• 제목/요약/키워드: Water improvement

검색결과 4,097건 처리시간 0.032초

우리나라의 주요가뭄해석을 위한 각종 가뭄지수의 적용 (An Application of Various Drought Indices for Major Drought Analysis in Korea)

  • 이재준;이창훈
    • 한국방재학회 논문집
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    • 제5권4호
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    • pp.59-69
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    • 2005
  • 가뭄을 미리 발견하고 감시하는 것은 어려우나, 가뭄지수를 이용하면 가뭄의 파악이 용이하다. PDSI는 통상적으로 가장 널리 이용되나 운영상 제한성을 가지고 있다. 최근 들어 가뭄을 인지하고 감시하는 능력이 향상된 SPI가 개발되었으며, 이는 기존의 지수들에 비해 모든 시간간격에 적용이 가능하고 간단하게 이용이 가능하다. KBDI는 상부토양층의 누적수분부족량을 산출함에 있어서 증발산과 강수량의 순영향을 나타내는 지수로 정의하였다. 본 연구에서는 PDSI, SPI, KBDI를 이용하여 산정된 가뭄지수의 상호비교 연구를 통하여 표준 가뭄지수를 제안하고자 한다. 이를 위하여 우리나라 8개 수계의 30년 이상의 기상자료를 보유한 기상청 강우관측소 자료를 이용하였다. 그 결과 PDSI는 누적되는 강우의 부족으로 가뭄심도를 나타내는 데 유리하고, SPI와 KBDI는 단기간 강우부족을 나타내는데 유리한 것으로 나타났다.

Effects of cinnamic acid on memory deficits and brain oxidative stress in streptozotocin-induced diabetic mice

  • Hemmati, Ali Asghar;Alboghobeish, Soheila;Ahangarpour, Akram
    • The Korean Journal of Physiology and Pharmacology
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    • 제22권3호
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    • pp.257-267
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    • 2018
  • The present study aimed to evaluate the cinnamic acid effect on memory impairment, oxidative stress, and cholinergic dysfunction in streptozotocin (STZ)-induced diabetic model in mice. In this experimental study, 48 male Naval Medical Research Institute (NMRI) mice (30-35 g) were chosen and were randomly divided into six groups: control, cinnamic acid (20 mg/kg day, i.p.), diabetic, and cinnamic acid-treated diabetic (10, 20 and 40 mg/kg day, i.p.). Memory was impaired by administering an intraperitoneal STZ injection of 50 mg/kg. Cinnamic acid was injected for 40 days starting from the 21st day after confirming STZ-induced dementia to observe its therapeutic effect. Memory function was assessed using cross-arm maze, morris water maze and passive avoidance test. After the administration, biochemical parameters of oxidative stress and cholinergic function were estimated in the brain. Present data indicated that inducing STZ caused significant memory impairment, whereas administration of cinnamic acid caused significant and dose-dependent memory improvement. Assessment of brain homogenates indicated cholinergic dysfunction, increase in lipid peroxidation and reactive oxygen species (ROS) levels, and decrease in glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) activities in the diabetic group compared to the control animals, whereas cinnamic acid administration ameliorated these indices in the diabetic mice. The present study demonstrated that cinnamic acid improves memory by reducing the oxidative stress and cholinergic dysfunction in the brain of diabetic mice.

다엽콜리매이터(Multileaf Collimator) 조사야의 반음영 및 선량분포 개선에 대한 연구 (A Study on the Improvement of Penumbra and Dose Distribution in the Multileaf Collimator Field Edge)

  • 김창욱;김회남;임충근;나수경;박병섭
    • 대한방사선치료학회지
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    • 제10권1호
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    • pp.88-93
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    • 1998
  • Multileaf collimator is essential equipment in conformal radiation therapy, however the use is limitted by increase of penumbra width and undulating dose distribution at the field edge. The purpose of this study is to improve the penumbra and dose distribution in the multileaf collimator field edge. Measurement were performed with X-omat V film in solid water phantom using 6MV photon beam from Siemens linear accelerator. All the measurement were made along the central axis of $5{\times}5cm,\;10{\times}10cm$ circular field for constant SSD of 100 cm. To improve the penumbra and dose distribution collimator was rotated by 15 degrees from 0 to 90 degrees (collimator rotation method) and center was shifted to the longitudinal direction by fourth of lead width (center shift method). We compare the penumbra and dose distribution at the field edge to alloy block. Dose distribution and penumbra width at the feild edge of MLC showed undulated dose pattern and increased penumbra compared with alloy block. However, in the collimator rotation method and center shift method we abtained simular results with alloy block. Through the study we expected that clinical use of MLC will be increase.

