• 농업과학연구
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• 제41권1호
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• pp.59-63
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• 2014

Precision farming aims at reduced environmental impacts with increased productivity. Soils are multi-functional media in which air, water and biota occur together and form an essential part of the landscape with a fundamental role in the environment. The requirement for herbicides and fertilizers can vary within a field in response to spatial differences in soil properties. Near infrared (NIR) spectroscopy is widely used today as a nondestructive analytical technique which is capable of determining a number of physio-chemical parameters. The objectives of this study were to develop optimal models to predict chemical properties of paddy soils by visible and NIR reflectance spectra. Total of 60 soil samples were collected in spring from 20 paddy fields within central regions in Korea. Reflectance spectra, moisture contents, pH, total nitrogen (N), organic matter, available phosphate ($P_2O_5$) of soil samples were measured. The reflectance spectra were measured in wavelength ranges of 400-2,500 nm with 2 nm interval. The method of partial least square (PLS) analysis was used to determine the soil properties. The PLS analyses showed good correlation between predicted and measured chemical properties of paddy soils in the wavelength range of 1,800-2,400 nm. Especially, it showed better performance than the previous results which used the entire wavelength range of the spectrophotometer, without considering the optimal wavelength of each soil properties.

• 한국환경과학회지
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• 제24권9호
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• pp.1101-1121
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• 2015

The seasonal variation of phytoplankton communities and its standing crops in accordance with environmental factors were investigated at Yeongrang-ho, Cheongcho-ho, Mae-ho and Hyang-ho which are located in the East coast of Korea during April to October 2011. High concentrations of T-N and T-P were observed in four lagoons due to the inflowing nutrients from farmlands and residential areas near lagoons. Nutrient salts mainly composed of nitrogen and phosphate caused the eutrophication of the lakes, leading to the robust growth of phytoplankton. During the period of investigation, 64 to 107 taxa of phytoplankton were observed in four lagoons. Diatoms were the most dominant species with high density. Non-point pollution source was estimated as the main cause of water pollution of lagoons. Trophic states of lagoons evaluated using the value of TSI and TSIKO indicated that all the investigated lagoons were in the eutrophication state.

• 한방재활의학과학회지
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• 제30권3호
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• pp.23-44
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• 2020

Objectives The purpose of this study is to evaluate the healing effect of Hyeolbuchugeo-tang (HC) in rats with rib fracture. Methods Rats were randomly divided into 5 groups (naive, control, positive control, HC-L and HC-H). All groups except naive group were subjected to bone fracture of rib. Naive group received no treatment at all. Control group was fed with phosphate buffered saline. Positive control group was orally medicated with tramadol. Experimental group was orally medicated with HC extract (50 mg/kg for low concentration [HC-L], 100 mg/kg for high concentration [HC-H]). X-ray and micro-computed tomography (micro-CT) were conducted to assess the effect of HC. We analysed the level of 2) transforming growth factor-β1 (TGF-β1), Ki67, alkaline phosphatase (ALP), receptor activator of nuclear factor kappa-β, runt-related transcription factor 2 (Runx2) and tartrate resistant acid phosphatase (TRAP) on 7 and 14 days after fracture. ALP, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, creatinine was measured for safety assessment. Results X-ray and micro-CT, showed HC enhance bone repair process. Callus formation was increased in experimental group at 7 days after fracture, but decreased at 14 days after fracture. 7 days after fracture, the level of TGF-β1 in experimental group was decreased. The level of Ki67, Runx2 in HC-H, TRAP in HC-L was increased. 14 days after fracture, the level of Ki67 in HC-L and HC-H was decreased. The level of ALP, Runx2, BUN in HC-L, TRAP in HC-L and HC-H was increased. Conclusions Taken together the results, HC promoted healing of bone fracture. In conclusion, HC has a potential to promote healing of bone fracture.

