도로표지용 도료의 품질기준은 KS M 6080의 품질기준을 만족하는 제품들의 경우에도 시공 후 일정기간이 경과한 후에는 도료 자체의 부착력 문제로 교통량 증가에 따른 자동차 차륜에 의한 도료 자체의 마모 손실에 의하여 재귀반사 기능을 부여하는 유리알의 마모 및 탈리로 시인성이 급격히 저하되고 있다. 이에 따른 야간 교통 사고율 증가와 동시에 추가 교통 안전을 위한 부가 보완시공으로 안전시설 제비용이 직접비용으로 유발되고 있으며, 직접비용보다 추가공사로 인한 교통체증으로 사회간접 비용이 증가되고 있다. 특히, 차선의 품질 규격이 KS M 6080 제품에 만족한다 하더라도 빗물의 수막(水膜)에 의한 유리알의 굴절율 차로 재귀반사기능을 하는 차선 도료용 유리알의 기능을 발휘하지 못하여 운전자의 시인성은 열악함을 알 수 있다. 따라서, 국외에서 많이 사용되고 있는 마모성이 우수한 수용성 차선도료, 고성능 융착식 도료, 상온경화형 도료를 도입하여 성능을 비교 검토하였다. 본 연구에서는 차선재료의 내구성 향상을 위해 EN 1436규격에 의한 내마모성 시험을 수용성, 융착식, 상온경화형 도료에 실시하여, 재귀반사도 성능이 우수한 차선재료의 적용 가능성을 확인하였다.

The behavior of abrasive wear on counterpart roughness of glass fiber reinforcement polyurethane resin (GF/PUR) composites were investigated at ambient temperature by pin-on-disc friction test. The friction coefficient, cumulative wear volume and surface roughness of these materials against SiC abrasive paper were determined experimentally. The major failure mechanisms were lapping layers, ploughing, delamination, deformation of resin and cracking by scanning electric microscopy (SEM) photograph of the tested surface. As increasing the counterpart roughness the GF/PUR composites indicated higher friction coefficient. The surface roughness of the GF/PUR composites was increased as the sliding velocity was higher and the counterpart roughness was rougher in wear test.

Saw wires have been widely used in industries to slice silicon (Si) ingots into thin wafers for semiconductor fabrication. This study investigated the microstructural and mechanical properties, such as abrasive wear and tensile properties, of a saw wire sample of 0.84 wt.% carbon steel with a 120 μM diameter. The samples were subjected to heat treatment at different linear velocities of the wire during the patenting process and two different wear tests were performed, 2-body abrasive wear (grinding) and 3-body abrasive wear (rolling wear) tests. With an increasing linear velocity of the wire, the tensile strength and microhardness of the samples increased, whereas the interlamellar spacing in a pearlite structure decreased. The wear properties from the grinding and rolling wear tests exhibited an opposite tendency. The weight loss resulting from grinding was mainly affected by the tensile strength and microhardness, while the diameter loss obtained from rolling wear was affected by elongation or ductility of the samples. This result demonstrates that the wear mechanism in the 3-body wear test is much different from that for the 2-body abrasive wear test. The ultra-high tensile strength of the saw wire produced by the drawing process was attributed to the pearlite microstructure with very small interlamellar spacing as well as the high density of dislocation.

최근 IT 융합 기술이 글로벌 시장의 핵심 화두로 떠오르면서, 스마트 의류 분야에서도 '의류+서비스 제공(service provider)' 기능을 갖는 PSS형 제품 디자인에 대한 수요가 크게 증가하고 있다. 본 연구에서는PSS형 제품 디자인의 일환으로서 안전보호 기능의 산악복 용도에 적합한 발광특성을 지닌 유연 광섬유 기반 직물 디스플레이의 제직구성을 모색하고, 이를 적용한 산악복 모형 디자인을 제시하였다. 이를 위하여 제직 구성, 즉 직물조직과 광섬유 밀도가 다른 총 15개 광섬유 직물 디스플레이 시료를 제직하여, 이를 대상으로 각각의 휘도를 측정함으로써 발광특성을 분석하였다. 그 결과, '주자직 2:1', '주자직 3:1' 및 '능직 2:1', '능직 3:1'인 경우가 안전보호 기능을 위한 산악복으로서 적용이 가장 적합한 발광효과를 보이는 것으로 나타났다. 발광특성에 관한 분석 결과 및 최근 스포츠 패션 트렌드를 기초로 하여, 유연 광섬유 직물 디스플레이 적용 산악복 모형 디자인을 전개하였다.

