• 제목/요약/키워드: slow-release

검색결과 234건 처리시간 0.022초

Concentration Dependent Effect of Heavy Metals on Soil Carbon Mineralization

  • Walpola, Buddhi Charana;Yoon, Min-Ho
    • 한국토양비료학회지
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    • 제45권4호
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    • pp.551-554
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    • 2012
  • The present laboratory investigation was conducted to assess the effect of heavy metals on carbon mineralization. Soil was treated with three concentrations (50, 100 and $150{\mu}mol\;g^{-1}$ soil) of two heavy metals (Cd and Zn) in a factorial combination of treatments replicated four times. Determination of carbon mineralization was carried out at 3, 7, 14, 21, 28, 42 and 56 days after metal treatments.. The amount of $CO_2$-C released from heavy metal treated soils was found to be decreased at an increasing rate during the first 28 days, followed by slow release as incubation progressed. The total amounts of $CO_2$-C released were 448, 382 and $348mg\;kg^{-1}$ soil respectively for soils treated with 50, 100 and $150{\mu}mol\;g^{-1}$ soil of Zn. The corresponding figures for Cd treated soils were 406, 354 and $282mg\;kg^{-1}$ soil implying that dose-dependent reduction in cumulative $CO_2$-C released from soils. The inhibition of carbon mineralization was found to be high in Cd treated soils than that of Zn treated. Therefore, tolerance and adaptation of the microbial community is likely to be related to the concentration and the type of metal. According to the results, carbon mineralization can be considered as possible indicator of soil pollution by means of heavy metals.

Effectiveness of Bioremediation on Oil-Contaminated Sand in Intertidal Zone

  • Oh, Young-Sook;Sim, Doo-Suep;Kim, Sang-Jin
    • Journal of Microbiology and Biotechnology
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    • 제13권3호
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    • pp.437-443
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    • 2003
  • Bioremediation technologies were applied to experimental microcosms, simulating an oil spill in a lower intertidal area. Three treatments (oil only, oil plus nutrients, and oil plus nutrients and microbial inocula) were applied, and each microcosm was repeatedly filled and eluted with seawater every 12 h to simulate tidal cycles. To minimize washing-out of the inoculum by the tidal cycles, microbial cells were primarily immobilized on diatomaceous earth before they were applied to the oiled sand. Oil degradation was monitored by gravimetric measurements, thin layer chromatography/flame ionization detector (TLC/FID) analysis, and gas chromatography (GC) analysis, and the loss of oil content was normalized to sand mass or nor-hopane. When the data were normalized to sand mass, no consistent differences were detected between nutrient-amended and nutrient/inoculum-amended microcosms, although both differed from the oil-only microcosm in respect of oil removal rate by a factor of 4 to 14. However, the data relative to nor-hopane showed a significant treatment difference between the nutrient-amended and nutrient/inoculum-treated microcosms, especially in the early phase of the treatment. The accelerating effect of inoculum treatment has hardly been reported in studies of oil bioremediation in the Tower intertidal area. The inoculum immobilized on diatomaceous earth seemed to be a very effective formulation for retaining microbial cells in association with the sand. Results of this study also suggest that interpretation of the effectiveness of bioremediation could be dependent on the selection of monitoring methods, and consequently the application of various analytical methods in combination could be a solution to overcome the limitations of oil bioremediation monitoring.

국내 골프 코스에서 시용되는 농약 및 비료의 환경적 영향 (The Environmental Effects of Agrochemical and Fertilizer Applied in Golf Courses in Korea)

