우리나라 논 관개용 지하수 수질 특성

김진호,조광래,임수정,이경자,경기천,엄미정,김희권,김찬용,이영한,이신찬,윤순강 한국환경농학회 2003 한국환경농학회지 Vol.22 No.4

This study was carried out to evaluate the status of the groundwater quality for paddy fields irrigation in Korea. Water samples were collected at 130 sites throughout the country. Samples were collected at three seasons-April, July and October-in 2000. According to our survey, the groundwater was found to be suitable for irrigation purpose. Average EC was shown 0.286 dS/m. Nitrate-nitrogen and Cl^(-) concentration was 5.6 ㎎/L, 32.95 ㎎/L which satisfied the Korean Standards for Irrigation Water. Nitrate-nitrogen concentration in each province was shown as following orders: Jeju (11.17 ㎎/L) > Chungnam (8.16 ㎎/L) > Gyeongbuk (6.64 ㎎/L) > Gyounggi (5.91 ㎎/L) > Chungnam (4.95 ㎎/L) > Gyeongnam (3.91 mgk) > Jeonbuk (3.50 ㎎/L) > Jeonnam (3.27 ㎎/L) > Gangwon (2.91 ㎎/L). The concentration by sampling seasons were October (6.62 ㎎/L) > July (5.88 mg&) > April (4.78㎎/L). As the soil of Jeju Province is usually derived from volcanic ash soils mainly used for upland drops, it may influence the nitrate-nitrogen concentration of groundwater. The amount of rainfall also influence the water quality. But the COD_(Cr), were shown April (3.17㎎/L) > July (2.91 ㎎/L) > October (2.40 ㎎/L), it is highly related in the basal dose of organic matter fertilizers. This study demonstrated that groundwater quality was suitable for irrigation, but continuous monitoring is recommended for agricultural policy and developing OECD agricultural environment indicators.

폐열 회수 시스템에 의한 탈황용 수산화마그네슘의 제조에 관한 연구

이찬원,하춘수 경남대학교 환경문제연구소 2003 환경연구 Vol.26 No.-

Magnesium oxide less than 45㎛ of particle size was utilized as a raw material for the production of magnesium hydroxide. The production rate was governed by heterogeneous non-catalytic chemical reaction. A deep 20㎥ volume of reactor with insulated wall was designed. This reactor had the same effect as a pressurized tank in terms of hydrolyzing rate. A heat exchanger was installed next to the hydrolyzing reactor to recover waste heat generated in the hydrolyzing process. The quality of magnesium hydroxide was tested and compared with variables of water temperature and reaction time. The best quality of magnesium hydroxide was produced under the condition of above 60℃ of temperature and 10 hrs of reaction time. Average particle size was 20.3㎛ and specific surface area was 0.648㎡/g. Better quality of magnesium hydroxide was obtained by the addition of 2%(wt.) sodium hydroxide.

우리나라 南西海岸의 海陸風 探究 : Centering around the city of Mokpo and Seochon

李承姬,柳贊洙 조선대학교 사범대학 부설 교과교육연구소 2000 敎科敎育硏究 Vol.3 No.1

Geographically, Three sides of Korea are surrounded by the sea(that is, the Korean Peninsular). Accordingly, the envioronment of our country has been greatly affected by the sea. For this study and taking an observation with AWS. I've selected the Mokpo city to which Taebul industrial complex is adjacent and Seochon, the central part of the western coast to which Asan industrial complex is adjacent. I've utilized the data on the change of the direction and the speed of the breeze of two areas(Mokpo and Seochon) through classifying all the data of the annual breeze into a daily unit, a monthly unit and a seasonal unit. As a result, there was a more vivid sea and land breeze character in Seochon area than in Mokpo area is due to the Mokpo's geographical location. In the frequency of breeze direction, NNW direction which occupied 27% of the whole was prevailing and in the frequency of breeze speed, the range of 0.3∼3.3㎧ appeared frequently, and it showed 48.9%. According to rarity analysis on the relations between breeze direction and breeze speed, a correlation coefficient was 0.56∼0.91 and through it. I could figure out correlation of breeze direction and breeze speed. But iti is matter of regret that this study has a statistical analytic basis mainly, so, from noe on, I intend to do profound research on factors which cause the change of sea and land breeze and I'd like to develop them to be processed as enviornmental factors.

