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1

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

2

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 2.7×10?19??mol) and 86,000 oxygenated hemoglobin molecules (140 zeptomol) using narrowband continuous-wave photoacoustics. The ultimate sensitivity of photoacoustics is fundamentally limited by thermal noise, which can present in the acoustic detection system as well as in the medium itself. Under the optimized conditions described herein and using commercially available detectors, photoacoustic microscopy can detect as few as 100s of oxygenated hemoglobin molecules. Realizable improvements to the detector may enable single molecule detection of select molecules. PMID:24026425

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

2013-01-01

3

Comparison of noise equivalent count rates and image noise  

Microsoft Academic Search

The aim of this paper was to investigate the correlation between noise equivalent count (NEC) Rates and the signal-to-noise ratio (S\\/N) in the reconstructed images. NEC rates were determined using uniform 20- and 60-cm-tall 20-cm-diameter cylinders filled with 18F. The phantoms were scanned in both two-dimensional (2-D) and 3-D mode. The reconstructed image noise, for each frame, was estimated using

Magnus Dahlbom; Christiaan Schiepers; Johannes Czernin

2005-01-01

4

Comparison of noise equivalent count rates and image noise  

Microsoft Academic Search

The aim of this study was to investigate the correlation between Noise Equivalent Count (NEC) Rates and the signal-to-noise ratio (S\\/N) in the reconstructed images. NEC rates were determined using uniform 20 cm and 60 cm tall, 20 cm diameter cylinders filled with 18F. The phantoms were scanned in both 2D and 3D mode. The reconstructed image noise, for each

Magnus Dahlbom; Christiaan Schiepers; Johannes Czernin

2004-01-01

5

Optimization of Noise Equivalent Count Rate Performance for a Partially Collimated PET Scanner by Varying the Number of Septa  

Microsoft Academic Search

We present a simulation study of the global count-rate performance of a positron emission tomography (PET) scanner with different levels of partial collimation to maximize the noise equivalent count rate for whole-body PET imaging. We achieve partial collimation by removing different numbers of septal rings from the standard 2-D septa set for the GE Advance PET scanner. System behavior is

Ruth E. Schmitz; Robert L. Harrison; Charles W. Stearns; Thomas K. Lewellen; Paul E. Kinahan

2007-01-01

6

Optimization of Injected Dose Based on Noise Equivalent Count Rates for 2- and 3Dimensional Whole-Body PET  

Microsoft Academic Search

The noise equivalent count (NEC) rate index is used to derive guidelines on the optimal injected dose to the patient for 2-di- mensional (2D) and 3-dimensional (3D) whole-body PET acqui- sitions. Methods: We performed 2D and 3D whole-body acqui- sitions of an anthropomorphic phantom modeling the conditions for 18F-FDG PET of the torso and measured the NEC rates for different

Carole Lartizien; Claude Comtat; Paul E. Kinahan; Nuno Ferreira; Bernard Bendriem; Regine Trebossen

2002-01-01

7

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

8

Investigation of noise equivalent count rate in positron imaging using a dual head gamma camera  

Microsoft Academic Search

In positron imaging, image quality depends on scatter, random and coincidence rate. It is known that noise equivalent count (NEC) rate is a good indicator of image quality and that it helps optimizing acquisition parameters. We measured the NEC curve with a SophyCamera DST (SMV) using a 20 cm cylinder phantom filled with 18F (59 MBq). The field of view

D. Brasse; M. Tararine; O. Lamer; B. Bendriem

1998-01-01

9

Optimisation of noise equivalent count rates for brain and body FDG imaging using gamma camera PET  

Microsoft Academic Search

Describes the use of Noise Equivalent Count rates to optimise the clinical use of a modified dual headed gamma camera for positron emission tomography. Phantoms were used to simulate the distribution and uptake for brain and body 18F-fluorodeoxyglucose imaging, including the presence of activity outside the imaging field of view. Camera count rates were recorded as a function of activity

D. Visvikis; T. Fryer; S. Downey

1998-01-01

10

Investigation of noise equivalent count rate in positron imaging using a dual head gamma camera  

Microsoft Academic Search

In positron imaging, Noise Equivalent Count (NEC) rate curves provide a good link between image quality and scatter, random and true coincidence rates. The NEC curve has been measured on a SophyCamera DST (SMV) with a 20 cm cylinder phantom filled with 18F (59 MBq). On that system, the field of view is determined by two rectangular parallel detectors (400*300

D. Brassel; M. Tararine; O. Lamer; B. Bendriem

1997-01-01

11

Optimisation of noise equivalent count rates for brain and body FDG imaging using gamma camera PET  

Microsoft Academic Search

Describes the use of noise-equivalent count (NEC) rates to optimise the clinical use of a modified dual-headed gamma camera for positron emission tomography (PET). Phantoms were used to simulate the distribution and uptake for brain and body 18F-fluorodeoxyglucose (FDG) imaging, including the presence of activity outside the imaging field of view. Camera count rates were recorded as a function of

D. Visvikis; T. Fryer; S. Downey

1999-01-01

12

Optimization of noise-equivalent count rates in 3D PET  

Microsoft Academic Search

We have used noise-equivalent count (NEC) rates to optimize count rate performance for 3D acquisition in PET in a wide range of situations, with particular reference to imaging of the torso. We have also compared NEC performance for 2D and 3D acquisition in order to establish the conditions under which 3D mode offers an improvement over 2D mode. Measurements were

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

1996-01-01

13

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

E-print Network

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

Ke Wang; Zheng Li; Wei Feng; Dong Han

2014-04-17

14

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

NASA Technical Reports Server (NTRS)

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

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

1980-01-01

15

Minimum findable temperature difference  

NASA Astrophysics Data System (ADS)

A new measure called minimum findable temperature difference (MFTD) is offered as a means of characterizing thermal imaging performance under scene clutter limited conditions. MFTD extends an older performance methodology called minimum detectable temperature difference (MDTD) which was offered in the 70's as a sensor performance characterization under noise limited conditions. MFTD departs from MDTD in that it addresses scene clutter plus noise as well as sensor-noise-only operating conditions. In addition, MFTD measures the in-FOV search performance of the thermal imager. This paper details the measurement procedures associated with MFTD using real target vehicles and equivalent bar targets. Methods of characterizing thermal target scenes in terms of vehicle signatures and scene clutter are offered that appear to correlate with measured probability of target finding. Methods used to train MFTD observers and procedures for processing displayed target embedded scenes are provided. Finally, applications of MFTD for modelling manned sensor performance in cluttered environments using TTPF model formulations are offered. A future application of MFTD with real targets to develop standard Army observer ROC curves is suggested as well.

D'Agostino, John A.; Moulton, J. R.

1994-07-01

16

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

17

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

18

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

NASA Astrophysics Data System (ADS)

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

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

2012-03-01

19

Validation of the land-surface temperature products retrieved from Terra Moderate Resolution Imaging Spectroradiometer data  

Microsoft Academic Search

This paper presents the status of land-surface temperature (LST) standard products retrieved from Earth Observing System (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS) data. Based on estimates of the channel-dependence error and noise equivalent temperature difference (NEDT) and the calibration accuracy of MODIS thermal–infrared data, the impact of instrument performance on the accuracy of LST is discussed. A double-screen scheme based

Zhengming Wan; Yulin Zhang; Qincheng Zhang; Zhao-liang Li

2002-01-01

20

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

21

Equivalence of Optical and Electrical Noise Equivalent Power of Hybrid NbTiN-Al Microwave Kinetic Inductance Detectors  

E-print Network

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

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

2014-01-01

22

Different types of El Niño affect global temperature differently  

NASA Astrophysics Data System (ADS)

The El Niño-Southern Oscillation is known to influence global surface temperatures, with El Niño conditions leading to warmer temperatures and La Niña conditions leading to colder temperatures. However, a new study by Banholzer and Donner shows that some types of El Niño do not have this effect, a finding that could explain recent decade-scale slowdowns in global warming.

Balcerak, Ernie

2014-06-01

23

films on silicon at different annealing temperatures  

NASA Astrophysics Data System (ADS)

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

Zhao, Yan; Zhou, Chunlan; Zhang, Xiang; Zhang, Peng; Dou, Yanan; Wang, Wenjing; Cao, Xingzhong; Wang, Baoyi; Tang, Yehua; Zhou, Su

2013-03-01

24

Scanning infrared radiometer for measuring the airsea temperature difference  

E-print Network

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

Shaw, Joseph A.

25

NMR measurement of bitumen at different temperatures  

NASA Astrophysics Data System (ADS)

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

Yang, Zheng; Hirasaki, George J.

2008-06-01

26

NMR measurement of bitumen at different temperatures.  

PubMed

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

Yang, Zheng; Hirasaki, George J

2008-06-01

27

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

E-print Network

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

Shaw, Joseph A.

28

The Analysis of the Difference between Infrared Soil Temperature and L Band Effective Soil Temperature  

Microsoft Academic Search

L band microwave can penetrate the soil and its bright temperature data contains the soil temperature information of different layers within the penetration depth. L band effective soil temperature and infrared soil temperature have different physical significance and value. The SHAW model is validated by using the observed data of automatic weather station in Huailai and is used to simulate

Hongzhang Ma; Qinhuo Liu

2011-01-01

29

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.

30

Finite difference program for calculating hydride bed wall temperature profiles  

SciTech Connect

A QuickBASIC finite difference program was written for calculating one dimensional temperature profiles in up to two media with flat, cylindrical, or spherical geometries. The development of the program was motivated by the need to calculate maximum temperature differences across the walls of the Tritium metal hydrides beds for thermal fatigue analysis. The purpose of this report is to document the equations and the computer program used to calculate transient wall temperatures in stainless steel hydride vessels. The development of the computer code was motivated by the need to calculate maximum temperature differences across the walls of the hydrides beds in the Tritium Facility for thermal fatigue analysis.

Klein, J.E.

1992-10-29

31

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

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

32

A high performance room temperature THz sensor  

NASA Astrophysics Data System (ADS)

Resonant THz antenna-coupled micro-bolometers are considered as a potential candidates for room temperature THz imaging, as well as spectroscopic applications. Micromachining technology is found to be well-suitable to fabricate a micro-meter bolometer sensor suitable for MEMS implementation. The sensitivity of the sensor is determined to be up to 1000V/W and the noise equivalent power (NEP) - is down to 5pW /?Hz. The sensor parameters are designed to be easily implemented with a low cost standard preamplifier array which increases the pixel sensitivity to 106V/W without compromising the noise equivalent power.

Trontelj, Janez; Valušis, Gintaras; Venckevi?ius, Rimvydas; Kašalynas, Irmantas; Sešek, Aleksander; Švigelj, Andrej

2014-09-01

33

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 23.4°C). 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 10.8°C and decreased at 23.4°C. Temperatures of maximum daily food intake values

Jari-Pekka J. Pääkkönen; Timo J. Marjomäki

2000-01-01

34

Ground surface temperature simulation for different land covers  

NASA Astrophysics Data System (ADS)

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

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

2008-07-01

35

Osmotic dispense pump for operation at different temperatures and pressures  

Microsoft Academic Search

Three different osmotic pumping devices are designed, developed and tested. These devices are intended for an application, wherein a constant flow rate of 1?L\\/h is required for a period of 1 year with capability to operate at different pressures and different temperatures. The devices are completely self-sustaining and self-contained, with a pressurized solvent supply to avoid phase changes that inhibit

Trent Deem; Phillip M. Ligrani; Dan Tower; John Connelly

2007-01-01

36

A comparison of different evaluation methods in modulated temperature DSC  

Microsoft Academic Search

Modulated temperature-DSC is a new method for measuring the thermal behaviour of materials. In this method, the response of the sample to a time-dependent signal (sinusoidal temperature change) is measured. Two different methods are known for the evaluation of the measured data. The first is the separation of the measured data into reversing and non-reversing components of heat flow. The

J. E. K. Schawe

1995-01-01

37

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 45°C-65°C for 5 hours. The gel being cut will merge together through intermolecular diffusion of dangling chain and/or chain slippage. The results showed that 60°C 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

38

Temperature rise during polymerization of three different provisional materials.  

PubMed

The purpose of this study was to evaluate the temperature rise during polymerization of three different provisional materials by direct method on two different dentin disc thicknesses. Two autopolymerizing; bis-acrylic composite (Fill-in; Kerr), polymethyl methacrylate (Temdent; Weil Dental), and one light polymerizing composite (Revotek LC; GC) provisional restoration materials were used in this study. Sixty dentin discs were prepared from extracted molars (diameter, 5 mm; height, 1 or 2 mm). These dentin discs (1 or 2 mm) were placed on apparatus developed to measure temperature rise. The temperature rise during polymerization was measured under the dentin disc with a J-type thermocouple wire that was connected to a data logger. Statistical analysis was performed with two-way analysis of variance followed by Tukey HSD test (alpha=0.05). Temperature rise values statistically varied according to the provisional restoration material used (light polymerized, auto polymerized; P<0.001) and the dentin thickness (1 and 2 mm; P<0.001). The polymethyl methacrylate based provisional material induced significantly higher temperature rise than other provisional restoration materials at 2-mm dentin thickness (P<0.01). At 1-mm dentin thickness, polymethyl methacrylate and composite induced significantly higher temperature increase than bis-acrylic composite provisional material (P<0.05). The risk for heat-induced pulpal damage should be taken into consideration during polymerization of provisional materials in deep cavities in which dentin thickness is less than 1 mm. PMID:18080818

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

2008-09-01

39

Urban-rural temperature differences in Buenos Aires  

Microsoft Academic Search

The hourly temperature differences between Buenos Aires City and Ezeiza Airport were calculated using 3 years of data. This paper describes statistical results on the Buenos Aires urban heat island and how it varies with days of the week, seasons, cloud cover, direction and speed of wind. The average value of the maximal heat island fell in winter from 4.6°C

Patricia I. Figuerola; Nicolás A. Mazzeo

1998-01-01

40

Pyrolysis behaviour of pulverised coals at different temperatures  

Microsoft Academic Search

This study reports the chemical and petrographic characteristics of chars obtained at 1000 and 1300°C (within the range of temperatures reached by coal particles in the near burner zone of pulverised fuel boilers) from three different coals. The coals were selected according to petrographic criteria: two of them are low and high volatile bituminous vitrinite-rich coals, and the third one

M. J. G. Alonso; A. G. Borrego; D. Alvarez; R. Menéndez

1999-01-01

41

High operating temperature interband cascade focal plane arrays  

NASA Astrophysics Data System (ADS)

In this paper, we report the initial demonstration of mid-infrared interband cascade (IC) photodetector focal plane arrays with multiple-stage/junction design. The merits of IC photodetectors include low noise and efficient photocarrier extraction, even for zero-bias operation. By adopting enhanced electron barrier design and a total absorber thickness of 0.7 ?m, the 5-stage IC detectors show very low dark current (1.10 × 10-7 A/cm2 at -5 mV and 150 K). Even with un-optimized fabrication and standard commercial (mis-matched) read-out circuit technology, infrared images are obtained by the 320 × 256 IC focal plane array up to 180 K with f/2.3 optics. The minimum noise equivalent temperature difference of 28 mK is obtained at 120 K. These initial results indicate great potential of IC photodetectors, particularly for high operating temperature applications.

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

2014-08-01

42

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

Holubcik, Michal; Papucik, Stefan

2014-01-01

43

Emission controls using different temperatures of combustion air.  

PubMed

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

Nosek, Radovan; Holub?ík, Michal; Papu?ík, Štefan

2014-01-01

44

Deposition Ice Nuclei Concentration at Different Temperatures and Supersaturations  

NASA Astrophysics Data System (ADS)

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

López, M. L.; Avila, E.

2013-05-01

45

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

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

46

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.

47

Sky view factor analysis implications for urban air temperature differences  

NASA Astrophysics Data System (ADS)

This study identifies the use of the sky view factor (SVF) in urban climate studies. In addition, it relates air temperature differences to the SVF and examines these differences with respect to the height at which fish-eye photographs are taken for the calculation of the SVF. The study focuses on night-time air temperature patterns within the urban canopy using data collected during clear, calm nights from sixteen permanent stations and from car measurements. Fish-eye photographs taken at two levels (2 m above ground and at ground level) are compared and shown to be statistically different. The results of the study performed in Göteborg, Sweden, indicate a fairly strong relationship between air temperature and SVF. The permanent stations used indicate that it is better to use fish-eye photographs taken at ground level. The relationship is determined by means of regression analysis. The SVF variation in urban areas and the importance of SVF in relation to other central parameters such as thermal admittance are also discussed.

Svensson, Marie K.

2004-09-01

48

Flowability analysis of uranium dioxide powder at different temperatures containing different lubricants.  

PubMed

Powder flowability characteristics are often intentionally modified in order to improve their production process. The UO(2) pellet manufacturing process can consist of many steps, e.g. milling, granulation, homogenization, die filling for pressing, etc. By the addition of flow additives, lubricants or glidants the desired workability can be achieved. Temperature also influences the powder processability, leading to an easier or more complex powder flow. The work aims to determine some flowability characteristics for UO(2) powder at different temperatures. PMID:21075001

Santana, H H S; Maier, G; Ródenas, J

2011-08-01

49

Piglets' surface temperature change at different weights at birth.  

PubMed

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 piglet's 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 Nääs, Irenilza; Foppa, Luciana; Garcia, Rodrigo Garófallo; de Kássia Silva Dos Santos, Rita

2014-03-01

50

Air - ground temperature coupling - results of the seven year temperature monitoring under different types of surface  

NASA Astrophysics Data System (ADS)

We present results of the seven year (2003-2009) ground - air temperature tracking at observatory Prague - Spo?ilov located at the campus of the Institute of Geophysics in Prague (50° 02' 27" N, 14° 28' 39" E, 274 m a.s.l.). The soil temperatures (GST) under different types of surface (grass, sand, bare soil, asphalt) at the depths of 2, 5, 10, 20 and 50 cm, as well as the air temperatures (SAT) at 5 cm above each of the surface types and at 2 m above the background grass surface are recorded every 5 minutes together with other meteorological variables of solar radiation, humidity, soil moisture, precipitation and wind speed. Also presented are the results from a new observation site established during summer 2008 in Bed?ichov (Jizerske Hory Mountains, Czech Republic) to determine GST difference under two typical types of vegetation cover (meadow and forest). The mean annual ground temperature depends strongly on albedo of the surface, intensity of insolation and evaporation, and presence or absence of some form of insulation like snow or vegetation covers. The highest difference between mean annual GST and SAT was observed under asphalt surface due to its low albedo of about 0.04, obtained as the ratio between reflected and incoming shortwave solar radiation. The difference varied between 4.1 and 4.8 °C in the period 2003 - 2009, depending mainly on the number of sunny hours during summer months. In the case of sand, bare soil and grass, the temperature differences were in the range 1.5 - 2 °C (sand), 1.1 - 1.6 °C (bare soil) and 0.3 - 0.5 °C (grass). Typical values of albedo are about 0.11 (sand and bare soil) and 0.14 (grass). Mean annual temperature difference between meadow and forest observed at the depth of 0.5 m in Bed?ichov was 1.5 °C.

D?de?ek, Petr; Afanda, Jan Å.; ?ermák, Vladimír.; Krešl, Milan

2010-05-01

51

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

52

Conserved temperature-dependent expression of RNA-binding proteins in cyanobacteria with different temperature optima.  

PubMed

The expression of the rbp genes, which encode small RNA-binding proteins with a single RNA-recognition motif, is known to increase at low temperature in Anabaena variabilis M3. The 5'-untranslated region (UTR) of the rbpA1 gene is involved in the cold-regulation. We compared the regulation of the rbp genes in three strains of cyanobacteria having different temperature optima, namely, a mesophilic strain Anabaena sp. PCC 7120, a thermophilic strain Thermosynechococcus elongatus BP-1, and a psychrophilic Antarctic strain Oscillatoria sp. SU1. In Anabaena 7120 and T. elongatus, all the rbp gene sequences are known, and the 5'-UTR sequences of some rbp genes have a high similarity to the 5'-UTR of rbpA1. We found that transcripts as well as protein products of these rbp genes accumulated at low temperature. In addition, the expression of rbp genes increased at low temperature in the Oscillatoria sp. SU1. This suggests that a mechanism of cold-regulation of rbp genes is common among various species of cyanobacteria that belong to different taxa and have different temperature optima. PMID:12900032

Ehira, Shigeki; Hamano, Takashi; Hayashida, Tsunefusa; Kojima, Kouji; Nakamoto, Hitoshi; Hiyama, Tetsuo; Ohmori, Masayuki; Shivaji, Sisinthy; Sato, Naoki

2003-08-01

53

Lateralized Difference in Tympanic Membrane Temperature: Emotion and Hemispheric Activity  

PubMed Central

We review literature examining relationships between tympanic membrane temperature (TMT), affective/motivational orientation, and hemispheric activity. Lateralized differences in TMT might enable real-time monitoring of hemispheric activity in real-world conditions, and could serve as a corroborating marker of mental illnesses associated with specific affective dysregulation. We support the proposal that TMT holds potential for broadly indexing lateralized brain physiology during tasks demanding the processing and representation of emotional and/or motivational states, and for predicting trait-related affective/motivational orientations. The precise nature of the relationship between TMT and brain physiology, however, remains elusive. Indeed the limited extant research has sampled different participant populations and employed largely different procedures and measures, making for seemingly discrepant findings and implications. We propose, however, that many of these discrepancies can be resolved by considering how emotional states map onto motivational systems, and further examining how validated methods for inducing lateralized brain activity might affect TMT. PMID:23459831

Propper, Ruth E.; Brunye, Tad T.

2013-01-01

54

Interhemispheric temperature difference as a predictor of boreal winter ENSO  

NASA Astrophysics Data System (ADS)

We use statistical analysis to show statistically significant relationship between the boreal winter MEI index of ENSO and HadCRUT3 temperature difference between Northern and Southern hemispheres (NH - SH) during the preceding summer. Correlation values increase (in absolute terms) if the correlated time periods are increased from month to seasonal length. For example December and January (DJ) MEI values anticorrelate stronger with the preceding MJJA period than with any of the four months taken separately. We believe this is further evidence that the correlation is caused by a real physical process as increase of the averaging period tends to reduce statistical noise. The motivation for looking for such a relationship comes from review of literature on paleoclimatic ENSO behavior. We have noticed that in many cases relatively cold NH coincided with "strong ENSO" (frequent El Niños), for example the Ice Age periods and Little Ice Age. On the other hand periods of relatively warm NH (the Holocene climate optimum or Medieval Climate Anomaly) are coincident with frequent or even "permanent" La Niñas. This relationship suggest the influence of the position of Intertropical Convergence Zone (ITCZ) on the frequency of El Niños. The simplest physical mechanism of the relationship is that the positive (negative) NH-SH temperature difference causes a north (south) shift of ITCZ with a parallel shift of trade wind zones. The North-South orographic difference between the Panama Isthmus and the South America may cause stronger (weaker) trade winds in Eastern Tropical Pacific increasing (decreasing) the thermochemical tilt which, in turn, causes a more negative (positive) ENSO values. Of course this may be only a first approximation of the real mechanism of this "teleconnection". The correlations we have found are not strong even if statistically significant. For example, the MJJA NH-SH temperature vs. DJ MEI correlation has r = -0.28 implying it explains only 8% of boreal winter ENSO variability. In, fact, we did not expect a high value for a phenomenon which is a self-regulated ocean-atmosphere oscillation with timing partly triggered by stochastic atmospheric forcing, especially as we predict ENSO with (semi)global parameters. It is possible that further research may identify smaller regions of both hemispheres which temperature differences explain a larger part of ENSO variability. However in our opinion, the importance of this result is that it may not only improve ENSO prediction but also help in better understanding of ENSO variability in different time scales.

Piskozub, Jacek; Gutowska, Dorota

2013-04-01

55

Chlorella Virus Encoded Deoxyuridine triphosphatases Exhibit different Temperature Optima  

SciTech Connect

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

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

2005-01-01

56

Evaluation of temperature-selection differences among juvenile muskellunge originating from different latitudes  

Microsoft Academic Search

Genetic differences among muskellunge Esox masquinongy populations are related to residence in major river drainages, suggesting the existence of divergent stocks. By use of radio-telemetry\\u000a we compared different seasonal and diel temperature selection in a southern Illinois reservoir for three geographically and\\u000a genetically distinct stocks of age-2 muskellunge from throughout the latitudinal range of the species. Muskellunge from the\\u000a Upper

Curtis P. Wagner; David H. Wahl

2007-01-01

57

Evaluation of temperature-selection differences among juvenile muskellunge originating from different latitudes  

Microsoft Academic Search

Genetic differences among muskellunge Esox masquinongy populations are related to residence in major river drainages, suggesting the existence of divergent stocks. By use of radio-telemetry\\u000a we compared different seasonal and diel temperature selection in a southern Illinois reservoir for three geographically and\\u000a genetically distinct stocks of age-2 muskellunge from throughout the latitudinal range of the species. Muskellunge from the\\u000a Upper

Curtis P. Wagner; David H. Wahl

58

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

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

59

Radiolysis of frozen methane by heavy ions at different temperatures  

NASA Astrophysics Data System (ADS)

Methane ice is found in several bodies of the Solar System, including Titan, interstellar medium and young stellar objects, where it is frequently exposed to cosmic ray and solar wind radiation. The chemical, physical and structural effects induced by fast heavy ion irradiation on methane (CH4) pure ice at different temperatures are analyzed. Experiments were performed in a high-vacuum chamber (P ~ 10-8 mbar) coupled to GANIL accelerator beam lines in France. Ice monitoring during irradiation was done by mid-infrared spectroscopy (FTIR). Irradiation by 6 MeV 16O2+ ion beam on the CH4 pure ice at 15, 25 and 35 K as well as by 220 MeV 16O7+ [1], 267 MeV 56Fe22+ and 606 MeV 70Zn26+ at 15 K were performed. The analysis show that the CH4 destruction rate at 15 K is higher than at 35 K, and that the production rate of new molecules (C2H2, C2H4, C2H6, C3H8, C4H8, C4H10 and radicals CH3 and C2H5) increases as the temperature decreases. These findings should be relevant for the understanding of chemical reactions involving CH4 induced by high energy radiation in the Titan’s atmosphere. References: [1] de Barros, A. L. F et al. Cosmic ray impact on astrophysical ices: laboratory studies on heavy ion irradiation of methane. A&A, v. 531, p. A160-A169, 2011. [2] M. Garozzo et al. The influence of temperature on the synthesis of molecules on icy grain mantles in dense molecular clouds. A&A v 528, A118 p 9 2011.

