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1

Noise equivalent temperature difference performance of an IR detector in a hybrid focal plane array  

NASA Astrophysics Data System (ADS)

Theoretical expressions to calculate the signal-to-noise ratio of an IR detector in a direct injection readout hybrid focal plane array (FPA) are developed in this paper. The theory takes into account the effect of shift of operating point of the pixel with small variations in scene temperature and contribution of shunt resistance due to surface leakage currents in the photodiode. These expressions are then used to calculate the noise equivalent temperature difference (NETD) performance of the IR detector in the FPA. The role of buffered direct injection (BDI) circuit in improving the NETD performance of hybrid pixels in a LWIR mercury cadmium telluride FPA array is analyzed. The results of our calculations show that the individual pixels in a LWIR HgCdTe FPA would not function to their ultimate performance and in certain conditions may even exhibit erratic behaviour in the absence of BDI interface.

Gopal, Vishnu

1995-10-01

2

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

SciTech Connect

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.

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

3

Noise-equivalent sensitivity of photoacoustics  

PubMed Central

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

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

2013-01-01

4

Noise equivalent circuit of a semiconductor laser diode  

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

5

The use of noise equivalent count rate and the NEMA phantom for PET image quality evaluation.  

PubMed

PET image quality is directly associated with two important parameters among others: count-rate performance and image signal-to-noise ratio (SNR). The framework of noise equivalent count rate (NECR) was developed back in the 1990s and has been widely used since then to evaluate count-rate performance for PET systems. The concept of NECR is not entirely straightforward, however, and among the issues requiring clarification are its original definition, its relationship to image quality, and its consistency among different derivation methods. In particular, we try to answer whether a higher NECR measurement using a standard NEMA phantom actually corresponds to better imaging performance. The paper includes the following topics: 1) revisiting the original analytical model for NECR derivation; 2) validating three methods for NECR calculation based on the NEMA phantom/standard; and 3) studying the spatial dependence of NECR and quantitative relationship between NECR and image SNR. PMID:25622772

Yang, Xin; Peng, Hao

2015-03-01

6

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

Microsoft Academic Search

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

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

1990-01-01

7

Noise-equivalent and signal-equivalent visual summation of quantal events in space and time.  

PubMed

Noise recorded in visual neurons, or variability in psychophysical experiments, may be quantified in terms of quantal fluctuations from an "equivalent" steady illumination. The conversion requires assumptions concerning how photon signals are pooled in space and time, i.e. how to pass from light fluxes to numbers of photon events relevant to the Poisson statistics describing signal/noise. It is usual to approximate real weighting profiles for the integration of photon events in space and time (the sensitivity distribution of the receptive field [RF] and the waveform of the impulse response [IR]) by sharp-bordered apertures of "complete," equal-weight summation of events. Apertures based on signal-equivalence cannot provide noise-equivalence, however, because greater numbers of events summed with smaller weights (as in reality) have lower variances than smaller numbers summed with full weight. Thus sharp-bordered apertures are necessarily smaller if defined for noise- than for signal-equivalence. We here consider the difference for some commonly encountered RF and IR profiles. Summation areas, expressed as numbers of photoreceptors (cones or rods) contributing with equal weight, are denoted NS for signal and NN for noise; sharply delimited summation times are correspondingly denoted tS and tN. We show that the relation in space is NN = 0.5 NS for the Gaussian distribution (e.g. for the RF center mechanism of retinal ganglion cells). For a photoreceptor in an electrically coupled network the difference is even larger, e.g., for rods in the toad retina NN = 0.2 NS (NS = 13.7 rods and NN = 2.8 rods). In time, the relation is tN approximately 0.7 tS for realistic quantal response waveforms of photoreceptors. The surround input in a difference-of-Gaussians RF may either decrease or increase total noise, depending on the degree of correlation of center and surround noise. We introduce a third useful definition of sharp-bordered summation apertures: one that provides the same signal-to-noise ratio (SNR) for large-long stimuli as the real integration profiles. The SNR-equivalent summation area is N* = N2S/NN and summation time t* = t2S/tN. PMID:9682874

Hemil, S; Lerber, T; Donner, K

1998-01-01

8

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

PubMed

The infrared imaging video bolometer (IRVB) used for measurement of the two-dimensional (2D) radiation profiles from the Large Helical Device has been significantly upgraded recently to improve its signal to noise ratio, sensitivity, and calibration, which ultimately provides quantitative measurements of the radiation from the plasma. The reliability of the quantified data needs to be established by various checks. The noise estimates also need to be revised and more realistic values need to be established. It is shown that the 2D heat diffusion equation can be used for estimating the power falling on the IRVB foil, even with a significant amount of spatial variation in the thermal diffusivity across the area of the platinum foil found experimentally during foil calibration. The equation for the noise equivalent power density (NEPD) is re-derived to include the errors in the measurement of the thermophysical and the optical properties of the IRVB foil. The theoretical value estimated using this newly derived equation matches closely, within 5.5%, with the mean experimental value. The change in the contribution of each error term of the NEPD equation with rising foil temperature is also studied and the blackbody term is found to dominate the other terms at elevated operating temperatures. The IRVB foil is also sensitive to the charge exchange (CX) neutrals escaping from the plasma. The CX neutral contribution is estimated to be marginally higher than the noise equivalent power (NEP) of the IRVB. It is also established that the radiation measured by the IRVB originates from the impurity line radiation from the plasma and not from the heated divertor tiles. The change in the power density due to noise reduction measures such as data smoothing and averaging is found to be comparable to the IRVB NEPD. The precautions that need to be considered during background subtraction are also discussed with experimental illustrations. Finally, the analysis algorithm with all the improvements is validated and found to reproduce the input power well within 10% accuracy. This article answers many fundamental questions relevant to the IRVB and illustrates the care to be exercised while processing the IRVB data. PMID:25554287

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

2014-12-01

9

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

10

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

NASA Astrophysics Data System (ADS)

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

Jaksic, Zoran; Jaksic, Olga; Matovic, Jovan

2009-04-01

11

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

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

12

Energy from low temperature differences  

NASA Astrophysics Data System (ADS)

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

Parsons, B. K.

1985-05-01

13

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

PubMed Central

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

Tang, Xiangyang; Yang, Yi; Tang, Shaojie

2012-01-01

14

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

Microsoft Academic Search

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

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

1998-01-01

15

Microclimatic Temperature Relationships over Different Surfaces.  

ERIC Educational Resources Information Center

Describes a study of temperature variations over different surfaces in an urban campus setting. Explains that researchers sampled temperatures over grass, bare soil, gravel, concrete, and blacktop. Reports that grassy areas registered the highest morning temperatures and lowest afternoon temperatures. (SG)

Williams, Thomas B.

1991-01-01

16

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

NASA Technical Reports Server (NTRS)

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 20-110 per cm. 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 as low as 3 kG. The magnitude of responsivity at the resonance peaks is roughly constant with magnetic field and is comparable to the low-frequency hot-electron bolometer response. The NEP at the peaks is found to be comparable to the best long wavelength results previously reported. For example, NEP = 4.5 x 10 to the 13th W/(square root of Hz) at 4.2 K, 6 kG, and 40 per cm was measured. The InSb CCR will provide a much improved detector for laboratory spectroscopy, as compared with hot electron bolometers, in the 20-100 per cm range.

Brown, E. R.; Wengler, M. J.; Phillips, T. G.

1985-01-01

17

Electron temperature differences and double layers  

NASA Technical Reports Server (NTRS)

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.

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

1983-01-01

18

Measurement of small differences between low temperatures  

Microsoft Academic Search

1.A manganin-constantan thermocouple was prepared.2.Calibration of the thermocouple between 273 and 73K showed that its electromotive force is close to that of a copper-constantan thermocouple, whereas its heat conductivity lies between 1 and 10% relative to the latter.3.The manganin-constantan thermocouple may be recommended for measuring small differences between low temperatures in adiabatic microcalorimeters.

M. G. Ostronov; Yu. B. Samarin; V. N. Koloshina

1972-01-01

19

Precise Measurement of Process Temperature Differences  

SciTech Connect

Measurement of power in a nuclear reactor system is comparable to measurement of yield in a chemical plant or to measurement of throughput in a paper mill process. In most reactor systems power is determined by measurement of heat transferred to the coolant. In this study reactor coolant heat-rise was determined by the differential-temperature measuring circuitry of a power calculator which computed and recorded reactor power. This paper presents measurement techniques involved in determining the differential temperature and may be of parallel interest to instrument engineers in other process fields.

Kitchen, B.G.

2003-01-16

20

M&M's in Different Temperatures  

NSDL National Science Digital Library

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

Kessler, James H.; Galvan, Patricia M.

2007-01-01

21

The Response of Avocado Fruits to Different Storage Temperatures1  

Microsoft Academic Search

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

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

1977-01-01

22

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.

23

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

E-print Network

Taking a Child's Temperature There are many different ways to take a child's temperature: · Digital. · Temperature strips are not as accurate as digital thermometers and should only be used for armpit or forehead temperatures. · Ear thermometers are quick and easy to use, but they are expensive; don't use ear thermometers

24

Feeding of Burbot, Lota lota, at Different Temperatures  

Microsoft Academic Search

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

Jari-Pekka J. Pkknen; Timo J. Marjomki

2000-01-01

25

Population difference thermometry for ultra-low temperatures  

Microsoft Academic Search

We report measurements of the asymmetry of the intensities of the quadrupolar fine structure of NMR lines in ferromagnetic MnSb down to 30 mK. The asymmetry ratios provide a means of measuring the temperature, and is an example of the use of population difference thermometry as a primary thermometer for ultra-low temperatures.

P. M. Andersen; N. S. Sullivan; B. Andraka; J. S. Xia; E. D. Adams

1992-01-01

26

Population difference thermometry for ultra-low temperatures  

SciTech Connect

The authors report measurements of the asymmetry of the intensities of the quadrupolar fine structure of NMR lines in ferromagnetic MnSb down to 30 mK. The asymmetry ratios provide a means of measuring the temperature, and is an example of the use of population difference thermometry as a primary thermometer for ultra-low temperatures. 5 refs., 2 figs.

Andersen, P.M.; Sullivan, N.S.; Andraka, B.; Xia, J.S.; Adams, E.D. [Univ. of Florida, Gainesville (United States)

1992-11-01

27

Temperature Rise during Resin Composite Polymerization under Different Ceramic Restorations  

PubMed Central

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

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

2011-01-01

28

Electron beam irradiated polyamide-6 at different temperatures  

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

29

Simulation of soil temperature dynamics with models using different concepts.  

PubMed

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

Sndor, Renta; Fodor, Nndor

2012-01-01

30

Effect of different healing temperature on self-healing hydrogel  

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

31

Nonlinear Relationship between Level of Blood Flow and Skin Temperature for Different Dynamics of Temperature Change  

PubMed Central

We present a study of the relationship between blood flow and skin temperature under different dynamics of skin-temperature-change: locally induced thermal shock and well controlled, gradual change. First, we demonstrate memory phenomena for blood flow and skin temperature under both conditions. Secondly, we point out that the hysteresis loops obtained are dependent on initial conditions, indicating physiological response times of more than twenty minutes. We also show that under thermal shock the level of blood flow is preserved up to some characteristic temperature limit, independently of subject. PMID:18339767

Vuksanovi?, Vesna; Sheppard, Lawrence William; Stefanovska, Aneta

2008-01-01

32

Temperature responses of mesophyll conductance differ greatly between species.  

PubMed

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

von Caemmerer, Susanne; Evans, John R

2014-09-16

33

Emission Controls Using Different Temperatures of Combustion Air  

PubMed Central

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

Holub?k, Michal; Papu?k, tefan

2014-01-01

34

Temperature profiles of different cooling methods in porcine pancreas procurement.  

PubMed

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

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

2014-01-01

35

Clay facial masks: physicochemical stability at different storage temperatures.  

PubMed

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

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

2007-01-01

36

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

PubMed

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

Keshk, Sherif M A S

2015-01-22

37

What is the Difference between Heat and Temperature?  

NSDL National Science Digital Library

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

38

Piglets Surface Temperature Change at Different Weights at Birth  

PubMed Central

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

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

2014-01-01

39

Different temperature sensitivities to land use change in the RCPs  

NASA Astrophysics Data System (ADS)

Land use change in the CMIP5 Representative concentration pathways (RCPs) has both positive and negative changes in forest fraction and crop land cover, which is not related linearly to the amount of radiative forcing in the scenario. The Land-use and Climate Identification of robust impacts project (LUCID) clearly showed that in RCP2.6 and RCP8.5 it is unlikely that anthropogenic land use and land cover change (LULCC) will have a significant effect on global climate. However, the LUCID study only considered future scenarios of deforestation (RCP2.6 and RCP8.5). In contrast, the two `middle' radiative forcing RCP scenarios (RPC4.5 and RCP6.0) have decreases in crop and pasture land projected over the century, resulting in very different LULCC scenarios compared to the two other RCPs. Using an ensemble of simulations with and without land use changes in the Hadley Centre earth system model HadGEM2-ES, we compare the climatic effects of the LULCC in RCP4.5, RCP2.6 and RCP8.5. Although there is extensive land use change in all three RCPs considered here, the latitude at which the LULCC occurs is a crucial factor in whether the change has a climatic impact. We show that the mid to high latitude afforestation LULCC in RCP4.5 results in significant biogeophysical temperature differences over Eurasia and North America, compared to no LULCC. This contrasts with RCP2.6 and RCP8.5 where the significant areas of temperature change are much smaller from the predominantly tropical deforestation. While the carbon emissions mainly make up for the temperature changes at a global scale, there may be residual local effects due to LULCC in RCP4.5, especially with regard to extremes. We show that LULCC in RCP4.5 has an effect on the extremes of temperature, whereas RCP2.6 and RCP8.5 are less affected. This work suggests that the different representations of LULCC in the RCPs result in different climate sensitivities to LULCC, which are not linear with the overall radiative forcing. Instead the sensitivity is related to the change in forest fraction at the mid to high latitudes. The scale, location, latitude, and type of LULCC change all affect whether there will be a significant temperature impact.

Davies-Barnard, Taraka; Valdes, Paul; Singarayer, Joy; Jones, Chris

2014-05-01

40

Different scaling behaviors in daily temperature records over China  

Microsoft Academic Search

Long-range correlations of five kinds of daily temperature records (i.e.daily average temperature records, daily maximum temperature records, daily minimum temperature records, diurnal temperature range and the sum of daily maximum and minimum temperature records) from 164 weather stations over China during 19512004 are analyzed by means of detrended fluctuation analysis (DFA). These five kinds of fluctuation series are found to

Naiming Yuan; Zuntao Fu; Jiangyu Mao

2010-01-01

41

Dielectric Behavior of Biomaterials at Different Frequencies on Room Temperature  

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

42

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

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

43

Measurement of relative permittivity of LTCC ceramic at different temperatures  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

44

Optimization of injection dose based on noise-equivalent count rate with use of an anthropomorphic pelvis phantom in three-dimensional 18F-FDG PET/CT.  

PubMed

The optimal injection dose for imaging of the pelvic region in 3D FDG PET tests was investigated based on the noise-equivalent count (NEC) rate with use of an anthropomorphic pelvis phantom. Count rates obtained from an anthropomorphic pelvis phantom were compared with those of pelvic images of 60 patients. The correlation between single photon count rates obtained from the pelvic regions of patients and the doses per body weight was also evaluated. The radioactivity at the maximum NEC rate was defined as an optimal injection dose, and the optimal injection dose for the body weight was evaluated. The image noise of a phantom was also investigated. Count rates obtained from an anthropomorphic pelvis phantom corresponded well with those from the human pelvis. The single photon count rate obtained from the phantom was 9.9 Mcps at the peak NEC rate. The coefficient of correlation between the single photon count rate and the dose per weight obtained from patient data was 0.830. The optimal injection doses for a patient with weighing 60 kg were estimated to be 375 MBq (6.25 MBq/kg) and 435 MBq (7.25 MBq/kg) for uptake periods of 60 and 90 min, respectively. The image noise was minimal at the peak NEC rate. We successfully estimated the optimal injection dose based on the NEC rate in the pelvic region on 3D FDG PET tests using an anthropomorphic pelvis phantom. PMID:22207566

Inoue, Kazumasa; Kurosawa, Hideo; Tanaka, Takashi; Fukushi, Masahiro; Moriyama, Noriyuki; Fujii, Hirofumi

2012-07-01

45

Contractions of a human skeletal muscle at different temperatures.  

PubMed Central

1. Influence of temperature on electrically evoked twitch contractions and maximal voluntary contractions was studied in human first dorsal interosseus muscle. The range of the muscle temperature was 35-12 degrees C. 2. The maximal twitch tension decreased by about 50% in cooling from 35-12 degrees C; the tension decrease was more pronounced below 25 degrees C. The temperature coefficients (Q10 values) estimated for muscle temperatures of 35-25 degrees C were 1.43 for time-to-peak and 1.7 for half-time of relaxation. 3. The maximum voluntary tension remained relatively constant on cooling to 25 degrees C but decreased by about 30% on cooling to 12-15 degrees C. The normalized rate of tension rise in voluntary contractions was largely independent of temperature. 4. Results are discussed in relation to previous work on temperature and muscle contraction in humans and in animals. PMID:3443940

Ranatunga, K W; Sharpe, B; Turnbull, B

1987-01-01

46

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

PubMed Central

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

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

2014-01-01

47

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

PubMed

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

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

2014-01-01

48

Food Consumption and Growth of Brook Trout at Different Temperatures  

Microsoft Academic Search

Food consumption (minnows) and weight gained by individual brook trout held at six temperatures within the range 3.5 to 21.0C. are described relative to their body weight. The trout consumed most food and made best growth at 13C. Utilization for growth of food consumed declined with increase in temperature.

N. S. Baldwin

1957-01-01

49

The same key to different doors - temperature puzzles  

E-print Network

The notion of temperature in many body elementary particle processes is in a common use for decades. Thermal models have become simple and universal effective tools to describe particle production -- not only in high energy heavy ion collisions but also in high energy elementary particle collisions. We perform a critical analysis of the temperature concepts in such processes. Although the temperature concept is a very useful tool, nevertheless it should be used with the care, taking into account that usually it is just model dependent fitted parameter.

Ludwik Turko

2014-12-27

50

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

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

51

Intrauterine temperatures of mares under different management conditions  

E-print Network

more susceptible to high ambient temperatures during the first 2 w post-breeding. Work with rabbits further supported this evidence. Wolfenson and Blum (1988) heat stressed rabbits during two specific stages of pregnancy: during the early stages...

Commaille, Lynn Frances

2009-05-15

52

Storage of Steindachneridion parahybae oocytes at different temperatures.  

PubMed

The objective of this study was to assess the influence of temperature and time on the storage of fresh Steindachneridion parahybae oocytes. Two experiments were carried out: (1) the fertilization rates of oocytes exposed to temperatures of 5, 15, 28 (room temperature) and 35C were assessed 15min (control), 115, 235 and 355min after release; (2) the fertilization and hatching rates, as well as the percentage of normal larvae of oocytes exposed to 14, 17 or 20C, 20min (control) were assessed 50, 80 and 110min after stripping. In the first experiment, the highest fertilization rates (P<0.05) were obtained in the control treatment (15min, 28C), with 74.345.48% oocytes showing loss of viability over time. In the second experiment, there was a reduction (P<0.05) in the fertilization rates at the temperatures and times tested. The artificial fertilization of S. parahybae oocytes is recommended immediately after collection, and if storage is necessary, it should be conducted at temperatures between 17 and 20C. PMID:25458322

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

2014-12-30

53

Prediction of deep eutectic solvents densities at different temperatures  

Microsoft Academic Search

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

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

2011-01-01

54

temperature coefficients in a few different forms. The two most common forms are discussed below.  

E-print Network

that the temperature used in the calculation is a change in temperature from the rated 25°C. For example: The Voc fluctuate? As temperature rises, voltage decreases. Conversely, as the temperature drops, voltage increasestemperature coefficients in a few different forms. The two most common forms are discussed below

Johnson, Eric E.

55

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

E-print Network

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

Hinch, Scott G.

56

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

PubMed

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

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

2011-02-01

57

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 Abstract ­ This study aims to explore the effect of ambient temperature on foraging the activity of Apis cerana and Apis mellifera colonies. We recorded ambient temperature, the time at which foraging commenced

58

The effect of different solar simulators on the measurement of short-circuit current temperature coefficients  

NASA Technical Reports Server (NTRS)

Gallium arsenide solar cells are considered for several high temperature missions in space. Both near-Sun and concentrator missions could involve cell temperatures on the order of 200 C. Performance measurements of cells at elevated temperatures are usually made using simulated sunlight and a matched reference cell. Due to the change in bandgap with increasing temperature at portions of the spectrum where considerable simulated irradiance is present, there are significant differences in measured short circuit current at elevated temperatures among different simulators. To illustrate this, both experimental and theoretical data are presented for gallium arsenide cells.

Curtis, H. B.; Hart, R. E., Jr.

1982-01-01

59

Compressive strength development of concrete with different curing time and temperature  

Microsoft Academic Search

In this experimental and analytic research, the strength development for various curing histories was investigated with particular regard to the influences of curing time points with given temperatures. For this purpose, four different points of curing time were considered with an individual interval of 24 h. Two different temperatures of 5C and 40C were applied for the selective intervals, whereas

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

1998-01-01

60

Dynamic properties and microstructural response to shock loading of Armco iron at different temperatures  

NASA Astrophysics Data System (ADS)

Using the method of inversed TAYLOR-Test in combination with a velocity interferometer VISAR, the response to high dynamic loading at different temperatures has been determined for Armco iron of different microstructures. A considerable influence of the microstructure and of the sample temperature on the dynamic behaviour has been observed. The examination of the microstructure by means of optical and SEM microscopy revealed a strong influence of the sample temperature for coarse grain material and only little influence for the other materials.

Nahme, H.; Hiltl, M.; Arnold, W.

1996-05-01

61

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

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.

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

2006-01-01

62

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

NASA Technical Reports Server (NTRS)

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.

Castro, Sandra L.; Emery, William J.

2002-01-01

63

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

NASA Astrophysics Data System (ADS)

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

Mursula, Kalevi; Asikainen, Timo; Maliniemi, Ville

64

Impact of temperature difference (water-solar collector) on solar-still global efficiency  

Microsoft Academic Search

Different theoretical and experimental studies carried out in the field of solar distillation with green-house effect, have shown that global efficiency of a simple solar still are affected by physical and building parameters, especially by the difference of temperature between the evaporation surface and that of the condensation. Optimising this difference allows us to obtain a solar still with a

Pr. Kaabi Abdenacer; Smakdji Nafila

2007-01-01

65

An experimental method for effusivity determination of different scratched temperature sensors  

Microsoft Academic Search

This paper presents an experimental method for evaluating the effusivity values of different scratched temperature sensors. These sensors have a response time on the order of microseconds (50 s) with a rise time less than (0.3 s). Two types of scratch were used, mainly abrasive papers with different grit sizes and scalpel blades with different thicknesses to form the sensor

H. Mohammed; H. Salleh; M. Z. Yusoff

2009-01-01

66

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

67

Salt uptake and water loss in hams with different water contents at the lean surface and at different salting temperatures.  

PubMed

The salt uptake homogeneity is crucial in assuring quality in dry-cured hams. The aim of this study was to evaluate the effect of the water contents at the lean surface before salting and of the temperature during salting on the salt uptake. Pieces of loin stored at 3C for 3 days before salting absorbed less salt through a surface that has been dried during storage. A group of raw hams were subjected to different pre-salting storage times (0, 3 and 6 days) and another group subjected to different set room temperatures during salting (-1.0, 0.5 and 4.0C). The duration of storage before salting and the temperature during salting had a negative and a positive effect on the average salt absorption, respectively. The most important effects appeared after 6 days of storage and at 4C. No significant differences in salt uptake homogeneity were found between storage times and between salting temperatures. PMID:23896138

Garcia-Gil, Nria; Muoz, Israel; Santos-Garcs, Eva; Arnau, Jacint; Gou, Pere

2014-01-01

68

Behaviour of ORC low-temperature power generation with different refrigerants  

Microsoft Academic Search

This article presents and discusses the behaviour of low-temperature Organic Rankine Cycle for power generation using waste heat. The performance has been compared at low- and medium waste heat temperatures to organic and non-organic fluids. In this article, energy and exergy analysis have also been presented and compared for the behaviour of the different refrigerants. Results showed that the use

Samuel M. Sami

2011-01-01

69

Properties of indium tin oxide films prepared by rf reactive magnetron sputtering at different substrate temperature  

Microsoft Academic Search

Indium tin oxide (ITO) films were deposited onto the glass substrates at different substrate temperatures (RT-500C) by rf reactive magnetron sputtering method. The structural, optical and electrical properties of ITO films have been characterized by X-ray diffraction, scanning electron microscopy, optical transmittance and reflectance, sheet resistance and electrical resistivity measurements. The films deposited at low substrate temperature have a very

Li-jian Meng; M. P dos Santos

1998-01-01

70

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

PubMed Central

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

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

2014-01-01

71

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

PubMed Central

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

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

2002-01-01

72

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

PubMed Central

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

Nagai, Takeshi; Makino, Amane

2009-01-01

73

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

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

74

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

PubMed Central

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

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

2014-01-01

75

[The correlation of liver mitochondrial respiration in mammals and reptiles at different temperatures].  

