• Title/Summary/Keyword: Soil degradation

검색결과 858건 처리시간 0.025초

식생(植生)이 비탈면의 안정(安定)에 미치는 영향 (Vegetation Influences on the Slope Stabilization)

  • 우보명
    • 한국산림과학회지
    • /
    • 제35권1호
    • /
    • pp.47-55
    • /
    • 1977
  • 우리나라에서는 최근에 고도의 경제성장(經濟成長)으로 인(因)한 국토개발사업(國土開發事業)이 전국토(全國士)에서 시행(施行)되고 있다. 특(特)히 경부고속도로(京釜高速道路)를 비롯한 각종(各種) 고속도로(高速道路)의 건설(建設)과 산업기지(産業基地) 및 택지(宅地) 공장부지(工場敷地)의 조성공사(造成工事) 등으로 자연(自然)비탈면이 많이 파괴(破壞) 훼손(毁損)되었으므로 이를 복구(復舊) 녹화(綠化)하기 위한 녹화공법(綠化工法)으로서 주로 식생공법(植生工法)이 채용되고 있으나 절토(切土)나 성토공사(盛土工事)로 인하여 인위적(人爲的)으로 만들어진 인공(人工) 비탈면의 안정에 미치는 식생(植生)의 영향에 관한 문제가 아직 종합적으로 보고(報告)된 바 있다. 그러므로 본(本) 연구(硏究)에서는 우선 비탈면의 피해형태(被害形態)를 분석(分析)하고, 식생(植生)이 비탈면의 물 수지(收支)에 미치는 영향을 분석(分析)하였으며, 또 식생(植生)이 표면침식방지(表面浸蝕防止) 및 표층붕괴(表層崩壞)에 미치는 영향을 분석(分析)하였다.

  • PDF

Polyethylene Glycol의 미생물학적 분해 (Microbial Degradation of Polyethylene Glycol)

  • 이종근;이상준;이재동;박송희;박재림
    • 미생물학회지
    • /
    • 제24권3호
    • /
    • pp.329-334
    • /
    • 1986
  • PEG 6,000을 유일한 탄소원으로 이용할 수 있는 세균을 하천수와 하천부끔의 토양으로부터 분리하였으며 이증 분해능이 우수한 EL-033 isolate-를 Micrococcus sp. 로 동정하였다, Micrococcus sp. EL-033은 mono-ethylene g glycol플 세외한 di-, tri-, tetra-ethylene glycol파 분자량 6,000까지의 PEG닫을 분해하였으며 그 중합도가 높윤 수복 생 앙상태까 좋은 분해특성을 가AI고 있였으며. PEG 20, 000에 대해서도 약간의 분해능음 가지고 있었다. 최적 배지 조성은 PEG 6,000 0.2% $K_2HPO_4$, 0.1% $NaH_2PO_4{\cdot}12H_2O0.1%MgSO_4{\cdot}7H_2O$0,1 %, polypeptone 0,1 %, $MgSO_4$, 0,05 % (pH7,5) 이었다. 생장 최적조건에서 PEG 6,000의 분해는 대수증식기인 48시간 배양하였을때 90%이상의 분 해융플 나타내있으며,72시간 후에 거의 완전히 분해되었다.

