Sample records for noise-equivalent temperature difference

  1. Computer simulation of fixed-pattern-noise-limited noise-equivalent-temperature differences in mercury cadmium telluride focal-plane arrays

    Microsoft Academic Search

    Vikram Dhar; R. Ashokan

    1995-01-01

    The noise-equivalent-temperature difference (NETD) is calculated in fixed-pattern-noise- limited mercury cadmium telluride focal-plane arrays (FPAs) for both 3- to 5-micrometers and 8- to 14-micrometers terrestrial imaging applications, on the basis of a model for MCT in which a linear two-point compensation scheme is considered. The contributions to the NETD from the fixed-pattern noise of an array--in terms of gain, offset,

  2. Calibration procedure for focal plane array cameras and noise equivalent material loss for quantitative thermographic NDT

    SciTech Connect

    Marinetti, S.; Maldague, X. [Univ. Laval, Quebec City, Quebec (Canada). Electrical and Computer Engineering Dept.; Prystay, M. [National Research Council of Canada, Boucherville, Quebec (Canada)

    1997-03-01

    In this paper, a complete procedure is proposed for the calibration of a focal plane array in quantitative infrared nondestructive testing (NDT). This procedure includes vignetting correction and gray level conversion into temperature. A noise analysis is also presented in the context of pulsed infrared thermography applied to NDT. In this analysis, the authors introduce a new parameter, the noise equivalent material loss (NEML). The NEML is a global figure of merit which allows the comparison of different experimental set-ups for infrared pulsed thermography. Theory, experimental validation of the proposed concepts, and comparison with a few infrared scanning thermal imagers are presented as well.

  3. 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

  4. Noise equivalent count measurements in a neuro-PET scanner with retractable septa

    Microsoft Academic Search

    D. L. Bailey; T. Jones; T. J. Spinks; M.-C. Gilardi; D. W. Townsend

    1991-01-01

    The noise-equivalent count-rate (NEC) performance of a neuro-positron emission tomography (PET) scanner has been determined with and without interplane septa on uniform cylindrical phantoms of differing radii and in human studies to assess the optimum count rate conditions that realize the maximum gain. In the brain, the effective gain in NEC performance for three-dimensions (3-D) ranges from >5 at low

  5. Noise equivalent circuit of a semiconductor laser diode

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  7. Quantum efficiency and noise equivalent power of nanostructured, NbN, single-photon detectors in the wavelength range from visible to infrared

    Microsoft Academic Search

    A. Korneev; V. Matvienko; O. Minaeva; I. Milostnaya; I. Rubtsova; G. Chulkova; K. Smirnov; V. Voronov; G. Gol'tsman; W. Slysz; A. Pearlman; A. Verevkin; R. Sobolewski

    2005-01-01

    We present our studies on the quantum efficiency (QE) and the noise equivalent power (NEP) of the latest-generation, nanostructured, superconducting, single-photon detectors (SSPDs) in the wavelength range from 0.5 to 5.6 ?m, operated at temperatures in the 2.0- to 4.2-K range. Our detectors are designed as 4-nm-thick and 100-nm-wide NbN meander-shaped stripes, patterned by electron-beam lithography and cover a 1010-?m2

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

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  9. 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. Absolute response and noise equivalent power of cyclotron resonance-assisted InSb detectors at submillimeter wavelengths

    Microsoft Academic Search

    Elliott R. Brown; M. J. Wengler; T. G. Phillips

    1985-01-01

    Spectra are presented of the responsivity and noise equivalent power (NEP) of liquid-helium-cooled InSb detectors as a function of magnetic field in the range 20110 cm?1. The measurements are all made using a Fourier transform spectrometer with thermal sources. The results show a discernable peak in the detector response at the conduction electron cyclotron resonance (CCR) frequency for magnetic fields

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

    SciTech Connect

    Tang Xiangyang; Yang Yi; Tang Shaojie [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.

  12. Plasma wave detection of terahertz radiation by silicon field effects transistors: Responsivity and noise equivalent power

    Microsoft Academic Search

    R. Tauk; F. Teppe; S. Boubanga; D. Coquillat; W. Knap; Y. M. Meziani; C. Gallon; F. Boeuf; T. Skotnicki; C. Fenouillet-Beranger; D. K. Maude; S. Rumyantsev; M. S. Shur

    2006-01-01

    Si metal oxide semiconductor field effect transistors (MOSFETs) with the gate lengths of 120-300 nm have been studied as room temperature plasma wave detectors of 0.7 THz electromagnetic radiation. In agreement with the plasma wave detection theory, the response was found to depend on the gate length and the gate bias. The obtained values of responsivity (=10-10 W\\/Hz0.5) demonstrate the

  13. Electron temperature differences and double layers

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  14. Interrelation of the energetic noise equivalent with the other parameters of silicon radiation detectors

    Microsoft Academic Search

    B. A. Nikitin; T. V. Nikolaeva; E. S. Serushkina; V. N. Antonova; V. M. Budnitskii

    1990-01-01

    By virtue of the high mobility of both the electrons and holes in a SRD, the independence of the pulse amplitude from the arrangement of the trajectories of the particles being recorded in the working space is assured. Because of the small forbidden bandwidth of the semiconductor, the energetic difference between the levels of defects inevitably present in a real

  15. Casimir forces between cylinders at different temperatures

    E-print Network

    Golyk, Vladyslav A.

    We study Casimir interactions between cylinders in thermal nonequilibrium, where the objects as well as the environment are held at different temperatures. We provide the general formula for the force, in a one reflection ...

  16. Noise equivalent circuit of a two-mode semiconductor laser with the contribution of both the linear and the nonlinear gain

    Microsoft Academic Search

    Tran Thi Bich-Ha; Jean-Claude Mollier

    1997-01-01

    An equivalent circuit model of a semiconductor laser diode and its MDS (microwave and RF design systems) implementation are described that allow a straightforward calculation of the noise characteristics of a laser diode combined with electronic components. This noise equivalent circuit model that is derived from the two-mode rate equations including both the self-saturation and cross-saturation contributions to the nonlinear

  17. Scanning infrared radiometer for measuring the airsea temperature difference

    E-print Network

    Shaw, Joseph A.

    when the airsea temperature difference is negative, and Hwang and Shemdin3 showed that sea-surfaceScanning infrared radiometer for measuring the airsea temperature difference Joseph A. Shaw a vertically scanning infrared radiometer for measuring the airsea temperature difference without disturbing

  18. NMR measurement of bitumen at different temperatures.

    PubMed

    Yang, Zheng; Hirasaki, George J

    2008-06-01

    Heavy oil (bitumen) is characterized by its high viscosity and density, which is a major obstacle to both well logging and recovery. Due to the lost information of T2 relaxation time shorter than echo spacing (TE) and interference of water signal, estimation of heavy oil properties from NMR T2 measurements is usually problematic. In this work, a new method has been developed to overcome the echo spacing restriction of NMR spectrometer during the application to heavy oil (bitumen). A FID measurement supplemented the start of CPMG. Constrained by its initial magnetization (M0) estimated from the FID and assuming log normal distribution for bitumen, the corrected T2 relaxation time of bitumen sample can be obtained from the interpretation of CPMG data. This new method successfully overcomes the TE restriction of the NMR spectrometer and is nearly independent on the TE applied in the measurement. This method was applied to the measurement at elevated temperatures (8-90 degrees C). Due to the significant signal-loss within the dead time of FID, the directly extrapolated M0 of bitumen at relatively lower temperatures (<60 degrees C) was found to be underestimated. However, resulting from the remarkably lowered viscosity, the extrapolated M0 of bitumen at over 60 degrees C can be reasonably assumed to be the real value. In this manner, based on the extrapolation at higher temperatures (> or = 60 degrees C), the M0 value of bitumen at lower temperatures (<60 degrees C) can be corrected by Curie's Law. Consequently, some important petrophysical properties of bitumen, such as hydrogen index (HI), fluid content and viscosity were evaluated by using corrected T2. PMID:18387325

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

    E-print Network

    Shaw, Joseph A.

    Air temperature profile and air/sea temperature difference measurements by infrared and microwave air temperature profile and air/sea temperature difference. The main advantage of this technique measurements, accounting for air attenuation and sea surface roughness. Then we show retrieval results

  1. Electrically induced temperature difference and deformation in hardened cement pastes

    SciTech Connect

    Sun Mingqing [Department of Engineering Structures and Mechanics, Wuhan University of Technology, Wuhan 430070 (China)]. E-mail: sunmingqing@yahoo.com; Wang Xiaoying [Department of Engineering Structures and Mechanics, Wuhan University of Technology, Wuhan 430070 (China); Zhao Kairui [Department of Engineering Structures and Mechanics, Wuhan University of Technology, Wuhan 430070 (China); Li Zhuoqiu [Department of Engineering Structures and Mechanics, Wuhan University of Technology, Wuhan 430070 (China)

    2006-12-15

    Electromechanical effect of hardened cement paste beam is investigated in this paper. When an external electrical current is applied to the electrodes attached to opposite surfaces of a cement beam, it is found that temperature on the positive electrode is always higher than that on the negative electrode. The sign of electrically induced temperature difference is determined by the direction of applied electrical current. Electrically induced temperature difference makes the beam bend towards the surface with a higher temperature. Both electrically induced temperature difference and electroosmosis lead to electromechanical effect of hardened cement paste. Finally, electromechanical effect becomes more obvious by adding NaCl to cement paste.

  2. Liquid crystal photonic bandgap fiber: different bandgap transmissions at different temperature ranges.

    PubMed

    Du, Jiangbing; Liu, Yange; Wang, Zhi; Zou, Bing; Liu, Bo; Dong, Xiaoyi

    2008-10-10

    The temperature tuning properties of a liquid crystal (LC) photonic bandgap fiber's bandgap transmission was investigated in this study. Because of the special temperature responses of the LC's indices and its phase transition property, the bandgap transmission was found to have different temperature responses at different temperature ranges below the LC's clearing point temperature. At temperatures lower or higher than the LC's clearing point, the bandgap transmissions are quite different, which permits switching with an extinction ratio as large as 45 dB. At temperatures around the LC's clearing point, the bandgap transmission was depressed. PMID:18846170

  3. 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

  4. United States Extreme Record Temperatures and Differences Map

    NSDL National Science Digital Library

    This map of the United States shows statewide extremes in temperature, expressed as the difference between record high and low temperature (in degrees Fahrenheit) for each state. It is accompanied by two tables that show record high and low temperatures for each state, along with date, city, and elevation for the location where the measurement was made. Temperature data is in both Fahrenheit and Centigrade degrees.

  5. 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.

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

    PubMed

    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

  7. Feeding of Burbot, Lota lota, at Different Temperatures

    Microsoft Academic Search

    Jari-Pekka J. Pkknen; Timo J. Marjomki

    2000-01-01

    Daily food intake of adult burbot, Lota lota, fed on vendace, Coregonus albula, were estimated experimentally at four different water temperatures (2.4, 5.1, 10.8 and 23.4C). Mean daily food intake (MDI; g d-1) and relative daily food intake (RDI; g g-1 d-1) increased with temperature from 2.4 to 10.8C and decreased at 23.4C. Temperatures of maximum daily food intake values

  8. Gender-related differences in rectal temperature in human neonates

    Microsoft Academic Search

    Emese Nagy

    2001-01-01

    The aim of this study was to examine the gender-related differences in human neonates' body temperature. Rectal temperatures of 101 newborns (52 girls and 49 boys) were measured using a calibrated glass-mercury thermometer five times during their first 5 days of life. Results show that the temperature of males, averaged over 5 days, was significantly lower (37.068C) than that of

  9. Temperature transport in Lysimeters – comparison of different setups

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  10. 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

  11. Regional differences in temperature sensation and thermal comfort in humans.

    PubMed

    Nakamura, Mayumi; Yoda, Tamae; Crawshaw, Larry I; Yasuhara, Saki; Saito, Yasuyo; Kasuga, Momoko; Nagashima, Kei; Kanosue, Kazuyuki

    2008-12-01

    Sensations evoked by thermal stimulation (temperature-related sensations) can be divided into two categories, "temperature sensation" and "thermal comfort." Although several studies have investigated regional differences in temperature sensation, less is known about the sensitivity differences in thermal comfort for the various body regions. In the present study, we examined regional differences in temperature-related sensations with special attention to thermal comfort. Healthy male subjects sitting in an environment of mild heat or cold were locally cooled or warmed with water-perfused stimulators. Areas stimulated were the face, chest, abdomen, and thigh. Temperature sensation and thermal comfort of the stimulated areas were reported by the subjects, as was whole body thermal comfort. During mild heat exposure, facial cooling was most comfortable and facial warming was most uncomfortable. On the other hand, during mild cold exposure, neither warming nor cooling of the face had a major effect. The chest and abdomen had characteristics opposite to those of the face. Local warming of the chest and abdomen did produce a strong comfort sensation during whole body cold exposure. The thermal comfort seen in this study suggests that if given the chance, humans would preferentially cool the head in the heat, and they would maintain the warmth of the trunk areas in the cold. The qualitative differences seen in thermal comfort for the various areas cannot be explained solely by the density or properties of the peripheral thermal receptors and thus must reflect processing mechanisms in the central nervous system. PMID:18845785

  12. 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

  13. Different incubation temperatures result in differences in mass in female red-eared slider turtle hatchlings

    Microsoft Academic Search

    Emily Willingham

    2005-01-01

    The CharnovBull model states that environmentally determined sex will prevail in patchy environments where males may fare best in one patch type, whereas females may fare well in a different patch type. To investigate whether or not potential differences manifest early in the life of a turtle with temperature-dependent sex determination, I assessed mass, carapace width and length, and plastron

  14. Characteristics of impact-generated plasma with different electron temperature and gas temperature

    NASA Astrophysics Data System (ADS)

    Li, Jianqiao; Song, Weidong; Ning, Jianguo; Tang, Huiping

    2014-07-01

    The characteristics of the plasma with difference between the electron temperature and gas temperature were investigated and the relationship between the plasma ionization degree and the internal energy of a system was obtained. A group of equations included the chemical reaction equilibrium equation, the chemical reaction rate equation and the energy conservation equation were adopted to calculate the electron density, the electron temperature and the atom temperature with a given internal energy. These equations combined with Navier-Stokes (N-S) equations is solved by a smooth particle hydrodynamic (SPH) code. The charges generated in hypervelocity impacts with five different velocities are calculated and verified with the empirical formulas. The influence of a critical velocity for plasma generation is considered in the empirical formula and the parameters are fitted by the numerical results. By comparing with the results in reference, the fitted new empirical formula is verified to be reasonable and useful for a wide range of impact velocity.

  15. Infectivity of PRRS virus in pig manure at different temperatures.

    PubMed

    Linhares, Daniel C L; Torremorell, Montserrat; Joo, Han Soo; Morrison, Robert B

    2012-11-01

    PRRSv is an economically important swine pathogen which can be disseminated from infected pig herds via movement of contaminated manure. The process of manure handling and inadequate cleaning of transport vehicles are commonly implicated as sources of PRRSv transmission. Stability of PRRSv in pig manure at different temperatures is unknown. The objective of this study was to determine PRRSv-infectivity half-life in manure and in a cell culture medium at 4, 20, 60 and 80C. To assure sample consistency across the study, all samples were prepared from common homogenized solutions (MEM and manure) and frozen at -20C. Samples were thawed, transferred to a water bath set at a specific temperature, inoculated with 100 ?l of PRRSv at designated time points and then tested for virus infectivity. Regression models were created to estimate PRRSv half-life based on incubation temperature. There was an exponential decrease in PRRSv infectivity with increasing temperature. At every temperature tested, PRRSv had shorter half-life when incubated in manure compared to MEM. PRRSv half-life in MEM and manure was estimated at 112.6 and 120.5 h at 4C, 14.6 and 24.5 h at 20C, 1.6 and 1.7 h at 40C, 2.9 and 8.5 min at 60C, and 0.36-0.59 min at 80C, respectively. Results of this study can be used as basis for developing strategies to inactivate PRRSv present in manure-contaminated environments using heating treatments. For example, these data suggest that submitting transport trailers to temperature of 50C for 8h would decrease PRRSv from 10(6) TCID(50)/ml to less than 10(1) TCID(50)/ml. PMID:22658630

  16. 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.

  17. Intrauterine temperatures of mares under different management conditions

    E-print Network

    Commaille, Lynn Frances

    2009-05-15

    The objective of this study was to determine whether exercise-induced hyperthermia results in an increase in uterine temperature, as measured by an iButton temperature-measurement device inserted into the uterus, comparable to temperatures measured...

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. Responses in rectal and skin temperatures to centrifugal forces in rats of different ambient temperatures

    NASA Astrophysics Data System (ADS)

    Ohara, K.; Sato, H.; Okuda, N.; Makino, Y.; Isobe, Y.

    1982-03-01

    Effects of centrifugation upon rectal (Tre) and tail skin temperatures (Ts) were studied in male Wistar rats at varying ambient temperature (Ta) using a centrifuge which was placed in a climatic chamber. Centrifugal forces of Gz of 3.0 were imposed on rats which were suspended at horizontal body position using a newly developed mesh suits holding method in the animal box placed on the rotating arm of the centrifuge. Headwards or tailwards forces were applied according to the experimental design. No significant difference of the responses was observed between the two force directions. Centrifugations imposed at different Ta of 15, 20, 25, 30 and 32.5C resulted in falls in Tre accompanied by rises in tail Ts at the cooler environments, while rises in Tre accompanied by falls in Ts in the warmer environments. The Ta at which the response pattern of Tre and Ts was reversed (critical ambient temperature) was 26.82.3 (mean and SE) and 27.92.8C, respectively. Tolerance to centrifugation was markedly increased in cooler environments than in wanner ones. It was suggested that the increased skin pressure due to centrifugation exerted some inhibitory effects upon central thermoregulatory ability.

  3. Maximum vehicle cabin temperatures under different meteorological conditions.

    PubMed

    Grundstein, Andrew; Meentemeyer, Vernon; Dowd, John

    2009-05-01

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

  4. 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.

  5. Maximum vehicle cabin temperatures under different meteorological conditions

    Microsoft Academic Search

    Andrew Grundstein; Vernon Meentemeyer; John Dowd

    2009-01-01

    A variety of studies have documented the dangerously high temperatures that may occur within the passenger compartment (cabin)\\u000a of cars under clear sky conditions, even at relatively low ambient air temperatures. Our study, however, is the first to examine\\u000a cabin temperatures under variable weather conditions. It uses a unique maximum vehicle cabin temperature dataset in conjunction\\u000a with directly comparable ambient

  6. Age Differences in the Associations between Felt Temperatures and Color Choices

    ERIC Educational Resources Information Center

    Morgan, George A.; And Others

    1975-01-01

    The present study was designed to explore age differences in the association of temperatures with specific colors, using as stimuli actual felt temperatures rather than the 'imagined' or ambient temperatures used in other studies. (Author)

  7. Rectal-skin temperature difference in septicaemic newborn infants

    Microsoft Academic Search

    J Messaritakis; D Anagnostakis; H Laskari; C Katerelos

    1990-01-01

    Serial skin (sole) and rectal temperatures were simultaneously taken from 55 healthy and 26 septicaemic newborn infants to find out prospectively whether septicaemic newborn infants have any thermoregulatory reaction to the septicaemia, and whether regular temperature measurements could help in the early diagnosis of septicaemia. The septicaemic infants were divided into three groups: the first comprised eight feverish infants, the

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

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

  9. Statistical difference at high temperature in particle creation

    NASA Astrophysics Data System (ADS)

    Majima, H.; Suzuki, A.

    2006-01-01

    The creation of particles is a natural consequence of quantum field theory in curved space-time. We study this phenomenon at finite temperature by using Thermo Field Dynamics (TFD). In the conventional TFD formulated in the thermal Schrdinger picture, temperature is included in the state vectors. We adopt another approach where the temperature is absorbed in operators, so that the double (time and thermal) Bogoliubov transformations of the operators in curved space-time can be unified consistently with TFD, giving a correct number of particles created from false vacuum at finite temperature. We found that the net number of particles created at time t due to thermal effects and curved space-time is given by , where is the number of particles at time t and the initial distribution for bosons (? = 1) and fermions (? = - 1) at temperature T(= 1/k B?), respectively. Thermal state condition in THP is also given in a general form.

  10. Prediction of deep eutectic solvents densities at different temperatures

    Microsoft Academic Search

    K. Shahbaz; F. S. Mjalli; M. A. Hashim; I. M. Alnashef

    2011-01-01

    Predicting densities of nonconventional solvents like deep eutectic solvents (DESs) as a function of temperature is of considerable importance in the development and design of new processes utilizing these solvents. Because of the nature of bonding existing between the salt and the hydrogen bond donor, conventional methods result in very large deviations. In this study, the density of DESs based

  11. Longevity of crapemyrtle pollen stored at different temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperatures for storage of crapemyrtle (Lagerstroemia app.) pollen over time were studied using clones of two interspecific hybrids (L. 'Cheyenne' and L. 'Wichita') and five species (L. indica 'Catawba', L. subcostata (NA 40181), L. limii, L. speciosa, and L. fauriei 'Kiowa'). Pollen samples were s...

  12. The response of high-temperature optical fiber sensor applied to different materials

    NASA Astrophysics Data System (ADS)

    Du, Chong; Xie, Weihua; Huo, Shiyu; Meng, Songhe; Xu, Kai; Jiao, Lichuang

    2013-08-01

    This paper mainly studies the response of high-temperature optical fiber sensor applied to different hot structural materials. Strain and temperature sensitivities of the optical fiber are discussed. The heat test on the bare FBG shows that wavelength and temperature are not of a simple linear relationship, and that using a quadratic function description is more reasonable at high temperature. A type of silica optical fiber sensor is attached to different structures using a special high-temperature adhesive. Two kinds of high-temperature materials, high-temperature alloy and ultra-high temperature ceramic, are used as the base materials. Experiments are carried out to break through the connection technology at high temperature. The response of temperature and strain are measured simultaneously from room temperature to maximum 750C. The response differences are compared by using the signal decoupling method. The relationship between wavelength change and structural thermal strain is studied; the first-order and the second-order temperature sensitivities coefficients are given for different materials. Through the experiment, the different strain transfer coefficients are given in the two cases. This study realized the concurrent monitoring of structural temperature and strain at high-temperature situation using only one sensor, and thus provides a new way for hot structure health monitoring in high-temperature environment.

  13. 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).

  14. Effect of air-sea temperature difference on ocean microwave brightness temperature estimated from AMSR, SeaWinds, and buoys

    Microsoft Academic Search

    Akira Shibata

    2007-01-01

    The effect of air-sea temperature differences on the ocean microwave brightness temperature (Tb) was investigated using the\\u000a Advanced Microwave Scanning Radiometer (AMSR) aboard the Advanced Earth Observing Satellite-II (ADEOS-II) during a period\\u000a of seven months. AMSR Tb in the global ocean was combined with wind data supplied by the scatterometer SeaWinds aboard ADEOS-II\\u000a and air temperature given by a weather

  15. Optimum Temperature Difference and Pressure Drop in Heat Exchangers

    E-print Network

    Steinmeyer, D.

    1991-01-01

    .ving- :=;('vefol valu~. makin~ orf'liminAr.v dpsigns. and findln~ the point wherf' savings in utility costs iust balanr.e incrpmental ~urfFlr.e ('osls. Where I he sums at s.1 Ake are large. I.hi~ should 'he don~. However. lor mAny t:8SPS the s.imple l1uideline... tempertlture chang:e; and the rpbniler, in which neither nuid im'ulves a temperature change, ie, one nuid con denses ancl the- 01 her hoits. Waste-Heal Boiler. In tl waslt'?heill boiler ~215/m2 :5107.5 K 1 "'---"'-- 2 yr (m 2 .yr) K =0.01'i, 88 ?)')h...

  16. Shock Initiation of Energetic Materials at Different Initial Temperatures

    SciTech Connect

    Urtiew, P A; Tarver, C M

    2005-01-14

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

  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. Differences induced by incubation temperature, versus androgen manipulation, in male leopard geckos (Eublepharis macularius)

    E-print Network

    Crews, David

    Differences induced by incubation temperature, versus androgen manipulation, in male leopard geckos of sexual selection is that in sexually dimorphic traits, there is variation within a sex. In leopard geckos in leopard geckos In species with temperature-dependent sex determination (TSD), it is the temperatur

  19. Viability of microencapsulated probiotic lactobacilli during storage at different temperatures.

    PubMed

    Jhne, Julia; Bonaparte, Christine; Khne, Michael; Klein, Gnter

    2013-01-01

    The aim of this study was to develop technological and microbiological basics for the use of microencapsulated probiotics in meat products. Probiotic Lactobacillus (L.) reuteri, L. rhamnosus, L. paracasei and L. gasseri strains were chosen for potential use in meat products. The effects of spices and NaCI on the microbiological stability were investigated in pilot studies. Lyophilised samples were stored for 6 months withoud additives. Microencapsulation was done with water-soluble and water-insoluble coatings. Samples were stored at 2 degrees C and 20 degrees C for six months in gelatine solutions: without additives, with 5% NaCI, with 10% cloves and with 10% black pepper. Spices and salt exhibited a strong inhibitive effect on the bacterial counts of the tested strains. During storage the lyophilised probiotic strains were stable at 2 degrees C and at 20 degrees C. Protective effects of the microencapsulation however were heterogenous. Although at the beginning protective effects against the antimicrobial activity of cloves were shown for L. rhamnosus, none of the tested coatings were able to protect durably. L. paracasei proved to be very stable in general. The use of probiotic lactobacilli strains in meat products seems possible as protective effects of the microencapsulation were recognised. However, these effects must be tested for each specific application, e.g. strain/additive combination, due to individual strain differences. PMID:23367663

  20. 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

    high effectiveness? The reason is that ppor heat exchanger performance results in large temp~ra? ture differences between the two streams, and la~ge temperature differences adversely affect the thetmo dynamic efficiency of the refrigeration cycle. I...

  1. Adsorption of CH3OD on Si(111) Surface at Different Temperatures

    NASA Astrophysics Data System (ADS)

    Wang, Zhuying; Huang, Hongwu; T, Hein; K, D. Brzoska

    1991-04-01

    Adsorption of deuterated methanol (CH3OD) on Si(111) surface has been studied at different temperatures by means of thermal desorption spectroscopy. For the adsorption temperature below 420 C, the desorption peak of hydrogen kept up almost unchanged at 510 C(7 C). But the desorption peak temperature of hydrogen increased obviously for the adsorption temperature above 420 C. We have also found an interesting change in desorption energy of hydrogen.

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

    USGS Publications Warehouse

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

    2006-01-01

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

  3. Local thermal discomfort due to draft and vertical temperature difference in rooms with displacement ventilation

    SciTech Connect

    Melikov, A.K. (Lab. of Heating and Air Conditioning, Technical Univ. of Denmark, Lyngby (DK)); Nielsen, J.B. (Danish Building Research Inst., Indoor Climate Div., Hoersholm (DK))

    1989-01-01

    The paper evaluates the thermal comfort conditions in 18 spaces in practice ventilated by the displacement ventilation principle recently developed in Scandinavia. The risk of local discomfort due to draft and vertical temperature difference is estimated by comprehensive measurement of mean velocity, turbulence intensity, and air temperature. The results indicate a high risk of draft and vertical temperature difference in the occupied zone of some of the spaces. The draft risk and vertical temperature difference varied substantially within the occupied zone. They may create serious complaints in the half of the occupied zone nearest to the outlets. In several cases there was a potential risk of combined discomfort due to draft and vertical temperature difference. This combined discomfort should be studied by subjective experiments.

  4. An analysis of the differences between monitored indoor temperatures and reported thermostat settings

    SciTech Connect

    Vine, E.; Barnes, B.K.

    1988-03-01

    We examined differences in reported winter thermostat settings and monitored temperatures, and contrasted those households with little difference, and those with a substantial difference. This analysis was conducted on households participating in Bonneville Power Administration's Residential Standards Demonstration Program (RSDP) in the Pacific Northwest. The reported thermostat settings were obtained from a survey of RSDP participants, and indoor temperatures were read from special recorders inside the house. 9 refs., 5 figs., 4 tabs.

  5. 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.

  6. 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

  7. Refractive index and density of ammonia ice at different temperatures of deposition

    NASA Astrophysics Data System (ADS)

    Satorre, M. .; Leliwa-Kopystynski, J.; Santonja, C.; Luna, R.

    2013-07-01

    The optical properties and density of ammonia have not been exhaustively studied despite the relevance of these characteristics in astrophysical scenarios. This work presents new data pertaining to the real part of the refractive index of ammonia at 632.8 nm and the density at different temperatures of deposition ranging from 13 K to ammonia's desorption temperature of approximately 110 K. The results indicate a significant variability for both parameters versus temperature: an increase of 50% for the density and of 10% for the refractive index as the temperature increases in the range of 13-60 K; at temperatures greater than 60 K, a constant value is reached for both parameters. This initial variation and the following plateau reflect structural differences in the form of ammonia at low and high temperatures of deposition that can play an important role in the interaction of ammonia with other molecules of astrophysical interest.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  9. 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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  11. Color gamut variation of LED-lit LCD at different module temperatures

    NASA Astrophysics Data System (ADS)

    Chiu, Tien-Lung; Lee, Jiun-Haw

    2010-02-01

    In this paper, we have investigated the color gamut variation of a liquid crystal display (LCD) system with tri-chromatic (red, green and blue) light-emitting diodes (LEDs) as the backlight source at different color and module temperatures. Since the transmission band of a color filter (CF) is broader than those of LEDs, light leakage from the CF results in changes in the color gamut with varying color temperatures. In our case, the color gamut increased and then saturated with increasing color temperatures. The color temperature increased monotonically with increasing module temperatures whereas the color gamut may increase, decrease, or assume an optimized value in different cases. The latter resulted from the temperature-dependent intensity and wavelength variation of the RGB-LEDs. Three sets of tri-chromatic LEDs with different emission wavelengths were used. We have shown that by using green and blue LEDs with longer and shorter emission wavelengths, respectively, crosstalk due to the light leakage could be effectively suppressed. A stably high LCD above 101% NTSC operating over a wide range of module temperatures from 5 to 70 C was demonstrated, and an optimal color performance with color gamut 102.52% NTSC was obtained at a color temperature of 6500 K and a module temperature of 25 C.

  12. The effects of two different kinds of quilt on human core temperature during night sleep

    Microsoft Academic Search

    MEGUMI OKADA; TOMOKO MIDORIKAWA-TSURUTANI; HIROMI TOKURA

    1994-01-01

    Effects of two kinds of quilt with different thermal insulation properties between the upper and lower halves on human core temperature during night sleep were compared at an ambient temperature of 16C and a relative humidity of 50% in five healthy adult women. One quilt has a thick part ( 110mm) in the upper half and a thin part (

  13. SURVIVAL AND REPRODUCTION OF A LABORATORY STRAIN OF BODY LICE (PHTHIRAPTERA: PEDICULIDAE) AT DIFFERENT AMBIENT TEMPERATURES

    Microsoft Academic Search

    GABRIELE SCHRADER; ERIK SCHMOLZ; MONIKA KNNING; RAMONA DAHL

    In order to elucidate the role of temperature as a crucial survival factor for human body lice (Pediculus humanus humanus), we investigated the influence of different temperature regimes on survival of adult lice after their last blood meal as well as on oviposition and egg hatch rates. The Federal Environment Agency (FEA) maintains a laboratory colony of the human body

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

    PubMed

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

    2015-09-15

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

  15. Density of CH 4 , N 2 and CO 2 ices at different temperatures of deposition

    Microsoft Academic Search

    M. . Satorre; M. Domingo; C. Milln; R. Luna; R. Vilaplana; C. Santonja

    2008-01-01

    In this work the density (?) and the real part of the refractive index (n) of frozen methane, nitrogen and carbon dioxide were obtained in the laboratory. The densities are given for different temperatures of deposition between 10K and the sublimation temperature of these molecules in our experimental setup (p?10-7mbar). We have found that methane and nitrogen have a constant

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

    PubMed Central

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

    2014-01-01

    Temperature affects all biological functions and will therefore modulate ecologically significant interactions between animals and their environment. Here, we examined the effect of ambient temperature (Ta) on the thermal biology and energy budget in striped hamsters acclimated to cold (5C), warm (21C) and hot temperatures (31C). Thermoneutral zone (TNZ) was 22.532.5C, 2532.5C and 3032.5C in the cold-, warm- and hot-acclimated hamsters, respectively. The cold acclimation decreased the lower critical temperature and made the TNZ wider, and hot exposure elevated the lower critical temperature, resulting in a narrow TNZ. Within the TNZ, cold-acclimated hamsters showed a significantly higher rate of metabolism and thermogenesis than those acclimated to hot temperature. Digestive enzymes activities, including intestinal sucrase, maltase, L-alanine aminopeptidase-N and leucine aminopeptidase were higher in the cold than in the hot. The changes in metabolic rate and thermogenesis at different temperatures were in parallel with cytochrome c oxidase activity and uncoupling protein 1 gene expression of brown adipose tissue. This suggests that the shift of the lower critical temperature of TNZ is possibly associated with the rate of metabolism and thermogenesis, as well as with the digestive capacity of the gastrointestinal tract at different Ta. The upper critical temperature of TNZ may be independent of the changes in Ta. The changes of lower critical temperature of TNZ are an important strategy in adaption to variations of Ta. PMID:24400087

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

    NASA Astrophysics Data System (ADS)

    Cermk, Vladimr; Dedecek, Petr; Bodri, Louise; Safanda, Jan; Kresl, Milan

    2015-04-01

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

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

    NASA Astrophysics Data System (ADS)

    Asikainen, Timo; Maliniemi, Ville; Mursula, Kalevi

    2015-04-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

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

    PubMed

    Fiore, Carlos E

    2011-09-21

    Parallel tempering Monte Carlo simulations have been applied to a variety of systems presenting rugged free-energy landscapes. Despite this, its efficiency depends strongly on the temperature set. With this query in mind, we present a comparative study among different temperature selection schemes in three lattice-gas models. We focus our attention in the constant entropy method (CEM), proposed by Sabo et al. In the CEM, the temperature is chosen by the fixed difference of entropy between adjacent replicas. We consider a method to determine the entropy which avoids numerical integrations of the specific heat and other thermodynamic quantities. Different analyses for first- and second-order phase transitions have been undertaken, revealing that the CEM may be an useful criterion for selecting the temperatures in the parallel tempering. PMID:21950850

  1. Recycled concrete made with different natural coarse aggregates exposed to high temperature

    Microsoft Academic Search

    Claudio Javier Zega; Angel Antonio Di Maio

    2009-01-01

    The recycled aggregates obtained from crushed waste concretes have different characteristics from those of natural aggregates. For that reason, the mixture proportions and the fresh and hardened properties of recycled concretes are different. The performance of recycled concrete exposed to high temperatures is not a very well-known subject since most studies have been conducted on conventional concretes. Recycled concretes with

  2. Effect of different temperature regimes on reproductive conditioning in the scallop Argopecten purpuratus

    Microsoft Academic Search

    Gloria Mart??nez; Hernn Prez

    2003-01-01

    Adult Argopecten purpuratus were conditioned under four different temperature regimes and their gonadal development and quality of the resulting offspring evaluated. Biochemical composition of muscle and gonad, during laboratory conditioning at the different treatments, was also examined. Spawned-out individuals were obtained from commercial culture centers for experimentation. Test groups of scallops were independently maintained at: (a) 15 C, (b) 19

  3. 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

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

    SciTech Connect

    Yang Jinhong; Zhu Sizheng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Center for Magnetic Fusion Theory, Chinese Academy of Sciences, Hefei 230031 (China); Yu Qingquan [Max-Planck-Institute fuer Plasmaphysik, EURATOM Association, 85748 Garching (Germany); Zhuang, G. [College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2009-09-15

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

  6. Influence of growth-promoting bacteria on the growth of wheat in different soils and temperatures

    Microsoft Academic Search

    Dilfuza Egamberdiyeva; Gisela Hflich

    2003-01-01

    Plant-growth-promoting bacteria isolated from the rhizosphere, phyllosphere and soil of the root zone in different climatic regions of Germany and Uzbekistan were analysed for plant-growth-promoting effects and nutrient uptake on winter wheat on different soils and under different temperature regimes. The investigations were carried out in pot experiments using loamy sand and sandy loam soils from Mncheberg, Germany and Calcisol

  7. Sulphate resistance of mortar containing ground brick clay calcined at different temperatures

    SciTech Connect

    Wild, S.; Khatib, J.M.; O`Farrell, M. [Univ. of Glamorgan, Pontypridd (United Kingdom). School of the Built Environment] [Univ. of Glamorgan, Pontypridd (United Kingdom). School of the Built Environment

    1997-05-01

    The sulphate resistance of mortar containing ground calcined brick clay (GCBC) calcined at different temperatures (600--1,100 C) and ground sand (GS) as cement replacement materials is investigated. Also the porosity, pore size distribution and strength of a selection of these mortars are determined. Mortars containing GCBC calcined at a temperature higher than 900 C show superior sulphate resistance to those containing GCBC calcined at temperatures below 900 C. Although the intruded pore volume is higher at early ages of curing, the inclusion of GCBC in the mortars leads to refinement of pore structure and its contribution to strength is significant after a curing period of 90 days. The influence of the incorporation of GCBC (calcined at different temperatures) on the sulphate resistance of mortar, is discussed in terms of fundamental mechanisms.

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

    PubMed

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

    2015-09-01

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

  9. Optoelectronic properties of CuPc thin films deposited at different substrate temperatures

    NASA Astrophysics Data System (ADS)

    Della Pirriera, M.; Puigdollers, J.; Voz, C.; Stella, M.; Bertomeu, J.; Alcubilla, R.

    2009-07-01

    Structural and optical characterization of copper phthalocyanine thin film thermally deposited at different substrate temperatures was the aim of this work. The morphology of the films shows strong dependence on temperature, as can be observed by atomic force microscopy and x-ray diffraction spectroscopy, specifically in the grain size and features of the grains. The increase in the crystal phase with substrate temperature is shown by x-ray diffractometry. Optical absorption coefficient measured by photothermal deflection spectroscopy and optical transmittance reveal a weak dependence on the substrate temperature. Besides, the electro-optical response measured by the external quantum efficiency of Schottky ITO/CuPc/Al diodes shows an optimized response for samples deposited at a substrate temperature of 60 C, in correspondence to the I-V diode characteristics.

  10. 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

  11. 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

  12. Sorption of naphthalene and 1-naphthol by biochars of orange peels with different pyrolytic temperatures

    Microsoft Academic Search

    Baoliang Chen; Zaiming Chen

    2009-01-01

    Biochars, derived from biomass, are increasingly recognized as an environmental-friendly sorbent to abate organic pollutants. Sorption variations of biochars with their pyrolytic temperatures are evaluated. Nine biochars of orange peels with different pyrolytic temperatures (150700C, referred as OP150OP700) were characterized via elemental analysis, BET-N2 surface area, and Fourier transform infrared spectroscopy. Sorption of naphthalene and 1-naphthol by the biochars in

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

    Microsoft Academic Search

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

    2011-01-01

    The forms of alkalis of the biochars produced from the straws of canola, corn, soybean and peanut at different temperatures (300, 500 and 700C) were studied by means of oxygen-limited pyrolysis. The alkalinity and pH of the biochars increased with increased pyrolysis temperature. The X-ray diffraction spectra and the content of carbonates of the biochars suggested that carbonates were the

  14. 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

  15. 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,

  16. 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

  17. 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 (mean SD): 24.0 (1.2)C; 56 (8%) relative humidity; <0.1 m/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 50 mm 50 mm, 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 (mean SD) 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 0.2-0.5 C. 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

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

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

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

  20. 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

  1. 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.

  2. 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

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

    SciTech Connect

    Wan, Z. [Univ. of California, Santa Barbara, CA (United States); Li, Z.L. [GRTR/LSIIT/CNRS, Illkirch-Graffenstaden (France)

    1997-07-01

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

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

    PubMed Central

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

    2012-01-01

    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

  5. Fluorescence spectroscopy of graphene quantum dots: temperature effect at different excitation wavelengths.

    PubMed

    Li, Changzheng; Yue, Yanan

    2014-10-31

    This paper reports a comprehensive study of temperature dependence of fluorescence spectroscopy of graphene quantum dots at different excitation wavelengths. Very significant (more than 50%) and similar decrease of normalized spectrum intensity is observed within temperature range less than 80 C for excitation wavelengths of 310 nm, 340 nm and 365 nm. Besides, the temperature dependence of the red-shift of spectrum peak shows different wavelength dependence characteristic with coefficient as high as 0.062 nm K(-1) for the same temperature range, which gives us a hint about selecting the right excitation wavelength by compromising the excitation efficiency for fluorescence intensity and the temperature coefficient for peak shift in thermal applications. Temperature dependence of peak width is in a weakly linear relationship with a coefficient of 0.026 nm K(-1). Regarding the excellent stability and reversibility during thermal measurement, graphene quantum dot is a good candidate for the implementation in the nanoscale thermometry, especially in the bio-thermal field considering its superior biocompatibility and low cytotoxicity. PMID:25299977

  6. Fluorescence spectroscopy of graphene quantum dots: temperature effect at different excitation wavelengths

    NASA Astrophysics Data System (ADS)

    Li, Changzheng; Yue, Yanan

    2014-10-01

    This paper reports a comprehensive study of temperature dependence of fluorescence spectroscopy of graphene quantum dots at different excitation wavelengths. Very significant (more than 50%) and similar decrease of normalized spectrum intensity is observed within temperature range less than 80 C for excitation wavelengths of 310 nm, 340 nm and 365 nm. Besides, the temperature dependence of the red-shift of spectrum peak shows different wavelength dependence characteristic with coefficient as high as 0.062 nm K?1 for the same temperature range, which gives us a hint about selecting the right excitation wavelength by compromising the excitation efficiency for fluorescence intensity and the temperature coefficient for peak shift in thermal applications. Temperature dependence of peak width is in a weakly linear relationship with a coefficient of 0.026 nm K?1. Regarding the excellent stability and reversibility during thermal measurement, graphene quantum dot is a good candidate for the implementation in the nanoscale thermometry, especially in the bio-thermal field considering its superior biocompatibility and low cytotoxicity.

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

    SciTech Connect

    Zhang, Minghuan; Cai, Rongsheng; Zhang, Yujuan; Wang, Chao [The Cultivation Base for State Key Laboratory, Qingdao University, No. 308, Ningxia Road, Qingdao 266071 (China); College of Chemistry and Chemical Engineering, Qingdao University, No. 308, Ningxia Road, Qingdao 266071 (China); Wang, Yiqian, E-mail: yqwang@qdu.edu.cn [The Cultivation Base for State Key Laboratory, Qingdao University, No. 308, Ningxia Road, Qingdao 266071 (China); College of Physics Science, Qingdao University, No. 308, Ningxia Road, Qingdao 266071 (China); Ross, Guy G.; Barba, David [INRS-EMT, 1650 Boulevard Lionel-Boulet, Varennes, Quebec J3X 1S2 (Canada)

    2014-07-01

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

  8. Interindividual differences in circadian patterns of catecholamine excretion, body temperature, performance, and subjective arousal.