PubMed

In the experiments with isolated mitochondria in vitro (25 degrees C) it was shown that the respiration rate in mice was 3-5 times higher compared with agamas; in this case both animal species exhibited close body mass. At the comparison of mice and tortoises with the body mass 25-30 times exceeding the one of mice 4-10 times difference in mitochondrial respiration was found. In addition this difference was more pronounced with caprilate and pyruvate than with succinate used as substrates. High rates of respiration for mice mitochondria are shown to persist at wide temperature range in vitro. However respiration parameters for mice and agamas are close in vitro at the temperature of 37 degrees C for mice mitochondria (the optimal mouse body temperature is about 37 degrees C) and the temperature of 42 degrees C for agama mitochondria (the optimal life temperature for agamas is about 42 degrees C). PMID:8779281

Akhmerov, R N; Gibarova, S; Allamuratova, Sh I; Almatov, K T

1995-01-01

76

An analysis of void coalescence in AL 5052 alloy sheets annealed at different temperatures formed under different stress conditions  

Microsoft Academic Search

In this paper the void growth, coalescence and fracture behavior of aluminium 5052 alloy are studied at different annealing temperature as a function of various void parameters, namely d-factor, ?d-factor, void area fraction (Va) and L\\/W ratio of the voids. The L\\/W ratio of the oblate or prolate voids at fracture is correlated with the mechanical properties, microstructure, minor strain

R. Ravindran; K. Manonmani; R. Narayanasamy

2009-01-01

77

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

E-print Network

the average difference between the sexes. This variance is often thought of as the spectrum of masculinityDifferences induced by incubation temperature, versus androgen manipulation, in male leopard geckos 2012 Received in revised form 19 June 2012 Accepted 23 June 2012 Available online 30 June 2012 Keywords

Crews, David

78

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

PubMed Central

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

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

2012-01-01

79

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

80

Photosynthesis of young apple trees in response to low sink demand under different air temperatures.  

PubMed

Gas exchange, chlorophyll fluorescence, photosynthetic end products and related enzymes in source leaves in response to low sink demand after girdling to remove the root sink were assessed in young apple trees (Malus pumila) grown in two greenhouses with different air temperatures for 5 days. Compared with the non-girdled control in the low-temperature greenhouse (diurnal maximum air temperature <32 degrees C), low sink demand resulted in lower net photosynthetic rate (P(n)), stomatal conductance (g(s)) and transpiration rate (E) but higher leaf temperature on Day 5, while in the high-temperature greenhouse (diurnal maximum air temperature >36 degrees C), P(n), g(s) and E declined from Day 3 onwards. Moreover, gas exchange responded more to low sink demand in the high-temperature greenhouse than in the low-temperature greenhouse. Decreased P(n) at low sink demand was accompanied by lower intercellular CO(2) concentrations in the low-temperature greenhouse. However, decreased maximal photochemical efficiency, potential activity, efficiency of excitation capture, actual efficiency and photochemical quenching, with increased minimal fluorescence and non-photochemical quenching of photosystem II (PSII), were observed in low sink demand leaves only in the high-temperature greenhouse. In addition, low sink demand increased leaf starch and soluble carbohydrate content in both greenhouses but did not result in lower activity of enzymes involved in metabolism. Thus, decreased P(n) under low sink demand was independent of a direct effect of end-product feedback but rather depended on a high temperature threshold. The lower P(n) was likely due to stomatal limitation in the low-temperature greenhouse, but mainly due to non-stomatal limitation in the high-temperature greenhouse. PMID:20071359

Fan, Pei G; Li, Lian S; Duan, Wei; Li, Wei D; Li, Shao H

2010-03-01

81

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

PubMed Central

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

Chuche, Julien; Thiry, Denis

2012-01-01

82

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

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

83

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

Microsoft Academic Search

We examined the cardiac responses of different fish species to anaerobic exercise at low temperatures (3 C). Three species of sympatric warmwater fish with perceived differences in winter activity were used for this comparative study: the winter-quiescent largemouth bass (Micropterus salmoides); the winter-active white bass (Morone chrysops); and the intermediately winter-active black crappie (Pomoxis nigromaculatus). Perceived differences in winter activity

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

2003-01-01

84

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

SciTech Connect

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.

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

85

Modifications of SiC under high fluence Kr-ion irradiation at different temperatures  

NASA Astrophysics Data System (ADS)

4 MeV Kr-ions were irradiated into 6H-SiC single crystals with fluences from 1.0 1016 to 5.0 1016 cm-2 at room temperature, 300 C and 500 C, respectively (5.0 1016 cm-2 at 550 C). The irradiation-induced modifications were measured by Atomic Force Microscope (AFM), Raman Spectrometer and Nano-indentation measurements. It was observed that the surface of RT-irradiated samples became rough as a result of crystallizing to amorphous state. The result of Raman spectra indicates that different migration behaviors of Si and C interstitials at different temperatures could have an effect on the stoichiometry of irradiated samples. It was also observed that the hardness of irradiated samples is higher than that of un-irradiated ones at high temperatures, with increase at low fluence and then decrease at high fluence. Finally, the effects of irradiation temperature and ion fluence are discussed.

Zang, Hang; Yang, Tao; Guo, Daxi; Xi, Jianqi; He, Chaohui; Wang, Zhiguang; Shen, Tielong; Pang, Lilong; Yao, Cunfeng; Zhang, Peng

2013-07-01

86

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

Microsoft Academic Search

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

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

2009-01-01

87

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

Microsoft Academic Search

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

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

2001-01-01

88

Further studies on the adaptation of fish myofibrillar ATPases to different cell temperatures  

Microsoft Academic Search

SummaryPrevious studies on fish Mg2+Ca2+ activated myofibrillar ATPases have been extended to species inhabiting diverse thermal environments. Cold adapted ATPases\\u000a have considerably higher catalytic centred activities at low temperatures than warm adapted ATPases. Differences in cell temperature\\u000a have also lead to evolutionary modifications in thermodynamic activation parameters. The free energies (?G2+), enthalpies (?H2+) and entropies (?S2+) of activation of the

I. A. Johnston; N. J. Walesby; W. Davison; G. Goldspink

1977-01-01

89

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

Microsoft Academic Search

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,

Carol Becker Lynch; Joseph P. Hegmann

1973-01-01

90

Hydraulic activity of water-cooled slag and air-cooled slag at different temperatures  

Microsoft Academic Search

Water-cooled slag (WS) and air-cooled slag (AS) with similar chemical compositions and produced from the same blast furnace were investigated for their hydraulic activities at different temperatures. The kinetics of hydration of WSlime and ASlime pastes were investigated at room temperature, 100C, and 180C by the determination of unreacted lime and combined water. The hydration products were identified by XRD.

N. Y. Mostafa; S. A. S. El-Hemaly; E. I. Al-Wakeel; S. A. El-Korashy; P. W. Brown

2001-01-01

91

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

PubMed Central

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

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

2014-01-01

92

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

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

93

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

NASA Astrophysics Data System (ADS)

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

Shan, Ning; Wang, Zhijing; Liu, Xia

2014-11-01

94

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

PubMed Central

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

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

2013-01-01

95

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

USGS Publications Warehouse

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

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

2003-01-01

96

Rheological characterization of novel physically crosslinked terpolymeric hydrogels at different temperatures  

NASA Astrophysics Data System (ADS)

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.

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

2012-09-01

97

Implant Surface Temperature Changes during Er:YAG Laser Irradiation with Different Cooling Systems  

PubMed Central

Objective: Peri-implantitis is one of the most common reasons for implant failure. Decontamination of infected implant surfaces can be achieved effectively by laser irradiation; although the associated thermal rise may cause irreversible bone damage and lead to implant loss. Temperature increments of over 10C during laser application may suffice for irreversible bone damage. Purpose of Study: The purpose of this study was to evaluate the temperature increment of implant surface during Er:YAG laser irradiation with different cooling systems. Materials and Methods: Three implants were placed in a resected block of sheep mandible and irradiated with Er:YAG laser with 3 different cooling systems namely water and air spray, air spray alone and no water or air spray. Temperature changes of the implant surface were monitored during laser irradiation with a K-type thermocouple at the apical area of the fixture. Results: In all 3 groups, the maximum temperature rise was lower than 10C. Temperature changes were significantly different with different cooling systems used (P<0.001). Conclusion: Based on the results, no thermal damage was observed during implant surface decontamination by Er:YAG laser with and without refrigeration. Thus, Er:YAG laser irradiation can be a safe method for treatment of periimplantitis. PMID:24910697

Monzavi, Abbas; Shahabi, Sima; Fekrazad, Reza; Behruzi, Roohollah; Chiniforush, Nasim

2014-01-01

98

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

PubMed

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

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

2013-01-01

99

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

PubMed Central

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

Kurtz, Stefan; LaRoche, Julie

2014-01-01

100

Temperature  

NSDL National Science Digital Library

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

Brieske, Joel A.

2002-01-01

101

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

SciTech Connect

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

Dahlborg, U. [University of Rouen; Besser, M. [Ames Laboratory; Kramer, Matthew J. [Ames Laboratory; Morris, J. R. [Oak Ridge National Laboratory; Calvo-Dahlborg, M. [University of Rouen

2013-12-21

102

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

PubMed Central

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

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

103

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

PubMed

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

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

2012-11-01

104

Long-term changes in insolation and temperatures at different altitudes  

NASA Astrophysics Data System (ADS)

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

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

2010-04-01

105

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

NASA Astrophysics Data System (ADS)

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.

Li, Changzheng; Yue, Yanan

2014-10-01

106

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

NASA Technical Reports Server (NTRS)

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.

Kranz, M

1954-01-01

107

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

PubMed

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

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

2011-02-01

108

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

SciTech Connect

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

Salas, E.; Jimenez Rioboo, R. J.; Prieto, C. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Cantoblanco, Madrid 28049 (Spain); Every, A. G. [School of Physics, University of the Witwatersrand, Wits 2050 (South Africa)

2011-07-15

109

Optical classification, existence temperatures, and coexistence of different polar stratospheric cloud types  

NASA Astrophysics Data System (ADS)

Multispectral lidar measurements of polar stratospheric clouds (PSCs) from two winter campaigns in 1994/1995 and 1996'1997 at Sodankyl, Finland, have been evaluated together with temperature data from local radiosondes to find optical parameters for a PSC classification of different particle types and their existence temperatures. Precise depolarization measurements show that both solid and liquid particles exist below the NAT (nitric acid trihydrate) temperature. A comparison of temperatures at the PSC base and at the cloud top shows a good agreement with the NAT-existence temperature for solid type Ia clouds and a 3-4 K lower temperature for liquid type Ib clouds. The two particle families are therefore consistent with solid NAT particle formation and condensational growth of HNO3, H2O and H2SO4 liquid ternary solutions. The coexistence of solid and liquid particles has been observed by means of the temporal development of parallel and perpendicular polarized lidar signals. These time series of subsequent lidar measurements show stronger and faster fluctuations in the liquid particle mode compared to the solid particles and thus indicate a higher sensitivity toward temperature fluctuations for the liquid PSCs. While the optical properties of most observations are consistent with the definition of PSC type Ia (solid) and type Ib (liquid) clouds, a third type has been observed which does not fit into the current type Ia/Ib optical classification. This cloud type consists of solid particles but has a higher backscatter than type Ia PSC.

Stein, B.; Wedekind, C.; Wille, H.; Immler, F.; Mller, M.; Wste, L.; del Guasta, M.; Morandi, M.; Stefanutti, L.; Antonelli, A.; Agostini, P.; Rizi, V.; Readelli, G.; Mitev, V.; Matthey, R.; Kivi, R.; Kyr, E.

1999-10-01

110

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

PubMed Central

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

Shi, Changzhi; Liu, Xiaowei; Chuai, Rongyan

2009-01-01

111

Plasmatic resistance and rate of respiration and photosynthesis of Zostera marina at different salinities and temperatures  

Microsoft Academic Search

Zostera marina L. was studied at the Izembek Lagoon, Alaska Peninsula. Two morphologically different forms, tidepool and subtidal, can be distinguished. Both show a high tolerance to different salinities and temperatures. The plasmatic resistance was found in a range of distilled H2O up to 3.0 seawater (24 h) and between-6 and 34C (12 h). Within these resistance limits, the photosynthesis,

R. Biebl; C. P. McRoy

1971-01-01

112

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

NASA Astrophysics Data System (ADS)

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

Mohan, V. P. Chandra; Talukdar, Prabal

2013-01-01

113

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

NASA Astrophysics Data System (ADS)

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.

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

114

Effects of wearing two different types of clothing on body temperatures during and after exercise  

NASA Astrophysics Data System (ADS)

The experiment was conducted to investigate the human thermoregulatory responses during rest, exercise and recovery at T a 20C and 60% R.H. under the conditions of wearing two different types of clothing. Six healthy men wore two types of clothing: one covering the whole body area except the head (Type A, weight 1656 g), and the other covering only the trunk, upper arms and thighs (Type B, weight 996 g). The level of rectal temperature was kept significantly higher in Type B than in Type A during rest and recovery. The increased and decreased rates of rectal temperature during exercise and recovery were significantly greater in Type A than in Type B, respectively. These findings are discussed from the viewpoint of the differences of skin temperatures of the extremities between Type A and Type B.

Jeong, Woon Seon; Tokura, Hiromi

1989-06-01

115

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

PubMed Central

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

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

2011-01-01

116

Ear emergence in perennial ryegrass as affected by differences in light and temperature before ear initiation  

Microsoft Academic Search

The effects of differences in daylength and temperature, before ear initiation, on subsequent emergence in perennial ryegrass selections were studied in the glasshouse. When no artificial light or heat was used, prolific and uniform emergence was observed. Of seven other combinations compared, uniform but much earlier emergence was obtained from only that treatment where the natural sequence of events, cold

S. O. Fejer

1960-01-01

117

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

PubMed

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

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

2014-09-12

118

Shelflife of Almond Pastry Cookies with Different Types of Packaging and Levels of Temperature  

Microsoft Academic Search

Almond pastries are typical cookies of the south of Italy. Introduction of new packaging for this kind of cookies requires shelf-life assessments. This study, related to different types of packaging under various storage conditions of time and temperature, identifies critical parameters, as color and texture, to track during storage studies and to extend the shelf-life. The cookies were packed in

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

2010-01-01

119

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

Microsoft Academic Search

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

James A. Bunce

1983-01-01

120

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

Microsoft Academic Search

The sulphate resistance of mortar containing ground calcined brick clay (GCBC) calcined at different tempertaures (6001100 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

S. Wild; J. M. Khatib

1997-01-01

121

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 ...

122

Appearance, temperature, and NO x emission of two inverse diffusion flames with different port design  

Microsoft Academic Search

Experiments were carried out to investigate the appearance, temperature distribution, and NOx 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

L. K. Sze; C. S. Cheung; C. W. Leung

2006-01-01

123

The mesopic effect of different color temperature LED light sources on road lighting  

Microsoft Academic Search

A equation, Emes = BEp, to deduce from the Ep(photopic illumination) to Emes(mesopic equivalent illumination) is proposed, where B is instant for modified coefficient. The equation is used to calculate the mesopic equivalent illumination of the different color temperature LED light sources under mesopic light levels.

Li Xuan; Shangzhong Jin; Songyuan Cen; Le Wang; Xiaoyan Li

2010-01-01

124

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

NSDL National Science Digital Library

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

125

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

ERIC Educational Resources Information Center

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)

Bradley, Karen; Mathewman, David

1984-01-01

126

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

E-print Network

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

Wu, Junqiao

127

Space temperature difference, cooling coil and fanenergy and indoor air quality issues revisited  

Microsoft Academic Search

In designing an energy-efficient air-conditioning system that also simultaneously addresses the needs of adequate ventilation and acceptable indoor air quality, several factors begin to play an important role. Among several others, the cooling coil, the fan and the temperature difference between the space and the supply air (commonly known as the Space ?T) can be considered to be crucial. For

S. C. Sekhar

2005-01-01

128

Considerations in determining thermal diffusivity from temperature time series using finite difference methods  

Microsoft Academic Search

The apparent thermal diffusivity, D, of the active layer and permafrost can be determined using finite difference methods provided that the heat flow is conductive, appropriate space (?x) and time (?t) intervals have been selected, accurate ( 0.01C) temperature measurements have been obtained, and phase change does not occur in the volume of interest. Selection of values for ?x

T. Zhang; T. E. Osterkamp

1995-01-01

129

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

PubMed

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

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

2011-07-01

130

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

PubMed Central

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

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

1934-01-01

131

Adaptive haemoglobin gene control in Daphnia pulex at different oxygen and temperature conditions.  

PubMed

Hypoxia-induced haemoglobin (Hb) expression is a central regulatory mechanism in Daphnia in response to environmental hypoxia or warm temperatures. Changes in Hb concentration as well as Hb subunit composition, which modulate Hb oxygen affinity, guarantee the oxygen supply of tissues under these environmental conditions. Based on the sequenced D. pulex genome, Hb genes were related to the properties of haemolymph Hb, which included its concentration and oxygen affinity (both measured by spectrophotometry) as well as the Hb subunit composition (determined by 2-D gel electrophoresis and ESI-MS analysis). Permanent cultures of D. pulex acclimated to different oxygen conditions (normoxia and hypoxia) and temperatures (10C, 20C, and 24C), showed characteristic changes in Hb concentration, subunit composition and oxygen affinity. Several subunits (Hb4, Hb7, Hb8, and Hb10) were obviously responsible for changes in oxygen affinity including those, which carry a number of hypoxia-responsive elements (HREs) upstream of the respective gene (hb4 and hb10). Analysing the effects of different oxygen- or temperature-acclimations on Hb subunit expression in D. pulex and D. magna on a common basis (Hb concentration or oxygen affinity) revealed a general pattern of oxygen and temperature effects on Hb, which implies that Hb quantity and quality are mostly influenced by the degree of tissue hypoxia. Differences between both species in the onset of hypoxia-induced differential Hb expression and Hb oxygen affinity, which are probably related to different HRE patterns and functionally important differences in the amino acid sequence of only a few subunits, cause a reduced ability of D. pulex to adjust Hb function to temperature changes in comparison to D. magna. PMID:21281731

Gerke, Peter; Brding, Christina; Zeis, Bettina; Paul, Rdiger J

2011-05-01

132

Effect of temperature on lignin-derived inhibition studied with three structurally different cellobiohydrolases.  

PubMed

Non-productive enzyme adsorption onto lignin inhibits enzymatic hydrolysis of lignocellulosic biomass. Three cellobiohydrolases, Trichoderma reesei Cel7A (TrCel7A) and two engineered fusion enzymes, with distinctive modular structures and temperature stabilities were employed to study the effect of temperature on inhibition arising from non-productive cellulase adsorption. The fusion enzymes, TeCel7A-CBM1 and TeCel7A-CBM3, were composed of a thermostable Talaromyces emersonii Cel7A (TeCel7A) catalytic domain fused to a carbohydrate-binding module (CBM) either from family 1 or from family 3. With all studied enzymes, increase in temperature was found to increase the inhibitory effect of supplemented lignin in the enzymatic hydrolysis of microcrystalline cellulose. However, for the different enzymes, lignin-derived inhibition emerged at different temperatures. Low binding onto lignin and thermostable structure were characteristic for the most lignin-tolerant enzyme, TeCel7A-CBM1, whereas TrCel7A was most susceptible to lignin especially at elevated temperature (55 C). PMID:23920120

Rahikainen, Jenni Liisa; Moilanen, Ulla; Nurmi-Rantala, Susanna; Lappas, Angelos; Koivula, Anu; Viikari, Liisa; Kruus, Kristiina

2013-10-01

133

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

PubMed

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

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

2015-04-01

134

Temperature dependent polarization switch of 850-nm VCSELs with different apertures  

NASA Astrophysics Data System (ADS)

Temperature greatly affects the polarization properties of VCSELs. In this paper, these polarization properties of top-emitting 850-nm VCSELs are simulated by numerical calculation and then they are verified by experimental measurement. For a 4-?m aperture VCSEL, polarization switch current reduces from 1.4 mA to 0.4 mA as the temperature increases from 273 K to 323 K, which is caused by the change of the reflectivity of DBR and differential gain for LP01 transverse-mode. For VCSELs with 8-?m aperture, the first polarization switch current reduces from 2.1 mA to 0.8 mA as temperature increases from 273 K to 313 K. However, the second polarization switch current increases from 3.8 mA to 6.3 mA for the same increase in temperature because of the competition and polarization selection among several higher-order transverse modes. When the device aperture is further increased to 12 ?m or 16 ?m, there are several high-order transverse modes emitting even at small injection current, resulting in a serious competition and selection among themselves. This is why the polarization characteristics of VCSELs with 12 ?m or larger aperture are irregular and different from those of smaller aperture devices. Our research results provide useful guidelines for the application of VCSELs operating at different ambient temperatures.

Wang, Qiang; Guan, Baolu; Liu, Ke; Liu, Xin; Jiang, Xiaowei; Ma, Yunhua; Arafin, Shamsul; Shen, Guangdi

2014-11-01

135

Co-doped sodium chloride crystals exposed to different irradiation temperature  

SciTech Connect

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

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

2013-07-03

136

Co-doped sodium chloride crystals exposed to different irradiation temperature  

NASA Astrophysics Data System (ADS)

Monocrystals of NaCl:XCl2:MnCl2(X = Ca,Cd) at four different concentrations have been analyzed. The crystals were exposed to different irradiation temperature, such as at room temperature (RT), solid water (SW), dry ice (DI) and liquid nitrogen (LN). The samples were irradiated with photon from 60Co irradiators. The co-doped sodium chloride crystals show a complex structure of glow curves that can be related to different distribution of traps. The linearity response was analyzed with the F(D) index. The F(D) value was less than unity indicating a sub-linear response was obtained from the TL response on the function of the dose. The glow curves were deconvoluted by using the CGCD program based on the first, second and general order kinetics.

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

2013-07-01

137

Autotrophic growth of bacterial and archaeal ammonia oxidizers in freshwater sediment microcosms incubated at different temperatures.  

PubMed

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

Wu, Yucheng; Ke, Xiubin; Hernndez, Marcela; Wang, Baozhan; Dumont, Marc G; Jia, Zhongjun; Conrad, Ralf

2013-05-01

138

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

PubMed Central

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

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

2013-01-01

139

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

PubMed Central

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

2014-01-01

140

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

PubMed

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

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

2010-06-01

141

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

PubMed

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

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

2014-01-01

142

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

PubMed Central

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

2013-01-01

143

Consideration of dielectric relaxation of pure DMSO liquid in different temperatures  

NASA Astrophysics Data System (ADS)

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

Wang, Feng; Jia, Guozhu

2014-10-01

144

Differences in the Growth of Aspergillus fumigatus on Cycloheximide Media at Three Temperatures  

PubMed Central

Cycloheximide (up to 0.4 g/liter) was significantly more inhibitory to the growth of three isolates of Aspergillus fumigatus at 23 C than at 37 or 45 C. Preincubation of the media for 7 days at 45 C did not alter the inhibitory effect of the cycloheximide at 23 C. Neither mutation nor adaptation in the fungus seems to be the reason for its growth on the antibiotic at the higher temperature. The mechanism for the differences in sensitivity as related to temperature of incubation cannot be explained at this time. PMID:4598610

Berger, Carole L.; Merz, W. G.; Silva-Hutner, Margarita

1973-01-01

145

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

PubMed

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

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

2013-01-01

146

Respiration and Alternative Oxidase in Corn Seedling Tissues during Germination at Different Temperatures  

PubMed Central

Respiration rates of Zea mays L. seedling tissues grown at 30 and 14C were measured at 25C at different stages of seedling growth. Accumulation of heat units was used to define the developmental stages to compare respiration between the two temperatures. At both temperatures, respiration rates of most tissues were highest at the youngest stages, then declined with age. Respiration rates of mesocotyl tissue were the most responsive to temperature, being nearly twofold higher when grown at 14 compared to 30C. Alternative pathway respiration increased concomitantly with respiration and was higher in mesocotyls grown in the cold. When seedlings were started at 30 then transferred to 14C, the increase in alternative pathway respiration due to cold was not observed unless the seedlings were transferred before 2 days of growth. Seedlings transferred to 14C after growth at 30C for 2 days had the same alternative oxidase capacity as seedlings grown at 30C. Seedlings grown at 14C for 10 to 12 days, then transferred to 30C, lost alternative pathway respiratory capacity over a period of 2 to 3 days. Western blots of mitochondrial proteins indicated that this loss of capacity was due to a loss of the alternative oxidase protein. Some in vitro characteristics of mitochondria were determined. The temperature optimum for measurement of alternative oxidase capacity was 15 to 20C. At 41C, very little alternative oxidase was measured, i.e., the mitochondrial oxygen uptake was almost completely sensitive to cyanide. This inactivation at 41C was reversible. After incubation at 41C, the alternative oxidase capacity measured at 25C was the similar to when it was measured at that temperature directly. Isolated mitochondria lost alternative oxidase capacity at the same rate when incubated at 41C as they did when incubated at 25C. Increasing the supply of electrons to isolated mitochondria increased the degree of engagement of the alternative pathway, whereas lower temperature decreased the degree of engagement. Lower temperatures did not increase the degree of engagement of the pathway in intact tissues. We interpret these observations to indicate that the greater capacity of alternative oxidase in cold-grown seedlings is a consequence of development at these low temperatures which results in elevated respiration rates. Low temperature itself does not cause greater capacity or engagement of the alternative oxidase in mitochondria that have developed under warm temperatures. Our hypothesis would be that the low growth temperatures require the seedlings to have a higher respiration rate for some reason, e.g., to prevent the accumulation of a toxic metabolite, and that the alternative pathway functions in that respiration. Images Figure 2 PMID:16667345

Stewart, Cecil R.; Martin, Barry A.; Reding, Linda; Cerwick, Sharon

1990-01-01

147

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

PubMed Central

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

Watanabe, Keiko; Yamamoto, Hideo; Yamamoto, Shuichi

2013-01-01

148

Rutile titanium dioxide films deposited with a vacuum arc at different temperatures  

NASA Astrophysics Data System (ADS)

Rutile crystalline phase of TiO2 has been one of the most investigated materials for medical applications. Its implementation as a surface layer on biomedical implants has shown to improve hemocompatibility and biocompatibility. In this work, titanium dioxide coatings were deposited on glass and steel 316L substrates using cathodic arc deposition. The coatings were obtained at different substrate temperatures; varying from room temperature to 600C. The crystalline structure of the films was identified by glancing angle X-ray diffraction. Depending on the substrate material and on its temperature during the deposition process, anatase, anatse+rutile and rutile structures were observed. It was determined that rutile films can be obtained below 600 C with this deposition method.

