• Applied Biological Chemistry
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• v.20 no.1
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• pp.88-94
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• 1977

A laboratory study was made of liming on the extractability of phosphate added to the uncultivated acid soils differing in clay content. The experiments were conducted with different rates of calcium carbonate and triple superphosphate at field capacity and 50% field capacity. The concentration of extractable phosphate was greatly reduced by simultaneous addition of calcium carbonate in the loam soil. When samples of the loam soil were preincubated for ranging from 0 to 50 days in the presence of calcium carbonate prior to phosphate application, the extractable phosphate concentration increased with preincubation time, and more phosphate was extracted from the soil maintained at 50% field capacity during the incubation. However, the extractable phosphate concentration in the sandyloam soil did not change with preincubation time and was not affected by moisture status. It may be concluded that the extractability of added phosphate was influenced by not only liming time but physical properties of soil.

• 보존과학연구
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• s.33
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• pp.45-55
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• 2012

A beeswax-treated paper has no air permeability but has the water repellency compared with a general Hanji. Because of these properties, the differences of the aging factors and mechanisms between the outer partition of beeswax-treated paper that is affected by the surrounding conservation environment and the inner partition of it that is not affected are bigger than general books. In this research, we analyzed and compared the aging characteristics through the accelerated aging of the beeswax-treated paper by some air and humidity conditions. The results of the physical and optical analysis after the artificial aging, it was shown that the oxygen accelerates the aging of the beeswax-treated paper and the condition with the humidity 50% RH is more stable than the condition with the humidity 0% RH. The results of the CG/MS analysis that was conducted to figure out the decomposition charateristics of the beeswax according to the air quality and the humidity, a low molecular weight compound that the number of carbon is C9-C20 including a fatty acid such as a palmitic acid was increased as the aging was progressed. However, under the same environment, a compound that the number of carbon is C21-C36 including a hydrocarbon and a aliphatic alcohol and a high molecular weight compound that the number of carbon is more than C34 including a wax ester were decreased. A rate of change according to the air quality and the humidity was similar to the beeswax-treated papers.

• The Journal of Dong Guk Oriental Medicine
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• v.4
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• pp.161-187
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• 1995

This study was perfomed to investigate causes of the senile hypotension, pathogenic mechanism, symptoms, and therapies through medical literatures, recent chinese medical literatures and chinese medical journals. The results are as follows ; 1. The senile hypotension has major symptoms of dizziness, weakness, syncope, palpitation, shortness of breath, and deficiency of Qi. Additionally, it has minor symtoms of letharhy, isomnia, tinnitus, amnesia etc... 2. The prodromal symptoms of Kwul and Kwul are relating to the symptoms of tachycardia, facial pallor, sweating, anxietas, ambiguous consciousness, and fainting. Weakness and dizziness due to deficiency make the symptoms of exhaustion, fatigue, vertigo, lethargy, and brachycardia. 3. The most principal cause of the senile hypotension is deficiency of Shen due to aging, congenital deficiency, and chronic illness. The rest of causes are defciency of Qi and blood, phlegm of retention, stagnation of Qi, blood stasis, blood prostration etc... In the view of the occidental meicine, the causes of the senile hypotension came from the reduction of cardiac output, the decretion of cardiovascular system's extention due to aging, hereditary factor, secondary factor due to exsanguination, diabetes mellitus, C.V.A etc..., and factor of neurogenic system's degeneration. 4. The principal pathogenic mechanisms are the insufficiency of Xing-Yang, the deficiency of Qi in middle jiao, and deficiency of Shen-Qi. The rest of mechanisms are the deficiency of both Qi and blood, stagnation of the Gan-Qi, and the deficiency of Gan and Shen. Zang-Pu Organs have something to do with Xing, Bi, and Shen. 5. As principal therapies, there are warming and recuperation the Xing-Yang, strengthing the middle-jiao and replenishing Qi, replenishing vital essence to tonify the Shen, and warming and recuperation the Shen-Yang. Additionally, the therapies of invigorating the Bi and relieving mental stress, strengthning the Bi and tonifing the Shen, invigorating Qi and nourishing Yin, soothing the Gan and regulating the circulation of Qi, and tonifing the Shen and nourishing the Gan help the cure of the senile hypotension. In prescriptions there are Baohe Yuan Tang, Buzhong Yigi Tang, Zuoguei Yin, Yougui Yin, Guipi Tang, Zhu Fu Tang, Shengmai San, Sini San, and Qi Ju Dihuang Wan. The medical herbs of Astragali Radix, Codonopsitis Pilosulae Radix, Ginseng Radix, Aconiti Tuber, Ephedrae Herba, Cinnamomi Ramulus, Cinnamomi Corfex Spissus, Zingiberis Rhizoma, Polygalae Radix, Liriopis Tuber, Polygonati Sibirici Rhifoma, Lycii Fructus, Schizandrae Fructus, and Glycyrrhizae Radix can be treated. 6. According to the clinical report, the principal causes are the deficiency of Qi, and insufficiency of Yang which symptoms are dizziness, vitality fatigue and acratia, amnesia, body cold and alger of extremity, spontaneous perspiration, and therady and weak pulse. It was improved by taking WenYang YiQi Tang, Zhu Fu Tang about 20-30 days. The improvement was shown on disappearance of subjective symptoms or the ascending of blood pressure to normal figure, and the rate of improvement was over 70%. 7. As regimens, taking warming and recuperating food(a sheep mutton, juglans regia, chiness date, longan aril etc...) and pungent food(chinese green onion, fress ginger, pipers fructns etc...), doing physical training, not being ill in bed at a long time, and preventing descent of blood pressure coming from sudden change of posture are needed. Additionally, the usage of diuretic, abirritant, and depressor needs to be extra cautious.

