• 제목/요약/키워드: chemical indicator

검색결과 331건 처리시간 0.03초

녹색경영 평가지표를 적용한 국내·외 정유/화학기업의 녹색경영 비교 연구 (A Study on Green Management of Petroleum Refining and Chemical Companies Applying to Assessment Indicator of Green Management)

  • 백장현
    • 한국기후변화학회지
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    • 제3권2호
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    • pp.101-116
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    • 2012
  • 녹색경영은 기후변화 대응이 전 세계적 이슈로 부각되면서 기존의 환경경영에 온실가스 저감, 대체에너지 개발 등 저탄소 녹색성장 요소가 추가된 확장된 개념으로 국내 외적으로 기업의 녹색경영 성과 측정에 대한 논의가 확산되고, 기업의 환경관리 수준 파악, 분석 및 평가의 중요성이 대두되면서 다양한 형태의 녹색경영 성과측정지표 체계가 개발되어 운영되고 있다. 하지만, 녹색경영에 관련한 구체적인 실행 방법론 제시는 미흡한 실정이다. 이에 본 연구에서는, 제시된 평가지표에 따라 기업간 녹색경영 수준 비교가 객관적으로 평가되게 하기 위해 가중치 산정을 위한 전문가 설문조사를 실시하였고, AHP(Analytic Hierarchy Process) 분석을 적용하였다. 국내외 10개 주요 정유/화학기업을 평가대상으로 선정하여 지속가능성 보고서 및 관련 문헌자료 등을 분석하였으며, 가중치가 부여된 세부 지표항목에 의거한 평가지표별 기업의 평가점수 도출 및 기업간 점수차이 분석을 실시 하였다.

화학적 특성과의 비교 분석을 통한 프랙탈 차원을 이용한 풍화도 추정 (The Estimation of the Extent of Weathering using Fractal Dimension through a Comparison with Chemical Characteristic)

  • 노수각;손영환;봉태호;박재성
    • 한국농공학회논문집
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    • 제54권2호
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    • pp.127-135
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    • 2012
  • The processes of chemical and physical weathering occur simultaneously. The objective of this study was to estimate the degree weathered using fractal dimension through comparison with chemical characteristic of soil samples from Pohang (PH) and Kimpo (KP). Comparing chemical characteristics with fractal dimension, $SiO_2$, $Na_2O$, $K_2O$ content decreased and loss of ignition increased as fractal dimension increased. And fractal dimension showed high correlation with CWI while ATI, STI CIW, PI, CIA and RR demonstrated different degrees of correlation with fractal dimension. The tendency of the changes in oxide content and chemical weathering index with increasing fractal dimension appeared to be similar with the chemical changes due to weathering. Therefore, fractal dimension could be a good indicator representing the extent of weathering and chemical changes.

제주도 연안 해역의 오염지표세균의 분포 (Distribution of Indicator Bacteria in Seawater off the Coast of Jeju Island)

  • 노형진;임윤진;김아란;김남은;김영재;박노백;황지연;권문경;김도형
    • 한국수산과학회지
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    • 제51권4호
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    • pp.450-455
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    • 2018
  • We examined correlations of the density of fish farms with the distributions of indicator bacteria (Escherichia coli, fecal streptococci) and a bacterial fish pathogen (Streptococcus parauberis) off the coastline of Jeju Island. Seawater samples were collected at four coastal sites on the Island [Aewol (control), Gujwa, Pyoseon and Daejeong] in June, August and October 2016. The indicator bacteria were generally more frequently isolated from samples taken in August when water temperatures and human activities on nearby beaches were highest. Although fish farms were least common at Daejeong, the numbers of isolated fecal indicator bacteria were highest in the seawater and effluent water collected from this site. Hence, fish farms were not likely major contributors of indicator bacteria at Daejeong. We found discrepancies between the isolated bacterial counts and the predicted bacterial copy numbers deduced from our qPCR results, indicating that this pathogen may exist in a viable but non-culturable (VBNC) state in seawater. Thus, livestock wastewater and chemical fertilizer loading off Jeju Island may negatively impact seawater quality more than the effluent released from fish farms does.

Isatin $\alpha-chloride$에 의한 인디고계 염료의 합성 (The Synthesis of Indigoid-Type Dyes Based on Isatin $\alpha-Chloride$)

  • 박수열;신승림;신종일;전근
    • 한국염색가공학회지
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    • 제19권3호
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    • pp.6-11
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    • 2007
  • The indigoid-type dyes based on isatin $\alpha-chloride$ were synthesized and the dyes were discussed with relevance to the "H-chromophore" or "cross-conjugated chromophore". The color-changed properties of the dyes were also investigated by means of visible absorption spectra. The novel dyes from isatin $\alpha-chloride$ are of theoretical interest and such dyes can be used as continuous pH indicators in acid/base titrimetric analyses.

