• Nuclear Engineering and Technology
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• 제32권6호
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• pp.566-594
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• 2000

In most LMFBR(Liquid Metal Fast Breed Reactor) design, the operating temperature is very high and the time-dependent creep and stress-rupture effects become so important in reactor structural design. Therefore, unlike with conventional PWR, the normal operating conditions can be basically dominant design loading because the hold time at elevated temperature condition is so long and enough to result in severe total creep ratcheting strains during total service lifetime. In this paper, elevated temperature design of the conceptually designed baffle annulus regions of KALIMER(Korea Advanced Liquid MEtal Reactor) reactor internal strictures is carried out for normal operating conditions which have the operating temperature 53$0^{\circ}C$ and the total service lifetime of 30 years. For the elevated temperature design of reactor internal structures, the ASME Code Case N-201-4 is used. Using this code, the time-dependent stress limits, the accumulated total inelastic strain during service lifetime, and the creep-fatigue damages are evaluated with the calculation results by the elastic analysis under conservative assumptions. The application procedures of elevated temperature design of the reactor internal structures using ASME Code Case N-201-4 with the elastic analysis method are described step by step in detail. This paper will be useful guide for actual application of elevated temperature design of various reactor types accounting for creep and stress-rupture effects.

• Asian-Australasian Journal of Animal Sciences
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• 제32권9호
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• pp.1332-1339
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• 2019

Heat stress exerts a substantial effect on dairy production. The temperature and humidity index (THI) is widely used to assess heat stress in dairy operations. Herein, we review the effects of high temperature and humidity on body temperature, feed intake, milk production, follicle development, estrous behavior, and pregnancy in dairy cows. Analyses of the effects of THI on dairy production have shown that body temperature is an important physiological parameter in the evaluation of the health state of dairy cows. Although THI is an important environmental index and can help to infer the degree of heat stress, it does not reflect the physiological changes experienced by dairy cows undergoing heat stress. However, the simultaneous measurement of THI and physiological indexes (e.g., body temperature) would be very useful for improving dairy production. The successful development of automatic detection techniques makes it possible to combine THI with other physiological indexes (i.e., body temperature and activity), which could help us to comprehensively evaluate heat stress in dairy cows and provide important technical support to effectively prevent heat stress.

• 중환자간호학회지
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• 제10권3호
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• pp.53-64
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• 2017

Purpose : This study investigated the effects of active warming using a Warm Touch warming system or a cotton blanket in postoperative patients after general anesthesia for abdominal surgery. Methods : This quasi-experimental study utilized two experimental groups and one control group: a cotton-blanket group (n = 25) were warmed with a cotton blanket and a sheet; a forced-air warming group (n = 24) were warmed with a Warm Touch warming system, a cotton blanket, and a sheet; and a control group (n = 25) were warmed with a sheet. Measurement variables were postoperative pain, body temperature, and thermal discomfort. Data were analyzed using a one-way ANOVA, ${\chi}^2-tests$, Fisher's exact test, and a repeated measures ANOVA. Results : The effects of active warming using a Warm Touch warming system and a cotton blanket on postoperative patients was significant in reducing pain (F = 13.91, p < .001) and increasing body temperature (F = 12.49, p < .001). Conclusion : Active warming made a significant difference in pain and body temperature changes. Active warming methods may help patients' postoperative recovery and prevent complications. Further research is needed to explore the effects and side effects of active warming on recovering normothermia.

• Tribology and Lubricants
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• 제9권1호
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• pp.22-31
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• 1993

The thermohydrodynamic performance of large tilting pad journal bearings is analyzed, taking into account the three dimensional variation of lubricant viscosity. The eddy viscosity model based on wall formula is applied. The effects of temperature rise and turbulence on the bearing performance are studied in comparision with the isothermal or the laminar analysis. It is shown that these effects have significant influence on temperature distribution, load capacity and power loss of the bearing.

• Tribology and Lubricants
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• 제11권3호
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• pp.31-39
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• 1995

Grease thermal elastohydrodynamic lubrication (TEHL) problems of line contacts are analyzed numerically. The effects of temperature and rheological paraineters on grease TEHL are investigated using the Herschel-Bulkley model as a theological model of greases. The pressure distribution, the shape of grease film, mean film temperature and surface temperature of solid wall in line contacts are obtained. It is found that thermal effects on the minimum film thickness become remarkable at high rolling speeds. The effect of yield stress of Herschel-Bulkley model on minimum film thickness is negligible, while the theological index and viscosity parameter have significant effects on minimum film thickness.