본 연구는 국제자유도시 제주의 친환경 소재 휴양복을 고찰해 봄으로써 앞으로 제주 의료관광 산업에서의 부가가치 및 수익 창출에 기여하고자 수행되었다. 의료관광 상품에 고품격 맞춤형 휴양복을 포함시킴으로써 관광객들이 제주에서 휴양복 착용의 쾌적한 체험을 하고 기념품으로 가져감으로써, 제주에 대한 좋은 인상과 추억을 갖게 된다면, 또다시 제주를 관광 목적지로 선택할 것이다. 잘 개발된 갈옷 휴양복은 다른 갈옷 상품과도 잘 매치될 수 있으므로 제주 문화상품 갈옷의 추가 구매 효과도 전망할 수 있다. 아울러 개발 휴양복의 사이즈 체계와 패턴 그레이딩을 구축을 통해 상품생산의 효율성이 상대적으로 매우 취약한 지역 업체의 애로사항을 해결하고자 하였다. 본 연구의 결과는 다음과 같다. 첫째, 제주지역 갈옷업체를 조사하여 애로사항 및 개선점을 고찰하였다. 둘째, 제주 의료관광을 위한 갈천 소재 휴양복을 정의하고 문헌 몇 시장조사, 디자인 논의 등의 결과를 반영하여 타당성 있는 대표 디자인을 선정하였다. 셋째, 생산표준화를 위한 상품제작 사이즈체계를 정립하고 패턴그레이딩을 구축하여 제안하였다.

Dry CVT(Continuously variable transmission) consists of a driving pulley and a driven pulley joined by rubber V-belt. Each pulley consists of a fixed flange and a movable flange. The movable flange of the driving pulley has the centrifugal roller and a ramp plate in the flange. The movable flange moves toward a fixed flange under the actuation of a centrifugal roller, as the driving pulley speed increases. The main advantages of the Dry CVT with V-belt, which has been popular in Asia, are a simple mechanism, less maintenance and low cost. The important claim which have an influence on the performance of the Dry CVT is the wear of the centrifugal roller. In this study proposed an improved design of driving pulley reducing the wear of the centrifugal roller in order to provide some design guidelines.

The effect of load and sliding speed on abrasive wear characteristics of glass fiber/polyurethane (GF/PUR) composites were investigated at ambient temperature by pin-on-disc friction test. The friction coefficient, cumulative wear volume and surface roughness of these materials against SiC abrasive paper were determined experimentally. Experimental results showed that the surface roughness of the GF/PUR composites was increased as applied load was higher in wear test. The cumulative wear volume tended to increase nonlinearly with increase of sliding distance and depended on applied load and sliding speed for these composites. It could be verified by scanning electric microscopy (SEM) photograph of surface tested that major failure mechanisms were lapping layers, ploughing, delamination, deformation of resin and cracking.

Two male reticulated giraffes (Giraffa camelopardalis reticulata), 21-year-old, died of nutritional deficiency that primarily caused by serious tooth wear at Seoul Zoo in winter. A 970 kg-weighed giraffe showed tooth wear of premolars, molars and incisors at necropsy. A foreign body in the rumen, congestion and ulcer of abomasum and duodenum were also observed. Mild appearance of serous fat atrophy in pericardial sac suggests that lack of nutritional intake caused by tooth wear can become harmful enough to threat life. At the necropsy of a 1,290 kg-weighed giraffe, a large quantity of sandy soil were found in the rumen which would stuck the pathway of well-fermented ruminal contents at esophageal groove. Nutritional deficiency could be suspected to urge this giraffe to graze grass on the ground along with sandy soil. Secondarily, the soil damaged teeth and become a culprit making irregular tooth wear and mild serous fat atrophy. Nutritionally good care of geriatric animals is needed especially for browsing animals like giraffes and critically in winter season.

