Journal articles on the topic 'Temperature sensitivity phenomenon'
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Zhu, Zhi-Wu, Yue Ma, Hai-Dong Zhang, Wei-Dong Song, and Yuan-Chao Gan. "Evaluation of thermal effects and strain-rate sensitivity in frozen soil." Thermal Science 18, no. 5 (2014): 1631–36. http://dx.doi.org/10.2298/tsci1405631z.
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Temperature variation is one important factor that affects the dynamic mechanical properties of frozen soil under impact loading. Thermal damage is a collective phenomenon that can be caused by temperature variation. This paper investigates the effects of thermal damage on strain course. A split Hopkinson pressure bar was employed to investigate the dynamic mechanical characteristics of frozen soil at different temperatures and different strain rates. The stress-strain curves were obtained under impact loading. The compressive strength of frozen soil showed a negative temperature sensitivity and positive strain-rate trend. Specifically, the strength of frozen soil increased with decreasing temperatures and increasing strain rates.
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Cole, Nancy L. "Temperature sensitivity of herpes simplex virus type 1 is a tissue-dependent phenomenon." Archives of Virology 127, no. 1-4 (March 1992): 49–63. http://dx.doi.org/10.1007/bf01309574.
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Okojie, Robert S., Dorothy Lukco, Vu Nguyen, and Ender Savrun. "Demonstration of SiC Pressure Sensors at 750 °C." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2014, HITEC (January 1, 2014): 000028–32. http://dx.doi.org/10.4071/hitec-ta21.
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We report the first demonstration of MEMS-based 4H-SiC piezoresistive pressure sensors tested at 750 °C and in the process confirmed the existence of strain sensitivity recovery with increasing temperature above 400 °C, eventually achieving near or up to 100 % of the room temperature values at 750 °C. This strain sensitivity recovery phenomenon in 4H-SiC is uncharacteristic of the well-known monotonic decrease in strain sensitivity with increasing temperature in silicon piezoresistors. For the three sensors tested, the room temperature full-scale output (FSO) at 200 psig ranged between 29 and 36 mV. Although the FSO at 400 °C dropped by about 60 %, full recovery was achieved at 750 °C. This result will allow the operation of SiC pressure sensors at higher temperatures, thereby permitting deeper insertion into the engine combustion chamber to improve the accurate quantification of combustor dynamics.
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Zhang, Zhen, M. A. Cuddihy, and F. P. E. Dunne. "On rate-dependent polycrystal deformation: the temperature sensitivity of cold dwell fatigue." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 471, no. 2181 (September 2015): 20150214. http://dx.doi.org/10.1098/rspa.2015.0214.
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A temperature and rate-dependent crystal plasticity framework has been used to examine the temperature sensitivity of stress relaxation, creep and load shedding in model Ti-6Al polycrystal behaviour under dwell fatigue conditions. A temperature close to 120°C is found to lead to the strongest stress redistribution and load shedding, resulting from the coupling between crystallographic slip rate and slip system dislocation hardening. For temperatures in excess of about 230°C, grain-level load shedding from soft to hard grains diminishes because of the more rapid stress relaxation, leading ultimately to the diminution of the load shedding and hence, it is argued, the elimination of the dwell debit. Under conditions of cyclic stress dwell, at temperatures between 20°C and 230°C for which load shedding occurs, the rate-dependent accumulation of local slip by ratcheting is shown to lead to the progressive cycle-by-cycle redistribution of stress from soft to hard grains. This phenomenon is termed cyclic load shedding since it also depends on the material's creep response, but develops over and above the well-known dwell load shedding, thus providing an additional rationale for the incubation of facet nucleation.
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Yan, Dong Ming, and Wei Xu. "Strain-Rate Sensitivity of Concrete: Influence of Temperature." Advanced Materials Research 243-249 (May 2011): 453–56. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.453.
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Knowledge about the dynamic properties of concrete is vital to the design and safety evaluation of large-scale concrete structures subjected to seismic excitation. There are many factors affecting the dynamic properties of concrete such as moisture content and temperature. Though a lot of concrete structures have been designed to withstand low temperature, research on the strain-rate sensitivity of concrete under low temperature condition is still very limited so far. In this study, both tensile and compressive experiments were carried out to investigate the influence of temperature on the rate-dependent characteristics of concrete. Tensile experiments of dumbbell-shaped specimens were carried out on a MTS810 testing machine and compressive tests on cubic specimens were performed using a servo-hydraulic testing machine. Specimens at two types of temperature, room temperature 20oC and low temperature -30oC, were characterized. The strain rate varied over a wide range. It was concluded from the test data that the strengths of specimens at both types of temperature tended to increase as strain rate increased. Temperature had slight influence on the rate-sensitive behavior of concrete when concrete specimens were dry; however, test on saturated specimens indicated that the role of temperature on the mechanical behavior of concrete subject to dynamic loading was very significant. This phenomenon may be attributed to the state of free water in concrete.
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Wang, Xiaoxue, Yuguo Li, Xinyan Yang, Pak Chan, Janet Nichol, and Qinglan Li. "The Street Air Warming Phenomenon in a High-Rise Compact City." Atmosphere 9, no. 10 (October 16, 2018): 402. http://dx.doi.org/10.3390/atmos9100402.
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The street thermal environment is important for thermal comfort, urban climate and pollutant dispersion. A 24-h vehicle traverse study was conducted over the Kowloon Peninsula of Hong Kong in summer, with each measurement period consisting of 2–3 full days. The data covered a total of 158 loops in 198 h along the route on sunny days. The measured data were averaged by three methods (direct average, FFT filter and interpolated by the piecewise cubic Hermite interpolation). The average street air temperatures were found to be 1–3 °C higher than those recorded at nearby fixed weather stations. The street warming phenomenon observed in the study has substantial implications as usually urban heat island (UHI) intensity is estimated from measurement at fixed weather stations, and therefore the UHI intensity in the built areas of the city may have been underestimated. This significant difference is of interest for studies on outdoor air temperature, thermal comfort, urban environment and pollutant dispersion. The differences were simulated by an improved one-dimensional temperature model (ZERO-CAT) using different urban morphology parameters. The model can correct the underestimation of street air temperature. Further sensitivity studies show that the building arrangement in the daytime and nighttime plays different roles for air temperature in the street. City designers can choose different parameters based on their purpose.
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Brown, Ross D., Marilyn G. Hughes, and David A. Robinson. "Characterizing the long-term variability of snow-cover extent over the interior of North America." Annals of Glaciology 21 (1995): 45–50. http://dx.doi.org/10.3189/s0260305500015585.
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Historical and reconstructed snow-cover data show evidence of a gradual increase in snow cover over the continental interior of North America (NA) during much of the 20th century, primarily in response to increasing snowfall. A rapid decrease in Canadian-prairies snow cover after 1970 is not observed over the Great Plains. Analysis of snow-cover-climate relationships revealed systematic increases in the sensitivity of snow cover to Northern Hemisphere (NH) temperatures over the 1940-65 period. This change is mainly due to an increase in snowfall-temperature sensitivity during this period. Seasonal analysis revealed that the observed increase in snow-cover and snowfall temperature sensitivity is primarily a spring phenomenon. A marked increase in the importance of the spring period is observed around 1960, which coincides with a well-documented change in atmospheric circulation over NA. The post-1960 period is characterized by a significant inverse relationship between snow cover and hemispheric air temperature over the Canadian prairies and northern Great Plains regions.
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Brown, Ross D., Marilyn G. Hughes, and David A. Robinson. "Characterizing the long-term variability of snow-cover extent over the interior of North America." Annals of Glaciology 21 (1995): 45–50. http://dx.doi.org/10.1017/s0260305500015585.
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Historical and reconstructed snow-cover data show evidence of a gradual increase in snow cover over the continental interior of North America (NA) during much of the 20th century, primarily in response to increasing snowfall. A rapid decrease in Canadian-prairies snow cover after 1970 is not observed over the Great Plains. Analysis of snow-cover-climate relationships revealed systematic increases in the sensitivity of snow cover to Northern Hemisphere (NH) temperatures over the 1940-65 period. This change is mainly due to an increase in snowfall-temperature sensitivity during this period. Seasonal analysis revealed that the observed increase in snow-cover and snowfall temperature sensitivity is primarily a spring phenomenon. A marked increase in the importance of the spring period is observed around 1960, which coincides with a well-documented change in atmospheric circulation over NA. The post-1960 period is characterized by a significant inverse relationship between snow cover and hemispheric air temperature over the Canadian prairies and northern Great Plains regions.
