• The Korean Journal of Ecology
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• v.20 no.1
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• pp.51-59
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• 1997

To investigate the distribution of heavy metal concentrations in Onsan bay, concentrations of cadmium, copper, zine and lead in surface sediments and the periwinkles (Littorina brevicula) were determined in Feburary and July, 1996. The ranges of cadmium, copper, zinc and lead concentrations in the surface sediments were 0.08-3.72, 3-307, 49-1273 and 15-399 ${\mu}g/g$ dry weight, respectively, The decrease of concentration in heavy metals with distance from Daejeong stream indicated that this stream is the pollutant source of heavy metals in Onsan Bay. The concentrations of cadmium, copper, zinc and led in L. brevicula were 0.11-11.81, 21-212, 30-96 and 0.26-4.12 ${\mu}g/g$ dry weigth in February and 1.01-24.9, 66-325, 54-225 and 0.68-8.41 ${\mu}g/g$ dry weight in July, respectively. These concentrations in L. brevicula were the significantly different (p<0.001) with the season of sampling. However, overall distribution of concentrations of heavy metals in L. brevicula had very similar tendency that concentrations of heavy metal decreased with the distance from the pollutant source irrespective of the two seasons. Therefore, L. brevicula is considered as a useful indicator for heavy metals pollution, According to analysis of the organs, tissues such as the digestive gland, gill and viceral mussel accumulate high concentrations of heavy metals.

• Journal of Korea Foresty Energy
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• v.2 no.2
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• pp.1-12
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• 1982

To study tile comparison of aboveground biomass of Pinus rigida Mill. of 18-year-old, plantations located in Whaseong, Yuseong and Wanju district were selected. Ten sample trees in each district selected taking account of DBH distribution were felled carefully to minimize loss of branches and stem analysed by 1m lag segment sectioned from base . The tree height and DBH were measured for sample trees in total growing within $200m^2$ experimental plot. The diagram of oven-dry weight distribution of stem, branch and needle for each 1m segment was constructed. The logarithmic regression equations between dry weight of each component and the two variables, $DBH^2$ and tree height, combined term were presented. The standing crops in the sample stand was estimated to be as much as 23.88, 54.09 and 42.68 tons of dry matter, above ground , per ha in Whaseong, Yuseong anf Wanju district respectively. Annual net production was estimated at 253,657 and 3.65 tons per ha per year respectively. The net assimilation rate was 1.65,1.95 and 1.81 kg/kg/yr in Whaseong, Yuseong and Wanju district respectively. The efficency of leaf to produce stem was 0.99, 1.12 and 1.30 kg/kg/yr respectively.

• Journal of Environmental Science International
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• v.14 no.7
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• pp.629-637
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• 2005

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were investigated in soil and pine needle samples taken from 16 sites of industrial and residential areas in Changwon, Korea to assess their distribution levels and to suggest the influence of industrial activities, PCDDs/DFs levels in the soil samples ranged from 0.57 to 20.79 pg I-TEQ/g dry weight with a mean value of 4.20 pg I-TEQ/g dry weight. PCDDs/DFs levels in the pine needle samples ranged from 0.39 to 8.75 pg I-TEQ/g dry weight with a mean value of 4.09 pg I-TEQ/g dry weight. In both soil and pine needle samples, the PCDDs/DFs concentrations in the industrial area sites were higher than those in the residential area sites. Homologue profiles in pine needle samples showed different patterns compared with soil samples. Based on the results of principal component analysis (PCA), it was confirmed that pine needles reflected a direct influence from local potential sources of PCDDs/DFs, showing a much higher degree of reflection than in soils. Pine needles are very useful as an indicator for monitoring or estimating the contamination of PCDDs/DFs in other areas which have been impacted by point pollution sources.

• Korean Journal of Veterinary Service
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• v.24 no.3
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• pp.279-285
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• 2001

The change of the body condition score(BCS) and milk production graph as days in milk by lactation number show that the productivity of cow is on the increase as increase the lactation number, but the health condition is much worse because of the inappropriate nutrition intake. Metabolic profiles test(MPT) results indicate that the early-lactation for directly after the parturition to the peak production of milk during the total lactation period is the time of the more likely to be exposed to lack of energy, protein, minerals. To solve this problem, the early-lactation cows should be sufficiently supplied the required nutrients and should maximum intake the supplied nutrients not to be suddenly decline body weight and BCS from postparturition to the peak production of milk. To maximize the dry matter intake of a cow, there is have got to improve the management of body weight for heifer's skeletal development and in the dry period which is carelessly deal by mostly farms. This study presents that the use of measurement of body weight, graph of body condition score, distribution of milk production, metabolic profiles test in the monitoring for dairy herd health management is very valuable.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.5
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• pp.23-32
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• 2015

In this study, chemical and physical changes of dissolving pulps which have similar viscosity by dry milling and fractionation were investigated. We used two types of dissolving pulp made from wood and cotton linter fiber, respectively. Dry milling was executed by knife cutter and pulp powders were fractionated by sieve shaker into 4 grades. We analyzed fiber properties, crystallinity index, viscosity, molecular weight of pulp sheet and powders. It was found that poly-dispersity index of cotton linter pulp was smaller than that of wood pulp, meaning that cotton pulp has more narrow molecular weight distribution. It was assumed that these were related to exposure times to chemical treatment which cut cellulose chains not evenly. At least 4 times of chemical treatments for wood pulp were executed and only two times of chemical treatments for cotton linter pulp were done. After dry milling average molecular weight and crystallinity index of cotton linter pulp powders were reduced and these were related to fines content and shape of pulp powders.

