• Title/Summary/Keyword: Tear index

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Changes of Handsheet Fracture Toughness by Wood and Cotton Fibers Mixing (목재섬유와 면섬유의 혼합에 따른 수초지의 파괴인성 변화)

  • Kim, Jeong-Jung;Jang, Dong-Uk;Yoon, Sang-Gu;Shin, Hyeon-Sik;Park, Jong-Moon
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.46 no.3
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    • pp.81-87
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    • 2014
  • Conditions of paper manufacturing process should be changed depending on the end use and paper properties. Most of the case, mixed pulps with long softwood fibers and short hardwood fibers are used to achieve proper qualities of product with reasonable production cost. For specialty paper manufacture the wood pulp and cotton linter pulp are usually mixed together. The objectives of this study is to analyze physical, mechanical and fracture mechanical properties of paper depending on SwBKP, HwBKP and cotton linter pulp(CLP) mixing. When the mixing ratio of SwBKP was increased, strength properties, such as tensile, tear, and folding endurance, were also increased. When the mixing ratio of SwBKP and HwBKP was increased, stress concentration index was decreased and fracture toughness was increased.

Peripheral Arterial Injuries in Pediatric Age Group

  • Ammar, Ahmed AbdulRaouf
    • Journal of Trauma and Injury
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    • v.29 no.2
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    • pp.37-42
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    • 2016
  • Purpose: Arterial injury in children is a challenging problem for its special characteristics. It is rare even during warfare. This review described a personal experience in the management and outcome of acute pediatric arterial injuries of extremities. Methods: Thirty-six children below age of 13 years were studied during period from 2004 through 2014 in Iraq. Results: Male patients were 27 (75%) and female were 9 (25%). Seven to twelve years old was the most affected age group. The incidence of iatrogenic injuries was greater in infants and toddlers while penetrating injuries were the most common in older children. Upper limbs arteries were affected in 17 (47.2%) and lower limb in 19 (52.8%) patients. Hard signs were the commonest mode of presentation (83.3%). Lateral wall tear and complete transection were the most frequent types of arterial injury (36.1% and 27.8% respectively). The most frequent procedures performed were end-to-end anastomosis and lateral arteriorrhaphy. Surgical outcome was good. In 27 cases distal pulsations were regained. Seven cases had impalpable distal pulses but still viable limbs. Limb length discrepancy was detected in one case. One case was complicated with limb loss. No death was recorded. Conclusion: Arterial injuries in children are age related. The proper treatment of arterial injuries in children requires high index of suspicion, early operative intervention and continuous postoperative follow-up throughout years of active growth. Angiogram has a limited role as a diagnostic tool in acute arterial injuries.

Aging Characteristics of Grape and Pear Growth Paper Bag (포도, 배 재배용 과수봉지의 열화 특성)

  • Ha, Jin-Yang;Chae, Su-Myoung;Yoon, Seung-Lak
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.46 no.6
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    • pp.41-49
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    • 2014
  • The research was performed to investigate the weathering characteristics of fruit growth paper bags. The bags were used to cover fruits such as grapes and pears. And then they were collected after 30 and 60 days exposure at the orchard. The physical and optical properties of the bags tended to decrease with the exposure times. The larger change on the properties were found on the papers exposed for 30 days. The cover paper for pear showed the largest density changes. The air permeability were decreased with the exposure time in all bags. The cover paper for pear showed the very low values of air permeability. The mechanical properties of the fruit bags showed to be gradually decreased with the length of exposure time. The tear index showed the largest differences. The cover paper for pear showed the rapid decrease on the mechanical properties after 60 days of the exposure. The inner paper, however, showed the strength enough to cover the fruits. The precipitation showed more effect on the degradation of fruit growth paper bags than the light hours.