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Shinohara, Ryuichiro, Yoji Tanaka, Ariyo Kanno, and Kazuo Matsushige. "Relative impacts of increases of solar radiation and air temperature on the temperature of surface water in a shallow, eutrophic lake." Hydrology Research 52, no. 4 (July 14, 2021): 916–26. http://dx.doi.org/10.2166/nh.2021.148.
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Abstract We monitored lake surface water temperatures from 1992 to 2019 in Lake Kasumigaura, a shallow lake in Japan. We hypothesized that increases of shortwave radiation had increased surface water temperatures and heat fluxes more than had the increases of air temperature. We used the heat flux analyses and the sensitivity analyses to test the hypothesis. The fluxes of solar radiation gradually increased during the study period in a manner consistent with the phenomenon of global brightening. The increase was especially apparent in the spring. The rate of increase of surface water temperature was especially significant in May. Air temperature did not significantly increase in May, but it increased significantly in June (0.40 °C decade−1). A sensitivity analysis of the heat fluxes at the lake surface (shortwave radiation, longwave radiation, latent heat flux, and sensible heat flux) revealed that surface water temperature was more sensitive to changes of shortwave radiation than to air temperature during the spring. Although other factors such as inflows of groundwater and river water may also have impacted surface water temperatures, the increase of solar radiation appeared to be the major factor responsible for the increase of surface water temperature during the spring in Lake Kasumigaura.
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Sarnowski, Michał, Karol Kowalski, Jan Król, and Piotr Radziszewski. "Influence of Overheating Phenomenon on Bitumen and Asphalt Mixture Properties." Materials 12, no. 4 (February 18, 2019): 610. http://dx.doi.org/10.3390/ma12040610.
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In the course of manufacturing, transport and installation, road bitumens and asphalt mixtures can be exposed to the impact of elevated process temperatures exceeding 240 °C. This mainly applies to the mixtures used for road pavements and bridge deck insulation during adverse weather conditions. The heating process should not change the basic and rheological properties of binders and the asphalt mixtures that to a degree cause the degradation of asphalt pavement durability. The work involved analyzing the properties of non-modified bitumens and SBS polymer modified bitumens, heated at temperatures of 200 °C, 250 °C and 300 °C for 1 h. Next, the asphalt mixtures were heated in the same temperatures. Based on the developed Overheating Degradation Index (ODI) it was demonstrated that polymer-modified bitumens were characterized by higher overheating sensitivity A(ODI) than non-modified bitumens, which was confirmed by mixture test results. Overheating limit temperatures T(ODI) were determined, which in the case of polymer-modified bitumens are up to 20 °C lower than for non-modified bitumens. When the temperature increases above T(ODI), loss of viscoelastic properties occurs in the material which causes, among other effects, a loss of resistance to fatigue cracking.
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Xiong, Bai Qing, Xi Wu Li, Yon Gan Zhang, Zhi Hui Li, Bao Hong Zhu, Feng Wang, and Hong Wei Liu. "Investigation of Quench Sensitivity of an Al-7.5Zn-1.7Mg-1.4Cu-0.12Zr Alloy." Materials Science Forum 706-709 (January 2012): 431–35. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.431.
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In the present work, quench sensitivity of an Al-7.5Zn-1.7Mg-1.4Cu-0.12Zr alloy is investigated by temperature-time-property (TTP) curve and TEM analysis, comparing with traditional AA 7B04 and AA 7150. The results indicate that the nose temperature of TTP curve and the corresponding incubation period of the alloy, AA 7150 and AA 7B04 are about 290°C/4.5s, 320°C/2.6s and 335°C/0.1s, respectively, The nose temperature of the alloy is the lowest among three alloys and the critical time at the nose temperature is the longest for the alloy, which is obvious that the alloy has lower quench sensitivity. Further TEM analysis shows that, with the prolongation of keeping time at the nose temperature, quench-induced precipitation phenomenon becomes obvious.
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Dutta, T., K. P. Sinhamahapatra, and S. S. Bandyopadhyay. "CFD Analysis of Energy Separation in Ranque-Hilsch Vortex Tube at Cryogenic Temperature." Journal of Fluids 2013 (November 14, 2013): 1–14. http://dx.doi.org/10.1155/2013/562027.
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Study of the energy separation phenomenon in vortex tube (VT) at cryogenic temperature (temperature range below 123 K) has become important because of the potential application of VT as in-flight air separator in air breathing propulsion. In the present study, a CFD model is used to simulate the energy separation phenomenon in VT with gaseous air at cryogenic temperature as working fluid. Energy separation at cryogenic temperature is found to be considerably less than that obtained at normal atmospheric temperature due to lower values of inlet enthalpy and velocity. Transfer of tangential shear work from inner to outer fluid layers is found to be the cause of energy separation. A parametric sensitivity analysis is carried out in order to optimize the energy separation at cryogenic temperature. Also, rates of energy transfer in the form of sensible heat and shear work in radial and axial directions are calculated to investigate the possible explanation of the variation of the hot and cold outlet temperatures with respect to various geometric and physical input parameters.
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Liu, Qiaoli, Huijun Tian, Shifeng Zhang, Bo Wang, Li Xu, Yuxin Jin, Anqi Hu, and Xia Guo. "High-sensitivity graphene/Cu2O hybrid photodetectors based on photo-induced quantum capacitance." AIP Advances 12, no. 4 (April 1, 2022): 045003. http://dx.doi.org/10.1063/5.0087675.
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Graphene/semiconductor hybrid photodetectors have attracted much attention recently for their excellent optoelectronic properties. However, high background current and 1/f noise limit their sensitivity. In this paper, the phenomenon of photo-induced quantum capacitance was found based on the transfer-free graphene/Cu2O/Cu structure. Under illumination, the Fermi level in graphene can be modulated by the photogenerated holes trapped in Cu2O nanoparticles, which causes the capacitance response phenomenon. The maximum capacitance response of 104 F/W with the minimum detectable light power of 5.3 fW was achieved at room temperature.
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Shalniene, Vida, and Rimantas Nivinskas. "Temperature sensitivity of the multiplication of bacteriophage T4 amber mutants on nonpermissive host: Characterization of the phenomenon." Virology 160, no. 2 (October 1987): 426–32. http://dx.doi.org/10.1016/0042-6822(87)90014-6.
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Yang, Chi-Ming, John C. Osterman, and John Markwell. "Temperature sensitivity as a general phenomenon in a collection of chlorophyll-deficient mutants of sweetclover (Melilotus alba)." Biochemical Genetics 28, no. 1-2 (February 1990): 31–40. http://dx.doi.org/10.1007/bf00554819.
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Lindberg, Lotte, Bent Kristensen, Jane F. Thomsen, Ebbe Eldrup, and Lars T. Jensen. "Characteristic Features of Infrared Thermographic Imaging in Primary Raynaud’s Phenomenon." Diagnostics 11, no. 3 (March 20, 2021): 558. http://dx.doi.org/10.3390/diagnostics11030558.
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Raynaud’s phenomenon (RP) is characterized by the episodic whitening of the fingers upon exposure to cold. Verification of the condition is crucial in vibration-exposed patients. The current verification method is outdated, but thermographic imaging seems promising as a diagnostic replacement. By investigating patients diagnosed with RP, the study aimed at developing a simple thermographic procedure that could be applied to future patients where verification of the diagnosis is needed. Twenty-two patients with primary RP and 58 healthy controls were examined using thermographic imaging after local cooling of the hands for 1 min in water of 10°C. A logistic regression model was fitted with the temperature curve characteristics to convey a predicted probability of having RP. The characteristics time to end temperature and baseline temperature were the most appropriate predictors of RP among those examined (p = 0.004 and p = 0.04, respectively). The area under the curve was 0.91. The cut-off level 0.46 yielded a sensitivity and specificity of 82% and 86%, respectively. The positive and negative predictive values were 69% and 93%, respectively. This newly developed thermographic method was able to distinguish between patients with RP and healthy controls and was easy to operate. Thus, the method showed great promise as a method for verification of RP in future patients. Trial registration: ClinicalTrials.gov NCT03094910.
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Giuliano, Gillo. "Comparison between Finite Element Commercial Codes to Simulate High-Temperature AA5083 Bulge Forming." Advanced Materials Research 457-458 (January 2012): 387–90. http://dx.doi.org/10.4028/www.scientific.net/amr.457-458.387.