Mejía, C. F.; Bordalo, V.; de Barros, A. L. F.; Domaracka, A.; Rothard, H.; Boduch, P.; da Silveira, E. F.

2012-04-01

60

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

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

2014-09-01

61

Specific heat of apple at different moisture contents and temperatures  

E-print Network

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

Viacheslav Mykhailyk; Nikolai Lebovka

2013-05-06

62

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

63

Maximum vehicle cabin temperatures under different meteorological conditions.  

PubMed

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

Grundstein, Andrew; Meentemeyer, Vernon; Dowd, John

2009-05-01

64

Maximum vehicle cabin temperatures under different meteorological conditions  

NASA Astrophysics Data System (ADS)

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

Grundstein, Andrew; Meentemeyer, Vernon; Dowd, John

2009-05-01

65

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

PubMed Central

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

Jutte, Lisa S.; Smith, Michael E.

2003-01-01

66

Optical Transition of Porous Silicon Prepared at Different Anodization Temperatures  

NASA Astrophysics Data System (ADS)

Photoluminescence, photoabsorption, and X-ray photoelectron spectroscopic study revealed that an optical transition of porous silicon from red-shift to blue-shift, and Si-2p binding energy transition from low to high at a critical anodization temperature, 343 K. Possible origin for the reverse variations happening at temperature below and above the critical temperature is discussed.

Pan, Likun; Li, Haibo; Sun, Zhuo; Sun, Changqing

67

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

Microsoft Academic Search

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

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

1990-01-01

68

Study of calcinations of ammonium diuranate at different temperatures  

NASA Astrophysics Data System (ADS)

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

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

2012-07-01

69

Dried sausages fermented with Staphylococcus xylosus at different temperatures and with different ingredient levels — Part II. Volatile components  

Microsoft Academic Search

Sausages, with added Staphylococcus xylosus, were fermented at different temperatures and with different added levels of salt, glucose, nitrite, nitrate and Pediococcus pentosaceus in accordance with a six factor fractional design. The volatile compounds from the sausages were collected by dynamic headspace sampling and quantified and identified by gas chromatography and gas chromatography-mass spectrometry. The effects of temperature and different

L. H. Stahnke

1995-01-01

70

Dried sausages fermented with Staphylococcus xylosus at different temperatures and with different ingredient levels — Part I. Chemical and bacteriological data  

Microsoft Academic Search

Sausages with added Staphylococcus xylosus were fermented at different temperatures and with different added levels of salt, glucose, nitrite, nitrate and Pediococcus pentosaceus in accordance with a six factor fractional design. The numbers of surviving Staphylococcus xylosus, lactic acid bacteria, pH, free fatty acids and residual amounts of nitrite and nitrate were measured. The effects of temperature and different ingredients

L. H. Stahnke

1995-01-01

71

Features of a tunnel diode oscillator at different temperatures  

Microsoft Academic Search

Current–voltage measurements were performed on a tunnel diode (TD) and the basic features of the I–V characteristics were analyzed in the temperature range 100–300K. Based on these characteristics, a TD-based oscillator is designed and simulated using circuit analysis software (PSpice). It is shown, in particular, that the amplitude and the frequency of the obtained sinusoidal waveforms can be practically temperature

S. Al-harthi; A. Sellai

2007-01-01

72

Evolution of uranium dislocation structure at different-rate deformation and different-temperature annealing  

NASA Astrophysics Data System (ADS)

The Williamson-Hall method based on analyzing the angular dependence of diffraction maximum broadening is used to study the dislocation structure. Densities of chaotically arranged dislocations on samples after their different-rate deformation are measured. Consideration is given to the dislocation structure of a spherical uranium sample after its shock-wave loading, as well as to the dislocation structure of model samples deformed at the rate of ˜ 10-3s-1 up to 5%, 20%, and 60% relative deformation. After deformation, samples were vacuum annealed at 200C, 400C, 600C, 720C, and 850C (in alpha-, beta-, and gamma-phases). Samples were cooled at the rate of ˜ 10?/min. Results for samples subjected to different-rate deformation and different-temperature annealing are compared. In the dislocation structure of the sample recovered after shock-wave loading, special features that cannot be described with the help of mechanisms observed at the low-rate deformation and cooling were elucidated. Systematic investigations of the uranium dislocation structure at the increasing speed of loading are to be continued).

Shestakov, A. E.; Artamonov, I. V.

2012-08-01

73

Comparison of Wind Vectors and Air-Sea Temperature Differences Measured during SHOWEX  

E-print Network

Comparison of Wind Vectors and Air-Sea Temperature Differences Measured during SHOWEX William J speed and direction, air temperature, and water temperature were measured from Air Sea Interaction Spar measured both water temperature and air temperature near the surface. The IR sensor gave a second

Long, David G.

74

Intrauterine temperatures of mares under different management conditions  

E-print Network

, with the suture hanging out of the vulva. Prior to this, the mare?s vulva and perineal area had been washed with a diluted Betadine scrub (Purdue Pharma, L.P., Stamford, Connecticut, 06901). Temperatures were recorded by the uterine device for 5 d; if at any..., with the suture hanging out of the vulva. Prior to this, the mare?s vulva and perineal area had been washed with a diluted Betadine scrub (Purdue Pharma, L.P., Stamford, Connecticut, 06901). Temperatures were recorded by the uterine device for 5 d; if at any...

Commaille, Lynn Frances

2009-05-15

75

Mixed solar wind originating from coronal regions of different temperatures  

NASA Technical Reports Server (NTRS)

Ionization states of elements in the solar wind are often used to determine thermal gradients in the lower corona. This method is based on the assumption, that in the beginning, solar wind material has a homogeneous temperature determining the original charge state of elements. Features in M/Q-spectra which might appear if the above assumption is violated are investigated and compared with observational evidence.

Bochsler, P.

1983-01-01

76

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.

77

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

NASA Astrophysics Data System (ADS)

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

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

2013-08-01

78

Monitoring water stress using time series of observed to unstressed surface temperature difference  

E-print Network

Monitoring water stress using time series of observed to unstressed surface temperature difference indices and soil moisture status to data assimilation of surface temperature into complex soil surface temperature as a baseline to monitor water stress. The unstressed temperature is the equilibrium

Gentine, Pierre

79

Effect of different extenders and storage temperatures on sperm viability  

E-print Network

a split-sample technique, in four different extenders: one for milk (Mi), one for sodium citrate (Na-osmotic resistance test (ORT) and a ¯uorophore staining (SYBR-14 and propidium iodide) technique. We evaluated better than both the sodium citrate- and the milk-based extender did when liquid ram semen was stored up

Zaragoza, Universidad de

80

Applications of ground source heat pump systems in different temperature zones in China  

Microsoft Academic Search

An analysis of the application of ground source heat pump (GSHP) systems to different temperature zones in China is presented in this paper. According to the climate characteristics, China is divided into six different temperature zones: the tropical zone, the subtropical zone, the warm temperate zone, the mid temperate zone, the cold temperate zone, and Qinghai-Tibet Plateau vertical temperature zone.

Y. Bi; X. Wang; Y. Liu; R. Tian; L. Chen; C. Wu

2009-01-01

81

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

E-print Network

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

Boyd, Sylke

82

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

NASA Astrophysics Data System (ADS)

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

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

2011-09-01

83

Performance of high temperature superconducting coils in high background fields at different temperatures  

SciTech Connect

Application of High Temperature Superconductors (HTS) to devices requires a detailed understanding of the effects of temperature, magnetic field and orientation of magnetic field n the critical current density. Measurements of the critical surface of PbBSCCO were made on long lengths of fully reacted multi-filamentary wire would into solenoids. These react and wind coils were tested in magnetic fields to 20 tesla and temperatures from 1.8 K to 77 K. Overall current densities of 200--300 A/mm{sup 2} were achieved at fields of 20 T. The effect of high electromagnetic forces on performance of high temperature superconducting (HTSC) coils is analyzed and compared with analytical models for the HTSC conductor and coil winding.

Aized, D.; Manlief, M.D.; Joshi, C.H. [American Superconductor Corp., Westborough, MA (United States)] [American Superconductor Corp., Westborough, MA (United States)

1994-07-01

84

Heart rate response to industrial work at different outdoor temperatures with or without temperature control system at the plant  

Microsoft Academic Search

Different outdoor temperatures, the association between indoor temperature control at the workplace and working heart rates of industrial employees were evaluated. The subjects, 6,016 male and female employees in 21 industrial plants in Israel, were screened for cardiovascular risk factors between 1985–87 (The CORDIS Study). The data collected included resting heart rate, working heart rate (based on one hour ambulatory

E. KRISTAL-BONEH; G. HARARI; M. S. GREEN

1997-01-01

85

Solvated electrons at elevated temperatures in different alcohols: Temperature and molecular structure effects  

NASA Astrophysics Data System (ADS)

The absorption spectra of solvated electrons in pentanol, hexanol and octanol are measured from 22 to 200, 22 to 175 and 50 to150 °C, respectively, at a fixed pressure of 15 MPa, using nanosecond pulse radiolysis technique. The results show that the peak positions of the absorption spectra have a red-shift (shift to longer wavelengths) as temperature increases, similar to water and other alcohols. Including the above mentioned data, a compilation of currently available experimental data on the energy of absorption maximum ( Emax) of solvated electrons changed with temperature in monohydric alcohols, diols and triol is presented. Emax of solvated electron is larger in those alcohols that have more OH groups at all the temperatures. The molecular structure effect, including OH numbers, OH position and carbon chain length, is investigated. For the primary alcohols with same OH group number and position, the temperature coefficient increases with increase in chain length. For the alcohols with same chain length and OH numbers, temperature coefficient is larger for the symmetric alcohols than the asymmetric ones.

Yan, Yu; Lin, Mingzhang; Katsumura, Yosuke; Fu, Haiying; Muroya, Yusa

2010-12-01

86

Temperature differences in the air layer close to a road surface  

Microsoft Academic Search

In this study, profiles of temperature and humidity (<250 cm above the road and 5 m into the surroundings) have been used to examine the development of temperature differences in the air layer close to the road. Temperature, humidity and wind profiles were measured, together with net radiation and observations of road surface state, at a test site at Road

Jörgen Bogren; Torbjörn Gustavsson; Maria Karlsson

2001-01-01

87

Elastic anharmonicity and elastic constants temperature dependences of different quality quartz crystals  

Microsoft Academic Search

Second order elastic constant temperature dependences of different quality quartz crystals were studied. The simplified phenomenological theory was applied to calculate second order elastic constant temperature dependences. The bulk acoustic waves propagation under the bias of temperature field or of the uniaxial mechanical pressure was considered. It was found that crystal quality changes have caused certain variations of some third

B. P. Sorokin; D. A. Glushkov; P. P. Turchin; S. V. Michailyuta; K. S. Aleksandrov; A. B. Doubovsky

2000-01-01

88

Dried sausages fermented with Staphylococcus xylosus at different temperatures and with different ingredient levels — Part III. Sensory evaluation  

Microsoft Academic Search

Sausages with added Staphylococcus xylosus were fermented at different temperatures and with different added levels of salt, glucose, nitrite, nitrate and Pediococcus pentosaceus in accordance with a six factor fractional design. The odour of the sausages was evaluated by a quantitative descriptive method with ten descriptors and by gas chromatography olfactometry. The sensory profile was correlated to the experimental design

L. H. Stahnke

1995-01-01

89

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

90

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

91

Temperature differences in the air layer close to a road surface  

NASA Astrophysics Data System (ADS)

In this study, profiles of temperature and humidity (<250 cm above the road and 5 m into the surroundings) have been used to examine the development of temperature differences in the air layer close to the road. Temperature, humidity and wind profiles were measured, together with net radiation and observations of road surface state, at a test site at Road 45, Surte, Sweden. Measured temperature differences were compared with present weather, preceding weather, surface status, wind direction and other parameters thought to be important for the development of temperature differences. The results showed that large temperature differences (1-3 °C between 250 cm and 10 cm above the road) occurred when there was a high risk of slipperiness caused by hoarfrost, snow or ice on the road. The temperature differences between different levels were associated with the exchange of humidity and temperature between the air layer and the road surface. The 10 cm level reflected the surface processes well. Higher levels were influenced by the surroundings because of turbulence and advection. This study emphasises the need for measurements to be taken at a height and place that reflects the processes at the road surface.

Bogren, Jörgen; Gustavsson, Torbjörn; Karlsson, Maria

2001-12-01

92

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

NASA Astrophysics Data System (ADS)

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

Yuan, Naiming; Fu, Zuntao

2014-04-01

93

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 (R² > 0.9 for all technologies). Compared to the previous analysis, we find comparable mean values and an increasing standard deviation. These results open a promising approach for PV module temperature estimation using meteorological parameters. References: [1] Skoplaki, E. et al., 2008: A simple correlation for the operating temperature of photovoltaic modules of arbitrary mounting, Solar Energy Materials & Solar Cells 92, 1393-1402 [2] Skoplaki, E. et al., 2008: Operating temperature of photovoltaic modules: A survey of pertinent correlations, Renewable Energy 34, 23-29 [3] Koehl, M. et al., 2011: Modeling of the nominal operating cell temperature based on outdoor weathering, Solar Energy Materials & Solar Cells 95, 1638-1646 [4] Mattei, M. et al., 2005: Calculation of the polycrystalline PV module temperature using a simple method of energy balance, Renewable Energy 31, 553-567 [5] Kurtz, S. et al.: Evaluation of high-temperature exposure of rack-mounted photovoltaic modules

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

2013-04-01

94

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

Microsoft Academic Search

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

Larry M. McMillin

1975-01-01

95

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

96

Development of the Temperature Sensor for Measuring Heat Based on the Difference between the Specific Enthalpy  

Microsoft Academic Search

Reducing energy consumption, improving the heat efficiency is one of the key work of energy conservation and emission reduction. The measuring heat instrument take the principle of the difference between specific enthalpy and use Pt resistance as temperature sensor, the curve of two temperature sensors do matching pairs. This new technology and new technique can solve some difficult problems in

Shenghua Bao; Shufen Wang

2010-01-01

97

Distributed Temperature Sensing of the Atmosphere with Fiber Optic Cables of Different Diameters and Albedos  

NASA Astrophysics Data System (ADS)

Distributed Temperature Sensing (DTS) combines optical time domain reflectrometry and Raman spectrometry to determine temperatures along fiber optic cables. Environmental applications of DTS have taken flight over the past years. The ability to measure temperatures in soils, snow, and water over large distances with high temporal and spatial resolutions and good accuracies has improved insight in many natural processes. Atmospheric measurements have, so far, been hindered by the heating effect of incoming radiation. For this reason, atmospheric sounding with DTS has mainly been limited to night time observations or to the distribution of shading in forested areas. Radiative heating is partially compensated by advection of heat away from the cable. Thermodynamic theory shows that when heated cylinders (cables) are in equilibrium with the advecting wind field, the final temperature scales with the square root of the diameter. By using cables of different diameters, it is, in theory, possible to calculate the actual air temperature by extrapolating the measurements to a diameter of zero. This idea is based on earlier discussions with Dr. Gaylon Campbell. In our experiment, we used cables of different diameters but the noise levels were in general too large, or the diameter differences too small, to obtain very accurate results. We also used cables with different albedos (black and white). Not surprisingly, white cable temperatures were close to air temperature as measured by the adjacent micro-met station. Detailed analysis shows to what extent, and with what accuracy, DTS cables can be used to measure air temperature during the day.

Van De Giesen, N.; Jansen, J.; de Jong, S.; Selker, J. S.

2011-12-01

98

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

E-print Network

for the Asian monsoon Rosanne D'Arrigo,1 Rob Wilson,1,2 and Jinbao Li1 Received 9 July 2006; revised 26 summer monsoon. We evaluate changes in the temperature difference between Eurasia and the tropics over this interval, and with other temperature and precipitation- sensitive proxies from the Asian monsoon regime

99

Temperature dependence of evolutionary diversification: differences between two contrasting model taxa support  

E-print Network

and environmental temperature. As environmental temperature affects metabolic rate in ecto- and endotherms, in the endothermic carnivorans a reverse, negative correlation was detected. These findings comply with predictions- and endotherms) might have been generated by different ecological and evolutionary processes. Introduction

Storch, David

100

Changes in selected biochemical indices related to transport of broilers to slaughterhouse under different ambient temperatures.  

PubMed

The effect of transport distance on selected biochemical parameters (corticosterone, uric acid, triglycerides, total protein, glucose, and lactate) under various ambient temperatures was monitored in a group of unsexed Ross 308 broilers aged 42 d. Broilers were transported to the slaughterhouse over 3 different travel distances (10, 70, and 130 km). They were sampled before and after each transportation in 3 various periods with different ambient temperatures (-5 to +5°C, 10 to 20°C, and 25 to 35°C), which approximately correspond to temperature conditions during transport in individual seasons of the year (winter, fall, summer). The changes in biochemical parameters were specific in their dependence on the travel distance and the ambient temperature under which the broilers were transported. The highest corticosterone concentration was found in broilers before transport (i.e., immediately after catching, crating, and loading) at all ambient temperatures. The concentration of corticosterone was higher at winter temperatures than at summer and fall temperatures. Triglycerides decreased with travel distance, although this effect was detected under summer temperatures only. The concentration of total protein was higher only after 10 km of transport and then it decreased with travel distance at all monitored ambient temperatures. A highly significant decrease (P < 0.01) in the glucose level of broilers was observed after 130 km of transport when compared with broilers before transport at fall and winter temperatures. The effect of travel distance on lactate concentrations was the same at all monitored ambient temperatures, with the lactate level decreasing with travel distance. The results obtained indicate that pretransport handling procedures (catching, crating, and loading) may be more stressful for broilers than the transport itself. To improve broiler meat quality, it is necessary to meet the need for broilers to recover before being slaughtered. With regard to different seasons of the year, we can assume that transport under conditions of low ambient temperatures in winter represents a more stressful event than transport during fall and summer. PMID:21076112

Vosmerova, P; Chloupek, J; Bedanova, I; Chloupek, P; Kruzikova, K; Blahova, J; Vecerek, V

2010-12-01

101

Evaluation of the temperature of different refrigerant sprays used as a pulpal test.  

PubMed

The temperature of different refrigerant sprays (Endo-Ice, Endo-Frost, Coolermatic and Sprayon Contact and Tuner Cleaner) used as pulpal tests were evaluated in vitro. A thermocouple placed inside the pulp chamber of a maxillary central incisor was used to register the temperature changes when the refrigerant sprays were applied with a cotton swab, for 10 s. Results indicate that Endo-Ice and Endo-Frost presented the lowest temperatures among the refrigerant sprays tested. Temperatures measured inside the pulp chamber, however, were statistically similar in all groups. PMID:19032640

de Morais, Carlos Alberto Herrero; Bernardineli, Norberti; Lima, Walter Moreira; Cupertino, Rogério Rodrigues; Guerisoli, Danilo Mathias Zanello

2008-12-01

102

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

103

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

PubMed Central

Background and Aims Jatropha curcas is a drought-resistant tree whose seeds are a good source of oil that can be used for producing biodiesel. A successful crop establishment depends on a rapid and uniform germination of the seed. In this work we aimed to characterize the responses of J. curcas seeds to temperature and water availability, using thermal time and hydrotime analysis, Methods Thermal and hydrotime analysis was performed on germination data obtained from the incubation of seeds at different temperatures and at different water potentials. Key Results Base and optimum temperatures were 14·4 and 30 °C, respectively. Approximately 20 % of the seed population displayed absolute dormancy and part of it displayed relative dormancy which was progressively expressed in further fractions when incubation temperatures departed from 25 °C. The thermal time model, but not the hydrotime model, failed to describe adequately final germination percentages at temperatures other than 25 °C. The hydrotime constant, ?H, was reduced when the incubation temperature was increased up to 30 °C, the base water potential for 50 % germination,?b(50), was less negative at 20 and 30 °C than at 25 °C, indicating either expression or induction of dormancy. At 20 °C this less negative ?b(50) explained satisfactorily the germination curves obtained at all water potentials, while at 30 °C it had to be corrected towards even less negative values to match observed curves at water potentials below 0. Hence, ?b(50) appeared to have been further displaced to less negative values as exposure to 30 °C was prolonged by osmoticum. These results suggest expression of dormancy at 20 °C and induction of secondary dormancy above 25 °C. This was confirmed by an experiment showing that inhibition of germination imposed by temperatures higher than 30 °C, but not that imposed at 20 °C, is a permanent effect. Conclusions This study revealed (a) the extremely narrow thermal range within which dormancy problems (either through expression or induction of dormancy) may not be encountered; and (b) the high sensitivity displayed by these seeds to water shortage. In addition, this work is the first one in which temperature effects on dormancy expression could be discriminated from those on dormancy induction using a hydrotime analysis. PMID:21917817

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

2012-01-01

104

Differences between radiosonde and dropsonde temperature profiles over the Arctic Ocean  

SciTech Connect

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

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

1994-10-01

105

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

PubMed

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

Lundahl, Gunnel

2007-01-01

106

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; Thiery, Denis

2012-01-01

107

Different mechanisms for Arabidopsis thaliana hybrid necrosis cases inferred from temperature responses.  

PubMed

Temperature is a major determinant of plant growth, development and success. Understanding how plants respond to temperature is particularly relevant in a warming climate. Plant immune responses are often suppressed above species-specific critical temperatures. This is also true for intraspecific hybrids of Arabidopsis thaliana that express hybrid necrosis due to inappropriate activation of the immune system caused by epistatic interactions between alleles from different genomes. The relationship between temperature and defence is unclear, largely due to a lack of studies that assess immune activation over a wide range of temperatures. To test whether the temperature-based suppression of ectopic immune activation in hybrids exhibits a linear or non-linear relationship, we characterised the molecular and morphological phenotypes of two different necrotic A. thaliana hybrids over a range of ecologically relevant temperatures. We found both linear and non-linear responses for expression of immunity markers and for morphological defects depending on the underlying genetic cause. This suggests that the influence of temperature on the trade-off between immunity and growth depends on the specific defence components involved. PMID:24641593

Muralidharan, S; Box, M S; Sedivy, E L; Wigge, P A; Weigel, D; Rowan, B A

2014-11-01

108

Statistical significance of trends and trend differences in layer-average atmospheric temperature time series  

Microsoft Academic Search

This paper examines trend uncertainties in layer-average free atmosphere temperatures arising from the use of different trend estimation methods. It also considers statistical issues that arise in assessing the significance of individual trends and of trend differences between data sets. Possible causes of these trends are not addressed. We use data from satellite and radiosonde measurements and from two reanalysis

B. D. Santer; T. M. L. Wigley; J. S. Boyle; D. J. Gaffen; J. J. Hnilo; D. Nychka; D. E. Parker; K. E. Taylor

1999-01-01

109

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

SciTech Connect

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

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

2009-09-15

110

Land Surface Temperature Derived from the MSG-SEVIRI Data  

NASA Astrophysics Data System (ADS)

We have developed a physical-based split-window algorithm for retrieving the land surface temperature (LST) from SEVIRI/MSG1 (Spinning Enhanced Visible and Infrared Imager/ Meteosat Second Generation1) data in two thermal infrared bands (IR 10.8 and IR 12.0). The proposed algorithm takes into account the SEVIRI angular dependence. MODTRAN3 code has been used to derive synthetic data which have allowed to obtain the numerical values of the split-window algorithm from a statistical regression method. The new LST algorithm has been tested with simulated SEVIRI/MSG1 data over a wide range of atmospheric and surface conditions. Comprehensive sensitivity and error analyses have been undertaken to evaluate the performance of the proposed algorithm and its dependence on surface properties, atmospheric conditions and on the noise-equivalent temperature difference. The results show that the algorithm is capable of producing LST with a standard deviation lower than 1.5K for viewing zenith angles lower than 50 degrees.

Romaguera, M.; Sobrino, J. A.; Sória, G.; Zaragoza, M. M.; Cuenca, J.; Gómez, M.; Jiménez-Muñoz, J. C.; Galdón-Ruiz

2004-11-01

111

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

112

Global Distributions of Temperature Variances At Different Stratospheric Altitudes From Gps/met Data  

NASA Astrophysics Data System (ADS)

The GPS/MET measurements at altitudes 5 - 35 km are used to obtain global distribu- tions of small-scale temperature variances at different stratospheric altitudes. Individ- ual temperature profiles are smoothed using second order polynomial approximations in 5 - 7 km thick layers centered at 10, 20 and 30 km. Temperature inclinations from the averaged values and their variances obtained for each profile are averaged for each month of year during the GPS/MET experiment. Global distributions of temperature variances have inhomogeneous structure. Locations and latitude distributions of the maxima and minima of the variances depend on altitudes and season. One of the rea- sons for the small-scale temperature perturbations in the stratosphere could be internal gravity waves (IGWs). Some assumptions are made about peculiarities of IGW gener- ation and propagation in the tropo-stratosphere based on the results of GPS/MET data analysis.

Gavrilov, N. M.; Karpova, N. V.; Jacobi, Ch.

