• 한국의류학회지
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• 제31권7호
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• pp.1119-1127
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• 2007

Nonwovens have been widely used in various regions from the households to the industrial, agricultural and medical goods. Synthetic fibers have been used for source of nonwovens commonly because of their useful and economic properties. They are not only main factor causing environmental problems but also spend huge cost to renew the environmental disruption by them. Nonwovens must have both cost-competitiveness and environment-friendly property to be the desirable sources in 21th centuries. For meet these needs, it is suitable for the times that economical and environmentally-safe kenaf fibers would be used as raw materials of nonwovens. Kenaf and polyester fibers were blended in 4 types of ratio : 0/100, 20/80, 40/60, 60/40 were needle-punched. The nonwovens properties such as color values, surface appearance, strength, elongations, stiffness, moisture regain, water and oil absorbency, and electrification were tested. As the results, tensile and tear strengths, water and oil absorbency were maximum at 20/80 kenaf/polyester blend nonwoven, because of effecting by nonwoven structure and fiber properties. The moisture regain were increased according to kenaf were blended and the eletrification reduced in proportion to the kenaf fibers by chemical property of fiber composed nonwovens.

• 대한치과교정학회지
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• 제35권2호
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• pp.127-136
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• 2005

광도 차이를 보이지 않았지만 전기도금한 선재 (p<0.001). 스테인레스스틸 선재 (p <0.05). 구리 (p<0.001) 는 배지만을 첨가한 경우보다 통계적으로 유의한 흡광도 감소를 보였다 ISO 10993, part 5에 따라 구리는 "강한 독성"을 보이는 반면 티타늄과 스테인레스스틸 선재는 "무독성". 그리고 전기도금 선재는 "중등도 독성"으로 나타났다 이상의 결과는 전기도금을 이용하여 교정용 선재의 직경을 증가시키는 방법이 임상에 적용되기 위해서는 세포독성을 줄이기 위한 추가의 연구가 필요함을 시사하였다.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2003년도 추계학술대회 논문집
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• pp.1371-1372
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• 2003

직물에서 구조적 요인이 쾌적성과 연관된 유체전달 특성들에 미치는 영향을 연구하였다. 고려된 구조변수는 직물을 구성하는 실의 구성성분 그리고 꼬임수이다. 측정한 쾌적성과 연관된 물성으로 수분 흡수성, 수분 증발성, 그리고 수분 투과성이다. 이들 물성은 고려된 구조 인자들에 의해 큰 영향을 받았다. 결과들에 대한 객관적 분석과 이해를 위해 실에서 접촉적각, 직물에서 모세관 흡수 곡선, 그리고 기공크기를 측정하였으며, 또한 기존 이론들을 수정한 모델을 도입하여 모사 설명하였다.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2008년도 제39차 학술발표회
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• pp.11-12
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• 2008

Poly(ethylene oxide)(PEO) of molecular weight of 300,000 was crosslinked by UV irradiation in the presence of crosslinker. The photochemical crosslinking of PEO was enhanced by the addition of dimethacrylate crosslinkers in the film. Percent conversion of the polymer into gel as well as water absorbency were investigated gravimetrically. Gel fraction of PEO films increased with increasing crosslinker concentration. In the case of photocrosslinked PEO films with benzophenone, gel fraction reached about 95%. The thermal behavior of crosslinked PEO films was characterized by thermogravimetric analysis. The maximum decomposition temperature increased with increasing crosslinker concentration.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 가을 학술발표회 논문집
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• pp.165-166
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• 2003

완전히 가수분해 된 폴리비닐알콜(PVA)은 에멜전 안정화와 계면활성이 약하다. $^{1)}$ 하지만 hydrophobically modified PVA는 높은 계면활성을 가지고 있을뿐더러 수용액에서 micelle을 형성할 수 있고 게다가 그의 수용액은 높은 viscosity, shear thinning, thixotropic, less salt sensitive 성질을 가지고 있어 enhanced oil recovery operations, drag reduction, flocculation, super absorbency, latex paints, hydraulic fluids, surface coatings등에 사용될 수 있다. $^{2.3)}$ (중략)

• Macromolecular Research
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• 제17권10호
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• pp.734-738
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• 2009

Biodegradable, pH-sensitive, glycol chitosan (GC) hydrogels were prepared using divinyl adipate (DVA) as a crosslinker and acetic acid as a catalyst. DVA has highly reactive double vinyl ester groups and GC contains a high density of hydroxyl groups, with two in every glucosamine unit. The transesterification reaction between vinyl esters and hydroxyl groups produced crosslinked GC hydrogels. The initial crosslinking reaction was monitored by measuring the viscosity of the reaction mixture. When DVA was added to the GC solution and heated to $50^{\circ}C$, the viscosity of the GC solution gradually increased, implying a crosslinking reaction and hydrogel formation. A new peak from the ester group was observed in the FTIR spectra of the GC hydrogels, confirming the crosslinking reaction. The synthesized GC hydrogel showed pH-dependent water absorbency, mainly due to the presence of amine groups ($-NH_2$) at the C-2 position of the glucosamine unit of GC. The water absorbency greatly increased at acidic pH and slightly decreased at alkaline pH. The GC hydrogel gradually degraded in $37^{\circ}C$ water due to hydrolysis of the ester bonds, which were intermolecular crosslinking sites. A red dye, 5-carboxyltetramethyl-rhodamine (CTMR), was entrapped in the GC hydrogels as a model compound. CTMR was released from GC hydrogels in two steps: an initial burst release mainly due to desorption and diffusion, and a second sustained release possibly due to gradual degradation.