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In this study in order to investigate the behavior of AA5083 aluminum sheet during high-temperature bulge forming a material model was used which accounts for the strain-rate sensitivity, the hardening and the softening of the material, the evolution of the grain growth and the phenomenon of the cavitation. The results obtained from the finite element commercial codes MSC.Marc® and ABAQUSTM were compared.
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Zhang, Zhijun, Wenchao Qin, Bin Shi, Jingxin Gao, and Shiwei Zhang. "Modelling of intermittent microwave convective drying: parameter sensitivity." Open Physics 15, no. 1 (June 14, 2017): 405–19. http://dx.doi.org/10.1515/phys-2017-0045.
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AbstractThe reliability of the predictions of a mathematical model is a prerequisite to its utilization. A multiphase porous media model of intermittent microwave convective drying is developed based on the literature. The model considers the liquid water, gas and solid matrix inside of food. The model is simulated by COMSOL software. Its sensitivity parameter is analysed by changing the parameter values by ±20%, with the exception of several parameters. The sensitivity analysis of the process of the microwave power level shows that each parameter: ambient temperature, effective gas diffusivity, and evaporation rate constant, has significant effects on the process. However, the surface mass, heat transfer coefficient, relative and intrinsic permeability of the gas, and capillary diffusivity of water do not have a considerable effect. The evaporation rate constant has minimal parameter sensitivity with a ±20% value change, until it is changed 10-fold. In all results, the temperature and vapour pressure curves show the same trends as the moisture content curve. However, the water saturation at the medium surface and in the centre show different results. Vapour transfer is the major mass transfer phenomenon that affects the drying process.
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Larionova, A. A., I. V. Yevdokimov, and S. S. Bykhovets. "Temperature response of soil respiration is dependent on concentration of readily decomposable C." Biogeosciences 4, no. 6 (December 4, 2007): 1073–81. http://dx.doi.org/10.5194/bg-4-1073-2007.
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Abstract. Temperature acclimation of soil organic matter (SOM) decomposition is one of the major uncertainties in predicting soil CO2 efflux associated with the increase in global mean temperature. A reasonable explanation for an apparent acclimation proposed by Davidson and colleagues (2006) based on Michaelis-Menten kinetics suggests that temperature sensitivity decreases when both maximal activity of respiratory enzymes (Vmax) and half-saturation constant (Ks) cancel each other upon temperature increase. We tested the hypothesis of the canceling effect by the mathematical simulation of data obtained in incubation experiments with forest and arable soils. Our data support the hypothesis and suggest that concentration of readily decomposable C substrate (as glucose equivalents) and temperature dependent substrate release are the important factors controlling temperature sensitivity of soil respiration. The highest temperature sensitivity of soil respiration was observed when substrate release was temperature dependent and C substrate concentration was much lower than Ks. Increase of substrate content to the half-saturation constant by glucose addition resulted in temperature acclimation associated with the canceling effect. Addition of the substrate to the level providing respiration at a maximal rate Vmax leads to the acclimation of the whole microbial community as such. However, growing microbial biomass was more sensitive to the temperature alterations. This study improves our understanding of the instability of temperature sensitivity of soil respiration under field conditions, attributing this phenomenon to changes in concentration of readily decomposable C substrate.
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Larionova, A. A., I. V. Yevdokimov, and S. S. Bykhovets. "Temperature sensitivity of soil respiration is dependent on readily decomposable C substrate concentration." Biogeosciences Discussions 4, no. 3 (June 26, 2007): 2007–25. http://dx.doi.org/10.5194/bgd-4-2007-2007.
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Abstract. Temperature acclimation of soil organic matter (SOM) decomposition is one of the major uncertainties in predicting soil CO2 efflux by the increase in global mean temperature. A reasonable explanation for an apparent acclimation proposed by Davidson and colleagues (2006) based on Michaelis-Menten kinetics suggests that temperature sensitivity decreases when both maximal activity of respiratory enzymes (Vmax) and half- saturation constant (Ks) cancel each other upon temperature increase. We tested the hypothesis of the canceling effect by the mathematical simulation of the data obtained in the incubation experiments with forest and arable soils. Our data confirm the hypothesis and suggest that concentration of readily decomposable C substrate as glucose equivalent is an important factor controlling temperature sensitivity. The highest temperature sensitivity was observed when C substrate concentration was much lower than Ks. Increase of substrate content to the half-saturation constant resulted in temperature acclimation associated with the canceling effect. Addition of the substrate to the level providing respiration at a maximal rate Vmax leads to the acclimation of the whole microbial community as such. However, growing microbial biomass was more sensitive to the temperature alterations. This study improves our understanding of the instability of temperature sensitivity of soil respiration under field conditions, explaining this phenomenon by changes in concentration of readily decomposable C substrate. It is worth noting that this pattern works regardless of the origin of C substrate: production by SOM decomposition, release into the soil by rhizodeposition, litter fall or drying-rewetting events.
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Kim, Hye-Mi, Carlos D. Hoyos, Peter J. Webster, and In-Sik Kang. "Sensitivity of MJO Simulation and Predictability to Sea Surface Temperature Variability." Journal of Climate 21, no. 20 (October 15, 2008): 5304–17. http://dx.doi.org/10.1175/2008jcli2078.1.
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Abstract The influence of sea surface temperature (SST) on the simulation and predictability of the Madden–Julian oscillation (MJO) is examined using the Seoul National University atmospheric general circulation model (SNU AGCM). Forecast skill was examined using serial climate simulations spanning eight different winter seasons with 30-day forecasts commencing every 5 days, giving a total of 184 thirty-day simulations. The serial runs were repeated using prescribing observed SST with monthly, weekly, and daily temporal resolutions. The mean SST was the same for all cases so that differences between experiments result from the different temporal resolutions of the SST boundary forcing. It is shown that high temporal SST frequency acts to improve 1) the MJO activity of 200-hPa velocity potential field over the entire Asian monsoon region at all lead times; 2) the percentage of filtered variance of the two leading EOF modes that explain the eastward propagation of MJO; 3) the power of the wavenumber 1 eastward propagating mode; and 4) the forecast skill of MJO, maintaining it for longer periods. However, the MJO phase relationship between MJO convection and SST, as is often the case with many atmosphere-only models, although well simulated at the beginning of forecast period becomes distorted rapidly as the forecast lead time increases, even with the daily SST forcing case. Comparison of AGCM simulations with coupled GCM (CGCM) integrations shows that ocean–atmosphere coupling improves considerably the phase relationship between SST and convection. The CGCM results reinforce that the MJO is a coupled phenomenon and suggest strongly the need of the ocean–atmosphere coupled processes to extend predictability.
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Dorozinska, H. V. "INFLUENCE MATERIAL OF PRISM ON THE SENSITIVITY OF SPR SENSORS." Optoelektronìka ta napìvprovìdnikova tehnìka 55 (December 31, 2020): 179–85. http://dx.doi.org/10.15407/iopt.2020.55.179.
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Theoretical analysis of the influence of the sensor prism material on the basis of the phenomenon of surface plasmon resonance (SPR) on its sensitivity and temperature stability of the measurement result is carried out. The analysis was performed for the infrared wavelength range of excitation surface plasmon radiation (980... 1550 nm) using materials for prisms with different refractive indices, namely: glass ceramics Zerodur (n D = 1,5423), optical glasses N-FK51A (n D = 1, 4865) and N-BK7 (n D = 1,5167) with low refractive index, single crystal material CaF 2 (n D = 1.4339), as well as flints N-SF2 (n D = 1,6475) and N-SF11 (n D = 1,7845). The temperature stability of the measurement result was determined for the temperature range from 20 °C to 70 °C, which corresponds to the operating temperature range of most refractometers and commercial SPR sensors. The coefficient of temperature shift of the minimum reflection characteristic for the investigated materials was calculated as the ratio of the magnitude of the angular shift ∆θ to the corresponding change of temperature ∆Т, which caused this shift. The results of the study showed that for all materials, regardless of the refractive index value, the temperature effect decreases with increasing wavelength of radiation. For the material with a lower refractive index (CaF 2 ), the temperature coefficient was 2 times higher than for flint glass (N-SF11). According to the results of the analysis, it was found that the sensitivity of the SPR sensor increases threefold from 52.83 deg./RIU to 173.16 deg./RIU when the refractive index of the prism changes from n D = 1.79 to n D = 1.43. It was also found that increasing the wavelength of the radiation increased both the sensitivity of the SPR sensor and temperature stability regardless of the prism material. The results of the study can be used both to develop new SPR sensors and to optimize the modes of operation of existing ones, in particular the choice of optimal sensitivity at a given range of measurement of the refractive index of the test substance.
