• Journal of the Korean Society for Heat Treatment
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• v.30 no.2
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• pp.43-52
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• 2017

Heat treatment condition for dissolution of the M23C6 carbides in 2.25Cr-1Mo-V-Ti material for thermal power plant tube was investigated using a dilatometer method. 2.25Cr-1Mo-V-Ti material was heat-treated at $900{\sim}1,100^{\circ}C$ for 0, 10, 30 min to find the proper dissolution condition of M23C6 carbides. The phase identification and volume fraction of the carbide were measured by using OM, SEM, EBSD and TEM analysis. Optimal heat treatment condition of M23C6 carbide dissolution was selected by predicting dissolution temperature of carbide using Bs points appeared at dilatometer curve. Experimental results showed that the conditions of carbide dissolution was 900, 1,000, $1,100^{\circ}C$ for 30 min. Eventually, the optimal heat treatment condition for dissolution was 30 min at $1,000^{\circ}C$ considering the minimum coarsening of Austenite grain size.

• Restorative Dentistry and Endodontics
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• v.2 no.1
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• pp.50-54
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• 1976

16 healthy teeth extracted have been selected and their color and structural change have been observed at the fixed temperatures of $200^{\circ}F$., $400^{\circ}F$., $600^{\circ}F$., and $800^{\circ}F$. respectively at the intervals of 10min. 30min and 60min. The results were as follows: 1) $200^{\circ}F$ Groop: At the 60 minutes interval, crown surface shows pattern simliars to mottled teeth and roots take on light yellowish colar and interglobular dentin tends to be rough. 2) $400^{\circ}C$ Groop: at the 30 minutes interval, cracks begin to show in the direction of long axis of the teeth and crown surface have been observed on the verge of fracture at the 60 minutes interval. 3) $600^{\circ}F$ Groop: Crowns take on grayish-white color thoroughout 10, 30 and 60 minutes intervals and roots reveal black color. Moreover the seperation of enamel from dentin has been confirmed at the 60 minutes interval and inner dentin has changed black. 4) $800^{\circ}F$ Groop: Crowns take on the same grayish-white color as at the $600^{\circ}F$ at the 10, 30 and 60 minutes intervals and roots reveal gray color at the 30 and 60 minutes intervals, while parts of the crown have fractured at the 10 minutes interval. Inner dentin has turned gray at the 60 minutes interval.

• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.61-66
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• 2016

It has been known that Arak, Salvadora persica, has a number of medicinal properties. We tried to investigate in vitro scolicidal effect of root extracts of this plant against protoscolices from hydatid cysts of Echinococcus granulosus. Protoscolices were aseptically collected from sheep livers containing hydatid cysts. S. persica root extract was used in 10, 30, and 50 mg/ml concentration for 10, 20, and 30 min. The viability of protoscolices was ascertained by 0.1% eosin staining. Scolicidal activity of S. persica extract at a concentration of 10 mg/ml was 36.3%, 50.3%, and 70.8% after 10, 20, and 30 min of exposure, respectively. The scolicidal effect of this extract at a concentration of 30 mg/ml was 52.9%, 86.7%, and 100% after 10, 20, and 30 min of exposure, respectively. S. persica extract at a concentration of 50 mg/ml, meanwhile, killed 81.4%, 100%, and 100% of protoscolices after 10, 20, and 30 min, respectively. Also, the cytotoxic potential of S. persica was assessed on human liver cells (HepG2) using trypan blue exclusion test. No cytotoxic effect was observed on HepG2 cell line. The present study confirmed for the first time that the ethanolic extract of S. persica has high scolicidal power in vitro. However, in vivo effect of this material remains to be studied for treatment of echinococcosis in humans and herbivorous animals.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.4
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• pp.318-328
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• 1993

A series of long wave measurements was made in the region of Shikotan Island (the South Kuril Islands) during 1990-1992: 7 bottom pressure stations were installed in 5 bays and inlets of Shikotan and 3 precise microbarographs were situated at the shore. The observations were taken in order to monitor tsunami waves, estimate resonance features of coastal topography, and investigate seiche generation mechanism. It was found that forced long waves dominate in the motions with periods exceeding 2 hours, freely propagating long waves prevail at periods of 30-120 min and eigen-oscillations of bays (seiches) are the predominant type of long waves at periods less than 30 min. The Helmholtz mode with period 30 min in Krabovaya Bay and 18.5 min in Malokurilskaya Bay is the most important type of wave motion in the inner Shikotan basins. There is a good correlation between passages of atmospheric disturbances and generation of seiches near the coast of Shikotan Island. In particular, jumps in atmospheric pressure excite seiches in different bays simultaneously, in each one with the corresponding dominant period. The atmospheric spectra were remarkably smooth and stable, and could be described by a $\omega$$^{-2}$26/ power law.

• The Korean Journal of Community Living Science
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• v.24 no.2
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• pp.233-241
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• 2013

This study was conducted to evaluate the quality characteristics and the hypoglycemic effect of cookies containing Helianthus tuberosus powder (HTP). To examine the effect of adding HTP, cookies with various HTP contents (0%, 10%, 20%, 30%, 40%) were made and compared for their quality characteristics. The pH of cookie doughs decreased significantly (p<0.05) as the content of HTP increased. However, the density did not show significant difference among samples. The spread ratio and loss rate in cookies showed significant increase (p<0.05) as the content of HTP increased. However the leavening rate and the hardness of the cookies decreased significantly (p<0.05) when HTP content increased. Color measurement also showed significant difference among samples, although the cookie sample with 10% HTP powder showed the highest scores from consumer tests and liking score, the cookie samples with 30% HTP were selected to measure the hypoglycemic effect of Helianthus tuberosus compared to control cookies and bread. Ten healthy subjects in their twenties participated in measuring blood glucose levels after intake of bread, control cookie, or 30% HTP cookie. Blood glucose level was measured after fasting 12 hours, before eating, and 30, 60, 90, and 120 minutes after taking the samples. As a result, the blood glucose levels at 30min after meals showed significant (p<0.05) difference among treatments: the lowest when taken the cookies added 30% HTP. However there was no difference in the blood glucose levels at 60min, 90min, and 120min after the sampling.

