• 제목/요약/키워드: purifying

검색결과 244건 처리시간 0.032초

상수처리시스템의 응집제 주입공정 모델링에 관한 연구 (A study on coagulant dosing process in water purification system)

  • 남의석;우광방
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.317-320
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    • 1997
  • In the water purification plant, chemicals are injected for quick purification of raw water. It is clear that the amount of chemicals intrinsically depends on the water quality such as turbidity, temperature, pH and alkalinity etc. However, the process of chemical reaction to improve water quality by the chemicals is not yet fully clarified nor quantified. The feedback signal in the process of coagulant dosage, which should be measured (through the sensor of the plant) to compute the appropriate amount of chemicals, is also not available. Most traditional methods focus on judging the conditions of purifying reaction and determine the amounts of chemicals through manual operation of field experts or jar-test results. This paper presents the method of deriving the optimum dosing rate of coagulant, PAC(Polymerized Aluminium Chloride) for coagulant dosing process in water purification system. A neural network model is developed for coagulant dosing and purifying process. The optimum coagulant dosing rate can be derived the neural network model. Conventionally, four input variables (turbidity, temperature, pH, alkalinity of raw water) are known to be related to the process, while considering the relationships to the reaction of coagulation and flocculation. Also, the turbidity in flocculator is regarded as a new input variable. And the genetic algorithm is utilized to identify the neural network structure. The ability of the proposed scheme validated through the field test is proved to be of considerable practical value.

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Improved recovery of active GST-fusion proteins from insoluble aggregates: solubilization and purification conditions using PKM2 and HtrA2 as model proteins

  • Park, Dae-Wook;Kim, Sang-Soo;Nam, Min-Kyung;Kim, Goo-Young;Kim, Jung-Ho;Rhim, Hyang-Shuk
    • BMB Reports
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    • 제44권4호
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    • pp.279-284
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    • 2011
  • The glutathione S-transferase (GST) system is useful for increasing protein solubility and purifying soluble GST fusion proteins. However, purifying half of the GST fusion proteins is still difficult, because they are virtually insoluble under non-denaturing conditions. To optimize a simple and rapid purification condition for GST-pyruvate kinase muscle 2 (GST-PKM2) protein, we used 1% sarkosyl for lysis and a 1 : 200 ratio of sarkosyl to Triton X-100 (S-T) for purification. We purified the GST-PKM2 protein with a high yield, approximately 5 mg/L culture, which was 33 times higher than that prepared using a conventional method. Notably, the GST-high-temperature requirement A2 (GST-HtrA2) protein, used as a model protein for functional activity, fully maintained its proteolytic activity, even when purified under our S-T condition. This method may be useful to apply to other biologically important proteins that become highly insoluble in the prokaryotic expression system.

호흡기보호구의 Fit Test 방법과 규정에 관한 고찰 (A Review on Fit Test for Respirators and the Regulations)

  • 한돈희
    • 한국산업보건학회지
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    • 제6권1호
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    • pp.38-54
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    • 1996
  • Respirator fit testing is required before entering specific work environmentals to ensure that the respirator worn satisfies a minimum of fit and that the user knows when the respirator fits properly. The fit of a respirator can be determined by qualitative (QLFT) or quantitative fit test (QNFT). The QNFT, having been universally accepted more than the QLFT, provide an objective and numerical basis by measuring a fit factor (FF). Until a few years age, only one QNFT technigue was available and accepted by U.S. Occupational Safety and Health Administration (OSHA) regulations. In the 1980's and 1990's, several new and fundamentally different QNFT methods were developed. Two of the newer methods are commercially availale and are accepted by OSHA as suitable alternatives. In this articles, the principle of operation of each ONFT technique is explained and each technique's major advantages and disadvantages are pointed out. Emphasis is given to negative-pressure air-purifying respirators, as they are in most frequent use today. The requirements and recommendations for fit testing positive-pressure respirators are discussed as well. Finally, the presently available QNFT standards and regulations are summarized to assist the user in making fit testing decisions.

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오존발생시스템을 이용한 하천수질 개선기법 (Techniques of Water Quality Improvement by Using Ozone Generation System)

  • 김민영;류재욱;이승윤;지홍기
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2008년도 학술발표회 논문집
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    • pp.2122-2126
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    • 2008
  • With the degradation of water quality and, at the same time increased water usage, the sources of high quality, for examples, river/stream, municipal reservoir, wells, artisan and surface water, are diminishing. Therefore, the importance of water quality has been emphasized over the years through publications and various literature sources. Even though considerable research has resulted in significant strides for providing interpretive information and mitigation strategies for improvement of waters, the quality of which is still questionable. This study aims to propose a completely independent self-contained system for purifying waters, solar-powered ozone generator. It is a semi-permanent and cost effective environmental solution. Functions of ozone treatment are: 1) to maintain oxidative flexibility, 2) remove harmful chemicals, wastes, and other substances, and 3) prevent epizootic microbial outbreaks. Recent advances in technology have allowed the development of the practical, self-contained and independent solar powered device. Solar electrical producing panels that charge batteries are the key to using these systems anywhere electrical power is not available. This paper invites the readers to examine the problem and consider the viable, proven solution the solar powered ozone purifying system. This paper also introduces basic concept and background of solar powered ozone generators and examine its feasibility for improving water quality in rivers and streams.