    PubMed

    Akerstedt, T; Frberg, J E

    1976-12-01

    Interindividual differences in circadian rhythms of urinary catecholamine excretion, performance, self-ratings of arousal and oral temperature were studied in 80 subjects divided into three groups--morning-active, evening-active, and intermediate. Catecholamine excretion, body temperature, and self-ratings of arousal exhibited pronounced circadian variations. Morning-active subjects exceeded other groups in the 24 h level of adrenaline excretion but crest phases did not differ, occurring close to 13.00 h. No differences between groups were found for noradrenaline excretion. Crest phases occurred close to noon. Self-rated alertness exhibited a significantly earlier (14.12 h) crest phase for morning-active than for evening-active subjects (16.09 h). The performance did not differ between groups. PMID:999994

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

    PubMed

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

    2013-01-01

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

  10. Systematic Pressure and Temperature Differences between Vaisala RS80 and RS92 Radiosonde-Systems

    NASA Astrophysics Data System (ADS)

    Steinbrecht, W.; Claude, H.; Schnenborn, F.

    2008-12-01

    National meteorological centers are replacing the widely used Vaisala RS80 radiosonde with the newer RS90 or RS92. Such change-overs often introduce erroneous steps into long-term atmospheric temperature records. We show that twin-flight campaigns with RS80 and RS92 sondes on the same balloon, and the transition from RS80 to RS92 in operational radio-soundings over Germany, consistently indicate higher temperature readings from RS92 sondes in the stratosphere. In our presentation we summarize these main differences between RS80 and RS92. Significant differences are found in the stratosphere, above the 100~hPa level. The accuracy of our temperature results is of the order of 0.1 to 0.5~K, and at this level we were not able to find significant differences in the troposphere, although there are indications for slightly higher daytime temperatures from RS92 sondes. During day-time and near 50~hPa, RS92s report +0.3 0.2~K higher temperature than RS80s, increasing to +0.7 0.4~K near 10~hPa (2? uncertainties). At night, the difference is smaller, +0.1 0.1~K near 50~hPa to +0.35 0.2~K near 10~hPa. The mean day-to-night difference (12-00~UT) is also larger for RS92s, by 0.1 0.06~K near 70~hPa, and by 0.76 0.16~K near 10~hPa. The main contribution to this stratospheric day-time difference comes from an over-correction of the radiation error in the Vaisala RS80 data processing. The night-time difference at stratospheric levels (and part of the day-time difference) is due to a low bias of the RS80 pressure measurement, typically by -0.4~hPa near 10~hPa. This shifts temperature readings to lower pressure/ higher altitude. For stratospheric levels, it results in lower temperatures from RS80 sondes (due to the vertical temperature increase). Generally, RS92s give better temperature repeatabiliy, 0.25~K (2?) near 50~hPa, and much more precise pressure, 0.2~hPa near 50~hPa, compared to RS80 systems, 0.5~K, or 1.5~hPa. Geopotential heights from RS92s are also much more precise, 100~m near 10~hPa compared to only 1000~m for RS80s. A major advantage of the RS92 is the on-board GPS receiver. It gives more precise altitude information (10~m), than previously available in the stratosphere. Geopotential heights from RS92s are in very good agreement with the on-board GPS altitudes, typically within 100 near 10~hPa (and better below), with some changes between production charges. Our results indicate that long-term records of stratospheric temperature should be corrected for the transition from Vaisala RS80 to the newer and better RS92 radiosonde system. In our presentation we show the main differences and give estimates for an appropriate correction. Reference Steinbrecht, W. et al., 2008, Pressure and Temperature Differences between Vaisala RS80 and RS92 Radiosonde-Systems, J. Atmos. Ocean. Tech., 25, 909--927, doi: 10.1175/2007JTECHA999.1 abstract&doi=10.1175%2F2007JTECHA999.1 class="ab'>

  11. First difference method: Maximizing station density for the calculation of long-term global temperature change

    NASA Astrophysics Data System (ADS)

    Peterson, Thomas C.; Karl, Thomas R.; Jamason, Paul F.; Knight, Richard; Easterling, David R.

    1998-10-01

    The calculation of global land surface air temperature trends using the instrumental record has been based primarily upon two methods of maximizing the availability of station records. Hansen and Lebedeff[l981] developed a technique that is still used today, known as the reference station method; Jones et al. [1986a] popularized the climate anomaly method in their calculations of global temperature trends. In this paper we introduce yet another approach designed to maximize station records, referred to as the first difference method. To test the sensitivity of global temperature trend analysis to the method used, we calculate worldwide-averaged land surface mean temperature using each of these methods with an identical data base, the Global Historical Climatology Network. For further comparisons, a global climate model (GCM) transient model simulation is interpolated to the Global Historical Climatology Network station locations and the three techniques are then applied to data interpolated to the station locations from the model. The Intergovernmental Panel on Climate Change (IPCC); [Nicholls et al. 1996] estimated a global land and ocean temperature change of 0.45C0.15C since the 19th century. Their assessment of the uncertainty associated with this temperature trend did not specifically address the differences that the method of calculating a global temperature time series might produce. Our results indicate that the differences in 1880-1990 trends produced by these three different methods are only a few hundredths of a degree centigrade per 100 years on trends of approximately 0.5C/100 years. This is quite small compared to the 0.15C/100 years uncertainty associated with the IPCC global land and ocean assessment which included factors such as data homogeneity which are not addressed here. Indeed, our results indicate that the source of differences in trends is more likely to be the method used to calculate a linear trend from a global temperature time series than the method used to create the global temperature time series. The modeled results confirm this finding but highlight other important characteristics: the reference station method has uncharacteristically low interannual variance, more similar to time series from the entire globe (land and ocean) than the global land area from which the data were observed. This lower variance can impact the statistical significance associated with linear trends.

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

    NASA Astrophysics Data System (ADS)

    Whitworth, Nicholas

    2013-06-01

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

  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

    2015-07-01

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

  14. Piezoresistive Sensitivity, Linearity and Resistance Time Drift of Polysilicon Nanofilms with Different Deposition Temperatures

    PubMed Central

    Shi, Changzhi; Liu, Xiaowei; Chuai, Rongyan

    2009-01-01

    Our previous research work indicated that highly boron doped polysilicon nanofilms (?100 nm in thickness) have higher gauge factor (the maximum is ?34 for 80 nm-thick films) and better temperature stability than common polysilicon films (? 200nm in thickness) at the same doping levels. Therefore, in order to further analyze the influence of deposition temperature on the film structure and piezoresistance performance, the piezoresistive sensitivity, piezoresistive linearity (PRL) and resistance time drift (RTD) of 80 nm-thick highly boron doped polysilicon nanofilms (PSNFs) with different deposition temperatures were studied here. The tunneling piezoresistive model was established to explain the relationship between the measured gauge factors (GFs) and deposition temperature. It was seen that the piezoresistance coefficient (PRC) of composite grain boundaries is higher than that of grains and the magnitude of GF is dependent on the resistivity of grain boundary (GB) barriers and the weight of the resistivity of composite GBs in the film resistivity. In the investigations on PRL and RTD, the interstitial-vacancy (IV) model was established to model GBs as the accumulation of IV pairs. And the recrystallization of metastable IV pairs caused by material deformation or current excitation is considered as the prime reason for piezoresistive nonlinearity (PRNL) and RTD. Finally, the optimal deposition temperature for the improvement of film performance and reliability is about 620 C and the high temperature annealing is not very effective in improving the piezoresistive performance of PSNFs deposited at lower temperatures. PMID:22399960

  15. Nanodiamond infiltration into porous silicon through etching of solid carbon produced at different graphitization temperatures

    Microsoft Academic Search

    C. R. B. Miranda; M. R. Baldan; A. F. Beloto; N. G. Ferreira

    Nanocrystalline diamond (NCD) was grown on the porous silicon (PS) substrate using Reticulated Vitreous Carbon (RVC) as an\\u000a additional solid carbon source. RVC was produced at different heat treatment temperatures of 1300, 1500, and 2000C, resulting\\u000a in samples with different turbostratic carbon organizations. The PS substrate was produced by an electrochemical method. NCD\\u000a film was obtained by the chemical vapor

  16. Shear behaviors of single crystal nickel at different temperatures: molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Li, Lili; Han, Ming

    2015-06-01

    Shear behaviors of a single crystal nickel along the [], [], [] and [] directions in the (111) crystallographic plane have been investigated at different temperatures by performing molecular dynamics simulations with an embedded atom method potential. Results show that shear stress-shear strain curves and atomic trajectory during shear process exhibit periodic behaviors, while the periods are varied for different shear directions. It sheds light on the inherent relationship between shear displacement for a period of the curve and the atomic configuration in corresponding crystallographic direction. Furthermore, shear modulus is extracted from the curves over a temperature range from 0 to 1700 K. It is demonstrated that the modulus is independent from the size of shear models and the shear directions, and that the modulus decreases with increasing temperature. In addition, this work also demonstrates that the classical description of shear modulus is still valid at the nanoscale, which might suggest a simple and direct way to obtain shear modulus at the atomic scale.

  17. Influence of the mode geometry on the strain and temperature sensitivity of different fibers

    NASA Astrophysics Data System (ADS)

    Murawski, M.; Holdynski, Z.; Szymanski, M.; Tenderenda, T.; Ostrowski, L.; ?ukowski, A.; Krisch, H.; Napiera?a, M.; Jaroszewicz, L. R.; Nasilowski, T.

    2013-05-01

    Sensitivity of optical fibers to the temperature, longitudinal strain or pressure, is a very important feature in many applications, such as sensors or telecommunication. The most common way to modify (depending on application - either mitigate or strengthen,) this sensitivity is changing the fiber material properties by appropriate glass doping or by employing appropriate microstructure in the fiber. In some cases the precise adjustment of a doping level and sophisticated design of air-holes arrangement is needed to obtain required features of the fiber. In this paper, for the first time, to the best of our knowledge, we report the investigation of the mode area and geometry influence on the fiber temperature and mechanical sensitivities. To do so, we engaged a dedicated all-fiber interferometer which enables the measurement of the temperature and longitudinal strain sensitivities of different fiber types, including conventional and microstructured fibers with different core diameters.

  18. 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

    2015-06-01

    During their lifetime, plants need to adapt to a changing environment, including light and temperature. To understand how these factors influence plant growth, we investigated the physiological and antioxidant responses of two Arabidopsis accessions, Shahdara (Sha) from the Shahdara valley (Tajikistan, Central Asia) in a mountainous area and Lovvik-5 (Lov-5) from northern Sweden to different light and temperature conditions. These accessions originate from different latitudes and have different life strategies, both of which are known to be influenced by light and temperature. We showed that both accessions grew better in high-light and at a lower temperature (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

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

    PubMed

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

    2013-05-01

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

  20. 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 ...

  1. Water sorption isotherms for lemon peel at different temperatures and isosteric heats

    Microsoft Academic Search

    J. V. Garca-Prez; J. A. Crcel; G. Clemente; A. Mulet

    2008-01-01

    Lemon peel constitutes a potential source of dietary fiber to formulate new and healthier products, as well as a source of essential oils. The relationship between moisture content and water activity provides useful information for lemon peel processing, especially for drying and storage. Water sorption isotherms of lemon peel were obtained using a standardized conductivity hygrometer at four different temperatures

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

    ERIC Educational Resources Information Center

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

    2015-01-01

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

  3. 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.

  4. 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

  5. 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)

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

    E-print Network

    Kansas, University of

    as the major distance limitation factor for high bit rate transmission systems. Different studies showed on the three fibers. Introduction Because the impairments caused by polarization mode dispersion (PMD) change of temperature. Because of the importance of mean DGD or wavelength-averaged DGD () in calculating system

  7. Effects of asphaltene content on the heavy oil viscosity at different temperatures

    Microsoft Academic Search

    Peng Luo; Yongan Gu

    2007-01-01

    Asphaltene content plays an important role in determining the high viscosity of heavy oil. This paper presents an experimental and theoretical study of the specific effects of asphaltene content on the heavy oil viscosity at different temperatures. In the experiment, a deasphalted heavy oil is obtained by using a standard ASTM method to precipitate asphaltenes from a crude heavy oil.

  8. Difference in growth behavior of human, swine, equine, and avian influenza viruses at a high temperature

    Microsoft Academic Search

    Y. Murakami; K. Nerome; Y. Yoshioka; S. Mizuno; A. Oya

    1988-01-01

    Summary Growth characteristics of a wide range of influenza A viruses from different mammals and bird species were examined in an established line of canine kidney (MDCK) cells at an ordinary (37C) and a high temperature (42C). Although all viruses employed in the present study possessed a capability of replicating at 37C, virus growth at 42C showed considerable variation and

  9. 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

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

    E-print Network

    Allan Sandage; G. A. Tammann

    2008-03-26

    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. The graphical demonstration uses an arbitrary (toy) ridge line 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 measured instability strip slopes argue that the observed P-L differences between the Galaxy and LMC are real. In another proof, the direct evidence for different P-L slopes in different galaxies is shown 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.

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

    NASA Astrophysics Data System (ADS)

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

    2005-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  13. Characteristics of three populations of a swamp annual under different temperature regimes

    SciTech Connect

    Christy, E.J.; Sharitz, R.R.

    1980-06-01

    This study was undertaken to examine rapid evolution in an herbaceous plant species in response to strong selection associated with increases in temperature. Differences in growth and reproduction in three populations of Ludwigia leptocarpa (Nutt.) Hara, an herbaceous plant dominant along the edges of streams receiving heated nuclear reactor effluent on the United States Department of Energy's Savannah River Plant (SR) in South Carolina, USA, were examined for two growing seasons. Two populations of this semi-aquatic herb were in areas with elevated water temperature, and one population was in an undisturbed swamp. In each of the populations in warmer water, growth and reproductive output were significantly higher than in plants from the undisturbed site. Total percentage germination under controlled temperatures from 22/sup 0/ to 42/sup 0/C did not differ among the three populations; however, initiation of germination was delayed in all three at 22/sup 0/. Seedlings from all three populations showed similar growth responses at 22/sup 0/, whereas at 32/sup 0/ seedlings from the higher temperature locations grew more rapidly. At 42/sup 0/, survivorship of seedlings from all three seed populations was low. These results indicate selection for temperature-tolerant ecotypes in the disturbed areas.

  14. 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. PMID:25834383

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  16. How Do Seasonal Temperature Patterns Vary Among Different Regions of the World?

    NSDL National Science Digital Library

    The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

    2003-08-01

    The purpose of this resource is to have students use GLOBE visualizations to display student data on maps and to learn about seasonal changes in regional and global temperature patterns. Students learn how sunlight spreads over the Earth at different times of the year, emphasizing the solstices and the equinoxes. Students investigate the effect of the Earth.s tilt on the spread of sunlight by modeling different tilts using a three-dimensional polyhedron which they construct from paper. Students calculate the relative sunlight intensity received by the Northern and Southern Hemispheres to understand seasonal differences between the hemispheres.

  17. Sex differences in behavioral outcomes following temperature modulation during induced neonatal hypoxic ischemic injury in rats.

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  19. Atmospheric Precipitable Water and its association with Surface Air Temperatures over Different Climate Regims

    NASA Astrophysics Data System (ADS)

    Ye, H.; Fetzer, E. J.; Olsene, E. T.; Granger, S. L.; Kahn, B. H.; Fishbein, E. F.; Chen, L.; Teixeira, J.; Lambrigtsen, B. H.

    2008-12-01

    As a greenhouse gas and a key component in the hydrologic cycle, atmospheric water vapor is very important in the earth's climate system. The relationship between air temperature and water vapor content at the surface and in different layers of the atmosphere have been examined in many studies in trying to better understand the magnitude of water vapor feedback in our climate system. Studies have found large spatial variability and large regional and vertical deviations from the Clapeyron-Clausius relation of constant relative humidity. However, there is an ongoing need to understand the climatology of the relationship between the surface air temperature and total column water vapor, and to examine any potential thresholds associated with sudden changes in this relationship as air temperatures continue to increase. This study uses 5-year total precipitable water vapor records measured by the Atmospheric Infrared Sounders (AIRS) and surface air temperature to examine their relationships at tropical to mid latitude conditions found at 60S- 60N for winter and summer seasons. In addition, the relationships will be examined for different climate regimes based on Koppen's system. This will help distinguish the geographical regions and physical processes where different relationships are found. This information will improve our understanding of the regional patterns of water vapor feedback associated with warming climate.

  20. The influence of the textural properties of activated carbons on acetaminophen adsorption at different temperatures.

    PubMed

    Galhetas, Margarida; Andrade, Marta A; Mestre, Ana S; Kangni-Foli, Eko; Villa de Brito, Maria J; Pinto, Moiss L; Lopes, Helena; Carvalho, Ana P

    2015-04-29

    The influence of temperature (20-40 C) on the acetaminophen adsorption onto activated carbons with different textures was studied. Different temperature dependences, not explained by kinetic effects, were observed for carbons with different micropore size distribution patterns: adsorption capacity increased for pine gasification residues (Pi-fa) derived carbons and decreased for sisal based materials. No significant variation was seen for carbon CP. The species identified by (1)H NMR spectroscopy on the back-extraction solution proved that during the adsorption process exist the conditions required to promote the formation of acetaminophen oligomers which have constrained access to the narrow microporosity. The rotation energy of the dihedral angle between monomers (estimated by electronic DFT methods) showed that conformations in the planar form are less stable than the non-planar conformation (energy barrier of 70 and 23 kJ mol(-1)), but have critical dimensions similar to the monomer and can access most of the micropore volume. The enthalpy change of the overall process showed that the energy gain of the system (endothermic) for Pi-fa samples (?40 kJ mol(-1)) was enough to allow a change in the dimer, or even a larger oligomer, conformation to the planar form. This will permit adsorption in the narrow micropores, thus explaining the uptake increase with temperature. Non-continuous micropore size distributions centered at pore widths close to the critical dimensions of the planar form seem to be crucial for a positive evolution of the adsorption capacity with temperature. PMID:25898008

  1. 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

  2. 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

  3. 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

  4. Differences in the H-mode pedestal width of temperature and density

    NASA Astrophysics Data System (ADS)

    Schneider, P. A.; Wolfrum, E.; Groebner, R. J.; Osborne, T. H.; Beurskens, M. N. A.; Dunne, M. G.; Ferron, J. R.; Gnter, S.; Kurzan, B.; Lackner, K.; Snyder, P. B.; Zohm, H.; the ASDEX Upgrade Team; the DIII-D Team; EFDA Contributors, JET

    2012-10-01

    A pedestal database was built using data from type-I ELMy H-modes of ASDEX Upgrade, DIII-D and JET. ELM synchronized pedestal data were analysed with the two-line method. The two-line method is a bilinear fit which shows better reproducibility of pedestal parameters than a modified hyperbolic tangent fit. This was tested with simulated and experimental data. The influence of the equilibrium reconstruction on pedestal parameters was investigated with sophisticated reconstructions from CLISTE and EFIT including edge kinetic profiles. No systematic deviation between the codes could be observed. The flux coordinate system is influenced by machine size, poloidal field and plasma shape. This will change the representation of the width in different coordinates, in particular, the two normalized coordinates ?N and r/a show a very different dependence on the plasma shape. The scalings derived for the pedestal width, ?, of all machines suggest a different scaling for the electron temperature and the electron density. Both cases show similar dependence with machine size, poloidal magnetic field and pedestal electron temperature and density. The influence of ion temperature and toroidal magnetic field is different on each of \\Delta_{T_\\rme} and \\Delta_{n_\\rme} . In dimensionless form the density pedestal width in ?N scales with \\rho^{0.6}_{i\\star} , the temperature pedestal width with \\beta_p,ped^{0.5} . Both widths also show a strong correlation with the plasma shape. The shape dependence originates from the coordinate transformation and is not visible in real space. The presented scalings predict that in ITER the temperature pedestal will be appreciably wider than the density pedestal.

  5. 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...

  6. Martensitic transformation and mechanical behavior of porous Ti50.0 at % Ni alloy, fabricated by self-propagating high temperature synthesis at different temperature

    Microsoft Academic Search

    N. Resnina; S. Belyaev; A. Voronkov; V. Mozgunov; A. Krivosheev; I. Ostapov

    2010-01-01

    A study of temperature annealing on the crystalline structure, the kinetics of martensitic transformation and the mechanical behaviour in the porous Ti-50.0 at % Ni alloy produced by self-propagating high-temperature synthesis at different pre-heating temperatures was carried out. It was found that annealing the porous TiNi alloy in the temperature range of 573 K to 773 K may be used

  7. 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.

  8. Development of uncooled miniaturized InSb photovoltaic infrared sensors for temperature measurements

    NASA Astrophysics Data System (ADS)

    Kuze, N.; Morishita, T.; Camargo, E. G.; Ueno, K.; Yokoyama, A.; Sato, M.; Endo, H.; Yanagita, Y.; Tokuo, S.; Goto, H.

    2009-03-01

    This paper reports the development of an InSb photovoltaic infrared sensor (InSb PVS) operating at room temperature for temperature measurements. The InSb PVS consists of 910 InSb p +-p --n + photodiodes connected in series on a semi-insulating GaAs (1 0 0) substrate. An Al 0.17In 0.83Sb barrier layer was grown between the p + and p - layers to reduce the diffusion of photo-excited electrons. As the InSb PVS operates in a photovoltaic mode, no thermal insulation is required, enabling its miniaturized plastic molding package. The sensitivity of the InSb PVS was 127 ?V/K, and a noise equivalent temperature difference (NETD) of 1.0 mK/Hz 1/2 was obtained at room temperature. The results demonstrate the potential for the sensor to be used both in non-contact thermometry, as well as human body detection.

  9. 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

  10. 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

  11. Energy allocation in juvenile roach and burbot under different temperature and feeding regimes.

    PubMed

    Binner, Maaike; Kloas, Werner; Hardewig, Iris

    2008-06-01

    Cold-active burbot (Lota lota (L.)) display reduced food intake during the summer. The impact of temperature on their energy budget was investigated in starved fish in a laboratory setting, simulating summer (20 degrees C) and winter (4 degrees C) conditions, to elucidate the impact of high temperature on burbot metabolism. Metabolic effects in burbot were compared to roach (Rutilus rutilus (L.)), which typically fast in winter. During warm acclimation, starvation (four weeks) resulted in a metabolic depression of oxygen consumption in both species. In roach, metabolic rate decreased by 55% after two weeks of starvation. Burbot, in contrast, displayed an immediate depression of metabolic rate by 50%. In both species, no reductions were observed in the cold. The temperature-induced differences between the metabolic rates at 20 degrees C and 4 degrees C showed a lower thermal sensitivity in burbot (Q (10) = 1.9) compared to roach (Q (10) = 2.7). Notably, for each species, energy consumption during starvation was highest under experimental conditions simulating their natural active periods, respectively. Warm acclimated roach relied mainly on muscle reserves, whereas in cold acclimated burbot, liver metabolic stores made a major contribution to the energy turnover. In cold acclimated roach and warm acclimated burbot, however, starvation apparently reduced swimming activity, resulting in considerable savings of energy reserves. These lower energy expenditures in roach and burbot corresponded to their natural inactive periods. Thus, starvation in burbot caused a lower energy turnover when exposed to high temperatures. These season-dependent adaptations of metabolism represent an advantageous strategy in burbot to manage winter temperature and withstand metabolism-activating summer temperatures, whereas roach metabolism correlates with the seasonal temperature cycle. PMID:18649028

  12. Temperature measurements in plasmas generated by using lasers at different intensities

    NASA Astrophysics Data System (ADS)

    Picciotto, A.; Torrisi, L.; Gammino, S.; Mezzasalma, A. M.; Caridi, F.; Margarone, D.; Ando, L.; Krasa, J.; Laska, L.; Wolowski, J.

    2005-10-01

    The temperature of laser-generated pulsed plasmas is an important property that depends on many parameters, such as the particle species and the time elapsed from the laser interaction with the matter and the surface characteristics. Laser-generated plasmas with low intensity (< 10(10) W/cm(2)) at INFN-LNS of Catania and with high intensity (> 10(14) W/cm(2)) in PALS laboratory in Prague have been investigated in terms of temperatures relative to ions, electrons, and neutral species. Time-of-flight (ToF) measurements have been performed with an electrostatic ion energy analyzer (IEA) and with different Faraday cups, in order to measure the ion and electron average velocities. The IEA was also used to measure the ion energy, the ion charge state, and the ion energy distribution. The Maxwell-Boltzmann function permitted to fit the experimental data and to extrapolate the ion temperature of the plasma core. The velocity of the neutrals was measured with a special mass quadrupole spectrometer. The Nd:Yag laser operating at low intensity produced an ion temperature core of the order of 400 eV and a neutral temperature of the order of 100 eV for many ablated materials. The ToF of electrons indicates the presence of hot electron emission with an energy of similar to 1 keV.

  13. Characteristics of wall sheath and secondary electron emission under different electron temperature in Hall thruster

    NASA Astrophysics Data System (ADS)

    Duan, Ping; Qin, Haijuan; Cao, Anning; Zhou, Xinwei; Chen, Long; Gao, Hong

    2013-09-01

    Characteristics of discharge channel wall plasma sheath in Hall thruster have great effects on its performance. In this paper, we establish a two-dimensional physical model in Hall thruster sheath area to investigate the influences of the different electron temperature, propellant and particle weight on sheath potential and secondary electron emission in Hall thruster, by the method of Particle In Cell (PIC) simulation. And the electric field at the particle position is obtained by solving the Poisson's equation. The numerical results show that when the electron temperature is low, the change of sheath potential drop is bigger than that with electrons at high temperature, the surface potential maintains a stable value and the stability of the sheath is good. When the electron temperature is high, the surface potential maintains persistent oscillation, and the stability of the sheath is reduced. Along with the increase of electron temperature, the coefficient of secondary electron emission in wall reduce after the first increasing. For three kinds of propellant (Ar, Kr, Xe), with the increase of ion mass, sheath potential and the secondary electron emission coefficient in turn reduce.

  14. 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).

  15. 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.

  16. Performance of Nile Tilapia (Oreochromis niloticus) Fingerlings. II. Influence of Different Water Temperatures

    Microsoft Academic Search

    MOHAMED SAAD EL-SHERIF; AMAL MOHAMED; IBRAHIM EL-FEKY

    Nile tilapia (Oreochromis niloticus) fingerlings with average weight of 19.01.0 g were used to study the effect of different temperatures on growth performance, survival rate and some physiological parameters. The fingerlings were stocked in 12 glass aquaria (407060 cm) at 15, 20, 30 and 25C (as control) for 60 days. Diet of 26.58% protein was offered as feed. Water was

  17. The effect of low temperatures on fatty acid composition of crops with different cold resistance

    Microsoft Academic Search

    S. P. Makarenko; L. V. Dudareva; A. I. Katyshev; T. A. Konenkina; A. V. Nazarova; E. G. Rudikovskaya; N. A. Sokolova; V. V. Chernikova; Yu. M. Konstantinov

    2011-01-01

    The study was focused on fatty acid (FA) composition of lipids from the seedlings and roots of crops having different cold\\u000a resistance and grown at 27C or 4C. Biosynthesis of FA in the lipids of seedlings and roots of cold-susceptible maize (Zea mays L.) at both growth temperatures was controlled by chloroplast ?6 desaturase and microsomal ?6 desaturase, respectively. The

  18. Evaluating Performance of Ecologically Sound Organic Substrates under Different Temperature Regimes

    Microsoft Academic Search

    SHAHIDUL ISLAM

    Greenhouse trials were carried out over two years to investigate the high temperature (25C, 30C & 35C) effects on ecologically sound untreated organic substrates viz., coconut coir and rice husk charcoal, in comparison to that of rock wool using tomato (Lycopersicon esculentum Miller) as a test crop. There were no significant differences in the root dry matter, stem dry matter,

  19. Comparison of temperature dependence of the fluorescence of Sm 2+-ion doped in different hosts

    Microsoft Academic Search

    Hongwei Song; Tomokatsu Hayakawa; Masayuki Nogami

    1999-01-01

    This paper presents new results about Sm2+ fluorescence in two host materials in a BaFCl0.5Br0.5 single-crystal and in an Al2O3SiO2 glass. The fluorescence emission channels were comparatively studied through measuring the temperature dependencies of the fluorescence intensities and lifetimes and these dependencies were found to be markedly different in the two materials. In the glass the fluorescence emission channel

  20. Adsorption of arsenic on the reused sanding wastes calcined at different temperatures

    Microsoft Academic Search

    Jae-Woo Lim; Yoon-Young Chang; Jae-Kyu Yang; Seung-Mok Lee

    2009-01-01

    The removal capacity of arsenic(III), As(III), by the reused sanding wastes prepared at different calcination temperatures was investigated in this study. As a pretreatment process for the preparation of the reused material from raw sanding wastes (RSW), calcination was performed in a furnace at 550, 750, 900, 1100, and 1300C. After calcination at 550C, aluminum hydroxide which is a major

  1. 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

  2. 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.

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

    PubMed

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

    2015-03-01

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

  4. 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,

  5. 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

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

    PubMed

    Baserisalehi, Majid; Bahador, Nima

    2011-12-01

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

  7. 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.

  8. Transformations in Sol-Gel Synthesized Nanoscale Hydroxyapatite Calcined Under Different Temperatures and Time Conditions

    NASA Astrophysics Data System (ADS)

    Seema, Kapoor; Uma, Batra; Suchita, Kohli

    2012-08-01

    Nano-hydroxyapatite (HAP) has been synthesized using sol-gel technique. Calcium nitrate tetrahydrate and potassium dihydrogen phosphate were used as precursors for calcium and phosphorus, respectively. A detailed study on its transformation during calcination at two crucial temperatures has been undertaken. The synthesized nanopowder was calcined at 600 and 800 C for different time periods. The results revealed that the obtained powders after calcining at 600 and 800 C are composed of hydroxyapatite nanoparticles. The nano-HAP powders were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, thermal gravimetric analysis (TGA), and BET surface area analyzer techniques. The results indicate that crystallite size as well as crystallinity of synthesized HAP nanopowders increase with increase in calcination temperature as well as calcination time, but the effect of temperature is more prominent as compared to that of calcination time. TEM micrograph revealed the presence of majority of HAP powder particles as agglomerates and a few as individual particles. It also revealed that HAP produced after sintering at 600 C is 26-45 nm in size, which is well in agreement with the crystallite size calculated using XRD data. TGA study showed the thermal stability of the as-synthesized nano-HAP powder. The BET surface area decreased with increase in calcination temperature and time. The results clearly demonstrate the significant role of calcination parameters on the characteristics of nano-HAP powders.

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

    PubMed Central

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

    2015-01-01

    Background: Heat-induced alterations to dental and restorative materials can be of great interest to forensic dentistry. Knowing the specific optical behavior of dental materials can be of high importance as recognition of changes induced by high temperatures can lead to the determination of material which was used in a dental restoration, facilitating identification of burned human remains. Aim: To observe the effects of predetermined temperatures (200C400C600C800C1000C) on unrestored teeth and different restorative materials macroscopically and then examine them under a stereomicroscope for the purpose of identification. Materials and Methods: The study was conducted on 375 extracted teeth which were divided into five groups of 75 teeth each as follows: group 1- unrestored teeth, group 2- teeth restored with all-ceramic crowns, Group 3- with class I silver amalgam filling, group 4- with class I composite restoration, and group 5- with class I glass ionomer cement restoration. Results: Unrestored and restored teeth display a series of specific macroscopic & stereomicroscopic structural changes for each range of temperature. Conclusion: Dental tissues and restorative materials undergo a series of changes which correlate well with the various temperatures to which they were exposed. These changes are a consequence of the nature of the materials and their physicochemical characteristics. PMID:26005305

  10. Shear behaviors of single crystal hcp Ti at different temperatures from molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Li, Lili; Han, Ming

    2015-01-01

    Shear behaviors of single crystal hcp titanium in a close-packed (0001) basal plane along the [\\bar{1}2\\bar{1}0], [1\\bar{2}10], [10\\bar{1}0], and [\\bar{1}010] directions at different temperatures were studied via molecular dynamics simulation using an embedded atom method (EAM) potential. Results show that periods of shear stressshear strain curves along four directions occur, where shear displacement for one period of the curve relates to one period of atomic configuration in the corresponding direction, and that the trajectory of the free atoms also shows periodic characteristics. It is demonstrated that shear behaviors along two orthogonal directions are different, while they perform the same in opposite directions. In addition, the shear modulus can be obtained from the slope of the shear stressshear strain curves and shows independence from the shear directions and the height of the models. The modulus was extracted over a temperature range of 0 to 1050 K, showing a decreasing trend with increasing temperature. Furthermore, this work also demonstrates that the classical description of shear modulus is still valid on the nanoscale, which might suggest a simple and direct way to obtain the shear modulus on the atomic scale.

  11. Bovine serum albumin recognition via thermosensitive molecular imprinted macroporous hydrogels prepared at two different temperatures.

    PubMed

    Ran, Dan; Wang, Yuzhi; Jia, Xiaopin; Nie, Chan

    2012-04-20

    A novel temperature-sensitive molecular imprinted hydrogel composed of 2-acrylamido-2-methyl-propanosulfonic acid (AMPS), N-isopropylacrylamide (NIPAm) and acrylamide (AAm) has been prepared by free-radical cross-linking copolymerization in aqueous solution under two different temperatures (25 C and -20 C). Bovine serum albumin (BSA, pI 4.9, MW 66.0 kDa) is used as the template protein. The influence of the external temperature stimuli on the affinity of the hydrogels was investigated, and the optimal binding conditions were tested. The adsorption capacity (Q(max)) and association constant (K) for the specific interaction between the hydrogel and the template protein were determined by Langmuir isotherm plots. Several types of reference protein, which are different in molecular weights and isoelectric points were chosen to investigate the selectivity of the hydrogels. It was shown that the shape memory and the charge effect were the major factors for the recognition. This imprinted hydrogel was used to specifically adsorb the BSA from the protein mixture and real sample, which demonstrated its potential selectivity. PMID:22444572

  12. 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.

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

    PubMed

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

    2015-08-01

    A study was undertaken to determine whether different concentrations of ordnance gelatine, water types, temperatures and curing times would have an effect on projectile penetration of a gelatine tissue surrogate. Both Federal Bureau of Investigation (FBI) and North Atlantic Treaty Organization (NATO) specified gelatines were compared against the FBI calibration standard. 10% w/w and 20% w/w concentrations of gelatine with Bloom numbers of 250 and 285 were prepared and cured at variable temperatures (3-20C) for 21hours-3weeks. Each block was shot on four occasions on the same range using steel calibre 4.5mm BBs fired from a Daisy() air rifle at the required standard velocity of 1804.5m/s, to ascertain the mean penetration depth. The results showed no significant difference in mean penetration depth using the three different water types (p>0.05). Temperature changes and curing times did affect penetration depth. At 10C, mean penetration depth with 20% gelatine 285 Bloom for the two water types tested was 49.71.5mm after 21h curing time, whereas the same formulation at 20C using two different water types was 79.12.1mm after 100h curing time (p<0.001). Neither of the NATO 20% concentrations of gelatine at 10C or a 20% concentration of 285 Bloom gelatine at 10C met the same calibration standard as the FBI recommended 10% formulation at 4C. A 20% concentration of 285 Bloom at 20C met the same calibration/penetration criteria as a 10% concentration of 250 Bloom at 4C after 100h of curing, therefore matching the FBI calibration standard for a soft tissue simulant for wound ballistics research. These results demonstrate significant variability in simulant properties. Failure to standardise ballistic simulants may invalidate experimental results. PMID:26165674

  14. 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.

  15. Estimating cutting front temperature difference in disk and CO2 laser beam fusion cutting

    NASA Astrophysics Data System (ADS)

    Scintilla, L. D.; Tricarico, L.

    2012-07-01

    A three-dimensional, semi-stationary, simplified thermal numerical model was developed. The average cutting front temperature difference in disk and CO2 laser beam fusion cutting of 90MnCrV8 was estimated by computing the conductive power loss. Basing on heat affected zone extension experimentally measured and using an inverse methodology approach, the unknown thermal load on the cutting front during laser cutting was calculated. The accuracy of the numerical power loss estimation was evaluated comparing the results from simulation with the ones from analytical models. A good agreement was found for all the test cases considered in this study. The conduction losses estimation was used for justifying the lower quality of disk laser cuts due to the lower average cut front temperature. This results in the increase of viscosity of molten material and in the subsequent more difficult ejection of the melted material from the cut kerf.

  16. Physiological responses of pre-ruminant kid goats and lambs to different environmental temperatures.

    PubMed

    Sanz Sampelayo, M R; Prieto, I; Lupiani, M J; Extremera, F G; Boza, J

    2000-09-01

    The purpose of this study was to establish the metabolic behaviour of both preruminant kid goats and lambs, when they are kept at different environmental temperatures (12, 24 and 30 degrees C). The animals were fed ad libitum with a milk replacer for the first two months of life. Blood samples were taken from all the animals on days 30, 40, 50 and 60 post partum, to determine serum levels of glucose, insulin, free fatty acids, triiodothyronine (T3) and thyroxine (T4), both when fasting and 4 hours after starting feeding. The high sensitivity of both kinds of animal to the lowest of the environmental temperatures used, particularly for the first periods of life here considered, was established from the glucose/insulin and T3/T4 molar ratios and from the concentrations of free fatty acids. The results obtained by species were also evidence of metabolic behaviour typical of leanner animals in kids. PMID:11198159

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

    E-print Network

    Antoine Brut; Artyom Petrosyan; Sergio Ciliberto

    2015-05-26

    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.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

    Li, Junwen; Zhao, Haidong; Chen, Zhenming

    2015-06-01

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

  20. Film Thickness and Flow Properties of Resin-Based Cements at Different Temperatures

    PubMed Central

    Bagheri, R

    2013-01-01

    Statement of Problem: For a luting agent to allow complete seating of prosthetic restorations, it must obtain an appropriate flow rate maintaining a minimum film thickness. The performance of recently introduced luting agents in this regard has not been evaluated. Purpose: To measure and compare the film thickness and flow properties of seven resin-containing luting cements at different temperatures (37C, 25C and10C). Material and Methods: Specimens were prepared from five resin luting cements; seT (SDI), Panavia F (Kuraray), Varioloink II (Ivoclar), Maxcem (Kerr), Nexus2 (Kerr) and two resin-modified glass-ionomer luting cements (RM-GICs); GC Fuji Plus (GC Corporation), and RelyX Luting 2 (3 M/ESPE). The film thickness and flow rate of each cement (n=15) was determined using the test described in ISO at three different temperatures. Results: There was a linear correlation between film thickness and flow rate for most of the materials. Cooling increased fluidity of almost all materials while the effect of temperature on film thickness was material dependent. At 37C, all products revealed a film thickness of less than 25m except for GC Fuji Plus. At 25C, all cements produced a film thickness of less than 27 m except for seT. At 10C, apart from seT and Rely X Luting 2, the remaining cements showed a film thickness smaller than 20 m. Conclusion: Cooling increased fluidity of almost all materials, however. the film thickness did not exceed 35 m in either condition, in spite of the lowest film thickness being demonstrated at the lowest temperature. PMID:24724120

  1. 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

  2. Survival kinetics of Listeria monocytogenes on raw sheep milk cured cheese under different storage temperatures.

    PubMed

    Valero, Antonio; Hernandez, Marta; De Cesare, Alessandra; Manfreda, Gerardo; Gonzlez-Garca, Patricia; Rodrguez-Lzaro, David

    2014-08-01

    Raw sheep milk cured cheese produced in the Castilla y Leon region (Spain) constitutes a traditional semi-hard aromatic cheese typically aged for three to six months. This product is catalogued as ready-to-eat since it is not submitted to any further treatment before consumption. Thus, foodborne pathogens such as Listeria monocytogenes can represent a health concern for susceptible consumers. This study was aimed at evaluating the survival of L. monocytogenes on raw sheep milk cured cheese under different storage temperatures. Log-linear+shoulder and Weibull type models were fitted to data observed in order to estimate kinetic parameters. The Arrhenius relationship was further used to predict the impact of temperature on L. monocytogenes behavior during storage at 4, 12 and 22C. Additionally, growth of lactic acid bacteria (LAB) as a representative group of the indigenous microbiota was evaluated. Results obtained indicated that the time to eradication (time when absence of L. monocytogenes in the analyzed samples was observed) was 114, 104, and 77 days for cheese samples stored at 4, 12 and 22C, respectively. The LAB population showed an increase at 12 and 22C during storage. However, an increase of 1 log CFU/g was observed during the first 2 weeks irrespectively of the storage temperature. The log-linear+shoulder model indicated a good fit to observed data. Likewise, the Arrhenius relationship explained sufficiently the dependency of temperature on L. monocytogenes behavior. This study demonstrated that cheese storage at ambient temperatures could lead to the preservation of its quality properties as well as its safety against L. monocytogenes. PMID:24630556

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

    PubMed

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

    2015-08-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

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

    NASA Astrophysics Data System (ADS)

    Green, D. H.

    2003-04-01

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

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

    NASA Astrophysics Data System (ADS)

    Barreiro, Ana; Lombao, Alba; Martin, Angela; Cancelo-Gonzlez, Javier; Carballas, Tarsy; Daz-Ravia, Montserrat

    2015-04-01

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

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

    NASA Astrophysics Data System (ADS)

    Mohiuddin, Mohammad; van Hoa, Suong

    2011-06-01

    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.

  8. Biology of Eutetranychus Banksi: Life Tables on Marsh Grapefruit Leaves at Different Temperatures (Acari: Tetranychidae)

    Microsoft Academic Search

    C. C. Childers; M. M. Abou-Setta; M. S. Nawar

    1991-01-01

    Females of Eutetranychus banksi (McGregor) developed from egg to adult in 29.6, 17.2, 13.1, 11.6, 11.7 and 9.6 days compared to 27.7, 16.4, 12.0, 10.1, 10.8 and 8.5 days for males at 15, 20, 25, 28, 30 and 32C. Developmental times were significantly different (P < 0.05) between the two sexes at each temperature. Mites were reared on whole leaf

  9. Structurally Similar Woodchuck and Human Hepadnavirus Core Proteins Have Distinctly Different Temperature Dependences of Assembly

    PubMed Central

    Kukreja, Alexander A.; Wang, Joseph C.-Y.; Pierson, Elizabeth; Keifer, David Z.; Selzer, Lisa; Tan, Zhenning; Dragnea, Bogdan; Jarrold, Martin F.

    2014-01-01

    ABSTRACT Woodchuck hepatitis virus (WHV), a close relative of human hepatitis B virus (HBV), has been a key model for disease progression and clinical studies. Sequences of the assembly domain of WHV and HBV core proteins (wCp149 and hCp149, respectively) have 65% identity, suggesting similar assembly behaviors. We report a cryo-electron microscopy (cryo-EM) structure of the WHV capsid at nanometer resolution and characterization of wCp149 assembly. At this resolution, the T=4 capsid structures of WHV and HBV are practically identical. In contrast to their structural similarity, wCp149 demonstrates enhanced assembly kinetics and stronger dimer-dimer interactions than hCp149: at 23C and at 100 mM ionic strength, the pseudocritical concentrations of assembly of wCp149 and hCp149 are 1.8 ?M and 43.3 ?M, respectively. Transmission electron microscopy reveals that wCp149 assembles into predominantly T=4 capsids with a sizeable population of larger, nonicosahedral structures. Charge detection mass spectrometry indicates that T=3 particles are extremely rare compared to the ?5% observed in hCp149 reactions. Unlike hCp149, wCp149 capsid assembly is favorable over a temperature range of 4C to 37C; van't Hoff analyses relate the differences in temperature dependence to the high positive values for heat capacity, enthalpy, and entropy of wCp149 assembly. Because the final capsids are so similar, these findings suggest that free wCp149 and hCp149 undergo different structural transitions leading to assembly. The difference in the temperature dependence of wCp149 assembly may be related to the temperature range of its hibernating host. IMPORTANCE In this paper, we present a cryo-EM structure of a WHV capsid showing its similarity to HBV. We then observe that the assembly properties of the two homologous proteins are very different. Unlike human HBV, the capsid protein of WHV has evolved to function in a nonhomeostatic environment. These studies yield insight into the interplay between core protein self-assembly and the host environment, which may be particularly relevant to plant viruses and viruses with zoonotic cycles involving insect vectors. PMID:25253350

  10. 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.

