algorithm. Experiments are performed to verify the effectiveness of the proposed method.

  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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

    PubMed

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

    2014-12-01

    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. PMID:25554287

  9. Asymmetry in the noise equivalent angle performance of the JWST fine guidance sensor

    NASA Astrophysics Data System (ADS)

    Rowlands, Neil; Warner, Gerry; Albert, Loic; Hardy, Tim; Pipher, Judith; Hutchings, John; Doyon, Rene

    2014-07-01

    The James Webb Space Telescope Fine Guidance Sensor makes use of three 20482048 five micron cutoff H2RG HgCdTe detectors from Teledyne Imaging Systems. The FGS consists of two Guider channels and a Near-InfraRed Imager and Slitless Spectrograph (NIRISS) channel. We report here on detailed tests results from the Guider channels originating in both instrument level performance testing and from recent Guider performance testing with the FGS integrated into JWST's Integrated Science Instrument Module (ISIM). A key performance parameter is the noise equivalent angle (NEA) or centroiding precision. The JWST requirement flowed down to the Guiders is a NEA of 4 milli-arcseonds, equivalent to approximately 1/20th of a detector pixel. This performance has been achieved in the testing to date. We have noted a systematic asymmetry in the NEA depending on whether the NEA in the row or column direction is considered. This asymmetry depends on guide star brightness and reaches its maximum, where the row NEA is 15% to 20% larger than the column NEA, at the dim end of the Guide star brightness range. We evaluate the detector level characteristics of spatially correlated noise and asymmetric inter-pixel capacitance (IPC) as potential sources of this NEA asymmetry. Modelling is used to estimate the impact on NEA of these potential contributors. These model results are then compared to the Guider test results obtained to date in an effort to isolate the cause of this effect. While asymmetric IPC can induce asymmetric NEA, the required magnitude of IPC is far greater than observed in these detectors. Thus, spatially correlated noise was found to be the most likely cause of the asymmetric NEA.

  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. 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.

  12. 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 [Imaging and Medical Physics, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1701 Uppergate Drive, C-5018, Atlanta, Georgia 30322 (United States)

    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.

  13. Temperature dependent microwave noise parameters and modeling of AlGaN\\/GaN HEMTs on Si substrate

    Microsoft Academic Search

    Z. H. Liu; S. Arulkumaran; G. I. Ng

    2009-01-01

    In this paper, we present the temperature dependent microwave noise measurements and modeling of AlGaN\\/GaN HEMTs on Si substrate over a wide temperature range from -50 to 200degC. The typical noise parameters including minimum noise figure (NFmin), noise equivalent resistance (Rn), optimum source reflection coefficient (Gammaopt) and associate gain (Ga) at different temperatures were measured and their dependencies on temperature

  14. A temperature and emissivity separation algorithm for Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images

    Microsoft Academic Search

    Alan Gillespie; Shuichi Rokugawa; Tsuneo Matsunaga; J. Steven Cothern; Simon Hook; Anne B. Kahle

    1998-01-01

    The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) scanner on NASA's Earth Observing System (EOS)-AM1 satellite (launch scheduled for 1998) will collect five bands of thermal infrared (TIR) data with a noise equivalent temperature difference (NE?T) of ⩽0.3 K to estimate surface temperatures and emissivity spectra, especially over land, where emissivities are not known in advance. Temperature\\/emissivity separation (TES)

  15. 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.

  16. Differences Between Ground and Air Temperatures

    NSDL National Science Digital Library

    In developing models for climate change and weather prediction, the measurements of surface and near-surface temperature are an important factor in the modeling process. As the Sun heats the Earth's surface, the atmosphere is warmed from below by the processes of conduction and convection from the surface. However, near-surface air temperature (approximately 10 meters above the surface) is often different than the surface temperature. The different properties of air, land and water, such as density or heat capacity, as well as seasonal changes of the surface type, can explain these differences. In this lesson, students will explore real NASA satellite data to compare the near-surface air temperature and surface temperature in different climate regions. They will then draw conclusions about the seasonal patterns and the effect of the underlying surface on the air temperature.

  17. M&M's in Different Temperatures

    NSDL National Science Digital Library

    James H. Kessler

    2007-01-01

    Learners design their own experiment to investigate whether the temperature of the surrounding water affects the rate at which the colored coating dissolves from an M&M. When they conduct their experiment, they find that the color dissolves faster in hot water than in cold.

  18. Precise Measurement of Process Temperature Differences

    Microsoft Academic Search

    Kitchen

    2003-01-01

    Measurement of power in a nuclear reactor system is comparable to measurement of yield in a chemical plant or to measurement of throughput in a paper mill process. In most reactor systems power is determined by measurement of heat transferred to the coolant. In this study reactor coolant heat-rise was determined by the differential-temperature measuring circuitry of a power calculator

  19. Radically Different Kinetics at Low Temperatures

    NASA Astrophysics Data System (ADS)

    Sims, Ian

    2014-06-01

    The use of the CRESU (Cintique de Raction 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 Franois Lique (Universit 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).

  20. Component analysis of a new Solid State X-ray Image Intensifier (SSXII) using photon transfer and Instrumentation Noise Equivalent Exposure (INEE) measurements

    PubMed Central

    Kuhls-Gilcrist, Andrew; Bednarek, Daniel R.; Rudin, Stephen

    2009-01-01

    The SSXII is a novel x-ray imager designed to improve upon the performance limitations of conventional dynamic radiographic/fluoroscopic imagers related to resolution, charge-trapping, frame-rate, and instrumentation-noise. The SSXII consists of a CsI:Tl phosphor coupled via a fiber-optic taper (FOT) to an electron-multiplying CCD (EMCCD). To facilitate investigational studies, initial designs enable interchangeability of such imaging components. Measurements of various component and configuration characteristics enable an optimization analysis with respect to overall detector performance. Photon transfer was used to characterize the EMCCD performance including ADC sensitivity, read-noise, full-well capacity and quantum efficiency. X-ray sensitivity was measured using RQA x-ray spectra. Imaging components were analyzed in terms of their MTF and transmission efficiency. The EMCCD was measured to have a very low effective read-noise of less than 1 electron rms at modest EMCCD gains, which is more than two orders-of-magnitude less than flat panel (FPD) and CMOS-based detectors. The variable signal amplification from 1 to 2000 times enables selectable sensitivities ranging from 8.5 (168) to over 15k (300k) electrons per incident x-ray photon with (without) a 4:1 FOT; these sensitivities could be readily increased with further component optimization. MTF and DQE measurements indicate the SSXII performance is comparable to current state-of-the-art detectors at low spatial frequencies and far exceeds them at higher spatial frequencies. The instrumentation noise equivalent exposure (INEE) was measured to be less than 0.3 ?R out to 10 cycles/mm, which is substantially better than FPDs. Component analysis suggests that these improvements can be substantially increased with further detector optimization. PMID:19763251

  1. The Response of Avocado Fruits to Different Storage Temperatures1

    Microsoft Academic Search

    G. Zauberman; Mina Schiffmann-Nadel; U. Yanko

    1977-01-01

    Additional index words. Persea americana Abstract. The response of fruits of avocado (Persea americana Mill.) to various temperatures was found to differ in the range 0 to 25C. This temperature range was divided into 3 groups: 1) between 10 and 25, the fruit softened at a rate which increases with increasing temperature; 2) between 5 and 8C, fruit softening was

  2. Scanning infrared radiometer for measuring the airsea temperature difference

    E-print Network

    Shaw, Joseph A.

    Scanning infrared radiometer for measuring the air­sea temperature difference Joseph A. Shaw a vertically scanning infrared radiometer for measuring the air­sea temperature difference without disturbing the water skin layer. The radiometer operates with a single wavelength channel that is 1.1 m wide, centered

  3. Stream water temperature difference between coniferous and deciduous forest

    NASA Astrophysics Data System (ADS)

    Onishi, T.; Senge, M.; Hiramatsu, K.

    2011-12-01

    Amount of solar radiation input into ground surface has a strong influence on underground heat condition. Stream water temperature is a gross index of underground heat condition of a watershed. As for stream water temperature of forest covered watershed, the effect of riparian forest on direct solar radiation input on stream water, and the effect of deforestation on stream water temperature have been studied. However, there is a few studies which deal with the impact of forest type difference on heat condition of a watershed. Thus, we measured stream water temperature of adjacent watersheds of which forest types are different; i.e. coniferous and deciduous forest. As a result, significant stream water temperature pattern difference between coniferous and deciduous forest was observed. While stream water temperature of coniferous forest was significantly lower than that of deciduous forest during the period of winter season (from the end of October to the start of May), tendency was converted during the period of summer season (from June to the end of October). No significant difference was found in the annual temperature amplitude of both forest types. We conducted numerical modeling study to explore the mechanism of stream water temperature difference. The result suggested that difference of snow cover pattern due to the leaf abscission of deciduous forest might play an important role in deciding stream water temperature during the winter season.

  4. 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.

  5. Taking a Child's Temperature There are many different ways to take a child's temperature

    E-print Network

    . Knowing the person's exact temperature will help you if you need to call your doctor. Never take a child it with 70 percent isopropyl alcohol. When Should I Call My Child's Doctor? In infants younger than 2 monthsTaking a Child's Temperature There are many different ways to take a child's temperature: · Digital

  6. Gender differences in thermal comfort and mental performance at different vertical air temperatures.

    PubMed

    Hashiguchi, Nobuko; Feng, Yue; Tochihara, Yutaka

    2010-05-01

    The purpose of this study was to investigate the effects of a thermal environment where air temperature closer to the ground was lower compared to that above on thermal comfort and mental performance in both sexes. Temperatures at the upper and lower parts of the body were controlled independently using a climatic box placed in a climatic chamber. Sixteen healthy subjects (8 males and 8 females) were exposed to the four conditions with various temperature differences between the upper (25 degrees C) and lower part of the body (16, 19, 22, or 25 degrees C). Skin temperature and subjective votes were measured, and two kinds of task using a computer were performed during exposure. Skin temperature on the back for females was higher than that for males during exposure, and the decrease in thigh skin temperature for females under lower air temperature conditions was significantly larger than that for males. A significant difference in thermal comfort at the beginning of the exposure was indicated between genders, especially in the 16 and 19 degrees C conditions, so females became aware of thermal discomfort before males. Although the score of mental performance based on perceptual speed for females was higher than that for males, there was no significant effect from the different vertical air temperatures. The effect of the unequal thermal environment, where air temperature closer to the ground was lower than above, on skin temperature and thermal discomfort for females was significantly higher compared to males. PMID:19701649

  7. 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

  8. Emission Controls Using Different Temperatures of Combustion Air

    PubMed Central

    Holub?k, Michal; Papu?k, tefan

    2014-01-01

    The effort of many manufacturers of heat sources is to achieve the maximum efficiency of energy transformation chemically bound in the fuel to heat. Therefore, it is necessary to streamline the combustion process and minimize the formation of emission during combustion. The paper presents an analysis of the combustion air temperature to the heat performance and emission parameters of burning biomass. In the second part of the paper the impact of different dendromass on formation of emissions in small heat source is evaluated. The measured results show that the regulation of the temperature of the combustion air has an effect on concentration of emissions from the combustion of biomass. PMID:24971376

  9. 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.

  10. MY NASA DATA: Differences Between Ground and Air Temperatures

    NSDL National Science Digital Library

    In this data activity, students explore real NASA satellite data to compare the near-surface air temperature and surface temperature in different climate regions, and draw conclusions about the seasonal patterns and the effect of the underlying surface on the air temperature. Step-by-step instructions for use of the MY NASA DATA Live Access Server (LAS) guide students through selecting a data set, importing the data into a spreadsheet, creating graphs, and analyzing data plots. The lesson provides detailed procedures, related links and sample graphs, follow-up questions, extensions, and teacher notes. Designed for student use, MY NASA DATA LAS samples micro datasets from large scientific data archives, and provides structured investigations engaging students in exploration of real data to answer real world questions.

  11. 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

  12. Lesion size estimator of cardiac radiofrequency ablation at different common locations with different tip temperatures.

    PubMed

    Lai, Yu-Chi; Choy, Young Bin; Haemmerich, Dieter; Vorperian, Vicken R; Webster, John G

    2004-10-01

    Finite element method (FEM) analysis has become a common method to analyze the lesion formation during temperature-controlled radiofrequency (RF) cardiac ablation. We present a process of FEM modeling a system including blood, myocardium, and an ablation catheter with a thermistor embedded at the tip. The simulation used a simple proportional-integral (PI) controller to control the entire process operated in temperature-controlled mode. Several factors affect the lesion size such as target temperature, blood flow rate, and application time. We simulated the time response of RF ablation at different locations by using different target temperatures. The applied sites were divided into two groups each with a different convective heat transfer coefficient. The first group was high-flow such as the atrioventricular (AV) node and the atrial aspect of the AV annulus, and the other was low-flow such as beneath the valve or inside the coronary sinus. Results showed the change of lesion depth and lesion width with time, under different conditions. We collected data for all conditions and used it to create a database. We implemented a user-interface, the lesion size estimator, where the user enters set temperature and location. Based on the database, the software estimated lesion dimensions during different applied durations. This software could be used as a first-step predictor to help the electrophysiologist choose treatment parameters. PMID:15490835

  13. What is the Difference between Heat and Temperature?

    NSDL National Science Digital Library

    In this laboratory activity, learners explore the difference between heat and temperature, and explore the rate of heat transfer from one substance to another as it depends on the density of the substances being investigated. The activity can be conducted either in a science lab or in a kitchen. It is one of two activities supporting the scientific investigation of the Interstellar Medium (ISM), and is linked to reading material, reading review questions and problems, a teacher answer sheet, and glossary.

  14. Considerations for Modeling Thin Cirrus Effects via Brightness Temperature Differences

    Microsoft Academic Search

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

    1995-01-01

    Brightness temperature difference (BTD) values are calculated for selected Geostationary Operational En- vironmental Satellite (GOES-6) channels (3.9, 12.7 pm) and Advanced Very High Resolution Radiometer channels (3.7, 12.0 pm). 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

  15. 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

  16. 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

  17. 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. [Center for High Technology Materials, Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87106 (United States)

    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??m, 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.

  18. 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.

  19. Chlorella virus-encoded deoxyuridine triphosphatases exhibit different temperature optima.

    PubMed

    Zhang, Yuanzheng; Moriyama, Hideaki; Homma, Kohei; Van Etten, James L

    2005-08-01

    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(2+) for optimal activity, while it retains some activity in the presence of other divalent cations. Kinetic studies of the enzyme revealed a K(m) of 11.7 microM, a turnover k(cat) of 6.8 s(-1), and a catalytic efficiency of k(cat)/K(m) = 5.8 x 10(5) M(-1) s(-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 degrees C) than PBCV-1 dUTPase (50 degrees C). The IL-3A dUTPase differs from the PBCV-1 enzyme by nine amino acids, including two amino acid substitutions, Glu81-->Ser81 and Thr84-->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-->Arg84, Glu81-->Ser81, and Glu81-->Ser81 plus Thr84-->Arg84. The single substitutions affected the optimal temperature for enzyme activity. The temperature optimum increased from 37 to 55 degrees 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. PMID:16014955

  20. 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.

  1. 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 (?') dielectric loss (?") decreases with increasing frequency while conductivity (?) increases with frequency increased.

  2. 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

  3. Specific heat of apple at different moisture contents and temperatures

    E-print Network

    Viacheslav Mykhailyk; Nikolai Lebovka

    2013-05-11

    This work discusses results of experimental investigations of the specific heat, $C$, of apple in a wide interval of moisture contents ($W=0-0.9$) and temperatures ($T = 283-363$ K). The obtained data reveal the important role of the bound water in determination of $C(W,T)$ behaviour. The additive model for description of $C(W)$ dependence in the moisture range of $0.1apple was considered as a mixture of water and hydrated apple material (water plasticised apple) with specific heat $C_h$. The difference between $C_h$ and specific heat of dry apple, $\\Delta Cb=C_h-C_d$, was proposed as a measure of the excess contribution of bound water to the specific heat. The estimated amounts of bound water $W_b$ were comparable with the monolayer moisture content in apple. The analytical equation was proposed for approximation of $C(W,T)$ dependencies in the studied intervals of moisture content and temperature.

  4. 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

    2014-08-01

    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.

  5. Cold Modalities With Different Thermodynamic Properties Produce Different Surface and Intramuscular Temperatures

    PubMed Central

    Jutte, Lisa S.; Smith, Michael E.

    2003-01-01

    Objective: To compare surface cooling and deep cooling produced by 3 common forms of cryotherapy. Design and Setting: We used a 3 4 4 factorial with repeated measures on measurement depth and treatment. Independent variables were measurement depth (surface, fat + 1 cm, and fat + 2 cm), treatment (ice bag, Wet-Ice, Flex-i-Cold, and control), and treatment order (first, second, third, and fourth). The lowest temperature recorded was the dependent variable. The treatment order was counterbalanced using a Latin square. Data were analyzed with a repeated-measures analysis of variance. Subjects: Fifteen collegiate volunteers who were free of lower extremity abnormalities. Measurements: Thigh skin and thigh intramuscular temperatures (1- and 2-cm subadipose) were measured at 30-second intervals both before and during the 30-minute treatments using fine-wire implantable and surface thermocouples. The coldest recorded temperatures were analyzed. Results: Statistical differences were observed for the depth-by-treatment interaction as well as for the depth and treatment main effects. During cold treatments, superficial depths were colder than deeper depths, and all cold treatments were colder than controls at all depths. For the interaction effect at both the skin surface and at 1-cm subadipose, the ice-bag and Wet-Ice treatments were colder than the Flex-i-Cold treatment. For the interaction at 2-cm subadipose, the cold treatments did not differ from each other. Order of treatments did not produce a significant effect. Conclusions: During a 30-minute cryotherapy treatment, modalities that undergo a phase change caused lower skin and 1-cm intramuscular temperatures than cold modalities that do not possess these properties. These differences were not seen at 2-cm subadipose but may become apparent with longer treatments. PMID:12937469

  6. 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.

  7. Intrauterine temperatures of mares under different management conditions

    E-print Network

    Commaille, Lynn Frances

    2009-05-15

    man-made shelter, with the intent to measure effects of ambient temperature. The Control- No device (Cont N) group was under the same management conditions, but did not have intrauterine temperature measurement devices implanted. The Control...

  8. On the bulk-skin temperature difference and its impact on satellite remote sensing of sea surface temperature

    Microsoft Academic Search

    Peter Schluessel; William J. Emery; Hartmut Grassl; Theodor Mammen

    1990-01-01

    Satellite infrared sensors only observe the temperature of the skin of the ocean rather than the bulk sea surface temperature (SST) traditionally measured from ships and buoys. In order to examine the differences and similarities between skin and bulk temperatures, radiometric measurements of skin temperature were made in the North Atlantic Ocean from a research vessel along with coincident measurements

  9. 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

  10. Adsorption of naphthenic acid on magnetite at different temperatures

    NASA Astrophysics Data System (ADS)

    Balmasova, O. V.; Ramazanova, A. G.; Korolev, V. V.

    2015-03-01

    Isotherms of naphthenic acid adsorption from heptane solutions on highly dispersed magnetite are studied using the adsorption equilibrium approach. The isosteric heats of naphthenic acid adsorption from heptane solutions are calculated over a temperature range of 293-308 K. The adsorption isotherms can be approximated using the equation for a straight line. Experimental adsorption isotherms are shown to be linear in the coordinates of the equation for the theory of volume filling of micropores (TVFM).

  11. Elastic Constants of CaF2 at Different Temperature

    NASA Astrophysics Data System (ADS)

    Sharma, Sheetal; Verma, Ajay Singh; Jindal, V. K.

    2011-07-01

    A simple and straightforward method for evaluating and predicting elastic constants as a function of temperature is presented on the basis of Murnaghan and Tallon models with first approximation. This theoretical method is used to predict successfully the values of elastic constants C11, C12 and C44 in GPa for CaF2 that are in reasonably good agreement with experimental data.

  12. Controlling suction by vapour equilibrium technique at different temperatures, application to the determination of the water

    E-print Network

    Paris-Sud XI, Université de

    1 Controlling suction by vapour equilibrium technique at different temperatures, application-mail : cui@cermes.enpc.fr #12;2 Controlling suction by vapour equilibrium technique at different temperatures, very often, a temperature independent water retention curve is considered in the analysis, which

  13. Heat energy Q: -energy exchanged between systems if they have a different temperature

    E-print Network

    Boyd, Sylke

    About heat Heat energy Q: - energy exchanged between systems if they have a different temperature - heat flows from higher to lower temperature - without temperature difference, no heat is exchanged If a system is receiving or releasing heat, then this heat is called a) Sensible heat, if the system changes

  14. Optimum and maximum temperatures of sockeye salmon (Oncorhynchus nerka) populations hatched at different temperatures

    E-print Network

    Hinch, Scott G.

    ARTICLE Optimum and maximum temperatures of sockeye salmon (Oncorhynchus nerka) populations hatched: Temperature tolerance and heart rates were compared among nine sockeye salmon (Oncorhynchus nerka (Walbaum variance is adaptive, or a constraint, or both. Key words: sockeye salmon, Oncorhynchus nerka, critical

  15. Effect and control on temperature measurement accuracy of the fiber- optic colorimeter by emissivity of different temperatures

    NASA Astrophysics Data System (ADS)

    Liu, Yu-fang; Han, Xin; Shi, De-heng

    2008-03-01

    Based on the Kirchhoff's Law, a practical dual-wavelength fiber-optic colorimeter, with the optimal work wavelength centered at 2.1 ?m and 2.3 ?m is presented. The effect of the emissivity on the precision of the measured temperature has been explored under various circumstances (i.e. temperature, wavelength) and for different materials. In addition, by fitting several typical material emissivity-temperature dependencies curves, the influence of the irradiation (radiant flux originating from the surroundings) and the surface reflected radiation on the temperature accuracy is studied. The results show that the calibration of the measured temperature for reflected radiant energy is necessary especially in low target temperature or low target emissivity, and the temperature accuracy is suitable for requirements in the range of 400-1200K.

  16. Air temperature profile and air/sea temperature difference measurements by infrared and microwave scanning radiometers

    E-print Network

    Shaw, Joseph A.

    scanning radiometers D. Cimini,1,2 J. A. Shaw,2,3 E. R. Westwater,4 Y. Han,4 V. Irisov,5 V. Leuski,4 and J February 2003. [1] A system of two scanning radiometers has been developed by the National Oceanic of a high-quality temperature sensor and two independent, vertically scanning radiometers, measuring

  17. Differences in foraging and broodnest temperature in the honey bees Apis cerana and A. mellifera

    E-print Network

    Differences in foraging and broodnest temperature in the honey bees Apis cerana and A. mellifera The ecological success of honey bees depends in part on their ability to thermoregulate and to thereby forage at lower temperatures than com- peting bee species (Goulson 2003). The internal temperature of a honey bee

  18. 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...

  19. The effect of rearing in different temperature regimes on the reproduction of Anagasta kuehniella (Lepidoptera: Pyralidae).

    PubMed

    Coelho, A; Parra, J R P

    2013-08-01

    Eggs of Anagasta kuehniella (Zeller) are widely used in mass rearing of parasitoids, especially Trichogramma spp. and predators in many biological-control programs. The objective of this study was to improve the efficiency of mass rearing of A. kuehniella through determining the optimal temperature conditions for rearing, by assessing the effect of temperature during the developmental stages on the reproduction of A. kuehniella. We evaluated 1) the effect of temperature at which A. kuehniella was kept from egg to adult death, on reproduction; 2) the effect of temperature during the larval and pupal stages on oviposition; and 3) the effect of different temperatures on adults that originated from larvae kept in a constant temperature of 25C. The results indicated that the optimal temperature range for the development of A. kuehniella is between 20-30C, as at 30C there was a marked decrease in viability of the egg and larval stages. The best temperature for maintaining A. kuehniella from egg to adult death is 25C. Temperatures of 30 and 32C lead to deformations in genitalia of males, reducing the viability of eggs, and also eggs and females from these temperatures have lower weights. The rearing temperature of immatures affects the egg-laying capacity of adults and the egg viability. The oviposition capacity of adults kept in different temperatures ranging from 18 to 32C, after being reared in constant temperature (25C) during the larval stages, was not affected. PMID:23905744

  20. Temperature dependence of quantum well infrared photodetector focal plane array characteristics

    NASA Astrophysics Data System (ADS)

    Sakachi, Yoichiro; Nishino, Hironori; Masalkar, Prafulla J.; Miyamoto, Yoshihiro; Fujii, Toshio

    1999-12-01

    We investigated the operation temperature dependence of the characteristics of quantum-well infrared photodetector focal plane arrays (QWIP-FPAs) for the 8 - 10 micrometer wavelength region from 65 K to 80 K. We found that a proposed simple circuit model explains the temperature dependence of the DC output and signal intensity of the QWIP-FPA. In this model, we used empirical current-voltage (I-V) characteristics of the QWIP, which was not hybridized with the readout integrated circuit (called 'QWIP itself'), measured at various temperatures and a simplified equivalent circuit model. The signal intensity of the QWIP-FPAs decreases as the temperature increases, while the photo-current of the QWIP itself increases slightly as the temperature increases. The difference between these behaviors is because the bias applied to QWIP in QWIP-FPA varies during the integration cycle and the bias applied to QWIP itself is constant. The noise equivalent temperature difference (NETD) increases from 0.10 K to 0.20 K as the operation temperature increases from 65 K to 80 K, since the signal intensity decreases and the shot noise increases with increasing the dark current.

  1. Different spatial cross-correlation patterns of temperature records over China: A DCCA study on different time scales

    NASA Astrophysics Data System (ADS)

    Yuan, Naiming; Fu, Zuntao

    2014-04-01

    Daily mean temperature records over China during the past 50 years are studied by means of detrended cross-correlation analysis (DCCA). Taking Beijing as a center, we calculate the DCCA cross-correlation coefficient ? between the temperatures in Beijing and those in other stations. After a statistical significance test, spatial cross-correlation patterns on different time scales are shown in this paper. We find the spatial cross-correlation patterns can vary with time scales. On small time scale of one week to one month, only the temperatures in nearby regions have close relations with that in Beijing, while on larger time scale of intra or inter-seasonal, temperatures in most of the regions, especially in the northeast show high level cross-correlations with that in Beijing. The southwest plateau (including the Tibetan Plateau and the YunGui Plateau) is a special region, where the temperatures take on significant anti-cross-correlations on inter-seasonal scale, but no significant correlations on inter-annual scale. By analyzing these different spatial patterns, we can better understand the influencing climatological processes of different scales. Therefore, DCCA are recommended as a reliable method in detecting the relations between two climatological variables, and further be useful for our understanding of the whole climate system.

  2. 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.

  3. 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

  4. Spatial distribution of Northern Hemisphere winter temperatures during different phases of the solar cycle

    NASA Astrophysics Data System (ADS)

    Mursula, Kalevi; Asikainen, Timo; Maliniemi, Ville

    Several recent studies have found variability in the Northern Hemisphere winter climate related to different parameters of solar activity. While these results consistently indicate some kind of solar modulation of tropospheric and stratospheric circulation and surface temperature, opinions on the exact mechanism and the solar driver differ. Proposed drivers include, e.g., total solar irradiance (TSI), solar UV radiation, galactic cosmic rays and magnetospheric energetic particles. While some of these drivers are difficult to distinguish because of their closely similar variation over the solar cycle, other suggested drivers have clear differences in their solar cycle evolution. For example, geomagnetic activity and magnetospheric particle fluxes peak in the declining phase of the sunspot cycle, in difference to TSI and UV radiation which more closely follow sunspots. Using 13 solar cycles (1868-2013) we study winter surface temperatures and North Atlantic oscillation (NAO) during four different phases of the sunspot cycle: minimum, ascending, maximum and declining phase. We find significant differences in the temperature patterns between the four cycle phases, which indicates a solar cycle modulation of winter surface temperatures. However, the clearest pattern of the temperature anomalies is not found during sunspot maximum or minimum, but during the declining phase, when the temperature pattern closely resembles the pattern found during positive NAO. We find this to be independent of the overall level of solar activity. The results support the idea that solar wind related drivers are more important than TSI/UV flux or cosmic rays in modulating Northern Hemisphere winter circulation and surface temperatures.

  5. 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 (R > 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

  6. Electrical resistivity behavior of substituted perovskite manganates sintered at different temperatures

    SciTech Connect

    Joy, P.A.; Kumar, P.S.A.; Date, S.K.

    1999-12-01

    Temperature dependence of the electrical resistivity of La{sub 1{minus}x}Ca{sub x}MnO{sub 3} (x = 0.2, 0.3) samples sintered at two different temperatures are compared to understand the origin of the double-maxima-type resistivity curves of some doped perovskite manganates reported in the literature. It is shown that compositional inhomogeneity is responsible for the anomalous electrical properties of the substituted manganate samples processed at low temperatures.

  7. Estimation of Sea Surface Temperatures From Two Infrared Window Measurements With Different Absorption

    Microsoft Academic Search

    Larry M. McMillin

    1975-01-01

    Radiances measured at two different wavelengths or angles, with a resulting difference in absorption, can t>e used to determine the atmospheric attenuation of the surface radiance so that sea surface temperatures can be derived. Previous investigations used a correction equal to a constant times the difference in measured radiances. Some of these investigations were based on radiances calculated from models

  8. 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

  9. 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...

  10. Heat tolerance, growth and regeneration in three North Sea bryozoans exposed to different constant temperatures

    Microsoft Academic Search

    N. R. Menon

    1972-01-01

    Three species of bryozoansMembranipora membranacea (L.), Electra pilosa (L.) and Conopeum reticulum (L.) are capable of acclimating to elevated temperatures, above the normal range experienced in nature, when exposed to a gradual increase in ambient temperature. Conspicuous differences in LD 50 values, as a consequence of acclimation, occur between representatives of the same species acclimated and grown at constant

  11. Critical phenomenon during photoinitiated gelation at different temperatures: A Photo-DSC study

    Microsoft Academic Search

    Zekeriya Do?ruyol; Nergis Arsu; Sevnur Keskin Do?ruyol; nder Pekcan

    2011-01-01

    The behaviour of photoinitiated radical polymerization of an 80wt% epoxy diacrylate (EA) and 20wt% tripropyleneglycoldiacrylate (TPGDA) mixture with 2-mercaptothioxanthone (TX-SH) photoinitiator was studied at different temperatures by using photo-differential scanning calorimetric (Photo-DSC) technique. All photopolymerization reactions were carried out under the same conditions. It was observed that all conversion curves during gelation at different temperatures present nice sigmoidal behaviour which

  12. How do seasonal temperature patterns vary among different regions of the world?

    NSDL National Science Digital Library

    GLOBE Program

    Students use the GLOBE Student Data Archive and visualizations to display current temperatures on a map of the world. They explore the patterns in the temperature map, looking especially for differences between different regions and hemispheres and zoom in for a closer look at a region that has a high density of student reporting stations (such as the US and Europe). Students compare and contrast the patterns in these maps, looking for seasonal patterns.

  13. Integrating hyperspectral imagery at different scales to estimate component surface temperatures

    Microsoft Academic Search

    N. A. L. Archer; H. G. Jones

    2006-01-01

    Different methods for classifying land cover and extracting temperatures of surface components from hyperspectral images at different scales were compared using airborne imagery (Reflective Optics System Imaging Spectrometer (ROSIS) at 1.2m spatial resolution and Digital Airborne Imaging Spectrometer (DAIS 7915) at 3.3m spatial resolution) for a montado\\/dehesa landscape in the Alentejo, Portugal. For calibration purposes, surface temperatures and stomatal conductance

  14. Openings in frog microvascular endothelium at different rates of increase in pressure and at different temperatures

    PubMed Central

    Savla, U; Neal, C R; Michel, C C

    2002-01-01

    Experiments were carried out on single mesenteric capillaries and venules of pithed frogs to determine whether the rate of increase in intravascular pressure (dP/dt) influenced the critical pressure (PB) which increases wall permeability. Vessels, microperfused with frog Ringer solutions containing 0.1 % bovine serum albumin and red cells, were occluded downstream before pressure was raised either as a ramp or in a series of 13.6 cmH2O steps. By varying step duration, the mean dP/dt could be matched to dP/dt applied as a steady ramp. PB was recorded as the pressure at which there was an abrupt increase in filtration with red cells passing to and through one or more sites in the vessel wall. In all vessels, increasing dP/dt raised PB, with no differences between steps and ramps. The relation between PB and dP/dt was linear, consistent with a latent period, T (the slope), between a critical pressure being reached and the abrupt increase in permeability being observed. Direct observation confirmed this latent period. Between 12 and 20 oC, T was 8.5 0.47 s; between 0 and 5 C, T was 11.5 0.97 s. Tissue cooling did not influence the time constant, ?, describing the rate of stretch of wall following a step increase in pressure and used to measure wall visco-elastic properties. Nor was the value of ? (1.15 0.06 s, n = 42) consistent with T being accounted for by visco-elasticity. It is suggested that the latent period may indicate an active response of the endothelium. PMID:11850520

  15. Differences Between Rice and Wheat in Temperature Responses of Photosynthesis and Plant Growth

    PubMed Central

    Nagai, Takeshi; Makino, Amane

    2009-01-01

    The temperature responses of photosynthesis (A) and growth were examined in rice and wheat grown hydroponically under day/night temperature regimes of 13/10, 19/16, 25/19, 30/24 and 37/31C. Irrespective of growth temperature, the maximal rates of A were found to be at 3035C in rice and at 2530C in wheat. Below 25C the rates were higher in wheat, while above 30C they were higher in rice. However, in both species, A measured at the growth temperature remained almost constant irrespective of temperature. Biomass production and relative growth rate (RGR) were greatest in rice grown at 30/24C and in wheat grown at 25/19C. Although there was no difference between the species in the optimal temperature of the leaf area ratios (LARs), the net assimilation rate (NAR) in rice decreased at low temperature (19/16C) while the NAR in wheat decreased at high temperature (37/31C). For both species, the N-use efficiency (NUE) for growth rate (GR), estimated by dividing the NAR by leaf-N content, correlated with GR and with biomass production. Similarly, when NUE for A at growth temperature was estimated, the temperature response of NUE for A was similar to that of NUE for GR in both species. The results suggest that the difference between rice and wheat in the temperature response of biomass production depends on the difference in temperature dependence of NUE for A. PMID:19251744

  16. Spatial distribution of Northern Hemisphere winter temperatures during different phases of the solar cycle

    NASA Astrophysics Data System (ADS)

    Maliniemi, V.; Asikainen, T.; Mursula, K.

    2014-08-01

    Several recent studies have found variability in the Northern Hemisphere winter climate related to different parameters of solar activity. While these results consistently indicate some kind of solar modulation of tropospheric and stratospheric circulation and surface temperature, opinions on the exact mechanism and the solar driver differ. Proposed drivers include, e.g., total solar irradiance (TSI), solar UV radiation, galactic cosmic rays, and magnetospheric energetic particles. While some of these drivers are difficult to distinguish because of their closely similar variation over the solar cycle, other suggested drivers have clear differences in their solar cycle evolution. For example, geomagnetic activity and magnetospheric particle fluxes peak in the declining phase of the sunspot cycle, in difference to TSI and UV radiation which more closely follow sunspots. Using 13 solar cycles (1869-2009), we study winter surface temperatures and North Atlantic oscillation (NAO) during four different phases of the sunspot cycle: minimum, ascending, maximum, and declining phase. We find significant differences in the temperature patterns between the four cycle phases, which indicates a solar cycle modulation of winter surface temperatures. However, the clearest pattern of the temperature anomalies is not found during sunspot maximum or minimum, but during the declining phase, when the temperature pattern closely resembles the pattern found during positive NAO. Moreover, we find the same pattern during the low sunspot activity cycles of 100 years ago, suggesting that the pattern is largely independent of the overall level of solar activity.

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

    SciTech Connect

    Skony, S.M.; Kahl, J.D.W.; Zaitseva, N.A. [Univ. of Wisconsin, Milwaukee, WI (United States)] [Univ. of Wisconsin, Milwaukee, WI (United States); [State Committee for Hydrometeorology, Dolgoprudny, Moscow (Russian Federation)

    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.

  18. Comparison of the accuracy of transpulmonary thermodilution measurement using indicators of different temperatures

    PubMed Central

    Chen, Shulan; Lin, Pingdong; Du, Zhenshuang; Lan, Fangchen; Wu, Shanshan; Zhong, Tiegang; Liang, Xiaohua; Liu, Hongyu; Zeng, Cuiping; Zhang, Chenghua

    2014-01-01

    Transpulmonary thermodilution measurement is a convenient method for hemodynamic monitoring. However, the previously reported indicator temperature was not consistent. This study aimed to compare the accuracy of Pulse index Continuous Cardiac Output (PiCCO) monitoring using indicators of different temperatures. A total of 104 critically ill patients received PiCCO monitoring using indicators of either 0C or 8C. The PiCCO measurements, including general ejection fraction, global end-diastolic index, and cardiac index, were compared between the two temperatures, and were also correlated with that of transesophageal echocardiography (TEE). The two indicator temperatures differed significantly in hemodynamic measurements (P<0.01). PiCCO measurements with either indicator temperatures showed positive correlation with TEE results (P<0.05). The 0C indicator had universally higher correlation coefficients than the 8C indicator. So, PiCCO monitoring with the 0C indicator might have better accuracy than the 8C indicator. PMID:25664096

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

    PubMed

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

    2013-08-01

    Microcystins (MCs) can cause evident hepatic apoptosis. In vitro studies indicated that uptake of MC by isolated hepatocytes was dramatically reduced as ambient temperature dropped, and some studies presented a hypothesis that differences in core body temperatures in animals result in diverse uptake of MC, as well as different toxic effects. Thus far, however, few in vivo studies have been conducted to investigate the effects of temperature on MC-induced hepatocyte apoptosis in fish, a typical poikilotherm. In the present study, zebrafish were treated with MC-LR, an MC metabolite, at three water temperatures (12, 22 and 32?C), and evident differences in apoptotic profiles were observed. Damage to liver ultrastructures revealed temperature-dependent early-stage patterns of apoptosis. Flow-cytometric analysis indicated that hepatocyte apoptotic rates varied with a temperature-dependent effect. The transcription levels of some apoptosis-related genes were determined using quantitative real-time polymerase chain reaction, and significantly elevated gene expressions of P53, Bcl-2, Bax and caspase-3 were found in the 12 and 32?C groups. Results of the present study indicate that different ambient temperatures can lead to various toxic effects of MCs on hepatic apoptosis in fish. PMID:22407967

  20. Germination responses to temperature and water potential in Jatropha curcas seeds: a hydrotime model explains the difference between dormancy expression and dormancy induction at different incubation temperatures

    PubMed Central

    Windauer, Liliana B.; Martinez, J.; Rapoport, D.; Wassner, D.; Benech-Arnold, Roberto

    2012-01-01

    Background and Aims Jatropha curcas is a drought-resistant tree whose seeds are a good source of oil that can be used for producing biodiesel. A successful crop establishment depends on a rapid and uniform germination of the seed. In this work we aimed to characterize the responses of J. curcas seeds to temperature and water availability, using thermal time and hydrotime analysis, Methods Thermal and hydrotime analysis was performed on germination data obtained from the incubation of seeds at different temperatures and at different water potentials. Key Results Base and optimum temperatures were 144 and 30 C, respectively. Approximately 20 % of the seed population displayed absolute dormancy and part of it displayed relative dormancy which was progressively expressed in further fractions when incubation temperatures departed from 25 C. The thermal time model, but not the hydrotime model, failed to describe adequately final germination percentages at temperatures other than 25 C. The hydrotime constant, ?H, was reduced when the incubation temperature was increased up to 30 C, the base water potential for 50 % germination,?b(50), was less negative at 20 and 30 C than at 25 C, indicating either expression or induction of dormancy. At 20 C this less negative ?b(50) explained satisfactorily the germination curves obtained at all water potentials, while at 30 C it had to be corrected towards even less negative values to match observed curves at water potentials below 0. Hence, ?b(50) appeared to have been further displaced to less negative values as exposure to 30 C was prolonged by osmoticum. These results suggest expression of dormancy at 20 C and induction of secondary dormancy above 25 C. This was confirmed by an experiment showing that inhibition of germination imposed by temperatures higher than 30 C, but not that imposed at 20 C, is a permanent effect. Conclusions This study revealed (a) the extremely narrow thermal range within which dormancy problems (either through expression or induction of dormancy) may not be encountered; and (b) the high sensitivity displayed by these seeds to water shortage. In addition, this work is the first one in which temperature effects on dormancy expression could be discriminated from those on dormancy induction using a hydrotime analysis. PMID:21917817

  1. Measurement of Temperature Differences between Micro-regions in Water Using Near-Infrared Spectroscopy.

    PubMed

    Kakuta, Naoto; Ozaki, Atsushi; Li, Fuguo; Arimoto, Hidenobu; Yamada, Yukio

    2007-01-01

    We have developed a method for measuring the temperature of micro-regions in aqueous solutions using near-infrared spectroscopy that enables us to measure the temperature of biological cells, tissues, and biochemical solutions in vitro. The measurement principle is based on the fact that the peak wavelength of the water absorption band with its center near 1450 nm shifts with changes in temperature. The measurement system, which consists of a biological microscope and two spectrophotometers, can measure respective absorbance spectra for two areas that are each 80 microm in diameter. We formed the temperature distribution in a 500-microm thick water film by heating an immersed Nichrome wire and measured the temperature difference between the two areas. The results of the measurement were compared to a calculated temperature distribution. PMID:18003021

  2. Effect of different genotypes of Phytophthora infestans (Mont. de Bary) and temperature on tuber disease development

    E-print Network

    Douches, David S.

    Effect of different genotypes of Phytophthora infestans (Mont. de Bary) and temperature on tuber Lines (ABL) of potato with different genotypes of the potato late blight pathogen (Phytophthora resistance. The US-8 genotype isolates were the most aggressive in tubers in most years causing rapid

  3. Effect of Different Genotypes of Phytophthora infestans (Mont. de Bary) and Temperature on Tuber

    E-print Network

    Douches, David S.

    Effect of Different Genotypes of Phytophthora infestans (Mont. de Bary) and Temperature on Tuber cultivars/Advance Breeding Lines (ABL) of potato with different genotypes of the potato late blight pathogen tuber resistance. The US-8 genotype isolates were the most aggressive in tubers in most years causing

  4. Trends, spectral characteristics, and rainfall relationships of low-latitude sea surface temperatures at different longitudes

    Microsoft Academic Search

    R. P. Kane

    2000-01-01

    The sea surface temperature (SST) data for low latitudes in the Pacific, Atlantic, and Indian Oceans for 1950-1996 (47 years) showed different seasonal variation patterns at different longitudes. When the seasonal patterns were subtracted from the monthly values, the deseasoned residuals showed considerable anomalies (interannual variability). In the Pacific the main features were the El Nio events. In the Atlantic,

  5. 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

  6. Temperature efficiency for dormancy release in apricot varies when applied at different amounts of chill accumulation.

    PubMed

    Campoy, J A; Ruiz, D; Nortes, M D; Egea, J

    2013-01-01

    Our aim was to assess the possible differential effect of increasing temperatures due to global warming on dormancy progression in apricot. The effect of a range of chilling temperatures on vegetative and reproductive bud dormancy progression in excised shoots was examined during two seasons. Temperature treatments were applied in different dormant stages to evaluate the possible interaction of date??temperature for dormancy release in apricot. During sampling, chill accumulated in the field ranged from 0 to 49 chill portions (CPs), corresponding to 0-100% of the chilling requirement (CR) of the apricot selection Z505-2. Forcing conditions were applied after a 60-day chill treatment on each sampling date, and rate to budbreak (1/mean time to bud break: MTB(-1) ) was established in vegetative (terminal and lateral) and reproductive buds to determine depth of dormancy. Results showed that the stage of dormancy has a strong influence on the effect of different temperatures on dormancy progression in apricot. For the first time, a non-linear effect of different chilling temperatures during the dormancy cycle in apricot was obtained, especially in the superior range of temperatures traditionally considered to release dormancy. Thus, introduction of this differential effect could help to improve the models to estimate dormancy release in the context of climate change. PMID:22845025

  7. 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.

  8. 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

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

    PubMed Central

    Chuche, Julien; Thiry, 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

  10. 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

    2014-11-01

    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.

  11. Sex Differences in the Cannabinoid Modulation of Appetite, Body Temperature and Neurotransmission at POMC Synapses

    Microsoft Academic Search

    Shanna Diaz; Borzoo Farhang; Joshua Hoien; Megan Stahlman; Nadira Adatia; Jeremy M. Cox; Edward J. Wagner

    2009-01-01

    We sought to determine whether sex differences exist for the cannabinoid modulation of appetite, body temperature and neurotransmission at pro-opiomelanocortin (POMC) synapses. Gonadectomized male and female guinea pigs were outfitted to monitor core body temperature and injected with either the CB1 receptor agonist WIN 55,212-2 (1 mg\\/kg s.c.), antagonist AM251 (3 mg\\/kg s.c.) or vehicle (1 ml\\/kg s.c.) and evaluated

  12. Duration of egg storage at different temperatures in the astacid crayfish Pacifastacus leniusculus: critical embryonic phase

    Microsoft Academic Search

    J. R Prez; J. D Celada; J Gonzlez; J. M Carral; M Sez-Royuela; R Fernndez

    2003-01-01

    The critical phase that would limit duration of egg storage in the astacid crayfish Pacifastacus leniusculus was investigated. Weekly monitoring was conducted during an 84-day period of storage at three different constant temperatures (15.51, 10.51.5 and 40.5 C). After artificial incubation, stage 2 juveniles were only obtained from the lowest storage temperature, the sole treatment in which eggs did not

  13. A comparison of growth and physiology in Picea glauca and Populus tremuloides at different soil temperatures

    Microsoft Academic Search

    Simon M. Landhusser; Annie DesRochers; Victor J. Lieffers

    2001-01-01

    Abstract: Trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) seedlings were grown at uniform air temperatures but different soil temperatures (5, 15, and 25C), and gas-exchange and growth characteristics were examined during active growth and early dormancy. At 5C, Populus tremuloides had no root growth,and limited growth,in leaf area and shoot mass,compared,with the large increases in

  14. Resolution of pheromone pulses in receptor cells of Antheraea polyphemus at different temperatures

    Microsoft Academic Search

    B. Kodadov

    1996-01-01

    The ability of pheromone receptor cells of male Antheraea polyphemus (Saturniidae) to resolve stimulus pulses was determined at different temperatures (8, 18, 28C). The cells were stimulated by repeated 20-ms puffs of the pheromone components (E, Z)-6, 11-hexadecadienyl acetate and (E, Z)-6,11-hexadecadienal. At higher temperatures, higher frequencies of stimulus pulses were resolved by the nerve-impulse response: about 1.25 pulses per

  15. The influence of serial feeding of drinks at different temperatures on thermoregulatory responses during cycling

    Microsoft Academic Search

    Jason K. W. Lee; Ron J. Maughan; Susan M. Shirreffs

    2008-01-01

    In this study, we examined thermoregulatory responses to ingestion of separate aliquots of drinks at different temperatures during low-intensity exercise in conditions of moderate heat stress. Eight men cycled at 50% (s=3) of their peak oxygen uptake ([Vdot]O2peak) for 90min (dry bulb temperature: 25.3C, s=0.5; relative humidity: 60%, s=5). Four 400-ml aliquots of flavoured water at 10C (cold), 37C (warm)

  16. Genetic differences influencing behavioral temperature regulation in small mammals. II. Genotype-environment interactions

    Microsoft Academic Search

    Carol Becker Lynch; Joseph P. Hegmann

    1973-01-01

    The importance of genotype by temperature interactions contributing to individual differences in nesting behavior has been demonstrated using two inbred strains ofMus musculus. Exposure to low ambient temperature increased amounts of cotton used by both the high-nesting (BALB\\/cJ) and low-nesting (C57BL\\/6J) strains. The larger total nesting scores of BALB\\/cJ mice compared to those of C57BL\\/6J mice resulted from differential increases,

  17. 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 180C 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 40C 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 180C and the warm plugger positioned at 3 mm from the root apex, both heating sources led to a temperature slightly higher than 40C at the apex of the root, suggesting that the gutta-percha was properly softened. Significance: A temperature level higher than 40C was maintained for a longer time with System MB, thus providing an ad-equate time for warm compaction of the gutta-percha. PMID:25614768

  18. 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.

  19. Electrical resistivity behavior of substituted perovskite manganates sintered at different temperatures

    Microsoft Academic Search

    P. A. Joy; P. S. Anil Kumar; S. K. Date

    1999-01-01

    Temperature dependence of the electrical resistivity of La1-xCxMnO3 (x =\\u000a 0.2, 0.3) samples sintered at two different temperatures are compared to\\u000a understand the origin of the double-maxima-type resistivity curves of\\u000a some doped perovskite manganates reported in the literature. It is shown\\u000a that compositional inhomogeneity is responsible for the anomalous\\u000a electrical properties of the substituted manganate samples processed at\\u000a low temperatures.

  20. 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.

  1. 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.

