• 한국자동차공학회논문집
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• 제5권4호
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• pp.110-120
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• 1997

One of the most important factor for the comfort of the passenger vehicles is the minimization of the compressible transmissibility during the running vehicles. Seat foam materials of I2 series(index 95 and the contents of isocyanate TDI was changed in percentages 75, 70, 65, 60, 50, 40) and DI series(density 50kg/$\textrm{m}^3$, index was changed 100, 95, 90) showed the significant differences in their transmissibility depended upon their chemical constitution such as index and contents of isocyanate TDI. The minimum trasmissibility of seat foam materials of I2 series was found from the materials with the contents of 65% isocyanate TDI and the index 95 at the frequency 4.79~5.31Hz. Also the minimum transmissibility of seat foam materials of DI series was found from the materials with the index 90 and the density of 50kg/$\textrm{m}^3$ at the frequency of 4.79~5.31Hz.

• Journal of Trauma and Injury
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• 제29권2호
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• pp.43-46
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• 2016

Traumatic diaphragmatic injury (TDI) occurs in 1% of patients of blunt abdominal trauma. Most TDIs involve the left diaphragm, however the authors experienced TDI accompanied by a liver laceration of the right diaphragm. When detected early, TDI can be easily treated, however serious complications can occur if not. When diaphragmatic injury is suspected due to clinical manifestation, comprehensive analysis of the patient data including radiologic findings is important.

• Korean Chemical Engineering Research
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• 제44권6호
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• pp.650-658
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• 2006

통계적 실험계획법을 이용하여 TDI 공정에서 발생하는 고체 폐기물(TDI-R)을 근임계수로 가수분해하여 TDA로 재활용하는 연구를 진행하였다. Batch 반응기를 이용한 실험으로부터 TDA 수율에 미치는 주요 인자들의 영향과 교호작용을 확인하였고, pilot plant를 이용한 연속공정 실험을 통해 TDA 수율과 공정 변수들의 상관 식을 도출하였다. TDA 수율에 영향을 주는 주요 인자들은 반응온도, 촉매 종류 및 농도, 물과 TDI-R의 중량비(WR) 등이 유효한 것으로 파악되었다. 반응 온도와 촉매 농도가 증가할수록 TDA 수율은 감소하였고, WR이 증가할수록 수율은 증가하였으며, 촉매로는 $Na_2CO_3$보다 NaOH를 사용하는 것이 효율적이었다. 주요 인자들의 교호작용으로는 촉매농도와 반응온도, WR과 반응온도, 촉매 종류와 반응시간 등이 유효한 것으로 파악되었다. 아임계 온도인 $300^{\circ}C$에서는 촉매 농도 영향이 작지만 초임계수 온도인 $400^{\circ}C$에서는 촉매 농도가 증가할수록 수율이 감소하였다. 반면 $300^{\circ}C$에서 WR이 증가하면 수율이 증가하지만 $400^{\circ}C$에서는 영향이 나타나지 않았다. Pilot plant를 이용하여 scale-up에 필요한 공정 변수의 최적화 실험을 실시하였다. 공정의 경제성, 효율성을 고려하여 공정변수로는 촉매농도와 WR을 정하였고, 중심합성 설계법을 이용하여 TDA 수율에 미치는 인자들의 영향을 파악하였다. 촉매 농도에 따라 수율은 증가하며, 촉매 농도가 낮을 때는 WR이 2.5 이하에서 수율이 최대값을 보인 후 WR이 증가함에 따라 수율이 감소하지만 촉매 농도가 증가하면서 최대값을 보이는 WR이 증가하는 경향을 보였다. Pilot plant 실험 결과를 회귀 분석하였으며 TDA 수율을 예측할 수 있도록 촉매 농도와 WR이 변수인 2차 식으로 상관식을 도출하였다.

• 생태와환경
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• 제45권3호
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• pp.289-301
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• 2012

