산업자재용 폴리에스터 섬유의 강도 향상에 관한 연구

박영신,남영식,정상영,최재호,장기혁,박원호,Park, Young-Shin,Nam, Young-Sik,Jung, Sang-Young,Choi, Jae-Ho,Jang, Ki-Hyuk,Park, Won-Ho 한국섬유공학회 2012 한국섬유공학회지 Vol.49 No.1

In this work, effects of total draw ratio change on the mechanical properties of polyester fibers were studied. The process parameter was a total draw ratio and the draw ratios that were used ranged from 6.6 to 7.0. Tensile properties are determined from the tensile tester, and crystallite parameters from the density measurement and X-ray diffraction were discussed with the different total draw ratios. The tenacity, young's modulus and crystallinity were increased to 10.6 g/d, 123.2 g/d and 42.1%, respectively, with increase in the total draw ratio. The relations between total draw ratio and mechanical properties of high tenacity polyester fiber were discussed.

Meta-aramid 나노섬유의 전기방사 공정인자들이 물성과 투습성에 미치는 영향

박영신,남영식,이민성,박원호,Park, Young Shin,Nam, Young Sik,Lee, Min Sung,Park, Won Ho 한국섬유공학회 2012 한국섬유공학회지 Vol.49 No.4

Meta-aramid nanofibers were prepared by the electrospinning process. In this study, electrospun meta-aramid nanofiber webs were prepared with various velocity ratios of a collector drum, the fiber diameter and thickness of electrospun nanofiber webs, and then compared with values of tensile properties and breathable water-resistance. The meta-aramid nanofiber webs were analyzed by field-emission scanning electron microscopy, a tensile tester, water vapor permeability, an X-ray diffractometer and thermogravimetric analysis. The diameter of meta-aramid nanofibers ranging from 165 to 252 nm was obtained by electospinning. The tenacity, young's modulus and crystallinity of meta-aramid webs were decreased by increasing the diameter of meta-aramid nanofibers, however, water vapor permeability increased. It was confirmed that the breathable water-resistance of meta-aramid nanofiber webs were similar to that of chemical treated PTFE film.

나고야의정서 하에서의 화장품산업의 최적 R&D 투자분석에 관한 연구

남영식(Young-sik Nam),이정현(Jung-hyun Lee) 한국산업경제학회 2015 산업경제연구 Vol.28 No.5

생물다양성협약(Convention on Biological Diversity)에서 요구되는 유전자원 이익공유의 원활한 이행을 위해 채택된 나고야의정서(Nagoya protocol)가 2014년 10월 발효됨으로 인해, 유전자원 이익공유가 관련 기업들에게 현실적인 문제로 인식되고 있다. 타 산업에 비해 해외유전자원의 활용도가 높은 화장품산업의 경우, 나고야의정서 발효로 인한 생산비용의 증가 및 R&D 투자의 위축이 예상된다. 그러므로 본 연구에서는 나고야의정서 하에서의 유전자원 이익공유를 고려한 국내 화장품기업들의 경제적 R&D 투자수준에 대한 실물옵션분석을 진행하였다. 경제적 R&D 투자수준 분석에 앞서, 동적패널분석을 통해 기업의 R&D 집약도가 생산성에 미치는 영향에 대해서 분석한 결과, R&D 집약도는 일정시차를 가지고 기업의 생산성에 긍정적 또는 부정적 영향을 미치는 것으로 나타났다. 또한 실물옵션을 활용한 경제적 R&D 투자수준 분석결과는 기업들의 다양한 이익공유 상황을 고려한 유전자원 이익공유에 대한 대응전략 마련 필요성과 극단적 R&D 투자전략으로 인한 수익성 위축 가능성을 제시하고 있다. ABS(Access to genetic resources and Benefit-Sharing) has been regarded as an important issue by the companies which are related with ABS, since Nagoya protocol to adopt for execution of ABS required in CBD(Convention on Biological Diversity) entered into force from October 2014. In the case of cosmetics industry has higher dependence on overseas genetic resources in production than other industries, increase of production cost and decrease of R&D investment are anticipated under Nagoya protocol. Therefore, this research analyzed the level of economic R&D investment under Nagoya protocol, using real option. The result of dynamic panel analysis which was analyzed prior to real option analysis shows that R&D intensity can affect productivity of the companies with previous time-lag. The result of real option analysis suggests two implications. The first is that the companies are necessary to prepare for the actions for ABS, considering several possible circumstances. The second is that the extreme strategy of R&D investment may cause deterioration of productivity of the companies.

