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[Display omitted] Traditional silicon-based pressure sensors cannot meet demand of pressure information acquisition in high-temperature extreme environments due to their low sensitivity, limited detection temperature and complex processing. Herein, a capacitive pressure sensor is fabricated using polymer-derived SiCN ceramics with convex microstructures via a sample replication strategy. Its performance is measured at different pressures (0–800 kPa) from room temperature to 500 °C. The results show that the SiCN ceramic capacitive pressure sensor exhibits low hysteresis, good non-linearity of 0.26 %, outstanding repeatability and high sensitivity of 0.197 pF/MPa under room temperature. When the test temperature reaches 500 °C, the performance of the prepared capacitive pressure sensor has no degradation, keeping competent sensitivity of 0.214 pF/MPa and nonlinear error of 0.24 %. Therefore, benefitting from the preeminent high-temperature properties, e.g., excellent oxidation/corrosion resistance and thermal stability, SiCN ceramics capacitive pressure sensors have great potential in the application of high-temperature and harsh environments. [ABSTRACT FROM AUTHOR]

Copyright of Journal of National University of Defense Technology / Guofang Keji Daxue Xuebao is the property of NUDT Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study is to investigate the factors that contribute to brittleness and to identify strategies for mitigating these factors in populations with varying degrees of thermal vulnerability, based on the potential impact of extreme heat exposure on human survival and habitability. The physiological condition of lower adaptability to high temperature environments and the assessment of individuals who may have higher tolerance time in high temperature environments based on spatial perspectives suggest the need for targeted spatial optimization strategies for commuters and disadvantaged populations. This is demonstrated through a case study. These optimization measures encompass a variety of aspects, including the integration of transportation systems, the expansion of grey space corridors, the improvement of green space layout, and the implantation of green infrastructure. The study aims to reduce the exposure time of thermally vulnerable individuals to high temperature environments through spatial optimization strategies, to enhance the resilience of urban green spaces to heat stress, and to reduce the probability of heat-wave occurrence. [ABSTRACT FROM AUTHOR]

Heat strain can reduce work efficiency and lead to heat-related diseases. In order to quantify the heat strain level of the sanitation worker in high temperature environments, a physiological state safety evaluation index (PSEI) was established. Firstly, the cusp catastrophe theory was introduced to analyze the changing trend of human physiological state under different thermal loads. Secondly, the information entropy method and variable weight theory were adopted to calculate the weights of the physiological indexes, and the cusp catastrophe progression method was used to establish human physiological state evaluation model. Finally, a new index-PSEI was proposed to quantify the safety level of the physiological state, and the safety interval of the PSEI was categorized. The results show that the weight of each physiological index varies with environmental conditions and physiological states. The weight range of mean skin temperature, tympanic membrane, systolic blood pressure and heart rate is 0. 09 ~ 0. 64, 0. 08 ~ 0. 41, 0. 07 ~ 0. 74 and 0. 06 ~ 0. 33, respectively. The safety level of PSEI is as follows: very safe (0. 948, 1], relatively safe (0. 886, 0. 948], moderate (0. 798, 0. 886], relatively dangerous (0. 649, 0. 798] and very dangerous [0, 0. 649]. The PSEI can be used to provide real-time physiological state evaluation and health warning for sanitation workers in high temperature environments. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Corrosion & Protection in Petrochemical Industry is the property of Corrosion & Protection in Petrochemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a cooling device for cooling the human body, the cooling garment has been used in many fields. This study was guided by the theory of traditional Chinese medicine, an acupoints-meridians cooling vest (AMCV) system was designed to cold and stimulate the acupoints and meridians of the human body. Three healthy male subjects were recruited to participate in the test, with AMCV or without AMCV (CON), in a high temperature environment (37 ±1, 46 ±3% RH) to simulate standing on duty for 50 minutes. The results showed that the skin temperature, Tskin, with AMCV was lower than that with CON (p < 0.05). The average Tskin with AMCV decreased by 0.45 more than that with CON (p < 0.05). The average tympanic temperature, Tty, with AMCV was lower than that with CON (p < 0.05). However, the average Tty with AMCV decreased by 0.05 more than that with CON (p < 0.05). The heart rate with AMCV was significantly lower than that with CON (p < 0.05). The average thermal sensation and thermal comfort with AMCV were better than those with CON in the corresponding period (p < 0.05). The results indicated that AMCV could improve thermal comfort and reduce the heat strain of the human body in a high temperature environment. [ABSTRACT FROM AUTHOR]