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연마제의 분산시간과 첨가량이 Oxide-CMP에 미치는 영향 (A Study on the Improvement of Oxide-CMP Characteristics by Dispersion Time and Content of Abrasive)

  • 박성우;한상준;이성일;이영균;최권우;서용진;이우선
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.527-527
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    • 2007
  • CMP가 1980년 IBM에 의해 반도체 웨이퍼의 표면 연마를 위해 적용된 후, 많은 연구 개발의 노력으로 반도체 집적회로의 제조 공정에서 필수 핵심기술이 되었으나, 소모자재(연마패드, 탄성지지대, 슬러리, 패드 컨디셔너)의 비용이 CMP 공정 비용의 70% 이상을 차지하는 등 제조단가가 높다는 단점을 극복할 수가 없었다. 특히, 고가의 슬러리가 차지하는 비중이 40% 이상을 넘고 있어, 슬러리 원액의 소모량을 줄이기 위한 연구들이 현재 활발히 연구 중이다. 슬러리의 변수로는 연마입자의 종류 및 특성, 용액의 pH, 연마입자의 슬러리내 안정성 등이 있다. 슬러리내 연마입자는 연마량과 균일도 측면에서 밀접한 관계를 가지고 있다. 또한, 연마제의 영향에 따라 연마율의 차이 즉, CMP 특성의 변화를 보이고 있기 때문에 투입량 또한 최적화가 필요하다. 본 연구에서는 새로운 연마제의 특성을 알아보기 위해 탈이온수(de-ionized water; DIW)에 $CeO_2,\;MnO_2,\;ZrO_2$ 등을 첨가한 후 분산시간에 따른 연마 특성과 atomic force microscopy (AFM)분석을 통해 표면 거칠기를 비교 분석하였다. 그리고, 세 가지 종류의 연마제를 각각 1wt%, 3wt%, 5wt% 첨가하여 산화막에 대한 CMP 특성을 알아본 후, scanning electron microscopy (SEM) 측정과 입도 분석을 통해 그 가능성을 알아보았다.

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합성수지계 사출성형 재생유로폼의 성능 평가에 관한 연구 (Performance Evaluation of Recycled Synthetic Resins Euro-form by Injection Modeling Method)

  • 정병열;이현철;김준희;고성석
    • 한국건축시공학회지
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    • 제10권2호
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    • pp.105-113
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    • 2010
  • 거푸집 공사는 부실공사의 예방 및 인력절감과 저비용 고효율의 공사관리 차원에서 공법개선이 요구되고 있으며, 자재 및 공법 채용과정에서 경제성과 합리화를 꾀하는 일은 전체 공사에 큰 영향을 미친다. 공사 효율성 제고를 위한 합판계 유로폼의 대체공법과 거푸집 폐자재의 재생기술, 고기능성 거푸집, 친환경을 고려한 재생 가능한 거푸집 등 경제, 시공, 안전측면에서의 효과적인 거푸집 개발 필요성이 요구되고 있다. 이에 본 연구에서는 구조체 공사 공기를 단축하고, 인력투입을 최소화하여 원가를 절감시키고, 조립 해체 과정에서 작업의 생산성과 안전성이 확보된 사출성형방식의 합성수지계 재생유로폼 공법을 개발하는데 목적을 두고 있다. 이에 1차적으로 제반 요구성능 및 필요기술에 대하여 조사하고, 이를 바탕으로 개발기술의 타당성 검토와 기존 거푸집 및 선행기술과의 비교 분석을 실시하고, 성능 평가를 실시하였다.

Augmentin 의 임상효과 (Clinical Study of Augmentin)