  2. The effect of using different regions of interest on local and mean skin temperature.

    PubMed

    Maniar, Nirav; Bach, Aaron J E; Stewart, Ian B; Costello, Joseph T

    2015-01-01

    The dynamic nature of tissue temperature and the subcutaneous properties, such as blood flow, fatness, and metabolic rate, leads to variation in local skin temperature. Therefore, we investigated the effects of using multiple regions of interest when calculating weighted mean skin temperature from four local sites. Twenty-six healthy males completed a single trial in a thermonetural laboratory (meanSD): 24.0 (1.2)C; 56 (8%) relative humidity; <0.1m/s air speed). Mean skin temperature was calculated from four local sites (neck, scapula, hand and shin) in accordance with International Standards using digital infrared thermography. A 50mm50mm, defined by strips of aluminium tape, created six unique regions of interest, top left quadrant, top right quadrant, bottom left quadrant, bottom right quadrant, centre quadrant and the entire region of interest, at each of the local sites. The largest potential error in weighted mean skin temperature was calculated using a combination of a) the coolest and b) the warmest regions of interest at each of the local sites. Significant differences between the six regions interest were observed at the neck (P<0.01), scapula (P<0.001) and shin (P<0.05); but not at the hand (P=0.482). The largest difference (SEM) at each site was as follows: neck 0.2 (0.1)C; scapula 0.2 (0.0)C; shin 0.1 (0.0)C and hand 0.1 (0.1)C. The largest potential error (meanSD) in weighted mean skin temperature was 0.4 (0.1)C (P<0.001) and the associated 95% limits of agreement for these differences was 0.2-0.5C. Although we observed differences in local and mean skin temperature based on the region of interest employed, these differences were minimal and are not considered physiologically meaningful. PMID:25774024

  3. 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.

  4. Temperature

    NSDL National Science Digital Library

    Brieske, Joel A.

    This topic in depth begins with the About Temperature (1) Web site, written by Beverly T. Lynds of Unidata, which is a program that works to enable university researchers and educators to acquire and use atmospheric and related data. The one-page site explains what temperature is, the development of thermometers, heat and thermodynamics, and other related topics. The second site is maintained by the University of Execter's Centre for Innovation in Mathematics Teaching. Actually an online tool called Conversion Calculator for Units of Temperature (2), the site allows users to type in any value, choose a significant figure, press "convert it," and get that value in Kelvin, Celsius, Fahrenheit, r'aumur, and rankine units. The next site is a lesson plan from AskEric.com entitled Temperature: Is it Hot or Cold? (3). Written for 2nd graders, the lesson demonstrates to how to read thermometers, determine their rise or fall, record temperatures, and take temperatures of various items. The fourth site, Surface Temperature Analysis (4), is presented by NASA's Goddard Institute for Space Studies. Here, visitors can view graphs, maps, animations, and station data of global surface temperatures. For example, the animation covers 12-month means from 1971 to 1999. The History Behind the Thermometer (5) Web site, from About.com, explores what a thermometer is, how it works, and how it came into being. The sixth site, entitled Science Shack (6) and offered by the BBC, answers the question, Why do we have two different temperature scales, Celsius and Fahrenheit? The site explains how to create your own thermometer like Galileo's, tells how it works, and why we use other types today. The next site is provided by National Oceanic and Atmospheric Administration (NOAA) and presents US State temperature extremes and drought information (7). Visitors can see all-time temperature maximums and minimums by state, monthly temperatures by state, and more. The last site is an all-inclusive temperature site called Temperature World (8). Everything from news, science, organizations, general interest, games, and more -- all related to temperature -- can be found here.

  5. Temperature and functional traits influence differences in nitrogen uptake capacity between native and invasive grasses.

    PubMed

    Leffler, A Joshua; James, Jeremy J; Monaco, Thomas A

    2013-01-01

    Performance differences between native and exotic invasive plants are often considered static, but invasive grasses may achieve growth advantages in western North America shrublands and steppe under only optimal growing conditions. We examine differences in N uptake and several morphological variables that influence uptake at temperatures between 5 and 25 C. We contrast two native perennial grasses in western North America: Elymus elymoides and Pseudoroegneria spicata; two invasive annual grasses: Bromus tectorum and Taeniatherum caput-medusae; and one highly selected non-native perennial grass: Agropyron cristatum. The influence of temperature on N uptake is poorly characterized, yet these invasive annual grasses are known to germinate in warm soils in the autumn, and both experience cool soils during the short growing season following snowmelt in the spring. To further explore the influence of temperature on the correlation between morphological variables and N uptake, our data are applied to a previously published path model and one proposed here. Differences in N uptake between native and invasive grasses were small at the lowest temperature, but were large at the highest temperature. At lower temperatures, uptake of N by annuals and perennials was correlated with leaf N and mass. At higher temperatures, uptake by annuals was correlated only with these leaf traits, but uptake by perennials was correlated with these leaf traits as well as root N and mass. Consequently, our results imply that annual grasses face fewer morphological constraints on N uptake than perennial grasses, and annual grasses may gain further advantage in warmer temperature conditions or during more frequent warm periods. PMID:22744743

  6. 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

  7. Low temperature cardiac response to exhaustive exercise in fish with different levels of winter quiescence.

    PubMed

    Cooke, Steven J; Grant, Emily C; Schreer, Jason F; Philipp, David P; Devries, Arthur L

    2003-01-01

    We examined the cardiac responses of different fish species to anaerobic exercise at low temperatures (3 degrees C). Three species of sympatric warmwater fish with perceived differences in winter activity were used for this comparative study: the winter-quiescent largemouth bass (Micropterus salmoides); the winter-active white bass (Morone chrysops); and the intermediately winter-active black crappie (Pomoxis nigromaculatus). Perceived differences in winter activity were reflected in cardiac responses; e.g. basal cardiac values were lowest for largemouth bass, highest for white bass, and intermediate for black crappie. In addition, cardiac recovery was most rapid for white bass, slowest for largemouth bass and intermediate for black crappie. When disturbed at low temperatures, largemouth bass and black crappie elevated cardiac output principally through increases in heart rate despite substantial decreases in stroke volume. Conversely, white bass principally used stroke volume modulation to change cardiac output. The results of this study indicate that different species respond differently to exercise at low temperatures. Management strategies should recognize that such variation exists and ensure that management decisions are based upon an understanding of the low temperature exercise physiology and winter biology of the species of interest. PMID:12507619

  8. Atomic dynamics in molten AlCu alloys of different compositions and at different temperatures by cold neutron scattering

    NASA Astrophysics Data System (ADS)

    Dahlborg, U.; Besser, M.; Kramer, M. J.; Morris, J. R.; Calvo-Dahlborg, M.

    2013-03-01

    The atomic motions in molten Al1-xCux (x=0.10, 0.171 and 0.25) around the eutectic composition (x=0.171) were studied by cold neutron inelastic scattering at three different temperatures (973 K, 1173 K and 1373 K). An alloy of eutectic composition containing the 63Cu isotope was also studied. Self-diffusion coefficients for the Cu ions were determined from the width of quasielastic peaks and were found to decrease slightly with increasing Cu concentration. Longitudinal current correlation functions Jl(Q,E) exhibit at all temperatures and at all compositions a shoulder at energies below 10 meV and one main maximum at higher energies. These features can be interpreted in terms of excitations of acoustic and optic nature. The shape of Jl(Q,E) is sensitive to composition, being considerably more structured for larger Cu content. This can be coupled to the existence of a prepeak in the measured zeroth moment of dynamic scattering function indicating an increased chemical ordering with increasing Cu concentration for all temperatures. Indications for an existence of a liquid-liquid phase transition are presented.

  9. 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.

  10. 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.

  11. 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

  12. Long-term changes in insolation and temperatures at different altitudes

    NASA Astrophysics Data System (ADS)

    Sanroma, E.; Palle, E.; Sanchez-Lorenzo, A.

    2010-04-01

    Over the past few years, ground- and space-based atmospheric measurements have revealed a large inter-decadal variability in the amount of radiation reaching the Earth's surface, also known as global dimming and brightening. However, the underlying physical causes of these changes remain unexplained. Clouds and aerosols, or their interactions, could both be responsible for the insolation changes, which in turn may impact the radiative balance of the planet. Here, making use of the special topology and clean environment of the Canary Islands, we compare trends in sunshine duration and temperature series, as a function of altitude. The temperature dataset is constituted by a series of mean, minimum and maximum temperatures, and daily temperature ranges. We find that the insolation and temperature trends are identical at sea level and at more than 2 km height, but the changes in diurnal temperature range are not, suggesting a possible urban heat effect at the sea level location, as well as a possible different influence of clouds and/or aerosols at different altitudes. We also find that during the summer, especially at the high altitude site, there is a clear correspondence between daytime insolation and nighttime cloud-free atmospheric extinction measurements. This suggests that atmospheric aerosol concentrations are the major contributor to the variations in the flux of solar radiation reaching the ground at high altitude sites over the Canary Islands.

  13. 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

    2015-02-01

    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.

  14. 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.

  15. Room temperature photoreflectance of different electron concentration GaN epitaxial layers

    Microsoft Academic Search

    R Kudrawiec; G S?k; J Misiewicz; R Paszkiewicz; B Paszkiewicz; M T?acza?a

    2002-01-01

    Wurtzite-structure GaN epilayers grown by metal-organic vapor phase epitaxy (MOVPE) on sapphire substrates were studied by photoreflectance (PR) spectroscopy performed at room temperature. Several nominally undoped samples with different electron concentrations (5101551018 cm?3), deposited under different growth conditions, were investigated. For low electron concentration we have observed three well-resolved excitonic transitions related to A, B, and C excitons. In this

  16. 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.

  17. Antioxidant activity and free radical-scavenging capacity of Gynura divaricata leaf extracts at different temperatures

    PubMed Central

    Wan, Chunpeng; Yu, Yanying; Zhou, Shouran; Liu, Wei; Tian, Shuge; Cao, Shuwen

    2011-01-01

    Background: Extraction temperature influences the total phenolic content (TPC), total flavonoid content (TFC) of medicinal plant extracts to a great extend. TPC and TFC are the principle activity constituents present in the plant. The effects of extraction temperature on TPC, TFC and free radical-scavenging capacity of Gynura divaricata leaf extracts are worth to study. Materials and Methods: FolinCiocalteu and aluminum chloride colorimetric assay were used to determine the TPC and TFC of Gynura divaricata leaf extracts at different temperatures. The antioxidant and free radical-scavenging activity were measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and phosphomolybdenum methods. Results: TPC and TFC were significantly elevated with increasing extraction temperature (from 40C to 100C). However, TPC and TFC were not significantly different (P > 0.05) at the extraction temperatures 90C and 100C. Also, the extracts obtained at a higher temperature exhibited a significant free radical-scavenging activity compared with extraction at lower temperatures (P < 0.05). The TPCs (13.95-36.68 mg gallic acid equivalent/g dry material) were highly correlated with DPPH (R2 = 0.9229), ABTS (R2 = 0.9951) free radical-scavenging capacity, and total antioxidant activity (R2 = 0.9872) evaluated by phosphomolybdenum method. Conclusion: The TPC and TFC of G. divaricata leaf was significantly influenced by the extraction temperatures, which were the main antioxidant constituents present in the G. divaricata plant. PMID:21472078

  18. Ventilatory responses to CO 2 at different body temperatures in the snake, Coluber constrictor

    Microsoft Academic Search

    W. F. Nolan; H. M. Frankel

    1982-01-01

    Summary Ventilatory responses to CO2 were examined at different temperatures in the snake,Coluber constrictor. CO2 sensitivity increased between 15 and 25C but not between 25 and 35C. A rapidly occurring off-CO2 transient hyperpnea suggested the presence of an intrapulmonary chemoreceptor.

  19. temperature differences exist between the day and night faces of the planet, consistent with a model

    E-print Network

    Carpick, Robert W.

    temperature differences exist between the day and night faces of the planet, consistent. 626, 523 (2005). 3. There is no official terminology for planets that orbit close to their parent, such as "Pegasids," "Pegasi planets," or "Roasters." 4. G. H. Rieke et al., Proc. SPIE 5487, 50 (2004). 5. M. W

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

    PubMed

    Szyma?ska, Renata; Nowicka, Beatrycze; Gabruk, Micha?; Gli?ska, S?awa; Michlewska, Sylwia; D?u?ewska, Jolanta; Sawicka, Anna; Kruk, Jerzy; Laitinen, Roosa

    2014-09-12

    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 (16C) than in low light and at 23C. 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

  1. Investigation of Heat capacity and Specific Heat: Using Different Temperatures of Water and Solids

    NSDL National Science Digital Library

    This activity is a chemistry lab-based investigation where students apply observational skills and critical thinking skills to finding specific heat and heat capacity using different temperatures of water and solids. A final activity will assess students understanding of specific heat and heat capacity and promote data analysis skills, using real-life situations.

  2. Effects of differing temperature management on development of Actinobacteria populations during composting

    Microsoft Academic Search

    Kristin Steger; sa Jarvis; Tuija Vasara; Martin Romantschuk; Ingvar Sundh

    2007-01-01

    Actinobacteria are believed to play a major role in organic matter degradation and humification processes in composts. In this study, the effects of different temperature regimes on the succession of Actinobacteria populations during composting were investigated in a laboratory reactor. Phospholipid fatty acid (PLFA) was used to investigate quantitative changes in the overall microbial biomass and community structure, and in

  3. Two-Temperature Generalized Thermopiezoelasticity of Finite Rod Subjected to Different Types of Thermal Loading

    Microsoft Academic Search

    E. Bassiouny; Hamdy M. Youssef

    2008-01-01

    In this work the theory of two-temperature generalized thermoelasticity, based on the theory of Youssef is used to solve boundary value problems of one-dimensional finite piezoelectric rod with loading on its boundary with different types of heating. The governing equations are solved in the Laplace transform domain by using a direct approach. The general solution obtained is applied to specific

  4. 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 ...

  5. Numerical simulation and laser holographic study on thermal diffusion in counterflow with different temperatures

    Microsoft Academic Search

    Seizo Kato; Naoki Maruyama; Sadegh Tabejamaat

    1997-01-01

    This paper presents a numerical simulation and a laser holographic interferometric study on thermal diffusion characteristics of combined forced and free heat convection in a counterflow with different temperatures. The purpose of this paper is to make clear the characteristics of a direct mixing heat exchanger for advanced energy conversion. In the numerical study, the flow patterns and isotherms for

  6. 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)

  7. Temperature Difference Leads to Magnetism | Physical Review Focus Previous Story / Volume 28 archive

    E-print Network

    Wu, Junqiao

    Temperature Difference Leads to Magnetism | Physical Review Focus Previous Story / Volume 28 Leads to Magnetism J. Wu/Univ. of California, Berkeley Heat field. Heating the right edge of an n a magnetic field pointing out of the screen, according to computer simulations. Computer simulations suggest

  8. 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.

  9. Decomposition of rice straw and microbial carbon use efficiency under different soil temperatures and moistures

    Microsoft Academic Search

    Olivier C Devvre; William R Horwth

    2000-01-01

    The management of crop residues has become an important aspect of sustaining long-term fertility in cropping systems. Incorporation of crop residues can change microbial processes, which affect nutrient availability and hence crop yield. Carbon (C) use efficiency by soil microorganisms during rice straw decomposition was determined in a rice paddy soil, under aerobic and anaerobic (flooded) conditions at different temperatures

  10. Photosynthetic characteristics of leaves developed at different irradiances and temperatures: an extension of the current hypothesis

    Microsoft Academic Search

    James A. Bunce

    1983-01-01

    Photosynthetic characteristics at high measurement irradiance were analyzed for single leaves of two C3 and one C4 species grown under twenty one combinations of irradiance level, irradiance duration, and air temperature in order to test the idea that photosynthetic characteristics developed by leaves in different environments are controlled by the daily amount of photosynthesis. Photosynthetic rates per unit area and

  11. 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

  12. THE GROWTH AND DURATION OF LIFE OF CELOSIA CRISTATA SEEDLINGS AT DIFFERENT TEMPERATURES.

    PubMed

    Edwards, T I; Pearl, R; Gould, S A

    1934-07-20

    Daily measurements of hypocotyl length were made on Celosia cristata seedlings cultured in darkness under aseptic conditions at six constant temperatures between 14.5 degrees and 40.5 degrees C. At 40.5 degrees roots did not penetrate the agar and only the hypocotyls that were supported by the wall of the test tube could be measured. The growth curves were of the generalized logistic type, but of different degrees of skewness. The degree of symmetry of the growth curves was influenced by temperature. At the lower temperatures the maximal growth rate came relatively late in the grand period of growth; at successively higher temperatures it came progressively earlier. The mean total time rate of growth (millimeter per diem) was found to be a parabolic function of the temperature. The maximum rate of growth was found from the curve to be at 30.48 degrees C. The maximum observed rate of growth, and the maximum yield, were found to be at 30 degrees C. At all temperatures above 14.5 degrees the maximum growth activity fell in the second quarter of the whole growth period. At all temperatures tested other than 30 degrees , and at all parts of the growth cycle, the growth yield as measured by height of hypocotyl at any given equivalent point was less than at 30 degrees . The total duration of life of the seedlings, and the duration of life after the end of the growth period (intermediate period) were inversely proportional to the mean total growth rate. The observations on Celosia cristata seedlings are thus in accord with the "rate of living" theory of life duration. The optimal temperature for life duration is the minimum temperature, within the range of these observations. PMID:19872811

  13. THE GROWTH AND DURATION OF LIFE OF CELOSIA CRISTATA SEEDLINGS AT DIFFERENT TEMPERATURES

    PubMed Central

    Edwards, Thomas I.; Pearl, Raymond; Gould, Sophia A.

    1934-01-01

    Daily measurements of hypocotyl length were made on Celosia cristata seedlings cultured in darkness under aseptic conditions at six constant temperatures between 14.5 and 40.5C. At 40.5 roots did not penetrate the agar and only the hypocotyls that were supported by the wall of the test tube could be measured. The growth curves were of the generalized logistic type, but of different degrees of skewness. The degree of symmetry of the growth curves was influenced by temperature. At the lower temperatures the maximal growth rate came relatively late in the grand period of growth; at successively higher temperatures it came progressively earlier. The mean total time rate of growth (millimeter per diem) was found to be a parabolic function of the temperature. The maximum rate of growth was found from the curve to be at 30.48C. The maximum observed rate of growth, and the maximum yield, were found to be at 30C. At all temperatures above 14.5 the maximum growth activity fell in the second quarter of the whole growth period. At all temperatures tested other than 30, and at all parts of the growth cycle, the growth yield as measured by height of hypocotyl at any given equivalent point was less than at 30. The total duration of life of the seedlings, and the duration of life after the end of the growth period (intermediate period) were inversely proportional to the mean total growth rate. The observations on Celosia cristata seedlings are thus in accord with the "rate of living" theory of life duration. The optimal temperature for life duration is the minimum temperature, within the range of these observations. PMID:19872811

  14. Effects of increasing temperatures on physiological changes in pigs at different relative humidities.

    PubMed

    Huynh, T T T; Aarnink, A J A; Verstegen, M W A; Gerrits, W J J; Heetkamp, M J W; Kemp, B; Canh, T T

    2005-06-01

    The effects of relative humidity (RH) and high ambient temperature (T) on physiological responses and animal performance were studied using 12 groups (10 gilts per group) in pens inside respiration chambers. The microclimate in the chamber was programmed so that T remained constant within a day. Each day, the T was increased by 2 degrees C from low (16 degrees C) to high (32 degrees C). Relative humidity was kept constant at 50, 65, or 80%. The pigs' average initial BW was 61.7 kg (58.0 to 65.5 kg), and their average ending BW was 70.2 kg (65.9 to 74.7 kg). Respiration rate (RR), evaporative water (EW), rectal temperature (RT), skin temperature (ST), voluntary feed intake (VFI), water-to-feed ratio (rW:F), heat production (HP), and ADG were analyzed. The animals had free access to feed and water. We determined the T above which certain animal variables started to change: the so-called inflection point temperature (IPt) or "upper critical temperature." The first indicator of reaction, RR, was in the range from 21.3 to 23.4 degrees C. Rectal temperature was a delayed indicator of heat stress tolerance, with IPt values ranging from 24.6 to 27.1 degrees C. For both these indicators the IPt was least at 80% RH (P < 0.05). Heat production and VFI were decreased above IPt of 22.9 and 25.5 degrees C, respectively (P < 0.001). For each degree Celsius above IPt, the VFI was decreased by 81, 99, and 106 g/(pig.d) in treatments 50, 65, and 80% RH, respectively. The ADG was greatest at 50% RH (P < 0.05). Ambient temperature strongly affects the pigs' physiological changes and performance, whereas RH has a relatively minor effect on heat stress in growing pigs; however, the combination of high T and high RH lowered the ADG in pigs. The upper critical temperature can be considered to be the IPt above which VFI decreased and RT then increased. Temperatures of the magnitude of both these IPt are regularly measured in commercial pig houses. We conclude that the upper critical temperatures for 60-kg, group-housed pigs fed ad libitum are between 21.3 and 22.4 degrees C for RR, between 22.9 and 25.5 degrees C for HP and VFI, and between 24.6 and 27.1 degrees C for RT. It is clear that different physiological and productive measurements of group-housed, growing-finishing pigs have different critical temperatures. PMID:15890816

  15. 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

    2015-04-01

    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 700C 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 500C was a suitable additive in pig manure composting. PMID:25209736

  16. The influence of different acupuncture manipulations on the skin temperature of an acupoint.

    PubMed

    Huang, Tao; Huang, Xin; Zhang, Weibo; Jia, Shuyong; Cheng, Xinnong; Litscher, Gerhard

    2013-01-01

    This study was performed to observe the influence of sham and different verum acupuncture manipulations on skin temperature of the stimulated acupoint in healthy volunteers. Thirty-seven healthy volunteers with a mean age of 25.4 2.2 years were enrolled in the study. All volunteers had experienced acupuncture before. They received sham acupuncture and two different kinds of verum acupuncture stimulation (lifting-thrusting and twisting-rotating) on Zusanli (ST36). The skin temperature of ST36 was measured before acupuncture, after needle insertion, after needle manipulation, immediately after removal of the needle, and as further control 5 minutes after removal of the needle using a FLIR i7 infrared thermal camera. During the measurement, the needling sensations of volunteers were enquired and recorded. During the sham acupuncture stimulation, the skin temperature of ST36 decreased in the first 5 minutes, when the point was exposed, and then increased gradually. During verum acupuncture stimulations, the skin temperature increased continually and then decreased in the last phase. The increase in temperature caused by lifting-thrusting stimulation was significantly higher than that of twisting-rotating manipulation, which may be related to the stimulation intensity. PMID:23476709

  17. 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 Tukeys 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 34.14C1.51C; clear lens: 34.43C2.27C; and pseudophakic: 34.97C1.57C. 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.

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

    SciTech Connect

    Ortiz-Morales, A. [Unidad Profesional Interdisciplinaria de Ingenieria y Tecnologias Avanzadas, IPN, Av. Instituto Politecnico Nacional 2580, Col. La Laguna Ticoman, 07340 Mexico D.F., Mexico and Unidad de Irradiacion y Segurid (Mexico); Cruz-Zaragoza, E.; Furetta, C. [Unidad de Irradiacion y Seguridad Radiologica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F (Mexico); Kitis, G. [Nuclear Physics Laboratory, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Flores J, C.; Hernandez A, J.; Murrieta S, H. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, AP. 20-364, 01000 Mexico D.F (Mexico)

    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.

  19. An Ultra-Low Noise Superconducting Antenna-Coupled Microbolometer With a Room-Temperature Read-Out

    Microsoft Academic Search

    Arttu Luukanen; Erich N. Grossman; Aaron J. Miller; P. Helisto; J. S. Penttila; H. Sipola; H. Seppa

    2006-01-01

    In this letter, we report the electrical and optical characteristics of a superconducting vacuum-bridge microbolometer with an electrical noise equivalent power of 26fW radicHz and an effective time constant of 380 ns, when operated at a bath temperature of 4K. We employ a novel room temperature external negative feedback readout architecture, that allows for noise matching to the device without

  20. 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 20C. 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 35C. 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

  1. Temperature Differences in the Cepheid Instability Strip Require Differences in the Period-Luminosity Relation in Slope and Zero Point

    NASA Astrophysics Data System (ADS)

    Sandage, Allan; Tammann, G. A.

    2008-10-01

    A graphical and an algebraic demonstration is made to show why the slope and zero point of the Cepheid period-luminosity (P-L) relation is rigidly coupled with the slope and zero point of the Cepheid instability strip in the HR diagram. In this way it is shown why it is logically inconsistent to adopt a fixed P-L slope for all galaxies if the intrinsic color-period relations differ in slope for some of them. The graphical demonstration of this inconsistency uses an arbitrary (toy) ridgeline in the instability strip, while the algebraic demonstration uses the pulsation equation into which the observed P-L relations for the Galaxy and the LMC are put to predict the temperature zero points and slopes of the instability strips. Agreement between the predicted and the observed slopes in the instability strips argue that the observed P-L differences between the Galaxy and LMC are real. The direct evidence for different P-L slopes in different galaxies is displayed by comparing the Cepheid data in the Galaxy, the combined data in NGC 3351 and NGC 4321, in M31, LMC, SMC, IC 1613, NGC 3109, and in Sextans A+B. The P-L slopes for the Galaxy, NGC 3351, NGC 4321, and M31 are nearly identical and are the steepest in the sample. The P-L slopes decrease monotonically with metallicity in the order listed, showing that the P-L relation is not the same in different galaxies, complicating their use in calibrating the extragalactic distance scale.

  2. Comparison of microbial diversity during column bioleaching of chalcopyrite at different temperatures.

    PubMed

    Chen, Bowei; Wu, Biao; Liu, Xingyu; Wen, Jiankang

    2014-06-01

    Column bioleaching of chalcopyrite was conducted at 33, 45, and 65?C, and the copper leaching rates after 220 days were 38.50, 51.35, and 56.75%, respectively. In order to compare the microbial diversity at different temperatures, the microbial community structures of both bacteria and archaea in the columns were analyzed using 16S rRNA gene clone library on day 220. Clone library results indicated that although both iron oxidizers and sulfur oxidizers occurred at all temperatures, iron oxidizers were dominant at 33 and 45?C and sulfur oxidizers were predominant at 65?C. With regard to bacterial community structure, Leptospirillum ferriphilum was the principal bacterium at 33 and 45?C, and uncultured sulfur-oxidizing symbiont bacteria were dominant at 65?C. On the other hand, with regard to archaea, only Ferroplasma sp. was detected at 33?C, cultures similar to uncultured archaeon clone were dominant at 45?C, and Metallosphaera sedula was predominant at 65?C. Thus, it is suggested that different community structures occur at different temperatures, and that thermophilic chalcopyrite bioleaching should be inoculated and operated at high temperature in order to allow thermophiles to become the dominant microorganism in the system. PMID:23832814

  3. Shelf-life of almond pastry cookies with different types of packaging and levels of temperature.

    PubMed

    Romeo, F V; De Luca, S; Piscopo, A; Santisi, V; Poiana, M

    2010-06-01

    Almond pastries are typical cookies of the south of Italy. Introduction of new packaging for this kind of cookies requires shelf-life assessments. This study, related to different types of packaging under various storage conditions of time and temperature, identifies critical parameters, as color and texture, to track during storage studies and to extend the shelf-life. The cookies were packed in three different ways and stored at two different temperatures. The pastries were separately stored: (1) in polyvinylchloride film; (2) in aluminum foil (ALL); (3) with modified atmosphere (MAP) in plastic vessels sealed into a polyamide/ polyethylene film; and (4) in vessels without any polymeric film. The storage temperatures were 20 and 30 C. Evolution of texture, water activity, dry matter and color was assessed. Texture was evaluated by a texture analyzer with a puncturing test. Indices for hardening were the area under the curve (N mm) up to 10 mm of distance, and the maximum force (N) corresponding to the crust fracture. The best results were obtained with ALL packaging and MAP condition, and above all, in all the trials a temperature of 30 C reduced the crust hardness. PMID:21339139

  4. Generalization of Logarithmic Mean Temperature Difference Method for Heat Exchanger Performance Analysis

    NASA Astrophysics Data System (ADS)

    Utamura, Motoaki; Nikitin, Konstantin; Kato, Yasuyoshi

    A generalized mean temperature difference (GMTD) method for heat exchangers is proposed. In the analysis of the performance of heat exchangers logarithmic temperature difference (LMTD) method has been widely used. This method, however, limits its application to those heating media with constant physical property. In turn GMTD method allows analysis with physical property distributed in an entire heat exchanger. Temperature profiles of the heat exchanger taken as function of heat load in place of axial position, mean temperature difference is evaluated numerically. It is mathematically demonstrated that LMTD method is an extremity of the GMTD method in the case of constant physical property. The GMTD method is applied to a hot water supplier with supercritical carbon dioxide as a heating media which is attracting attention as energy saving tactics. The hot water supplier operates under the condition of pseudo critical point of carbon dioxide where specific heat behaves anomaly. Incorporating GMTD method averaged overall heat transfer coefficient and subsequently formula of local Nusselt number are successfully derived for microchannel heat exchanger while formal application of LMTD method is found to give poor results i.e. two times less value with a larger error. This proves the validity of GMTD method.

  5. Thermographic imaging of facial skingender differences and temperature changes over time in healthy subjects

    PubMed Central

    Christensen, J; Vaeth, M; Wenzel, A

    2012-01-01

    Objectives To assess changes in facial skin temperature over time, to identify sources of variation related to skin temperature and to evaluate interobserver reproducibility in measurements of the thermograms. Methods 62 volunteers (32 females, 30 males, mean age 23.4, range 19.529.5 years) underwent thermography of the face (left and right side lateral images) on four occasions with approximately 2 months between each session. Three observers recorded the images and marked regions of interest (ROIs) in each image using dedicated software. Smoking, exercise habits and use of oral contraceptives were recorded. Results A significant difference between sessions (?1 C, p < 0.001) and between observers (?0.11 C, p < 0.001) was identified. The difference between sides was not significant (?0.07 C, p = 0.7). None of the interactions between side, session and observer were significant. Smoking, exercise habits and oral contraceptive intake were not significant impact factors when included as covariates in the analysis (p > 0.1). ROI temperature was significantly higher in males than in females (0.7 C, p < 0.001). A mixed model analysis of variance showed that observer had little impact on the expected standard deviation, whereas session and subject had a greater impact. Conclusions Face temperature is symmetrical and varies over time. The non-significant difference between sides is highly reproducible, even between observers. PMID:22554986

  6. 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.

  7. Behavior of Arcobacter butzleri and Arcobacter cryaerophilus in ultrahigh-temperature, pasteurized, and raw cow's milk under different temperature conditions.

    PubMed

    Giacometti, Federica; Serraino, Andrea; Pasquali, Frederique; De Cesare, Alessandra; Bonerba, Elisabetta; Rosmini, Roberto

    2014-01-01

    The growth and survival of Arcobacter butzleri and Arcobacter cryaerophilus in milk were investigated at different storage temperatures. Three strains of each Arcobacter species were inoculated into ultrahigh-temperature (UHT), pasteurized, and raw cow's milk and stored at 4, 10, and 20C for 6 days. The survival of Arcobacter spp. during storage was evaluated by a culture method. Results clearly showed that A. butzleri and A. cryaerophilus remained viable in milk when stored at 4C and 10C for a period of 6 days. When UHT and pasteurized milk were stored at 20C, the A. butzleri count increased, with a longer lag-phase in pasteurized milk, whereas the A. cryaerophilus count increased in the first 48?h and then rapidly decreased to below the detection limit on the sixth storage day. When raw milk was stored at 20C, the A. butzleri and A. cryaerophilus counts decreased from the first day of storage and no viable bacteria were recovered on the last day of storage. Generally, A. butzleri displayed a significantly better growth and survival capacity than A. cryaerophilus in milk. The present study is the first to assess the survival and/or growth of A. butzleri and A. cryaerophilus in milk. The evidence suggests that in case of primary contamination of milk or secondary contamination due to postprocessing contamination, milk can act as a potential source of Arcobacter infection in humans and could have public health implications, especially for raw milk consumption. PMID:24066903

  8. Void structure in silica glass with different fictive temperatures observed with positron annihilation lifetime spectroscopy

    NASA Astrophysics Data System (ADS)

    Ono, Madoka; Hara, Kenta; Fujinami, Masanori; Ito, Setsuro

    2012-10-01

    We examine voids in silica glasses with different fictive temperatures using positron annihilation lifetime spectroscopy. The pick-off annihilation lifetime of ortho-positronium increases with the fictive temperature, Tf, indicating that the void size increases. High Tf leads to high density and low degree of network polymerization so that increasing void size means that the density fluctuation of the silica glass increases with high Tf. Assuming that such density fluctuation causes light scattering, the previously reported Tf dependence of the Rayleigh scattering coefficient can be well explained by the change in void size.

  9. Consideration of dielectric relaxation of pure DMSO liquid in different temperatures

    NASA Astrophysics Data System (ADS)

    Wang, Feng; Jia, Guozhu

    2014-10-01

    This paper mainly analyzes the relaxation process of both CC model and Davidson-Cole (DC) model, depicting the process by relaxation time, broadening parameter and temperature dependent Kirkwood correlation factor. The Kirkwood correlation factor of CC model in adjustable infinite dielectric constant is more changeable with temperature than DC model. The Kirkwood factor with different conditions needs reinterpretation. CC model generally depicts molecular cooperative interactions with single channel and evaluates once relaxation act of DMSO cluster within a cutoff time. DC model couples multi-channels, including various relaxation modes such as monomeric, dimeric and cluster. So the relaxation time of DC model is higher than CC model.

  10. 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

  11. 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

  12. 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...

  13. Finite-differences model to predict temperatures on cryogenic focal plane arrays: first laboratory results

    NASA Astrophysics Data System (ADS)

    Guzmn, Dani; Bilbeny, Rodrigo; Szentgyorgyi, Andrew; Norton, Timothy J.

    2014-07-01

    The latest CCD science detectors have reached a size of 100 mm on its side. For delicate experiments, one needs to minimize or eliminate uncalibratable errors introduced by the instrument. This is especially critical in the case of any mechanical or electronic variations in large detectors caused by an unanticipated thermal behavior of the device, when operated at cryogenic temperatures. G-CLEF (GMT-Consortium Large Earth Finder) is an optical band echelle spectrograph that has been selected as the first light instrument for the Giant Magellan Telescope (GMT). As part of the Preliminary Design, we have developed a Finite Difference Model (FDM) that can predict the temperature profile of the CCD mounting plate. We present the model and the results we have obtained. This model is an important design tool for the optimization of the position for cold straps and heaters, when requirements such as temperature equalization or stability are considered.

  14. Temperature dependence of in vitro Rubisco kinetics in species of Flaveria with different photosynthetic mechanisms.

    PubMed

    Perdomo, Juan Alejandro; Cavanagh, Amanda P; Kubien, David S; Galms, Jeroni

    2015-04-01

    There is general consensus in the literature that plants with different photosynthetic mechanisms (i.e. C3 vs. C4) have Rubiscos characterised by different kinetic performances. However, potential differences in the temperature dependencies of Rubisco kinetic parameters between C3 and C4 plants are uncertain. Accordingly, six species of Flaveria with contrasting photosynthetic mechanisms (C3, C3/C4 and C4) were selected and their Rubisco Michaelis-Menten constants for CO2 and RuBP (K c and K RuBP), carboxylase catalytic turnover rate ([Formula: see text]) and CO2/O2 specificity factor (S c/o) were measured between 10 and 40C. The results confirmed different Rubisco characteristicsbetween C3 and C4 plants. Rubisco from the C3 species had higher E a for K c and [Formula: see text] than that from C4 species, which were translated into differences in the temperature response of the carboxylase catalytic efficiency ([Formula: see text]/K c). However, E a did not differ for S c/o or K RuBP. Although a mechanism remains uncertain, it appears that the Asp/Glu-149-Ala and Met-309-Ile substitutions lead to differences in the temperature responses of catalysis between C3 and C4 Rubiscos in Flaveria. Therefore, the above observations are consistent with the fact that C3 species have a higher photosynthetic efficiency and ecological dominance in cool environments, with respect to C4 species in temperate environments. PMID:25663529

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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.

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

    PubMed Central

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

    2013-01-01

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

  1. Effect of different temperature and culture media on the growth of Macrophomina phaseolina.

    PubMed

    Csndes, I; Kadlicsk, S; Gborjnyi, R

    2007-01-01

    The charcoal root disease caused by Macrophomina phaseolina (Tassi) Goidanich may cause considerable damages in hot as well as in dry seasons. The effect of temperature and culture media were studied on the growing patterns of 35 M. phaseolina isolates, collected from different districts of Hungary. The isolates were grown at 10, 15, 20, 25, 30, 35 and 40 degrees C temperatures respectively, and additionally at 25 degrees C on potato-dextrose-, malt-extract-, Czapek-Dox-, Sabouraud-glucose-, maize-flour- and watery agar media, using 90 mm Petri-dishes, 4 repetitions in each case. For all the isolates the most favourable temperature regime was 25 to 35 degrees C and the most advantageous media was the malt-extract-, Sabouraud-glucose- and potato-dextrose-agar media. At these conditions (temperatures and culture media) mycelia growth and the diameter of microsclerotial colonies reached the 90 mm at the 5th day. Mycelia growth of the pathogen was very low at 10, 15 and 40 degrees C, and did not form microsclerotia. On watery agar microsclerotial colony seldom developed, it needed 14 days, and no continuous mycelia developed even in a 8th months culture. Diameter of microsclerotia measured on different culture media varied between 39-308 microm. PMID:18396819

  2. [IR spectral-analysis-based range estimation for an object with small temperature difference from background].

    PubMed

    Fu, Xiao-Ning; Wang, Jie; Yang, Lin

    2013-01-01

    It is a typical passive ranging technology that estimation of distance of an object is based on transmission characteristic of infrared radiation, it is also a hotspot in electro-optic countermeasures. Because of avoiding transmitting energy in the detection, this ranging technology will significantly enhance the penetration capability and infrared conceal capability of the missiles or unmanned aerial vehicles. With the current situation in existing passive ranging system, for overcoming the shortage in ranging an oncoming target object with small temperature difference from background, an improved distance estimation scheme was proposed. This article begins with introducing the concept of signal transfer function, makes clear the working curve of current algorithm, and points out that the estimated distance is not unique due to inherent nonlinearity of the working curve. A new distance calculation algorithm was obtained through nonlinear correction technique. It is a ranging formula by using sensing information at 3-5 and 8-12 microm combined with background temperature and field meteorological conditions. The authors' study has shown that the ranging error could be mainly kept around the level of 10% under the condition of the target and background apparent temperature difference equal to +/- 5 K, and the error in estimating background temperature is no more than +/- 15 K. PMID:23586223

  3. Skeletal oxygen and carbon isotope compositions of Acropora coral primary polyps experimentally cultured at different temperatures

    NASA Astrophysics Data System (ADS)

    Nishida, Kozue; Ishikawa, Kei; Iguchi, Akira; Tanaka, Yasuaki; Sato, Mizuho; Ishimura, Toyoho; Inoue, Mayuri; Nakamura, Takashi; Sakai, Kazuhiko; Suzuki, Atsushi

    2014-07-01

    investigated temperature and growth-rate dependency of skeletal oxygen and carbon isotopes in primary polyps of Acropora digitifera (Scleractinia: Acroporidae) by culturing them at 20, 23, 27, or 31C. Calcification was most rapid at 27 and 31C. We obtained a ?18O-temperature relationship (-0.18 C-1) consistent with reported ranges for Porites, indicating that juvenile Acropora polyps can be used for temperature reconstruction. A growth-rate dependency of skeletal isotopes was detected in the experimental polyps cultured at lower water temperatures, when the skeletal growth rate of these polyps was also low. The estimated upper calcification flux limit for a kinetic isotope effect to be observed in the ?18O-growth rate relationship (0.4-0.7 g CaCO3 cm-2 yr-1) was similar to the calcification flux in Porites corresponding to a linear extension rate of 5 mm yr-1, the maximum rate at which the kinetic isotope effect is evident. This result suggests that the calcification flux can be used as a measure of growth rate-related isotope fractionation, that is, the kinetic isotope effect, in corals of different genera and at different growth stages.

  4. Analyzing the impact of ambient temperature indicators on transformer life in different regions of Chinese mainland.

    PubMed

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

    2013-01-01

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

  5. Implant Damage Studies with Different Implant Temperature by Spot and Ribbon Beam

    NASA Astrophysics Data System (ADS)

    Chen, Hank; Jen, Causon Ko-Chuan; Lin, Tony; Matsunaga, Yasuhiko

    2011-01-01

    Wafer temperature during implant has a dominate effect on the amorphous layer thickness and post anneal residual defects which can result in difference in device performance and difficulties in tool matching between different implant systems, namely batch type vs. single wafer implanter and spot beam vs. ribbon beam system. Although the implant temperature set point can be well defined and controlled, the instantaneous temperature on wafer during implant is quite complicated interactions among beam shape, dose rate, duty cycle and cooling system to the behavior of defect generation and dynamic annealing. A batch system, iStar, and a single wafer system, iPulsar, which delivers both spot beam and ribbon beam with cold implant capability were used to study the effect of implant temperature to the post anneal residual defects by BF2 15 keV 31015 cm-2 implant after 850 C/30s anneal. Measurements from Rs, SIMS, plane view TEM are compared and analyzed. The results by ribbon beam and spot beam are also compared.

  6. 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).

  7. Fabrication and optical characterization of nanoporous alumina films annealed at different temperatures

    NASA Astrophysics Data System (ADS)

    Marsal, L. F.; Vojkuvka, L.; Formentin, P.; Pallars, J.; Ferr-Borrull, J.

    2009-04-01

    We report on the structural and optical properties of self-ordered nanoporous anodic alumina (NAA) films annealed at different temperatures. The morphology of NAA films is examined by scanning electron microscopy (SEM). The results show that the porous structure have hexagonally ordered arrays of nanopores with interpore distance in the range of 90-100 nm and pore size between 30 and 40 nm. The structural properties studied by X-ray diffraction (XRD) show out that the nanoporous alumina experiences a transition from the amorphous phase to gamma and alpha phase when annealed from 800 to 1200 C. The optical transmission spectra of the annealed NAA films with different thicknesses (9, 24 and 45 ?m) are measured in the wavelength range of 300-1000 nm. Numerical simulations based on an optical model of the films show a good agreement with the measurements. The refractive index ( n) and the extinction coefficient ( k) are determined for each annealed temperature.

  8. Nitrite Intoxication of Common Carp (Cyprinus carpio L.) at Different Water Temperatures

    Microsoft Academic Search

    H. Kroupov; J. Mchov; V. Pia?kov; M. Flajhans; Z. Svobodov; G. Poleszczuk

    2006-01-01

    Kroupov H., J. Mchov, V. Piakov, M. Flajhans, Z. Svobodov, G. Poleszczuk: Nitrite Intoxication of Common Carp (Cyprinus carpio L.) at Different Water Temperatures. Acta Vet Brno 2006, 75: 561-569. Common carp (Cyprinus carpio L.) were exposed to nitrite (1.45 mmoll -1 NO 2 - ) for 48 hours at 14 C and 20 C, in order to investigate the

  9. 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 800C was discussed in this paper. The ECC specimens are exposed to 100, 200, 400, 600, and 800C 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

  10. 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.

  11. 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

  12. 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(?(?)) and Im(?(?)) in the frequency region of interest.

  13. Absorption of crystalline water ice in the far infrared at different temperatures

    NASA Astrophysics Data System (ADS)

    Reinert, C.; Mutschke, H.; Krivov, A. V.; Lhne, T.; Mohr, P.

    2015-01-01

    The optical properties of ice in the far infrared are important for models of protoplanetary and debris disks. In this report, we derive a new set of data for the absorption (represented by the imaginary part of the refractive index ?) of crystalline water ice in this spectral range. The study includes a detailed inspection of the temperature dependence, which has not been conducted in such detail before. We measured the transmission of three ice layers with different thicknesses at temperatures ? = 10...250 K and present data at wavelengths ? = 80...625 ?m. We found a change in the spectral dependence of ? at a wavelength of 175 6 ?m. At shorter wavelengths, ? exhibits a constant flat slope and no significant temperature dependence. Long-ward of that wavelength, the slope gets steeper and has a clear, approximately linear temperature dependence. This change in behaviour is probably caused by a characteristic absorption band of water ice. The measured data were fitted by a power-law model that analytically describes the absorption behaviour at an arbitrary temperature. This model can readily be applied to any object of interest, for instance a protoplanetary or debris disk. To illustrate how the model works, we simulated the spectral energy distribution (SED) of the resolved, large debris disk around the nearby solar-type star HD 207129. Replacing our ice model by another, commonly used data set for water ice results in a different SED slope at longer wavelengths. This leads to changes in the characteristic model parameters of the disk, such as the inferred particle size distribution, and affects the interpretation of the underlying collisional physics of the disk.

  14. 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 ? ? ? phase transition range, the impact safety of PBX-2 becomes significantly worse.

  15. Optical temperature switch based on microstructured fibre filled with different chemical mixtures

    NASA Astrophysics Data System (ADS)

    Marc, P.; Piliszek, P.; Murawski, M.; Szymanski, M.; Nasilowski, T.; Jaroszewicz, L. R.

    2012-04-01

    Size, shape and location of the air holes allow to tailor microstructured fibre (MSF) parameters in a very wide range way beyond classical fibres what opens up many possibilities for various applications. Additionally, the propagation parameters of MSF can be actively tuned when the air-holes are filled with different gases, liquids (e.g., liquid crystals) or solid materials (e.g., polymers). The mode confinement in such a filled MSF can be affected by temperature dependent refractive index of material filling the fibre. This idea puts forward a new type of components for creating novel fibre devices such as switches, attenuators and others. Variable optical attenuators (VOAs) play an important role in optical communications as equalizers for dynamic channel power and wavelength division multiplexing in a transmission system. Controlling and monitoring of optical power are also necessary in sensing applications, and especially, in optical systems which require high power laser operation or critical temperature threshold monitoring. Various types of VOA have been developed based on different mechanisms, such as bending loss control, light leaking from the fibre cladding, temperature tuning of the polymer incorporated into the tapered microstructured fibre or electrical tuning of the liquid crystal layers. In this paper we would like to discuss the highly dynamic VOA based on a tuneable microstructured fibre filled with different chemical mixtures used as an on/off temperature switch. Furthermore, the technology of low loss coupling and splicing of the applied MSF with a standard single mode fibre has been developed. Therefore, in the proposed application an optical signal can be transmitted to and from the switch by a standard telecom fibre which considerably reduces transmission losses and allows for the use of standard off-the-shelf components reducing costs of the overall system.

  16. [Changes in temperature and humidity at different layers inside clothing during rest, exercise, and recovery].

    PubMed

    Shimizu, H; Hino, S; Shinkai, S; Tomita, N; Hirose, M; Torii, J; Watanabe, S; Watanabe, S; Watanabe, T; Shimizu, Y

    1989-02-01

    This paper presents the results of experiments in which we measured humidity and temperature changes that took place in different layers inside and on clothing. The experiments were conducted during rest, exercise, and recovery. During each experiment, subjects wore one of three kinds of outerwear made of three different materials, respectively. These materials were nylon taffeta (N), nylon taffeta-Goretex-nylon tricot laminated fabric (G), and polyvinylchloride-coated plain cotton fabric (V). The subjects wore an undershirt and a T-shirt under the outerwear. The humidity and the temperature were measured in the following parts of each subjects' back: (1) the layer between the subject's skin and the undershirt (first layer), (2) the layer between the undershirt and the T-shirt (second layer), (3) the layer between the T-shirt and the outerwear (third layer), and (4) the surface of the outerwear (fourth layer). We also measured the sensation of comfort, the skin temperature, the oral temperature and the degree of sweating of the subjects. The experiments were conducted in a climatic chamber under conditions of 20.7 +/- 0.4 degrees C, 61.2 +/- 3.6% RH and 2.5 +/- 0.5 cm/sec. The results we obtained were as follows: 1) While the subjects kept still, little change of humidity was observed with time in all the four layers. When the subjects were in motion, humidity increased as they started sweating. After the exercise ended, the humidity reached its maximum and then gradually decreased. 2) When subjects kept still, there was no difference in humidity in all the four layers of the outerwear.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2746981

  17. 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.

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

    PubMed

    Krger, 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

  19. Differences between true mean daily, monthly and annual air temperatures and air temperatures calculated with three equations: a case study from three Croatian stations

    NASA Astrophysics Data System (ADS)

    Bonacci, Ognjen; eljkovi?, Ivana; Trogrli?, Robert aki?; Milkovi?, Janja

    2013-10-01

    Differences between true mean daily, monthly and annual air temperatures T0 [Eq. (1)] and temperatures calculated with three different equations [(2), (3) and (4)] (commonly used in climatological practice) were investigated at three main meteorological Croatian stations from 1 January 1999 to 31 December 2011. The stations are situated in the following three climatically distinct areas: (1) Zagreb-Gri? (mild continental climate), (2) Zavian (cold mountain climate), and (3) Dubrovnik (hot Mediterranean climate). T1 [Eq. (2)] and T3 [Eq. (4)] mean temperatures are defined by the algorithms based on the weighted means of temperatures measured at irregularly spaced, yet fixed hours. T2 [Eq. (3)] is the mean temperature defined as the average of daily maximum and minimum temperature. The equation as well as the time of observations used introduces a bias into mean temperatures. The largest differences occur for mean daily temperatures. The calculated daily difference value from all three equations and all analysed stations varies from -3.73 C to +3.56 C, from -1.39 C to +0.79 C for monthly differences and from -0.76 C to +0.30 C for annual differences.