This study proposes a split-type pressure sensor based on differential capacitance that can be applied to in-situ accurate pressure testing in high-temperature environments. The sensor is mainly composed of a high-temperature resistant chip and a high-temperature resistant encapsulation structure. The chip is made of a ceramic substrate and presents a differential capacitance structure that can withstand high temperatures and effectively restrain the temperature drift. The encapsulation presents a split-type structure, in which the chip and the test circuit board are placed at the front and back ends of the sensor, respectively. Therefore, the front end of the sensor can work in the high-temperature area for in-situ testing, while the back-end temperature remains below 60°C all the time, which ensures normal operation of the circuit board. Finally, the test results show that the pressure sensor's temperature drift coefficient is only 6.6% within the temperature range of 25°C-400°C. The sensor's sensitivity can reach 9.27 mV/kPa and the maximum repeatability error is less than 2.2% at 400°C, which shows that the proposed sensor has a higher working temperature and higher precision than the existing pressure sensors.

This experiment was conducted to study the effects of γ-amino butyric acid (GABA) on growth performance, blood biochemical indices and intestinal morphology of yellow-feathered broilers exposed to a high temperature environment. One hundred and forty four, 28-day-old male yellow-feathered broilers were separated into 2 groups with 6 replicates and 12 birds per replicate. The two experimental groups included: control group, which fed the basal diet, and GABA supplemented group, which fed the basal diet supplemented with 100 mg/kg GABA. After 7 days of feeding experimental diet at 26 °C, birds were fed the experimental diet and exposed to a high temperature environment at 35 °C and 60% RH for 14 days. Results revealed that average daily gain (ADG, p = .004) and average daily feed intake (ADFI, p = .003) of the GABA group were higher than control group, feed: gain ratio (F/G; p = .023) and mortality (p = .042) were lower than control group. The serum levels of glucose (GLU; p = .016), total cholesterol (T-CHO; p = .001), and low density lipoprotein (LDL; p = .001) as well as the activities of aspartate-aminotransferase (AST; p = .008), lactate dehydrogenase (LDH; p = .042) and creatine kinase (CK; p = .032) of the GABA group were lower than control group, while villus length (p = .016) of jejunum was higher than control group. In conclusion, adding 100 mg/kg GABA to diet can improve growth performance, reduce serum intracellular enzyme activities, protect the organs and intestinal morphology of yellow-feathered broilers exposed to a high temperature environment during 36-49 days of age.Highlights GABA improves growth performance of yellow-feathered broilers exposed to a high temperature environment. GABA protects the intestine of yellow-feathered broilers exposed to a high temperature environment.

This paper aims to present and analyze the materials adapted to design a machine that can work with a high current density without any specific cooling system. In other words, the machine is equipped with material that supports high internal temperature, about 500°C. Candidate materials are selected and the authors indicate that inorganic insulation should be preferred for conductors and slot insulations. Tests are carried out on material selection through measurement of the turn-to-turn voltage, insulation resistances, and the parallel capacitances.