  • 김형묵;임창영
    • Journal of Chest Surgery
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    • 제19권1호
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    • pp.174-179
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    • 1986
  • Augmentin is a formulation of amoxycillin trihydrate and potassium clavulanate, a fused beta-lactam molecule produced by the fermentation of Streptomyces clavuligerus. Most clinically important resistance is due to the production by bacteria of antibiotic destroying enzymes. In the case of penicillins and cephalosporins these enzymes are termed beta-lactamase as they destroy the beta-lectern ring of these antibiotics, completely inactivating them. The presence of clavulanic acid extends the spectrum of amoxycillin to include bet On clinical study of the intravenous Augmentin in the field of thoracic and cardiovascular surgical cases, we selected randomly 30 patients, 21 male and 9 female, age from 13 to 72, in the period from April to December 1985. Among the total 30 patients, 22 were preoperatively infected [11 thoracic empyema, 5 lobar pneumonia, 2 lung abscess, 2 bronchiectasis, one acute pyelonephritis with ureter stone and one rheumatic carditis], and 8 were not infected preoperatively [Table 1, 2]. Of the preoperatively infected group, 11 cases [50%] were culture positive [4 staphylococcus, 3 pseudomonas, 2 Serratia group, and one E. coli], and preoperatively non-infected group [8 cases] revealed expectedly negative findings on bacterial culture. All of the culture positive bacteria were sensitive to Augmentin on disc culture sensitivity test except one case of E. coli. Daily doses of intravenous Augmentin were 2.-1-6.0gm divided in 2-5 injections. Every injection administered [1.2gm at Augmentin dissolved in 20ml distilled water] slowly for more than 20 minutes. Duration of injection was variable according to the clinical conditions from minimum 5 to maximum 31 days. The results of antibiotic treatment with Augmentin and some other antibiotic combinations pre- and postoperatively were subgrouped as EXCELLENT, EFFECTIVE, and FAILURE. Clinical criteria of the therapeutic result were symptomatic, objective and laboratory improvement. 8 cases were excellent, 13 effective, and one failure among the preoperatively infected group, and all 8 cases of the preoperatively non-infected group were effective as pro;hylactive antibiotic therapy. Overall effective ratio was 97% in both subgroup. There was no side effect clinically and laboratory study including liver and kidney function test during and after the I.V. administration of Augmentin. Oral swallow tablets which were administered after discharge from hospital also revealed good effects with some degree of gastrointestinal trouble.

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해안간척지 토양의 생물학적 토성 개량에 관한 연구 3 (Biological improvement of reclaimed tidal land soil (III))

  • 홍순우;하영칠;최영길
    • 미생물학회지
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    • 제7권1호
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    • pp.29-40
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    • 1969
  • Two kinds of organic materials, powders of Salicornia and Oryza sativa L. wre added as a source of organic matter to the suspensions of saline soils(soil : water = 1:3) to be 4 per cent of dried saline soil grams. And then, the samples were incubated at $28^{\circ}C$ to improve the decomposition of organic materials by soil microflora. Resutls of this experiment are summarized as followings : 1) The pH of soil suspension showed its highest value on the second or third week after the treatments, which were similar to those of the soil microflora. Results of this experiment are summarized as follwings : 1) The pH of soil suspension showed its highest value on the second ot third week after the treatments, which were similar to those of the soil microflora populations. 2) Salinity increased up to the second week and the highest value of it appeared in the samples which were treated with the powder of Salicornia. In general, the salinity of all samples decreased on the third week after the treatment. The fact was assumed the possibilities of desalination from saline soil by the microbial actions. 3) Soil microflora such as bacteria, actinomycetes and fungi, were determined its populations soil microflora is to act as decomposer in soil. Both of the bacteria and actinomycytes population showed in the third weak after the tratment. In general, 30-years old of saline soil contained microbial population much more than those of 5-year old of saline soil. Salicornia powder favored the increase of both the bacteria and fungal population, and Oryza sativa L. seemed to have been a great role in increase of actinomycetes. Especially, fungal population of the untreated soil suspension contained higher microbial populations more than those of the soils treated with both of the organic materials. 4) Sugar contents of soil suspesions decreased remarkably on the first week after the treatments. 5) The amount of nitrate had similar tendency to those of population changes of soil microflora. Total acidity decreased continuously and the amount of potassium showed its highest value on the third week treatment. However, the amount of phosphorus was determined to be insignificant.

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Omega-7 producing alkaliphilic diatom Fistulifera sp. (Bacillariophyceae) from Lake Okeechobee, Florida

