• Journal of The Korean Society of Grassland and Forage Science
• /
• v.13 no.4
• /
• pp.278-285
• /
• 1993

This experiment was conducted to investigate the productivity in permanent orchardgrass grassland according to the urea fertilization levels of 0, 100, 200 kg N/ha and the animal excreta fertilization levels of 0. 40, 80, 160 kg N/ha on the basis of N contents respectively and NO$_3$-N content of the soil. The results were obtained as follows; 1. The productivity of grassland was significantly increased by the increase of the excreta fertilization levels until the urea-N level fertilization of 100 kg/ha but repressed and reduced by the increase to 160 kg/ha level of the animal excreta fertilization at urea-N fertilization level of 200 kg/ha. 2. Averaged seasonal productivity of the animal excreta N was decreased in first and third cutting time and was increased in second cutting time according to the increase of urea-N fertilization. 3. The increase of urea-N and animal excreta N increased the content of crude protein but the fertilization effect of urea-N was higher than that of animal excreta N. 4. The total yield of N was continuously increased at both of the urea-N and animal excreta N but the pure yield of N was decreased according to the increase of N fertilization and showed -63.1 kg/ha at the fertilization of the urea-N of 200 kg N/ha and animal excreta N of 160 kg/ha. 5. NO$_3$-N content of the soil of orchardgrass glassland established one year previously was no difference among the N variety and fertilization levels but was increased to the order of summer, autumn and winter. The highest content of NO$_3$-N was measured in winter with the value of 34.9 ppm.

• Journal of Korean Society of Forest Science
• /
• v.97 no.6
• /
• pp.597-604
• /
• 2008

Recognizing the necessity of the development of ecologically sound silvicultural system for the mature Korean pine (Pinus koraiensis), this study was carried out to examine the invasion and growth of understory vegetation after partial cutting. In 1997, the age class VII Korean pine forest in the Experimental Forest of Kangwon National University was opened up about 50% by modified shelterwood cutting with site preparation to induce succeeding regenerations. After 10 years, plenty of hardwood have come to the stand, forming understory vegetation. The abundance and composition of understory vegetation was periodically investigated in the ten $10m{\times}10m$ permanent sample plots, estimating importance values, species diversity index and the distribution of diameter and height of the understory vegetation. Encouraged by canopy opening, the coverage of understory reached perfect closure, composed of 22 tree species and 20 shrub species in 2007. Morus bombycis occupied 29.6% of the total importance value and Cornus controversa was 17.0%, followed by Styrax obassia, Quercus aliena, Quercus mongolica, Acer mono, and Pinus koraiensis. In the year of 2000 the species diversity was highest as 2.547 with 26 tree species and deceasing thereafter, showing 2.220 with 22 tree species in 2007. As understory layer was thickly covered and got grow bigger, some shade intolerant species were disappeared, lowering species diversity. In 2007 the biggest tree was a Quercus aliena with 11.3 cm of DBH and the tallest tree was a Cornus controversa with 9.8m of height. The frequency distribution of number of trees by diameter and height classes formed the inverted-J-shaped curve, supposed to be typical uneven-aged stand.

• Journal of Korean Society of Forest Science
• /
• v.96 no.6
• /
• pp.639-643
• /
• 2007

The use of forest biomass resources produced by forest tending and residual forest biomass that was not gathered on commercial thinning or cutting area was estimated to be come into the spotlight as bioenergy sources in these days of new high oil price. With considering these problems, This study was investigated about possibility with biomass calculation and convertibility to fossil fuel in these area. Total forest tending area in the year 2005 was 294, 115 ha and the yield gathered from these area was $143,747m^3$. It is equivalent to biomass of 115,000 ton and caloric value of 533,199Gcal. However, the potential and additional yield that is residual in forest stands was 2,483,000 ton. It is equivalent to 11,133 billion won of oil which is 20 times of the actual yield produced by forest tending. Therefore, these amount of biomass has a substitution effect of the fossil fuel. Moreover, the residual biomass that is not gathered at commercial thinning and cutting area was 475,000 ton. It is equivalent to 2,206,235 Gcal of heating value and about 2,211 billion won of oil. This potential amount could be a new energy source to be a substitution effect of fossil fuel. It is time to be interested in the forest biomass as a renewable and environment-friendly resource and its substitution effect of fossil fuel.

