Journal articles: 'Temperature x time exposure constants'

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Blank, Vladimir D., Sergei G. Buga, Gennadi A. Dubitsky, Nadejda R. Serebryanaya, Vyatcheslav M. Prokhorov, Boris N. Mavrin, Victor N. Denisov, Leonid A. Chernozatonskii, Sofia Berezina, and Vadim M. Levin. "Synthesis of Superhard and Ultrahard Materials by 3D-polymerization of C60, C70 Fullerenes Under High Pressure (15 GPa) and Temperatures up to 1820 K." Zeitschrift für Naturforschung B 61, no. 12 (December 1, 2006): 1547–54. http://dx.doi.org/10.1515/znb-2006-1211.

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Solid fullerenes C60 and C70 have been treated at high pressure of 15 GPa and high temperatures of 520 - 1820 K for a time of exposure of 60 s and a quenching rate of 300 K s−1 using a toroid-type apparatus. X-ray diffraction and Raman spectra confirm the realization of 3D-polymerized phases in these solids at 15 GPa. The pressure/temperature maps of synthesis of metastable carbon phases on the basis of C60 and C70 have thus been extended to 15 GPa. The longitudinal and shear sound wave velocities were measured by acoustic microscopy techniques. A maximum sound wave velocity of (21±1)×105 m s−1 was observed in the sample synthesized from C60 at T = 1170 K. The elastic constants were calculated using experimental data. The acoustic microscopy images of experimental samples have been investigated.

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Delplancke-Ogletree, M. P., M. Ye, R. Winand, J. F. de Marneffe, and R. Deltour. "Influences of thermal annealing and humidity exposure on surface structure of (100) single-crystal MgO substrate." Journal of Materials Research 14, no. 5 (May 1999): 2133–37. http://dx.doi.org/10.1557/jmr.1999.0288.

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We studied the influence of thermal annealing on the surface structure of (100) singlecrystal MgO substrates by atomic force microscopy (AFM). By annealing MgO substrates at various temperatures for 4 h in flowing oxygen, we showed that the surface reconstruction could be explained by considering surface diffusion, surface evaporation, and condensation. At an annealing temperature of 1473 K, a stepped structure was formed with screw dislocations acting as step sources. The influence of humidity on the surface morphology of MgO substrates was also studied by exposing them to a constant humidity of 40 and 80% for different times. After an exposure time of 1.5 h in 80% humidity, the substrate surface was already covered by reaction products. For the 40% humidity, the corresponding time is 10 h. The major reaction product was identified as Mg(OH)2 by x-ray diffraction.

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Botha, Sabine, Thomas Barends, Wolfgang Kabsch, Beatrice Latz, Karol Nass, Robert Shoeman, Florian Dworkowski, et al. "Room Temperature Serial Crystallography at Synchrotrons." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C326. http://dx.doi.org/10.1107/s2053273314096739.

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Serial Femtosecond Crystallography (SFX) is the most commonly used method for the emerging structure determination at X-ray free-electron lasers (FELs). The high peak brilliance of the FEL and the possibility of using femtosecond pulses afford use of nano-to-micron sized crystals in a diffraction-before-destruction approach for the acquisition of high-resolution undamaged diffraction data [1]. The crystals are obliterated upon exposure to an FEL X-ray pulse so only a single snapshot can be collected per crystal, necessitating a constant supply of fresh crystals. The crystals are therefore injected in a liquid microjet [2], [3]. We show that this serial method of data collection and the associated data analysis can be successfully adapted to serial crystallography (SX) measurements at synchrotrons, enabling room temperature studies using the unattenuated beam. Given the continuous supply of fresh crystals, the full tolerable dose can be used for each single crystal exposure, permitting analysis of small or weakly scattering crystals. FEL X-ray pulses are much shorter than the fraction of a second exposure time at a synchrotron, so SFX injection conditions are modified in SX such as to slow down the typically fast travelling crystals. By embedding the crystals in a viscous material the crystals remain in the beam long enough to yield measurable diffraction and smearing out of the diffraction peaks due to crystal tumbling is avoided. We demonstrate the successful application of room temperature SX at the Swiss Light Source at ambient pressure. Our experimental setup allows collection of both still and rotation data. Recent progress using model systems will be presented, establishing this high throughput, high dose rate approach as a new route to structure determination of macromolecules in their native environment and at room temperature.

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Judd, Gary J. R., Mark G. T. Gardiner, and Donald R. Thomson. "TEMPERATURE-DEPENDENT DEVELOPMENT AND PREDICTION OF HATCH OF OVERWINTERED EGGS OF THE FRUITTREE LEAFROLLER, ARCHIPS ARGYROSPILUS (WALKER) (LEPIDOPTERA: TORTRICIDAE)." Canadian Entomologist 125, no. 5 (October 1993): 945–56. http://dx.doi.org/10.4039/ent125945-5.

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AbstractThermal responses and temperature-dependent development of laboratory- and field-overwintered eggs of the fruittree leafroller, Archips argyrospilus (Walker), were described using data from constant-temperature laboratory experiments. The time required for completion of hatch of overwintering eggs declined throughout winter until the end of January, after which increasing exposure to natural or artificial cold conditions had minimal effect on median hatching time. There was little year to year variation in response to cold treatments, and thus it was concluded that diapause is terminated by 1 February. Time to hatch decreased with increasing temperature. Distributions of hatch times were near normal, with mean and median development times similar at any given temperature. Development time (days ± SD) at a mean temperature of 20 °C was similar under constant (10.7 ± 1.1) and fluctuating (9.1 ± 1.4) temperature regimes. A nonlinear, six-parameter, biophysical model, fitted (r2 = 0.99) to median hatching rates at 11 temperatures (0.5–30 °C) indicated development was nonlinear below 10 °C, increased linearly between 10 and 25 °C, was maximal at 27.5 °C, and decreased above 27.5 °C. The lower developmental threshold (± SE), estimated to be 4.95 ± 0.54 °C by linear regression (r2 = 0.98) and the x-intercept method, was used to construct a degree-day (DD) model for predicting egg hatch. Median egg development required 154 DD above 4.95 °C. Observed median egg hatch in two different field sites and years was within ± 3 days of the predicted date, using max–min air temperatures, a base temperature of 5 °C, and a starting date of 1 February for accumulating DD. This model should prove useful for scheduling management actions against fruittree leafroller on apples and pears.

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Cavin, O. Burl, and J. S. Wolf. "X-Ray Examination of Type 310S Stainless Steel during its Oxidation in Air at 900°C*." Advances in X-ray Analysis 36 (1992): 423–31. http://dx.doi.org/10.1154/s0376030800019042.

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AbstractType 310S stainless steel was exposed in air at 900°C and simultaneously examined periodically by X-ray diffraction in an attempt to determine the structural evolution of the compounds formed on its surface. The adherent oxide product was found to be a two-layered scale composed of an inner sesquioxide and an outer spinel layer. Both of these compounds exhibited systematic changes in their unit cell sizes as a function of increasing exposure time at constant temperature. The spinel showed an increase in its lattice parameter while the sesquioxide and stainless steel substrate both had decreases in their parameters proportional to the square root of exposure time. In each of the three phases, the rate of change was constant up to approximately four hours after which the parameters approached a limiting value. Evidence also exists for the presence of at least localized stresses in the scales.

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Wang, Pingping, Guoqin Chen, Longtao Jiang, Daguang Li, and Gaohui Wu. "Effect of thermal exposure on the microstructure of the interface in a Grf/Al composite." Science and Engineering of Composite Materials 23, no. 6 (November 1, 2016): 751–57. http://dx.doi.org/10.1515/secm-2014-0354.

