• 제목/요약/키워드: the year of chemistry

검색결과 381건 처리시간 0.04초

제초제 처리 과수원 포장에서 강우 사상의 효과. 2. 유거와 토양침식의 변화 (Effects of Rainfall Events on Soil in Orchard Field under Herbicide Treatment. 2. Characteristics of Runoff and Soil Erosion)

  • 정덕영;박미숙;이규승;이진호
    • 한국토양비료학회지
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    • 제43권1호
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    • pp.36-43
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    • 2010
  • 충남 공주 팔봉산 남쪽 측면에 위치한 3년간 배나무가 식재된 구릉성 침식포장에서 유거와 침식의 변화를 (1)Glyphosate 처리 (2) paraquat 처리의 두 가지 서로 다른 제초관리 형태하에서 조사하였다. 조사지의 경사도는 5.5% ~ 10.2%, 고도 125 m이며 조사면적은 896 $m^2$ ($28m{\times}32m$)였다. 2006년에서 2008년 사이 총강우사상은 각각 47, 52, 52회였다. 전체 강우사상 중 일 강우량이 20 mm보다 적은 날은 전체 강우일수의 약 65%를 차지하였다. 평형상태에서 침투율은 지표면의 잡초가 모두 제거된 나지에서 일반적으로 증가하였으며, 제초제처리구와 대조구에서는 감소하였다. 모든 대조구에서 유거는 제초제처리구와 나지구보다 항시 낮았다. 동일 강우강도에서 유거는 대조구, glyposate 처리구, paraquat 처리구 glyposate-처리 나지구 순으로 증가하였다. 높은 강우강도하에서 처리구가간 유거의 차이는 1년차에서 가장 높았다. 조사 기간 3년간 토양손실은 각각 달랐다. 미세입자 손실이 조립질보다 높았으나 토양손실은 유거나 총강우량과 상관성은 없는 것으로 조사되었다. 동일 강우강도하에서 토양침식율은 대조구, glyposate 처리구, paraquat 처리구 glyposate-처리 나지구 순으로 증가하였다. 상대적으로 30 mm 이하의 강우강도하에서는 조사구간 제초제 처리 여부 상관성이 거의 없었다. 이는 토양침식은 강우강도에 의존한다는 것을 의미한다.

방사성 추적자에 의한 솔잎혹파리 방제용 살충제 phosphamidon의 소나무 수간이동 구명 : I. 소나무 품종 및 계절별 이행 (Elucidation of the translocation of phosphamidon used for the control of pine leaf gall midges (Thecodiplosis japonensis Uchida et Inouye) in the trunks of pine trees by means of a radiotracer. Part 1. Translocation as affected by pine tree species and the treated season)

  • 이재구;이형래;경기성;변병호
    • Applied Biological Chemistry
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    • 제36권6호
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    • pp.463-468
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    • 1993
  • 솔잎혹파리(Thecodiplosis japonensis Uchida et Inouye) 방제용으로 소나무의 수간에 주입된 침투성 살충제 phosphamidon(2-chloro-2-diethylcarbamoyl-1-methylvinyl dimethyl phosphate)의 이행 및 분포를 구명하기 위하여 $[vinyl,\;carbonyl-^{14}C]phosphamidon$을 약 10년생의 적송과 해송에 각각 수간주사하였다. 이 약제의 최고이행속도는 적송(Pinus densiflora Sieb. et Zucc.)과 해송(Pinus thunbergii Parl.)에서 각각 약 10 cm/hr(7월)와 2 cm/hr(12월)이었다. 처리된 방사능은 하계의 적송에서는 75일까지 일정한 수준을 유지하였으나 동계의 해송에서는 150일까지 유지하였다. 본 약제가 살충가능한 농도로 top에 도달하는데 걸리는 기간은 적송(7월)에서는 3일 이내인 반면 해송(12월)에서는 15일 이내이었으며, 그 이행정도는 약제처리시기 및 수종에 의하여 영향을 받았다. 솔잎에 잔류하는 phosphamidon과 그 대사산물은 methanol로 잘 추출되었으며, 솔잎시료의 methanol 추출액을 autoradiography한 결과 phosphamidon은 소나무내에서 신속히 분해되어 7일 내에 약 80% 정도가 분해되었다.