Arias, L. Franco; Kleiman, A.; Heredia, E.; Mrquez, A.

2012-06-01

149

Sublattice-specific ordering of ZnO layers during the heteroepitaxial growth at different temperatures  

SciTech Connect

The effect of the substrate temperature on the sublattice ordering in ZnO layers grown by reactive pulsed magnetron sputtering on sapphire has been investigated by different techniques. The improvement of the crystal quality and heteroepitaxial growth at relatively low temperatures (550 deg. C) is verified by x-ray diffraction, high-resolution transmission electron microscopy, Rutherford backscattering spectrometry in channeling mode (RBS/C), and Raman spectroscopy. Sublattice-resolved analysis by resonant RBS/C and Raman spectroscopy reveals that the progressive transition to the single crystal phase is accomplished in a faster way for Zn- than for O-sublattice. This behavior is attributed to the preferential annealing of defects in the Zn sublattice at low temperatures when compared to those of the O sublattice.

Redondo-Cubero, A. [Instituto Tecnologico e Nuclear, Sacavem 2686-953 (Portugal); ISOM and DIE, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Madrid E-28040 (Spain); Vinnichenko, M.; Muecklich, A.; Kolitsch, A. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, PF 51019, Dresden D-01314 (Germany); Krause, M. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, PF 51019, Dresden D-01314 (Germany); Technische Universitaet Dresden, Institut fuer Festkoerperphysik, Dresden D-01062 (Germany); Munoz, E. [ISOM and DIE, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Madrid E-28040 (Spain); Gago, R. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Madrid E-28049 (Spain)

2011-12-01

150

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

PubMed

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

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

2014-12-01

151

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

152

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

Microsoft Academic Search

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

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

2006-01-01

153

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

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

154

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

PubMed

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

Binner, Maaike; Kloas, Werner; Hardewig, Iris

2008-06-01

155

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

NASA Astrophysics Data System (ADS)

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).

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

2014-12-01

156

A Study of Contact Binaries with Large Temperature Differences between Components  

NASA Astrophysics Data System (ADS)

We present an extensive analysis of new light and radial velocity (RV) curves, as well as high quality broadening function (BF) profiles of twelve binary systems for which a contact configuration with large temperature differences between components has been reported in the literature. We find that six systems (V1010 Oph, WZ Cyg, VV Cet, DO Cas, FS Lup, V747 Cen) have near contact configurations. For the remaining systems (CX Vir, FT Lup, BV Eri, FO Hya, CN And, BX And), our solutions of the new observations once again converge in a contact configuration with large temperature differences between the components. However, the bright regions discovered in the BFs for V747 Cen, CX Vir, FT Lup, BV Eri, FO Hya, and CN And, and further attributed to hot spots, shed new light on the physical processes taking place between the components and imply the possibility that the contact configurations obtained from light and RV curve modeling are a spurious result.

Siwak, M.; Zola, S.; Koziel-Wierzbowska, D.

2010-12-01

157

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

NASA Astrophysics Data System (ADS)

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

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

2010-08-01

158

Surface anisotropy characterization and microstructure of CuW thin films at different annealing temperatures  

Microsoft Academic Search

CuW films were deposited on Al2O3 substrates by magnetron sputtering and then annealed in Ar gas at different temperatures for an hour. The evolution of surface morphology of the films during deposition and annealing was investigated by mathematical techniques. A strategy integrating discrete wavelet transform and fractal geometry concepts was developed for analyzing the anisotropy of surface structure of CuW

Wang Yuan; Bai Xuanyu; Xu Kewei

2004-01-01

159

Low-Temperature Heat-Capacity Differences between Glasses and Their Crystals  

Microsoft Academic Search

It is suggested that the low-temperature heat-capacity difference between glasses and their crystal may be computed by considering the simple process, Cx(Vx) ?(a) Cx(Vg) ?(b) Cg(Vg), where Cx(Vx) is the constant volume heat capacity of the crystal at its equilibrium volume at normal pressures, Vx, Cx(Vg) is the heat capacity of the substance of identical structure as the crystal but

Charles M. Guttman

1972-01-01

160

Electrical Conductivity of Frozen Shrimp and Flounder at Different Temperatures and Voltage Levels  

Microsoft Academic Search

Electrical conductivity (EC) is an important property during ohmic thawing of seafood. EC of frozen flounder, tiger and white shrimp, and shrimp shells at different voltages and temperatures (T) was measured. The materials were homogenized in a blender. PVC tubes (lengths: 4.1 to 5.6 cm, diameter: 1.5 cm) were filled with the material and fitted with circular stainless steel electrodes

Diego A. Luzuriaga; Murat O. Balaban

1996-01-01

161

Modulation cancellation method for measurements of small temperature differences in a gas.  

PubMed

An innovative spectroscopic technique based on balancing and cancellation of modulated signals induced by two excitation sources is reported. For its practical implementation, we used quartz-enhanced photoacoustic spectroscopy as an absorption-sensing technique and applied the new approach to measure small temperature differences between two gas samples. The achieved sensitivity was 30 mK in 17 s. A theoretical sensitivity analysis is presented, and the applicability of this method to isotopic measurements is discussed. PMID:21326422

Spagnolo, Vincenzo; Dong, Lei; Kosterev, Anatoliy A; Thomazy, David; Doty, James H; Tittel, Frank K

2011-02-15

162

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

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

163

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

PubMed Central

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

Yu, Jiangtao; Weng, Wenfang; Yu, Kequan

2014-01-01

164

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

NASA Astrophysics Data System (ADS)

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

Morisaki, Takafumi.; Ikegami, Yasuyuki.

2014-02-01

165

Land Surface Temperature Measurements form EOS MODIS Data  

NASA Technical Reports Server (NTRS)

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.

Wan, Zhengming

1996-01-01

166

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

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

167

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

168

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

PubMed

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

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

2014-10-01

169

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

170

[Whole-body oxygen consumption at different temperatures during cardiopulmonary bypass].  

PubMed

For evaluation of the adequacy of tissue perfusion during cardiopulmonary bypass (CPB), whole-body oxygen consumption rates at different body weights and temperatures are basic and important data. But few studies have analyzed the oxygen consumption estimated from real-time data during CPB in clinical situations. We analyzed retrospectively the oxygen consumption at different body weights (BW) during normothermia (VO2 37) and the oxygen consumption ratio at different body temperatures (BT; %VO2X; X = BT) from the CPB charts of 189 cases. From these charts, 877 data points for oxygen consumption during total CPB were calculated by Fick's law. By statistical analysis of these data, we derived the following formulae: VO2 37 (ml/kg/min) = 7.6481 x BW0.0679, R2 = 1.0 (BW < 8 kg) VO2 37 (ml/kg/min) = 32.394 x BW-0.625, R2 = 0.92 (BW > or = 8 kg) %VO2X (%) = 4 x 10(-5) x BT4.0777, R2 = 0.42. These formulae indicate that (1) the whole-body oxygen consumption during total CPB can be measured by subtracting the oxygen consumption associated with circulatory and respiratory processes from the oxygen consumption derived from the basal metabolism; and (2) although the change in oxygen consumption induced by hypothermia is variable depending on body weight, the rate of change shows no difference regardless of the patient's weight. PMID:10998863

Higuchi, H; Yoshii, S; Osawa, H; Suzuki, S; Samuel, A; Hosaka, S; Shindou, S; Tada, Y

2000-09-01

171

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

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

172

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

NASA Astrophysics Data System (ADS)

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

Kaur, Manveen; Verma, N. K.

2013-08-01

173

Predictive models for estimating the vapor pressure of poly- and perfluorinated compounds at different temperatures  

NASA Astrophysics Data System (ADS)

Poly- and perfluorinated compounds (PFCs) are a class of global environmental pollutants that are of concern regarding their environmental fate and adverse effects. However, data on the basic physicochemical property of PFCs are still limited. To fill part of the data gaps, temperature-dependent predictive models for vapor pressure of PFCs were developed based on previously reported experimental data. The applicability domain of the models was analyzed using the Williams plot and the influential points and the response outliers were identified. The statistical performance of the models was significantly improved by removing these influential points and response outliers. This procedure confirmed the importance of properly defining the applicability domain of the predictive models. It is shown that the main factors governing the vapor pressure of PFCs, are intermolecular dispersive interactions, hydrogen bonding, temperature, intermolecular dipole-induced dipole interactions and dipole-dipole interactions. Although the model obtained could be used to reliably predict the vapor pressures of certain PFCs at different temperatures, it is essential that the prediction must fall within the applicability domain of the model and the temperature range for reliable predictions.

Ding, Guanghui; Shao, Mihua; Zhang, Jing; Tang, Junyi; Peijnenburg, Willie J. G. M.

2013-08-01

174

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

PubMed

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

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

2014-08-01

175

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

NASA Astrophysics Data System (ADS)

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.

Li, Lili; Han, Ming

2015-01-01

176

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

PubMed

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

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

2010-01-01

177

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

178

Thermal Diffusivity for III-VI Semiconductor Melts at Different Temperatures  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

179

Casting and microstructure of post and core at different mold temperatures.  

PubMed

In the present investigation the microstructure and bonding between the wrought and cast elements of the post and core specimens were evaluated with respect to the preheating temperature of the investment. Clinically sized specimens were produced from one type III gold casting alloy in combination with two different wrought wire precious alloys. Preheating temperatures of 500 degrees, 600 degrees, 700 degrees, 800 degrees and 900 degrees C were employed. Microscopic evaluation of polished and etched transverse and longitudinal sections of the specimens indicated that recrystallization of the wrought wire was initiated at 700 degrees C for one type of specimen. The best reproduction of the wax pattern was obtained at 800 degrees C for post and core combinations. The union between the wrought and cast elements was, regardless of wire type, better in the core portion than in the post. The best union between cast and wrought structures was obtained with a non-oxidizing wire at 700 degrees C. PMID:6753450

Brunell, G

1982-01-01

180

Calibration and simulation of ASM2d at different temperatures in a phosphorus removal pilot plant.  

PubMed

In this work, an organic and nutrient removal pilot plant was used to study the temperature influence on phosphorus accumulating organisms. Three experiments were carried out at 13, 20 and 24.5 degrees C, achieving a high phosphorus removal percentage in all cases. The ASM2d model was calibrated at 13 and 20 degrees C and the Arrhenius equation constant was obtained for phosphorus removal processes showing that the temperature influences on the biological phosphorus removal subprocesses in a different degree. The 24.5 degrees C experiment was simulated using the model parameters obtained by means of the Arrhenius equation. The simulation results for the three experiments showed good correspondence with the experimental data, demonstrating that the model and the calibrated parameters were able to predict the pilot plant behaviour. PMID:16889256

Garca-Usach, F; Ferrer, J; Bouzas, A; Seco, A

2006-01-01

181

Studies of Water Absorption Behavior of Plant Fibers at Different Temperatures  

NASA Astrophysics Data System (ADS)

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.

Saikia, Dip

2010-05-01

182

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

PubMed

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

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

2014-10-01

183

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

PubMed

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

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

2014-08-01

184

[Changes of rice yield and quality in different accumulated temperature zones in Heilongjiang Province of Northeast China].  

PubMed

Field experiments were installed in different accumulated temperature zones in Heilongjiang Province to study the changes of the grain yield and quality of five major rice varieties with accumulated temperature. The rice yield changed with accumulated temperature in quadratic curve, and the correlation degree differed with the varieties. The panicle number and the grain number per panicle changed significantly in quadratic curve with accumulated temperature, while the 1000-grain mass had less correlation with accumulated temperature. The sterile spikelet rate of grain increased obviously from suitable accumulated temperature zone to low accumulated temperature zone, but had no obvious change from suitable accumulated temperature zone to high accumulated temperature zone. The rates of chalky and head milled rice also changed with accumulated temperature in quadratic curve, i. e., there were both the lowest and the highest values in suitable accumulated temperature zone. The protein and amylose contents of the grain as well as the taste varied little with accumulated temperature. According to the sensitivity to temperature, the test rice varieties were divided into sensitive, medium, and blunt types, with the optimal and allowable cultivation accumulated temperature limits being 300 degrees C and 420 degrees C, 360 degrees C and 440 degrees C, and 380 degrees C and 520 degrees C, respectively. It would be very important to select the rice varieties with higher yield and better quality according to the local conditions, especially the accumulated temperature. PMID:24015559

Wang, Qiu-Ju; Zhang, Yu-Long; Liu, Feng; Wang, Lian-Min; Li, Ming-Xian

2013-05-01

185

The effect of temperature differences on the distribution of an airborne contaminant in an experimental room.  

PubMed

Estimating exposure to contaminants emitted into workroom air is essential for worker protection. Although contaminant concentrations are often not spatially uniform within workrooms, many methods for estimating exposure do not adequately account for this variability. Here the impact of temperature differences within a room on spatial contaminant distribution was studied. Tracer gas (99.5% propylene) concentrations were monitored automatically at 144 sampling points with a photoionization detector. One wall was chosen to represent a building's external wall and was heated or cooled to simulate summer or winter conditions. Experiments were preformed at two flow rates (5.5 and 3.3 m(3) min(-1)) and six thermal conditions (isothermal, three summer conditions and two winter conditions). For 5.5 m(3) min(-1) and all thermal conditions, the coefficient of variation (CV) ranged from 0.34 to 0.45 and the normalized average concentrations were similar. For 3.3 m(3) min(-1), winter conditions produced greater spatial variability of concentration (CV = 0.72 and 1.10) than isothermal or summer conditions (CV range = 0.29-0.34). Tests simulating winter conditions suggest that the resulting stable temperature structure inhibited the dilution of the tracer and enhanced its segregation in the lower portion of the room, especially for the lower flow rate (3.3 m(3) min(-1)). Therefore, not explicitly addressing thermal effect in exposure modeling may impact the estimated accuracy and precision when used for rooms that are non-isothermal and not well mixed. These findings also have implications for air monitoring. Dispersion patterns for different thermal conditions were found to be substantially different, even when the mean concentrations were nearly the same. Thus, monitoring data from a single season should not be taken as representative of the entire year, when summer and winter conditions create temperature gradients in a room. PMID:16611801

Lee, Eungyoung; Feigley, Charles E; Khan, Jamil A; Hussey, James R

2006-07-01

186

Phenological and morphological responses to different temperature treatments differ among a world-wide sample of accessions of Arabidopsis thaliana  

Microsoft Academic Search

A world-wide sample of 74 accessions of Arabidopsis thaliana was grown at two temperatures (14 and 22C). The main question raised in this study is whether the climate at the places of origin of the accessions correlates with their performances under experimental conditions. Sixteen morphological and five phenological characters were scored. The phenological responses to the temperatures correlate significantly with

Matthias H. Hoffmann; Jrgen Tomiuk; Heike Schmuths; Christina Koch; Konrad Bachmann

2005-01-01

187

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

PubMed Central

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

2011-01-01

188

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

Microsoft Academic Search

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

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

1997-01-01

189

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

190

Properties of Ti8C5 thin films created at different temperatures using magnetron sputtering  

NASA Astrophysics Data System (ADS)

We were able to create thin films of Ti8C5 on c-axis oriented single crystal Al2O3 using both co-deposition magnetron sputtering and reactive magnetron sputtering. While TiC is generally used as a precursor film when making ``on-chip'' super capacitors, Ti8C5 is of similar composition and may have some advantages when making super capacitors. The Ti8C5 is more porous and demonstrates slightly different properties than TiC. Film deposition was optimized using elemental composition data obtained by WDXRF and characterized using XRD. It was found that composition and phase of Ti8C5 greatly depended on the temperatures at which the samples were grown. We outline the different parameters at which Ti8C5 grows best by outlining features of the Ti-C phase diagram.

Rotella, Christopher; Hettinger, Jeffrey; Cortes, Emma; Lofland, Samuel; Heon, Min; Lunk, Carl

2013-03-01

191

Temperature dependence of greenhouse gas emissions from three hydromorphic soils at different groundwater levels.  

PubMed

Wetlands contribute considerably to the global greenhouse gas (GHG) balance. In these ecosystems, groundwater level (GWL) and temperature, two factors likely to be altered by climate change, exert important control over CO(2), CH(4) and N(2)O fluxes. However, little is known about the temperature sensitivity (Q(10)) of the combined GHG emissions from hydromorphic soils and how this Q(10) varies with GWL. We performed a greenhouse experiment in which three different (plant-free) hydromorphic soils from a temperate spruce forest were exposed to two GWLs (an intermediate GWL of -20 cm and a high GWL of -5 cm). Net CO(2), CH(4) and N(2)O fluxes were measured continuously. Here, we discuss how these fluxes responded to synoptic temperature fluctuations. Across all soils and GWLs, CO(2) emissions responded similarly to temperature and Q(10) was close to 2. The Q(10) of the CH(4) and N(2)O fluxes also was similar across soil types. GWL, on the other hand, significantly affected the Q(10) of both CH(4) and N(2)O emissions. The Q(10) of the net CH(4) fluxes increased from about 1 at GWL = -20 cm to 3 at GWL = -5 cm. For the N(2)O emissions, Q(10) varied around 2 for GWL = -20 cm and around 4 for GWL = -5 cm. This substantial GWL-effect on the Q(10) of CH(4) and N(2)O emissions was, however, hardly reflected in the Q(10) of the total GHG emissions (which varied around 2), because the contribution of these gases was relatively small compared to that of CO(2). PMID:19570105

Vicca, S; Janssens, I A; Flessa, H; Fiedler, S; Jungkunst, H F

2009-09-01

192

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

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

193

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

PubMed

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

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

1996-01-01

194

Leaf senescence and grain filling affected by post-anthesis high temperatures in two different wheat cultivars  

Microsoft Academic Search

High temperature is a major factor affecting grain yield and plant senescence in wheat growing regions of central and east\\u000a China. In this study, two different wheat cultivars, Yangmai 9 with low-grain protein concentration and Xuzhou 26 with high-grain\\u000a protein concentration, were exposed to different temperature regimes in growth chambers during grain filling. Four day\\/night\\u000a temperature regimes of 34C\\/22C, 32C\\/24C,

Hui Zhao; Tingbo Dai; Qi Jing; Dong Jiang; Weixing Cao

2007-01-01

195

Comparative analysis of selected exhaled breath biomarkers obtained with two different temperature-controlled devices  

PubMed Central

Background The collection of exhaled breath condensate (EBC) is a suitable and non-invasive method for evaluation of airway inflammation. Several studies indicate that the composition of the condensate and the recovery of biomarkers are affected by physical characteristics of the condensing device and collecting circumstances. Additionally, there is an apparent influence of the condensing temperature, and often the level of detection of the assay is a limiting factor. The ECoScreen2 device is a new, partly single-use disposable system designed for studying different lung compartments. Methods EBC samples were collected from 16 healthy non-smokers by using the two commercially available devices ECoScreen2 and ECoScreen at a controlled temperature of -20C. EBC volume, pH, NOx, LTB4, PGE2, 8-isoprostane and cys-LTs were determined. Results EBC collected with ECoScreen2 was less acidic compared to ECoScreen. ECoScreen2 was superior concerning condensate volume and detection of biomarkers, as more samples were above the detection limit (LTB4 and PGE2) or showed higher concentrations (8-isoprostane). However, NOx was detected only in EBC sampled by ECoScreen. Conclusion ECoScreen2 in combination with mediator specific enzyme immunoassays may be suitable for measurement of different biomarkers. Using this equipment, patterns of markers can be assessed that are likely to reflect the complex pathophysiological processes in inflammatory respiratory disease. PMID:19948050

2009-01-01

196

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

PubMed

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

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

2015-02-01

197

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

NASA Astrophysics Data System (ADS)

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

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

1997-10-01

198

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

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

199

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

PubMed Central

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

de Oliveira Ottone, Vincius; de Castro Magalhes, Flvio; de Paula, Fabrcio; Avelar, Nbia Carelli Pereira; Aguiar, Paula Fernandes; da Matta Sampaio, Pmela Fiche; Duarte, Tamiris Campos; Costa, Karine Beatriz; Arajo, Tatiane Lliam; Coimbra, Cndido Celso; Nakamura, Fbio Yuzo; Amorim, Fabiano Trigueiro; Rocha-Vieira, Etel

2014-01-01

200

Influence of different maceration time and temperatures on total phenols, colour and sensory properties of Cabernet Sauvignon wines.  

PubMed

Maceration and fermentation time and temperatures are important factors affecting wine quality. In this study different maceration times (3 and 6 days) and temperatures (15? and 25?) during production of red wine (Vitis vinifera L. Cabernet Sauvignon) were investigated. In all wines standard wine chemical parameters and some specific parameters as total phenols, tartaric esters, total flavonols and colour parameters (CD, CI, T, dA%, %Y, %R, %B, CIELAB values) were determined. Sensory evaluation was performed by descriptive sensory analysis. The results demonstrated not only the importance of skin contact time and temperature during maceration but also the effects of transition temperatures (different maceration and fermentation temperatures) on wine quality as a whole. The results of sensory descriptive analyses revealed that the temperature significantly affected the aroma and flavour attributes of wines. The highest scores for 'cassis', 'clove', 'fresh fruity' and 'rose' characters were obtained in wines produced at low temperature (15?) of maceration (6 days) and fermentation. PMID:23703104

?ener, Hasan; Yildirim, Hatice Kalkan

2013-12-01

201

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

PubMed Central

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

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

2012-01-01

202

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

PubMed

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

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

2012-08-01

203

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

PubMed

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

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

2015-03-01

204

Temperature dependence of the thermal conductivity of different forms of diamond  

NASA Astrophysics Data System (ADS)

We present a systematic theoretical investigation of the thermal conductivity of naturally abundant, isotopically enriched, fast neutron irradiated single crystals of diamond, and chemical vapor deposited diamond films of different types over a large temperature range. Existing experimental data have been analyzed using Callaway's theoretical model [Phys. Rev. 113, 1046 (1959)] for thermal conductivity based on an isotropic continuum phonon dispersion relation and using normal and umklapp phonon-phonon relaxation times derived from the application of time-dependent perturbation theory within an anharmonic continuum model. In contrast to existing theoretical studies of the thermal conductivity of diamond, our approach considers Grneisen's constant as the only (semi)adjustable parameter for anharmonic phonon interactions. This work quantifies the enhancement of the thermal conductivity of diamond with isotopic purity. This work also accounts for the dip in the thermal conductivity curve for hot filament chemical vapor deposition of diamond films and neutron irradiated diamond at low temperatures and provides an estimate of the amount, type, and size of defects present in such samples. We find that the N-drift term in Callaway's theory provides a significant contribution to the thermal conductivity of all the forms of diamond studied here.

Barman, Saswati; Srivastava, G. P.

2007-06-01

205

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

PubMed Central

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

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

206

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

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

207

Differences and Similarities in MaCWAVE Summer and Winter Temperatures and Winds  

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

208

Simulated sea surface temperature and heat fluxes in different climates of the Baltic Sea.  

