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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

The fundamental limitations of photoacoustic microscopy for detecting optically absorbing molecules are investigated both theoretically and experimentally. We experimentally demonstrate noise-equivalent detection sensitivities of 160,000 methylene blue molecules (270 zeptomol or 2.710-19??mol) and 86,000 oxygenated hemoglobin molecules (140 zeptomol) using narrowband continuous-wave photoacoustics. The ultimate sensitivity of photoacoustics is fundamentally limited by thermal noise, which can present in the acoustic detection system as well as in the medium itself. Under the optimized conditions described herein and using commercially available detectors, photoacoustic microscopy can detect as few as 100s of oxygenated hemoglobin molecules. Realizable improvements to the detector may enable single molecule detection of select molecules. PMID:24026425

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

2013-09-01

3

Minimum resolvable temperature difference measurements on undersampled imagers  

Microsoft Academic Search

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

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

2003-01-01

4

Noise equivalent circuit of a semiconductor laser diode  

Microsoft Academic Search

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

CHRISTOPH HARDER; S. Margalit; A. Yariv; J. Katz; J. Shacham

1982-01-01

5

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

Microsoft Academic Search

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

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

1991-01-01

6

Minimum temperature difference detected by the thermal radiation of objects  

Microsoft Academic Search

The spectral dependence of the Noise Equivalent Temperature Difference (NETD) that can be detected from the objects thermal radiation and is limited by photon fluctuations in quantum photodetectors is calculated. An absolute limit of its specific value (NETD*) depends only on one physical variable-the temperature of the object T: NETD*min = 5.07 10-8 &surd;300\\/T [K cm s1\\/2]. This relationship

Igor I. Taubkin; Michael A. Trishenkov; Nikolai V. Vasilchenko

1994-01-01

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

Noise-equivalent power characterization of an uncooled microbolometer-based THz imaging camera  

NASA Astrophysics Data System (ADS)

A THz camera based on an uncooled microbolometer 160X120 pixel array with nominal pitch of 52 ?m has been developed at INO and initial transmission and reflection images showed promise. In the present paper, the characterization of both standard infrared and THz-optimized uncooled microbolometer pixel arrays are presented at both infrared and THz wavelengths. Measurements in the THz region has been performed using non-uniform low-power quantum-cascade laser (QCL) and uniform high-power far-infrared laser (FIR laser) beams at 3 THz and 4.25 and 2.54 THz, respectively. A measurement comparison has been achieved in the infrared using a blackbody radiation. Different methods for noise-equivalent power (NEP) measurements have been investigated. These characterization methods are promising especially for non-uniform laser beams irradiated on pixel arrays. The NEP results obtained from the different methods are in good agreement independent of the method used in the experiments. The results show a high sensitivity of the THz-optimized pixel array in the THz region. Large beam area reflection imaging of obscured materials at 2.54 THz have been performed at video rates of 30 frames per second using the THz-optimized pixel array equipped with a semi-custom fast THz objective, proving that the INO THz camera provides a promising solution for stand-alone imaging systems.

Bolduc, Martin; Terroux, Marc; Tremblay, Bruno; Marchese, Linda; Savard, Eric; Doucet, Michel; Oulachgar, Hassane; Alain, Christine; Jerominek, Hubert; Bergeron, Alain

2011-05-01

9

Noise equivalent source for frequency domain measurements from the spontaneous fission of /sup 252/Cf  

SciTech Connect

An experiment was performed to determine the frequency domain noise equivalent source from the spontaneous fission of /sup 252/C. The measurements had maximum frequencies (<50 kHz) much lower than those corresponding to the frequencies associated with emission and detection times of particles from spontaneous fission of /sup 252/Cf. This experiment was performed with a /sup 252/Cf source on one plate of a parallel-plate ionization chamber and two large plastic scintillators (2 x 1 x 0.33 ft) at distances of 75 to 150 cm from the source. This noise equivalent source is important when using the /sup 252/Cf source-driven neutron noise analysis method to determine subcriticality at low values of k/sub eff/ (<<0.8) because at low k/sub eff/ values, fluctuations of the neutron population in the system caused by the varying numbers of neutrons from spontaneous fission of /sup 252/Cf become important. The noise equivalent source for these measurements has been formulated based on the Schottky formalism according to the method of Cohn.

Mihalczo, J.T.; King, W.T.

1986-01-01

10

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

SciTech Connect

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

Tang Xiangyang; Yang Yi; Tang Shaojie [Imaging and Medical Physics, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1701 Uppergate Drive, C-5018, Atlanta, Georgia 30322 (United States)

2012-07-15

11

Noise equivalent circuit of linear passive two-ports with applications to transmission lines  

SciTech Connect

A new representation of the thermal noise of linear passive two-ports, expressed in terms of the Thevenin equivalent circuit and convenient to circuit designers, has been derived. This representation is applied to the determination of the contribution of the noise of a transmission line (a special case of a two-port) to the total noise of a noise thermometer system. Preliminary experimental results from measurement of temperature with a noise thermometer connected via a long transmission line encourages further development of practical noise thermometers.

Agouridis, D.C.

1982-06-01

12

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.

2012-02-01

13

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 thermalinfrared 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

14

Precise and effective fixed-pattern correction for logarithmic high dynamic range CMOS image sensors achieving low noise equivalent contrast over illumination  

NASA Astrophysics Data System (ADS)

Logarithmic High Dynamic Range CMOS (HDRC) image sensors exhibit the highest Dynamic Range and a straight forward image acquisition compared to other High Dynamic Range imagers or techniques. The nearly constant pixel random noise over the illumination range, in contrast to sensors with linear or piece-wise linear Opto Electronic Conversion Function (OECF), gives rise to a balanced contrast resolution. The Noise Equivalent Contrast (NEC) will be introduced as a figure of merit to compare both imager types with nonlinear and linear OECF, which leads to the incremental Signal-to-Noise Ratio (iSNR) and SNR, respectively. This will be shown by measurements of OECF and NEC performed with a logarithmic HDRC imager. The resulting iSNR, related to ISO15739, will be quantitatively compared to SNR data of a linear imager according to EMVA1288 standard. The benefits of the logarithmic imager come with the necessity to correct CMOS technology dependent pixel to pixel variations, namely the MOS transistor threshold and gain variations and the photodiode dark current distribution contributing to an overlaid Fixed Pattern in the raw image data. Depending on the required quality and the allowed computational complexity a Fixed Pattern Correction (FPC) algorithm should correct from the most dominant up to all three non-uniformity parameters per pixel in the digital signal chain of a camera.

Strobel, M.

2012-05-01

15

Crystallization of Unvulcanized Rubber at Different Temperatures  

Microsoft Academic Search

The crystallization and melting of unvulcanized natural rubber in the unstretched state have been investigated at different temperatures. Change of volume has been used as a quantitative measure of the extent of crystallization, and mercury-filled dilatometers containing the rubber have been used for the volume measurements. Crystallization was observed to occur at temperatures between ?50 and +15C and to be

Lawrence A. Wood; Norman Bekkedahl

1946-01-01

16

Component analysis of a new solid state x-ray image intensifier (SSXII) using photon transfer and instrumentation noise equivalent exposure (INEE) measurements  

NASA Astrophysics Data System (ADS)

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

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

2009-02-01

17

Temperature sensitivity of different soil carbon sources  

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

18

THERMAL MODEL OF HUMAN BODY TEMPERATURE REGULATION CONSIDERING INDIVIDUAL DIFFERENCE  

Microsoft Academic Search

This paper proposes the methodology to quantify the individual difference in temperature regulation of human body for transient simulation of body temperature. Experiments of transient thermal exposure were conducted for four subjects and the characteristics of individual difference in themoregulatory response were observed quantitatively. As the result, the differences in core temperature and heart rate were significant. For each subject,

Satoru Takada; Hiroaki Kobayashi; Takayuki Matsushita

2007-01-01

19

The Response of Avocado Fruits to Different Storage Temperatures1  

Microsoft Academic Search

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

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

1977-01-01

20

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.

21

Influence of nonaxisymmetric temperature profile in layer of different-temperature components on radiant heat transfer  

NASA Astrophysics Data System (ADS)

On the basis of analysis of the radiant heat transfer in a layer of different-temperature components with a nonaxisymmetric temperature profile, the influence of the content of low-temperature components, the optical thickness of the layer, and the temperature profile on the resulting radiation flux is investigated. Practical recommendations for the design of steam-boiler furnaces are given.

Gorb, . I.; Akhmedov, D. B.

1991-05-01

22

Influence of roasting temperature on physicochemical properties of different coffees  

Microsoft Academic Search

Arabica and robusta coffees from different origins were characterized before and after roasting at different temperatures (between 220 and 295C). Samples were roasted (dark roast) until they attained the same colour. Colour development of the ground samples was measured throughout using CIE L*a*b* co-ordinates. The roasting temperature did not affect final weight loss and moisture content of the different coffees

M. D. Ortol; L. Londoo; C. L. Gutirrez; A. Chiralt

1998-01-01

23

Protein turnover in juvenile barramundi, Lates calcarifer at different temperatures.  

PubMed

Background - Temperature is recognized to be the most important environmental factor affecting growth and protein synthesis in ectothermic fish. The optimal temperature for barramundi is 27-28 degrees C, however culture of these fish often occurs in temperatures which are above and below optimum. Objective - Understanding how different temperatures affect the protein turnover rates of juvenile fish is important in understanding optimization of growth efficiency by juvenile fish. Design - Fish were placed in one of five experimental temperatures ranging from 21-33 degrees C. Fish were fed a 50% protein 15% lipid diet twice daily for 22 days. Growth was monitored weekly and at the end of the trial, fish were sampled for protein synthesis, protein degradation and whole body composition. Remaining fish were starved for 2 weeks to estimate maintenance. Outcomes - No significant differences were found among the highest temperatures (27-33 degrees C) for food conversion ratio, specific growth rate and growth (wet weight gain). Feed intake was significantly different between all treatment groups with the exception of the two highest temperature groups (30 and 33 degrees C). The capacity for protein synthesis (RNA:protein) was highest at 27 degrees C. This was not significant from the 30 degrees C group however it was significantly higher than the remaining treatments. Conclusions - Growth indices and protein turnover were affected by temperature. Higher temperature (27-33 degrees C) supported faster growth than the lower temperatures (21-24 degrees C). PMID:15023636

Katersky, R S; Carter, C G

2003-01-01

24

Pressure and temperature drawdown well testing: similarities and differences  

Microsoft Academic Search

Temperature and pressure are the most frequently observed physical parameters in boreholes. The same differential diffusivity equation describes the transient flow of incompressible fluid in porous media and heat conduction in solids. The similarities and differences in the techniques of pressure and temperature well testing are discussed. It is shown that the mathematical model of pressure well tests based on

L. V. Eppelbaum; I. M. Kutasov

2006-01-01

25

Structural Changes of Ni-DOPED Ybco at Different Temperature  

NASA Astrophysics Data System (ADS)

In YBa2Cu3-xNixOy at about 480C all the samples show a tetragonal phase. Comparing the structural changes at 480C with those at room temperature, the bond lengths such as Cu(1)-O(4) and Cu(2)-O(4) vary regularly with Ni-content increasing at room temperature, but not at high temperature. It suggests that there is a close correlation between structural changes and superconductivity in this system. The difference of orthorhombic- tetragonal phase -transition is also discussed between undoped YBCO and Ni-doped YBCO at high temperature.

Zhang, L.; Du, H. L.; Rui, X. F.; Sun, X. F.; Zhang, H.

26

Mechanical behavior at different temperatures and stresses for superelastic nickeltitanium orthodontic wires having different transformation temperatures  

Microsoft Academic Search

Objective: The purpose of this study was to investigate the mechanical properties of superelastic nickeltitanium orthodontic wires under controlled stress and temperature.Methods: Three different superelastic nickeltitanium wires were examined using differential scanning calorimetry (DSC), three-point bending test and micro X-ray diffraction (micro-XRD). The three-point bending test was carried out at constant temperature (23, 37 and 60C) and stepwise temperature changes

M. Iijima; H. Ohno; I. Kawashima; K. Endo; I. Mizoguchi

2002-01-01

27

Differences Between Solar Wind Alpha Particle and Proton Temperatures at Times of Proton Temperature Depressions  

NASA Astrophysics Data System (ADS)

Using ACE SWEPAM measurements from February 5, 1998 through October 30, 2001 we have examined hourly averages of the solar wind alpha particle temperature TA and compared it to the proton temperature TP. The ratio TA/TP ranges from about 1 to 10, with the most probable value near 4, indicating that protons and alpha particles typically have the same thermal speed. We find that this ratio tends to vary with solar wind speed; ratios less than 4 are more common at lower speeds. In this study we investigate the character of the alpha particle temperature during intervals of depressed proton temperature. In general, the solar wind proton temperature increases with increasing flow speed. The temperature is considered depressed when it is much lower (by a factor of approximately 2) than the typical temperature observed at a given speed. For this work, we developed an expression for the expected proton temperature as a function of speed appropriate for the ACE level 2 data, and used this expression to identify intervals of unusually low proton temperature. When proton temperatures are lower than expected, we find that TA/TP tends toward values of 1. We conclude that proton temperature depressions usually have corresponding alpha particle temperature depressions, and the relative difference between typical and depressed temperatures is 4 times greater for alpha particles than for protons. We note that, similar to proton temperature depressions, alpha particle temperature depressions can serve as useful indicators of CME flows.

Steinberg, J. T.; Davenport, T. A.; Reisenfeld, D. B.; Skoug, R. M.

2002-12-01

28

Temperature Rise during Resin Composite Polymerization under Different Ceramic Restorations  

PubMed Central

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

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

2011-01-01

29

Influence of perfusate temperature on nasal potential difference.  

PubMed

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

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

2012-10-25

30

Variability of Rotational Temperatures from Different OH Rovibrational Levels  

NASA Astrophysics Data System (ADS)

TThe Meinel band emission lines from rovibrationally excited OH in its electronic ground state in the nightglow are widely used as a diagnostic tool to investigate key mesospheric variables such as temperature, tides, and gravity waves. The OH rotational temperature has been extensively studied to ascertain both long- and short-term variability in the upper atmosphere. Current controversy in the literature regarding the possible variability of temperatures deduced from different OH rovibrational levels limits our ability to compare data from different sources. Researchers tend to use a monitoring vibrational level for OH Meinel bands that is most convenient for their instrument. Background sky spectra captured by astronomical instruments provide detailed records of optical emissions in the upper atmosphere. For this study we utilized existing sky spectra from the Keck telescopes in Mauna Kea and the Very Large Telescope in Chile for the OH Meinel bands bound by the extremes (? = 3, 8). We compared these results with the temperatures deduced from the O2 0-1 Atmospheric band at 865 nm. This latter emission, emanating from a long-lived species, should represent the true kinetic temperature at the altitude of emission and therefore puts a cap on how high the temperature difference can be between the nominal OH altitude (87 km) and the 95-km altitude of the O2 emission. We present the results of our analysis and discuss the implications for mesospheric temperature retrievals from OH emissions. This work was supported by NSF grant ATM-0924781 from NSF CEDAR.

Vimal, D. V.; Slanger, T. G.

2011-12-01

31

Application of the blackbody radiation source for characteristics measurement of submillimeter low-temperature direct detectors  

Microsoft Academic Search

As is well-known characteristics measurement of submillimeter low-temperature direct detectors can be fulfilled using their signal response for the radiation of temperature swept blackbody. We describe a method using the Fredholm integral equation of first kind which solution gives possibility to derive direct detector spectral characteristic from the signal response dependence on temperature with acceptable accuracy. Then a noise equivalent

Alexander N. Vystavkin; Andrey V. Pestriakov; Eugeny A. Vinogradov

2006-01-01

32

Simulation of soil temperature dynamics with models using different concepts.  

PubMed

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

Sndor, Renta; Fodor, Nndor

2012-06-18

33

Simulation of Soil Temperature Dynamics with Models Using Different Concepts  

PubMed Central

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

Sandor, Renata; Fodor, Nandor

2012-01-01

34

Potential Formation and Thermal Insulation between Different Temperature Plasmas  

Microsoft Academic Search

Potential formation and reduction of electron heat flow between different temperature plasmas are studied by particle simulations. It is found that the amplitude and even the polarity of the potential difference is controlled by the ion to electron thermal velocity ratio. When the ion thermal speed is smaller than the electron thermal speed, the positive potential jump from the cold

Seiji Ishiguro

1987-01-01

35

The accurate refractive indices of BIBO crystal at different temperatures  

NASA Astrophysics Data System (ADS)

The principal refractive indices of BiB3O6 (BIBO) crystal at different wavelengths in the temperature range from 30 to 170 C were measured by the autocollimation method. The Sellmeier equations at different temperatures have been obtained. In order to check their reliability, the refractive indices at 0.532 m and 1.319 m at different temperatures are calculated by the Sellmeier equations and compared with the measured values. As a result, the difference between the calculated results and the measured results is less than 2 10-4. The calculated type I second harmonic generation angle of BIBO at 1.0640 m is consistent with the measured result.

Lingxiong, Huang; Xiang, Lin; Ge, Zhang; Chenghui, Huang; Yong, Wei

2009-11-01

36

Analysis of Unsteady Turbulent Merging Jet Flows With Temperature Difference  

SciTech Connect

Suitable turbulence model is required in the course of establishing a proper analysis methodology for thermal stripping phenomena. For this purpose, three different turbulence models of k-e model, modified k-e model, and full Reynolds stress model and VLES are applied to analyze unsteady turbulent flows with temperature variation. Four test cases are selected for verification. These are vertical jet flows with water and sodium, parallel jet flow with sodium, and merging pipe flow through T-junction with sodium. The geometries of test cases well represent common places where thermal stripping might be occurred. The turbulence model computation shows overall jet flow characteristics well and good comparison of mean temperature distribution. Temperature variance (?2) is rather over-predicted, but location of high temperature variance is matched well with that of the large amplitude of temperature variation of experimental results. Meanwhile, mixing of hot and cold jet flow is found to be not that active. (authors)

Geun Jong Yoo; Won Dae Jeon [Changwon National University, 9 Sarim-dong, Changwon, Kyongnam, 641-773 (Korea, Republic of)

2002-07-01

37

Human physiological responses to immersion into water of different temperatures  

Microsoft Academic Search

To differentiate between the effect of cold and hydrostatic pressure on hormone and cardiovascular functions of man, a group\\u000a of young men was examined during 1-h head-out immersions in water of different temperatures (32C, 20C and 14C). Immersion\\u000a in water at 32C did not change rectal temperature and metabolic rate, but lowered heart rate (by 15%) and systolic and diastolic

P. rmek; M. ime?kov; L. Jansk; J. avlkov; S. Vybral

2000-01-01

38

Temperature rise during polymerization of three different provisional materials  

Microsoft Academic Search

The purpose of this study was to evaluate the temperature rise during polymerization of three different provisional materials\\u000a by direct method on two different dentin disc thicknesses. Two autopolymerizing; bis-acrylic composite (Fill-in; Kerr), polymethyl\\u000a methacrylate (Temdent; Weil Dental), and one light polymerizing composite (Revotek LC; GC) provisional restoration materials\\u000a were used in this study. Sixty dentin discs were prepared from

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

2008-01-01

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 4.6C

Patricia I. Figuerola; Nicols A. Mazzeo

1998-01-01

40

The Temperature in the Upper Stratosphere: Differences Between Hemispheres  

Microsoft Academic Search

Two years of infrared data received by the uppermost channel of the selective chopper radiometer, flown on Nimbus 4, are used for a description of the main features of the temperature distribution in the upper stratosphere, with emphasis on differences between the hemispheres. In the upper stratosphere the southern summer is warmer, and the early southern winter colder at all

Karin Labitzke

1974-01-01

41

The temperature change of regional difference in Anhui Province, China  

NASA Astrophysics Data System (ADS)

Three regions, Huaibei, Jianghuai, Jiangnan, are divided based on the topography, climatic characteristics, as well as surface temperature from 1957 to 2006 of 16 stations in Anhui province. The change with the year, season and month is analyzed in Anhui province and three areas. Some conclusions are as follows. Anhui province had the lowest temperature in 1980s, but after that the temperature raised step by step. The warming fastest region is Jianghuai. The same pace of warming is in three areas: the greatest warming in spring, then that in autumn, the last in summer. It is warming remarkable in February and the cooling time occurs in July and December. But the fluctuation in three areas is different in some details. The heat island in Hefei is also researched. It suggests that the urban heat island intensity in 1990s in Hefei was the maximum, and then weakened. At the meanwhile, the summer is cooling and the winter is warming in Hefei.

Liu, Ke; Gao, Zhiqiang; Gao, Wei

2009-08-01

42

Stability considerations of a high-temperature superconductor tape at different operating temperatures  

NASA Astrophysics Data System (ADS)

Stability of a Bi-2223/Ag multifilamentary composite conductor against fast transport current ramps was studied by using a numerical model. The model was based on the two-dimensional magnetic diffusion and heat conduction equations. Calculations were carried out both in an adiabatic mode and pool boiling modes in liquid helium, hydrogen and nitrogen. When estimating the heat load (AC losses), real temperature dependent current density-electric field characteristics were used. The results computed by the finite element method are presented and discussed with special emphasis on differences of the stability considerations between high-temperature and low-temperature superconductors.

Lehtonen, J.; Mikkonen, R.; Paasi, J.

1998-12-01

43

Degradation of TMAH treated aquatic humic matter at different temperatures  

Microsoft Academic Search

Lake aquatic fulvic acid was investigated with tetramethylammonium hydroxide (TMAH) treatment and pyrolysis-gas chromatography\\/mass spectrometry (Py-GC\\/MS). TMAH treatment was performed as an off-line procedure at 100C without significant thermochemolytic degradation (ensured with a solvent extraction) and the product distributions at three different pyrolysis temperatures (300, 450 and 600C) were studied. The degradation of TMAH treated fulvic acid was strongly thermally

T. Lehtonen; J. Peuravuori; K. Pihlaja

2000-01-01

44

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

Microsoft Academic Search

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

Emily Willingham

2005-01-01

45

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 Gteborg, 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

46

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; Rdenas, J

2010-10-27

47

Trends and differences of the temperature effect on mismatch in different CMOS technology nodes  

Microsoft Academic Search

Statistical drain-current differences between pairs of supposedly identical transistors, usually known as matching, represent a crucial aspect of analog and mixed-signal circuits. Although matching has been a subject of study for more than two decades, how the temperature affects it is still scarcely discussed in the open literature [1,2]. In previous work, we discussed temperature effects on matching properties for

P. Andricciola; H. Tuinhout; N. Wils

2010-01-01

48

Reactive Burn Modelling at Different Initial Temperatures Using Crest  

NASA Astrophysics Data System (ADS)

The CREST reactive burn model uses entropy-dependent reaction rates to simulate behaviour in plastic bonded explosives. A CREST model for the TATB-based explosive PBX 9502, described at the last conference, was shown to able to predict a range of shock initiation and detonation propagation data at ambient temperature. However, it is well known that the behaviour of PBX 9502 varies significantly with initial temperature. Modelling the change in response that occurs upon heating or cooling the explosive, without having to modify the equation of state (EOS) and reaction rate parameters, is a significant challenge for reactive burn models. An important feature of CREST is that the initial state of the explosive can be incorporated without having to change the reference EOS or reaction rate model. In this paper, CREST is applied to PBX 9502 shock initiation data at different initial temperatures. It is shown that the model can account reasonably well for the variation in shock sensitivity with initial temperature using a single set of parameters.

Whitworth, N. J.; Lambourn, B. D.

2009-12-01

49

TBARS predictive models of pork sausages stored at different temperatures.  

PubMed

2-Thiobarbituric acid reactive substances (TBARS) is an important quality index for pork sausages. To study this in pork sausages during storage, kinetic models were developed to predict TBARS content changes of pork sausages at different temperatures. The predictive models of TBARS content with respect to storage time and temperature were developed based on primary and Arrhenius equations. The regression coefficients (R(2)>0.95) indicated the acceptability of the primary reaction and Arrhenius model for predicting TBARS content changes of pork sausages. The activation energy (EA) of TBARS is 14.12kJmol(-1), and the corresponding rate constant (k0) is 9.26210(10). Relative errors between predicted and measured values of TBARS content are all within 8%. Thus, the established model could effectively predict the TBARS content of pork sausages between 5 and 35C during storage. PMID:23896130

Wenjiao, Fan; Yongkui, Zhang; Yunchuan, Chen; Junxiu, Sun; Yuwen, Yi

2013-06-22

50

Relation Between Electric Power and Temperature Difference for Thermoelectric Generator  

NASA Astrophysics Data System (ADS)

The thermoelectric generation is the direct energy conversion method from heat to electric power. The conversion method is a very useful utilization of waste energy because of its possibility using a thermal energy below 423K. This research objective is to establish the thermoelectric technology on an optimum system design method and efficiency, and cost effective thermoelectric element in order to extract the maximum electric power from a wasted hot water. This paper is considered in manufacturing a thermoelectric generator and manufacturing of thermoelectric generator with 32 thermoelectric modules. It was also found that the electric voltage of thermoelectric generator with 32 modules slowly changed along temperature differences and the maximum power of thermoelectric generator using thermoelectric generating modules can be defined as temperature function.

Woo, Byung Chul; Lee, Hee Woong

51

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 Nios), 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 Nias. This relationship suggest the influence of the position of Intertropical Convergence Zone (ITCZ) on the frequency of El Nios. 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

52

Evolution of negative small air ions at two different temperatures  

NASA Astrophysics Data System (ADS)

In this paper, we simulate the negative ion evolution shape considering 151 different ions, 66 trace gases and 493 ion-molecule reactions. The main attention is paid to the evolution interval from 30ms to 3s where the knowledge is most limited. The connections between the evolution shape and temperature have been studied. The simulated results have been compared with the relevant measurements, and the ions most likely responsible for a certain ion evolution shape observed by Nagato and Ogawa (J. Geophys. Res. 103(D12) (1998) 13917) have been revealed. Also, the composition of trace gases likely responsible for the observed shape can be derived. In the studied evolution interval the transformation O2-(H2O)n-- >CO3-(H2O)m-- >NO3-XY prevails. At the higher temperature, the ions CO3-(H2O)m are less abundant. In the respective steady (natural) state the most abundant ions are NO3-XY(HCl)n and NO3-(H2O)m. At the higher temperature, the ions NO3-(H2O)m are dominant.

Luts, Aare; Parts, Tiia

2002-05-01

53

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 Titans 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.

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

2012-04-01

54

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.

Jutte, Lisa S.; Smith, Michael E.

2003-01-01

55

Plant immune response to pathogens differs with changing temperatures.  

PubMed

Temperature fluctuation is a key determinant for microbial invasion and host evasion. In contrast to mammals that maintain constant body temperature, plant temperature oscillates on a daily basis. It remains elusive how plants operate inducible defenses in response to temperature fluctuation. Here we report that ambient temperature changes lead to pronounced shifts of the following two distinct plant immune responses: pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). Plants preferentially activate ETI signaling at relatively low temperatures (10-23?C), whereas they switch to PTI signaling at moderately elevated temperatures (23-32?C). The Arabidopsis arp6 and hta9hta11 mutants, phenocopying plants grown at elevated temperatures, exhibit enhanced PTI and yet reduced ETI responses. As the secretion of bacterial effectors favours low temperatures, whereas bacteria multiply vigorously at elevated temperatures accompanied with increased microbe-associated molecular pattern production, our findings suggest that temperature oscillation might have driven dynamic co-evolution of distinct plant immune signaling responding to pathogen physiological changes. PMID:24067909

Cheng, Cheng; Gao, Xiquan; Feng, Baomin; Sheen, Jen; Shan, Libo; He, Ping

2013-09-26

56

Survival of Airborne Pasteurella tularensis at Different Atmospheric Temperatures  

PubMed Central

The aerosol survival, recovery, and death rate of Pasteurella tularensis SCHU S5 disseminated in particle sizes of 1 to 5 ?m were significantly affected by air temperature. The highest aerosol recovery of viable P. tularensis was observed within -7 and 3 C; the recovery decreased significantly below and above this temperature range. The death rate of airborne P. tularensis was not significantly influenced by an increase in temperature from -40 to 24 C. However, a progressive increase in atmospheric temperature from 24 to 35 C resulted in increased death rates; thus, a linear relationship appeared to be present between the temperature and death rates. At 49 C, the recoveries of viable airborne P. tularensis were significantly lower and the death rates were higher than at the other temperatures.

Ehrlich, Richard; Miller, Sol

1973-01-01

57

Changes in population occupancy of Bradyrhizobia under different temperature regimes.  

PubMed

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

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

2010-01-01

58

Oxygen consumption in Mediterranean octocorals under different temperatures  

Microsoft Academic Search

Ecosystem resilience to climate anomalies is related to the physiological plasticity of organisms. To characterize the physiological response of some common Mediterranean gorgonians to fluctuations in temperature, four species (Paramuricea clavata, Eunicella singularis, Eunicella cavolinii and Corallium rubrum) were maintained in aquaria, in which the temperature was increased every ten days with increments of 23C, starting at 14C, ending at

Monica Previati; Alice Scinto; Carlo Cerrano; Ronald Osinga

2010-01-01

59

GERMINATION OF SWITCHGRASS UNDER DIFFERENT TEMPERATURE AND PH REGIMES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Switchgrass (Panicum virgatum L.), a native prairie grass, is being developed into a biomass energy crop. The effect of temperature and pH on the germination success of switchgrass cultivars was investigated. Seeds of eight switchgrass cultivars were germinated at five temperatures and nine pH level...