113

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

114

Semiconducting behaviour of thin bismuth films vacuum-deposited at different substrate temperatures  

Microsoft Academic Search

Thin bismuth films (thickness 25 nm) have been vacuum-deposited onto glass substrates at different substrate temperatures in a vacuum of 2×10-5 torr. The resistance of the films has been measured as a function of temperaturein situ during and after annealing. It is found that the resistance of all the annealed films decreases with increasing temperature thus showing a semiconducting type

V. Damodara Das; S. Vaidehi

1984-01-01

115

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 25°C), and gas-exchange and growth characteristics were examined during active growth and early dormancy. At 5°C, Populus tremuloides had no root growth,and limited growth,in leaf area and shoot mass,compared,with the large increases in

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

2001-01-01

116

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

117

Viscoelasticity and texture of spreadable cheeses with different fat contents at refrigeration and room temperatures.  

PubMed

The effect of the 2 common consumption temperatures, refrigeration temperature (10°C) and room temperature (22°C), on the viscoelasticity, mechanical properties, and perceived texture of commercial cream cheeses was studied. Two samples with different fat contents, regular and low fat, from each of 4 selected commercial brands were analyzed. The selection criteria were based on identification of brands with different percentages of fat content reduction between the regular- and low-fat samples (35, 50, 84, and 98.5%). The fat content of regular-fat samples ranged from 19.8 to 26.0% (wt/wt), and that of low-fat samples ranged from 0.3 to 13.0% (wt/wt). Viscoelasticity was measured in a controlled-stress rheometer using parallel-plate geometry, and the mechanical characteristics of samples were measured using the spreadability test. Differences in the intensity of thickness, creaminess, and roughness between the regular- and low-fat samples of each commercial brand were evaluated at each of the selected temperatures by using the paired comparisons test. At 10°C, all samples showed higher viscoelastic modulus values, firmness, and stickiness, and lower spreadability than when they were measured at 22°C. Differences in viscoelasticity and mechanical properties between each pair of samples of the same brand were greater at 10°C than at 22°C because of the influence not only of fat content but also of fat state. Ingestion temperature did not modify the sensory differences detected between each pair of samples in terms of creaminess and roughness, but it did modify the differences detected in thickness. The joint consideration of sample composition, fat state, and product behavior during oral processing could explain the differences detected in thickness perceived because of measurement temperatures. PMID:22999281

Bayarri, S; Carbonell, I; Costell, E

2012-12-01

118

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

PubMed

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; Sävmarker, Jonas; Thulin, Måns; Larhed, Mats

2013-01-01

119

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; Savmarker, Jonas; Thulin, Mans

2013-01-01

120

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

121

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 10ºC 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 10°C. 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

122

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

123

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 liquid–liquid 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

124

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

125

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

PubMed

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

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

2003-01-01

126

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

127

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

PubMed

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

Li, Changzheng; Yue, Yanan

2014-10-31

128

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 Å 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

129

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

130

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 700°C) 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 700°C. 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

131

Measured rotational and vibrational temperature differences in arc jet shock layers  

NASA Technical Reports Server (NTRS)

Shock-layer-radiation emission spectra from the first negative system of the nitrogen molecular ion N2(+) are analyzed over the wavelength region between 370 and 430 nm. The shock layer is produced by a blunt body placed in the expanded flow from an arc heater employing either pure nitrogen or a nitrogen-oxygen air mixture. A rotational temperature is obtained from analysis of (0,1) band emission from N2(+). Vibrational temperatures are extracted from population distributions obtained through spectral fitting of the N2(+) (B-X) band sequences. Rotational temperatures up to 9500 K near the front of the shocks are determined for different energy and flow conditions. The rotational temperatures are found to be lower than those obtained for vibration confirming previous measurements and contrary to expectation based on theory.

Blackwell, Harvel E.; Scott, Carl D.

1992-01-01

132

Models for prediction of temperature difference and ventilation effectiveness with displacement ventilation  

SciTech Connect

Displacement ventilation may provide better indoor air quality than mixing ventilation. Proper design of displacement ventilation requires information concerning the air temperature difference between the head and foot level of a sedentary person and the ventilation effectiveness at the breathing level. This paper presents models to predict the air temperature difference and the ventilation effectiveness, based on a database of 56 cases with displacement ventilation. The database was generated by using a validated CFD program and covers four different types of US buildings: small offices, large offices with partitions, classrooms, and industrial workshops under different thermal and flow boundary conditions. Both the maximum cooling load that can be removed by displacement ventilation and the ventilation effectiveness are shown to depend on the heat source type and ventilation rate in a room.

Yuan, X.; Chen, Q.; Glicksman, L.R.

1999-07-01

133

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

134

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: Folin–Ciocalteu 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 40°C to 100°C). However, TPC and TFC were not significantly different (P > 0.05) at the extraction temperatures 90°C and 100°C. 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

135

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

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

136

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

137

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

Microsoft Academic Search

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

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

138

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.

139

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

140

Growth and Survival of Larval and Juvenile Gila Chub at Different Temperatures  

E-print Network

Growth and Survival of Larval and Juvenile Gila Chub at Different Temperatures ANDREW A. SCHULTZ, and 328C) and two sizes of juvenile Gila chub (20, 23, 26, and 298C). Growth of larvae was highest at 288C. Although growth of small (32­49 mm total length) and large (52­72 mm) juveniles generally increased

Bonar, Scott A.

141

The effects of different dressings on the skin temperature of the knee during cryotherapy  

Microsoft Academic Search

Aim: To assess the effect of different dressing types on the efficiency of cryotherapy. Methods: Eighteen normal volunteers were divided equally into group 1—no dressing, group 2—thin adhesive dressing (tegaderm™), and group 3—bulky dressing (“wool and crepe”). Cryotherapy (cryocuff® and autochill®) was applied to one knee with the other knee serving as control. Skin temperature was measured bilaterally every 5

Talal Ibrahim; Shong Meng Ong; Grahame John Saint Clair Taylor

2005-01-01

142

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

Microsoft Academic Search

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

J. V. García-Pérez; J. A. Cárcel; G. Clemente; A. Mulet

2008-01-01

143

Influence of different daily mean formulas on monthly and annual averages of temperature  

Microsoft Academic Search

For eight Swiss stations with daily records available since the turn of the century, daily mean temperatures are computed in two ways. The long term behaviour of the resulting monthly and annual averages is compared for the two different daily mean formulas. Qualitatively both types of daily means show similar interannual variations. There are however changes in the quantitative description

R. O. Weber

1993-01-01

144

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 (600–1100 °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

145

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

Microsoft Academic Search

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

W. F. Nolan; H. M. Frankel

1982-01-01

146

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, Yunnan, People's Republic of China 2 Eastern Bee Research Institute, Yunnan Agricultural University The ecological success of honey bees depends in part on their ability to thermoregulate and to thereby forage

147

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

PubMed

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

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

1934-07-20

148

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 40.5°C. 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 30.48°C. The maximum observed rate of growth, and the maximum yield, were found to be at 30°C. 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

149

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

150

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 20°C. The response in terms of biomass production for the genotype MPA11 was clearly different from the other two genotypes: genotype MPA11 produced heavier seedlings at all temperatures but the root biomass of this genotype decreased with increasing temperature, reaching the lowest value at 35°C. In contrast, root biomass of genotypes MPB01 and IAC80 was not affected by temperature, suggesting that the roots of these genotypes are less sensitive to changes in temperature. In addition, an increasing temperature decreased the root to shoot ratio, which suggests that biomass allocation between below- and above ground parts of the plants was strongly affected by the temperature. Carbohydrate contents were reduced in response to increasing temperature in both roots and cotyledons, whereas amino acids accumulated to higher contents. Our results show that a specific balance between amino acids, carbohydrates and organic acids in the cotyledons and roots seems to be an important trait for faster and more efficient growth of genotype MPA11. Conclusions An increase in temperature triggers the mobilization of carbohydrates to support the preferred growth of the aerial parts, at the expense of the roots. A shift in the carbon-nitrogen metabolism towards the accumulation of nitrogen-containing compounds seems to be the main biochemical response to support growth at higher temperatures. The biochemical changes observed in response to the increasing temperature provide leads into understanding plant adaptation to harsh environmental conditions, which will be very helpful in developing strategies for R. communis crop improvement research. PMID:25109402

2014-01-01

151

Temperature and PMA affect different phases of exocytosis in bovine chromaffin cells.  

PubMed

Amperometry was used to study secretory kinetics of single bovine chromaffin cells stimulated by transient depolarizations at different temperatures. The initial rate of release was moderately enhanced when the temperature was raised from 18 to 22 and 37 degrees C. Secretion increased drastically at a later period, 5-10 s after the initiation of stimulus. Interestingly, incubation of the cells with phorbol 12-myristate 13-acetate (PMA) clearly enhanced fast secretory components. In addition, the rate of secretion of the slower component recruited by prolonged depolarizations (t > 30 s) was unaffected at the range of temperatures normally used in secretory experiments (22-37 degrees C). A 'counting events' analysis of secretion, which avoids the influence of event charge changes, showed specific increases in a population of vesicles fusing between 7 and 12 s over the same range of temperatures, and a marked increase in vesicles fusing during the initial phase (1-5 s), of PMA-treated cell secretion. An analysis of temperature influence on transient components released by high sucrose, the secretion elicited by cell permeabilization with digitonin, and studies of the individual characteristics of amperometric events, allow us to conclude that an increase in the size of a secondary-released vesicle population is the main factor contributing to temperature-dependent enhancement of secretion, in clear contrast to the enhancement of fast releasable pools caused by phorbol esters. PMID:11298798

Gil, A; Viniegra, S; Gutiérrez, L M

2001-04-01

152

Temperature dependence of Raman scattering in bulk 4H-SiC with different carrier concentration.  

PubMed

Raman spectra of three bulk 4H-SiC wafers with different free carrier concentration were measured at temperature from 80 K to 873 K. As temperature increases, Raman peaks of most optical phonon modes show monotonous down shift. An anomalous non-monotonous variation with temperature, was observed in the A(1) longitudinal optical (LO) mode from doped samples. Two methods of theoretical fitting, one-mode (LO-plasma coupled (LOPC) mode) and two-mode (A(1)(LO) + LOPC) fitting, are employed to analyze this anomalous phenomenon. Theoretical simulations for temperature dependent Raman spectra by using two methods are critically examined. It turns out that one-mode method conforms well the experimental results, while two-mode method is untenable in physics. The non-monotonous variation of blue-red shifts with temperature for LOPC mode from doped 4H-SiC could be explained by the influence from ionization process of impurities on the process of Raman scattering. A quantitative description on temperature dependent Raman spectra for doped 4H-SiC is achieved, which matches well to experimental data. PMID:24216868

Sun, Hua Yang; Lien, Siou-Cheng; Qiu, Zhi Ren; Wang, Hong Chao; Mei, Ting; Liu, Chee Wee; Feng, Zhe Chuan

2013-11-01

153

Dust detection over desert surfaces with thermal infrared bands using dynamic reference brightness temperature differences  

NASA Astrophysics Data System (ADS)

The brightness temperature difference (BTD) between two thermal infrared bands is a common index for dust detection. However, the BTD is sensitive to the observed temperature, which hinders its use in automatic dust detection, especially over desert land surfaces. In this paper, a dynamic reference brightness temperature differences (DRBTD) algorithm was developed to detect dust by removing the influence of the observed temperature on the BTD. Using long-term MODIS observations, the algorithm establishes the clear-sky linear relationships pixel by pixel between the brightness temperatures (BTs) at 12 and 11 µm channels and the relationships between the BTs at 8.6 and 11 µm channels. From these relationships, the reference BTDs are dynamically generated according to the observed brightness temperatures. Next, the DRBTDI, which is the difference of the observed BTD and the reference BTD, is created and used to separate the dust from other observed objects. This algorithm is applied to MODIS observations to detect several dust events during the daytime and the nighttime over Mongolia and northwestern and northern China. The results are compared with Ozone Monitoring Instrument aerosol index (OMI AI), MODIS Deep Blue aerosol optical depth (AOD), and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations. The comparisons indicate that the DRBTD algorithm can effectively distinguish dust from clouds and land surface. During the daytime, the DRBTDI is correlated with the OMI AI and MODIS AOD with a correlation coefficient of Pearson (r) of 0.79 and 0.77, respectively. At night, the DRBTDI is correlated with the CALIOP dust AOD with an r of 0.78.

Liu, Yang; Liu, Ronggao; Cheng, Xiao

2013-08-01

154

Photoreflectance Investigations of Temperature Dependence of the ``Different'' Energy Gaps in GaInNAs Compounds  

NASA Astrophysics Data System (ADS)

In this paper, we report photoreflectance investigations of GaInNAs layers almost lattice-matched to GaAs substrate and annealed at different temperatures. Our investigations done from 10 K to room temperature give evidence that these layers exhibit several distinct band gaps. These distinct band gaps, which were found to co-exist, are associated with different nitrogen bonding configurations (N-Ga4-mInm (0? m ?4) short-range-order clusters). The annealing-induced blueshift of GaInNAs band gap energy, which is usually observed in this system, is due to the change in the intensity of PR resonances related to different N-Ga4-mInm configurations.

Kudrawiec, R.; Misiewicz, J.; Pavelescu, E.-M.; Konttinen, J.; Pessa, M.

2005-06-01

155

Temperature Integration: an efficient procedure for calculation of free energy differences  

E-print Network

We propose a method, Temperature Integration, which allows an efficient calculation of free energy differences between two systems of interest, with the same degrees of freedom, which may have rough energy landscapes. The method is based on calculating, for each single system, the difference between the values of lnZ at two temperatures, using a Parallel Tempering procedure. If our two systems of interest have the same phase space volume, they have the same values of lnZ at high-T, and we can obtain the free energy difference between them, using the two single-system calculations described above. If the phase space volume of a system is known, our method can be used to calculate its absolute (versus relative) free energy as well. We apply our method and demonstrate its efficiency on a toy model of hard rods on a 1-dimensional ring.

Farhi, Asaf; Bon, Michael; Caticha, Nestor; Mak, Chi H; Domany, Eytan

2012-01-01

156

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

NASA Astrophysics Data System (ADS)

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

YAN, Y.; Onishi, T.

2013-12-01

157

Thermographic imaging of facial skin—gender differences and temperature changes over time in healthy subjects  

PubMed Central

Objectives To assess changes in facial skin temperature over time, to identify sources of variation related to skin temperature and to evaluate interobserver reproducibility in measurements of the thermograms. Methods 62 volunteers (32 females, 30 males, mean age 23.4, range 19.5–29.5 years) underwent thermography of the face (left and right side lateral images) on four occasions with approximately 2 months between each session. Three observers recorded the images and marked regions of interest (ROIs) in each image using dedicated software. Smoking, exercise habits and use of oral contraceptives were recorded. Results A significant difference between sessions (?1 °C, p < 0.001) and between observers (?0.11 °C, p < 0.001) was identified. The difference between sides was not significant (?0.07 °C, p = 0.7). None of the interactions between side, session and observer were significant. Smoking, exercise habits and oral contraceptive intake were not significant impact factors when included as covariates in the analysis (p > 0.1). ROI temperature was significantly higher in males than in females (0.7 °C, p < 0.001). A mixed model analysis of variance showed that observer had little impact on the expected standard deviation, whereas session and subject had a greater impact. Conclusions Face temperature is symmetrical and varies over time. The non-significant difference between sides is highly reproducible, even between observers. PMID:22554986

Christensen, J; Vaeth, M; Wenzel, A

2012-01-01

158

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

159

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 (6.8°C) 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

160

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 14°C were measured at 25°C 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 30°C. 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 14°C, 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 14°C after growth at 30°C for 2 days had the same alternative oxidase capacity as seedlings grown at 30°C. Seedlings grown at 14°C for 10 to 12 days, then transferred to 30°C, 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 20°C. At 41°C, very little alternative oxidase was measured, i.e., the mitochondrial oxygen uptake was almost completely sensitive to cyanide. This inactivation at 41°C was reversible. After incubation at 41°C, the alternative oxidase capacity measured at 25°C 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 41°C as they did when incubated at 25°C. 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

161

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

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

162

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

163

Comparison of the spores of Paenibacillus polymyxa prepared at different temperatures.  

PubMed

Paenibacillus polymyxa SQR-21, which is antagonistic against Fusarium oxysporum, is used as a biocontrol agent and, when mixed with organic substances for solid fermentation, produces a bioorganic fertilizer. The spores of P. polymyxa prepared at different temperatures were characterized with respect to the dipicolinic acid content, heat resistance, fatty acid composition and germination. Spores prepared at 37°C showed higher heat resistance than those prepared at 25 and 30°C. However, the germination rate was negatively correlated with the sporulation temperature. The maximum germination rate of the spores prepared at 25°C was 1.3-times higher than the spores prepared at 30°C. The sporulation temperature thus affects the resistance and germination properties of P. polymyxa spores. These results are useful for the production of improved bio-organic fertilizer. PMID:22294453

Huo, Zhenhua; Zhang, Nan; Raza, Waseem; Huang, Xinqi; Yong, Xiaoyu; Liu, Yunpeng; Wang, Dandan; Li, Shuqing; Shen, Qirong; Zhang, Ruifu

2012-05-01

164

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

PubMed

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

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

2008-06-01

165

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.

2014-03-01

166

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?×?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?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

167

Effect of temperature on different stages of Romanomermis iyengari, a mermithid nematode parasite of mosquitoes.  

PubMed

The effect of temperature (20 degrees-35 degrees C) on different stages of Romanomermis iyengari was studied. In embryonic development, the single-cell stage eggs developed into mature eggs in 4.5-6.5 days at 25-35 degrees C but, required 9.5 days at 20 degrees C. Complete hatching occurred in 7 and 9 days after egg-laying at 35 and 30 degrees C, respectively. At 25 and 20 degrees C, 85-96% of the eggs did not hatch even by 30th day. Loss of infectivity and death of the preparasites occurred faster at higher temperatures. The 50% survival durations of preparasites at 20 and 35 degrees C were 105.8 and 10.6 hr respectively. They retained 50% infectivity up to 69.7 and 30.3 hr. The duration of the parasitic phase increased as temperature decreased. Low temperature favoured production of a higher proportion of females which were also larger in size. The maximum time taken for the juveniles to become adults was 14 days at 20 degrees C and the minimum was 9 days at 35 degrees C. Oviposition began earlier at higher temperature than at lower temperature. However, its fecundic period was shorter at 20 degrees C than at 35 degrees C indicating enhanced rate of oviposition at 20 degrees C. Fecundity was adversely affected at 20 degrees C and 35 degrees C. It is shown that the temperature range of 25 degrees-30 degrees C favours optimum development of R. iyengari. PMID:8524066

Paily, K P; Balaraman, K

1994-01-01

168

Development of free-living stages of Strongyloides ratti under different temperature conditions.  

PubMed

It is well known that the Strongyloides species have two different developmental courses-direct and indirect development-and selection of these courses is affected by various environmental factors. This study examined the effect of temperature on the development of first-stage larvae (L1s) of Strongyloides ratti, to clarify how larvae adapt and survive at unsuitable temperatures. It was revealed that L1s cultured at 4 or 10 °C for 120 h could not develop because of growth arrest or delay. However, L1s could develop after transfer to culture at 25 °C for 48 h. Although larvae cultured at 25 °C take indirect development, larvae subjected to low-temperature stimulation (at 4 or 10 °C) take direct development into infective third-stage larvae (L3s), and only 1 min of low-temperature stimulation was sufficient to induce direct development. Morphological study of low-temperature-stimulated L3s revealed that those stimulated at 4 °C (L3-4) showed less development, but those stimulated at 10 °C (L3-10) developed as well as the control (no low-temperature stimulation). Furthermore, we revealed that L3-10 showed similar infectivity to the control when they were injected subcutaneously into rats as the final host, which indicated that L3-10 grew normally. We conclude that S. ratti has a survival strategy of growth arrest or delay if excreted in cold conditions. Moreover, even if they start development after transfer to suitable conditions, they memorize low-temperature stimulation, which leads them to direct development thereafter so that they can immediately infect the final host. PMID:24043614

Sakamoto, Maki; Uga, Shoji

2013-12-01

169

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

170

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

PubMed

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

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

2013-01-01

171

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 31°C. Calcification was most rapid at 27 and 31°C. 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

172

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

PubMed Central

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

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

2013-01-01

173

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

PubMed

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

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

2013-01-01

174

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

PubMed

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

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

2010-02-01

175

Numerical Modelling of Airflow and Temperature Distribution in a Living Room with Different Heat Exchange Conditions  

NASA Astrophysics Data System (ADS)

Numerical mathematical modelling of the indoor thermal conditions and of the energy losses for separate rooms is an important part of the analysis of the heat-exchange balance and energy efficiency in buildings. The measurements of heat transfer coefficients for bounding structures, the air-tightness tests and thermographic diagnostics done for a building allow the influence of those factors to be predicted more correctly in developed numerical models. The temperature distribution and airflows in a typical room (along with the heat losses) were calculated for different heater locations and solar radiation (modelled as a heat source) through the window, as well as various pressure differences between the openings in opposite walls. The airflow velocities and indoor temperature, including its gradient, were also analysed as parameters of thermal comfort conditions. The results obtained show that all of the listed factors have an important influence on the formation of thermal comfort conditions and on the heat balance in a room.

Gendelis, S.; Jakovi?s, A.

2010-01-01

176

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-25°C , and they are released at 3atm-10-6atm-25°C . 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

177

[An experimental research on different temperature sintered bone as carrier of bone morphogenetic protein].  

PubMed

This study was conducted to find perfect temperature sintered bone as carrier of bone morphogenetic protein (BMP). The different temperature active sintered bones, which were made up of calcine bone and bone morphogenetic protein, were implanted into the defects of rabbit radius. Compared with the sintered bone of 600 degrees C, the sintered bone of 900 degrees C and 1200 degrees C could induce more pieces of bone formation and be replaced by new bone. There were more pieces of new bone formation in sintered bone of 900 degrees C and 1200 degrees C than those in sintered bone of 600 degrees C (P<0.05). There was no difference between the sintered bone of 900 degrees C and 1 200 degrees C (P>0.05). In comparison with the sintered bone of 600 degrees C and 1200 degrees C, the sintered bone of 900 degrees C may be the choicest carrier of bone morphogenetic protein. PMID:16706368

Zang, Hongmin; Liu, Yiheng; Chen, Junchang; Wang, Kunzheng

2006-04-01

178

Thermodynamic and transport properties of some biologically active compounds in aqueous solutions at different temperatures  

Microsoft Academic Search

The experimental data of density and viscosity have been obtained for aqueous solutions of biologically active compounds like salbutamol sulphate (SS), diethylcarbamazine citrate (DEC), and chlorpheniramine maleate (CPM) in the concentration range (0 to 0.15)mol·kg?1 at three different temperatures. The derived parameters, such as apparent molar volume of solute (?V)), limiting apparent molar volume of solute (?V0), limiting apparent molar

Sudhakar S. Dhondge; Sangesh P. Zodape; Dilip V. Parwate

2011-01-01

179

Surface anisotropy characterization and microstructure of Cu–W thin films at different annealing temperatures  

Microsoft Academic Search

Cu–W 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 Cu–W

Wang Yuan; Bai Xuanyu; Xu Kewei

2004-01-01

180

Mineralization of Hormones in Breeder and Broiler Litters at Different Water Potentials and Temperatures  

Microsoft Academic Search

When poultry litter is landspread, steroidal hormones present in the litter may reach surface waters, where they may have undesirable biological effects. In a laboratory study, we determined the mineral- ization of (4- 14 C)-labeled 17b-estradiol, estrone, and testosterone in breeder litter at three different water potentials (256, 224, and 212 MPa) and temperatures (25, 35, and 45C), and in

Sarah N. J. Hemmings; Peter G. Hartel

2006-01-01

181

Charge-discharge characteristics of the mesocarbon microbeads heat-treated at different temperatures  

Microsoft Academic Search

Mesocarbon microbeads (MCMB) is one of the promising carbon materials as anodes for rechargeable lithium batteries among commercially available carbon materials. have examined the correlation between carbon structures and charge-discharge characteristics of the MCMBs prepared at different heat-treatment temperatures. It was found that the MCMB heat-treated at 700 C possesses a tremendously high charge-discharge capacity of 750 Ah\\/kg. This suggests

Akihiro Mabuchi; Katsuhisa Tokumitsu; Hiroyuki Fujimoto; Takahiro Kasuh

1995-01-01

182

Central–peripheral temperature difference, blood pressure, and arginine vasopressin in preterm neonates undergoing volume expansion  

Microsoft Academic Search

AIMTo examine the effect of intravascular volume expansion for the treatment of hypovolaemia in sick preterm neonates.METHODSAn intravenous infusion of 20 ml per kg of 4.5 % albumin was given to 14 preterm neonates. The effects on systolic blood pressure, central peripheral temperature difference (c-pT), and plasma arginine vasopressin concentration (pAVP) were measured.RESULTSThirteen babies showed a rise in systolic blood

Heather J Lambert; Peter H Baylis; Malcolm G Coulthard

1998-01-01

183

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

184

Evaluating Performance of Ecologically Sound Organic Substrates under Different Temperature Regimes  

Microsoft Academic Search

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

SHAHIDUL ISLAM

185

Shelf life of packaged sliced dry fermented sausage under different temperature.  

PubMed

The aim of this study was to investigate the shelf-life of commercial sliced dry fermented sausage during storage at different temperatures. Different laminate composition was used for vacuum and nitrogen (100% N(2)) packaging. The microbiological, physico-chemical and sensory parameters were analysed during 120 days storage at 4, 22 and 37°C. Packaging materials were analysed for their barrier characteristic (oxygen permeability). Sensory quality limited the shelf-life of sliced dry fermented sausages before the limiting effects of microbial proliferation occurred. Nitrogen atmosphere packaging allowed longer storage (>120 days) than vacuum (95 days) packaged dry fermented sausages at 4°C. PMID:23305830

S?etar, Mario; Kova?i?, Edita; Kurek, Mia; Gali?, Kata

2013-04-01

186

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

187

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.