  • Berthold, David Erwin;Rosa, Nina de la;Engene, Niclas;Jayachandran, Krish;Gantar, Miroslav;Laughinghouse, Haywood Dail IV;Shetty, Kateel G.
    • ALGAE
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    • 제35권1호
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    • pp.91-106
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    • 2020
  • Incorporating renewable fuel into practice, especially from algae, is a promising approach in reducing fossil fuel dependency. Algae are an exceptional feedstock since they produce abundant biomass and oils in short timeframes. Algae also produce high-valued lipid products suitable for human nutrition and supplement. Achieving goals of producing algae fuels and high-valued lipids at competitive prices involves further improvement of technology, especially better control over cultivation. Manipulating microalgae cultivation conditions to prevent contamination is essential in addition to promoting optimal growth and lipid yields. Contamination of algal cultures is a major impediment to algae cultivation that can however be mitigated by choosing extremophile microalgae. This work describes the isolation of alkali-tolerant / alkaliphilic microalgae native to South Florida with ideal characteristics for cultivation. For that purpose, water samples from Lake Okeechobee were inoculated into Zarrouk's medium (pH 9-12) and incubated for 35 days. Selection resulted in isolation of three strains that were screened for biomass and lipid accumulation. Two alkali-tolerant algae Chloroidium sp. 154-1 and Chlorella sp. 154-2 were poor lipid accumulators. One of the isolates, the diatom Fistulifera sp. 154-3, was identified as a lipid accumulating, alkaliphilic organism capable of producing 0.233 g L-1 d-1 dry biomass and a lipid content of 20-30% dry weight. Lipid analysis indicated the most abundant fatty acid within Fistulifera sp. was palmitoleic acid (52%), or omega-7, followed by palmitic acid (17%), and then eicosapentanoic acid (15%). 18S rRNA phylogenetic analysis formed a well-supported clade with Fistulifera species.

고과당식이 랫드모델에서 복분자 투여에 의한 대사증후군 개선효과 (Beneficial Effect of Rubus Coreanus Miq in a Rat Model of High Fructose Diet-induced Metabolic Syndrome)

  • 고민철;이윤정;윤정주;강대길;이호섭
    • 동의생리병리학회지
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    • 제29권1호
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    • pp.11-17
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    • 2015
  • Overconsumption of fructose results in dyslipidemia, hypertension, which have documented as a risk of cardiovascular diseases. This experimental study was designed to investigate the beneficial effects of Rubus coreanus Miq.(RCM) in high-fructose diet-induced metabolic syndrome. Animals were divided into three groups; Control group fed regular diet and tap water, fructose groups were fed the 65% high-fructose (HF) diet with/without RCM 100 mg/kg/day for 8 weeks, respectively. Chronic treatment with RCM significantly decreased body weight, fat weight and adipocyte size. Moreover, RCM significantly prevented the development of the metabolic disturbances such as hyperlipidemia and hypertension. RCM also led to increase in high density lipoprotein level in the HF group. In addition, RCM suppressed vascular cell adhesion molecule-1 (VCAM-1) expression and significantly recovered the levels of endothelial nitric oxide synthase (eNOS) expression in aorta. These results demonstrates that RCM may be a beneficial therapeutic for metabolic syndrome through the improvement of hyperlipidemia, obesity, and hypertension.

Biodistribution of 99mTc Tricarbonyl Glycine Oligomers

  • Jang, Beom-Su;Lee, Joo-Sang;Rho, Jong Kook;Park, Sang Hyun
    • Toxicological Research
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    • 제28권4호
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    • pp.235-240
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    • 2012
  • $^{99m}Tc$ tricarbonyl glycine monomers, trimers, and pentamers were synthesized and evaluated for their radiolabeling and in vivo distribution characteristics. We synthesized a $^{99m}Tc$-tricarbonyl precursor with a low oxidation state (I). $^{99m}Tc(CO)_3(H_2O)_3^+$ was then made to react with monomeric and oligomeric glycine for the development of bifunctional chelating sequences for biomolecules. Labeling yields of $^{99m}Tc$-tricarbonyl glycine monomers and oligomers were checked by high-performance liquid chromatography. The labeling yields of $^{99m}Tc$-tricarbonyl glycine and glycine oligomers were more than 95%. We evaluated the characteristics of $^{99m}Tc$-tricarbonyl glycine oligomers by carrying out a lipophilicity test and an imaging study. The octanol-water partition coefficient of $^{99m}Tc$ tricarbonyl glycine oligomers indicated hydrophilic properties. Single-photon emission computed tomography imaging of $^{99m}Tc$-tricarbonyl glycine oligomers showed rapid renal excretion through the kidneys with a low uptake in the liver, especially of $^{99m}Tc$ tricarbonyl triglycine. Furthermore, we verified that the addition of triglycine to prototype biomolecules (AGRGDS and RRPYIL) results in the improvement of radiolabeling yield. From these results, we conclude that triglycine has good characteristics for use as a bifunctional chelating sequence for a $^{99m}Tc$-tricarbonyl-based biomolecular imaging probe.