60

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

61

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

62

Daily rhythm of body and auricle temperature in goats kept at two different ambient temperatures  

Microsoft Academic Search

In fluctuating environmental temperature, homeotherms are able to maintain stable their body temperature, which however reveals a rhythmic daily pattern as described in literature. Because of the importance of body temperature rhythmicity in the knowledge of thermal homeostasis and as a means to facilitate the study of biological rhythmicity in general, the aim of our study was to assess the

G. Piccione; C. Bertolucci; A. Costa; S. Di Mauro; G. Caola

2005-01-01

63

Ground temperature and moisture distribution using different weather patterns  

Microsoft Academic Search

The article presents a theoretical model to describe coupled heat and moisture transfer in porous media which finds relevance in building sciences where thermal comfort and energy efficiency are of high interest and in geophysics where accurate prediction of subsurface water content and temperature distributions has been a major focus. The Philip and de Vries based model (Philip, J.R. and

Olukayode Dewumi Akinyemi; Nathan Mendes

2008-01-01

64

Cure Rate of Halthane 73-18 at Different Temperatures.  

National Technical Information Service (NTIS)

Halthane 73-18 is a new polyurethane type adhesive being developed for an assembly operation. This report includes the cure rate at ambient, 38, 78, and 100 C. An equation relating cure rate, time, and temperature is established. (ERA citation 04:024029)

P. A. Foster R. W. Ashcraft

1977-01-01

65

Fretting Resistance of Different Coating Materials in High Temperature.  

National Technical Information Service (NTIS)

The purpose of this work was to study coating materials suitable for use in spindle and sleeve in power plant valves. The valves will be sujected to vibration, high temperatures (530 deg C) and atmosphere of low oxygen content (<20 ppb). Under these condi...

U. Wiiala L. Lehtiniemi M. Pitkaenen

1986-01-01

66

The force of attraction between two solids with different temperatures  

Microsoft Academic Search

The methods of fluctuation electrodynamics and the molecular cohesive force theory have been used to obtain an expression for the attractive force density between two absorbing media varying in temperature and separated by a nonabsorbing plane-parallel layer. The spectral density of the attractive force was calculated as the stress tensor projection on the exterior normal to the solid surface. The

I. A. Dorofeyev

1998-01-01

67

Thermoregulation in naked neck chickens subjected to different ambient temperatures.  

PubMed

1. Heterozygous (Na/na) naked neck chickens and their normally feathered (na/na) sibs, were exposed to constant ambient temperatures (Ta) ranging between 15 and 35 degrees C and 12h: 12h diurnal high:low temperatures of 15 degrees C:35 degrees C. 2. No significant effect of genotype was obtained in weight gain and food intake. However, the naked neck birds tended to gain somewhat more weight at high Ta and consume more food at low Ta. 3. At 35 degrees C Na birds showed better regulation of body temperature (Tb) and demonstrated considerably higher radiation from the neck. 4. The greater food intake of the naked neck chickens at 15 degrees C was associated with significantly higher packed cell volume, haemoglobin concentration, heart and liver size. These appear to involve both higher heat production and haemodynamic changes to accommodate the higher oxygen demands of the naked neck chickens at low Ta. 5. The results indicate the ability of the naked neck chickens, on the one hand to thermoregulate at low Tas and, on the other their slightly better capacity to maintain Tb at high Tas. However, no genotype advantage was obtained under diurnal cyclic temperature conditions. PMID:9568311

Yahav, S; Luger, D; Cahaner, A; Dotan, M; Rusal, M; Hurwitz, S

1998-03-01

68

REACTIVE BURN MODELLING AT DIFFERENT INITIAL TEMPERATURES USING CREST  

Microsoft Academic Search

The CREST reactive burn model uses entropy-dependent reaction rates to simulate behaviour in plastic bonded explosives. A CREST model for the TATB-based explosive PBX 9502, described at the last conference, was shown to able to predict a range of shock initiation and detonation propagation data at ambient temperature. However, it is well known that the behaviour of PBX 9502 varies

N. J. Whitworth; B. D. Lambourn

2009-01-01

69

Reactive Burn Modelling at Different Initial Temperatures Using Crest  

Microsoft Academic Search

The CREST reactive burn model uses entropy-dependent reaction rates to simulate behaviour in plastic bonded explosives. A CREST model for the TATB-based explosive PBX 9502, described at the last conference, was shown to able to predict a range of shock initiation and detonation propagation data at ambient temperature. However, it is well known that the behaviour of PBX 9502 varies

N. J. Whitworth; B. D. Lambourn

2009-01-01

70

Compressional Viscosity and Sound Absorption in Water at Different Temperatures  

Microsoft Academic Search

The temperature dependence of the coefficient of absorption (2alphanu-2) of ultrasonic waves in water was measured from 0C to 33C. Values range from 13710-17 at 0C to 4010-17 at 33C. In particular at 4C where the sound propagation is isothermal the value 10110-17 is found, and is to be compared with a shear viscosity contribution of 3010-17. Therefore the excess

Francis E. Fox; George D. Rock

1946-01-01

71

Moisture sorption isotherms of cereals at different temperatures.  

PubMed

In this research, moisture sorption isotherms of wheat (Kink and Lancer) barley, rye, oat and corn were determined at 20, 25, 35, 50 and 70 degrees C. The sorption isotherm curves of all cereal samples showed the characteristics of type II isotherm. This indicated that the adsorption occurred in cereal samples was a multilayer adsorption and cereal samples were of a microcapillary structure. In addition, the adsorption in cereal samples decreased as temperature increased. PMID:10795577

Ertugay, M F; Certel, M

2000-04-01

72

Gender differences in temperature and vascular characteristics during exercise recovery.  

PubMed

Temperature and vascular responses during exercise recovery were examined in men and women of similar age and fitness status (VO2max: 76 +/- 5 vs 73 +/- 5 mL O2 / kg Fat Free Mass x min). Forearm blood flow (venous occlusion plethysmography; FBF), rectal (Trectal) and forearm skin (Tskin) temperatures (degree C) were measured before and every 15 min up to 105 min (t105) during recovery from a 45-min run at 75% of VO2max. Results indicate Trectal decreased to pre-exercise levels within 25 min in men but reached and remained at values lower than baseline between 60 and 105 min of recovery in women. From 90 to 105 min of recovery, Tskin was lower in women than men (t105 : 29.0 +/- 1.3 vs 30.7 +/- 1.5; p <.05). Recovery FBF (mL/100mL x min) was higher in men than women from the start (6.2 +/- 1.9 vs 4.9 +/- 1.9) to the end of recovery (t105 = 1.7 +/- 0.6 vs 2.6 +/- 1.1) (p <.05). Heat flux calculated at the forearm was higher in women and increased throughout the last hour of recovery (p <.05). Further investigations are needed to examine mechanisms underlying failure of post-exercise core and skin temperatures in women to stabilize at pre-exercise levels. PMID:11675532

Marchand, I; Johnson, D; Montgomery, D; Brisson, G R; Perrault, H

2001-10-01

73

Moisture sorption isotherms of broad bean seeds at different temperatures.  

PubMed

The equilibrium moisture contents in broad bean seeds were determined using the gravimetric static method at 5, 20, 40 and 60 degrees C over a range of water activities from 0.110 to 0.877. The sorption capacity of seeds decreased with the increase in temperature at constant water activity. Five models, modified Chung-Pfost, modified Halsey, modified Oswin, modified Henderson, and GAB (Guggenheim-Anderson-de Boer) equations, were applied to analyse the experimental data. The modified Oswin and GAB models were found to be the most suitable for describing the sorption isotherms. PMID:11190843

Menkov, N D

2000-12-01

74

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

Microsoft Academic Search

Application of high temperature superconductors (HTS) to devices requires a detailed understanding of the effects of temperature, magnetic field and orientation of magnetic field on the critical current density. Measurements of the critical surface of PbBSCCO were made on long lengths of fully reacted multi-filamentary wire wound into solenoids. These react and wind coils were tested in magnetic fields to

D. Aized; M. D. Manlief; C. H. Joshi

1994-01-01

75

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

Microsoft Academic Search

Application of High Temperature Superconductors (HTS) to devices requires a detailed understanding of the effects of temperature, magnetic field and orientation of magnetic field on the critical current density. Measurements of the critical surface of PbBSCCO were made on long lengths of fully reacted multi-filamentary wire wound into solenoids. These react & wind coils were tested in magnetic fields to

D. Aized; M. D. Manlief; C. H. Joshi

1994-01-01

76

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 750C. The response differences are compared by using the signal decoupling method. The relationship between wavelength change and structural thermal strain is studied; the first-order and the second-order temperature sensitivities coefficients are given for different materials. Through the experiment, the different strain transfer coefficients are given in the two cases. This study realized the concurrent monitoring of structural temperature and strain at high-temperature situation using only one sensor, and thus provides a new way for hot structure health monitoring in high-temperature environment.

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

2013-08-01

77

Adsorption mechanism of different coal ranks under variable temperature and pressure conditions  

Microsoft Academic Search

Variable temperature and pressure adsorption tests were conducted on four coal samples with different coal ranks, under simulated temperatures and pressures corresponding to coal reservoirs at different depths. The regularity of the variation in the amounts of adsorption by coals under variable temperature and pressure and 30 C isothermal conditions are compared and the adsorption characteristics of coal under the

Qing-ling ZHANG

2008-01-01

78

Study of Atmospheric Temperature at Different Altitudes using Muon Angular Distribution at Sea Level  

Microsoft Academic Search

It is well known that the cosmic ray flux at ground level depends on meteorological conditions and is related to changes in temperature T, and in atmospheric pressure P. The technique of monitoring of the atmospheric temperature at different altitudes was suggested more than 30 years ago (1). The qualitative assessment of the change of the temperature at three different

V. V. Borog; A. S. Davydova; G. M. Kruchenitskii; V. G. Yanke

79

DESCRIPTION OF INDIVIDUAL DIFFERENCE IN HUMAN BODY TEMPERATURE REGULATION BY USING TWO-NODE MODEL  

Microsoft Academic Search

The methodology to describe the individual difference in temperature regulation of human body in transient state is proposed in this paper. In order to clarify the individual difference experimentally, the change in skin and core temperatures was measured for four subjects exposed to a thermal transient condition including stepwise air temperature change of coming and going to lower and higher

Satoru Takada; Hiroaki Kobayashi; Takayuki Matsushita

80

Temperature-sensitive neurons in the brain stem: Their responses to brain temperature at different ambient temperatures  

Microsoft Academic Search

Unit recordings have been made in the hypothalamus of cats and rabbits under urethane anaesthesia. The final position of each electrode penetration was marked by the ejection of a dye. Techniques used enabled brain temperature and ambient temperature to be controlled.

R. F. Hellon

1972-01-01

81

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)

1994-07-01

82

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

NASA Astrophysics Data System (ADS)

Application of High Temperature Superconductors (HTS) to devices requires a detailed understanding of the effects of temperature, magnetic field and orientation of magnetic field on the critical current density. Measurements of the critical surface of PbBSCCO were made on long lengths of fully reacted multi-filamentary wire wound into solenoids. These react & 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(exp 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.

1994-07-01

83

Temperature characteristics of silicon avalanche photodiodes  

NASA Astrophysics Data System (ADS)

The paper presents the results of studies on temperature dependence of such parameters as a dark current, noise current, gain, noise equivalent power and detectivity of silicon epiplanar avalanche photodiodes at the ITE. The photodiode reach-through structure is of an nPLU-p-(pi) - p+ type with an under-contact ring and a channel stopper. The temperature range was stretching from -40 C to +40 C. Specially developed for this purpose an automatic system for low noise measurements was used. A two- stage micro-cooler with a Peltier's element was applied to control and stabilize the temperature of measured structures.

Wegrzecka, Iwona; Grynglas, Maria; Wegrzecki, Maciej; Bar, Jan; Grodecki, Remigiusz

2001-08-01

84

Effect of Different Temperatures on Viruses of the Small Pox Group in Tissue Cultures.  

National Technical Information Service (NTIS)

It has been established that there are critical temperatures above which no cytopathological action of smallpox and parasmallpox viruses manifest themselves in a tissue culture of chick fibroplasts. The difference in critical temperatures for smallpox and...

E. B. Gurvich

1968-01-01

85

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

NASA Astrophysics Data System (ADS)

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

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

2008-03-01

86

Respiration of Cytherissa lacustris (Ostracoda) at different temperatures and its tolerance towards temperature and oxygen concentration  

Microsoft Academic Search

The ostracod species Cytherissa lacustris was investigated with respect to its temperature and oxygen tolerance limits. In laboratory experiments the tolerance limits were found to be much wider than expected from field data. Hatching of first instars was observed in cultures up to 20 C. The tolerance limit for oxygen concentrations was less than 1 mg O2l-1 at 10 C

Peter Newrkla

1985-01-01

87

Temperature Increase in Human Heads Due to Different Models of Cellular Phones  

Microsoft Academic Search

The temperature increase in a realistic human head model exposed to five different cellular phone models is investigated by a bioheat equation and the finite-difference time-domain (FDTD) method at 900 and 1800 MHz, respectively. These five cellular phone models are greatly differ from each other in structure. The realistic human head model is used to investigate the temperature increase in

Hsing-Yi Chen; Han-Peng Yang

2006-01-01

88

Comparison of different theoretical models for flash temperature calculation under fretting conditions  

Microsoft Academic Search

The wear and friction properties of tribological interfaces depend significantly on the contact temperature, and its determination is therefore important for each tribological application. Temperature calculation methods available in the literature use quite different physical, dynamic and geometrical assumptions. Furthermore, the assumptions necessary for temperature calculations also include various interfacial properties, which are usually unknown due to many difficulties in

Mitjan Kalin; Joe Viintin

2001-01-01

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, Sr. , R. A.; Gallo, K. P.

2006-01-01

90

A preliminary study on growth and protein synthesis of juvenile barramundi, Lates calcarifer at different temperatures  

Microsoft Academic Search

Temperature is recognized to be the most important environmental factor affecting growth and protein synthesis in fish. The optimal temperature for growth of juvenile barramundi is 31C, although culture often occurs at temperatures which are above and below this optimum. Juveniles (2.960.46g) were held at five different temperatures ranging from 21 to 33C at 3C intervals. Fish were fed to

Robin S. Katersky; Chris G. Carter

2007-01-01

91

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

92

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

Microsoft Academic Search

An extensive investigation of 61 daily temperature records by means of detrended fluctuation analysis has revealed that the value of correlation exponent is not universal, contrary to earlier claims. Furthermore, statistically significant differences are found for daily minimum and maximum temperatures measured at the same station, suggesting different degrees of long-range correlations for the two extremes. Numerical tests on synthetic

Margit Pattantys-brahm; Andrea Kirly; Imre M. Jnosi

2004-01-01

93

Investigations on the fracture toughness of austempered ductile irons austenitized at different temperatures  

Microsoft Academic Search

Ductile cast iron was austenitized at four different temperatures and subsequently austempered at six different temperatures. Plane strain fracture toughness was evaluated under all the heat treatment conditions and correlated with the microstructural features such as the austenite content and the carbon content of the austenite. Fracture mechanism was studied by scanning electron microscopy. It was found that the optimum

P. Prasad Rao; Susil K. Putatunda

2003-01-01

94

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

PubMed

A fundamental tenet of sexual selection is that in sexually dimorphic traits, there is variation within a sex. In leopard geckos (Eublepharis macularius), a species with temperature-dependent sex determination, embryonic temperature contributes both to sex determination and polymorphisms within each sex. In this study we report that males from different incubation temperatures, one hitherto untested, exhibit significant differences in behavior even when castrated. Further, treatment with dihydrotestosterone increases scent marking, a territorial behavior. This supports previous results indicating that temperature has a direct organizing action on brain and sociosexual behavior independent of gonadal hormones. PMID:22750461

Huang, Victoria; Crews, David

2012-06-30

95

Complex Permeability of SiO2-COATED Fe-Ni Particles Reduced at Different Temperatures  

NASA Astrophysics Data System (ADS)

We have prepared Fe-Ni particles coated with 3 wt% SiO2 by chemical synthesis. The precursor compounds have been reduced in hydrogen gas at different temperatures. The dependence of complex permeability ? on different reduction temperatures is studied by using an impedance analyzer. The experiment results indicate that the domain wall pinning strength, the average domain thickness and the resistivity depend on different heat treatment conditions. The magnetization process is mostly contributed by the domain wall bulging and displacement.

Jiang, H. Y.; Zhong, W.; Tang, N. J.; Wu, X. L.; Liu, W.; Du, Y. W.

96

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

PubMed

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

Childs, Charmaine; Lunn, Kueh Wern

2013-04-22

97

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

98

Prediction of air temperature in the aircraft cabin under different operational conditions  

NASA Astrophysics Data System (ADS)

This paper deals with the prediction of the air temperature in the aircraft cabin by means of Computational Fluid Dynamics. The simulations are performed on the CFD model which is based on geometry and cabin interior arrangement of the Flight Test Facility (FTF) located at Fraunhofer IBP, Germany. The experimental test flights under three different cabin temperatures were done in FTF and the various data were gathered during these flights. Air temperature in the cabin was measured on probes located near feet, torso and head of each passenger and also surface temperature and air temperature distributed from inlets were measured. The data were firstly analysed in order to obtain boundary conditions for cabin surfaces and inlets. Then the results of air temperature from the simulations were compared with measured data. The suitability and accuracy of the CFD approach for temperature prediction is discussed.

Volav, F.; Fier, J.; Nske, I.

2013-04-01

99

Biochemical photosynthetic responses to temperature: how do interspecific differences compare with seasonal shifts?  

PubMed

Plants show flexible acclimation of leaf photosynthesis to temperature that depends both on their prevailing growth environment and the climate where they originated. This acclimation has been shown to involve changes in the temperature responses of the apparent maximum rate of Rubisco carboxylation (Vcmax) and apparent maximum rate of electron transport (Jmax), as well as changes in the ratio of these parameters. We asked whether such changes in photosynthetic biochemistry attributable to climate of origin are similar in nature and magnitude to those attributable to growth environment. To address this question, we measured temperature responses of photosynthesis and chlorophyll fluorescence on six Eucalyptus species from diverse geographical and climatic regions growing in a common garden. Measurements were made in three seasons, allowing us to compare interspecific differences with seasonal changes. We found significant interspecific differences in apparent Vcmax and Jmax standardized to 25 C, but there were no significant differences in the temperature responses of these parameters among species. Comparing data across seasons, we found significant seasonal changes in apparent Vcmax25, but not in Jmax25, causing a change in their ratio (J/V ratio). However, there were no seasonal changes in the temperature response of either parameter. We concluded that the growth environment had a much larger effect on temperature response than climate of origin among this set of species. Mean daytime temperature increased by 15 C from winter to summer, whereas we estimated that the seasonal change in J/V ratio would cause a change in the optimum temperature (Topt) for gross photosynthesis of 3.6 C. Use of a general relationship to describe photosynthetic temperature acclimation resulted in a strong underestimation of the Topt for photosynthesis for these species. Our results indicated that variation in photosynthetic temperature responses cannot be captured in one simple relationship with growth temperature. Further comparative research on species groups will be needed to develop a basis for modelling these interspecific differences in plant temperature acclimation. PMID:23843350

Lin, Yan-Shih; Medlyn, Belinda E; De Kauwe, Martin G; Ellsworth, David S

2013-07-09

100

Electrical resistivity behavior of substituted perovskite manganates sintered at different temperatures  

SciTech Connect

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

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

1999-12-01

101

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

PubMed

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

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

2012-11-29

102

ENERGETIC COST OF RUNNING WITH DIFFERENT MUSCLE TEMPERATURES IN SAVANNAH MONITOR LIZARDS  

Microsoft Academic Search

SUMMARY The purpose of this study was to determine whether the energetic cost of locomotion was independent of muscle temperature, or if it tripled with a 10 C increase in temperature, like the cost of generating isometric force in isolated muscle preparations. For a given running speed of Savannah Monitor lizards, the energetic cost of locomotion (the difference between running

LAWRENCE C. ROME

1982-01-01

103

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

104

Eclosion rate, development and survivorship of Aedes albopictus (Skuse)(Diptera: Culicidae) under different water temperatures.  

PubMed

In tropical areas, where vector insects populations are particularly numerous, temperature usually range between 25 degrees C and 35 degrees C. Considering the importance of such temperature variation in determining mosquitoes population dynamics, in this work the developmental, eclosion and survival rates of the immature stages of Aedes albopictus (Skuse) were compared under constant 25, 30 and 35 degrees C (using acclimatized chambers) and environmental (25 degrees C to 29 degrees C) temperatures. The hatching rate was considered as total number of larvae recovered after 24h. The development period as well as larval and pupal survival rate were evaluated daily. Eclosion rate was significantly higher under environmental temperature than under the studied constant temperatures, suggesting that temperature variation may be an eclosion-stimulating factor. The mean eclosion time increased with the temperature, ranging from 2.8h (25 degrees C) to 5.2h (35 degrees C). The larval period was greatly variable inside each group, although it did not differ significantly amongst groups (11.0 +/- 4.19 days), with individuals showing longer larval stages in water at 35 degrees C (12.0 +/- 4.95 days) and environmental temperature (13.6 +/- 5.98 days). Oppositely, survival was strongly affected by the higher temperature, where only one individual lived through to adult phase. The results suggest that population of Ae. albopictus from Recife may be adapting to increasing of environmental temperatures and that the limiting temperature to larval development is around 35 degrees C. PMID:18246274

Monteiro, Laura C C; de Souza, Jos R B; de Albuquerque, Cleide M R

105

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

PubMed

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

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

2013-06-16

106

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

NSDL National Science Digital Library

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

Program, Globe

107

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, Rogrio Rodrigues; Guerisoli, Danilo Mathias Zanello

2008-12-01

108

[Expression and catalysis of glucokinase of Thermoanaerobacter tengcongensis at different temperatures].  

PubMed

According to analysis of proteomic profiling for Thermoanaerobacter tencongensis, TTE0090 could be a novel gene of glucokianse (GLK), though no GLK gene was annotated in the genomic data. With the methods of cloning and expression in vitro, the recombinant TTE0090 was successfully expressed and purified. The recombinant TTE0090 exhibited the catalysis of GLK, even at high temperatures. Detection of expression levels and catalysis of TTE0090 in vivo was furthermore carried out at different temperatures. The expression of TTE0090 was attenuated during the culture temperature elevated; however, the specific activity was positively correlated to temperature raised. This leads a possibility that the metabolic capacity of glycolysis in T. tencongensis is relatively constant at different temperatures. All the results herein demonstrate that TTE0090 is a novel gene of GLK. The studies on TTE0090 and its protein product, thus, may deepen our understanding of the adaptation mechanism of thermophilic bacteria living in harsh environment. PMID:16736585

Qian, Zhong; Wang, Jing-Qiang; Zhou, Chuan-Qi; Ma, Yan-He; Liu, Si-Qi

2006-04-01

109

Effects of different fabrication techniques on the Yttrium-Barium-Copper oxide high temperature superconductor  

NASA Astrophysics Data System (ADS)

This study examines how several different parameters were changed in the yttrium-barium-copper oxide superconductor when the fabrication techniques were altered by using different barium precursors, including barium peroxide and barium carbonate; sintering at different temperatures, including 850, 900, 950 C; and annealing in an above ambient oxygen environment. Twelve different pellets were fabricated, and measurements were taken on them which included density, X-ray diffraction, critical temperature, critical current density, and magnetic susceptibility. The results showed that the barium peroxide derived samples had higher densities, better critical current densities and lower resistivities in the normal state.

Rhea, Paul A.

1988-12-01

110

Laser-induced damage thresholds at different temperature for optical devices  

NASA Astrophysics Data System (ADS)

Studies for temperature dependences of laser-induced damage thresholds for optical devise is introduced in this paper. Additionally, the temperature dependence of the laser-induced damage threshold of single-layer optical coatings as resent progress was clarified using Nd:YAG and Ti:sapphire lasers. The wavelengths of the lasers were 1064 nm and 800 nm and the pulse widths were 4 ns, 200 ps, 2 ps, and 100 fs. For pulses longer than a few picoseconds, the laser-induced damage threshold of coated substrates increased with decreasing temperature. This temperature dependence was reversed for pulses shorter than a few picoseconds. A flowchart was presented including the several mechanisms for laser damage mechanism. The differences in the temperature dependence are explained by the flowchart. As one of results in theoretical analysis, the electron resistivity i. e. electron mobility is key point to elucidate the temperature dependence of laser-induced damage threshold.

Mikami, Katsuhiro; Motokoshi, Shinji; Somekawa, Toshihiro; Jitsuno, Takahisa; Fujita, Masayuki; Tanaka, Kazuo A.

2013-07-01

111

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

PubMed

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

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

2012-03-09

112

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

113

Effects of permethrin at different temperatures on pyrethroid-resistant and susceptible strains of Anopheles.  

PubMed

The influence of temperature (16, 22, 28, 37 degrees C) on effects of permethrin was investigated for susceptible and pyrethroid-resistant strains of the mosquitoes Anopheles gambiae and An. stephensi (Diptera: Culicidae). Young unfed female adult mosquitoes were exposed to 0.25% permethrin test papers or to polyester netting treated with permethrin 500mg a.i./m2. The time to 50% knockdown (KT50) declined as temperature increased, i.e. there was a positive temperature coefficient of this effect of the pyrethroid. Resistance ratios (comparing KT50 values) between resistant and susceptible An. stephensi ranged between 2.5 and 4.4 at the different temperatures. Comparative tests of pyrethroid tolerance of different strains would be valid over the 22-28 degrees C range but, when using a discriminating dose to detect resistance, more precise temperature control is desirable. Mortality 24h after exposure to 0.25% permethrin of both susceptible and resistant strains of An. stephensi showed a negative correlation with temperature between 16 and 22 degrees C and a positive correlation at higher temperatures. In An. gambiae, however, the correlation was positive over the whole range. Irritancy of permethrin-treated netting to Anopheles females (measured as time lapse until first flight take-off, and the number of take-offs during 7.5 min exposure) was positively correlated with temperature in all four strains and was much greater for the susceptible than the resistant strains. PMID:10608231

Hodjati, M H; Curtis, C F

1999-10-01

114

Biochemical and growth acclimation of birch to night temperatures: genotypic similarities and differences.  

PubMed

The responses of plants to environmental factors are connected to the time of day. In this study, silver birch (Betula pendula) was grown in growth chambers at five different night temperatures (6-22?C), using gradual changes during the evening and morning hours. Despite the increased night respiration and unaffected daytime net photosynthesis (per square metre), the carbon uptake (biomass) of birch did not decrease, probably due to enhanced biochemical processes on warmer nights and the advantage of higher temperatures during the evening and morning hours. The plant stem height, internode length, stem dry weight (DW), stem mass fraction and specific leaf area increased with warmer night temperatures. Changes in growth and metabolite concentrations were partly nonlinear along the temperature gradient. Thus, the temperature effect depends on the temperature window considered. Genotypes had both common and genotype-specific biochemical responses to night temperatures. The common responses among genotypes were related to growth responses, whereas the unique responses may indicate genotype-specific differences in acclimation. The differences in genotypic growth and metabolite levels are valuable for assessing genotype qualities and understanding the connections between the metabolome and growth. PMID:22612878

Menp, M; Ossipov, V; Kontunen-Soppela, S; Keinnen, M; Rousi, M; Oksanen, E

2012-05-22

115

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

Microsoft Academic Search

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

R. P. Kane

2000-01-01

116

The performance improvement calculation of corrugated quantum well infrared photodetector (C-QWIP) with a high critical temperature (Tc) superconducting electron filter  

NASA Astrophysics Data System (ADS)

The Corrugated Quantum Well Infrared Photodetector (C-QWIP) holds significant performance and other advantages over other infrared (IR) detectors. However, one disadvantage of the detector is the relatively low operating temperature needed to suppress the dark current. By coating two additional layers (thin insulator and high critical temperature (Tc) superconductor) on the top contact layer of a C-QWIP wafer, the top three layers of the detector form a high-Tc superconducting single electron tunneling junction. It could act as an electron filter because of the presence of an energy gap in superconductors. For QWIPs, the photo electrons and dark electrons are well separated in energy, most dark current is conducting below the quantum well (QW) barrier height and most photo current is conducting above the barrier height. Most dark electrons thus could be blocked by the junction while most photo electrons pass the junction by applying an appropriate voltage. Therefore, both the sensitivity and the operating temperature of the detector could be improved. Our calculation shows that the filter could provide 40% or 70% improvement in Noise Equivalent Temperature Difference (NETD) of detector focal plane arrays (FPAs) at normal operating temperature, depending on whether the detector emitter photocurrent to dark current ratio is = 1 (Emitter is background limited BLIP) or = 0.1 (Emitter is far from BLIP). For both cases, the filter could increase the detector FPAs operating temperatures up to 90K (30K improvement) with 15% to 25% NETD improvement respectively.

Sun, Jason; Choi, K. K.

2011-09-01

117

The role of the air-sea temperature difference in air-sea exchange  

NASA Astrophysics Data System (ADS)

Recent laboratory measurements have shown that the stationary-state vapor pressures of aniline and n-heptanol are enhanced by the application of a positive temperature gradient in the vapor, that the vapor pressure of water over 50 percent sulfuric acid is enhanced by a positive temperature gradient and diminished by a negative temperature gradient, and that values of the Onsager heat of transport derived from these measurements are of similar magnitude to the latent heats of vaporization. When the vapor gap over which the temperature difference is applied is less than about 0.8 mean free paths, the liquid behaves as though its surface were at the temperature close to that of the gas on the other side of the Knudsen layer. These results are discussed in relation to field measurements of the rate of air-sea exchange of carbon dioxide.

Phillips, Leon F.