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Merla, A., G. L. Romani, S. Di Luzio, L. Di Donato, G. Farina, M. Proietti, S. Pisarri, and F. Salsano. "Raynaud's Phenomenon: Infrared Functional Imaging Applied to Diagnosis and Drugs Effects." International Journal of Immunopathology and Pharmacology 15, no. 1 (January 2002): 41–52. http://dx.doi.org/10.1177/039463200201500106.
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A non-invasive, innovative approach to the study of Raynaud's Phenomenon is proposed. A group of patients, with respect of a control group, underwent a simultaneous assessment of thermal properties of all ten fingers using infrared functional imaging (IRFI). The assessment highlighted a quite different behaviour between patients with Primary- (PRP) and those with scleroderma - Raynaud's Phenomenon (SSc) and, compared with other existing techniques, seems to be an objective and effective tool to discriminate between PRP and RP secondary to SSc. 18 healthy volunteers (Norm), 20 Primary Raynaud's Phenomenon (PRP) and 20 Secondary Scleroderma (SSc) patients were studied subsequently to clinical evaluation and nail fold capillaroscopy. High-resolution infrared imaging of finger re-warming processes, immediately after a 2 min cold stress, allowed to identify objective parameters. Temperature integral Q (the temperature evaluation of the area under the time-temperature curve along the re-warming period) provided particularly effective figures in describing thermal properties of the fingers. Grand average Q values were (383.4 ± 12.5) °C/min, (502.9 ± 88.1) °C/min and (1022.0 ± 110.2) ±C/min for the PRP, SSc and Normal groups, respectively. Separate evaluation of the temperature integral for each finger leads to very similar results for the fingers of all the PRP patients; a different thermoregulatory response was observed in SSc patients. The sensitivity of the method in order to distinguish healthy from ill fingers was 100 %. The specificity in distinguishing SSc from PRP was 95%. In addition, IRFI parameters provided a better understanding of the impaired control of the finger's temperature in PRP and SSc with respect to the Normal group. This pilot study also applied IRFI for the measurement of drug effects in patients with Raynaud's Phenomenon. Sixteen out of twenty SSc patients were tested in a single 1-hour session of N-acetylcysteine infusion. IRFI clearly documented a significant increase of face and hands temperature during the drug administration. The grand average value of the finger's temperature after the 1 hour NAC administration was (29.6 ± 3.7) °C, while its value before was (27.9 ± 3.7) °C (p<0.001). N-acetylcysteine seems to act as a vasodilator in patients with Raynaud's phenomenon secondary to systemic sclerosis (scleroderma).
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Zhang, Xuebin, Bruce Cornuelle, and Dean Roemmich. "Adjoint Sensitivity of the Niño-3 Surface Temperature to Wind Forcing." Journal of Climate 24, no. 16 (August 15, 2011): 4480–93. http://dx.doi.org/10.1175/2011jcli3917.1.
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Abstract The evolution of sea surface temperature (SST) over the eastern equatorial Pacific plays a significant role in the intense tropical air–sea interaction there and is of central importance to the El Niño–Southern Oscillation (ENSO) phenomenon. Effects of atmospheric fields (especially wind stress) and ocean state on the eastern equatorial Pacific SST variations are investigated using the Massachusetts Institute of Technology general circulation model (MITgcm) and its adjoint model, which can calculate the sensitivities of a cost function (in this case the averaged 0–30-m temperature in the Niño-3 region during an ENSO event peak) to previous atmospheric forcing fields and ocean state going backward in time. The sensitivity of the Niño-3 surface temperature to monthly zonal wind stress in preceding months can be understood by invoking mixed layer heat balance, ocean dynamics, and especially linear equatorial wave dynamics. The maximum positive sensitivity of the Niño-3 surface temperature to local wind forcing usually happens ~1–2 months before the peak of the ENSO event and is hypothesized to be associated with the Ekman pumping mechanism. In model experiments, its magnitude is closely related to the subsurface vertical temperature gradient, exhibiting strong event-to-event differences with strong (weak) positive sensitivity during La Niña (strong El Niño) events. The adjoint sensitivity to remote wind forcing in the central and western equatorial Pacific is consistent with the standard hypothesis that the remote wind forcing affects the Niño-3 surface temperature indirectly by exciting equatorial Kelvin and Rossby waves and modulating thermocline depth in the Niño-3 region. The current adjoint sensitivity study is consistent with a previous regression-based sensitivity study derived from perturbation experiments. Finally, implication for ENSO monitoring and prediction is also discussed.
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Theeuwes, N. E., G. J. Steeneveld, F. Krikken, and A. A. M. Holtslag. "Mesoscale modeling of lake effect snow over Lake Erie – sensitivity to convection, microphysics and the water temperature." Advances in Science and Research 4, no. 1 (March 17, 2010): 15–22. http://dx.doi.org/10.5194/asr-4-15-2010.
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Abstract. Lake effect snow is a shallow convection phenomenon during cold air advection over a relatively warm lake. A severe case of lake effect snow over Lake Erie on 24 December 2001 was studied with the MM5 and WRF mesoscale models. This particular case provided over 200 cm of snow in Buffalo (NY), caused three casualties and $10 million of material damage. Hence, the need for a reliable forecast of the lake effect snow phenomenon is evident. MM5 and WRF simulate lake effect snow successfully, although the intensity of the snowbelt is underestimated. It appears that significant differences occur between using a simple and a complex microphysics scheme. In MM5, the use of the simple-ice microphysics scheme results in the triggering of the convection much earlier in time than with the more sophisticated Reisner-Graupel-scheme. Furthermore, we find a large difference in the maximum precipitation between the different nested domains: Reisner-Graupel produces larger differences in precipitation between the domains than "simple ice". In WRF, the sophisticated Thompson microphysics scheme simulates less precipitation than the simple WSM3 scheme. Increased temperature of Lake Erie results in an exponential growth in the 24-h precipitation. Regarding the convection scheme, the updated Kain-Fritsch scheme (especially designed for shallow convection during lake effect snow), gives only slight differences in precipitation between the updated and the original scheme.
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Ma, Xinping, Hongying Bai, Chenhui Deng, and Tao Wu. "Sensitivity of Vegetation on Alpine and Subalpine Timberline in Qinling Mountains to Temperature Change." Forests 10, no. 12 (December 3, 2019): 1105. http://dx.doi.org/10.3390/f10121105.
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Alpine timberline is a great place for monitoring climate change. The study of alpine and subalpine timberline in Qinling Mountains has led to early warning that reveals the response and adaptation of terrestrial vegetation ecosystem to climate change. Based on the remote sensing image classification method, the typical timberline area in Qinling Mountains was determined. Temperature and normalized difference vegetation index (NDVI) data were extracted from the typical timberline area based on spatial interpolation and NDVI data. The relationship between NDVI and temperature change and the critical temperature value affecting vegetation response in the timberline area in Qinling Mountains were analyzed. Correlation between NDVI and air temperature in the alpine and subalpine timberline areas of Qinling Mountains exhibited an upward trend, which implied that temperature promotes vegetation activity. A strong correlation between temperature and NDVI in typical timberline areas of Qinling Mountains, and a significant correlation between temperature and NDVI in the early growing season. A phenomenon of NDVI lagging behind air temperature was observed. Temperature response showed synchronization and hysteresis. The correlation between cumulative temperature and vegetation was similar between Taibai Mountain and Niubeiliang timberline, and the correlation between NDVI in April and cumulative temperature in the first 12 months was the strongest. Temperature threshold range of Taibai Mountain timberline played a dominant role in vegetation growth. Our results provide insights and basis for future studies of early warning signs of climate change, specifically between 0.34 and 1.34 °C. The threshold ranges of temperature response of different vegetation types vary. Compared with alpine shrub meadow, the threshold ranges of temperature effect of Coniferous forest and Larix chinensis Beissn. are smaller, implying that these vegetation types are more sensitive to temperature change.
