대나무재의 접착성

노정관,김재경,김사익,조종수,윤승락 진주산업대학교 1999 산업과학기술연구소보 Vol.- No.6

3종의 죽재(맹종죽, 왕대 및 솜대)에 대한 특성(생재함수율, 절간길이, 두께등)의 변이 및 상온경화형 수지 접착제에 대한 죽재의 접착성능을 검토한 결과는 다음과 같다. 생재함수율은 죽고 및 절부나 절간부에 관계없이 솜대가 가장 낮았으며, 솜대나 맹종죽은 죽고가 증가함에 따라 점점 감소하는데 반해 왕대는 중간부가 가장 높았다. 절간부의 길이는 3죽종 모두 하간부나 상간부에서 보다 중간부에서 길었으며, 절간수 20까지의 절간길이의 평균은 왕대, 솜대, 맹종죽의 순이었다. 동일직경에서 간벽의 두께는 맹종죽이 가장 두꺼웠으며, 왕대가 가장 얇았다. 맹종죽에 대한 상온경화형 수지 접착제의 접착성능은 PVAc와 요소수지가 우수하였으며, 동일접착조건에서의 목재(낙엽송)와 목재 접착재료 보다도 내수접착강도는 약 2배 우수하였다. 구조용 상온경화형 수지 중에서는 수성고분자-이소시아네이트 수지 접착제의 접착성능이 가장 양호하였다. 접착성능이 비교적 우수한 PVAc 및 수성고분자-이소시아네디트수지에 의한 왕대의 접착성능은 양수지 모두 맹종죽 보다 우수하였다. 접착부위(절부+절부, 절부+절간부, 절간부+절간부)나 적층시의 접착면(외피부+외피부, 외피부+내피부, 내피부+내피부)에 따른 맹종죽의 접착성능에는 큰 차이가 없으나, 단지 내피부간의 절부와 절부의 접착성능은 타 접착면이나 접착부위 보다 10∼20㎏f/㎠ 낮았다. The variation of characteristics including green moisture content, internode length, and clum-wall thickness and the bonding properties of ambient setting resin adhesives in three bamboo species, Phyllostachys pubesens Mazel. et Z (Moso bamboo), P. bambusoides Sieb. et Zucc (Giant Timber bamboo), and P. nigra var. henosos Stapf (Hachiku bamboo), were evaluated. Among three species, Hachiku bamboo showed the lowest green moisture cintent without exception for culm height, node and internode parts. In species of Hachiko and Moso bamboos, as the culm height was increased, green moisture content in middle culm. Compared with lower or upper culms, the internode length was the longest in middle culm of all three species. and the order of averaged internode length under internode number 20 was as followed; Giant Timber bamboo>Hachiku bamboo>Moso bamboo. With same value of diameter, Moso bamboo contained the thickest culm-wall, while Giant Timber bamboo the thinnest. The superior bonding property of ambient setting resin for mon-structural uses in Moso bamboo was obtained in PVAc and urea-formaldehyde resin, and the wet bonding strength was two times better than in wood (Larix species) adhesion, Among the ambient setting resins for structural uses, water based polymer-isocyanate resin adhesives showed the best bonding properties. In Giant Timber bamboo, the bonding properties using PVAc and water based polymer-isocyanate resin adhesives were better than in Moso bamboo. There were no significant differences on bonding properties in Moso bamboo depending on adhesion position and zone, but the bonding property of node-node parts, which were bonded as inner layer and inner layer, was lower by 10 to 20㎏f/㎠ than other adhesion position and zone.