  • 이상재;허근영;사공영보
    • 아시안잔디학회지
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    • 제15권2호
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    • pp.87-104
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    • 2001
  • This Study was carried out to investigate on the environmental effects of golf courses and to find a solution to the negative effects in Korea. The results were ai follows. 1. There were 152 golf courses opened in December 2000. 113 golf courses were member-ship and 39 golf courses were public. Users (golfer) were over 12,000,000 in 2000. 2. Total area of golf courses was 0.8% as compared with total area of farmland in 1999. Total amount of agricultural chemicals used in golf courses was 0.3% of total amount of agricultural chemicals used in Korea. The remaining amount of agricultural chemicals in golf courses tested were almost below the permitted limits. 3. Recently, total amount of fertilizers in green decreased 5~7g/$m^2$/year as compared with the recommended. 4. The control by antagonistic microorganisms and the fertilizing of the organic matter or the organic fertilizer were effective to decrease the amount of agricultural chemicals used. To success the control of microorganisms, active antagonistic microorganisms had to be applied over the recommended dose eve교day. Though fertilizing of organic fertilizer, slow release fertilizer, was effective to suppress dollar spot, necrotic ring spot. fungicides were required as a supplementary means when disease symptom was very heavy. 5. Zoysiagrass was fertilized intensively from May to August. Cool-season grasses were fertilized intensively from March to May and September to October. The fall fertilizing of Zoysiagrass was carried out to the begining of October. The fall fertilizing of cool-season grasses were carried out to the end of November or the begining of December. The fertilizing amount of Zoysiagrass was 10g/$m^2$/year. The fertilizing amount of bentgrass was 25~27g/$m^2$/year.

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Effect of Surfactant-Coated Charcoal Amendment on the Composting Process and Nutrient Retention

  • Pinwisat, Phetrada;Phoolphundh, Sivawan;Buddhawong, Sasidhorn;Vinitnantharat, Soydoa
    • Environmental Engineering Research
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    • 제19권1호
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    • pp.37-40
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    • 2014
  • This research investigates the quality changes during composting of bagasse and pig manure amended with 30% of surfactant-coated charcoal (SC). Two treatments, 30% uncoated charcoal (UC) amendment and no charcoal (NC) amendment, were done as control. Charcoal was coated with 0.37 mM tetradecyltrimethylammonium bromide (TDMA), a cationic surfactant, at the dosage of 10 g/L. At the end of the composting period, the carbon to nitrogen (C/N) ratio of SC amendment was 9.7; whereas, the C/N ratios of UC and NC amendment were 12.6 and 21.4, respectively. Plant nutrients contents of the compost produced from SC amendment were 20.7 mg $NH_4{^+}-N/g$, 42.8 mg $NO_3{^-}-N/g$, and 41.7 mg P/g. High nitrate and phosphate concentrations in SC amendment were due to the adsorption of these anions on the positive charge of TDMA. Desorption of plant nutrients retained in the compost pellets was also investigated. It was predicted that nitrate was fully desorbed from a pellet at 23 days for SC amendment, which was later than UC (14 days) and NC (10 days) amendment. A slow release of nitrate from the compost pellet will reduce the nitrate leaching into the environment. Thus, the adding of SC in the compost pile is one of the alternative methods to improve the quality of compost and plant nutrient retention.

뼈조직과 세포에서의 칼슘이동기전에 대한 1,25 dihydroxycholecaliciferol과 Ca Ionophore A23187의 영향 (Effects of 1,25 Dihydroxycholecalciferol and Ca Ionophore A23187 on Ca Transports in Bone and Bone Cells)

  • 이선영
    • Journal of Nutrition and Health
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    • 제21권3호
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    • pp.173-181
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    • 1988
  • Various types of evidence suggest that some changes in cellular in cellular calcium may well signal the initiation of a chain of events leading to the physiological effects of the bone resorbing agents. The effects of 1,25-dihydorxycholecalciferol, $1.25\textrm{(OH)}_2\textrm{D}_3$, Ca ionophore A23187 and calcium antagonist, diltiazem on bone resprption and the cellular transport of Ca were investigated. Bone $^{45}\textrm{Ca}$ desaturation experiment was realized in isolated heterogenous rat bone cells after equilibrating the cells with $^{45}\textrm{Ca}$. Results of $^{45}\textrm{Ca}$ desaturation experiments were analysed by fitting the $^{45}\textrm{Ca}$ desaturation curve to a model of 2 exponential terms which indicated the presence of 2 exchangeable cellular calcium pools. $1.25\textrm{(OH)}_2\textrm{D}_3$ (0.5ng/$m\ell$) induced significantly bone resorption which was decreased by the physiological dose of diltiazeme(above 5nmol/$m\ell$) although it was ineffective alone. Ionophore A23187 (0.2$\mu\textrm{g}$/$m\ell$) decreased Ca release from bone but no additivity of effect with diltiazem(20nmol/$m\ell$) was observed. $1.25\textrm{(OH)}_2\textrm{D}_3$ (0.5ng/$10^{6}$ cells) had a moderate effect on the two kinetic phases of $^{45}\textrm{Ca}$ desaturation curve and these values were normalized when diltiazeme (20nmol/$10^{6}$ cells) was added along with $1.25\textrm{(OH)}_2\textrm{D}_3$. Ionophore($0.05\mu\textrm{g}$/$10^{6}$ cells) alone increased specifically the value of the slow turnover rate which was not affected by addition of diltiazem. The hypothesis concerning the involvement of calcium in bone resorption seems in fact to be verified in case of $1.25\textrm{(OH)}_2\textrm{D}_3$ but more unsettled for Ca inophore A23187.