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우슬 중 ${\beta}-Ecdysone$의 초임계추출법(SFE)과 용매추출법의 비교 (A Comparative Study on the Solvent Extraction and Supercritical Fluid Extration Method of ${\beta}-Ecdysone$ in Achyranthis radix)

  • 김미라;김명석;심재한
    • Applied Biological Chemistry
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    • 제44권3호
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    • pp.197-201
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    • 2001
  • 우슬(Achyranthis radix)중 ${\beta}-ecdysone$의 초임계추출법과 용매추출법의 비교를 위해 초임계유체추출(SFE) 및 용매추출 후 초임계유체크로마토그래피(SFC)에 의한 우슬 중 ${\beta}-ecdysone$ 분석을 실시하였다. SFE에 있어서 추출 최적압력은 300 atm이었으며, 온도는 $80^{\circ}C$, 추출량은 100 ml, 보조제인 methanol 함량비율은 20%였다. 우슬에서 ${\beta}-ecdysone$의 분석시 SFC의 최소검출량은 5 ng이었고, SFE의 회수율은 줄기에서는 $90.7{\sim}93.5%$였으며, 뿌리에서는 $77.8{\sim}81.9%$였다. 용매추출의 회수율은 줄기에서는 $76.4{\sim}93.0%$였고 뿌리에서는 $80.6{\sim}93.1%$였다. 우슬의 생육기별 조사에서 ${\beta}-ecdysone$은 주로 뿌리에서 많이 검출되었고 1년생이면서 8월에 수확한 것이 654.9 ppm으로 가장 많이 함유한 것으로 나타났다.

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전문대학 식품영양과의 실험실습 및 현장실습 운영실태에 관한 연구 (A Stidy on the Real Management of Experimental-practice and Spot-practice at Department of Food and Nutrition of Junior College in Korea)

  • 윤성식;소명환;남궁석
    • 한국식품영양학회지
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    • 제2권1호
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    • pp.61-72
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    • 1989
  • This study was conducted to gather the baseline data on realities of experimental-practice and opinions toward spot-practice, and to examine how to cope with the problems raised at the Department of Food and Nutrition of Junior Technical College in Korea. Questionnaires were gathered from 42 chairmans of the Department of Food and Nutrition and 140 Present dieticians worked in Seoul, Bucheon am Seongnam area. The results are as follows, First, as a whole, each college had 2~3 experimental laboratory (Lab), in which Cooking Science Lab. Chemistry Lab and Microbiology Lab were occurred at higher frequency as Lab's name. Second, the numbers per experimental-practice class were more than 40 at most colleges. 85% of Present dieticians have answered to feel too much numbers per the class during their college days, whereas professors' opinions toward the numbers per class were suitable at 20~30 persons per class. Third, professors' opinion toward the adquate ratio of the theory subject classes to experimental subject classes was suitable at 60 : 40. Dieticians answered to take the theory subject classes partly or mostly on behalf of the experimental-practice classes. Fourth, the main reasons which inhibited normal experimental-practice class were the class for emphasis on examination, the shortage of experiment budget, the excess of class members, the shortage of experimental Lab Also, this results showed same propensity to present dieticians' opinion toward the same question above. Fifth, among the experimenta1-practice subjects established at the Department of Food and Nutrition, Diet Therapy Lab was highest frequency class emphasized on theory followed by Nutrition Counselling Lab, Food Processing and Storage Lab, Food Hygiene Lab and Food Microbiology Lab in that order. Here, Basic Chemistry Lab, Biochemistry Lab, Food Microbiology Lab were pointed as subjects far from the present task of dieticians. Sixth, Department of Food and Nutrition, as a whole, has conferred with spot-practice arrangement About 50% (all who want to join spot-practice) of second year students took part in spot-practice. In the other way, all colleges except for 2 colleges didn't give the credit for the spot-practice system. Seventh, according to the on analysis on spot-practice places, manufacturing company was at highest frequcney followed by hospitals, elementary school having group feeding system in that order. Especially, 16.7% (5 colleges) of the total colleges sent the students to the research institute related to food industry for spot-practice experience. Eighth, Professors' opinions toward the spot-practice time and period were preferable on summer vacation of second year and for 1~2 weeks, respectively. On the contrary, 74 dieticians answered to the adquate period as for 4 weeks. Ninth, 86 dieticians of the total 140 answered to complete the spot-practice during their college days, which helps the present task of them. Lacks of spot-practice program, Lacks of comprehension of upper personals and lacks of group feeding equipments ranks higher as difficulties in spot-practice management.