2004-09-01

118

Retardation of Division of Three Ciliates by Intermittent and Continuous Ultraviolet Radiations at Different Temperatures  

PubMed Central

The same dosage of ultraviolet (UV) radiation retards division of several protozoans more effectively when the light is intermittent than when it is continuous, and especially at temperatures of 2535C. At lower temperatures the difference between the effects of intermittent and continuous radiations is less marked. Somewhat similar results were obtained with the ciliates Paramecium caudatum, Blepharisma japonicum, and Colpidium colpoda, the disparity between intermittent and continuous light decreasing in the order given. The data are taken to indicate that thermochemical dark reactions succeed the absorption of UV radiations by the cells. In Blepharisma, besides initial delay in division, the cells stop dividing after one or two divisions, a "stasis" ensuing. Stasis is marked when the cells are irradiated at higher temperatures but is slight when they are irradiated at low temperatures, as if the temperature-sensitive reaction involved stasis (in all cases cultures are grown at 25C). The data are related to findings in the literature.

Giese, A. C.; McCaw, B.; Cornell, R.

1963-01-01

119

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

Microsoft Academic Search

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

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

2008-01-01

120

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

121

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

Microsoft Academic Search

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

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

2011-01-01

122

Oxygen isotope fractionation during respiration for different temperatures of T. utilis and E. coli K12  

Microsoft Academic Search

Summary The temperature dependence of the oxygen isotope fractionation factor during respiration has been examined for two different microorganisms, namelyTorulopsis utilis andEscherichia coli K12 representing a yeast and a bacterium, respectively. The investigation covered a temperature range of 18 C, that is from 16 C to 34 C forT. utilis and from 19 C to 37 C forE. coli K12.

G. H. Schleser

1979-01-01

123

Thermal and mechanical characteristics of polylactide filaments drawn at different temperatures  

Microsoft Academic Search

Polylactide (PLA) filaments produced by melt spin-drawing in different conditions (draw ratio, temperature of the draw roll) have been studied to demonstrate the influence of the process conditions on the tensile properties of the PLA filaments. Draw ratio varies from 2 to 3.5 and temperature of the draw roll from 80C to 120C. The thermal characteristics have been investigated using

Samuel Solarski; Manuela Ferreira; Eric Devaux

2007-01-01

124

Exact ray-tracing computation of narcissus-equivalent temperature difference in scanning thermal imagers  

NASA Astrophysics Data System (ADS)

The formula for evaluation of narcissus equivalent temperature difference as a function of the scan angle in thermal imaging systems is made more meaningful by grouping the parameters in two factors: one depending on wavelength and temperature and the other, a function of the scan angle, depending on the geometry of the instrument. Exact ray tracing equations are used to evaluate the ratio of radiant energy reaching the detector from warm and cold areas of the instrument.

Rayces, Juan L.; Lebich, Lan

1992-12-01

125

Kinetic analysis of coupled transport of thiocyanate ions through liquid membranes at different temperatures  

Microsoft Academic Search

Non-steady-state kinetics of coupled transport of thiocyanate ions through liquid membrane (trichloromethane), containing hexadecyl trimethyl ammonium chloride as a carrier, was examined at different temperatures. The kinetics of thiocyanate transport could be analyzed in the formalism of two, consecutive, irreversible first order reactions. The influence of temperature on the kinetic parameters (k1d, k2m, Rmmax, tmax, Jdmax, Jamax) have been also

M. Kobya; N. Topu; N. Demircio?lu

1997-01-01

126

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

Microsoft Academic Search

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

Baoliang Chen; Zaiming Chen

2009-01-01

127

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

Microsoft Academic Search

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

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

2009-01-01

128

Physical Properties of Aqueous N-Methyl Pyrrolidone at Different Temperatures  

Microsoft Academic Search

Many physical properties of aqueous N-Methyl pyrrolidone mixtures were determined for molar fraction XNMP=0.02, 0.05, 0.125, 0.32, 0.37 at different temperatures ranging from 1565C. From the result we noticed that the viscosity coefficient was increased with increasing the molar fraction XNMP and reached a maximum value at XNMP=0.250.37, and decreased with temperature. We observed the same relationship of the thermodynamic

Iamir E. Maloka; Sabah Yassin Ibrahim

2004-01-01

129

Temperature of denture base resin under different protocols of microwave irradiation.  

PubMed

This in vitro study evaluated the temperature of dentures after different microwave irradiation protocols. Two complete dentures (one maxillary and one mandibular denture) were irradiated separately 4 times for each of the following 5 protocols: dentures immersed in water (G1- 6 min, G2- 3 min); dentures kept dry (G3- 6 min); dentures placed in the steam sterilizer (G4- 6 min, G5- 3 min). The final temperature of the dentures was gauged in a thin and in a thick area of each denture with an infrared thermometer. All groups presented an increase in the resin base temperature. The thin areas of the dentures underwent greater heating than the thick areas. There was no significant difference (p>0.05) between the final mean temperatures of dentures immersed in water for 6 (G1) and 3 min (G2). However, the final mean temperatures recorded in G1 and G2 exceeded 71C and were significantly higher (<0.001) than the final mean temperatures recorded in the other groups. It may be concluded that denture base resins subjected to microwave irradiation immersed in water may be exposed to deleterious temperatures. PMID:22011894

Sesma, Newton; Gil, Carlos; Kolikauskas, William Antunes; Silva, Rafael Andrade; Pannuti, Claudio Mendes

2011-01-01

130

Diurnal variations in moisture and temperature of a desert soil under different management practices  

NASA Astrophysics Data System (ADS)

A field study was conducted to find out the effect of some soil management practices on hydrothermal regime of soil under high radiation conditions of Jodhpur. Pulverization, compaction and pulverization + mulching formed the three treatments. The results showed vide variations in diurnal soil temperatures up to 15 cm depth. There were little differences in soil temperature under pulverization and compaction while pulverization + mulch reduced the maximum temperature by 4 to 10C. Diurnal oscillations in soil moisture were observed under the influence of thermal gradients. Maximum loss of moisture was observed from the pulverized plots while minimum was recorded from the pulverized + mulched plots.

Gupta, G. N.; Gupta, J. P.

1982-05-01

131

Obvious Temperature Difference Along a Pb Cluster-Decorated Carbon Nanowire  

PubMed Central

Pb nanoclusters were deposited onto a suspended carbon nanowire (CNW), where in situ temperature variable observation was carried out by a transmission electron microscope. The heating temperature was up to 450 C. Both the melting and evaporation of the Pb nanoparticles on the CNW were retarded when compared to the particles on the support frame. The obvious temperature difference of up to 10 K along the CNW of less than 1 ?m was demonstrated. It was attributed to the irradiating dissipation-dependent on the surface area of the decorating Pb particle by calculation. (See supplementary material 1)

2010-01-01

132

Comparison of different heating methods for the temperature-controlled measurement of convective transition boiling  

SciTech Connect

For the experimental investigation of the transition boiling regime, special heating and control methods have to be introduced to ensure stability. Typical problems of all these methods are the large axial temperature gradient after the transition boiling mode first appears on the heat transfer surface and the failure of stability under some conditions. Through numerical solution of the heat conduction problem related to the temperature-controlled test section, which has a strongly nonlinear boiling topography as one of its boundary conditions, different types of heating methods can be compared in terms of axial temperature gradient, extension of the transition boiling mode, and the second-order instability.

Huang, X.C.; Bartsch, G. (Technische Univ. Berlin (Germany). Institut fuer Energietechnik)

1994-04-01

133

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 (10C) and room temperature (22C), 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 10C, all samples showed higher viscoelastic modulus values, firmness, and stickiness, and lower spreadability than when they were measured at 22C. Differences in viscoelasticity and mechanical properties between each pair of samples of the same brand were greater at 10C than at 22C 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

2012-09-19

134

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

USGS Publications Warehouse

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

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

2003-01-01

135

Evolutionary determinants of population differences in population growth rate habitat temperature interactions in Chironomus riparius.  

PubMed

Little is known about intraspecific variation in fitness performance in response to thermal stress among natural populations and how this relates to evolutionary aspects of species ecology. In this study, population growth rate (PGR; a composite fitness measure) varied among five natural Chironomus riparius populations sampled across a climatic gradient when subjected to three temperature treatments reflecting the typical range of summer habitat temperatures (20, 24 and 28 C). The variation could be explained by a complex model including effects of genetic drift, genetic diversity and adaptation to average temperature during the warmest month, in addition to experimental temperature. All populations suffered a decrease in PGR from 20 to 28 C and ?PGR was significantly correlated with the respective average habitat temperature in the warmest month-populations from warmer areas showing lower ?PGR. This implies that long-term exposure to higher temperatures in the warmest month (the key reproductive period for C. riparius) is likely to be a key selective force influencing fitness at higher temperatures. A comparison of phenotypic divergence and neutral genetic differentiation revealed that one phenotypic trait--the number of fertile egg masses per female--appeared to be under positive selection in some populations. Our findings support a role for response to temperature selection along a climatic gradient and suggest population history is a key determinant of intraspecific fitness variation. We stress the importance of integrating different types of data (climatic, experimental, genetic) in order to understand the effects of global climate change on biodiversity. PMID:23124273

Nemec, Sabrina; Patel, Simit; Nowak, Carsten; Pfenninger, Markus

2012-11-03

136

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

SciTech Connect

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

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

1988-01-01

137

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

2012-06-29

138

Monitoring stiffness changes in lesions after radiofrequency ablation at different temperatures and durations of ablation.  

PubMed

The variations in the stiffness or stiffness contrast of lesions resulting from radiofrequency (RF) ablation of canine liver tissue at different temperatures and for different ablation durations at a specified temperature are analyzed. Tissue stiffness, in general, increases with temperature; however, an anomaly exists around 80 degrees C, where the stiffness of the lesion is lower than that of the lesion ablated at 70 degrees C. On the other hand, the stiffness increases monotonically with the duration of ablation. Plots illustrating the ratio of mean strains in normal canine liver tissue to mean strains in ablated thermal lesions demonstrate the variation in the stiffness contrast of the thermal lesions. The contrast-to-noise ratio (CNRe) of the lesions, which serves as an indicator of the detectability of the lesions under the different experimental imaging conditions described above, is also presented. The results presented in this paper show that the elastographic depiction of stiffer thermal lesions is better, in terms of the CNRe parameter. An important criterion in the elastographic depiction of RF-ablated regions of tissue is the trade-off between ablation temperature and duration of ablation. Tissue necrosis can occur either by ablating tissue to high temperatures for short durations or to lower temperatures for longer durations. In this paper, we attempt to characterize the elastographic depiction of thermal lesions under these different experimental conditions. This paper provides results that may be utilized by practitioners of RF ablation to decide the ablation temperature and duration, on the basis of the strain images of normal liver tissue and ablated thermal lesions discussed in this paper. PMID:15749565

Bharat, Shyam; Techavipoo, Udomchai; Kiss, Miklos Z; Liu, Wu; Varghese, Tomy

2005-03-01

139

Temperature stability improvement of a QVGA uncooled infrared radiation FPA  

NASA Astrophysics Data System (ADS)

We have developed a low-cost uncooled infrared radiation focal plane array (FPA) requiring no thermoelectric cooler (TEC), which has 320 x 240 detection pixels with 22 um pitch. The silicon single-crystal series p-n junction diodes and the low-noise readout circuit on the same SOI wafer fabricated by 0.13 um CMOS technology were utilized for infrared (IR) detection. The temperature dependence in the readout circuit was eliminated by correlated double sampling (CDS) operation with reference pixel that was insensitive to infrared radiation. In order to reduce the temperature dependence, we improved the reference pixel and the readout circuit. Although the reference pixels should be completely insensitive to IR radiation, prior reference pixels showed measurable sensitivity. The improved reference pixel was formed by partially releasing with bulk-micromachining and was verified to be insensitive to IR radiation by an object of 400C. The readout circuit had a differential amplifier instead of a singletransistor amplifier and an analog-to-digital converter (ADC). In each portion, CDS was applied to reduce temperature dependence. The first CDS operation was used for eliminating the pixel output variation and the second operation was used for canceling the variation of the differential amplifier. The output variation referred to input was reduced to 1/30 compared with that of the prior circuit. Moreover, the residual variation of output voltage was reduced by CDS operation in ADC and stable output data was obtained with ambient temperature variation. With these improvements, the sensitivity variation of the FPA was improved to 10% in the range of -30 degrees to 80 degrees and noise equivalent temperature difference (NETD) of 40 mK was achieved.

Ishii, Koichi; Honda, Hiroto; Fujiwara, Ikuo; Sasaki, Keita; Yagi, Hitoshi; Suzuki, Kazuhiro; Kwon, Honam; Atsuta, Masaki; Funaki, Hideyuki

2013-06-01

140

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

PubMed

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

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

2012-06-13

141

Laser-induced damage thresholds of optical coatings at different temperature  

NASA Astrophysics Data System (ADS)

Laser-induced damage thresholds for dielectric and metal single-layer coatings at different temperature conditions (123-473 K) were measured by 1064-nm wavelength and 4-ns pulses to elucidate the effects of initial temperature to laser damage mechanisms. SiO2, MgF2, gold, silver and copper single-layer coatings were prepared as experimental samples. In the experimental results, temperature dependence of LIDTs for optical substrates and all dielectric single-layer coatings indicated same trend as that for bulk silica glasses, which increased linearly with decreasing the temperature. However, all metallic coatings had the inverse trend of the dependence for dielectric coatings. The effects of initial temperature to laser damage mechanisms were considered with separated processes from the experimental results. In the conclusions, free-electron generation and electron multiple caused difficultly at low temperature and the laser-induced damage thresholds increased. On the other hand, plasma heating caused easily at low temperature and the laser-damage thresholds decreased.

Mikami, K.; Motokoshi, S.; Fujita, M.; Jitsuno, T.; Tanaka, K. A.

2011-10-01

142

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.

Shi, Changzhi; Liu, Xiaowei; Chuai, Rongyan

2009-01-01

143

Temperature-difference-driven mass transfer through the vapor from a cold to a warm liquid  

NASA Astrophysics Data System (ADS)

Irreversible thermodynamics provides interface conditions that yield temperature and chemical potential jumps at phase boundaries. The interfacial jumps allow unexpected transport phenomena, such as the inverted temperature profile [Pao, Phys. Fluids10.1063/1.1693429 14, 306 (1971)] and mass transfer from a cold to a warm liquid driven by a temperature difference across the vapor phase [Mills and Phillips, Chem. Phys. Lett.10.1016/S00092614(03)00467-6 372, 615 (2002)]. Careful evaluation of the thermodynamic laws has shown [Bedeaux , Physica A10.1016/03784371(90)90169-S 169, 263 (1990)] that the inverted temperature profile is observed for processes with a high heat of vaporization. In this paper, we show that cold to warm mass transfer through the vapor from a cold to a warm liquid is only possible when the heat of evaporation is sufficiently small. A necessary criterium for the size of the mass transfer coefficient is given.

Struchtrup, Henning; Kjelstrup, Signe; Bedeaux, Dick

2012-06-01

144

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

SciTech Connect

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

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

2011-07-15

145

Effects of different temperatures and duration on germination of caper (Capparis ovata) seeds.  

PubMed

Caperseed has poor germination because of the seed coat dormancy Germination of caperseeds are complex traits affected by a wide range of intemal and environmental influences. The effects of temperature preconditioning and period on germination of Capparis ovata were examined. Experiments were conducted in order to investigate germination behaviour of caperseeds subjected to different temperature and duration. The experiment revealed that the different temperature treatments were effective on mean germination percentage. The highest mean germination were obtained at 0 degree C 29.52% and 10 degrees C with 27.17% and the lowest mean germination were obtained at control seeds with 8.39%. Dry heat treatments effected germination rate, but it was not enough for removing germination obstacle of caper seed completely. PMID:20120507

Basbag, Mehmet; Toncer, Ozlem; Basbag, Sema

2009-07-01

146

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

PubMed Central

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

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

1934-01-01

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

Compositional and mechanical properties of peanuts roasted to equivalent colors using different time/temperature combinations.  

PubMed

Peanuts in North America and Europe are primarily consumed after dry roasting. Standard industry practice is to roast peanuts to a specific surface color (Hunter L-value) for a given application; however, equivalent surface colors can be attained using different roast temperature/time combinations, which could affect product quality. To investigate this potential, runner peanuts from a single lot were systematically roasted using 5 roast temperatures (147, 157, 167, 177, and 187 C) and to Hunter L-values of 53 1, 48.5 1, and 43 1, corresponding to light, medium, and dark roasts, respectively. Moisture contents (MC) ranged from 0.41% to 1.70% after roasting. At equivalent roast temperatures, MC decreased as peanuts became darker; however, for a given color, MC decreased with decreasing roast temperature due to longer roast times required for specified color formation. Initial total tocopherol contents of expressed oils ranged from 164 to 559 ?g/g oil. Peanuts roasted at lower temperatures and darker colors had higher tocopherol contents. Glucose content was roast color and temperature dependent, while fructose was only temperature dependent. Soluble protein was lower at darker roast colors, and when averaged across temperatures, was highest when samples were roasted at 187 C. Lysine content decreased with increasing roast color but was not dependent on temperature. MC strongly correlated with several components including tocopherols (R(2) = 0.67), soluble protein (R(2) = 0.80), and peak force upon compression (R(2) = 0.64). The variation in characteristics related to roast conditions is sufficient to suggest influences on final product shelf life and consumer acceptability. PMID:23145904

McDaniel, Kristin A; White, Brittany L; Dean, Lisa L; Sanders, Timothy H; Davis, Jack P

2012-11-12

149

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

NASA Astrophysics Data System (ADS)

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

Mohan, V. P. Chandra; Talukdar, Prabal

2013-01-01

150

Resistivity Variation due to CO2 Migration in Different Temperature and Pressure Conditions  

NASA Astrophysics Data System (ADS)

CO2 geological sequestration is one of the effective approaches solving the global warming problem. Captured CO2 is injected to the deep aquifers or depleted oil and gas fields. Injected CO2 migrates thorough the reservoir rock, however, the details behavior of injected CO2 under the ground at super critical phase is not yet fully understood. Migration of injected CO2 will change by the condition of the injected reservoir such as the temperature and pressure. Also density and permeability of the rock may be changed due to temperature or pressure variations. These changes control the migration behavior of injected CO2. In this study, experiments of resistivity measurements were conducted to detect the migration difference of CO2 in different temperature and pressure conditions by using sandstone core samples. Core sample was taken from Berea sandstone and processed to 5cm diameter and 12cm length. For the resistivity measurement, impression electrode was set on the both end and the measurement electrode of ring condition was set on the side of the rock sample. We stetted the core sample in the pressure vessel and recreated the condition of underground reservoir which is high pressure and high temperature. We injected supercritical CO2 in different pressure and temperature for each experiment. Pressure was changed in range of 8 to 11MPa and temperature was changed in range of 35 to 45. This means that all the experiments were conducted in supercritical phase. From the measured resistivity variation, we verified the migration of CO2 and compared the migration behavior of CO2 in different conditions.

Nakatsuka, Y.; Onishi, K.; Yamada, Y.; Matsuoka, T.; Xue, Z.

2007-12-01

151

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

PubMed

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

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

2011-06-01

152

Rocket measurements of electric fields, electron density and temperature during different phases of auroral substorms  

Microsoft Academic Search

On Jan. 27, 1979, three rocket payloads were launched from Kiruna, Sweden into different phases of two successive auroral substorms. Among other experiments, the payloads carried the RIT double probe electric field experiments providing electric field, electron density and temperature data which are presented here. These data, supported by rocket particle observations, are discussed mainly in association with ground-based observations

G. Marklund; L. Block; P.-A. Lindqvist

1981-01-01

153

Analysis of normalized difference and surface temperature observations over southeastern Australia  

Microsoft Academic Search

Relations between radiative surface temperature (TR) and visible and near-infrared reflectances expressed as the normalized difference (ND) from a Landsat Thematic Mapper scene were analysed to study the heat balance of agriculture and native evergreen forests in southeastern Australia. The scene was at 0922 h (local time) during late spring (15 October 1986) with phenology of winter annual species between

R. C. G. SMITH; B. J. CHOUDHURY

1991-01-01

154

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

Microsoft Academic Search

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

Olivier C Devvre; William R Horwth

2000-01-01

155

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.

156

A study on dynamic fracture toughness of composite laminates at different temperatures  

Microsoft Academic Search

The fracture toughness of glass-cloth\\/epoxy laminates has been determined under different temperatures and strain rates by means of the WEK fracture mode. To determine the parameters of WEK model, two groups of experiments must be conducted. One is the tensile experiment of smooth specimens (there is not a crack). Another is the tensile experiment of specimens with a crack. The

Han Xiaoping; Han Shenliang; Yu Liang

2003-01-01

157

Effect of different downstream temperatures on the performance of a two-layer porous burner  

Microsoft Academic Search

The influence of considering different downstream temperatures on the performance of a two-layer porous burner is studied numerically. A 3D numerical model based on a unit cell was implemented to correctly predict the momentum, heat and mass transfer at the interface of the two layers. Two operating modes are simulated corresponding to the burner radiating to cold and hot environments.

T. C. Hayashi; I. Malico; J. C. F. Pereira

2010-01-01

158

Theoretical and experimental investigation of heat conduction for large temperature differences at arbitrary Knudsen number  

Microsoft Academic Search

The plane steady-state heat conduction in monatomic gases at large temperature differences was studied. An approximate solution of the Boltzman equation, based on a two-sided Maxwellian velocity distribution function and the model of Maxwellian molecules, was investigated. This solution, obtained by using Maxwell's moment method, can be used to determine macroscopic quantities of state for arbitrary Knudsen numbers. A plane

D. Braun

1976-01-01

159

Individual differences in effects of secondary cognitive activity during driving on temperature at the nose tip  

Microsoft Academic Search

Several researches have pointed out that the temperature at the nose tip is possibly effective for evaluating driver mental condition. In order to establish methods for driver monitoring, whether a method should be adapted to each person or not is an important question. This paper investigates individual differences in effects of performing a cognitively distracting subtask during driving on the

Makoto Itoh

2009-01-01

160

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

161

Degradation and silicidation of Ta and W-filaments for different filament temperatures  

Microsoft Academic Search

Using typical conditions for hot wire chemical vapour deposition (HWCVD) of high quality thin silicon films in a UHV deposition chamber, we studied the silicidation of different filaments mainly varying the filament temperatures between 1700C and 2130C. The experiments were done with constant current, running the filament for 5 to 8h and even longer. The changes of filament resistance and

N. Kniffler; A. Pflueger; D. Scheller; B. Schroeder

2009-01-01

162

The Effect of Different Temperatures on Autolysis of Baker's Yeast for the Production of Yeast Extract  

Microsoft Academic Search

This study aimed to determine the optimum autolysis conditions for the production of yeast extract, which is used to give a meaty flavor to food products and to increase their nutritional value. Autolysis was induced by incubating baker's yeast cell suspensions at different temperatures (45, 50, 55, and 60 C) with a reaction time ranging from 8 to 72 h.

Hasan TANGLER; Hseyin ERTEN

163

Effect of elevated temperatures on the radiation sensitivity of yeast cells of different species  

Microsoft Academic Search

Summary The influence of hyperthermia on the survival of irradiated yeast cells of different species has been studied. The experiments reported in the paper have shown: (1) simultaneous action of ionizing radiation and high temperatures appeared to increase the radiation response by a factor of approximately 2.7 for diploid and only by a factor of 1.5 for haploid cells of

V. G. Petin; I. P. Berdnikova

1979-01-01

164

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

Microsoft Academic Search

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

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

2007-01-01

165

Comparison of different melting temperature calculation methods for short DNA sequences  

Microsoft Academic Search

Motivation: The overall performance of several molecular biology techniques involving DNA\\/DNA hybridization depends on the accur- ate prediction of the experimental value of a critical parameter: the melting temperature Tm. Till date, many computer software programs based on different methods and\\/or parameterizations are available for the theoretical estimation of the experimental Tm value of any given short oligonucleotide sequence. However,

Alejandro Panjkovich; Francisco Melo

2005-01-01

166

Low temperature silicon direct bonding for application in micromechanics: bonding energies for different combinations of oxides  

Microsoft Academic Search

Plain or structured hydrophillic silicon wafers covered with native oxide or with thermally grown oxide layers have been directly bonded at room temperature; afterwards, the samples were annealed at 100C to 400C. There is a significant difference in the observed bonding energy depending on the wafer pairing chosen. If one or both wafers are covered with a native oxide layer,

Gertrud Kruter; Andreas Schumacher; Ulrich Gsele

1998-01-01

167

Microbial oxidation of CH 4 at different temperatures in landfill cover soils  

Microsoft Academic Search

Biological oxidation of CH4 is an important constraint on the emission of this gas from areas, such as landfills to the atmosphere. We studied the effect of temperature on methanotrophic bacteria in three different landfill cover soils, incubated in the laboratory. In samples of a young cover, consisting of wood chips and sewage sludge, the phospholipid fatty acids (PLFAs), regarded

Gunnar Brjesson; Ingvar Sundh; Bo Svensson

2004-01-01

168

Kinetic changes in cooking quality of potatoes stored at different temperatures  

Microsoft Academic Search

Kinetics changes in cooking quality (texture and color) of potatoes stored at different temperatures (420 C) were evaluated in this study. At selected time intervals, potatoes were removed from storage and their cooking quality evaluated. Cylindrical test samples (20 mm diameter and 20 mm length cut beneath the skin) of potatoes were cooked in boiling water for 10 min, quickly

F. Nourian; H. S. Ramaswamy; A. C. Kushalappa

2003-01-01

169

Compositional and Mechanical Properties of Peanuts Roasted to Equivalent Colors using Different Time/Temperature Combinations  

Technology Transfer Automated Retrieval System (TEKTRAN)

Peanuts in North America and Europe are primarily consumed after dry roasting. Standard industry practice is to roast peanuts to a specific surface color (Hunter L-value) for a given application; however, equivalent surface colors can be attained using different roast temperature/time combinations,...

170

Effect of Different Time/Temperature Roast Combinations on Nutritional and Mechanical Properties of Peanuts  

Technology Transfer Automated Retrieval System (TEKTRAN)

Peanuts in North America and Europe are primarily consumed after dry roasting. Standard industry practice is to roast peanuts to a specific surface color (Hunter L-value) for a given application; however, equivalent surface colors can be attained using different roast temperature/time combinations....

171

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

PubMed

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

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

2013-05-01

172

Intake and coversion of food in the fish Limanda limanda exposed to different temperatures  

Microsoft Academic Search

In the flat fish Limanda limanda L., feeding rate and conversion efficiency were studied as functions of body weight, sex, temperature and food quality. When offered herring meat at 13 C (series I), females (live weights 1 to 150 g) consume more food than males; the magnitude of this difference is body weight-dependent. With increasing wieght, both females and males

T. J. Pandian

1970-01-01

173

Thermal expansion of epoxy resins with different cross-link densities at low temperatures  

Microsoft Academic Search

The thermal expansion of modified epoxy resins was investigated from 4.5 to 293 K with a highly sensitive capacitance dilatometer. The samples were made from diglycidyl ether modified with diols of different chain lengths. Increasing the diol chain length increases the thermal expansion coefficient. At temperatures lower than 40 K, expansion is determined only by the binding forces between the

U. Escher

1995-01-01

174

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

Microsoft Academic Search

The sulphate resistance of mortar containing ground calcined brick clay (GCBC) calcined at different tempertaures (6001100 C) and ground sand (GS) as cement replacement materials is investigated. Also the porosity, pore size distribution and strength of a selection of these mortars are determined. Mortars containing GCBC calcined at a temperature higher than 900 C show superior sulphate resistance to those

S. Wild; J. M. Khatib

1997-01-01

175

Soil organic carbon quality in forested mineral wetlands at different mean annual temperature  

Microsoft Academic Search

Forested mineral soil wetlands (FMSW) store large stocks of soil organic carbon (SOC), but little is known on: (i) whether the quality of SOC stored in these soils (proportion of active versus more resistant SOC compounds) differs from SOC in upland soils; (ii) how the quality of SOC in FMSW varies with mean annual temperature (MAT); and (iii) whether SOC

Cinzia Fissore; Christian P. Giardina; Randall K. Kolka; Carl C. Trettin

2009-01-01

176

Monoethanol amine modified zeolite 13X for CO adsorption at different temperatures  

Microsoft Academic Search

Zeolite 13X has been modified with monoethanol amine (MEA). MEA loadings of 0.5-25 wt % have been achieved using the impregnation method in different solvents. The mode of incorporation based on methanol with stirring at room temperature appears to be the most feasible. The adsorbent has been characterized for crystallinity, surface area, pore volume, and pore size. The thermal stability

P. D. Jadhav; R. V. Chatti; R. B. Biniwale; N. K. Labhsetwar; S. Devotta; S. S. Rayalu

2007-01-01

177

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

PubMed

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

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

2005-06-01

178

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

PubMed

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

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

2011-01-31

179

Oviposition behavior of Grapholita molesta Busck (Lepidoptera: Tortricidae) at different temperatures.  

PubMed

Cultivation of temperate-climate fruits is economically important for Brazil. Grapholita molesta Busck is a pest that causes damage to apples, peaches, plums, and pears growing in different micro-regions of southern Brazil, and understanding its reproductive behavior is essential to develop control strategies. The objective of this study was to ascertain the influence of different temperatures (13, 16, 19, 22, and 25C) on the oviposition behavior of G. molesta. Females of G. molesta were placed in individual plastic containers, and the pre-oviposition period and the number of eggs laid were assessed until adult death. Temperature influenced the pre-oviposition period, and females kept at 22 were the first to lay their eggs. Oviposition occurred over a longer period of time at 13C than at the higher temperatures. The highest total number of eggs was obtained at 19C, with the mean daily oviposition being directly proportional to the temperature. There was a negative interaction between the pre-oviposition period and the total number of eggs laid by females. The most suitable temperature for oviposition of G. molesta was 19C. PMID:21952955

da Silva, E D B; Kuhn, T M A; Monteiro, L B

180

Proteinase and phospholipase activities and development at different temperatures of yeasts isolated from bovine milk.  