PubMed

The physical state of the Baltic Sea in possible future climates is approached by numerical model experiments with a regional coupled ocean-atmosphere model driven by different global simulations. Scenarios and recent climate simulations are compared to estimate changes. The sea surface is clearly warmer by 2.9 degrees C in the ensemble mean. The horizontal pattern of average annual mean warming can largely be explained in terms of ice-cover reduction. The transfer of heat from the atmosphere to the Baltic Sea shows a changed seasonal cycle: a reduced heat loss in fall, increased heat uptake in spring, and reduced heat uptake in summer. The interannual variability of surface temperature is generally increased. This is associated with a smoothed frequency distribution in northern basins. The overall heat budget shows increased solar radiation to the sea surface, which is balanced by changes of the other heat flux components. PMID:15264603

Dscher, Ralf; Meier, H E Markus

2004-06-01

209

Evaluation of three different optical fiber temperature sensor types for application in gamma radiation environments  

SciTech Connect

The authors compare the gamma radiation response of three different types of commercially available optical fiber temperature sensors. These are semiconductor absorption, Fabry-Perot cavity and fluorescence sensors. In order to evaluate their possible application in nuclear environments, they first highlight the principles of operation and the constructions. They then report on the gamma irradiation results and explain the observed degradation phenomena. For all three sensor types, the basic transduction mechanism does not seem to be affected by gamma radiation. The semiconductor absorption sensor shows a good radiation resistance (up to 160 kGy) in its present form, whereas the other sensor constructions need to be adapted. For the semiconductor absorption sensor, additional neutron irradiation experiments are performed, which are found to affect the principle of operation of this sensor.

Berghmans, F.; Vos, F.; Decreton, M. [SCK-CEN, Mol (Belgium). Belgian Nuclear Research Centre] [SCK-CEN, Mol (Belgium). Belgian Nuclear Research Centre

1998-06-01

210

Effects of experimental reheating of natural basaltic ash at different temperatures and redox conditions  

NASA Astrophysics Data System (ADS)

A set of experiments have been performed on volcanic materials from Etna, Stromboli and Vesuvius in order to evaluate how the exposure to thermal and redox conditions close to that of active craters affects the texture and composition of juvenile pyroclasts. Selected samples were placed within a quartz tube, in presence of air or under vacuum, and kept at T between 700 and 1,130 C, for variable time (40 min to 12 h). Results show that reheating reactivates the melt, which, through processes of chemical and thermal diffusion, reaches new equilibrium conditions. In all the experiments performed at T = 700-750 C, a large number of crystal nuclei and spherulites grows in the groundmass, suggesting conditions of high undercooling. This process creates textural heterogeneities at the scale of few microns but only limited changes of groundmass composition, which remains clustered around that of the natural glasses. Reheating at T = 1,000-1,050 C promotes massive groundmass crystallization, with a different mineral assemblage as a function of the redox conditions. Morphological modifications of clasts, from softening to sintering as temperature increases, occur under these conditions, accompanied by progressive smoothing of external surfaces, and a reduction in size and abundance of vesicles, until the complete obliteration of the pre-existing vesicularity. The transition from sintering to welding, characteristic of high temperature, is influenced by redox conditions. Experiments at T = 1,100-1,130 C and under vacuum produce groundmass textures and glass compositions similar to that of the respective starting material. Collapse and welding of the clasts cause significant densification of the whole charge. At the same temperature, but in presence of air, experimental products at least result sintered and show holocrystalline groundmass. In all experiments, sublimates grow on the external surfaces of the clasts or form a lining on the bubble walls. Their shape and composition is a function of temperature and fO2 and the abundance of sublimates shows a peak at 1,000 C. The identification of the features recorded by pyroclasts during complex heating-cooling cycles allows reconstructing the complete clasts history before their final emplacement, during weakly explosive volcanic activity. This has a strong implication on the characterization of primary juvenile material and on the interpretation of eruption dynamics.

D'Oriano, C.; Pompilio, M.; Bertagnini, A.; Cioni, R.; Pichavant, M.

2013-05-01

211

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

NASA Astrophysics Data System (ADS)

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.

Kulakov, E.; Smirnov, A. V.

2013-05-01

212

Understanding Differences in Upper Stratospheric Ozone Response to Changes in Chlorine and Temperature as Computed Using CCMVal Models  

NASA Technical Reports Server (NTRS)

Projections of future ozone levels are made using models that couple a general circulation model with a representation of atmospheric photochemical processes, allowing interactions among photochemical processes, radiation, and dynamics. Such models are known as chemistry and climate models (CCMs). Although developed from common principles and subject to the same boundary conditions, simulated ozone time series vary for projections of changes in ozone depleting substances (ODSs) and greenhouse gases. In the upper stratosphere photochemical processes control ozone level, and ozone increases as ODSs decrease and temperature decreases due to greenhouse gas increase. Simulations agree broadly but there are quantitative differences in the sensitivity of ozone to chlorine and to temperature. We obtain insight into these differences in sensitivity by examining the relationship between the upper stratosphere annual cycle of ozone and temperature as produced by a suite of models. All simulations conform to expectation in that ozone is less sensitive to temperature when chlorine levels are highest because chlorine catalyzed loss is nearly independent of temperature. Differences in sensitivity are traced to differences in simulated temperature, ozone and reactive nitrogen when chlorine levels are close to background. This work shows that differences in the importance of specific processes underlie differences in simulated sensitivity of ozone to composition change. This suggests a) the multi-model mean is not a best estimate of the sensitivity of upper ozone to changes in ODSs and temperature; b) the spread of values is not an appropriate measure of uncertainty.

Douglass, A. R.; Stolarski, R. S.; Strahan, S. E.; Oman, L. D.

2012-01-01

213

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

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

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

214

The influence of internal and skin temperatures on active cutaneous vasodilation under different levels of exercise and ambient temperatures in humans  

NASA Astrophysics Data System (ADS)

To clarify the influence of internal and skin temperature on the active cutaneous vasodilation during exercise, the body temperature thresholds for the onset of active vasodilation during light or moderate exercise under different ambient temperature conditions were compared. Seven male subjects performed 30 min of a cycling exercise at 20 % or 50 % of peak oxygen uptake in a room maintained at 20, 24, or 28 C. Esophageal (Tes) and mean skin temperature (Tsk) as measured by a thermocouple, deep thigh temperature (Tdt) by the zero-heat-flow (ZHF) method, and forearm skin blood flow by laser-Doppler flowmetry (LDF) were monitored. The mean arterial pressure (MAP) was also monitored non-invasively, and the cutaneous vascular conductance (CVC) was calculated as the LDF/MAP. Throughout the experiment, the Tsk at ambient temperatures of 20, 24, and 28 C were approximately 30, 32, and 34 C, respectively, for both 20 % and 50 % exercise. During 50 % exercise, the Tes or Tdt thresholds for the onset of the increase in CVC were observed to be similar among the 20, 24, and 28 C ambient conditions. During 20 % exercise, the increase in Tes and Tdt was significantly lower than those found at 50 %, and the onset of the increase in CVC was only observed at 28 C. These results suggest that the onset of active vasodilation was affected more strongly by the internal or exercising tissue temperatures than by the skin temperatures during exercise performed at a moderate load in comparison to a light load under Tsk variations ranging from 30 C to 34 C. Therefore, the modification by skin temperature of the central control on cutaneous vasomotor tone during exercise may differ between different exercise loads.

Demachi, Koichi; Yoshida, Tetsuya; Kume, Masashi; Tsuji, Michio; Tsuneoka, Hideyuki

2013-07-01

215

The influence of internal and skin temperatures on active cutaneous vasodilation under different levels of exercise and ambient temperatures in humans.  

PubMed

To clarify the influence of internal and skin temperature on the active cutaneous vasodilation during exercise, the body temperature thresholds for the onset of active vasodilation during light or moderate exercise under different ambient temperature conditions were compared. Seven male subjects performed 30 min of a cycling exercise at 20 % or 50 % of peak oxygen uptake in a room maintained at 20, 24, or 28 C. Esophageal (Tes) and mean skin temperature (Tsk) as measured by a thermocouple, deep thigh temperature (Tdt) by the zero-heat-flow (ZHF) method, and forearm skin blood flow by laser-Doppler flowmetry (LDF) were monitored. The mean arterial pressure (MAP) was also monitored non-invasively, and the cutaneous vascular conductance (CVC) was calculated as the LDF/MAP. Throughout the experiment, the Tsk at ambient temperatures of 20, 24, and 28 C were approximately 30, 32, and 34 C, respectively, for both 20 % and 50 % exercise. During 50 % exercise, the Tes or Tdt thresholds for the onset of the increase in CVC were observed to be similar among the 20, 24, and 28 C ambient conditions. During 20 % exercise, the increase in Tes and Tdt was significantly lower than those found at 50 %, and the onset of the increase in CVC was only observed at 28 C. These results suggest that the onset of active vasodilation was affected more strongly by the internal or exercising tissue temperatures than by the skin temperatures during exercise performed at a moderate load in comparison to a light load under Tsk variations ranging from 30 C to 34 C. Therefore, the modification by skin temperature of the central control on cutaneous vasomotor tone during exercise may differ between different exercise loads. PMID:22960747

Demachi, Koichi; Yoshida, Tetsuya; Kume, Masashi; Tsuji, Michio; Tsuneoka, Hideyuki

2013-07-01

216

Differential Temporal Evolution Patterns in Brain Temperature in Different Ischemic Tissues in a Monkey Model of Middle Cerebral Artery Occlusion  

PubMed Central

Brain temperature is elevated in acute ischemic stroke, especially in the ischemic penumbra (IP). We attempted to investigate the dynamic evolution of brain temperature in different ischemic regions in a monkey model of middle cerebral artery occlusion. The brain temperature of different ischemic regions was measured with proton magnetic resonance spectroscopy (1H MRS), and the evolution processes of brain temperature were compared among different ischemic regions. We found that the normal (baseline) brain temperature of the monkey brain was 37.16C. In the artery occlusion stage, the mean brain temperature of ischemic tissue was 1.16C higher than the baseline; however, this increase was region dependent, with 1.72C in the IP, 1.08C in the infarct core, and 0.62C in the oligemic region. After recanalization, the brain temperature of the infarct core showed a pattern of an initial decrease accompanied by a subsequent increase. However, the brain temperature of the IP and oligemic region showed a monotonously and slowly decreased pattern. Our study suggests that in vivo measurement of brain temperature could help to identify whether ischemic tissue survives. PMID:23091367

Sun, Zhihua; Zhang, Jing; Chen, Yingmin; Zhang, Yunting; Zhang, Xuejun; Guo, Hong; Yu, Chunshui

2012-01-01

217

Developing a Heatwave Early Warning System for Sweden: Evaluating Sensitivity of Different Epidemiological Modelling Approaches to Forecast Temperatures  

PubMed Central

Over the last two decades a number of heatwaves have brought the need for heatwave early warning systems (HEWS) to the attention of many European governments. The HEWS in Europe are operating under the assumption that there is a high correlation between observed and forecasted temperatures. We investigated the sensitivity of different temperature mortality relationships when using forecast temperatures. We modelled mortality in Stockholm using observed temperatures and made predictions using forecast temperatures from the European Centre for Medium-range Weather Forecasts to assess the sensitivity. We found that the forecast will alter the expected future risk differently for different temperature mortality relationships. The more complex models seemed more sensitive to inaccurate forecasts. Despite the difference between models, there was a high agreement between models when identifying risk-days. We find that considerations of the accuracy in temperature forecasts should be part of the design of a HEWS. Currently operating HEWS do evaluate their predictive performance; this information should also be part of the evaluation of the epidemiological models that are the foundation in the HEWS. The most accurate description of the relationship between high temperature and mortality might not be the most suitable or practical when incorporated into a HEWS. PMID:25546283

strm, Christofer; Ebi, Kristie L.; Langner, Joakim; Forsberg, Bertil

2014-01-01

218

Effects of different cultivation temperatures on plasma membrane ATPase activity and lipid composition of sugar beet roots  

Microsoft Academic Search

Sugar beet seedlings (Beta vulgaris L. cv. Monohill) were cultivated for 3weeks at different root and shoot temperatures and the plasma membranes (PM) from roots were purified by aqueous two-phase partitioning and analyzed for lipid composition and ATPase activities. Lipid analyses, undertaken immediately after PM purification from the roots, showed that a low root zone temperature (10C) decreased the ratio

Sylvia Lindberg; Antoni Banas; Sten Stymne

2005-01-01

219

Developing a heatwave early warning system for sweden: evaluating sensitivity of different epidemiological modelling approaches to forecast temperatures.  

PubMed

Over the last two decades a number of heatwaves have brought the need for heatwave early warning systems (HEWS) to the attention of many European governments. The HEWS in Europe are operating under the assumption that there is a high correlation between observed and forecasted temperatures. We investigated the sensitivity of different temperature mortality relationships when using forecast temperatures. We modelled mortality in Stockholm using observed temperatures and made predictions using forecast temperatures from the European Centre for Medium-range Weather Forecasts to assess the sensitivity. We found that the forecast will alter the expected future risk differently for different temperature mortality relationships. The more complex models seemed more sensitive to inaccurate forecasts. Despite the difference between models, there was a high agreement between models when identifying risk-days. We find that considerations of the accuracy in temperature forecasts should be part of the design of a HEWS. Currently operating HEWS do evaluate their predictive performance; this information should also be part of the evaluation of the epidemiological models that are the foundation in the HEWS. The most accurate description of the relationship between high temperature and mortality might not be the most suitable or practical when incorporated into a HEWS. PMID:25546283

strm, Christofer; Ebi, Kristie L; Langner, Joakim; Forsberg, Bertil

2014-01-01

220

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)

Radiosondes provide one of the primary sources of upper atmosphere temperature data for numerical weather prediction, the assessment of long-term trends in atmospheric temperature, the study atmospheric processes and provide a source of intercomparison data for other temperature sensors e.g. satellites. When intercomparing different temperature profiles it is important to include the effect of temporal mis-match 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 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 to assess the diurnal variability temperature as a function of altitude, time of day and season of the year. This provides data on the appropriate correction factors to use for a 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 uncertainty of less than 0.1 K h-1 of temporal mis-match.

Butterfield, D.; Gardiner, T.

2014-08-01

221

Small change, big difference: Sea surface temperature distributions for tropical coral reef ecosystems, 1950-2011  

NASA Astrophysics Data System (ADS)

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.

Lough, J. M.

2012-09-01

222

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

NASA Astrophysics Data System (ADS)

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.

Guo, Biao; Wang, Fang; Dong, Shuanglin; Hou, Chunqiang

2010-09-01

223

EFFECT OF DRYING AIR TEMPERATURE AND GRAIN TEMPERATURE OF DIFFERENT TYPES OF DRYER AND OPERATION ON RICE QUALITY  

Microsoft Academic Search

Quality of aromatic rice (KDML-105) and non-aromatic rice (Suphanburi I) was studied using different methods and scales of drying. At the lab scale, rough rice at high moisture (211% w.b.) was subjected to shade drying, sun drying, oven drying at 45 C and 60 C and fluidized bed drying (for different time periods) at 120 C, with tempering for 2hrs.

Chouw Inprasit; Athapol Noomhorm

2001-01-01

224

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

E-print Network

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

Teubner, Katrin

225

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

PubMed

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

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

2012-01-01

226

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

227

Adaptation of fish to different environmental temperature by qualitative and quantitative changes in gene expression  

Microsoft Academic Search

In fish that coccupy a specific thermal habitat the contractile apparatus has been adapted during evolution for that specific temperature range. In Antarctic fish the myofibrillar ATPase activity is relatively high at temperatures around 0C, but this is at the expense of enzyme thermostability as this enzyme from antarctic fishes is heat inactivated at comparatively low temperatures (Johnston and Goldspink,

Geoffrey Goldspink

1995-01-01

228

Validation and application of different experimental techniques to measure electronic component operating junction temperature  

Microsoft Academic Search

Increasing power densities and changing component design have brought about the need for accurate measurement of die junction temperature. While many junction temperature measurement techniques exist it is difficult to compare their relative performance. To validate the accuracy of various direct and indirect test methods, the operating junction temperature of board-mounted SO-16 and plastic quad flat packs (PQFP)-160 components has

John Lohan; Peter Rodgers; Carl-Magnus Fager; Reijo Lehtiniemi; V. Eveloy; P. Tulikka; J. Rantala

1999-01-01

229

Characterization of precursors of methanol synthesis catalysts, copper\\/zinc\\/aluminum oxides, precipitated at different pHs and temperatures  

Microsoft Academic Search

Catalyst precursors for copper\\/zinc aluminum mixed oxide catalysts with an atomic ratio of 6\\/3\\/1 were prepared by co-current precipitation at different pH levels and different temperatures. The precursors, catalysts and reduced catalysts were characterized by means of infrared spectroscopy, X-ray diffraction, thermal analysis, temperature-programmed oxidation and BET surface measurements. The catalysts were also tested for methanol synthesis activity in a

J.-L. Li; T. Inui

1996-01-01

230

Comparative study of SAW temperature sensor based on different piezoelectric materials and crystal cuts for passive wireless measurement  

Microsoft Academic Search

As widely reported substrates for surface acoustic wave (SAW) temperature sensors, YX-cut quartz, YZ-cut LiNbO3 and 128YX-cut LiNbO3 are selected to fabricate different one-port SAW resonator temperature sensors and comprehensive comparative studies of their performance and specifications are conducted carefully in this paper. Firstly, SAW sensors of each cut with 50 different layouts were designed and fabricated according to the

Xuesong Ye; Qiong Wang; Lu Fang; Xuejun Wang; Bo Liang

2010-01-01

231

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

SciTech Connect

Pb thin films were prepared by pulsed laser deposition on a Si (100) substrate at different growth temperatures to investigate their morphology and structure. The morphological analysis of the thin metal films showed the formation of spherical submicrometer grains whose average size decreased with temperature. X-ray diffraction measurements confirmed that growth temperature influences the Pb polycrystalline film structure. A preferred orientation of Pb (111) normal to the substrate was achieved at 30?C and became increasingly pronounced along the Pb (200) plane as the substrate temperature increased. These thin films could be used to synthesize innovative materials, such as metallic photocathodes, with improved photoemission performances.

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

2014-03-15

232

Internal neutronics-temperature coupling in Serpent 2 - Reactivity differences resulting from choice of material property correlations  

SciTech Connect

This paper describes the unique way of simultaneously solving the power and temperature distributions of a nuclear system with the Monte Carlo neutron transport code Serpent 2. The coupled solution is achieved through the implementation of an internal temperature solver and material property correlations in the code. The program structure is reviewed concerning the temperature solver and the internal correlations as well as the internal coupling between these two and the neutron transport part. To estimate the reactivity differences resulting from correlation choices a simple pin-cell case has been calculated. It is established, that some correlation choices may result in difference in reactivity of approximately 100 pcm. (authors)

Valtavirta, V. [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT (Finland)

2013-07-01

233

Novel Low Temperature Co-Fired Ceramic Material System Composed of Dielectrics with Different Dielectric Constants  

NASA Astrophysics Data System (ADS)

We found that the co-firing low temperature co-fired ceramic (LTCC) materials of different dielectric constants (?r) with Cu wiring is achievable using a novel, original design. It was confirmed that the dielectric characteristics of the dielectrics designed in this study are very suitable for the use of the dielectrics in electronic components such as filters mounted in high-speed radio communication equipment. The dielectric constants of the lower- and higher-dielectric-coefficient materials were 8.1 and 44.5, respectively, which are sufficiently effective for downsizing LTCC components. Observing the co-fired interface, it was confirmed that excellent co-firing conditions resulted in no mechanical defects such as delamination or cracks. On the basis of the results of wavelength dispersive X-ray spectrometry (WDX) and X-ray diffractometry (XRD), it was confirmed that co-firing with minimal interdiffusion was realized using the same glass for both dielectrics. It is concluded that the materials developed are good for co-firing in terms of the mechanical defects and interdiffusion that appear in them.

Sakamoto, Sadaaki; Adachi, Hiroshige; Kaneko, Kazuhiro; Sugimoto, Yasutaka; Takada, Takahiro

2013-09-01

234

Investigation of potential waste material insulating properties at different temperature for thermal storage application  

NASA Astrophysics Data System (ADS)

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.

Ali, T. Z. S.; Rosli, A. B.; Gan, L. M.; Billy, A. S.; Farid, Z.

2013-12-01

235

[Development of Pythium ultimum var. ultimum trow on different cultural media depending on temperature].  

PubMed

Pythium ultimum var. ultimum 175 was isolated for the first time from root system of rape. Influences of two kinds of temperature (10 and 25 degrees C) and 8 different cultural media on the strain growth and development was investigated. Using the growth-rate criterion the author has determined linear velocity of growth, which varied from 0.43 to 0.68 mm/h at 10 degrees C and from 0.78 to 1.11 mm/h at 25 degrees C. As to the velocity of growth the culture P. ultimum var. ultimum 175 is comparable to the well-known cultures of Neurospora crassa, and in some cases its growth velocity is higher. The best growth and formation of the oospores of P. ultimum var. ultimum 175 is marked on oats agar at 25 degrees C. The obtained results characterize the studied isolate as a high-parasite culture with respect to the spring rape. PMID:16396111

Zubova, T I

2005-01-01

236

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

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

237

Detection of significant differences between absorption spectra of neutral helium and low temperature photoionized helium plasmas  

SciTech Connect

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.

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

238

Establishment of three Francisella infections in zebrafish embryos at different temperatures.  

PubMed

Francisella spp. are facultative intracellular pathogens identified in increasingly diverse hosts, including mammals. F. noatunensis subsp. orientalis and F. noatunensis subsp. noatunensis infect fish inhabiting warm and cold waters, respectively, while F. tularensis subsp. novicida is highly infectious for mice and has been widely used as a model for the human pathogen F. tularensis. Here, we established zebrafish embryo infection models of fluorescently labeled F. noatunensis subsp. noatunensis, F. noatunensis subsp. orientalis, and F. tularensis subsp. novicida at 22, 28, and 32C, respectively. All infections led to significant bacterial growth, as shown by reverse transcription-quantitative PCR (RT-qPCR), and to a robust proinflammatory immune response, dominated by increased transcription of tumor necrosis factor alpha (TNF-?) and interleukin-1? (IL-1?). F. noatunensis subsp. orientalis was the most virulent, F. noatunensis subsp. noatunensis caused chronic infection, and F. tularensis subsp. novicida showed moderate virulence and led to formation of relatively small granuloma-like structures. The use of transgenic zebrafish strains with enhanced green fluorescent protein (EGFP)-labeled immune cells revealed their detailed interactions with Francisella species. All three strains entered preferentially into macrophages, which eventually assembled into granuloma-like structures. Entry into neutrophils was also observed, though the efficiency of this event depended on the route of infection. The results demonstrate the usefulness of the zebrafish embryo model for studying infections caused by different Francisella species at a wide range of temperatures and highlight their interactions with immune cells. PMID:24614659

Brudal, Espen; Ulanova, Lilia S; O Lampe, Elisabeth; Rishovd, Anne-Lise; Griffiths, Gareth; Winther-Larsen, Hanne C

2014-06-01

239

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

SciTech Connect

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.

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

2009-07-01

240

Chemical spray pyrolysis of ?-In2S3 thin films deposited at different temperatures  

NASA Astrophysics Data System (ADS)

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.

Sall, Thierno; Mar Soucase, Bernab; Mollar, Miguel; Hartitti, Bouchaib; Fahoume, Mounir

2015-01-01

241

Temperature-dependent light-output characteristics of GaInN light-emitting diodes with different dislocation densities  

SciTech Connect

We have experimentally investigated the temperature dependence of optical-output power of light-emitting diodes (LEDs) with different threading dislocation densities (TDDs) to assess the influence of the TDD on the temperature stability of LEDs. Whereas the LED with high TDD shows a 64% decrease in optical-output power when the ambient temperature increases from 20 to 150?C, the LED with low TDD shows only a 54% decrease. The temperature dependence of the optical-output power and current dependence of the characteristic temperature T{sub ch} of LEDs shows that short radiative recombination lifetime and low TDDs are essential to obtain LED characteristics that are tolerant of high temperatures.

Chhajed, Sameer; Cho, Jaehee; Schubert, E. Fred; Kim, Jong Kyu; Koleske, Daniel D.; Crawford, Mary H.

2011-01-01

242

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

Microsoft Academic Search

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

Paula M. Periago; Roy Moezelaar

2001-01-01

243

Inactivation kinetics of apple polyphenol oxidase in different pressuretemperature domains  

Microsoft Academic Search

The impact of high hydrostatic pressure and temperature on the stability of polyphenol oxidase (PPO) was studied in cloudy apple juice. Application of 200500MPa near room temperature or heat treatment at 4555C at ambient pressure caused an increase of PPO activity of up to 65% in freshly squeezed apple juice. Combined pressuretemperature inactivation experiments with fully activated PPO (5min treatment

Roman Buckow; Ulrike Weiss; Dietrich Knorr

2009-01-01

244

Cryogenic Abrasive Jet Machining of Polydimethylsiloxane and Polytetrafluoroethylene at Different Temperatures.  

E-print Network

??The temperature dependence of the solid particle erosion of polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE) and high carbon steel using aluminum oxide particles was investigated. The most (more)

Gradeen, Aaron Glenn (Author)

2012-01-01

245

Regional differences in the surface temperature of Naked Neck laying hens in a semi-arid environment.  