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

    PubMed

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

    2015-01-01

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

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

    PubMed

    Steger, Kristin; Jarvis, Asa; Vasara, Tuija; Romantschuk, Martin; Sundh, Ingvar

    2007-09-01

    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 the size of Actinobacteria populations. Qualitative changes were determined using PCR-DGGE (denaturing gradient gel electrophoresis) and sequencing of 16S rRNA genes with Actinobacteria-specific primers. The peak in total microbial biomass was roughly twice as high and delayed in trials where the maximum temperature was 40 degrees C, compared to those where it was 55 or 67 degrees C. There was a shift from members of Corynebacterium, Rhodococcus and Streptomyces at the onset to species of thermotolerant Actinobacteria in the cooling phase, e.g. Saccharomonospora viridis, Thermobifida fusca and Thermobispora bispora. In conclusion, temperature was an important selective factor for the development of Actinobacteria populations in composts, and they constituted a substantial part of the community in the later compost stages. PMID:17683913

  13. Structure and mechanical properties of isotactic polypropylene (iPP) gels formed at different cooling temperatures

    NASA Astrophysics Data System (ADS)

    Okoshi, Ryusuke; Hotta, Atsushi

    2015-03-01

    The effects of the cooling temperature on the crystalline network formation and the mechanical properties of isotactic polypropylene (iPP) gels were evaluated. iPP/decahydronaphthalene gels were prepared at different cooling temperatures varying from 25 degrees C to -196 degrees C. Tensile test was carried out to measure the mechanical properties of the gels. Scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) analyses were conducted to observe the density and the homogeneity of the network structures. It was found that the iPP gel quenched at -196 degrees C was highly elastic, exhibiting the highest fracture strain and stress of 2500% and 230 kPa. The SEM analysis revealed that nano-crystals were formed, which acted as crosslinkers that were distributed throughout the gels by quenching below -40 degrees C. By contrast, spherulites were observed to have grown inhomogeneously by cooling above -20 degrees C. It was found by DSC that the amount of crystals was increased by decreasing the cooling temperatures, indicating an increase in the density of the network structures. From these results, it was therefore concluded that iPP gel quenched at -196 degrees C possessed the highest mechanical property due to its dense and homogeneous network structures.

  14. Individual differences in temperature perception: evidence of common processing of sensation intensity of warmth and cold.

    PubMed

    Green, Barry G; Akirav, Carol

    2007-01-01

    The longstanding question of whether temperature is sensed via separate sensory systems for warmth and cold was investigated by measuring individual differences in perception of nonpainful heating and cooling. Sixty-two subjects gave separate ratings of the intensity of thermal sensations (warmth, cold) and nociceptive sensations (burning/stinging/pricking) produced by cooling (29 degrees C) or heating (37 degrees C) local regions of the forearm. Stimuli were delivered via a 4 x 4 array of 8 mm x 8 mm Peltier thermoelectric modules that enabled test temperatures to be presented sequentially to individual modules or simultaneously to the full array. Stimulation of the full array showed that perception of warmth and cold were highly correlated (Pearson r = 0.83, p < 0.05). Ratings of nonpainful nociceptive sensations produced by the two temperatures were also correlated, but to a lesser degree (r = 0.44), and the associations between nociceptive and thermal sensations (r = 0.35 and 0.22 for 37 and 29 degrees C, respectively) were not significant after correction for multiple statistical tests. Intensity ratings for individual modules indicated that the number of responsive sites out of 16 was a poor predictor of temperature sensations but a significant predictor of nociceptive sensations. The very high correlation between ratings of thermal sensations conflicts with the classical view that warmth and cold are mediated by separate thermal modalities and implies that warm-sensitive and cold-sensitive spinothalamic pathways converge and undergo joint modulation in the central nervous system. Integration of thermal stimulation from the skin and body core within the thermoregulatory system is suggested as the possible source of this convergence. PMID:17558924

  15. Dielectrical Properties of CeO2 Nanoparticles at Different Temperatures

    PubMed Central

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

    2015-01-01

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

  16. 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

  17. A comparison of different methods of temperature measurements in sick newborns.

    PubMed

    Uslu, Sinan; Ozdemir, Hamus; Bulbul, Ali; Comert, Serdar; Bolat, Fatih; Can, Emrah; Nuhoglu, Asiye

    2011-12-01

    We aimed to compare the accuracy of digital axillary thermometer (DAT), rectal glass mercury thermometer (RGMT), infrared tympanic thermometer (ITT) and infrared forehead skin thermometer (IFST) measurements with traditional axillary glass mercury thermometer (AGMT) for intermittent temperature measurement in sick newborns. A prospective, descriptive and comparative study in which five different types of thermometer readings were performed sequentially for 3 days. A total of 1989 measurements were collected from 663 newborns. DAT and ITT measurements correlated most closely to AGMT (r = 0.94). The correlation coefficent for IFST and RGMT were 0.74 and 0.87, respectively. The mean differences for DAT, ITT, RGMT and IFST were +0.02C, +0.03C, +0.25C and +0.55C, respectively. There were not any clinical differences (defined as a mean difference of 0.2C) between both mean AGMT&DAT and AGMT&ITT measurements. Our study suggests that tympanic thermometer measurement could be used as an acceptable and practical method for sick newborn in neonatal units. PMID:21245075

  18. 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.

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

    PubMed Central

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

    2012-01-01

    Anaerobic oxidation of methane (AOM) was investigated in hydrothermal sediments of Guaymas Basin based on ?13C signatures of CH4, dissolved inorganic carbon and porewater concentration profiles of CH4 and sulfate. Cool, warm and hot in-situ temperature regimes (1520?C, 3035?C and 7095?C) were selected from hydrothermal locations in Guaymas Basin to compare AOM geochemistry and 16S ribosomal RNA (rRNA), mcrA and dsrAB genes of the microbial communities. 16S rRNA gene clone libraries from the cool and hot AOM cores yielded similar archaeal types such as Miscellaneous Crenarchaeotal Group, Thermoproteales and anaerobic methane-oxidizing archaea (ANME)-1; some of the ANME-1 archaea formed a separate 16S rRNA lineage that at present seems to be limited to Guaymas Basin. Congruent results were obtained by mcrA gene analysis. The warm AOM core, chemically distinct by lower porewater sulfide concentrations, hosted a different archaeal community dominated by the two deep subsurface archaeal lineages Marine Benthic Group D and Marine Benthic Group B, and by members of the Methanosarcinales including ANME-2 archaea. This distinct composition of the methane-cycling archaeal community in the warm AOM core was confirmed by mcrA gene analysis. Functional genes of sulfate-reducing bacteria and archaea, dsrAB, showed more overlap between all cores, regardless of the core temperature. 16S rRNA gene clone libraries with Euryarchaeota-specific primers detected members of the Archaeoglobus clade in the cool and hot cores. A V6-tag high-throughput sequencing survey generally supported the clone library results while providing high-resolution detail on archaeal and bacterial community structure. These results indicate that AOM and the responsible archaeal communities persist over a wide temperature range. PMID:22094346

  20. 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

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

    PubMed

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

    2012-08-01

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

  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. 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

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

    PubMed

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

    2015-01-01

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

  5. Rarefied Gas Flows Induced through a Pair of Parallel Meshes with Different Temperatures

    NASA Astrophysics Data System (ADS)

    Sugimoto, H.; Kawakami, S.; Moriuchi, K.

    2008-12-01

    A simple method to form micro-channels that induce a rarefied gas flow by the effect of the temperature field is proposed. A pair of parallel wire meshes, one is heated and the other is unheated, induces a gas flow through the pair of meshes in the direction from unheated mesh to heated mesh. Three test devices with different diameters, 1 mm, 100 ?m, and 25 ?m, of the wire of the mesh, have been devised and the flow through the device is detected by a thin film or a small windmill for various pressures of the gas. The flow is observed in a range of the pressure where the mean free path of gas molecules is close to the scale of the mesh structure, e.g., the diameter of the wire. It is extended to a wider range of the pressure in the device using combined meshes consisting of coarser and finer mesh.

  6. Determination of spectrum and different temperature of spontaneous chemiluminescence in rice seeds during early imbibition

    NASA Astrophysics Data System (ADS)

    Chen, WenLi; Xing, Da; Van Wijk, Roeland

    2005-02-01

    With high-sensitivity single-photon counter, spontaneous chemiluminescence (CL) spectrum and different temperature study on rice (Oryza sativa L.) seeds during early imbibition were carried out. The emission spectrum of whole rice seed, rice and coat had a greater proportion of red light during early imbibition. Comparing with spontaneous CL of barley (Hordeum vulgare L.) and soybean (Glycine max L. Merr) seeds, the spontaneous CL of rice seeds had a nonlinear, logarithmic-like increase of intensity in the T range 30-50C, the Van't Hoff coefficient Q10=IT+10/IT is equal to 2, which led us to the conclusion that spontaneous CL of rice seed during early imbibition partly came from enzyme catalyzing chemistry reaction.

  7. Effect of different extenders and storage temperatures on sperm viability of liquid ram semen.

    PubMed

    Paulenz, Heiko; Sderquist, Lennart; Prez-P, Rosaura; Berg, Kjell Andersen

    2002-01-15

    Semen was collected with an artificial vagina from four adult rams. The ejaculates were pooled and diluted, using a split-sample technique, in four different extenders: one for milk (Mi), one for sodium citrate (Na), and two for Tris-based extenders (T1 and T2) including egg yolk. Thereafter, the diluted semen was stored at 5 and 20 degrees C, respectively. We evaluated sperm viability after 0, 6, 12, 24 and 30 h of storage. We assessed sperm motility subjectively, and we determined sperm membrane integrity using both the hypo-osmotic resistance test (ORT) and a fluorophore staining (SYBR-14 and propidium iodide) technique. We evaluated acrosomal status with Spermac and capacitation status with Chlortetracycline (CTC assay). All sperm viability parameters were influenced by storage time and extender, while sperm motility was the only evaluated parameter that was influenced by the interaction between extender and temperature. Semen that was diluted and stored in the commercially available Tris-based extender (T2) maintained sperm motility for a longer period of time, and acrosome and membrane integrity was higher during storage for up to 30 h as compared to the other extenders independent of storage temperature. In general, however, storage of ram semen at 5 degrees C seemed to influence sperm viability parameters less than storage at 20 degrees C. In conclusion, the results of the present study indicate that Tris-based extenders, especially T2, preserved sperm viability better than both the sodium citrate- and the milk-based extender did when liquid ram semen was stored up to 30 h at 5 and 20 degrees C. Whether the differences found between the extenders will be reflected in the fertility results after AI is yet unknown and needs to be further studied. PMID:11991386

  8. 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.

  9. The interrelationship between air temperature and humidity as applied locally to the skin: The resultant response on skin temperature and blood flow with age differences

    PubMed Central

    Petrofsky, Jerrold S.; Berk, Lee; Alshammari, Faris; Lee, Haneul; Hamdan, Adel; Yim, Jong Eun; Kodawala, Yusufi; Patel, Dennis; Nevgi, Bhakti; Shetye, Gauri; Moniz, Harold; Chen, Wei Ti; Alshaharani, Mastour; Pathak, Kunal; Neupane, Sushma; Somanaboina, Karunakar; Shenoy, Samruddha; Cho, Sungwan; Dave, Bargav; Desai, Rajavi; Malthane, Swapnil; Al-Nakhli, Hani

    2012-01-01

    Summary Background Most studies of the skin and how it responds to local heat have been conducted with either water, thermodes, or dry heat packs. Very little has been accomplished to look at the interaction between air humidity and temperature on skin temperature and blood flow. With variable air temperatures and humiditys around the world, this, in many ways, is a more realistic assessment of environmental impact than previous water bath studies. Material/Methods Eight young and 8 older subjects were examined in an extensive series of experiments where on different days, air temperature was 38, 40, or 42C. and at each temperature, humidity was either 0%, 25%, 50%, 75%, or 100% humidity. Over a 20 minute period of exposure, the response of the skin in terms of its temperature and blood flow was assessed. Results For both younger and older subjects, for air temperatures of 38 and 40C., the humidity of the air had no effect on the blood flow response of the skin, while skin temperature at the highest humidity was elevated slightly. However, for air temperatures of 42C., at 100% humidity, there was a significant elevation in skin blood flow and skin temperature above the other four air humiditys (p<0.05). In older subjects, the blood flow response was less and the skin temperature was much higher than younger individuals for air at 42C. and 100% humidity (p<0.05). Conclusions Thus, in older subjects, warm humid air caused a greater rise in skin temperature with less protective effect of blood flow to protect the skin from overheating than is found in younger subjects. PMID:22460091

  10. 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.

  11. Changes in the Chemical Characteristics of Gulbi, Salted and Dried Yellow Corvenia, During Drying at Different Temperatures

    Microsoft Academic Search

    Hyun-Jung Gwak; Jong-Bang Eun

    2010-01-01

    A few chemical characteristics of Gulbi, a traditional Korean seafood prepared from salted and dried Yellow corvenia (Pseudosciaena manchurica), were investigated during drying at different temperatures. When Gulbi was manufactured by sun-drying (the control), it had the highest thiobarbituric acid reactive substances (TBARS) and volatile basic nitrogen (VBN) values. They increased with increasing drying time at all temperatures in the

  12. Phosphorus supplying capacity of heavily fertilized soils II. Dry matter yield of successive crops and phosphorus uptake at different temperatures

    Microsoft Academic Search

    B. R. Singh; V. Subramaniam

    1996-01-01

    Nine heavily fertilized soils were collected from southern and central Norway. A greenhouse experiment in the phytotron was conducted to evaluate the P supplying capacities of these soils at different temperatures (9, 12 and 18 C). The crops were grown in succession and the sequence was oat, rye grass (cut twice), oat, rape and oat. Effect of temperature on dry

  13. Seasonal differences in intraseasonal and interannual variability of Mediterranean Sea surface temperature

    NASA Astrophysics Data System (ADS)

    Zveryaev, Igor I.

    2015-04-01

    Sea surface temperature (SST) data from the NOAA OI SST data set for 1982-2011 are used to investigate intraseasonal and interannual variability of Mediterranean SST during winter and summer seasons. It is shown that during winter the intraseasonal SST fluctuations are larger than the interannual SST variations in the western Mediterranean (e.g., the Tyrrhenian Sea), but smaller in the central and eastern Mediterranean Sea. In summer, the intraseasonal SST fluctuations are larger in almost the entire Mediterranean basin. Also summertime intraseasonal SST fluctuations are larger (up to three times near the Gulf of Lions) than their wintertime counterparts in the entire Mediterranean basin. The interannual SST variations are larger during summer in the western and central Mediterranean Sea and during winter in its eastern part. The leading empirical orthogonal functions (EOFs) of the Mediterranean SST and of the intensities of its intraseasonal fluctuations are characterized by the differing spatial-temporal structures both during winter and summer implying that their interannual variability is driven by different physical mechanisms. During winter, the EOF-1 of SST is associated with the East Atlantic teleconnection, whereas EOF-1 of the intensity of intraseasonal fluctuations is not linked significantly to regional atmospheric dynamics. The second EOFs of these variables are associated, respectively, with the East Atlantic/West Russia and the North Atlantic teleconnections. While during summer the atmospheric influence on Mediterranean SST is generally weaker, it is revealed that the EOF-1 of the intensity of intraseasonal SST fluctuations is linked to the Polar teleconnection.

  14. 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.

  15. DOES PIGMENT COMPOSITION REFLECT PHYTOPLANKTON COMMUNITY STRUCTURE IN DIFFERING TEMPERATURE AND LIGHT CONDITIONS IN A DEEP ALPINE LAKE? AN

    E-print Network

    Teubner, Katrin

    DOES PIGMENT COMPOSITION REFLECT PHYTOPLANKTON COMMUNITY STRUCTURE IN DIFFERING TEMPERATURE / CHEMTAX pigment analyses were used to investigate seasonal and depth distributions of phytoplankton relationships with both approaches. Community structure derived from pigment ratios of homo- genous samples

  16. Differential sorption behaviour of aromatic hydrocarbons on charcoals prepared at different temperatures from grass and wood.

    PubMed

    Bornemann, Ludger C; Kookana, Rai S; Welp, Gerhard

    2007-03-01

    Naturally occurring charcoals are increasingly being recognized as effective sorbents for organic compounds. In this study we investigated the sorption of benzene and toluene in single-sorbate and bi-sorbate systems on different types of charcoals produced in laboratory, employing the batch sorption technique. Air dried plant materials from Phalaris grass (Phalaris tuberosa) and Red Gum wood (Eucalyptus camadulensis) were combusted under limited oxygen supply at 250 degrees C, 450 degrees C, and 850 degrees C. The resulting charcoals were characterized for their specific surface areas, total cation content, and pore size distributions (pore size distribution only for wood combusted at 450 degrees C and 850 degrees C). For the materials treated at 850 degrees C not only the surface area, microporosity, and total amount of sorbed sorbate increased markedly, but also the non-linearity of the sorption isotherm. The pore size distributions and surface areas as well as an indifferent sorption behaviour and competition effects for both sorbates indicated that pore filling mechanisms were the dominating processes governing the sorption on these microporous, high temperature treated materials. For the materials treated at lower temperatures the affinity of toluene was higher compared to that of benzene. In the bi-sorbate system the overall uptake of benzene increased. These phenomena might be due to the stronger hydrophobicity of toluene, and to a varying potential for swelling of the matrix and pore deformation by the two sorbates. The significantly lower sorption capacity of the Phalaris-derived material compared to the Red Gum charcoal correlated with its smaller surface area and higher cation content. PMID:17157349

  17. 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.

  18. Role of temperature differences between surface and deep reservoirs in geyser dynamics: Insights from laboratory experiments

    NASA Astrophysics Data System (ADS)

    Munoz Saez, C.; Shteinberg, A.; Manga, M.

    2012-12-01

    Geysers are springs that produce episodic eruptions of steam, liquid water, and non-condensable gases. Their eruptions are smaller and more frequent than other eruptive processes (volcanic, or hydrothermal eruptions), providing a feasible natural laboratory to understand eruptive processes. Moreover, the fluid dynamics of geysers probe processes that operate in more inaccessible geothermal systems. We developed laboratory experiments to understand the role of the surface temperature on geyser dynamics. For the experimental model, we followed to model developed by Steinberg et al. (1982), which produced periodic eruptions. In this experimental model, eruptions are driven by the ascent of bubbles. The "explosive" ejection of fluid occurs when bubbles reach the surface of the conduit. The eruption of a bubble influences the nucleation on the next bubble through the pressure changes in the conduit. The experimental apparatus consists of a bottom reservoir and a vertical conduit that opens into an upper chamber that collects and returns liquid to the reservoir after the eruption. The reservoir was heated from below at a constant rate. The fluid used was Freon 113, which has a boiling point of 48C. Temperature in the upper part of the tube was varied between 0 to 20C. As we increase the temperature difference between the reservoir and the surface of the tube we find (1) that vapor contained in the upper part of bubble tends condense, impeding its ascent to the surface, (2) an increase the number of bubbles generated during the time between eruptions, (3) that the volume of vapor in the tube remain almost constant during the period between eruptions (4) an increase the frequency of eruptions, (5) an increase the escape speed of fluid from the tube, and (6) an increase in Reynolds number. We interpret these results in terms of heat transport by the rising bubbles. Bubbles transport the heat as latent heat of evaporation. Because the amount of heating was the same in all cases, to transport the same amount of heat with bubbles that tend to condense in the upper conduit, they must be generated more rapidly and hence eruptions occur more frequently. Even though, natural eruptive systems are much more complex that these experiments, our model allows us to study the coupling between bubble nucleation, bubble growth and ascent, and surface eruption. Reference: Steinberg, G.S., Merzhanov, G.S., and Steinberg, A.S. (1982) Geyser process: Theory, modeling, and field experiments. Part 3.Theory of the geyser process, Modern Geology, 8, 67-70.

  19. 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

  20. Crystallographic structure and magnetic properties in L1(0) FePt thin films deposited at different temperature.

    PubMed

    Lu, Wei; He, Chenchong; Chen, Zhe; Wang, Yuxin; Yan, Biao

    2012-02-01

    The crystallographic structure and magnetic properties of L1(0) FePt thin films deposited at different substrate temperature were investigated systematically in present paper. The ordered L1(0) FePt thin film was developed when substrate temperature is higher than 300 degrees C. The ordering parameter S, the degree of tetragonality c/a, and the epitaxial quality of the films, increase with increasing substrate temperature. The squareness and coercivity in the direction perpendicular to the film increase as the substrate temperature is increased and the perpendicular anisotropy is developed when the substrate temperature is higher than 300 degrees C. The magnetic anisotropy Ku increases with increasing substrate temperature and it might be concluded that the magnetic anisotropy of ordered L1(0) FePt thin films mainly stems from the magnetocrystalline origin and also possibly due to pair ordering mechanism. PMID:22629899

  1. Changes in Temperature Sensitivity and Activation Energy of Soil Organic Matter Decomposition in Different Qinghai-Tibet Plateau Grasslands

    PubMed Central

    Li, Jie; He, Nianpeng; Wei, Xuehong; Gao, Yang; Zuo, Yao

    2015-01-01

    Qinghai-Tibet Plateau grasslands are unique geographical regions and store substantial soil organic matter (SOM) in the soil surface, which make them very sensitive to global climate change. Here, we focused on three main grassland types (alpine meadow, steppe, and desert) and conducted a soil incubation experiment at five different temperatures (5, 10, 15, 20, and 25C) to investigate SOM decomposition rates (R), temperature sensitivity (Q10), and activation energy (Ea). The results showed that grassland type and incubation temperature had significant impact on R (P < 0.001), and the values of R were exponential correlated with incubation temperature in three alpine grasslands. At the same temperature, R was in the following order: alpine meadow > alpinesteppe > alpine desert. The Q10 values differed significantly among different grasslands, and the overall trends were as follows: alpine meadow (1.56 0.09) < alpine steppe (1.88 0.23) < alpine desert (2.39 0.32). Moreover, the Ea values differed significantly across different grassland types (P < 0.001) and increased with increasing incubation time. The exponential negative correlations between Ea and R at 20C across all grassland types (all Ps < 0.001) indicated that the substrate-quality temperature hypothesis is applicable to the alpine grasslands. Our findings provide new insights for understanding the responses of SOM decomposition and storage to warming scenarios in this Plateau. PMID:26176705

  2. Fault current limiter based on high temperature superconductors - different concepts, test results, simulations, applications

    NASA Astrophysics Data System (ADS)

    Paul, W.; Chen, M.; Lakner, M.; Rhyner, J.; Braun, D.; Lanz, W.

    2001-05-01

    All electric equipment in a power system has to be designed to withstand the mechanical and thermal stresses of potential short-circuit currents. Any reduction of these currents can lead to significant cost savings. Among all current limiting devices, superconducting fault current limiters (SCFCL) offer ideal performance: in normal operation the SCFCL is in its superconducting state and has negligible impedance, in the event of a fault, the transition into the normal conducting state passively limits the current. Different high temperature superconductors (HTS) materials, like YBCO films, Bi2223 wires or Bi2212 bulk are under development for the use in SCFCL. Due to the brittle nature of HTS and the hot-spot problem, most HTS components for current limitation are composites comprising the HTS, a mechanical substrate or support, and an electrical bypass. The performance of the composites largely depend on the parameters: critical current density, I- V characteristics, thermal conductivity, thermal mass, and electrical bypass. Mainly two different concepts of SCFCL, namely, the resistive and the shielded core concept have been pursued in the past. In 1996 the first ever SCFCL was installed in a hydro-power plant. The device had a rated power of 1.2 MVA, it was of the shielded core type and was based on tubes of Bi2212-bulk material. The feasibility of the technology has been demonstrated in a one-year-endurance test. Recently more compact resistive SCFCLs based on the same Bi2212-bulk material have been developed. Theoretical models for the SCFCL show good agreement with experimental data. They are used to study the influence of SCFCLs in power systems in order to evaluate technical and economical advantages.

  3. 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.

  4. Difference in the relative intensities Raman of the perovskite PLT with temperature

    NASA Astrophysics Data System (ADS)

    Joya, M. R.; Fonseca, K. M.; Barba-Ortega, J.

    2014-11-01

    La-modified PbTiO3 -based ceramics (PLT) are the subject of many studies. The experimental measurement and the theoretical calculation of Raman scattering intensities present a number of challenges. In the treatment of experimental data, anharmonic force fields permit the calculation of combination and overtone intensities as well as the resolution of anharmonic resonances. Vibrational intensities provide information about the molecular charge distribution and its change during a vibration. On most cases Raman scattering is sensitive to the degree of crystallinity in a sample. Typically a crystalline material yields a spectrum with very sharp, intense Raman peaks, whilst an amorphous material will show broader less intense Raman peaks. Intensity reproducibility is not a trivial matter. Furthermore, properties of the sample such as optical transparency and homogeneity can affect observed intensity, even when the overall sample composition is fixed. A corrected spectrum showing relative peak areas (and therefore relative cross-sections) may be sufficient for sample identification. In this paper we make a comparison of the Raman intensities relative to the PLT compound for different temperatures.

  5. The role of Coulomb collisions in limiting differential flow and temperature differences in the solar wind

    NASA Technical Reports Server (NTRS)

    Neugebauer, M.

    1976-01-01

    Data obtained by OGO 5 are used to confirm IMP 6 observations of an inverse dependence of the helium-to-hydrogen temperature ratio in the solar wind on the ratio of solar-wind expansion time to the Coulomb-collision equipartition time. The analysis is then extended to determine the relation of the difference between the hydrogen and helium bulk velocities (the differential flow vector) with the ratio between the solar-wind expansion time and the time required for Coulomb collisions to slow down a beam of ions passing through a plasma. It is found that the magnitude of the differential flow vector varies inversely with the time ratio when the latter is small and approaches zero when it is large. These results are shown to suggest a model of continuous preferential heating and acceleration of helium (or cooling and deceleration of hydrogen), which is cancelled or limited by Coulomb collisions by the time the plasma has reached 1 AU. Since the average dependence of the differential flow vector on the time ratio cannot explain all the systematic variations of the vector observed in corotating high-velocity streams, it is concluded that additional helium acceleration probably occurs on the leading edge of such streams.

  6. 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.

  7. CO{sub 2}-gasification reactivity of different carbonaceous materials at elevated temperatures

    SciTech Connect

    Gu, J.; Wu, S.; Wu, Y.; Gao, J. [East China University of Science and Technology, Shanghai (China)

    2009-07-01

    At the atmospheric pressure and at the temperatures between 1,223 and 1,673 K, the CO{sub 2} gasification reactivity of seven different carbonaceous materials comprising coal tar pitch coke, petroleum coke, natural graphite, carbon black and three coal chars was investigated by using thermogravimetric analysis. Their crystalline structures were analyzed by X-ray diffraction (XRD). It is found that the reactivity of the chars, pitch coke and petroleum coke produced from liquid phase carbonization, is several times poorer than that of the coal chars produced from solid phase carbonization and even lower than that of natural graphite. At the same time, it is obtained that under the condition of the chemical reaction control, the apparent activation energies of the former are in the range of 135.82-174.92 kJ/mol, while those of the latter are between 89.95 kJ/mol and 110.05 kJ/mol. Besides, the reactivity of the sample has a certain correlation with the crystalline structure of the sample, i.e., the larger the fraction of the relatively better crystalline structure is, the poorer the reactivity of the sample is.

  8. 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.

  9. 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.

  10. Differences between tomato genotypes in net photosynthesis and dark respiration under low light intensity and low night temperatures

    Microsoft Academic Search

    SIEBREN J. VAN DE DIJK; Janien A. Maris

    1985-01-01

    Net photosynthesis and dark respiration of sixteen selected tomato genotypes grown under low light intensity and low night temperatures were measured. Differences between genotypes in net photosynthesis and dark respiration were present. In all genotypes an increase of net photosynthesis with time was observed. Significant genotypic differences in this respect were established. The rate of dark respiration remained constant throughout

  11. 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

  12. 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

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

    PubMed

    Khanday, M A; Hussain, Fida

    2015-02-01

    During cold exposure, peripheral tissues undergo vasoconstriction to minimize heat loss to preserve the maintenance of a normal core temperature. However, vasoconstricted tissues exposed to cold temperatures are susceptible to freezing and frostbite-related tissue damage. Therefore, it is imperative to establish a mathematical model for the estimation of tissue necrosis due to cold stress. To this end, an explicit formula of finite difference method has been used to obtain the solution of Pennes' bio-heat equation with appropriate boundary conditions to estimate the temperature profiles of dermal and subdermal layers when exposed to severe cold temperatures. The discrete values of nodal temperature were calculated at the interfaces of skin and subcutaneous tissues with respect to the atmospheric temperatures of 25 C, 20 C, 15 C, 5 C, -5 C and -10 C. The results obtained were used to identify the scenarios under which various degrees of frostbite occur on the surface of skin as well as the dermal and subdermal areas. The explicit formula of finite difference method proposed in this model provides more accurate predictions as compared to other numerical methods. This model of predicting tissue temperatures provides researchers with a more accurate prediction of peripheral tissue temperature and, hence, the susceptibility to frostbite during severe cold exposure. PMID:25660630

  14. Effect of biochar produced at different pyrolysis temperature on the soil respiration of abandoned mine soil

    NASA Astrophysics Data System (ADS)

    Kim, Yong Seong; Kim, Juhee; Hwang, Wonjae; Hyun, Seunghun

    2015-04-01

    Contaminated soils near an abandoned mine site included the high acidic mine tailing have received great interest due to potential risk to human health, because leachable elements in low pH continuously release from mine site soil with ground water and precipitation event. Biochar, which is the obtained pyrolysis process of biomass, is used as a soil amendments and carbon storage. Especially, many researchers report that the biochar application to soil show increasing soil pH, CEC, adsorption capacity of various elements, as well as, enhanced microbial activity. Therefore, biochar application to contaminated soil near abandoned mine site is expected to have a positive effects on management of these site and soils through the decreased leachability of contaminants. However, effects of biochar application to these site on the soil respiration, as a common measure of soil health, are poorly understood. The objective of this study is to evaluate the effects of biochar application to abandoned mine site soil on the microbial activity with soil respiration test. Biochar was obtained from giant Miscanthus in a slow pyrolysis process (heating rate of 10 C min-1 and N2 gas flow rate of 1.2 L min-1) at the temperature of 400 C (BC4) and 700 C (BC7), respectively. All biochar samples were prepared with grinding and sieving for particle size control (150~500?m). Soil sample was collected from abandoned mine site at Korea (36 58'N, 128 10'E). Main contaminants of this soil were As (12.5 g kg-1), Pb (7.3 g kg-1), and Zn (1.1 g kg-1). Biochars were applied (5% by dry weight) to the soil (final mixture weight were 800g), and then moisture contents were adjusted to 100% field capacity (-0.33 bar) in the respirometer with vacuum pump. CO2 efflux of each samples was continuously assessed using continuous aeration system (air flow rate 25 cc min-1) using air cylinder during 130hr (at 20 C and darkness condition). The CO2 emitted from the samples were carried to the infrared gas sensor, and these data were sent to a data logger. During the measuring periods, the cumulative CO2 emission were similar between the control (516.8 mg-CO2 kg-1-soil) and BC4 5% mixture (519.3 mg-CO2 kg-1-soil), while BC7 5% mixture was significantly decreased (356.1 mg-CO2 kg-1-soil) compared to other treatment and control. Because the degradation rate of biochar generally increased with decreasing pyrolysis temperature, this result suggest that the soil respiration rates of biochar amended soils are affected by physico-chemical properties of biochar during early incubation periods (about 1 weeks), For example, surface properties of used biochars, which are related to adsorption of soil organic matter and CO2, have different properties with pyrolysis temperature such as specific surface area (BC4=5.08 m2g-1; BC7=260.75 m2 g-1, respectively), average pore diameter (BC4=4,673 nm; BC7=2,606 nm, respectively), and functional groups of biochar surface. However, there was not clear evidence of biochar-mine soil interaction process, because of the short observation periods. Future work should focus on the adsorption of CO2 and soil organic matter of biochar and soil-biochar interaction with long time periods and various biological test.

  15. Critical Temperature Differences of a Standing Wave Thermoacoustic Prime Mover with Various Helium-Based Binary Mixture Working Gases

    NASA Astrophysics Data System (ADS)

    Setiawan, Ikhsan; Nohtomi, Makoto; Katsuta, Masafumi

    2015-06-01

    Thermoacoustic prime movers are energy conversion devices which convert thermal energy into acoustic work. The devices are environmentally friendly because they do not produce any exhaust gases. In addition, they can utilize clean energy such as solar-thermal energy or waste heat from internal combustion engines as the heat sources. The output mechanical work of thermoacoustic prime movers are usually used to drive a thermoacoustic refrigerator or to generate electricity. A thermoacoustic prime mover with low critical temperature difference is desired when we intend to utilize low quality of heat sources such as waste heat and sun light. The critical temperature difference can be significantly influenced by the kinds of working gases inside the resonator and stack's channels of the device. Generally, helium gas is preferred as the working gas due to its high sound speed which together with high mean pressure will yield high acoustic power per unit volume of the device. Moreover, adding a small amount of a heavy gas to helium gas may improve the efficiency of thermoacoustic devices. This paper presents numerical study and estimation of the critical temperature differences of a standing wave thermoacoustic prime mover with various helium-based binary-mixture working gases. It is found that mixing helium (He) gas with other common gases, namely argon (Ar), nitrogen (N2), oxygen (O2), and carbon dioxide (CO2), at appropriate pressures and molar compositions, reduce the critical temperature differences to lower than those of the individual components of the gas mixtures. In addition, the optimum mole fractions of Hegas which give the minimum critical temperature differences are shifted to larger values as the pressure increases, and tends to be constant at around 0.7 when the pressure increases more than 2 MPa. However, the minimum critical temperature differences slightly increase as the pressure increases to higher than 1.5 MPa. Furthermore, we found that the lowest critical temperature difference for He-Armixture gas is around 66 C which is achieved in pressure range of 1.5 MPa - 2.0 MPa and mole fractions of helium of 0.55 - 0.65. The He-N2 and He-O2 mixture gases demonstrate almost the same performances, both have the lowest critical temperature difference around 59 C atpressures of 1.0 MPa - 1.5 MPa and helium's mole fractions of 0.35 - 0.55. For all tested gases, the lowest critical temperature difference of around 51 C is provided by He-CO2 mixture gas at pressures of 0.5 MPa - 1.0 MPa with helium's mole fractions of 0.15 - 0.40.

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

    Microsoft Academic Search

    THOMAS I. EDWARDS; RAYMOND PEARL; SOPHIA A. GOULD

    1934-01-01

    Papers on the temperature relations of seedlings grown in darkness at several constant temperatures may be classified according to the length of the growing period during which measurements were made. Sierp (18), Silberschmidt (19), and Hamada (7) measured the lengths of oat coleoptiles throughout the grand period of growth, obtaining much the same results, although it is to be noted

  17. Different approaches for increasing the shelf life of partially baked bread: Low temperatures and hydrocolloid addition

    Microsoft Academic Search

    Mara Eugenia Brcenas; Cristina M. Rosell

    2007-01-01

    Partially baked bread is a product with short shelf life that requires sub-zero temperatures for extending it. The storage of par-baked bread at low temperatures and the addition of bread improvers with antistaling effects, such as hydroxypropylmethylcellulose (HPMC), are very attractive alternatives for extending the shelf life of these products. In this study, staling during storage of partially baked bread

  18. Temperature Dependence of Protein Dynamics Simulated With Three Different Water Models

    SciTech Connect

    Glass, Dennis C [ORNL; Krishnan, marimuthu [International Institute of Information Technology, Hyderbad, India; Nutt, David [University of Heidelberg; Smith, Jeremy C [ORNL

    2010-04-01

    Protein and hydration shell dynamics was investigated as function of temperature and water model. Overall dynamics was invariant under the exchange of the water model (TIP3P, TIP4P, TIP5P) for the investigated temperatures (20-300 K). The data provides evidence that changing the water model in protein simulations may be possible without loss of accuracy

  19. 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

  20. Solubility of cyclooctasulfur in pure water and sea water at different temperatures

    Microsoft Academic Search

    A. Kamyshny Jr.

    2009-01-01

    The solubility of cyclooctasulfur in water and sea water at various temperatures in the range between 4 and 80C was determined. Cyclooctasulfur in equilibrium with rhombic sulfur reacted with hot acidic aqueous potassium cyanide to form thiocyanate anion which was measured by anion chromatography. Sulfur solubility in pure water was found to increase with temperature by more than 78 times:

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

    PubMed Central

    Luoto, Tomi P.; Nevalainen, Liisa

    2013-01-01

    Long-term water temperature records are necessary for better understanding climate change impacts on freshwaters. We reconstruct summer water temperatures from three climatically sensitive mountain lakes in Austria using paleolimnological methods aiming to examine long-term thermal dynamics and lakes' responses to regional climate variability since the Little Ice Age. Our results indicate divergent trends for the lakes. In two of the lakes, which are located at the sunny southern slope of mountains, water temperature has increased several degrees concurrent with the observed air temperature increase. In contrast, no change is observed in the reconstructed water temperatures of a shaded lake, located at the northern slope, where also the ecological and thermal changes are most subtle. The results indicate the importance of cold water inputs, such as snowmelt and groundwater, on lakes' thermal conditions and suggest that watershed characteristics and lake stratification play a major role in defining the lake-specific thermal regime. PMID:23965988

  2. Fungal communities associated with the biodegradation of polyester polyurethane buried under compost at different temperatures.

    PubMed

    Zafar, Urooj; Houlden, Ashley; Robson, Geoffrey D

    2013-12-01

    Plastics play an essential role in the modern world due to their low cost and durability. However, accumulation of plastic waste in the environment causes wide-scale pollution with long-lasting effects, making plastic waste management expensive and problematic. Polyurethanes (PUs) are heteropolymers that made up ca. 7% of the total plastic production in Europe in 2011. Polyester PUs in particular have been extensively reported as susceptible to microbial biodegradation in the environment, particularly by fungi. In this study, we investigated the impact of composting on PUs, as composting is a microbially rich process that is increasingly being used for the processing of green waste and food waste as an economically viable alternative to landfill disposal. PU coupons were incubated for 12 weeks in fresh compost at 25C, 45C, and 50C to emulate the thermophilic and maturation stages of the composting process. Incubation at all temperatures caused significant physical deterioration of the polyester PU coupons and was associated with extensive fungal colonization. Terminal restriction fragment length polymorphism (TRFLP) analysis and pyrosequencing of the fungal communities on the PU surface and in the surrounding compost revealed that the population on the surface of PU was different from the surrounding compost community, suggesting enrichment and selection. The most dominant fungi identified from the surfaces of PU coupons by pyrosequencing was Fusarium solani at 25C, while at both 45C and 50C, Candida ethanolica was the dominant species. The results of this preliminary study suggest that the composting process has the potential to biodegrade PU waste if optimized further in the future. PMID:24056469

  3. 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.

  4. Development of a Novel Low Temperature Co-Fired Ceramics System Composed of Two Different Co-Firable Low Temperature Co-Fired Ceramics Materials

    NASA Astrophysics Data System (ADS)

    Murata, Takaki; Ohga, Satoshi; Sugimoto, Yasutaka

    2006-09-01

    Two co-firable low temperature co-fired ceramics (LTCC) materials with different permittivities were investigated. The first material has low-K and high stiffness, and the second material has high-K, high-Q, and near zero temperature coefficient of capacitance (TCC). A resistor material, which is mainly composed of RuO2 and glass, is able to be buried into the LTCC substrate. To adjust the properties to the electric circuits, laser trimming of the embedded capacitors and resistors was performed. The constrained sintering method was applied to the substrate, and the dimension accuracy of the substrate is excellent.

  5. Difference in effect of temperature on absorption and Raman spectra between all-trans-?-carotene and all-trans-retinol

    NASA Astrophysics Data System (ADS)

    Qu, Guan-Nan; Li, Shuo; Sun, Cheng-Lin; Liu, Tian-Yuan; Wu, Yong-Ling; Sun, Shang; Shan, Xiao-Ning; Men, Zhi-Wei; Chen, Wei; Li, Zuo-Wei; Gao, Shu-Qin

    2012-12-01

    Temperature dependencies (81 C-18 C) ofvisible absorption and Raman spectra of all-trans-?-carotene and all-trans-retinol extremely diluted in dimethyl sulfoxide are investigated in order to clarify temperature effects on different polyenes. Their absorption spectra are identified to be redshifted with temperature decreasing. Moreover, all-trans-?-carotene is more sensitive to temperature due to the presence of a longer length of conjugated system. The characteristic energy responsible for the conformational changes in all-trans-?-carotene is smaller than that in all-trans-retinol. Both of the Raman scattering cross sections increase with temperature decreasing. The results are explained with electronphonon coupling theory and coherent weakly damped electronlattice vibrations model.

  6. 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.

  7. Control of pore channel size during freeze casting of porous YSZ ceramics with unidirectionally aligned channels using different freezing temperatures

    Microsoft Academic Search

    Liangfa Hu; Chang-An Wang; Yong Huang; Chencheng Sun; Sheng Lu; Zijun Hu

    2010-01-01

    Porous yttria-stabilized zirconia (YSZ) ceramics with unidirectionally aligned pore channels were prepared by freezing YSZ\\/tert-butyl alcohol (TBA) slurry under different freezing temperatures of ?30, ?78 and ?196C, respectively. After removing the frozen TBA via freeze-drying in vacuum at ?50C, the green samples were sintered at 1450C for 2h in air. The results showed that the freezing temperature significantly influenced microstructure

  8. Use of palm mid-fraction in dark chocolate as base filling centre at different storage temperatures.

    PubMed

    Jinap, S; Ali, A A; Man, Y B; Suria, A M

    2000-11-01

    Dark chocolates filled with palm mid-fraction (PMF) were stored at different temperatures to evaluate the physical and chemical changes. Storage at low temperature (18 degrees C) reduces the PMF migration to negligible extent. Higher storage temperatures (30 and 35 degrees C) increased the PMF migration from the filling centre into the chocolate coating. As a consequence of fat migration, fatty acid composition, triglyceride composition, hardness, solid fat content, melting point and polymorphic structure changed, leading to bloom formation, which started by fat migration and was influenced by recrystallization tendency within the chocolate coating. PMID:11271851

  9. 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

  10. Numerical study of active control of mixing in electro-osmotic flows by temperature difference using lattice Boltzmann methods.