제품 특성별 유전자원 이익 공유를 고려한 제약기업의 연구개발 투자 경제성 분석

남영식(Young sik Nam),임재영(Jae Young Lim) 한국바이오경제학회 2018 바이오경제연구 Vol.1 No.1

본 연구는 제조방법에 따른 의약품 특성과 유전자원 이익 공유에 대한 제약기업들의 대응방안을 제시하였으며, 제품별 특성이 반영된 유전자원 이익 공유 비율을 고려하여 제약기업의 최적 연구개발 투자 관점에서 투자 경제성을 분석하였다. 이때 투자 경제성은 분석대상 기업의 연간 매출액 확률과정을 고려한 실물옵션 모형으로 분석하였으며, 이를 통해 기준 시점에서의 연구개발 투자 경제성 여부를 판단하였다. 분석결과, 할인율, 연구개발 투자로 인한 매출액 증가율 그리고 연구개발 투자시 매출액 증가에 영향을 미치는 기간이 타 요소들보다 투자 경제성 확보에 상대적으로 더 큰 영향을 미치는 것으로 나타났다. 분석결과를 통해 기업별 사업 환경을 고려한 연구개발 투자전략 수립 필요성 및 국내 유전자원 활용방안 마련 필요성을 주요 시사점으로 제시하였다. We summarized the characteristics of the pharmaceutical products according to the manufacturing method and suggested the countermeasures of the pharmaceutical companies on the benefit sharing of the genetic resources. In addition, we analyzed the economic feasibility of R&D investment from the viewpoint of optimal R&D investment of pharmaceutical companies considering the benefit sharing ratio of genetic resources that reflected characteristics of each product. In this case, we analyzed the economic feasibility on the investment based on real option model with stochastic process of the total sales. The results represented that the discount rate, the growth rate of sales due to R&D investment, and the effective duration of R&D investment affected the threshold value relatively more than other factors. The results suggest that it is necessary for the companies to establish R&D investment strategies considering the business environment and to utilize the domestic genetic resources.

내열성 아라미드 나노섬유의 제조 및 착색 특성

이명선,남영식,박원호,Lee, Myung Sun,Nam, Young Sik,Park, Won Ho 한국섬유공학회 2014 한국섬유공학회지 Vol.51 No.3

The dyeing of meta-aramids (m-aramids) has conventionally been difficult due to their rigid molecular and dense crystalline structure that results from hydrogen bonding, although various dyeing techniques have been applied in the past to improve their dyeability. In this study, m-aramid nanofibers were fabricated by electrospinning with a 15 wt% m-aramid/DMAc solution, followed by either water or thermal treatment. The thermal stability and crystalline structure of the m-aramid nanofibers were investigated by thermogravimetry (TGA) and X-ray diffractometry (XRD), respectively. The effects of the water and thermal treatments on the dyeability of m-aramid nanofibers containing either pigment or dye were compared based on the K/S value and color difference. The results indicated that the use of dye is preferable to the use of pigment to improve the color depth of m-aramid nanofibers.

용액/용융 전기방사법으로 제조된 Poly($\varepsilon$-caprolactone)(PCL) 웹의 형태 및 열적 특성 비교

조병민,남영식,오태환,정종호,박원호,Cho, Byoung-Min,Nam, Young-Sik,Oh, Tae-Hwan,Jung, Jong-Ho,Park, Won-Ho 한국섬유공학회 2009 한국섬유공학회지 Vol.46 No.2

PCL fiber web was fabricated through solution/melt electrospinning of PCL resin. PCL nanofibers were obtained by solution electrospinning of 10.5 wt% PCL solution and the resulting average fiber diameters were varied with the range of 150-500 nm. Melt electrospinning method has the advantage of solvent-free process and it is more eco-friendly than solution electrospinning process. The relationship between processing conditions and fiber morphologies of melt electrospun fibers was investigated and it was found that the temperature in the syringe and flow rate were the main factors in determining the average fiber diameter. In addition, thermal properties of PCL fibers obtained by solution/melt electrospinning were compared with PCL chip.