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한국산 은줄팔랑나비(Leptalina unicolor : Hesperiidae)의 생활환과 사육정보 (Life Cycle and Breeding Information of Leptalina unicolor from Korea (Lepidoptera : Hesperiidae))

  • 홍성진;윤춘식;김형곤;정선우
    • 한국환경과학회지
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    • 제25권12호
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    • pp.1633-1641
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    • 2016
  • Leptalina unicolor is a hesperiid butterfly with a restricted distribution in Korea, Japan, China, and Russia. Recently, the number of individuals is rapidly decreased in their natural habitat. This skipper has been classified as an endangered species in the 'Red Data Book', and according to an IUCN report, is under threat of extinction. Therefore, the conservation and restoration of this species both locally and globally are urgently needed. A population of L. unicolor was found in an unknown habitat in Jaeyaksan, Miryang, Gyeongsangnam-do, Korea in 2011, and these individuals were used in the present study. Here, the life cycle, characteristics of each instar larva and breeding information were determined by breeding L. unicolor in the laboratory from 2012 to 2015. The results indicated that L. unicolor occurs twice a year and over-winter as a fifth instar larva. A spring-form female individual laid $17.25{\pm}5.52eggs$, and summer form laid $29.00{\pm}5.86eggs$; it takes $53.79{\pm}0.73days$ for L. unicolor to develop from eggs to adults. After spawning, the eggs developed in $6.16{\pm}0.18days$, and larvae developed in $33.71{\pm}0.58days$; the pre-pupal stage to emergence required $14.22{\pm}0.31days$. Based on these results, we presented effective breeding information for the restoration and proliferation of the species. Several candidate plants species have been reported in the literature as a food source for L. unicolor, but we found that the preferred diet this butterfly was Miscanthus sinensis. The larvae could move easily when their preferred diet was planted in ${\geq}80%$ the cage floor area Year-round breeding was achieved by placing overwintering individuals in low temperatures in autumn. To our knowledge, this is the first study to the biology of L. unicolor in Korea, and the results of this study could be used as preliminary information for the conservation and restoration of this species in its natural habitat.

서양 심비디움 양액재배에서의 무기물 흡수 (Mineral Absorption by Cymbidium Jungfrau in the Solution Culture)

  • 송성준;부창호;유장걸
    • 한국환경농학회지
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    • 제18권1호
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    • pp.35-40
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    • 1999
  • 양액 재배에서 서양 심비디움(Cymbidium Jungfrau)의 질소와 인 흡수 및 재분배양상을 조사하였고 양액 재배와 관행인 화분 재배간의 심비디움의 생육, 광합성, 엽록소함량, 무기물 함량을 비교하였다. 질소$(^{15}N)$의 흡수는 자연광의 60% 광도에서 보다 자연광에서 많았고, 인$(^{32}P)$의 흡수는 이와 반대의 경향을 나타냈다. 흡수된 질소$(^{15}N)$는 벌브에 가장 많이 존재하였고 인$(^{32}P)$은 뿌리와 벌브에 많이 있었으며 잎으로 재분배된 양은 10% 정도였다. 2년생 어미주보다는 0.5 또는 1년생 새끼 주에서 질소$(^{15}N)$와 인$(^{32}P)$의 흡수가 더 많았다. 심비디움의 인 흡수율은 보리의 경우 보다 약 350배 정도 낮았다. 심비디움의 초장, 벌브크기, 생체증가율, 광합성 능, 엽록소 함량은 바크 또는 입상 암면을 배지로 이용하는 양액 재배가 일반 관행재배보다 더 높았다. 특히 양액 재배에서 사용된 바크와 입상 암면간에 생육과 무기물함량이 차이를 보이지 않았다. 또한, 질소, 인, 칼륨, 마그네슘의 함량은 양액 재배에서 높았으나 칼슘은 관행과 차이가 없었고 무기물의 흡수는 주로 영양생장기간 동안에 이루어졌다.