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AbstractThe microstructure of the interface in a Grf/Al composite after exposure at high temperature was investigated. The graphite fiber reinforced aluminum matrix composite was prepared by the pressure infiltration method. After being heat treated at 550°C, 600°C and 640°C for different times, the microstructure of the interface in the composite was studied by using transmission electron microscopy (TEM). Furthermore, the content of Al4C3 in the interface was examined using X-ray diffraction (XRD). The results showed that not only the micro morphology but also the content of Al4C3 in the interface varied with the increase in temperature. When the composite was heat treated at 550°C and 600°C, Al4C3 with a big length-to-diameter ratio was observed in the interface, while Al4C3 with a small length-to-diameter ratio was found when the heat treatment temperature was 640°C. With the increase in the time, the content of Al4C3 in the interface increased rapidly when the composite was heat treated at 640°C. Based on the dynamic calculation, the interface reaction diffusion rate constant of the Grf/Al composite increases rapidly when the temperature is higher than 600°C.

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Ryl, Jacek, Mateusz Cieslik, Artur Zielinski, Mateusz Ficek, Bartlomiej Dec, Kazimierz Darowicki, and Robert Bogdanowicz. "High-Temperature Oxidation of Heavy Boron-Doped Diamond Electrodes: Microstructural and Electrochemical Performance Modification." Materials 13, no. 4 (February 21, 2020): 964. http://dx.doi.org/10.3390/ma13040964.

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In this work, we reveal in detail the effects of high-temperature treatment in air at 600 °C on the microstructure as well as the physico-chemical and electrochemical properties of boron-doped diamond (BDD) electrodes. The thermal treatment of freshly grown BDD electrodes was applied, resulting in permanent structural modifications of surface depending on the exposure time. High temperature affects material corrosion, inducing crystal defects. The oxidized BDD surfaces were studied by means of cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM), revealing a significant decrease in the electrode activity and local heterogeneity of areas owing to various standard rate constants. This effect was correlated with a resultant increase of surface resistance heterogeneity by scanning spreading resistance microscopy (SSRM). The X-ray photoelectron spectroscopy (XPS) confirmed the rate and heterogeneity of the oxidation process, revealing hydroxyl species to be dominant on the electrode surface. Morphological tests using scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed that prolonged durations of high-temperature treatment lead not only to surface oxidation but also to irreversible structural defects in the form of etch pits. Our results show that even subsequent electrode rehydrogenation in plasma is not sufficient to reverse this surface oxidation in terms of electrochemical and physico-chemical properties, and the nature of high-temperature corrosion of BDD electrodes should be considered irreversible.

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Gamal, Hany, Salaheldin Elkatatny, Abdulazeez Abdulraheem, and Abdulaziz Al Majed. "Exposure Time Impact on the Geomechanical Characteristics of Sandstone Formation during Horizontal Drilling." Molecules 25, no. 11 (May 27, 2020): 2480. http://dx.doi.org/10.3390/molecules25112480.

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The rock geomechanical properties are the key parameters for designing the drilling and fracturing operations and for programing the geomechanical earth models. During drilling, the horizontal-section drilling fluids interact with the reservoir rocks in different exposure time, and to date, there is no comprehensive work performed to study the effect of the exposure time on the changes in sandstone geomechanical properties. The objective of this paper is to address the exposure time effect on sandstone failure parameters such as unconfined compressive strength, tensile strength, acoustic properties, and dynamic elastic moduli while drilling horizontal sections using barite-weighted water-based drilling fluid. To simulate the reservoir conditions, Buff Berea sandstone core samples were exposed to the drilling fluid (using filter press) under 300 psi differential pressure and 200 °F temperature for different exposure times (up to 5 days). The rock characterization and geomechanical parameters were evaluated as a function of the exposure time. Scratch test was implemented to evaluate rock strength, while ultrasonic pulse velocity was used to obtain the sonic data to estimate dynamic elastic moduli. The rock characterization was accomplished by X-ray diffraction, nuclear magnetic resonance, and scanning electron microscope. The study findings showed that the rock compression and tensile strengths reduced as a function of exposure time (18% and 19% reduction for tensile strength and unconfined compression strength, respectively, after 5 days), while the formation damage displayed an increasing trend with time. The sonic results demonstrated an increase in the compressional and shear wave velocities with increasing exposure time. All the dynamic elastic moduli showed an increasing trend when extending the exposure time except Poisson’s ratio which presented a constant behavior after 1 day. Nuclear magnetic resonance results showed 41% porosity reduction during the five days of mud interaction. Scanning electron microscope images showed that the rock internal surface topography and internal integrity changed with exposure time, which supported the observed strength reduction and sonic variation. A new set of empirical correlations were developed to estimate the dynamic elastic moduli and failure parameters as a function of the exposure time and the porosity with high accuracy.

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Moravcikova-Gouvea, Larissa, Zuzana Kovacova, Michael Kitzmantel, Erich Neubauer, Vít Jan, and Ivo Dlouhy. "Influence of Hot Pressing Sintering Temperature on the Properties of Low-Density Al_0.5NbTa_0.8Ti_1.5V_0.2Zr Refractory High-Entropy Alloy." Materials Science Forum 1016 (January 2021): 940–45. http://dx.doi.org/10.4028/www.scientific.net/msf.1016.940.

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In this work, the low-density Al0.5NbTa0.8Ti1.5V0.2Zr RHEA prepared by mechanical alloying combined with hot uniaxial pressing (HP) was investigated. The alloy was subjected to different sintering temperatures on the range of 1200°C up to 1600°C, while keeping a constant densification time. The influence of the increase in sintering temperatures on the RHEAs’ microstructural features, composition and basic mechanical properties was explored by means of x-ray diffraction and scanning electron microscopy, hardness testing, density determination by Archimedes’ principle and elastic moduli by ultrasonic measurements. Full density samples were obtained in all sintering temperatures. The alloy has shown a homogeneous distribution of phases, with presence of dispersed oxides inside the matrix, leading to a fine grain size distribution due to grain-boundary pinning effect, even during the exposure of the alloy at the highest sintering temperature. The mentioned effect is responsible for the achievement of high-hardness in all conditions. Powder metallurgy has been shown to be an advantageous technique for production of alloys for high-temperature applications, as the inherent in-situ formed oxides homogeneously distributed within the matrix may be beneficially used as reinforcement, thus potentially enhancing the mechanical properties of the parts.

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Perrusquia, N. López, M. Antonio Doñu Ruiz, E. Y. Vargas Oliva, and V. Cortez Suarez. "Diffusion of Hard Coatings on Ductile Cast Iron." MRS Proceedings 1481 (2012): 105–12. http://dx.doi.org/10.1557/opl.2012.1638.

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ABSTRACTThis work estimate the growth kinetics of Fe2B coatings created on surface nodular cast iron ASTM A-536 class 80-56-06. The Fe2B coatings were formed by power packaging boriding process, considering three temperatures and exposure times different treatment. The hard coatings were evaluated through X-ray diffraction (XRD) and scanning electron microscopy (SEM). The model of diffusion employs the mass balance equation at the (Fe2B/substrate) interface to evaluate the boron diffusion coefficient in the Fe2B coating DFe2B, an expression of the parabolic growth constant, the instantaneous velocity of the Fe2B/substrate interface, and the weight gain in the boriding sample were establish as a function of the parameter ε(T) and η(T), dependents of boriding process in function of the temperature related and the time of boriding t0 (T), respectively in the Fe2B coating. Model validation was extended considering the treatment of 1273 and 1123 K for 10 h respectively, obtaining a good correlation with experimental data.

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Tomeček, David, Lesia Piliai, Martin Hruška, Přemysl Fitl, Virginie Gadenne, Mykhailo Vorokhta, Iva Matolínová, and Martin Vrňata. "Study of Photoregeneration of Zinc Phthalocyanine Chemiresistor after Exposure to Nitrogen Dioxide." Chemosensors 9, no. 9 (August 24, 2021): 237. http://dx.doi.org/10.3390/chemosensors9090237.

