• 폴리머
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• 제26권4호
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• pp.468-476
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• 2002

순수한 PAN 섬유의 예비산화와 가수분해의 과정을 통하여 제조된 oxy-PAN은 염기와 산용액에 담그었을 때 신장과 수축 거동을 보임이 알려져 있다. 본 연구에서는, 염기 (NaOH) 용매에서 약 30%의 신장과 산 (HCl) 용매에서 30∼50%의 수축 거동을 관찰하였다. 기계적 특성에 대한 실험에서, oxy-PAN 섬유가 수축되었을 때 향상된 기계적 특성을 나타내었다. 이러한 거동과 기계적 특성은 인체의 근육과 선형 구동체의 그것들과 유사하였다. NaOH와 HCl 용액에서 oxy-PAN 섬유의 길이가 변화하는 중요한 요인으로는 친수화 또는 소수화 구조의 전환에 의한 영향이다. 다른 요인으로는 oxy-PAN 섬유와 용액간의 이온과 물의 교환, 이온의 농도차에 의한 삼투압 등이 영향을 준다. Oxy-PAN 섬유의 신장 및 수축과 기계적 특성에 영향을 미치는 여러 가지 요인들을 규명하기 위한 보다 많은 연구가 필요하지만, 본 연구실에서 제조된 oxy-PAN 섬유가 인공 근육 및 선형 구동체로 적용될 수 있는 충분한 가능성이 있음을 제시한다.

• 폴리머
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• 제26권4호
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• pp.492-500
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• 2002

일반 PAN 섬유를 $240^{\circ}C$에서 산화시킨 후 1 N NaOH 수용액에서 가수분해시켜 oxidized-PAN 섬유 (oxy-PAN)를 제조하였다. 산과 염기용액에서의 oxy-PAN 섬유의 구조를 $^{13}C-NMR$ 분광분석법을 이용하여 분석하였다. 가수분해에 의하여 -COOH 기를 포함하는 oxy-PAN 섬유는 산과 염기 수용액에서 수축 및 팽창 거동을 하였는데, 염기성 수용액에서는 반대전하로 작용하는 $Na^+$이온이 물 분자와 함께 섬유 내부로 침투하면서 팽창하였으며, 산성 수용액에서는 $Na^+$이온이 물 분자와 함께 섬유 기부로 축출되면서 수축하였다. 친수성의 섬유내부로 산/염기 작용기가 자유롭게 침투하여 oxy-PA기 섬유의 화학적인 구조는 쉽게 변화된다는 것을 확인하였으며, 모폴로지도 pH에 의하여 영향을 받는다는 것을 관찰하였다.

• 한국환경보건학회지
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• 제44권4호
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• pp.301-314
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• 2018

Objectives: The aim of this study was to introduce the overall progress of exposure assessment to humidifier disinfectant (HD); to present participants' demographic characteristics, exposure characteristics to humidifier disinfectant, and exposure classification; and furthermore to compare those characteristics between survivors and non-survivors. Methods: An assessment of environmental exposure to HD was conducted using modified HD-specific questionnaires that had been previously validated. We analyzed the data from 4,482 participants who had been potentially exposed to HD and had registered with the KEITI (Korea Environmental Industry & Technology Institute) from September 2016 to May 2018 (the fourth survey). Environmental exposure assessments were performed as follows: 1) contact with participants, 2) environmental exposure assessment though face-to-face interviews, 3) assessment review and coding, and 4) exposure rating. Results: Overall, survivors made up 77.1% (3,457 subjects) and non-survivors made up 22.9% (1,025 subjects). When compared with the survivors, non-survivors had a higher proportion of subjects aged >60 years and subjects who answered as suffering lung damage and having purchased HD because it is "Beneficial to health" (p<0.05). For the exposure characteristics compared to survivors, non-survivors had a higher proportion of cases of distance from humidifier to face being less that one meter and the spray direction being toward the face (p<0.05). Overall, respondents who used the "Oxy Ssak Ssak New Gaseupgi Dangbun", "Aekyung Gaseupgi Mate", "Homeplus Gaseupgi Chungjungje", and "E-Mart Gaseupgi Salgyunje" products made up 66.1, 12.3, 4.0, and 3.6%, respectively, and 72.5% of respondents used products with PHMG as the active chemical. When compared with survivors, non-survivors had a higher proportion of use of "Oxy Ssak Ssak New Gaseupgi Dangbun" but a lower proportion of use of products with CMIT/MIT, PGH, or PHMG as the active chemical. Conclusions: This study provided demographic characteristics and exposure assessment for applicants who have been injured by HD. In spite of the limitations of performing past exposure assessment through a questionnaire survey, such as recall bias, useful results may be obtained by comparing survivors with non-survivors. Further studies such as the exposure rating method and so on are necessary to assess past exposure to HD.

