• Journal of Korea Foresty Energy
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• v.20 no.2
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• pp.69-80
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• 2001

Larix kaemferi Carr. is one of main timber species in Korea that could be found in plantations and growing stands on all over the country The proper practice of thinning is one of very important techiques in silviculture, which greatly affects the quality and size of timber produced. Proper thinning period is considered to be important for maintaining stand growth before competition initiated. To investigate suitable thinning period, this study investigates the volume and radial growths of Larix kaemferi plantation in Mt. Worak located in the central part of Korea. The main findings and conclusions obtained from this study were as follow ; (1) The tree height curve equation for Larix kaemferi in Mt. Worak was calculated H=4.25783+0.80024D(H=Tree height, D=DBH). (2) To estimate tree volume for Larix kaemferi by DBH and tree height or only by DBH, regression equations were calculated as V=0.00147-0.002095D-0.000211H+0.00015D.H++$0.000744D^2$+$0.000008H^2$(V=Volume(($m^3$), H=Tree height(m), D=DBH(cm)), V=0.0000794-0.000512D+$0.000826D^2$. (3) The criteria of estimating thinning time of Larix kaemferi are the age when maximum tree height-MAI(mean annual increment) obtained and the age when annual DBH increments of dead trees decrease to below average. (4) The age of maximum tree height MAI was not significantly correlated with stocking. Therefore, it can not be used as a criterion for estimating thinning time of Larix kaemferi (5) The estimated thinning time equation of Larix kaemferi was obtained by regression analysis of the disk section collected from dead trees. The obtained equation is Y=0.2825+0.01752X(Y=Desirable thinning age, X=the sum total of nearest 4-trees interval(cm)). (6) General estimated thinning age of Larix kaemferi, which planted 3,086 stocks/ha, is concluded as 12 to 14 year.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.96-101
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• 2010

One of the restriction of wood as building material is its combustibility. The purpose of this paper is to examine the combustion properties of the quercus variabilis and zelkova serrata which are dried at room temperature and meet the desirable characteristics for use of construction materials. The cone calorimeter (ISO 5660-1) was used to determine the heat release rate (HRR) and fire smoke index, as well as CO production and smoke obscuration. The $HRR_{mean}$ 77.94 kW/$m^2$ of the quercus variabilis at 50 kW/$m^2$ was high in comparison with $HRR_{mean}$ 13.06 kW/$m^2$ for the zelkova serrata. Furthermore, the quercus variabilis has high specific extinction area ($SEA_{mean}$), 41.11 $m^2$/kg compared with $SEA_{mean}$ 9.23 $m^2$/kg of zelkova serrata. Thease results are depend on the density of tested wood species. In addition, the quercus variabilis has high CO production rate compared with that of zelkova serrata. Also, zelkova serrata showed an increase of retardant properties attributed to char formation compared with that of quercus variabilis.

• KSBB Journal
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• v.27 no.5
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• pp.308-312
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• 2012

Argon-plasma jet (Ar-PJ) is generated by ionizing Ar gas, and the resulting Ar-PJ consists of a mixture of neutral particles, positive ions, negative electrons, and various reactive species. Although Ar-PJ has been used in various biomedical applications, little is known about the biological effects on cells located near the plasma-exposed region. Here, we investigated the effects of the Ar-PJ on actin cytoskeleton of mouse embryonic fibroblasts (MEFs) in response to indirect as well as direct exposure to Ar-PJ. This Ar-PJ was generated at 500 mL/min of flow rate and 100 V electric power by our device mainly consisting of electrodes, dielectrics, and a high-voltage power supply. Because actin cytoskeleton is the key cellular machinery involved in cellular movement and is implicated in regulation of cancer metastasis and thus resulting in a highly desirable cancer therapeutic target, we examined the actin filament architectures in Ar-PJ-treated MEFs by staining with an actin-specific phalloidin labeled with fluorescent dye. Interestingly, the Ar-PJ treatment causes destabilization of actin filament architectures in the regions indirectly exposed to Ar-PJ, but no differences in MEFs treated with Ar gas alone and in untreated cell control, indicating that this phenomenon is a specific cellular response against Ar-PJ in the live cells, which are indirectly exposed to Ar-PJ. Collectively, our study raises the possibility that Ar-PJ may have potential as anti-cancer drug effect through direct destabilization of the actin cytoskeleton.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.5
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• pp.21-27
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• 2003

