• Journal of the Korea Fashion and Costume Design Association
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• v.20 no.2
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• pp.31-46
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• 2018

This study was carried out to offer basic data that can be used for outdoor wear production for active senior males, emerging as a new consumer bracket in the era of rapid aging. To this end, this study modified and complemented the patterns of outdoor jackets for active senior males based on existing outdoor jackets that received the most excellent evaluation. On the basis of the research outdoor wear wearing assessment results, this study confirmed those areas to be modified and proposed areas to be considered in manufacturing outdoor wear for this demographic. As a result of existing outdoor wear's wearing assessment, the jacket of brand B was shown to be the most excellent one. This study actually designed research outdoor wear patterns by modifying the problematic parts through the addition and subtraction of spare length or circumference in the sections where fit satisfaction was low by referring to the selected brands' patterns. The research outdoor wear was designed by referring to the preferred outdoor types and colors that were highlighted in the previous survey result of consumer wearing reality, based on the designs of the outdoor wear receiving the most excellent assessment in wearing assessment. Fabric that specially glued two-layered mesh that bonded the thin membrane of synthetic resin with polyester fabric was used as the material in this study. Wearing assessment was conducted by comparing the manufactured research outdoor wear and the existing outdoor wear selected as excellently assessed outdoor wear. Consequently, this study verified that the wearing fit of the research outdoor wear was more excellent in most items. This study proposed final patterns for outdoor jackets suitable for active senior males through the modification of several items that required improvements as per the wearing assessment of the research outdoor wear.

• Textile Coloration and Finishing
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• v.20 no.2
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• pp.53-58
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• 2008

New dyeable PP fiber and several products from it has been developed through dispersing polyester copolymer into PP resin by a Korean synthetic fiber manufacturer and its colleagues. The dyeing properties of PET/dyeable PP double knit fabric were examined with three different types of disperse dye in this study. It was found that the disperse dye, exhausted on dyeable PP at early stage of dyeing, migrated to PET at elevated dyeing temperature when two fibers were dyed in the same dye bath. The ratios of dye distribution between two substrates dyed at $120^{\circ}C$ and $130^{\circ}C$ showed no difference. S type disperse dyes showed good build-up properties and acceptable color fastness while high light fastness type exhibited the lowest amounts of exhaustion but excellent color fastness. It might be concluded that the most appropriate dye for PET/dyeable PP double knit fabric was S type, and that some color difference between PET side and dyeable PP side was unvoidable.

• Polymer(Korea)
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• v.26 no.3
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• pp.335-343
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• 2002

Blend resin (PET/PETG 70/30 blend) of poly (ethylene terephthalate) (PET) and poly (ethylene terephthalate glycol) (PETG) of weight percent 70/30 was prepared by a twin-screw extruder. Undrawn films of the blend and pure PETG were made by melt-press in hot press. Drawn films were made by capillary rheometer. Crystallinity, shrinkage, thermal, dynamic mechanical, and mechanical properties of these blends and PETG drawn films were investigated by wide angle X-ray diffractometer, dry oven, DSC thermal analyzer, and tensile tester. The crystallinity and density of these films increased with increasing draw ratio and draw rate but decreased with increasing draw temperature. The crystallinity and density of the blend films were higher than those of PETG films. The tensile strength and tensile modulus of these drawn alms increased with increasing draw ratio and draw rate but decreased with increasing draw temperature. The tensile strength and tensile modulus of blend films were higher than those of PETG films. Shrinkage of PETG md blend films decreased with draw ratio and draw rate. Shrinkage of undrawn blend film was 600% higher than that of pure PET film.

• Composites Research
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• v.14 no.6
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• pp.16-23
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• 2001

Analysis of mechanical behavior for a pultruded-wound hollow rod is presented. For this purpose, the pultruded-wound hollow rod is manufactured by the new winder attached to the conventional pultrusion system. And the conventional pultrusion process is newly altered to manufacture pultruded-wound specimens. A computer program, POST II, is modified to perform this study, In the nonlinear finite element formulation, the updated Lagrangian description method based on the second Piolar-Kirchhoff stress tensor and the Green strain tensor are used. For the finite element modeling of the composite hollow rod, the eight-node degenerated shell element is utilized. In order to estimate the failure, the maximum stress criterion is adopted to the averaged stress in the each layer of the finite elements. As numerical examples, the behavior of glass/up composite hollow rod is investigated from the initial loading to the final collapse. Present finite element results considering stiffness degradation and stress unload due to failure shows excellent agreement with experiments in the ultimate load, failure and deformations.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.106-106
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• 2012