    PubMed

    Alizadeh, A; Wang, J K; Pooyan, S; Mirbozorgi, S A; Wang, M

    2013-10-01

    In this paper, the effect of temperature difference between inlet flow and walls on the electro-osmotic flow through a two-dimensional microchannel is investigated. The main objective is to study the effect of temperature variations on the distribution of ions and consequently internal electric potential field, electric body force, and velocity fields in an electro-osmotic flow. We assume constant temperature and zeta potential on walls and use the mean temperature of each cross section to characterize the Boltzmann ion distribution across the channel. Based on these assumptions, the multiphysical transports are still able to be described by the classical Poisson-Boltzmann model. In this work, the Navier-Stokes equation for fluid flow, the Poisson-Boltzmann equation for ion distribution, and the energy equation for heat transfer are solved by a couple lattice Boltzmann method. The modeling results indicate that the temperature difference between walls and the inlet solution may lead to two symmetrical vortices at the entrance region of the microchannel which is appropriate for mixing enhancements. The advantage of this phenomenon for active control of mixing in electro-osmotic flow is the manageability of the vortex scale without extra efforts. For instance, the effective domain of this pattern could broaden by the following modulations: decreasing the external electric potential field, decreasing the electric double layer thickness, or increasing the temperature difference between inlet flow and walls. This work may provide a novel strategy for design or optimization of microsystems. PMID:23859813

  11. 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.

  12. Estimation of Solar Radiation from Measured Temperatures at Different Time Scales in Chongqing

    Microsoft Academic Search

    Mao-Fen Li; Hong-Bin Liu; Peng-Tao Guo; Wei Wu

    2010-01-01

    Solar radiation (Rs), a critical variable in eco-environmental models, is not measured at many meteorological stations. Prediction of Rs has drawn increasing attention in the recent years. The aim of the present research was to conduct a comparative study of estimating Rs from measured maximum and minimum temperature and dew point temperature at daily, five-day, ten-day, monthly time scales. Coefficient

  13. Performance of superconducting nanowire single photon detection system with different temperature variation

    Microsoft Academic Search

    X. F. Shen; L. X. You; S. J. Chen; X. Y. Yang; L. M. Qiu

    2010-01-01

    The performance of cryocooler-based superconducting single photon detection system suffers from the intrinsic temperature oscillation, which is typically ?300mK around 4.2K originated from the periodic expansion of the cryocoolers working fluid (He). By using a rare-earth alloy (ErNi) plate with a high heat capacity at cryogenic temperatures in between the cold head of the cryocooler and the detector block, the

  14. 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

  15. Breakdown characteristics of RTO 10 nm SiO2 films grown at different temperatures

    Microsoft Academic Search

    L. Fonseca; F. Campabadal

    1994-01-01

    Metal-oxide-semiconductor capacitors with 10 nm gate oxides grown by rapid thermal oxidation at temperatures of 1000, 1100 and 1150C have been electrically characterized by means of C-V techniques, time-zero and time-dependent breakdown experiments. The oxides grown at higher temperatures show superior interfacial and oxide integrity characteristics, which is consistent with a lower level of intrinsic stress in such layers. The

  16. 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

  17. 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.

  18. 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

  19. Cation-cation interactions between NpO2(+) and UO2(2+) at different temperatures and ionic strengths.

    PubMed

    Xian, Liang; Tian, Guoxin; Zheng, Weifang; Rao, Linfeng

    2012-07-28

    Cation-cation interactions between NpO(2)(+) and UO(2)(2+) were studied at different temperatures (283.15 K to 358.15 K) and different ionic strengths (3-4.5 mol dm(-3)) by spectrophotometry and microcalorimetry. The cation-cation complex between NpO(2)(+) and UO(2)(2+) was weak and became stronger as the temperature was increased from 283.15 K to 358.15 K. The molar enthalpy of complexation was directly determined for the first time by microcalorimetry to be (4.2 1.6) kJ mol(-1) at 298.15 K, in good agreement with the trend in the stability constant at different temperatures. The small and positive enthalpy and entropy of complexation support the argument that the cation-cation complex between NpO(2)(+) and UO(2)(2+) is of inner-sphere type. At each temperature, the stability constants of the cation-cation complex were found to increase as the ionic strength was increased. The specific ion interaction theory (SIT) was used to obtain the stability constants at infinite dilution and variable temperatures. PMID:22692197

  20. [Study on the vacuum ultraviolet transmittance of barium fluoride crystals at different temperature].

    PubMed

    Peng, Ru-Yi; Fu, Li-Ping; Tao, Ye

    2014-03-01

    Two VUV-grade BaF2 windows with 0.5 mm-thick and 1 mm-thick respectively were selected to study the transmittance variety with the temperature. The results show that the cutoff wavelength of BaF2 crystals will shift towards the long wave with the increase in temperature. In a certain temperature range, BaF2 crystals can depress 130.4 nm radiation well, and also has a high transmittance at 135.6 nm. Compared with the reported method in which SrF2 crystals can be applied to suppress 130.4 nm stray light by heating, BaF2 crystal can inhibit the 130. 4 nm emission line completely, and thus reduce the power consumption of the device at the same time. This indicates that BaF2 crystals can play an important role in the ionosphere optical remote sensing detection. PMID:25208398

  1. Environmental impact of submerged anaerobic MBR (SAnMBR) technology used to treat urban wastewater at different temperatures.

    PubMed

    Pretel, R; Robles, A; Ruano, M V; Seco, A; Ferrer, J

    2013-12-01

    The objective of this study was to assess the environmental impact of a submerged anaerobic MBR (SAnMBR) system in the treatment of urban wastewater at different temperatures: ambient temperature (20 and 33C), and a controlled temperature (33C). To this end, an overall energy balance (OEB) and life cycle assessment (LCA), both based on real process data, were carried out. Four factors were considered in this study: (1) energy consumption during wastewater treatment; (2) energy recovered from biogas capture; (3) potential recovery of nutrients from the final effluent; and (4) sludge disposal. The OEB and LCA showed SAnMBR to be a promising technology for treating urban wastewater at ambient temperature (OEB=0.19 kW h m(-3)). LCA results reinforce the importance of maximising the recovery of nutrients (environmental impact in eutrophication can be reduced up to 45%) and dissolved methane (positive environmental impact can be obtained) from SAnMBR effluent. PMID:24119499

  2. Temperature difference between the body core and arterial blood supplied to the brain during hyperthermia or hypothermia in humans.

    PubMed

    Bommadevara, Maithreyi; Zhu, Liang

    2002-10-01

    Avascular heat transfer model is developed to simulate temperature decay along the carotid arteries in humans, and thus, to evaluate temperature differences between the body core and arterial blood supplied to the brain. Included are several factors, including the local blood perfusion rate, blood vessel bifurcation in the neck, and blood vessel pairs on both sides of the neck. The potential for cooling blood in the carotid artery by countercurrent heat exchange with the jugular veins and by radial heat conduction to the neck surface was estimated. Cooling along the common and internal carotid arteries was calculated to be up to 0.87 degrees C during hyperthermia by high environmental temperatures or muscular exercise. This model was also used to evaluate the feasibility of lowering the brain temperature effectively by placing ice pads on the neck and head surface or by wearing cooling garments during hypothermia treatment for brain injury or other medical conditions. It was found that a 1.1 degrees C temperature drop along the carotid arteries is possible when the neck surface is cooled to 0 degrees C. Thus, the body core temperature may not be a good indication of the brain temperature during hyperthermia or hypothermia. PMID:14595546

  3. Uncovering different masking factors on wrist skin temperature rhythm in free-living subjects.

    PubMed

    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 (18-24 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

  4. 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

  5. Application of finite elementfinite difference method to the determination of transient temperature field in functionally graded materials

    Microsoft Academic Search

    Bao-Lin Wang; Zhen-Hui Tian

    2005-01-01

    A finite element\\/finite difference method (FEM\\/FDM) is developed to solve the time-dependent temperature field in non-homogeneous materials such as functionally graded materials. The method uses the finite element space discretization to obtain a first-order system of differential equations, which is solved by employing finite difference scheme to resolve the time-dependent response. A computation code is developed in the programming environment

  6. Gender-specific flowering responses to day length in the dioecious plant Silene latifolia at different temperatures

    Microsoft Academic Search

    Xianzhong Wang

    2007-01-01

    Silene latifolia Poiret is a reliable model system for studying many of the classical problems in biology because little difference in its\\u000a physiological response to environmental stimuli has been found between genders. In this experiment, we studied flowering responses\\u000a to day length in male and female S. latifolia plants grown at different temperatures. The primary objective was to examine whether

  7. 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

  8. 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.

  9. MERCURY ADSORPTION STOICHIOMETRY OF CERAMIC AND ACTIVATED CARBON FROM AQUEOUS PHASE UNDER DIFFERENT pH AND TEMPERATURE

    Microsoft Academic Search

    J. N. Bhakta; K. Yamasaki; Y. Munekage

    Experiment was performed to draw a mercury adsorption stoichiometry of ceramic and activated carbon from aqueous phase in two parts - first part dealt with the effect of three different pH - 4, 7 and 10, whereas second part was designed to determine the effect of three temperatures - 15, 25 and 35C. SEM-EDS analysis of adsorbents clearly showed highly

  10. Biofilm formation on polystyrene under different temperatures by antibiotic resistant Enterococcus faecalis and Enterococcus faecium isolated from food

    PubMed Central

    Marinho, A.R.; Martins, P.D.; Ditmer, E.M.; dAzevedo, P.A.; Frazzon, J.; Van Der Sand, S.T.; Frazzon, A.P.G.

    2013-01-01

    The ability of antibiotic resistant E. faecalis and E. faecium isolated from food to form biofilm at different temperatures in the absence or presence of 0.75% glucose was evaluated. A synergistic effect on biofilm at 10 C, 28 C, 37 C and 45 C and glucose was observed for E. faecalis and E. faecium. PMID:24294231

  11. 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...

  12. Summary The empirical calibration of Granier-type heat dissipation sap flow probes that relate temperature difference

    E-print Network

    Holbrook, N. Michele

    Summary The empirical calibration of Granier-type heat dissipation sap flow probes that relate temperature difference (T) to sap velocity (v) was reevaluated in stems of three tropical tree species. Analysis of the effects of nonuniform sap velocity profiles on heat dissipa- tion estimates showed

  13. 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.

  14. 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...

  15. 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.

  16. Optimization of low temperature solar thermal electric generation with Organic Rankine Cycle in different areas

    Microsoft Academic Search

    Li Jing; Pei Gang; Ji Jie

    2010-01-01

    The presented low temperature solar thermal electric generation system mainly consists of compound parabolic concentrators (CPC) and the Organic Rankine Cycle (ORC) working with HCFC-123. A novel design is proposed to reduce heat transfer irreversibility between conduction oil and HCFC-123 in the heat exchangers while maintaining the stability of electricity output. Mathematical formulations are developed to study the heat transfer

  17. Growth of Salmonella and Listeria monocytogenes on fresh-cut cantaloupe under different temperature abuse scenarios

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effective cold chain management is a critical component of food safety practice. In this study, we examined the impact of commonly encountered temperature abuse scenarios on the proliferation of Salmonela enterica and Listeria monocytogenes on fresh-cut cantaloupe. During one week of storage, Salmon...

  18. 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...

  19. DIFFERENCES IN THE TEMPERATURE QUOTIENTS OF AMMONIA EMISSION ON THE FERTILIZED SOILS FROM FLORIDA AND WASHINGTON

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperature is a very important factor for ammonia emission but not well understood yet. This research was conducted with Biscayne Marl Soil and Krome Gravelly Loam from Florida and Quincy Fine Sand and Warden Silt Loam from Washington. The soils were weighed (300 g dry weight) and placed in a 500 m...

  20. Increased Eurasian-tropical temperature amplitude difference in recent centuries: Implications for the Asian monsoon

    E-print Network

    for the Asian monsoon Rosanne D'Arrigo,1 Rob Wilson,1,2 and Jinbao Li1 Received 9 July 2006; revised 26 this interval, and with other temperature and precipitation- sensitive proxies from the Asian monsoon regime contributed to an intensified Asian monsoon system over recent centuries, and to a decoupling of the monsoon

  1. 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...

  2. 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...

  3. 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...

  4. CHARACTERIZATION OF DESIGNER BIOCHAR PRODUCED AT DIFFERENT TEMPERATURES AND THEIR EFFECTS ON A LOAMY SAND

    Microsoft Academic Search

    Jeffrey M. Novak; Isabel Lima; C NMR

    Biochar additions to degraded soils have the potential to improve crop yield and soil quality. We hypo- thesize that the biochar production process can be tailored to form designer biochars that have specific chemical characteristics matched to selective chemical and\\/or physical issues of a degraded soil. We produced biochars from peanut hulls, pecan shells, poultry litter, and switchgrass at temperatures

  5. Study of TEOS and TPOS anticorrosion coatings developed at different ranges of pyrolysis temperatures

    NASA Astrophysics Data System (ADS)

    Hashem, Khaled M. E.

    2003-07-01

    Anticorrosion coatings were produced by spraying pure simple silane compounds, either tetraethoxysilane (TEOS) or tetraphenoxysilane (TPOS), in a preheated furnace on specimens of carbon steel alloy. These specimens were thermally decomposed over various temperature ranges, covering a total temperature range of 20-1050 C. This temperature range was divided into four sectors. The specific functions of each of these sectors were described as: hydrolysis (20-50 C), low pyrolysis (50-250 C), middle pyrolysis (250-750 C), and high pyrolysis (750-1050 C). SEM, ultrasonic vibration (USV), plane-cross polarized microscope, micro-hardness tester, XRD, and cyclic voltammography were utilized for analysis of the produced coatings. A comparison study between the anticorrosion coatings produced using TEOS or TPOS was targeted to evaluate two aspects. The first was the microstructure morphologies and corresponding variations of the chemical constituents and textural surfaces of the TEOS and TPOS coating materials at the selected pyrolysis temperature ranges. The second was the property of the TEOS and TPOS anticorrosion coating materials producing minimal decay for electrochemical protection of carbon steel alloy against corrosion under low and high acidic conditions.

  6. HPLC profiles of mutagens in lean ground pork fried at different temperatures

    Microsoft Academic Search

    Preben Aagaard Nielsen; Martin Vahl; Jrn Gry

    1988-01-01

    Zusammenfassung Gehacktes, mageres Schweinefleisch wurde zu runden Scheiben (2 cm 7 cm, 83 g) geformt und unter Haushaltsbedingungen gebraten, ohne Zusatz von Fett und ohne die Kruste zu verbrennen. Die Bratversuche wurden mit Pfannentemperaturen von 200, 250 oder 300 C durchgefhrt, bis das Innere der Fleischscheiben eine Temperatur von 65 oder 70 C erreicht hatte. Die Kruste wurde mit

  7. Small differences in temperature interact with solar radiation to alter anthocyanin in grapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite a century of research, we still lack a concrete, mechanistic understanding of solar radiation and temperature effects on anthocyanin accumulation and composition, crucial for red wine grapes. Our aim was to elucidate the mechanistic response to microclimate of anthocyanin metabolism in Viti...

  8. The Effectiveness of Different Buffer Widths for Protecting Headwater Stream Temperature in Maine

    Microsoft Academic Search

    Ethel Wilkerson; John M. Hagan; Darlene Siegel; Andrew A. Whitman

    2006-01-01

    We evaluated the effect of timber harvesting on summer water temperature in first-order headwater streams in western Maine. Fifteen streams were assigned to one of five treatments: (1) clearcutting with no stream buffer; (2) clearcutting with 11-m, partially harvested buffers, both sides; (3) clearcutting with 23-m, partially harvested buffers; (4) partial cuts with no designated buffer; and (5) unharvested controls.

  9. Calibration factor of track etch detectors at different temperatures of water

    E-print Network

    Yasmeen, Nuzhat

    1997-01-01

    with the increase of integrated radon exposures in water. The CR-39 etch detector is observed to be more sensitive to alpha particles than LR 115 Type 2 film. The exposure period ranged from 1 to 10 days. The linearity test was done at room temperature. The actual...

  10. 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

  11. 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

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

    Microsoft Academic Search

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

    2009-01-01

    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 23C) on life history parameters

  13. 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.

  14. 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

  15. 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.

  16. Temperature-dependent inhibition of motility in spermatozoa from different avian species.

    PubMed

    Wishart, G J; Wilson, Y I

    1999-12-15

    This study demonstrates that the pattern of temperature-dependent inhibition of chicken sperm motility at 40 degrees C in vitro, and its release by calcium, is also found in drake spermatozoa and, partially, in turkey spermatozoa. However, no such temperature-dependent inhibition was found in spermatozoa from Japanese quail and Houbara bustard, for which physiological levels of calcium at 40 degrees C had an inhibitory and no effect on sperm motility, respectively. Thus, on the basis of this evidence on the regulation of avian sperm motility in vitro, the hypothesis that oviducal sperm storage tubules might immobilise spermatozoa by providing a calcium-free environment in vivo does not appear to be universally applicable to all species of birds. PMID:10610041

  17. Nanoscale piezoresponse of 70-nm poly(vinylidene fluoride-trifluoroethylene) films annealed at different temperatures.

    SciTech Connect

    Choi, Y.-Y.; Hong, J.; Hong, S.; Cheong, D.-S.; No, K.; Materials Science Division; KAIST; Imperial Coll.; Dankook Univ.

    2010-03-01

    In order to characterize the piezoelectric properties of 70 nm thick poly(vinylidene fluoride-trifluoroethylene), P(VDF-TrFE), films grown by a spin-coating technique, both nanoscale manipulation and polarization switching were studied using piezoresponse force microscopy (PFM). We varied the annealing temperature from 75 C to 145 C and achieved a high-quality 70 nm P(VDF-TrFE) film annealed at the temperature of 95 C. Ferroelectric domains and their properties were confirmed using X-ray diffraction, grazing incidence reflection absorption Fourier Transform Infrared (GIRA-FTIR) and PFM analysis. The ferroelectric domains in the film were homogeneously switchable below 5 V with a remnant d{sub 33} of 14.9 pm/V. This offers our rationale for a promise in energy harvesting and switchability would be good for plastic electronics.

  18. 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

  19. Tribological properties evaluation of AISI 1095 steel chromized at different temperatures

    Microsoft Academic Search

    Jyh-Wei Lee; Hsi-Chun Wang; Jai-Lin Li; Chao-Chih Lin

    2004-01-01

    Pack chromization process provides a surface modified coating on steel surface with high hardness, corrosion and temperature resistance. AISI 1095 carbon steels were chromized to form chromiumiron nitride and carbides on surface by pack cementation process at 850 and 900 C for 19 h, respectively. Chromized layer with an outer (Cr,Fe)2N1-x and inner (Cr,Fe)23C6 and (Cr,Fe)7C3 phases were observed. The

  20. Molecular and Cellular Effects Induced in Mytilus galloprovincialis Treated with Oxytetracycline at Different Temperatures.

    PubMed

    Banni, Mohamed; Sforzini, Susanna; Franzellitti, Silvia; Oliveri, Caterina; Viarengo, Aldo; Fabbri, Elena

    2015-01-01

    The present study evaluatedthe interactive effects of temperature (16C and 24C) and a 4-day treatment with the antibiotic oxytetracycline (OTC) at 1 and 100?g/L on cellular and molecular parameters in the mussel Mytilus galloprovincialis. Lysosomal membrane stability (LMS), a sensitive biomarker of impaired health status in this organism, was assessed in the digestive glands. In addition, oxidative stress markers and the expression of mRNAs encoding proteins involved in antioxidant defense (catalase (cat) and glutathione-S-transferase (gst)) and the heat shock response (hsp90, hsp70, and hsp27) were evaluated in the gills, the target tissue of soluble chemicals. Finally, cAMP levels, which represent an important cell signaling pathway related to oxidative stress and the response to temperature challenges, were also determined in the gills. Exposure to heat stress as well as to OTC rendered a decrease in LMS and an increase in malonedialdehyde accumulation (MDA). CAT activity was not significantly modified, whereas GST activity decreased at 24C. Cat and gst expression levels were reduced in animals kept at 24C compared to 16C in the presence or absence of OTC. At 16C, treatment with OTC caused a significant increase in cat and gst transcript levels. Hsp27 mRNA was significantly up-regulated at all conditions compared to controls at 16C. cAMP levels were increased at 24C independent of the presence of OTC. PCA analysis showed that 37.21% and 25.89% of the total variance was explained by temperature and OTC treatment, respectively. Interestingly, a clear interaction was observed in animals exposed to both stressors increasing LMS and MDA accumulation and reducing hsp27 gene expression regulation. These interactions may suggest a risk for the organisms due to temperature increases in contaminated seawaters. PMID:26067465

  1. 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

  2. Finite difference modelling of the temperature rise in non-linear medical ultrasound fields

    Microsoft Academic Search

    S. A Divall; V. F Humphrey

    2000-01-01

    Non-linear propagation of ultrasound can lead to increased heat generation in medical diagnostic imaging due to the preferential absorption of harmonics of the original frequency. A numerical model has been developed and tested that is capable of predicting the temperature rise due to a high amplitude ultrasound field. The acoustic field is modelled using a numerical solution to the KhokhlovZabolotskayaKuznetsov

  3. 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...

  4. Rayleigh-Brillouin scattering profiles of air at different temperatures and pressures.

    PubMed

    Gu, Ziyu; Witschas, Benjamin; van de Water, Willem; Ubachs, Wim

    2013-07-01

    Rayleigh-Brillouin (RB) scattering profiles for air have been recorded for the temperature range from 255 to 340 K and the pressure range from 640 to 3300 mbar, covering the conditions relevant for the Earth's atmosphere and for planned atmospheric light detection and ranging (LIDAR) missions. The measurements performed at a wavelength of ?=366.8 nm detect spontaneous RB scattering at a 90 scattering angle from a sensitive intracavity setup, delivering scattering profiles at a 1% rms noise level or better. The experimental results have been compared to a kinetic line-shape model, the acclaimed Tenti S6 model, considered to be most appropriate for such conditions, under the assumption that air can be treated as an effective single-component gas with temperature-scaled values for the relevant macroscopic transport coefficients. The elusive transport coefficient, the bulk viscosity ?(b), is effectively derived by a comparing the measurements to the model, yielding an increased trend from 1.0 to 2.510(-5) kgm(-1)s(-1) for the temperature interval. The calculated (Tenti S6) line shapes are consistent with experimental data at the level of 2%, meeting the requirements for the future RB-scattering LIDAR missions in the Earth's atmosphere. However, the systematic 2% deviation may imply that the model has a limit to describe the finest details of RB scattering in air. Finally, it is demonstrated that the RB scattering data in combination with the Tenti S6 model can be used to retrieve the actual gas temperatures. PMID:23842262

  5. Molecular and Cellular Effects Induced in Mytilus galloprovincialis Treated with Oxytetracycline at Different Temperatures

    PubMed Central

    Banni, Mohamed; Sforzini, Susanna; Franzellitti, Silvia; Oliveri, Caterina; Viarengo, Aldo; Fabbri, Elena

    2015-01-01

    The present study evaluatedthe interactive effects of temperature (16C and 24C) and a 4-day treatment with the antibiotic oxytetracycline (OTC) at 1 and 100?g/L on cellular and molecular parameters in the mussel Mytilus galloprovincialis. Lysosomal membrane stability (LMS), a sensitive biomarker of impaired health status in this organism, was assessed in the digestive glands. In addition, oxidative stress markers and the expression of mRNAs encoding proteins involved in antioxidant defense (catalase (cat) and glutathione-S-transferase (gst)) and the heat shock response (hsp90, hsp70, and hsp27) were evaluated in the gills, the target tissue of soluble chemicals. Finally, cAMP levels, which represent an important cell signaling pathway related to oxidative stress and the response to temperature challenges, were also determined in the gills. Exposure to heat stress as well as to OTC rendered a decrease in LMS and an increase in malonedialdehyde accumulation (MDA). CAT activity was not significantly modified, whereas GST activity decreased at 24C. Cat and gst expression levels were reduced in animals kept at 24C compared to 16C in the presence or absence of OTC. At 16C, treatment with OTC caused a significant increase in cat and gst transcript levels. Hsp27 mRNA was significantly up-regulated at all conditions compared to controls at 16C. cAMP levels were increased at 24C independent of the presence of OTC. PCA analysis showed that 37.21% and 25.89% of the total variance was explained by temperature and OTC treatment, respectively. Interestingly, a clear interaction was observed in animals exposed to both stressors increasing LMS and MDA accumulation and reducing hsp27 gene expression regulation. These interactions may suggest a risk for the organisms due to temperature increases in contaminated seawaters. PMID:26067465

  6. Moisture adsorptiondesorption isotherms of prickly pear cladode ( Opuntia ficus indica) at different temperatures

    Microsoft Academic Search

    S Lahsasni; M Kouhila; M Mahrouz; M Fliyou

    2003-01-01

    The equilibrium moisture contents of cladode of Opuntia ficus indica were determined using the gravimetric static method at 30, 40 and 50 C over a range of relative humidity (Rh) from 0.05 to 0.9. The sorption capacity of cladode decreased with increase in temperature at constant Rh. The experimental sorption curves are then described by the GAB, Hendersons and BET

  7. Vertically Aligned Carbon Nanotubes at Different Temperatures by Spray Pyrolysis Techniques

    Microsoft Academic Search

    Rakesh A. Afre; T. Soga; T. Jimbo; Mukul Kumar; Y. Ando; M. Sharon

    2006-01-01

    Vertically aligned arrays of multi-walled carbon nanotubes (VACNTs) were grown by spray pyrolysis of turpentine oil and ferrocene mixture at temperatures higher than 700C. Using this simple method, we report the successful growth of vertically aligned nanotubes of ~300mum length and diameter in the range of ?20-80nm on Si(100) substrate. The ferrocene acts as an in situ Fe catalyst precursor,

  8. 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 3 months) and indicate a role for local adaptation to temperature conditions in promoting evolutionary diversification and speciation in the marine environment. PMID:25782085

  9. Growth behavior of titanium dioxide thin films at different precursor temperatures

    NASA Astrophysics Data System (ADS)

    Nam, Sang-Hun; Cho, Sang-Jin; Boo, Jin-Hyo

    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.

  10. Preparation of Indium Tin Oxide films deposited by reactive evaporation at different substrate-temperature and the properties

    NASA Astrophysics Data System (ADS)

    Li, Lin-Na; Xue, Jun-Ming; Zhao, Ying; Li, Yang-Xian; Geng, Xin-Hua

    2007-11-01

    The Indium Tin Oxide films have been prepared at different substrate-temperature on glass substrates by reactive evaporation of In-Sn alloy with an oxygen pressure of 1.3 10-1 Pa and a deposition rate of 10-2 nm/s. The best ITO films obtained have an electrical resistivity of 4.35 10-4 ?cm, a carrier concentration of 4.02 1020 cm-3, and a Hall mobility of 67.5 cm2v-1s-1. The influence of the substrate-temperature on the structural, optical and electrical properties of the obtained films has been investigated.

  11. 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

  12. Noise-induced impulse pattern modifications at different dynamical period-one situations in a computer model of temperature encoding.

    PubMed

    Braun, H A; Huber, M T; Anthes, N; Voigt, K; Neiman, A; Pei, X; Moss, F

    2001-01-01

    We used a minimal Hodgkin-Huxley type model of cold receptor discharges to examine how noise interferes with the non-linear dynamics of the ionic mechanisms of neuronal stimulus encoding. The model is based on the assumption that spike-generation depends on subthreshold oscillations. With physiologically plausible temperature scaling, it passes through different impulse patterns which, with addition of noise, are in excellent agreement with real experimental data. The interval distributions of purely deterministic simulations, however, exhibit considerable differences compared to the noisy simulations especially at the bifurcations of deterministically period-one discharges. We, therefore, analyzed the effects of noise in different situations of deterministically regular period-one discharges: (1) at high-temperatures near the transition to subthreshold oscillations and to burst discharges, and (2) at low-temperatures close to and more far away from the bifurcations to chaotic dynamics. The data suggest that addition of noise can considerably extend the dynamical behavior of the system with coexistence of different dynamical situations at deterministically fixed parameter constellations. Apart from well-described coexistence of spike-generating and subthreshold oscillations also mixtures of tonic and bursting patterns can be seen and even transitions to unstable period-one orbits seem to appear. The data indicate that cooperative effects between low- and high-dimensional dynamics have to be considered as qualitatively important factors in neuronal encoding. PMID:11595322

  13. [Variation of apple tree canopy-air temperature difference and its relations to environment factors].

    PubMed

    Meng, Ping; Zhang, Jin-Song; Gao, Jun; Wang, He-Song; Ren, Qing-Fu

    2007-09-01

    By using portable infrared thermometer, the canopy temperature (Tc) of apple tree in its main growth season was measured in 2002-2005. Combined with the synchronous micro-meteorological data on the canopy, such as net radiation (Rn), wind speed (V), air temperature (Ta) and relative humidity (RH), as well as the soil water content (SW) at 0-80 cm depth, the variation of apple tree canopy-air temperature differential (DeltaT) and its relationships to environmental factor were analyzed. The results showed that from bud stage to fruit-developing stage, there were several peaks in the diurnal curve of DeltaT, with the maximum at 12:00-13:00 in fine days, and the absolute value of DeltaT in fine days was higher than that in overcast days. Based on data of 2003 and 2004, the DeltaT at 14:00 was significantly correlated with the RH, V, Rn, SW in fine days, and the regression equation was DeltaT = 7.159 - 0.002Rn - 0.061V - 0.7RH - 46.0SW (P < 0.01, r = 0.825). The partial coefficient for Rn, RH, V and SW was 0.125, -0.078, -0.036, -0.874, respectively, and the stepwise regression equation was DeltaT = 5.317 - 43.1SW (P < 0.01), suggesting that SW was the most important environmental factor affecting DeltaT. After validated with the measured data in 2002 and 2005, it was found that the measured DeltaT was highly accorded with the simulated one (r = 0.9083, P < 0.01, n = 40), and thus, it was of possibility to use the data of DeltaT at 14:00 in fine days to predict the soil water content in apple orchard. PMID:18062308

  14. 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

    2015-07-01

    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

  15. 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.

  16. Calibration factor of track etch detectors at different temperatures of water

    E-print Network

    Yasmeen, Nuzhat

    1997-01-01

    of dissolved radon for graduated exposure times. Many different experimental techniques were conducted to confirm the detector's linear response. The results show that the track densities of track detectors LR II 5 Type 2 and CR-3 9 increase linearly...

  17. 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

  18. 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

  19. Triacylglyceride composition and fatty acyl saturation profile of a psychrophilic and psychrotolerant fungal species grown at different temperatures.

    PubMed

    Pannkuk, Evan L; Blair, Hannah B; Fischer, Amy E; Gerdes, Cheyenne L; Gilmore, David F; Savary, Brett J; Risch, Thomas S

    2014-01-01

    Pseudogymnoascus destructans is a psychrophilic fungus that infects cutaneous tissues in cave dwelling bats, and it is the causal agent for white nose syndrome (WNS) in North American (NA) bat populations. Geomyces pannorum is a related psychrotolerant keratinolytic species that is rarely a pathogen of mammals. In this study, we grew P. destructans and G. pannorum in static liquid cultures at favourable and suboptimal temperatures to: 1) determine if triacylglyceride profiles are species-specific, and 2) determine if there are differences in fatty acyl (FA) saturation levels with respect to temperature. Total lipids isolated from both fungal spp. were separated by thin-layer chromatography and determined to be primarily sterols (?15%), free fatty acids (FFAs) (?45%), and triacylglycerides (TAGs) (?50%), with minor amounts of mono-/diacylglycerides and sterol esters. TAG compositions were profiled by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF). Total fatty acid methyl esters (FAMEs) and acyl lipid unsaturation levels were determined by gas chromatography-mass spectrometry (GC-MS). Pseudogymnoascus destructans produced higher proportions of unsaturated 18C fatty acids and TAGs than G. pannorum. Pseudogymnoascus destructans and G. pannorum produced up to a two-fold increase in 18:3 fatty acids at 5C than at higher temperatures. TAG proportion for P. destructans at upper and lower temperature growth limits was greater than 50% of total dried mycelia mass. These results indicate fungal spp. alter acyl lipid unsaturation as a strategy to adapt to cold temperatures. Differences between their glycerolipid profiles also provide evidence for a different metabolic strategy to support psychrophilic growth, which may influence P. destructans' pathogenicity to bats. PMID:25209638

  20. 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.

  1. Preparation of Indium Tin Oxide films deposited by reactive evaporation at different substrate-temperature and the properties

    Microsoft Academic Search

    Lin-Na Li; Jun-Ming Xue; Ying Zhao; Yang-Xian Li; Xin-Hua Geng

    2007-01-01

    The Indium Tin Oxide films have been prepared at different substrate-temperature on glass substrates by reactive evaporation\\u000a of In-Sn alloy with an oxygen pressure of 1.3 ? 10?1 Pa and a deposition rate of 10?2 nm\\/s. The best ITO films obtained have an electrical resistivity of 4.35 ? 10?4 ??cm, a carrier concentration of 4.02 ? 1020 cm?3, and a

  2. 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 900-1300 m 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

  3. Stability of oxide film formed at different temperatures on Alloy 600 in lithiated environment

    NASA Astrophysics Data System (ADS)

    Abraham, Geogy J.; Kain, V.; Dey, G. K.; Raja, V. S.

    2013-06-01

    The nickel base alloys are susceptible to localized corrosion attack and the major contributing factor in these corrosion mechanisms is the oxide film formed on the alloy. The chromium content in the oxide film determines its stability against localized attack that act as precursors for the initiation of stress corrosion cracking (SCC) in the material. The present study aimed at optimizing the hot conditioning parameter by varying the temperature of oxide formation for minimum ion release rate during reactor operation. The surface and in-depth compositional characterization of oxide film formed on Alloy 600 was carried out using micro-laser Raman spectroscopy (MLRS) and glow discharge quadrapole mass spectroscopy (GDQMS) respectively. The relative defect density of oxide films were studied using electrochemical impedance spectroscopy (EIS). The oxide film stability of Alloy 600 in chloride containing environment was correlated to chromium concentration in the film as well as relative defect density.

  4. 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

  5. Identification of quantum confined interband transitions in type-II InAs/GaSb superlattices using polarization sensitive photocurrent

    E-print Network

    Krishna, Sanjay

    lm) with a noise-equivalent temperature difference comparable to state of the art detectors based on mercury cad- mium telluride (MCT, HgCdTe) alloy.9 Although the infrared detector applications of T2SL have

  6. 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.

  7. 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.

  8. Differential sorption behaviour of aromatic hydrocarbons on charcoals prepared at different temperatures from grass and wood

    Microsoft Academic Search

    Ludger C. Bornemann; Rai S. Kookana; Gerhard Welp

    2007-01-01

    Naturally occurring charcoals are increasingly being recognized as effective sorbents for organic compounds. In this study we investigated the sorption of benzene and toluene in single-sorbate and bi-sorbate systems on different types of charcoals produced in laboratory, employing the batch sorption technique. Air dried plant materials from Phalaris grass (Phalaris tuberosa) and Red Gum wood (Eucalyptus camadulensis) were combusted under

  9. Low temperature and defoliation affect fructan-metabolizing enzymes in different regions of the rhizophores of Vernonia herbacea.

    PubMed

    Portes, Maria Teresa; Figueiredo-Ribeiro, Rita de Cssia L; de Carvalho, Maria Angela M

    2008-10-01

    In addition to the storage function, fructans in Asteraceae from floras with seasonal growth have been associated with drought and freezing tolerance. Vernonia herbacea, native of the Brazilian Cerrado, bears underground reserve organs, rhizophores, accumulating inulin-type fructans. The rhizophore is a cauline branched system with positive geotropic growth, with the apex (distal region) presenting younger tissues; sprouting of new shoots occurs by development of buds located on the opposite end (proximal region). Plants induced to sprouting by excision of the aerial organs present increased 1-fructan exohydrolase (1-FEH) activity in the proximal region, while plants at the vegetative stage present high 1-sucrose:sucrose fructosyltransferase (1-SST) in the distal region. The aim of the present study was to analyze how low temperature (5 degrees C) could affect fructan-metabolizing enzymes and fructan composition in the different regions of the rhizophores of intact and excised plants. 1-SST and 1-fructan:fructan fructosyltransferase (1-FFT) were higher in the distal region decreasing towards the proximal region in intact plants at the vegetative phase, and were drastically diminished when cold and/or excision were imposed. In contrast, 1-FEH increased in the proximal region of treated plants, mainly in excised plants subjected to cold. The ratio fructo-oligo to fructo-polysaccharides was significantly higher in plants exposed to low temperature (1.17 in intact plants and 1.64 in excised plants) than in plants exposed to natural temperature conditions (0.84 in intact vegetative plants and 0.58 in excised plants), suggesting that oligosaccharides are involved in the tolerance of plants to low temperature via 1-FEH, in addition to 1-FFT. Principal component analysis indicated different response mechanisms in fructan metabolism under defoliation and low temperature, which could be interpreted as part of the strategies to undergo unfavorable environmental conditions prevailing in the Cerrado during winter. PMID:18342987

  10. 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

  11. Secretion time of phytosiderophore differs in two perennial grasses and is controlled by temperature

    Microsoft Academic Search

    Daisei Ueno; Jian Feng Ma

    2009-01-01

    Some perennial grasses secrete phytosiderophores from the roots in response to Fe-deficiency. Here, we characterized the pattern\\u000a of phytosiderophore secretion by Lolium perenne (cv. Tove) and Poa pratensis (cv. Baron), which are used to correct iron-deficiency induced chlorosis in fruit trees grown on calcareous soils. Both\\u000a species showed a distinct diurnal rhythm in phytosiderophore secretion, but the secretion time differed

  12. Core temperature differences between males and females during intermittent exercise: physical considerations

    Microsoft Academic Search

    Daniel Gagnon; Lucy E. Dorman; Ollie Jay; Stephen Hardcastle; Glen P. Kenny

    2009-01-01

    We examined differences in dynamic heat balance between males and females during intermittent exercise. Six males (M) and\\u000a six females (F) performed three 30-min bouts of exercise (Ex1, Ex2, Ex3) at a constant rate of metabolic heat production ($$ \\\\dot{M} - \\\\dot{W} $$) of ~500W separated by three 15-min periods of inactive recovery. Rate of total heat loss ($$ \\\\dot{H}_{\\\\text{L}}

  13. Effect of different extenders and storage temperatures on sperm viability of liquid ram semen

    Microsoft Academic Search

    Heiko Paulenz; Lennart Sderquist; Rosaura Prez-P; Kjell Andersen Berg

    2002-01-01

    Semen was collected with an artificial vagina from four adult rams. The ejaculates were pooled and diluted, using a split-sample technique, in four different extenders: one for milk (Mi), one for sodium citrate (Na), and two for Tris-based extenders (T1 and T2) including egg yolk. Thereafter, the diluted semen was stored at 5 and 20C, respectively. We evaluated sperm viability

  14. The effects of urbanization on temperature trends in different economic periods and geographical environments in northwestern China

    NASA Astrophysics Data System (ADS)

    Fang, Feng; Guo, Junqin; Sun, Landong; Wang, Jing; Wang, Xinping

    2014-04-01

    Using data collected from 22 urban and 65 rural meteorological stations in northwestern China between 1961 and 2009, this paper presents a study concerning the effects of urbanization on air temperature trends. To distinguish among the potential influences that stem from the economic development levels, population scales, and geographic environments of the cities in this region, the 49-year study period was divided into two periods: a period of less economic development, from 1961 to 1978, and a period of greater economic development, from 1979 to 2009. Each of the cities was classified as a megalopolis, large, or medium-small, depending on the population, and each was classified as a plateau, plain, or oasis city, depending on the surrounding geography. The differences in the air temperature trends between cities and the average of their rural counterparts were used to examine the warming effects of urbanization. The results of this study indicate that the magnitude of warming effects due to urbanization depends not only on a city's economic level, but also on the population scale and geographic environment of the city. The urbanization of most cities in northwestern China resulted in considerable negative warming effects during 1961-1978 but evidently positive effects during 1979-2009. The population scale of a city represents a significant factor: a city with a larger population has a stronger warming influence, regardless of whether the effect is negative or positive. Among the three geographic environments of the cities considered, plateaus and plains more significantly enhance warming effects than oases. The urban population trend has a very significant logarithm relationship with the urban temperature effect, but no clear relationships between urban temperature effects and city elevation were detected. The majority of the temperature trends, accounting for more than 60 % of the trends during 1961-2009, can be explained by natural factors, although urbanization has had some obvious effects on temperatures in northwestern China.

  15. Comparison of the transport properties of two-temperature argon plasmas calculated using different methods

    NASA Astrophysics Data System (ADS)

    Zhang, X. N.; Li, H. P.; Murphy, A. B.; Xia, W. D.

    2015-06-01

    Two main methods have been used to calculate the transport properties of two-temperature (2-T) plasmas in local chemical equilibrium: the method of Devoto (method B), in which coupling between electrons and heavy species is neglected, and the method of Rat et al (method C), in which coupling is included at the cost of a considerable increase in complexity. A new method (method A) has recently been developed, based on the modified ChapmanEnskog solution of the species Boltzmann equations. This method retains coupling between electrons and heavy species by including the electronheavy-species collision term in the heavy-species Boltzmann equation. In this paper, the properties of 2-T argon plasmas calculated using the three methods are compared. The viscosity, electrical conductivity and translational thermal conductivity obtained using all three methods are very similar. method B does not allow a complete set of species diffusion coefficient to be obtained. It is shown that such a set can be calculated using method A without any significant loss of accuracy. Finally, it is important to note that, by using the physical fact that the mass of heavy particles is much larger than that of electrons (i.e. me?<< mh), the complexity of calculations using method A is not increased compared with method B; that is to say, the calculation procedure is much simpler than with method C.

  16. 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

  17. Chemical decomposition of iron in Spanish coal pyrolysis identified by Moessbauer spectroscopy at different temperatures

    SciTech Connect

    Ahmed, M.A.; Blesa, M.J.; Moliner, R. [Taif University, El Taif (Saudi Arabia). Faculty of Science

    2007-07-01

    Three chars from lignite (Se), sub bituminous (AA6), bituminous (BCA) Spanish coals produced at 673 K, 773 K, and 873 K were analyzed by Moessbauer spectroscopy at room temperature, and 80 K, except BCA char produced at 873 K, its analysis was extended down to 10 K. Least square fit analysis for the spectra of Se chars showed that, jarosite/Fe{sup 3+} was hydrolyzed into rozenite/Fe2+ at 873 K. Pyrite was reduced to troilite (FeS) at 773 K. Both jarosite and very broad doublet were observed at T = 673 K. The hyperfine parameters of this phase gave close values to microcrystalline iron in either Fe (II) or Fe (III) states. On the other hand, the spectral analysis of AA6 chars ascertained that rozenite was hydrolyzed to goethite (FeOOH) in the range of 773 K-873 K, whereas pyrite was reduced to pyrrohotite (Fe{sub 1-x}S). However, no chemical changes were observed for jarosite in all AA6-chars. Likewise, siderite was changed into magnetite in the BCA chars produced at 673 K and 773 K. Spectrum performed at 10 K for char produced at 873 K proved the presence of ferrihydrite (H = 489.2 kOe), troilite (H = 355.3 kOe) and a broad paramagnetic doublet belonging to an organic iron. These phases and still remaining siderite inferred also that such transformations are incomplete.

  18. 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...