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In this work, we present a complex study of photoregeneration of a zinc phthalocyanine (ZnPc) sensor by illumination from light-emitting diodes (LEDs). It includes an investigation of photoregeneration effectivity for various wavelengths (412–723 nm) of incident light carried out at sensor operating temperatures of 55 °C. It is demonstrated that the efficiency of photoregeneration is increasing with a decrease in the light wavelength. In the region of longer wavelengths (723–630 nm), the regeneration degree (RD) was low and ranged from 12% to 15%. In the region of shorter wavelengths (518–412 nm), the RD rose from 35% for 518 nm to 94% for 412 nm. The efficiency of photoregeneration is also shown to be higher in comparison with the temperature regeneration efficiency. In order to understand the chemism of photoregeneration processes, the electrical measurements are supplemented with Raman and near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) studies. The spectroscopic results showed that nitrogen dioxide bonds to the Zn atom in ZnPc in the form of NO2− and NO−, i.e., partial decomposition of NO2 molecules occurs during the interaction with the surface. NAP-XPS spectra proved that light illumination of the ZnPc surface is essential for almost complete desorption of NOx species. At the same time, it is demonstrated that in case of long-time exposure or exposure of a ZnPc chemiresistor with a high concentration of NO2, the oxygen, released due to the NO2 decomposition, slowly but irreversibly oxidizes the layer. This oxidation process is most probably responsible for the sensor deactivation observed in sensor experiments with high NO2 concentrations. Based on these studies, the mechanism of nitrogen dioxide interaction with zinc phthalocyanine both under LED illumination and in dark conditions is proposed, and a special method for the sensor operation called “constant exposure dose” is established.

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Vilhu, O., and A. Collier Cameron. "X-ray Spectral Diagnostics for Coronal Loops in the Active K Dwarf AB Doradus." International Astronomical Union Colloquium 115 (1990): 132–35. http://dx.doi.org/10.1017/s0252921100012239.

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AbstractWe discuss theoretical X-ray spectra for coronal loop models in the rapidly rotating young K dwarf AB Doradus (HD 36705), as a typical representative of active X-ray bright stars. The loop models are based on EXOSAT and IUE observations, and further motivated by a possible connection between the observed X-ray flares and co-rotating clouds of neutral hydrogen (a few/day). The resulting synthetic spectra between 0.5 – 7 keV can be approximated by a linear combination of three distinct temperature components. Two components are sufficient between 0.5 – 2.5 keV. Below 0.1 keV the loop spectra deviate significantly from the few component fits. To test some basic assumptions (dynamic vs. static, constant vs. variable cross-sectional area), useful constraints on the DEM(T)-distribution could be obtained with the grating-spectrometer of XMM with 103 – 104sec exposure times. The ratio of the He-type (O VII) forbidden and intercombination lines at 0.56 keV will provide sufficient density diagnostics, to distinguish e.g.between compact and large loops. The crystal-spectrometers of XMM and XSPECT could achieve the same but with longer (105 sec) observing time. The strong Ly α line of O VIII at 0.65 keV can be observed with the crystals in 104 sec, and used even for rotational modulation and flare studies, and giving additional information about flows in flaring loops. At the Iron 6.7 keV lines, where the gratings do not work, the crystals should be used together with low resolution devices, to set constraints on the hottest gas at loop summits. Our discussion applies also to several brighter cool stars but with shorter observing time (like Capella and HR 1099, which are over 3 times X-ray brighter than AB Dor).

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Stellato, Francesco, Dominik Oberthür, Mengning Liang, Richard Bean, Cornelius Gati, Oleksandr Yefanov, Anton Barty, et al. "Room-temperature macromolecular serial crystallography using synchrotron radiation." IUCrJ 1, no. 4 (May 30, 2014): 204–12. http://dx.doi.org/10.1107/s2052252514010070.

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A new approach for collecting data from many hundreds of thousands of microcrystals using X-ray pulses from a free-electron laser has recently been developed. Referred to as serial crystallography, diffraction patterns are recorded at a constant rate as a suspension of protein crystals flows across the path of an X-ray beam. Events that by chance contain single-crystal diffraction patterns are retained, then indexed and merged to form a three-dimensional set of reflection intensities for structure determination. This approach relies upon several innovations: an intense X-ray beam; a fast detector system; a means to rapidly flow a suspension of crystals across the X-ray beam; and the computational infrastructure to process the large volume of data. Originally conceived for radiation-damage-free measurements with ultrafast X-ray pulses, the same methods can be employed with synchrotron radiation. As in powder diffraction, the averaging of thousands of observations per Bragg peak may improve the ratio of signal to noise of low-dose exposures. Here, it is shown that this paradigm can be implemented for room-temperature data collection using synchrotron radiation and exposure times of less than 3 ms. Using lysozyme microcrystals as a model system, over 40 000 single-crystal diffraction patterns were obtained and merged to produce a structural model that could be refined to 2.1 Å resolution. The resulting electron density is in excellent agreement with that obtained using standard X-ray data collection techniques. With further improvements the method is well suited for even shorter exposures at future and upgraded synchrotron radiation facilities that may deliver beams with 1000 times higher brightness than they currently produce.

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Bouchard, R. A., and D. Bose. "Contribution of sarcolemmal sodium-calcium exchange and intracellular calcium release to force development in isolated canine ventricular muscle." Journal of General Physiology 99, no. 6 (June 1, 1992): 931–60. http://dx.doi.org/10.1085/jgp.99.6.931.

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The aim of this work was to determine the relationship between peak twitch amplitude and sarcoplasmic reticulum (SR) Ca2+ content during changes of stimulation frequency in isolated canine ventricle, and to estimate the extent to which these changes were dependent upon sarcolemmal Na(+)-Ca2+ exchange. In physiological [Na+]o, increased stimulation frequency in the 0.2-2-Hz range resulted in a positive inotropic effect characterized by an increase in peak twitch amplitude and a decrease in the duration of contraction, measured as changes in isometric force development or unloaded cell shortening in intact muscle and isolated single cells, respectively. Action potentials recorded from single cells indicated that the inotropic effect was associated with a progressive decrease of action potential duration and a marked reduction in average time spent by the cell near the resting potential during the stimulus train. The frequency-dependent increase of peak twitch force was correlated with an increase of Ca2+ uptake into and release from the SR. This was estimated indirectly using the phasic contractile response to rapid (less than 1 s) lowering of perfusate temperature from 37 degrees C to 0-2 degrees C and changes of twitch amplitude resulting from perturbations in the pattern of electrical stimulation. Lowering [Na+]o from 140 to 70 mM resulted in an increase of contractile strength, which was accompanied by a similar increase of apparent SR Ca2+ content, both of which could be abolished by exposure to ryanodine (1 x 10(-8) M), caffeine (3 x 10(-3) M), or nifedipine (2 x 10(-6) M). Increased stimulation frequency in 70 mM [Na+]o resulted in a negative contractile staircase, characterized by a graded decrease of peak isometric force development or unloaded cell shortening. SR Ca2+ content estimated under identical conditions remained unaltered. Rate constants derived from mechanical restitution studies implied that the depressant effect of increased stimulation frequency in 70 mM [Na+]o was not a consequence of a decreased rate of refilling of a releasable pool of Ca2+ within the cell. These results demonstrate that frequency-dependent changes of contractile strength and intracellular Ca2+ loading in 140 mM [Na+]o require the presence of a functional sarcolemmal Na(+)-Ca2+ exchange process. The possibility that the negative staircase in 70 mM [Na+]o is related to inhibition of Ca(2+)-induced release of Ca2+ from the SR by various cellular mechanisms is discussed.