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Hardcastle, F. D., and J. M. Harris. "Thermal Lens Absorption Measurements in Binary Liquid Mixtures near the Consolute Critical Point." Applied Spectroscopy 40, no. 5 (July 1986): 606–11. http://dx.doi.org/10.1366/0003702864508692.
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Binary liquid mixtures near their consolute critical points are shown to possess desirable thermophysical properties for thermal lens absorption measurements. By use of a 2,6-dimethylpyridine/water mixture near critical composition and temperature, sensitivity was found to be enhanced relative to pure liquids by the Soret effect in which a concentration gradient is created between the two solvent components by thermally induced mass diffusion within the laser-excited temperature gradient. A 35-fold increase in sensitivity relative to a thermal expansion lens effect in pure water was obtained. A mechanism of phase separation unique to the critical point region known as spinodol decomposition was observed, as the sample temperature was driven above the critical point by laser excitation. This phenomenon was also found to be a potentially useful spectrophotometric technique for the thermooptical detection of small absorbances.
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Garba, Salisu M., and Usman A. Danbaba. "Modeling the effect of temperature variability on malaria control strategies." Mathematical Modelling of Natural Phenomena 15 (2020): 65. http://dx.doi.org/10.1051/mmnp/2020044.
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In this study, a non-autonomous (temperature dependent) and autonomous (temperature independent) models for the transmission dynamics of malaria in a population are designed and rigorously analysed. The models are used to assess the impact of temperature changes on various control strategies. The autonomous model is shown to exhibit the phenomenon of backward bifurcation, where an asymptotically-stable disease-free equilibrium (DFE) co-exists with an asymptotically-stable endemic equilibrium when the associated reproduction number is less than unity. This phenomenon is shown to arise due to the presence of imperfect vaccines and disease-induced mortality rate. Threshold quantities (such as the basic offspring number, vaccination and host type reproduction numbers) and their interpretations for the models are presented. Conditions for local asymptotic stability of the disease-free solutions are computed. Sensitivity analysis using temperature data obtained from Kwazulu Natal Province of South Africa [K. Okuneye and A.B. Gumel. Mathematical Biosciences 287 (2017) 72–92] is used to assess the parameters that have the most influence on malaria transmission. The effect of various control strategies (bed nets, adulticides and vaccination) were assessed via numerical simulations.
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Wu, Zeen, Tiebang Zhang, Fan Zhang, Rui Hu, and Xiaoye Wang. "Microstructural Evolution and the Irradiation Sensitivity of Different Phases of a High Nb-Containing TiAl Alloy under He Ions Implantation at Room- and Elevated Temperatures." Metals 12, no. 2 (February 14, 2022): 335. http://dx.doi.org/10.3390/met12020335.
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A high Nb-containing TiAl alloy Ti-45Al-8.5Nb-(W, B, Y) with nearly lamellar microstructure has been irradiated by 200 kV He2+ to a fluence of 1 × 1021 ions/m2 with a dose of about 1.1 dpa at 298 K and 773 K in this work. It is found that an amorphous layer formed on the surface, and no helium bubbles can be observed in the alloy after room temperature ion implantation. The surface roughness of the alloy increases significantly with the bombardment of helium ions, indicating that the ion implantation increases the surface defects. The high-temperature ion implantation leads to the phenomenon of blistering on the alloy surface, and helium bubbles are observed in both α2 and γ phases of the alloy irradiated at 773 K. The average size of the helium bubbles in the α2 (15~20nm) is larger than that in the γ (3~5 nm) phase, while the helium bubble density is opposite. Moreover, the growth mechanism of helium bubble is also investigated. By means of nanoindentation, an obvious irradiation hardening phenomenon is measured after the room temperature ion implantation. In addition, the irradiation sensitivity of different phases is also discussed in this work. The results show that the γ phase has the highest irradiation sensitivity, α2 phase second, β phase minimum. The results of this work, especially microstructure evolution and the evaluation of phase-related irradiation sensitivity during ion implantation, can be expected to provide experimental evidence for the applications of TiAl intermetallic compounds in the nuclear industries.
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Yang, Xiaoyu, Ertian Hua, Hao Su, Jing Guo, and Shubin Yan. "A Nanostructure with Defect Based on Fano Resonance for Application on Refractive-Index and Temperature Sensing." Sensors 20, no. 15 (July 24, 2020): 4125. http://dx.doi.org/10.3390/s20154125.
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Herein, a nanosensor structure is proposed, which comprises metal-insulator-metal (MIM) waveguide with stub and circular ring cavity with a stub (CRCS). The phenomenon of Fano resonance appears in the transmission spectrum, which is formed by interaction between the narrowband mode of CRCS and broadband mode of stub on bus waveguide. The influence of geometric asymmetry on mode splitting of Fano resonance was discussed. The mode splitting of Fano resonance can vastly improve figure of merit (FOM) with a sight decrease of sensitivity. The best performance of the refractive-index nanosensor is attained, which is 1420 nm/RIU with a high FOM of 76.76. Additionally, the application of designed structure on temperature sensing was investigated, which has sensitivity of 0.8 nm/°C. The proposed structure also possesses potential applications on other on-chip nanosensors.
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Bréant, Camille, Patricia Martinerie, Anaïs Orsi, Laurent Arnaud, and Amaëlle Landais. "Modelling firn thickness evolution during the last deglaciation: constraints on sensitivity to temperature and impurities." Climate of the Past 13, no. 7 (July 13, 2017): 833–53. http://dx.doi.org/10.5194/cp-13-833-2017.
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Abstract. The transformation of snow into ice is a complex phenomenon that is difficult to model. Depending on surface temperature and accumulation rate, it may take several decades to millennia for air to be entrapped in ice. The air is thus always younger than the surrounding ice. The resulting gas–ice age difference is essential to documenting the phasing between CO2 and temperature changes, especially during deglaciations. The air trapping depth can be inferred in the past using a firn densification model, or using δ15N of air measured in ice cores. All firn densification models applied to deglaciations show a large disagreement with δ15N measurements at several sites in East Antarctica, predicting larger firn thickness during the Last Glacial Maximum, whereas δ15N suggests a reduced firn thickness compared to the Holocene. Here we present modifications of the LGGE firn densification model, which significantly reduce the model–data mismatch for the gas trapping depth evolution over the last deglaciation at the coldest sites in East Antarctica (Vostok, Dome C), while preserving the good agreement between measured and modelled modern firn density profiles. In particular, we introduce a dependency of the creep factor on temperature and impurities in the firn densification rate calculation. The temperature influence intends to reflect the dominance of different mechanisms for firn compaction at different temperatures. We show that both the new temperature parameterization and the influence of impurities contribute to the increased agreement between modelled and measured δ15N evolution during the last deglaciation at sites with low temperature and low accumulation rate, such as Dome C or Vostok. We find that a very low sensitivity of the densification rate to temperature has to be used in the coldest conditions. The inclusion of impurity effects improves the agreement between modelled and measured δ15N at cold East Antarctic sites during the last deglaciation, but deteriorates the agreement between modelled and measured δ15N evolution at Greenland and Antarctic sites with high accumulation unless threshold effects are taken into account. We thus do not provide a definite solution to the firnification at very cold Antarctic sites but propose potential pathways for future studies.
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Lorenzo, María N., Juan J. Taboada, and Isabel Iglesias. "Sensitivity of thermohaline circulation to decadal and multidecadal variability." ICES Journal of Marine Science 66, no. 7 (March 28, 2009): 1439–47. http://dx.doi.org/10.1093/icesjms/fsp061.
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Abstract Lorenzo, M. N., Taboada, J. J., and Iglesias, I. 2009. Sensitivity of thermohaline circulation to decadal and multidecadal variability. – ICES Journal of Marine Science, 66: 1439–1447. In this paper, stochastic freshwater inputs with different variabilities are introduced into an Earth Model of Intermediate Complexity to study their effect on the behaviour of the thermohaline circulation (THC). The variability in the stochastic signal was set to be either decadal or multidecadal (70 years), based on intensity modulation of the El Niño-Southern Oscillation (ENSO) phenomenon. The results demonstrate a weakening of the THC in both the decadal and the multidecadal cases. This weakening results in a reduction in air surface temperature, mainly in the North Atlantic. Moreover, the 500-mb stream function also weakens. This causes lower rainfall in Western Europe, except in the areas most influenced by the Gulf Stream. Sea surface temperature is reduced significantly in the area around Greenland, whereas sea surface salinity is reduced around Greenland and in the Gulf Stream, but increased in the Labrador Sea and in Hudson Strait. The latter effects are more marked in the case where the variability of the inputs is multidecadal. The main implication of these results is that the natural decadal or multidecadal variability in freshwater inputs could have noticeable effects on the fate of the THC, which may be superimposed on the effects of climate change.
