• 제목/요약/키워드: Presence Agent

검색결과 739건 처리시간 0.033초

유기물을 함유한 폐수의 물리화학적 처리에 관한 연구 (Physicochemical Treatment of Waste Water Containing Organic Materials)

  • 이한철
    • 한국산학기술학회논문지
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    • 제14권1호
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    • pp.493-498
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    • 2013
  • 합성 고분자 화합물의 생산과 ethanolamine(ETA, 원자력발전소에서 사용하는 pH 조절제)는 수질을 오염시키는 폐수를 발생한다. 본 연구는 유기물에 의해 유발된 COD를 감소시키기 위한 물리 화학적 처리법과 처리 약품을 개발하였다. $FeCl_2$$MgCl_2$를 1/1로 혼합하여 혼합응집제를 사용함이 COD 제거효율이 가장 좋은 결과를 얻었다. 유기물을 함유한 폐수처리에 복합응집제를 주입함으로써 COD제거율이 80%이상으로 나타났다.

산성황산동 용액 내에서 동판위에 녹청 형성에 관한 기초적 조사 (An Investigation on the Patination of Copper in Acidic Copper Sulfate Solution)

  • 윤승열
    • 한국표면공학회지
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    • 제5권3호
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    • pp.77-85
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    • 1972
  • A method of preparation of synthetic ignorgaic coating on copper (patina) has been presented . An Eh--pH diagram was constructed for the present Cu-H2O-SO$_4$ system using the most recently available thermodynamic data. In the path of the patination at room temperature the general behaviour of copper in acidic copper sulfate solutions with potassium chlorate as an oxidizing agent appeared to follow those predictable in this Eh-pH diagram. In the presence 0.05 molar cupric sulfate at a temperature of about 28$^{\circ}C$ a green brochantite (CuSO$_4$$.$3Cu(OH)$_2$) layer was formed on copper sheet in 20 days. In a solution having an initial pH of 3.5 the development of a brochantite coating has been observed to take place in two stages. In the first, a layer of cuprous oxide formed on the copper at a relatively rapid rate. In the ensuing step the outer layer of cuptrite was oxidized at much slower rate to form brochantite. The syntetic coatings appeared to consist of crystal-lites of brochanitite growing perpendicular to the cuprose oxide surface. The outer tips of the -crystallites were reasily broken off and gave to the layer a rather chalky character. Underneath, at the brochantite Cu$_2$O interface, however, the green layers were firmely attached. The effect of reagent concentration , solution agitation , and moderate temperature increase were investigated to improve the quality of coating. So also in a qualitative way were the effect of light.

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Initial Protein Concentration and Residual Denaturant Concentration Strongly Affect the Batch Refolding of Hen Egg White Lysozyme

  • Guise, Andrew D.;Chaudhuri, Julian B.
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제6권6호
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    • pp.410-418
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    • 2001
  • The effects of several variables on the refolding of hen egg white lysozyme have been studied, Lysozyme was denatured in both urea, and guanidine hydrochloride(GuHCl), and batch refolded by dilution (100 to 1000 fold) into 0.1 M Tris-HCI, pH 8.2 mM EDTA 3 mM reduced glutathione and 0.3 mM oxidised glutathions. Refolding was found to be sensitive to temperature, with the highest refolding yield obtained at 50$\^{C}$. The apparent activation energy for lysozyme re-folding wasf ound to be 56kJ/mol, Refolding by dilution results in low concentrations of both de-naturant and reducing agent species. It was found that the residual concentrations obtained dur-ing dilution(100-fold dilution:[GuHCI]=0.06 mM, [DTT]=0.15 mM) were significant and could inhibit lysozyme refolding. This study has also shown that the initial protein concentration (1-10mg/mL) that is refolded is an important parameter. In the presence of residual GuHCl and DTT higher refolding yields were obtained when starting from higher initial lysozyme concentra-tions. This trend was reversed when residual denaturant components were removed from the re-folding buffer.