• Korean Journal of Environment and Ecology
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• v.34 no.2
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• pp.170-178
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• 2020

There are few landscape ecological analyses of Khingan fir (Abies nephrolepis) and other habitats of the sub-alpine zone in South Korea. In this study, we tried to quantitatively interpret and assess the habitat characteristics by analyzing 15 landscape indices according to the differences in tree layer coverage, in the Khingan fir habitat growing naturally in the sub-alpine zone of Seoraksan National Park. It was difficult to identify the tendency of landscape ecology to increase and decrease the tree layer coverage in the study site, which was the entire Khingan fir habitat in Seoraksan National Park. However, the Khingan fir habitat was found to be generally low in coverage, and population density as the tree layer coverage of less than 50 percent accounts for 85 percent of the total habitat. Moreover, the Khingan fir habitat in the 10 to 50 percent range was fragmented into a total of 286 patches, making it relatively less connected to the habitat. The total edge length and edge density, which could determine the edge effect of the main part according to the physical form, were the highest in the habitat of 26 to 50 percent coverage, indicating a relatively high impact from outside than habitats of other coverages. The shape with the tree layer coverage of between 10 and 50 percent was more complex even with patches of the same size, and it is believed that these characteristics make it more susceptible to habitat fragmentation and external confounding. We expect that the results of this study can be useful for time series analysis of spatial expansion or reduction of the Khingan fir habitat in Seoraksan National Park and provide the reference data for the morphological change and movement of patches and the connectivity and break-off between forests.

• Clean Technology
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• v.24 no.3
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• pp.198-205
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• 2018

This study investigated the influence of catalyst preparation on the activity of $Co-CeO_2$ catalyst for $N_2O$ decomposition. $Co-CeO_2$ catalysts were synthesized by co-precipitation and incipient wetness impregnation. In order to estimate the performance of the as prepared catalysts, direct catalytic $N_2O$ decomposition test was carried out under $250{\sim}375^{\circ}C$. As a result, the catalyst prepared by co-precipitation (CoCe-CP) showed an enhanced performance on $N_2O$ decomposition reaction even in the presence of $O_2$ and/or $H_2O$, whereas the impregnation catalyst (CoCe-IM) did not. In order to investigate the difference in catalytic activity, characterization such as XRD, BET, TEM, $H_2-TPR$, $O_2-TPD$, and XPS was conducted. It is confirmed that the particle size and specific surface area were changed depending on the catalyst preparation method and the synthesis process influenced the physical properties of the catalysts. In addition, the improvement in the activity of the catalyst prepared by co-precipitation is due to the enhanced reduction from $Co^{3+}$ to $Co^{2+}$ and the improved oxygen desorption rate. However, it has been confirmed that the surface electron state and binding energy, which are related to $N_2O$ decomposition, do not change depending on the preparation method.