• Korean Journal of Food Science and Technology
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• v.45 no.4
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• pp.501-507
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• 2013

We evaluated the effects of temperature, time, solvent type, and solvent concentration on the phenolic content and antioxidant activity of rosemary extracts. The antioxidant capacity of rosemary extracts was demonstrated by their ability to scavenge stable free radicals, and the phenolic content of the extracts was determined using the Folin Ciocalteu method. The highest values were obtained by water-based extraction at $90^{\circ}C$ for 30 min, a 75% methanol solution at $60^{\circ}C$ for 30 min, and a 50% ethanol solution at $70^{\circ}C$ for 10 min. The aqueous solution of 75% methanol, extraction temperature of $60^{\circ}C$, and extraction time of 30 min were the most efficient parameters for the extraction of polyphenols from dry rosemary.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.6
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• pp.111-117
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• 2009

The RUSLE(Revised Universal Soil Loss Equation) has been most widely used to estimate sediment yield in Korea. However RUSLE factors have not been verified based on measured data of sediment yield. The analysis of characteristics for the rainfall erosivity factor R was performed in this study. The R factor of RUSLE is expressed as multiple of total rainfall energy and maximum 30 min rainfall intensity. In this study, the characteristics of 10 rainfall energy equations were investigated using data measured in Gangneung experimental watershed, and applicability of each equations was reviewed based on results of the correlation analysis between measured sediment yield and total rainfall, between measured sediment yield and maximum intensity, and between measured sediment yield and total rainfall energy yield. Also, the relationship of I30 and I60 was proposed using 10-min rainfall data during 9 years.

• Journal of the Korean Ceramic Society
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• v.44 no.3 s.298
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• pp.182-187
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• 2007

10 mol% $Gd_{2}O_{3}-CeO_{2}$ powder was sintered by microwave in a 2.45 GHz multimode cavity to develop a dense electrolyte layer for intermediate temperature solid oxide fuel cells (IT-SOFCs). Samples were sintered from $1100^{\circ}C$ upto $1500^{\circ}C$ by $50^{\circ}C$ difference and kept for 10 min and 30 min at the maximum temperature respectively. Theoretical density of the sample sintered at $1200^{\circ}C$ for 10 min was 95.4% and increased gradually upto 99% in the sample sintered at $1500^{\circ}C$ for 30 min. All of sintered samples showed very fine microstructures and the maximum average grain size of the sintered sample at $1500^{\circ}C$ for 30 min was $(0.87{\pm}0.42){\mu}m$. Ionic conductvity of the samples were measured by DC 4 probe method.

• Journal of Technologic Dentistry
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• v.13 no.1
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• pp.27-31
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• 1991

The purpose of this study was to evaluate the effect of curing time and curing temperature on the hear - Curing of acrylic resin using ring furnace. Specimens were fabricated from 2 kinds(Laboron, Bertex) heat-cured resin. Total 200 samples were divided into 4 groups(70$^{\circ}C$, 100$^{\circ}C$, 13$^{\circ}C$, 150$^{\circ}C$) and each group was divided into 5 small groups(30 min., 45min., 60min., 75min., 90min.). A microscope(Olympus Coll Co. Japan) was used to examine a randomly selected central zone, midzone and surface for each complete specimen. The results of the experiment were as follows : 1. To obtain non-polymerzation, cure the resin for 30 minutes at 70$^{\circ}C$ and 100$^{\circ}C$ in a ring furnace. 2. To obtain with porosity, cure the resin for 45 minutes, 60 minutes and 75 mintes at 70$^{\circ}C$ and for 90 minutes at 150$^{\circ}C$ in ring furnace. Porosity appears in Laboron for 30 minutes, 45 minutes at 150$^{\circ}C$ in a ring furnace. 3. Every other specimens connot get a sight of special problem with makes eye in the made surface.

• The Journal of Korean Medicine
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• v.24 no.2
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• pp.19-31
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• 2003

Objectives : This study examined effects of kyeong points (經穴)' acupuncture of three hand yang collaterals (手三陽經) on the facial thermography in health subjects, because the kyeong point in Yang collaterals belongs to the characteristic of the five elements (五行)meaning fire (火). Methods : The volunteers who participating in this study rested for 20-30 min. atroom temperature (23-$25^{\circ}C$) before the examination and were informed to avoid smoking, drinking and use of any drugsfor the previous day. The thermography of the face was taken using Infra-Red Imaging System (IR 2000, MEDI-CORE Co., Korea) at time intervals of 15 minutes : at 15 min before, just before and after, 15 min after, 30 min after and 45 min after acupuncture stimulation. Acupuncture was applied to the left kyeong points (經穴)' of three hand yang collaterals (手三陽經) for 30 minutes. Results : The results showed that kyeong points (經穴)' acupuncture of three hand yang collaterals (手三陽經) decreased the temperature of all the areas of the facial surface comparing to those of the control group. Also, it was observed that the quantities of thermal changes following acupuncture of ST36 increased in the all ROIs (regions of interest) compared to those of the control group. Conclusions : Observing the thermography classified by ROI, it was clear that acupuncture of kyeong points (經穴) of three hand yang collaterals (手三陽經) could modulate thermogram of the facial area however, it is necessary to undertake more investigation supporting these results.