본 연구는 강원도 정선군에 위치한 조양강 및 유입천을 대상으로 총 9개 정점을 선정하고 2008년 6월부터 2010년 9월까지 총 6회에 걸쳐 이화학적 환경요인과 생물량 및 부착규조류의 현존량을 조사하였다. 또한 부착규조류의 군집구조를 분석하고 생물학적 평가를 통해 수질을 평가하였다. 1. 조양강 일대는 석회암으로 구성되어 pH가 7.4~10.2로 중성~알칼리성의 범위를 보였다. 2. 조양강 수계에서 출현한 부착규조류는 2목 6과 23속 95종 15변종 2품종 5미동정종으로 총 117분류군이 출현하였고, 산성수역의 지표종은 출현하지 않았으며 중성~알칼리성의 pH에서 생육하는 Achnanthes laterostrata, Cymbella delicatula 등 11분류군이 출현하였다. 3. 특히 알칼리성 수역의 지표종인 Cymbella delicatula는 I3과 I4 정점의 일부 시기를 제외하고 10% 이상의 상대출현빈도를 나타냈다. 4. 조양강 및 유입천에 DAIpo를 적용한 결과 조양강은 평균 77.03로 A등급을 나타냈으며, 유입천은 평균 65.84로 B 등급으로 나타났다. TDI를 이용한 생물학적 평가시 조양강은 A~B 등급을 나타냈으며, 유입천은 A~D 등급에 걸쳐 나타남으로써, 조양강 본류가 유입천보다 수질이 양호한 것으로 나타났다. 5. 본 연구에서 유입천의 수질이 조양강에 미치는 영향은 낮은 것으로 나타났으나, 2009년 9월의 경우에는 본류인 J2와 J3 정점이 유입천 I1 정점의 영향으로 수질이 저하되었다.

• Toxicological Research
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• 제26권4호
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• pp.285-291
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• 2010

Recently, reproductive and neurobehavioral effects of bisphenol A (BPA) have been documented, and thus a review was requested for BPA management direction by the government. Therefore, this study was performed to establish a Korean tolerable daily intake (TDI) for BPA. An expert committee, consisting of specialists in fields such as toxicology, medicine, pharmacology, and statistics, was asked to evaluate BPA health based guidance values (HbGVs). Although many toxicological studies were reviewed to select a point of departure (POD) for TDI, rat and mouse reproductive studies by Tyl et al. (2002, 2006), which were performed according to GLP standards and OECD guidelines, were selected. This POD was the lowest value determined from the most sensitive toxicological test. The POD, a NOAEL of 5 mg/kg bw/day, was selected based on its systemic toxicity as critical effects. An uncertainty factor of 100 including interspecies and intraspecies differences was applied to calculate the TDI. According to the evaluation results, a TDI of BPA for Korean was suggested at 0.05 mg/kg bw/day. In addition, the BPA exposure level based on food consumption by the Korean population was estimated as 1.509 ${\mu}g/kg$ bw/day, and the HI was evaluated at 0.03 when the TDI of 0.05 mg/kg bw/day was applied. This HI value of 0.03 indicated that hazardous effects would not be expected from BPA oral exposures. Although highly uncertain, further studies on low dose neurobehavioral effects of BPA should be performed. In addition, it is recommended that the 'as low as reasonably achievable' (ALARA) principle be applied for BPA exposure from food packaging materials in newborn infants and children.

• 한국산업보건학회지
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• 제26권2호
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• pp.178-187
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• 2016

Objectives: Diisocyanates are a potent inducer of diseases of the airways, especially asthma. In this study, toluenediamine(TDA) and methylenedianiline(MDA) in urine were evaluated as biomarkers of exposure to tolunenediisocyanate(TDI) and methylenediphenyl diisocyanate(MDI), respectively. Methods: Workers exposed to TDI and MDI, as well as non-occupationally exposed subjects, were studied and pre- and post-shift urine samples were collected from 8 control subjects and 8 workers from a factory which manufactures polyurethane products for reducing noise and vibration in automobiles. Airborne TDI and MDI(n=8) were sampled on solvent-free glass filters impregnated with n-butylamine and detected by liquid chromatography atmospheric pressure ionization tandem mass spectrometry. Urinary TDA and MDA were detected as pentafluoropropionic acid anhydride(PFPA) derivatives by liquid chromatography electrospray ionization tandem mass spectrometry. Results: The median levels of urinary 2,6-TDA(p<0.001), 2,4-TDA(p=0.001), and MDA(p<0.001) of workers in post-shift samples were significantly higher than those of controls. The median levels of urinary 2,6-0TDA($0.63{\mu}g/g$ creatinine vs $0.34{\mu}g/g$ creatinine, p=0.017) and MDA($4.21{\mu}g/g$ creatinine vs $3.18{\mu}g/g$ creatinine, p=0.017) of workers in post-shift samples were significantly higher than those of the pre-shift samples. There were significant correlations between the urinary 2,6-TDA, 2,4-TDA, and MDA of workers in post-shift samples and the airborne 2,6-TDI(rho=0.952, p<0.001), 2,4-TDI(rho=0.833, p=0.001), and MDI(rho=0.952, p<0.001). Conclusions: These urinary diamines, metabolites of diisocyanates, in post-shift samples were useful biomarkers to assess occupational exposure to diisocyanates.