시비방법별 벼 재배에 따른 전과정평가 방법을 적용한 환경영향 평가 (Application of the Life Cycle Assessment Methodology to Rice Cultivation in Relation to Fertilization)

  • 신중두;임동규;김건엽;박문희;고문환;엄기철
    • 한국환경농학회지
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    • 제22권1호
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    • pp.41-46
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    • 2003
  • Consoli가 설명한 것처럼 전과정평가의 개념 및 일반적인 정의에 따르면, 전과정평가는 농업생산에 관련된 환경영향을 평가하는데 부합하는 방법이라고 생각되며, 특별히 전과정평가방법인 Eco-indicator 95는 농업 체재에 대한 환경영향을 분석하는데 적절한 기법인 것으로 입정되었다. Eco-indicator 95 method를 이용하여 지구온난화 및 수계부영양화와 관련된 시비체계에 따른 벼 재배에 대해 비교할만한 분석체계를 이루었다. 그렇지만 본 연구에서 전과정평가 항목에 기록된 모든 관련 정보가 환경 영향에 고려되지 않았기 때문에 Eco-indicator 95 method를 농업생산 체계에 적용할 때 몇 가지 난제에 부닥친다. Eco-indicator 95 method에 토양 및 자원의 이용과 같은 몇 몇 중요한 환경적인 문제가 포함되지 않았으며, 이 방법의 다른 문제는 환경 평가를 위하여 현장 정밀연구가 수행되지 않았다는 것이다. 그렇지만 본 연구에서 얻어진 생태지표 지수를 이용하여 벼 재배에 따른 시비방법 간의 차이점을 나타내기에 충분하다고 여겨지며, 가장 높은 생태지표 지수를 나타낸 화학비료를 시용한 구에서 가장 큰 환경영향이 관측되었고, 이러한 차이점은 주로 화학비료 투입에 의한 토양중의 높은 인산 함량의 축적 때문인 것으로 여겨진다. 분석한 시비체재는 특별히 지구온난화 보다는 수계의 부영양화의 환경적인 문제에 기여되는 것으로 나타났으므로 질소 시용비율 및 시용기술 이외에 액비 시용에 따른 양분 용탈이 수계 환경에 명확히 영향을 미치는 것으로 나타났다.

Thallium(Ⅰ)-Selective Membrane Potentiometric Sensor Based on Dibenzyldiaza-18-Crown-6

  • Khayatian, Gholamreza;Shariati, Satar;Salimi, Abdollah
    • Bulletin of the Korean Chemical Society
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    • 제24권4호
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    • pp.421-425
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    • 2003
  • A new thallium(Ⅰ) selective electrode based on dibenzylidaza-18-crown-6 as mambrane carrier was successfully prpared. The electrode exhibitis a near-Nernstian response for $ T1^+$ ions over a wide concentration range from $1.0×10^{15}-1.0×10^{-1}$M at 25℃, and was found to be selective, precise and useable within the pH range 4.0-11.0. The electrode was successfully used as an indicator electrode in potentiometric titration of thallium ions.

Effect of Chemical Passivation Treatment and Flow on the Corrosion of 304 Stainless Steel in Hydrochloric Acid Solution

  • Zhao, Jie;Cheng, Cong Qian;Cao, Tie Shan
    • Corrosion Science and Technology
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    • 제14권6호
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    • pp.273-279
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    • 2015
  • Effects of passive film quality by chemical passivation and solution flow on the corrosion behavior of 304 stainless steel in HCl solution were investigated using a coloration indicator, and by corrosion weight loss, electrochemical polarization and element dissolution measurements. A high redness degree suggests a low passive-film integrity for 304 stainless steel following air exposure, while the minimum redness degree for the samples after chemical passivation suggests a high passive-film integrity. In the static condition, samples subjected to air exposure exhibited a high corrosion rate and preferential dissolution of Fe. Chemical passivation inhibited the corrosion rate due to the intrinsically high structural integrity of the passive film and high concentrations of Cr-rich oxides and hydroxide. Solution flow accelerated corrosion by promoting both the anodic dissolution reaction and the cathodic reaction. Solution flow also altered the preferential dissolution to fast uniform dissolution of metal elements.

Percentage of motile spermatozoa at 22 hours after swim-up procedure: An indicator for intracytoplasmic sperm injection?