In this study, a silicon carbide (SiC) MOSFET driving circuit and its protection circuit applied to high temperature (HT) environment are designed by using commercial off‐the‐shelf discrete components. The proposed driving circuit can work at 200°C with a low driving dissipation. An isolation structure with a transformer is utilised to prevent the control circuits from being disturbed by the power circuit. The high value of output driving voltage VGS is 19 V to ensure the low on‐resistance of SiC MOSFET, while the low value of VGS is −5 V to ensure the SiC MOSFET not be turned on mistakenly. The driving circuit also solves the the contradiction between the BJT switch speed and power dissipation of conventional HT SiC MOSFET driving circuit. The rising time and falling time of the output VGS are reduced greatly, which can increase the performance of SiC MOSFET in high frequency application at a HT. [ABSTRACT FROM AUTHOR]

This experiment was conducted to study the effects of γ-amino butyric acid (GABA) on growth performance, blood biochemical indices and intestinal morphology of yellow-feathered broilers exposed to a high temperature environment. One hundred and forty four, 28-day-old male yellow-feathered broilers were separated into 2 groups with 6 replicates and 12 birds per replicate. The two experimental groups included: control group, which fed the basal diet, and GABA supplemented group, which fed the basal diet supplemented with 100 mg/kg GABA. After 7 days of feeding experimental diet at 26 °C, birds were fed the experimental diet and exposed to a high temperature environment at 35 °C and 60% RH for 14 days. Results revealed that average daily gain (ADG, p =.004) and average daily feed intake (ADFI, p =.003) of the GABA group were higher than control group, feed: gain ratio (F/G; p =.023) and mortality (p =.042) were lower than control group. The serum levels of glucose (GLU; p =.016), total cholesterol (T-CHO; p =.001), and low density lipoprotein (LDL; p =.001) as well as the activities of aspartate-aminotransferase (AST; p =.008), lactate dehydrogenase (LDH; p =.042) and creatine kinase (CK; p =.032) of the GABA group were lower than control group, while villus length (p =.016) of jejunum was higher than control group. In conclusion, adding 100 mg/kg GABA to diet can improve growth performance, reduce serum intracellular enzyme activities, protect the organs and intestinal morphology of yellow-feathered broilers exposed to a high temperature environment during 36-49 days of age. GABA improves growth performance of yellow-feathered broilers exposed to a high temperature environment. GABA protects the intestine of yellow-feathered broilers exposed to a high temperature environment. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a non-conduct and whole field measurement method,3D DIC (3D digital image correlation) is widely used in mechanical properties test of many types of materials in varies fields. Compared with other optical measurement methods, it has advantages as automation, simple optical path, strong universality and anti-interference and so on. But it has some problems in the process of application, i.e. the measurement accuracy is uncertain, the high temperature test condition seriously affects the experimental results, and the measurable area of large curvature specimen is limited. This paper gives a general introduction to the application of 3D DIC in the conventional mechanical property test of different types of materials, and verifies its accuracy by comparing with the traditional extensometer measurement results and the finite element simulation results. It focuses on some latest technological progress, such as the high-temperature speckle preparation and multi-camera DIC, as the application of 3D DIC in the high temperature and large deformation measurement is mostly studied. Moreover, it is pointed out that 3D DIC should be further studied for the influence of speckle on measurement precision,the effect of environmental factors, the measurement of micro strain scale and the application in fields of military and biomedical materials.

The article presents the results of experimental researches on determination of thermal and physical characteristics of thermal insulating materials using the principle of spatial three-dimensional presentation of the study object with distributed parameters. The proposed method of research and obtained experimental results provide an opportunity to determine thermal and physical properties of materials with high accuracy, which creates the conditions for improvement of the quality of special clothes designing. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Background Liquid feeding system has been introduced to domestic swine farms, but negative cognition about liquid feeding system has been remained for feed waste decay related with poor management and microbial contamination. For these reasons, this study was conducted to evaluate the effects of feeding method in lactating sows. Methods A total of 30 mixed-parity (average 4.13) lactating sows (Yorkshire × Landrace) with an initial BW of 218.8 ± 19.5kg was used in a 3 week trial. Sows were allotted to 1 of 2 treatments in a completely randomized design by their body weight, backfat thickness, parity and alive litter weight. One of treatments was dry feeding and the other was liquid feeding (water to feed ratio, 1:1). Experimental diets contained 3265 kcal ME/kg, 12.6 % CP, 5.76 % EE, 1.09 % total lysine, 0.25 % total methionine, as fed basis. Results Dry feeding treatment had high body weight loss rather than liquid feeding treatment (P = 0.04). Dry feeding treatment had tendency to increase litter weight at 21d of lactation (P = 0.06) and litter weight gain (P = 0.04) during lactation period (0–3 week). Sows fed dry feeding method made milk containing high content of casein and total solid rather than sows fed liquid feeding method (P = 0.04). In addition, dry feeding treatment had tendency to higher content of milk fat, protein and solid not fat on 21d of lactation (P = 0.07). Sows fed dry feeding type also showed higher milk energy content in milk of 21d lactation (P = 0.05). Furthermore, liquid feeding treatment showed high occurrence in feed waste during lactation period (P

