Polyethylene glycol (PEG) 처리에 의한 국내산 소경재의 치수안정화에 관한 연구 Ⅱ : 환경재와 산공재의 비교 Comparison of Ring-Porous Wood and Diffuse-Porous Wood

권구중,권성민,김남훈 한국목재공학회 2003 목재공학 Vol.31 No.4

본 연구에서는 국내산 소경재의 보다 효율적인 이용을 위하여 PEG처리한 활엽수재의 환공재 4수종(신갈나무, 굴참나무, 물푸레나무, 오동나무)과 산공재 4수종(산벚나무, 물박달나무, 층층나무, 은사시나무)에 대한 치수안정성을 평가하였다. 수축률은 공시수종 모두 PEG처리에 의해 감소하는 효과가 있었고, 산공재가 환공재보다 낮았다. 중량증가율은 PEG농도의 증가에 따라 증가되었고, 산공재가 환공재보다 다소 높은 증가율을 보여주었다. 벌킹효과는 PEG농도의 증가에 따라 증가하였지만, 분자량이 클수록 감소하였고, 산공재가 환공재보다 벌킹효과가 높게 나타났다. 결론적으로, 산공재가 환공재보다 높은 치수안정성을 보여주었다. 따라서 PEG처리재의 치수안정효과는 목재의 구조(도관의 분포상태 및 타이로시스 존재유무)와 밀도에 크게 영향받는 것으로 생각되었다. This study was carried out to investigate the dimensional stability of wood treated with PEG for better utilization of domestic small-diameter logs. Four species of ring-porous wood(Quercus mongolica F_(ISCH), Quercus variabilis B-(LUME), Fraxinus rbynchopbhlla H_(ANCE), Paulownia coreana U_(YEKI),) and fore species of diffuse-porous wood(Prunus sargentii R-(EHDER), Betjal davurica P_(ALL), Populus tomentiglandulosa T. L_(EE), cornus controversa H_(EMSLEY)) were used for this experiment. The shrinkage of wood decreased with increasing the concentration of PEG. The shrinkage of diffuse- porous woods was lower than that of ring-porous woods. The weight gain increased in proportional to the PEG concentration. Diffuse-porous woods showed a little higher weight gain than ring-porous woods. Bulking effect also increased with increasing the PEG concentration, but was in inverse proportional to the molecular weight of PEG. Diffuse-porous woods showed higher bulking effect than ring-porous woods. Consequently, diffuse-porous woods showed better dimensional stability than ring porous woods. It was considered that dimensional stability was affected by characteristics of wood such as vessel and tylosis, and density.

국내산 잣나무와 낙엽송의 재질

권성민,황원중,권구중,김남훈 江原大學校 森林科學硏究所 2004 Journal of Forest Science Vol.20 No.-

국산 잣나무와 낙엽송의 비중, 연륜폭, 만재율, 종압축강도, 횡압축강도 및 전단강도를 측정하고 방사 ?향의 병이를 조사하여 다음의 결과를 얻었다. 1) 비중은 잣나무가 0.48로 낙엽송의 0.88보다 약 2배정도 낮은 값을 보였다. 두 수종 모두 수심에서 낮은 값을 보여주고 그 후 약 15연륜 까지 다소 증가하다가 일정해지는 경향을 보여주었다. 2) 연륜폭은 잣나무 3.43㎜, 낙엽송 2.83㎜로 잣나무가 낙엽송에 비해 넓었으며, 만재율은 잣나무 30%, 낙엽송 47%로 낙엽송이 잣나무에 비해 높았다. 두 수종 모두 만재율이 커짐에 따라 비중은 커지는 경향을 나타냈다. 3) 종압축강도와 종압축 비례한도, 종압축 영계수는 잣나무가 각각 300kgf/㎠, 270kgf/㎠, 9.2×10³kgf/㎠로서 낙엽송의 600kgf/㎠, 550kgf/㎠, 20×10³kgf/㎠에 비해 모두 낮은 수치를 나타내었다. 종압축강도, 종압축 비례한도 및 영계수의 방사방향변이는 두 수종 모두 뚜렷한 경향을 보이지 않았다. 4) 방사단면의 전단강도는 잣나무가 51kgf/㎠, 낙엽송이 69kgf/㎠으로 낙엽송이 컸으며, 접선단면은 잣나무가 56kgf/㎠, 낙엽송이 86kgf/㎠으로 낙엽송이 큰 값을 나타내었다. Density, annual ring width, latewood percentage and compressive properties of Pinus koraiensis and Larix kaempferi grown in Research Forest of Kangwon National University were measured and their radial variations were investigated. Density(Wa/Va) of Pinus koraiensis and Larix kaempferi was 0.48g/cm² and 0.88g/cm², respectively. Density of both species was slightly lower at pith area, increased gradually with cambial age up to about 15 years and then became constant. Annual ring width of both species was 3.43㎜ and 2.83㎜, respectively. Annual ring width of both species was irregular at pith area but regular after about 20 years. Latewood percentage of both species was 30% and 47%, respectively. Latewood percentage of Pinus koraiensis and Larix kaempferi increased with cambial age up to 14 years and 10 years, respectively and then became constant. Compressive strength, proportional limit and Young's modulus parallel to the grain of Pinus koraiensis were 330 kgf/cm², 270 kgf/cm² and 9.2×10³ kgf/cm², and those of Larix kaempferi were 600 kgf/cm², 550 kgf/cm² and 20×10³ kgf/cm², respectively. Shearing strength in radial direction of Pinus koraiensis and Larix kaempferi was 51 kgf/cm² and 69 kgf/cm², and that of tangential direction was 56 kgf/cm² and 86 kgf/cm², respectively. In this study, compressive and shearing properties of both species did not show any significant differences between juvenile wood and adult wood. Both species showed significant differences in the measured values.