Poly(trimethylene terephthalate) 나노 섬유 웹과 마이크로 웹의 특성분석

강은옥,박초희,남영식,김진홍,박원호,Kang, Yun-Ok,Park, Cho-Hee,Nam, Young-Sik,Kim, Jin-Hong,Park, Won-Ho 한국섬유공학회 2010 한국섬유공학회지 Vol.47 No.6

A nanofibrous web was fabricated by electrospinning poly(trimethylene terephthalate)(PTT). The PTT web with an average diameter of 290 nm was obtained by electrospinning from a 16%(w/v) PTT solution, whereas a PTT film was obtained from solution casting. The water contact angle of the PTT web was much higher than that of the PTT film because the web had a nanofibrous structure with a high surface area and surface roughness. The PTT film crystallized isothermally in the temperature range of $182-231^{\circ}C$ and exhibited a multiple melting phenomenon. The degrees of crystallinity of the PTT film and PTT web were 59.2 and $38.7^{\circ}C$ respectively. The crystallinity of the PTT web was lower than that of the PTT film because the web solidified rapidly by fast solvent evaporation during electrospinning. To increase the thickness of the web, the spinning solvent was changed to 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). As a result, a nanofibrous web with average diameter of 900 nm and thickness of 0.36 mm was obtained under the same electrospinning conditions. The overall porosity of the nanofibrous web was higher than the microfibrous web. The tensile strength and tear strength of the microfibrous web was higher than those of the nanofibrous web, whereas the breaking elongation of the nanofibrous web is higher than that of the microfibrous web.

Polyurethane 함침된 Poly(trimethylene terephthalate) 나노섬유 웹과 마이크로섬유 웹의 특성 분석

박고은,강은옥,박초희,남영식,김진홍,박원호,Park, Ko Eun,Kang, Yun Ok,Park, Cho Hee,Nam, Young Sik,Kim, Jin Hong,Park, Won Ho 한국섬유공학회 2013 한국섬유공학회지 Vol.50 No.3

Poly(trimethylene terephthalate) (PTT), a semi-crystalline polyester, has been used in many applications because of its good dyeability and good mechanical properties such as elasticity. Sorona (DuPont) and Corterra (Shell Chemicals) are some trade names of PTT. We describe herein a PTT nanofibrous web fabricated by electrospinning, which is a simple technique for generating nanofibers from a polymer solution and a melt. PTT pellets were dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) followed by electrospinning to yield PTT nanofibers with an average diameter of $900{\pm}97nm$. Then, the PTT nanofibrous web was impregnated with a polyurethane (PU) solution. The resulting material had better mechanical properties and also displayed a lower water contact angle than the PTT nanofibers because a relatively hydrophilic PU was coated onto the PTT nanofibrous web. Additionally, the pilling property of the PU-impregnated PTT nanofibrous web was enhanced by the induced welding among the PTT nanofibers because of PU impregnation. The air permeability of the PTT nanofibrous web was evaluated both before and after PU-impregnation. The results indicated that the PU-impregnated PTT nanofibrous web could be used in various industrial applications.

실물옵션을 활용한 한국형 300 ㎿급 IGCC 실증플랜트 기술개발사업의 경제성 분석

엄수정(Eom, Su-Jeong),남영식(Nam, Young-Sik) 한국기후변화학회 2012 한국기후변화학회지 Vol.3 No.4

냉각효율에 미치는 3차원 스페이서 패브릭 섬유의 형태 효과

천자영,한선경,유룡,박미희,남영식,박원호,Cheon, Ja Young,Han, Sun-kyung,Ryu, Yong,Park, Mi Hee,Nam, Young Sik,Park, Won Ho 한국섬유공학회 2017 한국섬유공학회지 Vol.54 No.5

Evaporative cooling fans are being increasingly used in the industrial and livestock industries for air cooling. This process utilizes the vaporization cooling phenomenon when water evaporates. Most cooling filters for evaporative cooling fans consist of paper filters. However, the paper filter has a fatal disadvantage in that it has low durability and poor reusability because of contamination arising from the growth of fungi and moss and the fact that it is difficult to wash. In this study, a polyethylene terephthalate (PET) mono-filament-based 3D spacer fabric was fabricated and examined for use as a cooling pad to replace paper filters. In addition, the 3D spacer fabrics were fabricated by making mono-filaments with various types of cross-sections, as well as different types of circular shapes. The water absorption, drying rate, moisture evaporation, and cooling efficiency of the 3D spacer fabric were controlled by adjusting the cross-sectional shape of the filaments. In addition, the effect of air volume on the cooling efficiency was determined.