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

2014-10-01

188

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 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. PMID:24375056

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

2014-10-01

189

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

190

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

191

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

E-print Network

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 $\\kappa$) of crystalline water ice in this spectral range, including a detailed inspection of the temperature dependence, which had not been done in such detail before. We measured the transmission of three ice layers with different thickness at wavelengths $\\lambda=45...1000$ microns at temperatures $\\vartheta = 10...250$ K. We found a change in the spectral dependence of $\\kappa$ at a wavelength of $175 \\pm 6$ microns. At shorter wavelengths, $\\kappa$ 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 the behaviour is probably caused by a characteristic absorption band of water ice. The measured data were fitted by a power-law mo...

Reinert, Caroline; Krivov, Alexander; Löhne, Torsten; Mohr, Pierre

2014-01-01

192

Prediction of the thermal imaging minimum resolvable (circle) temperature difference with neural network application.  

PubMed

Thermal imaging is an important technology in both national defense and the private sector. An advantage of thermal imaging is its ability to be deployed while fully engaged in duties, not limited by weather or the brightness of indoor or outdoor conditions. However, in an outdoor environment, many factors, including atmospheric decay, target shape, great distance, fog, temperature out of range and diffraction limits can lead to bad image formation, which directly affects the accuracy of object recognition. The visual characteristics of the human eye mean that it has a much better capacity for picture recognition under normal conditions than artificial intelligence does. However, conditions of interference significantly reduce this capacity for picture recognition for instance, fatigue impairs human eyesight. Hence, psychological and physiological factors can affect the result when the human eye is adopted to measure MRTD (minimum resolvable temperature difference) and MRCTD (minimum resolvable circle temperature difference). This study explores thermal imaging recognition, and presents a method for effectively choosing the characteristic values and processing the images fully. Neural network technology is successfully applied to recognize thermal imaging and predict MRTD and MRCTD (Appendix A), exceeding thermal imaging recognition under fatigue and the limits of the human eye. PMID:18988953

Fang, Yi-Chin; Wu, Bo-Wen

2008-12-01

193

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 800 °C) 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

Ortuño, Nuria; Moltó, Julia; Conesa, Juan A; Font, Rafael

2014-08-01

194

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

PubMed

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

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

2013-08-01

195

Tilted microlens fabrication method using two photoresists with different melting temperatures  

NASA Astrophysics Data System (ADS)

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

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

2014-02-01

196

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

NASA Astrophysics Data System (ADS)

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

D'Agostino, Roberta; Lionello, Piero

2014-05-01

197

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

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

2006-01-01

198

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

199

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

200

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

NASA Astrophysics Data System (ADS)

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

Bérut, A.; Petrosyan, A.; Ciliberto, S.

2014-09-01

201

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

NASA Technical Reports Server (NTRS)

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

Fymat, A. L.

1977-01-01

202

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

PubMed Central

Statement of Problem: For a luting agent to allow complete seating of prosthetic restorations, it must obtain an appropriate flow rate maintaining a minimum film thickness. The performance of recently introduced luting agents in this regard has not been evaluated. Purpose: To measure and compare the film thickness and flow properties of seven resin-containing luting cements at different temperatures (37°C, 25°C and10°C). Material and Methods: Specimens were prepared from five resin luting cements; seT (SDI), Panavia F (Kuraray), Varioloink II (Ivoclar), Maxcem (Kerr), Nexus2 (Kerr) and two resin-modified glass-ionomer luting cements (RM-GICs); GC Fuji Plus (GC Corporation), and RelyX Luting 2 (3 M/ESPE). The film thickness and flow rate of each cement (n=15) was determined using the test described in ISO at three different temperatures. Results: There was a linear correlation between film thickness and flow rate for most of the materials. Cooling increased fluidity of almost all materials while the effect of temperature on film thickness was material dependent. At 37°C, all products revealed a film thickness of less than 25µm except for GC Fuji Plus. At 25°C, all cements produced a film thickness of less than 27 µm except for seT. At 10°C, apart from seT and Rely X Luting 2, the remaining cements showed a film thickness smaller than 20 µm. Conclusion: Cooling increased fluidity of almost all materials, however. the film thickness did not exceed 35 µm in either condition, in spite of the lowest film thickness being demonstrated at the lowest temperature. PMID:24724120

Bagheri, R

2013-01-01

203

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 22°C. 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 22°C, respectively. The LAB population showed an increase at 12 and 22°C 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; González-García, Patricia; Rodríguez-Lázaro, David

2014-08-01

204

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

205

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

PubMed

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

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

2013-03-15

206

Room-temperature AlGaAsSb/InGaAsSb heterojunction phototransistors  

NASA Astrophysics Data System (ADS)

We present room-temperature AlGaAsSb/InGaAsSb heterojunction phototransistors (HPT) with a cutoff wavelength (50% of maximum quantum efficiency) of 2.4 ?m and 2.15 ?m. AlGaAsSb/InGaAsSb HPT structures were grown by molecular beam epitaxy (MBE) or metal-organic chemical vapor deposition (MOCVD). This work is a continuation of a preceding project, which was carried out using liquid phase epitaxy (LPE) grown AlGaAsSb/InGaAsSb/GaSb heterostructures. Although the LPE-related work resulted in the fabrication of an HPT with excellent parameters, MBE and MOCVD - compared to LPE - provides better control over doping levels, composition and width of the AlGaAsSb and InGaAsSb layers, compositional and doping profiles, especially with regard to abrupt heterojunctions. HPT with different diameter of photosensitive area (75, 200, 300 and 1000 ?m) were fabricated and characterized. In particular, I-V characteristics, spectral response and noise, as well as detectivity and noise-equivalent-power were determined in a broad range of temperatures and bias voltages. Advantages of HPT integration with diffractive optical elements (DOE) were demonstrated.

Swaminathan, K.; Sulima, O. V.; Refaat, T. F.; Dillon, T.; Marchena, E.; Faleev, N. N.; Abedin, M. N.; Singh, U. N.; Prather, D.

2006-05-01

207

Air exchange through doorways. The effect of temperature difference, turbulence and ventilation flow.  

PubMed Central

Analytical expressions have been derived for the exchange of air across doorways or similar apertures, in terms of the temperature difference between the spaces on both sides of the opening and the net volume of air flowing through this as a result of unbalanced air supply or extract. A simple allowance for turbulence which gives reasonable correspondence with observation is included. The formulae, which assume complete air mixing on both sides of the doorway up to the plane of the aperture, predict outflows from the warmer side, when there is an excess air supply to this side, which are progressively smaller than those observed as the temperature difference rises above 2-3 degrees C and the volume of excess air supply increases to produce an averaged outflow velocity greater than 0-1-0-15 m/s. This seems to be due to lack of mixing of the warm outflowing air with the cooler air mass. A correction factor for this can be deduced as a function of the pressure difference due to the excess air supply. The limiting magnitude and general form of this function are compatible with a simple theoretical model of the air flow patterns involved. PMID:267666

Lidwell, O. M.

1977-01-01

208

Charge-discharge characteristics of the mesocarbon microbeads heat-treated at different temperatures  

SciTech Connect

Mesocarbon microbeads (MCMB) is one of the promising carbon materials as anodes for rechargeable lithium batteries among commercially available carbon materials. have examined the correlation between carbon structures and charge-discharge characteristics of the MCMBs prepared at different heat-treatment temperatures. It was found that the MCMB heat-treated at 700 C possesses a tremendously high charge-discharge capacity of 750 Ah/kg. This suggests that there is another mechanism for the charge-discharge reaction besides a graphite intercalation compound mechanism which is well known. Therefore, the authors propose a cavity mechanism in which intercrystallite spaces in MCMB are capable of storing lithium species.

Mabuchi, Akihiro; Tokumitsu, Katsuhisa; Fujimoto, Hiroyuki; Kasuh, Takahiro [Osaka Gas Co., Osaka (Japan). Research and Development Center

1995-04-01

209

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

NASA Astrophysics Data System (ADS)

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.

Mohiuddin, Mohammad; van Hoa, Suong

2011-06-01

210

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

PubMed

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

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

2014-06-15

211

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

212

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

213

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 37°C 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 37°C, 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 20°C 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 20°C the number of lactic-acid bacteria (LAB) was significantly lower (P<0·05) and the number of yeast significantly higher (P<0·05) 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 20°C to preserve kefir grains as whey-fermentation starters. PMID:22717048

Londero, Alejandra; Hamet, María F; De Antoni, Graciela L; Garrote, Graciela L; Abraham, Analía G

2012-08-01

214

Characterisation of YAG:Ce powders thermal treated at different temperatures  

NASA Astrophysics Data System (ADS)

Submicronic, spherical, polycrystalline YAG:Ce powders with luminescence properties were synthesised through aerosol processing route from the corresponding nitrates solution. Additional heat treatment was performed in the temperature range from 1000 to 1200 °C in order to increase the crystallinity of the obtained cubic garnet phase. SEM examination and subsequent morphological analysis allowed studying the surface properties and particle size distributions. An Image Processor was used to measure particle surface roughness. Quantitative SEM/EDS analysis indicated the synthesised materials present high purity and compositional homogeneity. TEM and selected area electron diffraction (SAED) showed a high crystallinity of the samples. XRD patterns of the powders were recorded in the region of 2? = 10°-80°. The evolution of crystallite size was performed measuring of the broadening of a particular peak using the Scherrer equation. It was found that the crystallite size and bulk particles size vary with the applied temperature. The observed changes in function of the different thermal treatments were correlated with the photoluminescence (PL) properties of these materials.

Del Rosario, G.; Ohara, S.; Mancic, L.; Milosevic, O.

2004-11-01

215

Hot-Wire Deposition Study of Amorphous and Microcrystalline Silicon Using Different Temperature and Gas Flow  

NASA Astrophysics Data System (ADS)

?c-Si:H and ?-Si:H films were deposited using a novel Hot Wire Chemical Vapor Deposition system that employs a coiled filament and three separate process gas inlets. A series of films were deposited at filament temperatures Tf ranging from 1500 to 2100 °C and substrate temperatures Ts from 150 to 300 °C. Raman, UV-Visible and IR transmission measurement were taken on these samples. Results show films deposited at low Ts and high Tf tend to be microcrystalline while films deposited at high Ts and low Tf tend to be amorphous. A second series of films were deposited using different gas flow geometries. Films were microcrystalline when Si_2H6 and H2 were directed into the chamber via separate inlets: one through the coiled filament and the other through a gas ring next to the substrate. When both gases were directed into the chamber via the same gas inlet, amorphous films were obtained. * Work was supported by NREL under Thin Film Partnership Program ZAF-8-17619-14 and NDJ-2-30630-08.

Povolny, Henry; Deng, Xunming

2002-03-01

216

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

SciTech Connect

The size effect in body-centered cubic metals is comprehensively investigated through micro/nano-compression tests performed on focused ion beam machined tungsten (W), molybdenum (Mo) and niobium (Nb) pillars, with single slip [2 3 5] and multiple slip [0 0 1] orientations. The results demonstrate that the stress-strain response is unaffected by the number of activated slip systems, indicating that dislocation-dislocation interaction is not a dominant mechanism for the observed diameter dependent yield strength and strain hardening. Furthermore, the limited mobility of screw dislocations, which is different for each material at ambient temperature, acts as an additional strengthening mechanism leading to a material dependent size effect. Nominal values and diameter dependence of the flow stress significantly deviate from studies on face-centered cubic metals. This is demonstrated by the correlation of size dependence with the material specific critical temperature. Activation volumes were found to decrease with decreasing pillar diameter further indicating that the influence of the screw dislocations decreases with smaller pillar diameter.

Arzt, Eduard (INM - Leibniz Institute for New Materials and Saarland University, SaarbrÞucken, Germany); Gruber, Patrick A. (Karlsruhe Institute of Technology, Institut fÞur ZuverlÞassigkeit von Bauteilen und Systemen, Karlsruhe, Germany); Clark, Blythe G.; Frick, Carl P. (University of Wyoming, Laramie, WY); Schneider, Andreas S. (Max Planck Institute for Metals Research, Stuttgart, Germany)

2010-09-01

217

Different families of volatile organic compounds pollution control by microporous carbons in temperature swing adsorption processes.  

PubMed

In this research work, the three different VOCs such as acetone, dichloromethane and ethyl formate (with corresponding families like ketone, halogenated-organic, ester) are recovered by using temperature swing adsorption (TSA) process. The vapors of these selected VOCs are adsorbed on a microporous activated carbon. After adsorption step, they are regenerated under the same operating conditions by hot nitrogen regeneration. In each case of regeneration, Factorial Experimental Design (FED) tool had been used to optimize the temperature, and the superficial velocity of the nitrogen for achieving maximum regeneration efficiency (R(E)) at an optimized operating cost (OP(€)). All the experimental results of adsorption step and hot nitrogen regeneration step had been validated by the simulation model PROSIM. The average error percentage between the simulation and experiment based on the mass of adsorption of dichloromethane was 3.1%. The average error percentages between the simulations and experiments based on the mass of dichloromethane regenerated by nitrogen regeneration were 4.5%. PMID:22551633

Ramalingam, Shivaji G; Pré, Pascaline; Giraudet, Sylvain; Le Coq, Laurence; Le Cloirec, Pierre; Baudouin, Olivier; Déchelotte, Stéphane

2012-06-30

218

The Giant Magnetostriction of [Fe/Tb/Fe/Dy]n Multilayer Films Under Different Annealing Temperature  

NASA Astrophysics Data System (ADS)

The effect of annealing temperature on the magnetic and giant magnetostriction (GMS) of [Fe/Tb/Fe/Dy]n multilayer films were investigated. X-ray diffraction showed that the multilayer films' microstructures were still in amorphous at annealing temperature 300°C. The multilayer films began to crystalline at annealing temperature 400°C. The saturation magnetization of multilayer films increased by the increasing annealed temperature. The coercivity first decreased at annealing temperature 300°C and then increased when the annealing temperature was higher than 400°C. The multilayer films had good low-field GMS, and the magnetostriction of the multilayer films increased by the increasing annealing temperature.

Li, X. D.; Zhao, Z. J.; Feng, T.; Pan, L. K.; Huang, S. M.; Chen, Y. W.; Sun, Z.

219

Nitrous oxide emission by nitrification and denitrification in different soil types and at different soil moisture contents and temperatures  

Microsoft Academic Search

Nitrous oxide is produced from denitrification and nitrification processes in soils, and contributes to global warming and stratospheric ozone depletion. Laboratory experiments with six soils ranging in clay content between 4–12% were designed to investigate the effect of water and temperature on the partitioning of N2O from denitrification and nitrification. The nitrification rates at 70% field capacity (FC) were significantly

M Maag; F. P Vinther

1996-01-01

220

Determination of aspoxicillin (TA-058) by high-performance liquid chromatography. Stability at different temperatures.  

PubMed

A rapid and sensitive HPLC-method has been developed for the determination of serum concentrations of aspoxicillin (TA-058), a new semisynthetic beta-lactam antibiotic. Aspoxicillin was chromatographed with a phosphate buffer/methanol (92:8 v/v) mobile phase and a C-18 reversed phase column and was detected at a wavelength of 220 nm. The stability of aspoxicillin in serum and buffer at different temperatures was studied over a time period of 3 months. Furthermore, the degradation of aspoxicillin versus piperacillin was determined in serum and buffer at 37 degrees C. Aspoxicillin remains stable only at -70 degrees C whereas degradation has been observed at -20 degrees C and 4 degrees C. At 37 degrees C, 20% of aspoxicillin is degraded in serum within 24 h whereas piperacillin is completely degraded under the same conditions. PMID:3673331

Knöller, J; Schönfeld, W; Bremm, K D; König, W

1987-06-01

221

Critical Current Density Performance of Malic Acid Doped Magnesium Diboride Wires at Different Operating Temperatures  

NASA Astrophysics Data System (ADS)

We investigated the effects of different operating temperatures on the performance of transport critical current density, Jc, for MgB2 + 10 wt% C4H6O5 MgB2/Fe wires. It was shown that the Jc values of the malic acid doped wires sintered at 900°C reached 104 Acm-2 at 20 K and 5 T. The Jc value extrapolated to 2 T and 20 K exceeds the practical level of 105 Acm-2. According to the Kramer plots, the pinning force, FK = Jc1/2 x B1/4, is expected to be a linear function of magnetic field B. The irreversibility field, Birr, at which extrapolated FK reaches zero, was 1.8 T at 32.8 K, 2.8 T at 30 K, 5.7 T at 25 K, 8.6 T at 20 K, and 12.5 T at 15 K, respectively.

Xu, X.; Kim, J. H.; Zhang, Y.; Jercinovic, M.; Babic, E.

222

Equator-to-pole temperature differences and the extra-tropical storm track responses of the CMIP5 climate models  

NASA Astrophysics Data System (ADS)

This paper aims to understand the physical processes causing the large spread in the storm track projections of the CMIP5 climate models. In particular, the relationship between the climate change responses of the storm tracks, as measured by the 2-6 day mean sea level pressure variance, and the equator-to-pole temperature differences at upper- and lower-tropospheric levels is investigated. In the southern hemisphere the responses of the upper- and lower-tropospheric temperature differences are correlated across the models and as a result they share similar associations with the storm track responses. There are large regions in which the storm track responses are correlated with the temperature difference responses, and a simple linear regression model based on the temperature differences at either level captures the spatial pattern of the mean storm track response as well explaining between 30 and 60 % of the inter-model variance of the storm track responses. In the northern hemisphere the responses of the two temperature differences are not significantly correlated and their associations with the storm track responses are more complicated. In summer, the responses of the lower-tropospheric temperature differences dominate the inter-model spread of the storm track responses. In winter, the responses of the upper- and lower-temperature differences both play a role. The results suggest that there is potential to reduce the spread in storm track responses by constraining the relative magnitudes of the warming in the tropical and polar regions.

Harvey, B. J.; Shaffrey, L. C.; Woollings, T. J.

2014-09-01

223

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 humidity’s 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 42°C. 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 40°C., 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 42°C., at 100% humidity, there was a significant elevation in skin blood flow and skin temperature above the other four air humidity’s (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 42°C. 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

224

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

225

Acute effects of ozone on heart rate and body temperature in the unanesthetized, unrestrained rat maintained at different ambient temperatures  

SciTech Connect

The present studies were conducted to investigate the concentration-response characteristics of acute ozone (O3) exposure on the cardiovascular and thermoregulatory function of the unanesthetized, unrestrained rat, and to examine the modulating effects produced by changes in ambient temperature (T[sub a]) on the induced toxic response. For all studies, groups of male Fischer 344 rats (n=4-6/group) were implanted with radiotelemetry transmitters and allowed to recover overnight. The transmitters permitted continuous monitoring of electrocardiogram (ECG) and body core temperature (T[sub co]); heart rate (HR) was derived from the ECG signal. Frequency of breathing (f) was obtained in selected experiments by means of a Fenn box. All animals were monitored according to the following protocol: control (filtered air; 0.25 h); exposure (O3; 2 h); recovery (filtered air; 3-18 h). For the concentration-response experiments, O3 concentration was varied from 0.25-1.0 ppm and all exposures were conducted at an T[sub a] of 18-20 C. Significant decreases in HR and T[sub co] were demonstrated at O3 concentrations as low as 0.37 ppm.

Watkinson, W.P.; Aileru, A.A.; Dowd, S.M.; Doerfler, D.L.; Tepper, J.S.

1993-01-01

226

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

227

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

Microsoft Academic Search

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

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

2004-01-01

228

Influence of nickel chloride, chlorpyrifos, and imidacloprid in combination with different temperatures on the embryogenesis of the zebrafish Danio rerio.  

PubMed

Two independent types of stressors, chemicals and high temperatures, which frequently act together in the environment, are addressed in this study. Pesticides (imidacloprid and chlorpyrifos) as well as a metal salt (nickel chloride) were investigated for their toxic effect at different temperatures. Tests focused on the early development of zebrafish (Danio rerio) embryos and larvae (from fertilization up to 168 h postfertilization) when exposed to the three respective chemicals at an optimum temperature (26 degrees C) and three higher temperatures (up to 33.5 degrees C). At all temperatures tested, the two pesticides did not have a significant impact on the early development of the zebrafish at the highest test concentrations (imidacloprid, 50 mg/l; chlorpyrifos, 1 mg/l). Nickel led to a significant decrease of hatching success at all temperatures; the combination of elevated temperature and nickel exposure revealed a synergistic effect of both stressors. PMID:18661094

Scheil, Volker; Köhler, Heinz-R

2009-02-01

229

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 0.4°C. 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 (+1.8°C) and less variable SST (80% of months within 3.3°C range) compared to non-reef areas (80% of months within 7.0°C 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 30°C-32°C 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

230

Microbiological quality of carbonated and non-carbonated mineral water stored at different temperatures.  

PubMed

The microbiological quality of five brands of carbonated and non-carbonated mineral water sold in Poland was studied. The study was carried out on the survival of heterotrophic bacteria at 22 and 37 degrees C (pour plate technique) in the samples of mineral waters stored at 4 and 22 degrees C. The one hundred ten bottles (twenty two bottles of each of the five brands) of carbonated and uncarbonated mineral waters with different levels of dissolved solids and organic content were chosen to microorganisms study. Ten bottles of mineral water were studied initially. Fifty bottles were stored at 4 degrees C, the other fifty were kept at 22 degrees C. The haemolysing bacteria in 1 cm3; E. coli, P. aeruginosa and A. hydrophila in 250 cm3 of mineral water were unidentifiable. Total viable count of heterotrophic bacteria at 22 and 37 degrees C in 1 cm3 of mineral water was the highest respectively for brand T and for brands T and M; the lowest for brand Z. Initially, approximately 29% of 110 water samples (respectively 4% of carbonated and 55% of uncarbonated) had bacterial counts greater than Ministry of Health's standards, notwithstanding the number of water samples which doesn't perform requirements grew up to 47% (respectively 36% of carbonated and 58% of uncarbonated) when the time of TVC 37 and 22 degrees C incubation was elongated from 1 and 3 days to 3 and 14 days respectively. The temperature of storage was inessential for the numbers of studied microorganisms. The most important factors were the brand, time of storage and the carbonating or non-carbonating of water. The highest numbers of the bacteria analysed were detected in non-carbonating water, irrespective of the water brand and temperature of storage. PMID:16457377

Korzeniewska, Ewa; Filipkowska, Zofia; Domeradzka, Sylwia; W?odkowski, Kamil

2005-01-01

231

Cardiac output and shunt during voluntary activity at different temperatures in the turtle, Trachemys scripta.  

PubMed

Red-eared slider turtles (Trachemys scripta) were chronically instrumented with blood flow probes for a long-term study of voluntary behavior in an enriched laboratory setting. Cardiovascular measures consisting of total cardiac output (Q(tot)), pulmonary blood flow (Q(pul)), systemic blood flow (Q(sys)), net cardiac shunt (Q(shunt)), heart rate (HR), and stroke volume (SV) were obtained during spontaneous activity at a constant body temperature (Tb=2 degrees C) and at unstable (variable) T(b)'s ranging from 19 degrees to 37 degrees C. The effects of temperature and activity differed between the pulmonary and systemic circuits, with increases in Q(sys) due to HR alone, while both HR and SV contributed to gains in Q(pul). At stable 20 degrees C, cardiovascular responses during diving, submerged swimming, and walking were qualitatively similar, and increases in Q(tot) during activity ( approximately 2 x resting levels) were due to greater gains in Q(pul) than Q(sys). At unstable T(b)'s and in general, net Q(shunt) while active depended on the integration of individual physiological influences such as heating, cooling, and initial behavioral state acting on the cardiovascular system. During activity, net left-to-right (L-R) shunts predominated at constant T(b) of 20 degrees C (mean shunt fraction approximately 30%-40%), while both net L-R and right-to-left (R-L) shunts of varying size were found at unstable T(b)'s (19 degrees - 37 degrees C). PMID:14671716

Krosniunas, Egle H; Hicks, James W

2003-01-01

232

High Temperature Convective Drying of a Packed Bed with Humid Air at Different Humidities  

Microsoft Academic Search

Problem statement: Drying a packed bed of porous particle at high temperature with varying humidity of hot air is an attractive process. Many researches on experimental and simulation on a fixed bed drying at low and average temperature are proposed. Few studies showed drying at high temperature with humid air or using superheated steam. The latest is compared to dry

J. Sghaier; S. Messai; D. Lecomte; A. Belghith

2009-01-01

233

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

234

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 37.16°C. In the artery occlusion stage, the mean brain temperature of ischemic tissue was 1.16°C higher than the baseline; however, this increase was region dependent, with 1.72°C in the IP, 1.08°C in the infarct core, and 0.62°C 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

235

The production of ochratoxin A by Aspergillus ochraceus in raw coffee at different equilibrium relative humidity and under alternating temperatures  

Microsoft Academic Search

The effect of alternating temperatures in the storage of coffee was studied. From the day and night values, two average temperatures (25 and 14 °C) were chosen. Such changes may occur, mainly during storage in farm barns and transport. The study was carried out under different conditions of equilibrium relative humidity (ERH): 80%, 87% and 95% for the production of

Héctor Palacios-Cabrera; Marta H Taniwaki; Hilary C Menezes; Beatriz T Iamanaka

2004-01-01

236

Detection of Variations in Air Temperature at Different Time Scales During the Period 1889–1998 at Firenze, Italy  

Microsoft Academic Search

In an attempt to contribute to studies on global climatic change, 110 years of temperature data for Firenze, Italy, were analysed. Means and trends of annual and monthly temperatures (minimum, maximum and average) were analysed at three different time scales: short (20 years), medium (36–38 years) and long (55 years). Comparative changes in extreme events viz. frosts in the first

P. Vijaya Kumar; Marco Bindi; Alfonso Crisci; Giampiero Maracchi

2005-01-01

237

Quality index chart for different alloys and temperatures: a case study on aluminium die-casting alloys  

Microsoft Academic Search

The possibility of developing an analytical quality index chart for applications above room temperature valid for different alloys is explored. The testing temperature and the chemical composition of the material are incorporated into the analysis through their respective effects on the material's strain hardening rate and yield strength. The resulting quality index chart has been used to compare the performance

C. H Cáceres; M Makhlouf; D Apelian; L Wang

2001-01-01

238

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 27°C to 17°C for the summer case (Cold temperature treatment), or from 17°C to 27°C for the winter case (Warm temperature treatment). After 0.5, 1, 3, 6, 12, 24, 48, and 72 h of exposure time, shrimps were sampled and prepared for further analysis. The results showed that the effect of acute temperature changes on activities of HK was significant. Patterns of variations of the two glycolytic enzymes suggested that enzymes in the glycolysis cycle could adjust their activities to meet the acute temperature change. The HSP70 level increased in both cold and warm temperature treatments, suggesting that the rapid temperature changes activated the process of body’s self-protection. But the difference in expression peak of HSP70 might be related to the different body size and the higher thermal sensitivity to temperature increase than to temperature decrease of L. vannamei.