  20. Validation of the SenseWear Armband in different ambient temperatures.

    PubMed

    Van Hoye, Karen; Boen, Filip; Lefevre, Johan

    2015-05-01

    This study examines the validity of the SenseWear Armband in different temperatures using the old (SenseWear v2.2) and newest version of the algorithm (SenseWear v5.2) against indirect calorimetry (IC). Thirty-nine male and female students (21.11.41years) completed an exercise trial in 19C, 26C and 33C consisting of 5min standing followed by alternating walking/running at 35% and 65% of their maximal oxygen uptake. The accuracy of the algorithms was evaluated by comparing estimated energy expenditure (EE) to IC using a mixed-model design. No difference was reported in EE between the different temperatures for IC. Both algorithms estimated EE significantly higher when exercising at high intensity in 33C compared to 19C. Compared to IC, SenseWear v2.2 accurately estimated EE during standing and light intensity exercise but underestimated EE when exercising in a hot environment and at high intensity. SenseWear v5.2 showed a difference when exercising at high intensity in thermoneutral and warm conditions. The new algorithm improved EE estimation in hot environments and at high intensity compared to the old version. However, given the inherent inaccuracy of the EE estimates of SenseWear, greater weight should be given to direct monitor outputs rather than the ability of a monitor to estimate EE precisely. PMID:25537112

  1. 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.

  2. a Molecular Dynamics Study of Oxygen Gas in Water at Different Temperatures

    NASA Astrophysics Data System (ADS)

    Thapa, S. K.; Adhikari, N. P.

    2013-03-01

    Molecular dynamics simulations of a binary mixture of oxygen gas and SPC/E water, with oxygen gas (O2) as solute and water as solvent, at oxygen mole fraction of 0.019 have been accomplished at different temperatures 288, 293, 298, 302 and 306 K using Groningen Machine for Chemical Simulations. The solvent-solvent, solute-solute and solute-solvent radial distribution functions (RDFs) have been estimated. The solvent-solvent (water-water) RDF has been found to agree with that obtained from NMR/X-ray data within 7%. Self-diffusion coefficients of both the solvent and the solute have been determined by means of mean-squared displacement curves using Einstein's relation. They are found to agree with experimental results very well. Darken's relation has also been invoked for the determination of mutual diffusion coefficients at the respective temperatures. The analysis of temperature dependence of the diffusion coefficients has revealed that they follow Arrhenius equation to a very good extent and are consistent with the nature of RDF's at the respective temperatures. The estimated activation energies are in excellent agreement with the available experimental data.

  3. Performance of dye-sensitized solar cell fabricated using titania nanoparticles calcined at different temperatures

    NASA Astrophysics Data System (ADS)

    Kaur, Manveen; Verma, N. K.

    2013-08-01

    Synthesis of titania (TiO2) nanoparticles by sol-gel method and their calcination at different temperatures, viz 450 C, 550 C and 650 C (defined as T450, T550 and T650) has been done. Structural analysis indicates that the T450 sample possesses anatase phase. The phase transformation to rutile starts occurring at T550, and, on increasing the calcination temperature, the crystallization and percentage of rutile phase increases. As the temperature increases from 450 to 650 C, the crystallite size increases by about a factor of two from 11.5 to 20.2 nm. From SEM micrographs, T550 electrode has been found to have appropriate aggregation, which led to enhanced dye desorption, as compared to T450 and T650 based electrodes. TEM images of the synthesized nanoparticles reveal that the particle size increases from 7 to 28 nm on increasing the calcination temperature from 450 to 650 C. From the photoluminescence and Fourier transform infrared studies, it has been concluded that the surface OH- groups are reduced on calcination, which affects the electron injection efficiency. The dye sensitized solar cell, fabricated using T550 sample, having a ratio of anatase/rutile 89:11, has been found to achieve the highest conversion efficiency.

  4. Stability of vitamin C in fresh and freeze-dried capsicum stored at different temperatures.

    PubMed

    Rahman, Mohammad Shafiur; Al-Rizeiqi, Mohamed Hamed; Guizani, Nejib; Al-Ruzaiqi, Mohammed Salom; Al-Aamri, Abeer Hamed; Zainab, Sumaiya

    2015-03-01

    The objective of this study was to determine vitamin C stability in fresh and freeze-dried capsicum during storage at different temperatures. Fresh capsicum stored at 20C showed an initial decrease in vitamin C with a minimum peak after 2days and then increased to a maximum peak after 13days followed by a gradual decay. In general a gradual decrease of vitamin C was observed in the cases of fresh (i.e. stored at 5, -20, -40C) and freeze-dried capsicum stored at all temperatures (i.e. 60 to -40C). The degradation kinetics of vitamin C was modeled by zero and first order reaction and rate constants were estimated. The rate constant increased with the increase in storage temperature, while it was decreased with the decrease of moisture content. At storage temperature 5C, first order rate constants were observed as 7.1??10(-2), 7.7??10(-2), and 4.3??10(-3) day(-1) in the cases of samples containing moisture contents 94, 15 and 5g/100g sample, respectively. PMID:25745242

  5. An ex vivo comparison of three different gutta-percha cones when compacted at different temperatures: rheological considerations in relation to the filling of lateral canals

    Microsoft Academic Search

    M. Venturi; R. Di Lenarda; L. Breschi

    2006-01-01

    Venturi M, Di Lenarda R, Breschi L. An ex vivo comparison of three different gutta-percha cones when compacted at different temperatures: rheological considerations in relation to the filling of lateral canals. International Endodontic Journal, 39, 648-656, 2006. Aim To compare ex vivo the penetration of three brands of gutta-percha cones, compacted under a constant force and heated to different temperatures,

  6. Kinetic differences at low temperatures between R and T state carbon monoxide-carp hemoglobin.

    PubMed Central

    Cobau, W G; LeGrange, J D; Austin, R H

    1985-01-01

    We use the low-temperature recombination kinetics of carbon monoxide with carp hemoglobin to determine that the R and T states of hemoglobin exhibit different low-temperature geminate recombination kinetics. The peak of the fitted Gaussian activation energy spectrum is at 1.5 kcal/mol for R state and 1.8 kcal/mol for T state. The distribution in activation energies is fit well by the Agmon-Hopfield linear strain model. The T state is fit with a stronger elastic constant than R, and has a larger displacement of the protein conformation coordinate than does the R state, indicating that the T state does have a significantly greater rigidity and also stores more strain energy in its conformational states than does R hemoglobin. The pre-exponential in the activation energy spectrum is only a factor of two greater in the R than the T state and the low-temperature activation energy spectrum does not correctly predict the difference in the on rates for R and T states at 300 degrees K, indicating that processes removed from the binding site are important in cooperativity. PMID:4016198

  7. The Response of Campylobacter jejuni to Low Temperature Differs from That of Escherichia coli?

    PubMed Central

    Hughes, Rebecca-Ayme; Hallett, Kathy; Cogan, Tristan; Enser, Mike; Humphrey, Tom

    2009-01-01

    Human infection with Campylobacter jejuni is often associated with the consumption of foods that have been exposed to both chilling and high temperatures. Despite the public health importance of this pathogen, little is known about the effects of cold exposure on its ability to survive a subsequent heat challenge. This work examined the effect of rapid exposure to chilling, as would occur in poultry processing, on the heat resistance at 56C of two C. jejuni strains, 11168 and 2097e48, and of Escherichia coli K-12. Unlike E. coli K-12, whose cold-exposed cells showed increased sensitivity to 56C, such exposure had only a marginal effect on subsequent heat resistance in C. jejuni. This may be explained by the finding that during rapid chilling, unlike E. coli cells, C. jejuni cells are unable to alter their fatty acid composition and do not adapt to cold exposure. However, their unaltered fatty acid composition is more suited to survival when cells are exposed to high temperatures. This hypothesis is supported by the fact that in C. jejuni, the ratio of unsaturated to saturated fatty acids was not significantly different after cold exposure, but it was in E. coli. The low-temperature response of C. jejuni is very different from that of other food-borne pathogens, and this may contribute to its tolerance to further heat stresses. PMID:19648365

  8. 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.

  9. Formation of brominated pollutants during the pyrolysis and combustion of tetrabromobisphenol A at different temperatures.

    PubMed

    Ortuo, Nuria; Molt, Julia; Conesa, Juan A; Font, Rafael

    2014-08-01

    Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant worldwide. A detailed examination of the degradation products emitted during thermal decomposition of TBBPA is presented in the study. Runs were performed in a laboratory furnace at different temperatures (650 and 800C) and in different atmospheres (nitrogen and air). More than one hundred semivolatile compounds have been identified by GC/MS, with special interest in brominated ones. Presence of HBr and brominated light hydrocarbons increased with temperature and in the presence of oxygen. Maximum formation of PAHs is observed at pyrolytic condition at the higher temperature. High levels of 2,4-, 2,6- and 2,4,6- bromophenols were found. The levels of polybrominated dibenzo-p-dioxins and furans have been detected in the ppm range. The most abundant isomers are 2,4,6,8-TeBDF in pyrolysis and 1,2,3,7,8-PeBDF in combustion. These results should be considered in the assessment of thermal treatment of materials containing brominated flame retardants. PMID:24792882

  10. Energy flow between two hydrodynamically coupled particles kept at different effective temperatures

    NASA Astrophysics Data System (ADS)

    Brut, A.; Petrosyan, A.; Ciliberto, S.

    2014-09-01

    We measure the energy exchanged between two hydrodynamically coupled micron-sized Brownian particles trapped in water by two optical tweezers. The system is driven out of equilibrium by random-forcing the position of one of the two particles. The forced particle behaves as it has an effective temperature higher than that of the other bead. This driving modifies the equilibrium variances and cross-correlation functions of the bead positions: we measure an energy flow between the particles and an instantaneous cross-correlation, proportional to the effective temperature difference between the two particles. A model of the interaction which is based on classical hydrodynamic coupling tensors is proposed. The theoretical and experimental results are in excellent agreement.

  11. Inversion methods in temperature and aerosol remote sounding: Their commonality and differences, and some unexplored approaches

    NASA Technical Reports Server (NTRS)

    Fymat, A. L.

    1977-01-01

    The two remote sensing problems of temperature profiling and aerosol characterization (complex refractive index, size distribution) are considered. These problems differ only in the explicit form of the source function which, for aerosols, includes contributions from both single and multiple scattering processes. When the observables are the spectral extinction or the single scattering of the source radiation, the associated problem is completely analogous to the linearized temperature inversion problem. Methods for obtaining the solution of the linear problem are classified following three main categories: (1) derivation of properties that all solutions satisfy, which must then be properties of the actual solution; (2) regularization of the ill-posed problem; and (3) data changes within their domain of uncertainty in order to avoid the basic instability. A number of unexplored methods are indicated.

  12. Cell chip temperature measurements in different operation regimes of HCPV modules

    NASA Astrophysics Data System (ADS)

    Rumyantsev, V. D.; Chekalin, A. V.; Davidyuk, N. Yu.; Malevskiy, D. A.; Pokrovskiy, P. V.; Sadchikov, N. A.; Pan'chak, A. N.

    2013-09-01

    A new method has been developed for accurate measurements of the solar cell temperature in maximum power point (MPP) operation regime in comparison with that in open circuit (OC) regime (TMPP and TOC). For this, an electronic circuit has been elaborated for fast variation of the cell load conditions and for voltage measurements, so that VOC values could serve as an indicator of TMPP at the first moment after the load disconnection. The method was verified in indoor investigations of the single-junction AlGaAs/GaAs cells under CW laser irradiation, where different modifications of the heat spreaders were involved. PV modules of the "SMALFOC" design (Small-size concentrators; Multijunction cells; "All-glass" structure; Lamination technology; Fresnel Optics for Concentration) with triple-junction InGaP/GaAs/Ge cells were examined outdoors to evaluate temperature regimes of their operation.

  13. Effects of helium and deuterium irradiation on SPS sintered W-Ta composites at different temperatures

    NASA Astrophysics Data System (ADS)

    Mateus, R.; Dias, M.; Lopes, J.; Rocha, J.; Catarino, N.; Franco, N.; Livramento, V.; Carvalho, P. A.; Correia, J. B.; Hanada, K.; Alves, E.

    2013-11-01

    Energetic He+ and D+ ions were implanted into different W-Ta composites in order to investigate their stability under helium and deuterium irradiation. The results were compared with morphological and chemical modifications arising from exposure of pure W and Ta. Special attention was given to tantalum hydride (Ta2H) formation due to its implications for tritium inventory. Three W-Ta composites with 10 and 20 at.% Ta were prepared from elemental W powder and Ta fibre or powder through low-energy ball milling in argon atmosphere. Spark plasma sintering (SPS) was used as the consolidation process in the temperature range from 1473 to 1873 K. The results obtained from pure elemental samples and composites are similar. However, Ta2H is easily formed in pure Ta by using a pre-implantation stage of He+, whereas in W-Ta composites the same reaction is clearly reduced, and it can be inhibited by controlling the sintering temperature.

  14. 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.

  15. Energy flow between two hydrodynamically coupled particles kept at different effective temperatures

    E-print Network

    Antoine Brut; Artyom Petrosyan; Sergio Ciliberto

    2015-02-06

    We measure the energy exchanged between two hydrodynamically coupled micron-sized Brownian particles trapped in water by two optical tweezers. The system is driven out of equilibrium by random forcing the position of one of the two particles. The forced particle behaves as it has an "effective temperature" higher than that of the other bead. This driving modifies the equilibrium variances and cross-correlation functions of the bead positions: we measure an energy flow between the particles and an instantaneous cross-correlation, proportional to the effective temperature difference between the two particles. A model of the interaction which is based on classical hydrodynamic coupling tensors is proposed. The theoretical and experimental results are in excellent agreement.

  16. Present Estimates of the Differences Between Thermodynamic Temperatures and the ITS-90

    NASA Astrophysics Data System (ADS)

    Fischer, J.; de Podesta, M.; Hill, K. D.; Moldover, M.; Pitre, L.; Rusby, R.; Steur, P.; Tamura, O.; White, R.; Wolber, L.

    2011-01-01

    At the request of the Consultative Committee for Thermometry (CCT), Working Group 4 (WG4) has critically reviewed all available measurements of the differences between thermodynamic and ITS-90 temperatures, ( T - T 90), and documented the conversion of older data to the ITS-90. Particular attention has been given to the uncertainties. Based on this review, we provide consensus estimates of T - T 90 for selected measurements from 0.65 K to 1358 K. We provide two analytic functions for T - T 90, one for use from 8 K to the triple point of water ( T TPW) and one for use above T TPW. The small discontinuity of the derivative d T 90/ d T at T TPW is discussed. We also identify temperature ranges where researchers are encouraged to undertake high-accuracy measurements of T - T 90.

  17. 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.

  18. Combined effects of the herbicide terbuthylazine and temperature on different flagellates from the Northern Adriatic Sea.

    PubMed

    Fiori, Emanuela; Mazzotti, Matilde; Guerrini, Franca; Pistocchi, Rossella

    2013-03-15

    The triazinic herbicide terbuthylazine (TBA) is becoming an emergent contaminant in Italian rivers and in coastal and groundwater. A preliminary analysis of the sensitivity of marine flagellates to TBA was performed by monitoring the photosynthetic efficiency of nine species (belonging to the Dinophyceae or Raphidophyceae class) isolated from the Adriatic Sea. Different sensitivity levels for each flagellate were observed and the most sensitive microalgae, based on PSII inhibition, were: Gonyaulax spinifera>Fibrocapsa japonica>Lingulodinium polyedrum while the most resistant were two species belonging to the Prorocentrum genus. Then the response of two microalgae to drivers, such as temperature and terbuthylazine, applied in combination was also investigated. Two potentially toxic flagellates, Prorocentrum minimum and G. spinifera, were exposed, under different temperature conditions (15, 20 and 25C), to TBA concentrations that did not completely affect PSII. For both flagellates, effects of TBA on algal growth, measured through cell density and carbon analysis, as well as on the photosynthetic activity are reported. All parameters analyzed showed a negative effect of TBA from the exponential phase. TBA effect on algal growth was significantly enhanced at the optimal temperature conditions (20 and 25C), while no difference between control and herbicide treatments were detected for G. spinifera grown at 15C, which represented a stress condition for this species. The maximum inhibition of photosynthetic efficiency was found at 20C for both organisms. Both flagellates increased cell carbon and nitrogen content in herbicide treatments compared to the control, except G. spinifera grown at 15C. Chlorophyll-a production was increased only in G. spinifera exposed to 5 ?g L(-1) of TBA and the effect was enhanced with the increase of temperature. Herbicide-induced variations in cellular components determined changes in cellular carbon:nitrogen (C:N) and chlorophyll:carbon (Chl:C) ratios. The C:N ratio decreased in both species, while only G. spinifera showed an increase in the Chl:C ratio at all temperature conditions. In response to TBA exposure G. spinifera increased extracellular polysaccharides release at 20 and 25C, while no difference was reported for P. minimum. Changes in nutrient uptake rates were also observed for P. minimum. Nitrate and phosphate uptake significantly increased in the presence of TBA and this response was enhanced at 25C, while nitrate uptake increased in G. spinifera only when grown at 25C. As for growth rates, the observed changes in intracellular component contents increased at optimal temperature conditions. In this work it is shown that temperature conditions can have an important role on the effect of terbuthylazine on algal growth and on the physiological responses of different species. Furthermore, the algal resistance and recovery can be dependent on nutrient availability. PMID:23280488

  19. Differences in SOM Decomposition and Temperature Sensitivity among Soil Aggregate Size Classes in a Temperate Grasslands

    PubMed Central

    Wang, Qing; Wang, Dan; Wen, Xuefa; Yu, Guirui; He, Nianpeng; Wang, Rongfu

    2015-01-01

    The principle of enzyme kinetics suggests that the temperature sensitivity (Q10) of soil organic matter (SOM) decomposition is inversely related to organic carbon (C) quality, i.e., the C quality-temperature (CQT) hypothesis. We tested this hypothesis by performing laboratory incubation experiments with bulk soil, macroaggregates (MA, 2502000 ?m), microaggregates (MI, 53250 ?m), and mineral fractions (MF, <53 ?m) collected from an Inner Mongolian temperate grassland. The results showed that temperature and aggregate size significantly affected on SOM decomposition, with notable interactive effects (P<0.0001). For 2 weeks, the decomposition rates of bulk soil and soil aggregates increased with increasing incubation temperature in the following order: MA>MF>bulk soil >MI(P <0.05). The Q10 values were highest for MA, followed (in decreasing order) by bulk soil, MF, and MI. Similarly, the activation energies (Ea) for MA, bulk soil, MF, and MI were 48.47, 33.26, 27.01, and 23.18 KJ mol?1, respectively. The observed significant negative correlations between Q10 and C quality index in bulk soil and soil aggregates (P<0.05) suggested that the CQT hypothesis is applicable to soil aggregates. Cumulative C emission differed significantly among aggregate size classes (P <0.0001), with the largest values occurring in MA (1101 ?g g?1), followed by MF (976 ?g g?1) and MI (879 ?g g?1). These findings suggest that feedback from SOM decomposition in response to changing temperature is closely associated withsoil aggregation and highlights the complex responses of ecosystem C budgets to future warming scenarios. PMID:25692291

  20. Differences in SOM Decomposition and Temperature Sensitivity among Soil Aggregate Size Classes in a Temperate Grasslands.

    PubMed

    Wang, Qing; Wang, Dan; Wen, Xuefa; Yu, Guirui; He, Nianpeng; Wang, Rongfu

    2015-01-01

    The principle of enzyme kinetics suggests that the temperature sensitivity (Q10) of soil organic matter (SOM) decomposition is inversely related to organic carbon (C) quality, i.e., the C quality-temperature (CQT) hypothesis. We tested this hypothesis by performing laboratory incubation experiments with bulk soil, macroaggregates (MA, 250-2000 ?m), microaggregates (MI, 53-250 ?m), and mineral fractions (MF, <53 ?m) collected from an Inner Mongolian temperate grassland. The results showed that temperature and aggregate size significantly affected on SOM decomposition, with notable interactive effects (P<0.0001). For 2 weeks, the decomposition rates of bulk soil and soil aggregates increased with increasing incubation temperature in the following order: MA>MF>bulk soil >MI(P <0.05). The Q10 values were highest for MA, followed (in decreasing order) by bulk soil, MF, and MI. Similarly, the activation energies (Ea) for MA, bulk soil, MF, and MI were 48.47, 33.26, 27.01, and 23.18 KJ mol-1, respectively. The observed significant negative correlations between Q10 and C quality index in bulk soil and soil aggregates (P<0.05) suggested that the CQT hypothesis is applicable to soil aggregates. Cumulative C emission differed significantly among aggregate size classes (P <0.0001), with the largest values occurring in MA (1101 ?g g-1), followed by MF (976 ?g g-1) and MI (879 ?g g-1). These findings suggest that feedback from SOM decomposition in response to changing temperature is closely associated withsoil aggregation and highlights the complex responses of ecosystem C budgets to future warming scenarios. PMID:25692291

  1. Life table of Tamarixia radiata (Hymenoptera: Eulophidae) on Diaphorina citri (Hemiptera: Psyllidae) at different temperatures.

    PubMed

    Gmez-Torres, Mariuxi Lorena; Nava, Dori Edson; Parra, Jos Roberto Postali

    2012-04-01

    Tamarixia radiata (Waterston, 1922) is the main parasitoid of Diaphorina citri (Kuwayama, 1907), and has been used in classical biological control programs in several countries. The current study investigated the biology and determined the fertility life table of T. radiata in different temperatures, to obtain information to support the establishment of a biological control program for D. citri in Brazil. Fifth-instar nymphs of D. citri were offered to females of T. radiata for parasitism, for 24 h. Then, the parasitoid was removed and the nymphs were placed in incubators at 15, 20, 25, 30, or 35 +/- 1 degrees C, 70 +/- 10% RH, and a 14-h photophase. The percentages of parasitism and emergence, the sex ratio, and the preimaginal period of T. radiata were determined. The fertility life table was developed from the biological data. The highest parasitism rate (77.24%) was obtained at a temperature of 26.3 degrees C, and the lowest parasitism rates occurred at 15 and 35 degrees C (23.1 and 40.2%, respectively). The highest percentages of emergence of the parasitoid occurred at 25, 30, and 35 degrees C (86.7, 88.3, and 78.8%, respectively), with the calculated peak at 30.8 degrees C (89.90%). The duration of the preimaginal developmental period for both females and males of T. radiata was inversely proportional to temperature in the thermal range of 15-35 degrees C. The development of T. radiata occurred at all temperatures studied, and the highest viability of the preimaginal period occurred at 25 degrees C. The highest values of net reproductive rate and finite growth ratio (lambda) were observed at 25 degrees C, so that in each generation the population of T. radiata increased 126.79 times, higher than the values obtained at the other temperatures. PMID:22606801

  2. Rheological behaviour of enzyme clarified sapota (Achras sapota L) juice at different concentration and temperatures.

    PubMed

    Deshmukh, Pranjal S; Manjunatha, S S; Raju, P S

    2015-04-01

    Rheological behaviour of enzyme clarified sapota (Achras sapota L.) juice at different temperatures (10 to 85C) and total soluble solid content (10.2 to 55.6 brix) corresponding to a water activity (aw) (0.986 to 0.865) was studied using controlled stress rheometer by coaxial cylinders attachment. The rheological parameter shear stress (Pa) was measured upto a shear rate of 1,000s(-1). The investigation showed that the enzyme clarified sapota juice and its concentrates behaved like a Newtonian liquid and the viscosity (?) values were in the range 4.340 to 56.418mPas depending upon temperature and concentration studied. The temperature dependency of viscosity of enzyme clarified sapota juice was described by Arrhenius equation (r?>?0.94) and activation energy (Ea) for viscous flow was in the range 5.218 to 25.439 KJ/mol depending upon concentration. The effect of total soluble solid content on flow activation energy was described by exponential relationship (r?>?0.95, rmse% <13.5, p??0.99, rmse% <5.80, p??0.99, rmse%?temperature used. The effect of water activity on viscosity of enzyme clarified sapota juice followed power law equation (r?>?0.98, rmse%?temperature and total soluble solid content/water activity on viscosity of enzyme clarified sapota was established. PMID:25829571

  3. Magnetic piston model for higher ion charge and different electron and ion plasma temperatures

    SciTech Connect

    Bogatu, I. N. [FAR-TECH, Inc., 10350 Science Center Drive, Bldg.14, Suite 150, San Diego, California 92121 (United States)] [FAR-TECH, Inc., 10350 Science Center Drive, Bldg.14, Suite 150, San Diego, California 92121 (United States)

    2013-05-15

    A new formula for the magnetic piston model, which explicitly describes how the momentum imparted to the ions by the magnetic pressure depends not only on the ion mass but also on the ion charge, as well as, on the plasma electron and ion temperatures, is derived following Rosenbluth's classical particle-field self-consistent plane approximation analytic calculation. The formula presented in this paper has implications in explaining the experimentally observed separation of the ions of different species and charges by the magnetic field penetrating the plasma and specularly reflecting them.

  4. Investigation of mass transfer between two parallel walls at different temperatures by a moment method

    NASA Technical Reports Server (NTRS)

    Sloat, T. N.; Edwards, R. H.; Collins, R. L.

    1971-01-01

    One-dimensional flow between two fixed parallel walls composed of the same substance but at different temperatures and spaced a distance 1 apart is considered. The hot plate is the evaporating surface (source) and the cold plate is the condensing surface (sink). The vapor between the two plates is assumed to be a monatomic gas consisting of Maxwell molecules. Lee's moment method is used to obtain a set of six nonlinear equations. Both the nonlinear equations and a linearized approximation to them are solved.

  5. Temperature dependence of the dynamics of methylene chains in aliphatic nylons of different chain length

    NASA Astrophysics Data System (ADS)

    Frick, B.; Franco, L.; Subirana, J.; Xenopoulos, A.

    2000-03-01

    Temperature-dependent inelastic neutron backscattering experiments with ? eV energy resolution on nylons of different chain length show the onset of dynamic processes on the time scale of 10 -8 s far below Tg, around 200 K. The evaluation in terms of non-Gaussian vibrations reveals an apparent mean square displacement which increases with the chain length. It is similar for nylon 6, 46 and 66, but shows lower values for nylon 3 and much larger mean square displacements for nylon 12.

  6. 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

  7. Comparisons between the microwave sounding unit temperature record and the surface temperature record from 1979 to 1996: Real differences or potential discontinuities?

    Microsoft Academic Search

    P. D. Jones; T. J. Osborn; T. M. L. Wigley; P. M. Kelly; B. D. Santer

    1997-01-01

    This paper reports a detailed comparison at the global, hemispheric, three 60°-latitude zone, and grid-box scale between lower tropospheric temperatures from the microwave sounding units (MSU2R) on board NOAA polar orbiting satellites and surface temperatures. The comparisons reveal differences in the course of temperature trends over the 19791996 period in the two sets of time series. The surface data warms

  8. 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.

  9. 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

  10. Texture and Mechanical Behavior of Zircaloy-2 Rolled at Different Temperatures

    NASA Astrophysics Data System (ADS)

    Goel, Sunkulp; Keskar, Nachiket; Jayaganthan, R.; Singh, I. V.; Srivastava, D.; Dey, G. K.; Jha, S. K.; Saibaba, N.

    2015-02-01

    Zircaloy-2 was deformed by cryorolling (CR) and room-temperature rolling (RTR) with different true strains, and the effects of true strains on microstructural characteristics, texture, and mechanical properties of the alloy were investigated in the current study. The alloy was subjected to rolling at liquid nitrogen temperature and room temperature with the maximum true strain of 1.89 after the initial heat treatment of the alloy at 800 C in inert atmosphere followed by quenching in mercury. The hardness and tensile properties of the CR, RTR, and annealed alloy upon rolling were systematically measured in rolling and transverse directions. The tensile strengths were found to be 891 and 679 MPa, while hardness values were found to be 282 and 269 VHN for the CR and RTR alloys, in the rolling direction, respectively. Texture results showed the activation of basal slip at higher strains in RTR zircaloy-2. In CR zircaloy-2, only activation of prism slip was observed. Grain refinement, substructures, and texture in the deformed alloy contribute to the improved mechanical properties observed in the current study.

  11. Effect of high pressure high temperature processing on the volatile fraction of differently coloured carrots.

    PubMed

    Kebede, Biniam T; Grauwet, Tara; Palmers, Stijn; Vervoort, Liesbeth; Carle, Reinhold; Hendrickx, Marc; Van Loey, Ann

    2014-06-15

    To get deeper insight into the effect of high pressure high temperature (HPHT) processing on the volatile fraction of carrots, differently coloured cultivars exhibiting orange, purple, red and yellow hues were investigated. The impact of HPHT sterilisation was compared with thermal sterilisation based on equivalent microbiological inactivation. The results of this study demonstrated HPHT sterilisation to exert a distinct effect on important chemical reactions in comparison to thermal sterilisation. A comprehensive integration of MS-based metabolomic fingerprinting (HS-SPME-GC-MS) and chemometric tools has been implemented as an untargeted multivariate screening tool to identify differences. In all carrot cultivars, two dominant discriminative quality-related reactions were found: oxidative degradation and the Maillard reaction. Regarding the first reaction, oxidative terpenes, free fatty acids and carotenoids degradation products were detected at higher levels after HPHT sterilisation. Regarding the latter reaction, HPHT sterilisation appeared to suppress the formation of Maillard and Strecker degradation products. PMID:24491739

  12. 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.

  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. 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

  15. RNA stability in human liver: comparison of different processing times, temperatures and methods.

    PubMed

    Lee, Serene M L; Schelcher, Celine; Gashi, Sevdije; Schreiber, Stefanie; Thasler, Reinhard M K; Jauch, Karl-Walter; Thasler, Wolfgang E

    2013-01-01

    The accuracy of information garnered by real-time quantitative polymerase chain reaction (RT-qPCR), an important technology for elucidating molecular mechanisms of disease, is dependent on tissue quality. Thus, this study aimed to determine the effects of intra-operative manipulation, extended processing times, different temperatures or storage in RNAlater on RNA quality in liver samples for tissue banking. Liver samples, flash-frozen or in RNAlater, were collected over a time course (during surgery before blood arrest up to 1 day after surgery) with samples kept either at room temperature (RT) or on ice. This study showed that at the longest time-point at RT, the RNA quality decreased significantly by 20%. However, relative gene expressions of FOS, GUSB, MYC, HIF1? and GFER were in general not significantly different when the time-points were compared. In conclusion, samples should be kept on ice during processing, and either RNAlater or snap-freezing should be utilised for storage. Further, intra-operative manipulation and extended postoperative processing time generally does not change relative gene expression levels for the 5 genes studied, making such sampling suitable for RT-qPCR analysis. Thus, if relative gene expression of a gene of interest is stable, these guidelines will lead to increased accrual of samples to the tissue bank. PMID:22271457

  16. Effects of plant growth substances on rooting of Hedychium spicatum under different temperature regimes.

    PubMed

    Giri, Dinesh; Tamta, Sushma

    2013-03-01

    Present study was carried out to develop a simple and efficient vegetative propagation protocol by applying various treatments to rhizome cuttings with different test solutions of auxins and phenolic compound. These were alpha-naphthalene acetic acid (NAA), Indole-3-butyric acid (IBA), Indole Acetic Acid (IAA), phloroglucinol and coumarin. The concentrations for each treatment were 10.0, 50.0 and 100.0 microM. After treatments the rhizome cuttings were planted in polybags containing forest soil and kept under different temperature regimes i.e., inside polyhose (at 20-25 degrees C), inside mist chamber (at 15-20 degrees C) and under nethouse (nursery condition, at 14-18 degrees C). The maximum rooting percentage (74.06%) was achieved at 20-25 degrees C (inside polyhouse) by applying 50.0 microM IBA. Inside poly house condition, the various developmental parameters showed better responses compare to other conditions. On the basis of present study emphasizes that the temperature play a crucial role in rooting and further growth of the plants in this species. By using this simple and significant conventional method of propagation we could be propagate this vulnerable medicinal and aromatic species at large scale for commercial purpose. PMID:24175432

  17. Susceptibility to low-temperature photoinhibition in three conifers differing in successional status.

    PubMed

    Robakowski, Piotr

    2005-09-01

    Susceptibility to photoinhibition of the evergreen conifers Abies alba Mill., Picea abies (L.) Karst. and Pinus mugo Turra was investigated in an unheated greenhouse during winter and spring 2003. Photosynthetic performance of the seedlings was assessed by chlorophyll a fluorescence and analyses of chlorophyll and total carotenoid concentrations in needles. During winter months, maximum quantum yield of PSII photochemistry (ratio of variable to maximum fluorescence, Fv/Fm) was significantly greater in A. alba than in P. abies and P. mugo. Abies alba also sustained higher maximum apparent electron transport rate (ETRmax) than P. abies and P. mugo. Total concentrations of chlorophyll and carotenoids in needles decreased during the winter in P. mugo and P. abies, but remained stable in A. alba. For all species, Fv/Fm decreased from December until February and then increased to a maximum in April. Photoinhibition was greatest (Fv/Fm < 0.80) in all seedlings in February, the month with the lowest mean temperature. Saturating photosynthetic photon flux (PPFsat) and ETRmax were positively related to air temperature. All species had lower values of ETRmax and PPFsat in winter than in spring. Non-photochemical quenching of chlorophyll fluorescence (NPQ) was highest at low air temperatures. Differences among species in susceptibility to winter photoinhibition resulted from their specific light preferences and led to different mechanisms to cope with photoinhibitory stress. The more shade-tolerant A. alba sustained a higher photosynthetic capacity in winter than P. abies and P. mugo. Winter photoinhibition in P. abies, P. mugo and, to a lesser extent, in A. alba may reflect adaptive photoprotection of the photosynthetic apparatus in winter. PMID:15996958

  18. A comparison of different thermal performance functions describing temperature-dependent development rates

    Microsoft Academic Search

    Peijian Shi; Feng Ge

    2010-01-01

    The impact of temperature on developmental duration of insects has been long kept a high profile in the studies of insect pests. The relationship between developmental rate, which is the reciprocal of developmental duration, is generally represented by a straight line over a range of moderate temperature; over two ranges of extreme temperature (i.e., low temperatures and high temperatures), the

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

    PubMed Central

    de Oliveira Ottone, Vincius; de Castro Magalhes, Flvio; de Paula, Fabrcio; Avelar, Nbia Carelli Pereira; Aguiar, Paula Fernandes; da Matta Sampaio, Pmela Fiche; Duarte, Tamiris Campos; Costa, Karine Beatriz; Arajo, Tatiane Lliam; Coimbra, Cndido Celso; Nakamura, Fbio 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 15C (CWI), 28C (TWI), 38C (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 RR (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

  20. Determining the temporal variability in atmospheric temperature profiles measured using radiosondes and assessment of correction factors for different launch schedules

    NASA Astrophysics Data System (ADS)

    Butterfield, D.; Gardiner, T.

    2015-01-01

    Radiosondes provide one of the primary sources of upper troposphere and stratosphere temperature data for numerical weather prediction, the assessment of long-term trends in atmospheric temperature, study of atmospheric processes and provide intercomparison data for other temperature sensors, e.g. satellites. When intercomparing different temperature profiles it is important to include the effect of temporal mismatch between the measurements. To help quantify this uncertainty the atmospheric temperature variation through the day needs to be assessed, so that a correction and uncertainty for time difference can be calculated. Temperature data from an intensive radiosonde campaign, at Manus Island in Papua New Guinea, were analysed to calculate the hourly rate of change in temperature at different altitudes and provide recommendations and correction factors for different launch schedules. Using these results, three additional longer term data sets were analysed (Lindenberg 1999 to 2008; Lindenberg 2009 to 2012; and Southern Great Plains 2006 to 2012) to assess the diurnal variability of temperature as a function of altitude, time of day and season of the year. This provides the appropriate estimation of temperature differences for given temporal separation and the uncertainty associated with them. A general observation was that 10 or more repeat measurements would be required to get a standard error of the mean of less than 0.1 K per hour of temporal mismatch.

  1. 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

  2. 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

  3. Comparison of three different thermometers in evaluating the body temperature of healthy young adult individuals.

    PubMed

    Basak, Tulay; Aciksoz, Semra; Tosun, Betul; Akyuz, Aygul; Acikel, Cengizhan

    2013-10-01

    The aim of this study was to compare the measurement values obtained with a non-contact infrared thermometer, a tympanic thermometer and a chemical dot thermometer. The research population was composed of students studying in two departments of a university in Ankara. A total of 452 students who fit the inclusion criteria of the study and volunteered to participate were included in the sample. Body temperature measurements with different thermometers were performed by the same researcher at the same room temperature. Data were analyzed in a computerized environment by SPSS 15.0 statistical program pack and Bland-Altman graph. Mean age of healthy young adults participating in the study was 19.66??0.94, and 55.1% of them were female. The agreement limits for non-contact infrared and chemical dot was between -1.30 and 0.32C; for non-contact infrared and tympanic was between -1.26 and 0.13C; and for chemical dot and tympanic -0.89 and 0.74C. It was determined that, although the measurement values of the tympanic membrane and chemical dot thermometers conformed with each other, the conformity of the non-contact infrared thermometer was weak. PMID:24093738

  4. 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

  5. Composition and temperature-induced structural changes in lead-tellurite glasses on different length scales.

    PubMed

    Chakraborty, S; Arora, A K; Sivasubramanian, V; Krishna, P S R; Krishnan, R Venkata

    2012-12-19

    Processes occurring at macroscopic and microscopic length scales across the glass transition (T(g)) in lead-tellurite glass (PbO)(x)(TeO(2))(1-x) (x = 0.1-0.3) are investigated using Brillouin and Raman spectroscopy, respectively. For all the samples, the temperature dependence of the longitudinal acoustic (LA) mode is found to exhibit a universal scaling below T(g) and a rapid softening above T(g). The lower value of elastic modulus at a higher concentration of network modifier PbO, estimated from Brillouin data, arises due to loss of network rigidity. From quantitative analysis of the reduced Raman spectra, several modes are found to exhibit anomalous changes across T(g). Instead of the expected anharmonic behaviour, several modes exhibit hardening, suggesting stiffening of the stretching force constants with temperature, the effect being more pronounced in glasses with higher x. In addition, incorporation of PbO in the glass is also found to narrow down the bond-length distribution, as evident from the sharpening of the Raman bands. The stiffening of the force constants of molecular units at a microscopic length scale and the decrease of elastic constant attributed to loss of network rigidity on a macroscopic length scale appear to be opposite. These different behaviours at two length scales are understood on the basis of a microscopic model involving TeO(n) and PbO units in the structure. PMID:23165000

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

    PubMed Central

    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

  7. 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.

  8. Shear strain determination of the polymer polydimethysiloxane (PMDS) using digital image correlation in different temperatures

    NASA Astrophysics Data System (ADS)

    de Oliveira, G. N.; Nunes, L. C. S.; dos Santos, P. A. M.

    2011-01-01

    In the present work a digital image correlation (DIC) method is used in order to analyze the adhesive shear modulus of poly-dimethylsiloxane (PDMS) submitted to different loads and temperatures. This is an optical-numerical full-field surface displacement measurement method. It is based on a comparison between two images of a specimen coated by a random speckled pattern in the undeformed and in the deformed states. A single lap joint testing is performed. This is a standard test specimen for characterizing adhesive properties and it is considered the simplest form of adhesive joints. For the single lap joint specimen, steel adherends are bonded using a flexible rubber elastic polymer (PDMS), which is a commercially available silicone elastic rubber

  9. Temperature dependent narrow-band terahertz pulse generation in periodically poled crystals via difference frequency generation

    NASA Astrophysics Data System (ADS)

    Yu, N. E.; Lee, K. S.; Ko, D.-K.; Kang, C.; Takekawa, S.; Kitamura, K.

    2011-03-01

    Femtosecond optical pulse is used to generate narrow-band terahertz pulses depending on a quasi-phase-matched condition in periodically poled lithium niobate (PPLN) and stoichiometric lithium tantalate (PPSLT) crystals by difference frequency generation. The origin of narrow-band THz generation proved that the two frequency components of the fs pulse contribute to the frequency mixing. By cryogenic cooling, the absorption of THz waves in the crystal is significantly reduced which results in efficient THz generation. Simultaneously generated forward and backward THz pulses were 1.38 and 0.65 THz with as narrow as the bandwidth of 32 GHz in the PPSLT sample. Temperature dependence of the generated THz waveforms had good agreement with the simulation result using one dimensional plane-wave propagation model.

  10. Widely tuned room temperature terahertz quantum cascade laser sources based on difference-frequency generation

    NASA Astrophysics Data System (ADS)

    Lu, Q. Y.; Bandyopadhyay, N.; Slivken, S.; Bai, Y.; Razeghi, M.

    2012-12-01

    We demonstrate room temperature THz quantum cascade laser sources with a broad spectral coverage based on intracavity difference-frequency generation. Two mid-infrared active cores based on the single-phonon resonance scheme are designed with a THz nonlinearity specially optimized at the high operating fields that correspond to the highest mid-infrared output powers. A ?erenkov phase-matching scheme along with integrated dual-period distributed feedback gratings are used for efficient THz extraction and spectral purification. Single mode emissions from 1.0 to 4.6 THz with a side-mode suppression ratio and output power up to 40 dB and 32 ?W are obtained, respectively.

  11. Swelling behavior of a Chinese bituminous coal at different pyrolysis temperatures

    SciTech Connect

    Dunxi Yu; Minghou Xu; Yun Yu; Xiaowei Liu [Huazhong University of Science and Technology, Wuhan (China). State Key Laboratory of Coal Combustion

    2005-12-01

    Pyrolysis experiments were performed in a drop tube furnace at 1373, 1523, and 1673 K to investigate the swelling behavior of a Chinese bituminous coal. Particle size distributions and morphologies of chars prepared from three size-classified fractions of the coal were analyzed by laser diffraction and SEM, respectively. The results show that significant swelling occurs during pyrolysis. It is found that both heating rate and particle size have important effects on coal swelling. For each size fraction used in the present study, the swelling ratio initially increases with increasing heating rate from 5 x 10{sup 3} to 2 x 10{sup 4} K/s, but then decreases when the heating rate further increases to 4 x 10{sup 4}K/s. A maximum swelling ratio is obtained at 2 x 10{sup 4} K/s for all coal samples, indicating that coal particles swell most at this heating rate. At the same temperature, the swelling ratios of the three size fractions are markedly different. It is shown that the finer the particle size, the higher is the swelling ratio. This is considered to be the result of the enrichment of vitrinite in small particles, as observed in this study, and the high volatile yields for them at elevated temperatures. It is also noted that the difference in swelling ratio diminishes with increasing particle size. The results also suggest that fragmentation observed in this study may contribute to reducing swelling ratio. Coal particles with a large size or undergoing a high heating rate have the tendency to fragment violently during pyrolysis, resulting in the decrease of their swelling ratios. 34 refs., 6 figs., 2 tabs.

  12. The effect of low-temperature demagnetization on paleointensity determinations from samples with different domain states

    NASA Astrophysics Data System (ADS)

    Kulakov, E.; Smirnov, A. V.

    2013-05-01

    It has been recently proposed that incorporation of low-temperature demagnetization (LTD) into the Thellier double-heating method increases the accuracy and success rate of paleointensity experiments by reducing the effects of magnetic remanence carried by large pseudo-singledomain (PSD) and multidomain (MD) grains (e.g., Celino et al., Geophysical Research Letters, 34, L12306, 2007). However, it has been unclear to what degree the LTD affects the remanence carried by single-domain (SD) and small PSD. To investigate this problem, we carried out paleointensity experiments on synthetic magnetite-bearing samples containing nearly SD, PSD, and multidomain MD grains as well as mixtures of MD and SD grains. Before the experiments, a thermal remanent magnetization was imparted to the samples in a known laboratory field. Paleointensities were determined using both the LTD-Thellier and multi-specimen parallel pTRM methods. The samples were subjected to a series of three LTD treatments in liquid nitrogen after each heating. LTD significantly improved the quality of paleointensity determinations from the samples containing large PSD and MD magnetite as well as SD-MD mixtures. In particular, LTD resulted in a significant increase of the paleointensity quality factor, producing more linear Arai plots and reducing data scatter. In addition, field intensities calculated after LTD fell within 2-4% of the known laboratory field. On the other hand, the effect of LTD on paleointensity determinations from samples with nearly SD magnetite is negligible. Paleointensity values based on both pre- and post-LTD data were statistically indistinguishable of the laboratory field. LTD treatment significantly reduced the systematic paleofield overestimation using the multi-specimen method from samples containing PSD and MD grains, as well as SD-MD mixtures. The results of multi-specimen paleointensity experiments performed on the PSD and MD samples using different heating temperatures suggest that the choice of temperature is crucial for accurate paleointensity determinations. The use of too low temperatures may result in up to 100% overestimation of the paleofield.

  13. Temperature dependence of AC losses in a BSCCO/Ag tape exposed to AC magnetic fields applied in different orientations

    NASA Astrophysics Data System (ADS)

    Wolfbrandt, A.; Magnusson, N.; Hrnfeldt, S.

    2002-08-01

    When high-temperature superconducting tapes are used in electrotechnical applications, they have an optimal working point in temperature. In the winding of e.g. a transformer the conductor carrying an AC current is exposed to an AC magnetic field oriented differently in separate parts of the winding. To determine the optimal working temperature it is essential to study the temperature dependence of the AC losses under these conditions. In this study, we present experimental results of the losses in a multi-filamentary silver-sheathed Bi-2223 high-temperature superconducting tape carrying an AC transport current in an AC magnetic field applied in different orientations perpendicular to the current path. The losses were measured calorimetrically in the temperature interval 40-85 K. The experimental results are compared to semi-empirical models of the AC losses.

  14. 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.

  15. 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.

  16. 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.

  17. Temperature dependence of performance of InGaN\\/GaN MQW LEDs with different indium compositions

    Microsoft Academic Search

    Chul Huh; William J. Schaff; Lester F. Eastman; Seong-Ju Park

    2004-01-01

    The temperature dependence of performance of InGaN\\/GaN multiple-quantum-well (MQW) light-emitting diodes (LEDs) with different indium compositions in the MQWs was investigated. With increasing In composition in the MQWs, the optical performance of the LEDs at room temperature was increased due to an increase in the localized energy states caused by In composition fluctuations in MQWs. As the temperature was increased,

  18. Fourier-transform infrared difference spectroscopy of rhodopsin and its photoproducts at low temperature.

    PubMed

    Bagley, K A; Balogh-Nair, V; Croteau, A A; Dollinger, G; Ebrey, T G; Eisenstein, L; Hong, M K; Nakanishi, K; Vittitow, J

    1985-10-22

    Fourier-transform infrared difference spectroscopy has been used to detect the vibrational modes in the chromophore and protein that change in position or intensity between rhodopsin and the photoproducts formed at low temperature (70 K), bathorhodopsin and isorhodopsin. A method has been developed to obtain infrared difference spectra between rhodopsin and bathorhodopsin, bathorhodopsin and isorhodopsin, and rhodopsin and isorhodopsin. To aid in the identification of the vibrational modes, we performed experiments on deuterated and hydrated films of native rod outer segments and rod outer segments regenerated with either retinal containing 13C at carbon 15 or 15-deuterioretinal. Our infrared measurements provide independent verification of the resonance Raman result that the retinal in bathorhodopsin is distorted all-trans. The positions of the C = N stretch in the deuterated pigment and the deuterated pigments regenerated with 11-cis-15-deuterioretinal or 11-cis-retinal containing 13C at carbon 15 are indicative that the Schiff-base linkage is protonated in rhodopsin, bathorhodopsin, and isorhodopsin. Furthermore, the C = N stretching frequency occurs at the same position in all three species. The data indicate that the protonated Schiff base has a C = N trans conformation in all three species. Finally, we present evidence that, even in these early stages of the rhodopsin photosequence, changes are occurring in the opsin and perhaps the associated lipids. PMID:4084506

  19. 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

  20. 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

  1. 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 27C to 17C for the summer case (Cold temperature treatment), or from 17C to 27C 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 bodys 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.

  2. Comparative physiological and proteomic response to abrupt low temperature stress between two winter wheat cultivars differing in low temperature tolerance.

    PubMed

    Xu, J; Li, Y; Sun, J; Du, L; Zhang, Y; Yu, Q; Liu, X

    2013-03-01

    Abrupt temperature reduction in winter wheat at either autumn seedling stage prior to vernalisation or early spring crown stage can cause severe crop damage and reduce production. Many studies have reported the physiological and molecular mechanisms underlying cold acclimation in winter wheat by comparing it with spring wheat. However, processes associated with abrupt temperature reduction in autumn seedling stage prior to vernalisation in winter wheat are less understood. In this study, physiological and molecular responses of winter wheat seedlings to abrupt low temperature (LT) stress were characterised in the relatively LT-tolerant winter wheat cultivar Shixin 828 by comparing it with the relatively LT-sensitive cultivar Shiluan 02-1 using a combination of physiological, proteomics and biochemical approaches. Shixin 828 was tolerant to abrupt LT stress, while Shiluan 02-1 exhibited high levels of reactive oxygen species (ROS) and leaf cell death. Significant increases in relative abundance of antioxidant-related proteins were found in Shixin 828 leaves, which correlate with observed higher antioxidant enzyme activity in Shixin 828 compared to Shiluan 02-1. Proteomics analysis also indicated that carbohydrate metabolism-related proteins were more abundant in Shiluan 02-1, correlating with observed accumulation of soluble sugars in Shiluan 02-1 leaves. Amino acid analysis revealed a strong response to LT stress in wheat leaves. A negative effect of exogenous sucrose on LT tolerance was also found. This study indicates that high ROS scavenging capacity and high abundance of photosynthesis-related proteins might play a role in winter wheat response to abrupt LT stress. In contrast, excess accumulation of soluble sugars might be disadvantageous for LT tolerance in the wheat cultivar Shiluan 02-1. PMID:22963252

  3. [Effect of temperature on proteinase activities of enteral microbiota and intestinal mucosa of fish of different ecological group].