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학교환경위생정화구역에 관한 인지도 조사 연구 (A Survey on Recognition of School Environment Hygiene Purification Zones)

  • 김은주
    • 한국학교보건학회지
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    • 제20권2호
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    • pp.69-80
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    • 2007
  • Purpose: The present study purposed to investigate the current state of harmful business places around schools and to survey and analyze how much middle school students know about school environment hygiene purification zones, which have not been much effective. Methods: In addition, this study clarified the problem of harmful environment around schools by inquiring into students' value and perception on worsening harmful environment around schools and provided basic materials necessary for making policies on school education and the protection of educational environment. For these purposes, we conducted a questionnaire survey of 1,000 middle school students in Gyeonggi-do on their perception on harmful environment around their schools, and drew conclusions as follows. Result: Students' knowledge about the School Health Act was low, and they generally thought that the law does not play its role substantially and efficiently in purifying and regulating harmful environment and regulations are superficial and temporary. To the question of whether harmful businesses observe laws for purifying environment around schools, most of the students replied negatively. In actuality, as most of harmful businesses running at school environment hygiene purification zones are stationeries with game rooms, comic book stores, PC rooms, etc., which are highly accessible to students, they become serious problems in school environment. Conclusion: As it is required to make continuous and systematic surveys and researches on the school environment hygiene purification zones, we need to manage school environment efficiently through cooperation among the government, education offices and individual schools.

리기다소나무 임분에서 산림관리작업이 토양의 물리성 및 산림의 수질정화기능에 미치는 영향 (Influence of Forest Practices on Soil Physical Properties and Facility of Purifying Water Quality in Pinus rigida Stands)

  • 박재현
    • 한국환경복원기술학회지
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    • 제10권2호
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    • pp.61-70
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    • 2007
  • This study aims to clarify the effect of forest management practices(thinning and pruning) on soil physical properties and water quality to get the fundamental information on the facility of purifying water quality after forestry practices. Rainfall, throughfall, stemflow, soil and stream water were sampled at the study site which consists of Pinus rigida in Jinju National University Experimental Forest for 4 years from Mar. 1, 2002 to Nov. 30, 2006. Averaged tree height of the management site increased by 1.6m, compared to the value of the non-management site in Pinus rigida. Increment of averaged D. B. H. at the management site showed 4.2cm more in Pinus rigida compared with that at non-management sites. Mesopore ratios (pF2.7) and total porosities of A layer soil at the management site increased more than those at the non-management sites in both stands. Otherwise, soil bulk density resulted in being reversely. Water qualities of throughfall, stemflow and buffered soil water were influenced more positively by the management practice. The average electrical conductivity of stream water was $32.9{\mu}S/cm$ within the range of non-polluted stream water.

고순도.미립 $TiO_2$분말 제조에 관한 연구 -고순도화 연구(I)- (Studies on Preparation of $TiO_2$Powder with Purity and Fine Particle -A Study of High Purifying(I)-)

  • 이미재;지미정;김환;이철태;최병현
    • 한국세라믹학회지
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    • 제37권10호
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    • pp.933-937
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    • 2000
  • 고기능성 전자재료용 TiO$_2$분말 및 박막제조에 사용되는 중간생성물인 TiCl$_4$는 99% 이상의 고순도가 요구된다. 고순도.미립의 TiO$_2$분말 및 TiCl$_4$는 황산법으로 제조한 저순도 TiO$_2$원료를 사용하여 염소화법으로 Ti-염화물 및 염화불순물로 제조한 후, 대부분의 염화불순물들은 3단계 과정을 거쳐 고순화 하였다. 대부분의 염화불순물은 분리.응축 및 분별증류로, VOCl$_3$는 mineral oil을 첨가하여 비등점을 변화시켜, 그리고 미량의 염화불순물은 열가수분해하여 침전시킨 후 유기용제 처리하여 제거하였다. 유기용제 처리는 TiO$_2$분말의 고순도화에 도움이 되었으며, 입자간의 응집을 적게 하여 TiO$_2$입자크기도 작아졌다. 또한 anatase에서 rutile 결정구조로의 전이온도도 낮아지는 부수적인 효과를 보였다.

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Rapid and Simple Method to Prepare Functional Pfu DNA Polymerase Expressed in Escherichia coli Periplasm

  • Chae, Young-Kee;Jeon, Woo-Chun;Cho, Kyoung-Suk
    • Journal of Microbiology and Biotechnology
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    • 제12권5호
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    • pp.841-843
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    • 2002
  • Pfu DNA polymerase from Pyrococcus furiosus was expressed in the E. coli periplasm, and the fully active polymerase was partially purified by applying osmotic shock, ammonium sulfate precipitation, and heat treatment. This method represents a new way of expressing and purifying functional Pfu DNA polymerase without the use of chromatography.

A high yield conversion of N-norapomorphine from apomorphine

  • Kim, Jack-C.
    • Archives of Pharmacal Research
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    • 제6권2호
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    • pp.137-140
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    • 1983
  • A rapid, high yield of N-norapomorphine from apomorphine was accomplished by allowing it to react with phenyl chloroformate without isolating and purifying the intermediate carbamate, and have found that the crude carbamate can be easily cleaved in situ with a 1:1 mixture of 64% and 95% hydrazine to afford analytically pure N-norapomorphine in 81% overall yields. Previously, various other methods gave an untoward ring opening reactions and scission of the hydropyridine ring in the apomorphine series.

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