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

2010-09-01

239

Surface temperature differences between minerals in crystalline rocks: Implications for granular disaggregation of granites through thermal fatigue  

NASA Astrophysics Data System (ADS)

Thermal expansion differences between minerals within rocks under insolation have previously been assumed to drive breakdown by means of granular disaggregation. However, there have been no definitive demonstrations of the efficacy of this weathering mechanism. Different surface temperatures between minerals should magnify thermal expansion differences, and thus subject adjacent minerals to repeated stresses that might cause breakdown through fatigue failure. This work confirms the existence of surface temperature differences between minerals in granitic rocks under simulated short-term temperature fluctuations so as to discriminate their potential for initiating granular disaggregation. The influence of colour, as a surrogate for albedo, and crystal size, as a function of thermal mass are specifically identified because of their ease of quantification. Four rock types with a range of these properties were examined, and subjected to repeated short-term temperature cycles by radiative heating and cooling under laboratory conditions. Results show that while albedo is the main control for overall and individual maximum temperatures, crystal size is the main factor controlling higher temperature differences between minerals. Thus, stones with large differences of mineral sizes can undergo magnified stresses due to thermal expansion differences.

Gómez-Heras, Miguel; Smith, Bernard J.; Fort, Rafael

2006-08-01

240

[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

241

Low temperatures enhance the toxicity of copper and cadmium to Enchytraeus crypticus through different mechanisms.  

PubMed

Knowledge about how toxicity changes with temperature is important for determining the extent of safety factors required when extrapolating from standard laboratory conditions to variable field scenarios. In the present study, the authors evaluated the toxicity of Cu and Cd to the potworm Enchytraeus crypticus at 6 temperatures in the range of 11 °C to 25 °C. For both metals, reproductive toxicity decreased approximately 2.5-fold with increasing temperature. This is contrary to what most other studies have found. Measurements of the bioavailable fraction of the metals in the soils and the internal metal concentrations in the worms over time showed that the major cause of change in toxicity with temperature for Cu was the worms' ability to regulate internal concentration at high temperatures. Uptake of Cd increased with time at all temperatures and with higher rates at high temperatures. Hence, the lower toxicity of Cd at high temperatures is proposed to be due to the E. crypticus being more efficient at immobilizing Cd and/or repairing damages at high compared to low temperatures. The present study concludes that no consistent relationship between metal toxicity and temperature across species can be made. The metabolic dependence of the species in terms of regulating metal uptake, excretion, immobilization, damage, and repair processes, will be crucial factors in determining species susceptibility to metals at varying temperatures. PMID:23661382

Cedergreen, Nina; Nørhave, Nils Jakob; Nielsen, Kristoffer; Johansson, Hanna K L; Marcussen, Helle; Svendsen, Claus; Spurgeon, David J

2013-10-01

242

Social interaction and sex differences influence rat temperature circadian rhythm under LD cycles and constant light.  

PubMed

Circadian rhythms produce an efficient organization of animal behaviour over the 24h day. In some species, social cues have been found to have a role as synchronizers of these rhythms. Here, the influence of social interaction on rat circadian behaviour was investigated, addressing the question of whether cohabitation would produce a delay in the appearance of arrhythmicity under constant light conditions. To this end, the circadian rhythms of male and female rat body temperature were studied for 10days under light-dark conditions, followed by 33days under constant bright light. Half of the animals were maintained in individual cages, whilst the others were maintained in larger cages in groups of three rats of the same sex. Results showed that individual circadian rhythms under 24hour light-dark (LD) cycles were more stable and with higher amplitude in grouped than in isolated animals, and higher in males than in females. During the first days under constant light (LL), the stability of the rhythm was also higher in males than in females, but there were no differences according to the group. Moreover, we did not find significant differences in the time of circadian rhythm loss under LL, since high individual variability was found for this variable. On the other hand, female rats living in isolation showed a delayed acrophase in the circadian rhythm under LD conditions compared with those living in groups. These results suggest that cohabitation increases the internal coherence of circadian behaviour, and could be interpreted as indicating that living in isolation may induce a level of stress that disturbs manifestation of the circadian rhythm, especially in females, which are also more reactive than males to external signals. PMID:21402091

Cambras, T; Castejón, L; Díez-Noguera, A

2011-06-01

243

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

PubMed

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

Regalado, Carlos M; Ritter, Axel

2007-08-01

244

Upgrade of egg quality through different heat-combating systems during high environmental temperature.  

PubMed

The aim of the study was to find out the effect of various heat-combating systems (HCS) on the egg quality characteristics of commercial laying hens during high environmental temperature of the year. Three hundred pullets were wing banded and randomly divided into 15 experimental units comprising of 20 pullets each. These units were randomly allotted to five treatment groups, replicated thrice according to four heat-combating systems (desert cooling, water sprinkling, time limit feeding, ascorbic acid supplementation), and the control was maintained under the same housing system. The mean values of egg weight, eggshell thickness, Haugh unit, thick albumen height, yolk height, and yolk diameter were calculated. The layers kept under the influence of desert cooling produced eggs with more weight and thicker shells than those under other systems. Results of the present study did not show any difference in the shell thickness between water sprinkling and ascorbic acid supplementation as compared to the control group. Haugh unit and yolk index values obtained from the layers kept under various HCS did not significantly differ from those of the control group. All HCS significantly reduced the occurrence of blood spots in the eggs as compared to the control. All the treatments in general markedly reduced the incidence of meat spots in the eggs especially with the supplementation of ascorbic acid being the most effective. Among all of the treatments, the desert cooling system proved to be the best for producing better-quality eggs during hot periods of the year with less humidity. PMID:24839898

Anjum, Muhammad Safdar; Sandhu, Mansur Abdullah; Mukhtar, Nasir; Rahman, Zia-Ur

2014-10-01

245

Finite difference modelling of bulk high temperature superconducting cylindrical hysteresis machines  

NASA Astrophysics Data System (ADS)

A mathematical model of the critical state based on averaged fluxon motion has been implemented to solve for the current and field distributions inside a high temperature superconducting hysteresis machine. The machine consists of a rotor made from a solid cylindrical single domain HTS placed in a perpendicular rotating field. The solution technique uses the finite difference approximation for a two-dimensional domain, discretized in cylindrical polar co-ordinates. The torque generated or equivalently the hysteresis loss in such a machine has been investigated using the model. It was found that to maximize the efficiency, the field needs to penetrate the rotor such that B 0 /µ0 Jc R = 0.56, where B 0 is the applied field amplitude, Jc is the critical current density and R is the rotor radius. This corresponds to a penetration that is 27% greater than that which reaches the centre of the rotor. An examination of the torque density distributions across the rotor reveal that for situations where the field is less than optimal, a significant increase in the performance can be achieved by removing an inner cylinder from the rotor.

Barnes, G. J.; Dew-Hughes, D.; McCulloch, M. D.

2000-02-01

246

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

NASA Astrophysics Data System (ADS)

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.

2013-11-01

247

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

PubMed

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

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

2013-01-01

248

Determination of apparent ileal amino acid digestibility in rapeseed meal and cake processed at different temperatures using the direct and difference method with growing pigs.  

PubMed

Studies were conducted with ten barrows, average initial body weight 34.5 +/- 2.1 kg, fitted with a T-cannula at the distal ileum, to study the accuracy of determination of the apparent ileal digestibility (AID) values of crude protein (CP) and amino acids (AA) in rapeseed meal and cake and the effects of processing, using the difference method. Five corn starch-based diets in the studies were formulated to contain 17.7% CP and based on soybean meal, prepress-extraction rapeseed meal, prepress-extraction rapeseed meal plus soybean meal, high-temperature press rapeseed cake plus soybean meal, or low-temperature press rapeseed cake plus soybean meal as the sole source of dietary protein. The design was an incomplete Latin Square involving two three-week periods and five-treatments. It was found that the AID values of CP and most AA determined with the difference or direct method were significantly lower in rapeseed meal or cakes than soybean meal. The AID values of CP and most AA in prepress-extraction rapeseed meal, high-temperature press or low-temperature cakes determined with the difference method were no difference from those in prepress-extraction rapeseed meal determined with the direct method. The AID values of CP and AA in rapeseed meal and cake determined with the difference method were accurate, when the contribution of CP and AA from rapeseed was more than 50%. The AID values of CP and AA (especially lysine) were lower in the high-temperature press rapeseed cake than in the low-temperature press cake or the prepress-extraction meal. PMID:12556045

Li, Defa; Pengbin, Xi; Liming, Gong; Shijun, Fan; Canghai, Huang

2002-10-01

249

Infrared spectra of N- tert-butoxycarbonyl-amino acids at different temperatures  

NASA Astrophysics Data System (ADS)

The IR spectra of N- tert-butoxycarbonyl-amino acids and of the complex between N- tert-butoxycarbonyl- L-phenylalanine and pyridine are investigated at temperatures ranging from 25 to -180°C. A decrease of the temperature results in a contraction of the NH⋯O or OH⋯O hydrogen bonds. In this temperature range, linear correlations between the ?(NH) and ?(OH) stretching vibrations and the temperature are established. The slope of these correlations decreases with the R(O⋯O) or R(N⋯O) distances previously determined by X-ray diffraction.

Bruyneel, C.; Zeegers-Huyskens, Th.

2000-09-01

250

WHITE SUCKER 'CATOSTOMUS COMMERSONI' EMBRYO DEVELOPMENT, AND EARLY GROWTH AND SURVIVAL AT DIFFERENT TEMPERATURES  

EPA Science Inventory

White suckers (Catostomus commersoni) were exposed from fertilization through hatching to seven constant temperatures from 6.2 through 24.1C. High percentages of apparently normal larvae hatched at temperatures from 9.0 through 17.2C. Maximum percent hatch occurred at 15.2C, whil...

251

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

E-print Network

a magnetic field pointing out of the screen, according to computer simulations. Computer simulations suggest to an electric field and a temperature gradient. The team ran computer simulations of a two-micron-wide sample at the center of charge of the electron or hole "cloud," whereas the temperature gradient

Wu, Junqiao

252

Densities of mixtures containing n-alkanes with sunflower seed oil at different temperatures  

SciTech Connect

Densities for mixtures containing sunflower seed oil with pentane, hexane, heptane, and octane have been determined at various temperatures between 298.15 K and 313.15 K using a vibrating tube densimeter. The derived excess volumes have been correlated by the Redlich-Kister equation. All the systems showed negative deviations from ideality. The excess volumes increased with an increase in temperature.

Gonzalez, C.; Resa, J.M.; Ruiz, A.; Gutierrez, J.I. [Univ. del Pais Vasco, Vitoria (Spain). Dept. of Chemical Engineering] [Univ. del Pais Vasco, Vitoria (Spain). Dept. of Chemical Engineering

1996-07-01

253

Mechanical Performance of Hemp Fiber Polypropylene Composites at Different Operating Temperatures  

Microsoft Academic Search

In order to quantify the effect of temperature on the mechanical properties of hemp fiber polypropylene composites, formulations containing 25% and 40% (by weight) hemp fiber were produced and tested at three representative temperatures of 256, 296, and 336 K. Flexural, tensile, and impact tests, as well as dynamic mechanical analysis, were performed and the reduction in mechanical properties were

MEHDI TAJVIDI; NAZANIN MOTIE; GHONCHE RASSAM; ROBERT H. FALK; COLIN FELTON

2009-01-01

254

Acute toxicity of copper, chromate, zinc, and cyanide to freshwater fish: Effect of different temperatures  

Microsoft Academic Search

,all chemical processes in the animal are affected by the water temperature. Generally, the metabolism of fish increases approximately two-fold for each rise of 10~ although there are exceptions (PROSSER 1973). It would, therefore, seem that the toxic effect of chemical pollutants on fish would be influenced by temperature. In a survey of the literature, CAIRNS et al. (1975) concluded

Micke J. Smith; Alan G. Heath

1979-01-01

255

Investigation of Marginal Fit and Surface Roughness of Crowns, Due to Different Bench Set and Different Burnout Temperature Using Base Metal Alloy  

Microsoft Academic Search

The conventional investing technique is used most commonly for casting. Inspite of the popularity of this technique, it is\\u000a very time consuming. To save time of the patient, dentist and dental laboratory technician, accelerated casting technique\\u000a can be used. This study uses different bench set and different burnout temperatures and has been carried to investigate their\\u000a effects on marginal fit

Anurag HastiNarendra; Narendra P. Patil

2010-01-01

256

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

257

Different temperature adaptation in Arctic and Atlantic heterotrophic bacteria in the Barents Sea Polar Front region  

NASA Astrophysics Data System (ADS)

In the northern Barents Sea, at and around the Polar Front, carbon cycle variables were investigated during 2 weeks in late summer of 2007. Arctic Water primary production in the experimental period averaged 50 mmol C m- 2 day- 1, as estimated from satellite sensed chlorophyll. In Atlantic waters, which appeared to just have passed the culmination of a late summer bloom, primary production was 125 mmol C m- 2 day- 1. Total organic carbon (TOC) averaged 82.4 ?M C in the mixed layer, and the values showed a gradient with highest values to the southeast and lowest to the northwest. The distribution of TOC was not related to the distribution of Atlantic and Arctic waters, although the highest values were found in Atlantic Water. Integrated bacterial production in the mixed layer, as estimated from thymidine incorporation rates, averaged 6.3% of primary production. In Atlantic Water, over the depth of the mixed layer, bacterial production rate averaged 0.40 mmol C m- 3 day- 1, which was 6.6 times the average in Arctic Water and 2.3 times the average in the front regions. Below 30 m depth, bacterial production rates were generally higher in the Arctic Water than in the Atlantic Water. Moreover, when production rates of bacteria were compared according to temperature, the rates in Arctic Water were systematically higher than the rates in Atlantic Water. This difference implies that the heterotrophic bacteria from the Arctic have adapted towards higher growth efficiency than the bacteria in Atlantic Water.

Børsheim, Knut Yngve; Drinkwater, Kenneth F.

2014-02-01

258

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 25°C, 45°C, and 50°C to emulate the thermophilic and maturation stages of the composting process. Incubation at all temperatures caused significant physical deterioration of the polyester PU coupons and was associated with extensive fungal colonization. Terminal restriction fragment length polymorphism (TRFLP) analysis and pyrosequencing of the fungal communities on the PU surface and in the surrounding compost revealed that the population on the surface of PU was different from the surrounding compost community, suggesting enrichment and selection. The most dominant fungi identified from the surfaces of PU coupons by pyrosequencing was Fusarium solani at 25°C, while at both 45°C and 50°C, Candida ethanolica was the dominant species. The results of this preliminary study suggest that the composting process has the potential to biodegrade PU waste if optimized further in the future. PMID:24056469

Zafar, Urooj; Houlden, Ashley

2013-01-01

259

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

PubMed

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

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

2013-12-01

260

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 15°C and 40°C. Indeed, the cross between UH005 and UH250 with lateral root growth temperature optima at 34°C and 28°C, respectively, resulted in intermediate hybrids. At temperatures below and above 31°C, 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

261

Differences between observed and a coupled simulation of North Atlantic sea surface currents and temperature  

NASA Astrophysics Data System (ADS)

North Atlantic sea surface temperature (SST) distributions derived from observations and a coupled model from NOAA's Geophysical Fluid Dynamics Laboratory, CM2.1, are compared to evaluate the model's ability to simulate recent (1900 to the present) oceanic surface characteristics. The North Atlantic focus will limit our analyses to spatial scales less than gyre, scales usually not addressed in previous model-observation comparisons. Identifying model differences from observations at these scales will assist modelers in identifying problems to be considered and remedies to be applied. The properties compared are the mean annual SST, standard deviation, amplitude of the annual and semiannual harmonic, decadal meridional movements of the axis of the Gulf Stream, propagation of SST anomalies along the axis of the Gulf Stream, and 100-year trends in SST records. Because of the dependence of SST on surface currents, observed flow from surface drifters and simulated flow from 15 m fields are also compared. The model simulates the large-scale properties of all the variables compared. However, there are areas of differences in some variables that can be related to inadequacies in the simulated current fields. For example, the model Gulf Stream (GS) axis after separation from the western boundary is located some 100 km north of the observed axis, which contributes to an area of warmer simulated SSTs. The absence of a slope current in the same region that advects colder water from the Labrador Sea in the observations also contributes to this area of higher model SSTs. The model North Atlantic Current (NAC) is located to the east of the observed NAC contributing to a large area of SST discrepancy. The patterns of the amplitude of the annual harmonic are similar with maximum amplitude off the east coast of northern North America. The semiannual harmonic exhibits relatively large amplitudes (>1°C) north of about 55°N, a signal not found in the observations. In both the model and observations, a region of increased standard deviations encompasses the GS and NAC. The model simulates north-south migrations of the GS core but at a longer period (20 years) than observed. The model does not simulate the SST anomalies that propagate along the observed GS and NAC. The model captures both the spatial and temporal characteristics of the Atlantic Multidecadal Oscillation. Both model and observations exhibit a dipole in trends, with positive trends in the subtropical Atlantic and negative trends in the subpolar gyre. The modeled region of negative trends is limited to the western subpolar Atlantic. The observed trends extend farther to the east.

Molinari, Robert L.; Garraffo, Zulema; Snowden, Derrick

2008-09-01

262

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

PubMed

Arctic charr Salvelinus alpinus of the Hólar strain (mean ± s.e. body mass = 152·1 ± 3·1 g) were reared at four different salinity regimes at a constant temperature of 7·4° 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 > 0·05) 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; Smáradóttir, H; Steinarsson, A; Gústavsson, A; Johansson, M; Björnsson, B Th

2014-10-01

263

Abrasive wear behavior of cast iron coatings plasma-sprayed at different mild steel substrate temperatures  

NASA Astrophysics Data System (ADS)

Three kinds of cast iron coatings were prepared by atmospheric plasma spraying. During the spraying, the mild steel substrate temperature was controlled to be averagely 50, 180, and 240°C, respectively. Abrasive wear tests were conducted on the coatings under a dry friction condition. It is found that the abrasive wear resistance is enhanced with the substrate temperature increasing. SEM observations show that the wear losses of the coatings during the wear tests mainly result from the spalling of the splats. Furthermore, the improved wear resistance of the coatings mainly owes to the formation of oxides and the enhancement in the mechanical properties with the substrate temperature increasing.

Xing, Ya-zhe; Wei, Qiu-lan; Jiang, Chao-ping; Hao, Jian-min

2012-08-01

264

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

PubMed

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

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

2009-02-01

265

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

266

Different temperature renormalizations for heavy and light-hole states of monolayer-thick heterostructures  

Microsoft Academic Search

We have found that the energy splitting between peaks in the linearly polarized emission from the cleaved surface of an InAs\\/GaAs monolayer structure triples with increasing temperature in the range from 5 to 150K. For each polarization the main emission line corresponds to the radiative recombination of either heavy or light-hole excitons bound to the monolayer. The striking temperature behavior

A. R Goñi; A Cantarero; H Scheel; S Reich; C Thomsen; P. V Santos; F Heinrichsdorff; D Bimberg

2000-01-01

267

Experiments on convection heat transfer along a vertical flat plate between pools with different temperatures  

Microsoft Academic Search

This paper reports that to evaluate the heat removal capability of an external water wall-type containment vessel, which is a passive system for containment cooling, thermal-hydraulic behavior in the suppression and outer pools has been examined experimentally. The following results are obtained: A thermal stratification boundary, which separates the pools into an upper high-temperature region and a lower low-temperature region,

Y. Kataoka; T. Fukui; S. Hatamiya; T. Nakao; M. Naitoh; I. Sumida

1992-01-01

268

Temperature Effects on Eggs and Yolk Sac Larvae of the Summer Flounder at Different Salinities  

Microsoft Academic Search

The combined effects of temperature and salinity on eggs and yolk sac larvae of summer flounder Paralichthys dentatus were examined under controlled laboratory conditions. Fertilized eggs (early gastrula stage), obtained by induced spawning of captive broodstock at 17°C and 36 g\\/L salinity, were stocked (60 eggs\\/L) into forty-five 5-L translucent containers at temperatures of 16, 20, and 24°C and at

Wade O. Watanabe; Simon C. Ellis; Eileen P. Ellis; Michael W. Feeley

1999-01-01

269

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

270

Colour, myoglobin denaturation and storage stability of raw and cooked mutton chops at different end point cooking temperature.  

PubMed

In our study effect of different end point temperature (51 °C, 65 °C, 71 °C and 79 °C) on physicochemical and storage stability of mutton chops were evaluated. The L* (lightness) value and b* (yellowness) increased (P?temperature increased. As internal cooking temperature increased soluble myoglobin content decreased with a corresponding increase in percent myoglobin denatured. Raw mutton chops (uncooked) had lower level of oxidation (less TBA values) than cooked mutton irrespective of storage length. Initial APC of raw and cooked mutton chops ranged from log 1.75 to log 3.73 and was lower in higher end point cooking temperature. It can be concluded that as end point temperature increased, mutton chops appear less red and raw mutton had lower level of oxidation than cooked mutton chops. PMID:24803706

Sen, A R; Naveena, B M; Muthukumar, M; Vaithiyanathan, S

2014-05-01

271

Telenomus remus Nixon egg parasitization of three species of Spodoptera under different temperatures.  

PubMed

Telenomus remus Nixon is a promising biocontrol agent as an egg parasitoid of Spodoptera spp., but the lack of information on the host-parasitoid interactions in this system precludes its applied use in agriculture. Therefore, we studied the parasitism capacity of T. remus on eggs of Spodoptera cosmioides (Walker), Spodoptera eridania (Cramer), and Spodoptera frugiperda (Smith) in a range of temperatures (19, 22, 25, 28, 31, and 34?±?1°C) under controlled conditions (70?±?10% RH and 12 h photophase). Egg masses of Spodoptera spp. were offered to a single-mated T. remus female on a daily basis. More than 80% lifetime parasitism on eggs of S. cosmioides, S. frugiperda, and S. eridania was reached from 1 to 5, 1 to 7, and 1 to 9 days, respectively, at temperatures from 19 to 34°C. More than 80% parasitization was obtained at extreme temperatures for all hosts studied. Lifetime parasitization of S. frugiperda, S. cosmioides, and S. eridania was affected by temperature, with the lowest values for S. frugiperda (34°C) and S. cosmioides (19 and 34°C). Parasitization of S. eridania eggs was reduced around 18% at 28 and 31°C, but dropped more severely at 34°C. Parasitoid longevity was reduced as temperature increased. Thus, our data indicated that T. remus might be suitable as a biocontrol agent against S. eridania, S. cosmioides, and S. frugiperda in geographical areas that fit the temperature range studied here, even though T. remus parasitism was reduced at 34°C. PMID:23949860

Pomari, A F; Bueno, A F; Bueno, R C O F; Menezes, A O

2013-08-01

272

Aquatic hyphomycete strains from metal-contaminated and reference streams might respond differently to future increase in temperature.  

PubMed

Aquatic hyphomycetes, a group of polyphyletic fungi, have been reported in streams contaminated with metals. This tolerance to metal contamination however can result in limited performance and limited ability to cope with additional environmental change. The predicted increase in water temperature, as a consequence of global warming, will have an additional effect on many streams. The sensitivity to temperature of strains of three aquatic hyphomycete species isolated from a metal-contaminated stream and an uncontaminated stream was assessed by determining their radial growth and activity (conidial production, oxygen consumption, mycelial biomass accumulation, fine particulate organic matter [FPOM] production, and microbial induced leaf mass loss) at 13 C (present water temperature in autumn) and at 18 C (predicted water temperature under global warming). Growth and reproductive activity generally were depressed for the strains isolated from the metal-contaminated stream when compared with those isolated from the unpolluted stream. These differences however were not translated into differences in FPOM production and leaf-litter mass loss, indicating that the strains isolated from the contaminated stream can decompose leaf litter similar to those of the reference stream. The 5 C increase in temperature stimulated fungal activity and litter decomposition, irrespective of species and strain. This might have strong effect on aquatic food-web and ecosystem functioning under global warming because increases in litter decomposition might lead to food shortage for higher trophic levels. The sensitivity to temperature depended on the response variable, species and strain. FPOM production was the variable most sensitive to temperature across strains and species and that for which temperature sensitivities differed most between strains. Fungal tolerance to metal contamination affects the extent to which its functions are stimulated by an increase in temperature, constituting an additional cost of metal tolerance. PMID:22123653

Ferreira, Verónica; Gonçalves, Ana Lúcia; Canhoto, Cristina

2012-01-01

273

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

274

A comparison of proline, thiol levels and GAPDH activity in cyanobacteria of different origins facing temperature-stress  

Microsoft Academic Search

Three cyanobacterial strains originating from different habitats were subjected to temperature shift exposures and monitored for levels of proline, thiol and activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Thermophile Mastigocladus laminosus (growth optimum, 40 °C), raised the proline level 4.2-fold at low temperature (20 °C), for the psychrophile Nostoc 593 (growth optimum, 20 °C), it was raised 8-fold at 40 °C while

A. P. Singh; R. K. Asthana; Aravind M. Kayastha; S. P. Singh

2005-01-01

275

Early warning signals of abrupt temperature change in different regions of China over the past 50 years  

NASA Astrophysics Data System (ADS)

In this paper, the early warning signals of abrupt temperature change in different regions of China are investigated. Seven regions are divided on the basis of different climate temperature patterns, obtained through the rotated empirical orthogonal function, and the signal-to-noise temperature ratios for each region are then calculated. Based on the concept of critical slowing down, the temperature data that contain noise in the different regions of China are preprocessed to study the early warning signals of abrupt climate change. First, the Mann-Kendall method is used to identify the instant of abrupt climate change in the temperature data. Second, autocorrelation coefficients that can identify critical slowing down are calculated. The results show that the critical slowing down phenomenon appeared in temperature data about 5-10 years before abrupt climate change occurred, which indicates that the critical slowing down phenomenon is a possible early warning signal for abrupt climate change, and that noise has less influence on the detection results of the early warning signals. Accordingly, this demonstrates that the model is reliable in identifying the early warning signals of abrupt climate change based on detecting the critical slowing down phenomenon, which provides an experimental basis for the actual application of the method.

