• Title/Summary/Keyword: Burst index

Search Result 80, Processing Time 0.018 seconds

Short-segment Pedicle Instrumentation of Thoracolumbar Burst-compression Fractures; Short Term Follow-up Results

  • Shin, Tae-Sob;Kim, Hyun-Woo;Park, Keung-Suk;Kim, Jae-Myung;Jung, Chul-Ku
    • Journal of Korean Neurosurgical Society
    • /
    • 제42권4호
    • /
    • pp.265-270
    • /
    • 2007
  • Objective : The current literature implies that the use of short-segment pedicle screw fixation for spinal fractures is dangerous and inappropriate because of its high failure rate, but favorable results have been reported. The purpose of this study is to report the short term results of thoracolumbar burst and compression fractures treated with short-segment pedicle instrumentation. Methods : A retrospective review of all surgically managed thoracolumbar fractures during six years were performed. The 19 surgically managed patients were instrumented by the short-segment technique. Patients' charts, operation notes, preoperative and postoperative radiographs (sagittal index, sagittal plane kyphosis, anterior body compression, vertebral kyphosis, regional kyphosis), computed tomography scans, neurological findings (Frankel functional classification), and follow-up records up to 12-month follow-up were reviewed. Results : No patients showed an increase in neurological deficit. A statistically significant difference existed between the patients preoperative, postoperative and follow-up sagittal index, sagittal plane kyphosis, anterior body compression, vertebral kyphosis and regional kyphosis. One screw pullout resulted in kyphotic angulation, one screw was misplaced and one patient suffered angulation of the proximal segment on follow-up, but these findings were not related to the radiographic findings. Significant bending of screws or hardware breakage were not encountered. Conclusion : Although long term follow-up evaluation needs to verified, the short term follow-up results suggest a favorable outcome for short-segment instrumentation. When applied to patients with isolated spinal fractures who were cooperative with 3-4 months of spinal bracing, short-segment pedicle screw fixation using the posterior approach seems to provide satisfactory result.

산화전분 코팅이 골판지 원지의 물성에 미치는 영향 (Effect of Coatings of Oxidized Starch on Properties of Linerboard)

  • 안병국;안원영
    • Journal of the Korean Wood Science and Technology
    • /
    • 제28권1호
    • /
    • pp.71-79
    • /
    • 2000
  • 산화전분을 골판지 구성원지인 표면라이너지와 이면라이너지에 각각 코팅하고 물성변화를 조사하였다. 산화전분 코팅에 의해 골판지 믈성과 관련된 각 라이너지의 물성이 개선되었고 링 크러시 강도의 경우 표면라이너지보다 이면라이너지에서 개선의 효과가 더욱 컸으며 도공하지 않은 경우에 비해 최대 19.7%의 증가를 보였다. 비교적 낮은 도공량으로도 파열지수는 증가하였으며 일정 수준의 도공량 이상에서는 더 이상 증가하지 않는 것으로 조사되었다. 파열강도가 증가함에 따라 링 크러시 강도도 증가하는 경향을 보였다. 표면라이너지, 이면라이너지 각각 1.41g/$m^2$, 1.58g/$m^2$의 도공량에 이를 때까지 TEA는 크게 증가하였으며 인장강도가 증가함에 따라 링 크러시 강도도 대체적으로 증가되었다. 낮은 도공량에서 stiffness가 증가하였으며 도공처리로 라이너지의 투기도는 감소하였지만 원지 간 결합에 장애를 일으킬 만큼의 염려는 없을 것으로 판단되었다.

  • PDF

Effect of the Inhibition of Phospholipase $A_2$ in Generation of Free Radicals in Intestinal Ischemia/Reperfusion Induced Acute Lung Injury

  • Lee, Young-Man;Park, Yoon-Yub;Kim, Teo-An;Cho, Hyun-G.;Lee, Yoon-Jeong;Repine, John E.
    • The Korean Journal of Physiology and Pharmacology
    • /
    • 제3권3호
    • /
    • pp.263-273
    • /
    • 1999
  • The role of phospholipase $A_2\;(PLA_2)$ in acute lung leak induced by intestinal ischemia was investigated in association with neutrophilic respiratory burst. To induce lung leak, we generated intestinal ischemia for 60 min prior to the 120 min reperfusion by clamping superior mesenteric artery in Sprague-Dawley rats. Acute lung leak was confirmed by the increased lung leak index and protein content in bronchoalveolar fluid. These changes were inhibited by mepacrine, the non-specific $PLA_2$ inhibitor. The lung myeloperoxidase (MPO) activity denoting the pulmonary recruitment of neutrophils was increased by intestinal I/R, but decreased by mepacrine. Simultaneously, the number of leukocytes in bronchoalveolar fluid was increased by intestinal ischemia/reperfusion (I/R) and decreased by mepacrine. Gamma glutamyl transferase activity, an index of oxidative stress in the lung, was increased after intestinal I/R but decreased by mepacrine, which implicates that $PLA_2$ increases oxidative stress caused by intestinal I/R. The $PLA_2$ activity was increased after intestinal I/R not only in the intestine but also in the lung. These changes were diminished by mepacrine. In the cytochemical electron microscopy to detect hydrogen peroxide, intestinal I/R increased the generation of the hydrogen peroxide in the lung as well as in the intestine. Expression of interleukin-1 (IL-1) in the lung was investigated through RT-PCR. The expression of IL-1 after intestinal I/R was enhanced, and again, the inhibition of $PLA_2$ suppressed the expression of IL-1 in the lung. Taken together, intestinal I/R seems to induce acute lung leak through the activation of $PLA_2$, the increase of IL-1 expression associated with increased oxidative stress by neutrophilic respiratory burst.