PubMed

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 (24.0-26.0C), 2 (26.1-28.9C) and 3 (29.0-31.0C). 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. PMID:22689146

de Souza, Joo Batista Freire; de Arruda, Alex Martins Varela; Domingos, Hrica Girlane Tertulino; de Macedo Costa, Leonardo Lelis

2013-05-01

246

Photoluminescence studies on nanostructured cadmium sulfide thin films prepared by chemical bath deposition method and annealed at different temperatures  

Microsoft Academic Search

Nanostructured cadmium sulfide (CdS) thin films have been prepared by chemical bath deposition (CBD) method and after post deposition annealing of the thin films at different temperatures, photoluminescence (PL) property has been studied. The effects of various photoexcitation wavelengths on the PL behaviour of different annealed films of CdS were studied by recording the PL spectra. The intensity of PL,

Manisree Majumder; Aloke Kumar Chakraborty; Biswanath Mallik

2010-01-01

247

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

PubMed Central

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

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

2012-01-01

248

[Effects of different accumulated temperature on photosynthetic performances of spring maize varieties during grain-filling period].  

PubMed

Taking cold-resistant maize variety Fengdan 3 and cold-sensitive maize variety Zhengdan 958 as test materials, field experiments were conducted in I, II, and III accumulated temperature zones in Heilongjiang Province of Northeast China to study the effects of different accumulated temperature on the photosynthetic performances of different types of cold-resistant spring maize varieties during their grain-filling period. In the three accumulated temperature zones, the tasseling and maturing periods of Fengdan 3 and Zhengdan 958 were prolonged in the order of I > II > and III, and the grain bulk density decreased in the same order. The RuBPCase and PEPCase activities of Fengdan 3 and Zhengdan 958 leaves had different temperature sensitivity. For Fengdan 3, its leaf RuBPCase and PEPCase activities were high in early grain filling period (0-20 days after anthesis), and the variety could ripen in temperature-limited region. For Zhengdan 958, its leaf RuBPCase and PEPCase activities were high within 0-10 days and 40-60 days after anthesis but not sensitive to the active accumulated temperature during 10-40 days after anthesis, and the variety could not ripen in temperature-limited region. The photosynthetic rates of the two varieties were significantly positively correlated with the active accumulated temperature during 0-10 days and 30-40 days after anthesis. The effects of the accumulated temperature in the three zones on the photosynthetic performances were significant at both early and later grain filling stages. For the same varieties, the higher the active accumulated temperature in grain filling period, the higher the grain yield. Zhengdan 958 had higher yield than Fengdan 3. PMID:24066545

Chen, Chuan-Xiao; Dong, Zhi-Qiang; Gao, Jiao; Xu, Tian-Jun; Jiao, Liu; Lu, Lin; Zhang, Feng-Lu

2013-06-01

249

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

Microsoft Academic Search

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

Hans-Dieter Vosteen; Rdiger Schellschmidt

2003-01-01

250

Genotypic Variation in the Response to Suboptimal Temperature at Different Plant Densities in Cut Chrysanthemum  

Microsoft Academic Search

Energy efficiency of greenhouse cut chrysanthemum (Chrysanthemum morifolium Ramat.) may be increased by breeding. In addition to breeding for cultivars with a shorter reaction time at suboptimal temperatures, an alternative approach would be to develop cultivars that are heavier at suboptimal temperatures so that they could be grown at a higher plant density, enhancing the production per unit area. Therefore,

Ploeg van der A; S. M. P. Carvalho; E. Heuvelink

2009-01-01

251

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

Microsoft Academic Search

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( 1987) 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

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

1998-01-01

252

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

E-print Network

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.

Luis C. Barbado

2015-01-12

253

Fungal Communities Associated with the Biodegradation of Polyester Polyurethane Buried under Compost at Different Temperatures  

PubMed Central

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

Zafar, Urooj; Houlden, Ashley

2013-01-01

254

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

PubMed

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

Luoto, Tomi P; Nevalainen, Liisa

2013-01-01

255

Long-term rearing of Arctic charr Salvelinus alpinus under different salinity regimes at constant temperature.  

PubMed

Arctic charr Salvelinus alpinus of the Hlar strain (mean s.e. body mass = 1521 31 g) were reared at four different salinity regimes at a constant temperature of 74 C. Two groups were given a three-month acclimation in salinity 18 before the salinity was increased to either 25 or 29 (groups called A25 and A29), and two groups were reared in salinities 25 or 29 over the full experimental period of 409 days (groups called F25 and F29). In the first 3 months, the A25 and A29 groups had the highest growth rates. By October 2011, there were no significant differences (two-way nested ANOVA, P > 005) in the mean body masses among A25, F25 and F29 (c. 1450 g), whereas A29 had a lower mean mass (1282 g). The growth in the last period from October 2011 to January 2012 was reduced by sexual maturation in the highest salinity regimes (A29 and F29), whereas fish in groups A25 and F25 showed high growth throughout the study. Males in all salinity groups had higher growth rates than females for the most part of the study, but the divergence between the sexes was most pronounced in the highest salinity regimes. All salinity groups showed distinct changes in Na(+) , K(+) -ATPase activity, with high activity in spring and summer, and lower activity in the autumn. Plasma sodium (Na(+) ) levels were stable indicating that none of the experimental groups had problems in maintaining hydromineral balance during the study. While plasma leptin levels were not affected by salinity regimes, it was noted that these levels were 13-30% higher in fish with empty guts compared with those having food in their gut at the time of sampling. This suggests a link between leptin levels and food intake, indicating that this hormone may play a role in food intake and energy allocation in fishes. PMID:25053158

Arnason, T; Gunnarsson, S; Imsland, A K; Thorarensen, H; Smradttir, H; Steinarsson, A; Gstavsson, A; Johansson, M; Bjrnsson, B Th

2014-10-01

256

Possibility of passive THz camera using for a temperature difference observing of objects placed inside the human body  

NASA Astrophysics Data System (ADS)

As it is well-known, application of the passive THz camera for the security problems is very promising way. It allows seeing concealed object without contact with a person and this camera is non-dangerous for a person. We demonstrate new possibility of the passive THz camera using for a temperature difference observing on the human skin if this difference is caused by different temperatures inside the body. We discuss some physical experiments, in which a person drinks hot, and warm, and cold water and he eats. After computer processing of images captured by passive THz camera TS4 we may see the pronounced temperature trace on skin of the human body. For proof of validity of our statement we make the similar physical experiment using the IR camera. Our investigation allows to increase field of the passive THz camera using for the detection of objects concealed in the human body because the difference in temperature between object and parts of human body will be reflected on the human skin. However, modern passive THz cameras have not enough resolution in a temperature to see this difference. That is why, we use computer processing to enhance the camera resolution for this application. We consider images produced by THz passive cameras manufactured by Microsemi Corp., and ThruVision Corp.

Trofimov, Vyacheslav A.; Trofimov, Vladislav V.; Kuchik, Igor E.

2014-06-01

257

Effect of different temperature-time combinations on lipid and protein oxidation of sous-vide cooked lamb loins.  

PubMed

Forty-five lamb loins were subjected to sous-vide cooking at different combinations of temperature (60, 70 and 80 C) and time (6, 12 and 24 h) to assess the effect on the oxidative stability of lipids and proteins. Heating induced both lipid and protein oxidation in lamb loins. Higher cooking temperature-time combinations increased conjugated dienes and decreased thiobarbituric reactive substances (TBARS) values and hexanal. Total protein carbonyls increased throughout time at all cooking temperatures considered, while ?-aminoadipic (AAS) and ?-glutamic semialdehydes (GGS) increased when cooking at 60 C but not at 80 C. Links between the decrease in secondary compounds from lipid oxidation due to cooking at higher temperatures and for longer times with the increased levels of 3-methylbutanal and greater differences between total protein carbonyls and AAS plus GGS were hypothesised. PMID:24295686

Roldan, Mar; Antequera, Teresa; Armenteros, Monica; Ruiz, Jorge

2014-04-15

258

Kinetic characterization of myoglobins from vertebrates with vastly different body temperatures.  

PubMed

Fish myoglobins are structurally distinct from the previously characterized mammalian myoglobins. Teleost fishes express generally lower levels of myoglobin than those found in mammals. Although the oxygen binding affinity is essentially the same as mammalian myoglobins, oxygen dissociation rates and carbon monoxide combination rates of the teleost myoglobins studied are significantly faster. Thus, the kinetic parameters of myoglobin from two Antarctic teleost species, measured close to their body temperature of -1 degree C, are comparable to those of mammalian myoglobins with higher body temperatures. These data suggest myoglobins from Antarctic teleosts may function at extreme environmental temperatures. PMID:9297803

Cashon, R E; Vayda, M E; Sidell, B D

1997-08-01

259

The effect of sub-zero temperatures on different lifestages of Lasioderma serricorne (F.) and Ephestia elutella (Hbner)  

Microsoft Academic Search

The effect of sub-zero temperatures on different lifestages of Lasioderma serricorne and Ephestia elutella was investigated as a means of disinfesting stored tobacco. Eggs, unacclimated cocoons and acclimated cocoons of L. serricorne were exposed to ?10C, ?15C and ?20C in insulated boxes. There was no adult emergence from eggs or unacclimated cocoons following exposure to the respective temperatures for 4h,

D. A. Collins; S. T. Conyers

2010-01-01

260

Differences in the catalytic mechanisms of mesophilic and thermophilic indole-3-glycerol phosphate synthase enzymes at their adaptive temperatures  

SciTech Connect

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.

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

261

Study of Single Mode Tapered Fiber-Optic Interferometer of Different Waist Diameters and its Application as a Temperature Sensor  

NASA Astrophysics Data System (ADS)

We have proposed a study on single-mode tapered optical fiber for temperature sensing application. A theoretical analysis and its experimental validation were carried out to study the taper profile for highly sensitive temperature sensor. Experiments were performed to observe a wavelength shift of transmission spectra with different taper profiles. The effects of taper profiles on the sensitivity of the sensor were also investigated. Our results indicate that the tapered fiber-based temperature sensor has sensitivity in the range of 0.01143 to 0.03406 nm/C. The findings also demonstrate that the sensor sensitivity can be adjusted with variation to the taper profile.

Yadav, T. K.; Mustapa, M. A.; Abu Bakar, M. H.; Mahdi, M. A.

2014-07-01

262

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

E-print Network

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

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

1980-01-01

263

Growth and biopigment accumulation of cyanobacterium Spirulina platensis at different light intensities and temperature  

PubMed Central

In order to find out optimum culture condition for algal growth, the effect of light irradiance and temperature on growth rate, biomass composition and pigment production of Spirulina platensis were studied in axenic batch cultures. Growth kinetics of cultures showed a wide range of temperature tolerance from 20 C to 40 C. Maximum growth rate, cell production with maximum accumulation of chlorophyll and phycobilliproteins were found at temperature 35 C and 2,000 lux light intensity. But with further increase in temperature and light intensity, reduction in growth rate was observed. Carotenoid content was found maximum at 3,500 lux. Improvement in the carotenoid content with increase in light intensity is an adaptive mechanism of cyanobacterium S.platensis for photoprotection, could be a good basis for the exploitation of microalgae as a source of biopigments. PMID:24031731

Kumar, Manoj; Kulshreshtha, Jyoti; Singh, Gajendra Pal

2011-01-01

264

Surface composition of high-nickel alloy after the impingement of atomic hydrogen at different temperatures  

NASA Astrophysics Data System (ADS)

Surface composition changes by incident atomic hydrogen have been investigated on Inconel samples. The samples have been exposed to thermal atomic hydrogen at temperatures of 100-400C and have been analyzed using Auger electron spectroscopy. Carbon, oxygen, and sulphur are the main impurities. At sample temperatures from 100 to 300C, the carbon concentration is significantly reduced by incident atomic hydrogen. An apparent cross section of this process has been determined. It increases from 110 to 170C by two orders of magnitude and is independent of temperature above 170C, being 2 10 -17cm 2. At 400C carbon migrates into the bulk. The disappearance of carbon is accompanied by the appearance of sulphur. We ascribe the appearance of sulphur at temperatures up to 300C to chemisorption-induced segregation. A relatively slow removal of oxygen was generally observed.

Seggern, J. v.; Tschersich, K. G.

1980-10-01

265

Effect of different temperatures on consumption of two spotted mite, Tetranychus urticae, eggs by the predatory thrips, Scolothrips longicornis.  

PubMed

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

Pakyari, Hajar; Enkegaard, Annie

2012-01-01

266

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

PubMed

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

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

2013-10-01

267

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

Microsoft Academic Search

Cold-active burbot (Lotalota (L.)) display reduced food intake during the summer. The impact of temperature on their energy budget was investigated in\\u000a starved fish in a laboratory setting, simulating summer (20C) and winter (4C) conditions, to elucidate the impact of high\\u000a temperature on burbot metabolism. Metabolic effects in burbot were compared to roach (Rutilusrutilus (L.)), which typically fast in winter.

Maaike Binner; Werner Kloas; Iris Hardewig

2008-01-01

268

The use of a DNA stabilizer in human dental tissues stored under different temperature conditions and time intervals  

PubMed Central

Objective The present study evaluated the use of a reagent to stabilize the DNA extracted from human dental tissues stored under different temperature conditions and time intervals. Material and Methods A total of 161 teeth were divided into two distinct groups: intact teeth and isolated dental pulp tissue. The samples were stored with or without the product at different time intervals and temperature. After storage, DNA extraction and genomic DNA quantification were performed using real-time PCR; the fragments of the 32 samples that represented each possible condition were analyzed to find the four pre-selected markers in STR analysis. Results The results of the quantification showed values ranging from 0.01 to 10,246.88 ng/?L of DNA. The statistical difference in the quantity of DNA was observed when the factors related to the time and temperature of storage were analyzed. In relation to the use of the specific reagent, its use was relevant in the group of intact teeth when they were at room temperature for 30 and 180 days. The analysis of the fragments in the 32 selected samples was possible irrespective of the amount of DNA, confirming that the STR analysis using an automated method yields good results. Conclusions The use of a specific reagent showed a significant difference in stabilizing DNA in samples of intact human teeth stored at room temperature for 30 and 180 days, while the results showed no justification for using the product under the other conditions tested. PMID:25141206

TERADA, Andrea Sayuri Silveira Dias; da SILVA, Luiz Antonio Ferreira; GALO, Rodrigo; de AZEVEDO, Aline; GERLACH, Raquel Fernanda; da SILVA, Ricardo Henrique Alves

2014-01-01

269

Changes in life history parameters of Rhopalosiphum maidis (Homoptera: Aphididae) under four different elevated temperature and CO2 combinations.  

PubMed

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 temperature (+4 degrees C). The elevated CO2 (700-750 microl/liter) reduced only the development time of fourth-instar nymph. The overall duration of nymphal stage was reduced in the second generation. Thus, the temperature was the dominant factor to development duration of corn leaf aphid. The fecundity of corn leaf aphid was significantly increased under the elevated temperature and CO2, as well as in the later generation. Elevated temperature and CO2 increased the number of alate production, which may enhance the aphid migration or dispersal and the spread of plant viruses. Corn leaf aphid had the highest intrinsic rate of increase under the elevated temperature and CO2 combination in the second generation. These results indicate that the combined effects of both elevated temperature and CO2 on aphid biology may exacerbate aphid damage on barley under the climate change in accompany with elevated temperature and CO2 level. PMID:25195429

Xie, Haicui; Zhao, Lei; Wang, Wenqiang; Wang, Zhenying; Ni, Xinzhi; Cai, Wanzhi; He, Kanglai

2014-08-01

270

Comparison of temperature increase in in vitro human tooth pulp by different light sources in the dental whitening process.  

PubMed

This work evaluated the increase in dental pulp temperature caused by different light sources, used in the dental whitening process, following the irradiation protocol from the light manufacturer. Human incisor, canine and premolar teeth were used. A whitening gel made of hydrogen peroxide 35% v/v and a condenser agent were applied to each tooth, on the vestibular surface, and was activated by five different light sources: photo-polymerizer with blue bandpass filtered halogen lamp (HL) (600 mW, lambda = 430-480 nm), blue light emitting diode (LED) (BL) (1 W, lambda = 470 nm), blue LED associated with infrared diode laser (BL+IL) (120 mW, lambda = 795 nm), green LED (GL) (600 mW, lambda = 530 nm) and green LED associated with infrared diode laser (GL+IL) (120 mW, lambda = 795 nm), with the equipment turned on, an exposure time of 1 min, and resting time of 30 s, repeated three times. The temperature was measured at the beginning and ending of exposure by a digital thermometer (type K thermocouple), placed inside the dental pulp chamber. Analyzing the mean temperature variation that occurred along the irradiation time, we found that the BL and BL+IL group presented the highest temperature variations, mainly in the incisor tooth. The GL and GL+IL presented the lowest temperature increase. The maximum temperature variation reached was 5.5 degrees C for the BL+IL in the incisor tooth. The HL presented a smaller temperature variation than the BL did, but it had a residual temperature when the light was off. The GL and GL+IL promoted a non-significant temperature increase, as low as 1 degrees C, even with total power equal to the that of the HL. PMID:18274815

Coutinho, Daniela Soares; Silveira, Landulfo; Nicolau, Renata Amadei; Zanin, Ftima; Brugnera, Aldo

2009-03-01

271

The study on characterizations of SrTiO3 thin films with different growth temperatures  

NASA Astrophysics Data System (ADS)

Strontium titanate (SrTiO3) thin films were deposited on cleaned p-type (1 0 0) oriented silicon substrates using radio frequency (RF) magnetron sputtering method at a substrate temperatures of 200 C, 300 C, 400 C and 500 C. During deposition, sputtering pressure (PS) was maintained at 3.9 10-3 Torr using argon (Ar) gas, and RF power (PRF) was set to a constant value of 100 W for all experiments. Crystalline quality, surface morphology and band gap of the films were investigated by X-ray diffraction (XRD) analysis, atomic force microscopy (AFM) and photoluminescence (PL) measurements. Experimental results showed crystalline quality, and surface morphology of the films were remarkably improved by high substrate temperature. In addition to above analyzes, SrTiO3/p-Si structure deposited at 500 C substrate temperature have been investigated using temperature dependent current-voltage (I-V-T) characteristics in the temperature range of 110-350 K by steps of 30 K due to its better characteristics. The ideality factor (n), barrier height (?b) and series resistance (Rs) values were extracted. Moreover, ?b and Rs values were recalculated using Norde's method.

K?nac?, B.; Ak?n, N.; Kars Durukan, ?.; Memmedli, T.; zelik, S.

2014-12-01

272

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

273

Ultrafast temperature jump in polymers: Phonons and vibrations heat up at different rates  

NASA Astrophysics Data System (ADS)

Optical calorimetry is used to study the dynamics of a polymer, poly-(methyl methylacrylate), (PMMA), subjected to a temperature jump which is faster than the time required for Boltzmann equilibrium. The temperature jump is produced by exciting a near-infrared dye embedded in the polymer with a 23 ps duration optical pulse. The magnitude of the temperature jump ?T was as large as 125 degrees. To attain such a large temperature jump with good spatial uniformity requires optical heating pulses which strongly saturate the heater dye absorption. A formalism is developed to quantitatively treat optical heating with saturation. The heat capacity of the polymer, Cpol, can be determined to an accuracy of 8% using this method. The temperature jump data could not be fit by assuming the polymer heats up in a single stage. A quasitemperature model with two-stage heating, where the dye first excites polymer phonons and then the phonons excite polymer vibrations by multiphonon up pumping, gave quantitative agreement. The data at several values of ?T were simultaneously fit using three adjustable parameters: ?vc, the molecular thermal conductivity for vibrational cooling of the heater dye; ?up, the molecular thermal conductivity for multiphonon up pumping; and Cpol. The value of ? vc was the same magnitude as ?th, the thermal conductivity of the polymer, despite the fact that the vibrational cooling process occurs on the 1 nm length scale. The value of ?up was 2 orders of magnitude smaller than ?th.

Wen, Xiaoning; Tolbert, William A.; Dlott, Dana D.

1993-09-01

274

Fracture Surface Analysis in HDPE Pipe Material Fatigued at Different Temperatures and Loading Frequencies  

NASA Astrophysics Data System (ADS)

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.

Khan, Zafarullah

2012-07-01

275

Low-temperature plastic deformation of AZ31 magnesium alloy with different microstructures  

NASA Astrophysics Data System (ADS)

The plastic deformation of AZ31 magnesium alloy under tension at temperatures of 4.2-295K is studied as a function of its microstructure following squeeze casting (SC) and after severe plastic deformation (SPD) by hot rolling and equal-channel angular pressing. SPD reduces the average grain size and creates a texture that favors basal-plane dislocation glide. It is found that plastic deformation becomes unstable (serrated) at temperatures of 4.2-25K and more stress jerks occur in the SPD polycrystal than in the SC alloy. The temperature dependence of the yield stress of the alloy is typical of thermally activated unpinning of dislocations from short-range barriers. The ratio of the yield stresses for the SPD and SC alloys at a given temperature is explained by hardening owing to a reduction in grain size and softening owing to a favorable texture. As the grain size is reduced, the rate of strain hardening of the alloy falls off, but its ductility (strain to fracture) increases because of the texture. The strain rate sensitivity of the alloy for T ?100K is independent of microstructure and is determined by intersections with forest dislocations. As the temperature is raised over 150-295K the strain rate sensitivity becomes greater owing to activation of dynamic recovery and an enhanced contribution from diffusion processes during plastic deformation of micrograined materials.

Estrin, Yu. Z.; Zabrodin, P. A.; Braude, I. S.; Grigorova, T. V.; Isaev, N. V.; Pustovalov, V. V.; Fomenko, V. S.; Shumilin, S. E.

2010-12-01

276

First Electrical Characterization of Prototype 600 A HTS Twisted-pair Cables at Different Temperatures  

NASA Astrophysics Data System (ADS)

Following the development of twisted-pair cables prepared with High Temperature Superconducting (HTS) tapes and their initial tests at 4.2 K in liquid helium at CERN, the cable samples of 2 m lengths were subsequently tested in flowing helium gas at temperatures between 10 K and 77 K at University of Southampton. A cryostat with optimized hybrid HTS current leads was purposely built for the tests up to 2.5 kA. The cryostat has two separate helium flow conduits, each accommodating a twisted pair and allowing independent temperature control. With the completion of the tests on the twisted-pair cables, a 5 m long semi-flexible Nexans cryostat was also set up for the testing of prototype HTS links assembled at CERN. The link, which is optimized for application to the remote powering of LHC 600 A electrical circuits, consists of a compact multi-cable assembly with up to 25 twisted-pair 600 A HTS tapes. The cables are cooled by a forced-flow of helium gas the inlet temperature of which can be changed in order to compare the electrical performance over a range of temperatures. The paper reports on the results of powering tests performed on the individual cables and the integration process for the forthcoming tests of the prototype links.

Yang, Y.; Young, E. A.; Bailey, W. O. S.; Beduz, C.; Ballarino, A.

277

Influence of light history on the photosynthetic and motility responses of Gymnodinium chlorophorum exposed to UVR and different temperatures.  

PubMed

In the wake of global climate change, phytoplankton productivity and species composition is expected to change due to altered external conditions such as temperature, nutrient accessibility, pH and exposure to solar visible (PAR) and ultraviolet radiation (UVR). The previous light history is also of importance for the performance of phytoplankton cells. In order to assess the combined impacts of UVR and temperature on the dinoflagellate Gymnodinium chlorophorum we analyzed the effective photochemical quantum yield (Y), relative electron transport rate vs. irradiance curves (rETR vs. I), percentage of motile cells and swimming velocity. Cells were grown at three different temperatures (15, 20 and 25 C) and two PAR intensities: low light (LL, 100 ?mol photons m(-2) s(-1)) and high light (HL, 250 ?mol photons m(-2) s(-1)). Pre-acclimated cells were then exposed to either PAR only (P), PAR+UV-A (PA) or PAR+UV-A+UV-B (PAB) radiation at two different irradiances, followed by a recovery period in darkness. The Y decreased during exposure, being least inhibited in P and most in PAB treatments. Inhibition was higher and recovery slower in LL-grown cells than in HL-grown cells at 15 and 20 C, but the opposite occurred at 25 C, when exposed to high irradiances. Maximal values of rETR were determined at t0 as compared to the different (before and after exposure) radiation treatments. The effects of temperature and UVR on rETR were antagonistic in LL-grown cells (i.e., less UVR inhibition at higher temperature), while it was synergistic in HL cells. Swimming velocity and percentage of motile cells were not affected at all tested temperatures and exposure regimes, independent of the light history. Our results indicate that, depending on the previous light history, increased temperature and UVR as predicted under climate change conditions, can have different interactions thus conditioning the photosynthetic response of G. chlorophorum. PMID:24998868

Hder, Donat-P; Richter, Peter R; Villafae, Virginia E; Helbling, E Walter

2014-09-01

278

Similarities and differences between the low-temperature acoustic properties of crystalline materials and glasses  

NASA Astrophysics Data System (ADS)

We report on measurements of the acoustic properties of single crystals of alkali halides and aluminum, and polycrystalline copper at kHz frequencies and temperatures down to 8 mK. The goal of this study was to examine in several crystals with a small number of defects the presence and influence of two-level tunneling systems which commonly govern the low-temperature behavior of amorphous solids. The samples were investigated using vibrating reed and torsional oscillator techniques. In contrast to recent reports on glasslike behavior for a large variety of pure polycrystalline metals, our results confirm the ``traditional'' point of view that the low-temperature acoustic properties of pure monatomic crystals can be well distinguished from those of amorphous solids.

