• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2124-2129
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• 2007

A VCHP was fabricated and tested for its thermal performance. The container was made of copper, and the working fluid was water. STS-316 screen of mesh number 100 was inserted as a capillary structure. As a baseline performance, a normal heat pipe of the same dimensions was tested in advance to compare with VCHP, where an inert gas container was attached. The outer diameter of the heat pipe was 12.8 mm and the total length was 600 mm. The evaporator and the condenser lengths were both 200 mm. The thermal load ranged from 20 to 300W. Typical result revealed that the operating temperature of the VCHP stayed almost constant, while that of the normal heat pipe varied as much as 40$^{\circ}C$. Therefore, it was demonstrated that the VCHP is very effective for temperature control of heat-dissipating devices.

• 대한약침학회지
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• 제21권2호
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• pp.48-60
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• 2018

Objective: The aim of this study is to optimize the extraction of beneficial substance from Cudrania tricuspidata leaves grown at Jirisan Mountain in South Korea by three different solvents depending on extraction time and at different temperature. Methods: The total phenolic contents were determined by the method reported by $S{\acute{a}}nchez$-Moreno et al. The total flavonoid contents were analyzed by Slinkard and Singleton. The DPPH radical scavenging activity was determined according to the method reported by Blois Results: The extraction yield for each solvent is 9.05-14.1%, 2.17-5.67%, and 2.3-3.9% for D.W., ethanol, and hexane, respectively. The overall results were maximized for the extract obtained with D.W. for 5 min at $100^{\circ}C$. The average phenol contents were 77.11, 45.64, and 0.343 mg/g at $100^{\circ}C$ in water, $78^{\circ}C$ in ethanol, and $68^{\circ}C$ in hexane, respectively. The flavonoid contents were the highest in the materials extracted with D.W., and were increased with increasing temperature, regardless of the extraction solvents, whether water (green), polar organic ethanol, or nonpolar organic hexane. In the ethanol extract, the flavonoid contents are increased gradually from 5.66 mg/g to 7.73 mg/g. The total flavonoid contents were proportional to the concentrations of the water extracts, ranging from 4.14 mg/g to 48.89 mg/g. The antioxidative activities of the water-extracted compounds are generally increased with increasing temperature from 42.5% to 85.5%. Those of the hexane extracts are increased slowly from 3.79% to 8.8%, while those of ethanol extracts are increased from 29.8% to 47.4%. Conclusion: The extraction yields were dependent upon solvents for extraction as well as extraction time and the temperature. The optimal extraction time was 5 min and the extraction yields were increased with increasing temperature excepted hexane. Of the three tested extraction solvents, the greenest solvent of water shows excellent results, suggesting that water is among the most effective solvents for natural sample extractions for general medicinal, pharmaceutical, and food applications.

• Korean Journal of Acupuncture
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• 제27권4호
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• pp.35-47
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• 2010

Objectives : To characterize the thermal properties of traditional warm needle and new warm needle with various air flows as an important environmental factor and to suggest the necessity of maintaining suitable environment of clinics to maximize their efficacy. Methods : We measured the temperature characteristics of traditional moxa warm needle and new moxa charcoal warm needle by applying an automatic temperature acquisition system with thermocouples while external various air flows were supplied. Temperatures of two positions at the needle body were measured while a moxa cone burned. Typical temperature characteristics like peak temperature, duration, curve shape and the efficiency of the heat stimuli by heat amount analysis were executed. Results : Both warm needles showed similar temperature curve with an increase in the air flow. Peak temperature and duration of effective heat decreased with the air flow, as shown in indirect moxibustion on garlic. The temperature change pattern by the air flow became more apparent when the total combustion heat was compared with the effective heat. The values from two positions on the needle body were significantly different, showing a distance dependency from the heat source of warm needle acupuncture. Conclusions : Thermal properties of warm needle acupuncture was observed variously with surrounding air flow of 0.0 - 0.7 m/s. It emphasized the importance of environmental control as well as the warm needle itself such as heat source and needle. The latter has already been known to deliver designated heat to subjects. It also indicated the importance of education and skill of the practitioners of warm needle acupuncture.