A significant requirement of low-cost sensing systems for defect detection is essential to bridge the gap in non-destructive testing and evaluation and structural health monitoring. In practical situation, the temperature variation will be unknown in a priori and hence will give rise to uncertainty and unreliability in the defect detection. This paper demonstrates the potential use of low-frequency radio frequency identification tag antenna-based wireless sensors to characterize corrosion and crack progression in high-temperature conditions for potential structural monitoring. Consideration of the parasitic parameters which depend on the temperature variation is presented. The key factors that influence the sensing accuracy with regards to different materials due to inhomogeneity are presented. A cost-effective self-compensation method is proposed by means of a self-swept frequency measurement through selection and fusion of temperature dependent feature near the tag’s resonance region. The experimental work validates the effectiveness of the method in temperature compensation and some initial results demonstrate the efficiency of the technique to overcome the inhomogeneity. [ABSTRACT FROM AUTHOR]

Ｔｈｅ ｅｘｔｅｒｎａｌ ｓｕｒｆａｃｅ ｏｆ ａ ｈｙｐｅｒｓｏｎｉｃ ｖｅｈｉｃｌｅ ｆｌｙｉｎｇ ｉｎ ｔｈｅ ａｔｍｏｓｐｈｅｒｅ ｉｓ ｆａｃｉｎｇ ａ ｓｅｖｅｒｅ ｈｉｇｈ⁃ｔｅｍｐｅｒａｔｕｒｅ ｅｎｖｉｒｏｎｍｅｎｔ ｄｕｅ ｔｏ ａｅｒｏｄｙｎａｍｉｃ ｈｅａｔｉｎｇ． Ｗｈｉｌｅ ｉｎ ｔｈｅ ａｅｒｏｄｙｎａｍｉｃ ｔｈｅｒｍａｌ ｓｉｍｕｌａｔｉｏｎ ｔｅｓｔ， ｔｈｅ ｄｅｆｏｒｍａｔｉｏｎ ｍｅａｓｕｒｅｍｅｎｔ ｏｆ ｈｅａｔｅｄ ｆｒｏｎｔ ｓｕｒｆａｃｅ ｏｆ ａｉｒｃｒａｆｔ ｃｏｍｐｏｎｅｎｔｓ ｕｎｄｅｒ ｈｉｇｈ ｔｅｍｐｅｒａｔｕｒｅ ｃｏｎｄｉｔｉｏｎｓ ｉｓ ｅｘｔｒｅｍｅｌｙ ｉｍｐｏｒｔａｎｔ ａｎｄ ｄｉｆｆｉｃｕｌｔ． Ａ ｈｅａｔｅｄ⁃ｆｒｏｎｔ⁃ｓｕｒｆａｃｅ ｓｔｒａｉｎ ｍｅａｓｕｒｅｍｅｎｔ ｓｙｓｔｅｍ ｆｏｒ ｈｙｐｅｒｓｏｎｉｃ ｖｅｈｉｃｌｅ ｃｏｍｐｏｎｅｎｔｓ ｗａｓ ｅｓｔａｂｌｉｓｈｅｄ， ａｎｄ ｂｙ ｍｅａｎｓ ｏｆ ｔｈｅ ｄｉｇｉｔａｌ ｉｍａｇｅ ｃｏｒｒｅｌａｔｉｏｎ ｍｅｔｈｏｄ， ｔｈｅ ｓｔｒａｉｎ ｍｅａｓｕｒｅｍｅｎｔ ｆｏｒ ｈｅａｔ⁃ｒｅｓｉｓｔａｎｔ Ａｌ２Ｏ３ ｃｅｒａｍｉｃ ｍａｔｅｒｉａｌ ｗｉｔｈ ｔｈｅ ｆｒｏｎｔ⁃ｓｕｒｆａｃｅ ｔｅｍｐｅｒａｔｕｒｅ ｕｐ ｔｏ １２００ ℃ ｗａｓ ｒｅａｌｉｚｅｄ ｕｎｄｅｒ ｔｈｅ ｏｘｉｄｉ⁃ｚｉｎｇ ｅｎｖｉｒｏｎｍｅｎｔ． Ｔｏ ｄｅｍｏｎｓｔｒａｔｅ ｔｈｅ ｃｏｒｒｅｃｔｎｅｓｓ ｏｆ ｔｈｅ ｍｅａｓｕｒｉｎｇ ｍｅｔｈｏｄ， ｔｈｅ ｅｘｐｅｒｉｍｅｎｔａｌ ｒｅｓｕｌｔｓ ｗｅｒｅ ｃｏｍｐａｒｅｄ ｗｉｔｈ ｔｈｅ ｃａｌｃｕｌａｔｉｏｎ ｒｅｓｕｌｔｓ ｆｒｏｍ ｔｈｅ ｒｅｌａｔｉｏｎ ｂｅｔｗｅｅｎ ｔｈｅ ｔｈｅｒｍａｌ ｅｘｐａｎｓｉｏｎ ｃｏｅｆｆｉｃｉｅｎｔ ａｎｄ ｔｈｅ ｔｅｍｐｅｒａｔｕｒｅ ｏｆ Ａｌ２Ｏ３ ｍａｔｅｒｉａｌ ｇｉｖｅｎ ｂｙ Ｈｉｌｌｍａｎ， ａｎｄ ｇｏｏｄ ａｇｒｅｅｍｅｎｔ ｗａｓ ｏｂｔａｉｎｅｄ． Ｔｈｅ ｐｒｏｐｏｓｅｄ １２００ ℃ ｈｉｇｈ ｔｅｍｐｅｒａｔｕｒｅ ｓｔｒａｉｎ ｍｅａｓｕｒｅｍｅｎｔ ｓｙｓｔｅｍ ａｎｄ ｔｈｅ ｈｅａｔ⁃ｅｄｆｒｏｎｔｓｕｒｆａｃｅ ｓｔｒａｉｎ ｍｅａｓｕｒｅｍｅｎｔ ｍｅｔｈｏｄ ｆｏｒ ｃｏｍｐｏｎｅｎｔｓ ｕｎｄｅｒ ｏｘｉｄａｔｉｏｎ ｅｎｖｉｒｏｎｍｅｎｔｓ ｐｒｏ⁃ｖｉｄｅ ａ ｉｍｐｏｒｔａｎｔ ｅｘｐｅｒｉｍｅｎｔａｌ ｍｅｔｈｏｄ ｆｏｒ ｔｈｅ ｔｈｅｒｍａｌ ｓｔｒｅｎｇｔｈ ａｎａｌｙｓｉｓ ａｎｄ ｓａｆｅ ｒｅｌｉａｂｉｌｉｔｙ ｄｅ⁃ｓｉｇｎ ｏｆ ｔｈｅ ｈｙｐｅｒｓｏｎｉｃ ｖｅｈｉｃｌｅ’ｓ ｈｅａｔｅｄ ｐａｒｔｓ． [ABSTRACT FROM AUTHOR]