  19. Effects of temperature and different food matrices on Cyclospora cayetanensis oocyst sporulation.

    PubMed

    Sathyanarayanan, Lakshmi; Ortega, Ynes

    2006-04-01

    Effects of temperature on the sporulation of the parasite Cyclospora cayetanensis were studied in 2 food substrates, dairy and basil. Unsporulated Cyclospora oocysts were subjected to freezing and heating conditions for time periods ranging from 15 min to 1 wk. Oocysts were then removed from the food substrates and placed in 2.5% potassium dichromate for 2 wk to allow viable unsporulated oocysts to differentiate and fully sporulate, and to determine the percentage sporulation as an indicator of viability. Sporulation occurred when oocysts resuspended in dairy substrates were stored within 24 hr at -15 C. When oocysts were placed in water or basil, sporulation occurred after incubation for up to 2 days at -20 C, and up to 4 days at 37 C. Few oocysts sporulated when incubated for 1 hr at 50 C. Sporulation was not observed in basil leaves or water at -70 C, 70 C, and 100 C. Sporulation was not affected when incubated at 4 C and 23 C for up to 1 wk, which was the duration of the experiment in both of the tested substrates. PMID:16729675

  20. 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.

  1. Osmotic Properties of Spheroplasts from Saccharomyces cerevisiae Grown at Different Temperatures

    PubMed Central

    Diamond, R. J.; Rose, A. H.

    1970-01-01

    Spheroplasts were prepared from cells of Saccharomyces cerevisiae NCYC 366, grown at 30 or 15 C, by incubating cells with snail-gut juice after pretreatment with 2-mercaptoethanol. Walls of cells grown batchwise or in continuous culture at 15 C were more resistant to digestion with snail juice than walls on cells grown under the same conditions as 30 C. Spheroplasts lysed when suspended in hypotonic solutions of mannitol. The resistance of spheroplasts to osmotic lysis tended to increase when the test temperature was lowered below 30 C. The increased resistance was greater with spheroplasts from cells grown at 15 C. Cations, especially Ca2+, protected spheroplasts against osmotic lysis. In general, the protective effects, measured at 30 C, were smaller with spheroplasts from cells grown at 15 C compared with 30 C. Citrate and ethylenediaminetetraacetate (EDTA) decreased the resistance of spheroplasts to osmotic lysis. On the whole, the decrease was greater with spheroplasts from cells grown at 30 C rather than 15 C. In the presence of EDTA, spheroplasts from cells grown at 30 C were less resistant to osmotic lysis at 5 C than at 30 C; when spheroplasts from cells grown at 15 C were similarly examined, they were more resistant to lysis at 5 C than at 30 C. Spheroplast membranes from cells grown at 15 C had slightly but significantly greater contents of Mg2+, Ca2+, K+, and Na+ compared with spheroplast membranes from cells grown at 15 C. Mg2+ and Ca2+ were more easily extracted with EDTA from membranes of 30 C-grown cells than from 15 C-grown cells. PMID:4986757

  2. 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.

  3. 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

  4. Linking microbial community structure and function to seasonal differences in soil moisture and temperature in a Chihuahuan desert grassland.

    PubMed

    Bell, Colin W; Acosta-Martinez, Veronica; McIntyre, Nancy E; Cox, Stephen; Tissue, David T; Zak, John C

    2009-11-01

    Global and regional climate models predict higher air temperature and less frequent, but larger precipitation events in arid regions within the next century. While many studies have addressed the impact of variable climate in arid ecosystems on plant growth and physiological responses, fewer studies have addressed soil microbial community responses to seasonal shifts in precipitation and temperature in arid ecosystems. This study examined the impact of a wet (2004), average (2005), and dry (2006) year on subsequent responses of soil microbial community structure, function, and linkages, as well as soil edaphic and nutrient characteristics in a mid-elevation desert grassland in the Chihuahuan Desert. Microbial community structure was classified as bacterial (Gram-negative, Gram-positive, and actinomycetes) and fungal (saprophytic fungi and arbuscular mycorrhiza) categories using (fatty acid methyl ester) techniques. Carbon substrate use and enzymic activity was used to characterize microbial community function annually and seasonally (summer and winter). The relationship between saprophytic fungal community structure and function remained consistent across season independent of the magnitude or frequency of precipitation within any given year. Carbon utilization by fungi in the cooler winter exceeded use in the warmer summer each year suggesting that soil temperature, rather than soil moisture, strongly influenced fungal carbon use and structure and function dynamics. The structure/function relationship for AM fungi and soil bacteria notably changed across season. Moreover, the abundance of Gram-positive bacteria was lower in the winter compared to Gram-negative bacteria. Bacterial carbon use, however, was highest in the summer and lower during the winter. Enzyme activities did not respond to either annual or seasonal differences in the magnitude or timing of precipitation. Specific structural components of the soil microbiota community became uncoupled from total microbial function during different seasons. This change in the microbial structure/function relationship suggests that different components of the soil microbial community may provide similar ecosystem function, but differ in response to seasonal temperature and precipitation. As soil microbes encounter increased soil temperatures and altered precipitation amounts and timing that are predicted for this region, the ability of the soil microbial community to maintain functional resilience across the year may be reduced in this Chihuahuan Desert ecosystem. PMID:19466479

  5. Low-level temperature inversions and their effect on aerosol condensation nuclei concentrations under different large-scale synoptic circulations

    NASA Astrophysics Data System (ADS)

    Li, Jun; Chen, Hongbin; Li, Zhanqing; Wang, Pucai; Cribb, Maureen; Fan, Xuehua

    2015-07-01

    Knowledge of the statistical characteristics of inversions and their effects on aerosols under different large-scale synoptic circulations is important for studying and modeling the diffusion of pollutants in the boundary layer. Based on results generated using the self-organizing map (SOM) weather classification method, this study compares the statistical characteristics of surface-based inversions (SBIs) and elevated inversions (EIs), and quantitatively evaluates the effect of SBIs on aerosol condensation nuclei (CN) concentrations and the relationship between temperature gradients and aerosols for six prevailing synoptic patterns over the the Southern Great Plains (SGP) site during 2001-10. Large-scale synoptic patterns strongly influence the statistical characteristics of inversions and the accumulation of aerosols in the low-level atmosphere. The activity, frequency, intensity, and vertical distribution of inversions are significantly different among these synoptic patterns. The vertical distribution of inversions varies diurnally and is significantly different among the different synoptic patterns. Anticyclonic patterns affect the accumulation of aerosols near the ground more strongly than cyclonic patterns. Mean aerosol CN concentrations increase during SBIs compared to no inversion cases by 16.1%, 22.6%, 24.5%, 58.7%, 29.8% and 23.7% for the six synoptic patterns. This study confirms that there is a positive correlation between temperature gradients and aerosol CN concentrations near the ground at night under similar large-scale synoptic patterns. The relationship is different for different synoptic patterns and can be described by linear functions. These findings suggest that large-scale synoptic patterns change the static stability of the atmosphere and inversions in the lower atmosphere, thereby influencing the diffusion of aerosols near the ground.

  6. Effect of cooling rate, cryoprotectant and holding time at different transfer temperatures on the survival of cryopreserved cell suspension culture ( Puccinellia distans (L.) Parl.)

    Microsoft Academic Search

    Lszl E. Heszky; Zsolt Jekkel; Abdel-Hamid Ali

    1990-01-01

    Reflexed saltmarsh-grass suspension cultures produced by seed callus were frozen to the liquid nitrogen temperature. Cooling rates, cryoprotectants and holding times were taken as a function of transfer temperatures. The highest survival of cells (45%) was found at a freezing rate of 1C min-1, without cryoprotectant treatments. The cryoprotectants (proline, dimethyl sulphoxide, glycerol), used at different concentrations and transfer temperatures,

  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. Low-temperature photoluminescence of detector grade Cd1 - xZnxTe crystal treated by different chemical etchants

    Microsoft Academic Search

    H. Chen; J. Tong; Z. Hu; D. T. Shi; G. H. Wu; K.-T. Chen; M. A. George; W. E. Collins; A. Burger; R. B. James; C. M. Stahle; L. M. Bartlett

    1996-01-01

    Low-temperature photoluminescence (PL) spectra of detector grade Cd1?xZnxTe (x=0.1) have been measured to obtain information about shallow level defect concentration introduced during mechanical polishing and chemical etching processes. We present here a comparative PL study of Cd0.9Zn0.1Te crystals treated by different chemical solutions used for nuclear detector surface treatment. The results show that the 5% BrMeOH+2%Br20% lactic acid in ethylene

  9. Single-crystal electronic absorption spectroscopy of synthetic chromium-, cobalt-, and vanadium-bearing pyropes at different temperatures and pressures

    Microsoft Academic Search

    M. N. Taran; K. Langer; C. A. Geiger

    2002-01-01

    Single crystals of synthetic vanadium-, chromium- and cobalt-bearing garnets, Pyr:V0.06, Pyr:V0.13, Pyr:Cr0.04, Pyr:Co0.10,\\u000a and Gt:Co3.00, and a natural vanadium-bearing grossular, Gross:V0.07 (Cr3+ ?1 under ambient conditions and at temperatures up to 600 K and pressures up to 8 GPa. The T and P behavior of the absorption band energies and intensities shows the following for the different transition metal-bearing garnets:

  10. Different effects of night versus day high temperature on rice quality and accumulation profiling of rice grain proteins during grain filling

    Microsoft Academic Search

    Haixia Li; Zhen Chen; Meixia Hu; Zhenmei Wang; Hua Hua; Changxi Yin; Hanlai Zeng

    High temperature has adverse effects on rice yield and quality. The different influences of night high temperature (NHT) and\\u000a day high temperature (DHT) on rice quality and seed protein accumulation profiles during grain filling in indica rice 9311 were studied in this research. The treatment temperatures of the control, NHT, and DHT were 28C\\/20C, 27C\\/35C,\\u000a and 35C\\/27C, respectively, and all

  11. Alpha-stat calibration of indo-1 fluorescence and measurement of intracellular free calcium in rat ventricular cells at different temperatures

    Microsoft Academic Search

    Shi-Qiang Wang; Zeng-Quan Zhou

    1999-01-01

    To explore how to manage pH when calibrating Ca2+ probes at different temperatures, the dissociation constant (Kd) of indo-1 was determined both in pH-stat (pH is fixed despite the temperature) and in ?-stat (pH changes with temperature as in cells). The results showed that the Kd was much more sensitive to temperature in pH-stat than in ?-stat, demonstrating that ?-stat

  12. Readme file for Stn-vs-Net Plots Stn-vs-net plots display differences between the GHCNMv3 annual average temperature for a station and the

    E-print Network

    neighbors. The above image displays GHCNMv3 station 14168588000 average annual anomaly differencesReadme file for Stn-vs-Net Plots Stn-vs-net plots display differences between the GHCNMv3 annual average temperature for a station and the annual average temperature of its neighboring stations

  13. 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.

  14. Seedlings of five boreal tree species differ in acclimation of net photosynthesis to elevated CO(2) and temperature.

    PubMed

    Tjoelker, M. G.; Oleksyn, J.; Reich, P. B.

    1998-11-01

    Biochemical models of photosynthesis suggest that rising temperatures will increase rates of net carbon dioxide assimilation and enhance plant responses to increasing atmospheric concentrations of CO(2). We tested this hypothesis by evaluating acclimation and ontogenetic drift in net photosynthesis in seedlings of five boreal tree species grown at 370 and 580 &mgr;mol mol(-1) CO(2) in combination with day/night temperatures of 18/12, 21/15, 24/18, 27/21, and 30/24 degrees C. Leaf-area-based rates of net photosynthesis increased between 13 and 36% among species in plants grown and measured in elevated CO(2) compared to ambient CO(2). These CO(2)-induced increases in net photosynthesis were greater for slower-growing Picea mariana (Mill.) B.S.P., Pinus banksiana Lamb., and Larix laricina (Du Roi) K. Koch than for faster-growing Populus tremuloides Michx. and Betula papyrifera Marsh., paralleling longer-term growth differences between CO(2) treatments. Measures at common CO(2) concentrations revealed that net photosynthesis was down-regulated in plants grown at elevated CO(2). In situ leaf gas exchange rates varied minimally across temperature treatments and, contrary to predictions, increasing growth temperatures did not enhance the response of net photosynthesis to elevated CO(2) in four of the five species. Overall, the species exhibited declines in specific leaf area and leaf nitrogen concentration, and increases in total nonstructural carbohydrates in response to CO(2) enrichment. Consequently, the elevated CO(2) treatment enhanced rates of net photosynthesis much more when expressed on a leaf area basis (25%) than when expressed on a leaf mass basis (10%). In all species, rates of leaf net CO(2) exchange exhibited modest declines with increasing plant size through ontogeny. Among the conifers, enhancements of photosynthetic rates in elevated CO(2) were sustained through time across a wide range of plant sizes. In contrast, for Populus tremuloides and B. papyrifera, mass-based photosynthetic rates did not differ between CO(2) treatments. Overall, net photosynthetic rates were highly correlated with relative growth rate as it varied among species and treatment combinations through time. We conclude that interspecific variation may be a more important determinant of photosynthetic response to CO(2) than temperature. PMID:12651406

  15. Filtration and clearance rates of Anadara grandis juveniles (Pelecypoda, Arcidae) with different temperatures and suspended matter concentrations.

    PubMed

    Miranda-Baeza, Anselmo; Voltolina, Domenico; Cordero-Esquivel, Beatriz

    2006-09-01

    The mangrove cockle Anadara grandis (Broderip and Sowerby, 1829) is a potential candidate for aquaculture and for bioremediation of aquaculture effluents in the tropical and subtropical coastal areas of the eastern Pacific Ocean. Laboratory-produced spat are available, but there is no information on their responses to the range of environmental conditions to which they might be subject during the growth cycle. The aim of this study was to evaluate the filtration and clearance rates ofA. grandis spat (shell length 9.50+/-0.37 mm) with a food concentration (7.5 mgxl(-1)) at four different temperatures (22, 25, 28 and 31 degrees C, with pH=7.5+/-0.2 and O2 concentration of 6.4+/-0.5 mgxl(-1); experiment one); and with a temperature (25 degrees C) and five concentrations of suspended matter (from 7.5 to 29 mgxl(-1) and pH and O2 values of 7.9+/-0.2 and 6.8+/-0.4 mgxl(-1); experiment two). Filtration and clearance rates were highest at 25 degrees C and significantly different (p<.05) from those obtained at 22, 28 and 31 degrees C; the clearance rates had the same tendency but the differences were not significant (p>.05). In the second experiment filtration increased according to the amount of food available, but there were no significant differences (p>.05) between 7.5 and 11 mgxl(-1) and from 22.4 to 29 mgxl(-1). The trend was similar for clearance, and in this case significant differences were found (p<.05) between 7.5, 22.4 and 29 mgxl(-1). Filtration at 31 degrees C was close to 80% at the optimum temperature of 25 degrees C, which indicates that A. grandis is a good candidate for tropical aquaculture. Clearance increased with high concentrations of suspended solids, but the production of biodeposits could be a source of environmental concern. Therefore, the possibility of using this species for bioremediation of aquaculture effluents should be studied with larger specimens and at higher seston concentrations. PMID:18491618

  16. Steroid Signaling System Responds Differently to Temperature and Hormone Manipulation in the Red-Eared Slider Turtle (Trachemys scripta elegans), a Reptile with Temperature-Dependent Sex Determination

    Microsoft Academic Search

    M. Ramsey; D. Crews

    2007-01-01

    Many reptiles, including the red-eared slider turtle (Trachemys scripta elegans), exhibit temperature-dependent sex determination (TSD). Temperature determines gonadal sex during the middle of embryogenesis, or the temperature-sensitive period (TSP), when gonadal sex is labile to both temperature and hormones particularly estrogen. The biological actions of steroid hormones are mediated by their receptors as defined here as the classic transcriptional

  17. Intercomparison of thermal-optical method with different temperature protocols: Implications from source samples and solvent extraction

    NASA Astrophysics Data System (ADS)

    Cheng, Yuan; Duan, Feng-kui; He, Ke-bin; Du, Zhen-yu; Zheng, Mei; Ma, Yong-liang

    2012-12-01

    Three temperature protocols with different peak inert mode temperature (Tpeak-inert) were compared based on source and ambient samples (both untreated and extracted using a mixture of hexane, methylene chloride, and acetone) collected in Beijing, China. The ratio of EC580 (elemental carbon measured by the protocol with a Tpeak-inert of 580C; similar hereinafter) to EC850 could be as high as 4.8 for biomass smoke samples whereas the ratio was about 1.0 for diesel and gasoline exhaust samples. The EC580 to EC850 ratio averaged 1.950.89 and 1.130.20 for the untreated and extracted ambient samples, whereas the EC580 to EC650 ratio of ambient samples was 1.220.10 and 1.200.12 before and after extraction. It was suggested that there are two competing mechanisms for the effects of Tpeak-inert on the EC results such that when Tpeak-inert is increased, one mechanism tends to decrease EC by increasing the amount of charring whereas the other tends to increase EC through promoting more charring to evolve before native EC. Results from this study showed that EC does not always decrease when increasing the peak inert mode temperature. Moreover, reducing the charring amount could improve the protocols agreement on EC measurements, whereas temperature protocol would not influence the EC results if no charring is formed. This study also demonstrated the benefits of allowing for the OC and EC split occurring in the inert mode when a high Tpeak-inert is used (e.g., 850C).

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

    PubMed

    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. PMID:25353876

  19. Effects of Different Force Fields and Temperatures on the Structural Character of Abeta (1228) Peptide in Aqueous Solution

    PubMed Central

    Cao, Zanxia; Liu, Lei; Zhao, Liling; Wang, Jihua

    2011-01-01

    The aim of this work is to investigate the effects of different force fields and temperatures on the structural character of A? (1228) peptide in aqueous solution. Moreover, the structural character of A? (1228) peptide is compared with other amyloid peptides (such as H1 and ?-syn12 peptide). The two independent temperature replica exchange molecular dynamics (T-REMD) simulations were completed by using two different models (OPLS-AA/TIP4P and GROMOS 43A1/SPC). We compared the models by analyzing the distributions of backbone dihedral angles, the secondary structure propensity, the free energy surface and the formation of ?-hairpin. The results show that the mostly populated conformation state is random coil for both models. The population of ?-hairpin is below 8 percent for both models. However, the peptide modeled by GROMOS 43A1 form ?-hairpin with turn located at residues F19-E22, while the peptide modeled by OPLS-AA form ?-hairpin with turn located at residues L17-F20. PMID:22174662

  20. Seasonal variation in mitochondrial responses to cadmium and temperature in eastern oysters Crassostrea virginica (Gmelin) from different latitudes.

    PubMed

    Cherkasov, A S; Taylor, C; Sokolova, I M

    2010-04-01

    Cadmium (Cd) is an important environmental pollutant that can lead to impairment of cellular functions, energy misbalance and negatively impact survival in estuarine organisms including oysters. Like other marine bivalves, oysters can accumulate high Cd burdens in their tissues and are susceptible to the toxic effects of this metal. Presently, the factors that affect sensitivity to Cd toxicity and its variation in wild oyster populations are poorly understood. We analyzed geographical and seasonal variability of mitochondrial responses to elevated temperatures and Cd stress in eastern oysters Crassostrea virginica from populations adapted to different thermal regimes (subtropical Texas (TX), warm temperate North Carolina (NC) and cold temperate Washington (WA) areas). Seasonality had a strong effect on mitochondrial function in oysters from the two studied southern populations (TX and NC) but not in their northern (WA) counterparts, with decreased mitochondrial abundance and increased rates of mitochondrial proton leak in gill tissues of TX and NC oysters in summer. Compared to WA oysters, oysters from the two southern populations accumulated Cd faster in their tissues, and their mitochondria were more sensitive to Cd inhibition in resting and ADP-stimulated states at 20 and 28 degrees C. At 12 degrees C, inter-populational differences in Cd accumulation rates and sensitivity of mitochondrial respiration to Cd were not significant. Within each of the three studied populations, sensitivity of mitochondrial ADP-stimulated respiration to Cd inhibition increased with increasing temperatures (28>20>12 degrees C). This indicates that oysters from the two southern sites may be more vulnerable to Cd toxicity due to exposure to high environmental temperatures in summer, elevated rates of Cd accumulation and high intrinsic sensitivity of their mitochondria to Cd. This study suggests that data on sensitivity to pollutants obtained for one population of oysters should be extrapolated to other conspecific populations with caution and that regulatory standards for water pollution based on the studies from one geographical region may not be protective for other areas. PMID:20047766

  1. The investigation of Raman spectrum of water with gas (CH4, CO2) solution under 40MPa pressure at different temperatures

    NASA Astrophysics Data System (ADS)

    Shi, Xiao-feng; Ma, Jun; Huang, Yang-yu; Yu, Zeng-hui; Cheng, Kai; Zheng, Rong-er

    2009-07-01

    In order to understand how pressure, temperature and CH4 and CO2 molecules effect Raman spectrum of liquid water better, some experimental investigations of Raman spectrum of water with gas (CH4, CO2 and mixture of CH4 and CO2) dissolved are carried out at different temperature (up to 350C) under high pressure (40MPa) and under different pressure (up to 40MPa) at room temperature using high-temperature and high-pressure set-up (top temperature is 350C and top pressure is 40MPa). The band of the stretching vibration of water between 3000 and 3800 cm-1 has been studied. The results show pressure has little influence on Raman spectrum of water for all samples in our pressure variation range while temperature affects Raman spectrum of water significantly in the range room temperature to 350C. Peak position, FWHM and the parameter R21 all vary sharply along temperature. As temperature is raised, peak positions shift to high frequency, FWHM decrease significantly and the parameters R21 increase with increasing temperature as EXP function in studied temperature range for all samples. All these variations have a relation with hydrogen bond. In addition, CO2 or CH4 dissolved in water makes all parameters vary along temperature more obviously and the CH4 molecule modifies the Raman spectrum of H2O much than the CO2 molecule.

  2. Correlation of spectral features of photoluminescence with residual native defects of ZnO thin films annealed at different temperatures

    NASA Astrophysics Data System (ADS)

    Kukreja, L. M.; Misra, P.; Fallert, J.; Phase, D. M.; Kalt, H.

    2012-07-01

    We investigated the effects of post-growth annealing in the temperature range of 873 to 1273 K on the spectral features of photoluminescence (PL) vis--vis the crystalline and compositional native defects of ZnO thin films grown at 773 K by pulsed laser deposition (PLD) on sapphire substrates. It is found in the PL spectra at 10 K that the deep level emission (DLE) shifted from red-orange spectral region of 1.8-2.4 eV to yellow-green region of 2.4-2.9 eV with the increasing temperature of annealing. We propose that the PL in red-orange region originating from the singly ionized oxygen vacancies diminished due to increased replenishment of oxygen with increasing annealing temperature and that in the yellow-green region originating from the oxygen interstitials and/or zinc vacancies increased due to enhanced concentration of these point defects. As the annealing temperature was increased, the overall intensity of PL in the DLE region increased slightly up to 973 K but beyond that it increased steeply and made a quantum leap at 1073 K. In contrast to that, intensity of PL due to the near band-edge emission (NBE) in UV region of 3.15 to 3.45 eV increased very steeply up to the annealing temperature of 973 K, which is found to be due to improvement in the crystalline and compositional qualities of the films and beyond that it dropped drastically due to deteriorations of these qualities. The high resolution PL spectra at 10 K in the NBE region mainly consisted of peaks due to the recombinations of neutral donor bound excitons' complexes (D0X) at 3.36 eV, free excitons (FXA) at 3.38 eV with their conspicuous LO phonon replicas and some other features such as exciton complexes bound to surface states or transitions of conduction band electrons to acceptor levels located in stacking faults and recombination of neutral acceptor bound excitons. The relative intensities of these individual features were strongly dependent on the annealing temperature of the films and the ensuing crystalline and compositional qualities. The 10 K PL spectra from the interfacial region of the annealed ZnO films and the sapphire substrates observed from the backside of the samples showed that the annealing temperature affected the crystalline and compositional qualities at the interface in a complex manner. Particularly, the features corresponding to the interface deteriorations resulting from the diffusion of Al into the ZnO films and the crystalline defects at the interface caused by the sputtering due to the PLD plume were prominently present in these PL spectra. These studies provide deeper insight into the fundamental PL processes in ZnO thin films annealed at different temperatures.

  3. 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.

  4. Effects of temperature on the properties of glycerol: a computer simulation study of five different force fields.

    PubMed

    Jahn, David A; Akinkunmi, Frederick O; Giovambattista, Nicolas

    2014-09-25

    We perform molecular dynamics simulations of glycerol (propane-1,2,3-triol) at normal pressure and a wide range of temperatures (300-460 K) and study the sensitivity of simulation results to the force field (FF) considered. We employ five commonly used FFs: (i) AMBER, (ii) CHARMM22, and (iii) three versions of the OPLS-AA FF (OPLS1, OPLS2, and OPLS3). We study thermodynamic (density ?(T), thermal expansion coefficient ?P(T), isobaric specific heat cP(T)), dynamic (diffusion coefficient D(T)), as well as structural properties (molecular conformations and hydrogen-bond statistics). In comparison with experiments, FFs i and iii provide reasonable estimations of ?(T) with deviations of ?4.5%; for FF ii, deviations in density are more pronounced, ?9%. Values of ?P(T) vary considerably among the FFs; e.g., deviations are ?9% for OPLS1-FF and ?60% for FF ii. For all models studied, values of cP(T) are approximately twice the corresponding experimental values. Diffusion coefficients are very sensitive to the FFs considered. Specifically, for FFs i and ii and OPLS3, the values of D(T) are remarkably close to the experimental values over the whole range of temperatures studied. Instead, in the cases of OPLS1 and OPLS2-FFs, D(T) is underestimated by approximately 2 orders of magnitude. Interestingly, in all cases, D(T) can be well described by a Vogel-Tamman-Fulcher equation, as observed in experiments. We present a detailed characterization of glycerol backbone conformation based on the traditional classification introduced by Bastiansen, defined in terms of glycerol's OCCC dihedral angles. All FFs indicate that the conformer population varies smoothly with temperature. However, the FFs provide very different conformer distributions. This implies that, from the microscopic point of view, these glycerol models may provide very different liquid environments for, for example, guest biomolecules and hence may play a relevant role in interpreting simulation results involving glycerol-based solutions. We also discuss the statistics of inter- and intramolecular hydrogen bonds (HBs). The FFs are qualitatively comparable regarding HB statistics; however, quantitative differences remain. For example, molecules form a total of 5.5-7 HBs at T = 350 K, depending on the FF considered, including at least one intramolecular HB. PMID:25188739

  5. Weather forecast uncertainty affecting hydrological modelling at different spatial scale: the key role of temperature in the evaluation of discharge

    NASA Astrophysics Data System (ADS)

    Ceppi, Alessandro; Ravazzani, Giovanni; Rabuffetti, Davide; Mancini, Marco

    2010-05-01

    In recent years, the interest in the prediction and prevention of natural hazards related to hydro-meteorological events has increased the challenge for numerical weather modelling, in particular for limited area models, to improve the Quantitative Precipitation Forecasts (QPFs) for hydrological purposes. In mountain river basins, where snow dynamics can affect both precipitation (snow accumulation) and runoff (snow melting), uncertainty of air temperature has to be deeply investigated too. After the encouraging results obtained in the MAP-D-PHASE Project and considering that orographic precipitation has often led to disastrous flooding events over the Alps, it was decided to devote further analyses to show recent improvements in the operational use of hydro-meteorological chain, consisting of atmospheric models, hydrological prediction systems and warnings for end users, but above all to investigate better the key role played by temperature during snowy precipitation. In this study we present a hindcast for some precipitation events, occurred between 2007 and 2009 in Piemonte region and in the Maggiore Lake basin (between Italy and Switzerland). The goal is to evaluate how the uncertainty of meteorological forecasts (precipitations and temperatures) influences the performance of hydrological predictions in terms of Quantitative Discharge Forecast (QDF) at different spatial scales. A non-hydrostatic meteorological limited area model is used to force the rainfall-runoff distributed hydrological model (FEST-WB), developed at Politecnico di Milano to generate the runoff simulations; COSMO-LEPS model is based on the 16 meteorological members, provided by ARPA Emilia-Romagna, with 5 day lead-time and a horizontal resolution of 10 km. The observed hydro-weather data to run the control simulations were supplied by ARPA-Piemonte, which uses the same model every day for nowcasting monitoring and as a civil protection tool.

  6. Water temperature differences by plant community and location in re-established wetlands in the Sacramento-San Joaquin Delta, California, July 2005 to February 2008

    USGS Publications Warehouse

    Crepeau, Kathryn L.; Miller, Robin L.

    2014-01-01

    Rates of carbon storage in wetlands are determined by the balance of its inputs and losses, both of which are affected by environmental factors such as water temperature and depth. In the autumn of 1997, the U.S. Geological Survey re-established two wetlands with different shallow water depthsabout 25 and 55 centimeters deepto investigate the potential to reverse subsidence of delta islands by preserving and accumulating organic substrates derived from plant biomass inputs over time. Because cooler water temperatures can slow decomposition rates and increase accretion of plant biomass, water temperature was recorded from July 2005 to February 2008 in the deeper of the two wetlands, where areas of emergent and submerged vegetation persisted throughout the study, to assess differences in water temperature between the two vegetation types. Water temperature was compared at three depths in the water column between areas of emergent and submerged vegetation and between areas near the water inflow and in the wetland interior in both vegetation types. The latter comparison was a way of evaluating the effect of the length of time water had resided in the wetland on water temperatures. There were statistically significant differences in water temperature at all depths between the two vegetation types. Overall, in areas of emergent marsh vegetation, the mean water temperature at the surface was 1.4 degrees Celsius (C) less than it was in areas of submerged vegetation; however, when analyses accounted for the changes in temperature due to seasonal and diurnal cycles, differences in the mean water temperature between the vegetation types were even greater than this. For example, in the spring, the mean temperatures in areas of emergent marsh vegetation at the surface, mid-point, and near the sediment in the water column were 2.0, 2.3, and 2.1 C less, respectively, than water temperatures in areas of submerged vegetation. When diurnal changes in temperature were accounted for by comparing temperatures in mid-afternoon (at 3 p.m.), water-temperature differences were even greater than the seasonal means indicated. In areas of emergent vegetation, the mean temperatures were cooler than temperatures in areas of submerged vegetation at the surface, the mid-point, and near the sediment in the water column by 3.9, 3.6, and 2.3 C, respectively. Furthermore, from July 2005 through December 2006, water temperatures at the surface in the interior of the wetland were significantly cooler than in areas near the inflow supplying water from the San Joaquin River by 1.0 C in areas of submerged vegetation and by 1.1 C in areas of emergent vegetation.

  7. Trapping induced N{sub eff} and electrical field transformation at different temperatures in neutron irradiated high resistivity silicon detectors

    SciTech Connect

    Eremin, V.; Li, Z.; Iljashenko, I.

    1994-02-01

    The trapping of both non-equilibrium electrons and holes by neutron induced deep levels in high resistivity silicon planar detectors have been observed. In the experiments Transient Current and Charge Techniques, with short laser light pulse excitation have been applied at temperature ranges of 77--300 k. Light pulse illumination of the front (p{sup +}) and back (n{sup +}) contacts of the detectors showed effective trapping and detrapping, especially for electrons. At temperatures lower than 150 k, the detrapping becomes non-efficient, and the additional negative charge of trapped electrons in the space charge region (SCR) of the detectors leads to dramatic transformations of the electric field due to the distortion of the effective space charge concentration N{sub eff}. The current and charge pulses transformation data can be explained in terms of extraction of electric field to the central part of the detector from the regions near both contacts. The initial field distribution may be recovered immediately by dropping reverse bias, which injects both electrons and holes into the space charge region. In the paper, the degree of the N{sub eff} distortions among various detectors irradiated by different neutron fluences are compared.

  8. Wavelength and temperature dependence of RAPD aser detectors.

    PubMed

    Su, Y K; Chang, C Y; Wu, T S; Houng, M P; Wang, Y H

    1981-12-15

    Wavelength and temperature-dependent characteristics of silicon reach-through avalanche photodiodes (RAPD) are studied using the modified Baraff's theory. The temperature and wavelength regions discussed are 100-500 K and 0.655-1.06 microm, respectively, for Si photodetectors. The effects of breakdown voltage, depletion region width, and efficiency on the avalanche region width are widely studied. Both n(+) (front) side and p(+) (back) side illumination are also considered. The noise equivalent power is significantly reduced with light incident on the p(+) surface with little sacrifice of efficiency. An RAPD structure is proposed in which the direction of radiation incidence causes photogeneration to precede avalanche multiplication reducing the multiplication noise substantially. This result should be useful in the design of RAPD laser detectors. PMID:20372361

  9. Ingesting Land Surface Temperature differences to improve Downwelling Solar Radiation using Artificial Neural Network: A Case Study

    NASA Astrophysics Data System (ADS)

    Malakar, N. K.; Bailey, M.; Latto, R.; Ekwedike, E.; Gross, B.; Gonzalez, J.; Vorosmarty, C. J.; Hulley, G. C.

    2014-12-01

    In order to study the effects of global climate change on regional scales, we need high resolution models that can be injected into local ecosystem models. Although the injection of regional Meteorological Models such as Weather Research and Forecasting (WRF) can be attempted where the Global Circulation Model (GCM) conditions and the forecasted land surface properties are encoded into future time slices - this approach is extremely computer intensive.We present a two-step mechanism in which low resolution meteorological data including both surface and column integrated parameters are combined with high resolution land surface classification parameters to improve on purely interpolative approaches by using machine learning techniques. In particular, we explore the improvement of surface radiation estimates critical for ecosystem modeling by combining both model and satellite based surface radiation together with land surface temperature differences.

  10. The influence of humidification and temperature differences between inlet gases on water transport through the membrane of a proton exchange membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Huang, Kuan-Jen; Hwang, Sheng-Jye; Lai, Wei-Hsiang

    2015-06-01

    This paper discusses the effects of humidification and temperature differences of the anode and cathode on water transport in a proton exchange membrane fuel cell. Heaters are used to cause a difference in gas temperature between two electrodes before the gases enter the fuel cell. The results show that when the temperature of the cathode is higher than that of the anode, the electro-osmotic drag is suppressed. In contrast, when the temperature of the anode is higher than that of cathode, it is enhanced. These effects are more significant when the temperature difference between the anode and cathode is greater. The same trends are seen with back diffusion. Three cases are tested, and the results show that the suppression due to the temperature difference occurs even when the relative humidity is low at the hotter side. The water transport tendencies of electro-osmotic drag and back diffusion in different situations can be expressed as dominant percentages calculated by the water masses collected at the anode and cathode. The suppression effect due to the temperature difference is relatively insignificant with regard to back diffusion compared to electro-osmosis, so water tends to accumulate on the anode rather than the cathode side.

  11. Appearance, temperature, and NO{sub x} emission of two inverse diffusion flames with different port design

    SciTech Connect

    Sze, L.K.; Cheung, C.S.; Leung, C.W. [Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong (China)

    2006-01-01

    Experiments were carried out to investigate the appearance, temperature distribution, and NO{sub x} emission index of two inverse diffusion flames, one with circumferentially arranged ports (CAPs) and the other with co-axial (CoA) jets, both burning LPG with 70% butane and 30% propane. Flame appearances were investigated first with a fixed fueling rate at different airflow rates equivalent to air jet Reynolds numbers (Re) of 1000 to 4500; and then at a fixed airflow rate with different fueling rates equivalent to overall equivalence ratios (F) of 1.0 to 2.0. The CAP flame is found to consist of two zones: a lower entrainment zone and an upper mixing and combustion zone. The CoA flame in most cases is similar to a diffusion flame. The two-zone structure can be observed only at Re larger than 2500. The temperature distributions of the flames are similar at overall equivalence ratios of 1.0 and 1.2 for Re=2500, except that the corresponding CoA flame is longer. The flame temperature is higher in the CAP flame than the CoA flame at higher overall equivalence ratios. A measurement of centerline oxygen concentrations shows that the oxygen concentration reaches a minimum value at a flame height of 50 mm in the CAP flame but decreases more gradually in the CoA flame. It can be concluded that there is more intense air-fuel mixing in a CAP flame than the CoA flame. Investigation of the emission index of NO{sub x} (EINO{sub x}) for both flames at Re=2500 and overall equivalence ratios of 1.0 to 6.0 reveals that the EINO{sub x} curve of each flame is bell-shaped, with a maximum value of 3.2 g/kg at F=1.2 for the CAP flame and 3 g/kg at F=2.2 for the CoA flame.

  12. Comparative study on the use of analytical software to identify the different stages of breast cancer using discrete temperature data.

    PubMed

    Tan, Joanna M Y; Ng, E Y K; Acharya, Rajendra U; Keith, Louis G; Holmes, Jim

    2009-04-01

    Breast cancer is the second leading cause of death in women. It occurs when cells in the breast begin to grow out of control and invade nearby tissues or spread throughout the body. The limitations of mammography as a screening modality, especially in young women with denser breasts, necessitated the development of novel and more effective screening strategies with acceptable sensitivity and specificity. The aim of this study was to develop a feasible interpretive software system which was able to detect and classify breast cancer patients by employing techniques of different analytical software. The protocol described uses 6,000 pieces of thermal data collected from 16-sensors, eight placed on the surface of each breast. Data was collected every 5 min for the duration of the test period. Placement of sensors was accomplished with the use of a template design from information provided by the national tumor registry to insure that the information was collected in areas of the breast where most breast cancers develop. Data in this study was collected from 90 individuals exhibiting four different breast conditions, namely: normal, benign, cancer and suspected-cancer. The temperature data collected from these 16 sensors placed on the surface of each breast were fed as inputs to the classifiers. Comparisons were made on five different kinds of classifiers: back-propagation algorithm, probabilistic neural network, fuzzy (Sugeno-type), Gaussian mixture modeland support vector machine. These classifiers were able to attain approximately 80% accuracy in classifying the four different diagnoses (normal, benign, cancer and suspected-cancer). Gaussian mixture model was the most sensitive classifier, achieving the highest sensitivity of 94.8%. Support vector machine was considered the best classifier as it was able to produce the most specific and accurate results. Based on these evaluations, this current effort shows the feasibility of applying analytical software techniques together with the real-time functional thermal analysis to develop a potential tool for the detection and classification of breast cancer. PMID:19397099

  13. Temperature dependence of the elastic modulus of crystalline regions of polyethylene with different microstructuresexplanation with the kinked-chain model

    Microsoft Academic Search

    T. Nishino; H. Ohkubo; K. Nakamae

    1992-01-01

    Temperature dependence of the elastic modulus E1 of crystalline regions in the direction parallel to the chain axis has been measured by x-ray diffraction for various kinds of polyethylene (PE) with different microstructures. The E1 value is 235 GPa for all kinds of PE at room temperature. However, in some cases, E1 began to decrease at a certain temperature, in

  14. A new evaluation method for zeotropic refrigerant mixtures based on the variance of the temperature difference between the refrigerant and heat transfer fluid

    Microsoft Academic Search

    Xing Jin; Xiaosong Zhang

    2011-01-01

    Compared to the pure refrigerants, the zeotropic refrigerant mixtures have the obvious temperature glide during phase change. Therefore, the Lorenz cycle can be approached with this special attribute. By analysing the heat transfer in the counter flow heat exchanger, a new evaluation method for zeotropic refrigerant mixtures based on the variance of the temperature difference between the refrigerant and heat

  15. The investigation of Raman spectrum of water with gas (CH4, CO2) solution under 40MPa pressure at different temperatures

    Microsoft Academic Search

    Xiao-Feng Shi; Jun Ma; Yang-Yu Huang; Zeng-Hui Yu; Kai Cheng; Rong-Er Zheng

    2009-01-01

    In order to understand how pressure, temperature and CH4 and CO2 molecules effect Raman spectrum of liquid water better, some experimental investigations of Raman spectrum of water with gas (CH4, CO2 and mixture of CH4 and CO2) dissolved are carried out at different temperature (up to 350C) under high pressure (40MPa) and under different pressure (up to 40MPa) at room

  16. Effects of rapid temperature changes on HK, PK and HSP70 of Litopenaeus vannamei in different seasons

    Microsoft Academic Search

    Biao Guo; Fang Wang; Shuanglin Dong; Chunqiang Hou

    2010-01-01

    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\\u000a from 27C to 17C for the summer case (Cold temperature treatment), or from 17C to 27C for the winter case (Warm temperature\\u000a treatment). After

  17. Research on Effects of the Thermal Stimulation by Moxibustion at Different Temperatures on Cardiac Function in Rats and on Mast Cells in the Local Site of Moxibustion

    PubMed Central

    Wang, Yao-Shuai; Zhang, Jian-Bin; Jiang, Jin-Feng; Wang, Ling-Ling

    2013-01-01

    Objective. To observe effects of the thermal stimulation by moxibustion at different temperatures on cardiac function in brachycardia rat model and on mast cells in the local site of moxibustion at the Ximen Acupoint and to compare the differences of the effects of moxibustion at different temperatures. Method. Establish the brachycardia rat model with propranolol and observe effects of the thermal stimulation by moxibustion at different temperatures (38C and 46C). Results. The thermal stimulation by moxibustion at 2 temperatures may increase HR, MAP, LVSP, and +dp/dtmax and reduce t-dp/dtmax in brachycardia rats; the 46C moxibustion group shows greater regulating effects on cardiac function in rats than that in the 38C moxibustion group (P < 0.05). The thermal stimulation by moxibustion at 2 temperatures may promote degranulation of mast cells in the local site of moxibustion at the Ximen Acupoint; the degranulation rate in the 46C moxibustion group is higher than that in the 38C moxibustion group (P < 0.05). Conclusion. There is a certain association between the effect on the target organ and the effect in the local site of moxibustion. The moxibustion effect possibly resulted from local mast cells degranulation and different thermoreceptors activated by the thermal stimulation at different temperatures. PMID:23970933

  18. Laser-induced damage of Ta2O5 films obtained from TaCl5 precursor and annealed at different temperatures

    NASA Astrophysics Data System (ADS)

    Xu, Cheng; Li, Dawei; Fan, Heliang; Qi, Jianwei; Deng, Jianxin; Yang, Shuai; Yi, Peng; Qiang, Yinghuai

    2015-07-01

    In this study, Ta2O5 sol was synthesized from TaCl5 precursor, and its time dependence of the viscosity, particle size distribution and photoluminescence spectra were studied. Then, Ta2O5 films were prepared using this sol and were succeeding annealed at different temperatures without carbonization and cracks. It was found that the films had good properties such as high transparency, small absorption and high laser-induced damage threshold (LIDT). The LIDT decreased with the increase of the annealing temperature probably due to the acetylacetone in the films. The laser-induced damage morphologies of the films after annealing were different. With the annealing temperature increase, the dominant factor of the laser-induced damage transformed gradually from the stress to the thermal. According to the LIDT and damage morphologies, a structure evolution model of the films annealed at different temperatures was proposed.

