• 한국지하수토양환경학회지:지하수토양환경
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• 제18권7호
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• pp.81-89
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• 2013

Concerns have been raised over the impact of nano materials on soil and groundwater environment with the increasing attention to the potential applications of carbon nano materials in various fields. Particularly, carbon nano materials introduced into water environment readily make complexes with humic acid (HA) due to their hydrophobic nature, so there have been increasing numbers of studies on the interaction between HA and carbon nano materials. In this study, we investigated the solubility of HA and multiwalled carbon nanotubes (MWCNT) in three different surfactant solutions of sodium dodecyl sulfate (SDS), Brij 30 and Triton X-100, and evaluated whether the HA can be effectively desorbed from the surface of MWCNT by surfactant. The objective of this study was to determine the optimal adsorption condition for HA to MWCNT. Futhermore, sodium dodecyl sulfate (SDS), Brij 30, Triton X-100 were used to elucidate the effect of desorption and separation on adsorbed HA on MWCNT. As a result, HA solution with 12.7 mg of total organic carbon (TOC) and 5 mg of MWCNT showed the highest adsorption capacity at pH 3 reacted for 72 hrs. Weight solubilizing ratio (WSR) of surfactants on HA and MWCNT was calculated. HA had approximately 2 times lower adsorption capacity for the applied three surfactants compared to those of MWCNT, implying that the desorption of HA may occur from the HA/MWCNT complex. According to the results of adsorption isotherm and weight solubilizing ratio (WSR), the most effective surfactants was the SDS 1% soluiton, showing 53.63% desorption of HA at pH 3.

• 대한한방소아과학회지
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• 제31권4호
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• pp.39-48
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• 2017

Objectives The purpose of this study is to investigate effectiveness of the Ha-Taedok treatment and discuss how to improve the Ha-Taedok method Methods We analyzed the medical records of 20 children who were treated by Ha-Taedok method. 20 questionnaires were administered to the mothers of those children and statistically analyzed by using PASW Statistics 18. Results The children who were treated by Ha-Taedok method weighed at birth ranged from a minimum of 2.7 kg to a maximum of 3.86 kg, and the children's weight after treated by Ha-Taedok method were varied from a minimum of 2.8 kg to a maximum of 4.7 kg. The Ha-Taedok treatment was initiated to children from 3 to 23 days after their birth. 15 out of 20 mothers of the children treated by the Ha-Taedok method were satisfied with Ha-Taedok method (75%). All of them answered that they were willing to repeat the treatment to their children again or recommend the treatment to others. 10 out of 20 mothers told that the main factor/point for improvement of Ha-Taedok method was publicity. Conclusions If the effectiveness of Ha-Taedok method is scientifically proven and recommended, the scope of Ha-Taedok method for newborn infants will be widely used.

• The Korean Journal of Ecology
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• 제15권1호
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• pp.35-46
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• 1992

To elucidate nutrient cyclings such as nitrogen, phosphorus and potassium in mongolian oak(quercus mongolica) forest, nutrient elements of precipitation, throughfall, outflow, soil, various plant organ and litter were determined at mt.nambyeongsan, pyeongchang-gun, gangwon province in central part of korean peninsula. Annual precipitation input, throughfall and outflow of nutrientswere 10.3, 8.6 and 4.2 kg/ha for the N, 0.11, 0.24 and 0.02 kg/ha for the Pand 1.3, 10.9 and 1.2 kg/ha for the K, respectively. Inseasonal changes of nutrient concentrations, N, P and Kconcentrations which were rich in young leaves decreased steadily until autumn and decreased abruptly during autumnal yellowing. The standing N, P and K concent were 565, 37 and 257 kg/ha for standing phytomass of overstory, 33, 3 and 18 kg/ha for understory, 132, 3.6 and 14 kg/ha for litter on ground including deadwood and 20, 752, 14 and 420 kg/ha for the soil, respectively. The amounts of annual uptake, reture and retain were 174.2, 57.2, 117.2 kg/ha for the N, 9.9, 3.5, 6.4 kg/ha for the P and 73.2, 30.3, 42.9 kg/ha for the K, respectively. Reabsorption efficiency, ratio of the nutrient amount reabsorbed into woody organs to that in the mature leaves before shedding, was 71%(or 99.8 kg/ha in the amount), 69%(or 5.1 kg/ha) and 57%(or 33.1% kg/ha) and recycling coeffciently made with which the large amount of nutrients is absorbed through roots during growing season(UPTAKE) and reasorbed from the leaves before shedding(RETAIN) but the small amount of nutrients is returned through litterfall(RETURN).