• The Korean Journal of Food And Nutrition
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• v.20 no.1
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• pp.88-95
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• 2007

The purpose of this study was to investigate the effects of a 12 week weight control program, which included nutrition education and regular physical fitness, on body weight, degree of obesity, BMI, and lowering of blood lipids in 16 obese male elementary school students. Changes in waist and hip circumferences and their ratios were measured at the conclusion of the 12 week program conducted from September 9 to November 25, 2005. Body weight after 12 weeks on the program slightly reduced from 55.4${\pm}$10.9 kg to 54.4${\pm}$9.7 kg. Degree of obesity and BMI decreased from 121.3${\pm}$8.1%, and 25.9${\pm}$3.3 to 120.0${\pm}$8.2% and, 25.6${\pm}$2.7, respectively. Body fat percentage decreased slightly from 38.3${\pm}$4.7% to 37.9${\pm}$5.2%. Waist to hip ratio did not change after 12 weeks. There were slight changes in weight of body fat and lean body mass from 22.12${\pm}$6.53 kg and 34.56${\pm}$4.75 kg to 21.68${\pm}$6.05 kg and 34.70${\pm}$4.54 kg, respectively. Also, after 12 weeks on the weight control program, body, waist, and hip circumferences decreased. However, there were no significant differences among the blood lipid components, including triglycerides, total cholesterol, and HDL-cholesterol. Finally, body weight, degree of obesity, BMI, and body fat showed more significant correlations to waist, hip circumference and their ratio than to blood lipid levels.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.352-363
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• 1999

It has been rare to obtain reliable information related to the size of forest land in North Korea. Several sources of forest statistics, ranging from the first map of forest distribution in Korean Peninsula produced in 1910 to official data reported by the North Korea Government in 1997, were gathered and analyzed to define the characteristics of forest cover changes over years. In addition, Landsat satellite data obtained from 1973 to 1993 were processed for the two study areas of the provinces of Pyungyang and Heasan, where the topography and land use pattern are significantly different each other. Using three sets of multitemporal Landsat imagery, land cover ma-ps were produced by computer classification. Although forest statistics reported before 1990 are somewhat inconsistent, they mere gradually decreasing over years. The estimates of 1991 satellite data and the recent statistics reported in 1998 shows very steep decline in forest lands as compared to the ones before 1990. The abrupt decrease of forest lands after 1990 was also found on the detailed analysis of Landsat data for the two study areas of Pyungyang and Heasan. The rapid decline of forest lands may have something to do with the poor economic situation of the country and the continuing natural disasters of severe flooding and drought. Unstocked forest, which was not classified into forest land, was a very distinct and pervasive land cover type that can be easily observed on satellite imagery. Since unstocked forest land in North Korea may be a critical factor for degrading environmental quality as well as for the continuing natural disasters, further analysis is necessary to define the exact extent and the physical characteristics of the cover type.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.6
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• pp.467-473
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• 2007

The most important factor for successful implantation is osseointegration between the implant and bone. The expression of bone morphogenetic proteins (BMPs) inducing bone formation would differ after maxillary sinus elevation. And within the same graft material. the expression of BMPs would change with time after graft. The aim of this study was to compare the relative expressions of BMP4 and BMP6 using real-time RT-PCR when maxillary sinus elevation was performed using deproteinated bovine bone powder (DBBP) as the graft material or absorbable gelatin sponge (AGS) as the filler without any graft material. Fifteen rabbits, each weighing between 3.0 to 3.5 Kg, were divided randomly into 5 groups of 3 animals each based on their time of sacrifice 0, 3, 5, 7 and 9 days). After exposure of the maxillary sinus bilaterally, bone graft was performed in the right maxillary sinus using DBBP ($BBP^{(R)}$ Oct Inc., Cheonan, Korea) and only AGS ($Gelfoam^{(R)}$ Pharmacia & Upjohn Company, Kalamazoo, MI, U.S.A) was placed into the left without any graft material. Each group of rabbits was sacrificed at 1, 3, 5, 7, or 9 days after operation and all specimens were harvested. And the following results were obtained using real-time RT-PCR from isolated total RNA of the samples. 1. The expression of BMP4 increased at postoperative 1 and 3 days in both DBBP group and AGS group. In AGS group. it decreased at postoperative 5 days. increased again at postoperative 7 days, and decreased at postoperative 9 days. In DBBP group, it increased until postoperative 7 days and decreased at postoperative 9 days. Although the expression of BMP4 was higher in DBBP group compared with AGS group, it was not statistically significant (p>0.05). 2. The expression of BMP6 increased at postoperative 1 and 3 days in both DBBP group and AGS group. In AGS group, it decreased at postoperative 5 days, increased again at postoperative 7 days, and decreased at postoperative 9 days. In DBBP group, it increased until postoperative 7 days and decreased at postoperative 9 days. Although the expression of BMP6 was higher in AGS group compared with DBBP group, it was not statistically significant (p>0.05). 3. There was no statistically significant difference in BMP expression in both groups during same period of time. It' s probably because DBBP and AGS both functioned as a space retainer so that the BMP expression in blood clot seemed to be similar. 4. Thus, DBBP would not offer many benefits for early bone regeneration compared with AGS. The expression of BMP in early bone formation seems to be more influenced by physical carrier rather than the graft type.

