• 제목/요약/키워드: Fines

검색결과 289건 처리시간 0.031초

제지 공정 적용을 위한 Cellulase의 정제 특성 및 처리 조건 선정에 관한 연구 (Purification Properties and Treatment Conditions of Cellulase for Papermaking Processes)

  • 김병현;전양
    • 펄프종이기술
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    • 제30권1호
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    • pp.18-28
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    • 1998
  • The main protein peak was observed in fraction No.9 and 109 when cellulase seperation was conducted by use of DEAE-Sephadex. The protein obtained from fraction No.9 has the characteristics of Cx component and that from fraction No.109 characteristics similiar to $C_1$ component. The effective reaction condition of the ensyme used was $40^{\circ}C$ in temperature. pH 5.0 and 90 minutes in treatment time. For the case of $C_1$ pH 5.5 in temperature range of $30^{\circ}C 50^^{\circ}C$, 4.0 5.5 in pH, and over 30 minutes of treatment time, the reaction was in the range of 80% of the maximum. Affinity of enzyme increased as freeness, increased, and this effect was more visible in fiber than in fines.

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오프라인 프로그래밍에서의 실시간 통신 (Real-time communication in an off-line programming)

  • 송종탁;손권;이민철
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.40-43
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    • 1996
  • An off-line programming, OLP, system is widely used in automation fines. To help an on-line robot system to carry out desirable tasks planned by the off-line simulation, an approach to the real-time communication is presented. The OLP system developed consists of a software, a host computer(PC), a SCARA robot body, four servo drivers, and four independent joint controllers. This study focuses on the software where real-time communication is included. The software, can be used in teaching, trajectory planning, real-time running, and performance evaluation. The evaluation of different control algorithms is one of the merits of the software. The software can give servo commands for task running. A comparison of generated and corresponding actual trajectories provides the evaluation of task performance. The safety, of the OLP system is ensured by alarming malfuntions of the system. The OLP system developed can reduce the teaching time and increase the user's convenience.

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강우조건을 고려한 불포화사면의 안정성 평가 (Evaluation of Rainfall Conditions on Slope Stability in Unsaturated Weathered Soils)

  • 권홍기;박성완
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.599-606
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    • 2010
  • It has been reported that many slope failures in unsaturated soils are mainly caused by downward infiltration due to rainfall. The rainfall characteristics could be an important factor, and more predictable slope failures can be achieved by considering more reasonable rainfall conditions. So, a need exists that these trends of infiltration in weathered soils, which is commonly found in Korea, are assessed by considering rainfall conditions based on phenomenological approach. In this paper, numerical analyses of unsaturated soil slope under rainfall conditions are presented based on the soil-water characteristic curve in the laboratory and huff method. Then the performance of unsaturated weathered soil slopes was evaluated under various conditions after applying the effect of overburden pressure on SWCCs and fines contents. The results demonstrated that the rainfall conditions using Huff method can be very effective and the proper application on analysis is very important to enhance the prediction on unsaturated slope stability.

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Stability of Unsaturated Soil Slopes considering the Effect of Wetting Front Suction Loss

  • Jeong, Sang-Seom;Kim, Jae-Young
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2007년 가을학술발표회
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    • pp.502-513
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    • 2007
  • This paper describes the rainfall-induced slope failures caused by infiltration due to prolonged rainfall. The emphasis was on quantifying the effect of fine-grained contents which are influencing on the infiltration rate in the wetting front of initially unsaturated slopes during rainfall. Suction tests by tensiometer were performed for five mixture specimens with varying fine-grained contents and then, numerical analyses for the stability of unsaturated slopes are carried out for different relative densities and mixture portions based on the soil water characteristic curves obtained by GCTS pressure plate. It is shown that the fines are highly influenced on wetting front suction of unsaturated soil slopes. Based on the results, it is found that until 15% fine content is the limit showing different wetting front suction, beyond which the wetting band depth do not affect considerably the stability of unsaturated slopes.

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고품질 현장 유동화 콘크리트 제조를 위한 유동화제 성능 개선에 관한 기초적 연구 (A Fundamental Study on the Improvement of Superplasticizer for Manufacturing the High Quality Flowing Concrete in the Field)

  • 강의영;한만철;오선교;한천구;반호용
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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    • pp.33-36
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    • 1998
  • Generally, the base concrete for manufacturing the flowing concrete has to increase the fine aggregate content or adjust the fines content prevent the concrete from segeration, However, it may not only increase the cost, but cause the inconvenience in production of base concrete. In this paper, the experiments is performed on the superplasticizer which is used for base concrete by mixing viscosity agents and AE admixtures. According to the results, it shows that it is possible to manufacture a flowing, non segregation, high durability and economical concrete in the field without increasing the fine aggregate content of base concrete, when the superplasticizer are mixed with viscosity agents and AE admixtures in an appropriate proportion.