• 한국의류학회지
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• 제33권11호
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• pp.1696-1706
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• 2009

Nonwoven fabrics have been widely used in various fields that include household, industrial, agricultural, medical goods, especially in the automobile industry. In this study, eco-friendly fiber materials were developed and investigated as a substitute material for polyester fibers in nonwovens. To make plant fiber bundles, stems of Indian mallow (IM), and Kuzu vine (KV) were retted; in addition, the non-cellulose component was partially removed. Plant fiber bundles and polyester fibers (P) were blended and needle punched to produce nonwovens. Five kinds of nonwovens were manufactured: P100 (Polyester 100%), IM10 (IM 10% and Polyester 90%), IM20 (IM 20% and Polyester 80%), KV10 (KV 10% and Polyester 90%), and KV20 (KV 20% and Polyester 80%). The color values, surface appearance, tensile strength, elongation, tear strength, abrasion strength, flexstiffness, moisture regain, water or oil absorbency, and static electricity of manufactured nonwovens are investigated. As the blended ratios of IM or KV increased, the brightness of nonwovens decreased compared to that of polyester 100%. Tensile strength, tear strength, abrasion strength, and flexstiffness of IM10 as well as KV10 were higher than those of P100, IM20, and KV20, resulting from the influence of the structure and properties of nonwoven fibers. Moisture regain and water or oil absorbency increased, while static electricity decreased in proportion to the amount of plant fibers. IM or KV and polyester blended nonwovens showed improved properties over P100 that could be substituted for P100 as a novel material for textiles.

• 폴리머
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• 제29권4호
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• pp.408-412
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• 2005

생체재료로 이용하기 위하여 키토산을 기질로 하여 Bembyx mori로부터 추출한 견 피브로인을 블렌드한 필름에 대한 구조와 특성을 X선 회절분석, 열분석, 적외선 분광분석, 전자현미경 관찰, 접촉각 측정, 흡수율 측정으로 조사하였다. $-\~30wt\%$ 피브로인을 포함하는 블렌드 필름은 리튬이온을 포함하는 초산수용액으로 제조되었다. 키토산/피브로인 블렌드 필름은 키토산의 아미노기와 피브로인의 아미드 카보닐기 사이의 수소결합과 같은 분자간 상호작용의 형성에 의해 결정성이 감소되었다. 피브로인의 비율이 증가할수록 키토산의 무수혈 견정상은 소실되었고, 수화형 결정상은 감소되었으며, 퍼브로인의 P형 결정이 형성되어 혼재된 결정구조를 이루었다. 표면 친수성과 수분 흡수성은 피브로인의 비율이 클수록 증가되었으며, 20 $wt\%$, 이상에서 수화젤 상의 필름을 형성하였다. 전자현미경에 의한 블렌드 필름의 표면과 단면은 균일한 상을 나타내었다.

• Imaging Science in Dentistry
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• 제42권3호
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• pp.163-167
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• 2012

Purpose: ANSI/ADA has established standards for adequate radiopacity. This study was aimed to assess the changes in radiopacity of composite resins according to various tube-target distances and exposure times. Materials and Methods: Five 1-mm thick samples of Filtek P60 and Clearfil composite resins were prepared and exposed with six tube-target distance/exposure time setups (i.e., 40 cm, 0.2 seconds; 30 cm, 0.2 seconds; 30 cm, 0.16 seconds, 30 cm, 0.12 seconds; 15 cm, 0.2 seconds; 15 cm, 0.12 seconds) performing at 70 kVp and 7 mA along with a 12-step aluminum stepwedge (1 mm incremental steps) using a PSP digital sensor. Thereafter, the radiopacities measured with Digora for Windows software 2.5 were converted to absorbencies (i.e., A=-log (1-G/255)), where A is the absorbency and G is the measured gray scale). Furthermore, the linear regression model of aluminum thickness and absorbency was developed and used to convert the radiopacity of dental materials to the equivalent aluminum thickness. In addition, all calculations were compared with those obtained from a modified 3-step stepwedge (i.e., using data for the 2nd, 5th, and 8th steps). Results: The radiopacities of the composite resins differed significantly with various setups (p<0.001) and between the materials (p<0.001). The best predicted model was obtained for the 30 cm 0.2 seconds setup ($R^2$=0.999). Data from the reduced modified stepwedge was remarkable and comparable with the 12-step stepwedge. Conclusion: Within the limits of the present study, our findings support that various setups might influence the radiopacity of dental materials on digital radiographs.

• Preventive Nutrition and Food Science
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• 제10권2호
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• pp.198-205
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• 2005

Korean medicated diet (KMD) is not a simple combination of food and Chinese drugs, but a special carefully constructed diet made from Sasang constitutional medicines, food and condiments under the theoretical guidance of diet preparation based on differentiation of symptoms and signs of traditional Sasang medicine (TSM). It combines the functional efficacy of medicine with the delicacy of food, and can be used to prevent and cure diseases, build up one's health and prolong one's life. Korean traditional medicated diet has a long history of development. Although influenced by Chinese medicine, Korean traditional medicine has been developed into a unique system of traditional medicine that has surpassed the continental medical practice, sublimating itself into a native medical practice suitable to Korean lifestyles and physical constitutions. In the 19th century, Lee Jema's Sasang medicine (medicine of four types of energy determining the physical constitution) was introduced. It is an integration of mind and body according to the individual's physical constitution that is categorized allowing a customized method of treatment ideal for each category-making the content of Korean traditional medicated diet even richer. The characteristics of Korean medicated diet are as follows: (1) Laying stress on the wole, selecting medicated diet on the basis of differential diagnosis. (2) Suitable for prevention and treatment, outstanding in effect. (3) Good in taste, convenient for taking. KMD refers to drink and food according to certain prescriptions, by processing and cooking that can be used either for prevention and cure of diseases, or for health care and recovery. The purpose of this review is to introduce TSM and KMD based on Sasang constitutional medicines.