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Xue, Yong, Li Hui Lang, Guo Liang Bu, and Li Li. "Deformation Behavior of Porous Ti-6Al-4V Alloy Samples Fabricated by Hot Isostatic Pressing." Advanced Materials Research 399-401 (November 2011): 1620–27. http://dx.doi.org/10.4028/www.scientific.net/amr.399-401.1620.
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In the present paper, hot uniaxial compression at elevated temperatures on the samples which had been hot isostatically pressed to 70%-100% relative densities was carried out to investigate the deformation behaviours of porous Ti-6Al-4V alloy. The results show that the flow stress and densification of Ti-6Al-4V alloy have a greater sensitivity on the deformation temperature and strain rate. The flow stress will increase as strain rate increases at the same temperature and the increasing of deformation temperature can lead to a decline in the flow stress at a specific rate. As the deformation temperature rises or the strain rate decreases, the relative density of compressed samples are higher. Moreover, the initial density affects the thermal deformation of powder compact to a certain extent. At the same strain, the greater the initial relative density of Ti-6Al-4V alloy is, the greater the flow stress will be. The flow stress sensitivity to relative density is much less than that to the temperature and strain rate. In addition, the higher the deformation temperature is, the more sufficient the process of alloy spheroidization will be. As the deformation rate decrease, the lamellar organization in the titanium alloy will convert into the equiaxed grains. The lower the deformation rate is, the more obvious the phenomenon of alloy globalization will be. There is not significant transition of the widmanstatten structure in the sample compressed for 2mm. When the sample was compressed for 5.6mm, a few equiaxed grains occurred. When the sample was compressed for 7mm, a large number of equiaxed grain occurred.
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Zhang, Yun Dong, Ying Wang, Yu Long Gai, Xue Nan Zhang, and Ping Yuan. "High-Sensitivity Sensor Using Frequency Sweeping Generated Ringing Effect in Single-Mode Fiber-Loops." Applied Mechanics and Materials 284-287 (January 2013): 2766–70. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.2766.
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In this article, we present propose a simple method to detect the minor fluid-environmental changes using ringing phenomenon generated by frequency sweeping in a single mode optical fiber resonator. The method is based on the fact that the insertion loss of the optical fiber resonator is determined by the environmental changes alone, which leads to the changes of cavity ringdown time of the fiber resonator. The method has several conspicuous advantages over the frequency-domain method, using which the minimal detectable optical loss is in the order of .We also show that the sensing system is insensitive to the temperature drifting, which overcome the main defect of fiber loop resonator, that it is extremely sensitive to temperature changes. The structure of the sensor is compact and stable due to the characteristic of optical fiber resonator, and it is easy to apply because the structure is not delicate and is easy to construct.
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Park, Sanggil, and Min Bum Park. "The Limitations of an Air-Oxidation Breakaway Model to Predict a Zirconium Fire in a Spent Nuclear Fuel Pool Accident." Sustainability 11, no. 22 (November 13, 2019): 6364. http://dx.doi.org/10.3390/su11226364.
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The OECD/NEA Spent Fuel Pool (SFP) project was conducted to investigate consequences of spent nuclear fuel pool accident scenarios. From the project, it was observed that cladding temperature could abruptly increase at a certain point and the cladding was completely oxidized. This phenomenon was called a “zirconium fire”. This zirconium fire is one of the crucial concerns for spent fuel pool safety under a postulated loss of coolant accident scenario, since it would lead to an uncontrolled mass release of fission products into the environment. To capture this critical phenomenon, an air-oxidation breakaway model has been implemented in the MELCOR code. This study examines this air-oxidation breakaway model by comparing the SFP project test data with a series of MELCOR code sensitivity calculation results. The air-oxidation model parameters are slightly altered to investigate their sensitivities on the occurrence of the zirconium fire. Through such sensitivity analysis, limitations of the air-oxidation breakaway model are identified, and needs for model improvement is recommended.
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Luo, Xian Long, Tian Bai Xu, and Li Hong Bi. "Research on Compensation Method of Temperature Drift in Pressure Sensor Using Double Wheatstone-Bridge Method." Advanced Materials Research 459 (January 2012): 311–14. http://dx.doi.org/10.4028/www.scientific.net/amr.459.311.
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this article deals with the influence of temperature on the output sensitivity of the piezo-resistive pressure sensor. In order to reduce the temperature drift of output for the piezo-resistive pressure sensor, the double Wheatstonce-bridge method is adopted to test the sensor with the ternperature controlled at the range of 300~373 K. Tlre results indicate that the temperature drift of the sensor output can be lowered by over 70% to improve surveying accuracy. Pressure senter is widely applied to many fields of the industry, so its accuracy can directly influence the quality of surveying system. Since the piezo-resistive pressure sensor is mostly made of semiconductor materials, the sensitivity and linearity of silicon sentor will be affected to some extent, among which non- linearity is connected with dopant density, temperature and pressure. In ideal condition, four resistor strips are equal in variables with temperature changing, in this way, electric bridge can keep balance to eliminate the effect of tempereature on the sentor. But it’s not the case in reality, temperature drift of output for the piezo-resistive pressure sensor is unavoidable, so some technical methods should be adopted to control the phenomenon. Temperature drift, playing an important role in affecting the quality and accuracy of sentor, has drawn public concern. Document 2 intrduces how to adjust supply voltage to control temperature drift of output for the piezo-resistive pressure sensor. Document 3 intrduces temperature compensation in the sensitivity of sentor. This article aims at making use of four resistors with negative temperature and Wheatstonce-bridge to reduce temperature drift and improve output accuracy of pressure sentor
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Zaman, Tayyaba, Rehan Qayyume, Amjad Ali, Shaheed Khan, and Chaoli Maa. "Superplastic Behavior of Al-Mg-Mn Alloy: An Experimental & Numerical Investigation." Key Engineering Materials 778 (September 2018): 45–52. http://dx.doi.org/10.4028/www.scientific.net/kem.778.45.
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Deformation response of Al-4.46Mg-0.48Mn alloy under uniaxial tensile loading was investigated at temperatures ranging from 400°C - 525°C and at strain rates of 3x10-3s-1, 1x 10-3s-1& 10-4s-1. The alloy exhibited a maximum elongation >480% at a strain rate of 10-3s-1and 525°C. At all conditions, the dominant deformation mechanism governing the superplastic deformation was investigated as a function of strain rate and temperature. The contributions of strain-rate sensitivity and strain hardening were analyzed in relation to the observed tensile ductility. The strain rate sensitivity index (m) and average activation energy (Q) values revealed that the dominant deformation mechanism is grain boundary sliding (GBS). The GBS phenomenon was further confirmed through high magnification examination of deformed surface. Optical microscopy (OM) and Scanning Electron Microscopy (SEM) showed that dynamic re-crystallization occurs during hot deformation of the alloy which causes reasonable enhancement of plasticity.
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Laursen, Willem J., Eve R. Schneider, Dana K. Merriman, Sviatoslav N. Bagriantsev, and Elena O. Gracheva. "Low-cost functional plasticity of TRPV1 supports heat tolerance in squirrels and camels." Proceedings of the National Academy of Sciences 113, no. 40 (September 16, 2016): 11342–47. http://dx.doi.org/10.1073/pnas.1604269113.
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The ability to sense heat is crucial for survival. Increased heat tolerance may prove beneficial by conferring the ability to inhabit otherwise prohibitive ecological niches. This phenomenon is widespread and is found in both large and small animals. For example, ground squirrels and camels can tolerate temperatures more than 40 °C better than many other mammalian species, yet a molecular mechanism subserving this ability is unclear. Transient receptor potential vanilloid 1 (TRPV1) is a polymodal ion channel involved in the detection of noxious thermal and chemical stimuli by primary afferents of the somatosensory system. Here, we show that thirteen-lined ground squirrels (Ictidomys tridecemlineatus) and Bactrian camels (Camelus ferus) express TRPV1 orthologs with dramatically reduced temperature sensitivity. The loss of sensitivity is restricted to temperature and does not affect capsaicin or acid responses, thereby maintaining a role for TRPV1 as a detector of noxious chemical cues. We show that heat sensitivity can be reengineered in both TRPV1 orthologs by a single amino acid substitution in the N-terminal ankyrin-repeat domain. Conversely, reciprocal mutations suppress heat sensitivity of rat TRPV1, supporting functional conservation of the residues. Our studies suggest that squirrels and camels co-opt a common molecular strategy to adapt to hot environments by suppressing the efficiency of TRPV1-mediated heat detection at the level of somatosensory neurons. Such adaptation is possible because of the remarkable functional flexibility of the TRPV1 molecule, which can undergo profound tuning at the minimal cost of a single amino acid change.