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DRAKE, S. R., H. R. MOFFITT, and J. P. MATTHEIS. "METHYL BROMIDE, TIME and TEMPERATURE of EXPOSURE ON APPLE QUALITY." Journal of Food Processing and Preservation 14, no. 2 (April 1990): 85–92. http://dx.doi.org/10.1111/j.1745-4549.1990.tb00830.x.

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Canistraro, Howard A., Eric H. Jordan, Shi Shixiang, Leroy H. Favrow, and Francis A. Reed. "Elastic Constants of Single Crystal Hastelloy X at Elevated Temperatures." Journal of Engineering Materials and Technology 120, no. 3 (July 1, 1998): 242–47. http://dx.doi.org/10.1115/1.2812350.

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An acoustic time of flight technique is described in detail for measuring the elastic constants of cubic single crystals that allows for the constants to be determined at elevated temperature. Although the overall technique is not new, various aspects of the present work may prove extremely useful to othersinterested in finding these values, especially for aerospace materials applications. Elastic constants were determined for the nickel based alloy, Hastelloy X from room temperature to 1000°C. Accurate elastic constants were needed as part of an effort to predict both polycrystal mechanical properties and the nature of grain induced heterogeneous mechanical response. The increased accuracy of the acoustically determined constants resulted in up to a 15 percent change in the predicted stresses in individual grains. These results indicate that the use of elastic single crystal constants of pure nickel as an approximation for the constants of gas turbine single crystal alloys, which is often done today, is inaccurate.

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Kodera, Sachiko, and Akimasa Hirata. "Comparison of Thermal Response for RF Exposure in Human and Rat Models." International Journal of Environmental Research and Public Health 15, no. 10 (October 22, 2018): 2320. http://dx.doi.org/10.3390/ijerph15102320.

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In the international guidelines/standards for human protection against electromagnetic fields, the specific absorption rate (SAR) is used as a metric for radio-frequency field exposure. For radio-frequency near-field exposure, the peak value of the SAR averaged over 10 g of tissue is treated as a surrogate of the local temperature elevation for frequencies up to 3–10 GHz. The limit of 10-g SAR is derived by extrapolating the thermal damage in animal experiments. However, no reports discussed the difference between the time constant of temperature elevation in small animals and humans for local exposure. This study computationally estimated the thermal time constants of temperature elevation in human head and rat models exposed to dipole antennas at 3–10 GHz. The peak temperature elevation in the human brain was lower than that in the rat model, mainly because of difference in depth from the scalp. Consequently, the thermal time constant of the rat brain was smaller than that of the human brain. Additionally, the thermal time constant in human skin decreased with increasing frequency, which was mainly characterized by the effective SAR volume, whereas it was almost frequency-independent in the human brain. These findings should be helpful for extrapolating animal studies to humans.

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Chiang, Chih-Hung, and Cho-Liang Tsai. "Time–temperature analysis of bond strength of a rebar after fire exposure." Cement and Concrete Research 33, no. 10 (October 2003): 1651–54. http://dx.doi.org/10.1016/s0008-8846(03)00139-x.

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Kim, Woo Gon, Sang Nan Yin, Woo Seog Ryu, and Jong Hwa Chang. "Creep Properties of Hastelloy-X Alloy for the High Temperature Gas-Cooled Reactor." Key Engineering Materials 326-328 (December 2006): 1105–8. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.1105.

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The creep properties for the Hastelloy-X alloy which is one of candidate alloys for a high temperature gas-cooled reactor are presented. The creep data was obtained with different stresses at 950oC, and a number of the creep data was collected through literature surveys. All of the creep data were combined together to obtain the creep constants and to predict a long-term creep life. In the Norton’s creep law and the Monkman-Grant relationship, the creep constants, A, n, m, and m’ were obtained. Creep master curves based on the Larson-Miller parameter were presented for the standard deviations of 1σ, 2σ and 3σ. Creep life at each temperature was predicted for a longer-time rupture above 105 hours. Failure probability was also estimated by a statistical process of all the creep rupture data.

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Kiefer, Dominik, Jens Gibmeier, and Andreas Stark. "Determination of Temperature-Dependent Elastic Constants of Steel AISI 4140 by Use of In Situ X-ray Dilatometry Experiments." Materials 13, no. 10 (May 21, 2020): 2378. http://dx.doi.org/10.3390/ma13102378.

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In situ dilatometry experiments using high energy synchrotron X-ray diffraction in transmission mode were carried out at the high energy material science beamline P07@PETRAIII at DESY (Deutsches Elektronen Synchrotron) for the tempering steel AISI 4140 at defined mechanical loading. The focus of this study was on the initial tempering state ( f e r r i t e ) and the hardened state ( m a r t e n s i t e ). Lattice strains were calculated from the 2D diffraction data for different h k l planes and from those temperature-dependent lattice plane specific diffraction elastic constants ( D E C s ) were determined. The resulting coupling terms allow for precise stress analysis for typical hypoeutectoid steels using diffraction data during heat treatment processes, that is, for in situ diffraction studies during thermal exposure. In addition, by averaging h k l specific Y o u n g ′ s m o d u l i and P o i s s o n r a t i o s macroscopic temperature-dependent elastic constants were determined. In conclusion a novel approach for the determination of phase-specific temperature-dependent DECs was suggested using diffraction based dilatometry that provides more reliable data in comparison to conventional experimental procedures. Moreover, the averaging of lattice plane specific results from in situ diffraction analysis supply robust temperature-dependent macroscopic elastic constants for martensite and ferrite as input data for heat treatment process simulations.

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Oliveira, Higor Henrique de Souza, Marco Aurélio Cebim, and Marian Rosaly Davolos. "Temperature and exposure time-dependent scintillation of Eu(III) polyoxometalate under X-ray excitation." Journal of Luminescence 203 (November 2018): 230–33. http://dx.doi.org/10.1016/j.jlumin.2018.06.062.

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Narita, Toshio. "Compatible Coating System to Provide Long-Life and High-Reliability." Materials Science Forum 696 (September 2011): 12–27. http://dx.doi.org/10.4028/www.scientific.net/msf.696.12.

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The concept of the diffusion barrier coating system (DBC system) is summarized and the latest results are presented. The DBC system is comprised of alloy substrate/diffusion barrier/Al-reservoir/an external scale. Diffusion flux (JAl) of Al through the barrier layer will be given approximately by JAl = DAl x SAl x (d CAl/d x), where DAl and SAl are the diffusion coefficient and solubility limit of Al in the barrier layer, respectively as well as d CAl / d x is driving force given by the concentration difference across the barrier (d CAl) divided by the thickness of the barrier layer (d x). A slow diffusion flux can be obtained by using low values of DAl, SAl, or (d CAl /d x). Accordingly, a selection of a barrier layer with lower DAl and SAl is essential. A low driving force is also an important factor, and can be achieved by using lower CAl witha constant barrier layer thickness dx. At higher temperatures, however, the barrier layer can react with the alloy substrate and Al-reservoir layer, resulting in gradual degradation of the barrier layer. This means that the thickness dx of the barrier layer tends to decrease and may finally disappear. With decreasing thickness of the diffusion barrier layer, the driving force (dCAl/dx) will increase, and the effectiveness of the barrier layer will be eliminated. Therefore, it is essential to maintain a constant thickness of the barrier layer for long exposure time. Several types of the DBC system are proposed, a single barrier layer and triple-layers with g + g’ and g’ inserted among these barrier layers.

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Teker, Kasif, Yassir A. Ali, and Ali Uzun. "UV-induced photosensing characteristics of SiC and GaN nanowires." Sensor Review 39, no. 4 (July 15, 2019): 488–94. http://dx.doi.org/10.1108/sr-09-2017-0199.

