2002년도 공동 춘계 학술발표회 논문집 : 발표장 ; 수질관리(3) : 해창만 수질환경 및 수질에 미치는 방조제의 영향

조현서,이문옥 한국물환경학회 ( 구 한국수질보전학회 ) 2002 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2002 No.-

알루미노 실리케이트계 고내화성 모르타르의 부착성능 평가

조현서,이건철 한국건축시공학회 2018 한국건축시공학회지 Vol.18 No.6

In modern society, a huge number of the buildings have been constructed with RC structure. RC structures havemany structural instabilities due to earthquake, typhoon, construction fault, design phase errors. Therefore, manyreinforcement methods are being implemented to solve this problem. In the reinforcement method, the organic epoxyadhesive used in the FRP reinforcing method is abruptly damaged when exposed to high temperature, which is directlyconnected to the fall of the reinforcing material. Therefore, the present study was conducted to develop inorganicrefractory mortar with a certain level of adhesion ability to reduce the heat transferred to FRP reinforcement whenexposed to high temperatures. As a result of the test, it showed high adhesion strength at room temperature conditionwith the inclusion of EVA resin, and showed no performance deterioration up to about 300℃ even under heatingconditions. Also, it was confirmed that the backside temperature was lower as the thickness increased, and convergedto a constant temperature of about 780℃ after 2 hours of heating. 현대사회에서 건축물은 대다수가 RC구조로 건설되어지고 있다. RC구조의 건축물은 시공상의 하자발생, 설계단계에서의 오차발생 등과 같은 인위적인 요인과 지진, 태풍 등의 자연적인 요인에 의해 구조적 불안정성이 발생하고 이를해결하기 위해 다수의 보수보강공법이 이루어지고 있다. 보강공법 중 FRP 보강공법에서 사용하는 유기계 에폭시 접착제는 고온에 노출되었을 때 부착파괴가 급격하게 발생하게되며 이는 보강재의 탈락으로 직결된다. 따라서 본 연구에서는 고온에 노출되었을 때 FRP 보강재에 전달되는 열을 감소시켜주며 일정수준 이상의 부착성능을 가진 무기계 내화 모르타르의 개발을 목적으로 실험을 진행하였다. 실험 결과EVA수지의 포함으로 상온조건에서 높은 부착강도를 나타내었으며, 가열조건에서도 약 300℃까지 전혀 성능저하를나타내지 않았다. 또한, 이면온도는 두께가 증가할수록 낮았으며, 가열 2시간 이후에에서는 약 780℃의 일정한 온도로 수렴되는 것을 확인하였다.

마산만에서의 유기주석화합물의 위해성 평가 및 관리 방안

조현서,김동명,박청길,이수형 한국해양환경·에너지학회 1998 한국해양환경공학회 학술대회논문집 Vol.1998 No.-

Bioaccumulation of Perfluoroalkyl Substances (PFASs) in coastal and river organisms in Korea

조현서,정현지,Mai Duc Hung 환경독성보건학회 2019 한국독성학회 심포지움 및 학술발표회 Vol.2019 No.10

ESG 기반의 경영 시뮬레이션의 효과성 및 개발 방법에 관한 연구

조현서,이근필,김상수 한국경영학회 2022 한국경영학회 통합학술발표논문집 Vol.2022 No.8

낙엽송과 잣나무림의 (林) 수고성장곡선 (樹高成長曲線) 및 지위지수에 (地位指數) 관한 연구

조현서,정영관 ( Hyun Seo Cho,Young Gwan Chung ) 한국산림과학회 1985 한국산림과학회지 Vol.68 No.1

Height growth curve to be required for estimating site index was formulated with 10 models based on the average tree height and tree age. Among them, the model of H=Kab^A was evaluated to be best fit for estimating average tree height(H) with tree age (A). Equations, H = 28.364 - 26.125(0.818)^A and H = 26.331 - 25.125 (0.886)^A, were situated from the model for estimating average tree height of Larix leptolepis and Pinus koraiensis, respectively (in this case the tree age was categorized into 0 for 5 -year- old tree, 1 for 10 -year- old tree and 2 for 15 -year- old tree ect.). Result of comparing the site indices calculated by the Bryant method, it was proved that the site index of Larix leptolepis was estimated higher than that of Pinus koraiensis within the limits of site index class 6 to 18. On the contrary the site index of Pinus koraiensis turned out to surpass that of Larix leptolepis at the site index class 20 or over.