  • PDF

EVALUATIN OF NALITA WOOD(Trema orientalis) AS SOURCE OF FIBER FOR PARERMAKING

  • ;문성필
    • 한국펄프종이공학회:학술대회논문집
    • /
    • 한국펄프종이공학회 2003년도 추계학술발표논문집
    • /
    • pp.17-26
    • /
    • 2003
  • Nalita wood(Trema orientalis) is one of the fastest growing woods in the world. It may be a viable species for pulpwood. The physical, chemical and morphological properties of Nalita were studied. The total lignin, pentosan and holocellulose content in Nalita wood were 24.7%, 22% and 81.2%, respectively. Its fiber length was about 0.92 mm, which are comparable to Acacia mangium. Nitrobenzene oxidation of Nalita wood meal indicated that the guaciayl and syringyl unit were the major constituent of Nalita lignin. Nalita produced 50% pulp yield at Kappa number 21 in soda-anthraquinone process. The strength properties of Nalita pulp were comparable to other tropical hardwood pulp. At $40_{\circ}$ SR, the breaking length, burst index, tear index and total energy absorption were 6000 m, $3.5kPa{\cdot}m^2/g\;and\;7.0mN{\cdot}m^2/g\;and\;75J/m^2$, respectively.

  • PDF

베트남산 대나무의 펄프화 특성 (Pulping Characteristics of Bamboo(Bambusa procera acher) Grown in Vietnam)

  • 원종명;김민현
    • 펄프종이기술
    • /
    • 제41권4호
    • /
    • pp.52-57
    • /
    • 2009
  • Soda and kraft pulping experiments were carried out in order to investigate the pulping characteristics of bamboo grown in Vietnam. The merit of kraft pulping was not observed for bamboo pulping from the viewpoint of delignification and screened pulp yield. The improvements of delignification during soda and kraft pulping of bamboo were observed by the addition of AQ. The bamboo pulp leaded the bulkier structure than those made from SwBKP and HwBKP. The average fiber length was 1.62mm which is shorter than those of SwBKP, but longer than those of HwBKP. It was found that the physical properties of bamboo pulp sheet could be varied by the pulping method, cooking condition, AQ addition, bleaching and refining etc.

Effect of Urea Addition on Soda Pulping of Oak Wood

  • Cho, Nam-Seok;Matsumoto, Yuji
    • 한국펄프종이공학회:학술대회논문집
    • /
    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
    • /
    • pp.285-290
    • /
    • 2006
  • As an alternative method to solve air pollution problem and difficulty of pulp bleaching of kraft pulping process, NaOH-Urea pulping was applied. The properties of NaOH-Urea pulp were compared to those of NaOH and kraft pulps. Addition of urea in low alkali charges retarded delignification rate compared to NaOH pulping. But, in high alkali application, delignification was significantly enhanced not from the addition of urea but from the high alkalinity. It was disclosed that urea did not participate on delignification reaction by the experiment using lignin model compound. Compared to paper strengths at the same level of sheet density, NaOH-Urea pulp gave as almost same breaking length and tensile index as those of kraft pulp. Especially tensile energy absorption and burst index were higher than those of kraft pulp.

  • PDF

Bio-Soda Pulping of Rice Straw with Pleurotus cornucopiae under Atmospheric Pressure