Five warm-season turfgrass [Zoysia japonica Steud., Stenotaphrum secundatum (Walt.) Kuntze, Buchloe dactyloides (Nutt.) Engelm., Eremochloa ophiuroides (Munro.) Hack. and Cynodon dactylon (L.) Pers.] were overseeded with 2 cool-season turfgrasses [Poa pratensis L. and Festuca arundinacea Schreb.] to examine suitability of these species for planting in mixture for producing a year-round turf. Percent of warm-season and cool-season turfgrasses in the mixture were estimated for 5 years. Also, to evaluate the fertilization times of the warm-season and cool-season turrfgras mixtures. Eremochloa ophiuroides and Buchloe dactyloides were not suitable for warm-season and cool-season turfgrass mixtures. However, Zoysia japonica, Stenotaphrum secundatum and Cynodon dactylon were suitable for warm-season and cool-season turfgrass mixtures. Zoysia japonica, Stenotaphrum secundatum and Cynodon dactylon were showed approximately 50% botanical composition five years after cool-season turfgrass overseeding. And, those three warm-season turfgrass mixtures showed approximately 20% visual ratings in winter period. Fertilization in early spring and late autumn had made cool-season turfgrass dominated in mixtures. Therefore, fertilization times in warm-season and cool-season turfgrass mixtures was desirable in summer period.

• Korean Journal of Weed Science
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• v.30 no.2
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• pp.153-163
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• 2010

This study was carried out to establish an improved bioassay system, whole-plant bioassay which is more effective in developing natural herbicides for foliar treatment such as herbicidal essential oils. Two bioassay systems using four weed species (Echinochloa crus-galli, Digitaria sanguinalis, Aeschynomene indica, and Abutilon theophrasti), spraying method and spotting method, were established. Spraying method is applicable if the amount of test compounds is enough, while spotting method is useful for the small amount of test compounds. The initial application rate was desirable at $2,500{\sim}5,000\;{\mu}g\;mL^{-1}$. Herbicidal activities were higher in the NOP treatment when compared to the Tween 20 treatment. To efficiently evaluate volatile compounds such as essential oils, if the compound-treated pots were incubated in dew chamber for about 10hrs, better results were obtained in the degree and stability of herbicidal responses. When the efficiency of bioassay systems established in this study was compared, the spraying method was minimized four times to the conventional method that has beed used for screening of synthetic compounds in KRICT. On the other hand, in the spotting method, screening for development of a natural herbicides was possible even in level of 1/100 test volume and 1/200 amounts of test compound compared to the spraying method.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.2
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• pp.144-148
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• 1999

This study was conducted to test actual oxygen consumption rates of Nile tilapia (Oreochromis niloticus) at a commercial scale high density culture tank in the recirculating culture system, with a special emphasis on the oxygen consumption rate of this species with different daily feeding frequencies. Nile tilapia, an average of 400 g and a total wright of 390 kg, were stocked in a circular concrete tank of 2.9 m in diameter and 0.8 m in depth, in a recirculating culture system. The fish were fed commercial diet 1, 2, 5, and 9 times per day between 09:00 h and 19:00 h. feed was evenly supplied where the fish were fed more than once a day. Dissolved oxygen of influent and effluent water was monitored every 50 seconds by a computer with electrodes for 24 hours. The standard metabolic rate of tilapia was $39.31{\pm}4.4mg\;O_2/kg$ fish/hr in the present study. The maximum oxygen consumption was reached between 30 to 50 minutes after feeding. The maximum oxygen consumption levels of 1, 2, 5, and 9 feeding times per day were 161.2, 123.4, 111.1 and 111.1 mg $O_2/kg$ fish/hr, respectively. While the mean oxygen consumption levels of 1, 2, 5, and 9 feeding times per day were $79.9{\pm}21.5,\;81.3{\pm}14.8,\;84.2{\pm}9,9$ and $98,9{\pm}11.0mg\;O_2/kg$ fish/hr, respectively. These results show that oxygen consumption rates are not much different between the feeding frequencies. These results could be used to design to provide desirable oxygen supply system in the recirculating high-density tilapia culture system.

• Journal of The Korean Association For Science Education
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• v.18 no.4
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• pp.635-641
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• 1998

The purpose of this study was to suggest a new direction of learning method in botany based on the analysis of a classification system and concepts in Science(Biology) textbooks of elementary and secondary school. Elementary and secondary school textbooks of Biology have been analyzed for plant classification system and concepts. Findings are summarized as belows. 1. In textbook of elementary school, the organization of life is grouped into Plantae and Animalia. Learning contents of plant are divided by the size and habitat. However, this system of classification might cause false concepts. Therefore, learning contents should be organized as whether they are flowering plants or not. 2. In a textbook of middle school, the organization of life is grouped into Plantae and Animalia. For a textbook of high school, it is grouped into three kingdoms; Plantae, Animalia and Prorista. With the idea of new age of Life Science, we should change the standards to 5 kingdoms; Plantae, Animalia, Proristae, Fungi and Monera. Moreover, it would be desirable if the concept of plant classification could be explained with a general outline, not by an individual interpretation focusing on characters of species only. In addition to the above indications, a learning course should provide present a standard classification according to a cognitive developemental level. It also has to teach students how to classify plant, in secondary school. Learning materials focusing on algae of the present system, but should be organized based on Seed plants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.10
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• pp.1487-1494
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• 2010