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Spatial distribution and temporal variation of hydrogeochemistry in coastal lagoons and groundwater on the eastern area of korea

  • Chanyoung Jeong;Soo Min Song;Woo-Hyun Jeon;Hee Sun Moon
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2023년도 학술발표회
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    • pp.247-247
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    • 2023
  • Coastal lagoons play a crucial role in water exchange, water quality, and biodiversity. It is essential to monitor and understand the dynamics of hydrogeochemistry in lagoon water and its groundwater to preserve and sustainably manage the groundwater-dependent ecosystems like coastal lagoons. This study investigated the spatial and temporal hydrogeochemical characteristics of coastal lagoon (Songjiho) and groundwater on the east coast of Korea. The concentrations of major ions, water isotopes, and nutrients (nitrogen and dissolved organic carbon) in lagoon water and groundwater were periodically monitored for one year. The study revealed that major ions and total dissolved solids (TDS) concentration were higher at deeper depths of aquifers and closer to the coastal area. The hydrogeochemical characteristics of coastal lagoon and groundwater chemistry were classified into two types, Ca-Mg-HCO3 and Na-Cl, based on their spatial location from inland to coastal area. Moreover, the hydrogeochemical characteristics of coastal lagoons and groundwater varied significantly depending on the season. During the wet season, the increased precipitation and evaporation lead to changes in water chemistry. As a result, the total organic carbon (TOC) of coastal lagoons increases during this season, likely due to increased runoff by rainfall whereas the variation of chemical compositions in the lagoon and groundwater were not significant because there is reduced precipitation, resulting in stable water levels and during the dry season. The study emphasizes the impact of spatial distribution and seasonal changes in precipitation, evaporation, and river discharge on the hydrogeochemical characteristics of the coastal aquifer and lagoon system. Understanding these impacts is crucial for managing and protecting coastal lagoons and groundwater resources.

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Long-Term Investigation of Regional Topographic Effects on Soil Chemical Properties and Heavy Metal Concentrations in Paddy Fields

  • Ahn, Byung-Koo;Kang, Seong-Soo;Shin, Jae-Yeon;Lee, Jin-Ho
    • 한국토양비료학회지
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    • 제45권5호
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    • pp.738-743
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    • 2012
  • Topographic conditions of agricultural fields work as a important factor to identify different soil properties. This study was conducted to investigate the selected soil chemical properties and the concentrations of heavy metals, Cd, Cr, Pb, Cu, Ni, and Zn, in the paddy fields of different topographic areas at four year intervals from 1999 to 2011. Three-hundred soil sampling sites in the paddy fields were selected from the different topographic areas that were local valley and fans, fluvio-marine deposits, alluvial plains, and diluvial terraces. The mean values of soil pH ranged 5.7~5.8 that were within optimal range for rice cultivation. The mean values of other properties such as soil organic matter (SOM) content, the concentrations of exchangeable cations, $K^+$, $Ca^{2+}$, and $Mg^{2+}$, and available silicate concentration were lower or close to the optimal values, but the mean concentrations of available phosphorus were exceeded the range of optimal value, $80{\sim}120mg\;kg^{-1}$, in many paddy fields. In particular, The concentrations of available phosphorus in the paddy fields of local valley and fans, alluvial plains, and fluvio-marine plains were mostly declined. However, in diluvial terrace areas, the phosphorus concentrations unexpectedly increased; furthermore, they were significantly higher than those in other topographic areas. The mean concentrations of 0.1 M HCl-extractable heavy metals, Cd, Cr, Pb, Cu, Ni, and Zn, in the paddy fields were slightly and gradually declined during the study years, but the Pb concentrations were not statistically changed. In addition, the concentrations of heavy metals were widely ranged depending on the different sampling sites. Nevertheless, the concentrations of heavy metals were significantly lower than the levels of Soil Contamination Warning Standard (SCWS) for agricultural lands (1-region) presented in Soil Environment Conservation Law (SECL).