Development and Properties of Rubber Sheet using Thermoplastic Elastomer (열가소성 고무를 사용한 RUBBER SHEET의 제조 및 물성)

  • Chun, Seung-Han;Han, Min-Hyeon;Mun, Il-Sik
    • Elastomers and Composites
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    • v.38 no.2
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    • pp.122-127
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    • 2003
  • Compounding, using such thermoplastic elastomer as styrene-ethylene-butadiene-styrene (SEBS) blended with polypropylene(PP), oil, and other ingredients, was studied to develop a new material with excellent impact resistance and resilience for the replacement of environmentally toxic PVC sheet. Hardness decreased linearly with oil content in the SEBS/oil blend, and the tensile strength increased with PP content whereas elongation showed no effects over 50 phr of PP in SEBS/oil/PP blend. In the practical SEBS composition, proposed to replace the PVC sheet material, tensile and tear strength, as well as hardness, increased proportionally with PP content, while melt index decreased.

Physical and Chemical Properties of Charcoal Added Paper for Cigarette Filter (활성탄 첨가에 따른 담배용 필터지의 이화학적 특성)

  • Lee, Moon-Yong;Jeon, Yang;Kim, Young-Ho;Lee, Jeong-Il
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.4
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    • pp.76-83
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    • 1999
  • This study was carried to investigate optimum conditions of charcoal added paper in making cigarette filter for the removal of smoke contents of cigarettes. We investigated the physical properties of charcoal added paper according to the ratio of pulps, the amounts of characoal , the weight of sheets and crimping conditions in dry method, and then analyzed the smoke contents of cigarettes. The results obtained were as follows. 1. Sw-BKP was higher than Hw-BKP in methylene blue absorption by UV test. 2. Charcoal had an effect on stiffness for decreasing factor greatly , while the addition amounts of Sw-BKP and high weigth of sheets increased it, and the interaction of weight of sheets and charcoal was higher than other factors. 3. Tear index decreased by charcoal addition greatly, on the other hand high weight of sheets and Sw-BKP/Hw-BKP ratio increased ter, and the interaction of pulps and chacoal acted on major factors. 4. We estimated crimp index with sensory evaluation , and charcoal hand an effect on decreasing factor in crimping greatly, while the interaction of weight of sheets and pulp ratio was higher than others. 5. In the case of charcoal added paper filter, tar removal efficiency of smoke contents was higher but about 6% than cigarette filter. Especially vapour phase(aldehyde) in smoke contents was removed greatly.

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Effect of Xylanase Pre-and Post-Treatment on oxygen Bleaching of Oak Kraft Pulp

  • Kim, Dong-Ho;Paik, Ki-Hyon
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 1999.11a
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    • pp.194-204
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    • 1999
  • The use of genetically cloned xylanase acquired from Bacillus strearthermophillus improves bleachability for oak kraft pulps. Combination of xylanase(X). oxygen(O), ozone(Z). peroxide(P), alkaline extraction(Eo. Eop), and chlorination(C/D, D) have been tested in a variety of bleaching sequences. The effectiveness of xylanase pre-treatment(XO) and post-treatment(OX) in oxygen bleaching is mainly compared. With xylanase treatment the brightness increase by 1.5-2.1% ISO in OZEP, OZEoP, OZEopP and OPZP sequences. There is only numerically difference of brightness gains between OX and XO sequences. With xylanase treatment chemical requirements for bleaching decrease by 42.6-48.6% in OC/DEoD sequence and 47.9-54.7% as active chlorine in OC/DEopD sequence at the same brightness. the reduction of bleaching chemicals is higher in XO sequence than those in OX sequence. Following xylanase treatment the viscosity increases from 11.7-12.0 mPa·s to 12.4-13.5 mPa·s and the brightness stability is considerably improved however the difference of effectiveness between XO and OX sequence is not present. Compared to tensile index vs tear index, the physical properties are similar for TCF bleaching sequences with and without xylanase treatments. However in OC/DEoD and OC/DEopD sequences the physical properties decrease with xylanase treatment. There is no difference in the physical properties between XO and OX sequences. COD, BOD and color of bleaching effluents increase slightly with xylanase treatment, however the discharge of COD end-load into environmental impact decrease.