  19. Behavior of Salmonella spp. and natural microbiota on fresh-cut dragon fruits at different storage temperatures.

    PubMed

    Sim, Hui Li; Hong, Yoon-Ki; Yoon, Won Byong; Yuk, Hyun-Gyun

    2013-01-01

    The aim of this study was to determine survival or growth of unadapted, acid-adapted and cold-stressed Salmonella spp., and natural microbiota on fresh-cut dragon fruits at different storage temperatures. Dragon fruits were sliced and spot inoculated with five-strain cocktail of Salmonella spp. at two inoculum levels (2.5 or 5.5 log CFU/g). Inoculated fruits were stored at 28C for 48h and at 4C and 12C for 96 h. Salmonella population significantly increased by 2.4 to 3.0 log CFU/g at low inoculum level, whereas the numbers increased by 0.4 to 0.7 log CFU/g at the high inoculum level on fruits held at 28C for 48h. Only unadapted and acid-adapted cells grew with 0.7 to 0.9log increase at the low inoculum level at 12C for 96h. No significant growth was observed at both inoculum levels during storage at 4C. Overall, acid, starved and cold adaptation of Salmonella spp. did not show significant difference in survival or growth on fresh-cut dragon fruits during storage compared to unadapted control cells. For natural microbiota on the fruit, mesophilic bacterial counts reached to 5-log CFU/g at 28 and 12C by 9.9 and 52.9h. Similar with Salmonella spp. there was no growth of natural microbiota at 4C. These results showed that Salmonella spp. could grow on fresh-cut dragon fruits under inappropriate storage conditions, indicating that fresh-cut dragon fruits could be a potential vehicle for salmonellosis. Thus, this study suggests that fresh-cut dragon fruits should be stored at 4C to ensure the safety as well as to extend the shelf life of fresh-cut dragon fruits. PMID:23290230

  20. The Relation Between Wind Speed and Air-Sea Temperature Difference in the Marine Atmospheric Boundary Layer off Northwest Europe

    NASA Astrophysics Data System (ADS)

    Kettle, A. J.

    2014-12-01

    Wind speed and atmospheric stability have an important role in determining the turbulence in the marine atmospheric boundary layer (MABL) as well as the surface wave field. The understanding of MABL dynamics in northwest Europe is complicated by fetch effects, the proximity of coastlines, shallow topography, and larger scale circulation patterns (e.g., cold air outbreaks). Numerical models have difficulty simulating the marine atmospheric boundary layer in coastal areas and partially enclosed seas, and this is partly due to spatial resolution problems at coastlines. In these offshore environments, the boundary layer processes are often best understood directly from time series measurements from fixed platforms or buoys, in spite of potential difficulties from platform flow distortion as well as the spatial sparseness of the data sets. This contribution presents the results of time series measurements from offshore platforms in the North Sea and Norwegian Sea in terms of a summary diagnostic - wind speed versus air-sea temperature difference (U-?T) - with important implications for understanding atmospheric boundary layer processes. The U-?T diagram was introduced in earlier surveys of data from coastal (Sletringen; O.J. Andersen and J. Lvseth, J. Wind Eng. Ind. Aerodyn., 57, 97-109, 1995) and offshore (Statfjord A; K.J. Eidsvik, Boundary-Layer Meteorol., 32, 103-132, 1985) sites in northwest Europe to summarize boundary layer conditions at a given location. Additional information from a series of measurement purpose-built offshore measurement and oil/gas production platforms from the southern North Sea to the Norwegian Sea illustrates how the wind characteristics vary spatially over large distances, highlighting the influence of cold air outbreaks, in particular. The results are important for the offshore wind industry because of the way that wind turbines accrue fatigue damage in different conditions of atmospheric stability and wind speed.

  1. The influence of six pharmaceuticals on freshwater sediment microbial growth incubated at different temperatures and UV exposures.

    PubMed

    Veach, Allison; Bernot, Melody J; Mitchell, James K

    2012-07-01

    Pharmaceutical compounds have been detected in freshwater for several decades. Once they enter the aquatic ecosystem, they may be transformed abiotically (i.e., photolysis) or biotically (i.e., microbial activity). To assess the influence of pharmaceuticals on microbial growth, basal salt media amended with seven pharmaceutical treatments (acetaminophen, caffeine, carbamazepine, cotinine, ibuprofen, sulfamethoxazole, and a no pharmaceutical control) were inoculated with stream sediment. The seven pharmaceutical treatments were then placed in five different culture environments that included both temperature treatments of 4, 25, 37C and light treatments of continuous UV-A or UV-B exposure. Microbial growth in the basal salt media was quantified as absorbance (OD(550)) at 7, 14, 21, 31, and 48d following inoculation. Microbial growth was significantly influenced by pharmaceutical treatments (P<0.01) and incubation treatments (P<0.01). Colonial morphology of the microbial communities post-incubation identified selection of microbial and fungal species with exposure to caffeine, cotinine, and ibuprofen at 37C; acetaminophen, caffeine, and cotinine at 25C; and carbamazepine exposed to continuous UV-A. Bacillus and coccus cellular arrangements (1000X magnification) were consistently observed across incubation treatments for each pharmaceutical treatment although carbamazepine and ibuprofen exposures incubated at 25C also selected spiral-shaped bacteria. These data indicate stream sediment microbial communities are influenced by pharmaceuticals though physiochemical characteristics of the environment may dictate microbial response. PMID:22200842

  2. 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

  3. Different Patterns of Gas Exchange and Photochemical Efficiency in Three Desert Shrub Species Under Two Natural Temperatures and Irradiances in Mu Us Sandy Area of China

    Microsoft Academic Search

    G. M. Jiang; G. J. Zhu

    2001-01-01

    Field studies of gas exchange and chlorophyll fluorescence of three desert shrub species, Hedysarum fruticosum var. mongolicum, Artemisia ordosia, and Salix pasmmophylla, showed different patterns under different leaf temperature (T1) and incident photosynthetic photon flux density (PPFD). H. fruticosum var. mongolicum and A. ordosia exhibited higher PN and gs than S. pasmmophylla, especially under very high T1 (>46 C) and

  4. Sub-THz radiation room temperature sensitivity of long-channel silicon field effect transistors

    NASA Astrophysics Data System (ADS)

    Sizov, F.; Golenkov, A.; But, D.; Sakhno, M.; Reva, V.

    2012-06-01

    Room temperature operating n-MOSFETs (n-type metal-oxide silicon field effect transistors) used for registration of sub-THz (sub-terahertz) radiation in the frequency range ? = 53-145 GHz are considered. n-MOSFETs were manufactured by 1-?m Si CMOS technology applied to epitaxial Si-layers (d ?15 ?m) deposited on thick Si substrates (d = 640 ?m). It was shown that for transistors with the channel width to length ratio W/L = 20/3 ?m without any special antennas used for radiation input, the noise equivalent power (NEP) for radiation frequency ? ?76 GHz can reach NEP 610-10 W/Hz1/2. With estimated frequency dependent antenna effective area Sest for contact wires considered as antennas, the estimated possible noise equivalent power NEPpos for n-MOSFET structures themselves can be from 15 to 103 times better in the specral range of ? 55-78 GHz reaching NEPpos ?10-12 W/Hz1/2.

  5. Growth of Salmonella enterica and Listeria monocytogenes on Fresh-Cut Cantaloupe under Different Temperature Abuse Scenarios.

    PubMed

    Huang, Jingwei; Luo, Yaguang; Nou, Xiangwu

    2015-06-01

    Effective cold chain management is a critical component of food safety practice. In this study, we examined the impact of commonly encountered temperature abuse scenarios on the proliferation of Salmonella enterica and Listeria monocytogenes on fresh-cut cantaloupe. Inoculated fresh-cut cantaloupe cubes were subjected to various temperature abuse conditions, and the growth of S. enterica and L. monocytogenes was determined. During 1 week of storage, Salmonella cell counts on fresh-cut cantaloupe increased by -0.26, 1.39, and 2.23 log units at 4C (control), 8C, and 12C (chronic temperature abuse), respectively, whereas that of L. monocytogenes increased by 0.75, 2.86, and 4.17 log units. Under intermittent temperature abuse conditions, where storage temperature fluctuated twice daily to room temperature for 30 min, Salmonella cell count increased by 2.18 log units, whereas that of L. monocytogenes increased by 1.86 log units. In contrast, terminal acute temperature abuses for 2 to 4 h resulted in upwards to 0.6 log unit for Salmonella, whereas the effect on L. monocytogenes was less significant compared with L. monocytogenes on cut cantaloupe stored at 4C. Significant deterioration of produce visual quality and tissue integrity, as reflected by electrolyte leakage, was also observed under various temperature abuse conditions. PMID:26038902

  6. Proton and Electron Irradiation of Solid Nitrous Oxide at Different Temperatures and Implications to the Solar System Ices

    NASA Astrophysics Data System (ADS)

    Sivaraman, Bhalamurugan; Moore, Marla; Mason, Nigel

    N2 O was the third molecule to be detected in space that contains the NO bond therefore demonstrating the universality of basic chemistry that, on Earth at least, led to evolution of life. Significant concentrations of nitrous oxide (a relative fractional abundance of 10-9 to molecular hydrogen, H2 ) have been observed in the SgrB2(M) and is believed to have been produced by neutral-neutral reactions. Although N2 O has not yet been detected in any of the outer solar system planets/satellites it is nevertheless likely that it will be formed by irradiation of common ices like N2 , CO2 and CO. Indeed irradiation of N2 and carbon dioxide (CO2 ) ice by energetic electrons at 5 keV (Jamieson et al., 2005) and N2 + CO ice by protons at 0.8 MeV (Moore and Hudson, 2003) have shown that N2 O will be easily formed in astrochemical ices. Therefore it is important to study irradiation of N2 O ices in order to determine subsequent chemical products. Earlier experiments (Liang et al., 1984) using 4 keV argon atoms/ions and (Sivaraman et al., 2008) using 1 keV electrons have revealed that, contrary to expectations, ozone is formed when solid nitrogen oxides are bombarded by energetic particles. Since ozone is widely suggested as a biomarker in extrasolar planets, the mechanisms and probability of ozone being formed at different temperatures by such abiotic processes should therefore be investigated. References: C. S. Jamieson, C. J. Bennett, A. M. Mebel, R. I. Kaiser, ApJ 624 (2005) 436. M. H. Moore, R. L. Hudson, Icarus 161 (2003) 486. J. Liang, J. Michl, J. Am. Chem. Soc. 106 (1984) 5039. B. Sivaraman, S. Ptasinska, S. Jheeta, N. J. Mason, Submitted to Chem Phys Lett (2008).

  7. 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

  8. 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.

  9. Spray pyrolysis deposition of ZnO thin films on FTO coated substrates from zinc acetate and zinc chloride precursor solution at different growth temperatures

    Microsoft Academic Search

    . Alver; A. Kudret; S. Tekerek

    2011-01-01

    ZnO thin films were fabricated using zinc chloride and zinc acetate precursors by the spray pyrolysis technique on FTO coated glass substrates. The ZnO films were grown in different deposition temperature ranges varying from 400 to 550C. Influences of substrate temperature and zinc precursors on crystal structure, morphology and optical property of the ZnO thin films were investigated. XRD patterns

  10. A simulation model of temperature transitory on rocks having different thermal inertia. Analysis of the theoretical capacity of rock discrimination by remote sensing data

    NASA Technical Reports Server (NTRS)

    Cassinis, R. (principal investigator); Tosi, N.

    1980-01-01

    The possibility of identifying ground surface material by measuring the surface temperature at two different and significant times of the day was investigated for the case of hypothetical island whose rocky surface contained no vegetation and consisted of dolomite, clay, and granite. The thermal dynamics of the soil surface during a day in which atmospheric conditions were average for a latitude of about 40 deg to 50 deg were numerically simulated. The line of separation between zones of different materials was delineated by the range of temperature variation. Results show that the difference between maximum and minimum value of the temperature of ground surface during the day is linked to the thermal inertia value of the material of which the rock is formed.

  11. 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

  12. Linking Microbial Community Structure and Function to Seasonal Differences in Soil Moisture and Temperature in a Chihuahuan Desert Grassland

    Microsoft Academic Search

    Colin W. Bell; Veronica Acosta-Martinez; Nancy E. McIntyre; Stephen Cox; David T. Tissue; John C. Zak

    2009-01-01

    Global and regional climate models predict higher air temperature and less frequent, but larger precipitation events in arid\\u000a regions within the next century. While many studies have addressed the impact of variable climate in arid ecosystems on plant\\u000a growth and physiological responses, fewer studies have addressed soil microbial community responses to seasonal shifts in\\u000a precipitation and temperature in arid ecosystems.

  13. 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;

  14. Glacier melt, air temperature, and energy balance in different climates: The Bolivian Tropics, the French Alps, and northern Sweden

    Microsoft Academic Search

    Jean Emmanuel Sicart; Regine Hock; Delphine Six

    2008-01-01

    This study investigates the physical basis of temperature-index models for three glaciers in contrasting climates: Zongo (16S, 5050 m, Bolivian Tropics), St Sorlin (45N, 2760 m, French Alps), and Storglaciren (67N, 1370 m, northern Sweden). The daily energy fluxes were computed during melt seasons and correlated with each other and with air temperature on and outside the glacier. The relative

  15. Effects of staged vessels on dissolver performance. Internal R and D final report. [Staged reactors at different temperatures

    SciTech Connect

    Sivasubramanian, R.; Givens, E.N.

    1983-09-01

    This report summarizes the work conducted under ICRC's Program Area 12.1.7, on the effects of staged vessels on dissolver performance. Results showed that operating the dissolvers in series decreased the preasphaltenes yield. From a process viewpoint, this should increase the amount of recoverable product, because recovery from the plant's critical solvent deashing unit will increase when preasphaltene content decreases. Neither conversion nor oil, asphaltene, or gas yields were affected by reactor configuration. Process data taken at residence times from 20 to 60 min and temperatures from 780 to 840/sup 0/F showed that oil yields were directly affected by reaction time, but relatively insensitive to temperature. Operating the dissolvers at staged temperatures may have some potential advantages. For Lafayette Kentucky number 9 coal, operating the first dissolver at 810/sup 0/F and the second at 840/sup 0/F, agreed with the results observed under similar conditions on Lafayette coal. By operating the first reactor at a lower temperature, the oil yields were improved, compared to operating both reactors at the same temperature. The hydrocarbon gas yields and hydrogen consumption were lower in the staged-temperature than in the isothermal mode. 8 references, 9 figures, 26 tables.

  16. 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

  17. Peculiarities of thermo-optic coefficient under different temperature regimes in optical fibers containing fiber Bragg gratings

    NASA Astrophysics Data System (ADS)

    Adamovsky, Grigory; Lyuksyutov, Sergei F.; Mackey, Jeffrey R.; Floyd, Bertram M.; Abeywickrema, Ujitha; Fedin, Igor; Rackaitis, Mindaugas

    2012-03-01

    Direct experimental measurements of the thermo-optic for fixed temperature intervals (20-200 C, 200-500 C, 500-660 C, 660-780 C) in fused silica fiber containing fiber Bragg gratings (FBGs) were conducted. The diffraction efficiency of a FBG fluctuated with temperature between 2.01 10 - 4 and 0.17 10 - 4 while the temperature shift of the Bragg's peak was monitored between 1300 and 1311 nm with sub-Angstrom precision. Numerical simulations were focused on FBG's diffraction efficiency calculations accounting for the temperature drift of the gratings, and found to be in excellent agreement with obtained experimental data. It was found that the first-order thermo-optic coefficient changes between 1.29 and 1.85 10 - 5 K - 1 for the linear fit and at T = 0 C its value was found to be close to 2.37 10 - 5 K - 1 for the polynomial fit of experimental data. The average thermo-optic coefficient undergoes a minimum in the vicinity of 440 C. Additional observation indicates a negative sign of the second-order thermo-optic coefficient. The value of thermal expansion coefficient was much less (0.5 10 - 6 K - 1 ) than that for the average thermo-optic coefficient. Based on the energy dispersive spectroscopy it was determined that thermal erasing of the FBGs at a temperature around 780 C corresponds to germanium monoxide diffusion out of core in silica-based fibers.

  18. 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 30 C to 20 C and 10 C) 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 10 C. Lower working temperature (10/20 C) 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

  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. Physico-Chemical Characterization of Carrageenan at Different Temperatures, Isolated from Hypnea musciformis from Karachi Coast Pakistan

    NASA Astrophysics Data System (ADS)

    Junaid Mahmood, Syed; Bi, Fatima; Taj, Noor; Seema; Farhan, M.; Shahid, M.; Azmat, Rafia; Uddin, Fahim

    This study describe the basic tools like viscosity measurements and thermodynamic parameters of the polysaccharide isolated from Hypnea musciformis (red algae) of Karachi Coast (Pakistan) showed characteristics of κ-carrageenan. An IR spectrum showed a fairly sharp band at 1210, 1225 cm-1 corresponding to sulphate ester and is in accordance with the high sulphate content of κ-carrageenan. Viscosity measurements revealed a linear relationship with increase in concentration and decreased with the rise in temperature of aqueous solutions of κ-carrageenan. Thermodynamic parameters were determined by the change in viscosity data as a function of temperature and concentration. The free energy change of activation ('Gη) increased regularly as the concentration of aqueous κ-carrageenan increased, as well as rises in temperature. Higher values of free energy change of activation, ('Gη) showed the higher association of κ-carrageenan with water at given temperature. The values of entropy change of activation ('Sη) of viscous flow also increased with the increase in concentration and temperature of aqueous κ-carrageenan solution. The high negative values of entropy change of activation ('Sη) showed that the solution of κ-carrageenan was more ordered in initial state than the activated one.

  1. Transient temperature responses of hydronic radiant floor heating system by different pipe embedding depth and water supply condition.

    PubMed

    Chung, K S; Sohn, J Y; Baik, Y K; Kang, J S

    1993-07-01

    "Ondol" is a Korean unique heating system. It is a specific radiant floor heating system using combustion heat of briquette or timber in Korea. Such traditional "Ondol" is changed to radiant heating system with pipe-coil embedded in the floor or slab. This study has contributed to the understandings of the transient behaviours of Ondol-heated floor panels and enclosure exposed to this type of heating system. The result is that the water supply temperature had a large effect on the rate of increase in floor surface and room air temperature. But, in spite of a higher water supply temperature, the heat flow rate was not increased considerably. The shallow pipe embedding depths, of course, result in a low heat flow rate. PMID:8373479

  2. Aerosolization of two strains (ice+ and ice-) of Pseudomonas syringae in a Collison nebulizer at different temperatures

    NASA Astrophysics Data System (ADS)

    Pietsch, Renee; David, Ray; Marr, Linsey; Vinatzer, Boris; Schmale, David

    2015-04-01

    The aerosolization of microorganisms from aquatic environments is understudied. In this study, an ice nucleation active (ice+) strain and a non-ice nucleation active (ice-) strain of the bacterium Pseudomonas syringae were aerosolized from aqueous suspensions under artificial laboratory conditions using a Collison nebulizer. The aerosolization of P. syringae was not influenced by water temperatures between 5 and 30C. In general, the culturability (viability) of P. syringae in aerosols increased with temperature between 5 and 30C. The ice+ strain was aerosolized in greater numbers than the ice- strain at all temperatures studied, suggesting a possible connection between the ice nucleation phenotype and aerosol production. Together, our results suggest that P. syringae has the potential to be aerosolized from natural aquatic environments, such as streams, rivers, ponds, and lakes; known reservoirs of P. syringae. Future work is needed to elucidate the mechanisms of aerosolization of P. syringae from natural aquatic systems.

  3. 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

  4. 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 temperature changes on the phantom, we took a screenshot of the thermograph with a digital camera every 20 seconds. [Results] With 1?MHz ultrasound at the distances of 2 and 3?cm, the temperature elevation near the bone was higher than that near the transducer. However, with 3?MHz ultrasound, the temperature elevation was higher near the transducer rather than near the bone. At this point, we consider that there is a possibility of heat injury to internal organs in spite of there being no elevation of skin temperature. [Conclusion] When performing ultrasonic therapy, not only should the frequency be taken into consideration, but also the influence of the absorption coefficient and the reflection of the tissue. We visually confirmed the thermal ultrasound effect by thermography. Special attention to the temperature elevation of the internal organs is necessary to avoid injuries. PMID:25642074

  5. Pressure, temperature and density drops along supercritical fluid chromatography columns in different thermal environments. III. Mixtures of carbon dioxide and methanol as the mobile phase.

    PubMed

    Poe, Donald P; Veit, Devon; Ranger, Megan; Kaczmarski, Krzysztof; Tarafder, Abhijit; Guiochon, Georges

    2014-01-01

    The pressure, temperature and density drops along SFC columns eluted with a CO2/methanol mobile phase were measured and compared with theoretical values. For columns packed with 3- and 5-?m particles the pressure and temperature drops were measured using a mobile phase of 95% CO2 and 5% methanol at a flow rate of 5mL/min, at temperatures from 20 to 100C, and outlet pressures from 80 to 300bar. The density drop was calculated based on the temperature and pressure at the column inlet and outlet. The columns were suspended in a circulating air bath, either bare or covered with foam insulation. The experimental measurements were compared to theoretical results obtained by numerical simulation. For the convective air condition at outlet pressures above 100bar the average difference between the experimental and calculated temperature drops and pressure drops were 0.1C and 0.7% for the bare 3-?m column, respectively, and were 0.6C and 4.1% for the insulated column. The observed temperature drops for the insulated columns are consistent with those predicted by the Joule-Thomson coefficients for isenthalpic expansion. The dependence of the temperature and the pressure drops on the Joule-Thomson coefficient and kinematic viscosity are described for carbon dioxide mobile phases containing up to 20% methanol. PMID:24315126

  6. 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

    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/cm(2) for 5 minutes. To record the temperature changes on the phantom, we took a screenshot of the thermograph with a digital camera every 20 seconds. [Results] With 1?MHz ultrasound at the distances of 2 and 3?cm, the temperature elevation near the bone was higher than that near the transducer. However, with 3?MHz ultrasound, the temperature elevation was higher near the transducer rather than near the bone. At this point, we consider that there is a possibility of heat injury to internal organs in spite of there being no elevation of skin temperature. [Conclusion] When performing ultrasonic therapy, not only should the frequency be taken into consideration, but also the influence of the absorption coefficient and the reflection of the tissue. We visually confirmed the thermal ultrasound effect by thermography. Special attention to the temperature elevation of the internal organs is necessary to avoid injuries. PMID:25642074

  7. Abnormal difference between the mobilities of left- and right-twisted conformations of C6H12N2 roto-symmetrical molecules at very low temperatures.

    PubMed

    Gabuda, S P; Kozlova, S G

    2015-06-21

    We report an abnormal difference of low-temperature mobility of left-twisted and right-twisted conformations of roto symmetric molecules C6H12N2 (dabco) located in the same positions in crystal Zn2(C8H4O4)2?C6H12N2. The difference between (1)H NMR (Nuclear Magnetic Resonance) spin-relaxation data for left-twisted and right-twisted molecules reaches ?3 10(3) times at 8 K and tends to grow at lower temperatures. We argue that taking into account four-component relativistic Dirac wave functions in the vicinity of the nodal plane of dabco molecules and vacuum fluctuations due to virtual particle-antiparticle pairs can explain the changes which C6H12N2 conformations undergo at low temperatures. PMID:26093554

  8. Abnormal difference between the mobilities of left- and right-twisted conformations of C6H12N2 roto-symmetrical molecules at very low temperatures

    NASA Astrophysics Data System (ADS)

    Gabuda, S. P.; Kozlova, S. G.

    2015-06-01

    We report an abnormal difference of low-temperature mobility of left-twisted and right-twisted conformations of roto symmetric molecules C6H12N2 (dabco) located in the same positions in crystal Zn2(C8H4O4)2?C6H12N2. The difference between 1H NMR (Nuclear Magnetic Resonance) spin-relaxation data for left-twisted and right-twisted molecules reaches 3 103 times at 8 K and tends to grow at lower temperatures. We argue that taking into account four-component relativistic Dirac wave functions in the vicinity of the nodal plane of dabco molecules and vacuum fluctuations due to virtual particle-antiparticle pairs can explain the changes which C6H12N2 conformations undergo at low temperatures.

  9. Characterizing heat shock protein 90 gene of Apolygus lucorum (Meyer-Dr) and its expression in response to different temperature and pesticide stresses.

    PubMed

    Sun, Yang; Sheng, Yang; Bai, Lixin; Zhang, Yongjun; Xiao, Yingfang; Xiao, Liubin; Tan, Yongan; Shen, Youmi

    2014-09-01

    In this study, we cloned a full-length cDNA of heat shock protein (HSP) gene of Apolygus lucorum (Meyer-Dr) [AlHSP90, KC109781] and investigated its expression in response to temperature and pesticide stresses. The open reading frame (ORF) of AlHSP90 is 2,169 bp in length, encoding a 722 amino acid polypeptide with a predicted molecular weight of 82.99 kDa. Transcriptional and translational expression profiles of AlHSP90 under extreme temperature or pesticide stresses were examined by fluorescent real-time quantitative PCR and Western blot. Results showed that the expression profiles of AlHSP90 protein were in high agreement with those of AlHSP90 RNA and indicated that AlHSP90 was not only an important gene for A. lucorum adults in response to extremely high temperature, but also involved in the resistance or tolerance to cyhalothrin, imidacloprid, chlorpyrifos, and emamectin benzoate, especially for female adults to emamectin benzoate and for male adults to cyhalothrin. Transcriptional results of AlHSP90 also confirmed that AlHSP90 was an important gene involved in the resistance or tolerance to both temperature and pesticide stresses. In addition, our study also revealed that ?24 C may be the suitable temperature range for A. lucorum survival, which is also confirmed by the results of the expression of AlHSP90, the nymph mortality, and the intrinsic rate of increase (r m) when A. lucorum is reared at six different temperatures. Therefore, these studies are significant in elucidating the AlHSP90 in response to temperature and pesticide stresses and would provide guidance for A. lucorum management with different pesticides or temperatures in fields. PMID:24623316

  10. Residual efficacy of methoprene for control of Tribolium castaneum (Coleoptera: Tenebrionidae) larvae at different temperatures on varnished wood, concrete, and wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The residual efficacy of the juvenile hormone analogue, methoprene (Diacon II), was evaluated in bioassays using larvae of Tribolium castaneum (Herbst) exposed on varnished wood or unsealed concrete treated with a liquid formulation and held at different temperatures. When these surfaces were stored...

  11. Effects of different methods of preparation of ice mantles of triple point of water cells on the temporal behaviour of the triple-point temperatures

    Microsoft Academic Search

    G T Furukawa; B W Mangum; G F Strouse

    1997-01-01

    We report results of an investigation of the temporal variation of the temperature of triple point of water (TPW) cells, in which the ice mantles were prepared by four different techniques using: (i) solid CO2, (ii) an immersion cooler, (iii) liquid-nitrogen-cooled rods, and (iv) liquid nitrogen (LN), first passing cold nitrogen vapours and then LN directly into the wells of

  12. SUMMARY: When temperature differences across the system create a gravitation-ally unstable stratification (top-heavy fluid), convection sets in. Two kinds of con-

    E-print Network

    Cushman-Roisin, Benoit

    Chapter 7 Convection SUMMARY: When temperature differences across the system create a gravitation on the effects of rotation and on methods to sim- ulate convection in computer models. 7.1 Gravitational atmosphere (lighter fluid created near the bottom1 ). In such case, the fluid still seeks gravitational

  13. A comparison of the growth and survival of two freshwater crayfish species, Astacus leptodactylus Eschscholtz and Pacifastacus leniusculus (Dana), under different temperature and density regimes

    Microsoft Academic Search

    Muzaffer Mustafa Harl?o?lu

    2009-01-01

    Growth experiments carried out with two juvenile crayfish species, Astacus leptodactylus Eschscholtz and Pacifastacus leniusculus (Dana), at different temperatures and densities highlighted the problem of cannibalism under conditions aimed at intensifying\\u000a crayfish production. Cannibalism proved to be much lower in A. leptodactylus than P. leniusculus, suggesting that the former might be the better candidate for astaciculture. In the first of

  14. Changes in life history parameters of corn leaf aphid, Rhopalosiphum maidus (Homoptera: Aphididae), under four different elevated temperature and CO2 combinations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological characteristics of corn leaf aphid, Rhopalosiphum maidis (Fitch), on barley, Hordeum vulgare L., were examined for two generations under four different elevated temperature and CO2 combinations. The developmental duration for each life stage was significantly reduced under the elevated te...

  15. How Consistent are Sea Surface Temperature Estimates from Different Proxies? An Assessment of the Alkenone, Mg/Ca, and Faunal Paleothermometers Using Records from the Plio-Pleistocene

    NASA Astrophysics Data System (ADS)

    Lawrence, K. T.; Peterson, L.; deMenocal, P. B.; Bochner, L.; Gorbey, D. B.

    2014-12-01

    A variety of different paleothermometers have been used to estimate past sea surface temperature (SST). However, a limited number of studies have explored the consistency of the temperature estimates produced by these proxies or assessed the cross proxy reproducibility of the major results gleaned from these records. Here, incorporating novel and previously published records from a variety of different sites (ODP Site 662 in the Eastern Equatorial Atlantic, DSDP Site 607 and Site 609 in the North Atlantic, and ODP Site 1125 in the Southwest Pacific), we assess the consistency of the long-term trends and orbital signatures of Uk'37 SST records, relative to faunal and Mg/Ca estimates from the same sites. Exploring the similarity of companion SST datasets generated for different time windows within the Plio-Pleistocene at several different sites, we find that while there are structural differences between records, they produce very similar long-term trends and produce absolute temperature estimates that are generally within error of each other. Furthermore, companion records successfully capture the same dominant milankovtich period and produce phase estimates relative to benthic oxygen isotope estimates that are within error of each other. While there are some differences in the strength, temporal persistence, and presence/absence of the non-dominant milankovitch periodicies and some intervals in which one proxy record is coherent with ?18O while another is not, our results suggest that the primary results gleaned from SST proxy records remain intact regardless of which SST proxy is used.

  16. Stress effect of different temperatures and air exposure during transport on physiological profiles in the American lobster Homarus americanus

    Microsoft Academic Search

    S. Lorenzon; P. G. Giulianini; M. Martinis; E. A. Ferrero

    2007-01-01

    Homarus americanus is an important commercial species that can survive 23days out of water if kept cool and humid. Once caught for commercial purpose and shipped around the world, a lobster is likely to be subjected to a number of stressors, including emersion and air exposure, hypoxia, temperature changes and handling. This study focused on the effect of transport stress

  17. Effect of temperature on the growth and fertility of the field-vole, Microtus arvalis, raised in different daylength

    E-print Network

    Paris-Sud XI, Universit de

    Effect of temperature on the growth and fertility of the field-vole, Microtus arvalis, raised of alfalfa harvest (april or june) on growth and fertility of the field-vole from birth to 45 days. Body of the three factors studied can therefore explain the seasonal cycles of growth and fertility in the field-vole

  18. Low temperature aging mechanism identification and lithium deposition in a large format lithium iron phosphate battery for different charge profiles

    NASA Astrophysics Data System (ADS)

    Ouyang, Minggao; Chu, Zhengyu; Lu, Languang; Li, Jianqiu; Han, Xuebing; Feng, Xuning; Liu, Guangming

    2015-07-01

    Charging procedures at low temperatures severely shorten the cycle life of lithium ion batteries due to lithium deposition on the negative electrode. In this paper, cycle life tests are conducted to reveal the influence of the charging current rate and the cut-off voltage limit on the aging mechanisms of a large format LiFePO4 battery at a low temperature (-10 C). The capacity degradation rates accelerate rapidly after the charging current reaches 0.25 C or the cut-off voltage reaches 3.55 V. Therefore the scheduled current and voltage during low-temperature charging should be reconsidered to avoid capacity degradation. Lithium deposition contributes to low-temperature aging mechanisms, as something needle-like which might be deposited lithium is observed on the surface of the negative electrode after disassembling the aged battery cell. To confirm our explanation, incremental capacity analysis (ICA) is performed to identify the characteristics of the lithium deposition induced battery aging mechanisms. Furthermore, the aging mechanism is quantified using a mechanistic model, whose parameters are estimated with the particle swarm optimization algorithm (PSO). The loss of reversible lithium originating from secondary SEI formation and dead lithium is confirmed as the cause of the aging.

  19. High-temperature annealing characteristics of tungsten and tungsten nitride Schottky contacts to GaAs under different annealing conditions

    NASA Astrophysics Data System (ADS)

    Yu, Kin Man; Jaklevic, J. M.; Haller, E. E.; Cheung, S. K.; Kwok, P. S.

    1988-08-01

    We have systematically investigated the structural and electrical characteristics of thin-film tungsten and reactively sputtered tungsten nitride (WNx) Schottky contacts to GaAs under high-temperature annealing conditions (with annealing temperatures ranging from 700 to 850 C) in an arsenic-overpressure and flowing nitrogen ambient with and without a silicon dioxide capping layer. Compositions of the WNx films measured by Rutherford backscattering spectrometry and proton resonant scattering techniques indicate a linear relationship between x and the nitrogen partial pressure during sputtering. Glancing angle x-ray diffraction studies revealed that for nonzero nitrogen partial pressure, the as-deposited films were amorphous, and after annealing these films converted to polycrystalline W2 N and W phases. A surface layer of W2 As3 phase was also observed after As-overpressure capless annealing and was believed to be the result of reactions between W and the ambient As gas. Electrical measurements showed that all WNx /GaAs contacts (with x=0-0.5) were thermally stable up to an annealing temperature of 850 C. A diode edge effect is observed for WNx /GaAs diodes cap annealed in As overpressure at temperatures higher than 800 C. The maximum achievable Schottky barrier heights for these contacts were found to be independent of the nitrogen content in the films but are influenced by the annealing conditions. We also explored the role played by nitrogen on the thermal stability and barrier height of the contacts.

  20. The Effectiveness of Different Buffer Widths for Protecting Water Temperature in Headwater Streams CFRU Research Report CFRU Research Report

    Microsoft Academic Search

    Ethel Wilkerson; John M. Hagan; Darlene Siegel

    We evaluated the eff ect of timber harvesting on water temperature in fi rst-order headwater streams in western Maine. Fifteen streams were assigned fi ve treatments: (1) clearcutting with no stream buff er, (2) clearcutting with 36-ft buff ers, both sides, (3) clearcutting with 75-ft buff ers, both sides, (4) extensive partial cutting with no designated buff er, and (5)

  1. Temperature induced variation in the distribution of different types of muscle fibre in the goldfish ( Carassius auratus )

    Microsoft Academic Search

    Ian Johnston; Margaret Lucking

    1978-01-01

    Goldfish (Carassius auratus L.) were acclimated to environmental temperatures of 3 C, 18 C and 31 C for a period of three months. Cytochemical techniques were used to study the metabolism and myofibrillar ATPase activities of individual muscle fibres. Fish muscle is composed of three basic fibre types each with distinct contractile and metabolic characteristics. Cold acclimation resulted in a

  2. Passivation mechanism of thermal atomic layer-deposited Al2O3 films on silicon at different annealing temperatures

    PubMed Central

    2013-01-01

    Thermal atomic layer-deposited (ALD) aluminum oxide (Al2O3) acquires high negative fixed charge density (Qf) and sufficiently low interface trap density after annealing, which enables excellent surface passivation for crystalline silicon. Qf can be controlled by varying the annealing temperatures. In this study, the effect of the annealing temperature of thermal ALD Al2O3 films on p-type Czochralski silicon wafers was investigated. Corona charging measurements revealed that the Qf obtained at 300C did not significantly affect passivation. The interface-trapping density markedly increased at high annealing temperature (>600C) and degraded the surface passivation even at a high Qf. Negatively charged or neutral vacancies were found in the samples annealed at 300C, 500C, and 750C using positron annihilation techniques. The Al defect density in the bulk film and the vacancy density near the SiOx/Si interface region decreased with increased temperature. Measurement results of Qf proved that the Al vacancy of the bulk film may not be related to Qf. The defect density in the SiOx region affected the chemical passivation, but other factors may dominantly influence chemical passivation at 750C. PMID:23452508

  3. Plasticity and constraints on fatty acid composition in the phospholipids and triacylglycerols of Arabidopsis accessions grown at different temperatures

    PubMed Central

    2013-01-01

    Background Natural selection acts on multiple traits in an organism, and the final outcome of adaptive evolution may be constrained by the interaction of physiological and functional integration of those traits. Fatty acid composition is an important determinant of seed oil quality. In plants the relative proportions of unsaturated fatty acids in phospholipids and seed triacylglycerols often increases adaptively in response to lower growing temperatures to increase fitness. Previous work produced evidence of genetic constraints between phospholipids and triacylglycerols in the widely studied Arabidopsis lines Col and Ler, but because these lines are highly inbred, the correlations might be spurious. In this study, we grew 84 wild Arabidopsis accessions at two temperatures to show that genetic correlation between the fatty acids of the two lipid types is not expected and one should not influence the other and seed oil evolution and also tested for the adaptive response of fatty acids to latitude and temperature. Results As expected no significant correlations between the two lipids classes at either growing temperature were observed. The saturated fatty acids and erucic acid of triacylglycerols followed a significant latitudinal cline, while the fatty acids in phospholipids did not respond to latitude as expected. The expected plastic response to temperature was observed for all the triacylglycerol fatty acids whereas only oleic acid showed the expected pattern in phospholipids. Considerable phenotypic variation of the fatty acids in both the lipid types was seen. Conclusion We report the first evidence supporting adaptive evolution of seed triacylglycerols in Arabidopsis on a latitudinal cline as seen in other species and also their plastic adaptive response to growing temperature. We show that as expected there is no genetic correlations between the fatty acids in triacylglycerols and phospholipids, indicating selection can act on seed triacylglycerols without being constrained by the fatty acid requirements of the phospholipids. Phospholipid fatty acids do not respond to latitude and temperature as seen elsewhere and needs further investigation. Thus, the adaptive response of Arabidopsis and the genetic tools available for manipulating Arabidopsis, makes it an excellent system for studying seed oil evolution and also for breeding seed oil crops especially the Brassica species. PMID:23594395

  4. InAs quantum well Hall devices for room-temperature detection of single magnetic biomolecular labels.

    SciTech Connect

    Mihajlovic, G.; Xiong, P.; von Molnar, S.; Field, M.; Sullivan, G. J.; Materials Science Division; Florida State Univ.; Teledyne Scientific Co. LLC

    2007-08-01

    Hall sensors with cross width of {approx}1 {micro}m were fabricated from InAs/AlSb quantum well semiconductor heterostructures containing two-dimensional electron gas. The room-temperature device characteristics were examined by Hall effect and electronic noise measurements along with analytical calculations. In the low-frequency range, from 20 Hz to 1.6 kHz, the noise-equivalent magnetic field resolution was found to be limited by 1/f and generation-recombination noise from 22 to 3.5 {micro}T/{radical}Hz. The corresponding noise-equivalent magnetic moment resolution reached 10{sub {mu}{sub B}}{sup 6}/{radical}Hz at {approx}700 Hz and was even lower at higher frequencies. Using a phase-sensitive measurement technique, detection of a single 1.2 {micro}m diameter bead, suitable for biological applications, was achieved with a signal to noise ratio of {approx}33.3 dB, as well as detection of six 250 nm beads with a signal to noise of {approx}2.3 dB per bead. The work demonstrates the efficacy of InAs quantum well Hall devices for application in high sensitivity detection of single magnetic biomolecular labels.

  5. Microbiological quality of bottled drinking water in the UAE and the effect of storage at different temperatures

    Microsoft Academic Search

    H. Al Kohaly; Z BABARINDE; H ALKOHALY

    1999-01-01

    The microbiological quality of bottled water from different sources in the United Arab Emirates was studied. The study was done on 80 commercial bottled water samples from 4 different manufacturing companies. The results showed that 75% of the 20-L bottles were contaminated by 10 different species of bacteria, whereas 10 to 40% of the 1.5-L bottles were contaminated by 24

  6. Real-time conductivity imaging of temperature and tissue property changes during radiofrequency ablation: an ex vivo model using weighted frequency difference.

    PubMed

    Wi, Hun; McEwan, Alistair Lee; Lam, Vincent; Kim, Hyung Joong; Woo, Eung Je; Oh, Tong In

    2015-04-01

    We demonstrated the feasibility of time difference and weighted frequency difference conductivity imaging for real-time monitoring of temperature distribution and ablation region estimation during radiofrequency (RF) ablation. The electrical conductivity spectrum of biological tissue reflects mobility of ions in intra- and extra-cellular fluids and changes in cellular morphology induced by heating. The time series conductivity spectra were measured in an ex vivo bovine liver by a high-speed electrical impedance tomography (EIT) system. The EIT system was protected by filters to suppress RF energy and allow interleaved real-time imaging. We recorded time and weighted frequency-difference conductivity images and direct temperature variations at the ablation region and control region during 8?min ablation and for the following 66?min of cooling. Conductivity variation in regions of interest was compared with temperature recordings. Contours of conductivity change were visualized and compared to estimate the ablation area. EIT images confirmed increase of conductivity at all frequencies and loss of frequency conductivity change associated with loss of cellular structure. Time difference conductivity images showed changes due to both heating during ablation and heat dissipation following ablation together with tissue property changes. Weighted frequency-difference images presented persistent changes following heating due to the morphological change in the ablation zone. PMID:25779916

  7. Characterization of cadmium removal from aqueous solution by biochar produced from a giant Miscanthus at different pyrolytic temperatures.

    PubMed

    Kim, Woong-Ki; Shim, Taeyong; Kim, Yong-Seong; Hyun, Seunghun; Ryu, Changkook; Park, Young-Kwon; Jung, Jinho

    2013-06-01

    The objective of this study was to investigate the feasibility of biochar for removing Cd from aqueous solution. Biochars were produced from a Miscanthus sacchariflorus via slow pyrolysis at 300, 400, 500 and 600C. Higher pyrolytic temperature resulted in biochar with a higher aromatic structure and fewer polar functional groups. In particular, pH and surface area of biochar increased greatly at pyrolytic temperatures ? 500C, which increased Cd sorption capacity up to 13.24 mgg(-1). The diffuse-controlled Cd removal was likely due to a surface sorption or a precipitation reaction depending on pH. A simulation with the visual MINTEQ program indicated that the precipitate was Cd(OH)2. In addition, biochar treatment significantly removed the acute toxicity of Cd toward Daphnia magna, resulting in increase of EC50 (50% effective concentration) value from 0.16 to 0.76 mgL(-1). PMID:23619139

  8. On the influence of column temperature on the isothermal retention indices of structurally different solutes on a poly(dimethylsiloxane) capillary column.