PubMed

The presence of yeasts in milk may cause physical and chemical changes limiting the durability and compromising the quality of the product. Moreover, milk and dairy products contaminated by yeasts may be a potential means of transmission of these microorganisms to man and animals causing several kinds of infections. This study aimed to determine whether different species of yeasts isolated from bovine raw milk had the ability to develop at 37C and/or under refrigeration temperature. Proteinase and phospholipase activities resulting from these yeasts were also monitored at different temperatures. Five genera of yeasts (Aureobasidium sp., Candida spp., Geotrichum spp., Trichosporon spp. and Rhodotorula spp.) isolated from bovine raw milk samples were evaluated. All strains showed one or a combination of characteristics: growth at 37C (9909% of the strains), psychrotrophic behaviour (509%), proteinase production (1681% of the strains at 37C and 409% under refrigeration) and phospholipase production (3636% of the isolates at 37C and 109% under refrigeration), and all these factors may compromise the quality of the product. Proteinase production was similar for strains incubated at 37C (1681% of the isolates) and room temperature (1727%) but there was less amount of phospholipase-producing strains at room temperature (1545% of the isolates were positive) when compared with incubation at 37C (3636%). Enzymes production at 37C by yeasts isolated from milk confirmed their pathogenic potential. The refrigeration temperature was found to be most efficient to inhibit enzymes production and consequently ensure better quality of milk. The viability of yeasts and the activity of their enzymes at different temperatures are worrying because this can compromise the quality of dairy products at all stages of production and/or storage, and represent a risk to the consumer. PMID:21791151

Melville, Priscilla A; Benites, Nilson R; Ruz-Peres, Monica; Yokoya, Eugenio

2011-07-27

181

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

PubMed Central

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

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

2013-01-01

182

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

Microsoft Academic Search

This study evaluates the effect of different levels of insulation on esophageal (T\\u000a es) and rectal (T\\u000a re) temperature responses during and following moderate exercise. Seven subjects completed three 18-min bouts of treadmill exercise\\u000a (75% VO2max, 22C ambient temperature) followed by 30min of recovery wearing either: (1) jogging shoes, T-shirt and shorts (athletic\\u000a clothing); (2) single-knit commercial coveralls worn over

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

1999-01-01

183

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

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

184

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

PubMed Central

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

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

1990-01-01

185

Thermal performance of a heat storage module using PCM's with different melting temperature; Experimental  

SciTech Connect

A latent heat storage module was constructed, consisting of 45 cylindrical capsules fixed vertically in 15 rows. The capsules, made of 0.335-m long copper tubes having external diameters of 31.8 mm, were fixed in an insulated rectangular duct. Three commercial waxes having melting temperatures of 44{degrees}C, 53{degrees}C, and 64{degrees}C were selected. Each of the three sets of 15 tubes was filled with different wax. For comparison purposes, experiments were also done with a single commercial wax, having a melting temperature of 53{degrees}C, in all the tubes. During heat charge, hot air flowed across the capsules such that the melting temperature of the waxes decreased in the flow direction. Air flow direction was reversed during heat discharge. This paper reports that experimental measurements showed some improvement in the heat transfer rates during both heat charge and discharge when three types of PCM's were used.

Farid, M.M. (Chemical Engineering Dept., College of Engineering, Univ. of Basrah (IQ)); Kim, Y.; Kansawa, A. (Chemical Engineering Dept., Tokyo Inst. of Technology, O-Okayama, Meguro-Ku, Tokyo 152 (JP))

1990-05-01

186

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 37C showed higher heat resistance than those prepared at 25 and 30C. However, the germination rate was negatively correlated with the sporulation temperature. The maximum germination rate of the spores prepared at 25C was 1.3-times higher than the spores prepared at 30C. 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

187

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

NASA Astrophysics Data System (ADS)

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

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

2012-06-01

188

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

189

Microbial oxidation of CH(4) at different temperatures in landfill cover soils.  

PubMed

Biological oxidation of CH(4) is an important constraint on the emission of this gas from areas, such as landfills to the atmosphere. We studied the effect of temperature on methanotrophic bacteria in three different landfill cover soils, incubated in the laboratory. In samples of a young cover, consisting of wood chips and sewage sludge, the phospholipid fatty acids (PLFAs), regarded as biomarkers for type I methanotrophs (16:1omega5t, 16:1omega6c, 16:1omega8c), primarily increased at low temperatures (5-10 degrees C). On the other hand, the PLFA marker for type II methanotrophs (18:1omega8c) was highly elevated only at 20 degrees C. These results suggest that temperature can determine the selection of methanotroph populations. PMID:19712300

Brjesson, Gunnar; Sundh, Ingvar; Svensson, Bo

2004-06-01

190

Behavioural, ventilatory and respiratory responses of epigean and hypogean crustaceans to different temperatures.  

PubMed

Impact of temperature (from -2 to 28 degrees C) on survival, oxygen consumption, locomotory and ventilatory activities was measured in two aquatic subterranean crustaceans (Niphargus rhenorhodanensis and Niphargus virei) and in a morphologically close surface-dwelling crustacean (Gammarus fossarum). The hypogean N. virei presented all characteristics of a stenothermal organism: it showed small thermal plasticity and optimised its performance on a narrow range of temperature. In contrast, the epigean G. fossarum and more surprisingly the hypogean N. rhenorodanensis can be both characterized as eurythermal organisms: they exhibited important survival times and conserved their performance optimum throughout a large range of temperature. Such differences of survival and performance patterns in two hypogean organisms were unexpected since they both live in very thermally buffered biotopes. Our data suggest fresh hypotheses about the role of glaciations in the history and adaptation of hypogean crustaceans. PMID:15893488

Issartel, Julien; Hervant, Frdric; Voituron, Yann; Renault, David; Vernon, Philippe

2005-05-01

191

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

PubMed Central

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

Watanabe, Keiko; Yamamoto, Hideo; Yamamoto, Shuichi

2013-01-01

192

Retardation of division of three ciliates by intermittent and continuous ultraviolet radiations at different temperatures.  

PubMed

The same dosage of ultraviolet (UV) radiation retards division of several protozoans more effectively when the light is intermittent than when it is continuous, and especially at temperatures of 25-35 degrees C. At lower temperatures the difference between the effects of intermittent and continuous radiations is less marked. Somewhat similar results were obtained with the ciliates Paramecium caudatum, Blepharisma japonicum, and Colpidium colpoda, the disparity between intermittent and continuous light decreasing in the order given. The data are taken to indicate that thermochemical dark reactions succeed the absorption of UV radiations by the cells. In Blepharisma, besides initial delay in division, the cells stop dividing after one or two divisions, a "stasis" ensuing. Stasis is marked when the cells are irradiated at higher temperatures but is slight when they are irradiated at low temperatures, as if the temperature-sensitive reaction involved stasis (in all cases cultures are grown at 25 degrees C). The data are related to findings in the literature. PMID:13947762

GIESE, A C; McCAW, B; CORNELL, R

1963-05-01

193

Thermomechanical fatigue of a 316L austenitic steel at two different temperature intervals  

SciTech Connect

Many investigations of the fatigue and fracture behavior of 316L austenitic steel at high temperatures have been carried out, because of wide applications of this material in high temperature components in the energy, transport and nuclear industries. However, most of these studies deal with problems under isothermal test conditions, and less attention has been paid to thermomechanical fatigue (TMF) studies in comparison with its great importance in engineering applications. In the scientific literature, a few studies are found concerning the TMF behavior of 316L stainless steel at different temperature ranges. In this paper, total strain-controlled TMF tests were performed in in-phase and out-of-phase forms on an AISI 316L austenitic stainless steel. The mechanics of deformation and damage for TMF is more complex than high temperature low cycle isothermal fatigue, for in thermomechanical fatigue the stress-strain behavior is associated with the mechanical cycles as well as the thermal ones and it is difficult to determine the effect of many variables which influence this behavior. In their study, the influences of temperature interval and the stress-strain response on the crack propagation and microstructural behaviors were investigated.

Shi, H.J [Tsinghua Univ., Beijing (China). Dept. of Engineering Mechanics; Wang, Z.G.; Su, H.H. [Academia Sinica, Shenyang (China). State Key Lab. for Fatigue and Fracture of Materials

1996-11-01

194

A comparison between high- and low-energy ion mixing at different temperatures  

NASA Astrophysics Data System (ADS)

High-energy ion mixing occurs when an ion beam of a few hundred keV bombards an interface under the surface. Low-energy ion mixing arises when an ion beam of a few keV bombards an interface near the surface during, e.g., sputter depth profiling and low-energy ion-assisted deposition. At low temperatures, the rate of both high- and low-energy ion mixing can be influenced by thermodynamic parameters, such as the heat of mixing and the cohesive energy of solids. These effects are demonstrated by ion mixing experiments using metallic bilayers consisting of high-atomic-number elements. A model of diffusion in thermal spikes is used to explain this similarity. Low-energy ion mixing can also be strongly affected by surface diffusion and the morphological stability of thin films. These effects are illustrated using results obtained from sputter depth profiling of Ag/Ni, Ag/Fe, and Ag/Ti bilayers at elevated temperatures. High-energy ion mixing at low temperatures can be influenced by the anisotropic momentum distribution in a collision cascade as seen from a set of marker experiments to determine the dominant moving species in high-energy ion mixing. An understanding of these similarities and differences between high- and low-energy ion mixing at different temperatures will provide useful guidelines for applications of ion mixing.

Yang-Tse, Cheng; Simko, Steven J.; Militello, Maria C.; Dow, Audrey A.; Auner, Gregory W.; Alkaisi, M. H.; Padmanabhan, K. R.

1992-02-01

195

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

PubMed

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

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

2012-10-10

196

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

NASA Astrophysics Data System (ADS)

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

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

2010-08-01

197

[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

198

Centralperipheral 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

199

The growth of Larix gmelinii seedlings as affected by charcoal produced at two different temperatures  

Microsoft Academic Search

Fires burn forest with spatially heterogeneous intensity and charcoals generated at various temperatures during fires exhibit\\u000a variable physical and chemical characteristics. These variable properties of charcoal may, in turn, influence germination\\u000a and growth of tree seedlings. To examine the effects of different charcoal properties on the growth of Gmelin larch (Larix gmelinii) seedlings, we conducted an experiment with larch-branch-derived charcoals

Kobayashi Makoto; Dongsu Choi; Yasuyuki Hashidoko; Takayoshi Koike

2011-01-01

200

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

Microsoft Academic Search

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 900C reached 104 Acm-2 at 20 K and 5 T. The Jc value extrapolated to 2 T and 20 K

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

2009-01-01

201

Immune responses of the scallop Chlamys farreri after air exposure to different temperatures  

Microsoft Academic Search

The present study examined the influence of air exposure at different temperatures: a common perturbation associated with aquaculture handling practices, on immune responses in zhikong scallop Chlamys farreri. Scallops were exposed to air for 2h, 6h, 12h and 24h at 5C, 17C and 25C respectively. Thereafter, a recovery period of 24h at 17C was applied. Haemocyte mortality, phagocytosis and reactive

Mu-yan Chen; Hong-sheng Yang; Maryse Delaporte; San-jun Zhao; Kun Xing

2007-01-01

202

Artifactual changes in hematological variables in equine blood samples stored at different temperatures and various anticoagulants  

Microsoft Academic Search

The objective of this study was to determine the effect of storage time, temperature, and anticoagulant on hematologic parameters\\u000a in equine blood samples. Blood samples were obtained from 50 clinically healthy warm-blooded horses at two major equestrian\\u000a complexes in Tehran, Iran. The samples were collected in three different tubes containing ethylenediaminetetraacetic acid\\u000a (EDTA), sodium citrate, or heparin and were analyzed

Maysam Tehrani-Sharif; Mehrdad Ameri; Sogand Moshfeghi; Hamid Sharifi; Seyed Mohammad Hoseini; Seyed Mohsen Alavi

203

Artifactual changes in hematological variables in equine blood samples stored at different temperatures and various anticoagulants  

Microsoft Academic Search

The objective of this study was to determine the effect of storage time, temperature, and anticoagulant on hematologic parameters\\u000a in equine blood samples. Blood samples were obtained from 50 clinically healthy warm-blooded horses at two major equestrian\\u000a complexes in Tehran, Iran. The samples were collected in three different tubes containing EDTA, sodium citrate, or heparin\\u000a and were analyzed within 4h

Maysam Tehrani Sharif; Mehrdad Ameri Mahabadi; Sogand Moshfeghi; Hamid Sharifi; Seyed Mohammad Hoseini; Seyed Mohsen Alavi

204

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

205

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

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

206

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

207

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

208

Temperature-induced gene expression associated with different thermal reaction norms for growth rate.  

PubMed

Although nearly all organisms are subject to fluctuating temperature regimes in their natural habitat, little is known about the genetics underlying the response to thermal conditions, and even less about the genetic differences that cause individual variation in thermal response. Here, we aim to elucidate possible pathways involved in temperature-induced phenotypic plasticity of growth rate. Our model organism is the collembolan Orchesella cincta that occurs in a wide variety of habitats and is known to be adapted to local thermal conditions. Because sequence information is lacking in O. cincta, we constructed cDNA libraries enriched for temperature-responsive genes using suppression subtractive hybridization. We compared gene expression of O. cincta with steep thermal reaction norms (high plasticity) to those with flat thermal reaction norms (low plasticity) for juvenile growth after exposure to a temperature switch composed of a cooling or a warming treatment. Using suppression subtractive hybridization, we found differential expression of ten nuclear genes, including several genes involved in energy metabolism, such as pantothenate kinase and carbonic anhydrase. In addition, seven mitochondrial genes were found in the cloned subtracted library, but further analysis showed this was caused by allelic variation in mitochondrial genes in our founder population, and that a specific haplotype was associated with high thermal responsiveness. Future work will focus on candidate genes from pathways such as the oxidative phosphorylation and biosynthesis of coenzyme A which are possibly involved in thermal responsiveness of juvenile growth rate. PMID:17886827

Ellers, Jacintha; Marin, Janine; Driessen, Gerard; van Straalen, Nico M

2008-03-15

209

Avian influenza virus H9N2 survival at different temperatures and pHs.  

PubMed

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

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

2010-03-01

210

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

NASA Astrophysics Data System (ADS)

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

Seema, Kapoor; Uma, Batra; Suchita, Kohli

2012-08-01

211

Mortality of life stages of cowpea weevil (Coleoptera: Bruchidae) exposed to low pressure at different temperatures.  

PubMed

Previous studies have shown that low pressure creates a low oxygen controlled atmosphere that can kill stored-product insects. The current study was conducted to determine the mortality of life stages of the cowpea weevil, Callosbruchus maculatus (F.) (Coleoptera: Bruchidae), exposed to different low pressures and temperatures for various exposure periods. The adults were the most susceptible life stage to low pressure; 99% mortality was achieved within 0.8 h at 32.5 mmHg, 30 degrees C. The pupae were the most tolerant life stage to low pressure, requiring exposure periods between 28.98 and 153.20 h at temperatures of 20-35 degrees C to achieve 99% mortality. Mortality increased with exposure time and also with increasing temperature in all life stages. Early stage eggs (3 h old) and late stage eggs (48 h old) experienced higher mortality (values for LT99 of 42.331 and 46.652 h, respectively) compared with intermediate aged eggs (24 h old; LT99 of 74.735 h) under the same conditions of low pressure and temperature. Dried beans, including cowpea, Vigna unguiculata (Walp.), are currently protected with fumigants. Application of low pressure as a pest management tool represents a potential nonchemical alternative to fumigants such as methyl bromide and phosphine for controlling the cowpea weevil and related bruchids. PMID:16022340

Mbata, George N; Johnson, Mario; Phillips, Thomas W; Payton, Mark

2005-06-01

212

Influence of Preslaughter Muscle Temperature on Muscle Metabolism and Meat Quality in Anesthetized Pigs of Different Halothane Genotypes  

Microsoft Academic Search

Preslaughter muscle temperature in anesthetized pigs of different halothane genotypes (NN, Nn, and nn) was raised or lowered during a 45-min period of anesthesia. The different treatments produced muscle and rectal temperature differentials of 1.5 to 2C across genotypes. Blood and muscle biopsy samples were taken during the period of anesthesia, to study muscle energy metabolism by measuring different metabolites.

R. E. Klont; E. Lambooy

2010-01-01

213

Determination of regional brain temperature using proton magnetic resonance spectroscopy to assess brain-body temperature differences in healthy human subjects.  

PubMed

Proton magnetic resonance spectroscopy ((1)H MRS) was used to determine brain temperature in healthy volunteers. Partially water-suppressed (1)H MRS data sets were acquired at 3T from four different gray matter (GM)/white matter (WM) volumes. Brain temperatures were determined from the chemical-shift difference between the CH(3) of N-acetyl aspartate (NAA) at 2.01 ppm and water. Brain temperatures in (1)H MRS voxels of 2 x 2 x 2 cm(3) showed no substantial heterogeneity. The volume-averaged temperature from single-voxel spectroscopy was compared with body temperatures obtained from the oral cavity, tympanum, and temporal artery regions. The mean brain parenchyma temperature was 0.5 degrees C cooler than readings obtained from three extra-brain sites (P < 0.01). (1)H MRS imaging (MRSI) data were acquired from a slice encompassing the single-voxel volumes to assess the ability of spectroscopic imaging to determine regional brain temperature within the imaging slice. Brain temperature away from the center of the brain determined by MRSI differed from that obtained by single-voxel MRS in the same brain region, possibly due to a poor line width (LW) in MRSI. The data are discussed in the light of proposed brain-body temperature gradients and the use of (1)H MRSI to monitor brain temperature in pathologies, such as brain trauma. PMID:17139620

Childs, Charmaine; Hiltunen, Yrj; Vidyasagar, Rishma; Kauppinen, Risto A

2007-01-01

214

Improvement of skin optical clearing efficacy by topical treatment of glycerol at different temperatures  

NASA Astrophysics Data System (ADS)

In the past decades, laser has been widely used in clinical diagnosis and cosmetic therapy. However, there is limitation for further usage in deeper tissue for high scattering property. Skin optical clearing technique, by introducing optical clearing agents (OCAs) into tissue, will have a potential impact on optical diagnosis and therapy. In this work, anhydrous glycerol at different temperatures of 4, 25, 32 and 45C were applied respectively to in vitro porcine skin, and reflectance and transmittance spectra were then measured dynamically using a spectrometry combined with integrating sphere system. Further, reduced scattering coefficient and penetration depth were obtained. Results showed that, glycerol at different temperatures could induce the reduced scattering coefficient of in vitro skin to decrease and the penetration depth to increase. 4 and 25C glycerol had similar effect, decreasing the scattering by 48.2% and 49.7%, and increasing penetration depth by 37.9% and 39.5%, respectively. However, 32 and 45C glycerol treatment could decrease scattering by 61.6% and 76.6%, and increase penetration depth by 53.3% and 84.1%, respectively. In conclusion, glycerol at higher temperature can induce greater and faster skin optical clearing efficacy.

Deng, Zijian; Liu, Caihua; Tao, Wei; Zhu, Dan

2011-01-01

215

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

SciTech Connect

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

P.D. Jadhav; R.V. Chatti; R.B. Biniwale; N.K. Labhsetwar; S. Devotta; S.S. Rayalu [National Environmental Engineering Research Institute, Nagpur (India)]. s_rayalu@neeri.res.in

2007-12-15

216

Interrelation of Tissue Temperature Versus Flow Velocity in Two Different Kinds of Temperature Controlled Catheter Radiofrequency Energy Applications  

Microsoft Academic Search

The influence of blood flow cooling down the energy delivering electrode during temperature controlled radiofrequency energy application is an important factor for ablation success. In this experimental in-vitro study, using tempered saline as blood equivalent, we observed a highly significant increase in tissue temperature, lesion depth and required energy amount with increasing flow velocity. Second, we found significant deeper lesions

Stephan Grumbrecht; Jrg Neuzner; Heinz F. Pitschner

1998-01-01

217

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

PubMed

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

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

2012-06-30

218

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

219

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

220

Temperature dependent electrical conductivity measurement of Ad-(TCNQ)2 grown by different methods  

NASA Astrophysics Data System (ADS)

We measured the temperature dependent electrical conductivity on single crystal of Radical Ion Salts (RIS), Ad-(TCNQ)2 grown by different methods. Where, Ad and TCNQ are representing acridinium and tetracyanoquinodimethane. The single crystal of this complex shows DC conductivity at room temperature 100 ohm-1 cm-1 with activation energy 0.022 eV in the sample grown by electrochemical method. Whereas it is found 82 ohm-1 cm-1 with activation energy 0.03 eV for the sample grown by diffusion method. In all conductivity measurements, the observations are carried out along high conducting chain direction, which happens to be needle direction of the single crystal and known as principal axis direction.

Singh, Yadunath

2013-06-01

221

Cell chip temperature measurements in different operation regimes of HCPV modules  

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

222

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

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

223

Temperature dependent electrical conductivity measurement of Qn-(TCNQ)2 grown by different methods  

NASA Astrophysics Data System (ADS)

We measured the temperature dependent electrical conductivity on single crystal of charge transfer complex (CTC), Qn-(TCNQ)2 grown by different methods. Where, Qn and TCNQ are representing qunolinium and tetracyanoquinodimethane. The room temperature conductivity is found 100 ohm-1 cm-1 with activation energy 0.021 eV in the sample grown by electrochemical method. Whereas it is found 22 ohm-1 cm-1 with activation energy 0.026 eV for the sample grown by solution growth method. In all conductivity measurements, the observations are carried out along high conducting chain direction, which happens to be needle direction of the single crystal and known as a-direction.

Singh, Yadunath

2013-06-01

224

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

NASA Astrophysics Data System (ADS)

Effects of temperatures and salinities on oxygen consumption and ammonia-N excretion rate of clam Meretrix meretrix were studied in laboratory from Oct. 2003 to Jan. 2004. Two schemes were designed in incremented temperature at 10, 15, 20, 25C at 31.5 salinity and in incremented salinity at 16.0, 21.0, 26.0, 31.5, 36.0, and 41.0 at 20C, all for 8 10 days. From 10 to 25C, both respiration and excretion rate were increased. One-way ANOVA analysis demonstrated significant difference ( P<0.01) in physiological parameters in this temperature range except between 15 and 20C. The highest Q 10 thermal coefficient value (12.27) was acquired between 10 and 15C, and about 1 between 15 and 20C, indicating M. meretrix could well acclimate to temperature changes in this range. Salinity also had significant effects on respiration and excretion rate ( P<0.05). The highest values of respiration and excretion rate of M. meretrix were recorded at 16.0 salinity (20C). These two physiological parameters decreased as salinity increased until reached the minimum Q 10 value at 31.5 (20C), then again, these parameters increased with increasing salinity from 31.5 to 41.0. M. meretrix can catabolize body protein to cope with osmotic pressure stress when environmental salinity is away from its optimal range. No significant difference was observed between 26.0 and 36.0 in salinity ( P>0.05), suggesting that a best metabolic salinity range for this species is between 26.0 and 36.0.

Tang, Baojun; Liu, Baozhong; Yang, Hongsheng; Xiang, Jianhai

2005-12-01

225

Mantle heterogeneity and temperatures inferred from magmas from different tectonic settings  

NASA Astrophysics Data System (ADS)

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

Green, D. H.

2003-04-01

226

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

Microsoft Academic Search

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

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

2006-01-01

227

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

PubMed

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

Xiong, Yaoyang; Qian, Chao; Sun, Jian

2012-01-01

228

Comparison of the effects of sucrose and hexose on furfural formation and browning in cookies baked at different temperatures  

Microsoft Academic Search

The influence of the type of sugar and baking temperature on sugar degradation, hydroxymethylfurfural (HMF) formation and browning was studied in model cookies. The baking process was characterised by the temperature in the cookie and the water content and activity. A reference browning was selected to compare the differently processed cookies. The accumulation of HMF was modelled at three temperatures

Lamia Ait Ameur; Odile Mathieu; Valrie Lalanne; Gilles Trystram; Ines Birlouez-Aragon

2007-01-01

229

Stationary Cylindrical Couette Flow at Different Temperature of Cylinders: the Local Knudsen Number Effect  

NASA Astrophysics Data System (ADS)

The stationary Couette gas flow between rotating inner cylinder and stationary outer one is studied using DSMC method and numerical solution of a continual model. Different cases were studied by varying the temperature of the stationary cylinder and the Knudsen number. The continuum model results are obtained by setting a local value of Knudsen number in the corresponding first order slip boundary conditions. The comparison results showed that the slip boundary conditions with local Knudsen number included improves the accuracy of the continual model.

Gospodinov, P.; Dankov, D.; Roussinov, V.; Stefanov, S.

2011-11-01

230

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

231

Thermoregulation in the cold after physical training at different ambient air temperatures.  

PubMed

Since human thermoregulation at rest is altered by cold exposure, it was hypothesized that physical training under cold conditions would alter thermoregulation. Three groups (n = 8) of male subjects (mean age 24.3 +/- 0.9 years) were evaluated: group T (interval training at 21 degrees C), group CT (interval training at 1 degrees C), and group C (no training, equivalent exposure to 1 degrees C). Each group was submitted, before and after 4 weeks of interval training (5 d/week), to a cold air test at rest (SCAT) (dry bulb temperature (Tdb) = 1 degrees C) for a 2-h period for evaluation of the thermoregulatory responses. During SCAT, after the training/acclimation period, group T exhibited a higher rectal temperature (Tre) (P < 0.05) without significant change in mean skin temperature (Tsk) whereas metabolic heat production (M) was higher at the beginning of the SCAT (P < 0.05). For group CT, no thermoregulatory change was observed. Group C showed a lower Tre (P < 0.05) without significant change in either Tsk or in M, suggesting the development of a hypothermic general cold adaptation. This study showed, first, that the cold thermoregulatory responses induced by an interval training differed following the climatic conditions of the training and, second, that this training performed in the cold prevented the development of a general cold adaptation. PMID:12430980

Launay, Jean-Claude; Besnard, Yves; Guinet, Anglique; Hanniquet, Anne-Marie; Bittel, Jacques; Savourey, Gustave

2002-09-01

232

Cold perception and cutaneous microvascular response to local cooling at different cooling temperatures.  

PubMed

The aim of the present study was to investigate the effect of quantitatively measured cold perception (CP) thresholds on microcirculatory response to local cooling as measured by direct and indirect response of laser-Doppler (LD) flux during local cooling at different temperatures. The CP thresholds were measured in 18 healthy males using the Marstock method (thermode placed on the thenar). The direct (at the cooling site) and indirect (on contralateral hand) LD flux responses were recorded during immersion of the hand in a water bath at 20C, 15C, and 10C. The cold perception threshold correlated (linear regression analysis, Pearson correlation) with the indirect LD flux response at cooling temperatures 20C (r=0.782, p<0.01) and 15C (r=0.605, p<0.01). In contrast, there was no correlation between the CP threshold and the indirect LD flux response during cooling in water at 10C. The results demonstrate that during local cooling, depending on the cooling temperature used, cold perception threshold influences indirect LD flux response. PMID:21256855

Music, Mark; Finderle, Zarko; Cankar, Ksenija

2011-01-21

233

Temperature dependence of magnetoresistance in magnetic tunnel junctions with different free layer structures  

NASA Astrophysics Data System (ADS)

The temperature and bias voltage dependence of magnetoresistance and the resistance of two types of magnetic tunnel junction (MTJ) samples were studied. These two types of MTJ samples have different free layer structures, while having the same pinned layer structures and with the same material for free and reference layers. The layer structure for type 1 MTJs is 80Ru-8CoFeB-15Al2O3-50CoFeB-9Ru-54FeCo-350CrMnPt (in angstroms). The layer structure for type 2 MTJs is 80Ru-40CoFeB-50RuTa-40CoFeB-15Al2O3-50CoFeB-9Ru-54FeCo-350CrMnPt . The tunneling magnetoresistance (TMR) ratio [(RAP-RP)/RP] is about 26% and 69% at room temperature for type 1 and type 2 MTJs, respectively. A TMR as high as 107% has been observed for type 2 MTJ samples at 13K . By analysis of the voltage and temperature dependence of the resistance and magnetoresistance in these MTJs, we discuss the effects of the magnetic behavior of the free layers, barrier qualities, and barrier interfaces. The results clearly indicate that the micromagnetization orientation at the interface between the free layer and the barrier layer is one of the important factors that determines the TMR ratio.

Yuan, L.; Liou, S. H.; Wang, Dexin

2006-04-01

234

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

NASA Astrophysics Data System (ADS)

In order to understand the behaviour of ruthenium oxides in the reactor coolant system during an air ingress accident, new tests were performed in the frame of the RUSET (RUthenium Separate Effect Test) experimental program. These aimed to ascertain the effects of different surfaces (quartz, stainless steel (SS), zirconium alloy, alumina, oxidised metal, and surfaces with Mo or Cs deposits) on the transport and decomposition of ruthenium oxides in air stream along the temperature gradient zone (1100-100 C). The results demonstrated that the heterogeneous phase decomposition of RuO3 and RuO4 to RuO2 is catalysed more efficiently by the quartz surface than by the SS or alumina surfaces. The presence of MoO3 layers decreased the RuOx precipitation extent on all investigated surfaces. The trapping effect of Cs deposit on Ru in the temperature gradient zone was proved in the case of the SS surface. On the contrary, presence of Cs precipitate on alumina and especially on quartz surfaces was found to decrease their catalytic effect on the decomposition of ruthenium oxides, and thus increased the RuO4 concentration in the outlet air. Similarly to the effect observed for Cs deposition, the presence of other fission products in the evaporation area (at 1100 C) decreased the partial pressure of RuO4 in the outlet air at the SS surface and increased it at quartz and alumina surfaces. When zirconium (E110) cladding material was placed in the temperature gradient zone, no Ru transmittance occurred until the high temperature end of the zirconium tube was completely oxidised. After the intense oxidation of E110, Ru release occurred only in the presence of other fission product species. Pre-oxidation of SS surfaces in steam had no significant effect on the Ru passage.