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Purpose This study aims to investigate photosensing characteristics of SiC and GaN nanowire-based devices through exposure to UV light. The photocurrent transients have been modeled to determine rise and decay process time constants. The 1D-semiconductor nanowires can exhibit higher light sensitivity compared to bulk materials because of their large surface area to volume ratio and the quantum size effects. Design/methodology/approach Nanowire devices have been fabricated through dielectrophoresis for integrating nanowires onto pre-patterned electrodes (10 nm Ti/ 90 nm Au) with a spacing about 3 µm onto SiO2/Si (doped) substrate. The photocurrent measurements were carried out under room temperature conditions with UV light of 254 nm wavelength. Findings SiCNWs yield very short rise and decay time constants of 1.3 and 2.35 s, respectively. This fast response indicates an enhanced surface recombination of photoexcited electron-hole pairs. Conversely, GaNNWs yield longer rise and decay time constants of 10.3 and 15.4 s, respectively. This persistent photocurrent suggests a reduced surface recombination process for the GaNNWs. Originality/value High selective UV light sensitivity, small size, very short response time, low power consumption and high efficiency are the most important features of nanowire-based devices for new and superior applications in photodetectors, photovoltaics, optical switches, image sensors and biological and chemical sensing.

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24

Amaechi, B. T., S. M. Higham, and W. M. Edgar. "Factors influencing the development of dental erosion in vitro: enamel type, temperature and exposure time." Journal of Oral Rehabilitation 26, no. 8 (August 1999): 624–30. http://dx.doi.org/10.1046/j.1365-2842.1999.00433.x.

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Kudiiarov, Viktor N., Andrey M. Lider, and Natalya S. Pushilina. "Hydrogen Redistribution in Technically Pure Titanium Alloy under X-Ray Exposure at Room Temperature." Advanced Materials Research 880 (January 2014): 74–79. http://dx.doi.org/10.4028/www.scientific.net/amr.880.74.

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This paper presents experimental results in study of hydrogen redistribution in technically pure titanium alloy under X-ray exposure at room temperature. It is demonstrated that X-ray exposure to titanium with hydrogen affects hydrogen diffusion and redistribution from the surface area to the depth of the samples irrespective of hydrogen condition in titanium: in hydride form or dissolved state. Increase of the exposure time increases the amount of hydrogen redistributed. Hydrogen desorption during irradiation by X-rays at room temperature does not happen.

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Reis, Adriano Gonçalves, Danieli Aparecida Pereira Reis, Antônio Jorge Abdalla, Antônio Augusto Couto, and Jorge Otubo. "An In Situ High-Temperature X-Ray Diffraction Study of Phase Transformations in Maraging 300 Steel." Defect and Diffusion Forum 371 (February 2017): 73–77. http://dx.doi.org/10.4028/www.scientific.net/ddf.371.73.

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An in situ high-temperature X-ray diffraction (HTXRD) study in maraging 300 steel was carried out to study the martensite to austenite transformation and effect of time of exposure in the austenite reversion below austenite start temperature. Solution annealed materials were subjected to controlled heating-holding cycles. The first sample was heated at a rate of 10 oC/min from room temperature to 800 oC, showing that the microstructure is completely martensitic (α’110) until 600 oC. From 650 oC until 800 oC, the microstructure is gradually changing from martensitic to austenitic, showed by the increasing peaks of γ111 and reducing peaks of α’110. At 800 oC the microstructure is completely austenitic (γ111). Another sample was heated at 10 oC/min from room temperature to 600 oC and held for 4 hours. At 600 oC, at 0 h time of exposure, only a martensitic peak was observed. An austenite peak can be observed after some time of exposure at this temperature. The volume fraction of austenite increased with increasing time of exposure at 600 oC, reaching 50/50 volume fraction after 4 hours of exposure. XRD diffraction patterns for the same sample that was held for 4 hours at 600 oC and then cooled down in air to room temperature showed the same intensity of austenite and martensitic peaks found in situ at 600 oC for 4 hours (retained austenite), with the volume fraction of 50/50 of austenite and martensite phases. The HTXRD technique can be used to identify and quantify martensite to austenite transformation and austenite retention.

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YU, Z., K. SCHULMEISTER, K. GALICHANIN, and P. SÖDERBERG. "Ocular temperature rise and light scattering development in the lens correlating with exposure time after in vivo exposure to 1090 nm infrared radiation." Acta Ophthalmologica 89, s248 (September 2011): 0. http://dx.doi.org/10.1111/j.1755-3768.2011.2362.x.

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Christensen, Karin L., Janne Ø. Christensen, Sven Frokjaer, Peter Langballe, and Lars L. Hansen. "Influence of temperature and storage time after light exposure on the quinine monohydrochloride chemical actinometric system." European Journal of Pharmaceutical Sciences 9, no. 3 (January 2000): 317–21. http://dx.doi.org/10.1016/s0928-0987(99)00072-x.

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29

Nickel, Klaus G., Melanie Keuper, and Christoph Berthold. "The Long-Time Low-Temperature Degradation (“LTD”) Kinetics in 3Y-TZP Bioceramics." Key Engineering Materials 529-530 (November 2012): 589–94. http://dx.doi.org/10.4028/www.scientific.net/kem.529-530.589.

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This work follows a study on hydrothermal aged 3Y-TZP bioceramics, which showed that the surface X-ray diffraction data from moisture exposed samples give distorted results, reflecting a simple linear growth of a partially transformed layer from the surface into the interior. There is no indication for a leveling off or retardation of this growth at elevated temperatures (134°C) and here we present evidence that this is probably true at body temperatures as well. However, the rate constants at body temperature for the studied material are low and indicate a long lifetime. It should be noted that this statement is specific and other materials with minor changes to chemistry or microstructure may behave much better or much worse under those conditions. Furthermore slow crack growth and crack interactions are not yet investigated and may necessitate a minimum of low-temperature degradation susceptibility to ensure reliable long-time use.

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30

Sasaki, Katsunari, Hideto Yamazaki, Kenji Masuda, and Ging-Ho Hsiue. "The Development of a Time-Resolved X-Ray Measurement System Using Imaging Plate." Advances in X-ray Analysis 37 (1993): 385–93. http://dx.doi.org/10.1154/s0376030800015901.

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A X-ray diffraction system using an Imaging Plate(IP) has been developed for time resolved X-ray measurements. The system consists of a new drum scanning type IP reader which includes a multiple time resolved X-ray exposure mechanism and a simple high temperature sample holder. Both are controlled from a personal computer. The new IP reader also supports 50μm/pixel reading for high resolution type IP (Blue IP), and has a spatial resolution better than 75μm.

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YARN, KAO-FENG. "HIGH SENSITIVE HYDROGEN SENSOR BY Pd/OXIDE/InGaP MOS STRUCTURE." Modern Physics Letters B 20, no. 28 (December 10, 2006): 1781–87. http://dx.doi.org/10.1142/s0217984906011888.

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Experimental formation of LPO (liquid phase oxidation)-grown InGaP native oxide near room temperature (~60° C ) is demonstrated. A high oxidation rate is obtained and checked by SEM and AES. The native oxide is determined to be composed of InPO 4 and Ga 2 O 3, analyzed by the results of XPS measurement. Due to the presence of the excellent quality of InGaP native oxide, high hydrogen ( H 2) sensitivity in output current of a Pd /oxide/ InGaP MOS Schottky diode is observed. Under the applied voltage of -1 V and 50 ppm H 2/air, a high sensitivity of 1090 is obtained. An obvious variation of output current and a short response time due to the exposure to different H 2 concentration are also achieved. For example, the adsorption (τa) and desorption (τb) time constants under 50 ppm H 2/air are 2.3 s and 2.7 s, respectively.