• Clean Technology
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• v.21 no.1
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• pp.76-82
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• 2015

Volatile organic compounds (VOC) free adhesives have been interested by many scientists and engineers due to environmental regulations and the safety of industrial workers. In this work, a series of composites composed with bisphenol A epoxy resin used as solvent, dicyandiamide, and promoter were prepared to investigate the most appropriate molar ratio for steel-steel adhesion. The cured test specimen of each composite were measured with universal testing machine (UTM) to figure out mechanical properties such as tensile strength, Young’s modulus, and elongation. Furthermore, the lap shear strength of the specimen was tested with UTM while impact resistance was measured with Izod impact tester. The composite whose molar ratio of epoxy resin to curing agent is 1 : 0.9 (sample 3), showed better tensile strength, coefficient of elastic modulus, elongation, and impact strength than other composites did. The highest tanδ from dynamic mechanical analysis (DMA) was observed from sample 2 (epoxy resin: dicy = 1 : 0.7) while sample 3 showed slightly lower tanδ than that of 2. The morphology of the fracture surface of the cured composites from SEM showed that the number of subtle lines on the surface caused by impact increase as the contents of amine curing agent accrete. Furthermore, the viscosity change of sample 5 (epoxy resin: dicy = 1 : 1.3) was observed to confirm its storage stability.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.231-238
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• 2018

Chlorophyll fluorescence, chlorophyll content, graft-taking and growth of grafted cucumber seedlings as affected by photosynthetic photon flux (PPF) of LED lamps were analyzed in this study. Four PPF levels, namely 25, 50, 100, $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ were provided to investigate the effect of light intensity on the chlorophyll fluorescence, chlorophyll content, graft-taking and growth of grafted cucumber seedlings. Air temperature, relative humidity, and photoperiod for graft-taking were maintained at $25^{\circ}C$, 90%, $16h{\cdot}d^{-1}$, respectively. Maximum quantum yield (Fv/Fm) of rootstock as affected by PPF was found to be 0.84-0.85 and there was no significant change in Fv/Fm. Even though Fv/Fm of scion measured at 2 days after grafting was lowered to 0.81-0.82, after then it gradually increased with increasing PPF. At 4 days after grafting, the chlorophyll content extracted from scion increased with increasing PPF. Graft-taking ratio of grafted cucumber seedlings was 90-95% as PPF was ranged from $25{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ to $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. However, the graft-taking ratio of grafted seedlings healed under PPF of $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ was decreased to 80%. Maximum PPF measured required for smooth joining of rootstock and scion was assumed to be $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. At healing stage of grafted cucumber seedlings, Fv/Fm of scion decreased and at least two days after grafting were required for rooting of grafted seedlings. Chlorophyll fluorescence response of rootstock and scion was linked to light irradiation. Therefore, it was concluded that physical environment including light and humidity during healing process of grafted seedlings should be controlled more precisely to facilitate root formation and to prevent scion from lowering Fv/Fm. Further studies are required to investigate the effects of root development and joining of vascular bundles of grafted seedlings on the chlorophyll content of scion.