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Bisamino-PEG가 함유된 키토산 비드의 팽윤성 및 방출 특성 (Swelling Properties and Releasing Characteristics of Chitosan Beads Containing Bisamino-PEG)

  • 하병조;이옥섭;이윤식
    • 공업화학
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    • 제7권1호
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    • pp.59-66
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    • 1996
  • 양말단에 아미노기가 결합된 일련의 bisamino-PEG($Jeffamine^{(R)}ED$)를 함유한 키토산 비드들을 알칼리 용액을 사용한 capillary extrusion method에 의해 제조하였다. 제조된 각각의 비드들에 대한 swelling kinetics를 조사한 결과, 키토산비드 내부에 PEG 사슬이 길어질수록 팽윤이 늦게 진행되었다. 또한 키토산 비드에 함유된 bisamino-PEG들의 방출현상을 정량적으로 알아 보기 위해 양말단의 1차 아민기에 fluorescamine을 결합시킨 후, UV spectra로 방출과정을 추적하였다. 실험결과 키토산 비드 내부에 있는 PEG 사슬이 길수록 방출시간은 $Jeffamine^{(R)}ED$-600 < $Jeffamine^{(R)}ED$-900 < $Jeffamine^{(R)}ED$-2001 순으로 지연되는 경향을 나타내었다. 이는 PEG 사슬이 길어질수록 키토산과의 수소결합에 의한 상호작용이 강화되고 그 결과 방출기간이 지연된 것으로 사료된다.

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항문호흡 수련 및 항문호흡의 한의학적 고찰 (Anal breathing training and oriental medical study of the anal breathing)

  • 송정민;강한주;김정환
    • 대한의료기공학회지
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    • 제11권1호
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    • pp.262-283
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    • 2009
  • 1. Anus is one of the nine holes, a soul store and on the lungs and the lungs, so the soulgate is said to meet. In addition, weight 450g, length 14.31inch, horizontal, and the 2.74inch, hit the road, the lungs and the reaction of the colon was found to represent the five viscera were dirty. 2. Spirit directly to the anus of the five viscera and the traffic outside and pass the information where I can get, and a close relation to the breathing, and each groups' je-hang-suk-sin-gong, je-hang-gong, anal breathing, jwa-sik training, jung-gi-dan-beop, martial arts method, Kegel exercises, breathing training, such as the anus is the name. 3.Anal way of breathing while breathing naturally slow down when you inhale air, tighten the anus and rectum to release when you breathe out, give way (or vice versa), the number of 5-20, he'll make you build up gradually. 4.Associated with respiratory training in Oriental medicine perspective, it is a Mac gi-gyeong eight vessel. In addition, out of gi-gyeong eight vessel in breathing training and more closely related to the Conception Vessel, Governor Vessel. 5.Governor Vessel, Conception Vessel and connect the energy up, down, left and right to communicate is the so-ju-cheon. To complete the Governor Vessel instantly without the energy leak from the Mir-yeo(尾閭) to reach the anus should be breathing. 6.Start the Conception Vessel Through fare Vessel hoeǔm, hoeǔm important acupuncture point can be activated by itself does not have the muscle to the hoeǔm around the anus energy and blood breathing helps circulation.