• Journal of the Korean Geosynthetics Society
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• v.10 no.4
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• pp.113-121
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• 2011

River sand has generally used for the backfill material of underground power cables. The thermal resistivity of it has $150^{\circ}C$-cm/Watt in wet condition and more than double in dry condition. The final goal of this study is to find the backfill material which has a small change in thermal resistivity with various water contents, for example thermal resistivity is $50^{\circ}C$-cm/Watt and $100^{\circ}C$-cm/Watt in wet and dry conditions respectively. In this study it is presented that the comparison of thermal resistivity using stone powder, crush rock, weathered granite soil and Jumunjin sand as well as river sand in the needle method regarding water content, dry unit weight and particle size distribution. As a result, the thermal resistivity of a material is minimized when they have maximum dry unit weight at optimum moisture content and maximum density by appropriately mixing materials for particle size distribution. Therefore thermal resistivity characteristics should be considered two factors: one is the difference between natural dry condition and dry state after optimum moisture content, and the other is the difference between unit weight of raw material and maximum dry density.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.458-464
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• 1994

The partitioning of dry matter into seed and pod-shell is important because yield increase can be achieved by improving the distribution rate of assimilation products to seeds. The present study was undertaken to characterize whether the partitioning of dry matter into seed was shoot- or root-controlled through graftiong techniques. Self- and reciprocal-grafts were made among four soybean genotypes, which were 'Baekunkong', 'Suwon 168', and two local soybeans with black seed coat (hereafter referred to as the 'black soybean'), 'Kangleungjarae' and 'Keumleungjarae'. Self-grafted black soybeans showed lower ratio of seed to pod-shell dry wight than self-grafted Baekunkong and Suwon 168. Varying the shoot genotypes in grafts resulted in significant differences in growth characters as well as pod and seed dry weight per plant at physiological maturity. There were significant effects of shoot genotypes on the ratio of seed to pod-shell dry weight, indication that the partitioning of dry matter into seed and pod-shell should be shoot- rather than root-controlled. The grafts with large pod-shell dry weight tended to partition relatively smaller dry matter into seed than pod-shell.

• The Journal of Engineering Geology
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• v.19 no.4
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• pp.493-499
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• 2009

Recently, the construction of Concrete Faced Rockfill Dam (CFRD) is increasing because rock material resources are plenty in Korea. Bedding zone in the CFRD is necessary enough bearing capacity to support the concrete face slab uniformly and enough impermeability to prevent the loss of fine soils in case of leakage from the concrete slab face. Therefore, cut-off the water leakage in bedding zone securely is the key factor influencing the safety of CFRD. Tested materials satisfied with the specification of particle size distribution at the Bedding Zone area are chosen for conducting permeability tests, which are done to evaluate the property of cut off the materials. Based on the test results, the effects of cut off the materials are investigated by considering the coefficient of permeability, the soil particle distribution, and the dry unit weight. Especially, the relationships between coefficient of permeability with effective size(D10), dry unit weight, and weight passing percent the No.4 sieve are suggested, and also the variation of coefficient of permeability with time are proposed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.57-69
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• 2011

This study examined the relationship between Phragmites australis' growth and sediment properties at mud tidal flat of Donggum-ri, Gilsang-myeon, Gangwha-gun, Incheon city. Field survey was carried out from May, 2010 to October, 2010. Water content, soil texture, electric conductivity and water table depth for sediment, density, height, dry weight and flowering for P. australis were examined at several plots from the starting point (the coastal embankment) to the end point of the two populations. The result was as follows. Firstly, the water table increased along distance from the embankment at one line (N-line) but was similar at the other line (S-line) in a P. asustralis population. Water tables were higher out of than within a P. australis population at two populations. Secondary, in N-line, the height and dry weight of P. australis decreased along the distance from embankment but, in S-line, those were similar in its population. P. australis' growth was dependent on electric conductivity at lower layer (water table level) rather than upper one (the surface). Thirdly, density of P. australis changed during growing season and was similar in a population, except for the end point of patch. In summary, the growth and distribution of P. australis were dependent on salt content of tidal flat's sediment (water table level) and this was affected by fresh water of the inland.

• Korean Journal of Plant Resources
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• v.33 no.6
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• pp.586-596
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• 2020

Chionanthus retusus has been used for landscaping and gardening trees, foods and medicines. This study was carried out to analyze the effect of fertilization on the growth performance of container seedlings (1-year-old) in C. retusus. We used multifeed 19 (MF) as a fertilizer, and measured the height, root collar diameter (RCD), biomass, seedling quality index (SQI) chlorophyll contents and chlorophyll fluorescence of the seedlings. The findings of this paper showed that the height, RCD, H/D ratio, T/R ratio and the fresh and dry weight of seedlings increased after fertilization. The moisture content of the stem and root did not show any significant difference among fertilizations, except in the case of the leaf. Production distribution such as the dry weight ratio of leaves and the stem dry weight ratio of fertilized seedlings had a higher value than that of non-treatment. SQI was the highest in MF 1,000 mg/L and 2,000 mg/L treatment. Chlorophyll contents (SPAD value) also increased with the increase in fertilization concentrations. Chlorophyll fluorescence (F_v/F_m) showed the highest value of 0.8 in MF 2,000 mg/L treatment.