On various statistical convergence of fuzzy numbers

권중성 선문대학교 자연과학대학 2001 자연과학논총 Vol.4 No.-

유리기판 위에 염화학증착법으로 투명전도성 산화주석막을 제조하였다. 박막은 원료물질로 tetramethyltin (TMT), 산화제로 산소나 오존이 포함된 산소의 흔할물로부터 제조되었다. 제조된 박막은 기판온도에 따라 물성이 크게 변하였고 최적화된 박막은 TMT 유량 8 sccm, 산소유량 150 sccm, 기판온도 380에서 제조되었다. 오곤존 사용함으로서 기판은도를 약 180℃정도 낮출 수 있었고 비저항은 ∼10-3Ω㎝에서 -10-3Ω㎝으로 감소시킬 수 있었다. Transparent and conducting tin oxide thin films were prepared on soda lime silicate glass by thermal chemical vapour deposition. Thin films were fabricated from mixtures of tetramethyltin (TMT) as a precursor, oxygen or oxygen containing ozone as an oxidant. The properties of fabricated tin oxide films are highly changed with variations of substrate temperature. Optimized thin films could be prepared on TMT, which flow rate of 8 sccm, oxygen flow rate of 150 sccm and substrate temperature of 380℃. We reduced deposition temperature about 180℃ by using of oxygen containing ozone instead of pure oxygen and resistivity of thin films was decreased from ∼×10-3Ω㎝ to ∼×10-3Ω㎝.

한국인 관상동맥의 변화양상에 대한 형태학적 연구

권태정,이상용,이한영,고영창,권기석,조재홍,김태공,김유훈,조갑래,서중석,이원태 內務部 國立科學搜査硏究所 2001 國立 科學 搜査 硏究所 年報 Vol.33 No.-

국내에서 생장한 Kenaf의 해부학적 특성

권영만,황원중,권성민,조준형,이명구,김남훈 江原大學校 森林科學硏究所 2005 Journal of Forest Science Vol.21 No.-

국내에서 재배한 kenaf의 해부학적 특성을 광학현미경법으로 조사하였다. Kenaf의 수피부에는 인피섬유, 사부방사조직, 피층유세포 등이 존해하였고, 목질부는 도관, 목섬유, 방사조직 등으로 구성되어 있었다. 도관은 고립관공과 2~3개가 방사방향으로 복합한 복합관공이 많이 존재하였고, 방사조직은 평복, 직립, 방형세포가 모두 분포하고 있었다. 접선단면에서 방사조직은 단열 및 다열방사조직으로 구성되었다. 수피비의 인피섬유층은 생장기간과 함께 증가하였다. Anatomical properties of Kenaf cultivated in Korea was investigated using light microscopy. Bast fiber, phloem ray and cortex parencyma cell were observed in bast, and vessel, wood fiber and rat in core. A lot of solitary and multiple radial pores in core existed. The cell type of ray parenchyma in radial section was procumbent, upright and square sell. Uniseriate and multiseriate rays existed in tangential section. The layer of bast fiber in bast increased with in creasing the growth period.

포스트-텐션 프리캐스트 외부 넓은 보-기둥 접합부의 비탄성 거동

박상욱,최윤철,김영찬,김대중,임재형,권기혁,문정호,이리형 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2(구조계)

Experimental results from the cycle lateral load tests for post-tensioned precast wide beam-column connections were presented. Six exterior beam-column assemblages of half scale were tested in the laboratory. The specimens consist of U-shaped precast wide beams and concrete columns. The continuity at the beam-column joint is achieved with the topping concrete and post-tensioning. The specimens were designed with parameters of the beam-to-column depth ration and the number of tendons within column core. The test results showed that the post-tensioned precast wide beam-column connection satisfied the provisional standard by ACI of acceptance criteria for concrete special moment frames.