    PubMed

    Santiuste, J M; Quintanilla-Lpez, J E; Becerra, R; Lebrn-Aguilar, R

    2014-10-24

    The dependence of isothermal retention indices (I) on column temperature over a wide temperature range has been studied for solutes belonging to nine chemical functions on a capillary column coated with poly(100% dimethyl siloxane). I values for some solutes are reported for the first time on capillary columns. I values increased with increasing column temperature, with the exception of the linear alcohols and the esters, which decreased with increasing temperature, and of cyclobutanol, 2-butanone, 2-pentanone, 1-butylamine and 1-pentylamine that showed a well-defined minimum in the 358-377K range. Moreover, a minimum at the higher temperature range for longer and less polar solutes such as 1-nonanol was observed for the first time. The three trends of I vs. T were perfectly described by the extended model (I=a+bT(-1)+clnT). On the other hand, the dependence of I on the carbon atom number (z) of the solute was linear and with a slope of similar magnitude for all homologous series studied, except for the alicyclic compounds. For the latter, higher slope values and worse correlations were obtained, owing to their larger surface area and to the different conformations that they adopt in order to minimize the ring strain. In addition, due to its higher chain stiffness, an important influence of the column temperature on these slopes was observed. PMID:25246099

  9. Models for Predicting the Lower Limit of the Canopy-Air Temperature Difference of Two Cool Season Grasses

    Microsoft Academic Search

    Dennis L. Martin; David J. Wehner; C. S. Throssell

    1994-01-01

    Estimation of the lower limit of the canopy-air temperature differential, (TcTa)LL, is required for calculation of an empirically-based crop water stress, index. This research determined the complexity of model needed for accurate estimation of (TcTa)LL for several field grown cultivars of Kentucky bluegrass (Poa pratensis L.) and for creeping bentgrass (Agrostis stolonifera L. var. palustris (Huds.) Farw.). Regression models using

  10. Apical seal comparison of low-temperature thermoplasticized gutta-percha technique and lateral condensation with two different master cones

    Microsoft Academic Search

    Mercedes Prez Heredia; Javier Clavero Gonzlez; Carmen Mara; Ferrer Luque; Mara Paloma Gonzlez Rodrguez

    2007-01-01

    Aim: To compare the apical sealing in mesio-buccal canals of extracted molars obturated with low-temperature ther- moplasticized gutta-percha or cold lateral condensation techniques using a .06 or a .02 mm\\/mm tapered gutta-percha master cone. The secondary aim was to evaluate the depth of spreader penetration in root canals using a .06 or a .02 mm\\/mm tapered gutta-percha master cone. Methodology:

  11. Influence of Drought on Graminicide Phytotoxicity in Wild Oat ( Avena fatua ) Grown under Different Temperature and Humidity Conditions

    Microsoft Academic Search

    H. S. Xie; A. I. Hsiao; W. A. Quick

    1997-01-01

    . Controlled environmental experiments were carried out to determine the phytotoxicity of several graminicides on wild oat\\u000a (Avena futua L.) as influenced by combination of drought and temperature stress or drought and low relative humidity. Compared with unstressed\\u000a conditions (20\\/15?C plus adequate soil moisture), imazamethabenz phytotoxicity to wild oat was reduced significantly when\\u000a plants were exposed to a combination of

  12. Temperature effects on key metabolic enzymes in Littorina saxatilis and L. obtusata from different latitudes and shore levels

    Microsoft Academic Search

    I. Sokolova; H. Prtner

    2001-01-01

    Effects of temperature on activities of key metabolic enzymes, citrate synthase (CS), NADP-dependent isocitrate dehydrogenase (NADP-IDH), aspartate aminotransferase (AAT), pyruvate kinase (PK) and phosphoenolpyruvate carboxykinase (PEPCK), were studied in high and low shore Littorina saxatilis and in low shore L. obtusata from the temperate North Sea and the sub-arctic White Sea. It was found that adaptation of L. saxatilis and

  13. Some observations on deformation banding and correlated microstructures of two aluminum alloys compressed at different temperatures and strain rates

    Microsoft Academic Search

    S. S. Kulkarni; E. A. Jr. Starke; D. Kuhlmann-Wilsdorf

    1998-01-01

    In compressed samples of high-purity aluminum alloys, without (Al0.5wt% Cu) and with hard precipitates (Al0.5wt% Cu1.0wt% Si), a variety of deformation band patterns has been observed, including occasional exquisite detailed structuring. According to the present preliminary results, the banding does not significantly depend on strain rates between 0.05 and 100%\\/s, nor on temperature from ambient to cryogenic (?193C). However, it

  14. Particle size distribution of PM10 and heavy metal emission with different temperature and HCl concentrations from incinerators

    Microsoft Academic Search

    Jong-Ik Yoo; Ki-Heon Kim; Ha-Na Jang; Yong-Chil Seo; Kwang-Seol Seok; Ji-Hyung Hong; Min Jang

    2002-01-01

    Emission characteristics of particulate matter and heavy metals from 12 small waste incinerators, whose capacity ranged from\\u000a 25 to 200 kg\\/h of waste, were investigated to determine the factors affecting the particulate matter generation and growth\\u000a mechanisms. The ratio of fine particles to coarse particles increased with the flue gas temperature. Particulate matter showed\\u000a bimodal forms in particle size distributions.

  15. The Mechanical Properties of Wood of Different Moisture Content Within -200 Degrees to +200 Degrees C Temperature Range

    NASA Technical Reports Server (NTRS)

    Kollmann, Franz

    1941-01-01

    Systematic experiments were undertaken with special reference to the effect of gross specific weight (specific weight inclusive of pores) and the moisture content of wood. It was found that the modules of elasticity of wood at room temperature and frozen at -8 degrees is practically the same. The effect of moisture on the compression strength of frozen wood was explored as well as the flexural and impact strength of frozen wood and frozen laminated wood.

  16. Excess parameter studies on binary liquid mixtures of 2-methyl-2-propanol with aliphatic nitriles at different temperatures

    Microsoft Academic Search

    K. Rajagopal; S. Chenthilnath

    2011-01-01

    Densities (?), viscosities (?) and ultrasonic speeds (u) of binary mixtures of 2-methyl-2-propanol (2M2P) with acetonitrile (AN), propionitrile (PN) and butyronitrile (BN) including those of pure liquids were measured over the entire composition range at temperatures 298.15, 303.15 and 308.15K respectively. The excess molar volume (VmE) calculated from density data and other volumetric properties, partial molar volumes (Vm,1 and Vm,2),

  17. Fourier transform infrared and Raman spectroscopic characterization of homogeneous solution concentration gradients near a container wall at different temperatures

    NASA Technical Reports Server (NTRS)

    Loo, B. H.; Burns, D. H.; Lee, Y. G. L.; Emerson, M. T.

    1991-01-01

    Fourier transform infrared (FTIR) and Raman spectroscopic techniques were used to study the solution concentration gradient in succino nitrile-rich and water-rich homogeneous solutions. The spectroscopic data shows significant concentration dependency. Although FTIR-attenuated total reflectance could not yield surface spectra since the evanescent infrared wave penetrated deep into the bulk solution, it showed that water-rich clusters were decreased at higher temperatures. This result is consistent with the calorimetric results reported earlier.

  18. The E-O curve and phase shift of LCoS panel at different temperature and wavelength

    NASA Astrophysics Data System (ADS)

    Hong, Sylvia; Liao, Engle; Stover, Mike; Liao, Li-Yuan; Chen, Cheng-Huan

    2013-08-01

    Liquid crystal on silicon (LCoS) can be devised as a pure phase type spatial light modulator (SLM) with proper arrangement of incident light polarization and choice of liquid crystal mode. The applications include digital holography, optical switching and adaptive optics etc. The phase retardation at each pixel on the LCoS SLM can be controlled by driving voltage, but the relationship is dependent of temperature and wavelength. In this paper, a vertical aligned nematics (VAN) mode LCoS has been used for investigation. Consideration the application environment, temperature range was set in between 30 to 70C, and the selected wavelength was 623 nm, 526 nm and 462 nm. We measured the E-O curve and converted into phase shift by equation. The result shows that the phase retardation decreases with both the increase of temperature and wavelength. The dynamic behavior of LC material is also reported in this paper, and a digital hologram from a digital-drive LCoS SLM with 6.4 ?m pixel is demonstrated.

  19. Evaluation of the stability of uranyl peroxo-carbonato complex ions in carbonate media at different temperatures.

    PubMed

    Kim, Kwang-Wook; Lee, Keun-Young; Chung, Dong-Yong; Lee, Eil-Hee; Moon, Jei-Kwon; Shin, Dong-Woo

    2012-09-30

    This work studied the stability of peroxide in uranyl peroxo carbonato complex ions in a carbonate solution with hydrogen peroxide using absorption and Raman spectroscopies, and evaluated the temperature dependence of the decomposition characteristics of uranyl peroxo carbonato complex ions in the solution. The uranyl peroxo carbonato complex ions self-decomposed more rapidly into uranyl tris-carbonato complex ions in higher temperature carbonate solutions. The concentration of peroxide in the solution without free hydrogen peroxide represents the concentration of uranyl peroxo carbonato complex ions in a mixture of uranyl peroxo carbonato complex and uranyl tris-carbonato complex ions. The self-decomposition of the uranyl peroxo carbonato complex ions was a first order reaction, and its activation energy was evaluated to be 7.14410(3) J mol(-1). The precipitation of sodium uranium oxide hydroxide occurred when the amount of uranyl tris-carbonato complex ions generated from the decomposition of the uranyl peroxo carbonato complex ions exceeded the solubility of uranyl tris-carbonato ions in the solution at the solution temperature. PMID:22831997

  20. Study of vegetation impact on the ground surface temperature using remote sensing data with different spatial resolution

    NASA Astrophysics Data System (ADS)

    Dvornikov, Yury; Heim, Birgit; Leibman, Marina

    2013-04-01

    Permafrost mapping and modeling is based on the understanding of the main controls affecting permafrost parameters: ground temperature, active-layer thickness, cryogenic processes. In the Tundra zone, remote sensing can provide necessary information on spatial distribution of surficial parameters represented by vegetation type and coverage. In this work we will consider shrub complexes, as far as they serve as an entrapment for snow and consequently affect the active layer depth. A case study was undertaken at central Yamal at the research station Vaskiny Dachi. In summer 2011 a 1.5 km long transect crossing main geomorphologic units of central Yamal was established and subject to multipurpose field study. Detailed description of vegetation and numeric parameters characterizing tundra complexes was followed by active-layer measurements. The main optical satellite data base is a high-spatial resolution GeoEye-1 acquisition with 0.5 m ground sampling distance acquired at the 15th August in 2009 (NGA license, University Alaska Fairbanks, NASA LCLUC Yamal). Spectral analyses were performed to extract surface class - shrub-dominant communities. Spectral discrimination of surface waters was done using a threshold value in the near infrared band 4. Various spectral analyses were tested to separate shrubs-dominated areas. Processed were 4 Principal Component (PC) (Schowengerdt, 2007) bands, including masking of surface waters. The lower PC bands contain the subordinate information that can often not be extracted using standard classification methods. PC bands 2 and 3 were interpreted to contain information on 'greenness' and 'moisture and structure', respectively. At this stage, the shrubs were manually digitized guided by the structure information in PC band 3. The communities sorted out in vector format were used for the following analysis. For the analysis of the shrub impact on permafrost, interpretation results were compared with a map of the surface temperature and with the field data. The comparison involves the spatial statistics calculation. The map of the surface temperature was plotted using data from Landsat 1999 with 30 meter spatial resolution (band 6-1, High Gain). First of all, an atmospheric correction of the data was made, and then surface temperature was calculated with the algorithm (Chavez, 1988). The average temperature of the surface was calculated, except for the areas of water bodies, and then the spatial statistics was calculated within the vegetation units subdivided at the initial stage of interpretation.

  1. TEMPERATURE Temperature

    E-print Network

    Cambridge, University of

    the coexistence of two phases and in our binary alloy. They will only be in equilibrium with each other Computation of Phase Diagrams (Revision) H. K. D. H. Bhadeshia The Equilibrium State Equilibrium is a state different chemical compositions. An equilibrium phase diagram is vital in the design of materials

  2. Photosynthetic functions of cembran pines and dwarf pines during winter at timberline as regulated by different temperatures, snowcover and light.

    PubMed

    Lehner, Gabriele; Ltz, Cornelius

    2003-02-01

    Trees at timberline in the high Alps are exposed to a variety of climatic conditions. Most climatic stresses occur during winter and spring, when frost, occasionally low snow cover, and high irradiation interact. In this study, we follow reactions of photosynthesis from high winter to spring in two dominating tree species of the alpine timberline, which may indicate the status of stress response to a changing environment. The results indicate a level of physiological stability in trees, which are important for stabilising natural high mountain ecosystems. Trees of Pinus cembra and of Pinus mugo were selected at altitudes between 1850 m a.s.l. and 1950 m a.s.l. near innsbruck, Austria. At six sampling times from January to May, fast chlorophyll fluorescence was measured in the field and twigs were collected for further investigation in the laboratory. The following measurements were taken: photosynthetic oxygen formation, needle chlorophyll and carotenoid determination, and kinetic studies of the xanthophyll cycle. In general, both tree species showed similar results in most parameters studied. P. mugo seems to have some advantages if winter precipitation is high, when, because of its growth habitus, most needles will be snow covered. Primary photochemistry (trapping per reaction centre) in PS II does not change with sampling dates despite the fact that temperature and light are changing. However, first events in electron transport and whole needle photosynthesis are strongly affected by light and temperature conditions during the days before sampling. The kinetics of the xanthophyll cycle indicate not only light, but also strong temperature effects. P. mugo photosynthesis seems to have a higher stability under changing weather. Both tree species are well prepared to start with photosynthesis in winter, if favourable conditions, like foehn events, occur. PMID:12685031

  3. Corrosion inhibition of stainless steel type AISI 304 by Mn coating and subsequent annealing with flow of nitrogen at different temperatures

    NASA Astrophysics Data System (ADS)

    Grayeli-Korpi, Ali-Reza; Savaloni, Hadi; Habibi, Maryam

    2013-07-01

    This work reports the enhancement of stainless steel corrosion resistance coated with Mn and post-annealed with flow of nitrogen at different annealing temperatures. Crystallographic variation of the samples by annealing temperature is studied by X-ray diffraction (XRD) while their surface morphology and surface roughness was obtained by means of atomic force microscope (AFM) and scanning electron microscope (SEM) analyses before and after corrosion test respectively. Elemental analysis of samples after corrosion test was investigated by energy dispersive spectroscope (EDS) analysis. The corrosion behaviour of the samples was evaluated by potentiodynamic polarization test in 0.6 M NaCl solution. A critical annealing temperature is found at which the highest corrosion resistance can be achieved. Correlation between corrosion resistance, structural and surface morphology results is obtained.

  4. Fatigue small crack growth threshold determination of a high-Nb TiAl alloy at different temperatures by in-situ observation

    NASA Astrophysics Data System (ADS)

    Zhang, Min; Song, Xi-ping; Yu, Long; Li, Hong-liang; Jiao, Ze-hui; Yu, Hui-chen

    2013-12-01

    The purpose of this paper is to estimate the fatigue crack growth threshold of a high-Nb TiAl alloy at the different temperatures based on scanning electron microscopy (SEM) in-situ observation. The results indicated that the fatigue crack growth threshold ? K th of a nearly lamellar high-Nb TiAl alloy with 8% Nb content at room temperature and 750C was determined as 12.89 MPam1/2 and 8.69 MPam1/2, respectively. The effect of the elevated temperature on the fatigue crack growth threshold cannot be ignored. At the same time, the early stage of fatigue crack propagation exhibited multicrack initiation and bridge-link behavior.

  5. Investigation of the Difference in Cool Flame Characteristics between Petroleum Diesel and Soybean Biodiesel Operating in Low Temperature Combustion Mode

    E-print Network

    Muthu Narayanan, Aditya

    2014-01-16

    flame in biodiesel purely due to oxygen content of the biodiesel. Cycle-to-cycle variation, exhaust gas constituents, rail pressure and fuel penetration length were analyzed to determine the causes for difference in the cool flame characteristic between...

  6. Thermo-mechanical behaviour of TRIP 1000 steel sheets subjected to low velocity perforation by conical projectiles at different temperatures

    E-print Network

    Paris-Sud XI, Universit de

    , perforation tests have been performed using a drop weight tower. Experiments were carried out at two different sectors like the automobile, naval or civil industries, which have invested substantial efforts

  7. Influence of water temperature and waterborne cadmium toxicity on growth performance and metallothionein-cadmium distribution in different organs of Nile tilapia, Oreochromis niloticus (L.).

    PubMed

    Abdel-Tawwab, Mohsen; Wafeek, Mohammed

    2014-10-01

    Cadmium (Cd) is believed to be one of the most abundant and ubiquitously distributed toxins in the aquatic system. This metal is released to the aquatic environment from both anthropogenic sources, such as industrial, agricultural and urban effluents as well as natural sources, such as rocks and soils. Otherwise, the temperature increase of water bodies, which has been observed due to global climatic changes, has been shown to increase Cd toxicity for several aquatic animal species including fish. In the present study, Nile tilapia, Oreochromis niloticus (L.), (26.0 0.38 g) were reared at 20, 24, 28, or 32 C and exposed to 0.0 or 0.5mg Cd/L for 8 weeks to investigate effects of water temperature, Cd toxicity and their interaction on fish performance as well as metallothionein (MT) and Cd distribution in different fish organs. It was found that fish reared in Cd-free group at 28 C showed the optimum growth and feed intake, while Cd-exposed fish showed low growth and feed intake irrespective to water temperature. A synergetic relationship between water temperature and Cd toxicity was observed where Cd toxicity increased as water temperature increased and the worse growth was obtained in Cd-exposed fish reared at 32 C. Additionally, the highest Cd residues in different fish organs were detected in Cd-exposed fish reared at 32 C. Similarly, MT concentrations in different fish organs increased as water temperature increased especially in Cd-exposed fish groups. A high positive correlation between MT and Cd concentrations in fish organs was detected. The distribution of MT and Cd levels was in the order of liver>kidney>gills>muscles. The present study revealed that the optimum water temperature suitable for Nile tilapia growth is 28 C. Additionally, Cd exposure had a deteriorate effect on the growth and health of Nile tilapia. This hazardous effect increased as water temperature increased. Further, liver and kidney were the prime sites of Cd accumulation, while Cd load in the muscles was the lowest as compared to the other investigated organs. PMID:25436965

  8. The variation of soil temperature and water content of seasonal frozen soil with different vegetation coverage in the headwater region of the Yellow River, China

    NASA Astrophysics Data System (ADS)

    Cheng, Huiyan; Wang, Genxu; Hu, Hongchang; Wang, Yibo

    2008-06-01

    The variation and distribution of temperature and water moisture in the seasonal frozen soil is an important factor in the study of both the soil water cycle and heat balance within the source region of the Yellow River, especially under the different conditions of vegetation coverage. In this study, the impact of various degrees of vegetation coverage on soil water content and temperature was assessed. Soil moisture ( ? v) and soil temperature ( T s) were monitored on a daily basis. Measurements were made under different vegetation coverage (95, 70 80, 40 50 and 10%) and on both thawed and frozen soils. Contour charts of T s and ? v as well as a ? v T s coupling model were developed in order to account for the influence of vegetation cover and the interaction between T s and ? v. It was observed that soil water content affected both the overall range and trend in the soil temperature. The regression analysis of ? v versus T s plots indicated that the soil freezing and thawing processes were significantly affected by vegetation cover changes. Vegetation coverage changes also caused variations in the ? v T s interaction. The effect of soil water content on soil temperature during the freezing period was larger than during the thawing period. Moreover, the soil with higher vegetation coverage retained more water than that with lower coverage. In the process of freezing, the higher vegetation coverage reduced the rate of the reduction in the soil temperature because the thermal capacity of water is higher than that of soil. Areas with higher vegetation coverage also functioned better for the purpose of heat-insulating. This phenomenon may thus play an important role in the environmental protection and effective uses of frozen soil.

  9. Systems Characterization of Temperature, Ph and Electrical Conductivity in Aerobic Biodegradation of Wheat Biomass at Differing Mixing Rates

    NASA Technical Reports Server (NTRS)

    Calhoun, M.; Trotman, A.; Aglan, H.

    1998-01-01

    The purpose of this preliminary study is to observe and relate the rate of mixing to pH and electrical conductivity in an aerobic, continuously stirred bioreactor. The objective is to use data collected from successive experiments as a means of a system characterization. Tests were conducted to obtain these data using a continuously stirred 20 L Cytostir glass reaction vessel as a bioreactor operated without built-in temperature or pH control. The tests were conducted on the lab bench at ambient temperatures. The substrate in the bioreactor was ground wheat biomass obtained from the Biomass Production Chamber at NASA Kennedy Space Center. In this study, the data reflect characteristics of the native (uninoculated) systems as well as inoculated systems. In the native systems, it was found that pi levels became stable after approximately 2 to 3 days. The electrical conductivity levels for the native systems tended to decrease over time. In contrast, ion activity was increased after the introduction of bacteria into the system. This could be correlated with the release of nutrients, due to the activity of the bacteria. Also, there were slight increases in pH in the inoculated system, a result which is expected for a system with no active pr controls. The data will be used to test a mathematical model in an automated system.

  10. Cool, cold or colder? Spatial segregation of prions and blue petrels is explained by differences in preferred sea surface temperatures.

    PubMed

    Quillfeldt, Petra; Cherel, Yves; Delord, Karine; Weimerkirch, Henri

    2015-04-01

    The Southern Ocean provides one of the largest environmental gradients on Earth that lacks geographical barriers, and small but highly mobile petrels living there may offer fine models of evolution of diversity along environmental gradients. Using geolocation devices, we investigated the winter distribution of closely related petrel species breeding sympatrically in the southern Indian Ocean, and applied ecological niche models to compare environmental conditions in the habitat used. We show that thin-billed prions (Pachyptila belcheri), Antarctic prions (Pachyptila desolata) and blue petrels (Halobaena caerulea) from the Kerguelen archipelago in the southern Indian Ocean segregate latitudinally, sea surface temperature being the most important variable separating the distribution of the species. Antarctic prions spent the winter north of the Polar Front in temperate waters, whereas blue petrels were found south of the Polar Front in Antarctic waters. Thin-billed prions preferred intermediate latitudes and temperatures. Stable isotope values of feathers reflected this near complete niche separation across an ecological gradient that spans large scales, and suggest evolutionary isolation by environment. In pelagic seabirds that exploit large areas of ocean, spatial niche partitioning may not only facilitate coexistence among ecologically similar species, but may also have driven their evolution in the absence of geographical barriers. PMID:25878044

  11. Some observations on deformation banding and correlated microstructures of two aluminum alloys compressed at different temperatures and strain rates

    SciTech Connect

    Kulkarni, S.S.; Starke, E.A. Jr.; Kuhlmann-Wilsdorf, D. [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Materials Science and Engineering] [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Materials Science and Engineering

    1998-09-18

    In compressed samples of high-purity aluminum alloys, without (Al-0.5 wt% Cu) and with hard precipitates (Al-0.5 wt% Cu-1.0 wt% Si), a variety of deformation band patterns has been observed, including occasional exquisite detailed structuring. According to the present preliminary results, the banding does not significantly depend on strain rates between 0.05 and 100%/s, nor on temperature from ambient to cryogenic ({minus}193 C). However, it is greatly decreased by the presence of precipitates in the Al-Cu-Si alloy and was barely if at all visible at and above 200 C. The banding is due to changing selections of operating slip systems, falling short of the five required in the Taylor model of homologous deformation in polycrystals. The occasional exquisite detail in the banding pattern is accepted as virtual proof of the low-energy dislocation structure (LEDS) hypothesis, the basic tenet from which the LEDS theory of crystal plasticity follows without further assumptions. In agreement with this interpretation, also the underlying dislocation cell structure, which did not reveal any evident correlation with the deformation banding, as well as the observed workhardening features as dependent on strain rate and temperature are in accord with the LEDS theory.

  12. Changes in biochemical characteristics and activities of ripening associated enzymes in mango fruit during the storage at different temperatures.

    PubMed

    Hossain, Md Anowar; Rana, Md Masud; Kimura, Yoshinobu; Roslan, Hairul Azman

    2014-01-01

    As a part of the study to explore the possible strategy for enhancing the shelf life of mango fruits, we investigated the changes in biochemical parameters and activities of ripening associated enzymes of Ashwina hybrid mangoes at 4-day regular intervals during storage at -10C, 4C, and 30 1C. Titratable acidity, vitamin C, starch content, and reducing sugar were higher at unripe state and gradually decreased with the increasing of storage time at all storage temperatures while phenol content, total soluble solid, total sugar, and nonreducing sugar contents gradually increased. The activities of amylase, ?-mannosidase, ?-glucosidase, and invertase increased sharply within first few days and decreased significantly in the later stage of ripening at 30 1C. Meanwhile polyphenol oxidase, ?-galactosidase, and ?-hexosaminidase predominantly increased significantly with the increasing days of storage till later stage of ripening. At -10C and 4C, the enzymes as well as carbohydrate contents of storage mango changed slightly up to 4 days and thereafter the enzyme became fully dormant. The results indicated that increase in storage temperature and time correlated with changes in biochemical parameters and activities of glycosidases suggested the suppression of ?-galactosidase and ?-hexosaminidase might enhance the shelf life of mango fruits. PMID:25136564

  13. Changes in Biochemical Characteristics and Activities of Ripening Associated Enzymes in Mango Fruit during the Storage at Different Temperatures

    PubMed Central

    Kimura, Yoshinobu

    2014-01-01

    As a part of the study to explore the possible strategy for enhancing the shelf life of mango fruits, we investigated the changes in biochemical parameters and activities of ripening associated enzymes of Ashwina hybrid mangoes at 4-day regular intervals during storage at ?10C, 4C, and 30 1C. Titratable acidity, vitamin C, starch content, and reducing sugar were higher at unripe state and gradually decreased with the increasing of storage time at all storage temperatures while phenol content, total soluble solid, total sugar, and nonreducing sugar contents gradually increased. The activities of amylase, ?-mannosidase, ?-glucosidase, and invertase increased sharply within first few days and decreased significantly in the later stage of ripening at 30 1C. Meanwhile polyphenol oxidase, ?-galactosidase, and ?-hexosaminidase predominantly increased significantly with the increasing days of storage till later stage of ripening. At ?10C and 4C, the enzymes as well as carbohydrate contents of storage mango changed slightly up to 4 days and thereafter the enzyme became fully dormant. The results indicated that increase in storage temperature and time correlated with changes in biochemical parameters and activities of glycosidases suggested the suppression of ?-galactosidase and ?-hexosaminidase might enhance the shelf life of mango fruits. PMID:25136564

  14. Pulsed electric field processing of different fruit juices: impact of pH and temperature on inactivation of spoilage and pathogenic micro-organisms.

    PubMed

    Timmermans, R A H; Nierop Groot, M N; Nederhoff, A L; van Boekel, M A J S; Matser, A M; Mastwijk, H C

    2014-03-01

    Pulsed electrical field (PEF) technology can be used for the inactivation of micro-organisms and therefore for preservation of food products. It is a mild technology compared to thermal pasteurization because a lower temperature is used during processing, leading to a better retention of the quality. In this study, pathogenic and spoilage micro-organisms relevant in refrigerated fruit juices were studied to determine the impact of process parameters and juice composition on the effectiveness of the PEF process to inactivate the micro-organisms. Experiments were performed using a continuous-flow PEF system at an electrical field strength of 20 kV/cm with variable frequencies to evaluate the inactivation of Salmonella Panama, Escherichia coli, Listeria monocytogenes and Saccharomyces cerevisiae in apple, orange and watermelon juices. Kinetic data showed that under the same conditions, S. cerevisiae was the most sensitive micro-organism, followed by S. Panama and E. coli, which displayed comparable inactivation kinetics. L. monocytogenes was the most resistant micro-organism towards the treatment conditions tested. A synergistic effect between temperature and electric pulses was observed at inlet temperatures above 35 C, hence less energy for inactivation was required at higher temperatures. Different juice matrices resulted in a different degree of inactivation, predominantly determined by pH. The survival curves were nonlinear and could satisfactorily be modeled with the Weibull model. PMID:24418831

  15. CO2 fluxes and respiration of branch segments of sycamore (Platanus occidentalis L.) examined at different sap velocities, branch diameters, and temperatures.

    PubMed

    McGuire, M A; Cerasoli, S; Teskey, R O

    2007-01-01

    Respiration of stems and branches of trees (R(S)) has typically been estimated by measuring radial CO(2) efflux from woody tissue (E(A)) and rates of efflux are often scaled temporally using a temperature relationship (Q(10)). High concentrations of CO(2) in xylem sap ([CO(2)*]) have been shown to affect E(A), and the transport of CO(2) in the xylem stream has been suggested as a mechanism to explain field observations of temperature-independent fluctuations in E(A). Sap velocity and temperature were manipulated in detached branch segments of sycamore (Platanus occidentalis L.) under controlled conditions to quantify these effects. Within individual branches of similar size, E(A) and [CO(2)*] were greater at low sap velocity, while the amount of respired CO(2) transported in sap (transport flux, F(T)) was greater at high sap velocity. E(A) was linearly correlated with [CO(2)*]. In branches of three diameter classes (1, 2, and 3 cm), volume-based E(A), F(T), and R(S) did not differ, but surface-area based CO(2) fluxes increased with diameter class. Regardless of diameter, E(A) accounted for only 30% of respired CO(2) at high sap velocity, while at low sap velocity, E(A) accounted for 71% of respired CO(2). E(A), F(T), and R(S) measured at 5, 20, and 35 degrees C at the same sap velocity showed a typical exponential response to temperature. However, at the lowest temperature, E(A) accounted for only 18% of the CO(2) released from respiring cells compared with 44% at the highest temperature, perhaps due to the effect of temperature on the solubility of CO(2) in water. These results directly demonstrate the transport of respired CO(2) in the xylem stream and may help to explain inconsistencies in stem and branch respiration measurements made in situ. PMID:17490994

  16. Measurement of gas species, temperatures, coal burnout, and wall heat fluxes in a 200 MWe lignite-fired boiler with different overfire air damper openings

    SciTech Connect

    Jianping Jing; Zhengqi Li; Guangkui Liu; Zhichao Chen; Chunlong Liu [Harbin Institute of Technology, Harbin (China). School of Energy Science and Engineering

    2009-07-15

    Measurements were performed on a 200 MWe, wall-fired, lignite utility boiler. For different overfire air (OFA) damper openings, the gas temperature, gas species concentration, coal burnout, release rates of components (C, H, and N), furnace temperature, and heat flux and boiler efficiency were measured. Cold air experiments for a single burner were conducted in the laboratory. The double-swirl flow pulverized-coal burner has two ring recirculation zones starting in the secondary air region in the burner. As the secondary air flow increases, the axial velocity of air flow increases, the maxima of radial velocity, tangential velocity and turbulence intensity all increase, and the swirl intensity of air flow and the size of recirculation zones increase slightly. In the central region of the burner, as the OFA damper opening widens, the gas temperature and CO concentration increase, while the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and coal particles ignite earlier. In the secondary air region of the burner, the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and the gas temperature and CO concentration vary slightly. In the sidewall region, the gas temperature, O{sub 2} concentration, and NOx concentration decrease, while the CO concentration increases and the gas temperature varies slightly. The furnace temperature and heat flux in the main burning region decrease appreciably, but increase slightly in the burnout region. The NOx emission decreases from 1203.6 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 0% to 511.7 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 80% and the boiler efficiency decreases from 92.59 to 91.9%. 15 refs., 17 figs., 3 tabs.

  17. [Distribution of bacteriochlorophyll between the pigment-protein complexes of the sulfur photosynthesizing bacterium Allochromatium minutissimum depending on light intensity at different temperatures].

    PubMed

    Solov'ev, A A; Erokhin, Iu E

    2008-01-01

    Variation of the distribution of bacteriochlorophyll a (BChl a) between external antenna (LH2) and core complexes (LHl + RC) of the photosynthetic membrane of the sulfur bacterium Allochromatium minutissimum was studied at light intensities of 5 and 90 Wt/m2 in the temperature range of 12-43 degrees C. The increase of light intensity was shown to result in a 1.5- to 2-times increase of a photosynthetic unit (PSU). PSU sizes pass through a maximum depending on growth temperature, and the increase of light intensity (5 and 90 Wt/m2) results in a shift of the maximal PSU size to higher temperatures (15 and 20 degrees C, respectively). In the narrow temperature interval of approximately 14-17 degrees C, the ratio of light intensity to PSU size is typical of phototrophs: lower light intensity corresponds to larger PSU size. The pattern of PSU size change depending on light intensity was shown to differ at extreme growth temperatures (12 degrees C and over 35 degrees C). The comparison of Alc. minutissimum PSU size with the data on Rhodobacter capsulatus and Rhodopseudomonas palustris by measuring the effective optical absorption cross-section for the reaction of photoinhibition of respiration shows a two to four times greater size of light-harvesting antenna for Alc. minutissimum, which seems to correspond to the maximum possible limit for purple bacteria. PMID:19004340

  18. Comparison of the different kinetic pathways to form the self-organized structure of 7-step Pb(111) islands on Si(111) at low temperature

    NASA Astrophysics Data System (ADS)

    Yeh, V.; Kremmer, S.; Abram, E.; Berbil-Bautista, L.; Budde, K.; Tringides, M. C.

    2000-03-01

    We have studied with SPA-LEED the formation of self-organized, uniform height islands on Pb/Si(111) for different kinetic pathways. The self-organized 7-step island structure forms in the temperature range 170 < T < 240K, either directly during growth with the incident flux on or in annealing experiments (with continous or stepwise variation of the temperature). For the same temperature the islands formed during annealing are larger and further separated than the ones formed during growth; however the edges of the islands are less steep with a larger number of single steps as evidenced from comparison of the profile of the out-of-phase conditions. In annealing experiments it is surprising that the islands reach a fixed size at a given temperature quickly (less than 5 seconds) despite prolonged annealing time; the size increases if the annealing temperature increases suggesting a novel diffusion mechanism. At T>240K the 7-step structure is destroyed as the islands grow with heights larger than 7 layers and separations exceeding the instrumental limit.

  19. Microbial Communities in Long-Term, Water-Flooded Petroleum Reservoirs with Different in situ Temperatures in the Huabei Oilfield, China

    PubMed Central

    Tang, Yue-Qin; Li, Yan; Zhao, Jie-Yu; Chi, Chang-Qiao; Huang, Li-Xin; Dong, Han-Ping; Wu, Xiao-Lei

    2012-01-01

    The distribution of microbial communities in the Menggulin (MGL) and Ba19 blocks in the Huabei Oilfield, China, were studied based on 16S rRNA gene analysis. The dominant microbes showed obvious block-specific characteristics, and the two blocks had substantially different bacterial and archaeal communities. In the moderate-temperature MGL block, the bacteria were mainly Epsilonproteobacteria and Alphaproteobacteria, and the archaea were methanogens belonging to Methanolinea, Methanothermobacter, Methanosaeta, and Methanocella. However, in the high-temperature Ba19 block, the predominant bacteria were Gammaproteobacteria, and the predominant archaea were Methanothermobacter and Methanosaeta. In spite of shared taxa in the blocks, differences among wells in the same block were obvious, especially for bacterial communities in the MGL block. Compared to the bacterial communities, the archaeal communities were much more conserved within blocks and were not affected by the variation in the bacterial communities. PMID:22432032

  20. Dealing with big circulation flow, small temperature difference based on verified dynamic model simulations of a hot water district heating system

    E-print Network

    Zhong, L.

    2014-01-01

    DEALING WITH BIG CIRCULATION FLOW RATE, SMALL TEMPERATURE DIFFERENCE BASED ON VERIFIED DYNAMIC MODEL SIMULATIONS OF A HOT WATER DISTRICT HEATING SYSTEM Li Lian Zhong, Senior Sales Consultant, Danfoss Automatic Controls Management (Shanghai...) Co.,Ltd, Anshan, China ABSTRACT Dynamic models of an indirect hot water district heating system were developed based on the first principle of thermodynamics. The ideal model was verified by using measured operational data. The ideal...

  1. Temperature-Dependent Electroluminescence Efficiency in Blue InGaNGaN Light-Emitting Diodes With Different Well Widths

    Microsoft Academic Search

    C. H. Wang; J. R. Chen; C. H. Chiu; H. C. Kuo; Y.-L. Li; T. C. Lu; S. C. Wang

    2010-01-01

    Temperature dependence of electroluminescence (EL) efficiency in blue InGaN-GaN multiple-quantum-well (MQW) light-emitting diodes (LEDs) with different well widths is systematically investigated. The EL efficiency at 300 K shows a maximum at the input current of 4, 10, and 60 mA for the LEDs with 1.5-, 2.0-, and 2.5-nm QWs, respectively. Nevertheless, the droop behavior at 80 K is mainly dominated

  2. Self-propagating high-temperature synthesis of nano-TiCx particles with different shapes by using carbon nano-tube as C source

    PubMed Central

    2011-01-01

    With using the carbon nano-tube (CNT) of high chemical activity, nano-TiCx particles with different growth shapes were synthesized through the self-propagating high temperature in the 80 wt.% metal (Cu, Al, and Fe)-Ti-CNT systems. The growth shapes of the TiCx particles are mainly octahedron in the Cu- and Al-Ti-CNT systems, while mainly cube- and sphere-like in the Fe-Ti-CNT system. PMID:21878133

  3. Low-temperature photoluminescence of detector grade Cd{sub 1-{ital x}}Zn{sub {ital x}}Te crystal treated by different chemical etchants

    Microsoft Academic Search

    H. Chen; J. Tong; Z. Hu; D. T. Shi; G. H. Wu; K. Chen; M. A. George; W. E. Collins; A. Burger; R. B. James; C. M. Stahle; L. M. Bartlett

    1996-01-01

    Low-temperature photoluminescence (PL) spectra of detector grade Cd{sub 1-{ital x}}Zn{sub {ital x}}Te ({ital x}=0.1) have been measured to obtain information about shallow level defect concentration introduced during mechanical polishing and chemical etching processes. We present here a comparative PL study of Cd{sub 0.9}Zn{sub 0.1}Te crystals treated by different chemical solutions used for nuclear detector surface treatment. The results show that

  4. Corrosion behaviour of micro-plasma arc welded stainless steels in H 3PO 4 under flowing conditions at different temperatures

    Microsoft Academic Search

    R. Snchez-Tovar; M. T. Montas; J. Garca-Antn; A. Guenbour; A. Ben-Bachir

    2011-01-01

    This paper studies the general corrosion behaviour of the micro-plasma arc welded AISI 316L stainless steel in phosphoric acid at different temperatures (2560C) and at a Reynolds number of 1456. Galvanic corrosion has been studied using zero-resistance ammeter (ZRA) measurements and polarization curves (by the mixed potential theory). Results show that the microstructure of the stainless steel is modified due

  5. Isoenzyme frequencies in long-term selection lines of Drosophila melanogaster II. Isoenzyme frequencies of Leucine Aminopeptidases (LAP) in selection lines under different temperature conditions

    Microsoft Academic Search

    Hans-J. Muhs

    1975-01-01

    1)Permanent population lines of Drosophila melanogaster, derived from a double cross of 4 laboratory stocks, were selected under different temperature conditions (18 C and 28 C) for at least 125 generations.2)The isoenzymes of the leucine aminopeptidases (LAP) controlled by two closely linked loci on the third chromosome were investigated: LAP-A-locus in position 98.0 and LAP-D-locus in position 98.3. Thus the

  6. Observation of different spin behavior with temperature variation and Cr substitution in a multiferroic compound YMn2O5

    NASA Astrophysics Data System (ADS)

    Mukherjee, K.; Kumar, Kranti; Banerjee, A.

    2013-01-01

    In this article, the collective response of the spins is explored through low field bulk magnetic measurement for the series YMn2-xCrxO5 (x=0.0, 0.05). Low field ac susceptibility and dc magnetization of YMn2O5 shows multiple transitions in analogy to those observed in electrical measurement of the compound. Perturbing the parent compound with a small doping (2.5% Cr) causes a drastic change in the long-range magnetic behavior. It is observed that, YMn1.95Cr0.05O5 undergoes a ferrimagnetic ordering with an enhanced magnetic ordering temperature as compared to the parent, which undergoes an antiferromagnetic ordering. Appearance of spontaneous magnetization without any major change in the atomic structure is rather significant since the parent compound is an important multiferroic material. In addition, magnetic memory effect is observed in the Cr substituted compound whereas it is absent in the parent compound.

  7. The effects of gibberellic acid, light quality, and temperature cycles on floral initiation in different sorghum maturity genotypes

    E-print Network

    Williams, Laurie

    1977-01-01

    'IFRENT SORGJIUM MATURITY UENOTYPl:. S A Thesis by LAURIE WILLIAMS Approved as to style and cont ent by: (Chairman of Commi ee) (Mea of artment) ber) C' (Member) December 1977 ABSTRACT Thc Effects of Gibberellic Acid, I, ight Quality, and Temperature...) . Perhaps the best evidence that I I mi ng I s I nscplir ii)i I y concoct oil to I IIC Il)l ih C OI;ill 1'ililc)')enon' 1'llvthm ciimils groin work with thc Rl))t, I, crnn 1 p)tirj)E)s I I I;i . I, c)t na c;lii bil grown iii culture and fed with glucose...

  8. Temperature dependence of far-infrared difference reflectivity of YBa/sub 2/Cu/sub 3/O/sub 7-//sub y/

    SciTech Connect

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

    1989-04-01

    Far-infrared difference reflectivity spectra (50--450 cm/sup -1/) below, across and above the transition temperature on polycrystalline single-phase YBa/sub 2/Cu/sub 3/O/sub 7-//sub 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 YBa/sub 2/Cu/sub 3/O/sub 7-//sub 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.

  9. Different Temperature and Cooling Patterns at the Blunt and Sharp Egg Poles Reflect the Arrangement of Eggs in an Avian Clutch

    PubMed Central

    lek, Miroslav E.; Zrybnick, Markta

    2015-01-01

    Incubation is an energetically demanding process during which birds apply heat to their eggs to ensure embryonic development. Parent behaviours such as egg turning and exchanging the outer and central eggs in the nest cup affect the amount of heat lost to the environment from individual eggs. Little is known, however, about whether and how egg surface temperature and cooling rates vary among the different areas of an egg and how the arrangement of eggs within the clutch influences heat loss. We performed laboratory (using Japanese quail eggs) and field (with northern lapwing eggs) experiments using infrared imaging to assess the temperature and cooling patterns of heated eggs and clutches. We found that (i) the sharp poles of individual quail eggs warmed to a higher egg surface temperature than did the blunt poles, resulting in faster cooling at the sharp poles compared to the blunt poles; (ii) both quail and lapwing clutches with the sharp poles oriented towards the clutch centre (arranged clutches) maintained higher temperatures over the central part of the clutch than occurred in those clutches where most of the sharp egg poles were oriented towards the exterior (scattered clutches); and (iii) the arranged clutches of both quail and lapwing showed slower cooling rates at both the inner and outer clutch positions than did the respective parts of scattered clutches. Our results demonstrate that egg surface temperature and cooling rates differ between the sharp and blunt poles of the egg and that the orientation of individual eggs within the nest cup can significantly affect cooling of the clutch as a whole. We suggest that birds can arrange their eggs within the nest cup to optimise thermoregulation of the clutch. PMID:25658846

  10. Influence of Different Media, Incubation Times, and Temperatures for Determining the MICs of Seven Antifungal Agents against Paracoccidioides brasiliensis by Microdilution

    PubMed Central

    Cruz, R. C.; Werneck, S. M. C.; Oliveira, C. S.; Santos, P. C.; Soares, B. M.; Santos, D. A.