In this work, the iron (Fe) and bismuth (Bi) added (0.05 wt% Fe and 1 wt% or 2 wt% Bi) Sn-1Ag-0.5Cu (SAC105) lead-free solder alloys were prepared and their microstructure and tensile properties under severe thermal environments were extensively investigated and compared with the base alloy SAC105. The isothermal aging was done at 200 °C for 100 h, 200 h, and 300 h. Fe/Bi added SAC105 showed a significant reduction in the IMCs size (Ag 3 Sn and Cu 6 Sn 5 ), especially the Cu 6 Sn 5 IMCs and a refinement in the microstructure, which is due to the existence of Bi in the alloys. Moreover, the existence of Fe and Bi gives the microstructure better stability under severe thermal aging conditions. The tensile testing results showed that the addition of Fe and Bi to SAC105 greatly improves yield stress and tensile strength, but decreases ductility level, which is because of the Bi solid solution strengthening mechanism. Under severe thermal aging, the Fe/Bi added SAC105 showed more stable tensile properties, because of the existence of both Fe and Bi in the alloys. [ABSTRACT FROM AUTHOR]

In summer, the high temperature affects animal growth and reproductive performance. Curcumin is a flavonoid with anti-oxidant and anti-inflammatory effects. To evaluate the effects of dietary curcumin supplement on the blood biochemical parameters and testicular gene expressions in Hu sheep in summer, a total of 144 male Hu sheep aged four months were randomly divided into three groups (Con, Cur1, and Cur2, n = 48). Sheep in Con, Cur1, and Cur2 groups were fed a basal diet supplement with 0, 450, and 900 mg (per sheep) curcumin daily, respectively. Sheep were fed for 35 days, including a pre-feed for seven days. The results showed that the supplement with 450 mg and 900 mg curcumin increased serum free fatty acid (NEFA) and glutathione peroxidase (GPX), as well as IgA and IgM. The supplement with 450 mg curcumin increased the IgG level, while the supplement with 900 mg curcumin had a lower IgG level than the supplement with 450 mg curcumin (p < 0.05). Dietary curcumin supplement increased testicular organ index, serum testosterone level, and testicular star mRNA expression (p < 0.05). Furthermore, dietary curcumin supplement linearly inhibited testicular apoptosis with increased testicular bcl-2 mRNA expression and decreased caspase-3 mRNA expression (p < 0.05). In conclusion, dietary curcumin supplement can promote lipid metabolism, antioxidant capacity, and immune response, as well as testicular development, in Hu sheep, which provides evidence of application of curcumin in sheep production.

In general, the pipelines within a nuclear power plant facility may experience high temperatures up to several hundred degrees. Thus it is absolutely vital to monitor these pipes to prevent leakage of radioactive substances which may lead to a catastrophic outcome of the surrounding environment. Over the years, one of the structural health monitoring technique known as the electromechanical impedance (EMI) technique has been of great interests in various fields including civil infrastructures, mechanical and aerospace structures. Although it has one of the best advantages to be able for a single piezoelectric transducer to act as a sensor and an actuator, simultaneously, its low curie temperature makes it difficult for the EMI technique to be conducted at high temperature environment. To overcome this problem, this study shows a method to avoid attaching the piezoelectric transducer directly onto the target structure using a metal wire for damage detection at high temperature. By shifting the frequency to compensate the signature changes subjected to the variations in temperature, the experimental results indicate that damage identification is more successful above 200 o C, making the metal wire method suitable for the EMI technique at high temperature environment. [ABSTRACT FROM AUTHOR]

The use of conventional radiation detectors in harsh environments is limited by radiation damage to detector materials and by temperature constraints. We fabricated a wide-band gap semiconductor radiation detector based on silicon carbide. All the detector components were considered for an application in a high temperature environment like a nuclear reactor core. The radiation response, especially to alpha particles, was measured using an 241Am source at variable operating voltages at room temperature in the air. The temperature on detector was controlled from 30°C to 250°C. The alpha-particle spectra were measured at zero bias operation. Even though the detector is operated at high temperature, the energy resolution as a function of temperature is almost constant within 3.5% deviation. [ABSTRACT FROM AUTHOR]