폐기 목질 재료로 제조한 학생용 책상 천판의 성능에 미치는 성형조건의 영향

노정관,김재경,김사익,조종수,윤승락,나종범,도정락 한국목재공학회 2002 목재공학 Vol.30 No.4

폐기 목질재료를 사용하여 학생용 책상 천판의 성형시 각 제조조건에 따른 천판의 성능을 검토하였다. 책상 천판의 파티클 구성은 고운 파티클과 거친 파티클을 적절히 혼합한 것이 고운 파티클이나 거친 파티클만으로 제조한 것보다는 전체적으로 성능이 양호하였으며, 특히 표층에는 고운 파티클을 중층에는 거친 파티클을 구성하는 것이 표면 마감성이 가장 우수하였다. 그리고 밀도가 높을수록 박리강도, 휨 강도는 우수하나, 흡수두께 팽창율은 증가하였으며, 수지 도포량이 많을수록 박리강도, 흡수두께 팽창율은 양호하나, 포름알데히드의 방출량은 높았다. 가압온도는 높을수록 대부분의 성능이 향상되었으며, 190℃가 가장 적절하였다. 가압시간은 1단계 2분과 2단계 2분이 비교적 양호하나 2단계의 가압시간을 1분으로 단축하여도 성능에는 큰 문제가 없어 앞으로 생산성의 향상을 기대할 수 있을 것으로 생각된다. This research was performed to investigate the effect of moulding conditions on properties of the table top for student desk manufactured by wood waste materials. The table top manufactured using the mat mixed properly with fine particles and coarse particles generally showed better physical properties than those manufactured using either fine particles or coarse particles did. Especially, highest performance for overlaying was observed when fine particles were used for face layer and coarse particles were used for core layer. The internal bond (IB) strength, the bending strength and thickness swelling increased with the increase of density. Most of physical properties were improved with the increase of hot pressing temperature. The best physical properties were found at 190℃ when the first hot pressing and the second hot pressing times were two minutes. However, the effect of the second hot pressing time of two minutes on the physical properties was not markedly different from that of one minute. This result suggests that the second hot pressing time of one minute is enough to increase the productivity in manufacturing the table top with the least decrease of the physical properties.

전립선 비대증 진단에 있어서 전립선 이행대 용적 지수의 유용성

임재성,노안식,김용웅,육승모 충남대학교 의과대학 의학연구소 2003 충남의대잡지 Vol.30 No.1

Purpose : Prostate volume has been poorly correlated to various parameters used to assess benign prostatic hyperplasia (BPH), including symptom score, peak urine flow and detrusor pressure at peak urine flow. The purpose of this study was 2-fold: 1) to determine if transrectal ultrasound measurement of the transition zone of the prostate served as a better proxy for determining prostate size and correlated better with IPSS, peak urine flow and detrusor pressure and 2) if the parameter transition zone index (the ratio between transition zone volume and prostate volume) was useful in evaluating clinical prostatism. Materials and Methods: We prospectively evaluated 30 men with symptomatic BPH (mean age 65.4 years) according to symptom sore, peak urine flow, pressure/flow study, transrectal ultrasound volume of the entire prostate and the transition zone and calculation of the transition zone index. Results : There was a week correlation between prostate volume and symptom score, peak urine flow and detrusor pressure at peak urine flow: a stronger correlation between volume of transition zone and symptom score (r=0.679 p=0.03), and peak urine flow (r=-0.672 p=0.05) and a significant correlation (p=0.001) between transition zone index and symptom score (r=0.868), and peak urine flow(r=-0.870). Conclusion : Transition zone index is a parameter that correlates siginificantly with parameters of BPH and may serve as a useful proxy for evaluating worsening obstruction. Studies are underway to determine whether transtion zone index can be used prospectively to predict and correlate response with therapies designed to ablate prostatic tissue medically or surgically.

펄프 고해과정중 발생되는 미세섬유의 구조(II) : 활엽수 펄프 Hardwood pulp

윤승락,김재경,김사익,조종수,노정관 진주산업대학교 2000 산업과학기술연구소보 Vol.- No.7

Freeness occurrence and types of deciduous fine fibers depending on beating time were examined to evaluate morphological characteristics of fine fibers produced by beating of Kraft pulp(KP) processes. The results were as foltows; As the beating time was increased, freeness and occurrence of fine fibers were gradually increased. The fibrillation of fiber was started at 20 minutes(22˚ SR) after beating, and the cell wall was destroyed or cut after 70 minutes(67˚ SR). Fine fibers produced during beating were composed of microfibrils from wood fibers, fragments caused by vessel destruction, and parenchyma cells. At initial stage of beating, the primary and secondary walls of fine fibers were coexisted, but as the beating was more processed, fine fibers which were composed of secondary wall were increased, indicating of destruction of secondary cell wall. The morphological change of parenchyma cell was not occurred by beating.