• 한국물환경학회지
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• 제29권1호
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• pp.1-6
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• 2013

This study was focused on improving nitrification efficiencies of M-dephanox (Modified-Dephanox) process. Rotating biological contactor (RBC) was used instead of floating sponge type media in nitrification reactor. High ammonia removal efficiencies were observed in nitrification reactor, regardless of organic loading from contactor of M-dephanox process. Denitrification efficiencies were also increased to maintain low $NO_3-N$ concentration in effluent. This enhanced phosphate release in anaerobic contactor and resulted in high removal efficiencies of phophorus. Average removal efficiencies of $TCOD_{Cr}$ and $SCOD_{Cr}$ were 93.8% and 81.6%, respectively, while those of TKN and ${NH_4}^+-N$ were 80.9% and 74.4%, respectively. As for phosphorous treatment, the average removal efficiencies of TP and OP were 94.7% and 94.3%, respectively. Also, effect of operating temperature on nitrogen removal was examined. Average removal efficiency of TN was 65.8 % at $15^{\circ}C$ or below (at average temperature of $13.3^{\circ}C$), while that was 82.8% at $15^{\circ}C$ or above (at average temperature of $21.9^{\circ}C$).

• 한국환경농학회지
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• 제31권4호
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• pp.328-343
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• 2012

BACKGROUND: For effective subwatershed management, it is very important to select the tributaries for improving water quality and understand the characteristics of tributaries. Until now, however, the case study of main streams has been managed. 17 tributaries in Geum river subwatershed were monitored to regulate the source of water contaminations and identify their current situations in this study. METHODS AND RESULTS: As pollution indicators, such as biological oxygen demand($BOD_5$), chemical oxygen demand($COD_{Mn}$), suspended solid(SS), total nitrogen (T-N), total phosphate(T-P) and total organic carbon(TOC) in Geum river were examined from January to December in 2011. The results were as follows : The annual average concentration of nutrients in Yongdam reservoir upsteam was 0.7 mg/L for BOD, 3.0 mg/L for COD, 8.4 mg/L for SS, 2.905 mg/L for T-N, 0.035 mg/L for T-P and 1.6 mg/L for TOC. Water quality of Daechung reservoir upstream was mostly similar tendency in comparison to Yongdam reservoir upstream. Among the 22 tributaries, water quality in Daechung reservoir downstream was more polluted. T-N contents were significantly high in Miho B4 located Daechung reservoir downstream(annual average concentration: 13.53 mg/L). In cases of Miho A1, A2 and C1, pollution degree was worsened during rainy season expecially. CONCLUSION(S): For improving water quality of Geum river subwatershed, the tributaries in the Mihocheon area should be preferentially considered. Mihocheon tributary is the highest in pollution site, and thus a study on long-term effects should be research.

• Mycobiology
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• 제39권2호
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• pp.96-102
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• 2011

We investigated diet supplementation with shiitake mushroom fruiting bodies on biochemical and histological changes in hypercholesterolemic rats. Six-wk old female Sprague-Dawley albino rats were divided into three groups of 10 rats each. A diet containing 5% Lentinus edodes fruiting bodies given to hypercholesterolemic rats reduced plasma total cholesterol, triglyceride, low-density lipoprotein (LDL), total lipid, phospholipids, and the LDL/high-density lipoprotein ratio by 34.33, 53.21, 75.00, 34.66, 25.73, and 71.43%, respectively. Feeding mushroom also significantly reduced body weight in hypercholesterolemic rats. However, it had no detrimental effects on plasma albumin, total bilirubin, direct bilirubin, creatinine, blood urea nitrogen, uric acid, glucose, total protein, calcium, sodium, potassium, chloride, inorganic phosphate, magnesium, or enzyme profiles. Feeding mushroom increased total lipid and cholesterol excretion in feces. The plasma lipoprotein fraction, separated by agarose gel electrophoresis, indicated that L. edodes significantly reduced plasma ${\beta}$ and pre-${\beta}$-lipoprotein but increased ${\alpha}$-lipoprotein. A histological study of hepatic cells by conventional hematoxylin-eosin and oil red-O staining showed normal findings for mushroom-fed hypercholesterolemic rats. These results suggest that shiitake mushrooms could be recommended as a natural cholesterol lowering substance in the diet.