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

2012-01-01

235

Effects of high temperature stress at different development stages on soybean isoflavone and tocopherol concentrations.  

PubMed

Soybean contains a range of compounds with putative health benefits including isoflavones and tocopherols. A study was conducted to determine the effects on these compounds of high temperature stress imposed at specific development stages [i.e., none, pre-emergence, vegetative, early reproductive (R1-4), late-reproductive (R5-8), or all stages]. Two cultivars (AC Proteina and OAC Champion) were grown in growth chambers set at contrasting temperatures [i.e., stress conditions of 33/25 C (day/night temperature) and control conditions of 23/15 C] in order to generate these treatments. Isoflavone and tocopherol concentrations in mature seeds were determined using high-performance liquid chromatography. In both cultivars isoflavone response was greatest when stress occurred during the R5-8 stages and during all development stages, these treatments reducing total isoflavone concentration by an average of 85% compared to the control. Stress imposed at other stages also affected isoflavone concentration although the response was smaller. For example, stress during the vegetative stages reduced total isoflavones by 33% in OAC Champion. Stress imposed pre-emergence had an opposite effect increasing daidzein concentration by 24% in AC Proteina. Tocopherol concentrations were affected the most when stress was imposed during all stages of development, followed by stress restricted to stages R5-8; response to stress during other stages was limited. The specific response of tocopherols differed, ?-tocopherol being increased by high temperature by as much as 752%, the reverse being observed for ?-tocopherol and ?-tocopherol. The present study demonstrates that while isoflavone and tocopherol concentrations in soybeans are affected the most by stress occurring during seed formation, concentrations can also be affected by stress occurring at other stages including stages as early as pre-emergence. PMID:22098462

Chennupati, Pratyusha; Seguin, Philippe; Liu, Wucheng

2011-11-30

236

Causes of differing temperature trends in radiosonde upper air data sets  

NASA Astrophysics Data System (ADS)

Differences between trends in different radiosonde temperature products resulting from the varying choices made by the developers of the data sets create obstacles for use of those products in climate change detection and attribution. To clarify the causes of these differences, one must examine results using a common subset of locations to minimize spatial sampling effects. When this is done for the Lanzante-Klein-Seidel (LKS) and Hadley Center (HadRT) radiosonde data sets, differences are reduced by at least one third. Differing homogeneity adjustment methods and differences in the source data are both important factors contributing to the remaining discrepancies. In contrast, subsampling the microwave sounding unit (MSU) satellite data sets according to the radiosonde coverage does not generally bring the trends in the satellite data closer to those in the radiosonde data so that adjustments and other processing differences appear to be the predominant sources of satellite-radiosonde discrepancies. Experiments in which we subsample globally complete data sets provide additional insight into the role of sampling errors. In the troposphere, spatial sampling errors are frequently comparable to the trends for 1979-1997, while in the stratosphere the errors are generally small relative to the trends. Sampling effects estimated from National Centers for Environmental Prediction reanalysis and MSU satellite data for seven actual radiosonde networks show little consistent relation between sampling error and network size. These results may have significant implications for the design of future climate monitoring networks. However, estimates of sampling effects using the reanalysis and the satellite data sets differ noticeably from each other and from effects estimated from actual radiosonde data, suggesting that these globally complete data sets may not fully reproduce actual sampling effects.

Free, Melissa; Seidel, Dian J.

2005-04-01

237

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

Microsoft Academic Search

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

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

2007-01-01

238

Sensitivity Study on Using Different Formulae for Calculating the Temperature of Insulated Steel Members in Natural Fires  

Microsoft Academic Search

The applicability of using different formulae for calculating the temperature of insulated steel members exposed to natural fires which include heating and cooling phases has been investigated. The widely referenced 'Swedish' fire curves and measured temperature time curves in real fire tests are adopted to represent different natural fire environments. Parameters including insulation thickness, section factor, and protection material are

Chao Zhang; Guo-Qiang Li; Yong Wang

2011-01-01

239

Temperature  

NSDL National Science Digital Library

Thermometers record the temperature in a given location. Temperature is a non-living thing because it doesn't physically move or eat, for example. However, temperature is a very important factor that effects where animals live and how long they stay in that particular spot.

Luis Miguel Orta Rial (None;)

2008-03-24

240

Diurnal soil temperature fluctuations for different erosion classes of an oxisol at Mlingano, Tanzania  

Microsoft Academic Search

Soil temperature affects crop growth through its impact on nutrient and water availability, yet few studies have quantitatively analyzed the effects of erosion on soil temperature regime. Therefore, this study was conducted to determine the impact of soil erosion on diurnal temperature fluctuations, and develop a simple model for predicting soil temperature regime from soil properties. Measurements of soil properties

A. J Tenge; F. B. S Kaihura; R Lal; B. R Singh

1998-01-01

241

Analysis of the Dynamics of Rhizomucor miehei Lipase at Different Temperatures  

Microsoft Academic Search

The dynamics of Rhizomucor miehei lipase has been studied by molecular dynamics simulations at temperatures ranging from 200500K. Simulations carried out in periodic boundary conditions and using explicit water molecules were performed for 400 ps at each temperature. Our results indicate that conformational changes and internal motions in the protein are significantly influenced by the temperature increase. With increasing temperature,

Gnther H. Peters; S. Toxvaerd; Kim Vilbour Andersen; A. Svendsen

1999-01-01

242

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

PubMed

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

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

2013-06-14

243

Temperature dependence of the thermal conductivity of different forms of diamond  

NASA Astrophysics Data System (ADS)

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

Barman, Saswati; Srivastava, G. P.

2007-06-01

244

Investigation of Li in Clay Interlayers at Different Temperatures by NMR  

NASA Astrophysics Data System (ADS)

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

Kim, Y.; Lee, J.

2007-12-01

245

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, Saarbrucken, Germany); Gruber, Patrick A. (Karlsruhe Institute of Technology, Institut fur Zuverlassigkeit 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

246

Micro X-ray diffraction study of superelastic nickeltitanium orthodontic wires at different temperatures and stresses  

Microsoft Academic Search

The phase transformation behavior in three commercial nickeltitanium orthodontic wires having different transformation temperatures was studied by micro X-ray diffraction (micro-XRD). Micro-XRD spectra were obtained at three different included bending angles (135, 146 and 157) and three different temperatures (25C, 37C and 60C). The regions analyzed by micro-XRD were within the separate areas of a given wire specimen that experienced

M. Iijima; H. Ohno; I. Kawashima; K. Endo; W. A. Brantley; I. Mizoguchi

2002-01-01

247

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

PubMed

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

Dscher, Ralf; Meier, H E Markus

2004-06-01

248

Terahertz absorption spectrum of water vapor at different humidity at room temperature  

NASA Astrophysics Data System (ADS)

We measured the absorption spectrum of water vapor in 0.2-2.4THz range at different humidity from 17% to 98% at room temperature using Er: doped fiber laser (IMRA America Inc.) based terahertz time-domain spectroscopy. The experiments were performed in a nitrogen-purged cage at atmosphere environment to obtain the reference and water absorption information. The seventeen absorption lines were observed due to water molecular rotations in the ground vibration state. The first three absorption lines at low frequencies increase with humidity, following the Beer-Lambert Law, while some of high frequency lines were found to decrease with humidity. These effects will be discussed. The observed line broadening is due to collisions occurring among water and nitrogen molecules.

Xin, Xuying; Altan, Hakan; Matten, David; Saint, Angelamaria; Alfano, Robert

2006-03-01

249

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 412% 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

250

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

251

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

2012-09-09

252

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

NASA Astrophysics Data System (ADS)

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

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

2013-07-01

253

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

Microsoft Academic Search

Two co-firable low temperature co-fired ceramics (LTCC) materials with different permittivities were investigated. The first material has low-K and high stiffness, and the second material has high-K, high-Q, and near zero temperature coefficient of capacitance (TCC). A resistor material, which is mainly composed of RuO2 and glass, is able to be buried into the LTCC substrate. To adjust the properties

Takaki Murata; Satoshi Ohga; Yasutaka Sugimoto

2006-01-01

254

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

PubMed

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

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

2012-09-10

255

Different Temperature Optima for Methane Formation When Enrichments from Acid Peat Are Supplemented with Acetate or Hydrogen  

PubMed Central

Laboratory studies of methane formation in peat samples from an acid subarctic mire in Sweden indicated the presence of a low-temperature-adapted methanogenic flora. Enrichment culture studies with ethanol, acetate, hydrogen, or a combination of these as substrate for methane formation provided evidence for the existence of two different methanogenic populations in the peat: one, unaffected by hydrogen and using acetate, with a temperature optimum at 20C; the other, oxidizing hydrogen, with a temperature optimum at ca. 28C.

Svensson, Bo H.

1984-01-01

256

The effects of temperature on metabolic rates of different life stages of Calanus glacialis in the Barents Sea  

Microsoft Academic Search

The effects of temperature on rates of respiration, excretion and gut evacuation were examined for copepodite stages and adult female Calanus glacialis collected in areas close to the ice-edge during the arctic summer in the Barents Sea. The various life history stages responded differently to acute temperature changes above the in situ temperature (ca.-1.7C). Respiration rates of early copepodite stages

Kurt S. Tande

1988-01-01

257

Understanding differences in upper stratospheric ozone response to changes in chlorine and temperature as computed using CCMVal-2 models  

NASA Astrophysics Data System (ADS)

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 coupled chemistry-climate models (CCMs). Although developed from common principles and subject to the same boundary conditions, simulated ozone time series vary among models for scenarios for ozone depleting substances (ODSs) and greenhouse gases. Photochemical processes control the upper stratospheric ozone level, and there is broad agreement among CCMs in that ozone increases as ODSs decrease and temperature decreases due to greenhouse gas increase. There are quantitative differences in the ozone sensitivity to chlorine and temperature. We obtain insight into differences in sensitivity by examining the relationship between the upper stratospheric seasonal cycles of ozone and temperature as produced by fourteen CCMs. 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. Analysis reveals differences in simulated temperature, ozone and reactive nitrogen that lead to differences in the relative importance of ozone loss processes and are most obvious when chlorine levels are close to background. Differences in the relative importance of loss processes underlie differences in simulated sensitivity of ozone to composition change. This suggests 1) that the multimodel mean is not a best estimate of the sensitivity of upper stratospheric ozone to changes in ODSs and temperature; and 2) that the spread of values is not an appropriate measure of uncertainty.

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

2012-08-01

258

Steroid signaling system responds differently to temperature and hormone manipulation in the red-eared slider turtle (Trachemys scripta elegans), a reptile with temperature-dependent sex determination.  

PubMed

Many reptiles, including the red-eared slider turtle (Trachemys scripta elegans), exhibit temperature-dependent sex determination (TSD). Temperature determines gonadal sex during the middle of embryogenesis, or the temperature-sensitive period (TSP), when gonadal sex is labile to both temperature and hormones--particularly estrogen. The biological actions of steroid hormones are mediated by their receptors as defined here as the classic transcriptional regulation of target genes. To elucidate estrogen action during sex determination, we examined estrogen receptor alpha (Esr1, hereafter referred to as ERalpha), estrogen receptor beta (Esr2, hereafter referred to as ERbeta), and androgen receptor (Ar, hereafter referred to as AR) expression in slider turtle gonads before, during and after the TSP, as well as following sex reversal via temperature or steroid hormone manipulation. ERalpha and AR levels spike at the female-producing temperature while ovarian sex is determined, but none of the receptors exhibited sexually dimorphic localization within the gonad prior to morphological differentiation. All three receptors respond differentially to sex-reversing treatments. When shifted to female-producing temperatures, embryos maintain ERalpha and AR expression while ERbeta is reduced. When shifted to male-producing temperatures, medullary expression of all three receptors is reduced. Feminization via estradiol (E(2)) treatment at a male-producing temperature profoundly changed the expression patterns for all three receptors. ERalpha and ERbeta redirected to the cortex in E(2)-created ovaries, while AR medullary expression was transiently reduced. Although warmer incubation temperature and estrogen result in the same endpoint (ovarian development), our results indicate different steroid signaling patterns between temperature- and estrogen-induced feminization. PMID:18391529

Ramsey, M; Crews, D

2007-01-01

259

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

260

CTE and QE measurement for ACS CCDs at three different temperatures  

NASA Astrophysics Data System (ADS)

The goal of this program is to characterize the variation in CTE and QE for the ACS/WFC and ACS/HRC CCDs when operated at temperatures colder and warmer than the current operational temperature. The range of temperature tested here should represent the coldest and warmest temperature at which the CCD can be operated after SM4 in the case the ASCS is installed or not installed {or installed and not connected to ACS}.

Sirianni, Marco

2005-07-01

261

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

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

2004-01-01

262

Temperature evolution and mass losses during immersion vacuum cooling of cooked beef joints A finite difference model  

Microsoft Academic Search

A finite difference model was developed to describe and predict the temperature and mass loss evolution in reconstructed beef joints during immersion vacuum cooling. Fast cooling is obtained within beef pores and at beef surface when evaporation in the surrounding liquid is high. The cooling rate diminishes as the vacuum chamber pressure stabilizes and the liquid temperature reaches its lower

Liana Drummond; Da-Wen Sun

2008-01-01

263

Nyfoedda Grisars Rektaltemperatu Under Olika Miljoefoerhallanden (Rectal Temperature of the Newborn Pig Measured under Different Environmental Conditions).  

National Technical Information Service (NTIS)

The purpose of this investigation was to study the rectal temperature of normal, newborn pigs during the period of time immediately after birth; to compare the rectal temperature of normal pigs over this time period with that of different groups of weak b...

K. Ahlmann J. Svensen A. C. Bengtsson

1983-01-01

264

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

Microsoft Academic Search

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.

Miguel Gmez-Heras; Bernard J. Smith; Rafael Fort

2006-01-01

265

Temperature  

NSDL National Science Digital Library

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

2008-04-08

266

Effects of different fabrication techniques on the yttrium-barium-copper oxide high-temperature superconductor. Master's thesis  

SciTech Connect

This study examines how several different parameters were changed in the yttrium-barium-copper oxide superconductor when the fabrication techniques were altered by using different barium precursors, including barium peroxide and barium carbonate; sintering at different temperatures, including 850, 900, and 950 C; and annealing in an above ambient oxygen environment. Twelve different pellets were fabricated, and measurements were taken on them which included density, x-ray diffraction, critical temperature, critical current density, and magnetic susceptibility. Results showed that the barium perioxide derived samples had higher densities, better critical current densities and lower resistivities in the normal state.

Rhea, P.A.

1988-12-01

267

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 Cermk 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

268

Detection and analysis of anomalies in the brightness temperature difference field using MSG rapid scan data  

NASA Astrophysics Data System (ADS)

The paper addresses anomalies in brightness temperature difference (BTD) between WV and IR window bands using MSG rapid scan data. One of our aims is to eliminate subjectivity in their detection. The important finding is that it is not possible to study the anomalous behavior when taking into account all pixels related to a storm cloud top. It is necessary to identify and study anomalous regions separately, otherwise their behavior is masked by the majority of the other pixels. We propose a detection algorithm based on the thresholding method with the threshold depending on the dispersion of the BTD data. Outputs of the algorithm and first analyses for one chosen case are shown. According to the first results, the typical relationship between BT and BTD (most of the pixels with growing BTD exhibit a decrease in BT) is retained during the time evolution of the storm also for anomalous pixels, even though their BTDs reach higher values than for non-anomalous pixels at a similar BT level.

?stka, Jind?ich; Radov, Michaela

2013-04-01

269

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

SciTech Connect

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

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

2009-07-01

270

Effect of moderate hypoxia at three acclimation temperatures on stress responses in Atlantic cod with different haemoglobin types.  

PubMed

This study examines stress responses in Atlantic cod (Gadus morhua) when exposed to a moderate and transient reduction (35% O(2) sat.) in dissolved oxygen at a range of temperatures (5 degrees C, 10 degrees C and 15 degrees C), conditions occurring in some areas they inhabit. Given their geographical distribution pattern, and differences in preferred temperature of cod with different haemoglobin types, the study was extended to include haemoglobin polymorphism. We hypothesised that the differences in temperature preference between HbI-1 and HbI-2 type cod might also be reflected in a difference in stress response to hypoxia exposure. Two hsp70-isoforms (labelled a and b) were detected and they differed in expression in the gills but not in the liver of Atlantic cod. Acclimation temperature significantly affected the expression of hsp70 in the liver, and in an isoform-specific manner in the gills. Hypoxia exposure increased the expression of hsp70 in the liver, but not the gills, of cod and this response was not influenced by the acclimation temperature. The expression of hsp70 in both tissues did not differ between fish with different haemoglobin types. Acclimation temperature significantly impacted plasma cortisol but not lactate levels. Also, acute oxygen limitation or HbI-type significantly elevated plasma cortisol and lactate levels but these responses were not modulated by acclimation temperature. Taken together, our results suggest that both temperature acclimation and acute hypoxic exposure influence the organismal and cellular stress responses in Atlantic cod. We hypothesise that HbI-2 fish are more tolerant to short-term hypoxic episodes than HbI-1 fish, and this adaptation may be independent of tissue hsp70 expression. PMID:20388549

Methling, Caroline; Aluru, Neelakanteswar; Vijayan, Mathilakath M; Steffensen, John F

2010-04-11

271

Influence of Patterns of Climate Variability on the Difference between Satellite and Surface Temperature Trends  

Microsoft Academic Search

During the past 20 years, satellite measurements of tropospheric temperature have shown a slower rate of global temperature increase than surface air temperature, yielding an increase in the surface to lower-troposphere lapse rate of 0.12 K decade 21 from 1979 to August 2001. This increase in lapse rate was preceded by a decrease over the previous 15-yr interval. The influence

Gabriele C. Hegerl; John M. Wallace

2002-01-01

272

Carbon incorporation in siliconcarbon films grown at different substrate temperatures  

Microsoft Academic Search

Hydrogenated microcrystalline siliconcarbon thin films have been deposited by plasma enhanced chemical vapour deposition technique at the substrate temperatures of 250C and 400C varying the radio frequency (RF) power in the 10100W range. The effects of substrate temperature and RF power on the structural, compositional, optical, and electrical properties have been investigated. The increase of substrate temperature or RF power

U. Coscia; G. Ambrosone; P. Maddalena; A. Setaro; A. R. Phani; M. Passacantando

2007-01-01

273

Effect of ambient temperature on the demanded energy of solar cells at different inclinations  

Microsoft Academic Search

With increase of ambient temperatue there is a deficiency in electrical energy that solar cells supply than their values under ideal conditions (25 c - 1000 w\\/m2), this sitiuation be of a high affection especially in countries of a hot climate. In this work the cell temperature inside a solar panel is calculated depending on values of ambient temperature, solar

A. M. Al-Sabounchi

1998-01-01

274

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

Microsoft Academic Search

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

Mara Eugenia Brcenas; Cristina M. Rosell

2007-01-01

275

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

Microsoft Academic Search

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

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

1934-01-01

276

Temperature Dependence of Protein Dynamics Simulated With Three Different Water Models  

SciTech Connect

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

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

2010-04-01

277

Molecular analysis of the microbial community structures in water-flooding petroleum reservoirs with different temperatures  

NASA Astrophysics Data System (ADS)

Analyses of microbial communities from six water-flooding petroleum reservoirs at temperatures from 21 to 63 C by 16S rRNA gene clone libraries indicates the presence of physiologically diverse and temperature-dependent microorganisms in these subterrestrial ecosystems. In samples originating from high-temperature petroleum reservoirs, most of the archaeal sequences belong to thermophiles affiliated with members of the genera Thermococcus, Methanothermobacter and the order Thermoplasmatales, whereas bacterial sequences predominantly belong to the phyla Firmicutes, Thermotogae and Thermodesulfobacteria. In contrast to high-temperature petroleum reservoirs, microorganisms belonging to the Proteobacteria, Methanobacteriales and Methanomicrobiales were the most encountered in samples collected from low-temperature petroleum reservoirs. Canonical correspondence analysis (CCA) revealed that temperature, mineralization, ionic type as well as volatile fatty acids showed correlation with the microbial community structures, in particular members of the Firmicutes and the genus Methanothermobacter showed positive correlation with temperature and the concentration of acetate. Overall, these data indicate the large occurrence of hydrogenotrophic methanogens in petroleum reservoirs and imply that acetate metabolism via syntrophic oxidation may represent the main methanogenic pathway in high-temperature petroleum reservoirs.

Wang, L.-Y.; Duan, R.-Y.; Liu, J.-F.; Yang, S.-Z.; Gu, J.-D.; Mu, B.-Z.

2012-11-01

278

Temperature dependence of APD-based PET scanners.  

PubMed

Purpose: Solid state detectors such as avalanche photodiodes (APDs) are increasingly being used in PET detectors. One of the disadvantages of APDs is the strong decrease of their gain factor with increasing ambient temperature. The light yield of most scintillation crystals also decreases when ambient temperature is increased. Both effects lead to considerable temperature dependence of the performance of APD-based PET scanners. In this paper, the authors propose a model for this dependence and the performance of the LabPET8 APD-based small animal PET scanner is evaluated at different temperatures.Methods: The model proposes that the effect of increasing temperature on the energy histogram of an APD-based PET scanner is a compression of the histogram along the energy axis. The energy histogram of the LabPET system was acquired at 21?C and 25?C to verify the validity of this model. Using the proposed model, the effect of temperature on system sensitivity was simulated for different detector temperature coefficients and temperatures. Subsequently, the effect of short term and long term temperature changes on the peak sensitivity of the LabPET system was measured. The axial sensitivity profile was measured at 21?C and 24?C following the NEMA NU 4-2008 standard. System spatial resolution was also evaluated. Furthermore, scatter fraction, count losses and random coincidences were evaluated at different temperatures. Image quality was also investigated.Results: As predicted by the model, the photopeak energy at 25?C is lower than at 21?C with a shift of approximately 6% per C. Simulations showed that this results in an approximately linear decrease of sensitivity when temperature is increased from 21?C to 24?C and energy thresholds are constant. Experimental evaluation of the peak sensitivity at different temperatures showed a strong linear correlation for short term (2.32 kcps/MBq/C = 12%/C, R = -0.95) and long term (1.92 kcps/MBq/C = 10%/C , R = -0.96) temperature changes. Count rate evaluation showed that although the total count rate is consistently higher at 21?C than at 24?C for different source activity concentrations, this is mainly due to an increase in scattered and random coincidences. The peak total count rate is 400 kcps at both temperatures but is reached at lower activity at 21?C. The peak true count rate is 138 kcps (at 100 MBq) at 21?C and 180 kcps (at 125 MBq) at 24?C. The peak noise equivalent count rate is also lower at 21?C (70 kcps at 70 MBq) than at 24?C (100 kcps at 100 MBq). At realistic activity levels, the scatter fraction is lower at higher temperatures, but at the cost of a strong decrease in true count rate.Conclusions: A model was proposed for the temperature dependence of APD-based PET scanners and evaluated using the LabPET small animal PET scanner. System sensitivity and count rate performance are strongly dependent on ambient temperature while system resolution is not. The authors' results indicate that it is important to assure stable ambient temperature to obtain reproducible results in imaging studies with APD-based PET scanners. PMID:24007182

Keereman, Vincent; Van Holen, Roel; Vandenberghe, Stefaan; Vanhove, Christian

2013-09-01

279

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

PubMed Central

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

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

2012-01-01

280

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

PubMed

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

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

2013-06-01

281

Viability of the sporocysts of Sarcocystis cruzi after exposure to different temperatures and relative humidities.  

PubMed

The effect of temperature and relative humidity (RH) on the survival of sporocysts of S. cruzi were investigated in vitro. Under all experimental conditions (temperature of 4 degrees C, 37 degrees C, or room temperature; RH of 18%, 75%, or 100%) some sporozoites retained their viability to excyst for at least 90 days. The best conditions for survival were 4 degrees C at 100% RH (more than 240 days) and 37 degrees C at 18% RH (more than 180 days). Sporocysts maintained at room temperature at all humidities had the lowest level of survival. It is concluded that sporocysts of S. cruzi are able to survive in most environments for several months and that the fluctuation of the daily ambient temperature is likely to influence the viability of the sporocysts. PMID:9017863

Savini, G; Robertson, I D; Dunsmore, J D

1996-12-31

282

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

PubMed

To investigate the effect of pyrolysis temperature on properties and nutrient values, biochars were produced from giant reed (Arundo donax L.) at 300-600C and their properties such as elemental and mineral compositions, release of N, P and K, and adsorption of N and P were determined. With increasing temperatures, more N was lost and residual N was transformed into heterocyclic-N, whereas no P and K losses were observed. P was transformed to less soluble minerals, resulting in a reduction in available-P in high-temperature biochars. A pH of?5 favored release of NH(4)(+), PO(4)(3-) and K(+) into water. Low-temperature biochars (? 400C) showed appreciable NH(4)(+) adsorption (2102mgkg(-1)). These results indicate that low-temperatures may be optimal for producing biochar from giant reed to improve the nutrient availability. PMID:23313694

Zheng, Hao; Wang, Zhenyu; Deng, Xia; Zhao, Jian; Luo, Ye; Novak, Jeff; Herbert, Stephen; Xing, Baoshan

2012-12-17

283

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

Microsoft Academic Search

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

Paula M. Periago; Roy Moezelaar

2001-01-01

284

Differences between tomato genotypes in stomatal resistance and specific leaf fresh weight in relation to differences in net photosynthesis under low light intensity and low night temperatures  

Microsoft Academic Search

Differences between tomato genotypes (Lycopersicon esculentumMill.) in stomatal resistance (rs) and specific leaf fresh weight (SLFW) were observed under low light intensity and low night temperature. No relationship between rs and previously published rates of net photosynthesis per dm2 leaf area (PA) was discovered. A negative relationship between SLFW and net photosynthesis per gram fresh weight (PFW) was found but

SIEBREN J. VAN DE DIJK

1985-01-01

285

The pulsation, temperatures and metallicities of Mira and semiregular variables in different stellar systems  

NASA Astrophysics Data System (ADS)

Data on angular diameters and infrared photometry for late-type stars are assembled. It is shown that a consistent T_eff scale can be established, combining results for Mira and non-Mira M-type stars. The log T_eff versus (J-K) relation is much steeper than previously adopted, but is consistent with predictions from model stellar atmospheres. Comparison of the linear diameters of Miras measured in the red spectral region with those measured in the infrared shows that models successfully predict the extension observed in the red, and the combined data provide strong evidence that Miras are pulsating in their first overtone. Data on Miras and semiregular (SR) variables in globular clusters are compared with predictions from stellar evolution and pulsation theory. These data also support a steep log T_eff versus (J-K) relation at low temperatures. The Miras and SR variables in 47 Tuc conform to theoretical expectation if they are undergoing an average mass loss of ~3x10^-7 M_ yr^-1. SR variables in both metal-rich and metal-poor globular clusters are probably pulsating, like the Miras in their first overtone. The general agreement between observations and theory now found suggests that infrared colour-period relations can be used to investigate overall metallicity differences between Miras in different stellar systems, at least at the shorter periods where circumstellar extinction is probably negligible. A comparison of Miras in Galactic globular clusters of known metallicity with those in the LMC and in the SgrI window of the Galactic Bulge indicates that Miras of periods 100 to 300d in the LMC have a mean metallicity log z~-0.6, whilst those in SgrI have log z~-0.2, close to that of K giants in the NGC 6522 Bulge window. No evidence has yet been found for a dependence of the Mira period-luminosity relation on metallicity, and it is pointed out that theory does not at present give a definitive prediction of such an effect. Some stars of special interest are discussed in an appendix.

Feast, M. W.

1996-01-01

286

Effect of pre-heating composite resin on gap formation at three different temperatures  

PubMed Central

Aim: The study aims to evaluate and compare total gap surface area formed after restoration of class II cavities with Filtek Z350 and P60 at room temperature, 37C and 54C. Materials and Methods: Thirty extracted maxillary and mandibular molars were taken and divided into six groups of five teeth each. Standardized class II cavities were made and were restored with Filtek Z350 and P60, both at room temperature, 37C and 54C. Group 1(a) was restored with Filtek Z350 at room temperature, Group 1(b) with Filtek Z350 at 37C and Group 1(c) with Filtek Z350 at 54C. Group 2(a) was restored with P60 at room temperature, Group 2(b) with P60 at 37C and Group 2(c) with P60 at 54C. After storing the samples in distilled water at room temperature for 48 hours, longitudinal sectioning was done to obtain tooth restoration interface. The interfaces were then examined under compound light microscope with digital output and analyzed using Image J analysis software. Results: The results demonstrated better adaptation and less total gap area formation at 54C as compared to room temperature and 37C. Conclusions: Based on the results of this study, it is suggested that use of P60 is better suited for posterior restorations at 54C as compared to Filtek Z350 universal nanohybrid at room temperature.

Choudhary, Nilabh; Kamat, Sharad; Mangala, TM; Thomas, Mohan

2011-01-01

287

Junction temperature in light-emitting diodes assessed by different methods  

NASA Astrophysics Data System (ADS)

The junction temperature of red (AlGaInP), green (GaInN), blue (GaInN), and ultraviolet (GaInN) light-emitting diodes (LEDs) is measured using the temperature coefficients of the diode forward voltage and of the emission-peak energy. The junction temperature increases linearly with DC current as the current is increased from 10 mA to 100 mA. For comparison, the emission-peak-shift method is also used to measure the junction temperature. The emission-peak-shift method is in good agreement with the forward-voltage method. The carrier temperature is measured by the high-energy-slope method, which is found to be much higher than the lattice temperature at the junction. Analysis of the experimental methods reveals that the forward-voltage method is the most sensitive and its accuracy is estimated to be +/- 3C. The peak position of the spectra is influenced by alloy broadening, polarization, and quantum confined Stark effect thereby limiting the accuracy of the emission-peak-shift method to +/-15C. A detailed analysis of the temperature dependence of a tri-chromatic white LED source (consisting of three types of LEDs) is performed. The analysis reveals that the chromaticity point shifts towards the blue, the color-rendering index (CRI) decreases, the color temperature increases, and the luminous efficacy decreases as the junction temperature increases. A high CRI > 80 can be maintained, by adjusting the LED power so that the chromaticity point is conserved.