흰쥐에서 염화비닐 폭로수준에 따른 소변내 thiodiglycolic acid 농도의 변화

왕승준,차봉석,노재훈,신동천,김명수,전근재 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.4

Objectives : It is the objective of this research to identify the variation of thiodiglycolic acid(TdGA) in urine with vinyl chloride monamer(VCM) exposure levels through methylation. Methods : After rats were exposed to vinyl chloride monomer of 4 levels, 0㎎/㎥, 50㎎/㎥, 150㎎/㎥, 500㎎/㎥, respectively, of which urine was sampled in each sampling time of 0 hour, 2 hours, 4 hours, 8 hours, 16 hours, 36 hours, 48 hours. After urine had been methylated with diazomethane in the preliminary experiment and the peak of 146 m/z had been verified, the main experiment was done. Results : In the variation of TdGA with sampling times, concentration of TdGA increased rapidly in 4 hours and then decreased after 8 hours. When the variation of urinary TdGA concentration in urine according to exposure level of VGM was verified through Kruskal-Wallis statistical method at each sampling time, the significant increment with the exposure levels at 2 hours, 4 hours, 8 hours after exposure was clarified. Conclusion : TdGA concentration in urine with increment of VCM exposure level increased, especially significantly at 2 hours, 4 hours, 8 hours of sampling time.

급성 포름알데히드 가스 흡입에 의한 흰쥐 후각상피의 형태학적 변화

백선용,전재기,문용석,황승영,노환중,고의경,왕수건 대한해부학회 1998 Anatomy & Cell Biology Vol.31 No.3

國內 Fiber Board 産業의 現況의 展望

金思翼,金在慶,趙鍾洙,尹承洛,盧正官 진주산업대학교 1999 산업과학기술연구소보 Vol.- No.6

상기에서 살펴본 바와 같이 국내 fiber board 산업은 생산 측면에서 목재 산업중 다른 판상제품에 비해 원자재 비율이 낮아 아직 개도국에 대한 경쟁우위를 일정기간 지속할 수 있을것으로 예상되지만, 인도네시아등에 비해 가격경쟁력이 취약하므로 고율의 수입관세가 지속유지되어야 하는 등 많은 문제점을 내포하고 있다. 따라서 국내 fiber board산업을 보호하기 위해서는 품질개선 및 기능성 부여, 원가절감등 을 통하여 fiber board산업의 안정화를 도모해야 할 것으로 생각된다. 또한 fiber board는 가구제조시 가장 중요한 원자재로써 그 용도가 거의 가구 재조용에 국한되어 있으나 향후 품질의 차별화 및 기능성 부여로 가구이외의 용도개발이 이루어져야만 그 수요확대에 따른 공급의 확대를 도모할 수 있을 것으로 판단된다. 최종적으로 국내의 현실을 감안한 fiber board산업은 양적인 성장을 위한 기술개발 투자가 지속적으로 이루어져야 할 것으로 판단된다. Domestic fiber board industry was less dependence rate of imported timber than plywood industry. So, until now fiber board industry will be estimate that domestic fiber board industry maintain competitive ability on the other developing countries. For the protection of domestic fiber board industry, it was necessary improving of quality, functional endowment and retrenchment of production cost. The use of fiber board has been limited to manufacturing furniture. If a use of fiber board is enlarged, supply on demand will be enlarged. Finally, domestic fiber board industry is needed more growth of quality than growth of quantity, and growth of quality on fiber board industry is required to much investment for technical development.

林産油脂樹種의 利用에 관한 硏究(Ⅳ) : 쉬나무 種實의 成分分析 Analysis of Component in Evodia daniellii Hemsley Seed