• Journal of Korean Society of Forest Science
• /
• v.83 no.2
• /
• pp.205-210
• /
• 1994

This study was conducted to develop a method of mass production by cutting of superior genotypes of Larix leptolepis and to examine the effects of ortet age, clone, crown position, and an applied plant growth substance upon the rooting of cuttings. Four different ortet ages, 2, 8, 16 and 30 years and three levels of root-promoting substances, indole butyric acid(IBA), at 1000, 2000, and 5000ppm were employed. Greenwood cuttings were taken from mother trees in late July and rooted for three months in rooting medium containing peatmoss : vermiculite : perlite(1 : 1 : 1 by volume). with temperature controlled at $20-25^{\circ}C$, humidity by intermittent misting and light by partial shading in the greenhouse. Cuttings treated with 1000ppm IBA showed highest rooting, with 80%, 71%, 52%, 25% for 2-, 8-, 16-. 30-year-old ortet, respectively. Untreated cuttings showed rooting of 52%, 48%, 36%, 20% for the ortet age of 2, 8, 16, 30 years, respectively. The average number of adventitious roots decreased with increasing ortet age from 2 to 30 years, whereas IBA treatment increased the number of roots in all ages. A variation in rooting among 20 clones tested was observed. The 4 clones, Chungnam 6, and 7 and Chonbuk 1, and 9 showed good rooting of about 67%, while Kangwon 49 showed boor rooting of 40% at 1000ppm IBA treatment. When crown position was compared, cuttings taken from middle crown showed highest rooting of 60%, while cuttings from upper crown showed lowest rooting of 53%.

• Journal of Korean Society of Forest Science
• /
• v.83 no.4
• /
• pp.531-539
• /
• 1994

We examined the in vitro rooting and survival of tissue cultured plantlets of Quercus acutissima Carr. and Pinus densiflora Sieb. et Zucc. after addition of Pisolithus tinctorius(Pt) ectomycorrhizal fungus inoculum to the medium and effects of three levels of sucrose and phosphorus in culture media. Shoots of Quercus acutissima were obtained from winter buds of a 30-year old tree and cuttings of Pinus densiflora from germinated seed, and they were inoculated with Pt in vitro. In both species, Pt enhanced shoot length, survival, number of adventitious roots, root length, and rooting percentage. Survival in Quercus acutissima was increased from 75% in control to 100% in Pt inoculation. Pt inoculation increased the percentage of rooting from 20% to 70% in Quercus acutissima cuttings and from 63% to 100% in Pinus densiflora cuttings. It is concluded that mycorrhizal inoculation to tissue cultured Quercus acutissima Carr. and to in vitro cutting of Pinus densiflora Sieb. et Zucc. has practical application to improvement of poor root development and initial period of reduced shoot growth in vitro.

• Korean Journal of Pharmacognosy
• /
• v.5 no.2
• /
• pp.111-124
• /
• 1974

The radioactive compound sodium $acetate-U-C^{14}\;(C^{14}-acetate)$ was administered to two- and four-year-old July and September American ginseng (Araliaceae, Panax quinquefolium L.) plants and cuttings. The $C^{14}-acetate$ uptake was approximately 99%. The autoradiochromatograms suggest that the saponins isolated by preparative thin-layer chromatography contained impurities, especially those isolated from the leaf and stem extracts. The root and fruit methanol extracts yielded relatively pure saponins. The large amounts of panaquilin B and its proximity to panaquilin C on preparative thin-layer plates resulted in some admixing. The average concentration (% plant dry weight) of semi-purified saponins were high in the leaves (13.8%), as compared to fruits (9.8%), stems (7.9%) and roots (6.3%). The average percentage of $C^{14}-acetate$ incorporation into panaquilins was 4.8%. The average percentage of $C^{14}-acetate$ incorporation into panaquilins B and C was higher (1.40% and 1.13%, respectively) than that into panaquilins C, (d), G-1 and G-2 (0.75%, 0.65%, 0.13% and 0.53%, respectively). Panaquilin synthesis may be depending upon the part, collection period and age of the plant. The average percentage of $C^{14}-acetate$ incorporation into panaquilin B is high in roots (0.58%) and stems (0.48%); that into panaquilins C and (d) high in leaves (0.40% and 0.45%, respectively); and that into panaquilin E high in roots and leaves (0.55% and 0.50%, respectively). Panaquilin G-2 was synthesized in all parts of plants. The panaquilins appear to be biosynthesized more actively in July than September (exception-panaquilin G-1). Panaquilins B, C and G-1 may be biosynthesized more actively in four-year-old plants and panaquilins (d) and E more actively in two-year-old plants. The results from expectance with cuttings suggest that the panaquilins are synthesized de novo in the above-ground parts of ginseng plants, and that panaquilin G-1 may be synthesized de novo in the leaf. It is known from the tissue culture studies that panaquilins are produced by leaf, stem and root callus tissues and cailus-root cultures of American and Korean ginseng plants. Panaquilins may actively be synthesized de novo in most any cell or organ of the ginseng plants. It was verified that $C^{14}-acetate$ was incorporated into the panaxadiol portions of the panaquilins of two-year-old plants (sp. act. 0.56 mmcCi/mg) and four-year-old plants $(sp.\;act.\;0.54\;m{\mu}Ci/mg)$.