  • PDF

Corrosion Cost and Corrosion Map of Korea - Based on the Data from 2005 to 2010

  • Kim, Y.S.;Lim, H.K.;Kim, J.J.;Hwang, W.S.;Park, Y.S.
    • Corrosion Science and Technology
    • /
    • 제10권2호
    • /
    • pp.52-59
    • /
    • 2011
  • Corrosion of metallic materials occurs by the reaction with corrosive environment such as atmosphere, marine, soil, urban, high temperature etc. In general, reduction of thickness and cracking and degradation are resulted from corrosion. Corrosion in all industrial facilities and infrastructure causes large economic losses as well as a large number of accidents. Economic loss by corrosion has been reported to be nearly 1-6% of GNP or GDP. In order to reduce corrosion damage of industrial facilities, corrosion map as well as a systematic investigation of the loss of corrosion in each industrial sector is needed. The Corrosion Science Society of Korea in collaboration with 15 universities and institutes has started to survey on the cost of corrosion and corrosion map of Korea since 2005. This work presents the results of the survey on cost of corrosion by Uhlig, Hoar, and input-output methods, and the evaluation of atmospheric corrosion rate of carbon steel, weathering steel, galvanized steel, copper, and aluminum in Korea. The total corrosion cost was estimated in terms of the percentage of the GDP of industry sectors and the total GDP of Korea. According to the result of Input/output method, corrosion cost of Korea was calculated as 2.9% to GDP (2005). Time of wetness was shown to be categories 3 to 4 in all exposure areas. A definite seasonal difference was observed in Korea. In summer and fall, time of wetness was higher than in other seasons. Because of short exposure period (12 months), significant corrosion trends depending upon materials and exposure corrosion environments were not revealed even though increased mass loss and decreased corrosion rate by exposure time.

Characterization of Protocatechuate 4,5-Dioxygenase Induced from p-Hydroxybenzoate -Cultured Pseudomonas sp. K82

  • Yun, Sung-Ho;Yun, Chi-Young;Kim, Seung-Il
    • Journal of Microbiology
    • /
    • 제42권2호
    • /
    • pp.152-155
    • /
    • 2004
  • Pseudomonas sp. K82 has been reported to be an aniline-assimilating soil bacterium. However, this strain can use not only aniline as a sole carbon and energy source, but can also utilize benzoate, p-hydroxybenzoate, and aniline analogues. The strain accomplishes this metabolic diversity by using dif-ferent aerobic pathways. Pseudomonas sp. K82, when cultured in p-hydroxybenzoate, showed extradiol cleavage activity of protocatechuate. In accordance with those findings, our study attempted the puri-fication of protocatechuate 4,5-dioxygenase (PCD 4,5). However the purified PCD 4,5 was found to be very unstable during purification. After Q-sepharose chromatography was performed, the crude enzyme activity was augmented by a factor of approximately 4.7. From the Q-sepharose fraction which exhibited PCD 4,5 activity, two subunits of PCD4,5 (${\alpha}$ subunit and ${\beta}$ subunit) were identified using the N-terminal amino acid sequences of 15 amino acid residues. These subunits were found to have more than 90% sequence homology with PmdA and PmdB of Comamonas testosteroni. The molecular weight of the native enzyme was estimated to be approximately 54 kDa, suggesting that PCD4,5 exists as a het-erodimer (${\alpha}$$_1$${\beta}$$_1$). PCD 4,5 exhibits stringent substrate specificity for protocatechuate and its optimal activity occurs at pH 9 and 15 $^{\circ}C$. PCR amplification of these two subunits of PCD4,5 revealed that the ${\alpha}$ subunit and ${\beta}$ subunit occurred in tandem. Our results suggest that Pseudomonas sp. K82 induced PCD 4,5 for the purpose of p-hydroxybenzoate degradation.

미국 서부 해안 IMPROVE 측정소에 대한 대기 중 PM2.5의 오염원 기여도 추정 (Estimation of Source Apportionment of Ambient PM2.5 at Western Coastal IMPROVE Site in USA)

  • 황인조;김동술
    • 한국대기환경학회지
    • /
    • 제24권1호
    • /
    • pp.30-42
    • /
    • 2008
  • In this study, the chemical compositions of $PM_{2.5}$ samples collected at the Redwood National Park IMPROVE site in California from March 1988 to May 2004 were analyzed to provide source identification and apportionment. A total of 1,640 samples were collected and 33 chemical species were analyzed by particle induced X-ray emission, proton elastic scattering analysis, photon induced X-ray fluorescence, ion chromatography, and thermal optical reflectance methods. Positive matrix factorization (PMF) was used to develop source profiles and to estimate their mass contributions. The PMF modeling identified five sources and the average mass was apportioned to motor vehicle (35.8%, $1.58\;{\mu}g/m^3$), aged sea salt (23.2%, $1.02\;{\mu}g/m^3$), fresh sea salt (21.4%, $0.94\;{\mu}g/m^3$), wood/field burning (16.1%, $0.71\;{\mu}g/m^3$), and airborne soil (3.5%, $0.15\;{\mu}g/m^3$), respectively. To analyze local source impacts from various wind directions, the CPF and NPR analyses were performed using source contribution results with the wind direction values measured at the site. These results suggested that sources of $PM_{2.5}$ are also sources of visibility degradation and then source apportionment studies derived for $PM_{2.5}$ are also used for understanding visibility problem.