Chhajed, Sameer; Xi, Yangang; Gessmann, Thomas; Xi, Jing-Qun; Shah, Jay M.; Kim, Jong Kyu; Schubert, E. Fred

2005-03-01

288

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 240C, 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

289

Junction temperature in light-emitting diodes assessed by different methods  

Microsoft Academic Search

The junction temperature of red (AlGaInP), green (GaInN), blue (GaInN), and ultraviolet (GaInN) light-emitting diodes (LEDs) is measured using the temperature coefficients of the diode forward voltage and of the emission-peak energy. The junction temperature increases linearly with DC current as the current is increased from 10 mA to 100 mA. For comparison, the emission-peak-shift method is also used to

Sameer Chhajed; Yangang Xi; Thomas Gessmann; Jing-Qun Xi; Jay M. Shah; Jong Kyu Kim; E. Fred Schubert

2005-01-01

290

Modeling of soil C-dynamics reveals different carbon pool sizes and decomposition rates under varying incubation temperatures  

NASA Astrophysics Data System (ADS)

Soils contain about two thirds of all organic carbon that is stored in terrestrial ecosystems. Annual release of soil carbon (C) to the atmosphere currently exceeds the rate of anthropogenic CO2 emissions by a factor of 10 demonstrating that even small changes in soil C cycling are highly relevant to the global C cycle. Total soil organic matter consists of different C pools with intrinsic turnover rates ranging from less than a year to thousands of years. The objectives of this study were to model soil C-dynamics of a long-term incubation study (336 days, Conant et al. 2008) under two different incubation temperatures (25C and 35C) to obtain i) soil CO2-efflux rates, ii) C-dynamics and iii) temperature sensitivities of C-pools with different turnover times. Respiration rates and soil C-dynamics of three different C-pools were modeled by a 1st order differential equation and data assimilation techniques were used to optimize parameter estimation. All C of the most labile pool (fast turnover time) was respired within the first ten days of the incubation study and pool size as well as absolute decline of the labile C-pool did not differ between temperatures. The intermediate C-pool (intermediate turnover time) was initially 70% larger at the higher temperature but as C was respired at a higher rate the intermediate pool was of equal size at both temperatures after 336 days of incubation. The most recalcitrant C-pool (slow turnover time) declined very slowly over time at both temperatures. However, the contribution of the recalcitrant C-pool to the whole CO2-efflux became more important towards the end of the incubation study. A 10K higher incubation temperature resulted in a larger intermediate C-pool and therefore in twice as much C released. This modeling study shows that higher temperatures increase the amount of easily decomposable C and that C-pool sizes vary at different temperatures. These results are of particular interest for high latitude regions as temperatures are predicted to increase more rapidly in arctic ecosystems and strong effects of higher temperatures on permafrost C are to be expected.

Schdel, C.; Luo, Y.; Schuur, E. A.; Zhou, J.

2011-12-01

291

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 electronphonon coupling theory and coherent weakly damped electronlattice 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

292

Similarities and differences among fluid milk products: traditionally produced, extended shelf life and ultrahigh-temperature processed.  

PubMed

Extended shelf life milk is a relatively new kind of fluid milk, generally manufactured by high-temperature treatment and/or micro-filtration. Being advertised as 'pasteurized milk with an extended shelf life', its flavour, compositional quality and labelling was questioned. Extended shelf life (high-temperature treatment), pasteurized ('traditionally produced') and ultrahigh-temperature milk were, therefore, compared at the beginning and end of shelf life. In triangle tests, panellists distinguished clearly between all products. High-temperature treatment milk's flavour was closer to ultrahigh-temperature and traditionally produced milk in the beginning and at the end of shelf life, respectively. Physicochemically and bacteriologically, all three types could be distinguished. Since 'extended shelf life' comprises many process varieties (each affecting flavour differently), consumer information and appropriate package labelling beyond 'long-lasting' is necessary, e.g. by mentioning the heat treatment applied. PMID:23478913

Grabowski, N T; Ahlfeld, B; Brix, A; Hagemann, A; von Mnchhausen, C; Klein, G

2013-03-11

293

Variation of the structural and optical properties of sol gel TiO2 thin films with different treatment temperatures  

NASA Astrophysics Data System (ADS)

Structural and optical properties of TiO2 thin films prepared using a sol gel process have been examined at different treatment temperatures and for different layer counts. XRD and Raman analyzes of our thin films of TiO2 show that 3 layer films crystallize in anatase and brookite phases, starting from the temperature of annealing 350?C. The grain size calculated from XRD patterns varies from 6.7 to 23.5 nm. Refractive index and porosity are found to vary with treatment temperature and number of dippings. Our films, irrespective of treatment temperature and number of dippings, are transparent in the visible range and opaque in the UV region. To cite this article: R. Mechiakh, R. Bensaha, C. R. Physique 7 (2006).

Mechiakh, Raouf; Bensaha, Rabah

2006-04-01

294

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, Vernica; Gonalves, Ana Lcia; Canhoto, Cristina

2011-11-28

295

Predicting the radiation induced loss in Ge doped optical fibres at different temperatures  

Microsoft Academic Search

A new method is described for predicting radiation induced losses in Ge doped optical fibres at various temperatures. Some physical justification is given for the recovery model employed, and model calculations are compared with experimental results

R. H. West

1999-01-01

296

Effect of psychrotrophic growth on the milk fat fraction at different temperatures of storage.  

PubMed

The use of cooling, without using adequate hygienic practices in primary milk production, allows for the growth of psychrotrophic microorganisms that produce the thermoresistant lipases that give milk a rancid flavor. This study aimed to verify how the variation in temperature influences the lipolytic metabolism of the psychrotrophic organisms. Samples of raw milk were collected and submitted to laboratorial analysis as follows: psychrotrophic bacteria count, lipolytic bacteria count, and free fatty acids dosage. Each sample was divided into 3 aliquots and then incubated at 4, 8, and 12 C, respectively. For each temperature, analyses were repeated after 12, 24, and 48 h of storage. Despite the psychrotrophs growth increase, according to temperature rise, the lipolytic metabolism was not consistent and presented the lower index at 8 C, suggesting an intensification of the proteolytic compensatory activity at this temperature. PMID:23489009

Izidoro, Thiago Braga; Pereira, Juliano Gonalves; Soares, Vanessa Mendona; de Almeida Nogueirapinto, Jos Paes

2013-03-11

297

Spontaneous behavior and body temperature in male Central American Agoutis (Dasyprocta punctata) under different social conditions.  

PubMed

Pair-bonded males did not change rhythmic or phasic components of body temperature and motoric or behavioral activity with changing situations. Non pair-bonded males displayed lowered oscillations of body temperature and decreased motoric activity, those living with a male under established conditions and those living with a female under changed conditions. Non pair-bonded males exhibited distinct changes in amounts of at least one of behavioral elements (scrapemark, scentmark, bury and scrape; indicating elevated sympathetic arousal) with changing situations. Variations in motoric activity and amounts of these behavioral elements were correlated with variations in rhythmic and phasic components of body temperature. For the regulation of arousal the results suggest a balance between behavioral and physiological activity effecting body temperature. The efforts for this regulation depend on the social situation of the animal. PMID:8559788

Korz, V; Hendrichs, H

1995-10-01

298

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

PubMed Central

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

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

2011-01-01

299

Low-temperature production of silicon carbide films of different polytypes  

SciTech Connect

The study is concerned with the effect of temperature on the structure of SiC films formed by deposition of the C and Si ions with the energy 120 eV. On the basis of the X-ray structural studies, it is unambiguously established that the structure of the growing polytype is finely dependent on the substrate temperature. In the temperature range from 1080 deg. C to 1510 deg. C, the sequence of films involving the 21R, 51R, 27R, and 6H polytypes is produced for the first time. The effect of temperature on the silicon-carbon atomic content ratio [Si]/[C] in the deposited films is determined. At optimized parameters of deposition the film structured as the 51R rhombohedral polytype is grown.

Semenov, A. V., E-mail: semenov@isc.kharkov.ua; Puzikov, V. M.; Golubova, E. P.; Baumer, V. N.; Dobrotvorskaya, M. V. [National Academy of Sciences of Ukraine, Institute for Single Crystals (Ukraine)

2009-05-15

300

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

Microsoft Academic Search

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

Maaike Binner; Werner Kloas; Iris Hardewig

2008-01-01

301

Temperature-dependent diffusion coefficient of oil from different sunflower seeds during extraction with hexane  

Microsoft Academic Search

Oil extraction from confectionery, oilseed and wild sunflower seeds with n-hexane was investigated by laboratory tests carried out in a stirred batch extractor at several temperatures (40, 50 and 60C). The rates of extraction were determined from ground sunflower seeds (particle sizes between 0.420 and 1.000mm). The oil yield in the extract increased with higher contact time and extraction temperature

Ethel E. Perez; Amalia A. Carelli; Guillermo H. Crapiste

2011-01-01

302

The Vertical Structure of Temperature in the Tropics: Different Flavors of El Nio  

Microsoft Academic Search

To explore the vertical coherence of the vertical temperature structure in the atmosphere, an analysis is performed of the full three-dimensional spatial structure of the temperature field monthly mean anomalies from the 40-yr ECMWF Re-Analysis (ERA-40) for a core region of the Tropics from 30N to 30S, with results projected globally. The focus is on the first three empirical orthogonal

Kevin E. Trenberth; Lesley Smith

2006-01-01

303

High-temperature wear behaviors of MoSi2 under different loads  

Microsoft Academic Search

MoSi2 was prepared by SHS, pressed at room-temperature and then vacuum sintered at 1 500 ? for 1 h. The tribological properties of MoSi2 against Al2O3 were investigated by using an XP-5 type High Temperature Friction and Wear Tester. Micrographs and phases of the worn surface of MoSi2 were observed by SEM with EDS and X-ray diffraction. The results show

HU Xiao-ping; TAN Wei-cheng; TANG Si-wen; ZHANG Hou-an; HUANG Zhi-chu

304

Temperature sensitivity of respiration differs among forest floor layers in a Pinus resinosa plantation  

Microsoft Academic Search

Decomposer microorganisms contribute to carbon loss from the forest floor as they metabolize organic substances and respire CO2. In temperate and boreal forest ecosystems, the temperature of the forest floor can fluctuate significantly on a day-to-night or day-to-day basis. In order to estimate total respiratory CO2 loss over even relatively short durations, therefore, we need to know the temperature sensitivity

Glenna M. Malcolm; Juan C. Lpez-Gutirrez; Roger T. Koide

2009-01-01

305

EFFECTS OF TEMPERATURE ON CHLOROPHENOL BIODEGRADATION KINETICS IN FLUIDIZED-BED REACTORS WITH DIFFERENT BIOMASS CARRIERS  

Microsoft Academic Search

Groundwater contaminants including 2,4,6-trichlorophenol (TCP), 2,3,4,6-tetrachlorophenol (TeCP), and pentachlorophenol (PCP) were mineralized in three aerobic fluidized-bed reactors (FBRs) employing sand, volcanite, and diatomaceous earth as biomass carriers. The effect of temperature on chlorophenol degradation kinetics was studied in FBR batch tests at temperatures ranging from 4 to 16.5C. TCP and TeCP degradation was modeled using the Michaelis-Menten kinetics. Specific maximum

ESA S. MELIN; KIMMO T. JARVINEN; JAAKKO A. PUHAKKA

1998-01-01

306

Effect of seedling temperature and its duration on development of wheat cultivars differing in vernalization response  

Microsoft Academic Search

The aim of the study was to determine the most effective vernalization temperature for wheat, and establish whether this changes with cultivars and duration. Four cultivars of wheat were used, ranging in response to vernalization from zero (Dollarbird), through moderate response (Oxley, Osprey), to that typical of North American winter wheats (JF87%014). They were exposed to temperature pre-treatments of 12,

H. M. Rawson; M. Zajac; L. D. J. Penrose

1998-01-01

307

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

Microsoft Academic Search

The emissions of modern cars are usually reduced in warm engine conditions by catalysts. Consequently emissions are significantly higher during the cold start, i.e. the warm-up phase of the car. The duration of this period and the emissions produced during it depend on the ambient temperature as well as on the initial temperature of the car's systems.The cold start emissions

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

2005-01-01

308

Comparative analysis of Bacillus weihenstephanensis KBAB4 spores obtained at different temperatures.  

PubMed

The impact of Bacillus weihenstephanensis KBAB4 sporulation temperature history was assessed on spore heat resistance, germination and outgrowth capacity at a temperature range from 7 to 30 degrees C. Sporulation rate and efficiency decreased at low temperature, as cells sporulated at 12, 20 and 30 degrees C with approximately 99% efficiency, whereas at 7 degrees C and 10 degrees C, a maximum 15% of sporulation was reached. Spores formed at 30 degrees C showed the highest wet heat resistance at 95 degrees C, with spores formed at 7 and 10 degrees C displaying only survival of 15min exposure at 70 degrees C, indicating their low level heat resistance. RT-PCR analysis revealed expression of sporulation sigma factor sigG, and germinant receptor operons gerI, gerK, gerL, gerR, gerS, and (plasmid-located) gerS2 to be activated in all sporulation conditions tested. Subsequent germination assays revealed a combination of inosine and L-Alanine to be very efficient, triggering over 99% of the spores to germinate, with spores obtained at 30 degrees C showing the highest germination rates (99%). Notably, spores obtained at 12, 20 and 30 degrees C, germinated at all tested temperatures, showing >70% spore germination even at temperatures as low as 5 degrees C. Less than 5% of spores obtained at 7 and 10 degrees C showed a germination response. Furthermore, spores produced at 12, 20 and 30 degrees C showed similar outgrowth effiency at these temperatures, indicating that low temperature sporulation history does not improve low temperature outgrowth performance. Insights obtained in sporulation and germination behaviour of B. weihenstephanensis KBAB4, in combination with the availability of its genome sequence, may contribute to our understanding of the behaviour of psychrotolerant spoilage and pathogenic Bacilli. PMID:20457473

Garcia, Diego; van der Voort, Menno; Abee, Tjakko

2010-04-10

309

Microbiological and physicochemical changes of naturally black olives fermented at different temperatures and NaCl levels in the brines  

Microsoft Academic Search

The effect of different temperatures (25C, 18C and ambient temperature) and NaCl levels in brines (4%, 6% and 8%) on the microbiological and physicochemical characteristics of naturally black olives of Conservolea variety was studied for up to 190 days. Fermentation was carried out according to the traditional anaerobic method. The initial microflora consisted of Gram-negative bacteria, lactic acid bacteria and

C. C. Tassou; E. Z. Panagou; K. Z. Katsaboxakis

2002-01-01

310

Seasonal and Geographical Differences in Oxygen Consumption with Temperature of Cerastoderma glaucum (Poiret) and a Comparison with C. edule (L.)  

Microsoft Academic Search

A comparison was made of the oxygen consumption over the temperature range 545C ofCerastoderma glaucum(Poiret) with season [summer (S) and winter (W)] and with latitude [Ireland (I), France (F)]. Maximum oxygen consumption rates for IW, IS, FW and FS groups were measured at 1020C, 2030C, 1525C and 2035C, respectively, reflecting the differences in the water temperatures at the time of

J. G. Wilson; B. Elkaim

1997-01-01

311

delta18O values of coexisting brachiopods and fish: Temperature differences and estimates of paleo water depths  

Microsoft Academic Search

To estimate vertical thermal gradients and paleo water depths to marine platforms we present a new method based on the difference between delta18O values of contemporaneous brachiopod carbonate and fish phosphate. Present-day marine fauna of well-known ecology from the surface to the sea floor record isotopic temperatures that agree with measured temperatures. We predict distributions of isotopic data that result

Stphanie Picard; Jean-Pierre Garcia; Christophe Lcuyer; Simon M. F. Sheppard; Henri Cappetta; Christian C. Emig

1998-01-01

312

Influence of Nickel Chloride, Chlorpyrifos, and Imidacloprid in Combination with Different Temperatures on the Embryogenesis of the Zebrafish Danio rerio  

Microsoft Academic Search

Two independent types of stressors, chemicals and high temperatures, which frequently act together in the environment, are\\u000a addressed in this study. Pesticides (imidacloprid and chlorpyrifos) as well as a metal salt (nickel chloride) were investigated\\u000a for their toxic effect at different temperatures. Tests focused on the early development of zebrafish (Danio rerio) embryos and larvae (from fertilization up to 168h

Volker Scheil; Heinz-R. Khler

2009-01-01

313

Molecular analysis of the microbial community structures in water-flooding petroleum reservoirs with different temperatures  

NASA Astrophysics Data System (ADS)

Temperature is one of the most important environmental factors regulating the activity and determining the composition of the microbial community. Analysis of microbial communities from six water-flooding petroleum reservoirs at temperatures from 20 to 63 C by 16S rRNA gene clone libraries indicates the presence of physiologically diverse and temperature-dependent microorganisms in these subterrestrial ecosystems. In high-temperature petroleum reservoirs, most of the archaeal sequences belong to the thermophilic archaea including the genera Thermococcus, Methanothermobacter and Thermoplasmatales, most of the bacterial sequences belong to the phyla Firmicutes, Thermotogae and Thermodesulfobacteria; in low-temperature petroleum reservoirs, most of the archaeal sequences are affiliated with the genera Methanobacterium, Methanoculleus and Methanocalculus, most of the bacterial sequences to the phyla Proteobacteria, Bacteroidetes and Actinobacteria. Canonical correspondence analysis (CCA) revealed that temperature, mineralization, ionic type as well as volatile fatty acids showed correlation with the microbial community structures. These organisms may be adapted to the environmental conditions of these petroleum reservoirs over geologic time by metabolizing buried organic matter from the original deep subsurface environment and became the common inhabitants in subsurface environments.

Wang, L.-Y.; Duan, R.-Y.; Liu, J.-F.; Yang, S.-Z.; Gu, J.-D.; Mu, B.-Z.

2012-04-01

314

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??1C) under controlled conditions (70??10% RH and 12h 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 34C. 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 (34C) and S. cosmioides (19 and 34C). Parasitization of S. eridania eggs was reduced around 18% at 28 and 31C, but dropped more severely at 34C. 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 34C. PMID:23949860

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

2013-05-31

315

Growth and lipid accumulation properties of a freshwater microalga Scenedesmus sp. under different cultivation temperature.  

PubMed

Microalgal lipid is a promising feedstock for biodiesel production. Effect of cultivation temperature on the growth and lipid accumulation properties of a freshwater microalga Scenedesmus sp. LX1 was studied. Scenedesmus sp. LX1 could grow in a wide range of temperature (10?30C), and the growth activation energy was 49.3 kJmol(-1). The optimal temperature to produce microalgal biomass and lipid was 20C, and after 15 days of batch cultivation the productivities of 313.3 g biomass(g P)(-1), 112 g lipid (g P)(-1) and 14.7 g TAGs(g P)(-1) were obtained. The content of polyunsaturated fatty acids decreased with the increase of cultivation temperature. The reactive oxygen species (ROS) levels at 10C and 20C were higher than that under higher temperature. For the first time the cultivation temperature, ROS level, specific growth rate and lipid content per microalgal biomass were correlated together. PMID:21055924

Li, Xin; Hu, Hong-ying; Zhang, Yu-ping

2010-10-20

316

Survival of emu (Dromaius novaehollandiae) sperm preserved at subzero temperatures and different cryoprotectant concentrations.  

PubMed

Three experiments were conducted to optimize the protocol for cryopreservation of emu sperm. Ejaculates were collected from trained male emus then diluted 1:1 and pooled before allocation to treatments and measured for sperm viability, motility, egg membrane penetration ability, membrane stability, and morphology. In Experiment 1, semen was either cooled to 5 C after dilution or diluted with a precooled to 5 C diluent before cooling to 5 C and then frozen at liquid nitrogen vapor temperatures of -140 C and -35 C, with 6% or 9% dimethylacetmide (DMA; a permeating cryoprotectant) and compared for sperm functions. The percentages of viable (42.8 1.1%), normal (39.0 1.3%), and motile (29.8 1.3%) sperm were higher (P < 0.001) for semen frozen at -14 C with 9% DMA (path 2) than for all other combinations. In Experiment 2, we assessed the value of combining DMA and trehalose in the diluent. Combining trehalose (3% to 9%) with DMA (3% to 9%) prior to freezing reduced (P < 0.001) the percentages of postthaw viable (by 4 to 9 1.2%), normal (by 5 to 11 1.3%), and motile sperm (by 13 to 17 2.5%) and the number of holes on the perivitelline layer (by 27 to 29 holes/mm(2)). Postthaw function was best preserved with 9% DMA alone. In experiment 3, we investigated the possibility of increasing DMA concentrations from 6% to 24%. Postthaw sperm viability (52 to 55 2.3%) and morphology (48 to 51 1.7%) were higher (P < 0.05) with 18% and 24% than with 6% to 12% DMA and did not differ between 18% and 24% DMA. However, sperm motility (36 to 43 2.9%) and the number of perivitelline holes were similar (P > 0.05) for 9% to 18% DMA (36 to 55 12%). We concluded that adding 6% to 9% trehalose to the diluent offered no advantage, and that the current best practice for preserving postthaw function in emu sperm is to dilute semen with a precooled to 5 C diluent and use 18% DMA. PMID:22980087

Sood, S; Malecki, I A; Tawang, A; Martin, G B

2012-10-15

317

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 5C, 15C, and 25C 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

2011-09-06

318

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

NASA Astrophysics Data System (ADS)

The plastic deformation of AZ31 magnesium alloy under tension at temperatures of 4.2-295 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 becomes unstable (serrated) at temperatures of 4.2-25 K and more stress jerks occur in the SPD polycrystal than in the SC alloy. The temperature dependence of the yield stress of the alloy is typical of thermally activated unpinning of dislocations from short-range barriers. The ratio of the yield stresses for the SPD and SC alloys at a given temperature is explained by hardening owing to a reduction in grain size and softening owing to a favorable texture. As the grain size is reduced, the rate of strain hardening of the alloy falls off, but its ductility (strain to fracture) increases because of the texture. The strain rate sensitivity of the alloy for T<=100 K is independent of microstructure and is determined by intersections with forest dislocations. As the temperature is raised over 150-295 K the strain rate sensitivity becomes greater owing to activation of dynamic recovery and an enhanced contribution from diffusion processes during plastic deformation of micrograined materials.

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

2010-12-01

319

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

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

320

Effect of Te Inclusions in CdZnTe Crystals at Different Temperatures  

SciTech Connect

CdZnTe crystals often exhibit nonuniformities due to the presence of Te inclusions and dislocations. High concentrations of such defects in these crystals generally entail severe charge-trapping, a major problem in ensuring the device's satisfactory performance. In this study, we employed a high-intensity, high-spatial-resolution synchrotron x-ray beam as the ideal tool to generate charges by focusing it over the large Te inclusions, and then observing the carrier's response at room- and at low-temperatures. A high spatial 5-{micro}m resolution raster scan revealed the fine details of the presence of extended defects, like Te inclusions and dislocations in the CdZnTe crystals. A noticeable change was observed in the efficiency of electron charge collection at low temperature (1 C), but it was hardly altered at room-temperature.

A Hossain; A Bolotnikov; G Camarda; R Gul; K Kim; Y Cui; G Yang; L Xu; R James

2011-12-31

321

Dengue structure differs at the temperatures of its human and mosquito hosts  

PubMed Central

We report on a conformational transition of dengue virus when changing the temperature from that present in its mosquito vectors to that of its human host. Using cryoelectron microscopy, we show that although the virus has a smooth surface, a diameter of ?500 , and little exposed membrane at room temperature, the virions have a bumpy appearance with a diameter of ?550 and some exposed membrane at 37 C. The bumpy structure at 37 C was found to be similar to the previously predicted structure of an intermediate between the smooth mature and fusogenic forms. As humans have a body temperature of 37 C, the bumpy form of the virus would be the form present in humans. Thus, optimal dengue virus vaccines should induce antibodies that preferentially recognize epitopes exposed on the bumpy form of the virus.

Zhang, Xinzheng; Sheng, Ju; Plevka, Pavel; Kuhn, Richard J.; Diamond, Michael S.; Rossmann, Michael G.

2013-01-01

322

Modeling compressive flow behavior of a tungsten heavy alloy at different strain rates and temperatures  

NASA Astrophysics Data System (ADS)

Room temperature stress-strain behavior was obtained for a tungsten heavy alloy at 9000, 0.1 and 0.0001/s strain rates. In addition, at the strain rate of 0.1/s, stress-strain data were obtained at 423 K, 573 K and 732 K. Deformation behavior was modeled using standard and modified Johnson-Cook (JC) and Power-Law (PL) models. In the modified models, the temperature terms are replaced by other functions that are proposed in the literature for these models as well as by Arrhenius type exponential functions. The best representation of the data was obtained from modified models with the exponential temperature functions. The model constants were determined using slow rate stress-strain data and the high rate yield stress. This paper presents the modified JC and PL models and the corresponding model constants for the tungsten heavy alloy.

Weerasooriya, Tusit

1998-07-01

323

Modeling compressive flow behavior of a tungsten heavy alloy at different strain rates and temperatures  

SciTech Connect

Room temperature stress-strain behavior was obtained for a tungsten heavy alloy at 9000, 0.1 and 0.0001/s strain rates. In addition, at the strain rate of 0.1/s, stress-strain data were obtained at 423 deg. K, 573 deg. K and 732 deg. K. Deformation behavior was modeled using standard and modified Johnson-Cook (JC) and Power-Law (PL) models. In the modified models, the temperature terms are replaced by other functions that are proposed in the literature for these models as well as by Arrhenius type exponential functions. The best representation of the data was obtained from modified models with the exponential temperature functions. The model constants were determined using slow rate stress-strain data and the high rate yield stress. This paper presents the modified JC and PL models and the corresponding model constants for the tungsten heavy alloy.

Weerasooriya, Tusit [Material Division, Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005 (United States)

1998-07-10

324

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

NASA Astrophysics Data System (ADS)

The emissions of modern cars are usually reduced in warm engine conditions by catalysts. Consequently emissions are significantly higher during the cold start, i.e. the warm-up phase of the car. The duration of this period and the emissions produced during it depend on the ambient temperature as well as on the initial temperature of the car's systems. The cold start emissions of Euro-3 gasoline cars, Euro-2 diesel cars and old pre-Euro-1 gasoline cars were investigated at cold ambient temperatures. Since the goal was to get real-world emissions, the measurements were done with cars belonging to private owners taken straight from the road with no maintenance. The chassis dynamometer tests were carried out at +23, -7 and -20 C. The test cycle employed is a representative urban ride from a real-world driving behaviour study. Besides the regulated pollutants, methane, benzene and toluene were also measured online by chemical ionisation mass spectrometry.

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

325

[Effects of mixture of 22 kinds of volatile organic compounds on human body at different temperature].  

PubMed

Ten healthy volunteers were exposed to mixture of 22 kinds of volatile organic compounds with concentrations of zero to 10 mg/m3 at the temperature of 18, 22 and 26 C, respectively in an artificial climate room for 60 minutes a day and six days week for two consecutive weeks to study their effects on human bodies. Results showed that quality of indoor air decreased significantly, odor intensity increased, number of the subjects who need more ventilation increased, and irritation to eyes, nose and skin intensified under the mixture concentration of 10 mg/m3 and at temperature of 26 degrees C. No significant changes in psychological tests, tear film stability and cytological studies were found. Room temperature at 26 degrees C has a significant synergetic effects on human health. Therefore, quality of indoor air can not be evaluated only by organic compounds polluted in air, but by meteorological conditions. PMID:9812622

Liu, Z; Molhave, L

1997-03-01

326

Interactive effects of radiation, temperature and salinity on different life history stages of the Arctic kelp Alaria esculenta (Phaeophyceae).  

