• Title/Summary/Keyword: TCB

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Photodegradation Study of 1, 3, 5-Trichlorobenzene Using Pt (IV)/AMM-Ti Photocatalyst in Humic Acid (HA) Solution (Pt (IV)/AMM-Ti 광촉매를 이용한 휴믹산에서의 1, 3, 5-Trichlorobenzene의 광분해반응의 연구)

  • Kim, Jae-Hyoun
    • Environmental Analysis Health and Toxicology
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    • v.15 no.3
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    • pp.93-98
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    • 2000
  • The photosatalytic oxidation of the model compound, 1, 3, 5-trichlorobenzene (1, 3, 5-TCB) has been investigated employing photolysis. The effects of parameters such as illumination time, initial concentration, pH and HA were investigated. Pt(IV)/AMM-Ti particles used as a photocatalyst showed a time-dependent enhancement of the photooxidation/reduction activity in the presence of HA.

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The Effect of the Mixture of Nonionic Surfactant and Bioactive Agent for Surfactant-enhanced Soil Flushing (SESF) of TCB Contaminated Soil

  • Lee, Dal-Heui;Cho, Heuy Nam;Chung, Sung-Lae
    • Journal of Soil and Groundwater Environment
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    • v.19 no.2
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    • pp.1-6
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    • 2014
  • The objective of this study was to find the effect of the mixture of the nonionic surfactant and bioactive agent that solubilizes trichlorobenzene (TCB) present as a contaminant for surfactant-enhanced soil flushing (SESF). Three different nonionic surfactants and two different bioactive agents were obtained from four companies. Separate funnel experiments and shaker table agitation / centrifugation experiments were used for the test. Based on the separate funnel experimental results, three suitable mixture agents (APG + OSE, Brij 35 + MOSE, T-Maz 60 + MOSE) were selected. In the shaker table agitation / centrifugation experiments, these three different mixture agents were reduced to one (T-Maz 60 +MOSE). The maximum removal (95%) of TCB was obtained using a mixture of the nonionic surfactant and bioactive agent. Therefore, the used test methods and results can be used for SESF.

The Acute Toxicity of 1, 2, 4-Trichlorobenzene in Sprague-Dawley Rats Depleted of Glutathione by Treatment with Buthionine Sulfoximine (BSO 유도 루타치온 저감 흰쥐에서 1, 2, 4-trichlorobenzene의 급성독성에 관한 연구)

  • 안영수;권명희;이정섭;김정우;김대선;류홍일;강인구
    • Environmental Analysis Health and Toxicology
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    • v.11 no.1_2
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    • pp.41-47
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    • 1996
  • 1, 2, 4-Trichlorobenzene (1, 2, 4-TCB) is used as a dye carrier, as an intermediate in the synthesis of herbicides, as a flame retardant, and for other purpose. After a single oral administration of 1, 2, 4-TCB (200 mg/kg, 400 mg/kg) in rats, toxic effects were studied by means of serum biochemical and heatological analysis, and liver calcium concentration. Administration of 1, 2, 4-TCB resulted in dose-dependent liver and kidney damage as estimated by increased serum alanine aminotransferase (ALT) activities, liver calcium concentration and blood urea nitrogen (BUN). Pretreatment with DL-buthionine sulfoximine (BSO, 2 mmol/kg, i.p. ) considerably decreased liver glutathione concentration, which was accompanied by markedly elevated serum ALT activites. It is well-known that toxicity of halogenated benzene such as bromobenzene, 1, 4-dichlorobenzene is increased by pretreatment of henobarbital (PB), and protected by pretreatment of cytochrome P450 inhibitor including metyrapone (MP). However, there was no obvious alterations in toxicity of 1, 2, 4-TCB by pretreatment of phenobarbital or metyrapone. In comparison with control group, treatment groups exhibited significant changes in some parameters of hematological analysis but all hematological values remined within normal ranges.

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The Acute Toxicity of 1,2,4-Trichlorobenzene in Sprague-Dawley Rats Depleted of Glutathione by Treatment with Buthionine Sulfoximine (BSO 유도 글루타치온 저감 흰쥐에서 1,2,4-trichlorobenzene의 급성독성)