Tong, Ji-Long; Wu, Hao; Hou, Wei; He, Wen-Ping; Zhou, Jie

2014-04-01

276

Elevated temperature differently affects foliar nitrogen partitioning in seedlings of diverse Douglas fir provenances.  

PubMed

Global climate change causes an increase in ambient air temperature, a major environmental factor influencing plant physiology and growth that already has been perceived at the regional scale and is expected to become even more severe in the future. In the present study, we investigated the effect of elevated ambient air temperature on the nitrogen metabolism of two interior provenances of Douglas ?r (Pseudotsuga menziesii var. glauca) originating from contrasting habitats, namely the provenances Monte Creek (MC) from a drier environment and Pend Oreille (PO) from a more humid environment. Three- to four-year-old seedlings of the two provenances were grown for 3 months in controlled environments under either control temperature (day 20?°C, night 15?°C) or high temperature (HT, 30/25?°C) conditions. Total nitrogen (N), soluble protein, chlorophyll and total amino acid (TAA) contents as well as individual amino acid concentrations were determined in both current-year and previous-year needles. Our results show that the foliar total N contents of the two provenances were unaffected by HT. Arginine, lysine, proline, glutamate and glutamine were the most abundant amino acids, which together contributed ?88% to the TAA pool of current- and previous-year needles. High temperature decreased the contents of most amino acids of the glutamate family (i.e., arginine, proline, ornithine and glutamine) in current-year needles. However, HT did not affect the concentrations of metabolites related to the photorespiratory pathway, such as [Formula: see text], glycine and serine. In general, current-year needles were considerably more sensitive to HT than previous-year needles. Moreover, provenance PO originating from a mesic environment showed stronger responses to HT than provenance MC. Our results indicate provenance-specific plasticity in the response of Douglas fir to growth temperature. Provenance-specific effects of elevated temperature on N-use efficiency suggest that origin might determine the sensitivity and growth potential of Douglas fir trees in a future warmer climate. PMID:25240727

Du, Baoguo; Jansen, Kirstin; Junker, Laura Verena; Eiblmeier, Monika; Kreuzwieser, Jürgen; Gessler, Arthur; Ensminger, Ingo; Rennenberg, Heinz

2014-10-01

277

Effect of compost, nitrogen salts, and NPK fertilizers on methane oxidation potential at different temperatures.  

PubMed

The effects of compost, nitrogen salts, and nitrogen-phosphorous-potassium (NPK) fertilizers on the methane oxidation potential (MOP) of landfill cover soil at various temperatures were assessed. For this, we used batch assays conducted at 5°C, 15°C, and 25°C with microcosms containing landfill cover soil slurries amended with these elements. Results indicated variable impacts dependent on the type of amendment and the incubation temperature. For a given incubation temperature, MOP varied from one compost to another and with the amount of compost added, except for the shrimp/peat compost. With this latter compost, independent of the amount, MOP values remained similar and were significantly higher than those obtained with other composts. Amendment with most of the tested nitrogen salts led to similar improvements in methanotrophic activity, except for urea. MOP with NPK fertilizer addition was amongst the highest in this study; the minimum value obtained with NPK (20-0-20) suggested the importance of P for methanotrophs. MOP generally increased with temperature, and nutrient limitation became less important at higher temperatures. Overall, at each of the three temperatures tested, MOP with NPK fertilizer amendments provided the best results and was comparable to those observed with the addition of the shrimp/peat compost. The results of this study provide the first evidence of the following: (1) compost addition to improve methanotrophic activity in a landfill cover soil should consider the amount and type of compost used and (2) the importance of using NPK fertilizers rather than nitrogen salts, in enhancing this activity, primarily at low temperatures. One can also consider the potential beneficial impact of adding these elements to enhance plant growth, which is an advantage for MOP. PMID:21894478

Jugnia, Louis-B; Mottiar, Yaseen; Djuikom, Euphrasie; Cabral, Alexandre R; Greer, Charles W

2012-03-01

278

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

279

[Parasitism capacity of Trichogramma pratissolii Querino & Zucchi (Hymenoptera: Trichogrammatidae) on alternative hosts, under different temperatures].  

PubMed

The successful use of Trichogramma as biocontrol agent depends on its mass production in laboratory, a fundamental step for any biological control program among other factors. This work investigated the parasitism capacity of Trichogramma pratissolii Querino & Zuchi (Hymenoptera: Trichogrammatidae), a new recorded Trichogramma species, parasitizing eggs of Anagasta kuehniella (Zeller) and Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) under the temperatures of 15, 18, 21, 24, 27, 30 and 33 degree Celsius. Eggs of these hosts were offered to newly emerged females during 24h. This procedure was repeated daily for each female and each temperature up to female death, in order to estimate daily and accumulated parasitism, and female longevity. On both hosts, the daily parasitism decreased as function of the female age. Under all temperatures studied and both hosts the highest rate of parasitism was observed during the first 24h of host exposure, and reached 80% of total parasitism in the 4th and 3rd days when parasitizing A. kuehniella and C. cephalonica, respectively. On both hosts, the highest parasitism rate was observed under temperatures from 21 degree Celsius to 27 degree Celsius. Average longevities of T. pratissolii females deprived of food emerging from A. kuehniella and C. cephalonica lived for 1.0 and 8.9 days when reared at 15 degree Celsius e 33 degree Celsius, respectively. The results indicate that eggs of A. kuehniella and C. cephalonica and temperatures from 21 degree Celsius to 27 degree Celsius were appropriate to rear T. pratissolii. PMID:17420865

Zago, Hugo B; Pratissoli, Dirceu; Barros, Reginaldo; Gondim, Manoel G C; Santos, Hugo J G Dos

2007-01-01

280

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

281

Temperature changes in different groups of teeth during cavity preparaton with Er:YAG laser  

NASA Astrophysics Data System (ADS)

Objective: Various studies have recommended parameters for the use of Er:YAG laser for the treatment of enamel and dentis caries; however, none have studied the increase in temperature caused by laser in individual groups of teeth. Summary Background Data: The effect of preparation with Er:YAG laser on the pulp temperature changes is one of the major problems in using the laser for preparation of dental hard tissue. Methods: The authors studied the intrapulpar temperature changes in 10 incisors, 10 canines, 10 premolars and 10 molars during Class V cavity preparation with focused short pulse (250 ?s/pulse) and very short pulse (80-120 ?s/pulse) Er:YAG laser, using the following parameters: 10 Hz frequency, 500 mJ per pulse, 6 s, 10 mm distance, 25 ml/min water flow, at 23°C and 65% humidity. Results: The greatest increase in temperature was foundin the incisors and the least increase in the molars at both pulse modes. Conclusions:The very short pulse mode caused less of an increase in temperature in the pulp chamber in all teeth than the short pulse mode.

Brugnera J"nior, Aldo, Jr.; Marchesan, Melissa A.; Zanin, Fatima A. A.; Guerisoli, Danilo Z.; Pécora, Jesus D.

2002-10-01

282

Effect of different ultrasound contrast materials and temperatures on patient comfort during intrauterine and tubal assessment for infertility.  

PubMed

Hysterosalpingo-contrast sonography (HyCoSy) is safe and easy to perform outpatient method in the evaluation of female infertility. During this procedure a certain level of discomfort and pain are experienced by patients. On the basis of reducing avoidable pain inductors the aim of this study was to compare pain sensation due to different warmth of applied contrasts (sterile saline and Echovist(®)). Prospective and randomized study was performed on patients requiring tubal and uterine assessment during standard infertility work up. One group of patients was examined using both contrasts at room temperature and the other group using preheated contrasts at body temperature. Pain experience of the procedure was rated by patients for each contrast by numerical scale (0-10) immediately after the procedure. There was significant statistical difference between pain scores during application of two contrasts in each group; Echovist induces significantly less pain in comparison to sterile saline at the same temperature (P=0.002, 0.001). Between two groups there is also statistically significant difference in pain during introduction of the same contrast at different temperature (P<0.001). The most tolerable for the patient is body temperature of the applied contrasts although their structure and concentrations can be another factor associated with tolerability of the procedure. PMID:22542789

Fenzl, Vanja

2012-12-01

283

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

SciTech Connect

It has been reported that the extreme power of astrophysical water masers can be obtained from purely collisional pumping in environments with two kinetic temperatures. It is found that this pumping vanishes when the latest rates are utilized for the collisional excitation of H{sub 2}O 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 H{sub 2}O molecules by ions. Including the effects of these ions does not restore the inversion, but rather reduces the pumping for H{sub 2}O masers in the proposed two-temperature environments. 20 refs.

Anderson, N.; Watson, W.D. (Illinois Univ., Urbana (USA))

1990-01-01

284

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 (18–24 years old) were recruited and their WT, activity, body position, light exposure, environmental temperature and sleep were recorded under free-living conditions for 1 week. WT demasking by categories or intercepts was applied to simulate a “constant routine” protocol (awakening, dim light, recumbent position, low activity and warm environmental temperature). Although the overall circadian pattern of WT was similar regardless of the masking effects, its amplitude was the rhythmic parameter most affected by environmental conditions. The acrophase and mesor were determined to be the most robust parameters for characterizing this rhythm. In addition, a circadian modulation of the masking effect was found for each masking variable. WT rhythm exhibits a strong endogenous component, despite the existence of multiple external influences. This was evidenced by simultaneously eliminating the influence of activity, body position, light exposure, environmental temperature and sleep. We therefore propose that it could be considered a valuable and minimally-invasive means of recording circadian physiology in ambulatory conditions. PMID:23577201

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

2013-01-01

285

Oxygen consumption and ammonia-N excretion of Meretrix meretrix in different temperature and salinity  

Microsoft Academic Search

Effects of temperatures and salinities on oxygen consumption and ammonia-N excretion rate of clamMeretrix meretrix were studied in laboratory from Oct. 2003 to Jan. 2004. Two schemes were designed in incremented temperature at 10, 15, 20,\\u000a 25°C at 31.5 salinity and in incremented salinity at 16.0, 21.0, 26.0, 31.5, 36.0, and 41.0 at 20°C, all for 8–10 days. From\\u000a 10

Baojun Tang; Baozhong Liu; Hongsheng Yang; Jianhai Xiang

2005-01-01

286

Cold-start emissions of modern passenger cars at different low ambient temperatures and their evolution over vehicle legislation categories  

NASA Astrophysics Data System (ADS)

The emissions of modern gasoline and diesel passenger cars are reduced by catalysts except in cold-starting. Since catalysts require a certain temperature (typically above 300 °C) to work to full efficiency, emissions are significantly higher during the warm-up phase of the car. The duration of this period and the emissions produced depend on the ambient temperature as well as on the initial temperature of the car's propulsion systems. The additional emissions during a warm-up phase, known as "cold-start extra emissions" (CSEEs) for emission inventory modelling, are mostly assessed by emission measurements at an ambient temperature of 23 °C. However, in many European countries average ambient temperatures are below 23 °C. This necessitates emission measurements at lower temperatures in order to model and assess cold-start emissions for real-world temperature conditions. This paper investigates the influence of regulated pollutants and CO 2 emissions of recent gasoline and diesel car models (Euro-4 legislation) at different ambient temperatures, 23, -7 and -20 °C. We present a survey and model of the evolution of cold-start emissions as a function of different car generations (pre-Euro-1 to Euro-4 legislations). In addition the contribution of CSEEs to total fleet running emissions is shown to highlight their increasing importance. For gasoline cars, it turns out that in average real-world driving the majority of the CO (carbon monoxide) and HC (hydrocarbon) total emissions are due to cold-start extra emissions. Moreover, the cold-start emissions increase considerably at lower ambient temperatures. In contrast, cold-start emissions of diesel cars are significantly lower than those of gasoline cars. Furthermore, the transition from Euro-3 to Euro-4 gasoline vehicles shows a trend for a smaller decline for cold-start extra emissions than for legislative limits. Particle and NO x emission of cold-starts are less significant.

Weilenmann, Martin; Favez, Jean-Yves; Alvarez, Robert

287

Controlled AFM detachments and movement of nanoparticles: gold clusters on HOPG at different temperatures.  

PubMed

The effect of temperature on the onset of movement of gold nanoclusters (diameter 27 nm) deposited on highly oriented pyrolytic graphite (HOPG) has been studied by atomic force microscopy (AFM) techniques. Using the AFM with amplitude modulation (tapping mode AFM) we have stimulated and controlled the movement of individual clusters. We show how, at room temperature, controlled detachments and smooth movements can be obtained for clusters having dimensions comparable to or smaller than the tip radius. Displacement is practically visible in real time and it can be started and stopped easily by adjusting only one parameter, the tip amplitude oscillation. Analysing the energy dissipation signal at the onset of nanocluster sliding we evaluated a detachment threshold energy as a function of temperature in the range 300-413 K. We also analysed single cluster thermal induced displacement and combining this delicate procedure with AFM forced movement behaviour we conclude that detachment threshold energy is directly related to the activation energy of nanocluster diffusion and it scales linearly with temperature as expected for a single-particle thermally activated process. PMID:22641421

Tripathi, Manoj; Paolicelli, Guido; D'Addato, Sergio; Valeri, Sergio

2012-06-22

288

SPATIAL DISTRIBUTION OF THE AIR TEMPERATURE IN THE AMERICAN ARCTIC FOR DIFFERENT DATABASES AND METHODS  

Microsoft Academic Search

Meteorological observations (mainly air temperature, pressure and wind direction) made in the 19th century in the Canadian Arctic on vessels sent there by the Royal Navy are very valuable in the study of the Artic climate. They were gathered during winterings sometimes far from any present meteorological site. To analyse the climate change we should know the present-day climate conditions

Vizi Zsuzsanna; Przybylak Rajmund

289

The Dislocation Microstructure of Cyclically Deformed Nickel Single Crystals at Different Temperatures  

Microsoft Academic Search

Using transmission electron microscopy a systematic study of the dislocation microstructure after cyclic deformation of nickel single crystals was undertaken in order to describe quantitatively the influence of deformation temperature on microstructural parameters. The frequency distributions of the heights and lengths of edge dislocation dipoles were measured in the walls and channels of persistent slip bands and in the matrix

B. Tippelt; J. Breitschneider; P. Hähner

1997-01-01

290

Nonuniversal atmospheric persistence: Different scaling of daily minimum and maximum temperatures  

E-print Network

interference or it is a nor- mal ``excursion'' of the variable climate 1 . Each of the most elaborated global filter out nonstationarities such as slow trends. Variations in surface air temperature is obviously one,9,10,12,13 , shorter-time correlations are usually explained by using first- or second-order linear autoregres- sive

Jánosi, Imre M.

291

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.; Vásquez, M.; Avalos-Borja, M.; Marcos-Fernández, A.

2014-04-01

292

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...

293

CHANGES IN THE RAT EEG SPECTRA AND CORE TEMPERATURE AFTER EXPOSURE TO DIFFERENT DOSES OF CHLORPYRIFOS.  

EPA Science Inventory

Our previous study showed that single exposure to 25 mg/kg (p.o.) of organophsphate pesticide chlorpyrifos (CHP) led to significant alterations in all EEG frequency bands within 0.1-50 Hz range, reduction in core temperature (Tc) and motor activity (MA). The alterations in EEG pe...

294

Density and Sound Velocity Studies of Aqueous Solutions of Tetradecyltrimethylammonium Nitrate at Different Temperatures  

Microsoft Academic Search

The density and ultrasound velocity of aqueous solutions of tetradecyltrimethylammonium nitrate were measured in the temperature range of 15 to 35°C in 5°C intervals. The concentration range covered the premicellar and micellar regimes. By assuming a pseudophase separation model for the micellar system, we applied the densitometric data to estimate the apparent molar volumes and the apparent thermal expansibility coefficients

J. J. Galán; J. L. Del Castillo; A. González-Pérez; J. Czapkiewicz; J. R. Rodríguez

2003-01-01

295

Qualitative assessment of hydrolytic activities in antarctic microfungi grown at different temperatures on solid media  

Microsoft Academic Search

Microfungi from Antarctica were grown at 10 °C, 21 °C, 28 °C and 37 °C on a series of plates each containing a single carbon source and designed to indicate the secretion of particular hydrolytic enzymes. Colony radius and hydrolytic activity were measured and a relative activity index (RA) established. In general, effective hydrolysis occurred at mesophilic temperatures. Some enzymes,

J. R. Bradner; M. Gillings; K. M. H. Nevalainen

1999-01-01

296

Stress-strain behaviour of reconstituted illitic clay at different temperatures  

Microsoft Academic Search

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

Naoto Tanaka; James Graham; Thomas Crilly

1997-01-01

297

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

PubMed

Annual suicide deaths outnumber the total deaths from homicide and war combined. Suicide is a complex behavioral endpoint, and a simple cause-and-effect model seems highly unlikely, but relationships with weather could yield important insight into the biopsychosocial mechanisms involved in suicide deaths. This study has been designed to test for a relationship between air temperature and suicide frequency that is consistent enough to offer some predictive abilities. Weekly suicide death totals and anomalies from Toronto, Ontario, Canada (1986-2009) and Jackson, Mississippi, USA (1980-2006) are analyzed for relationships by using temperature anomaly data and a distributed lag nonlinear model. For both analysis methods, anomalously cool weeks show low probabilities of experiencing high-end suicide totals while warmer weeks are more likely to experience high-end suicide totals. This result is consistent for Toronto and Jackson. Weekly suicide totals demonstrate a sufficient association with temperature anomalies to allow some prediction of weeks with or without increased suicide frequency. While this finding alone is unlikely to have immediate clinical implications, these results are an important step toward clarifying the biopsychosocial mechanisms of suicidal behavior through a more nuanced understanding of the relationship between temperature and suicide. PMID:25402561

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

2014-01-01

298

Production of biomass and nutraceutical compounds by Spirulina platensis under different temperature and nitrogen regimes  

Microsoft Academic Search

The cyanobacterium Spirulina platensis has been used by humans because of its nutritional and possibly medicinal effects. Our study evaluated the influence of temperature and nitrogen concentration in the medium on the production of biomass by this cyanobacterium and the biomass composition in protein, lipid and phenolic compounds. We found that at 35°C there was a negative effect on biomass

Luciane Maria Colla; Christian Oliveira Reinehr; Carolina Reichert; Jorge Alberto Vieira Costa

2007-01-01

299

Breeding patterns in the oniscid isopod, Porcellio ficulneus Verh., at high temperature and under different photophases  

Microsoft Academic Search

Porcellio ficulneus Verhoeff inhabits xeric Mediterranean grassland habitats. During winter vitellogenesis takes place and mancas are released in April. Under natural conditions some oocytes (about 20%) were lost. Both high temperature (25°C) at long or short photophases affected the reproductive pattern. Thus at 25°C and constant light vitellogenesis was markedly shorter than under field conditions. Oocytes matured sooner, but many

E. HORNUNG; M. R. WARBURG

1993-01-01

300

Calibration factor of track etch detectors at different temperatures of water  

E-print Network

Research was performed to determine track density as a function of radon exposure in water and exposure temperature for the track etch detectors Kodak LR II 5 Type 2 and CR-39. Films were submerged in water containing a known concentration...

Yasmeen, Nuzhat

2012-06-07

301

Differences between wafer and bake plate temperature uniformity in proximity bake: a theoretical and experimental study  

NASA Astrophysics Data System (ADS)

As the lithography industry moves toward finer features, specifications on temperature uniformity of the bake plates are expected to become more stringent. Consequently, aggressive improvements are needed to conventional bake station designs to make them perform significantly better than current market requirements. To this end, we have conducted a rigorous study that combines state-of-the-art simulation tools and experimental methods to predict the impact of the parameters that influence the uniformity of the wafer in proximity bake. The key observation from this detailed study is that the temperature uniformity of the wafer in proximity mode depends on a number of parameters in addition to the uniformity of the bake plate itself. These parameters include the lid design, the air flow distribution around the bake chamber, bake plate design and flatness of the bake plate and wafer. By performing careful experimental studies that were guided by extensive numerical simulations, we were able to understand the relative importance of each of these parameters. In an orderly fashion, we made appropriate design changes to curtail or eliminate the nonuniformity caused by each of these parameters. After implementing all these changes, we have now been able to match or improve the temperature uniformity of the wafer in proximity with that of a contact measurement on the bake plate. The wafer temperature uniformity is also very close to the theoretically predicted uniformity of the wafer.

Ramanan, Natarajan; Kozman, Austin; Sims, James B.

2000-06-01

302

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

303

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

304

Evaluation of Thermal Stability and Glass Transition Temperature of Different Aeronautical Polymeric Composites  

Microsoft Academic Search

In this work, the thermal stability of different polymeric composite laminates used in the aeronautical field was investigated by thermogravimetric (TGA) and dynamic mechanical thermal (DMTA) analyses. Four different types of laminates manufactured by combining two epoxy resin systems (F584 and F155) and two different types of carbon fiber fabric reinforcements were examined. The mass losses of the laminates were

Jane M. F. Paiva; Michelle L. Costa; Mirabel C. Rezende

2006-01-01

305

From a descriptive toward an explicative growth-based model on immature Oulema duftschmidi (Coleoptera: Chrysomelidae) development at different temperatures.  

PubMed

The developmental rates of Oulema duftschmidi (Redtenbacher) eggs, larvae, and pupae were studied at different constant temperatures. A linear regression model was fitted to the data obtained in this and in a previous study within a temperature range where the rate proportionally increases with temperature. Ratios of SEs to the mean thermal constant and to the mean developmental threshold indicated that reliable estimates have been obtained for the three life stages. Within the framework provided by the metabolic theory of ecology, a growth-based model was evaluated to explain developmental rates in the entire temperature range permissive of development of the three life stages. The model is based on component functions describing growth patterns through time, temperature-dependent consumption rates of biomass, transformation of consumed food into body biomass change, and respiration rates with respect to temperature. Experimental data were used for the selection and validation of models and for the estimation of the parameters of different regression models. Limitations and opportunities for using the growth-based model to explain developmental rates are discussed. An empirical function was used to describe the variability of developmental rates. PMID:17445358

Morlacchi, P; Limonta, L; Baumgártner, J

2007-04-01

306

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 25°C and 30°C. 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

307

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

PubMed

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

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

2013-12-01

308

Impact of device geometry at different ambient temperatures on the self-heating of GaN-based HEMTs  

NASA Astrophysics Data System (ADS)

The influence of the device geometry on the self-heating for GaN-based HEMTs was assessed at different ambient temperatures, from 25 °C to 175 °C. The results showed that the gate width can significantly affect the heat dissipation. In addition to this, the distribution of the generated heat in the channel has been demonstrated to be dependent on the distance between the gate and drain contacts. Besides the device geometry, the ambient temperature was also found to be relevant for the thermal resistance, mainly due to the temperature-dependent thermal conductivity of the layers and the substrate. The channel temperature and the thermal resistance extracted from the measurements were in good agreement with the simulations.

Martin-Horcajo, S.; Wang, A.; Romero, M. F.; Tadjer, M. J.; Koehler, A. D.; Anderson, T. J.; Calle, F.

2014-11-01

309

Pharmacokinetics of sulphadimidine in carp (Cyprinus carpio L.) and rainbow trout (Salmo gairdneri Richardson) acclimated at two different temperature levels.  

PubMed

The influence of temperature (10 degrees C and 20 degrees C) on pharmacokinetics and metabolism of sulphadimidine (SDM) in carp and trout was studied. At 20 degrees C a significantly lower level of distribution (Vdarea) and a significantly shorter elimination half-life (T(1/2)beta) was achieved in both species compared to the 10 degrees C level. In carp the body clearance parameter (ClB(SDM)) was significantly higher at 20 degrees C compared to the value at 10 degrees C, whereas for trout this parameter was in the same order of magnitude for both temperatures. N4-acetylsulphadimidine (N4-SDM) was the main metabolite of SDM in both species at the two temperature levels. The relative N4-SDM plasma percentage in carp was significantly higher at 20 degrees C than at 10 degrees C, whereas there was in trout no significant difference. In neither species was the peak plasma concentration of N4-SDM (Cmax(N4-SDM)) significantly different at two temperatures. The corresponding peak time of this metabolite (Tmax(N4-SDM)) was significantly shorter at 20 degrees C compared to 10 degrees C in both carp and trout. In carp at both temperatures, acetylation occurs to a greater extent than hydroxylation. Only the 6-hydroxymethyl-metabolite (SCH2OH) was detected in carp, at a significant different level at the two temperatures. Concentrations of hydroxy metabolites in trout were at the detection level of the HPLC-method (0.02-micrograms/ml). The glucuronide metabolite (SOH-gluc.) was not detected in either species at the two temperatures. PMID:1882494

van Ginneken, V J; Nouws, J F; Grondel, J L; Driessens, F; Degen, M

1991-04-01

310

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

Microsoft Academic Search

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

Alejandrina Jiménez-Mercado; Ramón Cajal-Medrano; Helmut Maske

2007-01-01

311

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

312

Temperature anisotropy instabilities; combining plasma and magnetic field data at different distances from the Sun  

NASA Astrophysics Data System (ADS)

We present a new data analysis method enabling the observation of magnetic field fluctuations associated with temperature anisotropy instabilities using the Ulysses spacecraft. The movement of the spacecraft away from the Sun causes the observed plasma conditions, turbulent fluctuation amplitude, magnetic field strength and important physical scales to change. We normalize wavelet power spectra of the magnetic field using local values for the proton gyroscale and large scale magnetic field fluctuation amplitude to remove the effects of varying heliocentric distance. We recover the enhancement of magnetic fluctuations where temperature anisotropy instability growth rates are large, as seen by previous studies in the ecliptic at 1 AU. This method can be applied to any spacecraft data that contains large changes in physical scales, magnetic field strength or other plasma parameters, for example the upcoming Solar Orbiter and Solar Probe Plus missions.