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Additive 공정을 이용한 미세 피치용 니켈 메탈마스크의 제조 및 특성평가 (Fabrication and Characterizations of Nickel Metal Mask with fine Pitch by Additive Process)

  • 박의철;임준형;김규태;박시홍;황수민;심종현;정승부;김봉수;주진호
    • 한국전기전자재료학회논문지
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    • 제20권11호
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    • pp.925-931
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    • 2007
  • We successively fabricated the Ni metal mask by additive method and evaluated the effects of wetting agents addition on the microstructure, hardness, and friction coefficient. In the process, the additive patterns with fine hole and pitch were made by photolithography technique and subsequently Ni plate was electroformed on the patterns. We found that the microstructure and mechanical properties were significantly varied when the different combinations of the wetting agents were used. When the wetting agents of both SF-1 and SF-2 were added, the microstructure consisted of crystal and amorphous phases, the grain size reduced to 5-40 nm, the RMS value decreased to 11.4 nm and the wear resistance improved. In addition, the hardness was as high as 638 Hv which is higher than that of commercial stainless steel mask and this improvement is probably due to the presence of amorphous Phase and fine grain size. The improvement of the wear resistance can provide a higher reliability and a longer service life.

Amiodarone으로 인한 Pulmonary Toxicity의 임상치험 1례 (The Clinical Report on the Amiodarone-induced Pulmonary Toxicity)

  • 손윤정;조영;류재환;이도형
    • 대한한방내과학회지
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    • 제24권2호
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    • pp.387-394
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    • 2003
  • Amiodarone is an effective antiarrhythmic agent because of its vasodilator actions. Nowadays it is mostly used to treat patients with severe cardiomyopathy or coronary artery disease complicated by disturbances in the supraventricular or ventricular rhythm. But, some doctors are reluctant to prescribe it because of its many side effects. These include impairment of liver and thyroid fuction and, rarely, damage to the lungs. Most of all, its most serious side effect is amiodarone-induced pulmonary toxicity, which can occur in up to 10% of patients, with mortality rates as high as 50%. We recently experienced one case of the patient with the Amiodarone-induced pulmonary toxicity. The clinical manifestations of the patient was cough, painful breathing, fever, presence of rales, decreased breath sounds, and sputum. We report the change of the patient's symptoms through both western medical treatment and oriental medical treatment.

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갈근(葛根)의 항산화작용에 의한 위점막 보호효과와 내인성 Sulfhydryl 화합물의 영향 (Antioxidants Effects and Roles of Endogenous Sulfhydryls in the Gastric Mucosal Protection of Puerariae Radix)

  • 최호정;신흥묵
    • 동의생리학회지
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    • 제14권2호통권20호
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    • pp.1-9
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    • 1999
  • Ethanol induces compoundhemorrhagic gastric lesions and causes a dose-dependent decrease in the concentration of endogenous nonprotein sulfhydryls in rat gastric mucosa. Sulfhydryl-containing drugs protect rats from ethanol - induced gastric lesions. Based on this findings, we investigated the involvement of sulfhydryl compounds in the antioxidant effects of Puerariae radix, a traditional herbal medicine, against ethanol - induced gastric lesions in the absence and presence of iodoacetamide(IDA. sulfhydryl blocking agent) in rats. respectively. Because of the known role of sulfhydryls in gastric cytoprotection, its role in gastric antioxidation was of intrest. In vitro, Puerariae radix extract(PRE) reduced linoleic acid autooxidation and exert DPPH radical scavenging effect. In vivo. PRE increased antioxidants(SOD, catalase. GSH) and reduced lipid peroxide level in ethanol-induced gastric mucosal lesions. But treatment with PRE plus IDA significantly inhibit the antioxidant effects such as SOD and GSH but did not affect catalase levels. These results suggest that Puerariae radix may play roles in the gastric cytoprotection through antioxidant effects and increase of SOD activity and GSH level are dependent of endogenous sulfhydryls.

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Inhibitory Effect of Vitamin C on Mutagenicity of 6-Sulfooxymethylbenzo[a]pyrene