Classen, J.; Hbner, M.; Enss, C.; Weiss, G.; Hunklinger, S.

1997-10-01

279

Laminar flow of a gas in a tube with large temperature differences  

NASA Astrophysics Data System (ADS)

The laminar low Mach number flow of a gas in a tube is analyzed for very small and very large values of the inlet-to-wall temperature ratio. When this ratio tends to zero, pressure forces confine the cold gas to a thin core around the axis of the tube. This core is neatly bounded by an ablation front that consumes it at a finite distance from the tube inlet. When the temperature ratio tends to infinity, the temperature of the gas increases smoothly from the wall to the axis of the tube and the shear stress and heat flux are positive at the wall despite the fact that the viscosity and thermal conductivity of the gas scaled with their inlet values tend to zero at the wall.

Higuera, F. J.

2011-12-01

280

HA/Bioglass composite films deposited by pulsed laser with different substrate temperature  

NASA Astrophysics Data System (ADS)

In this experiment, the HA/Bioglass composite films on Ti-6Al-4V were deposited by a pulsed laser at Ar atmosphere, and the influence of substrate temperature on the morphology, phase constitutions, bonding configurations and adhesive strength of the films was studied. The obtained films were characterized by an electron probe microanalyzer (EPMA), scanning electron microscope (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR), scratch apparatus, and so on. The results show that the amount of the droplets, the crystallinity, and the critical load of the deposited films all increase with the increase of the substrate temperature; however, the substrate temperature has little influence on the functional groups of the films.

Wang, D. G.; Chen, C. Z.; Jin, Q. P.; Li, H. C.; Pan, Y. K.

2014-03-01

281

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

PubMed

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

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

2014-03-01

282

Detonation initiation of JP-8-oxygen mixtures at different initial temperatures  

NASA Astrophysics Data System (ADS)

Liquid fuel with sufficient vapor proportion at micron scale is essentially required to increase specific energy density and reduce volume requirements for application of pulse detonation engine. For JP-8, the fully vaporized temperature ranges from 380 to 410 K. In this study, the fuel vapor with oxygen is not enough to induce the reaction and leads to failure of detonation initiation at the initial temperature of 373 K. Condensed fuel was also observed on the bottom of detonation tube. At 393 K, the detonation wave was successfully generated even though a portion of fuel was in a liquid state. The deflagration-to-detonation run-up distance and the pressure trace at fully vaporized conditions, in which the initial temperatures were at 413, 433, and 453 K, were similar to those of gaseous mixtures, such as propane-oxygen mixture.

Wen, C.-S.; Chung, K.-M.; Lai, W.-H.

2012-09-01

283

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

PubMed Central

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

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

2013-01-01

284

AC-Mode Short-Wavelength IR Radiation Thermometers for Measurement of Ambient Temperatures  

NASA Astrophysics Data System (ADS)

Recent improvements in the fabrication of short-wave infrared (SW-IR) quantum detectors have opened a new era in radiation thermometry. Ambient and higher temperatures can be measured with low uncertainties using thermoelectrically (TE) cooled extended-InGaAs (E-IGA) and short-wave photovoltaic-HgCdTe (SW-MCT) detectors. Since these detectors have low cut-off wavelengths (2.5 ?m and 2.8 ?m, respectively), they do not respond past cut-off and are less sensitive to the background infrared radiation, resulting in orders of magnitude lower background noise than traditional broad-band infrared detectors such as cryogenically cooled quantum detectors or thermal detectors. At the same time, the cut-off is far enough in the infrared to obtain a large enough signal from the source of interest. Because of the low detector cut-off wavelength, traditional glass-based optics can be used in the radiation thermometers. A chopper-produced alternating-current (AC) signal was used to measure low temperatures by separating the AC signal from the background-radiation-produced direct-current (DC) signal and its fluctuations. Design considerations and characteristics of a newly developed SW-IR radiation thermometer are discussed. A noise-equivalent temperature difference (NETD) of < 3mK for a 50C blackbody was measured. At the human body temperature of 36C, the obtained NETD of ~10mK indicates that these detectors can be used in non-contact temperature measurements to replace thermopile- or pyroelectric-based radiation thermometers.

Eppeldauer, G. P.; Yoon, H. W.

2008-06-01

285

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

Microsoft Academic Search

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

Carol Becker Lynch; Joseph P. Hegmann

1972-01-01

286

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

287

DNA COMET ASSAY TO IDENTIFY DIFFERENT FREEZING TEMPERATURES OF IRRADIATED LIVER CHICKEN  

Microsoft Academic Search

The cold chain is a succession of steps which maintain the food at low temperature. The thawed food never be frozen again and the best solution being to consume it quickly to avoid the microorganism growth which causes decay and nutrients damage. One of most important point is that freezing process, unlike irradiation, do not destroy microorganisms, only inactive them

Renato C. Duarte; Michel A. Mozeika; Gustavo B. Fanaro; Eric Marchioni; Anna L. C. H. Villavicencio

288

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...

289

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

Microsoft Academic Search

C-chlorpyrifos was uniformly higher in Cinygma than in Sigara in all experiments. These findings suggest that organisms with relatively large exchange epithelial surface areas are potentially more vulnerable to both osmoregulatory distress as well as contaminant accumulation. Temperature increases appear more likely to impact organisms that have relatively large exchange epithelial surface areas, both as an individual stressor and in

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

2003-01-01

290

Polyamide-6: The effects on mechanical and physicochemical properties by electron beam irradiation at different temperatures  

NASA Astrophysics Data System (ADS)

The electron beam irradiation of polyamide-6 (PA-6) films was carried out in air over a range of 50-1000 kGy at varying temperatures and a dose rate of 5.1 kGy min-1. The effects of the irradiation at temperatures above and below the glass transition temperature (Tg) on the thermal and mechanical properties were studied. Melting and crystallization temperatures decreased significantly with the increase in irradiation dose, whereas percent of crystallinity varied only slightly and Tg slightly increased for irradiated samples respect to non irradiated one with no significant effect of the dose. Mechanical properties were affected by irradiation. The material became more rigid with a direct relationship between the mechanical properties and the irradiation dose. The irradiation above Tg led to a larger variation in the thermal and mechanical properties respect to the irradiation below Tg. The changes in properties were related to the crosslinking produced in the amorphous part of the polymer by the electron beam irradiation.

Adem, E.; Burillo, G.; del Castillo, L. F.; Vsquez, M.; Avalos-Borja, M.; Marcos-Fernndez, A.

2014-04-01

291

Evaluation of glycerol intermolecular free lengths at different temperatures by a thermo-acoustic approach  

NASA Astrophysics Data System (ADS)

The mean intermolecular free length in glycerol is estimated over a wide range of temperatures by making use of thermo-acoustical parameters followed by measurements of glycerol surface tension. To achieve this objective, the glycerol surface tension is measured by using video digital image processing techniques to extract the entire experimental drop profile with subsequent numerical procedures based upon the Laplace equation of capillarity. Glycerol surface tension measurements are extended from 10C - 90C with a step of 10C. The developed model for the evaluation of the glycerol intermolecular free length requires the estimate of the glycerol internal pressure which is derived, in this study, from the Tait equation by exploiting the glycerol nonlinearity parameter and further glycerol properties already measured in a previous study. The experimental results show that the mean intermolecular free length increases, with rise in temperature, from a small value. Inversely, the internal pressure decreases by increasing temperature which describes perfectly the dispersion part of cohesion and reflects the molecular ordering of glycerol versus temperature.

Khelladi, Hassina; Plantier, Frdric; Daridon, Jean Luc

2012-05-01

292

RESPONSES OF LARGEMOUTH BASS FROM DIFFERENT LATITUDES TO ELEVATED WATER TEMPERATURES  

EPA Science Inventory

The effects of elevated temperatures on largemouth bass (Micropterus s. salmoides), from Minnesota and Wisconsin (our northern stock) and from Tennessee (our southern stock), were compared at four first-year life stages. The purpose of these tests was to determine the degree of a...

293

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

Microsoft Academic Search

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

Preben Aagaard Nielsen; Martin Vahl; Jrn Gry

1988-01-01

294

SEASONAL DIFFERENCES IN CLEAR-SKY NIGHTTIME FORAGE TEMPERATURE IN PROXIMITY TO DECIDUOUS TREES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Considerable research has been done on daytime forage shading by silvopasture trees since solar radiation is required for photosynthesis. However, trees also impact nighttime temperature on clear nights when trees also effectively shade forages from cold skies. Appalachia has a temperate climate a...

295

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...

296

CFD Simulation of High Temperature Air Combustion of Coal Gas at Different Air Straddle Angle  

Microsoft Academic Search

Numerical simulation was carried out on the High Temperature Air Combustion of coal gas in an industrial furnace with a multi-jet burner. A Beta-function PDF (Probability Density Function) combustion model was selected to simulate the gas combustion combined with the standard k-? turbulent model. The radiation was simulated by a Discrete Ordinates method. Thermal NOx model was used to calculate

Yaxin Su; Bingtao Zhao

2010-01-01

297

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

Microsoft Academic Search

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

Carol A. Lemm; Donald V. Rottiers

1986-01-01

298

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

NASA Astrophysics Data System (ADS)

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.

Hashem, Khaled M. E.

2003-07-01

299

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

Microsoft Academic Search

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

Li Jing; Pei Gang; Ji Jie

2010-01-01

300

Tenderizing Squid Mantle by Marination at Different pH and Temperature Levels  

Microsoft Academic Search

The very tough muscle tissues of broadtail shortfin squid (Illex coindetii) cause considerable marketing limitations. A tenderizing process involving the activation of squid mantle intramuscular proteases to counteract this problem was investigated. The effects of pH, temperature, and incubation time on the final texture of squid mantle rings were assessed by tensile tests, where strain was measured for given levels

A. Collignan; D. Montet

1998-01-01

301

Final optical density and growth rate; effects of temperature and NaCl differ from acidity  

Microsoft Academic Search

Most predictive models used in food microbiology accurately describe microbial growth rate responses to conditions in the environment, but do not improve understanding of mechanisms. The effects of temperature, water activity and acid constraints on the growth of Escherichia coli are investigated using substrate-limited batch culture experiments. Final optical densities of substrate-limited batch cultures indicate the efficiency of substrate conversion

Karen A Krist; Thomas Ross; Thomas A McMeekin

1998-01-01

302

SURVIVAL AND GROWTH OF LARVAE OF THE EUROPEAN OYSTER (OSTREA EDULIS L.) AT DIFFERENT TEMPERATURES  

Microsoft Academic Search

A small number of European oysters ( Ostrea edulis) was imported into the United States in 1949 for a study of the adaptability of this species to our waters. It was hoped that this oyster might be suitable for colder areas because in its northern range the European oyster reproduces at temperatures too low for the American oyster (Crcssostrea virginica)

HARRY C. DAVIS; ANTHONY CALABRESE

303

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

SciTech Connect

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.

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

304

Effects of injection molding weld on fatigue crack resistance of CPVC at different temperatures  

Microsoft Academic Search

This study addresses the effects of injection molding weld line on the fatigue crack resistance of commercial CPVC in the temperature range of ?10 to 70C. Fatigue crack growth (FCG) tests were conducted on SEN specimens prepared from 100mm. injection molded pipe-fittings with and without weld line. Crack growth behavior was studied using LEFM concepts where the stress intensity factor

N. Merah; M. Irfan-ul-Haq; Z. Khan

2004-01-01

305

Temperature  

NASA Technical Reports Server (NTRS)

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.

Berenson, P. J.; Robertson, W. G.

1973-01-01

306

Antenna noise temperatures of the 34-meter beam-waveguide antenna with horns of different gains installed at F1  

NASA Technical Reports Server (NTRS)

This article presents a set of theoretical and measured zenith-antenna noise temperatures at 8.45 GHz for the DSS-13 34-m beam-waveguide antenna when horns of different gains are installed at F1. The methodology for calculations is shown in detail. The major differences between calculated and measured values are attributed to changes in subreflector support leg scattering when illuminated by the various horns.

Otoshi, T. Y.; Lee, P. R.; Franco, M. M.

1994-01-01

307

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

Microsoft Academic Search

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

Bao-Lin Wang; Zhen-Hui Tian

2005-01-01

308

Effects of Cyclic Loading, Freeze-Thaw and Temperature Changes on Shear Bond Strengths of Different Concrete Repair Systems  

Microsoft Academic Search

An experimental study was performed to evaluate the residual shear bond strengths between different cementitious and resinous repair materials and substrate concrete after being subjected to cyclic loading, freeze-thaw, and temperature changes. In this paper, techniques and results of test methods that induce shear along the repair\\/concrete interface are discussed. In addition to the effect of surface preparation on the

Mahmood Naderi

2008-01-01

309

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

310

The effects of different temperature and salinity levels on the acute toxicity of zinc in the Pink Shrimp (Farfantepenaeus paulensis)  

Microsoft Academic Search

The purpose of this study was to measure the acute toxicity of zinc (Zn) on Farfantepenaeus paulensis at different salinities and temperatures by monitoring oxygen consumption. This aspect of the effect of zinc has not been studied in this important commercial species before. First, we examined the acute toxicity of zinc in F. paulensis at 24, 48, 72, and 96?h

Edison Barbieri; Snia Assami Doi

2011-01-01

311

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...

312

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

NASA Technical Reports Server (NTRS)

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

Anderson, Nels; Watson, William D.

1990-01-01

313

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

SciTech Connect

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.

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

2010-03-01

314

Flow and fracture behaviour of FV535 steel at different triaxialities, strain rates and temperatures  

Microsoft Academic Search

The new generation jet engines operate at highly demanding working conditions. Such conditions need very precise design which implies an exhaustive study of the engine materials and behaviour in their extreme working conditions. With this purpose, this work intends to describe a numerically-based calibration of the widely-used JohnsonCook fracture model, as well as its validation through high temperature ballistic impact

B. Erice; F. Glvez; D. A. Cendn; V. Snchez-Glvez

315

Osmoregulation in Atlantic salmon Salmo salar smolts transferred to seawater at different temperatures.  

PubMed

In order to investigate how changes in gill Na(+) , K(+) -ATPase (NKA) ?1a and ?1b subunits, Na(+) , K(+) , 2Cl(-) co-transporter (NKCC1) and the apical cystic fibrosis trans-membrane conductance regulator-I (CFTR-I) transcripts in wild strain of Atlantic salmon, Salmo salar, smolts are affected by temperature during spring, hatchery-reared parr (mean s.e. fork length = 141 05; mean s.e. body mass = 285 45 g) originating from broodstock from the Vosso river (western Norway) were acclimated to three temperature regimes (41, 81 and 129 C) in May and reared under gradually increasing salinity between May and June. Changes in plasma Na(+) , haematocrit (Hct) and PCO2 were monitored in order to assess and compare key physiological changes with the transcriptional changes in key ion transporters. The temperatures reflect the natural temperature range in the River Vosso during late spring. Overall, higher gill NKA ?1b mRNA levels, gill NKCC1a levels and CFTR-I levels were observed in the 41 C group compared to the 119 C group. This coincided with a 2-3 week period with decreased Hct and PCO2 and may indicate a critical window when smolts suffer from reduced physical performance during migration. Further research is needed to confirm the potential interaction between ecological and physiological conditions on mortality of hatchery-reared smolts from River Vosso during their natural migration. PMID:25098608

Handeland, S O; Imsland, A K; Nilsen, T O; Ebbesson, L O E; Hosfeld, C D; Pedrosa, C; Toften, H; Stefansson, S O

2014-10-01

316

Investigation on early divergence between populations of Drosophila melanogaster kept at different temperatures  

Microsoft Academic Search

An experiment was performed on Drosophila melanogaster populations kept at two temperatures (25C and 28C) with the aim of providing further evidence that:1phenotypic differentiation between the two populations is already detectable in earlier generations of selection;2the divergence is more related to a changed body shape than to body size;3this divergence is correlated with fitness and, therefore, natural selection may operate

S. Cavicchi; G. Giorgi; M. Mochi

1978-01-01

317

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...

318

Acid tolerance in Salmonella typhimurium induced by culturing in the presence of organic acids at different growth temperatures.  

PubMed

The influence of growth temperature and acidification of the culture medium up to pH 4.25 with acetic, citric, lactic and hydrochloric acids on the growth and subsequent acid resistance at pH 3.0 of Salmonella typhimurium CECT 443 was studied. The minimum pH value which allowed for S. typhimurium growth within the temperature range of 25-37 degrees C was 4.5 when the pH was reduced using citric and hydrochloric acids, and 5.4 and 6.4 when lactic acid and acetic acid were used, respectively. At high (45 degrees C) or low (10 degrees C) temperatures, the growth pH boundary was increased about 1 pH unit. The growth temperature markedly modified the acid resistance of the resulting cells. In all cases, D-values were lower for cells grown at 10 degrees C and significantly increased with increasing growth temperature up to 37 degrees C, at which D-values obtained were up to 10 times higher. Cells grown at 45 degrees C showed D-values similar to those found for cells grown at 25 degrees C. The growth of cells in acidified media, regardless of the pH value, caused an increase in their acid resistance at the four incubation temperatures, although the magnitude of the Acid Tolerance Response (ATR) observed depended on the growth temperature. Acid adapted cultures at 10 degrees C showed D-values ranging from 5.75 to 6.91 min, which turned out to be about 2 times higher than those corresponding to non-acid adapted cultures, while higher temperatures induced an increase in D-values of at least 3.5 times. Another finding was that, while at 10 and 45 degrees C no significant differences among the effect of the different acids tested in inducing an ATR were observed, when cells were grown at 25 and 37 degrees C citric acid generally turned out to be the acid which induced the strongest ATR. Results obtained in this study show that growth temperature is an important factor affecting S. typhimurium acid resistance and could contribute to find new strategies based on intelligent combinations of hurdles, which could prevent the development or survival of Salmonella spp. in foods. The fact that moderately low temperatures (10 degrees C) markedly decrease the acid resistance and increase the growth pH boundary of S. typhimurium suggests the convenience to control the temperature during food processing as a strategy to prevent the growth and survival of this pathogenic microorganism. PMID:19913691

Alvarez-Ordez, Avelino; Fernndez, Ana; Bernardo, Ana; Lpez, Mercedes

2010-02-01

319

[Biological efficacy and persistence of biphenthrin sprayed on maize at different grain temperatures].  

PubMed

The objective of this work was to evaluate the immediate and latent effects of the grain temperature, during the spraying process, on the persistence and biological efficacy of the biphenthrin insecticide against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). For such, biphenthrin was sprayed on the grain at the temperatures: 25, 30, 35, 40 and 45 degrees C. To access the persistence of biphenthrin, insecticide residue analyses were carried out monthly, just after spraying until 90 days of storage. To evaluate the biological efficacy of biphenthrin, 20 adults of each species were placed in petri dishes with sprayed grain, and kept in climate cabinets under 27 degrees C and 55% of RH, during 48h. Evaluations were done every 15 days, starting just after spraying and finishing at 90 days of storage. Both persistence and biological efficacy of biphenthrin reduced as storage time and grain temperatures increased. Additionally, S. zeamais was more tolerant to biphenthrin than T. castaneum. PMID:17348140

Silveira, Rodrigo D; Faroni, Lda R A; Pimentel, Marco A G; Peternelli, Luiz A; Zocolo, Guilherme

2006-01-01

320

Measurements of Sr/Ca in bones to evaluate differences in temperature  

NASA Astrophysics Data System (ADS)

Analysis of aragonite from sea shells and coral skeletons showed a clear correlation between the strontium and calcium concentrations for these crystals (Sr/Ca ratio) and seawater temperature obtained by satellites and ship readings. In this work we present the results of a study that correlates Sr/Ca ratio with formation temperature of another calcium crystal, the hydroxyapatite (Ca 10(PO 4) 6(OH) 2), main mineral compound of teeth and bones from vertebrates. These animals, independent of its thermoregulation pattern (endothermic or ectothermic) have variations of internal temperature along the body. One interesting application of this work is to differentiate warm-blooded animals from cold-blooded ones just by measuring Sr/Ca ratio in their bones. Bones from a crocodile from Caiman yacare species and two dogs, a poodle and a non defined race, were analyzed using PIXE technique and thick target correction. A 1.78 (18) MeV external proton beam was used in LAMFI-USP with an accumulated charge of about 10 ?C for probing the samples. Emitted X-rays were collected using Si-PIN detectors (140 keV for Fe). As in coral skeletons, the Sr/Ca ratio of animals is lower in the body's warmer parts and higher in colder parts.

Santos, P. R.; Added, N.; Aburaya, J. H.; Rizzutto, M. A.

2008-04-01

321

Stability of methylcellulose-based films after being subjected to different conservation and processing temperatures.  

PubMed

Methylcellulose films with and without sorbitol addition were developed. The major objective of this study was to attempt insights into the stability of the methylcellulose-based film properties after having been subjected to freezing, storage or a combination of both procedures. The importance of the sorbitol concentration and process temperature was also to be elucidated. As-prepared film solubility decreased at 100 C, as a result of the methylcellulose thermogelation property when the samples were exposed to high temperatures. By analyzing the film pattern behavior and its properties 0.25% w/v sorbitol concentration turned out to be an inflexion point. The moisture content as well as the mechanical and thermal properties made this fact evident. Moreover the elastic modulus (Ec) and glass transition temperature (Tg) did not undergo significant changes for higher plasticizer concentrations. The methylcellulose film properties remained more stable in the presence of sorbitol, which would act as a protective agent due to its hydrogen bonding capacity. This stability is crucial for film and coating applications in the food industry. PMID:23623115

Tavera Quiroz, M J; Lecot, J; Bertola, N; Pinotti, A

2013-07-01

322

Design and fabrication of a bidimentional microbolometer array for Terahertz detection characterized at different temperatures  

NASA Astrophysics Data System (ADS)

We present the design, micromachining and characterization of a bidimentional bolometer array for radiation detection in the 0.7-1.5 THz frequency range. The detector is based on a boron doped amorphous silicon film (a-Si-B:H). The film optimized for sensitivity enhancement was obtained using 500 sccm diborane flow with 95 nm thickness. The sensing layer was deposited using plasma enhanced chemical vapor deposition (PECVD) technique at low frequency on a 0.45 ?m thick silicon nitride membrane sustained by a micromachined frame in crystalline silicon. The design consists of four 5x5 bolometer arrays made by conventional lithography. The bolometer active area is 660 ?m x 420 ?m and the detector will operate as a focal plane array. The current-voltage characteristics present an ohmic behaviour; the temperature coefficient of resistance (TCR) was obtained by measuring the bolometer performance from room temperature down to liquid nitrogen temperature. The responsivity was measured under illumination from a black body radiating at 300, 500, 700, 900 and 1100 C, obtaining a value of R =1.17 x 10-2 A/W with a dark current of 4.43 x 10-9 A

Ordua-Daz, A.; Castillo-Domnguez, E.; Torres-Jacome, A.; De la Hidalga-Wade, F. J.; Trevio-Palacios, C. G.

2011-01-01

323

Effects of different application durations of ER:YAG laser on intrapulpal temperature change during debonding.  

PubMed

This study was done to determine the amount of lasing time required to remove ceramic brackets safely without causing intrapulpal damage by using Er:YAG laser with the scanning method. Part 1: 80 bovine mandibular incisors with ceramic brackets were randomly assigned into four groups of 20 as one control and three study groups. In the study groups, brackets were debonded after lasing for 3, 6, and 9 s, whereas debonding was performed without lasing in the control group. Shear bond strengths and ARI scores were also measured. Part 2: 30 human premolars with ceramic brackets were randomly divided into three groups of ten, as 3, 6, and 9s of lasing durations. Intrapulpal temperature was measured at the same lasing times by a thermocouple. Statistically significant lower shear bond strengths were found in study groups compared to the control. A negative correlation was seen between the bond strengths and ARI scores in such a way that, as the shear bond strengths decreased, the ARI scores increased. Temperature increases for all the study groups were measured below the 5.5C benchmark. All lasing times were effective for debonding without causing enamel tear outs or bracket failures. The temperature proportionally increased with the extension of the lasing duration. Six-second lasing by the scanning method using Er:YAG laser was found to be the most effective and safest way of removing the ceramic brackets without causing damage to the enamel and pulpal tissues. PMID:20535517

Nalbantgil, Didem; Oztoprak, M Oguz; Tozlu, Murat; Arun, Tlin

2011-11-01

324

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

PubMed

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

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

2014-12-01

325

Computation of temperature elevation in rabbit eye irradiated by 2.45-GHz microwaves with different field configurations.  