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SKVORTSOV, Arkady A., Danila E. PSHONKIN, and Mikhail N. Margarita R. LUK YANOV. "DEFORMATIONS OF ALUMINUM ALLOYS UNDER THE INFLUENCE OF AN ADDITIONAL LOAD." Periódico Tchê Química 15, no. 30 (August 20, 2018): 421–27. http://dx.doi.org/10.52571/ptq.v15.n30.2018.424_periodico30_pgs_421_427.pdf.

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Under the influence of a constant magnetic processes in the future lead to destruction. Therefore, the authors investigated these processes in more detail. When studying the creep of the samples, a lever temperature) simultaneously with the application of the load (carried out by steps), an elongation of the sample was recorded with a micrometer (division price 10 load during the measurement, as well as smoo it is found that creeping increases under stable magnetic field; the main features appear at the first creep stage. Thus, preliminary exposure of samples in a constant magnetic field (with induc room temperature) leads to an increase in the absolute deformation of the aluminum alloy to 35%. The material deformation constants are also determined under " constant at the first stage of creep was found to be more than 6 times. Investigation of these processes will help to predict time dependence of creep strain and its rate as well as durability and plasticity at destruction.

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Mosiori, Cliff Orori, and John Maera. "Tracking Intrinsic Properties of CH3NH3PbI3 Perovskite Thin Films Grown by Spin Coating Technique at Ambient Temperature." Asia Pacific Journal of Energy and Environment 6, no. 2 (December 31, 2019): 59–68. http://dx.doi.org/10.18034/apjee.v6i2.266.

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Methyl ammonium lead iodide has become a burgeoning class of hybrid halide perovskites of solution-processed semiconductors. Advancements in its processing and characterization underscore structural, optical, and electronic properties. They have led to the development of perovskite solar cells, photo detectors, lasers, and photo diodes with power conversion efficiencies mature to be classified as first and second-generation technologies. Characterizing forms an integral understanding the operating principles and fundamental limitations for optoelectronics applications. Studies outlined in this paper covers CH3NH3PbI3 using time-resolved pump-probe spectroscopy, X-ray diffractometry, spectrophotometry and other measurements. Thus this investigatiosn may serve as principle tool in analyzing excited state decay kinetics and optical nonlinearities in CH3NH3PbI3 thin films. It is demonstrated herein that non-resonant photoexcitation yields a large fraction of free carriers on a sub-picosecond time scale. If applied in practical optoelectronic applications then any photogenerated carriers may travel long carrier lengths before they are extracted to realize large external quantum efficiencies and efficient charge extraction. The optical constants of CH3NH3PbI3 are interpreted using ab initio calculations through models. Findings show good agreement between the optical constants derived from QSGW and those from related literature. Transition from the highest valence band (VB) to the lowest conduction band (CB) was found to be responsible for almost all the optical responses between 1.2 and 5.5 eV. It was concluded that optical constants and energy band diagrams of CH3NH3PbI3 can be used to simulate the contributions from different optical transitions to a typical transient absorption spectrum for many optoelectronic applications.

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34

Wang, Wei Hua, Ru Ju Wang, W. T. Yang, B. C. Wei, P. Wen, D. Q. Zhao, and M. X. Pan. "Stability of ZrTiCuNiBe Bulk Metallic Glass upon Isothermal Annealing Near the Glass Transition Temperature." Journal of Materials Research 17, no. 6 (June 2002): 1385–89. http://dx.doi.org/10.1557/jmr.2002.0206.

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The stability of Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass (BMG) upon isothermal annealing near the glass transition temperature has been investigated by using x-ray diffraction, differential scanning calorimetry, and the pulse echo overlap method. The density, elastic constants, and thermodynamic parameters as well as their annealing time dependence have been determined. The microstructural and properties changes of the annealed BMG were checked by acoustic measurement. Obvious structural and property changes were observed with prolonged annealing of the BMG near the glass transition temperature.

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Nazé, Yaël, Tahina Ramiaramanantsoa, Ian R. Stevens, Ian D. Howarth, and Anthony F. J. Moffat. "A detailed X-ray investigation of ζ Puppis." Astronomy & Astrophysics 609 (January 2018): A81. http://dx.doi.org/10.1051/0004-6361/201730729.

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Context. One of the optically brightest and closest massive stars, ζ Pup, is also a bright X-ray source. Previously, its X-ray emission was found to be variable with light curves harbouring “trends” with a typical timescale longer than the exposure length, i.e. >1 d. The origin of these changes was proposed to be linked to large-scale structures in the wind of ζ Pup, but further characterization of the variability at high energies was needed to investigate this scenario. Aims. Since the previous papers of this series, a number of new X-ray observations have become available. Furthermore, a cyclic behaviour with a 1.78 d period was identified in long optical photometric runs, which is thought to be associated with the launching mechanism of large-scale wind structures. Methods. We analysed these new X-ray data, revisited the old data, and compared the X-ray light curves with the optical data, notably those taken simultaneously. Results. The behaviour of ζ Pup in X-rays cannot be explained in terms of a perfect clock because the amplitude and shape of its variations change with time. For example, ζ Pup was much more strongly variable between 2007 and 2011 than before and after this interval. Comparing the X-ray spectra of the star at maximum and minimum brightness yields no compelling difference beyond the overall flux change: the temperatures, absorptions, and line shapes seem to remain constant, well within errors. The only common feature between X-ray datasets is that the variation amplitudes appear maximum in the medium (0.6–1.2 keV) energy band. Finally, no clear and coherent correlation can be found between simultaneous X-ray and optical data. Only a subgroup of observations may be combined coherently with the optical period of 1.78 d, although the simultaneous optical behaviour is unknown. Conclusions. The currently available data do not reveal any obvious, permanent, and direct correlation between X-ray and optical variations. The origin of the X-ray variability therefore still needs to be ascertained, highlighting the need for long-term monitoring in multiwavelengths, i.e. X-ray, UV, and optical.

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West, N. X., J. A. Hughes, and M. Addy. "Erosion of dentine and enamel in vitro by dietary acids: the effect of temperature, acid character, concentration and exposure time." Journal of Oral Rehabilitation 27, no. 10 (October 2000): 875–80. http://dx.doi.org/10.1046/j.1365-2842.2000.00583.x.

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West, N. X., J. A. Hughes, and M. Addy. "Erosion of dentine and enamel in vitro by dietary acids: the effect of temperature, acid character, concentration and exposure time." Journal of Oral Rehabilitation 27, no. 10 (July 7, 2008): 875–80. http://dx.doi.org/10.1111/j.1365-2842.2000.00583.x.

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38

David, J. R., P. Gibert, B. Moreteau, G. W. Gilchrist, and R. B. Huey. "The fly that came in from the cold: geographic variation of recovery time from low-temperature exposure in Drosophila subobscura." Functional Ecology 17, no. 4 (August 2003): 425–30. http://dx.doi.org/10.1046/j.1365-2435.2003.00750.x.

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39

Matija, L., J. Jovanović, B. Adnadjević, and Dj Koruga. "Kinetics of Interaction between Fullerol C₆₀(OH)₂₄ and Polyacrylic Hydrogels." Materials Science Forum 494 (September 2005): 555–60. http://dx.doi.org/10.4028/www.scientific.net/msf.494.555.