온산연안해역의 중금속오염에 관한 연구

조현서,박청길,변종률 한국물환경학회 1988 한국물환경학회지 Vol.4 No.2

온산연안 해역의 중금속 오염정도와 수중에 유입된 중금속의 化學種을 조사한 결과는 다음과 같다. 1. 해수중의 평균농도는 카드뮴이 0.53㎍/ℓg/ℓ, 구리가 3.96㎍/ℓ, 납이 4.52㎍/ℓ, 아연이 28.6㎍/ℓ로 비교해역인 진하보다 높게 나타났으며 外海로 갈수록 감소하였다. 2. 미끌도박중의 평균농도는 카드뮴이 0.18㎎/㎏, 구리가 9.38㎎/㎏, 납이 2.47㎎/㎏, 아연이 46.0㎎/㎏으로 비교해역인 진하의 값보다 대부분 높았으며 연안 가까이에서 보다 높은 농도 분포를 나타내었다. 3. 진주담치중의 평균농도는 카드뮴이 2.53㎎/㎏, 구리가 10.4㎎/㎏, 납이 6.43㎎/㎏, 아연이 48.7㎎/㎏으로 미끌도박중의 농도보다 높았으며 미끌도박의 경우와 비슷한 양상을 나타내었다. 4. 구리표준 용액을 대정천의 시수에 첨가하면, 상류는 최초의 미량첨가부터 거의 50% 이상이 이온상태로 존재하였으며 중류 및 하류는 거의 90% 이상이 결합된 상태로 존재하였다. 결합에 관여하는 성분으로는 상류가 대부분 Carbonate계통인 반면, 중류 및 하류에서는 강한 결합능력을 갖는 유기물인 것 같다. 5. 수중생물에 대한 구리의 독성은 대부분이 유기물과 결합된 형태로 존재하므로 중금속 중독이 있다면 급작스런 중독보다는 만성적인 중독이 생길것으로 보인다. This study was performed from November 19, 1982 to October 6, 1983 to investigate heavy metal pollution on Onsan coastal area. The arithmetic mean values of cadmium, copper, lead and zinc in the seawater were 0.53, 3.96, 4.52 and 28.6㎍/ℓ, respectively, which were higher than those of the reference area, Jinha. The concentrations(dry wt.basis) of cadmium, copper, lead and zinc in the seaweed, Grateloupia turuturu, were 0.18, 9.38, 2.47 and 46.0 ㎎/Kg, respectively. The concentrations(dry wt. basis) of cadmium, copper, lead and zinc in the Shellfish, Mytilus edulis, were 2.53, 10.4, 6.43 and 48.7㎎/Kg, respectively. These were higher than those of the reference area, Jinha. Chemical species of copper in Dae jeong stream, which was the main source of heavy metals in Onsan coastal area, was shown that most of cupric ions added to the stream water formed complex with organic ligands. The toxic effects of copper to the aquatic life might not seem to be acute because more than 90% of the copper was formed in complex.

광양만과 여수해만의 표층퇴적물에서 Nonylphenol의 오염에 관한 연구

조현서,김용옥,설순우,-- 한국환경과학회 2004 한국환경과학회지 Vol.13 No.6

This study was carried out to survey the pollution of nonvlphenol (NP) in surface sediments around Gwangyang bay and Yeosu sound. NP was suspected chemicals as endocrine disruption. Gwangyang bay is located on the mid south coast of Korea. It is a semi-closed bay which Yeosu petrochemical industrial complex, POSCO (Pohang Steel Company) and Gwangyang container harbor are there. The surface sediments were collected at 15 stations with gravity corer at October, 1999, February, May and August, 2000. Also, the stream and intertidal sediment were collected at 5 sites at August, 2000. Concentrations of NP in surface sediments were in the range of 6.89 to 202.70 ng/g dry wt.. Seasonal range (mean value) of NP is 13.98 to 30.48 (23.46) ng/g dry wt. at October, 10.35 to 54.91 (28.10) ng/g dry wt. at February, 29.05 to 202.70 (82.32) ng/g dry wt. at May and 6.98 to 83.40 (25.37) ng/g dry wt. at August. NP was seasonally fluctuated, and the highest mean value and range was detected at May, 2000. NP was highly distributed in the inner part of Gwangyang bay than Yeosu sound. Concentrations of NP in stream and intertidal sediments showed the highest value in downstream near Yeosu petrochemical industrial complex and Yondung stream. It suggests that the source of NP is industrial wastewater and municipal sewage.

여성의 참여없이 정치개혁 없다

趙顯玉(조현옥) 관훈클럽 2003 관훈저널 Vol.- No.86

재활용 종이 자원과 바이오차로 제조된 고형배지의 특성

조현서,성용주 한국펄프·종이공학회 2024 펄프.종이기술 Vol.56 No.1

The solid substrate cultivation methods for facility cultivation involve supplying nutrient solutions to the supporting substrate that sustains the plant roots, and traditional solid substrates such as coconut coir, rockwool, and perlite are commonly used. However, there have been issues related to environmental problems from disposal and instability in raw material supply. This study evaluated the feasibility of utilizing domestically generated waste paper and biochar as raw materials for the solid substrates. It has been observed that waste paper fibers exhibit a pH level close to neutral, along with suitable electrical conductivity (EC) characteristics and high hydrophilicity, making them applicable as raw material for the solid substrate. Solid substrates manufactured using waste paper fibers show a comparable level of water holding capacity to conventional cocopeat substrates, with slightly lower drainage characteristics. When different biochars were applied in the production of solid substrates, the use of wood biochar was found to increase water holding capacity, while the application of rice husk biochar was confirmed to enhance the drainage properties of ONP solid substrates. The results from this study could provide the foundational data for the development of alternative technologies in solid substrate cultivation for future facility cultivation.