In the Linz–Donawitz (LD) steelmaking process supersonic oxygen jets expand into the surroundings formed by hot and dense slag foam thus it is necessary to understand the innate characteristics of supersonic jets when expanding into such surroundings. In this study, the individual influences of both the elevated temperature and high density of the surrounding medium on the jet characteristics are presented. It was found that the supersonic jet characteristics were not affected significantly by the expansion into hot environments with no correlation between the Mach number profiles and changes in surrounding temperature. However, the influence of the dense surroundings on the jet characteristics was profound. The jet velocity was reduced when expanding into a dense medium in comparison with that expanding into a gaseous medium. The peak value of momentum at any cross-section of the jet was not at the axis but in the gas/dense medium interface. The confluence of these factors, i.e. severe reduction in jet velocity and the location of peak momentum within the jet, are expected to change the present understanding of flow dynamics within LD vessels and its influence on refining reactions. Further studies in this area are recommended for better understanding of these phenomena. [ABSTRACT FROM AUTHOR]

Abstract: High temperature oxidation and erosion resistant ceramic coating materials have been recently used for turbine rotor blades under high temperature dry steam conditions. It is, therefore, important to evaluate not only the physical or mechanical properties but also characteristics of erosion and fatigue of such materials for purposes of material selection and to predict the working life of plants. Ion plated CrN samples with a sublayer of plasma nitride on martensitic stainless steel were prepared. Dynamic hardness, in a high temperature environment of 723K, was obtained by the impact of a glass ball. Fatigue tests of the CrN coating materials were conducted at 723K, the same temperature as is typically used in the environment of turbine rotor blades, and the results were compared with fatigue resistance at room temperature. Erosion tests by the impact of SiO2 particles with a mean diameter of 326μm at an impact velocity of 104ms−1 were performed at room temperature to evaluate the fundamental erosion resistance, and the dependence of impact angle on erosion damage of CrN coating materials was compared with the resistance of an alumina bulk material. Consequently, the erosion rates at room temperature and the dynamic hardness distributions of the CrN coating materials at 723K indicated that the materials used in this study had excellent erosion resistance and the fatigue tests for the coating materials indicated the possibility of applications to actual turbine blades that are used at 723K. [Copyright &y& Elsevier]

This article presents a new method for embedding optical fibers into a nickel alloy and gives the results for a long-term test with thermal cycling of two fiber-optic Bragg gratings embedded in nickel alloy. We embedded these Bragg gratings in a piece of Inconel 600 (a nickel alloy) using vacuum brazing. We then thermally cycled this piece between 500, 525, and 550°C for about six months while monitoring the reflected wavelengths of the gratings. We tested two other embedded gratings for 68 hours at 600°C. Some microscopic cross sections of the embedded fibers are presented. The results show that fiber sensors embedded in metal can operate reliably at very high temperature and in harsh environments. We hope that the results from the long-term, elevated temperature test will make it possible to apply the technology of fiber-optic sensing in new and demanding monitoring applications, especially at high temperatures in energy production. [ABSTRACT FROM PUBLISHER]

In this paper, a three-axis accelerometer for high temperatures using constant temperature control of silicon on insulator (SOI) piezoresistors is proposed for reduction of temperature drift. The accelerometer has surrounding mass structure, and piezoresistors for four wheatstone bridges to detect three-axis acceleration. A temperature sensor using the whole resistance of four wheatstone bridges and micro-heaters are integrated on the beam structures. The structure of accelerometer was optimized with finite element method (FEM) simulation program, ANSYS. The accelerometer was fabricated with SOI wafers by bulk-micromachining. Temperature dependence of the fabricated three-axis accelerometer on variation of atmospheric temperature (from room temperature to 300 °C) is much reduced by keeping the temperature of piezoresistors at 300 °C. Temperature coefficient of sensitivity (TCS) is much reduced to 72% of the original TCS. [Copyright &y& Elsevier]