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In this paper kinetics of binding of fullerol to polyacrylic hydrogel at different temperatures, 298, 308 and 318 K, has been investigated. Time dependences of specific capacity of fullerol binding to hydrogel at defined temperatures are determined. Kinetic curves of specific binding capacity of fullerol for hydrogel are described by equations: t x k t x k x max 1 2 max 1 1+ = and x=k2tn. Rate constants k1 and k2 of the specific fullerol binding capacity at various temperatures are determined. Based on changes in constants k1 and k2 with temperature, kinetic parameters of the investigated process are calculated. Also, due to a great difference in values of kinetic parameters k1 and k2 obtained by varying the temperature, kinetic parameters are determined by using Friedman’s isoconversion method. The values of kinetic parameters based on temperature changes in k2 correspond to the values of kinetic parameters for 9 . 0 » a , while the values of kinetic parameters calculated according to the temperature change in k1, correspond to the Ea values. According to the obtained results it is concluded that the investigated process is controlled by diffusion.

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40

Dutta, R. K., R. M. Huizenga, M. Amirthalingam, H. Gao, A. King, M. J. M. Hermans, and I. M. Richardson. "Synchrotron Diffraction Studies on the Transformation Strain in a High Strength Quenched and Tempered Structural Steel." Materials Science Forum 777 (February 2014): 231–36. http://dx.doi.org/10.4028/www.scientific.net/msf.777.231.

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In-situ phase transformation behaviour of a high strength (830 MPa yield stress) quenched and tempered S690QL1 (Fe-0.16C-0.2Si-0.87Mn-0.33Cr-0.21Mo (wt. %)) structural steel, during continuous cooling under different mechanical loading conditions to promote the bainitic transformation, was studied. Time-temperature-load resolved 2D synchrotron diffraction patterns were recorded and used to calculate the transformation strains. The temperature dependent elastic constants of ferrite in the steel were also determined using \textit{in-situ} tensile tests at different temperatures in a synchrotron X-ray diffractometer. The transformation strains were calculated under different loading conditions.The elastic constants were calculated from the lattice parameters at 25 °C, 200 °C, 300 °C, 400 °C, 500 °C and 600 °C. The elastic constants varied from 202 GPa at 25 °C to 143 GPa at 600 °C. The variation in lattice plane strains during phase transformation under small external loads were calculated. Bulk measurement techniques such as dilatation experiments give the averaged transformation strains. However, in-situ synchrotron measurements performed in this work describe the transformation strains of the individual transforming phases and the strains arising due to possible variant selection.

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ROEBROECK, E. J. A., M. J. W. JANSEN, and J. J. MES. "A mathematical model describing the combined effect of exposure time and temperature of hot-water treatments on survival of gladiolus cormels." Annals of Applied Biology 119, no. 1 (August 1991): 89–96. http://dx.doi.org/10.1111/j.1744-7348.1991.tb04846.x.

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42

Reynolds, A. P., and D. M. Royster. "Retained mechanical properties of a new AlLiCuMgAg alloy as a function of thermal exposure time and temperature." Scripta Metallurgica et Materialia 30, no. 11 (June 1994): 1485–90. http://dx.doi.org/10.1016/0956-716x(94)90250-x.

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Wang, Hwa-Chi, Govind Doddi, and Stephen Chesters. "Estimating the Lifetime of Electropolished Stainless Steel (EPSS) Tubing in Corrosive Gas Services." Journal of the IEST 37, no. 4 (July 1, 1994): 28–31. http://dx.doi.org/10.17764/jiet.2.37.4.903011514538j103.

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Tubing lifetime in HCI service, defined as the time to begin particle shedding due to corrosion, can be estimated by the method described in this paper. This could provide an additional selection criterion for materials used in corrosive applications. In this method, particle shedding by a length of electropolished stainless steel (EPSS) tubing is measured before and after its controlled exposure to 100 percent HCl. The shedding is measured in dry nitrogen at several different flow rates. The experimental variables are moisture concentration, exposure duration, and shedding flow rates. A dosage-response model is used to correlate the particle data with a combined dosage parameter of moisture concentration and exposure duration. The time for the tube to begin to act as a particle source under HCl exposure is then estimated as follows. For a given allowable particle level C, at a specified flow rate, the dosage parameter X can be determined from C = exp (a+bX) where a and b are constants obtainable from the experimental correlation. Once the dosage parameter X is obtained, the lifetime of the EPSS tubing in HCl service can be estimated from {H2O in ppm} x {Lifetime in days} = X For EPSS tubing exposed to 100 percent HCl with I ppm moisture concentration, this method estimates 2.3 yr for this tubing to shed particles greater than 10 particles/scf at a 3.531 scfm (100 slm) flow rate. This estimate is in line with field experience.

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Biryukov, Jennifer, Jeremy A. Boydston, Rebecca A. Dunning, John J. Yeager, Stewart Wood, Allison Ferris, David Miller, et al. "SARS-CoV-2 is rapidly inactivated at high temperature." Environmental Chemistry Letters 19, no. 2 (February 3, 2021): 1773–77. http://dx.doi.org/10.1007/s10311-021-01187-x.

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AbstractIn the absence of a vaccine, preventing the spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the primary means to reduce the impact of the 2019 coronavirus disease (COVID-19). Multiple studies have reported the presence of SARS-CoV-2 genetic material on surfaces suggesting that fomite transmission of SARS-CoV-2 is feasible. High temperature inactivation of virus has been previously suggested, but not shown. In the present study, we investigated the environmental stability of SARS-CoV-2 in a clinically relevant matrix dried onto stainless steel at a high temperature. The results show that at 54.5 °C, the virus half-life was 10.8 ± 3.0 min and the time for a 90% decrease in infectivity was 35.4 ± 9.0 min. These findings suggest that in instances where the environment can reach temperatures of at least 54.5 °C, such as in vehicle interior cabins when parked in warmer ambient air, that the potential for exposure to infectious virus on surfaces could be decreased substantially in under an hour.

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Bae, Sungwoo, and Stefan Wuertz. "Survival of Host-Associated Bacteroidales Cells and Their Relationship with Enterococcus spp., Campylobacter jejuni, Salmonella enterica Serovar Typhimurium, and Adenovirus in Freshwater Microcosms as Measured by Propidium Monoazide-Quantitative PCR." Applied and Environmental Microbiology 78, no. 4 (December 2, 2011): 922–32. http://dx.doi.org/10.1128/aem.05157-11.

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ABSTRACTThe ideal host-associated genetic fecal marker would be capable of predicting the presence of specific pathogens of concern. Flowthrough freshwater microcosms containing mixed feces and inocula of the pathogensCampylobacter jejuni,Salmonella entericaserovar Typhimurium, and adenovirus were placed at ambient temperature in the presence and absence of diurnal sunlight. The totalEnterococcusDNA increased during the early periods (23 h) under sunlight exposure, even though cultivableEnterococcusand DNA in intact cells, as measured by propidium monoazide (PMA), decreased with first-order kinetics during the entire period. We found a significant difference in the decay of host-associatedBacteroidalescells between sunlight exposure and dark conditions (Pvalue < 0.05), whereas the persistence of host-associatedBacteroidalesDNA was comparable. The 2-log reduction times of adenovirus were 72 h for sunlight exposure and 99 h for dark conditions with similar decay rate constants (Pvalue = 0.13). The persistences of fecalBacteroidalescells andCampylobactercells exposed to sunlight were similar, and host-associatedBacteroidalesDNA and waterborne pathogen DNA were degraded at comparable rates (Pvalues > 0.05). Overall, the ratio of quantitative PCR (qPCR) cycle threshold (CT) values with and without PMA treatment was indicative of the time elapsed since inoculation of the microcosm with (i) fecal material from different animal sources based on host-associatedBacteroidalesand (ii) pure cultures of bacterial pathogens. The use of both PMA-qPCR and qPCR may yield more realistic information about recent sources of fecal contamination and result in improved prediction of waterborne pathogens and assessment of health risk.

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Slade, R., W. P. Watkinson, and G. E. Hatch. "Mouse strain differences in ozone dosimetry and body temperature changes." American Journal of Physiology-Lung Cellular and Molecular Physiology 272, no. 1 (January 1, 1997): L73—L77. http://dx.doi.org/10.1152/ajplung.1997.272.1.l73.