趙鍾洙,金在慶,金思翼,尹承洛,盧正官 진주산업대학교 1999 論文集 Vol.38 No.-

林産油脂의 資源活用을 위한 쉬나무 種實에 대한 脂肪酸 分析結果를 要約하면 다음과 같다. 쉬나무 種實의 化學的 組成은 組蛋白質 함량이 16.20%, 組脂肪이 52.45% 炭水化物이 18.70%, 分이 1.56%이였으며 物理-化學的 組成에서는 比重이 0.916, 屈折率이 1.4722, 酸價가 16.63, 비누化價가 191,11, 요오드價가 134.60, 過酸化物價가 15.30으로 나타났다. 總脂肪酸 組成에서 linolenic acid, linoleic acid와 oleic acid가 대부분을 차지했다. 그리고 總脂質중에서는 中性脂質이 95.1%로 가장 많이 나타났으며 脂質의 構成을 보면 中性, 糖脂質에서는 linolenic acid, linoleic acid 대체로 높은 含量을 보인 반면 燐脂質에서는 palmitic acid가 가장 높게 나타났다. We investigated the composition of chemical components of Evodia daniellii Hemsley seed. The chemical compositions of Evodia daniellii Hemsley seed consisted of 4.83% of moisture, 16.20% of crude protein, 52.45% of crude fat. 18.70% of carbohydrate and 1.56% of ash. The physico-chemical characteristics of the seed oil were determined as follows : specific gravity, refractive index, acid value, saponification value, iodine value and peroxide value were 0.916, 1.4722, 16.63, 191.11, 134.6 and 15.30, respectively. The lipids in the crude oil were almost composed of neutral lipids. The seed contained 6 different kinds of fatty acids which were linoletic acid, linolenic acid, oleic acid, lauric acid, palmitic acid and palmitolic acid. The content of linoleic acid in total lipid, neutral lipid and glyco lipid is the highest than that of other lipid. On the other hand. The content of palmitic acid in phospho lipid is the highest than that of other lipid.

Reaction Rates for the Oxidation of Pitch based Carbon Fibers in Air and Carbon Dioxide Gas

Jae-Seung Roh 한국탄소학회 2003 Carbon Letters Vol.4 No.4

Two types of carbon fiber based high modulus- and isotropic-pitch were exposed to isothermal oxidation in air and CO2 gas and the weight change was measured by TGA apparatus. The kinetic equation was introduced f=1--(-atb) and the constant b was obtained in the range of 1.02~1.68 for the isotropic fiber and obtained 0.91~1.93 for the high modulus fiber respectively. In considering the effect of the atmosphere for isothermal oxidation, the value of the constant b obtained in the carbon dioxide was higher than that obtained in the air. Therefore, it was found that the pitch based carbon fiber shows sigmoidal characteristic when it is oxidized in the carbon dioxide. In addition, it was also found that kf = 0.5, which was reaction constant at f = 0.5, was a very useful parameter for evaluation of the oxidation reactivity of pitch based carbon fibers. According to the consideration, it is suggested that the conversion-time curves of the pitch based carbon fibers are correlated by normalized equation f=1--(-AτB), where τ=t/tf= 0.5.

Optimal indication of single-incision laparoscopic cholecystectomy using Konyang Standard Method in benign gallbladder diseases

Seung Jae Lee,In Seok Choi,Ju Ik Moon,Dae Sung Yoon,Won Jun Choi,Sang Eok Lee,Nak Song Sung,Seong Uk Kwon,In Eui Bae,Seung Jae Roh,Sung Gon Kim 대한내시경로봇외과학회 2022 Journal of Minimally Invasive Surgery Vol.25 No.3

Purpose: The optimal indications for single-incision laparoscopic cholecystectomy (SILC) have not yet been established. Methods: This single-center retrospective study included consecutive patients who underwent SILC between April 2010 and June 2020. Dif f icult surger y (DS) (conversion to multiport or open cholecystectomy, adjacent organ injury, operation time of ≥90 minutes, or estimated blood loss of ≥100 mL) and poor postoperative outcome (PPO) (postoperative hospital stay ≥ 7 days or Clavien-Dindo grade ≥ II postoperative complications) were def ined to comprehensively evaluate surgical diff iculty and postoperative outcomes, respectively. Results: Of 1,405 patients (mean age, 51.2 years; 802 female [57.1%]), 427 (grade I, n = 358; grade II/III, n = 69) underwent SILC for acute cholecystitis (AC), 34 (2.4%) needed conversion to multiport (n = 33) or open cholecystectomy (n = 1), 7 (0.5%) had adjacent organ injury during surgery, and 49 (3.5%) developed postoperative complications. Of the patients, 89 and 52 had DS and PPO, respectively. In the multivariate analysis, grade I AC, grade II/III AC, and body mass index of ≥30 kg/m 2 were significant predictors of DS. Age of ≥70 years and DS were significant predictors of PPO. In a subgroup analysis of patients with AC, DS (9.5% vs. 27.5%, p < 0.001) and PPO (5.0% vs. 15.9%, p = 0.001) were more frequent in patients with grade II/III AC than in those with grade I AC. Conclusion: SILC is not recommended in patients with grade II/III AC and should be carefully performed by experienced and well-trained surgeons.