The impact of high-temperature effects is experimentally investigated in the octagonal layout style for planar silicon-on-insulator (SOI) metal–oxide–semiconductor (MOS) field-effect transistors (MOSFETs), named OCTO SOI MOSFETs (OSMs), in relation to the hexagonal [diamond SOI MOSFETs (DSMs)] and the standard (rectangular conventional SOI MOSFETs) ones regarding the same bias conditions. The devices were manufactured with a 1- \mu\mboxm fully depleted SOI complementary MOS (CMOS) technology. The main experimental findings demonstrate that OSM is capable of keeping active the longitudinal corner effect and the PArallel connection of MOSFET with Different channel Lengths Effect (PAMDLE) in its structure at high-temperature conditions, and consequently, it maintains its remarkably better electrical performance in comparison with the standard SOI MOSFET, mainly its capacity to reduce the leakage drain current, without causing any extra burden to the current planar SOI CMOS technology in relation to DSMs. [ABSTRACT FROM PUBLISHER]

(1) In order to improve the properties of antifriction and wear resistance of polyimide (PI) composite under high temperature conditions, (2) 3-Aminopropyltriethoxysilane (APTES) and Lanthanum (La) salt modifications were employed to manufacture poly-p-phenylenebenzobisoxazole (PBO)/PI composites with different interface properties. The representative ambient temperatures of 130 and 260 °C were chosen to study the friction and wear behavior of composites with different interface properties. (3) Results revealed that while both modification methods can improve the chemical activity of the surface of PBO fibers, the La salt modification is more effective. The friction coefficient of all composites decreases with the increase of sliding velocity and load at two temperatures, and the specific wear rate is increases. Contrary to the situation in the 130 °C environment, the wear resistance of the unmodified composite in the 260 °C environment is greatly affected by the sliding velocity and load, while the modified composites are less affected. Under the same test parameters, the PBO–La/PI composite has the lowest specific wear rate and friction coefficient, and (4) La salt modification is a more effective approach to improve the properties of antifriction and wear resistance of PI composite than APTES modification in high ambient temperatures. [ABSTRACT FROM AUTHOR]

Simple Summary: Heat stress can induce oxidative stress and has an adverse effect on the growth and reproductive performance in animals. Curcumin, a plant-derived substance, with the effect of scavenging oxidative free radicals, improving immune response and anti-apoptosis, has been widely used as a dietary supplement in the livestock industry. The present study aims to investigate the effect of a curcumin dietary supplement on the blood metabolites, antioxidant status, immune response, and testicular gene expression in Hu Sheep in summer. The results show that dietary curcumin supplementation (450 and 900 mg/per sheep daily) can promote lipid metabolism, antioxidant capacity, and immune response as well as testicular development in Hu sheep, which provides evidence for the protective role of curcumin against heat stress in sheep. In summer, the high temperature affects animal growth and reproductive performance. Curcumin is a flavonoid with anti-oxidant and anti-inflammatory effects. To evaluate the effects of dietary curcumin supplement on the blood biochemical parameters and testicular gene expressions in Hu sheep in summer, a total of 144 male Hu sheep aged four months were randomly divided into three groups (Con, Cur1, and Cur2, n = 48). Sheep in Con, Cur1, and Cur2 groups were fed a basal diet supplement with 0, 450, and 900 mg (per sheep) curcumin daily, respectively. Sheep were fed for 35 days, including a pre-feed for seven days. The results showed that the supplement with 450 mg and 900 mg curcumin increased serum free fatty acid (NEFA) and glutathione peroxidase (GPX), as well as IgA and IgM. The supplement with 450 mg curcumin increased the IgG level, while the supplement with 900 mg curcumin had a lower IgG level than the supplement with 450 mg curcumin (p < 0.05). Dietary curcumin supplement increased testicular organ index, serum testosterone level, and testicular star mRNA expression (p < 0.05). Furthermore, dietary curcumin supplement linearly inhibited testicular apoptosis with increased testicular bcl-2 mRNA expression and decreased caspase-3 mRNA expression (p < 0.05). In conclusion, dietary curcumin supplement can promote lipid metabolism, antioxidant capacity, and immune response, as well as testicular development, in Hu sheep, which provides evidence of application of curcumin in sheep production. [ABSTRACT FROM AUTHOR]