    PubMed

    Kuz'mina, V V; Shalygin, M V; Skvortsova, E G

    2012-01-01

    Effect of temperature on proteinases activities of enteral microbiota and of intestinal mucosa was studied in five fish species (roach Rutilus rutilus, crucian carp Carassius carassius, common perch Perca fluviatilis, pike-perch Zander lucioperca, and pike Esox lucius) belonging by the nutrition type to different ecological groups. Essential differences of temperature characteristics of proteinases of intestinal mucosa and of enteral microbiota are revealed in fish belonging by the nutrition type to different ecologic groups. The character of the t0-function of proteinases of intestinal mucosa and enteral microbiota by casein and hemoglobin as a rule is different. The highest values of relative proteinases activities for casein in the zone of low temperatures (38 and 45.3 % of the maximal activity) are found at study of proteinases of enteral microbiota in common perch and crucian carp. The latter indicates a significant adaptability of the enteral microbiota proteinases of common perch and crucial carp to functioning at low temperatures. PMID:22645973

  4. Decontamination treatments for psychrotrophic microorganisms on chicken meat during storage at different temperatures.

    PubMed

    Alonso-Hernando, Alicia; Capita, Rosa; Alonso-Calleja, Carlos

    2013-11-01

    The antimicrobial effectiveness of five chemical decontaminants (12 % trisodium phosphate [TSP], 1,200 ppm acidified sodium chlorite [ASC], 2 % citric acid [CA], 220 ppm of peroxyacids [PA], or 50 ppm of chlorine dioxide [CD]) against psychrotrophic populations on skinned chicken legs was assessed throughout 120 h of storage under various temperature abuse scenarios. Three different simulated cold chain disruptions were used: T1 (12 h at 1 1 C, 6 h at 15 1 C, and 102 h at 4 1 C), T2 (18 h at 1 1 C, 6 h at 15 1 C, and 96 h at 10 1 C), or T3 (18 h at 4 1 C, 6 h at 20 1 C, and 96 h at 7 1 C). Microbiological analyses were carried out at 0, 24, 72, and 120 h of storage. Substantial microbial reductions, with respect to control (untreated) samples, were obtained in legs treated with TSP, ASC, and CA, with average values ranging from 1.54 1.52 to 2.02 2.19 log CFU/cm(2). TSP was the most effective compound under mild abuse temperature conditions (T1), with mean reductions of 2.01 1.67 log CFU/cm(2), whereas ASC, followed by CA, proved to be particularly useful under moderate abuse conditions (T3; average reductions of 2.99 2.27 and 1.98 1.65 log CFU/cm(2), respectively). Treatment with PA or CD resulted in minimal microbial reductions. PMID:24215705

  5. 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.

  6. Evolution of morphology and structure of Pb thin films grown by pulsed laser deposition at different substrate temperatures

    SciTech Connect

    Lorusso, Antonella, E-mail: antonella.lorusso@le.infn.it; Maiolo, Berlinda; Perrone, Alessio [Dipartimento di Matematica e Fisica E. De Giorgi, Universit del Salento, 73100 Lecce (Italy); Gontad, Francisco [Istituto Nazionale di Fisica Nucleare e Universit del Salento, 73100 Lecce (Italy); Maruccio, Giuseppe [Dipartimento di Matematica e Fisica E. De Giorgi, Universit del Salento, 73100 Lecce, Italy and National Nanotechnology Laboratory, Istituto Nanoscienze-CNR, Arnesano I-73100 (Italy); Tasco, Vittorianna [National Nanotechnology Laboratory, Istituto Nanoscienze-CNR, Arnesano I-73100 (Italy)

    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.

  7. An influence of ethanol and temperature on products formation by different preparations of Zymomonas mobilis extracellular levansucrase.

    PubMed

    Vigants, A; Upite, D; Scherbaka, R; Lukjanenko, J; Ionina, R

    2013-01-01

    The ethanol and temperature effects on the ratio between Zymomonas mobilis 113S extracellular levansucrase activities were studied using fermentation broth supernatant, "levan-levansucrase" sediment precipitated by ethanol and highly purified enzyme. The fructooligosaccharide (FOS) production at different temperatures in the presence of ethanol was investigated. An ethanol increases FOS biosynthesis activity part of levansucrase. Especially, this effect was pronounced at lower temperatures (35-40 C) and using purified levansucrase. The inverse relationship between temperature and ratio synthetic activity/total activity of levansucrase was found. The FOS composition containing mostly 1-kestose, 6-kestose, and neokestose obtained in the presence of different ethanol concentrations was found relative constant, while the changes in the sucrose concentration and temperature gave slight changes in the ratio between 1-kestose and 6-kestose. PMID:22826021

  8. An alternative method to estimate zero flow temperature differences for Granier's thermal dissipation technique.

    PubMed

    Regalado, Carlos M; Ritter, Axel

    2007-08-01

    Calibration of the Granier thermal dissipation technique for measuring stem sap flow in trees requires determination of the temperature difference (DeltaT) between a heated and an unheated probe when sap flow is zero (DeltaT(max)). Classically, DeltaT(max) has been estimated from the maximum predawn DeltaT, assuming that sap flow is negligible at nighttime. However, because sap flow may continue during the night, the maximum predawn DeltaT value may underestimate the true DeltaT(max). No alternative method has yet been proposed to estimate DeltaT(max) when sap flow is non-zero at night. A sensitivity analysis is presented showing that errors in DeltaT(max) may amplify through sap flux density computations in Granier's approach, such that small amounts of undetected nighttime sap flow may lead to large diurnal sap flux density errors, hence the need for a correct estimate of DeltaT(max). By rearranging Granier's original formula, an optimization method to compute DeltaT(max) from simultaneous measurements of diurnal DeltaT and micrometeorological variables, without assuming that sap flow is negligible at night, is presented. Some illustrative examples are shown for sap flow measurements carried out on individuals of Erica arborea L., which has needle-like leaves, and Myrica faya Ait., a broadleaf species. We show that, although DeltaT(max) values obtained by the proposed method may be similar in some instances to the DeltaT(max) predicted at night, in general the values differ. The procedure presented has the potential of being applied not only to Granier's method, but to other heat-based sap flow systems that require a zero flow calibration, such as the Cermk et al. (1973) heat balance method and the T-max heat pulse system of Green et al. (2003). PMID:17472936

  9. 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. [Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw (Poland)] [Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw (Poland)

    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.

  10. 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.

  11. 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.

  12. Combined effect of nisin and carvacrol at different pH and temperature levels on the viability of different strains of Bacillus cereus

    Microsoft Academic Search

    Paula M. Periago; Roy Moezelaar

    2001-01-01

    The influence of pH and temperature on the bactericidal action of nisin and carvacrol on vegetative cells of different Bacillus cereus strains was studied. The five strains tested showed significant differences in sensitivity towards nisin, at pH 7.0 and 30C. Carvacrol concentrations of 0.3 mmol l?1 had no effect on viability of B. cereus cells. When the same carvacrol concentration

  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. Comparative study of different parameters of fibre Bragg gratings and long period gratings sensors for high-temperature measurements

    Microsoft Academic Search

    Luis B. Melo; Nara ngelo; Nelia Aberto; Carlos Marques; Jos Monteiro; Gaspar Rego; Paulo Caldas; Rogrio Nogueira

    2011-01-01

    This paper presents a comparative study of the behaviour of different kinds of optical fibre sensors in response to high temperatures. It compares the performance of regenerated fibre Bragg gratings (FBGs) written in hydrogen-loaded and non-loaded fibres with long period gratings (LPGs) written through the two different processes of ultraviolet (UV) irradiation and electrical arc discharges. This work shows the

  15. Temperature profiles of Agaricus bisporus in composting stages and effects of different composts formulas and casing materials on yield

    Microsoft Academic Search

    Mehmet COLAK

    Three compost formulas using different activator materials were prepared for Agaricus bisporus cultivation. A locally available casing material known as peat of Bolu district and its different combinations with perlite were used. Temperature profiles of all mixtures during composting were measured at every composting stages at various depth in order to determine the compostability level of substrates. Compost temparature steadily

  16. Transcriptome analysis of the Bombyx mori fat body after constant high temperature treatment shows differences between the sexes.

    PubMed

    Wang, Hua; Fang, Yan; Wang, Lipeng; Zhu, Wenjuan; Ji, Haipeng; Wang, Haiying; Xu, Shiqing; Sima, Yanghu

    2014-09-01

    Ambient temperature plays a large role in insect growth, development and even their distribution. The elucidation of the associated molecular mechanism that underlies the effect of constant high temperature will enables us to further understand the stress responses. We constructed four digital gene expression libraries from the fat body of female and male Bombyx mori. Differential gene expression was analyzed after constant high temperature treatment. The results showed that there were significant changes to the gene expression in the fat body after heat treatment, especially in binding, catalytic, cellular and metabolic processes. Constant high temperature may induce more traditional cryoprotectants, such as glycerol, glycogen, sorbitol and lipids, to protect cells from damage, and induce heat oxidative stress in conjunction with the heat shock proteins. The data also indicated a difference between males and females. The heat shock protein-related genes were up-regulated in both sexes but the expression of Hsp25.4 and DnaJ5 were down-regulated in the male fat body of B. mori. This is the first report of such a result. Constant high temperature also affected the expression of other functional genes and differences were observed between male and female fat bodies in the expression of RPS2, RPL37A and MREL. These findings provide abundant data on the effect of high temperature on insects at the molecular level. The data will also be beneficial to the study of differences between the sexes, manifested in variations in gene expression under high temperature. PMID:24972568

  17. Can we improve heterosis for root growth of maize by selecting parental inbred lines with different temperature behaviour?

    PubMed Central

    Hund, Andreas; Reimer, Regina; Stamp, Peter; Walter, Achim

    2012-01-01

    Tolerance to high and low temperature is an important breeding aim for Central and Northern Europe, where temperature fluctuations are predicted to increase. However, the extent to which genotypes differ in their response to the whole range of possible temperatures is not well understood. We tested the hypothesis that the combination of maize (Zea mays L.) inbred lines with differing temperature optima for root growth would lead to superior hybrids. This hypothesis is based on the concept of marginal overdominance in which the hybrid expresses higher relative fitness than its parents, summed over all situations. The elongation rates of axile and lateral roots of the reciprocal cross between two flint and two dent inbred lines were assessed at temperatures between 15C and 40C. Indeed, the cross between UH005 and UH250 with lateral root growth temperature optima at 34C and 28C, respectively, resulted in intermediate hybrids. At temperatures below and above 31C, the hybrids' root growth was comparable to the better parent, respectively, thereby increasing temperature tolerance of the hybrid compared with its parents. The implications of and reasons for this heterosis effect are discussed in the context of breeding for abiotic stress tolerance and of putatively underlying molecular mechanisms. This finding paves the way for more detailed investigations of this phenomenon in future studies. PMID:22527401

  18. Can we improve heterosis for root growth of maize by selecting parental inbred lines with different temperature behaviour?

    PubMed

    Hund, Andreas; Reimer, Regina; Stamp, Peter; Walter, Achim

    2012-06-01

    Tolerance to high and low temperature is an important breeding aim for Central and Northern Europe, where temperature fluctuations are predicted to increase. However, the extent to which genotypes differ in their response to the whole range of possible temperatures is not well understood. We tested the hypothesis that the combination of maize (Zea mays L.) inbred lines with differing temperature optima for root growth would lead to superior hybrids. This hypothesis is based on the concept of 'marginal overdominance' in which the hybrid expresses higher relative fitness than its parents, summed over all situations. The elongation rates of axile and lateral roots of the reciprocal cross between two flint and two dent inbred lines were assessed at temperatures between 15C and 40C. Indeed, the cross between UH005 and UH250 with lateral root growth temperature optima at 34C and 28C, respectively, resulted in intermediate hybrids. At temperatures below and above 31C, the hybrids' root growth was comparable to the better parent, respectively, thereby increasing temperature tolerance of the hybrid compared with its parents. The implications of and reasons for this heterosis effect are discussed in the context of breeding for abiotic stress tolerance and of putatively underlying molecular mechanisms. This finding paves the way for more detailed investigations of this phenomenon in future studies. PMID:22527401

  19. 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 25C, 20C, 15C, 5C, -5C and -10C. 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

  20. Temperature sensitivity of greenhouse gas production in wetland soils of different vegetation

    E-print Network

    Florida, University of

    and vegeta- tion type on both aerobic and anaerobic decomposi- tion of organic matter in subtropical wetland soils. As in many other studies, increased temperature resulted in higher rates of respiration and methanogenesis under both aerobic and anaerobic conditions, and the positive effect of temperature depended

  1. Optimum variables selection of thermoelectric generator-driven thermoelectric refrigerator at different source temperature

    Microsoft Academic Search

    Lingen Chen; Fankai Meng; Yanlin Ge; Fengrui Sun

    2012-01-01

    Based on the finite time thermodynamic model of thermoelectric generator-driven thermoelectric refrigerator with losses of external heat transfer, Joulean heat inside the thermoelectric device and the heat leakage through the thermoelectric couple leg, this paper analysed the effects of generator heat source temperature and refrigerator cooling temperature on the performance of the combined system using the combination of finite time

  2. Influence of temperature on thermal conductivity, thermal capacity and thermal diffusivity for different types of rock

    Microsoft Academic Search

    Hans-Dieter Vosteen; Rdiger Schellschmidt

    2003-01-01

    Thermal modeling down to great depth, e.g. down to the Mohorovicic discontinuity, requires representative values of thermal conductivity and thermal capacity at an appropriate depth. Often there is a lack of data, especially concerning temperature and pressure dependence of thermal conductivity and thermal capacity, due to missing or questionable data from boreholes. Studies of the temperature and pressure dependence of

  3. Differences between repeated borehole temperature logs in the southern Canadian Prairies-validating borehole climatology

    NASA Astrophysics Data System (ADS)

    Majorowicz, J.; Skinner, W.; Safanda, J.; Gosnold, W.

    2006-11-01

    Temperature-depth (T-z) profiles from twenty-four shallow boreholes of less than 250 m in depth located in flat, semi-arid areas of the southern Canadian Prairie Provinces initially measured in the late 1980's and early 1990's and repeated between 2004 and 2006 show strong ground surface temperature (GST) warming signatures. GST changes of 0.1-0.2C, and 0.4C, are observed between the measurements for the shorter (decade) and longer (two decades) time spans, respectively. Borehole sites with repeated temperature logs are selected to demonstrate that multiple T-z profiles provide general agreement between GST warming and observed surface air temperature (SAT) warming measured at nearby historical climate stations. A comparison of measured changes from repeated temperature logs with those simulated from SAT forcing demonstrates the influence of SAT on the observed deviation of temperature with depth despite variations in snow cover. Repeated borehole measurements from the northern Great Plains of the USA also identify a similar positive temperature change but of lower magnitude. Temperature changes since 1900 in the southern Canadian Prairies and the adjoining northern Great Plains of the USA, as derived from the functional state inversion (FSI) of deeper borehole logs, average 2.5C but show a strong latitudinal gradient.

  4. Influence of light intensity from different curing units upon composite temperature rise.

    PubMed

    Knezevi?, A; Tarle, Z; Meniga, A; Sutalo, J; Pichler, G

    2005-05-01

    The unavoidable consequence of composite resin photopolymerization is temperature rise in tooth tissue. The temperature rise depends not only on the illumination time, but also on light intensity, distance of light guide tip from composite resin surface, composition and shade of composite resin and composite thickness. The most commonly used units for polymerization today are halogen curing units, which emit a large spectrum of wavelengths. A proportion of the spectrum has no influence on degree of conversion and therefore causes unnecessary temperature rise. Units based on light source - blue light emitting diodes (LED), as an alternative for halogen curing units, have been introduced in clinical practice. The aim of this study was to show the influence of the light intensity of curing units Elipar Trilight, Astralis 7 and Lux-o-Max unit on temperature rise in composite resin sample of Tetric Ceram. The temperature was measurement with Metex M-3850 D multimeter with the tip of temperature probe put into unpolymerized composite resin sample 1 mm depth. The highest temperature rise was recorded with standard curing mode for Elipar Trilight halogen curing unit (13.3 +/- 1.21 degrees C after 40 s illumination), while the lowest temperature rise was recorded for the Lux-o-Max unit based on LED technology (5.2 +/- 1.92 degrees C after 40 s illumination). PMID:15842246

  5. 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...

  6. Temperature-dependent differences in foraging ability of two percids, Perca fluviatilis and Gymnocephalus cernuus

    Microsoft Academic Search

    Eva Bergman

    1987-01-01

    The effects of temperature on capture rate, handling time, capture probability and routine swimming performance were studied in two fish species, perch Perca fluviatilis and ruffe Gymnocephalus cernuus. In addition, the reaction distance (RD) of both species was measured. Handling time decreased and capture rate increased with increasing temperature for both perch and ruffe. The response of handling time and

  7. Long-term water temperature reconstructions from mountain lakes with different catchment and morphometric features.

    PubMed

    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

  8. Oxygen tension profiles in isolated hamster retractor muscle at different temperatures.

    PubMed

    Dutta, A; Wang, L; Meng, H; Pittman, R N; Popel, A S

    1996-05-01

    Oxygen tension (P0(2)) profiles within unperfused hamster retractor muscles were obtained at 25, 30, and 37 degrees by using sharpened, recessed oxygen microelectrodes. The microelectrode was driven vertically into freshly excised muscle lying on a flat, impermeable boundary inside a diffusion chamber. Intramuscular P0(2) profiles were measured as a function of electrode depth in 10-mu m steps during both inward and outward penetrations when the upper surface of the muscles was exposed to humidified gases containing 10, 21, 50, and 100% 0(2). The ratio of the 0(2) consumption (M) to the 0(2) permeability (K, Krogh diffusion coefficient = D alpha, diffusion coefficient-solubility product) was estimated by curve-fitting the experimental steady-state distribution of 0(2) through muscles to the analytic solution of the diffusion equation assuming that M obeys zero-order kinetics and K is constant, uniform, and independent of P0(2). The ratios of M/K were independent of temperature and were found to be independent of surface P0(2) and muscle thickness. The average value of M/K was 3.9 +/- 0.45 (SE; n = 30) x 10(5) mm Hg/cm(2), which is consistent with that estimated from previous measurements of M and D using different non-steady-state techniques (Bentley et aL, 1993). These results are consistent with other in vitro 0(2) consumption measurements (Sullivan and Pittman, 1984) and do not provide evidence for nonclassical respiratory activity in resting mammalian skeletal muscle. PMID:8992229

  9. Hawking and Unruh radiation perception by different observers: applications of the effective temperature function (in Spanish)

    E-print Network

    Luis C. Barbado

    2015-01-12

    We study the perception of the radiation phenomena of Hawking radiation and Unruh effect by using two main tools: the Unruh-DeWitt detectors and the effective temperature function (ETF), this last tool based on Bogoliubov transformations. Using the Unruh-DeWitt detectors we find an adiabatic expansion of the detection properties along linear trajectories with slowly varying acceleration in Minkowski, which allows us to calculate the spectrum detected, finding the thermal spectrum as the zeroth order contribution. Using the ETF we study the perception of Hawking radiation by observers following radial trajectories outside a Schwarzschild black hole. One of the most important results is that, in general, free-falling observers crossing the event horizon do detect some radiation, even when the field is in the Unruh vacuum state, due to a Doppler blue-shift that diverges at the horizon. We give a general expression for the ETF, which has a clear interpretation in terms of well-known physical phenomena. We discuss which contribution to the perception comes from the radiation emitted by the black hole, and which contribution is due to the Unruh effect caused by the movement of the observer. We conclude that the Unruh effect is not only due to the observer's proper acceleration and cannot even be defined locally, but is due to the observer's acceleration with respect to the asymptotic region. We apply the ETF to the analysis of different physical situations, in particular to a possible buoyancy scenario near the horizon due to Hawking radiation pressure. Finally, we propose a non-stationary vacuum state, which we call pulsating vacuum, for the radiation field outside a stellar object hovering closely to form an event horizon. In this vacuum state, we get nearly Hawking radiation emitted by the object, while avoiding the known problems of the information paradox and the trans-planckian problem.

  10. A unified degree day model describes survivorship of Copitarsia corruda Pogue & Simmons (Lepidoptera: Noctuidae) at different constant temperatures.

    PubMed

    Gmez, N N; Venette, R C; Gould, J R; Winograd, D F

    2009-02-01

    Predictions of survivorship are critical to quantify the probability of establishment by an alien invasive species, but survival curves rarely distinguish between the effects of temperature on development versus senescence. We report chronological and physiological age-based survival curves for a potentially invasive noctuid, recently described as Copitarsia corruda Pogue & Simmons, collected from Peru and reared on asparagus at six constant temperatures between 9.7 and 34.5 degrees C. Copitarsia spp. are not known to occur in the United States but are routinely intercepted at ports of entry. Chronological age survival curves differ significantly among temperatures. Survivorship at early age after hatch is greatest at lower temperatures and declines as temperature increases. Mean longevity was 220 (+/-13 SEM) days at 9.7 degrees C. Physiological age survival curves constructed with developmental base temperature (7.2 degrees C) did not correspond to those constructed with a senescence base temperature (5.9 degrees C). A single degree day survival curve with an appropriate temperature threshold based on senescence adequately describes survivorship under non-stress temperature conditions (5.9-24.9 degrees C). PMID:19006579

  11. 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.

  12. 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

  13. Formation and characterization of wear-resistant PEO coatings formed on ?-titanium alloy at different electrolyte temperatures

    NASA Astrophysics Data System (ADS)

    Habazaki, H.; Tsunekawa, S.; Tsuji, E.; Nakayama, T.

    2012-10-01

    Plasma electrolytic oxidation of single ?-phase Ti-15 mass% V-3 mass% Al-3 mass% Cr-3 mass% Sn (hereafter denoted as Ti-15-3) alloy has been conducted in alkaline aluminate electrolyte at different electrolyte temperatures between 278 and 313 K. The results obtained disclose the highly improved wear resistance of the coatings formed at the lowest temperature of 278 K. The coating formed at this temperature has lower porosity and contains higher concentration of ?-Al2O3 phase in addition to the Al2TiO5 major phase. In contrast, non-uniform coatings are formed at higher temperatures and their porosity is relatively high. Thus, the highest wear resistance of the Ti-15-3 is obtained when the coating is formed at 278 K. Such influence of the electrolyte temperature on the coating morphology and composition is discussed by direct imaging based on direct video imaging data during the coating process.

  14. 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 [Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (United States)] [Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (United States); Boehr, David D., E-mail: ddb12@psu.edu [Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (United States)

    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.

  15. In vitro analysis of human tooth pulp chamber temperature after low-intensity laser therapy at different power outputs

    Microsoft Academic Search

    Mrcio de Alencar Mollo; Lucio Frigo; Giovani Marino Favero; Rodrigo lvaro Brando Lopes-Martins; Aldo Brugnera Junior

    2011-01-01

    In vitro studies have provided conflicting evidence of temperature changes in the tooth pulp chamber after low-level laser\\u000a irradiation of the tooth surface. The present study was an in vitro evaluation of temperature increases in the human tooth\\u000a pulp chamber after diode laser irradiation (GaAlAs, ??=?808nm) using different power densities. Twelve human teeth (three\\u000a incisors, three canines, three premolars and

  16. Temperature

    NSDL National Science Digital Library

    2008-04-08

    This article discusses the relationship between temperature and heat and kinetic energy and it shows how to convert from degrees Fahrenheit to Centigrade. It also includes links to other resources, data, maps, and classroom activities.

  17. 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

  18. 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

  19. Optimizing the Mass Flow and Temperature Difference in a Cooling System for Energy Conservation

    E-print Network

    Hart, M. N.; Bond, S. K.

    1980-01-01

    Conventional wisdom in recent times has been to raise the chilled water temperature to conserve chiller power. This is an effective and well-proven conservation strategy; however, it may be less optimal than other available alternatives. Reducing...

  20. Characteristics of wall sheath and secondary electron emission under different electron temperatures in a Hall thruster

    NASA Astrophysics Data System (ADS)

    Duan, Ping; Qin, Hai-Juan; Zhou, Xin-Wei; Cao, An-Ning; Chen, Long; Gao, Hong

    2014-07-01

    In this paper, a two-dimensional physical model is established in a Hall thruster sheath region to investigate the influences of the electron temperature and the propellant on the sheath potential drop and the secondary electron emission in the Hall thruster, by the particle-in-cell (PIC) method. The numerical results show that when the electron temperature is relatively low, the change of sheath potential drop is relatively large, the surface potential maintains a stable value and the stability of the sheath is good. When the electron temperature is relatively high, the surface potential maintains a persistent oscillation, and the stability of the sheath reduces. As the electron temperature increases, the secondary electron emission coefficient on the wall increases. For three kinds of propellants (Ar, Kr, and Xe), as the ion mass increases the sheath potentials and the secondary electron emission coefficients reduce in sequence.

  1. Temperature imaging of laser-induced thermotherapy (LITT) by MRI: evaluation of different sequences in phantom.

    PubMed

    Bazrafshan, Babak; Hbner, Frank; Farshid, Parviz; Hammerstingl, Renate; Paul, Jijo; Vogel, Vitali; Mntele, Werner; Vogl, Thomas J

    2014-01-01

    The purpose of this study was to evaluate magnetic resonance (MR) temperature imaging of the laser-induced thermotherapy (LITT) comparing the proton resonance frequency (PRF) and T 1 thermometry methods. LITT was applied to a liver-mimicking acrylamide gel phantom. Temperature rise up to 70 C was measured using a MR-compatible fiber-optic thermometer. MR imaging was performed by a 1.5-T scanner utilizing fast gradient echo sequences including a segmented echo planar imaging (seg-EPI) sequence for PRF and the following sequences for T 1 method: fast low-angle shot (FLASH), inversion recovery turbo flash (IRTF), saturation recovery turbo flash (SRTF), and true fast imaging (TRUFI). Temperature-induced change of the pixel values in circular regions of interest, selected on images under the temperature probe tip, was recorded. For each sequence, a calibration constant could be determined to be -0.0088 0.0002 ppm C(-1) (EPI), -1.15 0.03 C(-1) (FLASH), -1.49 0.03 C(-1) (IRTF), -1.21 0.03 C(-1) (SRTF), and -2.52 0.12 C(-1) (TRUFI). These constants were evaluated in further LITT experiments in phantom comparing the calculated temperatures with the fiber optic-measured ones; temperature precisions of 0.60 C (EPI), 0.81 C (FLASH), 1.85 C (IRTF), 1.95 C (SRTF), and 3.36 C (TRUFI) were obtained. Furthermore, performing the Bland-Altman analysis, temperature accuracy was determined to be 0.23 C (EPI), 0.31 C (FLASH), 1.66 C (IRTF), 1.19 C (SRTF), and 3.20 C (TRUFI). In conclusion, the seg-EPI sequence was found to be more convenient for MR temperature imaging of LITT due to its relatively high precision and accuracy. Among the T 1 method sequences, FLASH showed the highest accuracy and robustness. PMID:23535892

  2. Alkaloid variations in Catharanthus roseus seedlings treated by different temperatures in short term and long term

    Microsoft Academic Search

    Xiao-rui Guo; Lei Yang; Jing-hua Yu; Zhong-hua Tang; Yuan-gang Zu

    2007-01-01

    A study was conducted to investigate the effects of high temperature on variations of alkaloid metabolism in C. roseus seedlings in Key Laboratory of Forest Plant Ecology, Northeast Forestry University, Heilongiang, China. 60-day-old C. roseus seedlings with 34 pairs of leaves were incubated in chambers with temperature of 30C and 40C for short-term heat shock\\u000a experiment and 20C, 25C and

  3. Microplasticity at room temperature of single-crystal titanium carbide with different stoichiometry

    Microsoft Academic Search

    E. Breval

    1981-01-01

    Single crystals of titanium carbide with a C-to-Ti range of 0.64 to 0.99 were plastically deformed at room temperature with a hardness indenter and a drill. The operating slip systems were determined by hardness anisotropy and transmission electron microscopy. The results were characteristic for bulk material deformation of TiC, below, as well as above, the brittle-to-ductile transition temperature. A typical

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

    Microsoft Academic Search

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

    2005-01-01

    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

  5. 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.

  6. Reproductive activity and survivorship of Liriomyza sativae (Diptera: Agromyzidae) at different temperatures and relative humidity levels.

    PubMed

    Costa-Lima, T C; Geremias, L D; Parra, J R P

    2010-02-01

    We studied a population of Liriomyza sativae Blanchard (Diptera: Agromyzidae) identified by morphological and molecular techniques from the semiarid region of the Brazilian northeast. The influence of temperature and relative humidity on the survival and reproductive parameters of L. sativae in cowpeas (Vigna unguiculata L. Walp.) (Fabales: Fabaceae) was evaluated. We used temperatures of 18, 20, 22, 25, 28, 30, and 32 +/- 1 degrees C (50 +/- 10% RH) and relative humidity values of 30, 50, 70, and 90 +/- 10% (25 +/- 1 degrees C) under a 14 L:10 D photoperiod. Adult longevity decreased as temperature and relative humidity increased and was greater, in general, for females. The preoviposition and oviposition periods also decreased as temperature increased, whereas relative humidity only caused reductions in the oviposition period at higher levels. Fecundity was similar in the range from 18 to 30 degrees C but decreased at 32 degrees C with respect to relative humidity; the best performances of L. sativae occurred at lower levels. The pattern of oviposition rate changed with temperature and relative humidity. Regardless of temperature and relative humidity, L. sativae laid between 75 and 92% of its eggs on the adaxial surface of the cowpea leaves. This information will be highly useful to design a leafminer production system aimed at the multiplication of natural enemies, as well as for pest management in the field. PMID:20146857

  7. 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

  8. 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, Jrgen; 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 ?r (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

  9. Ambient temperature effect on single-bubble sonoluminescence in different concentrations of sulfuric acid solutions.

    PubMed

    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. PMID:22400679

  10. 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.

  11. Life tables and development of Amblyseius swirskii (Acari: Phytoseiidae) at different temperatures.

    PubMed

    Lee, Heung-Su; Gillespie, David R

    2011-01-01

    Development time, reproduction, survival and sex ratio were determined for the omnivorous mite Amblyseius swirskii at nine constant temperatures (13, 15, 18, 20, 25, 30, 32, 34 and 36C) on pepper leaf disks with cattail, Typha latifolia, pollen for food. These data were used to derive life table parameters at these constant temperatures. No development was observed at 13C. The lower development threshold, based on the fit to the linear portion of the development curve, was 11.3C. The upper development threshold was 37.41.12C, and the optimum temperature was calculated to be 31.5C. Average lifetime fecundity ranged from a low of 1.30.24eggs/female at 15C to a high of 16.10.34 eggs/female at 25C, and r (m) was greatest at 32C. Non-linear regression of the relationship between temperature and r (m) produced an estimate of 15.490.905C for the lower threshold for population growth and 36.990.816C for the upper threshold for population growth, and an optimum temperature of 30.1C. These values suggest that A. swiskii populations should grow quickly in response to food availability (pollen or prey) between 20 and 32C, but that, especially below 20C, population growth could be slow and impacts on prey populations should be monitored carefully. PMID:20628894

  12. Fracture toughness and fracture behavior of SA508-III steel at different temperatures

    NASA Astrophysics Data System (ADS)

    Liu, Jia-hua; Wang, Lei; Liu, Yang; Song, Xiu; Luo, Jiong; Yuan, Dan

    2014-12-01

    The fracture toughness of SA508-III steel was studied in the temperature range from room temperature to 320C using the J-integral method. The fracture behavior of the steel was also investigated. It was found that the conditional fracture toughness ( J Q) of the steel first decreased and then increased with increasing test temperature. The maximum and minimum values of J Q were 517.4 kJ/m2 at 25C and 304.5 kJ/m2 at 180C, respectively. Dynamic strain aging (DSA) was also observed to occur when the temperature exceeded 260C with a certain strain rate. Both the dislocation density and the number of small dislocation cells effectively increased because of the occurrence of DSA; as a consequence, crack propagation was more strongly inhibited in the steel. Simultaneously, an increasing number of fine carbides precipitated under high stress at temperatures greater than 260C. Thus, the deformation resistance of the steel was improved and the J Q was enhanced.

  13. 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.

  14. Finite-element and finite-difference simulations of the mechanical behavior of austenitic steels at different strain rates and temperatures

    Microsoft Academic Search

    R. R. Balokhonov; V. A. Romanova; S. Schmauder

    2009-01-01

    Presented in this paper are the computational results on deformation of austenitic steels at different strain rates and temperatures. To describe the dynamic response of steels a relaxation constitutive equation was developed using a thermomechanical physically-based model. On the base of experimental data on uniaxial loading of new steels in the range of strain rates from 0.001 to 500s?1 the

  15. 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.

  16. Uncovering Different Masking Factors on Wrist Skin Temperature Rhythm in Free-Living Subjects

    PubMed Central

    Martinez-Nicolas, Antonio; Ortiz-Tudela, Elisabet; Rol, Maria Angeles; Madrid, Juan Antonio

    2013-01-01

    Most circadian rhythms are controlled by a major pacemaker located in the hypothalamic suprachiasmatic nucleus. Some of these rhythms, called marker rhythms, serve to characterize the timing of the internal temporal order. However, these variables are susceptible to masking effects as the result of activity, body position, light exposure, environmental temperature and sleep. Recently, wrist skin temperature (WT) has been proposed as a new index for evaluating circadian system status. In light of previous evidence suggesting the important relationship between WT and core body temperature regulation, the aim of this work was to purify the WT pattern in order to obtain its endogenous rhythm with the application of multiple demasking procedures. To this end, 103 subjects (1824 years old) were recruited and their WT, activity, body position, light exposure, environmental temperature and sleep were recorded under free-living conditions for 1 week. WT demasking by categories or intercepts was applied to simulate a constant routine protocol (awakening, dim light, recumbent position, low activity and warm environmental temperature). Although the overall circadian pattern of WT was similar regardless of the masking effects, its amplitude was the rhythmic parameter most affected by environmental conditions. The acrophase and mesor were determined to be the most robust parameters for characterizing this rhythm. In addition, a circadian modulation of the masking effect was found for each masking variable. WT rhythm exhibits a strong endogenous component, despite the existence of multiple external influences. This was evidenced by simultaneously eliminating the influence of activity, body position, light exposure, environmental temperature and sleep. We therefore propose that it could be considered a valuable and minimally-invasive means of recording circadian physiology in ambulatory conditions. PMID:23577201

  17. Strain fields for aluminum at different tooling temperatures and extrusion ratios

    SciTech Connect

    Peacock, H.B.; Berghaus, D.G.

    1985-03-01

    Strain distributions throughout the die region are obtained for axisymmetric extrusion of aluminum billets. Results which include the three extensional strains and accumulated shear are produced from an analysis of experimentally obtained laminar flow lines on extruded specimens. Extrusion experiments are performed at average tooling temperatures of 174/sup 0/C and 354/sup 0/C and for extrusion ratios from 1.9 to 12.4. Both tooling temperatures and extrusion ratios affect the magnitude and/or the distribution of plastic strains in extruded aluminum.

  18. Effect of composite resin polymerization modes on temperature rise in human dentin of different thicknesses: an in vitro study.

    PubMed

    Aguiar, Flvio Henrique Baggio; Barros, Gisele Kanda Peres; Lima, Dbora Alves Nunes Leite; Ambrosano, Glaucia Maria Bovi; Lovadino, Jos Roberto

    2006-09-01

    The aim of this in vitro study was to evaluate the effect of different polymerization modes on temperature rise in human dentin of different thicknesses, and to evaluate the relation between dentin thickness and temperature rise (TR). For this purpose, 60 specimens were assigned into 20 groups (n = 3): five polymerization modes (1-conventional; 2-soft-start; 3-high intensity; 4-ramp cure: progressive and high intensity; 5-high intensity with the tip of the light-curing unit at a distance of 1.3 cm for 10 s and the tip leaning on the sample) at four dentin thicknesses (0, 1, 2, 3 mm). During composite sample polymerization (2 mm), the temperature was measured by a digital laser thermometer (CMSS2000-SL/SKF). The statistical analyses were conducted by ANOVA (p = 0.05) and post-hoc Tukey's test. There were statistical differences of TR among polymerization modes and dentin thicknesses. The temperature rise was dependent on the polymerization mode and the dentin thickness: the thicker the dentin and the lower the polymerization mode energy, the lower the temperature rise. PMID:18458395

  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. Temperature sensitivity of extracellular enzyme kinetics in subtropical wetland soils under different nutrient and water level conditions

    NASA Astrophysics Data System (ADS)

    Goswami, S.; Inglett, K.; Inglett, P.

    2012-12-01

    Microbial extracellular enzymes play an important role in the initial steps of soil organic matter decomposition and are involved in regulating nutrient cycle processes. Moreover, with the recent concern of climate change, microbial extracellular enzymes may affect the functioning (C losses, C sequestration, greenhouse gas emissions, vegetation changes) of different ecosystems. Hence, it is imperative to understand the biogeochemical processes that may be climate change sensitive. Here, we have measured the Michaelis Menten Kinetics [maximal rate of velocity (Vmax) and half-saturation constant (Km)] of 6 enzymes involved in soil organic matter decomposition (phosphatase, phosphodiesterase, ?-D-glucosidase, cellobiohydrolase, leucine aminopeptidase, N-Acetyl-?-D glucosaminidase) in different nutrient(P) concentration both aerobically and anaerobically in Everglade water conservation area 2A (F1, F4-slough and U3-slough). Temperature sensitivity of different enzymes is assessed within soil of different P concentrations. We hypothesized that the temperature sensitivity of the enzyme changes with the biogeochemical conditions including water level and nutrient condition. Furthermore, we have tested specific hypothesis that higher P concentration will initiate more C demand for microbes leading to higher Vmax value for carbon processing enzymes in high P site. We found temperature sensitivity of all enzymes for Vmax and Km under both aerobic and anaerobic condition ranges from 0.6 to 3.2 for Vmax and 0.5 to 2.5 for Km. Q10 values of Km for glucosidase indicate more temperature sensitivity under anaerobic condition. Under aerobic condition higher temperature showed significant effect on Vmax for bisphosphatase between high P and low P site. Decreasing P concentration from F1 site to U3-S site had showed significant effect in all temperature on carbon processing enzyme. This suggests that in high P site, microbes will use more carbon-processing enzyme to get more carbon due to easily available P. N-Acetyl-?-D glucosaminidase, cellobiohydrolase, phosphatase showed significant site effect in 25C and 30C. Anaerobic condition also showed significant site effect on carbon processing enzyme's temperature sensitivity for Vmax. No enzyme showed significant interaction between sites and temperatures for Km. Only phosphatase showed significant interaction between site and temperature sensitivity for Km. Our results showed higher Q10 values for Vmax over Km; indicating more decomposition at higher temperature. In summary, the results suggest that increasing concentration of P will increase carbon processing enzyme activity that leads to higher decomposition rate.

  1. Genetic differences influencing behavioral temperature regulation in small mammals. I. Nesting by Mus musculus

    Microsoft Academic Search

    Carol Becker Lynch; Joseph P. Hegmann

    1972-01-01

    Nesting behavior was found to differ for animals of five different inbred strains ofMus musculus reared in the same environment, indicating heritable differences in level of nesting byMus. For two separate crosses, hybrid animals built larger nests than did animals of the inbred parental strains. In addition, from data of one of the crosses and derived generations, a very low

  2. 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...

  3. 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...

  4. Growth of Tiger Muskellunge Fed Different Amounts of Protein at Three Water Temperatures

    Microsoft Academic Search

    Carol A. Lemm; Donald V. Rottiers

    1986-01-01

    Growth rates of tiger muskellunge (muskellunge Esox masquinongy ? x northern pike E. lucius ?) fed diets containing 35, 45, or 55% crude protein for 5 weeks at 17, 20, or 23C were compared. Fish fed diets containing 45 or 55% protein grew faster at all temperatures than those fed 35% protein. Growth of tiger muskellunge fed a diet containing

  5. 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...

  6. Association of weekly suicide rates with temperature anomalies in two different climate types.

    PubMed

    Dixon, P Grady; Sinyor, Mark; Schaffer, Ayal; Levitt, Anthony; Haney, Christa R; Ellis, Kelsey N; Sheridan, Scott C

    2014-11-01

    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 (1986-2009) and Jackson, Mississippi, USA (1980-2006) 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

  7. Characteristics and nutrient values of biochars produced from giant reed at different temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Application of biochars to soils is suggested as an effective way for improving soil quality. To investigate the effect of pyrolysis temperature on properties and nutrients value, biochars were produced from giant reed [Arundo donax L.] at 300-600 degrees Celsius and characterized for their physical...

  8. Glacial-Postglacial Temperature Difference Deduced from Aspartic Acid Racemization in Fossil Bones

    Microsoft Academic Search

    Roy A. Schroeder; Jeffrey L. Bada

    1973-01-01

    The magnitude of the temperature increase that occurred in continental regions following the termination of the last glaciation has been determined from the degree of racemization of aspartic acid in fossil bones of known age. The results indicate an increase of 4 degrees C for the Mediterranean coast and 5 degrees to 6 degrees C for East Africa. These estimates

  9. 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

  10. 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...

  11. Comparison of diesel spray combustion in different high-temperature, high-pressure facilities.

    SciTech Connect

    Christiansen, Caspar (Technical University of Denmark); Hermant, Laurent (IFP); Malbec, Louis-Marie (IFP); Bruneaux, Gilles (IFP); Genzale, Caroline L.; Pickett, Lyle M.; Schramm, Jesper (Technical University of Denmark)

    2010-05-01

    Diesel spray experiments at controlled high-temperature and high-pressure conditions offer the potential for an improved understanding of diesel combustion, and for the development of more accurate CFD models that will ultimately be used to improve engine design. Several spray chamber facilities capable of high-temperature, high-pressure conditions typical of engine combustion have been developed, but uncertainties about their operation exist because of the uniqueness of each facility. For the IMEM meeting, we describe results from comparative studies using constant-volume vessels at Sandia National Laboratories and IFP. Targeting the same ambient gas conditions (900 K, 60 bar, 22.8 kg/m{sup 3}, 15% oxygen) and sharing the same injector (common rail, 1500 bar, KS1.5/86 nozzle, 0.090 mm orifice diameter, n-dodecane, 363 K), we describe detailed measurements of the temperature and pressure boundary conditions at each facility, followed by observations of spray penetration, ignition, and combustion using high-speed imaging. Performing experiments at the same high-temperature, high-pressure operating conditions is an objective of the Engine Combustion Network (http://www.ca.sandia.gov/ECN/), which seeks to leverage the research capabilities and advanced diagnostics of all participants in the ECN. We expect that this effort will generate a high-quality dataset to be used for advanced computational model development at engine conditions.

  12. TEMPERATURE INFLUENCES ON WATER PERMEABILITY AND CHLORPYRIFOS UPTAKE IN AQUATIC INSECTS WITH DIFFERING RESPIRATORY STRATEGIES

    Microsoft Academic Search

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

    2003-01-01

    C-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

  13. 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...

  14. Stress-strain behaviour of reconstituted illitic clay at different temperatures

    Microsoft Academic Search

    Naoto Tanaka; James Graham; Thomas Crilly

    1997-01-01

    Tests on specimens of reconstituted illitic clay have examined the influence of temperature on the mechanical behaviour of clay soils. The program involved consolidation to effective confining pressures up to 1.5 MPa, heating to 100C, and tests on normally consolidated and overconsolidated specimens with OCR = 2. The tests included isotropic consolidation, undrained triaxial compression with pore water pressure measurement,

  15. 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...

  16. 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...

  17. 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...

  18. Marine Heterotrophic Bacteria in Continuous Culture, the Bacterial Carbon Growth Efficiency, and Mineralization at Excess Substrate and Different Temperatures

    Microsoft Academic Search

    Alejandrina Jimnez-Mercado; Ramn Cajal-Medrano; Helmut Maske

    2007-01-01

    To model the physiological potential of marine heterotrophic bacteria, their role in the food web, and in the biogeochemical\\u000a carbon cycle, we need to know their growth efficiency response within a matrix of different temperatures and degrees of organic\\u000a substrate limitation. In this work, we present one part of this matrix, the carbon growth efficiencies of marine bacteria\\u000a under different

  19. Changes in the temperature of a dental light-cured composite resin by different light-curing units

    Microsoft Academic Search

    A. N. S. Rastelli; D. P. Jacomassi; V. S. Bagnato

    2008-01-01

    The purpose of this study was to evaluate the temperature increase during the polymerization process through the use of three different light-curing units with different irradiation times. One argon laser (Innova, Coherent), one halogen (Optilight 501, Demetron), and one blue LED (LEC 1000, MM Optics) LCU with 500 mW\\/cm2 during 5, 10, 20, 30, 40, 50, and 60 s of

  20. Changes in the temperature of a dental light-cured composite resin by different light-curing units

    Microsoft Academic Search

    A. N. S. Rastelli; D. P. Jacomassi; V. S. Bagnato

    2008-01-01

    The purpose of this study was to evaluate the temperature increase during the polymerization process through the use of three\\u000a different light-curing units with different irradiation times. One argon laser (Innova, Coherent), one halogen (Optilight\\u000a 501, Demetron), and one blue LED (LEC 1000, MM Optics) LCU with 500 mW\\/cm2 during 5, 10, 20, 30, 40, 50, and 60 s of

  1. 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.

  2. 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

  3. 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.

  4. 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; Mller, 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 ? values. Studies of the effect of roughness and surface flaws on wettability revealed that the cos ? 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.

  5. 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.

  6. 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...

  7. Fate of Listeria monocytogenes inoculated onto the surface of soudjouk and kippered beef and stored at different temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated the viability of Listeria monocytogenes on two ready-to-eat (RTE) specialty/ethnic meat products, namely soudjouk and kippered beef, during storage at different temperatures. Individual slices (1.5cm L x 2.0 cm W x 0.8 H) of these two products were separately inoculated on both the top ...

  8. 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 200C to 500C. 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 300C showed uniform polarization orientation together with higher piezoresponse magnitude.

  9. Collisional pumping of water masers by species of particles at different temperatures

    NASA Technical Reports Server (NTRS)

    Anderson, Nels; Watson, William D.

    1990-01-01

    It has been reported that the extreme power of astrophysical water masers can be obtained from purely collisional pumping in environments with two kinetic temepratures. It is found that this pumping vanishes when the latest rates are utilized for the collisional excitation of H2O molecules by neutrals. Energetic ions must also be present under the conditions that have been proposed for such 'two-temperature' pumping, but they have been ignored in the past due to lack of information about the relevant cross sections. Quantal, multichannel calculations in the impact parameter approximation are performed to provide a basis for estimating these rates for the collisional excitation of H2O molecules by ions. Including the effects of these ions does not restore the inversion, but rather reduces the pumping for H2O masers in the proposed 'two-temperature' environments.

  10. Combined effects of chemical and temperature stress on Chironomus riparius populations with differing genetic variability.

    PubMed

    Oetken, Matthias; Jagodzinski, Lucas S; Vogt, Christian; Jochum, Adrienne; Oehlmann, Jrg

    2009-08-01

    Exposure to pollutants under multiple environmental stressors (e.g., climate change and global warming) and the genetic diversity of populations are suspected to have serious impacts on populations and ecosystems but have only rarely been analysed. In the present study, we investigated the effects of the biocide tributyltin (TBT) within a temperature gradient (17, 20 and 23 degrees C) on life history parameters of a genetically diverse (GEN+) and a highly inbred population (GEN-) of the midge Chironomus riparius. While endpoints, mortality and reproduction parameters were considered, the population growth rate as an integrative endpoint was determined. We found severe effects for GEN-, indicating that populations with lower genetic diversity are more endangered by combined stressors such as increasing temperature and chemical pollution compared to genetically diverse populations. PMID:19827487

  11. Coupled removal of bisphenol A and copper ion by titanate nanotubes fabricated at different calcination temperatures

    Microsoft Academic Search

    Ruey-an Doong; Chia-wei Tsai; Chun-I Liao

    Onedimensional (1D) nanotubes are promising nanostructured materials for a wide variety of environmental applications. In this study, the 1D titanate nanotubes (TNTs) were fabricated using an alkaline hydrothermal method and then calcined at various temperatures ranging from 200600 C in air for 4 h for coupled removal of bisphenol A (BPA) and Cu(II) ion. The assynthesized TNTs showed tubular structures

  12. Effect of randomization on oxidative stability of vegetable oils at two different temperatures

    Microsoft Academic Search

    C. L. Tautorus; A. R. McCurdy

    1990-01-01

    Five vegetable oils were each randomized by chemical means (with the use of a sodium potassium alloy) and by enzymatic means\\u000a (using a nonspecific lipase). The success of the randomization procedure was confirmed via positional analysis. The oxidative\\u000a stabilities of the native and chemically randomized oils were determined at storage temperatures of 28C and 55C using absorbance\\u000a at 234 nm

  13. Difference characteristics of sea surface temperature observed by GLI and AMSR aboard ADEOS-II

    Microsoft Academic Search

    Kohtaro Hosoda; Hiroshi Murakami; Akira Shibata; Futoki Sakaida; Hiroshi Kawamura

    2006-01-01

    This study compares infrared and microwave measurements of sea surface temperature (SST) obtained by a single satellite. The\\u000a simultaneous observation from the Global Imager (GLI: infrared) and the Advanced Microwave Scanning Radiometer (AMSR: microwave)\\u000a aboard the Advanced Earth Observing Satellite-II (ADEOS-II) provided an opportunity for the intercomparison. The GLI-and AMSR-derived\\u000a SSTs from April to October 2003 are analyzed with other

  14. Respiratory metabolism of mosquitofish, Gambusia affinis : effects of temperature, dissolved oxygen, and sex difference

    Microsoft Academic Search

    Joseph J. Cech; Michael J. Massingill; Bruce Vondracek; Alison L. Linden

    1985-01-01

    Routine respiratory metabolic rates of mosquitofish (~0.2 g live weight) were determined at 10, 15, 20, 25, 30, and 35C at normoxic, hypoxic (= 40 torr PO2), and extreme hypoxic (= 25 torr PO2) conditions. Rates generally increased with increases in temperature (overall Q10 = 2.11 at normoxia). Significant depressions (PO2) at 25 and 30C, but not at 35C. Resting

  15. Temperature Distribution in Different Materials Due to Short Pulse Laser Irradiation

    Microsoft Academic Search

    Arindam Banerjee; Anil A. Ogale; Champak Das; Kunal Mitra; Chelakara Subramanian

    2005-01-01

    The purpose of this study is to analyze the heat-affected zone in materials such as meat samples, araldite resin-simulating tissue phantoms, and fiber composites irradiated using a mode-locked short pulse laser with a pulse width of 200 ps. The radial surface temperature profiles are compared with that of a continuous wave (CW) laser of the same average power. The short

  16. Near-threshold fatigue crack behaviour in EUROFER 97 at different temperatures

    Microsoft Academic Search

    J. Aktaa; M. Lerch

    2006-01-01

    The fatigue crack behaviour in EUROFER 97 was investigated at room temperature (RT), 300, 500 and 550C for the assessment of cracks in first wall structures built from EUROFER 97 of future fusion reactors. For this purpose, fatigue crack growth tests were performed using CT specimens with two R-ratios, R=0.1 and R=0.5 (R is the load ratio with R=Fmin\\/Fmax where

  17. 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...