Wicks, Robert T.; Matteini, Lorenzo; Horbury, Timothy S.; Hellinger, Petr; Roberts, D. Aaron

2013-06-01

313

New district-heating system economic factors vary with different supply temperatures  

SciTech Connect

District heating has been in use for many years and offers economic, environmental, and energy conservation benefits. A new district heating system may be based on either a steam or hot water distribution system. The supply media choice is based upon the composition of the load and other factors. This report discusses the relative advantages of steam vs hot water systems and between hot water systems of varying temperatures. Points of comparison include: capital costs, cogeneration efficiencies, building conversion costs, operating and maintenance costs, energy losses, maximum transport distances, and cooling applications. The major conclusion is that a thorough analysis of the market, including building equipment and consumer requirements, is essential in designing a district heating system and is of primary importance in determining the optimum supply temperature.

Borkowski, R.J.; Stovall, T.K.; Karnitz, M.A.

1982-10-01

314

Properties of amorphous silicon prepared at different temperatures by pyrolytic decomposition of silane  

NASA Astrophysics Data System (ADS)

Over the range 525temperature ts, the hydrogen content of amorphous silicon deposited by the pyrolytic decom-position of silane varies from 0.8 at% to 0.2 at%. This relatively small change is accompanied by order-of-magnitude variations in conductivity and field effect. The results are interpreted in terms of shifts of the Fermi level, density of states profiles, and change in the conduction mechanism.

Hey, P.; Raouf, N.; Booth, D. C.; Seraphin, B. O.

1981-06-01

315

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

Microsoft Academic Search

The plastic deformation of AZ31 magnesium alloy under tension at temperatures of 4.2-295 K 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

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

2010-01-01

316

Different temperature renormalizations for heavy and light-hole states of monolayer-thick heterostructures  

Microsoft Academic Search

We have found that the energy splitting between peaks in the linearly polarized emission from the cleaved surface of an InAs\\/ GaAs monolayer structure triples with increasing temperature in the range from 5 to 150 K. For each polarization the main emission line corresponds to the radiative recombination of either heavy or light-hole excitons bound to the monolayer. The striking

A. R. Gonia; A. Cantarero; H. Scheel; S. Reich; C. Thomsen; F. Heinrichsdorff; D. Bimberg

317

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

PubMed

Rayleigh-Brillouin (RB) scattering profiles for air have been recorded for the temperature range from 255 to 340 K and the pressure range from 640 to 3300 mbar, covering the conditions relevant for the Earth's atmosphere and for planned atmospheric light detection and ranging (LIDAR) missions. The measurements performed at a wavelength of ?=366.8 nm detect spontaneous RB scattering at a 90° scattering angle from a sensitive intracavity setup, delivering scattering profiles at a 1% rms noise level or better. The experimental results have been compared to a kinetic line-shape model, the acclaimed Tenti S6 model, considered to be most appropriate for such conditions, under the assumption that air can be treated as an effective single-component gas with temperature-scaled values for the relevant macroscopic transport coefficients. The elusive transport coefficient, the bulk viscosity ?(b), is effectively derived by a comparing the measurements to the model, yielding an increased trend from 1.0 to 2.5×10(-5) kg·m(-1)·s(-1) for the temperature interval. The calculated (Tenti S6) line shapes are consistent with experimental data at the level of 2%, meeting the requirements for the future RB-scattering LIDAR missions in the Earth's atmosphere. However, the systematic 2% deviation may imply that the model has a limit to describe the finest details of RB scattering in air. Finally, it is demonstrated that the RB scattering data in combination with the Tenti S6 model can be used to retrieve the actual gas temperatures. PMID:23842262

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

2013-07-01

318

Volumetric, ultrasonic speed, and viscometric studies of salbutamol sulphate in aqueous methanol solution at different temperatures  

Microsoft Academic Search

Values of density, ultrasonic speed, and viscosity of salbutamol sulphate (SBS) have been determined in aqueous methanol solutions at T=(303.15, 308.15, 313.15, and 318.15)K. The apparent molar volume V?, partial molar volume V?0, molar expansivity E20, isobaric thermal expansion coefficient (?2), and second derivative of infinite dilution of partial molar volume with temperature ?2V?0\\/?T2 are evaluated using density data. Isentropic

K. Rajagopal; S. S. Jayabalakrishnan

2010-01-01

319

Electrophoretic Properties of Casein from Sterilized Milk Stored at Different Temperatures1  

Microsoft Academic Search

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

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

1958-01-01

320

Comparison of temperature and work function measurements obtained with different GTA electrodes  

Microsoft Academic Search

This work was carried out on one standard electrode (W-ThO2,) and other electrodes developed by additions of La2O3, CeO2, and Y2O3,. The effect of rare-earth metal oxides on GTAW electrode phenomena, concerning electrode temperature, emissivity, and work function, was analyzed and compared from the point of view of those oxides' behavior during arcing. The experimental results indicate that the electrode

Masao Ushio; Alber A. Sadek; Fukuhisa Matsuda

1991-01-01

321

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 = 14·1 ± 0·5; mean ± s.e. body mass = 28·5 ± 4·5 g) originating from broodstock from the Vosso river (western Norway) were acclimated to three temperature regimes (4·1, 8·1 and 12·9° 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 4·1° C group compared to the 11·9° 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

322

Measured rotational and vibrational temperature differences in arc jet shock layers  

Microsoft Academic Search

Shock-layer-radiation emission spectra from the first negative system of the nitrogen molecular ion N2(+) are analyzed over the wavelength region between 370 and 430 nm. The shock layer is produced by a blunt body placed in the expanded flow from an arc heater employing either pure nitrogen or a nitrogen-oxygen air mixture. A rotational temperature is obtained from analysis of

Harvel E. Blackwell; Carl D. Scott

1992-01-01

323

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

Microsoft Academic Search

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

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

1985-01-01

324

Surface morphology and photoluminescence for InAs quantum dots of different growth temperature and capping layer  

Microsoft Academic Search

InAs QDs of eight different grown temperatures are measured by AFM and photoluminescence measurement. PL emission peak at 1.306 mum was obtained for InAs QDs with In0.1Ga0.9As capping layer grown at 510degC

T. E. Tzeng; D. J. Feng; C. Y. Chen; T. S. Lay; T. Y. Chang

2006-01-01

325

EFFECTS OF BT RICE ON THE FOOD CONSUMPTION, GROWTH AND SURVIVAL OF CHILO SUPPRESSAUS LARVAE UNDER DIFFERENT TEMPERATURES  

Microsoft Academic Search

The Bt transgenic rice line , i. e. KMD1 containing a synthetic cry1Ab gene from Bacillus thuringiensis Berliner was tested in the laboratory for evaluating its effects on larval food consumption , growth and survival of striped stem borer (SSB) , Chilo suppressalis (Walker) under different temperatures. The food consumption and body weight growth as well as the survival of

WANG Shi-gui; YE Gong-yin; HU Cui; SHU Qing-yao; XIA Yin-wu; Illimar Altosaar

2001-01-01

326

Assessment of Urban Versus Rural In Situ Surface Temperatures in the Contiguous United States: No Difference Found  

Microsoft Academic Search

All analyses of the impact of urban heat islands (UHIs) on in situ temperature observations suffer from inhomogeneities or biases in the data. These inhomogeneities make urban heat island analyses difficult and can lead to erroneous conclusions. To remove the biases caused by differences in elevation, latitude, time of observation, instrumentation, and nonstandard siting, a variety of adjustments were applied

Thomas C. Peterson

2003-01-01

327

Temperature Effects on Silicon-on-Insulator (SOI) Racetrack Resonators: A Coupled Analytic and 2-D Finite Difference Approach  

Microsoft Academic Search

This paper presents a detailed analysis of racetrack resonators on silicon on insulator substrates. Both the temperature effects and the particularities of silicon nanophotonics are considered throughout the approach. This paper provides a detailed description of the numerical modeling and its application to different designs, while providing several charts and fitting equations. The results presented in this paper can be

Nicolas Rouger; Lukas Chrostowski; Raha Vafaei

2010-01-01

328

A note on eating behaviour of dairy cows at different stocking systems—diurnal rhythm and effects of ambient temperature  

Microsoft Academic Search

This experiment was aimed at studying the diurnal rhythm of dairy cows eating behaviour at different stocking systems, and quantifying the effect of daily ambient temperature on this diurnal rhythm. In two experiments carried out in the summer of 2003 in The Netherlands, eight dairy cows were offered fresh pasture of perennial ryegrass. In the first experiment, four cows were

H. Z. Taweel; B. M. Tas; H. J. Smit; S. Tamminga; A. Elgersma

2006-01-01

329

A two-dimensional finite-difference solution for the temperature distribution in a radial gas turbine guide vane blade  

NASA Technical Reports Server (NTRS)

A two-dimensional finite difference numerical technique is presented to determine the temperature distribution in a solid blade of a radial guide vane. A computer program is written in Fortran IV for IBM 370/165 computer. The computer results obtained from these programs have a similar behavior and trend as those obtained by experimental results.

Hosny, W. M.; Tabakoff, W.

1975-01-01

330

Study of the performance of natural air \\/ low temperature in-bin drying of different corn types using simulation  

Microsoft Academic Search

The use of simulation for studying natural air\\/ low temperature (NA\\/LT) in-bin drying systems is a common practice. This tool was used in the past to determine, for instance, the most convenient airflow rate, the most convenient fan and burner control strategy according to the weather conditions, and the maximum allowable initial moisture content. However, the effect of different corn

R. Bartosik; D. E. Maier

331

TEM ANALYSIS OF THE GROWTH OF OXIDE SCALES AT DIFFERENT TEMPERATURES IN FeAl GRADE 3 INTERMETALLIC ALLOY  

E-print Network

TEM ANALYSIS OF THE GROWTH OF OXIDE SCALES AT DIFFERENT TEMPERATURES IN FeAl GRADE 3 INTERMETALLIC)546457272, e-mail: fpedraza@univ-lr.fr Abstract Upon the isothermal oxidation of an ODS FeAl Grade 3 intermetallic alloy, a structured oxide scale is developed between 800 and 950º C. TEM studies have revealed

Paris-Sud XI, Université de

332

Toxoplasma gondii: virulence of tachyzoites in serum free media at different temperatures.  

PubMed

Highly virulent Toxoplasma gondii tachyzoite multiplication was recorded on the 4th and 5th days post cultivation (dpc) in seven selected cell lines either with or without fetal calf serum (FCS) in the maintenance media. The multiplication rate was slightly lower in the absence of FCS. The cell line mono-layers collapsed dying by the 6th day of infection both in presence or absence of FCS at 37 degrees C. Carcinoma of human larynx (Hep2) and Madian Darby Bovine Kidney (MDBK) cell lines were the most suitable for in vitro multiplication, followed by that of African green monkey kidney cells (VERO), pooled kidney from 1-day-old hamster (BHK), rabbit kidney cells (RK13) and human rhabdomyosarcoma (RDA), while Chicken embryo cells (CER) were the least suitable. In absence of FCS, CER, BHK, Hep2, RDA and MDBK were able to maintain virulent tachyzoites at +4 degrees C for 14 days. The infectivity of the tachyzoites was however lower, killing 40% of the inoculated mice. Tachyzoites survived at room temperature, in the dark, for 14 days in Hep2, RDA and MDBK. However, Hep2 was the only one able to keep virulent tachyzoites until 21 dpc at room temperature and at +4 degrees C. Hep2 propagated tachyzoites were still alive but with low infectivity up to 28 dpc. The cell-lines failed to support the development of tachyzoites after 7 dpc at 37 degrees C and after the 35 dpc at lower temperatures. PMID:17904554

Diab, M R; El-Bahy, M M

2008-01-01

333

Low temperature survival in different life stages of the Iberian slug, Arion lusitanicus.  

PubMed

The slug Arion lusitanicus Mabille (Gastropoda: Pulmonata: Arionidae) is an invasive species which has spread to most parts of Europe. The area of origin is unknown, but A. lusitanicus seems to cope well with the local conditions in the countries to which it has migrated. It spreads rapidly, occurs often in high densities and has become a serious pest in most European countries. Therefore there is an urgent need for better knowledge of the ecophysiology of A. lusitanicus, such as the influence of climatic conditions, in order to develop prognostic models and strategies for novel pest management practises. The aim of our study was to investigate the influence of subzero temperatures in relation to winter survival. A. lusitanicus is shown to be freeze-tolerant in some life stages. Most juveniles and some adult slugs survived being frozen at -1.3°C for 3days, but none of the slugs survived freezing at -3°C. The eggs survived subzero temperatures (down to -2°C) probably by supercooling. Juveniles and adults may also survive in a supercooled state (down to -3°C) but are generally poor supercoolers. Therefore, the winter survival of A. lusitanicus depends to a high degree on migration to habitats protected from low winter temperatures, e.g. under plant litter, buried in the soil or in compost heaps. PMID:21168402

Slotsbo, Stine; Hansen, Lars Monrad; Holmstrup, Martin

2011-02-01

334

Heat-transfer dynamics during cryogen spray cooling of substrate at different initial temperatures.  

PubMed

Cryogen spray cooling (CSC) is used to minimize the risk of epidermal damage during laser dermatologic therapy. However, the dominant mechanisms of heat transfer during the transient cooling process are incompletely understood. The objective of this study is to elucidate the physics of CSC by measuring the effect of initial substrate temperature (T0) on cooling dynamics. Cryogen was delivered by a straight-tube nozzle onto a skin phantom. A fast-response thermocouple was used to record the phantom temperature changes before, during and after the cryogen spray. Surface heat fluxes (q") and heat-transfer coefficients (h) were computed using an inverse heat conduction algorithm. The maximum surface heat flux (q"max) was observed to increase with T0. The surface temperature corresponding to q"max also increased with T0 but the latter has no significant effect on h. It is concluded that heat transfer between the cryogen spray and skin phantom remains in the nucleate boiling region even if T0 is 80 degrees C. PMID:15656278

Jia, Wangcun; Aguilar, Guillermo; Wang, Guo-Xiang; Nelson, J Stuart

2004-12-01

335

Factors affecting the wettability of different surface materials with vegetable oil at high temperatures and its relation to cleanability  

NASA Astrophysics Data System (ADS)

The main aim of the work was to investigate the wettability of different surface materials with vegetable oil (olive oil) over the temperature range of 25-200 °C to understand the differences in cleanability of different surfaces exposed to high temperatures in food processes. The different surface materials investigated include stainless steel (reference), PTFE (polytetrafluoroethylene), silicone, quasicrystalline (Al, Fe, Cr) and ceramic coatings: zirconium oxide (ZrO2), zirconium nitride (ZrN) and titanium aluminum nitride (TiAlN). The ceramic coatings were deposited on stainless steel with two different levels of roughness. The cosine of the contact angle of olive oil on different surface materials rises linearly with increasing temperature. Among the materials analyzed, polymers (PTFE, silicone) gave the lowest cos ? values. Studies of the effect of roughness and surface flaws on wettability revealed that the cos ? values increases with increasing roughness and surface flaws. Correlation analysis indicates that the measured contact angle values gave useful information for grouping easy-clean polymer materials from the other materials; for the latter group, there is no direct relation between contact angle and cleanability. In addition to surface wettability with oil many other factors such as roughness and surface defects play an essential role in determining their cleanability.

Ashokkumar, Saranya; Adler-Nissen, Jens; Møller, Per

2012-12-01

336

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

337

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 25°C for thermophilic IGPS, near its adaptive temperature (75°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 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

338

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, 0-29°C) and from colder, more thermally stable spring-fed ponds (1-19°C). Salinity and predation pressure also differed between these locations. We acclimatized wild-caught fish to 6, 11, and 19°C in common garden conditions for 4-6 months and determined their aerobic scope and hepatosomatic index (HSI). The freshwater fish from the colder (2-14°C), 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. J. Exp. Zool. 321A: 550-565, 2014. © 2014 Wiley Periodicals, Inc. PMID:25389079

Bruneaux, Matthieu; Nikinmaa, Mikko; Laine, Veronika N; Lindström, Kai; Primmer, Craig R; Vasemägi, Anti

2014-12-01

339

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

PubMed

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

2014-11-01

340

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

SciTech Connect

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

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

2006-06-15

341

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 80°C to 120°C, 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 80°C. When the annealing temperature increases to 120°C, 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

342

Sorption of simazine to corn straw biochars prepared at different pyrolytic temperatures.  

PubMed

Simazine sorption to corn straw biochars prepared at various temperatures (100-600 °C) was examined to understand its sorption behavior as influenced by characteristics of biochars. Biochars were characterized via elemental analysis, BET-N(2) surface area (SA), FTIR and (13)C NMR. Freundlich and dual-mode models described sorption isotherms well. Positive correlation between log K(oc) values and aromatic C contents and negative correlation between log K(oc) values and (O + N)/C ratios indicate aromatic-rich biochars have high binding affinity to simazine (charge transfer (?-?*) interactions) and hydrophobic binding may overwhelm H-bonding, respectively. Dual-mode model results suggest adsorption contribution to total sorption increases with carbonization degree. Positive correlation between amounts of adsorption (Q(ad)) and SA indicates pore-filling mechanism. Comparison between our results and those obtained with other sorbents indicates corn straw biochars produced at higher temperature can effectively retain simazine. These observations will be helpful for designing biochars as engineered sorbents to remove triazine herbicides. PMID:21719171

Zhang, Guixiang; Zhang, Qing; Sun, Ke; Liu, Xitao; Zheng, Wenjuan; Zhao, Ye

2011-10-01

343

Structural Changes of Carbon Nanotubes Prepared by Fermented Glutinous Rice at Different Vaporization and Deposition Temperatures of Thermal-CVD  

NASA Astrophysics Data System (ADS)

A series of carbon nanotubes (CNTs) with different vaporization and deposition temperature deposited on nickel coated silicon were prepared by two-system thermal chemical vapor deposition (Thermal-CVD) method. The CNTs were prepared using fermented glutinous rice, a new approach of starting material that may create new market on nanotechnology fabrication. The purpose of this paper is to optimize the temperature of thermal-CVD method with intention it can be suitable used for the fermented glutinous rice as the starting material. The prepared samples were characterized using scanning electron microscopy (SEM) at various spots and magnification.

Nik, S. F.; Zainal, N. F. A.; Azira, A.; Rusop, M.

2009-06-01

344

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

PubMed Central

Introduction A number of studies have attempted to predict the effects of climate change on schistosomiasis risk. The importance of considering different species of intermediate host snails separately has never previously been explored. Methods An agent-based model of water temperature and Biomphalaria pfeifferi population dynamics and Schistosoma mansoni transmission was parameterised to two additional species of snail: B. glabrata and B. alexandrina. Results Simulated B. alexandrina populations had lower minimum and maximum temperatures for survival than B. pfeifferi populations (12.5–29.5°C vs. 14.0–31.5°C). B. glabrata populations survived over a smaller range of temperatures than either B. pfeifferi or B. alexandrina (17.0°C–29.5°C). Infection risk peaked at 16.5°C, 25.0°C and 19.0°C respectively when B. pfeifferi, B. glabrata and B. alexandrina were simulated. For all species, infection risk increased sharply once a minimum temperature was reached. Conclusions The results from all three species suggest that infection risk may increase dramatically with small increases in temperature in areas at or near the currents limits of schistosome transmission. The effect of small increases in temperature in areas where schistosomiasis is currently found will depend both on current temperatures and on the species of snail acting as intermediate host(s) in the area. In most areas where B. pfeifferi is the host, infection risk is likely to decrease. In cooler areas where B. glabrata is the host, infection risk may increase slightly. In cooler areas where B. alexandrina is the host, infection risk may more than double with only 2°C increase in temperature. Our results show that it is crucial to consider the species of intermediate host when attempting to predict the effects of climate change on schistosomiasis. PMID:24988377

McCreesh, Nicky; Booth, Mark

2014-01-01

345

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

346

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 25°C in dark microcosms that simulated enclosed ballast water tanks. Acetate breakdown indeed occurred faster at higher temperatures. At 25°C the highest bacteria growth, fastest nutrient and oxygen consumption and highest DOC reduction occurred. On the other hand, at -1°C bacterial growth was strongly delayed, only starting to increase after 12 days. Furthermore, at 25°C 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

347

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

348

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

PubMed Central

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

Gupta, V

2014-01-01

349

Adult eclosion timing of the onion fly, Delia antiqua, in response to daily cycles of temperature at different soil depths.  

PubMed

For insects pupating in the soil, the day/night temperature cycle may provide a primary time cue (Zeitgeber) for adult eclosion to occur at an appropriate time of the day. In the soil, however, the phase of temperature cycle is delayed with depth because of the low heat conductivity of the soil. Therefore pupae located deeper in the soil may compensate for the depth-dependent phase delay of Zeitgeber to avoid mistimed emergence. We examined the adult eclosion timing of the onion fly, Delia antiqua, pupating at different depths in soil and under various thermoperiods in the laboratory to determine if such compensation indeed occurs. We found that D. antiqua is able to compensate for the depth-dependent phase delay of the Zeitgeber by advancing the eclosion timing in response to the amplitude of the temperature cycle decreasing with depth. PMID:12590302

Tanaka, Kazuhiro; Watari, Yasuhiko

2003-02-01

350

Effect of sodium bicarbonate supplementation on carcass characteristics of lambs fed concentrate diets at different ambient temperature levels.  

PubMed

The objective of this study was to investigate the influence of ambient temperatures on carcass characteristics of lambs fed concentrate diets with or without NaHCO3 supplementation. A slaughter study was carried on 12 male Black Belly Barbados lambs randomly drawn from a growth trial (35 weeks). The lambs were divided into four equal groups and allotted in a 2×2 factorial design. The lambs were allotted at random to two dietary treatments of a basal diet (35:65 roughage:concentrate) or basal diet supplemented with 4% NaHCO3 at different ambient temperatures (20°C and 30°C) in an environment controlled chamber for 10 days. Lambs were slaughtered for carcass evaluation at about 262 days of age (245 days of growth trial, 7 days adaptation and 10 days of experimental period). Ambient temperature had significant (p<0.05, p<0.05, p<0.01, and p<0.001) effects on meat color from the ribeye area (REA), fat, leg and longissimus dorsi muscles with higher values recorded for lambs in the lower temperature group than those from the higher ambient temperature group. Significant differences (p<0.05) in shear force value (kg/cm(2)) recorded on the leg muscles showed higher values (5.32 vs 4.16) in lambs under the lower ambient temperature group compared to the other group. Dietary treatments had significant (p<0.01, p<0.01, and p<0.05) effects on meat color from the REA, fat, and REA fat depth (cm(2)) with higher values recorded for lambs in the NaHCO3 supplementation group than the non supplemented group. Similarly, dietary treatments had significant differences (p<0.05) in shear force value (kg/cm(2)) of the leg muscles with the NaHCO3 groups recording higher (5.30 vs 4.60) values than those from the other group. Neither ambient temperature nor dietary treatments had any significant (p>0.05) effects on pH, and water holding capacity on both muscles. These results indicated that NaHCO3 supplementation at low ambient temperatures had caused an increase in carcass characteristics leading to significant effect on meat quality. PMID:25083103

Jallow, Demba B; Hsia, Liang Chou

2014-08-01

351

A Comparison of the Performance of Different PV Module Types in High Ambient Temperatures.  

E-print Network

@fizzy.murdoch.edu.au Abstract The performances of five different types of photovoltaic modules have been measured during spring test conditions (STC) have been measured for each module prior to, and at regular intervals during photovoltaics (PV) there is a basic requirement to accurately estimate the output from the proposed PV array

352

The Complete Genome and Proteome of Laribacter hongkongensis Reveal Potential Mechanisms for Adaptations to Different Temperatures and Habitats  

PubMed Central

Laribacter hongkongensis is a newly discovered Gram-negative bacillus of the Neisseriaceae family associated with freshwater fish–borne gastroenteritis and traveler's diarrhea. The complete genome sequence of L. hongkongensis HLHK9, recovered from an immunocompetent patient with severe gastroenteritis, consists of a 3,169-kb chromosome with G+C content of 62.35%. Genome analysis reveals different mechanisms potentially important for its adaptation to diverse habitats of human and freshwater fish intestines and freshwater environments. The gene contents support its phenotypic properties and suggest that amino acids and fatty acids can be used as carbon sources. The extensive variety of transporters, including multidrug efflux and heavy metal transporters as well as genes involved in chemotaxis, may enable L. hongkongensis to survive in different environmental niches. Genes encoding urease, bile salts efflux pump, adhesin, catalase, superoxide dismutase, and other putative virulence factors—such as hemolysins, RTX toxins, patatin-like proteins, phospholipase A1, and collagenases—are present. Proteomes of L. hongkongensis HLHK9 cultured at 37°C (human body temperature) and 20°C (freshwater habitat temperature) showed differential gene expression, including two homologous copies of argB, argB-20, and argB-37, which encode two isoenzymes of N-acetyl-L-glutamate kinase (NAGK)—NAGK-20 and NAGK-37—in the arginine biosynthesis pathway. NAGK-20 showed higher expression at 20°C, whereas NAGK-37 showed higher expression at 37°C. NAGK-20 also had a lower optimal temperature for enzymatic activities and was inhibited by arginine probably as negative-feedback control. Similar duplicated copies of argB are also observed in bacteria from hot springs such as Thermus thermophilus, Deinococcus geothermalis, Deinococcus radiodurans, and Roseiflexus castenholzii, suggesting that similar mechanisms for temperature adaptation may be employed by other bacteria. Genome and proteome analysis of L. hongkongensis revealed novel mechanisms for adaptations to survival at different temperatures and habitats. PMID:19283063

Curreem, Shirly O. T.; Tsang, Alan K. L.; Fan, Rachel Y. Y.; Wong, Gilman K. M.; Huang, Yi; Loman, Nicholas J.; Snyder, Lori A. S.; Cai, James J.; Huang, Jian-Dong; Mak, William; Pallen, Mark J.; Lok, Si; Yuen, Kwok-Yung

2009-01-01

353

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 5 °C 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

354

[Effect of locomotion and feeding on metabolic mode of juvenile lenok, Brachymystax lenok (Pallas) under different water temperatures].  