  • 안영수
    • Toxicological Research
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    • v.12 no.1
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    • pp.29-34
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    • 1996
  • 1,2,4-trichlorobenzene (1,2,4-TCB) is used as a dye carrier, an intermediate in the syn[hesis of herbicides, aflame retardant, and for other purpose. After a single oral administration of 1,2,4-TCB (200 mg/kg, 400 mg/kg) in rats, toxic effects were studied by means of serum biochemical and hematological analysis, and liver calcium concentration. Administration of 1,2,4-TCB resulted in dose-dependent manner liver and kidney damage being suggested by increased serum alanine aminbtransferase (ALT) activities, liver calcium concentration and blood urea nitrogen (BUN). Pretreatment with DL-buthionine sulfoximine (BSO, 2 mmol/kg, i.p.) considerably decreased liver glatathione concentration, which was accompanied by markedly elevated serum ALT activites. It is well-known that toxicity of halogenated benzene such as bromobenzene, 1,4-dichlorobenzene is increased by pretreatment of phenobarbital, and protected by pretreatment of cytochrorn P450 inhibitor including metyrapone. However, there were no obvious alterations in toxicity of 1,2,4-TCB by pretreatment of phenobarbital or metyrapone. In comparison with control group, treatment groups exhibited significant changes in some parameters of hematological analysis but all hematological values remained within normal ranges.

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Effect of Surfactant Concentration and pH on Surfactant-Enhanced Remediation in lowa Soil Contaminated by TCB (삼염화벤젠으로 오염된 아이오와토양의 복원시 계면활성제의 농도와 pH의 영향)

  • Dal-Heui Lee;Robert D. Cody
    • Economic and Environmental Geology
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    • v.35 no.2
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    • pp.149-154
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    • 2002
  • Column tests were carried out to examine the effect of surfactant solution conditions on surfactant-enhanced remediation of contaminated soil. The selected conditions of the surfactant solution were concentration and pH. 1,2,4-trichlo-robenzene (TCB) was chosen as the model hydrophobic organic substances. Sodium diphenyl oxide disulfonate (DOSL) and octylphenoxypoly ethoxyethanol (OPEE) surfactants were selected for this study. Two Iowa soils, Fruitfield sand and Webster clay loam, were leached with surfactant solution. The test results revealed that an optimum condition was achieved for 4 %(v/v) of concentration and 10 of pH, respectively. The maximum recoveries of added TCB (93-98%) were obtained when optimal conditions of each surfactant solution parameter were simultaneously met. The optimum conditions of these parameters may be useful for surfactant-assisted remediation in soil contaminated by TCB.

Implementation of Thyristor Circuit Breaker for Microgird Applications (마이크로그리드를 위한 Thyristor Circuit Breaker의 구현)

  • Kim, Jin-Young;Kim, Seul-Gi;Kim, In-Dong;Nho, Eui-Cheol;Kim, Heung-Geun
    • Proceedings of the KIPE Conference
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    • 2011.07a
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    • pp.516-517
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    • 2011
  • 마이크로그리드는 분산전원 또는 계통의 Sag/Swell 및 단락사고, 지락사고 등으로 인한 정전 발생 시에 사고 지점을 제외한 독립운전이 가능해야 한다. 따라서 사고 발생지점을 신속하게 분리할 수 있는 기술이 필요하다. 이러한 배경으로 본 연구에서는 신속하게 사고지점을 차단하는 고속차단 시스템(TCB :Thyristor Circuit Breaker)을 제안한다. 도통손실이 작고 경제적인 Thyristor를 이용하여 25 [kVA]급 TCB 시스템을 제작하고 사고를 모의하여 사고 발생 시의 TCB 시스템 동작특성에 대해 연구한다.

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A Novel Oxidation Model with Photolysis for Degradation of Trichlorobenzenes (TCBs)

  • Kim, Jae-Hyoun
    • Environmental Analysis Health and Toxicology
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    • v.12 no.3_4
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    • pp.1-13
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    • 1997
  • First- and second-order kinetic oxidation rates of trichlorobenzenes (TCBs) were obtained and compared by a chemical activation system (CAS) which mimics mixed functional oxidase activity. The system consists of EDTA, ferrous sulfate, ascorbic acid, and $H_2O_2$ in potassium phosphdte buffer (monobasic at pH 7.4). The rate of transformation in CAS was enhanced in the presence and absence of catalase in the sequence 1, 2, 3-TCB < 1, 2, 4-TCB < 1, 3, 5-TCB. In general, the rates of degradation were greater in the test media with catalase. The effect of photolysis on the degradation of the TCBs with the CAS were examined. Sensitized photolysis with nitrite, Fenton's reagent, TiO$_2$ and triethylamine (TEA) studied in concert with the CAS demonstrated significant enhancement of the degradation rate of TCBs. Disappearance rates of TCBs in CAS with prior photolysis or prior photosensitization were at least 10-fold higher than the sum of the rate for each single experiment. This study proves that the combination of the CAS and photolysis can be used as a suitable technique for enhancing degradation of TCBs in aqueous systems.