• Structural Engineering and Mechanics
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• 제52권3호
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• pp.603-612
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• 2014

A series of experimental work is carried out with the aim to understand the flexural performance of laminated glass (LG) beams using polyvinyl butyral (PVB) and Ionoplast interlayers subjected to short term duration loads in the circumstance of elevated temperature. The study is based on a total of 42 laboratory tests conducted in ambient temperature ranging from $25^{\circ}C$ to $80^{\circ}C$. The load duration is kept within 20 seconds. Through the tests, load-stress and load-deflection curves of the LG are established; appropriate analytical models for the LG are indentified; the effective thicknesses as well as the shear transfer coefficients of the LG are semi-empirically determined. The test results show that within the studied temperature range the bending stresses and deflections at mid-span of the LG develop linearly with respect to the applied loads. From $25^{\circ}C$ to $80^{\circ}C$ the flexural behavior of the PVB LG is found constantly between that of monolithic glass and layered glass having the same nominal thickness; the flexural behavior of the Ionoplast LG is equivalent to monolithic glass of the same nominal thickness until the temperature elevates up to $50^{\circ}C$. The test results reveal that in calculating the effective thicknesses of the PVB and Ionoplast LG, neglecting the shear capacities of the interlayers is uneconomic even when the ambient temperature is as high as $80^{\circ}C$. In the particular case of this study, the shear transfer coefficient of the PVB interlayer is found in a range from 0.62 to 0.14 while that of the Ionoplast interlayer is found in a range from 1.00 to 0.56 when the ambient temperature varies from $25^{\circ}C$ to $80^{\circ}C$.

• Membrane and Water Treatment
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• 제2권3호
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• pp.159-173
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• 2011

The air gap membrane distillation (AGMD) process was applied for water desalination. The main objective of the present work was to study the heat and mass transfer mechanism of the process. The experiments were performed on a flat sheet module using aqueous NaCl solutions as a feed. The membrane employed was hydrophobic PTFE of pore size 0.22 ${\mu}m$. A mathematical model is proposed to evaluate the membrane mass transfer coefficient, thermal boundary layers' heat transfer coefficients, membrane / liquid interface temperatures and the temperature polarization coefficients. The mass transfer model was validated by the experimentally and fitted well with the combined Knudsen and molecular diffusion mechanism. The mass transfer coefficient increased with an increase in feed bulk temperature. The experimental parameters such as, feed temperature, 313 to 333 K, feed velocity, 0.8 to 1.8 m/s (turbulent flow region) were analyzed. The permeation fluxes increased with feed temperature and velocity. The effect of feed bulk temperature on the boundary layers' heat transfer coefficients was shown and fairly discussed. The temperature polarization coefficient increased with feed velocity and decreased with temperature. The values obtained were 0.56 to 0.82, indicating the effective heat transfer of the system. The fouling was observed during the 90 h experimental run in the application of natural ground water and seawater. The time dependent fouling resistance can be added in the total transport resistance.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권1호
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• pp.72-79
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• 2016

Bioremediation is one of the most effective ways to remediate TPH-contaminated sites. However, under actual field conditions that are not at the optimum temperature, degradation of microorganisms is generally reduced, which is why the efficiency of biodegradation is known to be significantly affected by the soil temperature. Therefore, in this study, the labscale experiment was conducted using indigenous crude oil degrading microorganisms isolated from crude oil contaminated site to evaluate the remediation efficiency. Crude oil degrading microorganisms were isolated from crude oil contaminated soil and temperature, which is a significant factor affecting the remediation efficiency of land farming, was adjusted to evaluate the microbial crude oil degrading ability, degradation time, and remediation efficiency. In order to assess the field applicability, the remediation efficiency was evaluated using crude oil contaminated soil (average TPH concentration of 10,000 mg/kg or more) from the OO premises. Followed by the application of microorganisms at 30℃, the bioremediation process reduced its initial TPH concentration of 10,812 mg/kg down to 1,890 mg/kg in 56 days, which was about an 83% remediation efficiency. By analyzing the correlation among the total number of cells, the number of effective cells, and TPH concentration, it was found that the number of effective microorganisms drastically increased during the period from 10 to 20 days while there was a sharp decrease in TPH concentration. Therefore, we confirmed the applicability of land farming with isolated microorganisms consortium to crude oil contaminated site, which is also expected to be applicable to bioremediation of other recalcitrant materials.

• 대한간호학회지
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• 제47권4호
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• pp.456-466
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• 2017