Structured lipid (SL) for cocoa butter alternative was synthesized by interesterification of coconut oil fraction and palm stearin (6:4 and 8:2, by weight) in a shaking water bath at $60^{\circ}C$ and 180 rpm. It was performed for various reaction times (1, 2, 3, and 6 hr). The reaction was catalyzed by sn-1,3 specific Lipozyme TLIM (immobilized lipase from Thermomyces lanuginosus). SL-solid part was obtained from acetone fractionation at $0^{\circ}C$. SL-solid part was blended with other palm oils and fractions for desirable property of cocoa butter alternative (SL-solid part : palm middle fraction : palm stearin solid : palm oil, 70.4:18.4:2.9:8.3, by weight). In reversed-phase HPLC analysis, triacylglycerol species of cocoa butter alternative had partition number of 40 (10.77%), 42 (13.06%), 44~46 (17.38%) and 48 (51.88%). Major fatty acids of cocoa butter alternative were lauric acid (16.5%), myristic acid (12.28%), palmitic acid (46.03%), and linoleic acid (14.75%). Solid fat content (SFC) and polymorphic form (${\beta}'$ form) of cocoa butter alternative prepared were similar to those of commercial cocoa butter replacer (CBR).

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.2
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• pp.249-256
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• 2019

Objective: The present study aimed at comparing the nutritional composition and color traits between two meat types: Horse meat and pork from Korean native black pigs raised in Jeju Island. Methods: After slaughter 24 h, the longissimus dorsi samples were taken from left side carcasses of the 32-mo-old Jeju female breed horses and the 6-mo-old Korean native black pigs (n = 10 each). The samples were then placed into cool boxes containing ice packs and transported to the Laboratory of Meat Science where all visual fats and connective tissues were trimmed off and then the samples were ground. All the samples were analyzed for nutritional composition (proximate composition, minerals, vitamins, fatty acids, and amino acids) and color traits. Results: The horse meat contained significantly higher collagen, moisture and protein than the pork (p<0.05). The Jeju horse meat showed more desirable fatty acid profiles such as containing significantly lower saturated fatty acids (SFA), higher polyunsaturated fatty acids (PUFA) contents and PUFA/SFA ratios than the pork (p<0.05). Differences in concentrations of ten amino acids existed between the two meat types in which the horse meat had higher values for all these amino acids, total amino acids (20.33 g/100 g) and essential amino acids (10.06 g/100 g) than the pork (p<0.05). Also, the horse meat showed significantly higher concentrations of Fe (34.21 mg/100 g) and Cu (2.47 mg/100 g) than the pork (Fe, 17.42 mg/100 g and Cu, 1.51 mg/100 g) (p<0.05). All the vitamins detected showed statistical differences between the two meat types in which the horse meat had higher concentrations of vitamin B1 (25.19 mg/100 g), B2 (92.32 mg/100 g), B3 (2,115.51 mg/100 g), and B5 (67.13 mg/100 g) than the pork (p<0.05). Conclusion: Based on the results obtained in the study, it is concluded that the two meat types studied are rich in nutrients and the animal species strongly affected the nutritional values and color traits of the muscle tissues.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.2
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• pp.124-130
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• 1986

To find out the optimum split application ratios of fertilizer nitrogen and potassium in the newly opened pasture at spring, a field experiment was conducted. Two levels of nitrogen and potassium application and three split application ratios of both fertilizer were treated by split design with 4 replications. The experiment was carried out from March, 1984 to October, 1985 on the experimental field of the Livestock Experiment Station in Suweon. The results obtained are summarized as follow: 1. Total DM yield was not showed signigicant difference among split application ratios of nitrogen and potassium. 2. DM yield of grasses was 4,854 kg/ha in heavy basal application of N and $K_2$O (160 kgN: 140 kg $K_2$O/ha), it was significantly increased by 16% than of conventional dressing (80 kg N: 70 kg $K_2$O/ha). But there was almost no difference in dry matter among N and $K_2$O split application ratios. 3. Dry matter yield of legume in heavy basal dressing was decreased by 23% than that of conventional dressing. In the methods of NK application, dry matter yield of legume was tended to decrease by 3% with equal application and 9% with heavy dressing in autumn, when compared with that of heavy dressing in spring. 4. There was no significant difference in dry matter yield of native species between different basic fertilization levels, but dry matter yield of native species was decreased by 6% with equal application and more increased by 11% with heavy dressing in autumn, when compared with the yield of heavy dressing in spring. 5. In aspect of the botanical composition, the percentage distribution of grasses was increased and the ratio of legume was greatly decreased by heavy dressing at basal fertilization. Also for good maintenance of botanical composition, it is suggested that the equal split application of N and $K_2$O was desirable.