PubMed

This study calculated the temperature elevation in the rabbit eye caused by 2.45-GHz near-field exposure systems. First, we calculated specific absorption rate distributions in the eye for different antennas and then compared them with those observed in previous studies. Next, we re-examined the temperature elevation in the rabbit eye due to a horizontally-polarized dipole antenna with a C-shaped director, which was used in a previous study. For our computational results, we found that decisive factors of the SAR distribution in the rabbit eye were the polarization of the electromagnetic wave and antenna aperture. Next, we quantified the eye average specific absorption rate as 67 W kg(-1) for the dipole antenna with an input power density at the eye surface of 150 mW cm(-2), which was specified in the previous work as the minimum cataractogenic power density. The effect of administrating anesthesia on the temperature elevation was 30% or so in the above case. Additionally, the position where maximum temperature in the lens appears is discussed due to different 2.45-GHz microwave systems. That position was found to appear around the posterior of the lens regardless of the exposure condition, which indicates that the original temperature distribution in the eye was the dominant factor. PMID:18188048

Hirata, Akimasa; Watanabe, Soichi; Taki, Masao; Fujiwara, Osamu; Kojima, Masami; Sasaki, Kazuyuki

2008-02-01

326

Production of oogonia and oospores of Leptolegnia chapmanii Seymour (Straminipila: Peronosporomycetes) in Aedes aegypti (L.) larvae at different temperatures.  

PubMed

The aquatic oomycete fungus Leptolegnia chapmanii Seymour is pathogenic to mosquito larvae, but it has been little studied since it was first isolated. Although studies have been performed on different biological isolates of L. chapmanii around the world, they were made on zoospores and a very little or even nothing is known about the sexual stage (oogonia and oospores), which allows L. chapmanii to remain in the environment when conditions are not favorable. The main objective of this study was to determine the relationship between temperature and time of onset of L. chapmanii oogonia and oospores in Ae. aegypti larvae. Leptolegnia chapmanii-infected IV instar Ae. aegypti larvae were incubated at different temperatures between 5 and 45 degrees C and photoperiod-controlled for 90 days. The number of oogonia and oospores was examined daily for each tested temperature. As was expected, low temperatures extended the times of oogonia formation, as much as seven times. Likewise, temperatures significantly affect the number of oogonia produced. PMID:19603285

Pelizza, S A; Scorsetti, A C; Lastra, C C Lpez; Garca, J J

2010-01-01

327

[Effects of temperature and illumination on flag leaf photosynthetic characteristics and senescence of wheat cultivars with different grain quality].  

PubMed

Taking wheat cultivars Yumai 34 (high protein content in grain) and Yangmai 9 (low protein content in grain) as test materials, and by the method of growth chamber, this paper studied the effects of different combinations of temperature and illumination on the photosynthetic characteristics and senescence of their flag leaves at grain-filling stage. The results showed that both high temperature and low illumination had negative effects on the photosynthesis. They decreased the net photosynthetic rate (Pn), photochemical efficiency (Fv/Fm), and actual photochemical efficiency (PhiPSII) significantly, but their action mechanisms were differed. High temperature mainly decreased the chlorophyll content (SPAD value) and Pn, while low illumination mainly decreased the chlorophyll fluorescence parameters Fv,/Fm and PhiPSII, and thus, inhibited the activity of PS II. High temperature increased the MDA content and decreased the soluble protein content and SOD activity, resulting in the acceleration of senescence, while low illumination increased the SOD activity and slowed down the senescence. Yumai 34 was more sensitive to high temperature and low illumination than Yangmai 9. PMID:18464636

Zhang, Li-Ping; Jing, Qi; Dai, Ting-Bo; Jiang, Dong; Cao, Wei-Xing

2008-02-01

328

Differences in the catalytic mechanisms of mesophilic and thermophilic indole-3-glycerol phosphate synthase enzymes at their adaptive temperatures.  

PubMed

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 25C for thermophilic IGPS, near its adaptive temperature (75C), 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 CO2 release, and the thermophilic IGPS-catalyzed reaction being rate limited afterwards. PMID:22274606

Zaccardi, Margot J; Mannweiler, Olga; Boehr, David D

2012-02-10

329

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

SciTech Connect

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

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

2010-05-15

330

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

PubMed Central

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

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

2014-01-01

331

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

SciTech Connect

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

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

2009-09-01

332

Differences in the metabolic response to temperature acclimation in nine-spined stickleback (Pungitius pungitius) populations from contrasting thermal environments.  

PubMed

Metabolic responses to temperature changes are crucial for maintaining the energy balance of an individual under seasonal temperature fluctuations. To understand how such responses differ in recently isolated populations (<11,000 years), we studied four Baltic populations of the nine-spined stickleback (Pungitius pungitius L.) from coastal locations (seasonal temperature range, 0-29C) and from colder, more thermally stable spring-fed ponds (1-19C). Salinity and predation pressure also differed between these locations. We acclimatized wild-caught fish to 6, 11, and 19C in common garden conditions for 4-6 months and determined their aerobic scope and hepatosomatic index (HSI). The freshwater fish from the colder (2-14C), predator-free pond population exhibited complete temperature compensation for their aerobic scope, whereas the coastal populations underwent metabolic rate reduction during the cold treatment. Coastal populations had higher HSI than the colder pond population at all temperatures, with cold acclimation accentuating this effect. The metabolic rates and HSI for freshwater fish from the pond with higher predation pressure were more similar to those of the coastal ones. Our results suggest that ontogenic effects and/or genetic differentiation are responsible for differential energy storage and metabolic responses between these populations. This work demonstrates the metabolic versatility of the nine-spined stickleback and the pertinence of an energetic framework to better understand potential local adaptations. It also demonstrates that instead of using a single acclimation temperature thermal reaction norms should be compared when studying individuals originating from different thermal environments in a common garden setting. PMID:25389079

Bruneaux, Matthieu; Nikinmaa, Mikko; Laine, Veronika N; Lindstrm, Kai; Primmer, Craig R; Vasemgi, Anti

2014-12-01

333

Laser-Induced Damage Threshold of TiO2 Films with Different Preparation Methods and Annealing Temperatures  

NASA Astrophysics Data System (ADS)

Sol-gel TiO2 films are prepared by the dip-coating method and the spin-coating method, and then annealing is performed at different temperatures. The structures, optical properties, surface morphologies, absorption and laser-induced damage threshold (LIDT) at 1064 nm and 12 ns of the films are investigated. The results show that the dip-coating method can be used to obtain a higher LIDT than the spin-coating method. When the annealing temperature increases from 80C to 120C, the dip-coated film obtains a higher LIDT, whereas the spin-coated film obtains a lower LIDT. In addition, the damage morphology is a spalling pit for the dip-coated film annealed at 80C. When the annealing temperature increases to 120C, it shows a melting area. For both the spin-coated films annealed at different temperatures, the damage morphologies are the combination of spalling and melting. The differences in LIDT and damage morphologies of the films are discussed.

Xu, Cheng; Yang, Shuai; Wang, Zhen; Deng, Jian-Xin; Zhao, Yu-Long; Fan, He-Liang; Qiang, Ying-Huai; Li, Da-Wei

2014-07-01

334

Combination of differential growth at two different temperatures with a quantitative real-time polymerase chain reaction to determine temperature-sensitive phenotype of Mycoplasma synoviae.  

PubMed

Mycoplasma synoviae infections result in significant economic losses in the chicken and turkey industries. A commercially available live temperature-sensitive (ts (+)) vaccine strain MS-H has been found to be effective in controlling M. synoviae infections in commercial layer and broiler breeder farms in various countries, including Australia. Detection and differentiation of MS-H from field strains (ts (-)) and from ts (-) MS-H reisolates in vaccinated flocks is vital in routine flock status monitoring. At present microtitration is the only available technique to determine the ts phenotype of M. synoviae. This technique is time consuming and not amenable to automation. In the present study, a quantitative real-time polymerase chain reaction (Q-PCR) was combined with simultaneous culturing of M. synoviae at two different temperatures (33C and 39.5C) to determine the ts phenotype of 22 Australian M. synoviae strains/isolates. The M. synoviae type strain WVU-1853 was also included for comparison. A ratio of the copy numbers of the variable lipoprotein haemagglutinin (vlhA) gene at the two temperatures was calculated and a cut-off value was determined and used to delineate the ts phenotype. In all M. synoviae strains/isolates tested in this study, the ts phenotype determined using Q-PCR was in agreement with that determined using conventional microtitration. Combination of Q-PCR with differential growth at two different temperatures is a rapid, reliable and accurate technique that could be used as an effective tool in laboratories actively involved in ts phenotyping of M. synoviae strains/isolates. PMID:23581447

Shahid, Muhammad A; Ghorashi, Seyed A; Agnew-Crumpton, Rebecca; Markham, Philip F; Marenda, Marc S; Noormohammadi, Amir H

2013-04-01

335

20. At different temperatures, for example, synthetic rutile accommodates nonstoichiometry through  

E-print Network

different types of defects, including vacancies, crystallographic shear planes, and planar fea- tures known, 1975). 30. P. W. McMillan, Glass-Ceramics (Academic Press, New York, ed. 2, 1979). 31. G. L. Nord, Jr

Noone, David

336

Carbon mineralization of flooded boreal soil and vegetation under different temperature and oxygen conditions  

NASA Astrophysics Data System (ADS)

Flooding of terrestrial ecosystems significantly alters carbon (C) mineralization rates, which results in increasing emissions of carbon dioxide (CO2) and methane (CH4). To better understand the changes after water impoundment, C mineralization under flooded conditions needs to be investigated. This study investigates CO2 and CH4 fluxes from flooded boreal soil and vegetation, compares them to the fluxes of non- flooded treatment, and examines how environmental factors affect the fluxes. We conducted short-term in vitro experiments using boreal forest soil (FH layer), peat soil (0 to 5 and 5 to 15 cm) layer, and black spruce needles and small twigs, and shrub, sedge, lichen, and moss tissues. Flooded samples were incubated in 1- L Mason jars without light, under three temperatures (5, 12, and 24degC) and 0 and 50 percent of ambient oxygen (O2) concentration, and non-flooded ones were incubated in 1-L plastic containers under same light and temperature conditions to those of flooded samples and ambient oxygen concentration. We collected gas samples after flushing with nitrogen gas and air, and the fluxes of CO2 and CH4 were determined by gas chromatography. The average CO2 and CH4 fluxes in all materials were 200 and 0.8 microgram C/g organic matter/day, with smaller CO2 fluxes and larger CH4 fluxes than the fluxes of non-flooding (CO2 and CH4: 370 and 0.2 microgram C/g organic matter/day). Among the flooded samples, forest and peatland ground vegetation showed much high CO2 fluxes, and peat soils released more CH4 than other materials. Higher temperatures increased emissions of both CO2 and CH4, and the lower O2 concentration increased CH4 emissions. These results suggest the flooded vegetation and peat soil largely contribute to the total C emission in the flooded ecosystem and that spatial and temporal variability in CO2 and CH4 emissions can be related to substrate type, temperature and O2 concentration.

Kim, Y.; Ullah, S.; Roulet, N.; Moore, T.

2009-05-01

337

Strain build-up in SiC implanted at different temperatures  

NASA Astrophysics Data System (ADS)

Single crystals of 4H-SiC were implanted with helium ions at temperatures of 400 and 700 C in a large range of fluences. The damage accumulation versus fluence was studied through the tensile elastic strain determined by using X-ray diffraction measurements. Results were analyzed via the multi-step damage accumulation model. At low dose (step 1) the strain can be described assuming a thermally activated process with low activation energy. Damage cross-sections, independent of implantation temperature, for interstitial-type defects were determined. With increasing dose, the contribution of other defects arises leading to an accelerated strain build-up namely the second step of the disordering process. However, in this regime, the strain cannot be fully described due to others operative mechanisms such as the formation of tiny bubbles under severe conditions of implantation. The formation of bubbles accelerates the development of the elastic strain. The values of damage cross-sections show that only small clusters contribute to the tensile elastic strain.

Barbot, J.-F.; Beaufort, M.-F.; Declmy, A.

2014-05-01

338

Transformation of synthetic allicin: the influence of ultrasound, microwaves, different solvents and temperatures, and the products isolation.  

PubMed

The transformation of the synthesized allicin, using conventional method, the influence of ultrasound and microwaves, in different organic solvents (acetonitrile, acetone, methanol, and chloroform), at various temperatures (room temperature, 45 C, and 55 C) was investigated. Allicin degradation kinetic was monitored by HPLC. Allicin transformation under the effect of microwaves is faster than transformations performed under the influence of ultrasound or by conventional method. Increase of the temperature accelerates allicin transformation. Pharmacologically active compounds of (E)-ajoene, (Z)-ajoene, 3-vinyl-4H-1,2-dithiin, 2-vinyl-4H-1,3-dithiin, and diallyl disulfide were isolated from the mixture of transformation products of allicin under the influence of microwaves in methanol at 55 C, which is according to kinetic parameters (highest values of the order of reaction and the lowest activation energy) the optimal method. PMID:22629145

Ili?, Duica; Nikoli?, Vesna; Stankovi?, Mihajlo; Nikoli?, Ljubia; Stanojevi?, Ljiljana; Mladenovi?-Ranisavljevi?, Ivana; Smelcerovi?, Andrija

2012-01-01

339

Transformation of Synthetic Allicin: The Influence of Ultrasound, Microwaves, Different Solvents and Temperatures, and the Products Isolation  

PubMed Central

The transformation of the synthesized allicin, using conventional method, the influence of ultrasound and microwaves, in different organic solvents (acetonitrile, acetone, methanol, and chloroform), at various temperatures (room temperature, 45C, and 55C) was investigated. Allicin degradation kinetic was monitored by HPLC. Allicin transformation under the effect of microwaves is faster than transformations performed under the influence of ultrasound or by conventional method. Increase of the temperature accelerates allicin transformation. Pharmacologically active compounds of (E)-ajoene, (Z)-ajoene, 3-vinyl-4H-1,2-dithiin, 2-vinyl-4H-1,3-dithiin, and diallyl disulfide were isolated from the mixture of transformation products of allicin under the influence of microwaves in methanol at 55C, which is according to kinetic parameters (highest values of the order of reaction and the lowest activation energy) the optimal method. PMID:22629145

Ili?, Duica; Nikoli?, Vesna; Stankovi?, Mihajlo; Nikoli?, Ljubia; Stanojevi?, Ljiljana; Mladenovi?-Ranisavljevi?, Ivana; melcerovi?, Andrija

2012-01-01

340

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

PubMed

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

Laepple, Thomas; Huybers, Peter

2014-11-25

341

Hole mobilities of periodic models of DNA double helices in the nucleosomes at different temperatures  

NASA Astrophysics Data System (ADS)

Using the Hartree-Fock crystal orbital method band structures of poly(G-C) and poly(A-T) were calculated (G, etc. means a nucleotide) including water molecules and Na+ ions. Due to the close packing of DNA in the ribosomes the motion of the double helix and the water molecules around it are strongly restricted, therefore the band picture can be used. The mobilities were calculated from the highest filled bands. The hole mobilities increase with decreasing temperatures. They are of the same order of magnitude as those of poly(A) and poly(T). For poly(G) the result is 5 times larger than in the poly(G-C) case.

Bende, Attila; Bogr, Ferenc; Ladik, Jnos

2013-04-01

342

Cavitation erosion of silver plated coating at different temperatures and pressures  

SciTech Connect

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

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

2014-04-11

343

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

PubMed

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

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

2013-10-01

344

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

PubMed

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

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

2014-10-15

345

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

PubMed

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

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

2014-01-01

346

Geopolymeric binders with different fine fillers Phase transformations at high temperatures  

Microsoft Academic Search

Geopolymers based on metakaolin were synthesised under addition of different fine filler materials. The material properties were measured after hardening and burning; especially strength, porosity and shrinkage. The phase transformation after burning was measured by X-ray diffraction and quantified.

Anja Buchwald; Mnica Vicent; Ralf Kriegel; Christian Kaps; Maria Monz; Antonio Barba

2009-01-01

347

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

ERIC Educational Resources Information Center

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

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

2009-01-01

348

Dust acoustic solitary waves in a dusty plasma with two kinds of nonthermal ions at different temperatures  

SciTech Connect

The nonlinear dust acoustic solitary waves in a dusty plasma with two nonthermal ion species at different temperatures is studied analytically. Using reductive perturbation method, the Kadomtsev-Petviashivili (KP) equation is derived, and the effects of nonthermal coefficient, ions temperature, and ions number density on the amplitude and width of soliton in dusty plasma are investigated. It is shown that the amplitude of solitary wave of KP equation diverges at critical points of plasma parameters. The modified KP equation is also derived, and from there, the soliton like solutions of modified KP equation with finite amplitude is extracted. Results show that generation of rarefactive or compressive solitary waves strongly depends on the number and temperature of nonthermal ions. Results of KP equation confirm that for different magnitudes of ions temperature (mass) and number density, mostly compressive solitary waves are generated in a dusty plasma. In this case, the amplitude of solitary wave is decreased, while the width of solitary waves is increased. According to the results of modified KP equation for some certain magnitudes of parameters, there is a condition for generation of an evanescent solitary wave in a dusty plasma.

Dorranian, Davoud; Sabetkar, Akbar

2012-01-15

349

Temperature dependence of APD-based PET scanners  

SciTech Connect

Purpose: Solid state detectors such as avalanche photodiodes (APDs) are increasingly being used in PET detectors. One of the disadvantages of APDs is the strong decrease of their gain factor with increasing ambient temperature. The light yield of most scintillation crystals also decreases when ambient temperature is increased. Both effects lead to considerable temperature dependence of the performance of APD-based PET scanners. In this paper, the authors propose a model for this dependence and the performance of the LabPET8 APD-based small animal PET scanner is evaluated at different temperatures.Methods: The model proposes that the effect of increasing temperature on the energy histogram of an APD-based PET scanner is a compression of the histogram along the energy axis. The energy histogram of the LabPET system was acquired at 21 C and 25 C to verify the validity of this model. Using the proposed model, the effect of temperature on system sensitivity was simulated for different detector temperature coefficients and temperatures. Subsequently, the effect of short term and long term temperature changes on the peak sensitivity of the LabPET system was measured. The axial sensitivity profile was measured at 21 C and 24 C following the NEMA NU 4-2008 standard. System spatial resolution was also evaluated. Furthermore, scatter fraction, count losses and random coincidences were evaluated at different temperatures. Image quality was also investigated.Results: As predicted by the model, the photopeak energy at 25 C is lower than at 21 C with a shift of approximately 6% per C. Simulations showed that this results in an approximately linear decrease of sensitivity when temperature is increased from 21 C to 24 C and energy thresholds are constant. Experimental evaluation of the peak sensitivity at different temperatures showed a strong linear correlation for short term (2.32 kcps/MBq/C = 12%/C, R = ?0.95) and long term (1.92 kcps/MBq/C = 10%/C , R = ?0.96) temperature changes. Count rate evaluation showed that although the total count rate is consistently higher at 21 C than at 24 C for different source activity concentrations, this is mainly due to an increase in scattered and random coincidences. The peak total count rate is 400 kcps at both temperatures but is reached at lower activity at 21 C. The peak true count rate is 138 kcps (at 100 MBq) at 21 C and 180 kcps (at 125 MBq) at 24 C. The peak noise equivalent count rate is also lower at 21 C (70 kcps at 70 MBq) than at 24 C (100 kcps at 100 MBq). At realistic activity levels, the scatter fraction is lower at higher temperatures, but at the cost of a strong decrease in true count rate.Conclusions: A model was proposed for the temperature dependence of APD-based PET scanners and evaluated using the LabPET small animal PET scanner. System sensitivity and count rate performance are strongly dependent on ambient temperature while system resolution is not. The authors results indicate that it is important to assure stable ambient temperature to obtain reproducible results in imaging studies with APD-based PET scanners.

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

2013-09-15

350

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

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

351

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

SciTech Connect

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

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

2012-07-25

352

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

353

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

PubMed

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

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

2014-05-01

354

The misfit dislocation density profile in graded SiGe/Si(001) layers prepared at different temperatures  

NASA Astrophysics Data System (ADS)

We present a generalization of the Dodson-Tsao kinematic model of misfit dislocation for graded SixGe1-x/Si(001) layers. The layers were prepared under different growing conditions (temperature). The misfit dislocation distribution has been determined by means of high-resolution x-ray scattering. Analysis of the reciprocal space maps was compared with the kinematic Dodson-Tsao model and the equilibrium Tersoff model.

Endres, J.; Dani, S.; Bauer, G.

2013-05-01

355

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

NASA Technical Reports Server (NTRS)

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.

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

356

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

SciTech Connect

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

Aflaki, R.; Handy, L.L.

1992-12-01

357

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

SciTech Connect

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

Aflaki, R.; Handy, L.L.

1992-12-01

358

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

USGS Publications Warehouse

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.

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

1988-01-01

359

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

PubMed Central

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

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

2009-01-01

360

Elevated CO2 mitigates drought and temperature-induced oxidative stress differently in grasses and legumes.  

PubMed

Increasing atmospheric CO2 will affect plant growth, including mitigation of stress impact. Such effects vary considerably between species-groups. Grasses (Lolium perenne, Poa pratensis) and legumes (Medicago lupulina, Lotus corniculatus) were subjected to drought, elevated temperature and elevated CO2. Drought inhibited plant growth, photosynthesis and stomatal conductance, and induced osmolytes and antioxidants in all species. In contrast, oxidative damage was more strongly induced in the legumes than in the grasses. Warming generally exacerbated drought effects, whereas elevated CO2 reduced stress impact. In the grasses, photosynthesis and chlorophyll levels were more protected by CO2 than in the legumes. Oxidative stress parameters (lipid peroxidation, H2O2 levels), on the other hand, were generally more reduced in the legumes. This is consistent with changes in molecular antioxidants, which were reduced by elevated CO2 in the grasses, but not in the legumes. Antioxidant enzymes decreased similarly in both species-groups. The ascorbate-glutathione cycle was little affected by drought and CO2. Overall, elevated CO2 reduced drought effects in grasses and legumes, and this mitigation was stronger in the legumes. This is possibly explained by stronger reduction in H2O2 generation (photorespiration and NADPH oxidase), and a higher availability of molecular antioxidants. The grass/legume-specificity was supported by principal component analysis. PMID:25575986

AbdElgawad, Hamada; Farfan-Vignolo, Evelyn Roxana; Vos, Dirk de; Asard, Han

2015-02-01

361

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

PubMed Central

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

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

1995-01-01

362

Microbial growth on broiler carcasses stored at different temperatures after air- or water-chilling.  

PubMed

Poultry meat has a high risk of contamination during its processing. Storage temperature, type of packaging, and types and numbers of psychrotrophic bacteria are the major factors determining the spoilage of poultry meat. Before packaging, poultry carcasses are chilled by air or water currents in commercial slaughterhouses. The packaging material and methods are other factors influencing the spoilage of poultry meat. Although unpackaged carcasses had lower production costs, they were found to contain high numbers of microorganisms. The unpackaged carcasses are often not recommended for food safety and public health risks. The present study examines the growth of some spoilage microorganisms on unpackaged carcasses and on broiler carcasses packaged in polyethylene bags or synthetic plates. The carcasses examined in this study were collected from the slaughterhouses of the Bolu region of Turkey. All carcasses were subjected to an air or water chilling process in the slaughterhouse and then stored at 0, 4, or 7 degrees C for 14 d. Samples were taken on d 0, 4, 8, 10, and 14 of storage and analyzed for total bacterial count, and for Pseudomonas spp., Enterobacteriaceae, yeasts, and molds. The carcasses packaged in synthetic plates or polyethylene bags and kept at 0 degrees C were microbiologically safer and had longer shelf life, so they are found to be the most reliable for consuming. The shelf life of broiler carcasses could be further increased by improving hygiene and sanitation procedures at the slaughterhouse. PMID:18340003

Tuncer, B; Sireli, U T

2008-04-01

363

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

E-print Network

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...

Barbado, Luis C

2015-01-01

364

Quality of fried broiler chicken leg muscles stored at different temperatures.  

PubMed

Chicken leg pieces (60 g each). with optimized quantity of additives were fried in hydrogenated vegetable oil at 180C for 8 min. The fried product was packed in paper-foil-polyethylene pouches (PFP) and stored under ambient (20 5C, 65-80% RH), refrigerator (5C, 80% RH) and deep freezer (-18C, 85-90% RH) conditions. The changes in microbial profile, oxidative and hydrolytic rancidity and sensory quality were evaluated periodically. It was found that the product was microbiologically (standard plate count (SPC) < 3 log cfu/g) safe and sensorily acceptable (overall acceptability >7) up to 4 days under ambient conditions. Hydrolytic and oxidative rancidity values during four days storage at room temperature were less than 0.16 % oleic acid and 3.5 mg malonaldehyde/kg, respectively. The products stored under refrigerated and deep freezer exhibited a shelf stability of 10 and 18 weeks, respectively. SPC was 1.3 log cfu/g while rancidity parameters were free fatty acid < 0.43% oleic acid and thiobarbituric acid reactive substances were <6.13 mg malonaldehyde/kg. Sensorily the product exhibited an overall acceptability score of >7 on a 9-point Hedonic scale during refrigerated and frozen storage. PMID:23572670

Pandey, M C; Manral, Mallika; Srihari, K A; Jayathilakan, K; Radhakrishna, K; Bawa, A S

2010-08-01

365

Pyrolysis behavior of tire-derived fuels at different temperatures and heating rates.  