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Strain differences in susceptibility to inhaled ozone (O3) have been observed in mice, with C57BL/6J (B6) mice reported to be more sensitive than C3H/HEJ (C3) mice when exposed to equal concentrations of O3. To determine whether differences in the delivered dose of O3 to the lung could help explain these differences, C3 and B6 mice were exposed to 18O-labeled ozone (18O3), and the resulting 18O concentrations in pulmonary tissues were monitored as an indicator of O3 delivered dose. Body core temperatures (Tco) of similarly treated mice were measured during O3 exposures (using surgically implanted temperature probes) in an effort to correlate lung O3 dose to changes in basal metabolism. Immediately after exposure to 18O3, C3 mice had 46% less 18O (per mg dry wt) in lungs and 61% less in tracheas than B6 mice. Nasal 18O tended to be lower in the C3 mice, but these differences were not significant. Although both strains responded to the O3 exposure with significant decreases in Tco, C3 mice had a 70% greater mean temperature x time product decrease during the exposure than B6 mice. These results suggest that the strain differences in O3 susceptibility may be due to differences in O3 dose to the lung, which may be related to differences in the ability of the mice to lower their Tco in response to O3 exposure.

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Tanley, Simon W. M., Antoine M. M. Schreurs, Loes M. J. Kroon-Batenburg, and John R. Helliwell. "Room-temperature X-ray diffraction studies of cisplatin and carboplatin binding to His15 of HEWL after prolonged chemical exposure." Acta Crystallographica Section F Structural Biology and Crystallization Communications 68, no. 11 (October 26, 2012): 1300–1306. http://dx.doi.org/10.1107/s1744309112042005.

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The anticancer complexes cisplatin and carboplatin are known to bind to both the Nδand the N∊atoms of His15 of hen egg-white lysozyme (HEWL) in the presence of dimethyl sulfoxide (DMSO). However, neither binds in aqueous media after 4 d of crystallization and crystal growth, suggesting that DMSO facilitates cisplatin/carboplatin binding to the N atoms of His15 by an unknown mechanism. Crystals of HEWL cocrystallized with cisplatin in both aqueous and DMSO media, of HEWL cocrystallized with carboplatin in DMSO medium and of HEWL cocrystallized with cisplatin andN-acetylglucosamine (NAG) in DMSO medium were stored for between seven and 15 months. X-ray diffraction studies of these crystals were carried out on a Bruker APEX II home-source diffractometer at room temperature. Room-temperature X-ray diffraction data collection removed the need for cryoprotectants to be used, ruling out any effect that the cryoprotectants might have had on binding to the protein. Both cisplatin and carboplatin still bind to both the Nδand N∊atoms of His15 in DMSO media as expected, but more detail for the cyclobutanedicarboxylate (CBDC) moiety of carboplatin was observed at the N∊binding site. However, two molecules of cisplatin were now observed to be bound to His15 in aqueous conditions. The platinum peak positions were identified using anomalous difference electron-density maps as a cross-check withFo−FcOMIT electron-density maps. The occupancies of each binding site were calculated usingSHELXTL. These results show that over time cisplatin binds to both N atoms of His15 of HEWL in aqueous media, whereas this binding is speeded up in the presence of DMSO. The implication of cisplatin binding to proteins after a prolonged period of time is an important consideration for the length of treatment in patients who are given cisplatin.

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Samulionis, Vytautas, Juras Banys, and Yulian Vysochanskii. "Piezoelectric and Ultrasonic Studies of Mixed Ag_xCu_1-xInP₂(S,Se)₆ Layered Crystals." Materials Science Forum 636-637 (January 2010): 398–403. http://dx.doi.org/10.4028/www.scientific.net/msf.636-637.398.

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The paper reviews recent results of ultrasonic and piezoelectric investigation in CuInP2S6 family ferroelectric layered crystals and their solid solutions in the temperature range 100-360 K. It was shown that, Cu substitution by Ag lowers the phase transition temperature. In investigated AgxCu1-xInP2(S,Se)6 crystals above the phase transition (PT) temperature the piezoelectric response was absent and appeared only below the transition. At low temperatures T < 220 K the layered AgxCu1-xInP2Se6 crystals are ferroelectric. Piezoelectric sensitivity in the ferroelectric phase increases with DC field applied along the c-axis, then saturates, and after reversion of voltage the piezoelectric signal decreases, at field near coercive changes sign, and saturates again at high voltage of opposite polarity In the paraelectric phase under external DC electric field, applied along c-axis normal to layers, thin AgxCu1-xInP2Se6 plates can effectively excite and detect ultrasonic waves, due to electrostriction. The same behaviour was observed and in AgxCu1-xInP2S6 crystals. The critical ultrasonic velocity anomalies were observed in the vicinity of PT. In CuInP2S6 crystals with addition of In i.e. indium rich materials the phase transition temperature could be raised to T > 330 K what is important for applications in medical diagnostics ultrasonic transducers. In all these materials the poling conditions were investigated and it was shown that after long time exposing in DC field the piezoelectric sensitivity sufficiently increases and electromechanical coupling constants as high as > 50 % could be obtained.

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49

Chakartnarodom, Parinya, Nuntaporn Kongkajun, and Wichit Prakaypan. "X-Ray Diffraction Analysis of ZnO Particles Prepared by Microwave Plasma." Key Engineering Materials 751 (August 2017): 195–201. http://dx.doi.org/10.4028/www.scientific.net/kem.751.195.

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The aim of this work is to use x-ray diffraction (XRD) technique to analyze ZnO particles prepared by the reaction between the zinc vapor and oxygen within microwave plasma. The microwave plasma was created by the interaction between the 1200-W 2.45-GHz microwave, the conductive material, and the argon-oxygen gas mixture. Due to the high effective temperature of the plasma, it was thermodynamically and kinetically possible to generate zinc vapor from the solid zinc and then reacted with the oxygen in the gas mixture to form ZnO particles. The synthesis of ZnO in the microwave plasma has been done for 10 to 15 minutes. The XRD results show that the synthesized ZnO samples have wurtzite structure. Moreover, the increasing of synthesis time from 10 to 15 minutes affects the lattice constants, the crystallite size, and the magnitude of strain in ZnO crystals.

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50

Roknuzzaman, M., and A. K. M. A. Islam. "Ab Initio Investigation of Nitride in Comparison with Carbide Phase of Superconducting InX (X = C, N)." ISRN Condensed Matter Physics 2013 (January 14, 2013): 1–9. http://dx.doi.org/10.1155/2013/646042.

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The structural, elastic, electronic, thermal, and optical properties of superconducting nanolaminates Ti2InX (X = C, N) are investigated by density functional theory (DFT). The results obtained from the least studied nitride phase are discussed in comparison with those of carbide phase having value half as that of the former. The carbide phase is found to be brittle in nature, while the nitride phase is less brittle. Elastic anisotropy demonstrates that the c-axis is stiffer in Ti2InN than in Ti2InC. The band structure and density of states show that these phases are conductors, with contribution predominantly from the Ti 3d states. The bulk modulus, Debye temperature, specific heats, and thermal expansion coefficient are obtained as a function of temperature and pressure for the first time through the quasiharmonic Debye model with phononic effects. The estimated values of electron-phonon coupling constants imply that Ti2InC and Ti2InN are moderately coupled superconductors. The calculated thermal expansion coefficient is in fair agreement with the only available measured value for Ti2InC. Further the first time calculated optical functions reveal that the reflectivity is high in the IR-visible-UV region up to ~10 eV and 12.8 eV for Ti2InC and Ti2InN, respectively, showing these to be promising coating materials.

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