  18. Electrophoretic Properties of Casein from Sterilized Milk Stored at Different Temperatures1

    Microsoft Academic Search

    Lalitha Murthy; E. O. Herreid; R. Mc L. Whitney

    1958-01-01

    R. M~'L. WHITNEY Departme~t of Food TveI~ology, Uniformity of lllh~ois, ~rba~a SUMMARY High-temperature short-time steriliz~tion of nlilk did not hydrolyze the proteins but it denatured some serum proteins which were precipitated with the casein, and either moved at the same mobility at pH 8.7 as u-casein, or was associated with it and increased the area under the peak. A split

  19. 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 (Ca 10(PO 4) 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 ?C 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.

  20. 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

  1. [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

  2. Evaluation of the accuracy of different methods of monitoring body temperature in anesthetized brown bears (Ursus arctos).

    PubMed

    Ozeki, Larissa Mourad; Fahlman, Asa; Stenhouse, Gordon; Arnemo, Jon M; Caulkett, Nigel

    2014-12-01

    There is some evidence that the handheld rectal thermometer does not accurately measure core temperature in bears. The objective of this study was to compare body temperature measured by the handheld digital thermometer (HDT), deep rectally inserted core temperature capsules (CTCs), and gastrically inserted CTCs in anesthetized brown bears (Ursus arctos). Twenty-two brown bears were immobilized with a combination of zolazepam-tiletamine and xylazine or medetomidine. After immobilization, one CTC was inserted 15 cm deep into the animal's rectum (DRTC) with a standard applicator, and another CTC was inserted into the stomach (GTC) via a gastric tube inserted orally. Temperature was measured every 5-10 min with an HDT. Paired temperature data points were analyzed with the Bland-Altman technique for repeated measurements and regression analysis with a significance level of 0.05. The mean difference SD of the difference between HDT and GTC readings was 0.27 0.47 degrees C and the 95% limits of agreement (LoA) were 1.20 and -0.66 degrees C. The determination coefficient (r2) found between these methods was 0.68 (P < 0.0001). The mean difference SD of the difference between HDT and DRTC readings was 0.36 0.32 degreesC and the 95% LoA were 1.0 and -0.28 degrees C. The r2 between HDT and DRTC was 0.83 (P < 0.0001). The mean difference SD of the difference between the two insertions of the VitalSense capsules was -0.06 0.24 degrees C and the 95% LoA were 0.42 and -0.54 degrees C. The r2 found between GTC and DRTC was 0.91 (P < 0.0001). This study demonstrates that DRTC provided accurate measurement of core temperature and that HDT did not accurately measure core temperature, compared with GTC in anesthetized brown bears. PMID:25632668

  3. Synthesis of zeolite from Italian coal fly ash: Differences in crystallization temperature using seawater instead of distilled water

    SciTech Connect

    Belviso, Claudia, E-mail: belviso@imaa.cnr.i [Laboratory of Environmental and Medical Geology, IMAA-CNR, Tito Scalo (Italy); Cavalcante, Francesco; Fiore, Saverio [Laboratory of Environmental and Medical Geology, IMAA-CNR, Tito Scalo (Italy)

    2010-05-15

    In this study Italian coal fly ash was converted into several types of zeolite in laboratory experiments with temperatures of crystallization ranging from 35 up to 90 deg. C. Distilled and seawater were used during the hydrothermal synthesis process in separate experiments, after a pre-treatment fusion with NaOH. The results indicate that zeolites could be formed from different kind of Italian coal fly ash at low temperature of crystallization using both distilled and seawater. SEM data and the powder patterns of X-ray diffraction analysis show that faujasite, zeolite ZK-5 and sodalite were synthesized when using both distilled and seawater; zeolite A crystallized only using distilled water. In particular the experiments indicate that the synthesis of zeolite X and zeolite ZK-5 takes place at lower temperatures when using seawater (35 and 45 deg. C, respectively). The formation of sodalite is always competitive with zeolite X which shows a metastable behaviour at higher temperatures (70-90 deg. C). The chemical composition of the fly ash source could be responsible of the differences on the starting time of synthesized zeolite with distilled water, in any case our data show that the formation of specific zeolites takes place always at lower temperatures when using seawater.

  4. Environmental systems biology of cold-tolerant phenotype in Saccharomyces species adapted to grow at different temperatures.

    PubMed

    Paget, Caroline Mary; Schwartz, Jean-Marc; Delneri, Daniela

    2014-11-01

    Temperature is one of the leading factors that drive adaptation of organisms and ecosystems. Remarkably, many closely related species share the same habitat because of their different temporal or micro-spatial thermal adaptation. In this study, we seek to find the underlying molecular mechanisms of the cold-tolerant phenotype of closely related yeast species adapted to grow at different temperatures, namely S.kudriavzevii CA111 (cryo-tolerant) and S.cerevisiae 96.2 (thermo-tolerant). Using two different systems approaches, i. thermodynamic-based analysis of a genome-scale metabolic model of S.cerevisiae and ii. large-scale competition experiment of the yeast heterozygote mutant collection, genes and pathways important for the growth at low temperature were identified. In particular, defects in lipid metabolism, oxidoreductase and vitamin pathways affected yeast fitness at cold. Combining the data from both studies, a list of candidate genes was generated and mutants for two predicted cold-favouring genes, GUT2 and ADH3, were created in two natural isolates. Compared with the parental strains, these mutants showed lower fitness at cold temperatures, with S.kudriavzevii displaying the strongest defect. Strikingly, in S.kudriavzevii, these mutations also significantly improve the growth at warm temperatures. In addition, overexpression of ADH3 in S.cerevisiae increased its fitness at cold. These results suggest that temperature-induced redox imbalances could be compensated by increased glycerol accumulation or production of cytosolic acetaldehyde through the deletion of GUT2 or ADH3, respectively. PMID:25243355

  5. Parametric Evaluation of Large-Scale High-Temperature Electrolysis Hydrogen Production Using Different Advanced Nuclear Reactor Heat Sources

    SciTech Connect

    Edwin A. Harvego; Michael G. McKellar; James E. O'Brien; J. Stephen Herring

    2009-09-01

    High Temperature Electrolysis (HTE), when coupled to an advanced nuclear reactor capable of operating at reactor outlet temperatures of 800 C to 950 C, has the potential to efficiently produce the large quantities of hydrogen needed to meet future energy and transportation needs. To evaluate the potential benefits of nuclear-driven hydrogen production, the UniSim process analysis software was used to evaluate different reactor concepts coupled to a reference HTE process design concept. The reference HTE concept included an Intermediate Heat Exchanger and intermediate helium loop to separate the reactor primary system from the HTE process loops and additional heat exchangers to transfer reactor heat from the intermediate loop to the HTE process loops. The two process loops consisted of the water/steam loop feeding the cathode side of a HTE electrolysis stack, and the sweep gas loop used to remove oxygen from the anode side. The UniSim model of the process loops included pumps to circulate the working fluids and heat exchangers to recover heat from the oxygen and hydrogen product streams to improve the overall hydrogen production efficiencies. The reference HTE process loop model was coupled to separate UniSim models developed for three different advanced reactor concepts (a high-temperature helium cooled reactor concept and two different supercritical CO2 reactor concepts). Sensitivity studies were then performed to evaluate the affect of reactor outlet temperature on the power cycle efficiency and overall hydrogen production efficiency for each of the reactor power cycles. The results of these sensitivity studies showed that overall power cycle and hydrogen production efficiencies increased with reactor outlet temperature, but the power cycles producing the highest efficiencies varied depending on the temperature range considered.

  6. Headwater stream temperature response to clear-cut harvesting with different riparian treatments, coastal British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Gomi, Takashi; Moore, R. Dan; Dhakal, Amod S.

    2006-08-01

    A 6-year study documented the effects of clear-cut harvesting with and without riparian buffers (10 m and 30 m wide) on headwater stream temperature in coastal British Columbia. The experiment involved a replicated paired catchment design. Pretreatment calibration relations between the treatment and control streams were fitted using time series of daily minimum, mean, and maximum temperatures. Generalized least squares (GLS) regression was used to account for autocorrelation in the residuals. While water temperature in streams with 10 and 30 m buffers did not exhibit marked warming, daily maximum temperature in summer increased by up to 2-8C in the streams with no buffer. The effectiveness of the buffers may have been maximized by the north-south orientation of the streams, which meant that the streams would be well shaded from late morning to early afternoon by the overhead canopy, even under the 10 m buffer. The variation in response for the no-buffer treatments is consistent with the differences in channel morphology that influence their exposure to solar radiation and their depth. Relations between treatment effect and daily maximum air temperature suggested that recovery toward preharvest temperature conditions was occurring, with rates appearing to vary with stream and by season.

  7. Comparison of bacterial community changes in fermenting kimchi at two different temperatures using a denaturing gradient gel electrophoresis analysis.

    PubMed

    Hong, Yeun; Yang, Hee-Seok; Chang, Hae-Choon; Kim, Hae-Yeong

    2013-01-01

    A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique followed by sequencing of the 16S rDNA fragments eluted from the bands of interest on denaturing gradient gels was used to monitor changes in the bacterial microflora of two commercial kimchi, salted cabbage, and ingredient mix samples during 30 days of fermentation at 4C and 10C. Leuconostoc (Lc.) was the dominant lactic acid bacteria (LAB) over Lactobacillus (Lb.) species at 4C. Weissella confusa was detected in the ingredient mix and also in kimchi samples throughout fermentation in both samples at 4C and 10C. Lc. gelidum was detected as the dominant LAB at 4C in both samples. The temperature affected the LAB profile of kimchi by varing the pH, which was primarily caused by the temperature-dependent competition among different LAB species in kimchi. At 4C, the sample variations in pH and titratable acidity were more conspicuous owing to the delayed growth of LAB. Temperature affected only initial decreases in pH and initial increases in viable cell counts, but affected both the initial increases and final values of titratable acidity. The initial microflora in the kimchi sample was probably determined by the microflora of the ingredient mix, not by that of the salted cabbage. The microbial distributions in the samples used in this study resembled across the different kimchi samples and the different fermentation temperatures as the numbers of LAB increased and titratable acidity decreased. PMID:23314371

  8. Excitonic BCS-BEC crossover at finite temperature: Effects of repulsion and electron-hole mass difference

    SciTech Connect

    Tomio, Yuh; Honda, Kotaro; Ogawa, Tetsuo [CREST, JST, and Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2006-06-15

    The BCS to Bose-Einstein condensation (BEC) crossover of electron-hole (e-h) pairs in optically excited semiconductors is studied using the two-band Hubbard model with both repulsive and attractive interactions. Applying the self-consistent t-matrix approximation combined with a local approximation, we examine the properties of a normal phase and an excitonic instability. The transition temperature from the normal phase to an e-h pair condensed one is studied to clarify the crossover from an e-h BCS-like state to an excitonic Bose-Einstein condensation, which takes place on increasing the e-h attraction strength. To investigate effects of the repulsive interaction and the e-h mass difference, we calculate the transition temperature for various parameters of the interaction strengths, the e-h particle density, and the mass difference. While the transition temperature in the e-h BCS regime is sufficiently suppressed by the repulsive interaction, that of the excitonic BEC is largely insensitive to it. We also show quantitatively that in the whole regime the mass difference leads to large suppression of the transition temperature.

  9. Genetically distinct populations of northern shrimp, Pandalus borealis, in the North Atlantic: adaptation to different temperatures as an isolation factor.

    PubMed

    Jorde, Per Erik; Svik, Guldborg; Westgaard, Jon-Ivar; Albretsen, Jon; Andr, Carl; Hvingel, Carsten; Johansen, Torild; Sandvik, Anne Dagrun; Kingsley, Michael; Jrstad, Knut Eirik

    2015-04-01

    The large-scale population genetic structure of northern shrimp, Pandalus borealis, was investigated over the species' range in the North Atlantic, identifying multiple genetically distinct groups. Genetic divergence among sample localities varied among 10 microsatellite loci (range: FST =-0.0002 to 0.0475) with a highly significant average (FST =0.0149; P<0.0001). In contrast, little or no genetic differences were observed among temporal replicates from the same localities (FST =0.0004; P=0.33). Spatial genetic patterns were compared to geographic distances, patterns of larval drift obtained through oceanographic modelling, and temperature differences, within a multiple linear regression framework. The best-fit model included all three factors and explained approximately 29% of all spatial genetic divergence. However, geographic distance and larval drift alone had only minor effects (2.5-4.7%) on large-scale genetic differentiation patterns, whereas bottom temperature differences explained most (26%). Larval drift was found to promote genetic homogeneity in parts of the study area with strong currents, but appeared ineffective across large temperature gradients. These findings highlight the breakdown of gene flow in a species with a long pelagic larval phase (up to 3months) and indicate a role for local adaptation to temperature conditions in promoting evolutionary diversification and speciation in the marine environment. PMID:25782085

  10. The Effect of Simulating Different Intermediate Host Snail Species on the Link between Water Temperature and Schistosomiasis Risk

    PubMed Central

    McCreesh, Nicky; Booth, Mark

    2014-01-01

    Introduction A number of studies have attempted to predict the effects of climate change on schistosomiasis risk. The importance of considering different species of intermediate host snails separately has never previously been explored. Methods An agent-based model of water temperature and Biomphalaria pfeifferi population dynamics and Schistosoma mansoni transmission was parameterised to two additional species of snail: B. glabrata and B. alexandrina. Results Simulated B. alexandrina populations had lower minimum and maximum temperatures for survival than B. pfeifferi populations (12.529.5C vs. 14.031.5C). B. glabrata populations survived over a smaller range of temperatures than either B. pfeifferi or B. alexandrina (17.0C29.5C). Infection risk peaked at 16.5C, 25.0C and 19.0C respectively when B. pfeifferi, B. glabrata and B. alexandrina were simulated. For all species, infection risk increased sharply once a minimum temperature was reached. Conclusions The results from all three species suggest that infection risk may increase dramatically with small increases in temperature in areas at or near the currents limits of schistosome transmission. The effect of small increases in temperature in areas where schistosomiasis is currently found will depend both on current temperatures and on the species of snail acting as intermediate host(s) in the area. In most areas where B. pfeifferi is the host, infection risk is likely to decrease. In cooler areas where B. glabrata is the host, infection risk may increase slightly. In cooler areas where B. alexandrina is the host, infection risk may more than double with only 2C increase in temperature. Our results show that it is crucial to consider the species of intermediate host when attempting to predict the effects of climate change on schistosomiasis. PMID:24988377

  11. Temperature dependence of APD-based PET scanners

    SciTech Connect

    Keereman, Vincent; Van Holen, Roel; Vandenberghe, Stefaan; Vanhove, Christian [MEDISIP, Department of Electronics and Information Systems, Ghent University-iMinds-IBiTech, De Pintelaan 185, B-9000 Ghent (Belgium)] [MEDISIP, Department of Electronics and Information Systems, Ghent University-iMinds-IBiTech, De Pintelaan 185, B-9000 Ghent (Belgium)

    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.

  12. Why COBE and CN spectroscopy cosmic background radiation temperature measurements differ, and a remedy

    NASA Astrophysics Data System (ADS)

    Leach, Sydney

    2012-04-01

    In 2004, the cosmic background radiation (CBR) temperature T?(CN) determined from interstellar CN absorption spectra was found to be 50 20 mK higher than the COBE bolometer measured value. It was proposed that this was due, at least in part, to an error in the evaluation of the rotational components of the oscillator strengths of the rovibronic transitions corresponding to the CN B 2?+-X 2?+(0 - 0), R(0), R(1) and P(1) lines. Corrections to the standard Hnl-London (HL) rotational line intensity factors used were determined. New data on interstellar CN absorption show that T?(CN) is 29 2 mK greater than the latest value of the cosmological CBR temperature, T?(COBE) = 2.72548 0.00057 K. These new results and CN fluorescence lifetime data are shown to give similar derived values for improved HL corrections as well as providing further evidence for the intramolecular coupling between the relevant B 2?+ state rotational levels and close-lying levels of the A 2? state which invalidates the standard HL factors. Revised HL factors may be required in future T?(CN) measurements, in particular in high-redshift sites, which cannot be studied by bolometric means.

  13. Formation of methyl benzoate from cocaine hydrochloride under different temperatures and humidities

    NASA Astrophysics Data System (ADS)

    Dejarme, Lindy E.; Gooding, Rachel E.; Lawhon, Sara J.; Ray, Prasenjit; Kuhlman, Michael R.

    1997-02-01

    It is of interest for drug enforcement agencies to know the fate of cocaine hydrochloride when in storage. Reported here are results obtained on vapor samples collected from cocaine hydrochloride stored under several combinations of temperature and humidity. The storage conditions were varied from ambient temperature to 40 degrees C and from zero humidification to 80 percent relative humidity. Cocaine hydrochloride samples were coated onto glass beads and loaded into a glass reactor which was in turn placed inside a heated metal chamber. Ultra-zero air, conditioned to the desired humidification, was purged into the glass container, through the glass frit, over the coated beads, and the exit gas was collected onto a sorbent tube packed with Tenax TA. Any chemical product arising from the interaction between cocaine hydrochloride and the flowing air was effectively collected onto the sorbent tube, which was analyzed using a split column GC/MS technique. The results of these storage experiments showed that methyl benzoate is a predominant volatile product, even at zero percent humidification. The average formation of methyl benzoate was found to range from 1.89 ng/min with ambient/dry conditions after one hour to 62 ng.min at 40 degrees C/80 percent RH upon introduction of flowing air. These results indicate that cocaine hydrochloride exposed to any realistic humidity level in the environment will produce methyl benzoate, a volatile organic material which can be much more readily detected than cocaine hydrochloride itself.

  14. Influence of thermodisinfection and duration of cryopreservation at different temperatures on pull out strength of cancellous bone.

    PubMed

    Flsch, Christian; Mittelmeier, Wolfram; von Garrel, Thomas; Bilderbeek, Uwe; Timmesfeld, Nina; Pruss, Axel; Matter, Hans-Peter

    2015-03-01

    Thermodisinfection of human femoral heads from living donors harvested during hip joint replacement is an established processing procedure. This study was designed to examine the influence of heat sterilization on pull out strength of cancellous bone and storage at different temperatures up to 2years since we had previously studied the storage of unprocessed cancellous bone. Porcine cancellous bone resembling human bone structure was obtained from 140 proximal humerus of 6-8months old piglets. Pull out strength of screws after thermodisinfection was compared with unprocessed cancellous bone and tested immediately and after 6, 12 and 24months of storage at -20 and -80C. A three-way ANOVA was performed and significance level was 5%. The thermodisinfected bone showed a pull out force of 2729N (1657-3568N). The reduction of pull out strength compared with unprocessed bone over all periods of storage was 276N on average with 95% confidence interval ranging from 166N to 389N (p<0.0001). Different freezing temperatures did not influence this mechanic property within 24months storage and showed no difference compared with fresh frozen bone. Thermodisinfection of cancellous bone preserves tensile strength necessary for clinical purposes. The storage at -20C for at least 2years did not show relevant decrease of pull out strength compared with -80C without difference between thermodisinfected and fresh frozen bone. The increase of the storage temperature to -20C for at least 2years should be considered. PMID:24692177

  15. Apparent digestibility of protein, amino acids and energy in rainbow trout ( Oncorhynchus mykiss) fed a fish meal based diet extruded at different temperatures

    Microsoft Academic Search

    M Srensen; K Ljkjel; T Storebakken; K. D Shearer; A Skrede

    2002-01-01

    A fish meal\\/wheat flour based dry ingredient mix was extruded at three different temperatures (100, 125 and 150 C), by varying extrusion conditions according to two different methods. Employing method 1, the temperature of the conditioner, torque, screw speed, pressure, feed rate and process water of the extruder were varied. Whereas in method 2, conditioner temperature and screw speed were

  16. Generalized Thermoelastic Medium with Temperature-Dependent Properties for Different Theories under the Effect of Gravity Field

    NASA Astrophysics Data System (ADS)

    Othman, Mohamed I. A.; Elmaklizi, Yassmin D.; Said, Samia M.

    2013-03-01

    The problem of the generalized thermoelastic medium for three different theories under the effect of a gravity field is investigated. The Lord-Shulman (L-S), Green-Lindsay (G-L), and classical-coupled (CD) theories are discussed. The modulus of the elasticity is given as a linear function of the reference temperature. The exact expressions for the displacement components, temperature, and stress components are obtained by using normal mode analysis. Numerical results for the field quantities are given in the physical domain and illustrated graphically in the absence and presence of gravity. A comparison also is made between the three theories for the results with and without a temperature dependence.

  17. Evaluation of bioactive compounds of black mulberry juice after thermal, microwave, ultrasonic processing, and storage at different temperatures.

    PubMed

    Jiang, Bo; Mantri, Nitin; Hu, Ya; Lu, Jiayin; Jiang, Wu; Lu, Hongfei

    2014-06-10

    The effect of different sterilization methods (thermal, microwave, and ultrasonic processing) on the main bioactive compounds and antioxidant activity of black mulberry juice during selected storage time (8 days) and temperatures (5, 15, and 25??) was investigated. The antioxidant activity of thermal-treated juice depleted with storage time, whilst both ultrasound- and microwave-treated juices showed transient increase in antioxidant activity during the first 2 days that later decreased with storage time. Lower temperature storage preserved more bioactive compounds and antioxidant activity, especially in ultrasound sterilized samples. The activation energy values were 15.99, 13.07, and 12.81?kJ/mol for ultrasonic, microwave, and thermal pasteurization processes, respectively. In general, ultrasound-sterilized samples showed higher total phenolics, anthocyanin, and antioxidant activity compared to the microwave- and thermal-processed juice during the storage time especially at lower temperatures. PMID:24917651

  18. Assessment of Red Blood Cell Parameters and Peripheral Smear at Different Temperatures in Case of Cold Agglutination Disease

    PubMed Central

    Gupta, V

    2014-01-01

    Cold agglutination disease (CAD) is characterized by an auto-antibody which is able to agglutinate red blood cells (RBCs) at temperatures lower than that of the body, and subsequently to activate the complement system responsible for lysis of RBCs. Patients show hemolytic anemia of varying degrees of severity, which arise or worsen upon exposure to low temperatures. We describe a case who presented with fever and symptoms of asthenia. His investigations yielded bizarre RBC parameters which led to suspicion of a rare CAD, which was confirmed on reviewing RBC parameters, peripheral smear and direct Coomb's test at different temperatures. Hence, we suggest assessment of bizarre RBC parameters and peripheral smear can help in laboratory testing and diagnosis of CAD. It should also not pose embarrassment in laboratory testing to the pathologist for making an early and accurate diagnosis, thus emphasizing the need for an early treatment of CAD. PMID:25031901

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

    PubMed Central

    Jallow, Demba B.; Hsia, Liang Chou

    2014-01-01

    The objective of this study was to investigate the influence of ambient temperatures on carcass characteristics of lambs fed concentrate diets with or without NaHCO3 supplementation. A slaughter study was carried on 12 male Black Belly Barbados lambs randomly drawn from a growth trial (35 weeks). The lambs were divided into four equal groups and allotted in a 22 factorial design. The lambs were allotted at random to two dietary treatments of a basal diet (35:65 roughage:concentrate) or basal diet supplemented with 4% NaHCO3 at different ambient temperatures (20C and 30C) in an environment controlled chamber for 10 days. Lambs were slaughtered for carcass evaluation at about 262 days of age (245 days of growth trial, 7 days adaptation and 10 days of experimental period). Ambient temperature had significant (p<0.05, p<0.05, p<0.01, and p<0.001) effects on meat color from the ribeye area (REA), fat, leg and longissimus dorsi muscles with higher values recorded for lambs in the lower temperature group than those from the higher ambient temperature group. Significant differences (p<0.05) in shear force value (kg/cm2) recorded on the leg muscles showed higher values (5.32 vs 4.16) in lambs under the lower ambient temperature group compared to the other group. Dietary treatments had significant (p<0.01, p<0.01, and p<0.05) effects on meat color from the REA, fat, and REA fat depth (cm2) with higher values recorded for lambs in the NaHCO3 supplementation group than the non supplemented group. Similarly, dietary treatments had significant differences (p<0.05) in shear force value (kg/cm2) of the leg muscles with the NaHCO3 groups recording higher (5.30 vs 4.60) values than those from the other group. Neither ambient temperature nor dietary treatments had any significant (p>0.05) effects on pH, and water holding capacity on both muscles. These results indicated that NaHCO3 supplementation at low ambient temperatures had caused an increase in carcass characteristics leading to significant effect on meat quality. PMID:25083103

  20. Temperature rise caused in the pulp chamber under simulated intrapulpal microcirculation with different light-curing modes.

    PubMed

    Ramoglu, Sabri Ilhan; Karamehmetoglu, Hilal; Sari, Tugrul; Usumez, Serdar

    2014-10-15

    ABSTRACT Objective: To evaluate and compare intrapulpal temperature rise with three different light-curing units by using a study model simulating pulpal blood microcirculation. Materials and Methods: The roots of 10 extracted intact maxillary central incisors were separated approximately 2mm below the cement-enamel junction. The crowns of these teeth were fixed on an apparatus for the simulation of blood microcirculation in pulp. A J-type thermocouple wire was inserted into the pulp chamber through a drilled access on the palatal surfaces of the teeth. Four measurements were made using each tooth for four different modes: group 1, 1000mW/cm(2) for 15seconds; group 2, 1200mW/cm(2) for 10seconds; group 3, 1400mW/cm(2) for 8seconds; and group 4, 3200mW/cm(2) for 3seconds. The tip of the light source was positioned at 2mm to the incisor's labial surface. Results: The highest temperature rise was recorded in group 1 (2.6C 0.54C), followed by group 2 (2.57C 0.62C) and group 3 (2.35C 0.61C). The lowest temperature rise value was found in group 4 (1.74C 0.52C); this value represented significantly lower ?T values when compared to group 1 and group 2 (P ?=? .01 and P ?=? .013, respectively). Conclusions: The lowest intrapulpal temperature rise was induced by 3200mW/cm(2) for 3seconds of irradiation. Despite the significant differences among the groups, the temperature increases recorded for all groups were below the critical value of 5.6C. PMID:25317750

  1. Biodegradation of dispersed Macondo oil in seawater at low temperature and different oil droplet sizes.

    PubMed

    Brakstad, Odd G; Nordtug, Trond; Throne-Holst, Mimmi

    2015-04-15

    During the Deepwater Horizon (DWH) accident in 2010 a dispersant (Corexit 9500) was applied at the wellhead to disperse the Macondo oil and reduce the formation of surface slicks. A subsurface plume of small oil droplets was generated near the leaking well at 900-1300m depth. A novel laboratory system was established to investigate biodegradation of small droplet oil dispersions (10?m or 30?m droplet sizes) of the Macondo oil premixed with Corexit 9500, using coastal Norwegian seawater at a temperature similar to the DWH plume (4-5C). Biotransformation of volatile and semivolatile hydrocarbons and oil compound groups was generally faster in the 10?m than in the 30?m dispersions, showing the importance of oil droplet size for biodegradation. These data therefore indicated that dispersant treatment to reduce the oil droplet size may increase the biodegradation rates of oil compounds in the deepwater oil droplets. PMID:25746198

  2. Ocean surface temperature variability: large model-data differences at decadal and longer periods.

    PubMed

    Laepple, Thomas; Huybers, Peter

    2014-11-25

    The variability of sea surface temperatures (SSTs) at multidecadal and longer timescales is poorly constrained, primarily because instrumental records are short and proxy records are noisy. Through applying a new noise filtering technique to a global network of late Holocene SST proxies, we estimate SST variability between annual and millennial timescales. Filtered estimates of SST variability obtained from coral, foraminifer, and alkenone records are shown to be consistent with one another and with instrumental records in the frequency bands at which they overlap. General circulation models, however, simulate SST variability that is systematically smaller than instrumental and proxy-based estimates. Discrepancies in variability are largest at low latitudes and increase with timescale, reaching two orders of magnitude for tropical variability at millennial timescales. This result implies major deficiencies in observational estimates or model simulations, or both, and has implications for the attribution of past variations and prediction of future change. PMID:25385623

  3. Cavitation erosion of silver plated coating at different temperatures and pressures

    SciTech Connect

    Hattori, Shuji; Motoi, Yoshihiro [Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fuku-shi, Fukui 910-8507 (Japan); Kikuta, Kengo; Tomaru, Hiroshi [IHI Corperation, TOYOSU IHI BUILDING, 1-1, Toyosu 3-chome, Koto-ku, Tokyo 1358710 (Japan)

    2014-04-11

    Cavitation often occurs in inducer pumps used for space rockets. Silver plated coating on the inducer liner faces the damage of cavitation. Therefore, it is important to study about the cavitation erosion resistance for silver plated coating at several operating conditions in the inducer pumps. In this study, the cavitation erosion tests were carried for silver plated coating in deionized water and ethanol at several liquid temperatures (273K400K) and pressures (0.10MPa0.48MPa). The mass loss rate is evaluated in terms of thermodynamic parameter ? proposed by Brennen [9], suppression pressure pp{sub v} (p{sub v}: saturated vapor pressure) and acoustic impedance ?c (?: density and c: sound speed). Cavitation bubble behaviors depending on the thermodynamic effect and the liquid type were observed by high speed video camera. The mass loss rate is formulated by thermodynamic parameter ?, suppression pressure pp{sub v} and acoustic impedance ?c.

  4. Microbial dynamics in acetate-enriched ballast water at different temperatures.

    PubMed

    Stehouwer, Peter Paul; van Slooten, Cees; Peperzak, Louis

    2013-10-01

    The spread of invasive species through ships' ballast water is considered as a major ecological threat to the world's oceans. For that reason, the International Maritime Organization (IMO) has set performance standards for ballast water discharge. Ballast water treatment systems have been developed that employ either UV-radiation or 'active substances' to reduce the concentration of living cells to below the IMOs standards. One such active substance is a chemical mixture known as Peraclean() Ocean. The residual of Peraclean() Ocean is acetate that might be present at high concentrations in discharged ballast water. In cold coastal waters the breakdown of acetate might be slow, causing a buildup of acetate concentrations in the water if regularly discharged by ships. To study the potential environmental impact, microbial dynamics and acetate degradation were measured in discharge water from a Peraclean() Ocean treatment system in illuminated microcosms. In addition, microbial dynamics and acetate degradation were studied at -1, 4, 10, 15 and 25C in dark microcosms that simulated enclosed ballast water tanks. Acetate breakdown indeed occurred faster at higher temperatures. At 25C the highest bacteria growth, fastest nutrient and oxygen consumption and highest DOC reduction occurred. On the other hand, at -1C bacterial growth was strongly delayed, only starting to increase after 12 days. Furthermore, at 25C the acetate pool was not depleted, probably due to nutrient and oxygen limitation. This means that not all acetate will be broken down in ballast water tanks, even during long voyages in warm waters. In addition, at low temperatures acetate breakdown in ballast water tanks and in discharged water will be extremely slow. Therefore, regular discharge of acetate enriched ballast water in harbors and bays may cause eutrophication and changes in the microbial community, especially in colder regions. PMID:23871568

  5. Equilibrium adsorption studies of some aromatic pollutants from dilute aqueous solutions on activated carbon at different temperatures

    SciTech Connect

    Khan, A.R.; Ataullah, R.; Al-Haddad, A. [Kuwait Univ., Safat (Kuwait). Dept. of Chemical Engineering] [Kuwait Univ., Safat (Kuwait). Dept. of Chemical Engineering

    1997-10-01

    Aqueous solutions of phenol, p-chlorophenol, and p-nitrophenol have been used to determine the adsorption isotherm for single solute systems on activated carbon at different temperatures. The experimental program has been conducted to investigate the influence of concentration and temperature. All the reported equilibrium isotherm equations have been tried on present and published experimental data. A generalized isotherm equation which was proposed by Khan et al. and tested for bi-solute adsorption data has been modified for single-solute system. The temperature dependency has also been incorporated into a generalized equation. It has been noticed that the Radke and Prausnitz and generalized isotherm equations could represent the entire data with a minimum average percentage error. The influence of different adsorbents, sorbate concentrations, and pH of aqueous solutions has also been discussed in detail. The temperature dependency has been investigated using both the Dubinin-Astakov and the modified generalized equation. The generalized equation describes the experimental and published data adequately and provides a single value of differential molar heat of adsorption, {Delta}H{sub ads}, for a single solute adsorption system. The Dubinin-Astakov isotherm equation has shown an increasing trend of {Delta}H{sub ads} as the loading of adsorbent has increased.

  6. A modelling study of the performance of conventional diffused P/N junction and heterojunction solar cells at different temperatures

    NASA Astrophysics Data System (ADS)

    Chakraborty, S.; Datta, A.; Labrune, M.; Cabarrocas, P. Roca i.; Chatterjee, P.

    2013-09-01

    Conventional crystalline silicon (c-Si) diffused P/N junction solar cells remain the largest contributor to solar electricity. In order to retain a high efficiency and as well, reduce the cost of solar electricity, Sanyo has proposed the "heterojunction with intrinsic thin layer (HIT)" solar cells where the emitter and the back surface field layers are deposited using low temperature (<200 C) plasma processes, thus reducing the thermal budget and allowing for thinner wafers. Since solar cells are used in extremes of climate, we felt that it would be interesting to study the behaviour of c-Si and HIT cells, based on both P- and N-type wafers at different temperatures. Our results indicate that in HIT cells the amorphous doped layers form a heterojunction on the c-Si substrate, with a large valence band discontinuity that acts as a barrier for hole collection, specially at low temperatures. It is the aim of this article to investigate the effect of this valence band offset on solar cell performance at different ambient temperatures.

  7. Characteristics of easterly-induced snowfall in Yeongdong and its relationship to air-sea temperature difference

    NASA Astrophysics Data System (ADS)

    Nam, Hyoung-Gu; Kim, Byung-Gon; Han, Sang-Ok; Lee, Chulkyu; Lee, Seoung-Soo

    2014-08-01

    Characteristics of snowfall episodes have been investigated for the past ten years in order to study its association with lowlevel stability and air-sea temperature difference over the East Sea. In general, the selected snowfall episodes have similar synoptic setting such as the Siberian High extended to northern Japan along with the Low passing by the southern Korean Peninsula, eventually resulting in the easterly flow in the Yeongdong region. Especially in the heavy snowfall episodes, convective unstable layers have been identified over the East sea due to relatively warm sea surface temperature (SST) about 810C and specifically cold pool around 12 km above the surface level (ASL), which can be derived from Regional Data Assimilation and Prediction System (RDAPS), but that have not been clearly exhibited in the weak snowfall episodes. The basic mechanism to initiate snowfall around Yeongdong seems to be similar to that of lake-effect snowstorms around Great Lakes in the United States (Kristovich et al., 2003). Difference of equivalent potential temperature ( ? e ) between 850 hPa and surface as well as difference between air and sea temperatures altogether gradually began to increase in the pre-snowfall period and reached their maximum values in the course of the period, whose air (850 hPa) sea temperature difference and snowfall intensity in case of the heavy snowfall episodes are almost larger than 20C and 6 tims greater than the weak snowfall episodes, respectively. Interestingly, snowfall appeared to begin in case of an air-sea temperature difference exceeding over 15C. The current analysis is overall consistent with the previous finding (Lee et al., 2012) that an instabilityinduced moisture supply to the lower atmosphere from the East sea, being cooled and saturated in the lower layer, so to speak, East Sea-Effect Snowfall (SES), would make a low-level ice cloud which eventually moves inland by the easterly flow. In addition, a longlasting synoptic characteristics and convergence-induced invigoration also appear to play the important roles in the severe snowstorms. Improvements in our understanding of mesoscale sea-effect snowstorms require detailed in-situ and remote sensing observations over and around East Sea since observations of the concurrent thermodynamic and microphysical characteristics have not been available there and this study emphasizes the importance of low level stability as quantitative estimation of moist static energy generation over the East Sea.

  8. The effect of pressure on tricalcium silicate hydration at different temperatures and in the presence of retarding additives

    SciTech Connect

    Jupe, Andrew C.; Wilkinson, Angus P.; Funkhouser, Gary P. (Halliburton); (GIT)

    2012-07-25

    The hydration of tricalcium silicate (C{sub 3}S) is accelerated by pressure. However, the extent to which temperature and/or cement additives modify this effect is largely unknown. Time-resolved synchrotron powder diffraction has been used to study cement hydration as a function of pressure at different temperatures in the absence of additives, and at selected temperatures in the presence of retarding agents. The magnitudes of the apparent activation volumes for C{sub 3}S hydration increased with the addition of the retarders sucrose, maltodextrin, aminotri(methylenephosphonic acid) and an AMPS copolymer. Pressure was found to retard the formation of Jaffeite relative to the degree of C{sub 3}S hydration in high temperature experiments. For one cement slurry studied without additives, the apparent activation volume for C{sub 3}S hydration remained close to {approx} -28 cm{sup 3} mol{sup -1} over the range 25 to 60 C. For another slurry, there were possible signs of a decrease in magnitude at the lowest temperature examined.

  9. Comparative lipidomic profiling of two Dunaliella tertiolecta strains with different growth temperatures under nitrate-deficient conditions.

    PubMed

    Kim, So-Hyun; Ahn, Hye Min; Lim, Sa Rang; Hong, Seong-Joo; Cho, Byung-Kwan; Lee, Hookeun; Lee, Choul-Gyun; Choi, Hyung-Kyoon

    2015-01-28

    The metabolic changes that occur in Dunaliella tertiolecta upon exposure to low temperatures and nitrate deficiency were analyzed by exploring the fatty acid composition and lipid profile of two strains that were acclimated to different temperatures. The results indicate that the levels of linolenic acid (C18:3) and diacylglyceryl-N,N,N-trimethylhomoserine (DGTS) were significantly higher in the low-temperature (15 C) strain (SCCAP K-0591) than in a strain grown at 21 C (UTEX LB999). In addition, DGTS accumulated in LB999 under nitrate-deficient conditions, while the levels of most lipids, including DGTS, remained almost consistent in K-0591. The higher levels of DGTS in K-0591 suggest that DGTS could play a role in adaptation to low temperatures and nitrate deficiency in this organism. The results of this research could be applied to the development of new microalgal strains with tolerance of low temperature and nitrate deficiency by metabolic engineering targeted to DGTS species. PMID:25549757

  10. Sustained Attention to Local and Global Target Features Is Different: Performance and Tympanic Membrane Temperature

    ERIC Educational Resources Information Center

    Helton, William S.; Hayrynen, Lauren; Schaeffer, David

    2009-01-01

    Vision researchers have investigated the differences between global and local feature perception. No one has, however, examined the role of global and local feature discrimination in sustained attention tasks. In this experiment participants performed a sustained attention task requiring either global or local letter target discriminations or

  11. Temperature dependence of wavelength-averaged DGD on different buried fibers David L. Harris1

    E-print Network

    Kansas, University of

    on the wavelength, the deviation in differential group delay (DGD) was positive, negative or neutral as a function rule as ( )= += m n nnmR 1 1, Measurement setup A commercial femtosecond PMD test unit was used to measure DGD on three different buried fibers (1, 2 and 3) under test (FUT). The test unit utilized a fully

  12. Difference

    NSDL National Science Digital Library

    2006-01-01

    This interactive Flash applet models the difference meaning of subtraction. A child or teacher can compare two rows of beads and analyze the calculation they represent. Once a user sets up the two rows of beads (up to 30 each), the applet provides a series of animations which represents the rows with two number lines and then as a single number line with the difference indicated by a "jump". This applet works well with an interactive white board. A teacher's guide to this series of applets is cataloged separately.

  13. Can we predict temperature-dependent chemical toxicity to marine organisms and set appropriate water quality guidelines for protecting marine ecosystems under different thermal scenarios?

    PubMed

    Zhou, Guang-Jie; Wang, Zhen; Lau, Edward Tak Chuen; Xu, Xiang-Rong; Leung, Kenneth Mei Yee

    2014-10-15

    Temperature changes due to climate change and seasonal fluctuation can have profound implications on chemical toxicity to marine organisms. Through a comprehensive meta-analysis by comparing median lethal or effect concentration data of six chemicals for various saltwater species obtained at different temperatures, we reveal that the chemical toxicity generally follows two different models: (1) it increases with increasing temperature and (2) it is the lowest at an optimal temperature and increases with increasing or decreasing temperature from the optimal temperature. Such observations are further supported by temperature-dependent hazardous concentration 10% (HC10) values derived from species sensitivity distributions which are constructed using the acute toxicity data generated at different temperatures. Considering these two models and natural variations of seawater temperature, we can scientifically assess whether applying an assessment factor (e.g. 10) to modify water quality guidelines of the chemicals can adequately protect marine ecosystems in tropics, subtropics and temperate regions, respectively. PMID:25176278

  14. Basalt Weathering, Nutrient Uptake, And Carbon Release By An Exotic And A Native Arizona Grass Species Under Different Temperature Conditions

    NASA Astrophysics Data System (ADS)

    Gallas, G.; Dontsova, K.; Chorover, J.; Hunt, E.; Ravi, S.

    2010-12-01

    During this past summer, the National Science Foundation funded a 10-week Research Experience for Undergraduates (REU) program Environmental and Earth Systems Research at Biosphere 2. This program provides undergraduates with an opportunity to conduct guided research in environmental and Earth systems science and has resulted in this work. Biosphere 2 allows for the exploration of complex questions in Earth sciences because of its large scale and the precise control allowed over many experimental elements. The goal of this study was to observe plant-mediated weathering of granular basalt under two temperature conditions. Two grass species were studied, one native to Arizona: Tanglehead, Heteropogan contortus, and one exotic to Arizona: Buffelgrass, Pennisetum ciliar. The grasses were grown in pots located in the Desert and the Savannah Biomes in the Biosphere 2 to take advantage of a 4 C temperature difference. Understanding differences in how native and invasive grasses weather soil and take up nutrients may explain the mechanism behind current invasion of Sonoran Desert by exotic species and help predict response of native and invasive vegetation to expected increase in temperatures. Each biome also contained three replicate control pots without vegetation, and mixtures of the two grass species to observe possible competition between the species. Three factors were compared in this study: 1. Temperature: the same species of grass under two different temperature conditions 2. Species: Native Arizonan species vs. a species exotic to Arizona 3. Temporal: How the grasses use resources differently as they grow Leachate samples were collected and analyzed for pH, electrical conductivity, total organic carbon, total nitrogen, inorganic carbon by high temperature combustion coupled with infrared gas analysis; F-, Cl-, Br-, NO3-, NO2-, SO42-, and PO43- by ion chromatography; and cations and metals by ICP-MS. The data trends indicate that plants enhanced basalt weathering. All of the leachate samples showed higher pH than the input water, and the pH was elevated in treatments that contained grass. This indicated that in the presence of vegetation there was more proton absorption. The trends in total nitrogen concentrations indicate a dependence on temperature; the same can be said of anion concentrations. Anion leaching is lower at higher temperatures possibly due to greater plant uptake. Both organic and inorganic carbon concentrations were found to be higher in grass treatments than in control treatments. Because both dissolved CO2 and soluble organic exudates encourage mineral dissolution, this could be causative of the weathering enhancements observed. Denudation of nutrient elements differed between plant species and between temperatures, possibly relating to plant uptake and secondary mineral formation. This study gives unique insight into plant-mineral interactions as a function of plant species and temperature that is essential for understanding Earth systems under changing climate.

  15. [Characteristics of soil organic carbon mineralization at different temperatures in paddy soils under long-term fertilization].

    PubMed

    Lin, Shan; Chen, Tao; Zhao, Jin-Song; Xiang, Rong-Biao; Hu, Rong-Gui; Zhang, Shui-Qing; Wang, Mi-Lan; Lu, Zhao-Qi

    2014-05-01

    Dynamics of soil organic carbon mineralization affected by long-term fertilizations and temperature in relation to different soil carbon fractions were investigated in paddy soils. Soil samples were collected from the plough layer of 3 long-term national experimental sites in Xinhua, Ningxiang and Taojiang counties of Hunan Province. Mineralization of soil organic C was estimated by 33-day aerobic incubation at different temperatures of 10, 20 and 30 degrees C. The results showed that the rates of CO2 production were higher during the earlier phase (0-13 d) in all treatments, and then decreased according to a logarithm function. Higher incubation temperature strengthened C mineralization in the different treatments. The quantities of cumulative CO2 production in NPK with manure or straw treatments were greater than in inorganic fertilizers treatments. The Q10 values in the different soil treatments ranged from 1.01-1.53. There were significantly positive correlations between the Q10 values and soil total organic carbon (TOC), easy oxidation organic carbon (EOOC), humic acid carbon (C(HA)), fulvic acid carbon (CFA). The cumulative amount of mineralized C was significantly positively correlated with microbial biomass carbon (MBC) at 10 and 20 degrees C, but not significantly at 30 degrees C. Significant correlations were found between the cumulative amount of mineralized C and different soil carbon fractions and C(HA)/C(FA). The correlations of differ- ent soil carbon fractions with the ratio of cumulative mineralized C to TOC were negatively correlated at 10 degrees C, but not significantly at 20 and 30 degrees C. These results suggested that the application of NPK with manure or straw would be helpful to increase the sequestration of C in paddy soils and reduce its contribution of CO2 release in the atmosphere. PMID:25129934

  16. Oxidative stability of sunflower oils differing in unsaturation degree during long-term storage at room temperature

    Microsoft Academic Search

    M. Martn-Polvillo; G. Mrquez-Ruiz; M. C. Dobarganes

    2004-01-01

    The objective of this work was to study the evolution of oxidation in sunflower oils differing in unsaturation degree during\\u000a long-term storage at room temperature. For this purpose, a combination of adsorption and size-exclusion chromatographies was\\u000a used for quantification of oxidized triacylglycerol (TG) monomers, dimers, and polymers. Conventional sunflower oil, genetically\\u000a modified high-oleic sunflower oil, and a 1?1 mixture of

  17. Effect of testing temperature on corrosion behaviour of different heat treated stainless steels in the active-passive region

    Microsoft Academic Search

    Mojca Slemnik

    2008-01-01

    Purpose This paper aims to focus on the effects of temperature of the immersion media on the corrosion behaviour of differently heat-treated X20Cr13 stainless steel. Design\\/methodology\\/approach Specimens, quenched on air, quenched in oil and quenched in oil and then tempered, were tested during exposure in 0.1 M H2SO4 at 30, 40 and 50C. The results were interpreted on

  18. Temperature and electron density distributions of laser-induced plasmas generated with an iron sample at different ambient gas pressures

    Microsoft Academic Search

    J. A Aguilera; C. Aragon

    2002-01-01

    Intensity, temperature and electron density distributions of laser-induced plasmas (LIPs) have been measured by emission spectroscopy with two-dimensional spatial resolution and temporal resolution. The plasmas have been generated with an iron sample at different pressures of air, in the range 101000mbar. An experimental system based in an imaging spectrometer equipped with an intensified CCD detector has been used to obtain

  19. Room temperature InGaAs hot electron detector for THz/subTHz regions

    NASA Astrophysics Data System (ADS)

    Tong, Jinchao; Huang, Jingguo; Huang, Zhiming; Chu, Junhao

    2014-02-01

    A THz/subTHz radiation detector based on MOCVD-grown modulation-doped InxGa1-xAs/InP structure is proposed. Devices have bow-tie metallic antennas to improve the couple efficiency about 5 dB and are fabricated with mesas of 3 ?m depth by wet etching. Detection by hot electron effects under external electromagnetic radiation is explained. Measurements performed at electromagnetic wave frequency f=0.0375 THz show the detector having sensitivity about 6 V/W and noise equivalent power (NEP) about 1.610-9 W/Hz1/2 at room temperatures.