PubMed

Pyrolytic product distribution rates and pyrolysis behavior of tire-derived fuels (TDF) were investigated using thermogravimetric analyzer (TGA) techniques. A TGA was designed and built to investigate the behavior and products of pyrolysis of typical TDF specimens. The fundamental knowledge of TGA analysis and principal fuel analysis are applied in this study. Thermogravimetry of the degradation temperature of the TDF confirms the overall decomposition rate of the volatile products during the depolymerization reaction. The principal fuel analysis (proximate and ultimate analysis) of the pyrolytic char products show the correlation of volatilization into the gas and liquid phases and the existence of fixed carbon and other compounds that remain as a solid char. The kinetic parameters were calculated using least square with minimizing sum of error square technique. The results show that the average kinetic parameters of TDF are the activation energy, E = 1322 +/- 244 kJ/mol, a pre-exponential constant of A = 2.06 +/- 3.47 x 10(10) min(-1), and a reaction order n = 1.62 +/- 0.31. The model-predicted rate equations agree with the experimental data. The overall TDF weight conversion represents the carbon weight conversion in the sample. PMID:16739798

Unapumnuk, Kessinee; Keener, Tim C; Lu, Mingming; Khang, Soon-Jai

2006-05-01

366

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

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

367

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

368

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

369

Ball Impact Reliability of Zn-Sn High-Temperature Solder Joints Bonded with Different Substrates  

NASA Astrophysics Data System (ADS)

In this study, the high-speed deformation behavior of solder joints formed with Pb-free Zn-Sn and commercial Pb-Sn alloys bonded on different substrates was investigated by the ball impact test method. Overall, Zn-Sn joints exhibited greater impact strength but inferior impact toughness than Pb-Sn joints. This can be ascribed to the high hardness of Zn-Sn solders resulting in partial or overall interfacial fracture. In contrast, the joints with soft Pb-Sn solders all showed a ductile fracture feature. It is suggested that, for the joints revealing brittle fracture, the impact toughness (impact energy) increased with the plastic ability of interfacial intermetallic compounds, while for those showing a ductile fracture mode, the impact energy deteriorated with a hardened solder matrix resulting from substrate dissolution.

Song, Jenn-Ming; Lin, Meng-Ju; Hsieh, Kun-Hung; Pai, Tsung-Yun; Lai, Yi-Shao; Chiu, Ying-Ta

2013-09-01

370

Characteristics of Oxidation-Reduction Potential, VFAs, SCOD, N, and P in an ATAD System Under Different Thermophilic Temperatures.  

PubMed

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 65C) in the one-stage ATAD. Results showed that the ORP values remained between approximately -350 and -120mV 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 55C 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 65C 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 65C could hinder its further use for land applications. Therefore, the optimal temperature of 55C is suitable for the ATAD process. PMID:25245680

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

2015-01-01

371

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

PubMed

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

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

2015-03-01

372

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

PubMed Central

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

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

2012-01-01

373

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

PubMed Central

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

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

2012-01-01

374

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

PubMed Central

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

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

2013-01-01

375

Sanitation ability of anaerobic digestion performed at different temperature on sewage sludge.  

PubMed

A small amount of ammonia is used in full-scale plants to partially sanitize sewage sludge, thereby allowing successive biological processes to enable the high biological stability of the organic matter. Nevertheless, ammonia and methane are both produced during the anaerobic digestion (AD) of sludge. This paper describes the evaluation of a lab-scale study on the ability of anaerobic process to sanitize sewage sludge and produce biogas, thus avoiding the addition of ammonia to sanitize sludge. According to both previous work and a state of the art full-scale plant, ammonia was added to a mixture of sewage sludge at a rate so that the pH values after stirring were 8.5, 9 and 9.5. This procedure determined an ammonia addition lower than that generally indicated in the literature. The same sludge was also subjected to an AD process for 60 days under psychrophilic, mesophilic and thermophilic conditions. The levels of fecal coliform, Salmonella spp. helmints ova, pH, total N, ammonia fractions and biogas production were measured at different times during each process. The results obtained suggested that sludge sanitation can be achieved using an AD process; however, the addition of a small amount of ammonia was not effective in sludge sanitation because the buffer ability of the sludge reduced the pH and thus caused ammonia toxicity. Mesophilic and thermophilic AD sanitized better than psychrophilic AD did, but the total free ammonia concentration under the thermophilic condition inhibited biogas production. The mesophilic condition, however, allowed for both sludge sanitation and significant biogas production. PMID:23973551

Scaglia, Barbara; D'Imporzano, Giuliana; Garuti, Gilberto; Negri, Marco; Adani, Fabrizio

2014-01-01

376

Effects of algae frozen at different temperatures on chronic assessment endpoints observed with Daphnia magna.  

PubMed

The Daphnia magna 21-day juvenile production test is not yet fully standardized because of many sources of variation. One is the diet provided to daphnids: the ration must be sufficient and the quality of algal cells must be optimal for achieving the required number of offspring defined by the new OECD guidelines. The experiments reported herein first examined the effects of Raphidocelis subcapitata after it had been maintained under four different conditions of storage (4, -20, -80, and -196 degrees C) on the survival, reproductive performance (over 21 days), and growth (ascertained by dry weight) of individually held D. magna for three generations. Under all of the four regimes tested, daphnids survived and reproduced in a manner which fulfilled the current OECD guidelines for a valid test, but the best results were obtained with fresh algae and algae frozen at -80 degrees C. Second, although D. magna has been widely used to determine toxicity of chemical substances, there are no reports in the literature that describe a rigorous study of the nutritional quality of the algae given to daphnids. Therefore, cell number, optical density, amount of organic carbon, and esterasic activity (assessed by intracellular breakdown of FDA to fluorescein) of algae that have been preserved at 4, -20, -80, and -196 degrees C were investigated. This part of the study indicated that freezing had no effect on cell numbers, in contrast to optical density, amount of organic carbon, and esterasic activity. First, it was found that esterasic activity was closely correlated to the reproductive performance of daphnids. It appears important, therefore, to consider the inclusion of this enzymatic activity as part of the routine quality control given to this microinvertebrate chronic procedure. PMID:8723750

Cotelle, S; Ferard, J F

1996-03-01

377

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

NASA Astrophysics Data System (ADS)

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

Schneider, Michael; Bittner, Achim; Schmid, Ulrich

2013-05-01

378

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

379

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

PubMed

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

Xiao, Xin; Chen, Baoliang; Zhu, Lizhong

2014-03-18

380

Volatile metabolites of higher plants cenoses as photosynthesizing LSS component under optimum conditions and temperature stress at different light intensities  

NASA Astrophysics Data System (ADS)

One of major yet still poorly known functions of the photosynthesizing component in life support system (LSS) is to improve the quality of air through volatile emissions (VE) of plants capable of accumulating in closed volumes, interacting between themselves and having favorable or adverse impact on humans. In all likelihood, the effect of stress changing the functional condition of plants is to be accompanied with alteration in composition and quantity of VE. There are practically no works dealing with effect of such environmental factors as light intensity and elevated air temperature on qualitative and quantitative composition of VE by higher plants' cenoses. Meanwhile experimental modeling and investigation of stability of man-made human life support systems make this problem of very important. The aim of this work is to experimentally evaluate relationship between qualitative and quantitative composition of VE and the functional condition of wheat cenoses as the basic culture of LSS photosynthesizing component under normal conditions and under temperature stress against light of different intensity. Effect of elevated temperature 35 and 45C (with the light intensity of 70, 150 or 240 W/m2 PAR) on photosynthesis, respiration, qualitative and quantitative composition of VE of wheat (Triticum aestuvi L., variety 232) cenoses was studied in the atmosphere of growth chambers. More than 20 volatile compounds (terpenoids - a pinene, +3 carene, limonene, benzene, a - and trans-caryophylene, a - and ?-terpinene, their derivatives, aromatic hydrocarbons, etc.) were qualitatively and quantitatively estimated by chromatomassspectroscopy (GC-MS). The light intensity of 240 W/m2 PAR at 35 increase, and at 45 - decrease of thermal stability of photosynthesis and respiration. Elevated temperatures resulted in non- uniform variation of the rate and direction of VE synthesis. VE was highest at irradiance 70 W/m 2 and lowest at 240 W/m2 and 35 . During the reparation period the content and the ratio of volatile emissions differed from the initial values. The degree of damage and subsequent recovery of the functional condition of a cenosis depended on the intensity of light during the exposure to elevated temperature. Besides, VE composition was determined in the atmosphere of the growth chamber without plants but with all construction materials, substrate and nutrient solution at the temperature variations identical to experiments with plants.

Gitelson, J.; Tikhomirov, A.; Parshina, O.; Ushakova, S.; Kalacheva, G.

381

Application of a difference-frequency-mixing based diode-laser sensor for carbon monoxide detection in the 4.4-4.8 ?m spectral region  

NASA Astrophysics Data System (ADS)

An all-solid-state continuous-wave (cw) laser system for mid-infrared absorption measurements of the carbon monoxide (CO) molecule has been developed and demonstrated. The single-mode, tunable output of an external-cavity diode laser (ECDL) is difference-frequency mixed with the output of a 550-mW diode-pumped cw Nd:YAG laser in a periodically poled lithium niobate (PPLN) crystal to generate tunable cw radiation in the mid-infrared region. The wavelength of the 860-nm ECDL can be coarse tuned from 860.782 to 872.826 nm, allowing the sensor to be operated in the spectral region 4.4-4.8 ?m. CO-concentration measurements were performed in CO/CO2/N2 mixtures in a room-temperature gas cell, in the exhaust stream of a well-stirred reactor (WSR) at Wright-Patterson Air Force Base and in a near-adiabatic hydrogen/air CO2-doped flame. The noise equivalent detection limits were estimated to be 1.1 and 2.5 ppm per meter for the gas cell and flame experiments, respectively. These limits were computed for combustion gas at 1000 K and atmospheric pressure assuming a signal-to-noise ratio of 1. The sensor uncertainty was estimated to be 2% for the gas-cell measurements and 10% for the flame measurements based on the repeatability of the peak absorption.

Barron-Jimenez, R.; Caton, J. A.; Anderson, T. N.; Lucht, R. P.; Walther, T.; Roy, S.; Brown, M. S.; Gord, J. R.

2006-11-01

382

N-type PTCDIC 13H 27 thin-film transistors deposited at different substrate temperature  

Microsoft Academic Search

N-type organic thin-film transistors based on N,N?-ditridecylperylene-3,4,9,10-tetracarboxylic diimide have been fabricated by thermal evaporation at different substrate temperatures. The best device was obtained at 120C with a field-effect mobility of 0.12cm2\\/Vs and threshold voltage around 46V. In this work, the microstructure of the films is correlated with the device performance. In particular, the dependence of the activation energy for the

J. Puigdollers; M. Della Pirriera; A. Marsal; A. Orpella; S. Cheylan; C. Voz; R. Alcubilla

2009-01-01

383

Different incubation temperatures affect viral polymerase activity and yields of low-pathogenic avian influenza viruses in embryonated chicken eggs  

Microsoft Academic Search

Various incubation conditions (35C38C, 27days) have been used in surveillance studies of the prevalence of avian influenza\\u000a viruses in wild birds. Here, we studied viral polymerase activity and virus growth kinetics of low-pathogenic avian influenza\\u000a viruses (LPAIVs) isolated from field samples [A\\/duck\\/Hong Kong\\/365\\/1978 (H4N6) and A\\/duck\\/Nanchang\\/20480\\/2000 (H9N2)] during\\u000a incubation at different temperatures (35C, 37C, and 39C) in the allantoic cavity

Victoria Lang; Henju Marjuki; Scott L. Krauss; Richard J. Webby; Robert G. Webster

2011-01-01

384

Effect of dynamic high-pressure microfluidization at different temperatures on the antigenic response of bovine ?-lactoglobulin  

Microsoft Academic Search

The antigenic response of ?-lactoglobulin (?-Lg), treated by dynamic high-pressure microfluidization (DHPM) at different temperatures,\\u000a was determined by an indirect competitive enzyme-linked immunosorbent assay using polyclonal antibodies from rabbit serum.\\u000a DHPM treatment causes changes in the protein structure and may influence the antigenicity of ?-Lg. DHPM treatment of ?-Lg\\u000a at 90C showed significant effects with the antigenic response of 5.2?gmL?1

Junzhen ZhongChengmei; Chengmei Liu; Wei Liu; Xiaofei Cai; Zongcai Tu; Jie Wan

2011-01-01

385

Effect of temperature on the sensitivity to gamma radiation of Serratia marcescens (Nima) at different phases of growth  

E-print Network

EF1'ECT OF TEMPERATURE ON THE SENSITIVITY TO GAEA RADIATION C OF SERRATIA MARCESCENS (NINA) AT DIFFERENT PHASES OF GROWTH A Thesis by Herbert Henry Hellen III Submitted to the Graduate College of Texas A&M University in partial fulfillment...) at Diffezent, Phases of Growth December 1972 Herbert Henry Hellen III, B. S. in Ed. , Oklahoma State University; M. S. , Texas A%M University Directed by: Dr. R. D. Neff snd Dr. G. A. O'Donovan The relative radiosensitivity of pigmented and non- 6O...

Hellen, Herbert Henry

2012-06-07

386

Non-Markovian stochastic Schrdinger equations in different temperature regimes: a study of the spin-boson model.  

PubMed

Stochastic Schrodinger equations are used to describe the dynamics of a quantum open system in contact with a large environment, as an alternative to the commonly used master equations. We present a study of the two main types of non-Markovian stochastic Schrodinger equations, linear and nonlinear ones. We compare them both analytically and numerically, the latter for the case of a spin-boson model. We show in this paper that two linear stochastic Schrodinger equations, derived from different perspectives by Diosi, Gisin, and Strunz [Phys. Rev. A 58, 1699 (1998)], and Gaspard and Nagaoka [J. Chem. Phys. 13, 5676 (1999)], respectively, are equivalent in the relevant order of perturbation theory. Nonlinear stochastic Schrodinger equations are in principle more efficient than linear ones, as they determine solutions with a higher weight in the ensemble average which recovers the reduced density matrix of the quantum open system. However, it will be shown in this paper that for the case of a spin-boson system and weak coupling, this improvement does only occur in the case of a bath at high temperature. For low temperatures, the sampling of realizations of the nonlinear equation is practically equivalent to the sampling of the linear ones. We study further this result by analyzing, for both temperature regimes, the driving noise of the linear equations in comparison to that of the nonlinear equations. PMID:15836368

de Vega, Ins; Alonso, Daniel; Gaspard, Pierre; Strunz, Walter T

2005-03-22

387

Non-Markovian stochastic Schrdinger equations in different temperature regimes: A study of the spin-boson model  

NASA Astrophysics Data System (ADS)

Stochastic Schrdinger equations are used to describe the dynamics of a quantum open system in contact with a large environment, as an alternative to the commonly used master equations. We present a study of the two main types of non-Markovian stochastic Schrdinger equations, linear and nonlinear ones. We compare them both analytically and numerically, the latter for the case of a spin-boson model. We show in this paper that two linear stochastic Schrdinger equations, derived from different perspectives by Disi, Gisin, and Strunz [Phys. Rev. A 58, 1699 (1998)], and Gaspard and Nagaoka [J. Chem. Phys. 13, 5676 (1999)], respectively, are equivalent in the relevant order of perturbation theory. Nonlinear stochastic Schrdinger equations are in principle more efficient than linear ones, as they determine solutions with a higher weight in the ensemble average which recovers the reduced density matrix of the quantum open system. However, it will be shown in this paper that for the case of a spin-boson system and weak coupling, this improvement does only occur in the case of a bath at high temperature. For low temperatures, the sampling of realizations of the nonlinear equation is practically equivalent to the sampling of the linear ones. We study further this result by analyzing, for both temperature regimes, the driving noise of the linear equations in comparison to that of the nonlinear equations.

de Vega, Ins; Alonso, Daniel; Gaspard, Pierre; Strunz, Walter T.

2005-03-01

388

Hot Corrosion Studies of HVOF-Sprayed Coating on T-91 Boiler Tube Steel at Different Operating Temperatures  

NASA Astrophysics Data System (ADS)

The aim of the present work is to investigate the usefulness of high velocity oxy fuel-sprayed 75% Cr3C2-25% (Ni-20Cr) coating to control hot corrosion of T-91 boiler tube steel at different operating temperatures viz 550, 700, and 850 C. The deposited coatings on the substrates exhibit nearly uniform, adherent and dense microstructure with porosity less than 2%. Thermogravimetry technique is used to study the high temperature hot corrosion behavior of uncoated and coated samples. The corrosion products of the coating on the substrate are analyzed by using XRD, SEM, and FE-SEM/EDAX to reveal their microstructural and compositional features for the corrosion mechanisms. It is found that the coated specimens have shown minimum weight gain at all the operating temperatures when compared with uncoated T-91 samples. Hence, coating is effective in decreasing the corrosion rate in the given molten salt environment. Oxides and spinels of nickel-chromium may be the reason for successful resistance against hot corrosion.

Bhatia, Rakesh; Singh, Hazoor; Sidhu, Buta Singh

2013-11-01

389

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

SciTech Connect

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.

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

390

SEM/EDS and XRD characterization of raw and washed MSWI fly ash sintered at different temperatures.  

PubMed

The disposal of fly ash generated during municipal solid waste incineration (MSWI) may pose a significant risk to the environment due to the possible leaching of hazardous pollutants, such as toxic metals. Sintering technology attracted more attention than the vitrification process because of its low energy needed. Generally, a preliminary washing treatment of raw fly ash with water was necessary for this sintering technology. This study investigated the composition and morphology of raw fly ash (RFA) and washed fly ash (WFA) at different sintering temperatures, and examined the newly formed minerals during sintering. Toxicity characteristic leaching procedure (TCLP) tests were carried out to investigate the effect of the washing treatment and sintering process on the leaching performance of heavy metals in fly ash. Results showed that, with an increase of sintering temperature more complex aluminosilicates were formed; the incorporation of Mg, Fe and Pb into the aluminosilicates occurred during the sintering process at higher temperatures (800 and 900 degrees C). The washing treatment reduced the leachable concentration of Cd, Pb and Ni, but increased that of Cr. A CaCrO(4) compound was considered as a potential soluble species. PMID:18555594

Liu, Yangsheng; Zheng, Liting; Li, Xiaodong; Xie, Shaodong

2009-02-15

391

Differences in efficiency of protective effect caused by high ambient temperature in mice infected with diverse substrains of rabies virus.  

PubMed

We have shown previously that a non-fatal outcome of infection with street rabies virus occurs more often when mice are exposed to a high ambient temperature (HAT = 35 degrees C) early in the course of the infection. To determine what influence the virus strain had on this protective effect of HAT, we have extended these observations to studies of a fixed rabies strain, CVS and several substrains of CVS virus derived from temperature-sensitive (ts) mutants. In all cases, mortality was reduced to some extent by exposure of the animals to HAT; however, dramatic strain-specific differences in the extent of the effect were noted. Although each of the virus substrains tested was revertant in the ts character (as tested in vitro using a non-permissive temperature of 40-5 degrees C), several substrains (ts 1, ts 4, RT51) caused disease that was sensitive (greater than 90% reduction in mortality) to HAT. Mortality induced by the parental CVS virus was reduced approx. 50% at HAT. A single CVS virus substrain, VSW89, caused disease that wal less affected by HAT than was disease induced by the parental strain. As in previous studies with street virus, the incubation periods for infection with CVS virus substrains were consistently prolonged at HAT. PMID:894265

Bell, J F; Clark, H F; Moore, G J

1977-08-01

392

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

PubMed

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

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

1998-11-01

393

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

PubMed

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

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

2006-09-01

394

Effect of temperature and photoperiod on the reproductive condition and performance of a tropical damselfish Chrysiptera cyanea during different phases of the reproductive season  

Microsoft Academic Search

Effects of temperature and photoperiod on the reproductive activity of a reef associated tropical damselfish Chrysiptera cyanea were evaluated under three phases with different environmental patterns, phase I (AprilMay; increasing water temperature\\u000a and photoperiod), phase II (JuneJuly; increasing water temperature and peak\\/decreasing photoperiod), and phase III (AugustSeptember;\\u000a peak\\/decreasing water temperature and decreasing photoperiod). When the fish were reared at 20,

Mohammad Abu Jafor Bapary; Akihiro Takemura

2010-01-01

395

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

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

M. Ramsey; D. Crews

2007-01-01

396

Photosynthetic Responses to Heat Treatments at Different Temperatures and following Recovery in Grapevine (Vitis amurensis L.) Leaves  

PubMed Central

Background The electron transport chain, Rubisco and stomatal conductance are important in photosynthesis. Little is known about their combined responses to heat treatment at different temperatures and following recovery in grapevines (Vitis spp.) which are often grown in climates with high temperatures. Methodology/Findings The electron transport function of photosystem II, the activation state of Rubisco and the influence of stomatal behavior were investigated in grapevine leaves during heat treatments and following recovery. High temperature treatments included 35, 40 and 45C, with 25C as the control and recovery temperature. Heat treatment at 35C did not significantly (P>0.05) inhibit net photosynthetic rate (Pn). However, with treatments at 40 and 45C, Pn was decreased, accompanied by an increase in substomatal CO2 concentration (Ci), decreases in stomatal conductance (gs) and the activation state of Rubisco, and inhibition of the donor side and the reaction center of PSII. The acceptor side of PSII was inhibited at 45C but not at 40C. When grape leaves recovered following heat treatment, Pn, gs and the activation state of Rubisco also increased, and the donor side and the reaction center of PSII recovered. The increase in Pn during the recovery period following the second 45C stress was slower than that following the 40C stress, and these increases corresponded to the donor side of PSII and the activation state of Rubisco. Conclusions Heat treatment at 35C did not significantly (P>0.05) influence photosynthesis. The decrease of Pn in grape leaves exposed to more severe heat stress (40 or 45C) was mainly attributed to three factors: the activation state of Rubisco, the donor side and the reaction center of PSII. However, the increase of Pn in grape leaves following heat stress was also associated with a stomatal response. The acceptor side of PSII in grape leaves was responsive but less sensitive to heat stress. PMID:21887227

Luo, Hai-Bo; Ma, Ling; Xi, Hui-Feng; Duan, Wei; Li, Shao-Hua; Loescher, Wayne; Wang, Jun-Fang; Wang, Li-Jun

2011-01-01

397

Role and Regulation of Fatty Acid Biosynthesis in the Response of Shewanella piezotolerans WP3 to Different Temperatures and Pressures?  

PubMed Central

Members of the genus Shewanella inhabit various environments; they are capable of synthesizing various types of low-melting-point fatty acids, including monounsaturated fatty acids (MUFA) and branched-chain fatty acids (BCFA) with and without eicosapentanoic acid (EPA). The genes involved in fatty acid synthesis in 15 whole-genome-sequenced Shewanella strains were identified and compared. A typical type II fatty acid synthesis pathway in Shewanella was constructed. A complete EPA synthesis gene cluster was found in all of the Shewanella genomes, although only a few of them were found to produce EPA. The roles and regulation of fatty acids synthesis in Shewanella were further elucidated in the Shewanella piezotolerans WP3 response to different temperatures and pressures. The EPA and BCFA contents of WP3 significantly increased when it was grown at low temperature and/or under high pressure. EPA, but not MUFA, was determined to be crucial for its growth at low temperature and high pressure. A gene cluster for a branched-chain amino acid ABC transporter (LIV-I) was found to be upregulated at low temperature. Combined approaches, including mutagenesis and an isotopic-tracer method, revealed that the LIV-I transporter played an important role in the regulation of BCFA synthesis in WP3. The LIV-I transporter was identified only in the cold-adapted Shewanella species and was assumed to supply an important strategy for Shewanella cold adaptation. This is the first time the molecular mechanism of BCFA regulation in bacteria has been elucidated. PMID:19201790

Wang, Feng; Xiao, Xiang; Ou, Hong-Yu; Gai, Yingbao; Wang, Fengping

2009-01-01

398

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

NASA Astrophysics Data System (ADS)

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

Zhang, Jie; Song, Hong-qiang

2014-06-01

399

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

PubMed Central

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

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

2014-01-01

400

Growth of ZnSe thin layers on different substrates and their structural consequences with bath temperature  

NASA Astrophysics Data System (ADS)

Refractory zinc selenide (ZnSe) semiconductor thin films have been prepared for different thicknesses by cathodic electrodeposition from aquatic solution containing SeO 32- and Zn 2+. A systematic study on the structural evolution of ZnSe on various commercially pure substrates, titanium (Ti), stainless steel (SS) and aluminium (Al) has been studied in the working solution at different bath temperatures (333, 343 and 353 K). Thickness of the films was monitored and was found to be in the range 1-5 ?m depending on the substrate used. At high temperature depositions (>333 K), nanocrystalline cubic ZnSe ( a=5.8814 ) thin films on titanium substrates with smaller grain size of about 30-80 nm were observed. Other related structural parameters such as dislocation density, microstrain, number of crystallites per unit area were evaluated from the X-ray diffraction data. The ZnSe films deposited over SS and Al substrates were crystalline and were indexed for hexagonal lattice. The outcome of the preparation process has been analyzed for the suitability of engaged substrates for the production of high quality single phase ZnSe films. The grain orientations on the surface were examined using atomic force microscopy and the observed grain size was compared with those evaluated through X-ray diffraction analysis.

Moses Ezhil Raj, A.; Mary Delphine, S.; Sanjeeviraja, C.; Jayachandran, M.

2010-05-01

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