• Title/Summary/Keyword: white stock

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Analysis of the Wet-end Dynamics in Paper Mills

  • Ryu, Jae-Yong;Yeo, Yeong-Koo;Seo, Dong-Jun;Kang, Hong
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2003.11a
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    • pp.306-330
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    • 2003
  • The wet-end dynamics of a paper mill was analyzed to characterize its dynamic behavior during the grade change. The model representing the wet-end section is developed based on the mass balance relationships written for the simplified wet-end white water network. From the linearization of the dynamic model, higher-order Laplace transfer functions were obtained followed by the reduction procedure to give simple lower-order models in the form of $1^{st}$-order or $2^{nd}$-order plus dead times. The dynamic response of the wet-end is influenced both by the white water volume and by the level of wire retention. Effects of key manipulated variables such as the thick stock flow rate, the ash flow rate and the retention aid flow rate on the major controlled variables were analyzed by numerical simulations. The simple dynamic model developed in the present study can be effectively used in the operation and control.

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Analysis of the Wet-end Dynamics in Paper Mills

  • Ryu, Jae-Yong;Yeo, Yeong-Koo;Yi, Sung-Chul;Seo, Dong-Jun;Hong Kang
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.5
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    • pp.26-36
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    • 2003
  • The wet-end dynamics of a paper mill was analyzed to characterize its dynamic behavior during the grade change of paper. The model representing the wet-end section is developed based on the mass balance relationships written for the simplified wet-end white water network. From the linearization of dynamic model, higher-order Laplace transfer functions were obtained followed by the reduction procedure to give simple lower-order models in the form of 1$^{st}$-order or 2$^{nd}$ -order plus dead times. The dynamic response of the wet-end is influenced both by the white water volume and by the level of wire retention. Effects of key manipulated variables such as the thick stock flow rate, the ash flow rate and the retention aid flow rate on the major controlled variables were analyzed by numerical simulations. The simple dynamic model developed in the present study can be effectively used in the operation and control of paper mills.s.

Effects of Unsaturated Fatty Acid Diets Feeding PEriods on the Antithrombosis the Hematological Changes in the Blood and Fatty Acid Compositions of Platelets in Rats (불포화 지방산의 종류와 사육기간이 흰쥐의 항혈전 작용, 혈액구성 및 혈소판의 지방산 조성 변화에 미치는 영향)

  • 김정선
    • Journal of Nutrition and Health
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    • v.25 no.5
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    • pp.339-350
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    • 1992
  • This study was performed to investigate the effect on polyunsaturate fatty acid diets and feeding periods on the antithrombosis. the hematological changes in the blood and fatty acid compositions of platelets in rats. Each group of rats was fed a diet containing 20%(W/W) corn oil beef tallow sardine oil and the general stock diet for 10, 20. 40 and 80 days. Rats fed sardine oil diet showed significantly longer bleeding time than any other diet groups after 20 days feeding The whole blood clotting time of sardine oil group fed for 80 days was increased significantly. The number of platelet and the concentration of hemoglobin showed no significant difference among all groups. The number of white blood cell was decreased continously in sardine oil group after 10 days feeding. The level of malondialdehyde generation during thrombin-induced aggregation of platelets was decreased continously in sardine oil grou after 20 days feeding. With regard to the composition of platelet fatty acid the ratio of eicosapentaenoic acid(EPA 20: 5 $\omega$-3) to arachidonic acid(AA 20:4 $\omega$-6) was increased in sardine oil group but decreased in corn oil groups and beef tallow groups with days. In conclusion the rats fed sardine oil diet for more than 20 days showed the fact that EPA induced the antithrombosis. the changes in number of white blood cell and the fatty acid composition of platelets.

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Studies on the Coated Broke Recycling in the Papermaking(II)-Effect of Sulfuric acid Treatment on Coated Broke Recycling - (도공파지의 재생에 관한 연구(제 2보)-황산처리가 도공파지 재생공정에 미치는 영향)

  • 이용규;김창근
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.4
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    • pp.23-29
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    • 1999
  • The effect of dilute sulfuric acid treatment was examined to improve recyclability of coated brokes. Turbidity , electric conductivity , and cationic demand of the white water from coated broke prepared from an alkaline base paper was determined. Sulfuric acid treatment was found to be effective in dissolving undisintegrated substances such as binders, pigments, and fibers. The properties of papers prepared by adding the broke to pulp stock up to 30% dry weight were examined . With the increase of broke addition, retention, sizing degree and smoothness were improved ; on the other hand, formation uniformness, air permeability and internal bonding strength were decreased. The extent of improvement by broke addition was greater for the surfuric acid-treated broke than the control broke. It was concluded that the use of coated broke should be limited within 10-15% weight of the product for either type of broke.