  20. Lower Stratospheric Temperature Differences Between Meteorological Analyses in two cold Arctic Winters and their Impact on Polar Processing Studies

    NASA Technical Reports Server (NTRS)

    Manney, Gloria L.; Sabutis, Joseph L.; Pawson, Steven; Santee, Michelle L.; Naujokat, Barbara; Swinbank, Richard; Gelman, Melvyn E.; Ebisuzaki, Wesley; Atlas, Robert (Technical Monitor)

    2001-01-01

    A quantitative intercomparison of six meteorological analyses is presented for the cold 1999-2000 and 1995-1996 Arctic winters. The impacts of using different analyzed temperatures in calculations of polar stratospheric cloud (PSC) formation potential, and of different winds in idealized trajectory-based temperature histories, are substantial. The area with temperatures below a PSC formation threshold commonly varies by approximately 25% among the analyses, with differences of over 50% at some times/locations. Freie University at Berlin analyses are often colder than others at T is less than or approximately 205 K. Biases between analyses vary from year to year; in January 2000. U.K. Met Office analyses were coldest and National Centers for Environmental Prediction (NCEP) analyses warmest. while NCEP analyses were usually coldest in 1995-1996 and Met Office or NCEP[National Center for Atmospheric Research Reanalysis (REAN) warmest. European Centre for Medium Range Weather Forecasting (ECMWF) temperatures agreed better with other analyses in 1999-2000, after improvements in the assimilation model. than in 1995-1996. Case-studies of temperature histories show substantial differences using Met Office, NCEP, REAN and NASA Data Assimilation Office (DAO) analyses. In January 2000 (when a large cold region was centered in the polar vortex), qualitatively similar results were obtained for all analyses. However, in February 2000 (a much warmer period) and in January and February 1996 (comparably cold to January 2000 but with large cold regions near the polar vortex edge), distributions of "potential PSC lifetimes" and total time spent below a PSC formation threshold varied significantly among the analyses. Largest peaks in "PSC lifetime" distributions in January 2000 were at 4-6 and 11-14 days. while in the 1996 periods, they were at 1-3 days. Thus different meteorological conditions in comparably cold winters had a large impact on expectations for PSC formation and on the discrepancies between different meteorological analyses. Met Office. NCEP, REAN, ECMWF and DAO analyses are commonly used for trajectory calculations and in chemical transport models; the choice of which analysis to use can strongly influence the results of such studies.

  1. Land Surface Temperature Measurements from EOD MODIS Data

    NASA Technical Reports Server (NTRS)

    Wan, Zheng-Ming

    1998-01-01

    We made more tests of the version 2.0 daily Level 2 and Level 3 Land-Surface Temperature (LST) code (PGE 16) jointly with the MODIS Science Data Support Team (SDST). After making minor changes a few times, the PGE16 code has been successfully integrated and tested by MODIS SDST, and recently has passed the inspection at the Goddard Distributed Active Archive Center (DAAC). We conducted a field campaign in the area of Mono Lake, California on March 10, 1998, in order to validate the MODIS LST algorithm in cold and dry conditions. Two MODIS Airborne Simulator (MAS) flights were completed during the field campaign, one before noon, and another around 10 pm PST. The weather condition for the daytime flight was perfect: clear sky, the column water vapor measured by radiosonde around 0.3 cm, and wind speed less than a half meter per second. The quality of MAS data is good for both day and night flights. We analyzed the noise equivalent temperature difference (NE(delta)T) and the calibration accuracy of the seven MAS thermal infrared (TIR) bands, that are used in the MODIS day/night LST algorithm, with daytime MAS data over four flat homogeneous study areas: two on Grant Lake (covered with ice and snow, respectively), one on Mono Lake, and another on the snow field site where we made field measurements. NE(delta)T ranges from 0.2 to 0.6 k for bands 42, 45, 46, and 48. It ranges from 0.8 to 1.1 K for bands 30-32. The day and night MAS data have been used to retrieve surface temperature and emissivities in these bands. A simple method to correct the effect of night thin cirrus has been incorporated into the day/night LST algorithm in dry atmospheric conditions. We compared the retrieved surface temperatures with those measured with TIR spectrometer, radiometers and thermistors in the snow test site, and the retrieved emissivity images with topographic map. The daytime LST values match well within 1 K. The night LST retrieved from MAS data is 3.3 K colder than those from field measurements most likely because of the effect of haze at night. The good agreement among the regional averaged surface temperatures obtained from LST values retrieved at different resolutions increased our confidence in the MODIS day/night LST algorithm.

  2. MAGMIX: a basic program to calculate viscosities of interacting magmas of differing composition, temperature, and water content

    USGS Publications Warehouse

    Frost, T.P.; Lindsay, J.R.

    1988-01-01

    MAGMIX is a BASIC program designed to predict viscosities at thermal equilibrium of interacting magmas of differing compositions, initial temperatures, crystallinities, crystal sizes, and water content for any mixing proportion between end members. From the viscosities of the end members at thermal equilibrium, it is possible to predict the styles of magma interaction expected for different initial conditions. The program is designed for modeling the type of magma interaction between hypersthenenormative magmas at upper crustal conditions. Utilization of the program to model magma interaction at pressures higher than 200 MPa would require modification of the program to account for the effects of pressure on heat of fusion and magma density. ?? 1988.

  3. DEHYDRATION, TEMPERATURE, AND LIGHT TOLERANCE IN MEMBERS OF THE AEROTERRESTRIAL GREEN ALGAL GENUS INTERFILUM (STREPTOPHYTA) FROM BIOGEOGRAPHICALLY DIFFERENT TEMPERATE SOILS

    PubMed Central

    Karsten, Ulf; Herburger, Klaus; Holzinger, Andreas

    2015-01-01

    Unicellular green algae of the genus Interfilum (Klebsormidiales, Streptophyta) are typical components of biological soil crusts. Four different aeroterrestrial Interfilum strains that have previously been molecular-taxonomically characterized and isolated from temperate soils in Belgium, Czech Republic, New Zealand, and Ukraine were investigated. Photosynthetic performance was evaluated under different controlled abiotic conditions, including dehydration, as well as under a light and temperature gradient. For standardized desiccation experiments, a new methodological approach with silica gel filled polystyrol boxes and effective quantum yield measurements from the outside were successfully applied. All Interfilum isolates showed a decrease and inhibition of the effective quantum yield under this treatment, however with different kinetics. While the single cell strains exhibited relatively fast inhibition, the cell packet forming isolates dried slower. Most strains fully recovered effective quantum yield after rehydration. All Interfilum isolates exhibited optimum photosynthesis at low photon fluence rates, but with no indication of photoinhibition under high light conditions suggesting flexible acclimation mechanisms of the photosynthetic machinery. Photosynthesis under lower temperatures was generally more active than respiration, while the opposite was true for higher temperatures. The presented data provide an explanation for the regular occurrence of Interfilum species in soil habitats where environmental factors can be particularly harsh.

  4. Simultaneous translational temperature measurements of different atomic species in plasma flows using scanning Fabry-Perot interferometry

    SciTech Connect

    Loehle, Stefan; Lein, Sebastian [Institut fuer Raumfahrtsysteme, Pfaffenwaldring 31, 70569 Stuttgart (Germany)

    2012-05-15

    A revised scientific instrument to measure simultaneously kinetic temperatures of different atoms from their optical emission profile is reported. Emission lines are simultaneously detected using one single scanning Fabry-Perot-interferometer (FPI) for a combined spectroscopic setup to acquire different emission lines simultaneously. The setup consists in a commercial Czerny-Turner spectrometer configuration which is combined with a scanning Fabry-Perot interferometer. The fast image acquisition mode of an intensified charge coupled device camera allows the detection of a wavelength interval of interest continuously while acquiring the highly resolved line during the scan of the FPI ramp. Results using this new setup are presented for the simultaneous detection of atomic nitrogen and oxygen in a high enthalpy air plasma flow as used for atmospheric re-entry research and their respective kinetic temperatures derived from the measured line profiles. The paper presents the experimental setup, the calibration procedure, and an exemplary result. The determined temperatures are different, a finding that has been published so far as due to a drawback of the experimental setup of sequential measurements, and which has now to be investigated in more detail.

  5. Chemical composition profiles during alkaline flooding at different temperatures and extended residence times

    SciTech Connect

    Aflaki, R.; Handy, L.L.

    1992-12-01

    The objective of this work was to investigate whether or not caustic sweeps the major portion of the reservoir efficiently during an alkaline flood process. It was also the objective of this work to study the state of final equilibrium during a caustic flood through determination of the pH and chemical composition profiles along the porous medium. For this purpose, a long porous medium which provided extended residence times was required. It was necessary to set up the porous medium such that the changes in the pH and chemical composition of the solution could be monitored. Four Berea sandstone cores (8 in. length and1 in. diameter) placed in series provided the desired length and the opportunity for sampling in-between cores. This enabled establishment of pH and chemical composition profiles. The experiments were run at, temperatures up.to 180[degrees]C, and the flow rates varied from 4.8 to 0.2 ft/day. The samples were analyzed for pH and for Si and Al concentrations.The results show that caustic consumption is insignificant for temperatures up to 100[degrees]C. Above 100[degrees]C consumption increases and is accompanied by a significant decrease in pH. The sharp decline in pH also coincides with a sharp decline in concentration of silica in solution. The results also show that alumina is removed from the solution and solubility of alumina ultimately reaches zero. Sharp silica and pH declines take place even in the absence of any alumina in solution. As a result, removal of silica from solution is attributed to the irreversible caustic/rock interaction. This interaction is in the form of chemisorption reactions in which silica is adsorbed onto the rock surface consuming hydroxyl ion. Once these reactions were satisfied, caustic breakthrough occurs at a high pH. However, significant pore volumes of caustic must be injected for completion of the chemisorption.

  6. Chemical composition profiles during alkaline flooding at different temperatures and extended residence times

    SciTech Connect

    Aflaki, R.; Handy, L.L.

    1992-12-01

    The objective of this work was to investigate whether or not caustic sweeps the major portion of the reservoir efficiently during an alkaline flood process. It was also the objective of this work to study the state of final equilibrium during a caustic flood through determination of the pH and chemical composition profiles along the porous medium. For this purpose, a long porous medium which provided extended residence times was required. It was necessary to set up the porous medium such that the changes in the pH and chemical composition of the solution could be monitored. Four Berea sandstone cores (8 in. length and1 in. diameter) placed in series provided the desired length and the opportunity for sampling in-between cores. This enabled establishment of pH and chemical composition profiles. The experiments were run at, temperatures up.to 180{degrees}C, and the flow rates varied from 4.8 to 0.2 ft/day. The samples were analyzed for pH and for Si and Al concentrations.The results show that caustic consumption is insignificant for temperatures up to 100{degrees}C. Above 100{degrees}C consumption increases and is accompanied by a significant decrease in pH. The sharp decline in pH also coincides with a sharp decline in concentration of silica in solution. The results also show that alumina is removed from the solution and solubility of alumina ultimately reaches zero. Sharp silica and pH declines take place even in the absence of any alumina in solution. As a result, removal of silica from solution is attributed to the irreversible caustic/rock interaction. This interaction is in the form of chemisorption reactions in which silica is adsorbed onto the rock surface consuming hydroxyl ion. Once these reactions were satisfied, caustic breakthrough occurs at a high pH. However, significant pore volumes of caustic must be injected for completion of the chemisorption.

  7. Viability of Lolium endophyte fungus in seed stored at different moisture contents and temperatures

    Microsoft Academic Search

    M. P. Rolston; M. D. Hare; K. K. Moore; M. J. Christensen

    1986-01-01

    The effect of storage on viability of the Lolium endophyte fungus (Acremonium loliae Latch, Christensen and Samuels) in seed of perennial ryegrass was studied. Treatments included four initial seed moistures (13.8, 12.1, 10.0, and 8.6%); different storage bags (calico, polyethylene film (9, 35, or 70 ?m thickness), and laminated aluminium foil-polyethylene); and four storage conditions (ambient 525C, 5C\\/70% RH; 0C\\/30%

  8. Chronotype differences in circadian rhythms of temperature, melatonin, and sleepiness as measured in a modified constant routine protocol

    PubMed Central

    Lack, Leon; Bailey, Michelle; Lovato, Nicole; Wright, Helen

    2009-01-01

    Evening chronotypes typically have sleep patterns timed 23 hours later than morning chronotypes. Ambulatory studies have suggested that differences in the timing of underlying circadian rhythms as a cause of the sleep period differences. However, differences in endogenous circadian rhythms are best explored in laboratory protocols such as the constant routine. We used a 27-hour modified constant routine to measure the endogenous core temperature and melatonin circadian rhythms as well as subjective and objective sleepiness from hourly 15-minute sleep opportunities. Ten (8f) morning type individuals were compared with 12 (8f) evening types. All were young, healthy, good sleepers. The typical sleep onset, arising times, circadian phase markers for temperature and melatonin and objective sleepiness were all 23 hours later for the evening types than morning types. However, consistent with past studies the differences for the subjective sleepiness rhythms were much greater (59 hours). Therefore, the present study supports the important role of subjective alertness/sleepiness in determining the sleep period differences between morning and evening types and the possible vulnerability of evening types to delayed sleep phase disorder. PMID:23616692

  9. Spectroscopic Investigation of Nano-Sized Strontium Ferrite Particles at Different Annealing Temperatures

    NASA Astrophysics Data System (ADS)

    Mangai, K. Alamelu; Priya, M.; Rathnakumari, M.; Sureshkumar, P.

    2014-07-01

    Strontium ferrite enjoys a high degree of chemical stability and is completely nontoxic, which makes it ideal for a wide range of applications. Magnetoplumbite-type (M-type) hexagonal strontium ferrite particles were synthesized via the sol-gel technique employing ethylene glycol as the gel precursor. The phase morphology, particle diameter, and magnetic properties of the prepared samples were studied using X-ray diffractometry (XRD), scanning electron microscope (SEM), and a vibrating sample magnetometer (VSM), respectively. The effect of temperature on the crystal structure, morphology, and magnetic studies were carried out. Also, the thermal decomposition of assynthesized powdered samples has been studied by thermogravimetric (TG) and differential thermal analysis (DTA) methods. The optical properties were analyzed using fluorescence spectra. The XRD results showed that the samples synthesized at 600C, 800C, and 1000C were of single phase and smaller crystallite size. The intensity of the emission spectra of strontium ferrite was also examined. The yield percentage along with structure determination and VSM studies of the prepared samples are discussed in detail.

  10. Mathematical models for growth in alligator (Alligator mississippiensis) embryos developing at different incubation temperatures.

    PubMed Central

    Bardsley, W G; Ackerman, R A; Bukhari, N A; Deeming, D C; Ferguson, M W

    1995-01-01

    A variety of model-based (growth models) and model-free (cubic splines, exponentials) equations were fitted using weighted-nonlinear least squares regression to embryonic growth data from Alligator mississippiensis eggs incubated at 30 and 33 degrees C. Goodness of fit was estimated using a chi 2 on the sum of squared, weighted residuals, and run and sign tests on the residuals. One of the growth models used (Preece & Baines, 1978) was found to be superior to the classical growth models (exponential, monomolecular, logistic, Gompertz, von Bertalanffy) and gave an adequate fit to all longitudinal measures taken from the embryonic body and embryonic mass. However, measurements taken from the head could not be fitted by growth models but were adequately fitted by weighted least squares cubic splines. Data for the stage of development were best fitted by a sum of 2 exponentials with a transition point. Comparison of the maximum growth rates and parameter values, indicated that the growth data at 30 degrees C could be scaled to 33 degrees C to multiplying the time by a scaling factor of 1.2. This is equivalent to a Q10 of about 1.86 or, after solving the Arrhenius equation, an E++ of 46.9 kJmol-1. This may be interpreted as indicating a common rate-limiting step in development at the 2 temperatures. PMID:7591979

  11. Comparison of different Geostatistical Approaches to map Sea Surface Temperature (SST) of Southern South China Sea

    NASA Astrophysics Data System (ADS)

    Ali, Azizi; Mohd Muslim, Aidy; Lokman Husain, Mohd; Fadzil Akhir, Mohd

    2013-04-01

    Sea surface temperature (SST) variation provides vital information for weather and ocean forecasting especially when studying climate change. Conventional methods of collecting ocean parameters such as SST, remains expensive and labor intensive due to the large area coverage and complex analytical procedure required. Therefore, some studies need to be conducted on the spatial and temporal distribution of ocean parameters. This study looks at Geo-statisctical methods in interpolating SST values and its impact on accuracy. Two spatial Geo-statistical techniques, mainly kriging and inverse distance functions (IDW) were applied to create variability distribution maps of SST for the Southern South China Sea (SCS). Data from 72 sampling station was collected in July 2012 covering an area of 270 km x 100 km and 263 km away from shore. This data provide the basis for the interpolation and accuracy analysis. After normalization, variograms were computed to fit the data sets producing models with the least RSS value. The accuracy were later evaluated based on on root mean squared error (RMSE) and root mean kriging variance (RMKV). Results show that Kriging with exponential model produced most accuracy estimates, reducing error in 17.3% compared with inverse distance functions.

  12. Hawking and Unruh radiation perception by different observers: applications of the effective temperature function (in Spanish)

    E-print Network

    Barbado, Luis C

    2015-01-01

    We study the perception of the radiation phenomena of Hawking radiation and Unruh effect by using two main tools: the Unruh-DeWitt detectors and the effective temperature function (ETF), this last tool based on Bogoliubov transformations. Using the Unruh-DeWitt detectors we find an adiabatic expansion of the detection properties along linear trajectories with slowly varying acceleration in Minkowski, which allows us to calculate the spectrum detected, finding the thermal spectrum as the zeroth order contribution. Using the ETF we study the perception of Hawking radiation by observers following radial trajectories outside a Schwarzschild black hole. One of the most important results is that, in general, free-falling observers crossing the event horizon do detect some radiation, even when the field is in the Unruh vacuum state, due to a Doppler blue-shift that diverges at the horizon. We give a general expression for the ETF, which has a clear interpretation in terms of well-known physical phenomena. We discuss...

  13. Transport critical current density of Fe sheath MgB 2 tapes sintered at different temperatures

    NASA Astrophysics Data System (ADS)

    Ruan, K. Q.; Li, H. L.; Yu, Y.; Wang, C. Y.; Cao, L. Z.; Liu, C. F.; Du, S. J.; Yan, G.; Feng, Y.; Wu, X.; Wang, J. R.; Liu, X. H.; Zhang, P. X.; Wu, X. Z.; Zhou, L.

    2003-04-01

    Fe sheath MgB 2 tapes sintered at 650, 750, 850 and 950 C, respectively, for 2 h in a high purity argon gas were prepared using the powder-in-tube method. Transport critical current densities of tapes were measured in the fields up to 10 T from 4 to 30 K. Both tapes sintered at 850 and 950 C completely lost the capacity of carrying superconducting current over the temperature range from 4 to 30 K. Compared to a tape sintered at 650 C, an improvement in the in-field critical current density Jc and irreversibility field ?0H*( T) was observed in a tape sintered at 750 C. At 20 K, the Jc value was ?1.3210 5 A/cm 2 in self-field and the ?0H* value 4.2 T for the tape sintered at 750 C, whereas the Jc in self-field and ?0H* values were ?5.910 4 A/cm 2 and 2.8 T for that sintered at 650 C.

  14. Secretome weaponries of Cochliobolus lunatus interacting with potato leaf at different temperature regimes reveal a CL[xxxx]LHM - motif

    PubMed Central

    2014-01-01

    Background Plant and animal pathogenic fungus Cochliobolus lunatus cause great economic damages worldwide every year. C. lunatus displays an increased temperature dependent-virulence to a wide range of hosts. Nonetheless, this phenomenon is poorly understood due to lack of insights on the coordinated secretome weaponries produced by C. lunatus under heat-stress conditions on putative hosts. To understand the mechanism better, we dissected the secretome of C. lunatus interacting with potato (Solanum tuberosum L.) leaf at different temperature regimes. Results C. lunatus produced melanized colonizing hyphae in and on potato leaf, finely modulated the ambient pH as a function of temperature and secreted diverse set of proteins. Using two dimensional gel electrophoresis (2-D) and mass spectrometry (MS) technology, we observed discrete secretomes at 20C, 28C and 38C. A total of 21 differentially expressed peptide spots and 10 unique peptide spots (that did not align on the gels) matched with 28 unique protein models predicted from C. lunatus m118 v.2 genome peptides. Furthermore, C. lunatus secreted peptides via classical and non-classical pathways related to virulence, proteolysis, nucleic acid metabolism, carbohydrate metabolism, heat stress, signal trafficking and some with unidentified catalytic domains. Conclusions We have identified a set of 5 soluble candidate effectors of unknown function from C. lunatus secretome weaponries against potato crop at different temperature regimes. Our findings demonstrate that C. lunatus has a repertoire of signature secretome which mediates thermo-pathogenicity and share a leucine rich CL[xxxx]LHM-motif. Considering the rapidly evolving temperature dependent-virulence and host diversity of C. lunatus, this data will be useful for designing new protection strategies. PMID:24650331

  15. Emissivity Spectra of Meteoritic Powders mixed with Liquid Formamide (NH2COH) at Different Temperatures

    NASA Astrophysics Data System (ADS)

    Raffaele, S.; Maturilli, A.; D'Amore, M.; Ferrari, S.; Helbert, J.

    2013-12-01

    We set-up an experiment at the Planetary Emissivity Laboratory (PEL) to investigate a key aspect in the prebiotic chemistry of formamide: the surface reactivity of minerals used as catalysts. The interaction of formamide and the reaction products on mineral surface, as well as, the sequestration processes in the mineral pores, can facilitate the concentration of products allowing for possible polymerization. Three meteorites, NWA2828 (PEL ID 00000887), Al Haggounia (PEL ID 00000888), and Dhofar959 (PEL ID 00000889), were used in this experiment. All the samples were reduced in the grain size fraction < 125 ?m and stored in a desiccator before measuring. Each sample was poured in one from a set of identical stainless steel cups, having 5 mm thick bottom, internal diameter 50 mm, rim thickness 2 mm, and 20 mm total height. Emissivity of the samples was measured by means of a Bruker Vertex 80V coupled to an emissivity chamber (equipped with a rotating carousel to measure several samples without breaking the vacuum), both evacuable to < 1 mbar. The dry samples were placed in the emissivity chamber, each of them having a temperature sensor in contact with the surface of the sample, reading the effective temperature of the emitting skin. The 'dry' meteorites were measured in vacuum (0.8 mbar) at 70 C on the sample surface, successively liquid formamide was vaporized on the samples surface, the cup was immediately transferred in the emissivity chamber, and evacuated. Each sample was measured at 70, 100, 140, and 200 C. Then each cup was cooled in vacuum and put back in the desiccator. For each sample after this thermal processing, a small amount of heated material was used to fill a cup for reflectance measurements. Since cold reflectance measurements cannot be compared with hot emissivity, those measurements have been taken to better understand the processes happening in the moisturized soil after heating. For all of the samples, when heating at 70C we noticed in the emissivity spectra strong signatures attributable to liquid formamide. We interpret them as being originated from a column of hot vaporized formamide, lying above the sample surface. For all the samples this effect vanished already at 100C, probably due to complete evaporation of liquid formamide that was deposited on the meteorite sample surfaces. However, all the spectra measured at 100 and 140 C show signs of the presence of formamide, that we infer from comparing them with the 70 C dry measurement of the same sample. For 2 samples out of 3, when heating at 200C (and only there) a new feature appears at 7.08 ?m. This band is very close to a similar band that liquid formamide has at 7.19 ?m, and that was even present in all the spectra of wet meteorites taken at 70C. We interpret this band shift as a possible sign of interaction of formamide with the catalyst (the meteorite powder): the CH bend responsible for that is probably strengthening.

  16. Wetland restoration and methanogenesis: the activity of microbial populations and competition for substrates at different temperatures

    NASA Astrophysics Data System (ADS)

    Jerman, V.; Metje, M.; Mandi?-Mulec, I.; Frenzel, P.

    2009-06-01

    Ljubljana marsh in Slovenia is a 16 000 ha area of partly drained fen, intended to be flooded to restore its ecological functions. The resultant water-logging may create anoxic conditions, eventually stimulating production and emission of methane, the most important greenhouse gas next to carbon dioxide. We examined the upper layer (~30 cm) of Ljubljana marsh soil for microbial processes that would predominate in water-saturated conditions, focusing on the potential for iron reduction, carbon mineralization (CO2 and CH4 production), and methane emission. Methane emission from water-saturated microcosms was near minimum detectable levels even after extended periods of flooding (>5 months). Methane production in anoxic soil slurries started only after a lag period of 84 d at 15C and a minimum of 7 d at 37C, the optimum temperature for methanogenesis. This lag was inversely related to iron reduction, which suggested that iron reduction out-competed methanogenesis for electron donors, such as H2 and acetate. Methane production was observed only in samples incubated at 14-38C. At the beginning of methanogenesis, acetoclastic methanogenesis dominated. In accordance with the preferred substrate, most (91%) mcrA (encoding the methyl coenzyme-M reductase, a key gene in methanogenesis) clone sequences could be affiliated to the acetoclastic genus Methanosarcina. No methanogens were detected in the original soil. However, a diverse community of iron-reducing Geobacteraceae was found. Our results suggest that methane emission can remain transient and low if water-table fluctuations allow re-oxidation of ferrous iron, sustaining iron reduction as the most important process in terminal carbon mineralization.

  17. Differences in Daily Rhythms of Wrist Temperature Between Obese and Normal-Weight Women: Associations With Metabolic Syndrome Features

    PubMed Central

    Corbaln-Tutau, M. D.; Madrid, J. A.; Ordovs, J. M.; Smith, C. E.; Nicols, F.; Garaulet, M.

    2015-01-01

    The circadian rhythm of core body temperature is associated with widespread physiological effects. However, studies with other more practical temperature measures, such as wrist (WT) and proximal temperatures, are still scarce. The aim of this study was to investigate whether obesity is associated with differences in mean WT values or in its daily rhythmicity patterns. Daily patterns of cortisol, melatonin, and different metabolic syndrome (MetS) features were also analyzed in an attempt to clarify the potential association between chronodisruption and MetS. The study was conducted on 20 normal-weight women (age: 38 11 yrs and BMI: 22 2.6 kg/m2) and 50 obese women (age: 42 10 yrs and BMI: 33.5 3.2 kg/m2) (mean SEM). Skin temperature was measured over a 3-day period every 10 min with the Thermochron iButton. Rhythmic parameters were obtained using an integrated package for time-series analysis, Circadianware. Obese women displayed significantly lower mean WT (34.1C 0.3C) with a more flattened 24-h pattern, a lower-quality rhythm, and a higher intraday variability (IV). Particularly interesting were the marked differences between obese and normal-weight women in the secondary WT peak in the postprandial period (second-harmonic power [P2]), considered as a marker of chronodisruption and of metabolic alterations. WT rhythmicity characteristics were related to MetS features, obesity-related proteins, and circadian markers, such as melatonin. In summary, obese women displayed a lower-quality WT daily rhythm with a more flattened pattern (particularly in the postprandial period) and increased IV, which suggests a greater fragmentation of the rest/activity rhythm compared to normal-weight women. These 24-h changes were associated with higher MetS risk. PMID:21721858

  18. Characteristics of oxidation-reduction potential, VFAs, SCOD, N, and P in an ATAD system under different thermophilic temperatures.

    PubMed

    Cheng, Jiehong; Kong, Feng; Zhu, Jun; Wu, Xiao

    2015-01-01

    One-stage autoheated thermophilic aerobic digestion (ATAD) can stabilize sludge to meet class A standard. In this study, batch experiments were conducted to investigate the characteristics of oxidation-reduction potential (ORP), volatile fatty acids (VFAs), soluble chemical oxygen demand (SCOD), and nutrients at different temperatures (45, 55, and 65 C) in the one-stage ATAD. Results showed that the ORP values remained between approximately -350 and -120 mV in the primary 5-day digestion despite of excessive aeration in the digester, indicating that the aeration level could be decreased in an ATAD system to save energy. The pH exhibited a poor correlation (R (2)?temperatures. The volatile suspended solid (VSS) removal rate for sludge at 55 C was the highest among three digestion temperatures, reaching 41.4 % on day 13 and meeting Class A standard. VSS removal rate of 30.1 % under 65 C did not satisfy the effluent standard because of the high soluble content of ammonium nitrogen. The majority of nitrogen and phosphorus left in the sludge supernatant under 65 C could hinder its further use for land applications. Therefore, the optimal temperature of 55 C is suitable for the ATAD process. PMID:25245680

  19. Electrical characteristics of multilayer MoS2 transistors at real operating temperatures with different ambient conditions

    NASA Astrophysics Data System (ADS)

    Kwon, Hyuk-Jun; Jang, Jaewon; Kim, Sunkook; Subramanian, Vivek; Grigoropoulos, Costas P.

    2014-10-01

    Atomically thin, two-dimensional (2D) materials with bandgaps have attracted increasing research interest due to their promising electronic properties. Here, we investigate carrier transport and the impact of the operating ambient conditions on back-gated multilayer MoS2 field-effect transistors with a thickness of 50 nm at their realistic working temperatures and under different ambient conditions (in air and in a vacuum of 10-5 Torr). Increases in temperature cause increases in Imin (likely due to thermionic emission at defects), and result in decreased Ion at high VG (likely due to increased phonon scattering). Thus, the Ion/Imin ratio decreases as the temperature increases. Moreover, the ambient effects with working temperatures on field effect mobilities were investigated. The adsorbed oxygen and water created more defect sites or impurities in the MoS2 channel, which can lead another scattering of the carriers. In air, the adsorbed molecules and phonon scattering caused a reduction of the field effect mobility, significantly. These channel mobility drop-off rates in air and in a vacuum reached 0.12 cm2/V s K and 0.07 cm2/V s K, respectively; the rate of degradation is steeper in air than in a vacuum due to enhanced phonon mode by the adsorbed oxygen and water molecules.

  20. The role of climatic forcings in long-term variations of the Portuguese temperature: A comparison of different mathematical methods

    NASA Astrophysics Data System (ADS)

    Morozova, Anna; Barlyaeva, Tatiana; Ponyavin, Dmitrij

    2013-04-01

    Century-long monthly series of temperature parameters measured in the three Portuguese meteorological stations from 1888 to 2001 were used to study the effect of different climatic forcings. Four types of forcings have been studied: volcanic aerosols, anthropogenic greenhouse gases and aerosols, atmospheric circulation, and solar and geomagnetic activity variations. Long-term trends of temperature as well as forcings parameters with characteristic periods of decades have been studied by the different statistical methods including correlation and multiple regression, seasonal-trend decomposition and wavelet (including wavelet coherency) analyses. Obtained results confirm the significances of the volcanic and anthropogenic influences as well as solar activity impact on the climate variations in Portugal. In particular, surprisingly strong 22-year cycle was observed in temperature series whereas 11-year cycle is very weak or absent. It was also observed, that the prevalence of CO2 influence over other forcings (volcanic, circulation, solar activity) has started only around 1950. Another interesting result is the apparent "dimming" of the solar influence during periods of strong volcanic eruptions.

  1. The Impact of Root Temperature on Photosynthesis and Isoprene Emission in Three Different Plant Species

    PubMed Central

    Medori, Mauro; Michelini, Lucia; Nogues, Isabel; Loreto, Francesco; Calfapietra, Carlo

    2012-01-01

    Most of the perennial plant species, particularly trees, emit volatile organic compounds (BVOCs) such as isoprene and monoterpenes, which in several cases have been demonstrated to protect against thermal shock and more generally against oxidative stress. In this paper, we show the response of three strong isoprene emitter species, namely, Phragmites australis, Populus x euramericana, and Salix phylicifolia exposed to artificial or natural warming of the root system in different conditions. This aspect has not been investigated so far while it is well known that warming the air around a plant stimulates considerably isoprene emission, as also shown in this paper. In the green house experiments where the warming corresponded with high stress conditions, as confirmed by higher activities of the main antioxidant enzymes, we found that isoprene uncoupled from photosynthesis at a certain stage of the warming treatment and that even when photosynthesis approached to zero isoprene emission was still ongoing. In the field experiment, in a typical cold-limited environment, warming did not affect isoprene emission whereas it increased significantly CO2 assimilation. Our findings suggest that the increase of isoprene could be a good marker of heat stress, whereas the decrease of isoprene a good marker of accelerated foliar senescence, two hypotheses that should be better investigated in the future. PMID:22701360

  2. Initial enamel wear of glazed and polished leucite-based porcelains with different fusing temperatures.

    PubMed

    Adachi, Lena Katekawa; Saiki, Mitiko; de Campos, Tomie Nakakuki; Adachi, Eduardo Makoto; Shinkai, Rosemary Sadami

    2009-01-01

    This study used the radiotracer method to measure the initial enamel wear caused by low- and high-fusing porcelains after glazing or polishing. It also tested the correlation between enamel wear and porcelain surface roughness (Ra). Surface morphology was assessed by optical microscopy. Cylindrical specimens of three porcelains (two high-fusing, one low-fusing) were either autoglazed or polished. Flattened enamel specimens were irradiated with neutrons and submitted to the wear assay for 2,500 cycles in distilled water using a 285 g load; the released beta 32P particles were measured for 10 minutes. For all samples, Ra was recorded with a profilometer before and after testing. Enamel wear was not significantly different for porcelain or finishing method but there was a trend of interaction between the two variables (p = 0.08). A positive correlation was found between enamel wear and the initial Ra of porcelain (r = 0.71). The glazed surfaces of high-fusing porcelains were wavy and had a greater Ra, while the polished surfaces had grooves and pores prior to wear testing. The low-fusing porcelain demonstrated lower Ra and a more homogeneous surface. All abraded surfaces had similar morphology after the wear assay. PMID:19903616

  3. Lateralized differences in tympanic membrane temperature, but not induced mood, are related to episodic memory.

    PubMed

    Propper, Ruth E; Barr, Taylor D; Bruny, Tad T

    2015-03-01

    The present research examined the effects of pre-encoding and pre-recall induced mood on episodic memory. It was hypothesized that happy and/or angry mood prior to encoding (increasing left hemisphere activity), in tandem with fearful mood prior to recall (increasing right hemisphere activity) would be associated with superior episodic memory. It was also hypothesized that tympanic membrane measures (TMT), indicative of hemispheric activity, would change as a function of induced mood. Although subjectively-experienced mood induction was successful, pre-encoding and pre-recall mood did not alter memory, and only altered TMT in the pre-encoding fear and pre-recall angry mood induction conditions. Interestingly, baseline absolute difference between left and right TMT, a measure of differential hemispheric activity, regardless of the direction of that activity, was significantly positively related to number of total words written, number of correctly recalled words, and corrected recall score. This same TMT measure pre-encoding, regardless of specific mood, was significantly negatively related to false recall. Results are discussed in terms the HERA model of episodic memory, and in the nature of interhemispheric interaction involved in episodic recall. PMID:25647603

  4. A survey of global radiation damage to 15 different protein crystal types at room temperature: a new decay model

    PubMed Central

    Leal, Ricardo Miguel Ferraz; Bourenkov, Gleb; Russi, Silvia; Popov, Alexander N.

    2013-01-01

    The radiation damage rates to crystals of 15 model macromolecular structures were studied using an automated radiation sensitivity characterization procedure. The diffracted intensity variation with dose is described by a two-parameter model. This model includes a strong resolution-independent decay specific to room-temperature measurements along with a linear increase in overall DebyeWaller factors. An equivalent representation of sensitivity via a single parameter, normalized half-dose, is introduced. This parameter varies by an order of magnitude between the different structures studied. The data show a correlation of crystal radiation sensitivity with crystal solvent content but no dose-rate dependency was detected in the range 0.05300 kGy?s?1. The results of the crystal characterization are suitable for either optimal planning of room-temperature data collection or in situ crystallization plate screening experiments. PMID:23254652

  5. Microbial diversity in long-term water-flooded oil reservoirs with different in situ temperatures in China

    PubMed Central

    Zhang, Fan; She, Yue-Hui; Chai, Lu-Jun; Banat, Ibrahim M.; Zhang, Xiao-Tao; Shu, Fu-Chang; Wang, Zheng-Liang; Yu, Long-Jiang; Hou, Du-Jie

    2012-01-01

    Water-flooded oil reservoirs have specific ecological environments due to continual water injection and oil production and water recycling. Using 16S rRNA gene clone library analysis, the microbial communities present in injected waters and produced waters from four typical water-flooded oil reservoirs with different in situ temperatures of 25C, 40C, 55C and 70C were examined. The results obtained showed that the higher the in situ temperatures of the oil reservoirs is, the less the effects of microorganisms in the injected waters on microbial community compositions in the produced waters is. In addition, microbes inhabiting in the produced waters of the four water-flooded oil reservoirs were varied but all dominated by Proteobacteria. Moreover, most of the detected microbes were not identified as indigenous. The objective of this study was to expand the pictures of the microbial ecosystem of water-flooded oil reservoirs. PMID:23094135

  6. Investigation on the dielectric behavior of aluminum nitride thin films at different temperatures applying a time-zero approach

    NASA Astrophysics Data System (ADS)

    Schneider, Michael; Bittner, Achim; Schmid, Ulrich

    2013-05-01

    In MEMS (micro electromechanical system) devices, piezoelectric aluminum nitride (AlN) thin films are commonly used as functional material for sensing and actuating purposes. Additionally, AlN features excellent dielectric properties as well as a high chemical and thermal stability, making it also a good choice for passivation purposes for microelectronic devices. With those aspects and current trends towards minimization in mind, the dielectric reliability of thin AlN films is of utmost importance for the realization of advanced device concepts. In this study, we present results on the transversal dielectric strength of 100 nm AlN thin films deposited by dc magnetron sputtering. The dielectric strength was measured using a time-zero approach, where the film is stressed using a fast voltage ramp up to the point of breakdown. The measurements were performed using different contact pad sizes, different voltage ramping speeds and device temperatures, respectively. In order to achieve statistical significance, at least 12 measurements were performed for each environment parameter set and the results analyzed using the Weibull approach. The results show, that the breakdown field in positive direction rises with the pad size, as expected. Furthermore, lower breakdown fields with increasing temperatures up to 300C are observed with the mean field to failure following an exponential law typical for temperature activated processes. The activation energy was determined to 27 meV, allowing an estimation of the breakdown field towards even higher temperatures. In negative field direction no breakdown occurred, which is attributed to the metal-insulator-semiconductor configuration of the sample and hence, the larger depletion layer forming in the silicon dominates the observed current behavior.

  7. Salt weathering in Egyptian limestone after laboratory simulations with continuous flow of salt solutions at different temperatures

    NASA Astrophysics Data System (ADS)

    Aly, Nevin; Gomez-Heras, Miguel; Hamed, Ayman; Alvarez de Buergo, Monica

    2013-04-01

    weathering in Egyptian limestone after laboratory simulations with continuous flow of salt solutions at different temperatures Nevin Aly Mohamed (1), Miguel Gomez - Heras(2), Ayman Hamed Ahmed (1), and Monica Alvarez de Buergo(2). (1) Faculty of Pet. & Min. Engineering- Suez Canal University, Suez, Egypt, (2) Instituto de Geociencias (CSIC-UCM) Madrid. Spain. Limestone is one of the most frequent building stones in Egypt and is used since the time of ancient Egyptians and salt weathering is one of the main threats to its conservation. Most of the limestone used in historical monuments in Cairo is a biomicrite extracted from the Mid-Eocene Mokattam Group. During this work, cylindrical samples (2.4 cm diameter and approx. 4.8 cm length) were subjected, in a purpose-made simulation chamber, to simulated laboratory weathering tests with fixed salt concentration (10% weight NaCl solution), at different temperatures, which were kept constant throughout each test (10, 20, 30, 40 oC). During each test, salt solutions flowed continuously imbibing samples by capilarity. Humidity within the simulation chamber was reduced using silica gel to keep it low and constant to increase evaporation rate. Temperature, humidity inside the simulation chamber and samples weight were digitally monitored during each test. Results show the advantages of the proposed experimental methodology using a continuous flow of salt solutions and shed light on the effect of temperature on the dynamics of salt crystallization on and within samples. Research funded by mission sector of high education ministry, Egypt and Geomateriales S2009/MAT-1629.

  8. Kinetics of the sodium pump in red cells of different temperature sensitivity.

    PubMed

    Ellory, J C; Willis, J S

    1982-06-01

    Ouabain-sensitive K influx into ground squirrel and guinea pig red cells was measured at 5 and 37 degrees C as a function of external K and internal Na. In both species the external K affinity increases on cooling, being three- and fivefold higher in guinea pig and ground squirrel, respectively, at 5 than at 37 degrees C. Internal Na affinity also increased on cooling, by about the same extent. The effect of internal Na on ouabain-sensitive K influx in guinea pig cells fits a cubic Michaelis-Menten-type equation, but in ground squirrel cells this was true only at high [Na]i. There was still significant ouabain-sensitive K influx at low [Na]i. Ouabain-binding experiments indicated around 800 sites/cell for guinea pig and Columbian ground squirrel erythrocytes, and 280 sites/cell for thirteen-lined ground squirrel cells. There was no significant difference in ouabain bound per cell at 37 and 5 degrees C. Calculated turnover numbers for Columbian and thirteen-lined ground squirrel and guinea pig red cell sodium pumps at 37 degrees C were about equal, being 77-100 and 100-129 s-1, respectively. At 5 degrees C red cells from ground squirrels performed significantly better, the turnover numbers being 1.0-2.3 s-1 compared with 0.42-0.47 s-1 for erythrocytes of guinea pig. The results do not accord with a hypothesis that cold-sensitive Na pumps are blocked in one predominant form. PMID:6286844

  9. Temperature-related mortality in France, a comparison between regions with different climates from the perspective of global warming

    NASA Astrophysics Data System (ADS)

    Laaidi, Mohamed; Laaidi, Karine; Besancenot, Jean-Pierre

    2006-11-01

    This paper aims to explain the results of an observational population study that was carried out between 1991 and 1995 in six regions (departments) in France. The study was to assess the relationship between temperature and mortality in a few areas of France that offer widely varying climatic conditions and lifestyles, to determine their thermal optimum, defined as a 3C temperature band with the lowest mortality rate in each area, and then to compare the mortality rates from this baseline band with temperatures above and below the baseline. The study period was selected because it did not include extreme cold or hot events such as a heatwave. Data on daily deaths from each department were first used to examine the entire population and then to examine men, women, various age groups and various causes of death (respiratory disease, stroke, ischmic heart disease, other disease of the circulatory system, and all other causes excluding violent deaths). Mean temperatures were provided by the National Weather Service. The results depicted an asymmetrical V- or U-shaped relationship between mortality and temperature, with a thermal optimum lower for the elderly, and generally lower for women than for men except in Paris. The relationship was also different depending on the cause of death. In all cases, more evidence was collected showing that cold weather was more deadly than hot weather, and it would now be interesting to enlarge the study to include years with cold spells and heatwaves. Furthermore, the results obtained could be of great use in estimating weather-related mortality as a consequence of future climate-change scenarios.

  10. Transformation, morphology, and dissolution of silicon and carbon in rice straw-derived biochars under different pyrolytic temperatures.

    PubMed

    Xiao, Xin; Chen, Baoliang; Zhu, Lizhong

    2014-03-18

    Biochars are increasingly recognized as environmentally friendly and cheap remediation agents for soil pollution. The roles of silicon in biochars and interactions between silicon and carbon have been neglected in the literature to date, while the transformation, morphology, and dissolution of silicon in Si-rich biochars remain largely unaddressed. In this study, Si-rich biochars derived from rice straw were prepared under 150-700 C (named RS150-RS700). The transformation and morphology of carbon and silicon in biochar particles were monitored by FTIR, XRD, and SEM-EDX. With increasing pyrolytic temperature, silicon accumulated, and its speciation changed from amorphous to crystalline matter, while the organic matter evolved from aliphatic to aromatic. For rice straw biomass containing amorphous carbon and amorphous silicon, dehydration (<250 C) made silicic acid polymerize, resulting in a closer integration of carbon and silicon. At medium pyrolysis temperatures (250-350 C), an intense cracking of carbon components occurred, and, thus, the silicon located in the inside tissue was exposed. At high pyrolysis temperatures (500-700 C), the biochar became condensed due to the aromatization of carbon and crystallization of silicon. Correspondingly, the carbon release in water significantly decreased, while the silicon release somewhat decreased and then sharply increased with pyrolytic temperature. Along with SEM-EDX images of biochars before and after water washing, we proposed a structural relationship between carbon and silicon in biochars to explain the mutual protection between carbon and silicon under different pyrolysis temperatures, which contribute to the broader understanding of biochar chemistry and structure. The silicon dissolution kinetics suggests that high Si biochars could serve as a novel slow release source of biologically available Si in low Si agricultural soils. PMID:24601595

  11. Differences in body temperature, cell viability, and HSP-70 concentrations between Pelibuey and Suffolk sheep under heat stress.

    PubMed

    Romero, Rosita Denny; Montero Pardo, Arnulfo; Montaldo, Hugo Horacio; Rodrguez, Ana Delia; Hernndez Cern, Joel

    2013-11-01

    Pelibuey and Suffolk sheep were compared as to their capacity to regulate body temperature under environmental hyperthermia by measuring their differences in cellular response to heat stress (HS). In a first experiment, seven Pelibuey and seven Suffolk ewes were kept in a climatic chamber for 6h daily during 10days (temperatures within the 18 to 39.5C range). As chamber temperature rose, sheep rectal temperature increased in both groups, but to a lesser extent in Pelibuey (0.3C) than in Suffolk sheep (0.7C) (P??0.05]. HS significantly increased HSP-70 average concentrations for both breeds at 43C. A significant effect was observed for the breed by temperature interaction (P?difference between Pelibuey and Suffolk at 43C (2.85 vs. 0.53ng/mL, respectively; P??0.05). In conclusion, Pelibuey sheep show more effective body temperature regulation under conditions of environmental hyperthermia. Also, cell viability after HS was higher in Pelibuey than in Suffolk, an effect that could be mediated by an HSP-70-related mechanism. PMID:23677527

  12. Influence of temperature, hypercapnia, and development on the relative expression of different hemocyanin isoforms in the common cuttlefish Sepia officinalis.

    PubMed

    Strobel, Anneli; Hu, Marian Y A; Gutowska, Magdalena A; Lieb, Bernhard; Lucassen, Magnus; Melzner, Frank; Prtner, Hans O; Mark, Felix C

    2012-12-01

    The cuttlefish Sepia officinalis expresses several hemocyanin isoforms with potentially different pH optima, indicating their reliance on efficient pH regulation in the blood. Ongoing ocean warming and acidification could influence the oxygen-binding properties of respiratory pigments in ectothermic marine invertebrates. This study examined whether S. officinalis differentially expresses individual hemocyanin isoforms to maintain optimal oxygen transport during development and acclimation to elevated seawater pCO(2) and temperature. Using quantitative PCR, we measured relative mRNA expression levels of three different hemocyanin isoforms in several ontogenetic stages (embryos, hatchlings, juveniles, and adults), under different temperatures and elevated seawater pCO(2). Our results indicate moderately altered hemocyanin expression in all embryonic stages acclimated to higher pCO(2), while hemocyanin expression in hatchlings and juveniles remained unaffected. During the course of development, total hemocyanin expression increased independently of pCO(2) or thermal acclimation status. Expression of isoform 3 is reported for the first time in a cephalopod in this study and was found to be generally low but highest in the embryonic stages (0.2% of total expression). Despite variable hemocyanin expression, hemolymph total protein concentrations remained constant in the experimental groups. Our data provide first evidence that ontogeny has a stronger influence on hemocyanin isoform expression than the environmental conditions chosen, and they suggest that hemocyanin protein abundance in response to thermal acclimation is regulated by post-transcriptional/translational rather than by transcriptional modifications. PMID:22791630

  13. The ecological significance of phenology in four different tree species: effects of light and temperature on bud burst

    NASA Astrophysics Data System (ADS)

    Caffarra, Amelia; Donnelly, Alison

    2011-09-01

    The process of adaptation is the result of stabilising selection caused by two opposite forces: protection against an unfavourable season (survival adaptation), and effective use of growing resources (capacity adaptation). As plant species have evolved different life strategies based on different trade offs between survival and capacity adaptations, different phenological responses are also expected among species. The aim of this study was to compare budburst responses of two opportunistic species ( Betula pubescens, and Salix x smithiana) with that of two long-lived, late successional species ( Fagus sylvatica and Tilia cordata) and consider their ecological significance. Thus, we performed a series of experiments whereby temperature and photoperiod were manipulated during dormancy. T. cordata and F. sylvatica showed low rates of budburst, high chilling requirements and responsiveness to light intensity, while B. pubescens and S. x smithiana had high rates of budburst, low chilling requirements and were not affected by light intensity. In addition, budburst in B. pubescens and S. x smithiana was more responsive to high forcing temperatures than in T. cordata and F. sylvatica. These results suggest that the timing of growth onset in B. pubescens and S. x smithiana (opportunistic) is regulated through a less conservative mechanism than in T. cordata and F. sylvatica (long-lived, late successional), and that these species trade a higher risk of frost damage for the opportunity of vigorous growth at the beginning of spring, before canopy closure. This information should be considered when assessing the impacts of climate change on vegetation or developing phenological models.

  14. An evaluation on the growth rate of small fatigue cracks in cast AM50 magnesium alloy at different temperatures in vacuum conditions

    Microsoft Academic Search

    Xi-shu Wang; Jing-hong Fan

    2006-01-01

    Based on in situ observations with scanning electron microscope (SEM), we present the cracking process of small fatigue cracks and the influence of higher temperatures and vacuum conditions on the growth behavior of these cracks in cast AM50 magnesium alloy. We report and discuss some differences of small fatigue crack propagation behaviors at elevated temperatures from those at room temperature.

  15. Volumetric, Viscometric, Ultrasonic, and Refractive Index Properties of Liquid Mixtures of Benzene with Industrially Important Monomers at Different Temperatures

    NASA Astrophysics Data System (ADS)

    Ali, A.; Nabi, F.; Tariq, M.