• 생태와환경
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• 제42권3호
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• pp.331-339
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• 2009

영천호와 대청호 어류들의 각 조직들(근육, 간, 내장, 아가미)에 농축된 microcystin-LR의 농도 및 TDI(total daily intake)값에 기초하여 인체의 건강위해성을 평가하였다 영천호의 분석결과에서 조식성(藻飾性)인 떡붕어(Carassius cuvieri)는 다른 종들과 비교하여 간을 포함한 대부분의 조직에서 높은 microcystin-LR의 농축양상을 보였다. 대청호에서 잡식성(雜食性)인 누치와 조식성인 떡붕어의 각 조직에서 높은 microcystin-LR 농도가 관찰된 가운데 내장에서는 누치와 떡붕어가 매우 높은 microcystin-LR 농도를 보였으며, 떡붕어는 다른 종들과 비교하여 내장이외에도 간과 아가미에서 높은 microcystin-LR농도를 나타내었다. 인체의 건강위해성 평가를 위해 각 조직에서 도출된 microcystin-LR의 EDI(estimated daily intake) 값들을 TDI 값과 비교하였다. 결과에서, 두 조사지역에서 모두 떡붕어(Carassius cuvieri)는 근육을 제외한 대부분의 조직들에서 EDI값들이 TDI 값을 초과하는 양상을 보였다.

• 한국산업보건학회지
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• 제30권2호
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• pp.134-152
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• 2020

Objectives: The objective of this study was to evaluate volatile organic compounds (VOCs) and toluene diisocyanates (TDIs) exposure among polyurethane waterproofing workers in the construction industry. Methods: Task-based personal air samplings were carried out at seven construction sites using organic vapor monitor for VOCs (n=88) and glass fiber filters coated with 1-(2-pyridyl)piperazine(1-2PP) for TDIs (n=81). The concentration of VOCs and TDIs were shown for four different work types(mixing paint, primer roller painting, urethane resin spread painting, painter assistant) at five different worksites (rooftop, ground parking lot, piloti, bathroom, and swimming pool). The two TDI sampling methods (filter vs impinger) were evaluated in parallel to compare the concentrations. Results: The geometric mean(GM) concentration of VOCs Exposure Index (EI) was highest for primer roller painting (1.4), followed in order by, urethane resin spread painting (0.85), mixing paint (0.53), and painter assistant (0.35) by work types. The GM of VOCs EI was highest for bathroom (1.4) followed in order by, swimming pool (0.85), piloti (0.89), ground parking lot (0.82) and rooftop (0.57) by worksites. The GM of 2,4-/2,6-TDI concentration was 0.052 ppb and 0.432 ppb each. There was no statistical difference in TDIs concentrations among worksites. The concentration of 2,6-TDI was ten times higher than that of 2,4-TDI. The concentration of 2,6-TDI by impinger method was 5.7 times higher than that by filter method. Conclusions: In this study, we found 38.6% of the VOCs samples exceeded the occupational exposure limits and 19.8% of the 2,6-TDI samples exceeded 1 ppb among polyurethane waterproofing workers. The most important determinants that increase the concentration of VOCs and TDIs was indoor environment and primer painting work.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2002년도 봄 학술발표회 논문집
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• pp.289-292
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• 2002

전분을 이용한 환경친화성 고분자 플라스틱 재료에는 전분충진형, blend형 등이 있으나, 대체로 전분은 보조재료로 사용된다. 이에 반해 extruder를 이용한 전분발포체나 TPS (Thermoplastic starch) 등은 전분을 주재료로 사용하여 플라스틱 재료를 만드는 것이지만, TPS 필름의 Tg가 실온보다 높아 glassy 상태의 brittle한 성질로 인해 물성이 낮으며, 수분 친화적인 성질로 인해 플라스틱 재료로서의 사용이 제한되는 단점이 있다[1,2]. (중략)

• Elastomers and Composites
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• 제50권3호
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• pp.210-216
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• 2015

Polyurethane modified silicone (PUMS) was synthesized from various molecular weights of polydimethylsiloxane (PDMS 2000, PDMS 6000, PDMS 20000), polypropyleneglycol with molecular weight of 3000 g/mol (PPG 3000) and 2,4-toluenediisocyanate (TDI) under tin catalyst. Their structures were confirmed by the measurement of FT-IR and $^1H-NMR$, and the thermal properties were studied from DSC and TGA. Glass transition temperature of PUMS exhibited exothermic peak at $-63{\sim}-69^{\circ}C$, and residual weight was 19~35% at $800^{\circ}C$.