한국인 관상동맥의 변화양상에 대한 형태학적 연구

이상용,권태정,정낙은,서중석,이한영,이원태 大韓法醫學會 2002 대한법의학회지 Vol.26 No.1

삭골(Bone shaving)한 골의 재생에 골막이 미치는 영향

강진성,권건영,송중원,오석희,한기환 大韓成形外科學會 1989 Archives of Plastic Surgery Vol.16 No.5

Many orientals have a more prominent malar eminence and mandibular angle than westerners so their faces often look rough and unattracive. In recent years more people want to have a more attractive and beautiful face due to economic prosperity and westernization. Therefore people receiving bone shavings or osteotomies for cosmetic purposes are increasing. The effects of the periosteum on lay bone grafts were investigated but the effect of the periosteum after bone shaving or osteotomy is little known. The authors investigated the effect of the periosteum on the regeneration of bone in membranous and endochondral bone of rabbits. Bony defects each measuring about 5.0×5.0×1.5mm were made on the left and right sides of the parietal bones of 15 rabbits and femurs of 15 other rabbits respectively. The periosteum was preserved on the left and removed on the right. The following results were obtained: 1) The average thickness of the regenerated bones in groups 2 δ4 were thinner than those in groups 1 δ 3 at 4, 8 and 12 weeks postoperatively but the differences of thickness were statistically significant at onl 4weeks postoperatively(P<0.05). 2) The histological findings in groups 2 δ 4 showed lesser regeneration of the shaved bone than those in groups 1 δ 3 at 4, 8 and 12weeks postoperatively. 3) There was no significant increase in the thickness of the regenerated bone after 8 weeks postoperatively in all groups. 4) At 12 weeks postoperatively, the thickness of the regenerated bone in all groups was over 70% of the thickness of the resected bone. In summary, the authors found that it is important to perform overcorrection and resect the periosteum simultaneously in bone shaving to prevent the unwanted regeneration.

야간 혈압 변동과 좌심실 질량, 이완기 기능 및 QT 간격과의 관계

김수중,이병호,손일석,강흥선,조정휘,김권삼,송정상,배종화 대한간질학회 2003 대한간질학회지 Vol.9 No.1

백서 Paraquat 두여에 의한 간과 폐 조직의 산화성 손상에서 Vitamin C와 Deferoxamine의 항산화 효과에 관한 연구

정연권,서길준,정중식,정성은,최국진,윤여규 대한응급의학회 2000 대한응급의학회지 Vol.11 No.4

Background: The toxicity of paraquat has been known to be caused by oxygen free radicals which leads to the lipid peroxidation and multiple organ failure. Although vitamin C has been known to be a potent antioxidant, recently there are numerous data which have shown that a low dose of vitamin C may act as a prooxidant due to the stimulation of the Fenton reaction with metal ions, which produces hydroxyl radicals. It has been reported that a deferoxamine in paraquat intoxication could reduce the production of the hydroxyl radicals by the inhibition of the Fenton reaction through the reduction of iron ion in tissue. The aim of this study was to evaluate the effect of the high and low dose of vitamin C and deferoxamine on lipid peroxidation and plasma TNF-α in paraquat intoxication. Methods: Female Sprague -Dawley rats were divided into seven groups: control group which was not given paraquat(20 mg/kg), P group which was given paraquat only, PVH group given paraquat and high dose of vitamin C(100 mg/kg), PVL group given paraquat and low dose of vitamin C(10 mg/kg), PVHD given paraquat, high dose of vitamine C and deferoxamine(100 mg/kg), PVLD given paraquat, low dose of vitamin C and deferoxamine, and PD given paraquat and deferoxamine. Animals were killed at 6 and 24 hours after treatment. Malondialdehyde(MDA), superoxide dismutase(SOD) and glutathione(GSH) contents, catalase activity, plasma TNF-α, and histologic changes in the lung and liver tissue were measured. Results: The lung histology in the PVH and PD or PVHD groups showed the significant decreases in the alveolar edema and interstitial thickness compared to the P group. The liver histololgy in the PVH and PVHD groups demonstrated marked differences in the central venous and sinusoidal dilatation compared to that of the P group. While the MDA levels of the lung and liver in the PVH and PD groups showed the significant reduction compared to that of the P group at 6 hours after treatment, all groups showed the significant changes compared to the P group at 24 hours. There was no significant change of the SOD levels of the lung and liver at 6 hours among all groups. At 24 hours, the SOD levels of the lung in PVH, PVL, and PVHD groups showed the significant increases compared to the P group. The increase of the SOD level in groups combined with deferoxamine, however, revealed a little reduction. The SOD level of the liver in PVH group only significantly increased compared to the P group at 24 hours. There was no significant change of the GSH level of the lung and liver among all groups at 6 hours. At 24 hours, the GSH level of the lung and liver were significantly increased in both PVH and PD group and PVH group, respectively, compared to the P group. Although the catalase activity of the lung was not significantly increased, that of liver was signiflcantly increased in both PVHD and PD groups compared to the P group at 6 hours. The catalase activities of the lung and liver were significantly increased in PVH, PD, and PVHD at 24 hours. The concentrations of the plasma TNF-α were slightly decreased at 6 hours and slightly increased at 24 hours compared to that of the P group, but they were not significant. Conclusion: This study showed that although the low dose of vitamin C had no effect, the high dose of vitamin C revealed a decrease of the MDA level and an increase of SOD, GSH, and catalase activity in the lung and liver tissues, and the effect of the high dose of vitamin C increased with time. The administration of the deferoxamine with or without high dose of vitamin C, however, significantly showed the inhibition of the lipid peroxidation and antioxidant effect and low dose vitamin C decreased the effect of deferoxamine. The effects of the vitamin C and deferoxamine on plasma TNP-α were not clearly shown.