    2009-04-01

    The densities, ?, viscosities, ?, ultrasonic speeds, u, and refractive indices, n D, of pure benzene, methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), styrene (STY), and their binary liquid mixtures have been measured over the entire composition range at 298.15 K, 303.15 K, 308.15 K, and 313.15 K. The experimental data have been used to calculate excess molar volumes. Partial molar volumes of MA/EA/BA/STY in benzene at infinite dilution and at different temperatures have also been evaluated. The results were discussed in terms of molecular interactions prevailing in the mixtures.

  16. Frequency dependence of Nel temperature in CaMnO3-? ceramics: Synthesized by two different methods

    NASA Astrophysics Data System (ADS)

    Kompany, A.; Ghorbani-Moghadam, T.; Kafash, S.; Ebrahimizadeh Abrishami, M.

    2014-01-01

    Calcium manganese oxide CaMnO3-? (?=0.02) nanopowders were synthesized by two different methods; sol-gel and solid-state reaction. X-ray diffraction patterns indicated that both types of the prepared powders have orthorhombic symmetry structures at room temperature. Further characterizations of the samples were preformed employing SEM and TEM techniques. At low magnetic fields, the phase transition temperature from antiferromagnetic to paramagnetic was found to be slightly higher in the sintered O-ring shape specimens made from powders synthesized by sol-gel method. This result can be described in relation to Mn3+-O-Mn4+ double-exchange interaction and also electron hopping mechanism which occur more in these specimens than those made from solid-state reaction powders. The frequency dependence of Nel temperature and the shape of the hysteresis loops, observed in both types of the prepared ceramics specimens, can be attributed to the reduction of relaxation time which occurs with increasing the frequency.

  17. Comparison of different algebraic stress models in predicting temperature fluctuations and mean velocity in liquid-metals

    SciTech Connect

    de Lemos, M.J.S.

    1985-01-01

    The present work consists of a numerical investigation comparing three algebraic stress closures for turbulence in predicting the variance of temperature fluctuations and mean velocity for flow of mercury. The models of Ljuboja and Rodi, Sha and Launder, and Lemos and Sesonske are used, as they handle differently the modeling of the dissipation rate of temperature fluctuations, and several terms in the algebraic equations for the turbulent fluxes. A sensitivity analysis on some constants of the latter model is also presented. Pipe flow with constant wall heat flux were the geometry and boundary condition. The range for Re was from 30000 to 60000, and the buoyancy parameter Ra/Re/sup 2/ was varied from 10/sup -5/ to 10/sup -4/, where Ra is the Rayleigh number. The model of Lemos and Sesonske shows a substantial improvement in predicting temperature fluctuations, whereas predictions for the mean velocity show a weak dependence on the model used. Nevertheless, the model of Lemos and Sesonske gives results closer to available experimental data.

  18. The characterisation of lead-free thick-film resistors on different low temperature Co-fired ceramics substrates

    SciTech Connect

    Hrovat, Marko, E-mail: marko.hrovat@ijs.si [Joef Stefan Institute, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia) [Joef Stefan Institute, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); CoE NAMASTE, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); Kielbasinski, Konrad [Institute of Electronic Materials Technology, Wlczy?ska 133, 01-919 Warsaw (Poland) [Institute of Electronic Materials Technology, Wlczy?ska 133, 01-919 Warsaw (Poland); Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Makarovi?, Kostja [Joef Stefan Institute, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia) [Joef Stefan Institute, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); CoE NAMASTE, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); Belavi?, Darko [HIPOT-RR d.o.o., entpeter 18, SI-8222 Oto?ec (Slovenia) [HIPOT-RR d.o.o., entpeter 18, SI-8222 Oto?ec (Slovenia); CoE NAMASTE, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); Jakubowska, Malgorzata [Institute of Electronic Materials Technology, Wlczy?ska 133, 01-919 Warsaw (Poland) [Institute of Electronic Materials Technology, Wlczy?ska 133, 01-919 Warsaw (Poland); Faculty of Mechatronics, Warsaw University of Technology, ?w. Andrzeja Boboli 8, 02-525 Warsaw (Poland)

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ? Lead free thick film resistors based on ruthenium oxide were developed. ? The compatibility of resistors with different LTCC substrates was evaluated. ? The interactions between resistors and glassy LTCC substrates were not detected. ? Electrical characteristics were comparable with commercial thick film resistors. -- Abstract: Lead-free thick-film resistors were synthesised and investigated. The thick-film resistor materials with nominal sheet resistivities from 50 ohm/sq. to 50 kohm/sq. were prepared using combinations of two lead-free glasses with reflow temperatures at 940 C and 1240 C, respectively, and two RuO{sub 2} powders (fine-grained and coarse-grained RuO{sub 2}). The thick-film resistors were printed and fired on alumina and on low temperature co-fired ceramics substrates and fired at 850 C and 950 C. The fired resistors were investigated by X-ray powder diffraction, by scanning electron microscopy and by energy dispersive X-ray analysis. The sheet resistivities, temperature coefficients of resistivity, gauge factors and noise indices were measured.

  19. Is the exoproteome important for bacterial pathogenesis? Lessons learned from interstrain exoprotein diversity in Listeria monocytogenes grown at different temperatures.

    PubMed

    Cabrita, Paula; Trigo, Maria Joo; Ferreira, Ricardo Boavida; Brito, Luisa

    2014-09-01

    Bacterial exoproteomes vary in composition and quantity among species and within each species, depending on the environmental conditions to which the cells are exposed. This article critically reviews the literature available on exoproteins synthesized by the foodborne pathogenic bacterium Listeria monocytogenes grown at different temperatures. The main challenges posed for exoproteome analyses and the strategies that are being used to overcome these constraints are discussed. Over thirty exoproteins from L. monocytogenes are considered, and the multifunctionality of some of them is discussed. Thus, at the host temperature of 37C, good examples are provided by Lmo0443, a potential marker for low virulence, and by the virulence factors internalin C (InlC) and listeriolysin O (LLO). Based on the reported LLO-induced mucin exocytosis, a model is proposed for the involvement of extracellular LLO in optimizing the conditions for InlC intervention in the invasion of intestinal epithelial cells. At lower growth temperatures, exoproteins such as flagellin (FlaA) and oligopeptide permease (OppA) may explain the persistence of particular strains in the food industry environment, eventually allowing the development of new tools to eradicate L. monocytogenes, a major concern for public health. PMID:25127015

  20. Beam displacement as a function of temperature and turbulence length scale at two different laser radiation wavelengths.

    PubMed

    Isterling, William M; Dally, Bassam B; Alwahabi, Zeyad T; Dubovinsky, Miro; Wright, Daniel

    2012-01-01

    Narrow laser beams directed from aircraft may at times pass through the exhaust plume of the engines and potentially degrade some of the laser beam characteristics. This paper reports on controlled studies of laser beam deviation arising from propagation through turbulent hot gases, in a well-characterized laboratory burner, with conditions of relevance to aircraft engine exhaust plumes. The impact of the temperature, laser wavelength, and turbulence length scale on the beam deviation has been investigated. It was found that the laser beam displacement increases with the turbulent integral length scale. The effect of temperature on the laser beam angular deviation, ?, using two different laser wavelengths, namely 4.67 ?m and 632.8 nm, was recorded. It was found that the beam deviation for both wavelengths may be semiempirically modeled using a single function of the form, ?=a(b+(1/T)(2))(-1), with two parameters only, a and b, where ? is in microradians and T is the temperature in C. PMID:22270413

  1. Recovery of the energy metabolism after a hypoxic challenge at different temperature conditions: a 31P-nuclear magnetic resonance spectroscopy study with common carp

    Microsoft Academic Search

    Robert Borger; Gudrun De Boeck; Johan Van Audekerke; Roger Dommisse; Ronny Blust; Annemie Van der Linden

    1998-01-01

    We determined the effects of a mild hypoxic challenge on the energy metabolism of the common carp, Cyprinus carpio, under different temperature conditions, by 31P-nuclear magnetic resonance spectroscopy (31P-NMR). Fish were acclimated to the optimal temperature of 25C or the acute sublethal temperature of 33C. A group of the 25C acclimated fish was also exposed to a temperature shock of

  2. Behavioral thermoregulation, temperature tolerance and oxygen consumption in the Mexican bullseye puffer fish, Sphoeroides annulatus Jenyns (1842), acclimated to different temperatures

    Microsoft Academic Search

    Izbelt Reyes; Fernando Daz; Ana Denisse Re; Javier Prez

    2011-01-01

    An inverse and unusual relationship was found between preferred temperature and acclimation temperature in the bullseye puffer, Sphoeroides annulatus. The final preferendum temperature (PT) was 26.8C. The critical thermal maxima (CTMax) were 37.7, 38.8, 40.0, 40.8 and 41.3C where the temperatures of acclimation were 19, 22, 25, 28 and 31C1C, respectively, and the endpoint of CTMax was loss of the

  3. Deformities in larvae and juvenile European lobster (Homarus gammarus) exposed to lower pH at two different temperatures

    NASA Astrophysics Data System (ADS)

    Agnalt, A.-L.; Grefsrud, E. S.; Farestveit, E.; Larsen, M.; Keulder, F.

    2013-05-01

    Trends of increasing temperatures and ocean acidification are expected to influence benthic marine resources, especially calcifying organisms. The European lobster (Homarus gammarus) is among those species at risk. A project was initiated in 2011 aiming to investigate long-term synergistic effects of temperature and projected increases in ocean acidification on the life cycle of lobster. Larvae were exposed to pCO2 levels of ambient water (water intake at 90 m depth, tentatively of 380 ?atm pCO2), 727 and 1217 ?atm pCO2, at temperatures 10 and 18 C. Long-term exposure lasted until 5 months of age. Thereafter the surviving juveniles were transferred to ambient water at 14 C. At 18 C the development from Stage 1 to 4 lasted from 14 to 16 days, as predicted under normal pH values. Growth was very slow at 10 C and resulted in only two larvae reaching Stage 4 in the ambient treatment. There were no significant differences in carapace length at the various larval stages between the different treatments, but there were differences in total length and dry weight at Stage 1 at 10 C, Stage 2 at both temperatures, producing larvae slightly larger in size and lighter by dry weight in the exposed treatments. Stage 3 larvae raised in 18 C and 1217 ?atm pCO2 were also larger in size and heavier by dry weight compared with 727 ?atm. Unfortunate circumstances precluded a full comparison across stages and treatment. Deformities were however observed in both larvae and juveniles. At 10 C, about 20% of the larvae exposed to elevated pCO2were deformed, compared with 0% in larvae raised in pH above 8.0. At 18 C and in high pCO2 treatment, 31.5% of the larvae were deformed. Occurrence of deformities after 5 months of exposure was 33 and 44% in juveniles raised in ambient and low pCO2, respectively, and 20% in juveniles exposed to high pCO2. Some of the deformities will possibly affect the ability to find food, sexual partner (walking legs, claw and antenna), respiration (carapace), and ability to swim (tail-fan damages).

  4. Different Temperature Evolution In Magnetic Flux Rope and Near-Surface Flare Loop Source In A Failed Solar Eruption

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; Song, Hong-qiang

    2014-06-01

    Solar eruption is a transient energetic phenomenon that involves sophisticated kinematic, morphological and thermal evolution. The observed evolution bears the knowledge on the physical mechanism of solar eruptions. Here we report a detailed study of a failed solar eruption occurred on January 05, 2013, which generated an M1.7 X-ray flare and a giant "fire ball" that likely represent a magnetic flux rope. The flux rope, a well-organized structure in the corona, was initially impulsively accelerated to a speed of $\\sim$400 km/s in the first minute, then decelerated and came to a complete stop in two minutes. The failed eruption resulted in a large-size high-lying ($\\sim$100 Mm above the surface) high-temperature ``fire ball" sitting in the corona for more than two hours. The time evolution of the thermal structure of the flux rope was revealed through the differential emission measure analysis technique, which produced temperature maps using observations of the Atmospheric Imaging Assembly on board \\textit{Solar Dynamic Observatory}. The average temperature of the flux rope steadily increased from $\\sim$5 MK to $\\sim$10 MK during the first nine minutes of the evolution. On the other hand, the temperature increase of the near surface flare loop source lasted only three minutes, similar to the rise time of the associated soft X-ray flare. We suggest that the flux rope is heated by the thermal energy release of the continuing magnetic reconnection in the high corona, which is different from the heating of the low-lying flare loops. The low-lying loops are likely heated by chromospheric plasma evaporation during the flare main phase. The large ambient loops overlying the flux rope was pushed up by $\\sim$10 Mm during the attempted eruption. The pattern of the velocity variation of the ambient loops strongly suggests that the failure of the eruption is caused by the strapping effect of the overlying loops.

  5. Mixed Micelles of Sodium Cholate and Sodium Dodecylsulphate 1:1 Binary Mixture at Different Temperatures Experimental and Theoretical Investigations

    PubMed Central

    Jjrt, Balzs; Poa, Mihalj; Fiser, Bla; Sz?ri, Miln; Farka, Zita; Viskolcz, Bla

    2014-01-01

    Micellisation process for sodium dodecyl sulphate and sodium cholate in 1?1 molar ratio was investigated in a combined approach, including several experimental methods and coarse grained molecular dynamics simulation. The critical micelle concentration (cmc) of mixed micelle was determined by spectrofluorimetric and surface tension measurements in the temperature range of 050C and the values obtained agreed with each other within the statistical error of the measurements. In range of 025C the cmc values obtained are temperature independent while cmc values were increased at higher temperature, which can be explained by the intensive motion of the monomers due to increased temperature. The evidence of existing synergistic effect among different constituent units of the micelle is indicated clearly by the interaction parameter (?1,2) calculated from cmc values according to Rubingh. As the results of the conductivity measurements showed the negative surface charges of the SDS-NaCA micelle are not neutralized by counterions. Applying a 10 s long coarse-grained molecular dynamics simulation for system including 30-30 SDS and CA (with appropriate number of Na+ cations and water molecules) we obtained semi-quantitative agreement with the experimental results. Spontaneous aggregation of the surfactant molecules was obtained and the key steps of the micelle formation are identified: First a stable SDS core was formed and thereafter due to the entering CA molecules the size of the micelle increased and the SDS content decreased. In addition the size distribution and composition as well as the shape and structure of micelles are also discussed. PMID:25004142

  6. Energy harvesting through gas dynamics in the free molecular flow regime between structured surfaces at different temperatures

    NASA Astrophysics Data System (ADS)

    Baier, Tobias; Dlger, Julia; Hardt, Steffen

    2014-05-01

    For a gas confined between surfaces held at different temperatures the velocity distribution shows a significant deviation from the Maxwell distribution when the mean free path of the molecules is comparable to or larger than the channel dimensions. If one of the surfaces is suitably structured, this nonequilibrium distribution can be exploited for momentum transfer in a tangential direction between the two surfaces. This opens up the possibility to extract work from the system which operates as a heat engine. Since both surfaces are held at constant temperatures, the mode of momentum transfer is different from the thermal creep flow that has gained more attention so far. This situation is studied in the limit of free-molecular flow for the case that an unstructured surface is allowed to move tangentially with respect to a structured surface. Parameter studies are conducted, and configurations with maximum thermodynamic efficiency are identified. Overall, it is shown that significant efficiencies can be obtained by tangential momentum transfer between structured surfaces.

  7. Temperature-pressure induced nano-structural inhomogenities for vortex pinning in bulk MgB2 of different connectivity

    NASA Astrophysics Data System (ADS)

    Prikhna, Tatiana; Eisterer, Michael; Weber, Harald W.; Gawalek, Wolfgang; Kovylaev, Valeriy; Karpets, Myroslav; Moshchil, Viktor; Kozyrev, Artem; Basyuk, Tatiana; Chaud, Xavier; Goldacker, Wilfried; Sokolovsky, Vladimir; Noudem, Jacques; Borimskiy, Alexandr; Sverdun, Vladimir; Prisyazhnaya, Elena

    2014-08-01

    Higher critical current densities, jc, (up to 1.6-0.15 MA/cm2 at 10-35 K) at low magnetic fields can be attained in MgB2-based materials, if a high manufacturing temperature (1050 C) is used, while low temperatures (600-800 C) usually lead to higher critical currents in high magnetic fields (10-4 kA/cm2 in 6-10 T at 10 K). This tendency was observed for MgB2-based materials having 55-99% density and 17-98% connectivity, which were prepared by different methods from different precursors in a wide range of pressure (0.1 MPa-2 GPa). The variation of the manufacturing temperature led to a redistribution of the magnesium, boron, and impurity oxygen. At 2 GPa, its increase results in the segregation of the oxygen in MgB2 and the transformation of 15-20 nm thick layers of MgB0.6-0.8O0.8-0.9 into separate MgB0.9-3.5O1.6-2 grains and to a reduction of the size of MgB11-13O0.2-0.3 inclusions located in the MgB2 (MgB2.2-1.7O0.4-0.6) matrix. The size reduction of B-enriched inclusions and the localization of O in MgB2 seem to be the reason for the increase of jc in low fields and for the shift from grain boundary to point pinning of vortices witnessed by an increase of the k-ratio.

  8. Room temperature GaN/AlGaN self-mixing terahertz detector enhanced by resonant antennas

    NASA Astrophysics Data System (ADS)

    Sun, Y. F.; Sun, J. D.; Zhou, Y.; Tan, R. B.; Zeng, C. H.; Xue, W.; Qin, H.; Zhang, B. S.; Wu, D. M.

    2011-06-01

    This letter focuses on the fabrication and characterization of a terahertz detector integrated with a group of low pass filters and resonant antennas. The detector operates as a self-mixer on GaN/AlGaN high electron mobility transistor (HEMT). At room temperature, a strong dc photocurrent is produced with the aid of the antennas and filters. The responsivity of our HEMT device is estimated to be 53 mA/W and a noise equivalent power of 1 nW/?Hz can be achieved at 300 K. In addition, the sensor properties of a similar HEMT detector without filter are tested as a comparison.

  9. Effects of orbital drift on advanced very high resolution radiometer products: Normalized difference vegetation index and sea surface temperature

    SciTech Connect

    Privette, J.L.; Fowler, C.; Wick, G.A.; Baldwin, D.; Emery, W.J. [Univ. of Colorado, Boulder, CO (United States). Dept. of Aerospace Engineering Sciences] [Univ. of Colorado, Boulder, CO (United States). Dept. of Aerospace Engineering Sciences

    1995-09-01

    Although orbits of the NOAA TIROS-N satellites are designed to be sun-synchronous, epheremis data shows that the afternoon, ascending node satellites currently cross the equator hours later than they did upon launch. This delay results in different illumination conditions for measurements made by the Advanced Very High Resolution Radiometer (AVHRR). The effects of illumination on two standard AVHRR products--normalized difference vegetation index (NDVI) and sea surface temperature (SST)--are modeled here. Combining orbital data with model results, the effects of the NOAA-11 orbital drift on NDVI are quantitatively assessed for three earth targets: an equatorial Africa site (0{degree} N), the First ISLSCP field Experiment (FIFE) site (39{degree} N), and the Boreal Ecosystem-Atmosphere Study (BOREAS) site (55{degree} N). Top-of-atmosphere NDVI corrections for solar zenith angle are developed for a dense, deciduous forest. Orbital drift effects on SST are given for an equatorial site. Although results vary with season, latitude, atmosphere and time since launch, NDVI differences of up to 0.23 and SST differences of up to 0.5 K may occur due strictly to orbital drift.

  10. Relationships Between the Bulk-Skin Sea Surface Temperature Difference, Wind, and Net Air-Sea Heat Flux

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    The primary purpose of this project was to evaluate and improve models for the bulk-skin temperature difference to the point where they could accurately and reliably apply under a wide variety of environmental conditions. To accomplish this goal, work was conducted in three primary areas. These included production of an archive of available data sets containing measurements of the skin and bulk temperatures and associated environmental conditions, evaluation of existing skin layer models using the compiled data archive, and additional theoretical work on the development of an improved model using the data collected under diverse environmental conditions. In this work we set the basis for a new physical model of renewal type, and propose a parameterization for the temperature difference across the cool skin of the ocean in which the effects of thermal buoyancy, wind stress, and microscale breaking are all integrated by means of the appropriate renewal time scales. Ideally, we seek to obtain a model that will accurately apply under a wide variety of environmental conditions. A summary of the work in each of these areas is included in this report. A large amount of work was accomplished under the support of this grant. The grant supported the graduate studies of Sandra Castro and the preparation of her thesis which will be completed later this year. This work led to poster presentations at the 1999 American Geophysical Union Fall Meeting and 2000 IGARSS meeting. Additional work will be presented in a talk at this year's American Meteorological Society Air-Sea Interaction Meeting this May. The grant also supported Sandra Castro during a two week experiment aboard the R/P Flip (led by Dr. Andrew Jessup of the Applied Physics Laboratory) to help obtain additional shared data sets and to provide Sandra with a fundamental understanding of the physical processes needed in the models. In a related area, the funding also partially supported Dr. William Emery and Daniel Baldwin in the preparation of their publication "Accuracy of in situ sea surface temperatures used to calibrate infrared satellite measurements". The remainder of this report is drawn from these publications and presentations.

  11. Changes of c-fos, malondialdehyde and lactate in brain tissue after global cerebral ischemia under different brain temperatures.

    PubMed

    Zhang, Hong; Li, Li; Xu, Guo-ying; Mei, Yuan-wu; Zhang, Jun-jian; Murong, Shen-xing; Sun, Sheng-gang; Tong, E-tang

    2014-06-01

    Under global cerebral ischemia, the effect of different brain temperature on cerebral ischemic injury was studied. Male Sprague-Dawley rats were divided into normothermic (37-38C) ischemia, mild hypothermic (31-32C) ischemia, hyperthermic (41-42C) ischemia and sham-operated groups. Global cerebral ischemia was established using the Pulsinelli four-vessel occlusion model and brain temperature was maintained at defined level for 60 min after 20-min ischemia. The expression of c-fos protein and the levels of malondialdehyde (MDA) and lactate in brain regions were detected by immunochemistry and spectrophotometrical methods, respectively. C-fos positive neurons were found in the hippocampus and cerebral cortex after cerebral ischemia reperfusion. Mild hypothermia increased the expression of c-fos protein in both areas, whereas hyperthermia decreased the expression of c-fos protein in the hippocampus at 24 h reperfusion, and the cerebral cortex at 48 h reperfusion when compared to normothermic conditions. In normothermic, mild hypothermic and hyperthermic ischemia groups, the levels of MDA and lactate in brain tissue were increased at 24, 48 and 72 h reperfusion following 20-min ischemia as compared with the sham-operated group (P<0.01). The levels of MDA and lactate in mild hypothermic group were significantly lower than those in normothermic group (P<0.01). It is suggested that brain temperature influences the translation of the immunoreactive protein product of c-fos after global cerebral ischemia, and MDA and lactate are also affected by hypothermia and hyperthermia. PMID:24939298

  12. Determination of inorganic and total mercury by vapor generation atomic absorption spectrometry using different temperatures of the measurement cell

    NASA Astrophysics Data System (ADS)

    Kaercher, Luiz Eduardo; Goldschmidt, Fabiane; Paniz, Jos Neri Gottfried; de Moraes Flores, rico Marlon; Dressler, Valderi Luiz

    2005-06-01

    A simple and inexpensive laboratory-built flow injection vapor generation system coupled to atomic absorption spectrometry (FI-VG AAS) for inorganic and total mercury determination has been developed. It is based on the vapor generation of total mercury and a selective detection of Hg 2 + or total mercury by varying the temperature of the measurement cell. Only the inorganic mercury is measured when the quartz cell is at room temperature, and when the cell is heated to 650 C or higher the total Hg concentration is measured. The organic Hg concentration in the sample is calculated from the difference between the total Hg and Hg 2 + concentrations. Parameters such as the type of acid (HCl or HNO 3) and its concentration, reductant (NaBH 4) concentration, carrier solution (HCl) flow rate, carrier gas flow rate, sample volume and quartz cell temperature, which influence FI-VG AAS system performance, were systematically investigated. The optimized conditions for Hg 2 + and total Hg determinations were: 1.0 mol l - 1 HCl as carrier solution, carrier flow rate of 3.5 ml min - 1 , 0.1% (m/v) NaBH 4, reductant flow rate of 1.0 ml min - 1 and carrier gas flow rate of 200 ml min - 1 . The relative standard deviation (RSD) is lower than 5.0% for a 1.0 ?g l - 1 Hg solution and the limit of quantification (LOQ, 10 s) is 55 ng g - 1 . Certified samples of dogfish muscle (DORM-1 and DORM-2) and non-certified fish samples were analyzed, using a 6.0 mol l - 1 HCl solution for analyte extraction. The Hg 2 + and CH 3Hg + concentrations found were in agreement with certified ones.

  13. Development of a model for predicting hydroxyl radical reaction rate constants of organic chemicals at different temperatures.

    PubMed

    Li, Chao; Yang, Xianhai; Li, Xuehua; Chen, Jingwen; Qiao, Xianliang

    2014-01-01

    The reaction rate constants of hydroxyl radicals with organic chemicals (kOH) are of great importance for assessing the persistence and fate of organic pollutants in the atmosphere. However, experimental determination of kOH seems fairly unrealistic, due to the soaring number of the emerging chemicals additional to the large number of existing chemicals. Quantitative structure-activity relationship (QSAR) models are excellent choices for evaluating and predicting kOH values. In this study, a QSAR model that can predict kOH at different temperatures was developed by employing quantum chemical descriptors and DRAGON descriptors. The adjusted determination coefficient Radj(2) of the model is 0.873, and the external validation coefficient Qext(2) is 0.835, implying that the model has satisfactory robustness and good predictability. Additionally, a QSAR model was also built for kOH prediction at room-temperature (298 K). The development of the two models followed the guidelines for development and validation of QSAR models proposed by the Organization for Economic Co-operation and Development (OECD). The applicability domains of the current models were extended to several classes of compounds including long-chain alkenes (C8-C13), organophosphates, dimethylnaphthalenes, organic selenium and organic mercury compounds that have not been covered in the previous studies. PMID:24210594

  14. The effect of different annealing temperatures on tin and cadmium telluride phases obtained by a modified chemical route

    SciTech Connect

    Mesquita, Anderson Fuzer [Departamento de Qumica, CCE, Universidade Federal do Esprito Santo, Campus Goiabeiras, 29075-910 Vitria, Esprito Santo (Brazil)] [Departamento de Qumica, CCE, Universidade Federal do Esprito Santo, Campus Goiabeiras, 29075-910 Vitria, Esprito Santo (Brazil); Porto, Arilza de Oliveira, E-mail: arilzaporto@yahoo.com.br [Departamento de Qumica, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais (Brazil); Magela de Lima, Geraldo [Departamento de Qumica, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais (Brazil)] [Departamento de Qumica, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais (Brazil); Paniago, Roberto [Departamento de Fsica, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais (Brazil)] [Departamento de Fsica, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais (Brazil); Ardisson, Jos Domingos [Centro de Desenvolvimento da Tecnologia Nuclear, CDTN/CNEN, Belo Horizonte, Minas Gerais (Brazil)] [Centro de Desenvolvimento da Tecnologia Nuclear, CDTN/CNEN, Belo Horizonte, Minas Gerais (Brazil)

    2012-11-15

    Graphical abstract: Display Omitted Highlights: ? Synthesis of cadmium and tin telluride. ? Chemical route to obtain pure crystalline cadmium and tin telluride. ? Effect of the annealing temperature on the crystalline phases. ? Removal of tin oxide as side product through thermal treatment. -- Abstract: In this work tin and cadmium telluride were prepared by a modification of a chemical route reported in the literature to obtain metallacycles formed by oxidative addition of tin-tellurium bonds to platinum (II). Through this procedure it was possible to obtain tin and cadmium telluride. X-ray diffraction and X-ray photoelectron spectroscopy were used to identify the crystalline phases obtained as well as the presence of side products. In the case of tin telluride it was identified potassium chloride, metallic tellurium and tin oxide as contaminants. The tin oxidation states were also monitored by {sup 119}Sn Mssbauer spectroscopy. The annealing in hydrogen atmosphere was chosen as a strategy to reduce the tin oxide and promote its reaction with the excess of tellurium present in the medium. The evolution of this tin oxide phase was studied through the annealing of the sample at different temperatures. Cadmium telluride was obtained with high degree of purity (98.5% relative weight fraction) according to the Rietveld refinement of X-ray diffraction data. The modified procedure showed to be very effective to obtain amorphous tin and cadmium telluride and the annealing at 450 C has proven to be useful to reduce the amount of oxide produced as side product.

  15. Low temperature fabrication & photocatalytical activity of carbon fiber-supported TiO2 with different phase compositions.

    PubMed

    Wang, Zhifeng; Yoshinaga, Kohji; Bu, Xiu R; Zhang, Ming

    2015-06-15

    Crystalline TiO2 nanoparticles with different phase compositions were fabricated on carbon fibers. The fabrication is achieved at low temperature. The process includes the treatment of Ti(OH)4 with hydrogen peroxide in the presence of carbon fibers. Neither additional acids nor bases, or additives are used during the process. Carbon fibers prior to and after TiO2 loading are characterized by FE-SEM, XRD, and UV-vis absorption spectroscopy. The photocatalytic activity was assessed via photocatalytic degradation of methyl orange solution, and found to be phase composition-dependent & pH dependent. Carbon fibers loaded with mixed-phase TiO2 led to the best photocatalytic performance. HRTEM reveals the anatase/rutile heterojunction which helps explain the high efficiency of photocatalysis. They have been demonstrated to be re-usable in the continuous photocatalytic degradation process. PMID:25791498

  16. Bacterial Production and Enzymatic Activities in Deep-Sea Sediments of the Pacific Ocean: Biogeochemical Implications of Different Temperature Constraints

    NASA Astrophysics Data System (ADS)

    Danovaro, R.; Corinaldesi, C.; dell'Anno, A.

    2002-12-01

    The deep-sea bed, acting as the ultimate sink for organic material derived from the upper oceans primary production, is now assumed to play a key role in biogeochemical cycling of organic matter on global scale. Early diagenesis of organic matter in marine sediments is dependent upon biological processes (largely mediated by bacterial activity) and by molecular diffusion. Organic matter reaching the sea floor by sedimentation is subjected to complex biogeochemical transformations that make organic matter largely unsuitable for direct utilization by benthic heterotrophs. Extracellular enzymatic activities in the sediment is generally recognized as the key step in the degradation and utilization of organic polymers by bacteria and a key role in biopolymeric carbon mobilization is played by aminopeptidase, alkaline phosphatase and glucosidase activities. In the present study we investigated bacterial density, bacterial C production and exo-enzymatic activities (aminopeptidase, glucosidase and phosphatase activity) in deep-sea sediments of the Pacific Ocean in relation with the biochemical composition of sediment organic matter (proteins, carbohydrates and lipids), in order to gather information on organic matter cycling and diagenesis. Benthic viral abundance was also measured to investigate the potential role of viruses on microbial loop functioning. Sediment samples were collected at eight stations (depth ranging from 2070-3100 m) along two transects located at the opposite side (north and south) of ocean seismic ridge Juan Fernandez (along latitudes 33 20' - 33 40'), constituted by the submerged vulcanoes, which connects the Chilean coasts to Rapa Nui Island. Since the northern and southern sides of this ridge apparently displayed small but significant differences in deep-sea temperature (related to the general ocean circulation), this sampling strategy allowed also investigating the role of different temperature constraints on bacterial activity and biogeochemical processes and to define possible scenarios dealing with climate induced changes in deep-sea conditions.

  17. Nanosecond laser-induced damage at different initial temperatures of Ta{sub 2}O{sub 5} films prepared by dual ion beam sputtering

    SciTech Connect

    Xu, Cheng, E-mail: xucheng@cumt.edu.cn; Jia, Jiaojiao; Fan, Heliang; Qiang, Yinghuai; Liu, Jiongtian [School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou 221116 (China); Yang, Di [College of Science, Minzu University of China, Beijing 10081 (China); Hu, Guohang; Li, Dawei [Key Laboratory of High Power Laser Materials, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2014-08-07

    Ta{sub 2}O{sub 5} films were deposited by dual ion beam sputtering method. The nanosecond laser-induced damage threshold (LIDT) at different initial temperatures and time of the films was investigated by an in situ high temperature laser-induced damage testing platform. It was shown that, when the initial temperature increased from 298?K to 383?K, the LIDT at 1064?nm and 12?ns significantly decreased by nearly 14%. Then the LIDT at 1064?nm and 12?ns decreased slower with the same temperature increment. Different damage morphologies were found at different initial temperatures. At low initial temperatures, it was the defects-isolated damage while at high initial temperatures it was the defects-combined damage. The theoretical calculations based on the defect-induced damage model revealed that both the significant increase of the highest temperature and the duration contributed to the different damage morphologies. With the initial temperature being increased, the thermal-stress coupling damage mechanism transformed gradually to the thermal dominant damage mechanism.

  18. New insights into collision-induced rototranslational absorption and scattering spectra of gaseous methane at different temperatures

    NASA Astrophysics Data System (ADS)

    El-Kader, M. S. A.; Maroulis, G.

    2012-11-01

    Quantum mechanical lineshapes of collision-induced absorption (CIA) and of collision-induced light scattering (CILS) at different temperatures for gaseous molecular methane are computed using as input theoretical values for induced dipole moments and pair-polarizability anisotropy. The quantum lineshapes of absorption are reproduced accurately by the extended Birnbaum Cohen (EBC) model with the parameters based on certain function of different coefficients for the octopole and hexadecapole mechanisms. For the scattering, the spectrum consists essentially of an intense, purely translational component which includes scattering due to free pairs and bound dimers and of another component due to the induced rotational scattering. This spectrum has been interpreted by means of pair-polarizability terms, which arise from a short range dipole-induced-dipole (DID) with small dispersion corrections and long range interaction mechanism involving higher-order dipole-quadrupole (A) and dipole-octopole (E) polarizabilities. Good agreement between computed and experimental lineshapes of both absorption and scattering is obtained with potential models constructed from thermophysical and transport properties.

  19. The effect of storage at different temperatures on the stability of Hepatitis C virus RNA in plasma samples.

    PubMed

    Jos, Marta; Curtu, Snia; Gajardo, Rodrigo; Jorquera, Juan I

    2003-03-01

    One important issue related to Hepatitis C virus (HCV) RNA nucleic acid amplification testing (NAT) is the storage conditions of plasma samples in order to obtain reliable results. Many authors have reported that the storage conditions could affect the RNA stability and, hence, HCV RNA detection. We have studied HCV RNA stability in plasma samples after storage at different temperatures (-70, -20, 5 and 25 degrees C). Samples containing different HCV titres were stored and analysed by qualitative or quantitative NAT techniques at defined time points. At -20 degrees C, samples containing high HCV RNA titres were followed-up during approximately 2.6-2.7 years, samples with intermediate concentrations during approximately 1 year and samples with 100 International Units/millilitre (IU/ml) during 2.5 years. Independently of the HCV RNA concentration, the results show absence of decay in HCV RNA detectability. Samples stored at 25 degrees C maintain their HCV RNA titre during 14 days and samples at 5 degrees C were stable for at least 3 months. PMID:12623054

  20. The Effects of Light and Temperature on Different Phases of the Life Cycle in the Carrageenan Producing Alga Chondracanthus chamissoi (Rhodophyta, Gigartinales)

    Microsoft Academic Search

    C. R. Bulboa; J. E. Macchiavello

    2001-01-01

    Growth of female gametophyte and sporophyte phases of Chondracanthus chamissoi was measured under controlled laboratory conditions, examining effects of different combinations of photon flux density and temperature. Apical segments of both (isomorphic) phases of this alga were cultivated in Von Stosch medium using 12 combinations of photon flux density (PFD; 20 to 120 mmol m22 s21) and temperature (10 to

  1. Deformities in larvae and juvenile European lobster (Homarus gammarus) exposed to lower pH at two different temperatures

    NASA Astrophysics Data System (ADS)

    Agnalt, A.-L.; Grefsrud, E. S.; Farestveit, E.; Larsen, M.; Keulder, F.

    2013-12-01

    The ongoing warming and acidification of the world's oceans are expected to influence the marine ecosystems, including benthic marine resources. Ocean acidification may especially have an impact on calcifying organisms, and the European lobster (Homarus gammarus) is among those species at risk. A project was initiated in 2011 aiming to investigate long-term effects of ocean acidification on the early life-cycle of lobster under two temperatures. Larvae were exposed to pCO2 levels of ambient water (water intake at 90 m depth), medium 750 (pH = 7.79) and high 1200 ?atm pCO2 (pH = 7.62) at temperatures 10 and 18 C. The water parameters in ambient water did not stay stable and were very low towards the end of the experiment in the larval phase at 10 C,with pH between 7.83 and 7.90. At 18, pH in ambient treatment was even lower, between 7.76 and 7.83, i.e. close to medium pCO2 treatment. Long-term exposure lasted 5 months. At 18 C the development from stage 1 to 4 lasted 14 to 16 days, as predicted under optimal water conditions. Growth was very slow at 10 C and resulted in three larvae reaching stage 4 in high pCO2 treatment only. There were no clear effects of pCO2 treatment, on either carapace length or dry weight. However, deformities were observed in both larvae and juveniles. The proportion of larvae with deformities increased with increasing pCO2 exposure, independent of temperature. In the medium treatment about 23% were deformed, and in the high treatment about 43% were deformed. None of the larvae exposed to water of pH >7.9 developed deformities. Curled carapace was the most common deformity found in larvae raised in medium pCO2 treatment, irrespective of temperature, but damages in the tail fan occurred in addition to a bent rostrum. Curled carapace was the only deformity found in high pCO2 treatment at both temperatures. Occurrence of deformities after five months of exposure was 33 and 44% in juveniles raised in ambient and low pCO2 levels, respectively, and 21% in juveniles exposed to high pCO2. Deformed claws were most often found in ambient and medium treatment (56%, followed by stiff/twisted walking legs (39%) and puffy carapace (39%). In comparison, at high pCO2 levels 71% of the deformed juveniles had developed a puffy carapace. Overall, about half of the deformed juveniles from the ambient and medium pCO2 treatment displayed two or three different abnormalities; 70% had multiple deformities in the high pCO2 treatment. Some of the deformities in the juveniles may affect respiration (carapace), the ability to find food, or sexual partners (walking legs, claw and antenna), and ability to swim (tail-fan damages).

  2. Association between the increase in brain temperature and physical performance at different exercise intensities and protocols in a temperate environment

    PubMed Central

    Kunstetter, A.C.; Wanner, S.P.; Madeira, L.G.; Wilke, C.F.; Rodrigues, L.O.C.; Lima, N.R.V.

    2014-01-01

    There is evidence that brain temperature (Tbrain) provides a more sensitive index than other core body temperatures in determining physical performance. However, no study has addressed whether the association between performance and increases in Tbrain in a temperate environment is dependent upon exercise intensity, and this was the primary aim of the present study. Adult male Wistar rats were subjected to constant exercise at three different speeds (18, 21, and 24 m/min) until the onset of volitional fatigue. Tbrain was continuously measured by a thermistor inserted through a brain guide cannula. Exercise induced a speed-dependent increase in Tbrain, with the fastest speed associated with a higher rate of Tbrain increase. Rats subjected to constant exercise had similar Tbrain values at the time of fatigue, although a pronounced individual variability was observed (38.7-41.7C). There were negative correlations between the rate of Tbrain increase and performance for all speeds that were studied. These results indicate that performance during constant exercise is negatively associated with the increase in Tbrain, particularly with its rate of increase. We then investigated how an incremental-speed protocol affected the association between the increase in Tbrain and performance. At volitional fatigue, Tbrain was lower during incremental exercise compared with the Tbrain resulting from constant exercise (39.30.3 vs 40.30.1C; P<0.05), and no association between the rate of Tbrain increase and performance was observed. These findings suggest that the influence of Tbrain on performance under temperate conditions is dependent on exercise protocol. PMID:25003543

  3. Differences in thermal balance, body temperature and activity between non-melanic and melanic two-spot ladybird beetles (Adalia bipunctata) under controlled conditions

    PubMed

    Jong; Gussekloo; Brakefield

    1996-01-01

    The consequences of the elytral colour difference between non-melanic (red) and melanic (black) two-spot ladybirds for their thermal properties were studied by applying and testing a biophysical model. The expected differential effects of variation in transmission through the elytra, body size, width of the subelytral cavity, ambient temperature, radiation intensity and wind speed are described, assuming that the two colour patterns represent differences in elytral reflectance and transmittance. The model predicts a higher body temperature for melanic beetles under most conditions. Invasive temperature measurements on living beetles under ranges of specified conditions with respect to ambient temperature, radiative regime and wind speed were in qualitative agreement with the model predictions and, considering the assumptions made, closely corresponded at the quantitative level. The consequences of the temperature differences for morph activity were studied by measuring walking speeds and the time needed to become active for each morph under the various conditions. The results are consistent with the differences in body temperature, assuming an optimum curve relating performance to body temperature. The colour difference between morphs appeared to be the principal factor influencing activity. PMID:9320589

  4. Differences in daily rhythms of wrist temperature between obese and normal-weight women: associations with metabolic syndrome features

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The circadian rhythm of core body temperature is associated with widespread physiological effects. However, studies with other more practical temperature measures, such as wrist (WT) and proximal temperatures, are still scarce. The aim of this study was to investigate whether obesity is associated w...

  5. Analysis of reciprocal-transfer experiments to estimate the length of phases having different responses to temperature

    Microsoft Academic Search

    X. Yin

    2008-01-01

    Background and Aims: The responsiveness of plant ontogeny to temperature may change with plant age. These changes may best be identified by experiments in which individual plants are transferred in a time series from low temperature (LT) to high temperature (HT), and vice versa. Any change in the value of the slope for a plot of the duration taken to

  6. TECHNICAL ARTICLE Analysis of Reciprocal-transfer Experiments to Estimate the Length of Phases having Different Responses to Temperature

    Microsoft Academic Search

    XINYOU YIN

    2008-01-01

    Background and Aims The responsiveness of plant ontogeny to temperature may change with plant age. These changes may best be identified by experiments in which individual plants are transferred in a time series from low temperature (LT) to high temperature (HT), and vice versa. Any change in the value of the slope for a plot of the duration taken

  7. Mechanical response and microcrack formation in a fine-grained duplex TiAl at different strain rates and temperatures

    SciTech Connect

    Jin, Z.; Cady, C.; Gray, G.T. III [Los Alamos National Lab., NM (United States); Kim, Y.-W. [Universal Energy Systems, Inc., Dayton, OH (United States)

    1996-10-01

    Compressive behavior of this alloy was studied at strain rates of 0. 001 and 2000 sec{sup -1} and temperatures from -196 C to 1200 C. Temperature dependence of yield stress was found to depend on strain rate: At the quasi-static strain rate, 0.001 sec{sup -1}, the yield stress decreases with temperature with a plateau between 200 and 800 C. At the high strain rate, 2000 sec{sup -1}, the yield stress exhibits a positive temperature dependence above 600 C. Strain hardening rate decreases dramatically with temperature in the very low and high temperature regions with a plateau at intermediate temperatures for both strain rates. As the strain rate increases, the strain hardening rate plateaus extended to higher temperatures. The strain rate sensitivity increases slightly with temperature (but less than 0.1) for strain rates above 0.001 sec{sup -1}. However, at a strain rate of 0.001 sec{sup -1}, there is a dramatic increase in the strain rate sensitivity with temperature; above 1100 C, the rate sensitivity becomes much larger. Microcracks occurring in grain interiors and at grain boundaries were observed at all strain rates and temperatures. Formation and distribution of microcracks were found to vary depending on strain rate and deformation temperature.

  8. Reference Genes Selection and Normalization of Oxidative Stress Responsive Genes upon Different Temperature Stress Conditions in Hypericum perforatum L

    PubMed Central

    Velada, Isabel; Ragonezi, Carla; Arnholdt-Schmitt, Birgit; Cardoso, Hlia

    2014-01-01

    Reverse transcription-quantitative real-time PCR (RT-qPCR) is a widely used technique for gene expression analysis. The reliability of this method depends largely on the suitable selection of stable reference genes for accurate data normalization. Hypericum perforatum L. (St. John's wort) is a field growing plant that is frequently exposed to a variety of adverse environmental stresses that can negatively affect its productivity. This widely known medicinal plant with broad pharmacological properties (anti-depressant, anti-tumor, anti-inflammatory, antiviral, antioxidant, anti-cancer, and antibacterial) has been overlooked with respect to the identification of reference genes suitable for RT-qPCR data normalization. In this study, 11 candidate reference genes were analyzed in H. perforatum plants subjected to cold and heat stresses. The expression stability of these genes was assessed using GeNorm, NormFinder and BestKeeper algorithms. The results revealed that the ranking of stability among the three algorithms showed only minor differences within each treatment. The best-ranked reference genes differed between cold- and heat-treated samples; nevertheless, TUB was the most stable gene in both experimental conditions. GSA and GAPDH were found to be reliable reference genes in cold-treated samples, while GAPDH showed low expression stability in heat-treated samples. 26SrRNA and H2A had the highest stabilities in the heat assay, whereas H2A was less stable in the cold assay. Finally, AOX1, AOX2, CAT1 and CHS genes, associated with plant stress responses and oxidative stress, were used as target genes to validate the reliability of identified reference genes. These target genes showed differential expression profiles over time in treated samples. This study not only is the first systematic analysis for the selection of suitable reference genes for RT-qPCR studies in H. perforatum subjected to temperature stress conditions, but may also provide valuable information about the roles of genes associated with temperature stress responses. PMID:25503716

  9. Controlling suction by vapour equilibrium technique at different temperatures, application to the determination of the water retention properties of MX80 clay

    E-print Network

    Tang, Anh-Minh

    2005-01-01

    Problems related to unsaturated soils are frequently encountered in geotechnical or environmental engineering works. In most cases, for the purpose of simplicity, the problems are studied by considering the suction effects on volume change or shear strength under isothermal conditions. Under isothermal condition, very often, a temperature independent water retention curve is considered in the analysis, which is obviously a simplification. When the temperature changes are too significant to be neglected, it is necessary to account for the thermal effects. In this paper, a method for controlling suction using the vapour equilibrium technique at different temperatures is presented. First, calibration of various saturated saline solutions was carried out from temperature of 20 degrees C to 60 degrees C. A mirror psychrometer was used for the measurement of relative humidity generated by saturated saline solutions at different temperatures. The results obtained are in good agreement with the data from the literatu...

  10. Environmental temperature and thermal indices: what is the most effective predictor of heat-related mortality in different geographical contexts?

    PubMed

    Morabito, Marco; Crisci, Alfonso; Messeri, Alessandro; Capecchi, Valerio; Modesti, Pietro Amedeo; Gensini, Gian Franco; Orlandini, Simone

    2014-01-01

    The aim of this study is to identify the most effective thermal predictor of heat-related very-elderly mortality in two cities located in different geographical contexts of central Italy. We tested the hypothesis that use of the state-of-the-art rational thermal indices, the Universal Thermal Climate Index (UTCI), might provide an improvement in predicting heat-related mortality with respect to other predictors. Data regarding very elderly people (? 75 years) who died in inland and coastal cities from 2006 to 2008 (May-October) and meteorological and air pollution were obtained from the regional mortality and environmental archives. Rational (UTCI) and direct thermal indices represented by a set of bivariate/multivariate apparent temperature indices were assessed. Correlation analyses and generalized additive models were applied. The Akaike weights were used for the best model selection. Direct multivariate indices showed the highest correlations with UTCI and were also selected as the best thermal predictors of heat-related mortality for both inland and coastal cities. Conversely, the UTCI was never identified as the best thermal predictor. The use of direct multivariate indices, which also account for the extra effect of wind speed and/or solar radiation, revealed the best fitting with all-cause, very-elderly mortality attributable to heat stress. PMID:24523657

  11. Environmental Temperature and Thermal Indices: What Is the Most Effective Predictor of Heat-Related Mortality in Different Geographical Contexts?

    PubMed Central

    Morabito, Marco; Crisci, Alfonso; Messeri, Alessandro; Capecchi, Valerio; Modesti, Pietro Amedeo; Gensini, Gian Franco; Orlandini, Simone

    2014-01-01

    The aim of this study is to identify the most effective thermal predictor of heat-related very-elderly mortality in two cities located in different geographical contexts of central Italy. We tested the hypothesis that use of the state-of-the-art rational thermal indices, the Universal Thermal Climate Index (UTCI), might provide an improvement in predicting heat-related mortality with respect to other predictors. Data regarding very elderly people (?75 years) who died in inland and coastal cities from 2006 to 2008 (MayOctober) and meteorological and air pollution were obtained from the regional mortality and environmental archives. Rational (UTCI) and direct thermal indices represented by a set of bivariate/multivariate apparent temperature indices were assessed. Correlation analyses and generalized additive models were applied. The Akaike weights were used for the best model selection. Direct multivariate indices showed the highest correlations with UTCI and were also selected as the best thermal predictors of heat-related mortality for both inland and coastal cities. Conversely, the UTCI was never identified as the best thermal predictor. The use of direct multivariate indices, which also account for the extra effect of wind speed and/or solar radiation, revealed the best fitting with all-cause, very-elderly mortality attributable to heat stress. PMID:24523657

  12. Molecular characterisation and expression of Atlantic cod (Gadus morhua) myoglobin from two populations held at two different acclimation temperatures.