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Poszwa, Przemysław, Paweł Brzęk, and Marek Szostak. "Influence of process parameters and runner geometry on shear heating effect." Mechanik 91, no. 1 (January 8, 2018): 36–38. http://dx.doi.org/10.17814/mechanik.2018.1.6.
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Shear heating effect that occurs in melted polymers can cause serious quality problems with production of injection molded parts. The source of this effect is high viscosity of polymers and low thermal conductivity what leads to significant temperature gradients at the cross section of runners. In this work the influence of processing parameters on this phenomenon for difference runner diameters and lengths was presented for two polymers that have different thermal sensitivity.
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Ye, Zhoujing, Ya Wei, Biyu Yang, and Linbing Wang. "Performance Testing of Micro-Electromechanical Acceleration Sensors for Pavement Vibration Monitoring." Micromachines 14, no. 1 (January 7, 2023): 153. http://dx.doi.org/10.3390/mi14010153.
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Pavement vibration monitoring under vehicle loads can be used to acquire traffic information and assess the health of pavement structures, which contributes to smart road construction. However, the effectiveness of monitoring is closely related to sensor performance. In order to select the suitable acceleration sensor for pavement vibration monitoring, a printed circuit board (PCB) with three MEMS (micro-electromechanical) accelerometer chips (VS1002, MS9001, and ADXL355) is developed in this paper, and the circuit design and software development of the PCB are completed. The experimental design and comparative testing of the sensing performance of the three MEMS accelerometer chips, in terms of sensitivity, linearity, noise, resolution, frequency response, and temperature drift, were conducted. The results show that the dynamic and static calibration methods of the sensitivity test had similar results. The influence of gravitational acceleration should be considered when selecting the range of the accelerometer to avoid the phenomenon of over-range. The VS1002 has the highest sensitivity and resolution under 3.3 V standard voltage supply, as well as the best overall performance. The ADXL355 is virtually temperature-independent in the temperature range from −20 °C to 60 °C, while the voltage reference values output by the VS1002 and MS9001 vary linearly with temperature. This research contributes to the development of acceleration sensors with high precision and long life for pavement vibration monitoring.
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Kumar, Shalander, B. M. K. Raju, C. A. Ramarao, and Thiagarajah Ramilan. "Sensitivity of Livestock Production to Climatic Variability Under Indian Drylands and Future Perspective." Current Agriculture Research Journal 3, no. 2 (October 17, 2015): 142–49. http://dx.doi.org/10.12944/carj.3.2.08.
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The livestock production system is considered equally sensitive to climate change as that of core agriculture system and at the same time livestock itself is also contributing to the phenomenon. The present paper attempts to analyze the sensitivity of livestock productivity in rainfed regions to climatic variability, significance of climate change with respect to Indian livestock and mitigation options and leverage points in such a scenario. The sensitively of livestock productivity was examined by using district level data of milk productivity of cow as well as buffalo for the year 1992 and 1997 for 100 districts which was regressed on important weather variables. The analysis shows that weather variables like rainfall and temperature do significantly influence the milk productivity of animals in rainfed regions. Increased climatic variability due to changing climate is likely to negatively influence the livestock productivity. Based on analysis and stakeholders consultation the paper suggests appropriate adaptation strategies particularly focusing on mitigating feed scarcity situations arising due to climatic variability.
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Cochrane, Corey J., Jordana Blacksberg, Patrick M. Lenahan, and Mark A. Anders. "Magnetic Field Sensing with Atomic Scale Defects in SiC Devices." Materials Science Forum 858 (May 2016): 265–68. http://dx.doi.org/10.4028/www.scientific.net/msf.858.265.
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Silicon carbide (SiC) is well known by the semiconductor industry to have significant potential for electronics used in high temperature environments due to its wide bandgap. It is not so well-known, however, that SiC also has great potential in the area of magnetic field sensing. Using the recently demonstrated zero-field spin dependent recombination (SDR) phenomenon that naturally arises in SiC based devices, near-zero magnetic field measurements can be made with moderately high sensitivity.
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Jogana, Musa Ali, Jibril Danazumi Jibril, and Bashir Sabo Abubakar. "Technological Approaches to the Threat of Climate Change for Greener Environment in Nigeria." Advanced Materials Research 935 (May 2014): 302–6. http://dx.doi.org/10.4028/www.scientific.net/amr.935.302.
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Climate change is a phenomenon of great sensitivity which becomes a global issue that requires a concerted solution. This paper is interested in the resultant effects of average global temperature variation leading to greenhouse effects to the global environment particularly in Nigeria. Natural events and human activities are believed to be the major contributing factors that fuelled the increase in average global temperature, as a result, it leads to the greenhouse emission of gases such as carbon dioxide (CO2) due to the burning of fossil fuels. This emerged as a challenge to the eco-environment and sustainable development. Technological approaches were drawn from the academic literature to enlighten the polluters to immediately begin to reduce greenhouse gas emission, if the rise in global temperature is to be held in check to avoid drastic consequences later.
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Dobeš, Ferdinand, Petr Dymáček, and Martin Friák. "The Influence of Niobium Additions on Creep Resistance of Fe-27 at. % Al Alloys." Metals 9, no. 7 (June 30, 2019): 739. http://dx.doi.org/10.3390/met9070739.
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Results of creep tests of two Fe-27 at. % Al-based alloys with additions of 2.7 and 4.8 at. % of niobium conducted in the temperature range from 650 °C to 900 °C in the authors’ laboratory are presented. The purpose of the study is to supplement previous work on Fe-Al-Nb alloys to obtain a more complete overview of creep properties from the dilute alloy with 1% of Nb up to the eutectic alloy with 10% of niobium. At higher temperatures and lower stresses, the creep resistance of the 10% niobium alloy is better than that of the lower niobium alloys. On the other hand, the eutectic alloy loses its preference at lower temperatures and higher deformation rates. This phenomenon is similar to that reported by Yildirim et al. for Fe-50 at. % Al-based alloys and is probably associated with an increased stress sensitivity of the eutectic alloy.
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Huang, Jin, and Kenneth P. Bowman. "Climate Sensitivity and Equilibrium Climate States Of A Two-Dimensional Energy Balance Model." Annals of Glaciology 14 (1990): 340. http://dx.doi.org/10.3189/s0260305500009034.
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A two-dimensional energy balance model (EBM) with a seasonal cycle and a realistic land–ocean distribution is used to study climate sensitivity and the properties of equilibrium climate states. The land–ocean distribution is represented by the heat capacity of the surface. The horizontal heat flux is parameterized by diffusion. Nonlinearity is introduced into the model by the albedo–temperature feedback. A multi-grid finite difference method is used to solve the model equation. This method shows great advantages compared to other numerical methods.The sensitivity of snow cover to changes in the solar constant is examined. It is found that the climate is more sensitive in summer due to a more effective albedo–temperature feedback. The local annual mean temperature and the amplitude of the seasonal cycle depend on the land–ocean distribution. Because Eurasia has the largest annual cycle of temperature and is the coldest in winter, winter snow appears first in Eurasia as the solar constant is reduced. Wintertime snow appears next in Greenland because of its low annual mean temperature and last in North America. Perennial snow cover appears first in Greenland because of the low annual mean temperature and the small annual cycle, and next appears in North America. Perennial snow in Eurasia appears only when the solar constant is reduced to a very low value, since the Eurasian land mass is too hot in summer for perennial snow cover. The sensitivity of the model climate to changes in the orbital parameters is also investigated and discussed.Small polar ice caps in one-dimensional mean-annual EBMs are unstable to small perturbations. The ice caps either vanish or grow to a stable finite size. This phenomenon, referred to as the small ice-cap instability (SICI), is a consequence of the multiple stable equilibrium states in one-dimensional models. The SICI may be related to glacial–interglacial transitions. However, numerical results with the two-dimensional EBM demonstrate that the existence of the SICI depends on the land–ocean distribution. The SICI exists in the southern hemisphere, but not in the northern hemisphere. This casts doubt on the role of the SICI in northern hemisphere glaciations. Experiments with a one-dimensional seasonal EBM with simplified geography have been made to analyze the two-dimensional results. Mechanisms for the existence of the SICI in seasonal EBMs are discussed.