• Journal of Conservation Science
• /
• v.9 no.1
• /
• pp.48-52
• /
• 2000

A hundred wooden foundation piles were found underground during reconstruction for Heungreamun after removing ex-Chosunchongdokbu (ex-Government General of Chosun) building, which was built in 1916, at Kyungbok Palace in Seoul. It is known that larch piles had been collected from the Yaru area near Mt. Baekdu (Changbai). in North Korea. We examined 15 piles for identification of the species and their tree-ring structure. The species is identified as Larix gmelini by microscopic observation. Average diameter of the piles was 27 cm and average age 103 years. We obtained 151 year tree-ring chronology. However, we could not date the exact cutting years because there was no reference chronology yet. When we can obtain chronologies from living trees near the Yaru area, we could make a absolute and longer chronology for studying past history and environments around Mt. Baekdu.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.1
• /
• pp.55-64
• /
• 2015

Wind turbine market is showed height growth rate of about 30% for year, and is increasingly growing. Total rate of domestic wind turbine installation is showing share of 0.2% of the global market that is 380MW. However, wind turbine installed in domestic are foreign product more than 90%. Similarly, Datalogger of pretest system for ocean wind turbine plant installation has been leaked huge cost to abroad by mostly abroad company product. In this paper, we proposed pretest weather resource measurement system for efficiency and investment cost cutting of wind turbine construction work. Preset weather resource measurement system is ocean weather resource measurement datalogger based on wireless communication(wifi) that have consist of hardware and software(wind rose) that is able to monitoring as datalogger of wireless bridge and battery state, wind direction, wind speed, temperature, humidity, radiation around weather tower and is able to analysis of measured data.

• Journal of Korean Society for Atmospheric Environment
• /
• v.7 no.3
• /
• pp.208-218
• /
• 1991

To compare the resistance of landscape trees by acid rain, simulated acid rain was treated on the seeds of 6 coniferous species (Pinus densiflora, Pinus thunbergii, Pinus koraiensis, Taxus cuspidata, Cedrus deodara, Thuja occidentalis) and 6 broad-leafed species (Ligustrum obtusifolium, Acer Buergerianum, Acer Ginnala, Styrax obassia, Cornus Kousa, Magnolia obovata). The experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agri-Tech Junior College. The seeds of 12 tree species were planted on the nursery soil in the early spring of 1991. The regime of artificial acid rain, in terms of spray frequency per monthly and spray amount at year records. Simulated acid rain (pH 2.0, pH 4.0, pH 5.6 as control) containing sulfuric and nitric acid in the ratio of 3:2 (chemical equivalant basis) diluted ground water, were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season (April 8 to August 31) in 1991. Seedling establishment, seedling growth and nutrient contents in needles and leaves were measured and compared among the treatment. The results were summerized as follows; 1. In general, coniferous species were more resistant than broad-leafed species in the resistant comparisons of landscape trees by simulated acid rain. But there were resistant tree species to acid rain among the broad-leafed species. 2. Among 6 coniferous species used in this experiment, Pinus densiflora, Pinus koraiensis, Taxus cuspidata, Cedrus deodara and Pinus thunbergii revealed the resistant tree species to acid rain. But Thuja occidentalis was very susceptible to acid rain, because of no germination in pH 2.0 treatment plot of acid rain. 3. Among 6 broad-leafed species used in this study, Magnolia obovata, Styrax obassia and Ligustrum obtusifolium showed relative resistant tree species to acid rain. But Acer Buergerianum, Acer Ginnala and Cornus Kousa were very susceptible to acid rain, because of no germination in pH 2.0 plot of acid rain treatment.

• Journal of Power System Engineering
• /
• v.13 no.6
• /
• pp.95-101
• /
• 2009

The generator for gas turbine power generation consists of the rotor which generates magnetic field, the winding coil which is the path for the field current and the wedge and retaining ring which prevents the radial movement of the coil. Relatively severe deformation was observed at the coil end section during the inspection of the generator for peaking-load operation, and the thermal-electricity and the centrifugal force were evaluated by the simple modeling of the windings to find the cause. But the simulation stress was not sufficient to induce the coil plastic deformation. The analysis result seems to be applicable to the base-load generators which runs continuously without shut down up to a year, but there had been more deformation than simulated for the generator which is started up and shut down frequently. The cause of the coil deformation was the restriction of the expansion and shrinkage. The restriction occurs when the winding coil shrinks, and the stress overwhelms the yield stress and cause the plastic deformation. The deformation is accumulated during the start-ups and shut-downs and the thermal growth occurs. The factors which induce the coil restriction during the expansion and shrinkage should be reduced to prevent the unallowable deformation. The resolutions are cutting off the field current earlier during the generator shut-down, modifying the coil end section to remove the stress concentration and making the insulation plate inserted between the coil end section and the retaining ring have the constant thickness.