PubMed

To estimate the potential effects of climate change on polar marine macroalgae, studies on interactive stress effects of multiple climate-related parameters are essential. Interactions of temperature, radiation and salinity on two different life history stages of Alaria esculenta (L.) Greville from the Kongsfjord (Spitsbergen) were investigated for the first time within this study. Adult macroscopic sporophytes of A. esculenta were exposed to different temperatures between 4 and 21 degrees C combined with artificial irradiation conditions [photosynthetically active radiation, ultraviolet (UV) radiation: UV-A/UV-B, first experiment] and with different salinities [34, 28, 20 practical salinity units (p.s.u.) second experiment]. Effects of photosynthetic activity were determined by measuring variable chlorophyll fluorescence of photosystem II. Germination success of young microscopic zoospores of A. esculenta was studied under multifactorial stress. Zoospore suspensions were exposed to the three different salinities and irradiation conditions at four temperatures between 2 and 16 degrees C. Overall, A. esculenta exhibited a highly stage-specific susceptibility towards the experimental treatments. In both experiments using sporophytes, photosynthetic activity showed significant temperature effects and only very few significant radiation and salinity effects. Microscopic stages of A. esculenta were shown to be more sensitive than the adult macroscopic stages, since germination capacity of zoospores was significantly affected by temperature and salinity changes, and interactions of both. These results suggest that multiple stress factors interact synergistically. Temperature seems to be a predominant environmental parameter for the kelp A. esculenta. Overall, A. esculenta proved to be relatively tolerant and adaptable to increasing temperature and UV radiation, as well as to diluted salinities, but only up to a specific limit. PMID:19330357

Fredersdorf, Jana; Mller, Ruth; Becker, Susanne; Wiencke, Christian; Bischof, Kai

2009-03-29

327

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 25C at 31.5 salinity and in incremented salinity at 16.0, 21.0, 26.0, 31.5, 36.0, and 41.0 at 20C, all for 810 days. From\\u000a 10

Baojun Tang; Baozhong Liu; Hongsheng Yang; Jianhai Xiang

2005-01-01

328

Different forcings and their effect on temperature variations in Portugal: volcanic eruptions, anthropogenic aerosols, atmospheric circulation and solar activity  

NASA Astrophysics Data System (ADS)

The aim of this study is to recognize the imprints of different forcings in portuguese climate variations using a better-quality temperature time series. Obtained results confirm the influence of the volcanic eruptions as well as solar and geomagnetic activities variations on the climate changes in this Iberian region. It is also shown how the character of the response depends on the type of studied temperature parameter, on the time period and on the season. Series of monthly minimum (Tmin) and maximum (Tmax) temperatures measured in the three meteorological stations of Lisbon, Coimbra and Porto over more than 100 years were treated. Non-climatic breaks were identified and the series were homogenized. These series, together with monthly series of mean temperature (meanT) and temperature range (DTR) derived from them, were subjected to Principal Component Analysis to extract the leading principal components. The first principal component (PC1) accounts for as much of the variability in the original data as possible. In our case the PC1 series for Tmin, Tmax, meanT and DTR accounts for 78.8-96.1% of the variability depending on different temperature parameters and months. The PC1s were used to study the effect of different forcings on variations of the portuguese climate during the period from 1888 to 2001. We focused our attention on four types of forcings: volcanic eruptions, anthropogenic greenhouse gases, global atmospheric circulation and solar and geomagnetic activity variations. To parameterize these forcings we used the following data: different ice core data sets which give us the information about volcanic activity and greenhouse gases variability; NAO index as the longest available data set to describe the atmospheric circulation in the studied region; sunspot number, cosmic ray flux and aa-index series to describe the variability of solar and geomagnetic activities. Different statistical tests as correlation analysis, multiple regression analysis and superposed epoch analysis were used to identify the response of the temperature parameters to the forcings. The advantage of the new temperature series in use is their length. It allows to study separately the climatic variations during two periods of large volcanic eruptions (from 1888 to 1912 and from 1963 to 2001) and during a period of small eruptions (from 1912 to 1962). The analysis we made shows, in particular, that during the large eruptions periods Tmin, Tmax and meanT have often lower values and correlate better with atmospheric aerosol concentration than with solar and geomagnetic parameters. However, the variations of DTR are ambiguous and need additional investigation. Also, the length of the temperature series allows us to compare the significance of different forcings during pre-industrial and industrial periods.

Morozova, A. L.; Pais, M. A.

2012-04-01

329

Feed intake, growth rate and body composition of juvenile Baltic salmon exposed to different constant temperatures  

Microsoft Academic Search

Feed intake, specific growth rate and changes in body composition of age 1+ and 2+ Baltic salmon, Salmo salar L, were studied for fish held under constant temperature conditions. The 1+ fish (60 g) were reared for 6 weeks at 11, 15, 17, 19 or 23 C and 2+ fish (250 g) were held at 15 C. Feed intake of

J. Koskela; J. Pirhonen; M. Jobling

1997-01-01

330

PHOSPHOROSCOPE DESIGNED FOR THE STUDY OF LUMINESCENT DECAYS AT DIFFERENT TEMPERATURES  

Microsoft Academic Search

In order to study luminescent decay in a large temperature interval ; (from --190 to 400 deg C), a photoelectric phosphoroscope was constructed with an ; exciting radiation source arranged on an optical layer, a removable metallic ; Dewar flask, a photomultiplier, and a modulator for the PM electron beam. ; Schematic diagrams of the apparatus are given. The conditions

J. Janin; R. Dunand

1963-01-01

331

TEMPERATURE QUOTIENTS OF AMMONIA EMISSION OF DIFFERENT NITROGEN SOURCES APPLIED TO FOUR AGRICULTURAL SOILS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Emitted ammonia (NH3) is the primary gaseous form of nitrogen (N) loss from N sources applied to soils, which contain instant or transformable ammonium (NH4+). However, our knowledge of NH3 volatilization in relation to temperature is incomplete. This research was conducted using Biscayne Marl Soil ...

332

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

SciTech Connect

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

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

2010-05-01

333

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

334

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

335

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

Microsoft Academic Search

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

HARRY C. DAVIS; ANTHONY CALABRESE

336

Use of protein microarray to identify gene expression changes of Yersinia pestis at different temperatures.  

PubMed

Yersinia pestis is a bacterium that is transmitted between fleas, which have a body temperature of 26 C, and mammalian hosts, which have a body temperature of 37 C. To adapt to the temperature shift, phenotype variations, including virulence, occur. In this study, an antigen microarray including 218 proteins of Y. pestis was used to evaluate antibody responses in a pooled plague serum that was unadsorbed, adsorbed by Y. pestis cultivated at 26 C, or adsorbed by Y. pestis cultivated at 26 and 37 C to identify protein expression changes during the temperature shift. We identified 12 proteins as being expressed at 37 C but not at 26 C, or expressed at significantly higher levels at 37 C than at 26 C. The antibodies against 7 proteins in the serum adsorbed by Y. pestis cultivated at 26 and 37 C remained positive, suggesting that they were not expressed on the surface of Y. pestis in LB broth in vitro or specifically expressed in vivo. This study proved that protein microarray and antibody profiling comprise a promising technique for monitoring gene expression at the protein level and for better understanding pathogenicity, to find new vaccine targets against plague. PMID:21491980

Li, Bei; Tan, Yafang; Guo, Jingyu; Cui, Baizhong; Wang, Zuyun; Wang, Hu; Zhou, Lei; Guo, Zhaobiao; Zhu, Ziwen; Du, Zongmin; Yang, Ruifu

2011-04-01

337

Microbial decomposition of skeletal muscle tissue ( Ovis aries) in a sandy loam soil at different temperatures  

Microsoft Academic Search

A laboratory experiment was conducted to determine the effect of temperature (2, 12, 22C) on the rate of aerobic decomposition of skeletal muscle tissue (Ovis aries) in a sandy loam soil incubated for a period of 42 days. Measurements of decomposition processes included skeletal muscle tissue mass loss, carbon dioxide (CO2) evolution, microbial biomass, soil pH, skeletal muscle tissue carbon

David O. Carter; Mark Tibbett

2006-01-01

338

Predator-released compounds, ambient temperature and competitive exclusion among differently sized Daphnia species  

Microsoft Academic Search

1. We studied the effects of fish water and temperature on mechanisms of competitive exclusion among two Daphnia species in flow-through microcosms. The large-bodied D. pulicaria outcompeted the medium sized D. galeata hyalina in fish water, but not in the control treatment. Daphnia galeata hyalina was competitively displaced 36 days earlier at 18 C than at 12 C.

JACOBUS VIJVERBERG; MATTHIJS VOS

2006-01-01

339

Vulnerability of lodging risk to elevated CO2 and increased soil temperature differs between rice cultivars  

Technology Transfer Automated Retrieval System (TEKTRAN)

Anthropogenic increases in atmospheric carbon dioxide concentration, [CO2], and subsequent increases in surface temperatures, are likely to impact the growth and yield of cereal crops. One means for yield reduction is for climate parameters to increase the occurrence of lodging. Using an in situ f...

340

Temperature and precipitation changes in different environments in the arid region of northwest China  

NASA Astrophysics Data System (ADS)

Using 51 meteorological stations in the arid region of northwest China in the mountain, oasis, and the desert areas obtained from 1960 to 2010, this paper conducted a comparative analysis for detecting temperature and precipitation changes in the diverse environments. In recent 50 years, temperature has increased at 0.325, 0.339, and 0.360 C per decade in the mountain, oasis, and the desert areas, respectively; and also, precipitation has increased at 10.15, 6.29, and 0.87 mm per decade, but in which the increasing trend of precipitation in desert area was not significant. Before the 1990s, the increase in temperature was the fastest in the desert area, up to 0.214 C per decade, but was the slowest in the mountain area, only 0.103 C per decade. The temperature rising was faster after the 1990s, 0.606 C per decade, in the oasis area was fastest, but was the slowest in the desert region with 0.402 C per decade. The precipitation in each area was stable from 1960 to 1986, but an increase in the oasis and mountain area was larger from 1987 to 2010.

Li, Baofu; Chen, Yaning; Shi, Xun; Chen, Zhongsheng; Li, Weihong

2013-05-01

341

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

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

342

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

Microsoft Academic Search

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

Yaxin Su; Bingtao Zhao

2010-01-01

343

Crystallization of Polymers Studied by Temperature Modulated Calorimetric Measurements at Different Frequencies  

Microsoft Academic Search

Quasi-isothermal temperature modulated DSC (TMDSC) were performed during crystallization to determine heat capacity as function of time and frequency. Non-reversible and reversible phenomena in the crystallization region of polymers were distinguished. TMDSC yields new information about the dynamics of local processes at the surface of polymer crystals, like reversible melting. The fraction of material involved in reversible melting, which is

C. Schick; M. Merzlyakov; A. Minakov; A. Wurm

2000-01-01

344

RESPONSES OF LARGEMOUTH BASS FROM DIFFERENT LATITUDES TO ELEVATED WATER TEMPERATURES  

EPA Science Inventory

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

345

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 100C, and tests on normally consolidated and overconsolidated specimens with OCR = 2. The tests included isotropic consolidation, undrained triaxial compression with pore water pressure measurement,

Naoto Tanaka; James Graham; Thomas Crilly

1997-01-01

346

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

Microsoft Academic Search

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

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

2003-01-01

347

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

NASA Astrophysics Data System (ADS)

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.

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

2012-06-01

348

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 35C there was a negative effect on biomass

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

2007-01-01

349

Clearance of yellow pigments lutein and zeathanxin in channel catfish reared at different water temperatures  

Technology Transfer Automated Retrieval System (TEKTRAN)

A study was conducted to determine clearance time of yellow pigments lutein and zeaxanthin in channel catfish at various temperatures. Fish of initial weight of 13.4 g were stocked into flow-through aquaria and fed once daily with a yellow pigment enhanced diet for 11 weeks when the yellow color be...

350

Modeling Compressive Flow Behavior of a Tungsten Heavy Alloy at Different Strain Rates and Temperatures  

NASA Astrophysics Data System (ADS)

Room temperature stress-strain behavior was obtained as a function of strain rate for a tungsten heavy alloy at 9000, 0.1 and 0.0001/s strain rates. Stress-strain data were also obtained at temperatures of 423, 573 and 732 degree Kelvin, at a strain rate of 0.1/s. Deformation behavior was modeled using standard and modified Johnson-Cook (JC) and Power-Law (PL) models. In the modified models, the temperature terms are replaced by other functions that are proposed in the literature for these models as well as by Arrhenius type exponential functions. The best representation of the data was obtained from modified models with the exponential temperature functions. The model constants were determined using slow rate stress-strain data and the high rate yield stress. This paper presents the modified JC and PL models and the corresponding model constants for the tungsten heavy alloy. The ability of these models to predict the adiabatic high strain rate behavior is examined in this paper.

Weerasooriya, Tusit

1997-07-01

351

Newborn skin temperature two days postpartum during breastfeeding related to different labour ward practices  

Microsoft Academic Search

AimTo investigate (1) the skin temperature pattern in newborns two days after birth in connection to breastfeeding and to examine (2) if the administration of epidural analgesia (EDA) and oxytocin (OT) infusion during labour influences this parameter at this point of time.

W. Jonas; I. Wiklund; E. Nissen; A.-B. Ransj-Arvidson; K. Uvns-Moberg

2007-01-01

352

Effects of Antioxidants and Dehanding Methods under Different Temperature Levels on Control of Banana Crown Browning  

Microsoft Academic Search

Two experiments were conducted at the National Institute for the Promotion of Horticultural Exports, University of Gezira, Sudan, during the period from 2000 to 2001 to investigate the effects of dehanding methods and antioxidants under two temperature levels on the control of banana crown browning. Dehanding methods included separation of hands under water or in air and cutting the hands

Elawam S. Ismail; Mohamed E. ElKashif; Osman M. Elamin; Abas Elsir

353

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

Microsoft Academic Search

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

Jeffrey M. Novak; Isabel Lima; C NMR

354

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 33C), and a controlled temperature (33C). To this end, an overall energy balance (OEB) and life cycle assessment (LCA), both based on real process data, were carried out. Four factors were considered in this study: (1) energy consumption during wastewater treatment; (2) energy recovered from biogas capture; (3) potential recovery of nutrients from the final effluent; and (4) sludge disposal. The OEB and LCA showed SAnMBR to be a promising technology for treating urban wastewater at ambient temperature (OEB=0.19kWhm(-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

2013-09-20

355

[The relationship between soil respiration and the temperature at different soil depths in subalpine coniferous forest of western Sichuan Province].  

PubMed

By using closed chamber IRGA technique, a continuous measurement of soil respiration rate was conducted in the subalpine natural coniferous forest mainly composed of Abies faxoniana in the eastern edge of Qinghai-Tibet Plateau, with the temperature at different soil depths (0, 5, 10, 15 and 20 cm) measured simultaneously. Base on the measurements, the quantitative relationships between soil respiration rate and the temperature at different soil depths were explored, and the results showed that the soil respiration rate in the forest had remarkable diurnal and seasonal changes, being the highest at 12:00-14:00 and in August, and the lowest at 8:00-10:00 and in November, which were accorded with the dynamics of soil temperature. Soil respiration rate had a significant exponential correlation with the temperature at different soil depths, and the highest correlation occurred at the soil depth of 15 cm (R2 =0.82, P <0.01). The Q10, value at soil depths of 0, 5, 10, 15 and 20 cm was 2. 36, 4.75, 4.90, 6.27 and 5.46, respectively, indicating that the Q10 value of soil respiration tended to be larger at high elevation with low temperature. PMID:17763719

Chen, Bao-yu; Liu, Shi-rong; Ge, Jian-ping; Wang, Hui; Chang, Jian-guo; Sun, Tian-tian; Ma, Jiang-ming; Shi, Gong-jian

2007-06-01

356

Effect of temperature difference between manikin and wet fabric skin surfaces on clothing evaporative resistance: how much error is there?  

NASA Astrophysics Data System (ADS)

Clothing evaporative resistance is one of the inherent factors that impede heat exchange by sweating evaporation. It is widely used as a basic input in physiological heat strain models. Previous studies showed a large variability in clothing evaporative resistance both at intra-laboratory and inter-laboratory testing. The errors in evaporative resistance may cause severe problems in the determination of heat stress level of the wearers. In this paper, the effect of temperature difference between the manikin nude surface and wet textile skin surface on clothing evaporative resistance was investigated by both theoretical analysis and thermal manikin measurements. It was found that the temperature difference between the skin surface and the manikin nude surface could lead to an error of up to 35.9% in evaporative resistance of the boundary air layer. Similarly, this temperature difference could also introduce an error of up to 23.7% in the real clothing total evaporative resistance ( R et_real < 0.1287 kPa m2/W). Finally, it is evident that one major error in the calculation of evaporative resistance comes from the use of the manikin surface temperature instead of the wet textile fabric skin temperature.

Wang, Faming; Kuklane, Kalev; Gao, Chuansi; Holmr, Ingvar

2012-01-01

357

Clostridium tyrobutyricum strains show wide variation in growth at different NaCl, pH, and temperature conditions.  

PubMed

Outgrowth from Clostridium tyrobutyricum spores in milk can lead to butyric acid fermentation in cheeses, causing spoilage and economical loss to the dairy industry. The aim of this study was to investigate the growth of 10 C. tyrobutyricum strains at different NaCl, pH, and temperature conditions. Up to 7.5-fold differences among the maximum growth rates of different strains in the presence of 2.0% NaCl were observed. Five of 10 strains were able to grow in the presence of 3.0% NaCl, while a NaCl concentration of 3.5% was completely inhibitory to all strains. Seven of 10 strains were able to grow at pH 5.0, and up to 4- and 12.5-fold differences were observed among the maximum growth rates of different strains at pH 5.5 and 7.5, respectively. The maximum growth temperatures varied from 40.2 to 43.3C. The temperature of 10C inhibited the growth of all strains, while 8 of 10 strains grew at 12 and 15C. Despite showing no growth, all strains were able to survive at 10C. In conclusion, wide variation was observed among different C. tyrobutyricum strains in their ability to grow at different stressful conditions. Understanding the physiological diversity among the strains is important when designing food control measures and predictive models for the growth of spoilage organisms in cheese. PMID:23043827

Ruusunen, Marjo; Surakka, Anu; Korkeala, Hannu; Lindstrm, Miia

2012-10-01

358

Development and survival of embryos of lake herring at different constant oxygen concentrations and temperatures  

USGS Publications Warehouse

Eggs of lake herring (Coregonus artedii) were incubated in a continuous-flow system at four constant water temperatures (2-8A?C) and five dissolved oxygen (DO) concentrations (1-12 mg/L). In comparison with incubation time at 12 mg/L DO, time to median hatch was significantly longer (P < 0.05) at 2 mg/L at 6A?C (no hatch at 1 mg/L), at 3 mg/L or less at 4A?C, and at 4 mg/L or less at 2A?C. The time between hatching of the first and last eggs varied inversely with temperature. Mean total lengths of newly hatched fry were significantly shortened (P < 0.05) at 1 and 2 mg/L DO. At 6 and 8A?C , percent survival through hatching was greater than at 2 and 4A?C at DO of 4 mg/L or more, but fell to zero at 1 mg/L. The percentage of normal fry produced decreased noticeably below 4 mg/L DO. The optimum temperature for highest percentage survival of normal fry decreased directly with the level of dissolved oxygen. The temperatures at which the highest percentages of normal fry hatched from eggs incubated at DO concentrations of 4 or 8, 2, and 1 mg/L, were 6, 4, and 2A?C, respectively - indicating a decreasing DO demand by embryos incubated at the lower temperatures. Our findings supported a previously published hypothesis that DO concentrations below 4 mg/L can be adverse to survival and development of coregonid embryos in nature.

Brooke, L. T.; Colby, P. J.

1980-01-01

359

Effects of Different Fabrication Techniques on the Yttrium-Barium-Copper Oxide High Temperature Superconductor.  

National Technical Information Service (NTIS)

This study examines how several different parameters were changed in the yttrium-barium-copper oxide superconductor when the fabrication techniques were altered by using different barium precursors, including barium peroxide and barium carbonate; sinterin...

P. A. Rhea

1988-01-01

360

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

361

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

Microsoft Academic Search

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

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

2008-01-01

362

The dependence on ionic strength of protonation constants of carboxylic acids in aqueous tetraethylammonium iodide solution, at different temperatures  

Microsoft Academic Search

The data regarding the protonation of 22-(mono-, di-,, penta-) carboxylic acids in aqueous tetraethylammonium iodide at different ionic strengths 0temperatures 5?T?55C, have been re-examined. Dependence on ionic strength was taken into account by using different models (DebyeHckel type, Pitzer and Bromley equations). The parameters obtained for these equations were found to be a simple function of

Claudia Foti; Silvio Sammartano; Graziella Signorino

1998-01-01

363

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

Microsoft Academic Search

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

Mahmood Naderi

2008-01-01

364

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

Microsoft Academic Search

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

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

365

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

National Technical Information Service (NTIS)

The primary purpose of this project was to evaluate and improve models for the bulk-skin temperature difference to the point where they could accurately and reliably apply under a wide variety of environmental conditions. To accomplish this goal, work was...

W. J. Emery S. L. Castro

2002-01-01

366

Thermoregulatory effect of intracerebral injections of neuropeptide Y in rats at different environmental temperatures.  

PubMed

1. In order to characterize the thermoregulatory actions of brain neuropeptide Y (NPY), the effects of intra-third ventricular (I3V) injection of NPY on temperatures of colon (Tco), brown adipose tissue (TBAT) and tail skin (Ts) were observed at ambient temperatures (Ta) of 19 and 8 degrees C. 2. The injection of NPY in a dose of 8 mcg/100 g body wt evoked a fall of Tco by about 2 degrees C in both neutral and cold environments. NPY (4 and 8 mcg/100 g body wt) induced dose-dependent Tco falls in rats at thermoneutral environment. The thermolytic reactions induced by I3V administration of NPY were associated with a fall in TBAT but no changes in Is were observed. 3. The results suggest that NPY may mediate hypothermic response in neutral and cold environments mainly by its effects on the brown adipose tissues in the rat. PMID:8026718

Szreder, Z; Hori, T; Kaizuka, Y

1994-01-01

367

Evaluation of the Validity of Crystallization Temperature Measurements Using Thermography with Different Sample Configurations  

NASA Astrophysics Data System (ADS)

We describe further progress of a previously reported novel crystallization temperature (Tx) measurement method applicable for small sample sizes. The method uses thermography and detects Tx as a change in emissivity of thin film amorphous alloy samples. We applied this method to various sample configurations of Pd-Cu-Si thin film metallic glass (TFMG). The validity of the detected Tx was determined by electrical resistivity monitoring and differential scanning calorimetry (DSC). Crystallization temperature can be detected in all sample configurations; however, it was found that the magnitude of the detected change of emissivity at Tx depended on the sample configuration. This emissivity change was clear in the absence of a higher emissivity material. The results suggest that this method can achieve high-throughput characterization of Tx for integrated small samples such as in a thin film library.

Yuko Aono,; Junpei Sakurai,; Akira Shimokohbe,; Seiichi Hata,

2010-07-01

368

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 35C at normoxic, hypoxic (= 40 torr PO2), and extreme hypoxic (= 25 torr PO2) conditions. Rates generally increased with increases in temperature (overall Q10 = 2.11 at normoxia). Significant depressions (PO2) at 25 and 30C, but not at 35C. Resting

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

1985-01-01

369

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 2.510(-5) kgm(-1)s(-1) for the temperature interval. The calculated (Tenti S6) line shapes are consistent with experimental data at the level of 2%, meeting the requirements for the future RB-scattering LIDAR missions in the Earth's atmosphere. However, the systematic 2% deviation may imply that the model has a limit to describe the finest details of RB scattering in air. Finally, it is demonstrated that the RB scattering data in combination with the Tenti S6 model can be used to retrieve the actual gas temperatures. PMID:23842262

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

2013-07-01

370

Chemical study of extracted rockrose and of chars and activated carbons prepared at different temperatures  

Microsoft Academic Search

This paper discusses the chemical composition and chemical structure of rockrose (Cistus ladaniferus L.) extracted into petroleum ether and resulting chars as well as activated carbons. The isothermal temperature of carbonization of extracted rockrose (Jex) in N2 ranged between 600 and 1000C. The char (CJex-600) employed in the preparation of activated carbons was prepared by treatment of Jex at 30600C.

J Pastor-Villegas; V Gmez-Serrano; C. J Durn-Valle; F. J Higes-Rolando

1999-01-01

371

Grain growth in electric sheet during high-temperature annealing in different atmospheres  

Microsoft Academic Search

1.The atmosphere of high-temperature annealing has a substantial effect on the growth rate of secondary recrystallized grains.2.The oxygen concentration is the determining factor in the effect of the annealing atmosphere on the process of texture formation in electric sheet.3.The maximum perfection of the edge texture in electric sheet is achieved by annealing in hydrogen with a dew point of -80C.

V. V. Sosnin; I. G. Yastrebov

1974-01-01

372

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

Microsoft Academic Search

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

S Lahsasni; M Kouhila; M Mahrouz; M Fliyou

2003-01-01

373

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

Microsoft Academic Search

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

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

374

Growth and development of Hydromedion sparsutum (Mller) (Coleoptera, Perimylopidae) from South Georgia at different temperatures  

Microsoft Academic Search

Adaptation of Hydromedion sparsutum (Coleoptera, Perimylopidae) to the cool, moderate climate of South Georgia Island was studied under lab conditions. Because there are no native vertebrate herbivores on the island, the Perimylopidae as primary destruents occupy an important role in the ecosystem of S. G. H. sparsutum was reared at constant temperatures of 4, 7.5, 10, 12.5 and 14C. Constant

S. Meyer-Arndt

1984-01-01

375

Differential stability of TATA box binding proteins from archaea with different optimal growth temperatures  

NASA Astrophysics Data System (ADS)

The TATA box binding protein (TBP) is involved in promoter recognition, the first step of transcription initiation. TBP is universally conserved and essential in archaea and eukaryotes. In archaea, TBPs have to be stable and to function in species that cover an extremely wide range of optimal growth temperatures (OGTs), from below 0 C to more than 100 C. Thus, the archaeal TBP family is ideally suited to study the evolutionary adaptation of proteins to an extremely wide range of temperatures. We characterized the thermostability of one mesophilic and one thermophilic TBP by infrared spectroscopy. Transition temperatures ( Tms) of thermal unfolding have been determined using TBPs from Methanosarcina mazei (OGT 37 C) and from Methanothermobacter thermautotrophicus (OGT 65 C). Furthermore, the influence of protein and salt concentration on thermostability has been characterized. Together with previous studies, our results reveal that the Tms of archaeal TBPs are closely correlated with the OGTs of the respective species. Noteworthy, this is also true for the TBP from M. mazei representing the first characterized TBP from a mesophilic archaeon. In contrast, the only characterized eukaryotic TBP of the mesophilic plant Arabidopsis thaliana has a Tm more than 40 C above the OGT.

Kopitz, Annette; Soppa, Jrg; Krejtschi, Carsten; Hauser, Karin

2009-09-01

376

Growth behavior of titanium dioxide thin films at different precursor temperatures  

PubMed Central

The hydrophilic TiO2 films were successfully deposited on slide glass substrates using titanium tetraisopropoxide as a single precursor without carriers or bubbling gases by a metal-organic chemical vapor deposition method. The TiO2 films were employed by scanning electron microscopy, Fourier transform infrared spectrometry, UV-Visible [UV-Vis] spectroscopy, X-ray diffraction, contact angle measurement, and atomic force microscopy. The temperature of the substrate was 500C, and the temperatures of the precursor were kept at 75C (sample A) and 60C (sample B) during the TiO2 film growth. The TiO2 films were characterized by contact angle measurement and UV-Vis spectroscopy. Sample B has a very low contact angle of almost zero due to a superhydrophilic TiO2 surface, and transmittance is 76.85% at the range of 400 to 700 nm, so this condition is very optimal for hydrophilic TiO2 film deposition. However, when the temperature of the precursor is lower than 50C or higher than 75C, TiO2 could not be deposited on the substrate and a cloudy TiO2 film was formed due to the increase of surface roughness, respectively.

2012-01-01

377

Differences in human birth weight and corollary attributes as a result of temperature regime.  

PubMed

Abstract Background: Birth weight (BW) is an important attribute of human populations affecting post-natal mortality and later life morbidity, such as diabetes and reduced cognitive skills. BW is influenced by many factors, whereof temperature regime represents an important factor. Methods: By applying a generalized linear model, the impact of temperatures, altitude, nutrition, age at motherhood and other potential causes for BW variation were evaluated in more than 60 countries worldwide. National IQ scores were analysed in the same model. Results: This study identified a model explaining 2/3 of the global variation in BW. This model suggests that BW will decrease by 0.44-1.05% per C increase in temperature under projected climate change. National IQ scores revealed a close relationship between IQ and BW. However, the model of IQ variation did not appear robust when challenged with variables not correlated with BW. Conclusion: Climate change will affect BW, but it cannot be assumed that other human attributes such as IQ will change because (i) BW, in mainly being sensitive to intra-uterine conditions in the last quarter of pregnancy, is a poor predictor of intra-uterine conditions as such and (ii) developmental plasticity may require post-natal stimuli to unfold. PMID:23803160

Jensen, Per M; Srensen, Marten

2013-06-27

378

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

PubMed

The hydrophilic TiO2 films were successfully deposited on slide glass substrates using titanium tetraisopropoxide as a single precursor without carriers or bubbling gases by a metal-organic chemical vapor deposition method. The TiO2 films were employed by scanning electron microscopy, Fourier transform infrared spectrometry, UV-Visible [UV-Vis] spectroscopy, X-ray diffraction, contact angle measurement, and atomic force microscopy. The temperature of the substrate was 500C, and the temperatures of the precursor were kept at 75C (sample A) and 60C (sample B) during the TiO2 film growth. The TiO2 films were characterized by contact angle measurement and UV-Vis spectroscopy. Sample B has a very low contact angle of almost zero due to a superhydrophilic TiO2 surface, and transmittance is 76.85% at the range of 400 to 700 nm, so this condition is very optimal for hydrophilic TiO2 film deposition. However, when the temperature of the precursor is lower than 50C or higher than 75C, TiO2 could not be deposited on the substrate and a cloudy TiO2 film was formed due to the increase of surface roughness, respectively. PMID:22280933

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

2012-01-26

379

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

NASA Astrophysics Data System (ADS)

The solubility of cyclooctasulfur in water and sea water at various temperatures in the range between 4 and 80 C was determined. Cyclooctasulfur in equilibrium with rhombic sulfur reacted with hot acidic aqueous potassium cyanide to form thiocyanate anion which was measured by anion chromatography. Sulfur solubility in pure water was found to increase with temperature by more than 78 times: from 6.1 nM S 8 at 4 C to 478 nM S 8 at 80 C. The following thermodynamic values for solubilisation of S 8 in water were calculated from the experimental data: K = 3.01 1.04 10 -8, ? G r = 42.93 0.73 kJ mol -1, ? H r = 47.4 3.6 kJmol -1, ? S r = 15.0 11.7 J mol -1 K -1). Solubility of cyclooctasulfur in sea water was found to be 61 13% of the solubility in pure water regardless of the temperature.

