• Title/Summary/Keyword: Freeness

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Effect of Refining Load on the Drainage Characteristics of Pulp (고해부하가 지층 형성시 탈수특성에 미치는 영향)

  • 김용식;원종명
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.32 no.4
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    • pp.10-17
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    • 2000
  • The change of fiber length, freeness, initial forming drainage velocity, specific filtration resistance, final drainage time and wet web dryness were measured to investigate the effect of the refining load on the drainage characteristics of pulp. The arithmetic average fiber length after refining with higher refining load was shorter than that obtained with lower refining load. Higher refining load decreased initial forming drainage velocity, final drainage time and wet web dryness. The refining load also affected the relationship between freeness and specific filtration resistance, initial forming drainage velocity, final drainage time. It was found that the specific filtration resistance is better than freeness to predict the drainage characteristics of pulp and the wet dryness.

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Study on Filtration Characteristics of Wood Pulp and Non-Wood Fiber (목재펄프 및 비목재 섬유의 여과제 특성에 관한 연구)

  • Cho, Jun-Hyung;Han, James S.;Lee, Beom-Goo
    • Journal of the Korean Wood Science and Technology
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    • v.26 no.4
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    • pp.86-91
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    • 1998
  • The drainage was used to determine the specific filtration resistance for wood and non-wood fibers. The drainage rate is also affected by factors that can be changed on consistency, pressure drop across the mat, basis weight, additives, and viscosity. Recent development of theoretical studies in flow through porous media and filtration operation emphasize the urgent need for more accurate data for porosity and specific filtration resistance. This study was investigated to determine specific filtration resistance of Hw, Sw-BKP and Kenaf fiber by filtration experimental. Freeness levels selected were 150,250,and $350m\ell$ CSF. The average specific filtration resistance decreased as freeness increased and resistance of Sw-BKP was greater than that of Hw-BKP. The filtrate and porosity increased and specific filtration resistance decreased as particle size of fiber increased.

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Improvement of Paper Smoothness for the Printed Electronics Base Paper (인쇄 전자 용지의 특성 구현을 위한 종이의 평활도 증가에 대한 연구)

  • Kim, Byong-Hyun;Yoo, Hee-Tae;Kang, Young-Ree
    • Journal of the Korean Graphic Arts Communication Society
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    • v.29 no.1
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    • pp.89-99
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    • 2011
  • The making of high leveled smoothness for the printed electronics base paper, wood pulp and sea algal pulp were mixed. If sea algal pulp contents is increased to 9%, the smoothness was moderately increased, and more effective in Softwood mixture than Hardwood, low freeness(high wetness) than high freeness(low wetness).

Asymptotic Behavior of the output SINR at MMSE receivers in a MIMO MC-CDMA system (MIMO MC-CDMA시스템에서 MMSE 수신기 출력의 점근적 양상)

  • Kim, Kyeong-Yeon;Shim, Sei-Joon;Ham, Jae-Sang;Lee, Chung-Yong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.44 no.4
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    • pp.10-16
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    • 2007
  • This paper analyzes the output signal-to-interference-plus-noise ratio (SINR) for a multiple-input-multiple-output (MIMO) multicarrier code division multiple access (MC-CDMA) system with minium mean square error receivers. A previous work of a single antenna MC-CDMA system cannot directly applied to a MIMO MC-CDMA system because some assumptions for single antenna do not match the case of multiple antenna. Therefore this paper expands the concept of freeness to MIMO system by using the Marcenko Pastur law. The analysis shows that the output SINR asymptotically converges to a deterministic value and finds the value on the assumption of freeness. From the analysis, it is easy to calculate bit error rate and the calculation is verified by simulations.

A New Universally Verifiable and Receipt-free Electronic Voting Scheme Using Only One-way Untappable Channels (일방향 도청 불가능한 채널만을 이용하여 전체검증과 매표방지를 제공하는 새로운 전자선거 기법)

  • 조진현;김상진;오희국
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.13 no.2
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    • pp.49-61
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    • 2003
  • Electronic voting schemes must provide universal verifiability and receipt-freeness, as well as basic properties such as privacy, eligibility, to make the election fair and transparent. But it is difficult to provide both universal verifiability and receipt-freeness because they are mutually contradictory in their objective. To date, most electronic voting schemes provide only one of these properties and those few that provide both properties are not practical due to heavy computational load. In this paper, we present an efficient electronic voting scheme that provides both properties. The proposed scheme uses a trusted third party called HR(Honest Randomizer) and requires only one-way untappable channels from HRs to voters. Among the schemes that assume only one-way untappable channel this scheme requires the least amount of computation. Among the schemes that provide both properties, this scheme uses the weakest physical assumption. We also discuss the security of the system and compare our scheme with other related schemes.