• Coupled systems mechanics
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• 제6권4호
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• pp.399-415
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• 2017

This paper deals with the nonlinear static deflections of functionally graded (FG) porous under thermal effect. Material properties vary in both position-dependent and temperature-dependent. The considered nonlinear problem is solved by using Total Lagrangian finite element method within two-dimensional (2-D) continuum model in the Newton-Raphson iteration method. In numerical examples, the effects of material distribution, porosity parameters, temperature rising on the nonlinear large deflections of FG beams are presented and discussed with porosity effects. Also, the effects of the different porosity models on the FG beams are investigated in temperature rising.

• 한국자기공명학회논문지
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• 제16권2호
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• pp.122-132
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• 2012

The effects of the sample viscosity and volume on the convective flows induced by temperature gradient in PGSE-NMR self-diffusion measurements at high temperature have been investigated. The experimental results showed that the viscosity of the liquid sample strongly affects the magnitude of the convective flows as well as the diffusion coefficient itself. It was also found that the convective flows increase as the sample volume increase.

• Corrosion Science and Technology
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• 제19권2호
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• pp.75-81
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• 2020

To reduce structural weight, light metals, including aluminum and magnesium alloys, have been widely used in various industries such as aircraft, transportation and automobiles. Recently, composite materials such as Carbon Fiber Reinforced Plastics (CFRP) and Graphite Epoxy Composite Material (GECM) have also been applied. However, aluminum and its alloys suffer corrosion from various factors, which include aggressive ions, pH, solution temperature and galvanic contact by potential difference. Moreover, carbon fiber in CFRP and GECM is a very efficient cathode, and very noble in the galvanic series. Galvanic contact between carbon fiber composites and metals in electrolytes such as rain or seawater, is highly undesirable. Notwithstanding the potentially dangerous effects of chloride and temperature, there is little research on galvanic corrosion according to chloride concentration and temperature. This work focused on the effects of chloride concentration and solution temperature on AA7075T6. The increased galvanic corrosion between CRFP and AA7075T6 was evaluated by electrochemical experiments, and these effects were elucidated.

• 패션비즈니스
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• 제6권3호
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• pp.84-93
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• 2002

The purpose of this study was to design functional clothing based on the physical characteristics of old women. The subjects of this experiment were 5 healthy old women and 5 college women. While the subjects were exposed to the circumstances of $28{\pm}0.5^{\circ}C$ and local heating at 7 areas (chest, abdomen, back, loin, hand, thigh and instep), their skin temperature, physiological reaction and psychological reaction were determined. The conclusions about the effects of local heating are as follows : 1. Skin temperature before heating was in the order of head-neck> trunk> upper limbs> lower limbs (Group A: old subjects) and head-neck> trunk> lower limbs> upper limbs (Group B: young subjects). 2. The heating pad was attached and detached for 30 minutes each. The sharpest rise and fall were recorded at 5 minutes with the pad on and off. Both groups had great changes in the body parts near trunk. 3. With the pad on and off, both groups showed no change in body temperature, blood pressure, and pulse rate. 4. Concerning the pervasive effects of local heating on whole body skin temperature, loin heating greatly increased other body parts in Group A. In Group B, the effects were large in heating chest, abdomen, back, loin, and thigh. 5. The loin part of old women has the greatest pervasive effect of local body heating.

• 상하수도학회지
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• 제21권4호
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• pp.467-475
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• 2007

This study was conducted to examine temperature effects on hydrogen production in anaerobic fermentation. 18 batch reactors were operated at mesophilic ($35^{\circ}C$) and thermophilic conditions ($55^{\circ}C$) to achieve maximum hydrogen production in anaerobic fermentation. Optimum hydrogen production conditions were also investigated at each temperature. Different trends were observed regarding pH effects on hydrogen production. This effect was not significant for mesophilic fermentation ($35^{\circ}C$). In this case, pH may not drop to interfere hydrogen production during the test. However, hydrogen production decreased without pH control for thermophilic condition ($55^{\circ}C$). Effects of heat treatment were observed for both fermentation process. Hydrogen production with heat treatment was higher than hydrogen production without heat treatment for both fermentation processes. The amount of produced hydrogen for each substrate concentration with temperature changes showed that more hydrogen was produced at $35^{\circ}C$ than at $55^{\circ}C$.