막구조(Membrane structure)란 건축분야에서 "fabric structure" 또는 tension structure"와 같이 사용되는 용어로 코팅된 직물(coated fabrics)을 주재료로 사용하는 구조를 말한다. 특히 구조체로서 연성의 막을 이용 이것에 초기 장력을 주어 강성을 늘림으로서 외부하중에 대하여 안정된 형태를 유지하는 장점을 갖고 있다. 초기 창안된 독일의 온화한 기후에 적용되는 반면 한국이나 일본에는 60m/sec를 넘나드는 태풍의 피해와 많은 적설량을 보이는 기후적 제약으로 발달되지 못하였다. 그러나 최근 새로운 소재의 막구조 제품 개발과 구조해석 방법 및 시공기술 등이 개발되어 보편화되어지고 있는 실정이다. 막구조용 재료로 사용되는 섬유소재는 주로 Polyester직물을 기재로 한 PVC 코팅 제품으로 일반 PVC 막재는 장력이 약하고, 광선에 의한 물성이 쉽게 변화되어 내구연한이 5~15년에 불과하다. 유리섬유나 아라미드섬유 등으로 제직한 기재에 고내열 실리콘이나 PTFE 수지를 코팅한 제품은 약품에 대한 내구성이 높고 자외선에 대해서는 매우 큰 저항성을 가지기 때문에 내구연한이 10년에서 30년 까지도 향상된다. 그러나 실리콘 코팅막은 세계적으로 가장 좋은 막재로 알려졌으나 자정능력(Self Cleaning)에 문제가 발생되어 사용량이 감소 추세라고 할 수 있다. 일반적인 코팅 가공의 경우 MEK, Toluene, DMF 등과 같은 유기용제를 다량 사용함에 따라 작업환경 및 대기오염, 화재 위험 등의 문제점이 있으며 특히 가공시 잔류되는 유기용제의 심각성이 대두되고 있는 상황이다. 이와 같이 코팅 가공제 자체를 친환경적인 물질로 대체하여 각종 환경규제에 대응하고 유해 폐기물의 발생을 줄일 수 있는 코팅 가공제 및 가공기술 개발이 절실하다. 이에 본 연구에서는 Glass-Fiber, Aramid 등의 슈퍼 섬유와 고 강력 섬유 등을 이용하여 PTFE 코팅제품과 비슷한 수준의 성능을 부여하는 무용제형 실리콘 코팅 수지를 개발하고 내구성능 향상, Self Cleaning성, 난연성, 자외선 차단, 인장강도 및 인열 강도의 향상 등 다양한 기능성을 부여하는 최적의 환경 친화적 코팅 공정 기술을 개발하여 차세대 건축용 막구조 제품을 개발하고자 한다.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.5
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• pp.95-105
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• 1996

This study was performed to evaluate the mechanical properties of permeable polymer concrete using fillers and unsaturated polyester resin. The following conclusions were drawn; 1. The unit weight was in the range of 1, 663~ l, 892kg/$cm^3$, the weights of those concrete were decreased 18~28% than that of the normal cement concrete. 2. The highest strength was achieved by fly ash filled permeable polymer concrete, it was increased 22% by compressive strength, 190% by tensile strength and 192% by bending strength than that of the normal cement concrete, respectively. 3. The external strength of permeable pipe was in the range of 3, 083~3, 793kg/m, the external strengths of those concrete were increased 2~26% than that of the normal cement concrete. Accordingly, these permeable polymer concrete pipe can be used to the members and structures which need external strength. 4. The static modulus of elasticity was in the range of $5.7{\times} 10^4 ~ 15.4{\times} 10{^4}kg/cm^2 $, which was approximately 35~64% of that of the normal cement concrete. Fly ash filled permeable polymer concrete was showed relatively higher elastic modulus. The poisson's number of permeable polymer concrete was less than that of the normal cement concrete. 5. The dynamic modulus of elasticity was in the range of $83{\times} 10^3 ~ 211{\times} 10{^3}kg/cm^2 $, which was approximately Ins compared to that of the normal cement concrete. Fly ash filled permeable polymer concrete was showed higher dynamic modulus. The dynamic modulus of elasticity were increased approximately 22~45% than that of the static modulus. 6. The ultrasonic pulse velocity was in the range of 2, 584 ~ 3, 587m/sec, . which was showed about the same compared to that of the normal cement concrete. Fly ash filled permeable polymer concrete was in the range of$0.58~8.88 {\ell}/cm^2/hr$, , and it was larglely dependent upon the mixing ratio. These concrete can be used to the structures which need water permeability.