황사의 확산예측을 위한 기상정보의 시간해상도에 관한 수치연구

이순환,곽은영,류찬수,문윤섭 한국환경과학회 2004 한국환경과학회지 Vol.13 No.10

In order to predict air pollution and Yellow-sand dispersion precisely, it is necessary to clarify the sensitivity of meteorological field input interval. Therefore numerical experiment by atmospheric dynamic model(RAMS) and atmospheric dispersion model(PDAS) was performed for evaluating the effect of temporal and spatial resolution of meteorological data on particle dispersion. The results are as follows: 1) Base on the result of RAMS simulation, surface wind direction and speed can either synchronize upper wind or not. If surface wind and upper wind do not synchronize, precise prediction of Yellow-sand dispersion is strongly associated with upwelling process of sand of particle. 2) There is no significant discrepance in distribution of particle under usage of difference temporal resolution of meteorological information at early time of simulation. but the difference of distribution of particles become large as time goes by. 3) There is little difference between calculated particles distributions in dispersion experiments with high temporal resolution of meteorological data. On the other hand, low resolution of meteorological data occur the quantitative difference of particle density and there is strong tendency to the quantitative difference.

무선 애드 혹 기반 액티브네트워크상에서 QoS지원에 관한 연구

李基源,裵振勝,丁燦赫,金玄郁,李光培,姜景仁,朴京培,文泰洙,郭承郁,河載承 明知大學校 産業技術硏究所 2003 産業技術硏究所論文集 Vol.22 No.-

Abstract - In this thesis, we propose a QoS supporting method on wireless ad hoc-based active network for improving reliability. On the loss of route path, the existing DSR routing protocol has several problems with wireless network communication because of decease of data reception rate and increase of network load. The proposed method improves reliability of data transfer by using functions of active network. That is, by using functions of active nodes and active packets, the proposed method supports QoS with reservation transfer method that saves data packets on transfer at intermediate nodes with lost path and then re-transmit the packets after route reconfiguration.

수온 변동 자극이 양식 넙치, Paralichthys olivaceus의 비특이적 생체 방어에 미치는 영향

이덕찬,김도형,김수미,강명석,홍미주,김현정,박수일 한국어병학회 2002 한국어병학회지 Vol.15 No.2

본 연구는 넙치에 대한 수온 변동 자극의 영향을 생체 방어적인 측면에서 검토하고자 하였다. 수온 변동 자극은 매일 18℃에서 25℃까지 상승과 하강을 반복하는 방법을 사용하였으며 그 기간은 30일간 지속하였다. 실험어는 온도변화를 주기 시작한 후 28일째까지 무작위로 채포하여 말초혈액 중의 백혈구 수, 전혈의 식작용능, 활성산소, 환원능, chemiluminescence(CL) response 및 lysozyme용균능과 같은 각종 비특이적 생체방어와 관련한 실험을 수행하였다. 수온 변동 자극을 주기 시작한 후 1일째부터 시작하여 1주일 이내에 약 18%의 넙치가 폐사하였으며 이후에는 대조구와 유사하였다. 또한, 수온 변동 자극을 준 실험구의 호중구 수는 2주째에 유의적인 증가를 보였으며, 림프구 수는 2일과 3일째에 감소하였으나 1주째부터 대조구와 유사한 수준으로 회복되었다. 실험구에서는 식작용 결과 식균율과 식균지수에서 이물질 투여 후의 반응이 늦게 나타났다. 식세포의 활성을 조사한 NBT reduction 실험에서는 실험 기간 동안 대조구와 유사한 경향ㅇ르 나타내었다. 또한, CL response의 경우, 실험구는 온도 변동 자극초기에 대조구에 비하여 유의적으로 낮았다. 그리고, 식세포가 분비하는 용균성 효소인 점액 내 lysozyme의 활성은 실험 기간 동안 실험구에서 낮게 나타나는 경향을 보였다. 이러한 여러 가지 비특이적 생체 방어 반응의 저하 현상은 수온 변동 자극 초기에 나타났으며, 1주일 정도 지속하면 그 환경에 적응하는 것을 알 수 있었다. 그리고 이러한 현상은 이들이 초기 폐사 발생과 어떤 상관 관계에 있는 것으로 생각되었다. This study was performed to know the effects of stress nduced by the daily fluctuation of water temperature fro 18? to 25? up and down for 30 days on the defence mechanism of olive flounde,r Paralichthys olivaceus. To make clear the temperature stress on the defense mechanism of the tested fish, several factors of immune response such as counting of leucocyte appearance in periopheral blood, phagocytic activity in whole blood cells, nitroblue tetrazolium(NBT) reduction, chemiluminescence(CL) response, and lysozyme activity were investigated at 28 days after giving the change of water temperature. The fish was controlled under the none feeding condition during experimental period. Mortality of the tested fish was rapidly increased up to 22% within the first one week of the experimental period without any additional stress factors. The number of neutrophil of peripheral blood in the tested group was significantly higher than the control group at the 2nd week, but the number of lymphocyte was significantly lower than the control group at the 1st and 3rd day of the experimental period, respectively. In the NBT reduction test, the activity of macrophage in the control group fish was the highest on the 7th day while that in the tested group was on the 3rd day. Also, the phagocytosis of tested group against formalin killed cells was retarded compared with the control CL response of the tested group was significantly lower from 2nd to 5th day of the experimental period than the contro. The lysozyme activity of tested group was remained higher during the experimental period than the contro. Even through the tested fish showed different results in some non-specific factors of immune responses between tested and control group fish, olive flounder seems highly adaptable in repeated water temperature change in condition after one week under the given temperature fluctuation range