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PREPERATION OF AMPHOTERIC STARCHS AND STUDY ON WET END CHEMISTRY IN PAPERMAKING

  • Shan, Chen-Fu;Su, Xie-Lai;Yi, Wang-Hai;Quan, Long-Yan
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 1999.04b
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    • pp.386-389
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    • 1999
  • Amphoteric polymers have brought to papermakers' attention gradually. In this paper, a series of amphoteric starches with different cationic and anionic degree of substitution (DS) are prepared. Better product has been selected and used under different condition. As retention and drainage aids, amphoteric starches were used in shorter fiber length, weak strength and poor drainage bleached AQ-Soda wheat straw pulp. In neutral and alkaline papermaking system, when amphoteric starches contain 0.024-0.026 anionic degree of substitution (DS), it is shown that the higher the cationic degree of substitution (DS) in amphoteric starches, the better the filler retention. The filler retention is improved 12.5%, 30.3%, and 35.1% and 32.5% respectively by adding 1% amphoteric starch LS-L2 -1 (0.034), LS-L2-2 (0.040), LS-L2-3 (0.047) and LS-L2-4 (0.052). But the strength of handsheets if affected a little. By adding 2% Al2 (SO4)3 and 1.5% LS-L2-3 at pH 7.5, filler retention can be improved from 38% to 80%, and breaking length of sheet only decreases 3.2%. As dry strengthening aids, amphoteric starches were used in eucalyptus APMP. Amphoteric starches are used in eucalyptus APMP. The amphoteric starch LS-L2-2 is better dry strength aid. Adding 1% LS-L2-2 can improve breaking length 24.5%, burst index 42.9%, tear index 38.8%, folding endurance and density of the handsheets.

Manufacture of Specialty Paper with Hemp Bast Fiber Cultivated in Korea (Part 1) - Characteristics of Hemp-Wood Paper by Soda Pulping - (삼섬유를 이용한 특수기능지 개발 (제 1보) - 소다펄프화 삼 섬유의 수초지 특성 -)

  • Lee, Dah-Hee;Lee, Myoung-Ku
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.45 no.6
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    • pp.30-35
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    • 2013
  • To conserve wood resources for papermaking, chemical compositions of the hemp (Cannabis sativa L.) bast fiber cultivated in Korea such as holocellulose, ${\alpha}$-cellulose, lignin, alcohol-benzene extractives, hot and cold water extractives, and ash contents were investigated to manufacture the specialty packaging paper effectively. Significantly very low klason lignin content of 3.3% was accomplished by removing of the outer shell of bark. Laboratory soda pulping method which is very useful for the nonwood fiber was adapted, and it was found that there was no significant difference in both kappa number and H-factor between 25% and 30% NaOH charge. Hemp pulp cooked with the laboratory digester in 25% NaOH at $170^{\circ}C$ were mixed together with the wood pulp(NBKP:LBKP=1:1) in order to find the optimum mixture ratio which exhibited acceptable paper strength properties such as tensile index, burst index, and tear strength. When 10% of hemp soda pulps was mixed with 90% of wood pulps comprised of SwBKP and HwBKP (1:1), all physical strength increased significantly. The physical strength decreased as the amount of hemp pulp increased because the cell wall of bast fiber is very thick which causes low conformability and low fiber-fiber bonding. These results showed that paper made of hemp-wood pulp can be used for the specialty packaging paper which requires both the characteristic surface properties and the high physical strength of hemp fiber.

Ultrasonic Osteotome Assisted Posterior Endoscopic Cervical Foraminotomy in the Treatment of Cervical Spondylotic Radiculopathy Due to Osseous Foraminal Stenosis