  • Ju, Yong-Chan;Kang, Jin-Ha
    • 펄프종이기술
    • /
    • 제35권5호
    • /
    • pp.62-71
    • /
    • 2003
  • This study was carried out to develop the bio-chemical pulping method to enhance the energy saving and decrease the capital cost through the soda pulping under atmospheric pressure ($100^{\circ}C$). Nonwood substrates, rice straw, were pretreated by white-rot fungi, Pleurotus cornucopiae. Several basic pieces of data that can be applied in soda pulping were acquired. The results of this study were as follows. Under the conditions without any nutrients or with glucose, N and glucose + N, the weight losses of rice straws inoculated by Pleurotus cornucopiae were 12.1∼32.6 %, 12.0∼26.3 %, 13.0∼25.4 % and 15.3∼24.7 % for 5, 10, 15, 20, 25 and 30 days incubation periods respectively. The more the fungal incubation was extended, the more the weight losses were gained. The yield of untreated rice straw was 54.8 % after pulping. When any nutrients was not added or glucose, N and glucose + N were added for the pretreatment, the total yields were ranged to 57.3∼42.9 %, 51.0∼43.3 %, 51.7∼43.9 % and 52.1∼46.1 % for 5 different incubation periods respectively. The yields were gradually decreased based on the extending of the incubation periods. The physical properties of the rice straw soda pulp without fungal treatment, the density, breaking length, burst index, tear index and folding endurance were 0.24g/㎤, 2.32 Km, 0.91 kPaㆍ$m^2$/g, 46.7 mNㆍ$m^2$/g and 21 times, respectively. In the case of pretreatment without any nutrients or with glucose, N and glucose + N as nutrients, the density was 0.24g/㎤, the breaking length was 3.30∼6.46 Km, the burst index was 1.36∼3.01 kPaㆍ$m^2$/g, the tear index was 33.0∼57.0 mNㆍ$m^2$/g and the folding endurance was 14∼381 times at most incubating periods, when pulping was done. The physical properties were increased as the incubation duration was extended. Especially, when N and glucose + N were added, the physical properties showed superior results during each incubation period.

초음파처리에 의한 KOCC의 개질 (Modification of KOCC with Ultrasonic Wave Treatment)

  • 허밍;이용규;원종명
    • 펄프종이기술
    • /
    • 제45권5호
    • /
    • pp.44-48
    • /
    • 2013
  • Ultrasonic treatment of KOCC was tried to explore the possibility for improvement of KOCC quality as a raw material for making industrial packaging paper and paperboard. The effect of pH, stock consistencies and treatment times on the ultrasonic response of KOCC were investigated. WRV, apparent density, tensile index and burst index were improved as pH of KOCC slurry is increased. However highest tear index and stiffness were obtained at pH 8. It was also found that the highest WRV and strength properties could be obtained at 0.5% of KOCC consistency during ultrasonic treatment. WRV and most strength properties were improved with ultrasonic treatment time. It was found that ultrasonic treatment can be used as a useful mean for KOCC modificaton.

TMP의 LB 공융용매 처리 시 젖산/베타인 몰 비율이 리그닌 함량 및 수초지 특성에 미치는 영향 (Effect of Molar Ratios of DES on Lignin Contents and Handsheets Properties of Thermomechanical Pulp)

  • 최경화;이명구;류정용
    • 펄프종이기술
    • /
    • 제48권2호
    • /
    • pp.28-33
    • /
    • 2016
  • This study was conducted to investigate the effects of deep eutectic solvent (DES) treatment on properties of TMP fibers and handsheets. DES was prepared by mixing of lactic acid and betaine (L and B), and the molar ratio of these two components mixtures was controlled to 2:1 (L:B=2:1) and 5:1 (L:B=5:1). As results, lignin was partly extracted from the TMP fibers. Especially, the delignification of TMP samples was promoted according to the increase of the molar ratio of lactic acid. Except for tear index, both tensile index and burst index of handsheets were increased when higher molar ratio of lactic acid was mixed for DES preparation. However, the LB DES treatment of TMP fibers didn't give any effect on the optical properties of TMP handsheets. The plausibility of TMP fiber was to be enhanced by LB DES treatment.

O, Eo 및 C/D단계를 이용한 신갈나무 크라프트펄프표백 (Bleaching of Oak Kraft Pulp by O, Eo and C/D Stage)

  • 김동호;백기현
    • 펄프종이기술
    • /
    • 제29권3호
    • /
    • pp.43-50
    • /
    • 1997
  • The purpose of this study was to decrease pollutants of effluents from KP bleaching. Multistage bleaching that combined with O, Eo, and C/D stage was conducted, after optimum bleaching conditions of O, Eo, and C/D stage were determined. Moreover the properties for bleached pulps and pollution level of bleaching effluent were measured by each standard method. Due to increase on the brightness and delignification of pulps by O, Eo, and C/D stage bleaching. It was possible that bleaching sequences were reduced from five stage to four stage. In addition to, OC/DEoD and OC/DEopD bleaching sequences had higher brightness than CEDED bleaching sequence. The pulps bleached by O and Eo stage had higher in tensile index than conventional bleaching sequences with the similar results in burst and tear index. While each bleaching sequences had little differences, bleaching sequences with Eo stage had higher in physical properties than with Eop stage. The pollution level measured by Chemical Oxygen Demand(COD), Biochemical Oxygen Demand(BOD) and Color of bleaching effluents were much lower in combined bleaching sequences of O, Eo and C/D stage than that of CEDED sequence. Particularly, a pollution index of bleaching effluents generated by C/DEoDEB and OC/DEopDED bleaching sequences were lower than that from the other bleaching sequences.

  • PDF