• 한국축산식품학회지
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• 제28권2호
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• pp.196-203
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• 2008

본 연구는 한우우사 바닥면의 톱밥두께가 도축후 등심의 육질에 미치는 영향을 구명하고자 실시하였다. 7개월 령의 비거세 수소 22두를 톱밥이 10, 15 및 20 cm로 깔린 단방우사($3{\times}8\;m^2$)에서 27개월령까지 사육한 후 도축하여 등심(M. longissimus) 부위를 $4{\pm}0.2$에서 9일 동안 저장하였다. 도체성적, pH, 보수력, 드립감량, 가열감량, 전단력, 전자코에 의한 향기패턴 및 관능적 기호도는 톱밥두께에 따른 유의적인 차이가 없었다. 일반성분 함량 및 지방산 조성은 20cm가 가장 높은 조지방 함량과 가장 낮은 n6/n3을 보였다(p<0.05). 저장중 총환원력은 9일째에 10cm가 가장 높았던 반면(p<0.05), TBARS는 가장 낮았다(p<0.05). 표면육색소 함량은 저장기간 동안 10 및 20 cm의 MetMb이 15cm보다 낮았던 반면(p<0.05), OxyMb은 높았다(p<0.05). 표면육색은 저장기간 동안 10 및 20 cm가 15 cm보다 붉은 육색을 나타내었다(p<0.05).

• 한국환경보건학회지
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• 제46권4호
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• pp.433-443
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• 2020

Objective: This study aimed to introduce the use of humidifier disinfectant (HD) in hospitals based on an on-site investigation. Methods: A preliminary survey and on-site investigation of HD use were conducted in 23 hospitals. Among them, one hospital without previous information on HD use was selected for a pilot investigation; 22 hospitals were selected based on previous documents and exposure statements from parliamentary investigation and exposure assessment regarding HD. Descriptive statistics were used to present distribution and characteristics of HD purchase and HD use in hospitals. Also, details on interviews from the on-site investigation were described. Results: Among the 23 hospitals, a total of ten were confirmed to have purchased and used an HD (nine hospitals) or HD-like product (one hospital). For the purchased HD products, four hospitals reported 'Aekyung Gaseupgi Mate', two hospitals reported 'Oxy Ssakssak New Gaseupgi Dangbun', and one hospital reported 'Homeplus Gaseupgi Chungjungje' (one hospital used three kinds of HD products). One hospital reported an HD-like product and four hospitals were 'Unknown'. For the number of HD products purchased, five hospitals reported '100 or less', two hospitals reported 'More than 100', and three hospitals were 'Unknown'. For each of the ten hospitals, we described detailed characteristics of HD purchase and its exposure status obtained through on-site investigation, including the purchase volume (i.e., number of products), exposure space (i.e., patient's room, staff space), and exposure period. Additionally, a comparison of on-site investigation and parliamentary investigation or exposure assessment regarding HD was reported. Conclusion: This study introduced detailed cases of HD purchase and HD use in hospitals based on an on-site investigation, and our findings revealed a possibility of a considerable volume of HD exposure in various multiuse facilities, including hospitals.