• 한국산림과학회지
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• 제96권2호
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• pp.214-221
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• 2007

The effect of nutrient availability and forest type on the nutrient turnover of fine roots is important in terrestrial nutrient cycling, but it is poorly understood. I measured nutrient turnover of hardwoods and softwoods at three well studied sites in the northeastern US: Sleepers River, VT; Hubbard Brook, NH; Cone Pond, NH. Significant differences in nutrient turnover by fine roots were observed among sites, but not between forest types. The magnitude of differences for each element ranged from 3 times for P and N to 8 times for Ca and Mg between sites. Smaller differences of 0.2 to 0.8 times were observed between forest types. In hardwoods, the Sleepers River 'new' site had $23kg\;ha^{-1}\;yr^{-1}$ Ca, $7kg\;ha^{-1}\;yr^{-1}$ Mg, and $16kg\;ha^{-1}\;yr^{-1}$ K turnover, owing to high root nutrient contents and turnover. Cone Pond had the highest turnover for Mn ($0.8kg\;ha^{-1}\;yr^{-1}$) and Al ($16kg\;ha^{-1}\;yr^{-1}$), owing to high nutrient contents. The Hubbard Brook hardwood site exhibited the lowest turnover of these elements. In softwoods, the variation in turnover of Ca, Mg, and K was lower than in hardwoods. The Hubbard Brook had the highest turnover for P ($1.6kg\;ha^{-1}\;yr^{-1}$), N ($31kg\;ha^{-1}\;yr^{-1}$), Mn ($0.4kg\;ha^{-1}\;yr^{-1}$), Al ($10kg\;ha^{-1}\;yr^{-1}$), Fe ($6.4kg\;ha^{-1}\;yr^{-1}$), Zn ($0.3kg\;ha^{-1}\;yr^{-1}$), Cu ($34g\;ha^{-1}\;yr^{-1}$), and C ($1.1Mg\;ha^{-1}\;yr^{-1}$). Root Ca turnover exponentially increased as soil percentage Ca saturation increased because of greater root nutrient contents and more rapid turnover at the higher Ca sites. These results imply that nutrient inputs by root turnover significantly increase as soil Ca availability improves in temperate forest ecosystems.

• 한국기후변화학회지
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• 제7권4호
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• pp.499-506
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• 2016

This study was conducted to estimate carbon stock and uptake for Larix kaempferi Lamb., the single species, which is the most widely distributed one following Pinus densiflora, using data from 6th national forest inventory and forest type map of 1:5,000. Overall distribution area of Larix kaempferi in South Korea was shown as 272,800ha, in detail, Gangwon-do was the most widely distributed region with 39.6% (108,141 ha) of the whole forest area, and Gyeongsangbuk-do was 18.6%(50,839 ha), Chungcheongbuk-do was 15.1%(41,205ha) in order. As the results of analysis in carbon stock and uptake for each province, the values were high with Gyeonggi-do 109.0 tC/ha, $10.3tCO_2/ha/yr$, Gangwon-do 349.1 tC/ha, $9.7tCO_2/ha/yr$ in order, and Jeollabuk-do was the lowest with 78.3 tC/ha, $7.6tCO_2/ha/yr$. Also, the results of estimation in total carbon stocks and uptakes by year (1989~2015) were turned out that total carbon stocks and uptakes were 24,891 thousand tC, $2,428thousand\;tCO_2$ in 2015, increasing about 4.8 times and 3.8 times each compared with 5,238 thousand C/ha, $640thousand\;CO_2$ in 1989. Although forest area was decreased 26.6% with 371,884 ha in 1989 to 272,800 ha in 2015, carbon stocks and uptakes were increased in 2015 in that forest stock was increased 126% compared to 1989.

• 대한금속재료학회지
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• 제47권8호
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• pp.508-515
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• 2009

Ti-6Al-4V biomaterial is widely used as a bone alternative. However, Ti-6Al-4V ELI alloy suffers from numerous problems such as a high elastic modulus and high toxicity. Therefore, non-toxic biomaterials with low elastic moduli need to be developed. Ti-HA(hydroxyapatite) composites were fabricated in the present work by pulsed current activated sintering (PCAS) at $1000^{\circ}C$ under 60 MPa using mixed Ti and HA powders. The effects of HA content on the physical and mechanical properties of the sintered Ti-HA composites have been investigated. X-ray diffraction(XRD) analysis of the Ti-HA composites, including Ti-40 wt%HA in particular, revealed new phases, $Ti_{2}O$, CaO, $CaTiO_3$, and TixPy, formed by chemical reactions between Ti and HA during sintering. The hardness of the Ti-HA composites decreased with an increase in HA content. The corrosion resistance of these composites was observed to be an excellent candidate as a commercial Ti-6Al-4 V ELI alloy. A Ti-5 wt%HA composite fabricated by PCAS is recommended as a new biomaterial, because it offers good corrosion resistance, compressive strength, wear resistance, and biocompatibility, and a low Young's modulus.