PubMed

To investigate the effect of locomotion and feeding on the metabolic mode of juvenile lenok, Brachymystax lenok (Pallas) under different water temperatures, the pre-exercise oxygen consumption rate (MO2p), active oxygen consumption rate (MO2a), metabolic scope (MS), critical swimming speed (Uc) and swimming metabolic rate of both fasting and fed fish were measured at five temperature levels (4 degrees C, 8 degrees C, 12 degrees C, 16 degrees C and 20 degrees C) and ten flow velocities with saturated dissolved oxygen (> 8.0 mg x L(-1)). The results showed that the MO2p and MO2a of the feeding group were significantly higher (P < 0.05) than the fasting group under different temperatures, and the increases in MO2p and MO2a at 4 degrees C, 8 degrees C, 12 degrees C, 16 degrees C and 20 degrees C were 15%, 47%, 30%, 43% and 8%, and 12%, 23%, 21%, 36% and 7%, respectively. No significant differences were observed for Uc and MS between the fasting and the feeding groups (P > 0.05), but the MS showed a trend of decline with increase in water temperature. Swimming metabolic rate of fish was increased with increasing the flow velocity, and further increase of flow velocity resulted in a decline in swimming metabolic rate, and the swimming metabolic rate of the feeding group was significantly higher than that of the fasting group (P < 0.05). The metabolic rate increased with increasing the swimming speed up to 70% Uc, and then decreased with increasing the swimming speed up to Uc. It was concluded that, under certain temperature, the maximum metabolic rate was induced by exercise and feeding; the metabolic rate exhibited the additive metabolic mode before increasing to the maximum and thereafter, the metabolic rate induced by feeding reduced with decreasing the swimming metabolic rate, exhibiting the locomotion prioritized mode. PMID:25011313

Xu, Ge-Feng; Wang, Yu-Yu; Han, Ying; Li, Xiang; Ma, Bo; Liu, Yang; Mou, Zhen-Bo

2014-04-01

355

Levels of Vibrio vulnificus and organoleptic quality of raw shellstock oysters (Crassostrea virginica) maintained at different storage temperatures.  

PubMed

Temperature abuse during raw oyster harvesting and storage may allow for the multiplication of natural spoilage flora as well as microbial pathogens, thus posing a potential health threat to susceptible consumers and compromising product quality. The objective of this study was to provide a scientific basis for determining whether different refrigeration and abuse temperatures for raw oysters would result in a spoiled product before it became unsafe. Raw shellstock oysters (Crassostrea virginica) purchased from a commercial Virginia processor were subjected to different temperature abuse conditions (7, 13, and 21 degrees C) over a 10-day storage period. Salinity, pH, halophilic plate count (HPC), total culturable Vibrio counts, and culturable Vibrio vulnificus counts were determined at each abuse condition. V. vulnificus isolates were confirmed by a specific enzyme-linked immunosorbent assay. Olfactory analysis was performed to determine consumer acceptability of the oysters at each abuse stage. The pH of the oysters decreased over time in each storage condition. The HPC increased 2 to 4 logs for all storage conditions, while olfactory acceptance decreased over time. V. vulnificus levels increased over time, reaching 10(5) to 10(6) CFU/g by day 6. The length of storage had a greater effect on the bacterial counts and olfactory acceptance of the oysters (P < 0.05) over time than did the storage temperature (P < 0.05). PMID:11726149

Lorca, T A; Pierson, M D; Flick, G J; Hackney, C R

2001-11-01

356

ION TEMPERATURE AND NON-THERMAL VELOCITY IN A SOLAR ACTIVE REGION: USING EMISSION LINES OF DIFFERENT ATOMIC SPECIES  

SciTech Connect

We have studied the characteristics of the ion thermal temperature and non-thermal velocity in an active region observed by the EUV Imaging Spectrometer onboard Hinode. We used two emission lines of different atomic species (Fe XVI 262.98 A and S XIII 256.69 A) to distinguish the ion thermal velocity from the observed full width at half-maximum. We assumed that the sources of the two emission lines are the same thermal temperature. We also assumed that they have the same non-thermal velocity. With these assumptions, we could obtain the ion thermal temperature, after noting that M{sub sulfur} approx 0.6M{sub iron}. We have carried out the ion thermal temperature analysis in the active region where the photon counts are sufficient (>4500). What we found is as follows: (1) the common ion thermal temperatures obtained by Fe XVI and S XIII are approx2.5 MK, (2) the typical non-thermal velocities are approx13 km s{sup -1}, (3) the highest non-thermal velocities (>20 km s{sup -1}) are preferentially observed between the bright points in Fe XVI, while (4) the hottest material (>3 MK) is observed relatively inside the bright points compared with the highest non-thermal velocity region.

Imada, S.; Hara, H.; Watanabe, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka-shi, Tokyo 181-8588 (Japan)

2009-11-10

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

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

359

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 8˜10°C and specifically cold pool around 1˜2 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 20°C 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 15°C. 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

360

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

361

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 600°C, 800°C, and 1000°C 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

362

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

SciTech Connect

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

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

2007-07-01

363

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

E-print Network

Rayleigh Brillouin (RB) scattering profiles for air have been recorded for the temperature range from 255 to 340 K and the pressure range from 640 to 3300 mbar, covering the conditions relevant for the Earth's atmosphere and for planned atmospheric light detection and ranging (LIDAR) missions. The measurements performed at a wavelength of 366.8 nm detect spontaneous RB scattering at a 90 degree scattering angle from a sensitive intracavity setup, delivering scattering profiles at a 1 percent rms noise level or better. The elusive transport coefficient, the bulk viscosity, is effectively derived by a comparing the measurements to the model, yielding an increased trend. The calculated (Tenti S6) line shapes are consistent with experimental data at the level of 2 percent, meeting the requirements for the future RB scattering LIDAR missions in the Earth's atmosphere. However, the systematic 2 percent deviation may imply that the model has a limit to describe the finest details of RB scattering in air. Finally, it...

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

2013-01-01

364

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

365

Temperature-Shifted White-Light Interferometry for Equalization of a Fiber Coupler to Near-Zero Path Length Difference  

Microsoft Academic Search

A method for equalizing the path lengths of two arms of an optical fiber coupler is presented as a critical step towards construction of a high-resolution 3-D interferometric imaging system. Based on white-light interferometry (WLI), the technique combines absolute measurement capability with the ability to accurately measure near-zero path length differences. A controlled temperature increase in one arm of the

Evan Lally; Tyler Shillig; Yunmiao Wang; Anbo Wang

2009-01-01

366

Suitable dissolved oxygen levels for common octopus ( Octopus vulgaris cuvier, 1797) at different weights and temperatures: analysis of respiratory behaviour  

Microsoft Academic Search

The dissolved oxygen level is an essential parameter for defining water quality in aquaculture. However, the optimal values of this gas can vary greatly depending on the species, body weight, or water temperature. In this study, different oxygen level categories (optimal, suboptimal, dangerous, and lethal) were established for Octopus vulgaris (0.18–2.20 kg; 15.5–27.4 °C) according to ventilatory frequency (Vf) and

Jesús Cerezo Valverde; Benjamín García García

2005-01-01

367

Reactive wetting of molten Al on different oriented ?-Al 2O 3 single crystals at high temperatures  

Microsoft Academic Search

The reactive wetting of molten Al on three different oriented ?-Al2O3 single crystals, R(011?2), A(112?0) and C(0001), was investigated by an improved sessile drop method at temperatures between 1350 and 1500 °C in a reduced Ar–3%H2 atmosphere. The wettability is in the order of R>A>C. The spreading is reaction-limited and the rate is dominated by the change in the solid–liquid

Ping Shen; Hidetoshi Fujii; Taihei Matsumoto; Kiyoshi Nogi

2003-01-01

368

A finite-difference model to predict 2D depletion profiles arising from high temperature oxidation of alloys  

Microsoft Academic Search

ODIN is a 2-D finite-difference diffusion\\/interdiffusion computer model capable of predicting the solute depletion profiles evolved in binary and ternary alloys due to high temperature oxidation. The 2-D geometries that can be analysed include corners, rectangular edges and rib features. Empirical mass gain kinetics in the form of a general power law are employed as a boundary condition to define

W. M. Pragnell; H. E. Evans

2006-01-01

369

Structural evolution and optical characterization of indium doped cadmium sulfide thin films obtained by spray pyrolysis for different substrate temperatures  

Microsoft Academic Search

Indium doped cadmium sulfide thin films were prepared by spray pyrolysis on glass substrates at different temperatures ranging from 300°C to 450°C in 25°C steps, using aqueous solution of copper chloride and thiourea salts. We used In(COOH)3 as the dopant. Structural characterization was carried out by X-ray diffractometry and scanning electron microscopy and high resolution electron microscopy were used together

Dwight R. Acosta; Carlos R. Magaña; Arturo I. Mart??nez; Arturo Maldonado

2004-01-01

370

[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

371

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

372

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

SciTech Connect

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

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

2012-05-15

373

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

374

Coexistance of two Different Methane Hydrate Phases at Moderate Pressure and Temperature Conditions  

NASA Astrophysics Data System (ADS)

For a better understanding of the formation and decomposition of natural gas hydrates, detailed data on their thermodynamical properties are an important prerequisite. Until now, it was generally accepted that small guest molecules such as methane and carbondioxid form structure I hydrates whereas large molecules such as propane form structure II hydrates. Expectedly, natural gas hydrates and synthesized methane hydrates grown under natural conditions, prefer structure I. The formation of structure II methane hydrates was only observed at very high pressures ( 100 MPa) by Chou et al. 1 In this contribution, results from Raman spectroscopic investigation on pure methane hydrates are presented. It will be shown, that a coexistence of structure I and structure II methane hydrates at pressures between 3.0 and 9.0 MPa and at temperatures between -15° C and +15° C is possible. However, structure II methane hydrate are present as a metastable phase in a kinetic inhibited equilibrium with the established structure I methane hydrate phase. A slight variation of the T-P-x-conditions initiates the transformation of the structure II methane hydrates into structure I hydrates. This (exothermic) process results in a re crystallization of the complete hydrate phase until a stable state is reached. It turned out, that the instability of the structure II methane hydrate phase is also the driving force for other processes, such as the exchange of CH4 with CO2: A change in the composition of the gaseous phase through the addition of CO2 induces an immediate replacement of methane with carbondioxid in the structure II hydrate. In contrast, the exchange of CH4 with CO2 in structure I hydrates is a very slow process. 1 Chou, I-M.; Sharma, A.; Burrus, R. C.; Shu, J.; Mao, H-k.; Hemley, R. J.; Goncharov, A. F.; Stern, L. A.; Kirby, S. H.; PNAS; vol. 97; no. 25;13484-13487 (2000)

Erzinger, J.

2003-12-01

375

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

PubMed

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

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

2014-10-15

376

Difference  

NSDL National Science Digital Library

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

2006-01-01

377

Calcium-activated force responses in fast- and slow-twitch skinned muscle fibres of the rat at different temperatures.  

PubMed Central

1. Force responses from mechanically skinned fibres of rat skeletal muscles (extensor digitorum longus and soleus) were measured at different temperatures in the range 3-35 degrees C following sudden changes in Ca2+ concentration in the preparations. 2. At all temperatures there were characteristic differences between the slow- and fast-twitch muscle fibres with respect to the relative steady-state force-[Ca2+] relation: such as a lower [Ca2+] threshold for activation and a less steep force-pCa curve in slow-twitch muscle fibres. 3. At 3-5 degrees C the force changes in both types of muscle fibres lagged considerably behind the estimated changes in [Ca2+] within the preparations and this enabled us to perform a comparative analysis of the Ca2+ kinetics in the process of force development in both muscle fibre types. This analysis suggest that two and six Ca2+ ions are involved in the regulatory unit for contraction of slow- and fast-twitch muscle fibres respectively. 4. The rate of relaxation following a sudden decrease in [Ca2+] was much lower in the slow-twitch than in the fast-twitch muscle at 5 degrees C, suggesting that properties of the contractile apparatus could play an essential role in determining the rate of relaxation in vivo. 5. There was substantial variation in Ca2+ sensitivity between muscle fibres of the same type from different animals at each temperature. However the steepness of the force-[Ca2+] relation was essentially the same for all fibres of the same type. 6. A change in temperature from 5 to 25 degrees C had a statistically significant effect on the sensitivity of the fast-twitch muscle fibres, rendering them less sensitive to Ca2+ by a factor of 2. However a further increase in temperature from 25 to 35 degrees C did not have any statistically significant effect on the force-[Ca2+] relation in fast-twitch muscle fibres. 7. The effect of temperature on the Ca2+ sensitivity of slow-twitch muscle fibres was not statistically significant, mainly because of the large variation in sensitivity amongst these preparations at room temperature. 8. Two types of oscillatory processes not associated with intracellular membranes were observed in the force response of all slow-twitch muscle fibres when submaximally activated (less than 60% maximum force) at 25 and 35 degrees C, but never at 3-5 degrees C. The frequency of oscillations increased with temperature. 9. Maximum Ca2+-activated force in both muscle fibre types was greatly dependent upon temperature over the range 0-25 degrees C, but increased only slightly above 25 degrees C. 10. Experiments on the rigor state suggest that the number of possible actomyosin interacting sites diminishes considerably as temperature is decreased below 25 degrees C. PMID:7310735

Stephenson, D G; Williams, D A

1981-01-01

378

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

379

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

PubMed

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

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

2009-11-01

380

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

381

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 25°C, 40°C, 55°C and 70°C 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

382

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

NASA Astrophysics Data System (ADS)

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 25°C, 40°C, 55°C and 70°C 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.

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

2012-10-01

383

Using finite element modelling to examine the flow process and temperature evolution in HPT under different constraining conditions  

NASA Astrophysics Data System (ADS)

High-pressure torsion (HPT) is a metal-working technique used to impose severe plastic deformation into disc-shaped samples under high hydrostatic pressures. Different HPT facilities have been developed and they may be divided into three distinct categories depending upon the configuration of the anvils and the restriction imposed on the lateral flow of the samples. In the present paper, finite element simulations were performed to compare the flow process, temperature, strain and hydrostatic stress distributions under unconstrained, quasi-constrained and constrained conditions. It is shown there are distinct strain distributions in the samples depending on the facility configurations and a similar trend in the temperature rise of the HPT workpieces.

Pereira, P. H. R.; Figueiredo, R. B.; Cetlin, P. R.; Langdon, T. G.

2014-08-01

384

Advantages of different source/drain engineering on scaled UTBOX FDSOI nMOSFETs at high temperature operation  

NASA Astrophysics Data System (ADS)

The influence of different spacer lengths and tilt-implantation on underlapped devices compared to the standard S/D junctions (with Lightly Doped Drain - LDD) on fully depleted (FD) SOI MOSFETs with Ultra-Thin Buried Oxide (UTBOX) at room and high temperatures is explored. It is shown that devices with longer spacers and no LDD implantation increase the underlap region between the gate edge and the S/D regions, increase the immunity to short channel effects and improve the analog performance even at high temperatures. However, the lateral dopant diffusion can reduce or suppress the underlap formation, mainly for smaller spacer length. Tilt-implanted devices exhibit the same trend as the devices with LDD. The angled implantation favors the dopant diffusion into the underlap regions, which degrades the transistor performance.

Nicoletti, Talitha; Santos, Sara Dereste dos; Martino, João Antonio; Aoulaiche, Marc; Veloso, Anabela; Jurczak, Malgorzata; Simoen, Eddy; Claeys, Cor

2014-01-01

385

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 300°C 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

386

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

387

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

388

Time-Series Analysis of Natural Tracers: Comparison of Electrical Conductivity and Temperature in Different Frequency Ranges  

NASA Astrophysics Data System (ADS)

Natural tracers can be used for quantification of exchange fluxes between surface waters and groundwater. Especially temperature has become a widely-used parameter due to progress in sensor technique and data loggers. Compared to solute mass, heat is retarded. The retardation depends on porosity, heat capacity and heat conductivity of the saturated riverbed sediments. As the porosity and mineral composition of the sediments can only be roughly estimated, the retardation factor remains uncertain. Electrical conductivity (EC) is a valuable amendment to temperature in losing river systems, if distinctive fluctuations exist. EC is an easy to measure parameter, but it is not conservative due to mineralization processes and cation exchange in the aquifer. However, the propagation of the EC signal into the aquifer reflects solute transport. We present results of a study on bank filtration at a test site in northeast Switzerland. The field site has been established by the RECORD Project (Assessment and Modeling of Coupled Ecological and Hydrological Dynamics in the Restored Corridor of a River (Restored Corridor Dynamics)); it is located at a channelized and a restored section of the prealpine losing River Thur. We analyze time series of temperature and EC in the river and riparian groundwater wells to quantify travel times. Both signals show variations on various time scales, which we analyze by different methods. For the diurnal and seasonal signal, sinusoidal functions are fitted to the data and the time shifts are determined. Cross-correlation and non-parametric deconvolution methods are used to calculated mean travel times and mixing ratios from filtered data sets without diurnal and seasonal signal. The comparison of the travel times of temperature and EC shows that the retardation of the temperature signal varies in space.

Vogt, Tobias; Schirmer, Mario; Cirpka, Olaf A.

2010-05-01

389

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

NASA Astrophysics Data System (ADS)

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

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

2006-11-01

390

Pressurized liquid extraction of coumarins from fruits of Heracleum leskowii with application of solvents with different polarity under increasing temperature.  

PubMed

Coumarins are nowadays an important group of organic compounds from natural sources that are useful in a number of fields. Because they possess different pharmacological properties, finding the proper extraction conditions for their separation from plant matrices is a very important step. In this report Pressurized Liquid Extraction (PLE) under different temperature conditions and with different types of extraction solvents were tested. As a matrix, fruits of Heracleum leskowii have been used. A simple reverse phase high-performance liquid chromatographic method (RP-HPLC) coupled with a photodiode array detector (DAD) has been developed for separation and quantitative analysis of the main coumarins. Umbelliferone, xanthotoxin, angelicin, isopimpinellin, bergapten, imperatorin and isoimperatorin were investigated. Bergapten and imperatorin were dominant in almost all extracts in the range of 9.92 ± 0.02-20.93 ± 0.06 and 12.19 ± 0.98-19.07 ± 0.03 mg/100 g, respectively. Dichloromethane and methanol were chosen as the most proper suitable solvents for extraction of coumarins. By increasing the temperature the amount of extracted coumarins increases in petroleum ether and dichloromethane extracts. PMID:22481536

Skalicka-Wo?niak, Krystyna; G?owniak, Kazimierz

2012-01-01

391

Comparisonof different -nucleators for isotactic polypropylene, characterisation byDSC and temperature-modulated DSC (TMDSC) measurements  

Microsoft Academic Search

The nucleating efficiency and selectivity of different\\u000a ?-nucleating agents was characterised and compared by differential scanning\\u000a calorimetry, (DSC) and temperature-modulated DSC (TMDSC). The nucleating agents\\u000a were the calcium salts of pimelic and suberic acid (Ca-pim and Ca-sub), linear trans-?-quinacridone (LTQ), a commercial nucleator\\u000a NJ Star (NJS) and an experimental product (CGX-220). The efficiency and the\\u000a selectivity of Ca-sub and Ca-pim

A. Menyhárd; J. Varga; G. Molnár

2006-01-01

392

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

Microsoft Academic Search

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

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

1990-01-01

393

Investigation of marginal fit and surface roughness of crowns, due to different bench set and different burnout temperature using base metal alloy.  

PubMed

The conventional investing technique is used most commonly for casting. Inspite of the popularity of this technique, it is very time consuming. To save time of the patient, dentist and dental laboratory technician, accelerated casting technique can be used. This study uses different bench set and different burnout temperatures and has been carried to investigate their effects on marginal fit and surface roughness. A total of 40 wax patterns were made simulating the artificial crown from the first master die and 20 rectangular wax patterns were made from the second master die. Twenty castings simulating the crown and 10 castings of rectangular plates were obtained by short protocol represented as Group A and C, similarly the remaining castings were obtained by standard protocol and represented as Group B and D. Marginal discrepancy of both Group A and B were determined by using Travelling microscope, whereas Perthometer was used for quantitative evaluation of average surface roughness of both Group C and D. Scanning electron microscope evaluated the surface roughness qualitatively for the specimens of both Groups C and D. The obtained values of Group A and C and Group C and D were subjected to statistical analysis. Qualitative analysis of Group C and D were done. Accelerated/short protocol gives similar results in terms of marginal fit and surface roughness as compared to the conventional/standard protocol and is definitely a time saving procedure. PMID:21886406

Hasti, Anurag; Patil, Narendra P

2010-09-01

394

Temperature Meets Tree Physiology: Potential Influence of Different Characteristics of Recorded Temperature Increases in Alaska on the Diverging Growth Responses of White Spruce  

Microsoft Academic Search

To be useful for temperature reconstructions, tree growth must respond to the same climate parameters today in the same way it has in the past. Recent studies which show tree ring widths from the northern high latitudes are diverging from previous sensitivity to temperature parameters may be partly influenced by new patterns of warm temperature anomalies as well as the

G. P. Juday

2007-01-01

395

Formation of biofilm by Listeria monocytogenes ATCC 19112 at different incubation temperatures and concentrations of sodium chloride  

PubMed Central

Biofilm formation can lead to various consequences in the food processing line such as contamination and equipment breakdowns. Since formation of biofilm can occur in various conditions; this study was carried out using L. monocytogenes ATCC 19112 and its biofilm formation ability tested under various concentrations of sodium chloride and temperatures. Cultures of L. monocytogenes ATCC 19112 were placed in 96-well microtitre plate containing concentration of sodium chloride from 1–10% (w/v) and incubated at different temperature of 4 °C, 30 °C and 45 °C for up to 60 h. Absorbance reading of crystal violet staining showed the density of biofilm formed in the 96-well microtitre plates was significantly higher when incubated in 4 °C. The formation of biofilm also occurs at a faster rate at 4 °C and higher optical density (OD 570 nm) was observed at 45 °C. This shows that storage under formation of biofilm that may lead to a higher contamination along the processing line in the food industry. Formation of biofilm was found to be more dependent on temperature compared to sodium chloride stress. PMID:24159283

Lee, H.Y.; Chai, L.C.; Pui, C.F.; Mustafa, S.; Cheah, Y.K.; Nishibuchi, M.; Radu, S.

2013-01-01

396

Effect of temperature and humidity on sperm morphology in duroc boars under different housing systems in Thailand.  

PubMed

The aim of this study was to investigate the effect of season, temperature, humidity, age of the boar, and semen collection interval on sperm morphology in Duroc boars in Thailand, kept either in a conventional open air system (CONV) or in an evaporative cooling system (EVAP). In total, 1176 ejaculates from 110 sexually mature boars in six CONV herds and five EVAP herds were morphologically examined during a one-year period. Analysis of variance was applied to the data. Minor differences in the sperm morphology traits analyzed were found between the housing systems. There was a significant seasonal effect (two-month periods) on the percentage of morphologically normal spermatozoa (normal1), morphologically normal spermatozoa including spermatozoa with distal cytoplasmic droplets (normal2), proximal cytoplasmic droplets (prox), and sperm head abnormalities (PTemperature had a significant effect on normal1 in the CONV system (Ptemperatures and high humidity had negative effects on sperm morphology. PMID:16141664

Suriyasomboon, Annop; Lundeheim, Nils; Kunavongkrit, Annop; Einarsson, Stig

2005-08-01

397

Development of an analytical method for yam saponins using HPLC with pulsed amperometric detection at different column temperatures.  

PubMed

Yam saponins (dioscin, gracillin, protodioscin, and protogracillin) were analyzed with three different C18 columns at incremental column temperatures from 15 to 45°C to investigate the effect of temperature on the retention and resolution of yam saponins. At low temperature, yam saponins showed decreased retention times and improved resolutions in the C18 columns. In the Kinetex C18 column at 15°C, the four saponins achieved baseline separation (Rs > 1.5) within 30 min. Pulsed amperometric detection was used to identify saponins with high sensitivity. The limits of detection and quantification of saponins were 0.11-0.31 and 0.33-0.95 ng, respectively. The correlation coefficients ranged 0.9986-1.0000. Intra- and inter-day precisions were <4.2% of retention times and <9.5% of the calculated contents. Average recoveries ranged from 92.18 to 105.98%. Saponin contents in Dioscorea nipponica tubers and commercial yam foods were determined without sample purification or concentration. Among the ten commercial yam foods investigated, only three showed significant saponin contents. PMID:23303619

Kwon, Ha-Jeong; Choi, Seung-Hee; Yoo, Chang-Seon; Choi, Hwa-Young; Lee, Soo-Eon; Park, Yong-Duk

2013-02-01

398

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