Kamyshny, A., Jr.

2009-10-01

380

Changing trends of daily temperature extremes with different intensities in China  

NASA Astrophysics Data System (ADS)

By comparing two sets of quality-controlled daily temperature observation data with and without the inhomogeneity test and adjustment from 654 stations in China during 1956-2004 and 1956-2010, impacts of inhomogeneity on changing trends of four percentile temperature extreme indices, including occurrences of cold days, cold nights, warm days, and warm nights with varying intensities, were discussed. It is found that the inhomogeneity affected the long-term trends averaged over extensive regions limitedly. In order to minimize the inhomogeneity impact, the 83 stations identified with obvious inhomogeneity impacts were removed, and an updated analysis of changing trends of the four temperature extreme indices with varying intensities during 1956-2010 was conducted. The results show that annual occurrences of both cold nights and cold days decreased greatly while those of warm nights and warm days increased significantly during the recent 20 years. The more extreme the event is, the greater the magnitude of changing trends for the temperature extreme index is. An obvious increasing trend was observed in annual occurrences of cold days and cold nights in the recent four years. The magnitude of changing trends of warm extreme indices was greater than that of cold extreme indices, and it was greater in northern China than in southern China. Trends for summer occurrence of cold days were not significant. Decreasing trends of occurrences of both cold nights and cold days were the greatest in December, January, and February (DJF) but the least in June, July, and August (JJA), while increasing trends of warm nights were the greatest in JJA. Cold nights significantly decreased from 1956 to 1990, and then the decreasing trend considerably weakened. The decreasing trend also showed an obvious slowdown in recent years for occurrence of cold days. However, increasing trends of warm nights and warm days both have been accelerated continuously since the recent decades. Further analysis presents that the evolution of the trends for occurrences of the four temperature extreme indices was dominated by the changes in northern China.

Wang, Zunya; Ding, Yihui; Zhang, Qiang; Song, Yafang

2012-08-01

381

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

PubMed

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

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

2013-04-01

382

Different temperature dependence of excitonic and defect-related photoluminescence spectra in ZnS nanobelts and nanowires  

NASA Astrophysics Data System (ADS)

In this paper, both excitonic and defect-related information of ZnS nanobelts and nanowires have been investigated by a temperature-dependent photoluminescence (PL) spectrum. PL spectra of ZnS nanobelts and nanowires differ significantly in the ultraviolet (UV) and visible emission regions. In UV emission regions, due to high-quality crystals, free exciton B (FXB), free exciton A (FXA), FXA-one longitudinal optical (LO) phonon replica are observed in ZnS nanobelts, as well as free-to-bound (e, A) with its one LO phonon replica, while neutral-donor bound exciton (Do, X) and free-to-bound (e, A) are observed in ZnS nanowires at 10 K. The peak and relative intensity of the FX and (Do, X) versus temperature follow well with conventional empirical relations. In the visible emission regions, weak donor-acceptor pair (DAP) and self-activated (SA) emission from ZnS nanowires are commonly observed, but the Y band emission is only observed at 10 K in ZnS nanobelts. The Y band emission disappears at some temperature lower than 50 K. The peak position and full width at half maximum of DAP and SA emission bands display different temperature dependences. Detailed study on temperature-dependent PL spectra of ZnS nanobelts and nanowires provides crucial information on the nature of the electronic states and recombination mechanisms in these nanostructures.

Wang, H. Y.; Wang, C. R.; Xu, J.; Liu, X.; Xu, X. F.; Xing, H. Z.; Zhao, L. J.; Chen, X. S.

2012-03-01

383

Asymmetry of the surface air temperature response on climatological heat imbalances due to differences in the planetary boundary layer height  

NASA Astrophysics Data System (ADS)

There are a number of asymmetries in the surface air temperature response to forcing including polar amplification and changes to the diurnal and seasonal temperature ranges. We propose that such spatial-temporal signatures of climate change can, in part, be explained from differences in effective heat capacity of the atmosphere - defined by the depth of the planetary boundary-layer. We have demonstrated that predictions arising from this hypothesis are simultaneously satisfied through the analysis of temperature records from daily to inter-decadal timescales using observational and reanalysis datasets. This mechanism can help explain why we see the largest temperature trends in the winter months (0.42 K/decade in winter compared to 0.18 K/decade in summer) and why diurnal temperature range decreases in a warming world, having decreased by ~0.4 K since 1950. The unevenness in effective heat capacity of the atmosphere also underlies some of the global differences in natural variability, which explains the difficulty in identifying the signature of anthropogenic global warming against the background of natural variability, even in places with rapid warming such as the arctic.

Davy, Richard; Esau, Igor; Outten, Stephen

2013-04-01

384

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

385

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

NASA Astrophysics Data System (ADS)

The purpose of this study was to evaluate the temperature increase during the polymerization process through the use of three different light-curing units with different irradiation times. One argon laser (Innova, Coherent), one halogen (Optilight 501, Demetron), and one blue LED (LEC 1000, MM Optics) LCU with 500 mW/cm2 during 5, 10, 20, 30, 40, 50, and 60 s of irradiation times were used in this study. The composite resin used was a microhybrid Filtek Z-250 (3M/ESPE) at color A2. The samples were made in a metallic mold 2 mm in thickness and 4 mm in diameter and previously light-cured during 40 s. A thermocouple (Model 120 202 EAJ, Fenwal Electronic, Milford, MA, USA) was introduced in the composite resin to measure the temperature increase during the curing process. The highest temperature increase was recorded with a Curing Light 2500 halogen LCU (5 and 31C after 5 and 60 s, respectively), while the lowest temperature increase was recorded for the Innova LCU based on an argon laser (2 and 11C after 5 and 60 s, respectively). The temperature recorded for LCU based on a blue LED was 3 and 22C after 5 and 60 s, respectively. There was a quantifiable amount of heat generated during the visible light curing of a composite resin. The amount of heat generated was influenced by the characteristics of the light-curing units used and the irradiation times.

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

2008-08-01

386

Study of vanadium doped ZnO films prepared by dc reactive magnetron sputtering at different substrate temperatures.  

PubMed

ZnO films doped with vanadium (ZnO:V) have been prepared by dc reactive magnetron sputtering technique at different substrate temperatures (RT-500 degrees C). The effects of the substrate temperature on ZnO:V films properties have been studied. XRD measurements show that only ZnO polycrystalline structure has been obtained, no V2O5 or VO2 crystal phase can be observed. It has been found that the film prepared at low substrate temperature has a preferred orientation along the (002) direction. As the substrate temperature is increased, the (002) peak intensity decreases. When the substrate temperature reaches the 500 degrees C, the film shows a random orientation. SEM measurements show a clear formation of the nano-grains in the sample surface when the substrate temperature is higher than 400 degrees C. The optical properties of the films have been studied by measuring the specular transmittance. The refractive index has been calculated by fitting the transmittance spectra using OJL model combined with harmonic oscillator. PMID:23646642

Meng, Lijian; Teixeira, Vasco; Dos Santos, M P

2013-02-01

387

The effect of different volumes and temperatures of saline on the bladder pressure measurement in critically ill patients  

PubMed Central

Introduction Intra-abdominal hypertension is common in critically ill patients and is associated with increased severity of organ failure and mortality. The techniques most commonly used to estimate intra-abdominal pressure are measurements of bladder and gastric pressures. The bladder technique requires that the bladder be infused with a certain amount of saline, to ensure that there is a conductive fluid column between the bladder and the transducer. The aim of this study was to evaluate the effect of different volumes and temperatures of infused saline on bladder pressure measurements in comparison with gastric pressure. Methods Thirteen mechanically ventilated critically ill patients (11 male; body mass index 25.5 4.6 kg/m2; arterial oxygen tension/fractional inspired oxygen ratio 225 48 mmHg) were enrolled. Bladder pressure was measured using volumes of saline from 50 to 200 ml at body temperature (35 to 37C) and room temperature (18 to 20C). Results Bladder pressure was no different between 50 ml and 100 ml saline (9.5 3.7 mmHg and 13.7 5.6 mmHg), but it significantly increased with 150 and 200 ml (21.1 10.4 mmHg and 27.1 15.5 mmHg). Infusion of saline at room temperature caused a significantly greater bladder pressure compared with saline at body temperature. The lowest difference between bladder and gastric pressure was obtained with a volume of 50 ml. Conclusion The bladder acts as a passive structure, transmitting intra-abdominal pressure only with saline volumes between 50 ml and 100 ml. Infusion of a saline at room temperature caused a higher bladder pressure, probably because of contraction of the detrusor bladder muscle.

Chiumello, Davide; Tallarini, Federica; Chierichetti, Monica; Polli, Federico; Li Bassi, Gianluigi; Motta, Giuliana; Azzari, Serena; Carsenzola, Cristian; Gattinoni, Luciano

2007-01-01

388

Modeling of low-temperature plasmas: some case studies of different modeling approaches  

Microsoft Academic Search

In this talk, some examples will be given of different modeling approaches, used in our group. Special attention will be put on input data, needed for the models. As an example of fluid modeling, we will illustrate the detailed plasma chemistry in a DBD used for gas conversion purposes. In this model, a large number of different species (various molecules,

Annemie Bogaerts

2009-01-01

389

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

NASA Astrophysics Data System (ADS)

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

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

2009-05-01

390

Dislocation structures in zirconium and zircaloy-4 fatigued at different temperatures  

Microsoft Academic Search

The development of characteristic dislocation structures in pure zirconium and zircaloy-4 fatigued under pull-push strain\\u000a control as the testing temperature and the cyclic strain range varied was examined using a thin-foil transmission electron\\u000a microscopy (TEM) technique. The slip planes and the twinning planes were determined by a standard stereographic trace analysis\\u000a technique. The first-order prismatic slip {10\\u000a $$\\\\bar 1$$\\u000a 0}

Lin Xiao; Haicheng Gu

1997-01-01

391

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

PubMed

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

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

2013-01-01

392

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

NASA Astrophysics Data System (ADS)

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

Leach, Sydney

2012-04-01

393

RayleighBrillouin scattering profiles of air at different temperatures and pressures  

NASA Astrophysics Data System (ADS)

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 is demonstrated that the RB scattering data in combination with the Tenti S6 model can be used to retrieve the actual gas temperatures.

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

2013-07-01

394

[Effects of morphology evolution on surface plasmon resonance of nano-Ag films treated by different thermal annealing temperatures].  

PubMed

The nano-Ag films were prepared by RF magnetron sputtering technique, and all of them were treated by rapid thermal annealing at different temperatures. The structure, the morphology and the optical properties of the annealed nano-Ag films were characterized by X-ray diffraction, scanning electron microscopy, and UV-Vis-NIR spectroscopy. The experimental results show that the open area fraction of the film and spacing between islands or nanoparticles increase with the increase of the annealing temperature, while the aspect ratio decreases. The anisotropic worm-like island films have been reshaped into isotropic nanospheres. The surface plasmon (SP) resonance band blue shifts and narrows continuously with increasing heating temperature. Analyses show that the SP resonance of the nano-Ag films can be modulated by morphology evolution induced by rapid thermal annealing. PMID:23841396

Yu, Wei; Liu, Yu-Mei; Dai, Wan-Lei; Wang, Xin-Zhan; Lu, Wan-Bing; Li, Xiao-Wei; Fu, Guang-Sheng

2013-04-01

395

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

PubMed Central

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

Ilic, Dusica; Nikolic, Vesna; Stankovic, Mihajlo; Nikolic, Ljubisa; Stanojevic, Ljiljana; Mladenovic-Ranisavljevic, Ivana; Smelcerovic, Andrija

2012-01-01

396

Acidosis and blockade of orthodromic responses caused by anoxia in rat hippocampal slices at different temperatures.  

PubMed Central

1. Interstitial pH (pHo) and field responses (to stratum radiatum stimulation) were recorded simultaneously with double-barrelled microelectrodes in the CA1 region of hippocampal slices from Sprague-Dawley rats. 2. Both the relative acidity and amplitude of field responses increased with depth, reaching a maximum near the centre of the slice. When the temperature was raised from 22 to 37 degrees C, this pHo gradient was greater than 2 times steeper, but the field responses were much diminished. 3. Standard anoxic tests (substituting 95% N2 + 5% CO2 for 95% O2 + 5% CO2, for 2 min) tended to reduce pHo and population spikes, but these effects were highly temperature sensitive: at approximately 22 degrees C the blocking rate was only 12.3 +/- 4.6% and delta pHo -0.018 +/- 0.0157 units, both per minute; corresponding changes at 34-35 degrees C were 67.6 +/- 11.9% and -0.065 +/- 0.0046 units per minute. Highly significant linear correlations between rates of block and delta pHo gave a mean slope of 90.4 +/- 17.6% per 0.1 unit of acid change. 4. Anoxia caused similar temperature-dependent increases in acidity in stratum pyramidale and radiatum, but in the latter field responses (EPSPs) were much less depressed after 2 min of anoxia. 5. When slices were superfused with acid medium (low [HCO3-]), much greater reductions in pHo were needed to depress responses, giving a mean slope of 17.7% per 0.1 pH unit. 6. In glucose-free medium, there was a slow alkaline shift in pHo (0.13 +/- 0.036 units); population spikes and the acid transients evoked by anoxia disappeared. 7. It was concluded that acidosis cannot be the immediate cause of the similar depressions of postsynaptic excitability seen during anoxia and hypoglycaemia. 8. In further tests, DL-p-hydroxyphenyl-lactic acid, a blocker of lactate transport, failed to diminish acid transients evoked by anoxia, indicating that these are not mediated principally by lactate transport.

Krnjevic, K; Walz, W

1990-01-01

397

Microstructure Changes of Plasma Spraying Tungsten Coatings on Cfc after Different Temperature Annealing  

NASA Astrophysics Data System (ADS)

Thermal behaviors of tungsten coating of 0.5 mm thick with multi-layers interface of tungsten (W) and rhenium (Re) coated on CFC (CX-2002U) substrate by vacuum plasma spraying (VPS) technique were examined by annealing with an electron beam thermal load facility between 1200 C and 2000 C. Change of the microstructure was observed and its chemical composition was analyzed by EDS after annealing. It was observed that remarkable recrystallization of VPS-W occurred above 1400 C. The structure of the multi-layers of W and Re become obscure by the mutual diffusion of W, Re and C above 1600C and finally disappeared after annealing at 2000 C for one hour. Very hard tungsten carbides are formed at the interface above 1600 C and they were broadening with increasing annealing temperature and time.

Liu, X.; Tamura, S.; Tokunaga, K.; Yoshida, N.; Noda, N.

2003-06-01

398

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

Microsoft Academic Search

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

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

2002-01-01

399

Surface wetting and its effect on body and surface temperatures of domestic laying hens at different thermal conditions.  

PubMed

This study investigated the efficacy of surface wetting at different thermal conditions on core body, head, and dorsal surface temperatures in laying hens. Hens were sprinkled on the head and dorsal surface by releasing a sprinkling dosage of 10 mL.bird(-1). The first measurement was taken presprinkling, and the second was taken immediately postsprinkling and then repeated every 5 min for 20 min. The cooling water needs for intermittent partial surface wetting to relieve acute heat stress in the laying hens were quantified for 48 domestic laying hens under 4 experimental thermal conditions. The hens were kept at 4 thermal conditions at average dry-bulb temperatures of 31.30 +/- 0.03, 33.20 +/- 0.08, 36.01 +/- 0.12, and 40.24 +/- 0.08 degrees C; RH of 67.68 +/- 0.37, 51.78 +/- 1.98, 24.59 +/- 0.90, and 16.12 +/- 1.55%; and air velocities of 0.09 +/- 0.00, 0.07 +/- 0.00, 0.08 +/- 0.00, and 0.09 +/- 0.00 m.s(-1), respectively. The differences in core body, head, and dorsal surface temperatures among the 4 thermal groups were 0.15, 0.18, 0.23, and 0.22 degrees C for core body temperature; 1.63, 1.44, 2.51, and 0.97 degrees C for core head temperature; and 1.23, 1.37, 1.41, and 0.64 degrees C for core dorsal temperature at thermal conditions 1, 2, 3, and 4, respectively. There were significant differences in core body, head, and dorsal surface temperatures among the 4 thermal condition groups. It was concluded that the spraying interval was directly proportional to the product of the vapor pressure deficit and the thermal resistance of convective mass transfer of the wetted hens, because there were no significant differences in the air velocity among the 4 thermal condition groups and the air velocity was very low. PMID:19038798

Mutaf, S; Kahraman, N Seber; Firat, M Z

2008-12-01

400

Effect of different postharvest drying temperatures on Aspergillus flavus survival and aflatoxin content in five maize hybrids.  

PubMed

After harvest, maize is dried artificially to halt fungal growth and mycotoxin production while in postharvest storage. The process often limits harvest capacity and has been a frequent cause of seed injury. Higher drying temperatures could lead to shorter drying periods and faster turnover; however, there is often a deterioration of the physical grain quality, including increased breakage susceptibility and loss of viability. The goals of this study were to determine the effect of different postharvest drying temperatures on Aspergillus filavus and Fusarium verticillioides survival and aflatoxin content in maize and to determine the viability of the seed. Five corn hybrids varying in resistance to A. flavus were side needle-inoculated with A. flavus, harvested at physiological maturity, and dried at temperatures ranging from 40 to 70 degrees C. Kernels were evaluated for aflatoxin, stress cracks, germination, and kernel infection by A. flavus and a natural infestation of F. verticillioides. Drying temperature had no effects on aflatoxin concentration given the heat stability of the toxin. With increased temperatures from 40 to 70 degrees C, germination decreased significantly, from 96 to 27%, and stress cracks increased significantly (1.4 up to 18.7). At temperatures above 60 degrees C, F. verticillioides kernel infection was significantly reduced to less than 18%. At 70 degrees C, there was a significant reduction in A. flavus kernel infection, from 11 to 3%. This information is useful in determining a range of temperatures that can be used for drying seed when fungal infection, stress cracks, and seed viability are of interest. PMID:16013400

Hawkins, Leigh K; Windham, Gary L; Williams, W Paul

2005-07-01

401

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

SciTech Connect

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

Dorranian, Davoud; Sabetkar, Akbar

2012-01-15

402

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

403

Effect of three different preservative systems on the stability of extruded dog food subjected to ambient and high temperature storage.  

PubMed

Three different preservative treatments were applied to extruded dog food. After processing the dog foods were placed in bags and stored for 16 wk at 48.8 degrees C for 12 mo at 22.2 degrees C. The preservative treatments were as follows: 1) ethoxyquin and butylated hydroxyanisole (EX/BHA), 2) mixed tocopherols (TC/TC) and 3) ascorbyl palmitate and mixed tocopherols (ATL/TC). There were no significant differences among treatments for thiobarbituric acid values for either the high or ambient temperature tests, whereas peroxide value (PV) showed significant treatment and storage effects. For products stored at 22.2 degrees C, PV increased linearly from week 4 to week 16 in both the TC/TC and ATL/TC preservative treatments and was significantly higher than the PV for EX/BHA. In the ambient temperature test, the PV was also higher for the TC/TC and the ATL/TC treatments compared to the EX/BHA treatment after 5 and 12 mo of storage. Results of the sensory evaluations were closely associated with PV. In both the high and ambient temperature tests the dogs consumed more of the foods with the lowest PV when given a two-bowl choice. Using PV and sensory tests as criteria, we concluded that the ATL/TC and TC/TC preserved dog foods deteriorated during storage compared to the EX/BHA preserved food in both the high and ambient temperature tests. PMID:7996259

Gross, K L; Bollinger, R; Thawnghmung, P; Collings, G F

1994-12-01

404

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

ERIC Educational Resources Information Center

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

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

2009-01-01

405

Pore distribution and material properties of bone cement cured at different temperatures  

Microsoft Academic Search

Implant heating has been advocated as a means to alter the porosity of the bone cement\\/implant interface; however, little is known about the influence on cement properties. This study investigates the mechanical properties and pore distribution of 10 commercially available cements cured in molds at 20, 37, 40 and 50C. Although each cement reacted differently to the curing environments, the

Matthew H. Pelletier; Abe C. B. Lau; Peter J. Smitham; Gary Nielsen; William R. Walsh

2010-01-01

406

ESTABLISHING DIFFERENT COTTON WATER LEVELS USING MULTIPLE TEMPERATURE-TIME THRESHOLDS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Subsurface drip irrigated cotton was controlled by the BIOTIC (Biologically Identified Optimal Thermal Interactive Console) irrigation timing protocol in 2003 and 2004. Specific amounts of daily stress time, referred to as time thresholds (TT) established different irrigation levels in cotton. Stres...

407

Growth Differences Among Stocks of Yellow Perch, Perca flavescens, Are Temperature Dependent  

Microsoft Academic Search

In a series of studies, growth and chemical composition of yellow perch, Perca flavescens originating from different stocks were compared. Juvenile yellow perch from Lake Mendota, Wisconsin were acquired in each year of four years and compared to stocks from Green Bay, Wisconsin; Pennsylvania; North Carolina; or Nebraska. Quadruplicate groups of each stock were cultured at 16C, 22C, or 28C

P. B. Brown; J. E. Wetzel; J. Mays; K. A. Wilson; C. S. Kasper; J. Malison

2002-01-01

408

ANALYSIS OF GENES EXPRESSED IN RESPONSE TO COLD TEMPERATURES UNDER DIFFERENT PHOTOPERIODS AND PEACH BARK  

Technology Transfer Automated Retrieval System (TEKTRAN)

Living cells respond to environmental stresses by up-regulating specific subsets of genes while down-regulating others. Global approaches to identifying these different groups of genes have been successfully applied to several plant systems. However, certain limitations restrict the degree to whi...

409

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

ERIC Educational Resources Information Center

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

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

2009-01-01

410

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

411

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

412

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 (0.182.20 kg; 15.527.4 C) according to ventilatory frequency (Vf) and

Jess Cerezo Valverde; Benjamn Garca Garca

2005-01-01

413

Residual Temperature Stresses in Shadow Pyrographite Grids of the Microwave Electrovacuum Devices Arising at Laser Cutting on Different Modes  

Microsoft Academic Search

Laser processing of pyrographite was carried out on different technological setups by radiation of the solid-state laser with wavelength X= 1.064 mum and pulse duration tau = 4middot10-3 s, tau = 1.5middot10-4 s, tau = 1.2middot10 -7 s. The power density of falling radiation was changed in a range 106-107 W\\/cm2. Residual temperature stresses were studied by the X-ray method.

O. A. Trofimova; T. N. Sokolova; A. V. Konyushin; S. V. Busel

2006-01-01

414

Chiral discrimination of quinine and quinidine based on notable room temperature phosphorescence lifetime differences with ?-cyclodextrin as chiral selector  

Microsoft Academic Search

Upon addition of small amount of bromocyclohexane (BrCH), quinine (QN) and quinidine (QD) display strong room temperature phosphorescence (RTP) in ?-cyclodextrin (?-CD) solution without deoxygenation. The associated phosphorescence decay curves can be best fitted to biexponential patterns and quite different RTP lifetimes are obtained for QN (86.9 and 12.5ms) and QD (12.1 and 4.17ms), indicating a distinct chiral discrimination of

Xiao Hua Zhang; Yu Wang; Wei Jun Jin

2007-01-01

415

Interactive effects of radiation, temperature and salinity on different life history stages of the Arctic kelp Alaria esculenta (Phaeophyceae)  

Microsoft Academic Search

To estimate the potential effects of climate change on polar marine macroalgae, studies on interactive stress effects of multiple\\u000a climate-related parameters are essential. Interactions of temperature, radiation and salinity on two different life history\\u000a stages of Alaria esculenta (L.) Greville from the Kongsfjord (Spitsbergen) were investigated for the first time within this study. Adult macroscopic\\u000a sporophytes of A. esculenta were

Jana Fredersdorf; Ruth Mller; Susanne Becker; Christian Wiencke; Kai Bischof

2009-01-01

416

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

Microsoft Academic Search

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

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

2004-01-01

417

Presence of mature eggs in olive fruit fly, Bactrocera oleae (Diptera Tephritidae), at different constant photoperiods and at two temperatures  

Microsoft Academic Search

The effect of the constant photoperiod on presence of mature eggs in olive fruit fly was investigated. Adults of B. oleae were submitted to different photoperiodic treatments (LL:DD), at temperature of 20 C: 9:15, 10:14, 12:12, 15:9, 16:8, continuous light (LL) and continuous dark (DD). Light was obtained from neon tubes and the light intensity, estimated inside the plexiglas cage,

Alfio RASPI; Angelo CANALE; Augusto LONI

418

Differences between laminar convections through parallel plain planes with uniform wall temperature and heat flux in terms of process parameter  

Microsoft Academic Search

Using the process parameter description, we analyzed the difference between the characteristics of laminar convections through\\u000a parallel plain planes with uniform temperature and heat flux. The results show the following. (1) On the wall surface of the\\u000a developing region, under uniform heat flux boundary condition, the heat flux normal to the wall surface is transported through\\u000a a convection process although

LiangBi Wang; ZhiMin Lin; Xiang Wu; KeWei Song

2010-01-01

419

FINITE DIFFERENCE METHOD-BASED SIMULATION OF TEMPERATURE FIELDS FOR APPLICATION TO ORTHOGONAL CUTTING WITH COATED TOOLS  

Microsoft Academic Search

A finite difference method was proposed to model the effect of a variety of tool coatings on the magnitude and distribution of temperatures through the tool-chip contact region and the coating\\/substrate boundaries. For each workpiece-tool pair tested the intensity of uniformly distributed heat flux and relevant analytically obtained values of the heat partition coefficient were assumed to change with variations

W. Grzesik; M. Bartoszuk; P. Nieslony

2005-01-01

420

Surface Properties of the AlGaN\\/GaN Superlattice Grown at Different Temperatures by Metalorganic Chemical Vapor Deposition  

Microsoft Academic Search

AlGaN\\/GaN strained layer superlattice (SLS) structures were prepared by metalorganic vapor deposition (MOCVD) under various growth conditions. It was found that the surface morphology and V-shaped pits were determined by growth temperature. Two different types of pit were observed namely, minute pits and open V-shape pits, in scanning electronic microscopy (SEM) and atomic force microscopy (AFM) images. The density of

Wei-Chih Lai; Cheng-Huang Kuo; Wei-Yu Yen; Jinng-Kong Sheu; Shoou-Jinng Chang

2008-01-01

421

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

422

Dustiness of different high-temperature insulation wools and refractory ceramic fibres.  

PubMed

Recent regulations are encouraging the replacement of older types of man-made mineral fibre by more soluble and, thus, less biopersistent compositions. In order for there to be any health benefits from this policy and to gain maximum benefit from such substitutions, the use of the new materials should not increase exposure. The work reported here was undertaken to investigate the use of new high-temperature glass insulation wools in place of refractory ceramic fibres (RCF). Airborne fibre levels occurring during the manufacture of both RCF and calcium magnesium silicate wools (CMS) were compared using measurements of genuine workplace exposure from a routine monitoring operation on the same plant. Exposures during use were compared in one customer facility where RCF and CMS blankets were used for the same task. Further comparisons were made in a laboratory test of dustiness using a "shaking box test". For some manufacturing tasks there are only a few workplace samples and there are few opportunities for genuine comparisons with both RCF and CMS in identical uses. However, both materials produced very similar exposure levels during manufacture, use and in the laboratory test. The novel magnesium silicate fibre was significantly dustier in the laboratory test. PMID:11418088

Class, P; Deghilage, P; Brown, R C

2001-07-01

423

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

424

SAXS/DSC/WAXD study of temperature evolution in nanocomposite polymer electrolytes with different nanofillers.  

PubMed

Polymer electrolytes are nanostructured materials which are very attractive components for batteries and opto-electronic devices. (PEO)8ZnCl2 polymer electrolytes were prepared from PEO and ZnCl2. The nanocomposites (PEO)8ZnCI2 themselves contained TiO2, Al2O3, MgO, ZnO and V2O5 nanograins. In this work, the influence of the Al2O3, MgO and V2O5 nanograins on the morphology and ionic conductivity of the nanocomposite was systematically studied by transmission small-angle X-ray scattering simultaneously recorded with wide-angle X-ray diffraction and differential scanning calorimetry at the synchrotron ELETTRA (Trieste, Italy). These three measurement methods yielded insight into the temperature-dependent changes of the grains of the electrolyte. The heating and cooling rate was 0.5 degrees C/min. Environment friendly galvanic cells as well as solar cells of the second generation are to be constructed with such nanocomposite polymer as electrolyte. PMID:23421266

Turkovi?, A; Dubcek, P; Jurai?, K; Bernstorff, S

2012-11-01

425

Temperature dependence of evolutionary diversification: differences between two contrasting model taxa support the metabolic theory of ecology.  

PubMed

Biodiversity patterns are largely determined by variation of diversification rates across clades and geographic regions. Although there are multiple reasons for this variation, it has been hypothesized that metabolic rate is the crucial driver of diversification of evolutionary lineages. According to the metabolic theory of ecology (MTE), metabolic rate - and consequently speciation - is driven mainly by body size and environmental temperature. As environmental temperature affects metabolic rate in ecto- and endotherms differently, its impact on diversification rate should also differ between the two types of organisms. Employing two independent approaches, we analysed correlates of speciation rates and, ultimately, net diversification rates for two contrasting taxa: plethodontid salamanders and carnivoran mammals. Whereas in the ectothermic plethodontids speciation rates positively correlated with environmental temperature, in the endothermic carnivorans a reverse, negative correlation was detected. These findings comply with predictions of the MTE and suggest that similar geographic patterns of biodiversity across taxa (e.g. ecto- and endotherms) might have been generated by different ecological and evolutionary processes. PMID:23116407

Machac, A; Zrzav, J; Smrckova, J; Storch, D

2012-11-01

426