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Application of Dynamic Simulation for Efficient Filler-Loading in Papermaking System (제지 공정의 효율적인 충전제 투입에 대한 동적 시뮬레이션 적용)

  • 함충현;윤혜정
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.3
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    • pp.1-12
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    • 2003
  • The complexity of the papermaking system accelerates interactions between a large number of variables involved. The process operation, therefore, is subject to frequent perturbations by disturbance. Dynamic modelling is a useful tool for characterizing the transient behavior and selecting the best control strategies to reject disturbances. In this study we developed a dynamic simulation model of a fine paper production process, which consists of stock preparation, wire sections, white water circulations, and broke system. It focused on dynamic simulation in its role for developing control strategies and studying control loop dynamics related to filler loading for ash control. The results emphasized the importance of filler-loading position and length of control loop for rapid ash control and process stabilization.

Aquatic animal health management in stock enhancement (방류용 수산종묘의 질병 관리에 대한 고찰)

  • Seo, Jang-Woo;Cho, Mi-Young;Kim, Jin-Woo;Park, Gyeong-Hyun;Jee, Bo-Young;Choi, Dong-Lim;Park, Myoung-Ae;Oh, Myung-Joo
    • Journal of fish pathology
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    • v.23 no.1
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    • pp.85-98
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    • 2010
  • Ministry of Agriculture, Fisheries and Food (MAFF) and National Fisheries Research and Development Institute (NFRDI) have inspected the hatchery-reared seeds of 22 marine species and 11 freshwater species for aquatic animal diseases in stock enhancement program in 2009. Results showed that total 12 local selfgovernments have been restocking the sea with cultured juveniles. Gyeongsangnam-do, Jeollanam-do, Jejudo and Chungcheongnam-do have a preference for marine species seeds to freshwater species. On the contrary, freshwater species were released mostly in Gyeonggi-do, Jeollabuk-do and Chungcheongbuk-do. In the marine species group, abalone was the most abundant as 24.5%, and then sea cucumber (15.2%), olive flounder (11.5%), swimming crab (5.6%), black sea bream and rockfish (6.8%), rock bream (5.1%), black rockfish (4.6%) and scorpionfish (4.5%) were followed. Crucian carp was the most abundant as 19.4%, and then eel (17.0%), Korean bullhead (12.3%), melanian snail (12.0%), catfish (8.4%) were followed in the freshwater species group. The total number of inspection cases in this study were 1,080 and disqualification cases were 19 by detection of aquatic animals pathogens such as red sea bream iridovirus (RSIV), koi herpesvirus (KHV) or white spot syndrome virus (WSSV).

Cultivating Status of Paeonia lactiflora Pallas in Central Part of Gyeong Bug Province (경북 중부지역에서의 작약 재배실태)

  • Kim, Se-Jong;Park, So-Deuk;Whang, Wheong-Baeg;Kim, Jae-Cheol
    • Korean Journal of Medicinal Crop Science
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    • v.3 no.3
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    • pp.259-264
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    • 1995
  • This study was carried out to find cultivation condition of peony in Euiseong district from 1994 to 1995. 1. Age distribution in cultivation of peony was from 30's to 50's and cultivated years was mainly from 5 years to 10 years, but there was more than 15 years 2. Cultivating area per house hold were 1300 pyeong average, there were moderate $400{\sim]1000$ pyeong and also those are occupied 22.6% more than 2000 pyeong. 3. The mothods of transplanting in Euiseong peony which Euiseong district was mostly divided peony but Yeongchen district used seedling stock. No. of sprout was mostly $3{\sim}4$ and planting time was mainly from Mid to Late of October. 4. The percentage of sterilization of soil and seedling stock was 77. 4%, in mulching by vinyl in tran­splanting 64. 5% in black vinyl and 25. 8% in white one. 5. Number of plant in peony planting was $3000{\sim}4000$ plant per l0a even more there was more than 8000 plant. 6. Chemical spraying time in peony field was 2 time in $1{\sim}2$ years cultivating, and $3{\sim}4$ time in $3{\sim}4$ years one. 7. Condition of fertilizer application in peony field was 40% in non-application, but $56.7{\sim}76.7%$ in 2 year to 3 years, and the time of fertilizer was mainly 3 time. 8. Drying time peony after havesting was from 12 to 24 hours by briquet stove and 24 hours by ma­chine of hot wind, also dry method of peony was mixed briquet stove and hot wind machine.