Purpose: This study was designed to determine the effects of pre-warming on core body temperature (CBT) and hemodynamics from the induction of spinal anesthesia until 30 min postoperatively in surgical patients who undergo total hip replacement under spinal anesthesia. Our goal was to assess postoperative shivering and inflammatory response. Methods: Sixty-two surgical patients were recruited by informed notice. Data for this study were collected at a 1,300-bed university hospital in Incheon, South Korea from January 15 through November 15, 2013. Data on CBT, systemic blood pressure (SBP), and heart rate were measured from arrival in the pre-anesthesia room to 3 hours after the induction of spinal anesthesia. Shivering was measured for 30 minutes post-operatively. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were measured pre-operatively, and 1 and 2 days postoperatively. The 62 patients were randomly allocated to an experimental group (EG), which underwent pre-warming for 30 minutes, or a control group (CG), which did not undergo pre-warming. Results: Analysis of CBT from induction of spinal anesthesia to 3 hours after induction revealed significant interaction between group and time (F=3.85, p=.008). In addition, the incidence of shivering in the EG was lower than that in the CG ($x^2=6.15$, p=.013). However, analyses of SBP, heart rate, CRP, and ESR did not reveal significant interaction between time and group. Conclusion: Pre-warming for 30 minutes is effective in increasing CBT 2 and 3 hours after induction of spinal anesthesia. In addition, pre-warming is effective in decreasing post-operative shivering.

• 성인간호학회지
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• 제14권3호
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• pp.428-437
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• 2002

Purpose: The purpose of this study is to examine the changes of surgical patients' body temperature in applying warming to patients. The study of an effective nursing intervention, which aims to prevent hypothermia during surgical operations, use of anesthesia, and to remove dermal discomforts. The nonequivalent control group pre-test/post-test design was used for this quasi-experimental study. Method: The study subjects were adult patients who would take a surgical operation under general anesthesia in C Hospital; the surgical operations done were, total abdominal hysterectomy or Myomectomy; 20 patients were included in experimental group I, 20 patients were included in experimental group II, and 20 patients were in the comparative group. The total number of study subjects was 60. The data was collected from September the 1st, 2001 to October the 20th, 2001. The data was analyzed by SPSS program, F-test and Repeated measures of ANOVA. Multi-comparison method of DUNCAN was used for the sections that show the significant differences at the level of p<.05, which was a posterior examination. Result: 1) "The body temperatures of the three groups of patients will be respectively different at the end of the operations; experimental group I to which warming was applied before the operations, experimental group II to which warming was applied during the operations, and the comparative group with no warming being given," showed (F=12.609, p=.000). 2) "Degrees of shivering symptoms for the three groups will be respectively different at the end of the operations; experimental group I which applied warming before operations, experimental group II which applied warming during operations and the comparative group with no warming." Showed assumed (F=6.626, p=.000). Conclusion: Summing up the above study, the warming assumed during operations was a more effective nursing intervention for preventing patients' hypothermia than the warming assumed before operations.

• 한국작물학회지
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• 제63권1호
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• pp.57-63
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• 2018

The effects of endophytic microbial inoculation and temperature on the phenolic content of tartary buckwheat (TP) sprouts were investigated. TP seeds were inoculated with Herbaspirillum spp. at concentrations (%v/v) of 0 (control), 10, 20, and 40% at 20, 25, and $30^{\circ}C$ in a growth chamber for seven days. It was observed that the phenolic content (PC) including flavonoid, rutin, and tanin increased with an increase in inoculant rate at $20^{\circ}C$, whereas the PC content increased with an increase in temperature regardless of the inoculant rate. Therefore, it is suggested that increasing the inoculant rate is effective at achieving higher phenolic contents when plants are grown at lower temperatures.

• 한국식품영양과학회지
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• 제46권11호
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• pp.1366-1372
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• 2017

본 실험은 36주(9개월) 동안 오미자음료의 저장용기 및 저장온도에 따른 이화학적 품질 특성을 비교 분석하였다. 저장 3주부터 흡광도는 저장용기에서 고도로 유의적인 차이를 보였고, 총 가용성 고형분 함량은 저장용기, 저장온도, 저장용기${\times}$온도 등 모든 요인에서 고도로 유의한 차를 나타냈다. 총 페놀성 화합물, 총산도는 투명병 처리, 갈색병 처리 모두 저장후기에 조금 감소하였고, pH는 조금 증가하였다. 전반적으로 $4^{\circ}C$ 저장이 $20^{\circ}C$ 및 $36^{\circ}C$ 저장보다 오미자음료 품질 특성 변화가 적었다. 각 인자들의 상관성을 분석한 결과 저장기간에 의한 흡광도, 가용성 고형분, 총 페놀성 화합물, pH, 총산도는 모두 각각의 항목들에 대한 양의 상관관계를 보였다. 오미자음료의 투명병 처리는 저장기간이 경과되면서 오미자음료의 흡광도 감소에 많은 영향을 주는 것으로 나타났다. 갈색병 처리는 9개월 동안 품질 변화가 적었고, 각각의 저장온도에 의한 안전성이 확인되었다. 위 결과로 보아 갈색병 처리는 36주 동안 오미자음료 품질유지에 적합한 것으로 생각된다.