Improvement of Papermaking Properties of Recycled Fiber with Enzyme (효소처리에 의한 재생섬유의 제지적성 개선)

  • 최윤성;원종명
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.33 no.1
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    • pp.30-37
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    • 2001
  • The effects of enzymatic treatment of recycled fiber were investigated to obtain the basic informations which can be used to improve the papermaking properties of recycled fiber. The recycled fibers were prepared by the repeated handsheet making and disintegrating of hardwood of hardwood and softwood kraft pulp. Novozym 342, Dinimax and Pulpzyme HC were used for enzymatic treatment. The change of fiber length distribution, freeness, contact angle and crystallinity of pulp were measured. The brightness, opacity, breaking and tear index of paper were also measured. The enzymatic treatment decreased long fiber fraction of recycled hardwood fiber, but increased long fiber fraction of recycled softwood fiber. Freeness was decreased with 0.1% enzyme and then increased again with the increase of th enzyme dosage. The improvement of flexibility of recycled fiber was obtained through the decrease of contact angle that is resulted from the decrease of crystallinity of fiber. Brightness and opacity were affected by the type of pulp and enzyme, and dosage of enzyme. Breaking length of recycled hardwood fiber was improved with enzyme treatment, but breaking length of recycled softwood fiber was decreased except for 0.01% Pulpzyme treatment. Tear index was decreased with enzymatic treatment and the lowest decrease was observed with the treatment to Pulpzyme.

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Development of On-line Technology for Measuring Stock Consistency Using Optical Sensor (Part 2) - Effect of stock properties on the relationship between the turbidity and transmittance of stocks and consistency - (광학센서를 이용한 지료의 농도 평가 기술 개발(제2보) - 펄프의 특성 변화가 농도와 탁도 및 투과율의 상관관계에 미치는 영향 -)

  • Lee Ji-Young;Youn Hye-Jung;Lee Hak-Lae
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.38 no.1 s.113
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    • pp.16-20
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    • 2006
  • The effect of the freeness of pulp slurries on turbidity and transmittance of papermaking stocks was investigated using beaten bleached hardwood pulp stocks with freeness ranging from 651 mL to 403 mL CSF. Also the influence of fiber length on the turbidity and transmittance was examined with fractionated pulp stocks. Increases in stock consistency increased the turbidity. Transmittance of stock samples decreased, however, with the increase of stock consistency. Second order equations and exponential equations have been obtained as regression equations for the turbidity and transmittance of these stock samples, respectively.

Effect of separate and mixed refining of hardwood and softwood pulps on paper properties

  • Chauhan, Vipul S.;Kumar, Nitin;Kumar, Manoj;Chakrabarti, Swapan K.;Thapar, S.K.
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.43 no.4
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    • pp.1-10
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    • 2011
  • Beating or refining is an energy intensive process in paper industry. In India, most of the paper industries blend long fibered softwood pulps with short fibered hardwood or agro based pulps to get the paper properties of competitive level. Refining characteristics of the blend of pulps is very crucial with respect to freeness and strength properties. This study has been carried out to understand the refining behavior of three hardwood pulps and a softwood pulp. The hardwood and softwood pulps are blended in different proportions in two different ways; a) blending after their separate refining, and b) blending before refining followed by mixed refining of the blended pulps. Freeness of pulp, strength, optical and surface properties of paper along with formation have been determined and compared for both the refining methods. The fiber classification of refined pulps was also carried out to analyze the effect of refining method on fiber morphology. The mixed refining of hardwood and softwood pulps marginally affects the fiber morphology in comparison to separate refining of pulps. The strength and other properties of paper prepared from mixed refining of pulps are either better or comparable than those of separately refined pulps.

Enzymatic Deinking of Mixed Office Waste Paper(1) -Pulping properties of mixed office waste paper with enzymes- (혼합사무용지의 효소 탈목(1) -혼합사무용지의 효소 해섬 특성-)

  • Park, Soung-Bae;Yoon, Kyung-Dong;Yoon, Byung Tae;Eom, Tae-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.1 s.109
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    • pp.47-52
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    • 2005
  • Enzymatic pulping properties of mixed office waste paper in standard disintegrator were investigated for successful enzymatic deinking of mixed office waste paper. Enzymatic pulping need more revolution in standard disintegrator than alkaline pulping and Cellusoft need more revolution than Denimax. The freeness of disintegrated pulp with enzyme was higher than those of disintegrated pulps with alkaline and heat killed enzyme. The freeness of disintegrated pulp with Denimax was higher than that of disintegrated pulp with Cellusoft. The freeness of disintegrated pulps were increased with a dosage of enzymes. The mechanical properties of disintegrated pulp were improved with enzyme addition comparing with heat killed enzyme. The tensile and burst index of hand sheet of disintegrated pulps with acidic Cellusoft were higher than that of others.