한반도에서 지속농업의 실천방안 지속적 벼 생산체계 개발을 중심으로 (Practices of Sustainable Agriculture in Korea With References for the Development of Sustainable Rice Production Systems)

  • 최진룡;김정부;조영손
    • 한국작물학회:학술대회논문집
    • /
    • 한국작물학회 1998년도 21세기 한반도 농업전망과 대책(한국작물학회.한국육종학회 공동주관 심포지움 회보)
    • /
    • pp.288-312
    • /
    • 1998
  • In Korea, chemical fertilizers and agricultural chemicals have had a significant impact on food production and these are today thought to be an indispensable part of modern agriculture. On the other hand, socioeconomical and IMF and WTO status in Korea are constant reminders of the vulnerability of our fossil fuel dependent agriculture. A new crop production system to improve economic, environmental and production efficiency must be exploited. Our particular concern has been given to an integrated cropping system involving recycling of crop residues, soil and N management, biological N fixation and multipurpose legumes. As a new integrated crop production system, a no-till direct-sown rice-vetch relaying cropping system has been proposed in this paper. The formulation of this system is based on the conception that N fertilizers being neither limitlessly available nor affordable, the current high-input crop production systems have produced troubled results severe labour shortage ill rural areas, balance of payment, environmental degradation and reduction of human health far exceed economic concerns. A natural and logical consequence is that long-term sustainability of agricultural systems must rely on the use and effective management of internal resources. Based on the information obtained throughout a series of experiments last years we have proved that the no-till direct-sown rice-vetch relaying cropping system dictates biological alternative which can augment, and in some cases replace, N fertilizers. Comprehensive discussions were made for the proposed system and it concluded that the system can offer an economically attractive and ecologically sound means of reducing external nitrogen input and improving the quality and quantity of internal resources, and consequently improving the farmers as well as the national returns.

  • PDF

Bacillus sp. MS202에 의한 Dinitroaniline계 제초제인 Pendimethalin의 부분환원 (Partial Reduction of Dinitroaniline Herbicide Pendimethalin by Bacillus sp. MS202)

  • 이영근;장화형;장유신;형석원;정혜영
    • 한국환경농학회지
    • /
    • 제23권4호
    • /
    • pp.197-202
    • /
    • 2004
  • 토양과 지하수에서 pendimethalin의 지속성은 환경에 해로운 영향을 미친다. 경남 마산에서 분리한 pendimealalin분해 균주는 API CHB50 kit 시험, FAME분석, 그리고 16S rDNA 염기서열분석 결과로 Bacillus sp. MS202로 잠정적으로 동정하였다. TLC, GC, 그리고 GC-MS 분석에 의해 Bacillus sp. MS202가 pendimethalin의 $-NO_2$$-NH_2$로 환원시킨다는 것을 알 수 있었다. 이는 일반적으로 알려진 호기성 미생물에 의한 pendimethalin 분해가 탈알킬화가 우선한다는 보고와 상반되는 새로운 결과이다.