• 한국미생물·생명공학회지
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• 제16권5호
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• pp.384-388
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• 1988

우리나라 연근 해역의 유류 오염물질중 주종을 이루는 고황 함유 Bunker-C유를 대상으로 이를 유화 분산 처리시키는 해양세균 Achromobacter sp. M-1220 균주를 분리하여 그 유화분산에 미치는 영향을 조사하였다. 우선 Bunker-C유에 유도된 세포를 사용할 경우 생균수가 최고 1000배까지, 유탁도는 대략 10정도까지 증가되나, 적응되지 않은 세포를 사용할 경우는 5일 정도의 적응기를 거친 다음 유화를 시작하였으며 pH 완충제를 첨가하지 않으면 적응된 세포나 적응되지 않은 세포 모두 유탁도의 변화를 나타내지 못하였다. 유화능력은 염분농도 3%, 온도 18$^{\circ}C$, pH 7.5 부근에서 가장 높게 나타났으며 또한 분리균의 유화처리에 있어서 해수배지에 질소원과 인산원의 첨가가 필수적으로 요구되고 기질 유류의 양은 7.5g/$\ell$까지 잘 유화 분산시켰다. 그리고 고황함량의 Bunker-C유와 원유를 잘 유화처리시킬 수 있었으며 석유계 화합물중에서 n-hexadecane, n-paraffin, benzene 등의 자화능력도 보여주었다.

• 농업생명과학연구
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• 제46권3호
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• pp.19-26
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• 2012

본 연구는 산마늘의 임간재배를 위한 기초 환경자료를 제공하고자 실시하였다. 울릉도 산마늘은 너도밤나무, 우산고로쇠나무, 섬잣나무, 솔송나무, 소나무, 곰솔, 섬피나무, 두메오리나무 군락에 자생하고 있으며, 입지환경은 평균 해발고도 563.4 m, 평균 경사는 $27.8^{\circ}$ 이었다. 토성은 사토, 사질양토, 양질사토, 양토가 다양하게 나타났으며, 유기물층의 깊이는 평균 6 cm, 토양 pH는 5.40, 유효인산은 18.5 ppm, 양이온 치환용량은 $18.6cmol_c/kg$으로 나타났다. CCA분석에 의한 입지와 토양인자와의 상관관계를 보면 너도밤나무군락은 탄소, 질소, 모래함량, 양이온치환용량과 정의 상관관계를 나타내었다.

• 한국토양비료학회지
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• 제36권3호
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• pp.113-118
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• 2003

국내 3대 절화류중 하나인 장미의 시설재배지 토양 화학적 특성을 조사하기 위하여 전국 72개 절화 장미 시설 재배 농가를 대상으로 본 조사을 수행하였다. 조사지역의 평균 토성분포는 양토 43%, 미사질식양토 19%, 식양토 17%를 차지하였으며, 표토의 평균 양분함량은 pH 5.85, 전기 전도도 $3.61dS\;m^{-1}$, 유기물 함량 $37g\;kg^{-1}$, 질산태 질소 $205mg\;kg^{-1}$, 유효인산 $844mg\;kg^{-1}$, 그리고 교환성 칼륨 $1.41cmol_c\;kg^{-1}$이었다. 유효인산과 교환성 칼륨은 조사지역의 70% 이상이 적정 수준 이상이었으며, 토양양분함량 중 유기물 함량은 레드 산드라 품종의 절화장과 정의 상관관계를 보였으나 전기 전도도와는 부의 상관관계를 보였다.

• 한국환경농학회지
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• 제16권3호
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• pp.227-232
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• 1997

UV-B 조사에 의한 오이의 생장 및 생리 기능에 미치는 영향을 조사하기 위하여 비료처리에 의한 오이 제1 엽의 UV-B의 영향을 조사하였다. UV-B 조사에 의한 가시장해는 처리 1주일부터 나타났으나 생장 저해 현상은 볼 수 없었다. 그러나 UV-B 조사에 의한 생장 저해 현상은 비료 첨가에 의해 나타났으며 가장 큰 저해 효과는 질소 시용에 의해 나타났다. 이 결과는 UV-B가 질소대사에 관여하고 있음을 시사한다. 따라서 질소대사에 관여하고 있는 주 효소인 질산 환원효소 활성을 조사한 결과 UV-B 조사 7일째에 비료 처리구에서 현저히 증가하는 경향을 나타냈다. 또한 UV-B 조사에 의한 엽면적의 생장감소는 세포의 신장, 분열 생장에 관여하고 있는 식물호르몬 활성에 영향을 미치는 것으로 보여 오이의 제 1엽에서의 BA 처리에 의한 사이토카이닌의 감수성을 조사했다. UV-B 조사에 의한 사이토카이닌의 감수성은 UV-B를 조사하지 않은 구에 비해 억제되었다. 이 결과에 의해 UV-B 조사가 식물 생장에 관여하고 있는 사이토카이닌의 활성을 억제시켜 엽면적의 감소가 발생된 것으로 생각되었다.