• 한국응용곤충학회지
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• 제34권3호
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• pp.169-173
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• 1995

파밤나방의 합성 성페로몬의 교미교란 효과를 이용한 방제 기능성를 구명하기 위하여 1993년 부터 1994년까지 2년간 야외포장에서 검정한 결과 충의 밀도는 '93년에는 무처리에 비해 외대파에서 1.9%, 고추에서는 12.5%, 감자에서는 4.4%정도이었으며, '94년에는 외대파 처리면적 10 ha, 20 ha 에서 각각 5.9%, 5.2% 수준이었다. 또한 작물별 피해율은 '93년에 외대파 0.2%, 고추와 감자에서는 0.0%이엇고 '94년에는 10ha에서 16%, 20ha에서 3.0%로 낮게 조절되었다. 처리면적에 따른 방제효과는 10월까지 10ha에서 80%, 20 ha 에서는 90% 수준을 유지하여 1회처리로 방제가 가능하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.754-758
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• 2006

The purpose of this study is to propose calculation and application method of a common factor from different noise source unit such as $L_{eq}$ and WECPNL, A calculation was conducted by method that propose TNO-PG. Also, An applied example is a noise environmental standard of Korea and Japan. After %HA of two country are calculated, noise standards of two countries were compared by using %HA. The result by a equation of %HA is to convert a noise level($L_{dn}$) into a %HA. To calculate a %HA, First $L_{eq}$ is converted into $L_{dn}$. Then, $L_{dn}$, has inputted into and %HA has deduced from a %HA equation of TNO-PG. If the same area is applied the same %HA value according to area categories, it can be applied the same %HA to different noise sources. As a results. a noise levels have computed different values because responses of human change in accordance with a noise sources. This results can be applied to the noise environmental assessment for a domestic railway and aircraft noise.

• 한국초지조사료학회지
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• 제21권2호
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• pp.103-108
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• 2001

This study was carried out to investigate the introduced route of exotic weeds and the effects of herbicide treatment. Herbicide trial was arranged as a completely randomized block design with treatment 1(\circled1 Dicamba $1\ell$/ha, \circled2 Mecoprop $5\ell$/ha, \circled3 Bentazone $3\ell$.ha, \circled4 Glyphosate $4\ell$/ha and \circled5 Pyrazosulfuron-ethyl 2kg/ha), and treatment 2(\circled1 Dicamba $2\ell$/ha, \circled2 Dicamba $4\ell$/ha, \circled3 Glyphosate $6\ell$/ha, \circled4 Glyphosate 4+Dicamba $1\ell$/ha and \circled5 Glyphosate 4+dicamba $2\ell$/ha) against 10 exotic weed species, and conducted in Suwon, Seosan and Yeongam from 1997 to 1999. Exotic weeds have been mostly introduced within imported cereals for concentrate feed or within seeds for forage production. Most of exotic weeds in forage crop field were controlled more than 95% by herbicide, but it was desirable that the control of exotic weeds was abreast of chemical and ecological method.

• 한국식품저장유통학회지
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• 제5권2호
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• pp.123-126
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• 1998

This study was carried out investigate to optimum levels of nitrogen and phosphate fertilizer to get a higher yield and a quality of an onion(Allium Cepa L.) from 1993 to 1994. Three fertilizer levels were applied with 120, 240 and 360kg/ha of nitrogen and 100, 200 and 300kg/ha of P2O5 during the onion growing season. After harvesting the onion, it was storaged at given deposit. The growth and yield of the onion were better at the fertilizer levels of both 240 and 360kg/ha of nitrogen and of both 200 and 300kg/ha of P2O5 than at the level of 120kg/ha in nitrogen and 100kg/ha of P2O5. The content of total nitrogen and P2O5 in plant was decreased with reduced application levels of nitrogen and phosphate fertilizer. The rotting rate was higher at the levels of both 360kg/ha in nitrogen and 300kg/ha in P2O5 than the other treatment during the storage period. The sprouting rate tended to be high at 240kg/ha of nitrogen and 100kg/ha of P2O5.