Cubic boron nitride (c-BN) is a promising material for use in many potential applications because of its outstanding physical properties such as high thermal stability, high abrasive wear resistance, and super hardness. Even though 316L austenitic stainless steel (STS) has poor wear resistance causing it to be toxic in the body due to wear and material chips, 316L STS has been used for implant biomaterials in orthopedics due to its good corrosion resistance and mechanical properties. Therefore, in the present study, c-BN films with a B4C layer were applied to a 316L STS specimen in order to improve its wear resistance. The deposition of the c-BN films was performed using an r.f. (13.56 MHz) magnetron sputtering system with a B4C target. The coating layers were characterized using XPS and SEM, and the mechanical properties were investigated using a nanoindenter. The friction coefficient of the c-BN coated 316L STS steel was obtained using a pin-on-disk according to the ASTM G163-99. The thickness of the obtained c-BN and B4C were about 220 nm and 630 nm, respectively. The high resolution XPS spectra analysis of B1s and N1s revealed that the c-BN film was mainly composed of sp3 BN bonds. The hardness and elastic modulus of the c-BN measured by the nanoindenter were 46.8 GPa and 345.7 GPa, respectively. The friction coefficient of the c-BN coated 316L STS was decreased from 3.5 to 1.6. The wear property of the c-BN coated 316L STS was enhanced by a factor of two.

목적: 본 연구는 임상에서 건성안의 진단 및 눈물막의 평가 방법으로 많이 사용되고 있는 Tear Film Break-up Time(BUT) 검사를 통해 BUT의 평균값을 알아보고 콘택트렌즈 착용자와 비 착용자와의 값을 비교 하였다. 방법: 대상자는 눈물의 분비량에 영향을 미칠 수 있는 안과적 질환을 동반하지 않은 20~40대까지의 성인남녀 155명(310안)을 대상으로 BUT값을 측정하였다. 결과: BUT 평균치는 남성이 12.585±3.999초, 여성은 9.761±3.339를 나타냈으며, 콘택트렌즈 착용자와 미 착용자의 BUT는 콘택트렌즈 착용자가 10.516±3.244초, 콘택트렌즈 미 착용자가 12.198±4.158초로 나타났다(p

Dry CVT(Continuously variable transmission) consists of a driving pulley and a driven pulley joined by rubber V-belt. Each pulley consists of a fixed flange and a movable flange. The movable flange of the driving pulley has the centrifugal roller and a ramp plate in the flange. The movable flange moves toward a fixed flange under the actuation of a centrifugal roller, as the driving pulley speed increases. The main advantages of the Dry CVT with V-belt, which has been popular in Asia, are a simple mechanism, less maintenance and low cost. The important claim which has an influence on the performance of the Dry CVT is the wear of the centrifugal roller. In this study proposed an improved design of ramp plate reducing the wear of the centrifugal roller in order to provide some design guidelines.

The purpose of this study was to observe street fashion, to determine preferred design of jean and to analyze preferred jean styling based on types of jean pants design, toward 20s to 30s women. We observed outfits of jean styles on the street using photography method and conducted a survey to 400 females to get information of consumers. Four hundred questionnaires were analyzed using SPSS. As a result of street research, the majority of people were wearing jean pants with T-shirts, sandal/high heel shoes and totes. The results of market research showed that preferred jean styles were significantly associated with age and marital status. Preferred color of jean pants was also significantly associated with age variable. Current popular jean style was a skinny style. We evaluated results of styling with different jean pants, creating five different images. There was a significant relationship between age/marital status and styling image in different jean styles. In a bootcut style, age variable was significantly associated with different styling images. Generally, most of people responded cute/casual image styling was the best for the bootcut style. In skinny pants, there was a significant association between a residence area and a styling image. Modern/chic image styling with skinny pants was the most favored one. In cropped jean pants, marital status was significantly associated with styling image created. We realized that we can create different images through a styling.

The present study was undertaken to evaluate the effect of temperature on the results of Charpy impact test for glass fiber reinforced polyurethane(GF/PUR) composites. The Charpy impact test were conducted in the temperature range from -50˚ to 50˚. The impact fracture toughness of GF/PUR composites was considerably affected by temperature and it was shown that the maximum value was appeared at room temperature. It is believed that sensitivity of notch on impact fracture energy were increased with decrease in temperature of specimen. As the GF/PUR composites exposed in low temperature, impact fracture toughness of composites decreased gradually owing to the decrease of interface bonding strength caused by difference of thermal expansion coefficient between the glass fiber/polyurethane resin. And decrease of interface bonding strength of composites with decrease in specimen temperature was ascertained by SEM photographs of Charpy impact fracture surface.