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An Evaluation of the Recognition, Preferences and Quality Factors on Sauces (소스(Sauce)의 인식과 기호도 및 품질요인에 대한 평가분석)

  • 김현덕;이연정;한재숙
    • Journal of the East Asian Society of Dietary Life
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    • v.12 no.3
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    • pp.197-209
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    • 2002
  • This study was performed to investigate and analyze the level of recognition, preferences and quality factors of sauces. A total of 1,340 subjects, 660 males and 680 females in the Daegu and Kyeongbuk areas participated in a questionnaire for this study. The results were summarized as follows: Among the respondents, 41.1% answered that they learned about the sauces from a western style restaurant. 73.4% of the respondents suggested that the taste and the quality of sauces had an influence on their preferences of western dishes. 51.2% of the respondents recognized that sauces are mainly used when baking and broiling; it was widely known that demiglace sauce is used on steaks. The preferred colors of sauces from most popular to least popular were brown, blond, white, yellow and red. The overall favorite stock material of demiglace sauce was beef bone. Foods that were preferred to be served with sauces were found to be beef, pea seafood, fish, shellfish, poultry and cereals from most preferred to least preferred. The favorite sauces were brown stock sauce, tomato sauce, liquor sauce, and cream sauce from most preferred to least preferred. The oil and butter sauces were preferred the least. Using a scale of 1 to 5 with 5 being the highest, the respondents rated the way sauces were cooked as the most important the quality-determining factor, with a mean value of 4.31. The raw ingredient as the most important factor was rated 4.45. Among sensory factors, the respondents agreed taste was that the most important characteristic, with a mean value of 4.65. 36.0% evaluated the overall quality of sauces as good and 47.0% as ordinary when served with western dishes. 44.1% of the respondents stated that the taste is was the topmost characteristic that needed to be improved, and that flavor and color were next in order.

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Preparation of Stand Volume Table by the Multivariate Statistical Analysis Method (다변량해석법(多變量解析法)을 이용(利用)한 임분재적표조제(林分材積表調製))

  • Kim, Dong-Chun
    • Journal of Korean Society of Forest Science
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    • v.19 no.1
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    • pp.49-54
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    • 1973
  • Surveys of stock volume on steep and vast expanse of mountains, involves various difficulties. And it is extremely uneconomical in forest management point of view, to spend lots of time and man power for surveying such tree volume as the value is much cheaper in comparison with volume and weight. Therefore, a stand volume table estimate easely stock volume per hectare basis from aerial photographs was prepared and correlations to stand volume among factors affecting tree volumation, were studied. Data were 114 places selected from planted Korean white pine, Pinus koreiensis Sieb. et Zucc. stands in Kwangnung Experiment Forest and were computed and analysed by the means of the quantification in the multi-variate statistical analysis. Electronic Data Processing System was applied for data processing at Korean Instiute of Science and Technology. Coefficients of multiple correlations of stand volume table was ranged 0.85~0.88.

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Teak (Tectona grandis Linn. f.): A Renowned Commercial Timber Species

  • Palanisamy, K.;Hegde, Maheshwar;Yi, Jae-Seon
    • Journal of Forest and Environmental Science
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    • v.25 no.1
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    • pp.1-24
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    • 2009
  • Teak (Tectona grandis) is one of the most valuable timber yielding species in the world, with predominant distribution in tropical or sub-tropical countries. However, natural teak available only in few countries like India, Myanmar, Laos People's Democratic Republic and Thailand. Teak grows well in deep, well-drained alluvial soils, fairly moist, warm, tropical climate with pH ranges from 6.5-7.5. Teak is cultivated in many Asian, African and South American countries for timber production. The global teak plantations are estimated to be three million hectare with major share in India (44%) followed by Indonesia (33%). India is considered as richest genetic resources of teak with large areas of natural teak bearing forests (8.9 million ha), plantations (1.5 million ha), clonal seed orchards (1000 ha) and seed production areas (5000 ha). The studies on diversity of teak populations showed that teak is an out crossing species with major portion of diversity present within the populations. The productivity and quality of teak timber varies depending upon the site and environmental conditions. Teak wood is moderately heavy, strong and tough,straight grained, coarse textured and ring porous with specific gravity varies from 0.55 to 0.70. The sapwood is white to pale yellow in colour and clearly demarcated while heartwood is dark brown or dark golden yellow in colour. Teak is one of the most durable timbers in the world, practically, impervious to fungus and white ant attack and resistant to decay. Teak wood is used in ship and boat constructions, furnitures and aesthetic needs. Genetic improvement programmes have been undertaken in countries like Thailand, India, Malaysia and Indonesia. The programme includes provenance identification and testing, plus tree selection and clonal multiplication, establishment of seed orchards and controlled hybridization. Several aspects like phenology, reproductive biology, fruit characteristics, silvicultural practices for cultivation, pest and diseases problems, production of improved planting stock, harvesting and marketing, wood properties and future tree improvement strategy to enhance productivity have been discussed in this paper.

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