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Approximate analysis for performance evaluation of serial production line

  • Lee, Noh-Sung;Seo, Ki-Sung;Ahn, Ihnseok;Choi, Joon-Youl;Woo, Kwang-Bang
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.458-462
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    • 1992
  • This paper presents a decomposition method to evaluate the performance measures of transfer line with unreliable machine and finite buffers. The proposed method is to decompose the transfer fine into a set of two machine lines for analysis. Nonhomogeneous lines are considered. In such fines, the machines may take the different lengths of time performing operations on parts. A simple transformation is employed in order to replace the line by a homogeneous line. The approximate transformation enables one to determine parameters of performance such as production rate and average buffer levels, and it also shows better applications for a large class of systems.

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Recovery of ultrafine particles from Chemical-Mechanical Polishing wastewater discharged by the semiconductor industry

  • Tu, Chia-Wei;Wen, Shaw-Bing;Dahtong Ray;Shen, Yun-Hwei
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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    • pp.715-718
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    • 2001
  • This study uses traditional alum coagulation and sedimentation process to treat CMP wastewater from cleaning after polishing. The primary goal is to successfully recycle both solid fines and water for semiconductor manufacturing. Results indicated that CMP wastewater may be successfully treated to recover clean water and fine particles by alum coagulation. The optimum operating conditions for coagulation are as fellowing: alum dosage of 10 ppm, pH at 5, rapid mixing speed at 800 rpm, 5 min rapid mixing time, and long slow mixing time. The treated water with low turbidity and an average residual aluminum ion concentration of 0.23 ppm may be considered for reuse. The settled sludge after alum coagulation contains mainly SiO$_2$particle with a minor content of aluminum (1.7 wt%) may be considered as raw materials for glass and ceramic industry.

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Optimization of Repulping Process of Unsorted ONP for Pulp Mold (II) - Pilot trial -

  • Cho, Byoung-Uk;Ryu, Jeong-Yong;Fabry, Benjamin;Song, Bong-Keun
    • 펄프종이기술
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    • 제39권5호
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    • pp.39-44
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    • 2007
  • In order to utilize unsorted ONP, which contains leaflets (printed coated papers), as a raw material to produce pulp mold, optimum conditions for repulping were investigated with the pilot Helico pulper at Centre Technique du Paper (CTP), France. Two major process factors were focused: repulping concentration and rotor speed. Repulping at a higher concentration showed more rapid defibering kinetics. Increasing the rotational speed of rotor at the optimum repulping concentration accelerated the defibering kinetics while it also led to higher fines generation and faster decrease in drainage property of the produced pulp. Hence, an alternative way was suggested: starting repulping at a conventional rotor speed and then accelerating the rotor speed for the last minute(s) of repulping.

양이온성 구아검과 콜로이달 실리카를 이용한 마이크로파티클 보류시스템의 탈수 및 전단안정성 (Drainage and Shear Stability of Microparticle Retention Systems Based on Cationic Guar Gums and Colloidal Silicas)

  • 함충현;이학래
    • 펄프종이기술
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    • 제40권2호
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    • pp.1-7
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    • 2008
  • The trend of using more hardwood and recycled fibers, and closing more tightly of the paper mill white water system has resulted in build-up of fines as well as organic and inorganic contaminants in the white water. This changes in papermaking wet end requires developing chemical additive system that provides good fiber retention and drainage in closed white water system. In this study the effect of charge densities and chemical characteristics of microparticle systems consisted of cationic guar gums and anionic colloidal silica sols on drainage and retention have been examined. Results showed that higher charge density of cationic guar gum and anionic colloidal silica sol gave better retention and drainage. Particularly highly structured silica gave greater retention efficiency.

준설점토의 지지력에 대한 모래 혼합효과 (SAND MIXING EFFECT FOR THE SUPPORT CAPACITY OF DREDGED SLURRIES)

  • 유건선
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1992년도 가을학술발표회 논문집
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    • pp.47-54
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    • 1992
  • When marine clay is hydraulically dredged from seabed and pumped into the pond enclosed by contatinment dykes, marine clay is mixed and flocculated with water and then settled. At this time, the fines will interact with the water to form a Bingham plastic slurry which has non-Newtonian characteristics. The dredged slurry has different physical properties depending on settling locations and settling depths in the pond and has few hundred percent of water content and almost nil of shear strenght. In order to make this condition of the dredged slurry the final formation for public use within a short period, sand spreading method to enhance the support capacity of the dredged slurry is developed. In this paper, the effect of sand mixing into the dredged slurry of this method is analyzed based on reference study, laboratory tests and actual construction results.

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