BaTiO_3결정의 사각형 강유전 구역에 관한 온도와 전기장 특성

이찬구,이수대,문준규 慶南大學校 附設 工業技術硏究所 2003 硏究論文集 Vol.21 No.2

BaTiO_3 결정의 (100)면에 수직한 방향에서 관측되는 강유전 구역을 온도와 전기장의 변화에 따라 편광현미경으로 관측하였다. BaTiO_3 결정의 (100)면에 수직한 방향에서 관측되는 그물모양의 사각형 강유전 구역이 90℃-구역이라는 사실을 밝혔다 우리는 사각형 강유전 구역의 온도특성과 정전기장 특성에 관하여 조사하였다 사각형 강유전 구역은 상전이 온도인 120℃ 이상에서 사라졌다. 24℃에서 외부 전기장을 인가한 경우, 4 0×10^7 V/m에서 구역의 변화가 관측되며, 5.5×10^7 V/m의 전기장을 가하여도 단일 강유전 구역은 형성되지 않으며, 5.5×10^7 V/m 이상에서는 누설전류가 흘렀다. 한편 온도를 114℃로 올리고 전기장을 5 5×10^7 V/m 이상으로 가하면 단일 강유전 구역이 형성되었다. We observed the ferroelectric domain in a vertical direction of the (100) plane of BaTiO_3 crystal by a polarizing microscope We find out that ferroelectric domains of the square pattern are 90℃0domain. The electric field Properties and the temperature dependent of ferroelectric domain in BaTiO_3 Crystal was investigated From these results, it was concluded that the square domains disappeared from sight at above 120℃, and the Change of the domain pattern observed at 24℃ and 4.0×10^7V/m, it Showed the leakage current 5.5×10^7 V/m. A single domain do not formed 24℃ and above 5.5×10^7 V/m. On the other hand, a single domain formed at 114℃and above 5.5×10^7 V/m.