    2013-01-01

    MIC assays with Paracoccidioides brasiliensis, the etiological agent of paracoccidioidomycosis, had been conducted with variable protocols, employing both macrodilution and microdilution tests and including differences in inoculum preparation, media used, incubation periods, and temperatures. Twenty-one clinical and environmental isolates of Paracoccidioides were tested using amphotericin B, itraconazole, ketoconazole, fluconazole, sulfamethoxazole, sulfamethoxazole-trimethoprim, and terbinafine, according to the National Committee for Clinical Laboratory Standards (National Committee for Clinical Laboratory Standards, document M27-A2, 2002), with modifications such as three medium formulations (RPMI 1640 medium, McVeigh and Morton [MVM] medium, and modified Mueller-Hinton [MMH] medium), two incubation temperatures (room temperature [25 to 28C] and 37C), and three incubation periods (7, 10, and 15 days). The antifungal activities were also classified as fungicidal or fungistatic. The best results were obtained after 15 days of incubation, which was chosen as the standard incubation time. The MICs for most individual isolates grown for the same length of time at the same temperature varied with the different media used (P < 0.05). Of the isolates, 81% showed transition from the yeast to the mycelial form in RPMI 1640 medium at 37C, independent of the presence of antifungals. MMH medium appears to be a suitable medium for susceptibility testing of antifungal drugs with P. brasiliensis, except for sulfamethoxazole and the combination of sulfamethoxazole-trimethoprim, for which the MVM medium yielded better results. The incubation temperature influenced the MICs, with, in general, higher MICs at 25C (mycelial form) than at 37C (P < 0.05). Based on our results, we tentatively propose a microdilution assay protocol for susceptibility testing of antifungal drugs against Paracoccidioides. PMID:23175254

  11. Evaluation and predictive modeling of shelf life of minced beef stored in high-oxygen modified atmosphere packaging at different temperatures.

    PubMed

    Limbo, S; Torri, L; Sinelli, N; Franzetti, L; Casiraghi, E

    2010-01-01

    The aims were: (1) to follow the freshness decay of minced beef stored in high-oxygen modified atmosphere packaging at different temperatures (4.3, 8.1 and 15.5 degrees C) by applying traditional methods (microbiological counts, color evaluation, thiobarbituric acid assay TBA, headspace gas composition) and e-nose; (2) to model the decay kinetics to obtain information about the maximum shelf life as function of storage conditions. The minced beef, packaged in modified atmosphere was supplied by a manufacturer at the beginning of its commercial life. The study demonstrated the ability of the traditional methods to describe the kinetics of freshness decay. The modeling of the experimental data and the comparison with microbiological or chemical thresholds allowed the setting, for each index, of a stability time above which the meat was no longer acceptable. The quality decay of meat was also evaluated by the headspace fingerprint of the same set of samples by means of a commercial e-nose. A clear discrimination between "fresh" and "old" samples was obtained using PCA and CA, determining at each temperature a specific range of stability time. The mean value of the stability times calculated for each index was 9 days at 4.3 degrees C (recommended storage temperature), 3-4 days at 8.1 degrees C (usual temperature in household refrigerators) and 2 days at 15.5 degrees C (abuse temperature). Resolution of the stability times allowed calculation of mean Q(10) values, i.e. the increase in rate for a 10 degrees C increase in temperature. The results show that the Q(10) values from the traditional methods (3.6-4.0 range) overlapped with those estimated with e-nose and color indexes (3.4 and 3.9, respectively). PMID:20374764

  12. Solubility and thermodynamic behavior of vanillin in propane-1,2-diol+water cosolvent mixtures at different temperatures.

    PubMed

    Shakeel, Faiyaz; Haq, Nazrul; Siddiqui, Nasir A; Alanazi, Fars K; Alsarra, Ibrahim A

    2015-12-01

    The solubilities of bioactive compound vanillin were measured in various propane-1,2-diol+water cosolvent mixtures at T=(298-318)K and p=0.1MPa. The experimental solubility of crystalline vanillin was determined and correlated with calculated solubility. The results showed good correlation of experimental solubilities of crystalline vanillin with calculated ones. The mole fraction solubility of crystalline vanillin was recorded highest in pure propane-1,2-diol (7.0610(-2) at 298K) and lowest in pure water (1.2510(-3) at 298K) over the entire temperature range investigated. Thermodynamic behavior of vanillin in various propane-1,2-diol+water cosolvent mixtures was evaluated by Van't Hoff and Krug analysis. The results showed an endothermic, spontaneous and an entropy-driven dissolution of crystalline vanillin in all propane-1,2-diol+water cosolvent mixtures. Based on solubility data of this work, vanillin has been considered as soluble in water and freely soluble in propane-1,2-diol. PMID:26041164

  13. Room-temperature synthesis of zinc oxide nanoparticles in different media and their application in cyanide photodegradation

    PubMed Central

    2013-01-01

    Cyanide is an extreme hazard and extensively found in the wastes of refinery, coke plant, and metal plating industries. A simple, fast, cost-effective, room-temperature wet chemical route, based on cyclohexylamine, for synthesizing zinc oxide nanoparticles in aqueous and enthanolic media was established and tested for the photodegradation of cyanide ions. Particles of polyhedra morphology were obtained for zinc oxide, prepared in ethanol (ZnOE), while spherical and some chunky particles were observed for zinc oxide, prepared in water (ZnOW). The morphology was crucial in enhancing the cyanide ion photocatalytic degradation efficiency of ZnOE by a factor of 1.5 in comparison to the efficiency of ZnOW at an equivalent concentration of 0.02 wt.% ZnO. Increasing the concentration wt.% of ZnOE from 0.01 to 0.09 led to an increase in the photocatalytic degradation efficiency from 85% to almost 100% after 180 min and a doubling of the first-order rate constant (k). PMID:24314056

  14. Room-temperature synthesis of zinc oxide nanoparticles in different media and their application in cyanide photodegradation

    NASA Astrophysics Data System (ADS)

    Bagabas, Abdulaziz; Alshammari, Ahmad; Aboud, Mohamed FA; Kosslick, Hendrik

    2013-12-01

    Cyanide is an extreme hazard and extensively found in the wastes of refinery, coke plant, and metal plating industries. A simple, fast, cost-effective, room-temperature wet chemical route, based on cyclohexylamine, for synthesizing zinc oxide nanoparticles in aqueous and enthanolic media was established and tested for the photodegradation of cyanide ions. Particles of polyhedra morphology were obtained for zinc oxide, prepared in ethanol (ZnOE), while spherical and some chunky particles were observed for zinc oxide, prepared in water (ZnOW). The morphology was crucial in enhancing the cyanide ion photocatalytic degradation efficiency of ZnOE by a factor of 1.5 in comparison to the efficiency of ZnOW at an equivalent concentration of 0.02 wt.% ZnO. Increasing the concentration wt.% of ZnOE from 0.01 to 0.09 led to an increase in the photocatalytic degradation efficiency from 85% to almost 100% after 180 min and a doubling of the first-order rate constant ( k).

  15. Room-temperature synthesis of zinc oxide nanoparticles in different media and their application in cyanide photodegradation.

    PubMed

    Bagabas, Abdulaziz; Alshammari, Ahmad; Aboud, Mohamed Fa; Kosslick, Hendrik

    2013-01-01

    Cyanide is an extreme hazard and extensively found in the wastes of refinery, coke plant, and metal plating industries. A simple, fast, cost-effective, room-temperature wet chemical route, based on cyclohexylamine, for synthesizing zinc oxide nanoparticles in aqueous and enthanolic media was established and tested for the photodegradation of cyanide ions. Particles of polyhedra morphology were obtained for zinc oxide, prepared in ethanol (ZnOE), while spherical and some chunky particles were observed for zinc oxide, prepared in water (ZnOW). The morphology was crucial in enhancing the cyanide ion photocatalytic degradation efficiency of ZnOE by a factor of 1.5 in comparison to the efficiency of ZnOW at an equivalent concentration of 0.02 wt.% ZnO. Increasing the concentration wt.% of ZnOE from 0.01 to 0.09 led to an increase in the photocatalytic degradation efficiency from 85% to almost 100% after 180 min and a doubling of the first-order rate constant (k). PMID:24314056

  16. Stability of 11 prevalent synthetic cannabinoids in authentic neat oral fluid samples: glass versus polypropylene containers at different temperatures.

    PubMed

    Kneisel, Stefan; Speck, Michael; Moosmann, Bjoern; Auwrter, Volker

    2013-07-01

    Although synthetic cannabinoids have been intensively investigated in recent years and oral fluid testing is becoming increasingly popular in suspected driving under the influence of drugs cases, only scarce data on their stability in authentic neat oral fluid (nOF) samples are yet available. However, especially for these new psychoactive drugs, investigations focusing on stability issues are necessary as inappropriate storage conditions may lead to considerable analytical problems. Since it has been shown for ?(9) -tetrahydrocannabinol that adsorption to plastic surfaces may lead to considerable drug loss, we aimed to evaluate whether adsorption also has to be taken into account for synthetic cannabinoids in nOF samples. In this paper, the results of investigations on the recovery of 11 prevalent synthetic cannabinoids from authentic nOF samples stored over 72?h in RapidEASE (high quality borosilicate glass) and Sciteck Saliva Split Collector (polypropylene) tubes at 4 and 25?C are presented. Our findings clearly demonstrate that lipophilic synthetic cannabinoids present in nOF samples adsorb to the surface of polypropylene containers when stored at room temperature, leading to considerable drug loss. Hence, when using polypropylene tubes, samples should be shipped cooled in order to avoid a substantial decrease of the analyte concentration during transportation. PMID:23704054

  17. The Fragment Constant Method for Predicting Octanol-Air Partition Coefficients of Persistent Organic Pollutants at Different Temperatures

    NASA Astrophysics Data System (ADS)

    Li, Xuehua; Chen, Jingwen; Zhang, Li; Qiao, Xianliang; Huang, Liping

    2006-09-01

    The octanol-air partition coefficient (KOA) is a key physicochemical parameter for describing the partition of organic pollutants between air and environmental organic phases. Experimental determination of KOA is costly and time consuming, and sometimes restricted by lack of sufficiently pure chemicals. There is a need to develop a simple but accurate method to estimate KOA. In the present study, a fragment constant model based on five fragment constants and one structural correction factor, was developed for predicting logKOA at temperatures ranging from 10 to 40C. The model was validated as successful by statistical analysis and external experimental logKOA data. Compared to other quantitative structure-property relationship methods, the present model has the advantage that it is much easier to implement. As aromatic compounds that contain C, H, O, Cl, and Br atoms, were included in the training set used to develop the model, the current fragment model applies to a wide range of chlorinated and brominated aromatic pollutants, such as chlorobenzenes, polychlorinated naphthalenes, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans, polycyclic aromatic hydrocarbons, and polybrominated diphenyl ethers, all of which are typical persistent organic pollutants. Further study is necessary to expand the utility of the method to all halogenated aliphatic and aromatic compounds.

  18. Changes in the physiological parameters, fatty acid metabolism, and SCD activity and expression in juvenile GIFT tilapia (Oreochromis niloticus) reared at three different temperatures.

    PubMed

    Ma, X Y; Qiang, J; He, J; Gabriel, N N; Xu, P

    2015-08-01

    We evaluated the effects of rearing temperature on the composition of fatty acids and stearoyl-CoA desaturase (SCD) activity and gene expression in GIFT (genetically improved farmed tilapia) tilapia. Three triplicate groups of fish were reared for 40days at 22, 28, or 34C. At the end of the trial, the final body weight of juveniles reared at 28C was higher than that of fish reared at 22 or 34C. Feed intake, feed efficiency, and the protein efficiency ratio were also higher at 28C. The fatty acid composition of muscle tissue differed significantly (P<0.05) among the treatment groups. The content of SFA decreased with decreasing temperature, whereas the UFA content increased. We observed high levels of PUFA, particularly n-3 PUFAs, in fish reared at the lower temperature. Rearing at low temperature significantly (P<0.05) increased the expression and activity of the SCD gene. Increased SCD activity and gene expression can increase the biosynthesis of MUFAs in GIFT tilapia muscle. Additionally, cold acclimation can decrease the content of TC and TG in GIFT tilapia, which can help increase cold tolerance. PMID:25939714

  19. Characterization of Al2O3 coatings oxidized from Al with different proportion of seed crystals at a lower temperature

    NASA Astrophysics Data System (ADS)

    Wang, Chen; Lin, Yuebin; He, Fei; Luo, Xinyi; Tao, Jie

    2013-10-01

    Al layer with ?-Al2O3 seed crystals was prepared on the surface of 316L stainless steel (SS) by a double cathodes discharge technique, in which the mixed targets of pure Al doped with different proportions of ?-Al2O3 were used. Then, Al2O3 coatings were obtained after plasma oxidization at 580 C. The phase composition, microstructure and morphology of the coatings were studied respectively by means of glancing-angle (1) X-ray diffractometry (GAXRD) and scanning electron microscopy (SEM). Furthermore, the bonding force and corrosion resistance of the coatings were measured. The results indicated that ?-Al2O3 nucleated and grew surrounding the seed crystals as the Volmer-Weber Mode. The Al2O3 coating was compact, performing a good corrosion resistance and metallurgical bonding. The inducing effects of ?-Al2O3 with different fractions were discussed. ?-Al2O3 (5.5 wt.%) was distributed in the Al layer when the target possessing 10% ?-Al2O3 was used. After plasma oxidation, 65.54 wt.% ?-Al2O3 was obtained which was 10.34% more than that obtained by the oxidation of pure Al at the same condition. However, the inducing effects became weak with the further increment of content of ?-Al2O3 seed crystals.

  20. Microbiological shelf life at different temperatures and fate of Listeria monocytogenes and Escherichia coli inoculated in unflavored and strawberry yogurts.

    PubMed

    Tirloni, E; Bernardi, C; Colombo, F; Stella, S

    2015-07-01

    Three different trials were performed on unflavored and strawberry yogurts produced in a small-scale dairy plant. In the first trial, the microbiological shelf life of the products was evaluated at 4, 8, and 20C. At 4C the product showed low total viable counts until the end of the trial (d 35=3.00.7 and 1.50.0 log cfu/g in unflavored and strawberry yogurt, respectively). The loads were lower in strawberry yogurt at 4C compared with unflavored yogurt because of the antimicrobial activity exerted by potassium sorbate present in the fruit puree added. Yeasts were confirmed to be the specific spoilage agents of this product, reaching rapidly high loads with thermal abuse (5.9-7.4 log cfu/g at d 18). In the second trial, Escherichia coli and especially Listeria monocytogenes added at 2 concentrations (2 and 5 log cfu/g) showed a rapid decrease in both types thanks to the acidic conditions provided by the products, but L. monocytogenes was very resistant; its presence was always detected until the end of the period considered (d 68). In the third trial, no statistically significant differences were detected between wild and acid-adapted strains of L. monocytogenes added to the products, due to the quick adaptation that probably occurred after inoculation. PMID:25981065

  1. Efficacy of methoprene applied at different temperatures and rates on surface substrates to control eggs and fifth instars of Plodia interpunctella.

    PubMed

    Jenson, Emily A; Arthur, Frank H; Nechols, James R

    2009-10-01

    A series of studies was conducted to determine the effects of temperature on toxicity of the insect growth regulator methoprene to eggs and larvae of Plodia interpunctella (Hbner), the Indianmeal moth. When methoprene was applied to Kraft paper at the rate of 0.0003 mg of active ingredient [(AI)]/cm2, there was little direct toxicity against eggs of P. interpunctella, and temperature did not affect insecticide efficacy. Similarly, exposure of eggs on a paperboard surface treated with different rates of methoprene resulted in delayed adult emergence but not a reduction in adult emergence. However, wandering-phase larvae ofP. interpuctella were susceptible to methoprene, and exposure of larvae for 0.5, 1, and 2 h on different packaging materials resulted in reduced adult emergence. There was variation in emergence depending on the specific surface, but temperature had no effect on resulting adult emergence from exposed larvae. A partial budget analysis described treatment costs and reduction of risks associated with control of eggs and larvae of P. interpunctella. Results indicate methoprene could be used in management programs to control larvae of P. interpunctella, but eggs may be able to compensate for exposure to methoprene residues on treated surfaces. PMID:19886467

  2. Surface plasmon resonances of Ag-Au alloy nanoparticle films grown by sequential pulsed laser deposition at different compositions and temperatures

    NASA Astrophysics Data System (ADS)

    Verma, Shweta; Rao, B. T.; Detty, A. P.; Ganesan, V.; Phase, D. M.; Rai, S. K.; Bose, A.; Joshi, S. C.; Kukreja, L. M.

    2015-04-01

    We studied localized surface plasmon resonances (LSPR) at different compositions, substrate temperatures, and mass thicknesses of Ag-Au alloy nanoparticle films grown by sequential pulsed laser deposition. The LSPRs were pronounced at all compositions of the films grown at high substrate temperature of about 300 C as compared to those grown at room temperature. The alloy formation and composition of the films were determined using X-ray photoelectron and energy dispersive spectroscopy. Films' mass thickness and compositional uniformity along the thickness were determined using X-ray reflectometry and secondary ion mass spectroscopy. Atomic force microscopic analysis revealed the formation of densely packed nanoparticles of increasing size with the number of laser ablation pulses. The LSPR wavelength red shifted with increasing either Au percentage or film mass thickness and corresponding LSPR tuning was obtained in the range of 450 to 690 nm. The alloy dielectric functions obtained from three different models were compared and the optical responses of the nanoparticle films were calculated from modified Yamaguchi effective medium theory. The tuning of LSPR was found to be due to combined effect of change in intrinsic and extrinsic parameters mainly the composition, morphology, particle-particle, and particle-substrate interactions.

  3. Semiconductor nanowires for highly sensitive, room-temperature detection of terahertz quantum cascade laser emission

    NASA Astrophysics Data System (ADS)

    Vitiello, Miriam S.; Viti, Leonardo; Romeo, Lorenzo; Ercolani, Daniele; Scalari, G.; Faist, J.; Beltram, F.; Sorba, L.; Tredicucci, A.

    2012-06-01

    We report on the development of nanowire-based field-effect transistors operating as high sensitivity terahertz (THz) detectors. By feeding the 1.5 THz radiation field of a quantum cascade laser (QCL) at the gate-source electrodes with a wide band dipole antenna, we record a photovoltage signal corresponding to responsivity values >10 V/W, with impressive noise equivalent power levels <6 10-11 W/?Hz at room temperature and a wide modulation bandwidth. The potential scalability to even higher frequencies and the technological feasibility of realizing multi-pixel arrays coupled with QCL sources make the proposed technology highly competitive for a future generation of THz detection systems.

  4. Comparison of mathematical models of lactic acid bacteria growth in vacuum-packaged raw beef stored at different temperatures.

    PubMed

    Li, M Y; Sun, X M; Zhao, G M; Huang, X Q; Zhang, J W; Tian, W; Zhang, Q H

    2013-04-01

    The lactic acid bacteria grown in vacuum-packaged raw beef under 7, 10, 15, and 20?C has been studied in this paper. Four primary models, the modified Gompertz, logistic, Baranyi, and Huang model were used for data fitting. Statistical criteria such as the bias factor and accuracy factor, mean square error, Akaike's information criterion, and the residual distribution were used for comparing the models. The result showed that all of the 4 models can fit the data well and they were not significantly different in the performance. They were equally capable of describing bacterial growth, but the growth rate and lag time estimated from the modified Gompertz model were a little higher than other models. The estimate for the lag time was not accurate as the growth rate. PMID:23560997

  5. Study on the Mechanism of Interaction Between Tubeimoside I and Human Serum Albumin at Different Temperatures by Three-Dimensional Fluorescence Spectrum

    NASA Astrophysics Data System (ADS)

    Lin, Xiaogang; Li, Wenchao; Ye, Changbin; Liu, Zhiyuan

    2014-07-01

    Tubeimoside (TBMS), the bulb of Bolbostemma paniculatum (Maxim.) Franquet (Cucurbitaceae), is one of the traditional Chinese medicines often used for the treatment of tumors as well as for detoxication. Tubeimoside I (TBMS I) is one of the main active ingredients of TBMS, the mechanism of action of which remains unknown. Human serum albumin (HSA) is the most abundant carrier protein in blood circulation. Three-dimensional (3D) fluorescence spectra and the excitation-emission matrix of interaction between TBMS I and HSA were measured at different temperatures. The results showed that HSA fluorescence was quenched by TBMS I through a static quenching mechanism. Also, the HSA fluorescence was quenched with the temperature increase from 283 K to 353 K. 3D spectral results revealed the changes in the secondary structure of HSA upon interaction with TBMS I.

  6. Room-temperature nanowire terahertz photodetectors

    NASA Astrophysics Data System (ADS)

    Romeo, Lorenzo; Coquillant, Dominique; Viti, Leonardo; Ercolani, Daniele; Sorba, Lucia; Knap, Wojciech; Tredicucci, Alessandro; Vitiello, Miriam S.

    2013-01-01

    Semiconductor nanowires (NWs) represent an ideal building block for implementing rectifying diodes or plasma wave detectors that could operate well into the THz, thanks to the typical attofarad-order capacitance. Despite the strong effort in developing these nanostructures for a new generation of complementary metal-oxide semi conductors (CMOS), memory and photonic devices, their potential as radiation sensors into the Terahertz is just starting to be explored. We report on the development of NW-based field effect transistors operating as high sensitivity THz detectors in the 0.3 - 2.8 THz range. By feeding the radiation field of either an electronic THz source or a quantum cascade laser (QCL) at the gate-source electrodes by means of a wide band dipole antenna, we measured a photovoltage signal corresponding to responsivity values up to 100 V IW, with impressive noise equivalent power levels < 6 x 10-11W/Hz at room temperature and a > 300kHz modulation bandwidth. The potential scalability to even higher frequencies and the technological feasibility of realizing multi-pixel arrays coupled with QCL sources make the proposed technology highly competitive for a future generation of THz detection systems.

  7. Wetting process and interfacial characteristic of Sn-3.0Ag-0.5Cu on different substrates at temperatures ranging from 503 K to 673 K

    NASA Astrophysics Data System (ADS)

    Zang, Likun; Yuan, Zhangfu; Xu, Hongyan; Xu, Bingsheng

    2011-03-01

    Wetting process and interfacial characteristic of Sn-3.0Ag-0.5Cu have been investigated at temperatures ranging from 503 K to 673 K on Cu, Ni, stainless steel and quartz, respectively. The reactive wetting behavior of Sn-3.0Ag-0.5Cu melt alloy on Cu and Ni substrates were investigated. Contact angles decrease as exponential decay and equilibrium contact angles decrease between the solder and Cu, Ni substrates monotonously with the temperature increasing. The configuration of the triple line of Sn-3.0Ag-0.5Cu/Cu is discussed by the description of equilibrium. The calculated results based on experimental values of tension balances along each of the three interfaces at this final state show good agreement with theoretical analysis. Intermetallics of the Sn-3.0Ag-0.5Cu/Ni interface are identified as (Cu, Ni) 6Sn 5 adjacent to the solder and Ni 3Sn 4 adjacent to the Ni substrate, respectively. The contact angles between Sn-3.0Ag-0.5Cu and quartz, stainless steel substrates were measured to be greater than 90, which means non-wetting, in the temperature range from 503 K to 673 K. Liquid-solid interfacial energy between the solder and different substrates are obtained based on the surface tension of molten solder and equilibrium contact angles at different temperatures. These results are of practical interest for composite lead-free solders preparations and joining of Sn-3.0Ag-0.5Cu to various substrates.

  8. Performance optimization of apodized FBG-based temperature sensors in single and quasi-distributed DWDM systems with new and different apodization profiles

    SciTech Connect

    Mohammed, Nazmi A. [Research Center, Smart Village, College of Engineering, Arab Academy for Science, Technology, and Maritime Transport, Cairo (Egypt)] [Research Center, Smart Village, College of Engineering, Arab Academy for Science, Technology, and Maritime Transport, Cairo (Egypt); Ali, Taha A., E-mail: Taha25@gmail.com; Aly, Moustafa H. [Department of Electronics and Communications Engineering, College of Engineering, Arab Academy for Science, Technology, and Maritime Transport, Cairo (Egypt)] [Department of Electronics and Communications Engineering, College of Engineering, Arab Academy for Science, Technology, and Maritime Transport, Cairo (Egypt)

    2013-12-15

    In this work, different FBG temperature sensors are designed and evaluated with various apodization profiles. Evaluation is done under a wide range of controlling design parameters like sensor length and refractive index modulation amplitude, targeting a remarkable temperature sensing performance. New judgment techniques are introduced such as apodization window roll-off rate, asymptotic sidelobe (SL) decay level, number of SLs, and average SL level (SLav). Evaluation techniques like reflectivity, Full width at Half Maximum (FWHM), and Sidelobe Suppression Ratio (SLSR) are also used. A New apodization function is proposed, which achieves better performance like asymptotic decay of 18.4 dB/nm, high SLSR of 60 dB, high channel isolation of 57.9 dB, and narrow FWHM less than 0.15 nm. For a single accurate temperature sensor measurement in extensive noisy environment, optimum results are obtained by the Nuttall apodization profile and the new apodization function, which have remarkable SLSR. For a quasi-distributed FBG temperature sensor the Barthann and the new apodization profiles obtain optimum results. Barthann achieves a high asymptotic decay of 40 dB/nm, a narrow FWHM (less than 25 GHZ), a very low SLav of ?45.3 dB, high isolation of 44.6 dB, and a high SLSR of 35 dB. The new apodization function achieves narrow FWHM of 0.177 nm, very low SL of ?60.1, very low SLav of ?63.6 dB, and very high SLSR of ?57.7 dB. A study is performed on including an unapodized sensor among apodized sensors in a quasi-distributed sensing system. Finally, an isolation examination is performed on all the discussed apodizations and a linear relation between temperature and the Bragg wavelength shift is observed experimentally and matched with the simulated results.

  9. Bacteria in the injection water differently impacts the bacterial communities of production wells in high-temperature petroleum reservoirs

    PubMed Central

    Ren, Hongyan; Xiong, Shunzi; Gao, Guangjun; Song, Yongting; Cao, Gongze; Zhao, Liping; Zhang, Xiaojun

    2015-01-01

    Water flooding is widely used for oil recovery. However, how the introduction of bacteria via water flooding affects the subsurface ecosystem remains unknown. In the present study, the distinct bacterial communities of an injection well and six adjacent production wells were revealed using denaturing gradient gel electrophoresis (DGGE) and pyrosequencing. All sequences of the variable region 3 of the 16S rRNA gene retrieved from pyrosequencing were divided into 543 operational taxonomic units (OTUs) based on 97% similarity. Approximately 13.5% of the total sequences could not be assigned to any recognized phylum. The Unifrac distance analysis showed significant differences in the bacterial community structures between the production well and injection water samples. However, highly similar bacterial structures were shown for samples obtained from the same oil-bearing strata. More than 69% of the OTUs detected in the injection water sample were absent or detected in low abundance in the production wells. However, the abundance of two OTUs reached as high as 17.5 and 26.9% in two samples of production water, although the OTUs greatly varied among all samples. Combined with the differentiated water flow rate measured through ion tracing, we speculated that the transportation of injected bacteria was impacted through the varied permeability from the injection well to each of the production wells. Whether the injected bacteria predominate the production well bacterial community might depend both on the permeability of the strata and the reservoir conditions. PMID:26052321

  10. Bacteria in the injection water differently impacts the bacterial communities of production wells in high-temperature petroleum reservoirs.

    PubMed

    Ren, Hongyan; Xiong, Shunzi; Gao, Guangjun; Song, Yongting; Cao, Gongze; Zhao, Liping; Zhang, Xiaojun

    2015-01-01

    Water flooding is widely used for oil recovery. However, how the introduction of bacteria via water flooding affects the subsurface ecosystem remains unknown. In the present study, the distinct bacterial communities of an injection well and six adjacent production wells were revealed using denaturing gradient gel electrophoresis (DGGE) and pyrosequencing. All sequences of the variable region 3 of the 16S rRNA gene retrieved from pyrosequencing were divided into 543 operational taxonomic units (OTUs) based on 97% similarity. Approximately 13.5% of the total sequences could not be assigned to any recognized phylum. The Unifrac distance analysis showed significant differences in the bacterial community structures between the production well and injection water samples. However, highly similar bacterial structures were shown for samples obtained from the same oil-bearing strata. More than 69% of the OTUs detected in the injection water sample were absent or detected in low abundance in the production wells. However, the abundance of two OTUs reached as high as 17.5 and 26.9% in two samples of production water, although the OTUs greatly varied among all samples. Combined with the differentiated water flow rate measured through ion tracing, we speculated that the transportation of injected bacteria was impacted through the varied permeability from the injection well to each of the production wells. Whether the injected bacteria predominate the production well bacterial community might depend both on the permeability of the strata and the reservoir conditions. PMID:26052321

  11. Proteomic study of low-temperature responses in strawberry cultivars (Fragaria x ananassa) that differ in cold tolerance.

    PubMed

    Koehler, Gage; Wilson, Robert C; Goodpaster, John V; Snsteby, Anita; Lai, Xianyin; Witzmann, Frank A; You, Jin-Sam; Rohloff, Jens; Randall, Stephen K; Alsheikh, Muath

    2012-08-01

    To gain insight into the molecular basis contributing to overwintering hardiness, a comprehensive proteomic analysis comparing crowns of octoploid strawberry (Fragaria ananassa) cultivars that differ in freezing tolerance was conducted. Four cultivars were examined for freeze tolerance and the most cold-tolerant cultivar ('Jonsok') and least-tolerant cultivar ('Frida') were compared with a goal to reveal how freezing tolerance is achieved in this distinctive overwintering structure and to identify potential cold-tolerance-associated biomarkers. Supported by univariate and multivariate analysis, a total of 63 spots from two-dimensional electrophoresis analysis and 135 proteins from label-free quantitative proteomics were identified as significantly differentially expressed in crown tissue from the two strawberry cultivars exposed to 0-, 2-, and 42-d cold treatment. Proteins identified as cold-tolerance-associated included molecular chaperones, antioxidants/detoxifying enzymes, metabolic enzymes, pathogenesis-related proteins, and flavonoid pathway proteins. A number of proteins were newly identified as associated with cold tolerance. Distinctive mechanisms for cold tolerance were characterized for two cultivars. In particular, the 'Frida' cold response emphasized proteins specific to flavonoid biosynthesis, while the more freezing-tolerant 'Jonsok' had a more comprehensive suite of known stress-responsive proteins including those involved in antioxidation, detoxification, and disease resistance. The molecular basis for 'Jonsok'-enhanced cold tolerance can be explained by the constitutive level of a number of proteins that provide a physiological stress-tolerant poise. PMID:22689892

  12. Using an Unmanned Arial Vehicle (UAV) and a thermal infrared camera to estimate temperature differences on a lake surface, revealing incoming groundwater seepage.

    NASA Astrophysics Data System (ADS)

    Hoffmann, Helene; Mller, Sascha; Friborg, Thomas

    2014-05-01

    UAVs are at the budding stage of becoming efficient tools in geosciences due to their fast coverage of large areas, creating opportunities to collect comprehensive amounts of spatially distributed data. In this survey a fixed-wing UAV is equipped with a thermal infrared camera (Optris PI 450) conducting spatially distributed measurements of radiometric surface temperature, from a small groundwater-fed lake. We hypothesis that larger temperature differences in the lake surface will reveal locations of incoming groundwater seepage. During wintertime, warmer groundwater will have great incentive to rise to the lake surface without significant mixing with colder lake water and hence enable detection of incoming groundwater seepage with surface measurements. The investigated area is a 300x150 m section of Lake Vaeng in southern Jutland, Denmark. Detecting areas of groundwater seepage into lakes and quantifying these fluxes are of great importance not only for water budgets but also in relation to lake environments. Incoming groundwater might be a large nutrient source in lakes. GPS coordinates from the UAV are correlated with each thermal image based on UTC time stamps. Geo-reference is further improved with ground control points in the form of 0.2x0.2 m aluminum foil rectangles. Aluminum stands out clearly in thermal images and using seven of these ground control points, evenly distributed in the investigated area, led to an accuracy of 0.3 m. Using the Structure from Motion photogrammetric technique, a point cloud model is produced and camera positions along with intrinsic and extrinsic properties are established. Distinct temperature differences of 1.5 C have been detected along the south-eastern shore of Lake Vaeng. The location of these hotspots is in agreement with temperature differences measured with Distributed Temperature Sensing (DTS) system - indicating zones of groundwater seepage into the lake. In addition to faster execution of large spatially distributed measurements, UAVs have greater accessibility to areas that are difficult to reach with instruments on ground such as DTS systems.

  13. Modeled Interactive Effects of Precipitation, temperature, and [CO2] on Ecosystem Carbon and Water Dynamics in Different Climatic Zones

    SciTech Connect

    Luo, Yiqi [University of Oklahoma; Gerten, Dieter [Potsdam Institute for Climate Impact Research, Potsdam, Germany; Le Maire, Guerric [Laboratoire des Sciences du Climat et de l'Environement, France; Parton, William [University of Colorado, Fort Collins; Weng, Ensheng [University of Oklahoma, Norman; Zhou, Xuhuui [University of Oklahoma; Keough, Cindy [University of Colorado, Fort Collins; Beier, Claus [Riso National Laboratory, Roskilde, Denmark; Ciais, Philippe [Laboratoire des Sciences du Climat et de l'Environement, France; Cramer, Wolfgang [Potsdam Institute for Climate Impact Research, Potsdam, Germany; Dukes, Jeff [University of Massachusetts, Boston; Emmett, Bridget [Centre for Ecology and Hydrology, Bangor, Gwynedd, United Kingdom; Hanson, Paul J [ORNL; Knapp, Alan [Colorado State University, Fort Collins; Linder, Sune [Swedish University of Agricultural Sciences, Upsalla, Sweden; Nepstad, Daniel [Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA; Rustad, Lindsey [USDA Forest Service

    2008-01-01

    Interactive effects of multiple global change factors on ecosystem processes are complex. It is relatively expensive to explore those interactions in manipulative experiments. We conducted a modeling analysis to identify potentially important interactions and to stimulate hypothesis formulation for experimental research. Four models were used to quantify interactive effects of climate warming (T), altered precipitation amounts [doubled (DP) and halved (HP)] and seasonality (SP, moving precipitation in July and August to January and February to create summer drought), and elevated [CO2] (C) on net primary production (NPP), heterotrophic respiration (Rh), net ecosystem production (NEP), transpiration, and runoff.We examined those responses in seven ecosystems, including forests, grasslands, and heathlands in different climate zones. The modeling analysis showed that none of the threeway interactions among T, C, and altered precipitation was substantial for either carbon or water processes, nor consistent among the seven ecosystems. However, two-way interactive effects on NPP, Rh, and NEP were generally positive (i.e. amplification of one factor s effect by the other factor) between T and C or between T and DP. A negative interaction (i.e. depression of one factor s effect by the other factor) occurred for simulated NPP between T and HP. The interactive effects on runoff were positive between T and HP. Four pairs of two-way interactive effects on plant transpiration were positive and two pairs negative. In addition, wet sites generally had smaller relative changes in NPP, Rh, runoff, and transpiration but larger absolute changes in NEP than dry sites in response to the treatments. The modeling results suggest new hypotheses to be tested in multifactor global change experiments. Likewise, more experimental evidence is needed for the further improvement of ecosystem models in order to adequately simulate complex interactive processes.

  14. Characterization of different Capsicum varieties by evaluation of their capsaicinoids content by high performance liquid chromatography, determination of pungency and effect of high temperature.

    PubMed

    Gonzlez-Zamora, Alberto; Sierra-Campos, Erick; Luna-Ortega, J Guadalupe; Prez-Morales, Rebeca; Rodrguez Ortiz, Juan Carlos; Garca-Hernndez, Jos L

    2013-01-01

    The chili pepper is a very important plant used worldwide as a vegetable, as a spice, and as an external medicine. In this work, eight different varieties of Capsicum annuum L. have been characterized by their capsaicinoids content. The chili pepper fruits were cultivated in the Comarca Lagunera region in North of Mexico. The qualitative and quantitative determination of the major and minor capsaicinoids; alkaloids responsible for the pungency level, has been performed by a validated chromatographic procedure (HPLC-DAD) after a preliminary drying step and an opportune extraction procedure. Concentrations of total capsaicinoids varied from a not detectable value for Bell pepper to 31.84 mg g(-1) dried weight for Chiltepn. Samples were obtained from plants grown in experimental field and in greenhouse without temperature control, in order to evaluate temperature effect. Analysis of the two principal capsaicinoids in fruits showed that the amount of dihydrocapsaicin was always higher than capsaicin. In addition, our results showed that the content of total capsaicinoids for the varieties Serrano, Puya, Ancho, Guajillo and Bell pepper were increased with high temperature, while the content of total capsaicinoids and Scoville heat units (SHU) for the varieties De rbol and Jalapeo decreased. However, the pungency values found in this study were higher for all varieties analyzed than in other studies. PMID:24184818

  15. [Effects of different organic matter mulching on water content, temperature, and available nutrients of apple orchard soil in a cold region].

    PubMed

    Zhou, Jiang-Tao; L, De-Guo; Qin, Si-Jun

    2014-09-01

    The effects of different organic matter covers on soil physical-chemical properties were investigated in a 'Hanfu' apple orchard located in a cold region. Four treatments were applied (weed mulching, rice straw mulching, corn straw mulching, and crushed branches mulching), and physical-chemical properties, including orchard soil moisture and nutrient contents, were compared among treatment groups and between organic matter-treated and untreated plots. The results showed that soil water content increased in the plots treated with organic matter mulching, especially in the arid season. Cover with organic matter mulch slowed the rate of soil temperature increase in spring, which was harmful to the early growth of fruit trees. Organic matter mulching treatments decreased the peak temperature of orchard soil in the summer and increased the minimum soil temperature in the fall. pH was increased in soils treated with organic matter mulching, especially in the corn straw mulching treatment, which occurred as a response to alleviating soil acidification to achieve near-neutral soil conditions. The soil organic matter increased to varying extents among treatment groups, with the highest increase observed in the weed mulching treatment. Overall, mulching increased alkali-hydrolyzable nitrogen, available phosphorus, and available potassium in the soil, but the alkali-hydrolyzable nitrogen content in the rice straw mulching treatment was lower than that of the control. PMID:25757304

  16. Multiple pulse-heating experiments with different current to determine total emissivity, heat capacity, and electrical resistivity of electrically conductive materials at high temperatures.

    PubMed

    Watanabe, Hiromichi; Yamashita, Yuichiro

    2012-01-01

    A modified pulse-heating method is proposed to improve the accuracy of measurement of the hemispherical total emissivity, specific heat capacity, and electrical resistivity of electrically conductive materials at high temperatures. The proposed method is based on the analysis of a series of rapid resistive self-heating experiments on a sample heated at different temperature rates. The method is used to measure the three properties of the IG-110 grade of isotropic graphite at temperatures from 850 to 1800 K. The problem of the extrinsic heating-rate effect, which reduces the accuracy of the measurements, is successfully mitigated by compensating for the generally neglected experimental error associated with the electrical measurands (current and voltage). The results obtained by the proposed method can be validated by the linearity of measured quantities used in the property determinations. The results are in reasonably good agreement with previously published data, which demonstrate the suitability of the proposed method, in particular, to the resistivity and total emissivity measurements. An interesting result is the existence of a minimum in the emissivity of the isotropic graphite at around 1120 K, consistent with the electrical resistivity results. PMID:22299976

  17. Multiple pulse-heating experiments with different current to determine total emissivity, heat capacity, and electrical resistivity of electrically conductive materials at high temperatures

    NASA Astrophysics Data System (ADS)

    Watanabe, Hiromichi; Yamashita, Yuichiro

    2012-01-01

    A modified pulse-heating method is proposed to improve the accuracy of measurement of the hemispherical total emissivity, specific heat capacity, and electrical resistivity of electrically conductive materials at high temperatures. The proposed method is based on the analysis of a series of rapid resistive self-heating experiments on a sample heated at different temperature rates. The method is used to measure the three properties of the IG-110 grade of isotropic graphite at temperatures from 850 to 1800 K. The problem of the extrinsic heating-rate effect, which reduces the accuracy of the measurements, is successfully mitigated by compensating for the generally neglected experimental error associated with the electrical measurands (current and voltage). The results obtained by the proposed method can be validated by the linearity of measured quantities used in the property determinations. The results are in reasonably good agreement with previously published data, which demonstrate the suitability of the proposed method, in particular, to the resistivity and total emissivity measurements. An interesting result is the existence of a minimum in the emissivity of the isotropic graphite at around 1120 K, consistent with the electrical resistivity results.

  18. Characterization of water binding and germination traits of magnetically exposed maize (Zea mays L.) seeds equilibrated at different relative humidities at two temperatures.

    PubMed

    Vashisth, Ananta; Nagarajan, Shantha

    2009-04-01

    A study was undertaken to characterize the water sorption properties and enhancement in germination and seedling vigour of maize (Zea mays L.) seeds exposed to static magnetic fields of 100 mT and 200 mT for 2 and 1 h, respectively. Water sorption isotherms were constructed for magnetically- exposed and unexposed seeds by equilibrating over different saturated salt solutions at 25 and 35 degrees C. The germination and vigour parameters were evaluated for magnetically-exposed and unexposed seeds, equilibrated over the wide range of relative humidities (RHs) at 25 and 35 degrees C. Moisture content increased with increase in RH and decreased with increase in equilibrium temperature. The germination and vigour reduced at high and very low humidities. Magnetically-exposed seeds maintained higher germination and vigour at both temperatures and all RHs, indicating the better quality of magnetically-exposed seeds. The leachate conductivity of magnetically-exposed seeds was lower than unexposed seeds at all RHs, suggesting better membrane integrity in magnetically-exposed seeds. Analysis of the isotherms using D'Arcy-Watt equation revealed that irrespective of the temperature, in magnetically-treated seeds weak binding sites were more and strong and multi-molecular binding sites were less compared to the unexposed seeds. Total binding sites were more in unexposed control seeds. The modification of binding properties of seed water and increased seed membrane integrity in magnetically-exposed seeds might have enhanced the germination traits and early seedling growth of maize. PMID:19517997

  19. Effect of V addition to Al and Al grain refined by Ti on chemical corrosion rates in NaOH solution with and without inhibitor at different temperatures

    NASA Astrophysics Data System (ADS)

    Zaid, Adnan I. O.; Al-Haj-Ali, Ahmad M.; Allawi, G. T. A.

    2014-06-01

    The paper presents the effect of vanadium addition to aluminum grain refined by titanium, in the range from 0.005 wt % to 0.236 wt %, on corrosion rate of these micro alloys in caustic soda (NaOH) solution at different temperatures. The corrosion rate decreased by the addition of any percent of vanadium at 25C compared to pure Al. The corrosion rate increased with increase of solution temperature from 25 to 40 and 60 C at any percent of vanadium addition. However, addition of vanadium reduced the corrosion rate at these temperatures at most wt.% of V addition. The maximum achieved reduction in corrosion rate due to vanadium addition was 40 % at 0.148 wt % and 60C. The addition of 3 % potassium dichromate as corrosion inhibitor to NaOH solution reduced the average corrosion rates at any wt.% of vanadium. The inhibition efficiency ranged from 44- 58% at 25 C and from 97-99% at 40 and 60C.

  20. The reverse temper embrittlement characteristics of two sets of CrMo steel high temperature turbine bolts with different service times

    SciTech Connect

    Bulloch, J.H. [Electricity Supply Board, Power Generation, Dublin (Ireland)

    1996-08-01

    This article describes a reverse temper embrittlement (RTE) assessment of two series of Cr-Mo turbine bolts that had experienced differing service times at operating temperatures of around 670 K. It was established that when RTE was identified, the condition was one of only partial embrittlement, and two distinct regimens, partial and nonembrittled, were clearly identified using a plot of average grain size, d, versus percent bulk phosphorus. The interface between the two stages of embrittlement could be described by the simple expression, d {times} (%P) = Constant. It was observed that the bolts with the longer service time, approx 1.76 {times} 10{sup 5} h, were more prone to embrittlement than those that had only been subjected to approx 6 {times} 10{sup 4} h of service. Finally, it was suggested that such embrittlement differences were the result of accumulated strain during service and not a result of service time per se.