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Tracking Cold Blocks for Static Wear Leveling in FTL-based NAND Flash Memory (메모리에서 정적 마모도 평준화를 위한 콜드 블록 추적 기법)

  • Jang, Yonghun;Kim, Sungho;Hwang, Sang-Ho;Lee, Myungsub;Park, Chang-Hyeon
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.3
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    • pp.185-192
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    • 2017
  • Due to the characteristics of low power, high durability and high density, NAND flash memory is being heavily used in various type of devices such as USB, SD card, smart phone and SSD. On the other hand, because of another characteristic of flash cell with the limited number of program/erase cycles, NAND flash memory has a short lifetime compared to other storage devices. To overcome the lifetime problem, many researches related to the wear leveling have been conducted. This paper presents a method called a TCB (Tracking Cold Blocks) using more reinforced constraint conditions when classifying cold blocks than previous works. TCB presented in this paper keeps a MCT (Migrated Cold block Table) to manage the enhanced classification process of cold blocks, with which unnecessary migrations of pages can be reduced much more. Through the experiments, we show that TCB reduces the overhead of wear leveling by about 30% and increases the lifetime up to about 60% compared to BET and BST.

GC/MS analysis of hydrocarbons and 2-alkylcyclobutanones from γ-ray irradiated walnut (Juglans nigra) (호두(Juglans nigra)의 감마선 조사에 따른 hydrocarbon류와 2-alkylcyclobutanone류의 GC/MS 분석)

  • Nho, Eun Yeong;Choi, Ji Yeon;Kim, Kyong Su
    • Food Science and Preservation
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    • v.21 no.6
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    • pp.859-865
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    • 2014
  • This study was conducted to analyze the hydrocarbons and 2-alkylcyclobutanones as marker compounds in walnuts after the walnuts' exposure to ${\gamma}$ irradiation. The samples were irradiated with gamma rays at 0, 1, 3, 5, 7, and 10 kGy doses. The lipids were extracted via soxhlet extraction using hexane, and were separated by florisil column and identified via gas chromatography / mass spectrometry (GC/MS). The hydrocarbons that were detected were 8-heptadecene ($C_{17:1}$) and 1,7-hexadecadiene ($C_{16:2}$) from oleic acid and 8,11-heptadecadiene ($C_{17:2}$) and 1,7,10-hexadecatriene ($C_{16:3}$) from linoleic acid. The 2-alkylcyclobutanones that were detected were 2-dodecylcyclobutanone (DCB) from palmitic acid, 2-tetradecylcyclobutanone (TCB) from stearic acid, 2-(5'-tetradecenyl)cyclobutanone (TECB) from oleic acid, and 2-(5',8'-tetradecadienyl)cyclobutanone (5',8'-TCB) from linoleic acid. The correlation between the irradiation dose and the concentrations of the hydrocarbons and 2-alkylcyclobutanones in the walnuts was found to be linear. The radio-induced hydrocarbons and 2-alkylcyclobutanones were clearly detected in the irradiated walnuts at 1 kGy and above, but not in the non-irradiated ones. The major hydrocarbons obtained after irradiation were 8-heptadecene from oleic acid and 8,11-heptadecadiene and 1,7,10-hexadecatriene from linoleic acid, and the major 2-alkylcyclobutanones were TECB from oleic acid and 5',8'-TCB from linoleic acid. Therefore, these major compounds were concluded to be the marker compounds for determining the irradiated and non-irradiated samples.

A Study on Correlation Analysis between TCB Evaluation Indicator and Technology Rating (기술신용평가기관(TCB) 효율성 제고 및 기업기술력 강화를 위한 평가지표간 상관관계 분석연구)

  • Son, Seokhyun;Kim, Jaeyoung;Kim, Jaechun
    • Journal of Technology Innovation
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    • v.25 no.4
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    • pp.1-15
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    • 2017
  • In 2014, the Financial Services Commission designated the Tech Credit Bureaus(TCB) to issue technical credit evaluation reports. The Five credit rating agencies, KEB Hana Bank and others have issued the technical credit reports since the summer in 2014. Meanwhile, the technology evaluation model of KEB Hana Bank consists of 25 detailed evaluation items. These item classes are weighted and the technology rating is systematically. The technology rating is combined with the credit rating to calculate the technology-credit rating. In this paper, we analyzed the 406 evaluation results issued by KEB Hana Bank. Based on the number of years of work experience, company managerial years, technical personnel score, the possession of R&D department, the amount of R&D investment, the number of certifications, and the number of patents, the Correlation between the above items and the technical grade was analyzed. It was found that quantitative indicators such as the presence of R&D department, patent numbers, and R&D investment expenses had a significant effect on the company's technology grade, and in particular, the presence of R&D department was shown a high correlation with the technology rating.