  • Ye Jiang;Chen Li;Lutao Yuan;Cong Luo;Yuhang Mao;Yong Yu
    • Journal of Korean Neurosurgical Society
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    • v.66 no.4
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    • pp.426-437
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    • 2023
  • Objective : To investigate the efficacy and safety of the posterior endoscopic cervical foraminotomy (PECF) using ultrasonic osteotome for the treatment of cervical osseous foraminal stenosis, focusing on introduction of the advantages of ultrasonic osteotome in partial pediculectomy and ventral osteophyte resection in PECF. Methods : Nineteen patients with cervical osseous foraminal stenosis who underwent PECF using ultrasonic osteotome in our institution between April 2018 and April 2021 were enrolled in this study. All the patients were followed up more than 12 months. The patients' medical data, as well as pre- and postoperative radiologic findings were thoroughly investigated. The visual analogue score (VAS), Japanese Orthopaedic Association (JOA) score, cervical dysfunction index (Neck disability index, NDI), and modified MacNab criteria were used to assess the surgical efficacy. Results : All the patients were successfully treated with PECF using ultrasonic osteotome. The pre- and postoperative VAS, NDI, and JOA scores were significantly improved (p<0.05). According to the modified MacNab criteria, 17 patients were assessed as "excellent", two patients were assessed as "good" at the last follow-up. There was no dura tear, nerve root damage, incision infection, neck deformity, or other complications. Conclusion : Adequate nerve root decompression can be accomplished successfully with the help of ultrasonic osteotome in PECF, which has the advantage of reducing the probability of damage to the nerve root and dura mater, in addition to the original merits of endoscopic surgery.

Repeated Dose and Reproductive/Developmental Toxicities of Acetanilide in Rats (랫드를 이용한 Acetanilide의 반복투여 및 생식/발생독성 병행시험)

  • Chung, Moon-Koo;Baek, Sung-Soo;Lee, Sang-Hee;Kim, Hyun-Mi;Choi, Kyung-Hee;Han, Sang-Seop
    • Toxicological Research
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    • v.23 no.4
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    • pp.391-403
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    • 2007
  • The study was conducted to assess the repeated dose and reproduction and developmental toxicities of acetanilide, an intermediate for drug production, as a part of OECD Screening Information Data Set (SIDS) program. The test agent was administered by gavage at dose levels of 0, 22, 67, 200 and 600 mg/kg to Sprague-Dawley rats (12/group/sex) during pre-mating and mating period for males(up to 30 days) and females and pregnancy and early lactation period for females (up to 39-50 days). At 22 mg/kg, decreases in HGB, HCT (males) and MCHC (females), hyperplasia of spleen red pulp, hyperplasia of femur bone marrow (both sexes) were observed. At 67 mg/kg, salivation (males), reduced food consumption (both sexes), decreases in RBC, HGB, HCT and MCHC (males), increases in MCV (males) and spleen weight (males), hyperplasia of spleen red pulp and femur bone marrow (both sexes) were observed. At 200 mg/kg, decreases in locomotor activity and salivation (both sexes), reduced food consumption (both sexes), decreases in RBC, HGB, HCT and increases in MCV, MCH, BUN, T-BIL (males), enlargement of spleen (both sexes), increased weight of spleen (males), hyperplasia of spleen red pulp and femur bone marrow and extramedullary hematopoiesis of liver (both sexes), atrophy of thymus and corpus luteum hyperplasia of ovary (females) were observed. At 600 mg/kg, decreases in locomotor activity, cyanosis (both sexes), reddish tear, and salivation (males), mortality (4 out of 12 females), decreased body weight (females), reduced food consumption (both sexes), decreases in RBC, HGB, HCT and MCHC and increases in WBC, MCV, MCH, reticulocyte, neutrophil, lymphocyte, monocyte, AST, ALT, BUN, T-BIL, ALB, Ca and A/G ratio (males), enlargement of spleen, increased weights of spleen (both sexes), liver (males), kidney and ovary, decreased weights of thymus (females), hyperplasia of spleen red pulp, hyperplasia of femur bone marrow and extramedullary hematopoiesis of liver (both sexes), and atrophy of thymus and corpus luteum hyperplasia of ovary (females) were observed. Regarding the reproduction and development toxicities, there were no treatment-related changes in precoital time, mating index, fertility index and pregnancy index at all doses tested. At 22 and 67 mg/kg, there were no adverse effects on all the parameters observed. At 200 mg/ kg, decreased body weight of pups (day 4 p.p.) were observed. At 600 mg/kg, decreased body weight of pups (day 0 and 4 p.p.) and viability index (day 4 p.p.), increased incidence of newborns dead or with abnormal clinical signs were observed. The results suggest that the NOAELs for general toxicity are < 22 mg/kg, LOAELs are 22 mg/kg and the NOAELs for reproductive toxicity are 67 mg/kg.