  • Cho, Young-Sik;Hong, Sun-Taek;Chung, An-Sik
    • Toxicological Research
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    • 제12권1호
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    • pp.21-27
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    • 1996
  • Vitamin C has been well known to be a potential chemopreventive agent for several toxic compounds. It reduced the mutation frequencies of 6-sulfooxymethylbenzo[a]pyrene (SMBP) and 6hydroxymethylbenzo[a]pyrene (HMBP) in Salmonella typhimurium TA98 and TA100, indicating that corbic acid affects both frameshift and base-pair substitution mtltations. A similar type of dose-response relationship was shown in the V79 cells, although the inhibitory effect was less dramatic compared with that in S. typhimurium. However, SMBP or HMBP binding to calf thymus DNA was not affected by the presence of vitamin C, suggesting that SMBP seems to be much more reactive to calf thymus DNA than vitamin C. This was supported by migration pattern and fluorescence intensity of SMBP-modified plasmid on the gel. These restilts were not correlated with mutation tests in bacterial and mammalian cell systems. It has been already reported that vitamin C inactivates SMBP through the formation of covalently bound addact. It was found from HPLC analysis that the reaction between vitamin C and SMBP was accomplished within just 5 min and then produced the several products. These findings indicate that the beneficiary of vitamin C is not merely derived from the covalent adducts. On the other hand, the addition of DNA to incubation mixture reduced the amounts of vitamin C adducts while the magnitude of HMBP peak increased, suggesting that DNA accelerates the SMBP hydrolysis to intercept the interaction between SMBP and vitamin C or forms rapidly complex with SMBP.

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Molecular Identification of Adenocephalus pacificus (Cestoda) from Three Human Cases in Lima Province, Peru

  • Mondragon-Martinez, Aaron;Martinez-Rojas, Rosa;Garcia-Candela, Enrique;Delgado-Escalante, Abraham;Tantalean-Vidaurre, Manuel;Cruz-Neyra, Lidia
    • Parasites, Hosts and Diseases
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    • 제58권4호
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    • pp.457-460
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    • 2020
  • The Pacific tapeworm Adenocephalus pacifcus (syn. Diphyllobothrium pacificum) is a causative agent of diphyllobothriosis occurred in Pacific coast of South America, mainly in Peru. Source of infections are traditional meal from raw or undercooked marine fish such as "cebiche". We confirmed 3 new cases, one including scolex and the other two headless. A strobila 46 cm long without scolex was discharged from an 8-year-old boy before treatment. Specimens were confirmed morphologically by presence of tegumental protuberances on proglottids and small sized eggs. Partial sequence of cytochrome c oxidase subunit 1 gene was congruent with A. pacificus sequences.

동아시아 지역에 있어 전염성조혈기괴사증 바이러스 (IHNV)의 분자역학 및 병독성의 변화 (Molecular epidemiology and virulence changes of infectious hematopoietic necrosis virus (IHNV) in East Asia)

  • 니시자와 토요히코
    • 한국어병학회지
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    • 제31권1호
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    • pp.1-8
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    • 2018
  • Causative agent of infectious hematopoietic necrosis (IHN) belonging to genus Novirhabdovirus (Rhabdoviridae). Economic losses caused by IHNV are serious in mainly Oncorhynchus spp. including rainbow trout O. mykiss and Atrantic salmon Salmo salar. IHNV was initially found by endemic presence in U.S. West Coast for sockeye salmon fry O. nerka and chinook salmon fry O. tshawytscha in the 1950s, and it has spread to Japan, Korea and Taiwan in the 1970s, and also to Italy and France in the 1990s. Currently, IHNV is detectable in many parts of the world, including Russia and South America. Mortality due to IHNV infection in fish with ${\leq}0.5g$ of body weight reaches 60% to 100%, while the mortality reduces by fish growing. In recent years, onset of IHNV infection has increased also in fish with large sizes. Here, we introduce molecular epidemiology and virulence changes of IHNV in East Asia, furthermore, we discuss on future prospects in IHNV researches.

Analysis of Vibrio parahaemolyticus OMPs and Production of Antibodies against OMPs

  • Kim, Soo-Min;Noh, Bong-Soo;Kim, Hae-Yeong;Park, Se-Jin;Ji, Geun-Eog
    • Food Science and Biotechnology
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    • 제14권3호
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    • pp.410-412
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    • 2005
  • Vibrio parahaemolyticus is a gram-negative bacterium which acts as a causative agent for food poisoning. Studies with respect to specific extracellular proteins of V. parahaemolyticus would be useful for the development of specific detection methods against V. parahaemolyticus. In our present study, outer membrane proteins (OMPs) of V. parahaemolyticus were obtained from insoluble traction of 1% sarkosyl treated-cell wall materials. SDS-PAGE analysis showed the presence of several conserved outer membrane proteins among five strains of V. parahaemolyticus, and three bands were identified as V. parahaemolyticus OMPs through MALDI-TOF analysis. Polyclonal antibodies enriched with anti-OmpU were obtained from immunized rabbits. The antibodies against these proteins may be useful for the development of detection methods for V. parahaemolyticus.