퇴행성관절염(退行性關節炎) 치료제 개발을 위한 수종의 한약재활성 검색 및 기전연구 (The Study on the Effectiveness and Mechanism of Several Herbal Medicines for Development of Osteoarthritis Treatment)

  • 허정은;조은미;양하루;김대성;백용현;이재동;최도영;박동석
    • 대한한의학회지
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    • 제27권1호
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    • pp.229-239
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    • 2006
  • Objectives : Articular cartilage is a potential target for drugs designed to inhibit the activity of matrix metalloproteinases (MMPs) to stop or slow the destruction of the proteoglycan and collagen in the cartilage extracelluar matrix. The purpose of this study was to investigate the effects of KHBJs for cartilage-protective effect in human and rabbit articular cartilage explants. Methods : The cartilage-protective effects of KHBJ were evaluated by using glycosaminoglycan degradation assay, collagen degradation assay, colorimetric analysis of MMPs activity, and histological analysis in rabbit and human cartilage explants culture. Results : KHBJs significantly inhibited GAG and collagen release of rabbit and human cartilage explant in a concentration-dependent manner. Also, KHBJs inhibited MMP-3 and MMP-13 activities from IL-$1{\alpha}$-treated cartilage explants cultures. Histological analysis indicated that KHBJ004 reduced the degradation of the cartilage matrix compared with that of IL-$1{\alpha}$-treated cartilage explants. KHBJ004 had no harmful effect on chondrocytes viability or cartilage morphology in cartilage explants. Conclusions : These results indicate that KHBJs inhibits the degradation of proteoglycan and collagen through the downregulation of MMP-3 and MMP-13 activities without affecting the viability or morphology of IL-$1{\alpha}$-stimulated rabbit and human articular cartilage explants.

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싸락눈 종단 속도의 불확실성이 구름 모의에 미치는 영향 (Effects of Uncertainty in Graupel Terminal Velocity on Cloud Simulation)

  • 이현호;백종진
    • 대기
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    • 제26권3호
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    • pp.435-444
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    • 2016
  • In spite of considerable progress in the recent decades, there still remain large uncertainties in numerical cloud models. In this study, effects of uncertainty in terminal velocity of graupel on cloud simulation are investigated. For this, a two-dimensional bin microphysics cloud model is employed, and deep convective clouds are simulated under idealized environmental conditions. In the sensitivity experiments, the terminal velocity of graupel is changed to twice and half the velocity in the control experiment. In the experiment with fast graupel terminal velocity, a large amount of graupel mass is present in the lower layer. On the other hand, in the experiment with slow graupel terminal velocity, almost all graupel mass remains in the upper layer. The graupel size distribution exhibits that as graupel terminal velocity increases, in the lower layer, the number of graupel particles increases and the peak radius in the graupel mass size distribution decreases. In the experiment with fast graupel terminal velocity, the vertical velocity is decreased mainly due to a decrease in riming that leads to a decrease in latent heat release and an increase in evaporative cooling via evaporation, sublimation, and melting that leads to more stable atmosphere. This decrease in vertical velocity causes graupel particles to fall toward the ground easier. By the changes in graupel terminal velocity, the accumulated surface precipitation amount differs up to about two times. This study reveals that the terminal velocity of graupel should be estimated more accurately than it is now.

Metal tip FEA 의 제조시 식각 용액이 게이트 산화막에 미치는 영향 (The effect of wet-etching process on the gate insulator for fabrication of metal tip FEA)

  • 정유호;정재호;박흥우;송만호;이윤희;주병권;오명환;김철주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 C
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    • pp.1450-1452
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    • 1996
  • In order to optimize the characteristics of gate insulator for FED(field emission device), we investigated the effect of wet-etching process on the gate insulator for fabrication of FED. We used the general three types of etchants for fabrication of the metal tip FEA(field emitter array), they are MO and oxide etchants to form the gate hole, and Al etchant to remove the release layer. In the result of the breakdown field of the insulator by the measure of the current-voltage characteristics, the breakdown field of insulator for immersing in oxide etchant was rapidly lowering with increasing etching time, but that for immersing in Al etchant was slow lowering. Also, in comparing cleaning with non-cleaning samples, the breakdown field of the cleaning samples was higher than that of non-cleaning samples.

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