바이오안전성에 대한 세계적인 동향 : 유전자변형 생물체(LMO)를 중심으로

이이,정찬문,이학수,신주식 충북대학교 연초연구소 2006 煙草硏究 Vol.20 No.-

현대 분자생물학의 발달에 따른 유전자변형 생물체의 개발은 시간과 경제적으로 전통적인 육종의 한계를 많이 극복하고 있으며 세계적으로 유전자변형생물체의 개발이 빠른 속도로 진행되고 있다. 유전자의 변형에 따른 환경의 파괴, 인체에 대한 위해 가능성 때문에 바이오안전성의정서가 채택되는 등 세계적으로 바이오안전성에 대한 관심이 증가하고 있다. 바이오안전성은 유전자특성분석, 환경위해성평가, 인체위해성평가 등 3단계의 평가에 의해서 이루어지며 최종적으로 인체와 환경에 해를 끼칠 가능성이 있는 유전자변형생물체를 규제하기 위해서 이루어진다. 우리나라도 최근에 바이오안전성에 대한 관심이 증대되면서 바이오안전성 평가체계가 확립중이다. The development of molecular biology enabled us to overcome the restrictions of conventional breeding system and the number of genetically modified organisms are dramatically increasing. The possibility of the genetically modified organism's risk on human health and environment caused concerns on the biosafety. Biosafety test contains gene characteristics analysis, health safety test, and environmental risk test. The final aim of these tests is to prevent the commercialization of genetically modified organism which have possible risk on human health and environment. Biosafety evaluation system is being built in Korea.

PLZT 세라믹을 이용한 SAW Filter의 특성

이수대,이찬구,안형주,문준규 경남대학교 신소재연구소 2003 신소재연구 Vol.15 No.2

현재 사용되고 있는 SAW 필터 기관물질 중 세라믹 기관은 다공정과 생산에 따른 물성의 재현성 부족을 제외한다면 단결정 기관에 비해 생산단가의 저렴화, 생산공정의 단순화 및 대량생산의 측면에서는 훨씬 경쟁력이 있다. 따라서 본 연구에서는 고온 압축성형법에 의해 1235℃의 온도와 200㎏/㎠의 압력에서 30시간동안의 제조조건에서 조성비 x/65/35(x=5-8)인 PLZT 세라믹 기관들을 제조하여 SAW필터로써의 응용가능성을 살펴보았다. 각 조성별 유전을, SAW 전파 속도, 기계결합계수 등을 측정 비교한 결과 SAW 필터 기관물질로 가장 적합한 조성비는 7/65/35였다. 이 조성비로 제작한 SAW 필터에서 상대적으로 양호한 출력 특성을 얻었고 단결정 기관으로 제작한 SAW 필터에 버금가는 특성을 확인할 수 있었다. The single crystal substrate has been the industrial standard for the design of SAW filters for a long time. However, the ceramics substrate had more simple fabricated process than the crystal. In this study, it was attempted that single crystal was substituted for PLZT(La/Zr/Ti = x/65/35, x=5∼8 at. %) ceramics. The ceramics substrate was prepared by hot-pressed method at temperature 1235C, 200㎏/㎠, 30hrs. The real permittivity, SAW velocity and mechanical coupling factor of PLZT ceramics were measured for a different La mol% content. In the results, we could observed that 7/65/35 composition SAW filter had a good characteristics of frequency response.

BaTiO₃단결정의 전왜효과에 관한 연구

이수대,이찬구,손종윤 慶南大學校 附設 工業技術硏究所 1999 硏究論文集 Vol.17 No.-

BaTiO₃단결정의 전왜효과와 압전특성을, 임의의 방향으로 가하는 전기장에 대한 역압전변형분포의 SGP(stereographic projection) 그림과 전왜효과에 의한 전왜변형분포에 대한 SGP그림을 그려 분석하였다. 상유전상에 있을 때 인가된 전기장에 의한 변형은 전왜효과에 의해서만 생기며. 강유전상에 있을 때 인가된 전기장에 의한 변형은 역압전효과와 전왜효과의 중첩 영향을 받는다. 각 상에서의 종적 변형과 횡적 변형의 최대 값과 최소 값을 갖는 방향 및 크기를 구하였고 압전변형과 전왜변형의 크기가 같은 등변형전기장을 계산하였다. The electrostriction and the piezoelectric properties of BaTiO₃ single crystal were analyzed by the SGP(stereographic projection) diagram of the electrostriction strain and the converse piezoelectric strain to the applied electric field. In paraelectric phase the strain is only due to the electrostriction, but in ferroelectric phase it is affected by the converse piezoelectric effect with the electrostriction effect. We obtained the directions and the magnitudes with the maximum value and the minimum of the longitudinal strain and the transversal strain at each phase, and calculated the electric field of the equivalent strain which has the same magnitude of the piezoelectric and the electrostriction.