    PubMed

    Lurman, Glenn J; Koschnick, Nils; Prtner, Hans-O; Lucassen, Magnus

    2007-11-01

    Much previous research has demonstrated the plasticity of myoglobin concentrations in both cardiac and skeletal myocytes in response to hypoxia and training. No study has yet looked at the effect of thermal acclimation on myoglobin in fish. Atlantic cod (Gadus morhua) from two different populations, i.e. the North Sea and the North East Arctic, were acclimated to 10 and 4 degrees C. Both the myoglobin mRNA and myoglobin protein in cod hearts increased significantly by up to 3.7 and 2.3 fold respectively as a result of acclimation to 4 degrees C. These increments were largest in the Arctic population, which in earlier studies have been shown to possess cold compensated metabolic demands at low temperatures. These metabolic demands associated with higher mitochondrial capacities may have driven the increase in cardiac myoglobin concentrations, in order to support diffusive oxygen supply. At the same time the increase in myoglobin levels may serve further functions during cold acclimation, for example, protection of the cell against reactive oxygen species, and scavenging nitric oxide, thereby contributing to the regulation of mitochondrial volume density. PMID:17884647

  13. Effect of different temperatures on viability of seven encysted metacercariae recovered from freshwater fishes in Qualyobia, Egypt.

    PubMed

    Abdallah, Karim F; Hamadto, Hassan H A; El-Hayawan, Ibrahim A H; El-Motayam, Mona H; Ahmed, Waleed El-Awamy M

    2009-08-01

    Encysted metacercariae (EMC) from seven trematod-zoonotic parasites were exposed to different temperature mechanisms. Boiling of the infected fishes was sufficient to kill the EMC, frying of fishes for five minutes was quite sufficient to inhibit the viability of EMC, but frying for 10 minutes killed all EMC. Grilling of infected Tilapia zillii was sufficient to kill EMC after 10 minutes; however five minutes were sufficient only to kill EMC in Clarias gariepinus. Regarding chilling at 5 degrees C, T. zillii EMC showed variation in response. Complete loss of viability of Prohemistomatidae EMC was achieved after 14 days, for Haplorchidae after 11 days, for Diplostomatidae after 12 days, while Clinostomatidae EMC required 15 days. For Cl. gariepinus, Bagrus bajad and Chrysichthys auratus achieved results were similar to those for T. zillii but with fewer days of withstanding chilling. The EMC infecting Tilapia lost their viability by freezing at -5 degrees C & -10 degrees k for Prohemistomatidae after 48 & 40 hours, for Diplostomatidae after 24 & 16 hours and for Clinostomatidae cysts after 48 &32 hours respectively. In infected Clarias gariepinus, Bagrus bajad and Chrysichthys auratus the EMC lost their viability by fireezing at -5 degrees C & -10 degrees C for periods shorter than those of Tilapia sp. PMID:19795748

  14. Estimation of teaching-learning-based optimization primer design using regression analysis for different melting temperature calculations.

    PubMed

    Cheng, Yu-Huei

    2015-01-01

    Primers plays important role in polymerase chain reaction (PCR) experiments, thus it is necessary to select characteristic primers. Unfortunately, manual primer design manners are time-consuming and easy to get human negligence because many PCR constraints must be considered simultaneously. Automatic programs for primer design were developed urgently. In this study, the teaching-learning-based optimization (TLBO), a robust and free of algorithm-specific parameters method, is applied to screen primers conformed primer constraints. The optimal primer frequency (OPF) based on three known melting temperature formulas is estimated by 500 runs for primer design in each different number of generations. We selected optimal primers from fifty random nucleotide sequences of Homo sapiens at NCBI. The results indicate that the SantaLucia's formula is better coupled with the method to get higher optimal primer frequency and shorter CPU-time than the Wallace's formula and the Bolton and McCarthy's formula. Through the regression analysis, we also find the generations are significantly associated with the optimal primer frequency. The results are helpful for developing the novel TLBO-based computational method to design feasible primers. PMID:25222953

  15. Temperature Meets Tree Physiology: Potential Influence of Different Characteristics of Recorded Temperature Increases in Alaska on the Diverging Growth Responses of White Spruce.

    NASA Astrophysics Data System (ADS)

    Juday, G. P.

    2007-12-01

    To be useful for temperature reconstructions, tree growth must respond to the same climate parameters today in the same way it has in the past. Recent studies which show tree ring widths from the northern high latitudes are diverging from previous sensitivity to temperature parameters may be partly influenced by new patterns of warm temperature anomalies as well as the limits of possible physiological response by trees. Both factors may be influencing white spruce growth in Alaska. In the 104-year record at UES/Fairbanks, daily maximum temperatures (May:August) have increased only slightly (~0.5 C), while daily minima have increased over 3 C per century, and frost-free growing season length has increased 50% to about 120 days (ca. 150 days at lower temperature thresholds suitable for native species). Total yearly days above freezing have increased by about 20 days. Spring snow and ice dissipation is earlier by about 5 to 6 days. Winters mean temperatures are 2 to 3 C greater and include fewer days below -20, -30, and -40 C. At stations across central Alaska with a shorter 60 to 90-year record (McGrath, Bettles, Talkeetna) trends are similar. In Alaska chronologies, high summer temperatures "kill" growth the following year on many sites. Years with high numbers of days with daily maxima above 70 F (21.1 C) are followed by significant "pointer" years (e.g. 1924, 1940-41, 1958-59, 1974-75, 2005) with small tree rings. White spruce is a determinate growth species, meaning current year growth is disproportionately influenced by reserves accumulated in the previous growing season. In a given year, when maximum moisture stress encountered by a particular tree first exceeds a critical threshold, cell production switches from earlywood (large diameter, thin-walled) to latewood (small diameter, thick-walled) type, which limits further width expansion. These climate trends and tree chronology patterns are consistent with (1) a shorter snow accumulation season and longer evapotranspiration season reducing potential spring melt input, which (2) exhausts early season soil moisture earlier and on previously non-sensitive sites, thus (3) inducing cell type switch earlier in the year and on previously non-sensitive sites, resulting in smaller ring formation and negative sensitivity to previous (and secondarily current) summer-season temperature. The next stage in the warming process would be temperature and moisture combinations near lethal conditions which could injure white spruce so severely that their actual realized growth would underperform previous climatic predictions for a 1 to 3 year period. In addition, outbreaks of insects that reduce tree growth would be released from previous climatic limits and become a more significant factor in determining annual net growth, and thus size of ring formed. Finally, empirical relations of growth versus temperature predictors in existing, negative-responding Alaska white spruce populations suggest that temperature increases of 2.5 to 4 C would result in tree death at low elevations represented by climate stations. Environments suitable for white spruce survival might be found in mountain environments.

  16. Effects of different acute high ambient temperatures on function of hepatic mitochondrial respiration, antioxidative enzymes, and oxidative injury in broiler chickens.

    PubMed

    Tan, G-Y; Yang, L; Fu, Y-Q; Feng, J-H; Zhang, M-H

    2010-01-01

    This study investigated the effects of different acute high ambient temperatures on dysfunction of hepatic mitochondrial respiration, the antioxidative enzyme system, and oxidative injury in broiler chickens. One hundred twenty-eight 6-wk-old broiler chickens were assigned randomly to 4 groups and subsequently exposed to 25 (control), 32, 35, and 38 degrees C (RH, 70 +/- 5%) for 3 h, respectively. The rectal temperatures, activity of antioxidative enzymes (superoxide dismutase, catalase, and glutathione peroxidase), content of malondialdehyde and protein carbonyl, and the activity of mitochondrial respiratory enzymes were determined. The results showed that exposure to high ambient temperature induced a significant elevation of rectal temperature, antioxidative enzyme activity, and formation of malondialdehyde and protein carbonyl, as well as dysfunction of the mitochondrial respiratory chain in comparison with control (P < 0.05). Almost all of the indicators changed in a temperature-dependent manner with the gradual increase of ambient temperature from 32 to 38 degrees C; differences in each parameter (except catalase) among the groups exposed to different high ambient temperatures were also statistically significant (P < 0.05). The results of the present study suggest that, in the broiler chicken model used here, acute exposure to high temperatures may depress the activity of the mitochondrial respiratory chain. This inactivation results subsequently in overproduction of reactive oxygen species, which ultimately results in oxidative injury. However, this hypothesis needs to be evaluated more rigorously in future studies. It has also been shown that, with the gradual increase in temperature, the oxidative injury induced by heat stress in broiler chickens becomes increasingly severe, and this stress response presents in a temperature-dependent manner in the temperature range of 32 to 38 degrees C. PMID:20008809

  17. Preparation and characterization of Nickel Oxide thin films by direct current reactive magnetron sputtering at different substrate temperatures

    NASA Astrophysics Data System (ADS)

    Reddy, A. Mallikarjuna; Byun, Chang Woo; Joo, Seung Ki; Reddy, A. Sivasankar; Reddy, P. Sreedhara

    2014-09-01

    The influence of substrate temperature on the properties NiO films, prepared by dc reactive magnetron sputtering technique, is studied by various characterization methods. X-ray diffraction studies revealed that the crystal structure is highly influenced by the substrate temperature. The optical results indicated that the optical transmittance and band gap of the films increased with the increase of substrate temperature up to 523 K. The optical band gap of NiO films decreases from 3.82 to 3.70 eV with the increase of substrate temperature from 523 to 723 K. The electrical resistivity decreased with the increase of substrate temperature from 303 to 723 K, whereas carrier concentration and Hall mobility increased with increasing the substrate temperature.

  18. Growth, oxygen consumption and activity of juvenile turbot ( scophthalmus maximus L.) reared under different temperatures and photoperiods

    Microsoft Academic Search

    Albert K. Imsland; A. Folkvord; S. O. Stefansson

    1995-01-01

    Juvenile turbot (5125 g) were reared under two experimental temperatures: 10C and 16C, and three experimental photoperiods: LDN (natural photoperiod), LD 16:8 (16 h light: 8 h darkness), LD24:0 (continuous light), to study effects of temperature and photoperiod on growth, activity and oxygen consumption. Growth was strongly affected by temperature and was higher at 16C than at 10C. Continuous light

  19. Toward a "molecular thermometer" to estimate the charring temperature of wildland charcoals derived from different biomass sources.

    PubMed

    Schneider, Maximilian P W; Pyle, Lacey A; Clark, Kenneth L; Hockaday, William C; Masiello, Caroline A; Schmidt, Michael W I

    2013-10-15

    The maximum temperature experienced by biomass during combustion has a strong effect on chemical properties of the resulting charcoal, such as sorption capacity (water and nonpolar materials) and microbial degradability. However, information about the formation temperature of natural charcoal can be difficult to obtain in ecosystems that are not instrumented prior to fires. Benzene polycarboxylic acids (BPCA) are molecular markers specific for pyrogenic carbon (PyC) which can provide information on the degree of aromatic condensation in charcoals. Here we apply the BPCA molecular marker method to a set of 10 charcoals produced during an experimental fire in a Pitch pine-scrub oak forest from litter and bark of pitch pine and inkberry plants in the Pinelands National Reserve in New Jersey, USA. We deployed temperature-sensitive crayons throughout the burn site, which recorded the maximum air temperature and made comparisons to the degree of thermal alteration recorded by BPCA molecular markers. Our results show an increase of the degree of aromatic condensation with monitored temperatures for bark biomass, while for needles no clear trend could be observed. For leaf-derived charcoals at increasing monitored fire temperatures, decreasing degree of aromatic condensation was obtained. This suggests that molecular markers can be used to roughly estimate the maximum fire temperatures experienced by bark and wood materials, but not based on leaf- and needle-derived materials. Possible applications include verifying declared pyrolysis temperatures of biochars and evaluating ecosystem fire temperature postburn. PMID:24040784

  20. A comparison of the low temperature transcriptomes and CBF regulons of three plant species that differ in freezing tolerance: Solanum commersonii, Solanum tuberosum, and Arabidopsis thaliana

    PubMed Central

    Pino, Mara-Teresa; Jekni?, Zoran; Zou, Cheng; Shiu, Shin-Han; Chen, Tony H. H.; Thomashow, Michael F.

    2011-01-01

    Solanum commersonii and Solanum tuberosum are closely related plant species that differ in their abilities to cold acclimate; whereas S. commersonii increases in freezing tolerance in response to low temperature, S. tuberosum does not. In Arabidopsis thaliana, cold-regulated genes have been shown to contribute to freezing tolerance, including those that comprise the CBF regulon, genes that are controlled by the CBF transcription factors. The low temperature transcriptomes and CBF regulons of S. commersonii and S. tuberosum were therefore compared to determine whether there might be differences that contribute to their differences in ability to cold acclimate. The results indicated that both plants alter gene expression in response to low temperature to similar degrees with similar kinetics and that both plants have CBF regulons composed of hundreds of genes. However, there were considerable differences in the sets of genes that comprised the low temperature transcriptomes and CBF regulons of the two species. Thus differences in cold regulatory programmes may contribute to the differences in freezing tolerance of these two species. However, 53 groups of putative orthologous genes that are cold-regulated in S. commersonii, S. tuberosum, and A. thaliana were identified. Given that the evolutionary distance between the two Solanum species and A. thaliana is 112156 million years, it seems likely that these conserved cold-regulated genesmany of which encode transcription factors and proteins of unknown functionhave fundamental roles in plant growth and development at low temperature. PMID:21511909

  1. TEM ANALYSIS OF THE GROWTH OF OXIDE SCALES AT DIFFERENT TEMPERATURES IN FeAl GRADE 3 INTERMETALLIC ALLOY

    E-print Network

    Paris-Sud XI, Universit de

    . At these temperatures, aluminium outward diffusion does not seem to be suppressed neither by the spinel sub-layer nor on the oxidation temperature and time [2-4]. Conversely, in more aluminium- rich binary and ODS FeAl alloys in agreement with the previous observations of Montealegre et al. [7] as a result of the extrusion process

  2. Headwater stream temperature response to clear-cut harvesting with different riparian treatments, coastal British Columbia, Canada

    Microsoft Academic Search

    Takashi Gomi; R. Dan Moore; Amod S. Dhakal

    2006-01-01

    A 6-year study documented the effects of clear-cut harvesting with and without riparian buffers (10 m and 30 m wide) on headwater stream temperature in coastal British Columbia. The experiment involved a replicated paired catchment design. Pretreatment calibration relations between the treatment and control streams were fitted using time series of daily minimum, mean, and maximum temperatures. Generalized least squares

  3. TEMPERATURE-RESPIRATION RELATIONSHIPS DIFFER IN MYCORRHIZAL AND NON-MYCORRHIZAL ROOT SYSTEMS OF PICEA ABIES (L.) KARST.

    EPA Science Inventory

    Root respiration has been shown to increase with temperature, but less is known about how this relation ship is affected by the fungal partner in mycorrhizal root systems. In order to test respiratory temperature dependence, in particular Q10 of mycorrhizal and non-mycorrhizal r...

  4. Behavioural thermoregulation in Daphnia carinata from different depths of a natural water body: influence of environmental oxygen levels and temperature

    Microsoft Academic Search

    P. R Wiggins; P. B Frappell

    2002-01-01

    The influence of environmental parameters (water temperature and dissolved oxygen content) on the haemoglobin content of a naturally occurring population of Daphnia carinata was studied in a population resident in an intermittently flowing, shallow body of water. It was found that the Hb content of the animals was influenced by a combination of both the water temperature and dissolved oxygen

  5. Meteorology (Temperature)

    Atmospheric Science Data Center

    2014-09-25

    Air Temperature ( C) Daily Temperature Range ( C) Difference between the average daily maximum ... The monthly accumulation of degrees when the daily mean temperature is above 18 C. Heating Degree Days below 18 C ...

  6. Minor loading vein acclimation for three Arabidopsis thaliana ecotypes in response to growth under different temperature and light regimes

    PubMed Central

    Cohu, Christopher M.; Muller, Onno; Demmig-Adams, Barbara; Adams, William W.

    2013-01-01

    In light of the important role of foliar phloem as the nexus between energy acquisition through photosynthesis and distribution of the products of photosynthesis to the rest of the plant, as well as communication between the whole plant and its leaves, we examined whether foliar minor loading veins in three Arabidopsis thaliana ecotypes undergo acclimation to the growth environment. As a winter annual exhibiting higher rates of photosynthesis in response to cooler vs. warmer temperatures, this species might be expected to adjust the structure of its phloem to accommodate greater fluxes of sugars in response to growth at low temperature. Minor (fourth- and third-order) veins had 14 or fewer sieve elements and phloem tissue comprised 50% or more of the cross-sectional area. The number of phloem cells per minor loading vein was greater in leaves grown under cool temperature and high light vs. warm temperature and moderate light. This effect was greatest in an ecotype from Sweden, in which growth under cool temperature and high light resulted in minor veins with an even greater emphasis on phloem (50% more phloem cells with more than 100% greater cross-sectional area of phloem) compared to growth under warm temperature and moderate light. Likewise, the number of sieve elements per minor vein increased linearly with growth temperature under moderate light, almost doubling over a 27C temperature range (21C leaf temperature range) in the Swedish ecotype. Increased emphasis on cells involved in sugar loading and transport may be critical for maintaining sugar export from leaves of an overwintering annual such as A. thaliana, and particularly for the ecotype from the northern-most population experiencing the lowest temperatures. PMID:23847643

  7. Hyperspectral imagery for disaggregation of land surface temperature with selected regression algorithms over different land use land cover scenes

    NASA Astrophysics Data System (ADS)

    Ghosh, Aniruddha; Joshi, P. K.

    2014-10-01

    Land surface temperature (LST), a key parameter in understanding thermal behavior of various terrestrial processes, changes rapidly and hence mapping and modeling its spatio-temporal evolution requires measurements at frequent intervals and finer resolutions. We designed a series of experiments for disaggregation of LST (DLST) derived from the Landsat ETM + thermal band using narrowband reflectance information derived from the EO1-Hyperion hyperspectral sensor and selected regression algorithms over three geographic locations with different climate and land use land cover (LULC) characteristics. The regression algorithms applied to this end were: partial least square regression (PLS), gradient boosting machine (GBM) and support vector machine (SVM). To understand the scale dependence of regression algorithms for predicting LST, we developed individual models (local models) at four spatial resolutions (480 m, 240 m, 120 m and 60 m) and tested the differences between these using RMSE derived from cross-validated samples. The sharpening capabilities of the models were assessed by predicting LST at finer resolutions using models developed at coarser spatial resolution. The results were also compared with LST produced by DisTrad sharpening model. It was found that scale dependence of the models is a function of the study area characteristics and regression algorithms. Considering the sharpening experiments, both GBM and SVM performed better than PLS which produced noisy LST at finer spatial resolutions. Based on the results, it can be concluded that GBM and SVM are more suitable algorithms for operational implementation of this application. These algorithms outperformed DisTrad model for heterogeneous landscapes with high variation in soil moisture content and photosynthetic activities. The variable importance measure derived from PLS and GBM provided insights about the characteristics of the relevant bands. The results indicate that wavelengths centered around 457, 671, 1488 and 2013-2083 nm are the most important in predicting LST. Nevertheless, further research is needed to improve the performance of regression algorithms when there is a large variability in LST and to examine the utility of narrowband vegetation indices to predict the LST. The benefits of this research may extend to applications such as monitoring urban heat island effect, volcanic activity and wildfire, estimating evapotranspiration and assessing drought severity.

  8. High and Low Temperatures Differently Affect Infection Density and Vertical Transmission of Male-Killing Spiroplasma Symbionts in Drosophila Hosts?

    PubMed Central

    Anbutsu, Hisashi; Goto, Shunsuke; Fukatsu, Takema

    2008-01-01

    We investigated the vertical transmission, reproductive phenotype, and infection density of a male-killing Spiroplasma symbiont in two Drosophila species under physiological high and low temperatures through successive host generations. In both the native host Drosophila nebulosa and the nonnative host Drosophila melanogaster, the symbiont infection and the male-killing phenotype were stably maintained at 25C, rapidly lost at 18C, and gradually lost at 28C. In the nonnative host, both the high and low temperatures significantly suppressed the infection density of the spiroplasma. In the native host, by contrast, the low temperature suppressed the infection density of the spiroplasma whereas the high temperature had little effect on the infection density. These results suggested that the low temperature suppresses both the infection density and the vertical transmission of the spiroplasma whereas the high temperature suppresses the vertical transmission preferentially. The spiroplasma density was consistently higher in the native host than in the nonnative host, suggesting that the host genotype may affect the infection density of the symbiont. The temperature- and genotype-dependent instability of the symbiont infection highlights a complex genotype-by-genotype-by-environment interaction and may be relevant to the low infection frequencies of the male-killing spiroplasmas in natural Drosophila populations. PMID:18708518

  9. Phase transformations and defect clusters in single crystal SrTiO3 irradiated at different temperatures

    NASA Astrophysics Data System (ADS)

    Zhuo, M. J.; Yan, L.; Fu, E. G.; Wang, Y. Q.; Misra, A.; Nastasi, M.; Uberuaga, B. P.; Jia, Q. X.

    2013-11-01

    Radiation damage mechanisms in single crystal SrTiO3 irradiated with 250 keV Ne ions to a fluence of 1.11 1020 ions/m2 at both room temperature and 773 K were systematically investigated. The irradiation-induced microstructural evolution was characterized using transmission electron microscopy. Ion irradiation at room temperature results in amorphization of crystalline SrTiO3 near the peak damage region at this fluence. On the other hand, ion irradiation at high temperature leads to less irradiation-induced damage in SrTiO3 due to the higher recovery rate of defects. Nevertheless, the formation of dislocation loops has been observed in the SrTiO3 crystals irradiated at high temperature. These dislocation loops were determined to be unfaulted loops with Burgers vector along <0 1 1>.

  10. Metabolic plasticity and critical temperatures for aerobic scope in a eurythermal marine invertebrate (Littorina saxatilis, Gastropoda: Littorinidae) from different latitudes.

    PubMed

    Sokolova, Inna M; Prtner, Hans-Otto

    2003-01-01

    Effects of latitudinal cold adaptation and cold acclimation on metabolic rates and aerobic scope were studied in the eurythermal marine gastropod Littorina saxatilis from temperate North Sea and sub-arctic White Sea areas. Animals were acclimated for 6-8 weeks at control temperature (13 degrees C) or at 4 degrees C, and their respiration rates were measured during acute temperature change (1-1.5 degrees C h(-1)) in a range between 0 degrees C and 32 degrees C. In parallel, the accumulation of anaerobic end products and changes in energy status were monitored. Starting from 0 degrees C, aerobic metabolic rates of L. saxatilis rose quickly with increasing temperatures up to a point at or slightly above the respective acclimation temperature. Beyond this value, thermal sensitivity of oxygen consumption rate V((O(2))) greatly decreased in a wide, 15 degrees C range of experimental temperatures. This change in metabolic regulation was also reflected in the activation energy of aerobic metabolism (E(a)), which was approximately seven times lower at temperatures above Arrhenius breakpoint temperatures (ABTs) than at temperatures below ABTs. Warming progressively led to a discrepancy between energy demand and energy production, as demonstrated by a decrease in the levels of high-energy phosphates [phosho-L-arginine (PLA) and ATP], and resulted in the onset of anaerobiosis at critically high temperatures, indicating a limitation of aerobic scope. The comparison of aerobic and anaerobic metabolic rates in L. saxatilis in air and water suggests that the heat-induced onset of anaerobiosis is due to the insufficient oxygen supply to tissues at high temperatures. Cold acclimation led to an increase in aerobic metabolic rates and a considerable downward shift of the upper critical temperature in North Sea L. saxatilis but not in White Sea L. saxatilis. Limited metabolic plasticity in response to cold acclimation in sub-arctic White Sea snails as compared with their temperate North Sea counterparts suggests that metabolic depression occurs during overwintering under the more extreme winter conditions at the White Sea. PMID:12456709

  11. Egg survival, embryonic development, and larval characteristics of northern shrimp ( Pandalus borealis ) females subject to different temperature and feeding conditions

    Microsoft Academic Search

    Sophie Brillon; Yvan Lambert; Julian Dodson

    2005-01-01

    Laboratory experiments on ovigerous females of northern shrimp (Pandalus borealis) were used to assess the effects of temperature and food ration on female condition during incubation and examine how combined effects of temperature and female condition influenced egg survival, embryonic development, and larval characteristics. Ovigerous females were maintained at 2C, 5C, and 8C and fed on a low (three times\\/week;

  12. Hot as You Like It: Models of the Long-term Temperature History of Earth Under Different Geological Assumptions

    NASA Astrophysics Data System (ADS)

    Domagal-Goldman, S.; Sheldon, N. D.

    2012-12-01

    The long-term temperature history of the Earth is a subject of continued, vigorous debate. Past models of the climate of early Earth that utilize paleosol contraints on carbon dioxide struggle to maintain temperatures significantly greater than 0C. In these models, the incoming stellar radiation is much lower than today, consistent with an expectation that the Sun was significantly fainter at that time. In contrast to these models, many proxies for ancient temperatures suggest much warmer conditions. The surface of the planet seems to have been generally free of glaciers throughout this period, other than a brief glaciation at ~2.9 billion years ago and extensive glaciation at ~2.4 billion years ago. Such glacier-free conditions suggest mean surface temperatures greater than 15C. Measurements of oxygen isotopes in phosphates are consistent with temperatures in the range of 20-30C; and similar measurements in cherts suggest temperatures over 50C. This sets up a paradox. Models constrained by one set of geological proxies cannot reproduce the warm temperatures consistent with another set of geological proxies. In this presentation, we explore several potential resolutions to this paradox. First, we model the early Earth under modern-day conditions, but with the lower solar luminosity expected at the time. The next simulation allows carbon dioxide concentrations to increase up to the limits provided by paleosol constraints. Next, we lower the planet's surface albedo in a manner consistent with greater ocean coverage prior to the complete growth of continents. Finally, we remove all constraints on carbon dioxide and attempt to maximize surface temperatures without any geological constraints on model parameters. This set of experiments will allow us to set up potential resolutions to the paradox, and to drive a conversation on which solutions are capable of incorporating the greatest number of geological and geochemical constraints.

  13. Effect of different constant incubation temperatures on egg survival and embryonic development in lake whitefish (Coregonus clupeaformis)

    USGS Publications Warehouse

    Brooke, L.T.

    1975-01-01

    Eggs of lake whitefish (Coregonus clupeaformis) were incubated in a constant-flow incubator at constant temperatures of 0.5, 2.0, 4.0, 5.9, 7.8, and 10.0 C. The time from fertilization to median hatch was inversely related to temperature, and ranged from 41.7 days at 10.0 C to 182 days at 0.5 C. The percentage hatch was highest (70.9-73.3%) at 4.0, 5.9, and 7.8 C, and was greatly reduced (6.0-28.4%) at 0.5, 2.0, and 10.0 C. The mortality of embryos was greatest during the early stages of development. Abnormally developed fry were most frequent (85.9% of the hatch) at 10.0 C and least frequent (2.8%) at 4.0 C. Mean lengths of fry at hatching were shorter at 7.8 and 10.0 C (12.4 and 8.8 mm, respectively) than at lower temperatures (13.1 to 13.5 mm). The optimum temperature range for incubation of lake whitefish eggs was 3.2 to 8.1 C. Equations were derived for predicting development time to 20 successive stages, and to hatching, at constant incubation temperatures and at fluctuating daily mean water temperatures.

  14. Mortality and carrier status of bluegills exposed to viral hemorrhagic septicemia virus genotype IVb at different temperatures.

    PubMed

    Goodwin, Andrew E; Merry, Gwenn E

    2011-06-01

    The emergence of the viral hemorrhagic septicemia virus (VHSV) genotype IVb (VHSV-IVb) in the Great Lakes of North America has led to concern that the virus might spread to natural fisheries and aquaculture in the southern USA. We exposed bluegills Lepomis macrochirus to VHSV-IVb by intraperitoneal injection at six temperatures from 10 degrees C to 30 degrees C and followed the disease course by quantitative real-time reverse transcriptase polymerase chain reaction (qrt-RT-PCR). Mortality of injected fish was 90% at 10 degrees C, 35% at 14 degrees C, and 10% at 18 degrees C; no mortality attributable to VHSV was observed at temperatures of 22-30 degrees C. In survivors tested at 21 d postchallenge, viral copies and prevalence determined by qrt-RT-PCR were inversely related to temperature, and VHSV-IVb could not be detected in fish held at temperatures above 22 degrees C. Similar results were obtained for bluegills that were exposed by cohabitation with the intraperitoneally injected fish. Acclimation of the fish to 12 degrees C after 21 d at higher temperatures did not appear to cause a re-emergence of the virus. Based on our findings, the temperature range of VHSV-IVb appears to be the same as published values for VHSV genotype I, which has an optimum of 9-12 degrees C and an upper limit of 18-20 degrees C. PMID:21834331

  15. Contrasting trait syndromes in angiosperms and conifers are associated with different responses of tree growth to temperature on a large scale

    PubMed Central

    Carnicer, Jofre; Barbeta, Adri; Sperlich, Dominik; Coll, Marta; Peuelas, Josep

    2013-01-01

    Recent large-scale studies of tree growth in the Iberian Peninsula reported contrasting positive and negative effects of temperature in Mediterranean angiosperms and conifers. Here we review the different hypotheses that may explain these trends and propose that the observed contrasting responses of tree growth to temperature in this region could be associated with a continuum of trait differences between angiosperms and conifers. Angiosperm and conifer trees differ in the effects of phenology in their productivity, in their growth allometry, and in their sensitivity to competition. Moreover, angiosperms and conifers significantly differ in hydraulic safety margins, sensitivity of stomatal conductance to vapor-pressure deficit (VPD), xylem recovery capacity or the rate of carbon transfer. These differences could be explained by key features of the xylem such as non-structural carbohydrate content (NSC), wood parenchymal fraction or wood capacitance. We suggest that the reviewed trait differences define two contrasting ecophysiological strategies that may determine qualitatively different growth responses to increased temperature and drought. Improved reciprocal common garden experiments along altitudinal or latitudinal gradients would be key to quantify the relative importance of the different hypotheses reviewed. Finally, we show that warming impacts in this area occur in an ecological context characterized by the advance of forest succession and increased dominance of angiosperm trees over extensive areas. In this context, we examined the empirical relationships between the responses of tree growth to temperature and hydraulic safety margins in angiosperm and coniferous trees. Our findings suggest a future scenario in Mediterranean forests characterized by contrasting demographic responses in conifer and angiosperm trees to both temperature and forest succession, with increased dominance of angiosperm trees, and particularly negative impacts in pines. PMID:24146668

  16. Contrasting trait syndromes in angiosperms and conifers are associated with different responses of tree growth to temperature on a large scale.

    PubMed

    Carnicer, Jofre; Barbeta, Adri; Sperlich, Dominik; Coll, Marta; Peuelas, Josep

    2013-01-01

    Recent large-scale studies of tree growth in the Iberian Peninsula reported contrasting positive and negative effects of temperature in Mediterranean angiosperms and conifers. Here we review the different hypotheses that may explain these trends and propose that the observed contrasting responses of tree growth to temperature in this region could be associated with a continuum of trait differences between angiosperms and conifers. Angiosperm and conifer trees differ in the effects of phenology in their productivity, in their growth allometry, and in their sensitivity to competition. Moreover, angiosperms and conifers significantly differ in hydraulic safety margins, sensitivity of stomatal conductance to vapor-pressure deficit (VPD), xylem recovery capacity or the rate of carbon transfer. These differences could be explained by key features of the xylem such as non-structural carbohydrate content (NSC), wood parenchymal fraction or wood capacitance. We suggest that the reviewed trait differences define two contrasting ecophysiological strategies that may determine qualitatively different growth responses to increased temperature and drought. Improved reciprocal common garden experiments along altitudinal or latitudinal gradients would be key to quantify the relative importance of the different hypotheses reviewed. Finally, we show that warming impacts in this area occur in an ecological context characterized by the advance of forest succession and increased dominance of angiosperm trees over extensive areas. In this context, we examined the empirical relationships between the responses of tree growth to temperature and hydraulic safety margins in angiosperm and coniferous trees. Our findings suggest a future scenario in Mediterranean forests characterized by contrasting demographic responses in conifer and angiosperm trees to both temperature and forest succession, with increased dominance of angiosperm trees, and particularly negative impacts in pines. PMID:24146668

  17. Temperature modulation of thermal tolerance of a CAM-tank bromeliad and the relationship with acid accumulation in different leaf regions.

    PubMed

    Chaves, Cleber Juliano Neves; Leal, Brbara Simes Santos; de Lemos-Filho, Jos Pires

    2014-10-01

    Physiological changes that increase plant performance during exposure to high temperatures may play an inverse role during exposure to low temperatures. The objective of this study was to test variations in photosystem II response to heat and cold stress in the leaves of a bromeliad with crassulacean acid metabolism submitted to high or low temperatures. Leaves were maintained under constant temperatures of 10 and 35C and used to examine possible relationships among physiological responses to high and low temperatures and organic acid accumulation. We also tested if distinct parts of bromeliad leaves show differences in photosynthetic thermotolerance. The samples from leaves maintained at 35C showed greater heat tolerance values, while those from leaves maintained at 10C showed lower cold tolerance values. Our results identified a strong negative relationship between the organic acid accumulation and thermal tolerance of bromeliad leaves that largely explained the differences in thermal tolerance among groups. One of these differences occurred among regions of a single leaf, with the base showing critical heat values of up to 8C higher than the top region, suggesting a possible partitioning of leaf response among its regions. Differences in thermal tolerance were also observed between sampling times, with higher values observed in the morning. PMID:25271368

  18. Effect of Boron Addition and Initial Heat-Treatment Temperature on Microstructure and Mechanical Properties of Modified 9Cr-1Mo Steels Under Different Heat-Treatment Conditions

    NASA Astrophysics Data System (ADS)

    Das, C. R.; Albert, S. K.; Bhaduri, A. K.; Murty, B. S.

    2013-05-01

    The effect of initial heat treatment on microstructure and mechanical properties of boron-free and boron-containing modified 9Cr-1Mo steel (P91 and P91B, respectively) has been studied under different heat-treatment conditions. The prior austenite grains evolved in P91 steel, having different prior austenite grain sizes, were found to be similar in size after heat treatment in the range of 1073 K to 1448 K (800 C to 1175 C) for 5 minutes. The microstructural evolution in P91B steel having different prior austenite grain sizes appeared to be uniform when subjected to different heat-treatment temperatures with the prior austenite grain size being similar to that of initial grain size. Lath martensite was observed in P91B steel after all heat treatments. On the other hand, lath martensite was observed in P91 steel only when subjected to high-temperature heat treatment, whereas subgrain/substructure as well as coarse precipitates were observed after a lower temperature heat treatment. Large differences in the hardness/strength values between different microstructures corresponding to coarse-grained heat-affected zone (CGHAZ) and intercritical HAZ (ICHAZ) of P91 steel weldment were due to the distinct difference in these microstructures. The difference in hardness/strength values between the CGHAZ and ICHAZ was found to be insignificant in P91B steel under similar heat-treatment conditions.

  19. A comparative study of the mechanical performance of Glass and Glass/Carbon hybrid polymer composites at different temperature environments

    NASA Astrophysics Data System (ADS)

    Shukla, M. J.; Kumar, D. S.; Mahato, K. K.; Rathore, D. K.; Prusty, R. K.; Ray, B. C.

    2015-02-01

    Glass Fiber Reinforced Polymer (GFRP) composites have been widely accepted as high strength, low weight structural material as compared to their metallic counterparts. Some specific advanced high performance applications such as aerospace components still require superior specific strength and specific modulus. Carbon Fiber Reinforced Polymer (CFRP) composites exhibit superior specific strength and modulus but have a lower failure strain and high cost. Hence, the combination of both glass and carbon fiber in polymer composite may yield optimized mechanical properties. Further the in-service environment has a significant role on the mechanical performance of this class of materials. Present study aims to investigate the mechanical property of GFRP and Glass/Carbon (G/C hybrid) composites at room temperature, in-situ and ex-situ temperature conditions. In-situ testing at +70C and +100C results in significant loss in inter-laminar shear strength (ILSS) for both the composites as compared to room temperature. The ILSS was nearly equal for both the composite systems tested in-situ at +100C and effect of fiber hybridisation was completely diminished there. At low temperature ex-situ conditioning significant reduction in ILSS was observed for both the systems. Further at -60C G/C hybrid exhibited 32.4 % higher ILSS than GFRP. Hence this makes G/C hybrid a better choice of material in low temperature environmental applications.

  20. Temporal change of 13C-isotope signatures and methanogenic pathways in rice field soil incubated anoxically at different temperatures

    NASA Astrophysics Data System (ADS)

    Fey, Axel; Claus, Peter; Conrad, Ralf

    2004-01-01

    Production of CH 4 and CO 2 was quantified in anoxically incubated soil samples taken from an Italian rice field. The rates increased with temperature between 10 and 37C. The ? 13C of the accumulated CO 2, CH 4 and acetate changed with time in a systematic way. The data were used in mass balance equations to constrain isotopic fractionation factors and pathways of CH 4 production. The calculations were further constrained by the determination of 14CH 4 production from 14CO 2 at steady state. At 50C, CH 4 was exclusively produced from CO 2, indicating a fractionation factor of ? CO2/CH4 = 1.073. Between 10 and 37C, the results showed a temporal change in the methanogenic pathway. A relatively high (40-60%) CO 2-derived fraction of CH 4 production in the beginning was followed by a phase in which contribution of CO 2-derived CH 4 decreased to low (<15%) values, and ultimately by the steady state phase in which values increased to <40% (the theoretically expected value). The rate of change from one phase to the next increased with temperature. Incubation temperature had a strong effect on the overall fractionation of 13C during the formation and consumption of acetate, with stronger fractionation at low than at high temperature. The results further showed that, especially at low temperatures, fractionation occurred during acetate turnover and acetoclastic methanogenesis, despite the fact that steady-state conditions caused (apparent) substrate-limitation.

  1. Sewage treatment by an UAFB-EGSB biosystem with energy recovery and autotrophic nitrogen removal under different temperatures.

    PubMed

    Gao, Da-Wen; Huang, Xiao-Li; Tao, Yu; Cong, Yan; Wang, Xiao-Long

    2015-04-01

    A system combined an upflow anaerobic fixed bed (UAFB) and an expanded granular sludge bed (EGSB) was designed and verified as a success for treating real sewage with simultaneous energy recovery and autotrophic nitrogen removal. The impact of temperature (stepwise decreased from 30C to 20C and 10C) was a primary focus, aiming to reveal the response of the anaerobic digestion (AD) and anammox efficiency to the temperature variation. As the temperature decreases, the soluble chemical oxygen demand (sCOD) removal rate was 90.6%, 90.0% and 84.7%, respectively; total nitrogen (TN) removal was 69.4%, 48.8%, 38.4%, respectively; NH4(+)-N removal was 91.3%, 74.9%, 65.1%, respectively. Methanogenic activity of UAFB was significantly influenced by low temperatures, while the unavoidable growth of heterotrophic organisms in EGSB also contributed to the sCOD removal, even at 10C. Lower working temperature (10/20C) limited the growth and activity of ammonia-oxidizing bacteria (AOB) and anaerobic ammonia oxidation bacteria (AnAOB), but improved the nitrite-oxidizing bacteria (NOB) activity. PMID:25625463

  2. Balancing photosynthetic light-harvesting and light-utilization capacities in potato leaf tissue during acclimation to different growth temperatures

    NASA Technical Reports Server (NTRS)

    Steffen, K. L.; Wheeler, R. M.; Arora, R.; Palta, J. P.; Tibbitts, T. W.

    1995-01-01

    We investigated the effect of temperature during growth and development on the relationship between light-harvesting capacity, indicated by chlorophyll concentration, and light-utilization potential, indicated by light- and bicarbonate-saturated photosynthetic oxygen evolution, in Solanum tuberosum L. cv. Norland. Clonal plantlets were transplanted and grown at 20 degrees C for 2 weeks before transfer to 12, 16, 20, 24 and 28 degrees C for 6 weeks. After 4 weeks of the temperature treatments, leaf tissue fresh weights per area were one-third higher in plants grown at 12 degrees C vs those grown at 28 degrees C. Conversely, chlorophyll content per area in tissue grown at 12 degrees C was less than one-half of that of tissue grown at 28 degrees C at 4 weeks. Photosynthetic capacity measured at a common temperature of 20 degrees C and expressed on a chlorophyll basis was inversely proportional to growth temperature. Leaf tissue from plants grown at 12 degrees C for 4 weeks had photosynthetic rates that were 3-fold higher on a chlorophyll basis than comparable tissue from plants grown at 28 degrees C. These results suggest that the relationship between light-harvesting capacity and light-utilization potential varies 3-fold in response to the growth temperatures examined. The role of this response in avoidance of photoinhibition is discussed.

  3. The differential response of photosynthesis to high temperature for a boreal and temperate Populus species relates to differences in Rubisco activation and Rubisco activase properties.

    PubMed

    Hozain, Moh'd I; Salvucci, Michael E; Fokar, Mohamed; Holaday, A Scott

    2010-01-01

    Significant inhibition of photosynthesis occurs at temperatures only a few degrees (temperature is a major factor limiting the geographic ranges of most plants, the aim of this study was to use two Populus species adapted to contrasting thermal environments for determining the factors that constrain photosynthetic assimilation (A) under moderate heat stress in tree species. Consistent with its native range in temperate regions, Populus deltoides Bartr. ex Marsh. exhibited a significantly higher temperature optimum for A than did Populus balsamifera L., a boreal species. The higher A exhibited by P. deltoides at 33-40 degrees C compared to that for P. balsamifera was associated with a higher activation state of Rubisco and correlated with a higher ATPase activity of Rubisco activase. The temperature response of minimal chlorophyll a fluorescence for darkened leaves was similar for both species and was not consistent with a thylakoid lipid phase change contributing to the decline in A in the range of 30-40 degrees C. Taken together, these data support the idea that the differences in the temperature response of A for the two Populus species could be attributed to the differences in the response of Rubisco activation and ultimately to the thermal properties of Rubisco activase. That the primary sequence of Rubisco activase differed between the species, especially in regions associated with ATPase activity and Rubisco recognition, indicates that the genotypic differences in Rubisco activase might underlie the differences in the heat sensitivity of Rubisco activase and photosynthesis at moderately high temperatures. PMID:19864261

  4. P210-T Comparative Environmental Proteomics of Different Temperature Areas in Octopus Hot Spring, Yellowstone National Park.

    PubMed Central

    Steinke, L.; Ramaley, R.

    2007-01-01

    The microbial mats growing in the runoff channels of the hot springs of Yellowstone National Park (YNP) are a rich mix of bacterial, archaeal, and eukaryotic species. Mat samples were gathered from Octopus Hot Spring in 2005 and 2006.The samples were subjected to labeling with iTRAQ reagents followed by shotgun proteomics. Mascot was used to query an in-house YNP database derived from the microbial portion of the NCBInr. It was expected that the majority of the proteins mapping to species with high temperature optima would be associated with the sample taken at a higher temperature, while those proteins from species with lower optima would be associated with the sample from lower temperature. Although Synechococcus is the most abundant microorganism in the mat community when abundance is measured by the percentage of DNA in a metagenomics sample, more peptides were identified from Roseiflexus sp. RS-1 than from any other organism. This discrepancy is most likely due to the sample being a mix of the large red and small green layers of the mat. Synechococcus resides only in the green layer. The large number of distinct peptides from the Roseiflexus extracellular binding protein resulted in the highest Mowse score of the proteins identified. Eighty percent of the peptides associated with the extracellular binding protein were isolated from the 58C sample, while only 20% of this protein came from the 71C sample. This trend continues throughout the housekeeping proteins quantified from Roseiflexus, as might be expected of a thermophile with a lower temperature optimum. The remainder of the identified proteins showed the association with collection temperature that would be expected from the temperature optimums of the mciroorganisms from which they were extracted. The majority of the proteins identified in this experiment were housekeeping and structural proteins.

  5. Characterization of uncertainty associated with the construction of TIR derived profiles and investigation of river temperature longitudinal patterns at different spatial scales

    NASA Astrophysics Data System (ADS)

    Wawrzyniak, V.; Vaudor, L.; Allemand, P.; Pigay, H.; R-Bahuaud, J.; Grandjean, P.

    2013-12-01

    Thermal infrared (TIR) remote sensing can be worthwhile to assess fine-scale thermal patterns over river reaches of several kilometres. TIR data can be used to create longitudinal profiles of water temperature. However, the measurement uncertainty associated with the construction of such profiles is often not considered. In this study we use airborne TIR imagery to investigate summer and winter longitudinal patterns of water temperature. We studied the lower Ain River (50 km) and the Cze River (20 km) in south-east of France. These two rivers are characterized by significant groundwater inputs. Based on a statistical analysis of temperature differences between overlapping images we calculate measurement uncertainty associated with the construction of TIR derived profiles. Errors are produced by the absolute temperature accuracy and the recalibration of the TIR camera. This uncertainty allows the discrimination between artifacts and real longitudinal thermal trends. To understand these trends, we perform a multi-scale analysis using wavelets (MODWT Maximal Overlap Discrete Wavelet Transform). This analysis allows the differentiation between fine, intermediate and large scale spatial patterns of water temperature. These patterns can be associated with different processes or conditions (such as river hydraulics and geometry, thermal effluents, groundwater inputs, dams and boundary conditions) depending of the scale. Key words: River temperature; thermal infrared (TIR) remote sensing; longitudinal patterns; measurement uncertainty; multi-scale analysis

  6. Order-disorder phenomena in myelinated nerve sheaths: V. Effects of temperature on rat sciatic and optic nerves, and structural differences between the two types of nerve.

    PubMed

    Mateu, L; Luzzati, V; Vonasek, E; Mateu, E; Villegas, G M; Vargas, R

    1995-01-13

    We describe in this work X-ray scattering and electron microscope studies of rat sciatic and optic nerves as a function of temperature. The scattering experiments were analyzed as described in the previous papers of this series: a variety of parameters were determined, some of which characterize the lattice disorder, others the structure of the motif. The main results are the following. All the parameters determined by the X-ray scattering study vary with temperature and the temperature-dependence is specific for the type of nerve (sciatic or optic). Most of the disorder-related parameters display a minimum or a maximum in the vicinity of physiological temperature (38 degrees C in rat); this observation, strongly supported by the electron microscope study, shows that the degree of organization of myelin is highest near physiological temperature. The structure of the motif, as revealed by the electron density profile, is fairly different in the two types of nerves (in contrast with the assumption made by previous workers); the structure also varies with temperature and the temperature-induced alterations are nerve-type specific. In the two types of nerve the thickness of the lipid bilayer varies with temperature as expected for a lipid-containing system with hydrocarbon chains in the disordered conformation. In sciatic nerve the thickness of the (thinner) cytoplasmic polar layer, which is also the layer most affected by lattice disorder in this type of nerve, decreases dramatically with increasing temperature. In optic nerve, in which lattice disorder predominantly affects the extracellular layer, the thickness of both the cytoplasmic and the extracellular layer is barely affected by temperature. PMID:7799430

  7. Genetic and phenotypic relationships between immune defense, melanism and life-history traits at different temperatures and sexes in Tenebrio molitor

    PubMed Central

    Prokkola, J; Roff, D; Krkkinen, T; Krams, I; Rantala, M J

    2013-01-01

    Insect cuticle melanism is linked to a number of life-history traits, and a positive relationship is hypothesized between melanism and the strength of immune defense. In this study, the phenotypic and genetic relationships between cuticular melanization, innate immune defense, individual development time and body size were studied in the mealworm beetle (Tenebrio molitor) using three different temperatures with a half-sib breeding design. Both innate immune defense and cuticle darkness were higher in females than males, and a positive correlation between the traits was found at the lowest temperature. The effect of temperature on all the measured traits was strong, with encapsulation ability and development time decreasing and cuticle darkness increasing with a rise in temperature, and body size showing a curved response. The analysis showed a highly integrated system sensitive to environmental change involving physiological, morphological and life-history traits. PMID:23572120

  8. Genetic and phenotypic relationships between immune defense, melanism and life-history traits at different temperatures and sexes in Tenebrio molitor.

    PubMed

    Prokkola, J; Roff, D; Krkkinen, T; Krams, I; Rantala, M J

    2013-08-01

    Insect cuticle melanism is linked to a number of life-history traits, and a positive relationship is hypothesized between melanism and the strength of immune defense. In this study, the phenotypic and genetic relationships between cuticular melanization, innate immune defense, individual development time and body size were studied in the mealworm beetle (Tenebrio molitor) using three different temperatures with a half-sib breeding design. Both innate immune defense and cuticle darkness were higher in females than males, and a positive correlation between the traits was found at the lowest temperature. The effect of temperature on all the measured traits was strong, with encapsulation ability and development time decreasing and cuticle darkness increasing with a rise in temperature, and body size showing a curved response. The analysis showed a highly integrated system sensitive to environmental change involving physiological, morphological and life-history traits. PMID:23572120

  9. Temperature changes caused by the difference in the distance between the ultrasound transducer and bone during 1?mhz and 3?mhz continuous ultrasound: a phantom study

    PubMed Central

    Ohwatashi, Akihiko; Ikeda, Satoshi; Harada, Katsuhiro; Kamikawa, Yurie; Yoshida, Akira; Inoue, Kazuhiro; Yanagida, Nobuhiko; Fukudome, Kiyohiro; Kiyama, Ryoji; Ohshige, Tadasu; Maeda, Tetsuo

    2015-01-01

    [Purpose] This study aimed to use a thermograph to observe temperature changes caused by different distances between an ultrasound transducer and bone during 1?MHz and 3?MHz continuous ultrasound emission on a phantom. [Materials and Methods] We observed the distribution of temperature elevations on a phantom consisting of pig ribs and tissue-mimicking material. One megahertz and 3?MHz ultrasound were delivered at 2.0?W/cm2 for 5 minutes. To record the