In this work, effects of carbon matrix on sliding friction and wear behavior of four kinds of C/C have been investigated against 40 Cr steel ring mate. Composite A with rough lamination carbon matrix (RL) shows the highest volume loss and coefficient of friction, while composite D with smooth lamination/resin carbon matrix (SL/RC) shows the lowest volume loss. The worn surface of composite A appears smooth, whereas that of composite C with smooth lamination carbon (SL) appears rough. The worn surface of composite D appears smooth under low load but rough under high load. Atomic force microscope images show that the size of wear particles on the worn surface is also dependent on the carbon matrix.

Purposes : The effect on corneal swelling and curvature changes in the region of center and peripheral under wearing of therapeutic lenses on a daily and extended wear basis is analyzed. Methods : Thirty three college students(22.4±1.92 years old. 12 males and 21 femaJes) who consent to this clinical triaJ and have no ocuJar surgicaJ history and contact Jens complications were participated in clinical trial. Six therapeutic Jenses which are being prescribed most commonly in the clinic were fitted on the r ight eye(wear group) and no Jens fitted on the Jeft eye(control group). Each eye was examined after 8hours and 24 hours to compare cornea thickness and curvature changes. ln order to fit another Jens in turn. 48 hours interval at the !east was required and no other lenses were not allowed during trial Jens wear. Results : Comeal swelling induced by therapeutic soft contact Jens wear was significantly different in 8 hours(F=33.00. p=O.OO) and in 24 hours(F=38.83. p=O.OO). The degree of swelling in 8 hours of Jens wear was : A Jens(HENIA+ NV. WC : 38%. Dk/t : 7.86) 3.57±2.22%. D Jens(HEMA, WC : 55%. Dkft: 15.68) 3.18±2.05%. F Jens(HEMA+NVP, WC: 55%, Dk/t: 15.92) 2.79±1.61%. C Jens(Vifilcon A. WC: 55%, Dk/t : 23.88) 1.54±1.66%. B Jens(Ocufilcon D. WC: 55%. Dk/t : 26.85) -0.59±2.13%, E Jens(Lotrafilcon A. WC : 24%, Dk/t : 160.92) -0.70±1.53% in that order. The degree of swelling in 24 hours was : A Jens 8.50±3.71. D Jens 8.16±3.58%. F Jens 6.68±3.66%, C Jens 4.31±2.11%. B Jens 2.86±2.84%. E lens -0.03±1.97% respectiveJy. The order in 8 hours was ass that in 24 hours. Conclusions : Therefore. B Jens, C lens, E Jens are found to be more suitabJe for therapeutic Jens in this study. In case of A Jens, D Jens, F Jens which caused significant swelling, in order to confirm if those lenses are suitable for therapeutic Jens, further study on deswelling during day time after extended Jens wear is needed.

The objective of this study was to compare the differences on the activity and power of the wrist flexors and extensors in subjects before the use of a wrist extension splint, after nighttime wearing of the splint, and after daytime wearing of the splint. Ten healthy male and ten healthy female students (mean: 22.4±1.2 years old) volunteered to wear custom-made wrist splints either during the night or during the day, The hand force of the wrist flexor and extensor, and grip force were measured by PowerTrack II and Dynatron, respectively. At the same time, the activities of the wrist flexor and extensor were recorded by' surface electromyography. The maximal hand force and motor unit recruitment of the flexor carpi ulnatis (FCU) increased significantly (p<.05) when tile subjects wore the wrist splints during the daytime, but the maximal hand power of the FCU decreased with nighttime use of the splints. The maximal hand power and motor unit recruitment of the extensor carpi radialis (ECR) and the ECR/FCU ratio decreased both during nighttime and daytime use. The decrement of the ECR/FCU ratio was significant (p<.05). Wearing a wrist extension splint during nighttime led to the maintenance of a lengthened position of the wrist flexor, resulting in the wrist flexor becoming weak. Wearing a wrist extension splint during the day induced the wrist flexors to be greater. In healthy people, the imbalance between the wrist flexors and extensors may be caused by the use of a wrist extension splint. This study indicates that therapists have to consider whether a splint will be effective, as well as the wearing time, when prescribing splints to people with problems of the musculoskeletal system.