• The korean journal of orthodontics
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• v.19 no.2
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• pp.57-73
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• 1989

The purpose of this study was to investigate the tissue response of the rat molar periodontium incident to intermittent orthodontic force. The author intended to observe the healing process of injured periodontium and the response of injured tissue to the resumed force. Oxytetracyclin 50mg/Kg was given to each rat intraperitonially. 5 days later, maxillary 1st molars were moved mesially from the incisors with closed coil spring of 100gram. 7 days later, the appliances were removed and 20mg/Kg of calcein were given intraperitonially to each rat. At the same time, maxillary left 1st molars of 15 rats were moved by the same method, but force was lowered to 20 gram. After 1 day, maxillary left 1st molars of another 15 rats were moved by the same method and 50mg/Kg of oxytetracycline was given intraperitonially. After 4 days, another 15 rats were treated as above. After 7 days, another 15 rats were treated as above. 1,4,7,10 and 14 days after change of force, 3 rats were sacrificed in each group respectively. 2 rats were decalcified, embedded in paraffin, and stained with hematoxylin-eosin stain and with Masson's trichrome stain. Another rat was embedded in polyester resin and undecalcified specimen were made. Microradiograms were taken with the undecalcified sections. Observations were made with light and fluorescence microscope. Following conclusions were made. 1. Connective tissue cells and vessels were infiltrated into the hyalinized tissue from the bony cleft and along the border of the hyalinized tissue with bone and root surface. At the same time, elimination of hyalinized tissue, bone and root resorption occurred. 2. Bone and root were resorbed directly and indirectly. 3. Hyalinized tissue was removed within 5 days after force removal. 4. Hyalinized zone was less extensive and easily removed as the rest period prolonged. 5. Hyalinized tissue developed more rapidly and extensively and lasted over 10 days as the force resumed on the already formed hyalinized tissue.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.9-20
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• 2005

This study was carried out to select most efficient bonding methods of geogrid at the interface of old concrete pavement before placing asphalt overlay layer for reflection cracking retardation. Three bonding methods, a RSC-4 emulsified asphalt, a compound and an unsaturated polyester resin (UPR) were compared in this study. Three types of asphalt mixture (AC 60-80, RLDPE 8%, PG 76-22) and a dense-graded aggregate were used for overlay asphalt pavement. A reinforcing material which consists of a woven fabric underneath a glass fiber grid was used. An expedite test method which is for simulating mixed mode (mode I and II) fracture test was performed using a wheel tracker in laboratory. Cracking development by load repetition was measured as fatigue life (number of load cycle) and expansion of specimen body were measured for each test specimen. The results showed that UPR was the best and RSC-4 the next. But considering field applicability, RSC-4 was considered as an appropriate choice for bonding reinforcing material.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.445-448
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• 2008

The unsaturated polyester(UP) and epoxy resin have a superior material properties and a chemical resistance using sewerage pipes rehabilitation. However, UP and epoxy have not a low temperatures harding, the requirement $8{\sim}11$ hours long times harding and heating system used by reinforcement liner. This study is to evaluate the effects of low temperature harding properties methyl methacrylate(MMA) monomer using expanded polystyrene(EPS) and UP in addition of initiator and promoters. From the test result, viscosity tends to increase with increasing EPS and UP contents. However, harding time change of the MMA resins which it follows in addition of the initiator and promoter.

• Advanced Composite Materials
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• v.16 no.4
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• pp.299-314
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• 2007

In the present study, natural fibers (jute, kenaf and henequen) reinforced thermoplastic (poly(lactic acid) and polypropylene) and thermosetting (unsaturated polyester) matrix composites were well fabricated by a compression molding technique using all chopped natural fibers of about 10 mm long, respectively. Prior to green composite fabrication, natural fiber bundles were surface-treated with tap water by static soaking and dynamic ultrasonication methods, respectively. The interfacial shear strength, flexural properties, and dynamic mechanical properties of each green composite system were investigated by means of single fiber microbonding test, 3-point flexural test, and dynamic mechanical analysis, respectively. The result indicated that the properties of the polymeric resins were significantly improved by incorporating the natural fibers into the resin matrix and also the properties of untreated green composites were further improved by the water treatment done to the natural fibers used. Also, the property improvement of natural fiber-reinforced green composites strongly depended on the treatment method. The interfacial and mechanical results agreed with each other.