Alkaline protease를 생산하는 미생물의 분리, 동정 및 효소성질 (Isolation, Identification and Enzyme Properties of a Bacterium producing Alkaline Protease)

  • 신공식;강상모;고정연
    • Applied Biological Chemistry
    • /
    • 제43권3호
    • /
    • pp.169-173
    • /
    • 2000
  • 저온에서 높은 세척력을 갖는 호소세제의 개발을 위하여 토양으로부터 alkaline protease의 활성이 높은 균주를 분리, 동정하였으며, 호소의 성질을 조사하였다. 분리균주의 형태적 특징은 Gram 음성균 이고, 간균$(0.6{\sim}0.7{\times}1.3{\sim}2.6\;{\mu}m\;in\;size)$ 형태를 하고 있으며, 운동성을 보였다. 또한 catalase 양성, aesculin, gelatin 및 casein 분해능이 있었다. 분리균주의 세포벽 구성 성분은 meso-DAP를 함유하였으며, G+C mol 함량은 43.3%를 나타내었다. 이러한 형태적, 생리 생화학적 특성의 결과로부터 분리 균주는 Acinetobacter 속으로 동정되었다. 분리 균주를 이용한 alkaline protease의 생산은 초기 pH 10과 $40^{\circ}C$에서 36시간 배양하였을 때 3,300 D.U/mL로 최대 효소 활성을 보였으며, 최적 pH와 온도는 9와 $60^{\circ}C$이었다. 또한 본 균주에 의해 생산된 alkaline protease는 두개의 활성 band를 나타내었다.

  • PDF

Development of Innovative Technologies for Enhancing Low Flow Discharge and Reducing Turbid Material from Overcrowded Forest Plantations by Intensive Thinning in Japan

  • Otsuki, Kyoichi;Kasahara, Tamao;Onda, Yuichi
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2012년도 학술발표회
    • /
    • pp.18-18
    • /
    • 2012
  • In Japan, about 67% of the land is covered by forests and about 41% of them consist of plantations. About 35% of the plantations consist of old-aged plantations of older than 50 yearsand the percentage is projected to 67% in ten years' time. Although the trees of these plantations are supposed to be cut for timber production, most of them remain unmanaged and thus overcrowded mainly due to declining domestic forest industry. Since the forests are mostly located in headwater watershed, there are growing concerns about the degradation of water resources by these unmanaged plantations. To understand the ecohydrological processes in these plantations and examine the effect of intensive 50-60 % thinning to increase infiltration rate and reduce overland flow and soil erosion by recovering understory vegetation, the JST-CREST project "Development of Innovative Technologies for Increasing in Watershed Runoff and Improving River Environment by the Management Practice of Devastated Forest Plantation (Representative: Yuichi Onda)" has been launched since 2009. The ultimate objective of this project is to provide potential scenario to enhance low flow discharge in drought period and reduce turbid material in high flow period. We have been conductingintensive field observation campaign in five research sites across Japan. In Fukuoka site, integrated ecohydrological observations have been conductedin two contrastive watersheds since 2010. Intensive 50% thinning was conducted from January to April 2012 and comparative studies of ecohydrological processes before and after thinning have been started. The interim results from all the sites of this project will be presented in the 3rd International Congress for Forest and Water in a Changing Environment held in Fukuoka during 18-20 September, 2012 (http://www.forest.kyushu-u.ac.jp/~ecohydrol/3ForestWater/index.html).

  • PDF

배양기법을 활용한 제주도내 내산 및 호염성 미생물의 분리 및 특성 분석 (Isolation and characterization of acid-resistanct and halophilic bacteria using cultivation technique in Jeju island)

  • 한빛;김민지;류다정;이기은;이병희;이은영;박수제
    • 미생물학회지
    • /
    • 제55권3호
    • /
    • pp.248-257
    • /
    • 2019
  • 본 연구에서는 제주 지역의 토양 및 해양 환경으로부터 약 70주의 미생물들을 분리하였으며, 16S ribosomal RNA 유전자 분석을 통하여 최종 21종의 미생물을 발굴하였다. 이들 미생물들은 5 강(Class) 16 속(Genus)에 속하며, 모두 국내 미기록종으로 확인되었다. 분리된 미생물의 기질 특이성 및 고분자 물질 분해능을 바탕으로 내산성과 호염성 미생물들의 생리활성 표현형은 서로 구별되는 것으로 관찰되었다. 본 연구결과는, 국내 미생물 자원활용에 기초적 정보를 제공할 것으로 기대된다.