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Huang, Jin, and Kenneth P. Bowman. "Climate Sensitivity and Equilibrium Climate States Of A Two-Dimensional Energy Balance Model." Annals of Glaciology 14 (1990): 340. http://dx.doi.org/10.1017/s0260305500009034.
Full textAbstract:
A two-dimensional energy balance model (EBM) with a seasonal cycle and a realistic land–ocean distribution is used to study climate sensitivity and the properties of equilibrium climate states. The land–ocean distribution is represented by the heat capacity of the surface. The horizontal heat flux is parameterized by diffusion. Nonlinearity is introduced into the model by the albedo–temperature feedback. A multi-grid finite difference method is used to solve the model equation. This method shows great advantages compared to other numerical methods. The sensitivity of snow cover to changes in the solar constant is examined. It is found that the climate is more sensitive in summer due to a more effective albedo–temperature feedback. The local annual mean temperature and the amplitude of the seasonal cycle depend on the land–ocean distribution. Because Eurasia has the largest annual cycle of temperature and is the coldest in winter, winter snow appears first in Eurasia as the solar constant is reduced. Wintertime snow appears next in Greenland because of its low annual mean temperature and last in North America. Perennial snow cover appears first in Greenland because of the low annual mean temperature and the small annual cycle, and next appears in North America. Perennial snow in Eurasia appears only when the solar constant is reduced to a very low value, since the Eurasian land mass is too hot in summer for perennial snow cover. The sensitivity of the model climate to changes in the orbital parameters is also investigated and discussed. Small polar ice caps in one-dimensional mean-annual EBMs are unstable to small perturbations. The ice caps either vanish or grow to a stable finite size. This phenomenon, referred to as the small ice-cap instability (SICI), is a consequence of the multiple stable equilibrium states in one-dimensional models. The SICI may be related to glacial–interglacial transitions. However, numerical results with the two-dimensional EBM demonstrate that the existence of the SICI depends on the land–ocean distribution. The SICI exists in the southern hemisphere, but not in the northern hemisphere. This casts doubt on the role of the SICI in northern hemisphere glaciations. Experiments with a one-dimensional seasonal EBM with simplified geography have been made to analyze the two-dimensional results. Mechanisms for the existence of the SICI in seasonal EBMs are discussed.
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Han, A., and Y. Qiao. "Infiltration pressure of a nanoporous liquid spring modified by an electrolyte." Journal of Materials Research 22, no. 3 (March 2007): 644–48. http://dx.doi.org/10.1557/jmr.2007.0088.
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In a hydrophobic zeolite, the infiltration and defiltration of water can be controlled by adjusting external pressure, and therefore the system behaves as a “liquid spring.” Since the hysteresis of sorption isotherm is negligible and the working pressure is thermally controllable, volume memory devices can be developed based on this phenomenon. With the addition of sodium chloride, both infiltration and defiltration pressures increase, which should be attributed to the cation exchange. The temperature sensitivity of the system increases with the electrolyte concentration, beneficial to improving the output energy density.
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Wang, Yi, Zhilong Bao, Ying Zhu, and Jian Hua. "Analysis of Temperature Modulation of Plant Defense Against Biotrophic Microbes." Molecular Plant-Microbe Interactions® 22, no. 5 (May 2009): 498–506. http://dx.doi.org/10.1094/mpmi-22-5-0498.
Full textAbstract:
Plant-pathogen interactions are known to be affected by environmental factors including temperature; however, the temperature effects have not been systematically studied in plant disease resistance. Here, we characterized the effects of a moderate increase in temperature on resistance to bacterial pathogen Pseudomonas syringae and two viral elicitors in Arabidopsis thaliana and Nicotiana benthamiana. Both the basal and the resistance (R) gene–mediated defense responses to Pseudomonas syringae are found to be inhibited by a moderately high temperature, and hypersensitive responses induced by R genes against two viruses are also reduced by an increase of temperature. These indicate that temperature modulation of defense responses to biotrophic and hemibiotrophic pathogens might be a general phenomenon. We further investigated the roles of two small signaling molecules, salicylic acid and jasmonic acid, as well as two defense regulators, EDS1 and PAD4, in this temperature modulation. These components, though modulated by temperature or involved in temperature regulation or both, are not themselves determinants of temperature sensitivity in the defense responses analyzed. The inhibition of plant defense response by a moderately high temperature may thus be mediated by other defense signaling components or a combination of multiple factors.
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Pham, Binh T. T., Robert G. Gilbert, and Christopher M. Fellows. "Synthesis and Structure - Property Relations of Latexes Containing Graft Copolymers between Telechelic Polybutadiene and Dodecyl Methacrylate." Australian Journal of Chemistry 57, no. 8 (2004): 765. http://dx.doi.org/10.1071/ch04030.
Full textAbstract:
Latexes comprising novel copolymers were formed by second-stage emulsion polymerization of dodecyl methacrylate (DMA) onto a hydroxylated polybutadiene-based polyurethane prepolymer (PUD) as seed latex, with persulfate initiator. Morphology data from TEM imaging (including chemical fixation ultra-microtoming), glass transition temperature, dynamic mechanical analysis, and other mechanical-property data were all consistent with a system showing extensive grafting and compatibilization between the different polymeric components. Water adsorption and AFM measurements showed that samples with poorer film-forming properties had higher water sensitivity, greater mixing of the polymer phases, and poorer mechanical properties. These properties were related to a phase-inversion phenomenon occurring above a critical dodecyl methacrylate/prepolymer ratio. The compatibilization of the PUD and poly(DMA) given by these modifications resulted in a product with increased tackiness, although with a higher water sensitivity.
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Baron, Christian, Natalie Domke, Michael Beinhofer, and Siegfried Hapfelmeier. "Elevated Temperature Differentially Affects Virulence, VirB Protein Accumulation, and T-Pilus Formation in Different Agrobacterium tumefaciens andAgrobacterium vitis Strains." Journal of Bacteriology 183, no. 23 (December 1, 2001): 6852–61. http://dx.doi.org/10.1128/jb.183.23.6852-6861.2001.
Full textAbstract:
ABSTRACT That gene transfer to plant cells is a temperature-sensitive process has been known for more than 50 years. Previous work indicated that this sensitivity results from the inability to assemble a functional T pilus required for T-DNA and protein transfer to recipient cells. The studies reported here extend these observations and more clearly define the molecular basis of this assembly and transfer defect. T-pilus assembly and virulence protein accumulation were monitored in Agrobacterium tumefaciens strain C58 at different temperatures ranging from 20°C to growth-inhibitory 37°C. Incubation at 28°C but not at 26°C strongly inhibited extracellular assembly of the major T-pilus component VirB2 as well as of pilus-associated protein VirB5, and the highest amounts of T pili were detected at 20°C. Analysis of temperature effects on the cell-bound virulence machinery revealed three classes of virulence proteins. Whereas class I proteins (VirB2, VirB7, VirB9, and VirB10) were readily detected at 28°C, class II proteins (VirB1, VirB4, VirB5, VirB6, VirB8, VirB11, VirD2, and VirE2) were only detected after cell growth below 26°C. Significant levels of class III proteins (VirB3 and VirD4) were only detected at 20°C and not at higher temperatures. Shift of virulence-induced agrobacteria from 20 to 28 or 37°C had no immediate effect on cell-bound T pili or on stability of most virulence proteins. However, the temperature shift caused a rapid decrease in the amount of cell-bound VirB3 and VirD4, and VirB4 and VirB11 levels decreased next. To assess whether destabilization of virulence proteins constitutes a general phenomenon, levels of virulence proteins and of extracellular T pili were monitored in different A. tumefaciens and Agrobacterium vitis strains grown at 20 and 28°C. Levels of many virulence proteins were strongly reduced at 28°C compared to 20°C, and T-pilus assembly did not occur in all strains except “temperature-resistant” Ach5 and Chry5. Virulence protein levels correlated well with bacterial virulence at elevated temperature, suggesting that degradation of a limited set of virulence proteins accounts for the temperature sensitivity of gene transfer to plants.