화력발전소 SCR 촉매의 활성저하 특성 (Deactivation of SCR Catalysts Applied in Power Plants)

  • 이정빈;김동화;이창용
    • 공업화학
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    • 제21권1호
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    • pp.104-110
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    • 2010
  • 국내에서 가동 중인 석탄, 오리멀젼, LNG 등의 화력발전소에서 선택적 촉매 환원(SCR) 공정에 사용되고 있는 촉매의 재생을 연구하기 위하여 이들 촉매의 활성 저하를 고찰하였다. XRD, ICP-AES, BET, SEM 분석 등으로 촉매의 특성분석을 수행하였고 이들 촉매에 대하여 암모니아 SCR을 행하였다. 석탄 화력발전소의 SCR 촉매는 연료 성분과 관련된 황산염과 분진의 침적에 의한 기공 폐색에 기인하여 활성저하가 발생하였다. 오리멀젼 화력발전소의 SCR 촉매는 연료에 함유된 바나듐과 황 성분 그리고 연료에 첨가된 마그네슘 화합물의 침적에 의한 기공 폐색에 기인하여 촉매 표면적이 크게 감소하였다. 그러나 촉매의 암모니아 SCR 활성은 약간 감소하였다. LNG 화력발전소의 SCR 촉매는 사용 기간이 2년 이상임에도 불구하고 활성저하는 거의 일어나지 않았다.

Arctigenin from Burdock Root Exhibits Potent Antibacterial and Anti-Virulence Properties against Pseudomonas aeruginosa

  • Abdulrahman E. Koshak;Mahmoud A. Elfaky;Hossam M. Abdallah;Dina A. I. Albadawi;Gamal A. Mohamed;Sabrin R. M. Ibrahim;Abdulrahim A. Alzain;El-Sayed Khafagy;Azza A. H. Rajab;Wael A. H. Hegazy
    • Journal of Microbiology and Biotechnology
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    • 제34권8호
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    • pp.1642-1652
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    • 2024
  • Arctium lappa (Burdock) root is used in various culinary applications especially in Asian Cuisine. Arctigenin (ARC) is a polyphenolic compound abundant in the roots of the burdock plant from which it derives its name. The emergence of bacterial resistance is a growing global worry, specifically due to the declining availability of new antibiotics. Screening for the antibacterial candidates among the safe natural products is a promising approach. The present study was aimed to assess the antibacterial activity of ARC against Pseudomonas aeruginosa exploring its effect on the bacterial cell membrane. Furthermore, the anti-virulence activities and anti-quorum sensing (QS) activities of ARC were in vitro, in vivo and in silico assessed against P. aeruginosa. The current results showed the ARC antibacterial activity was owed to its disruption effect of the cell membrane. ARC at sub-MIC significantly decreased the formation of biofilm, motility, production of extracellular enzymes and in vivo protected mice against P. aeruginosa. These anti-virulence activities of ARC are owed to its interference with bacterial QS and its expression. Furthermore, ARC showed mild effect on mammalian erythrocytes, low probability to induce resistance and synergistically combined with antibiotics. In summary, the promising anti-virulence properties of ARC indicate its potential as an effective supplement to conventional antibiotics for treating severe P. aeruginosa infections.