  • Inoue, Taketo;Yonezawa, Yukiko;Sugimoto, Hironobu;Uemura, Mikiko;Ono, Yuri;Kishi, Junji;Emi, Nobuyuki;Ono, Yoshiyuki
    • Clinical and Experimental Reproductive Medicine
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    • 제43권3호
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    • pp.157-163
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    • 2016
  • Objective: The decision to use in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), or split insemination (IVF-ICSI) in the first cycle is based on the number of motile sperm. Hence, total fertilization failure (TFF) often occurs during IVF cycles, despite normozoospermia. To investigate whether the cumulative motile swim-up spermatozoa percentage at 22 hours post-insemination (MSPPI) is an indicator for ICSI, we analyzed TFF, fertilization, blastocyst development, chemical pregnancy, clinical pregnancy, and live birth rates. Methods: This prospective study was performed using data obtained from 260 IVF cycles. At 22 hours after insemination, the remaining swim-up spermatozoa were observed and divided into six groups according to MSPPI (<10%, 10% to <30%, 30% to <50%, 50% to <70%, 70% to <90%, and 90% to 100%). Results: Regardless of the ejaculated motile sperm concentration ($0.6-280{\times}10^6/mL$ motile spermatozoa), the incidence of TFF significantly increased when MSPPI was <10%, and the fertilization rate significantly decreased when MSPPI was <30%. We found that cumulative MSPPI correlated with the cumulative fertilization rate (Spearman correlation, 0.508, p<0.001). Regarding embryo development, we observed no significant differences in the rates of blastocyst development, chemical pregnancy, clinical pregnancy, or live birth among all groups. Conclusion: Our findings suggest that MSPPI is a viable indicator for split IVF-ICSI and ICSI. Taken together, by employing the MSPPI test in advance before IVF, ICSI, or split IVF-ICSI cycles, unnecessary split IVF-ICSI and ICSI may be avoided.

A Liquid-Based Colorimetric Assay of Lysine Decarboxylase and Its Application to Enzymatic Assay

  • Kim, Yong Hyun;Sathiyanarayanan, Ganesan;Kim, Hyun Joong;Bhatia, Shashi Kant;Seo, Hyung-Min;Kim, Jung-Ho;Song, Hun-Seok;Kim, Yun-Gon;Park, Kyungmoon;Yang, Yung-Hun
    • Journal of Microbiology and Biotechnology
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    • 제25권12호
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    • pp.2110-2115
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    • 2015
  • A liquid-based colorimetric assay using a pH indicator was introduced for high-throughput monitoring of lysine decarboxylase activity. The assay is based on the color change of bromocresol purple, measured at 595 nm in liquid reaction mixture, due to an increase of pH by the production of cadaverine. Bromocresol purple was selected as the indicator because it has higher sensitivity than bromothymol blue and pheonol red within a broad range and shows good linearity within the applied pH. We applied this for simple determination of lysine decarboxylase reusability using 96-well plates, and optimization of conditions for enzyme overexpression with different concentrations of IPTG on lysine decarboxylase. This assay is expected to be applied for monitoring and quantifying the liquid-based enzyme reaction in biotransformation of decarboxylase in a high-throughput way.

훼로시안化 칼리움에 依한 鐵의 微量適定法 (Volumetric Determination of a small amount of Iron with Potassium Ferrocyanide)

  • 원종훈
    • 대한화학회지
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    • 제5권1호
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    • pp.42-47
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    • 1961
  • A titration of a small amount of iron with standard potassium ferrocyanide using potassium thiocyanate as indicator has been studied. A sample solution containing $0.1{\sim}1.0$ mg. $Fe^{3+}$ in 60 ml. is pipeted into 100 ml. Erlenmyer flask and the pH of the solution is adjusted to $1.5{\sim}3.0$ with 0.1 N or 1 N $HNO_3$ and $NH_4OH.$ To this solution one ml. of 1 M KCNS solution as indicator is added. The solution colored by iron thiocyanate complex is titrated with 1/200 M or 1/400 M standard solution of potassium ferrocyanide from a 5 ml. micro-buret. Near the end point, when the color of sample changes from deep red to green, about 20 ml. of ether is added and shake the flask vigorously. The red color is extracted to the ether layer. To settle the ether layer a few drops of ethanol is added and then standard solution is added dropwise and shake vigorously. The end point is reached when the color of the ether layer disappears owing to the quantitative formation of $Fe_4[Fe(CN)_6]_3.$ In this titration, 0.lmg. of $Fe^{3+}$ can be determined within 1.0% of titration error, provided the following optimum conditions, i.e., pH $1.5{\sim}3.0$, final concentration of KCNS indicator; $0.01{\sim}0.02M$, at room temperature. The titration found to be interfered by the presence of slightly soluble salts, stable complex forming ions and the ions which would be reduced by ferrocyanide or oxidized by ferric ion.

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