• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.11a
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• pp.14-14
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• 2001

현재 제지용 펄프 및 펼프 원료의 국내 자급상태는 매우 낮은 수준이다. 따라서 원료 가격변동과 환율에 따라 수익성은 물론, 원료 수급에도 큰 영향을 받게 된다. 최근 버 진펄프의 가격상승은 재생펄프 사용량과 고지수입량을 더욱 늘리고 있으며, 이들의 사 용에 따른 품질저하 개선노력도 꾸준히 행해지고 있다. 그러나 원가절감과 품질유지라 는 두 마리 토끼를 한꺼번에 잡는 것은 그리 쉬운 일이 아니며 그 효과 또한 점점 미 미해 지고 있는 실정이다. 외국의 경우 이러한 문제점들을 펄프소재면에서 접근하여 해 결하고자 하는 시도가 있었다. 중국은 벗짚펄프를 제지용으로 적용하여 오랜 시행착오 끝에 성공을 거두고 있으며, 남미에서도 수수 등을 이용한 제지용 펼프 개발에 노력과 투자를 아끼지 않고 있다. 이는 제한된 원료의 사용만으로 직면하고 있는 여러 문제점 들을 해결하기가 힘들다는 언식에서 출발한 것이며, 새로운 원료개발 자체가 그 해결방 안으로서 충분한 가치가 있음을 보여준다고 하겠다. 이와 같은 맥락에 따라 국내에서 적용이 가능한 소재를 조사하였으며 우선적으로 신서란을 선택하게 되었다. 신서란은 뉴질랜드가 원산지로 알려져 있으며 오래전부터 제주도에 자생하고 있는 다년생 초본류이다. 수많은 경질섬유(hard fiber)중에서도 경제적으로 재배되는 유일한 작물로 선박용 로프, 그물, 범포 등의 원료로 사용되었으나 현재는 화학섬유로 대체되 어 그 사용이 전무한 실정이다. 선서란은 고강도와 우수한 유연성, 탄력성 및 양호한 광학적 성질을 가지고 있으며 무엇보다 척박한 땅에서도 생장이 왕성하여 재배가 쉽다 는 것이 가장 큰 장점이다. 본 연구는 펄프용 섬유로서 양호한 기본특성을 가진 신서란 을 이용한 펄프를 기존 제지공정에 일정량 투입함으로써 얻고자 하는 종이의 일반물성 개선 및 특수기능 향상에 도움이 되는 제지용 펄프로서의 가능성을 알아보고자 하였다.이어서 몇십%의 현을 억제하지는 못한다는 결론을 도출할 수 있었다. 연구의 결과를 요약하면 다음과 같다. 첫째, 한국과 미국 패션제품의 지난 십년간의 가격 과 품질의 상관관계는 매우 약한 정(+)의 상관을 가지고 있었다. 한국패션제품의 전체 서열상관계수의 평균은 0.091이었고, 미국의 상관계수 평균은 0.192였 다. 상관계수의 수치만으로 볼 때 한국보다는 미국 패션제품의 가격과 품질간의 상관관계가 조금 높게 나타났으나, 양국간 통계적인 차이는 없었다. 또한, 한국 패션제품의 경우에는 제품군의 가격대별 상관관계를 살펴보았는데, 그 결과 1만원 미만의 저가 제품군과 330만원이상의 고가의 제품군의 경우 부(-)의 상관계수를 나타냈다. 둘째. 1990년대 한국과 미국 패션시장의 가격과 품질간의 상관계수의 범위는 제품군별. 산업범주별 로 상이한 분포를 보이고 있었다. 패션제품군별로 보 면, 한국의 경우는 가장 높은 '여행용가방(r = 0.707)' 에서 가장 낮은 '자외선 차단화장품(r = -0.58)'까지, 그리고 미국 패션제품군의 상관계수의 범위는 '팬티 스타킹'의 0.820에서 '남성용 런닝슈즈'의 -0.472까지의 분포를 나타냈다. 마지막으로, 제품의 가격과 품질에 대한 정보를 소비자가 알 경우 얻을 수 있는 소비자의 구매이득 을 추산한 결과 패션제품시장에서 완전한 품질정보를 가지고 있다고 가정한 '현명한 사람'은, 최고가격의 제품만을 구입한다고 가정한 '부유한 사람들'의 구입방식에 비해 최고 좋은 품질의 상품을 총 지불액의 비율로 보아, 한국의 소비자는 약 50% 정도를, 미국의 소비자는 약 91%나 되는 액수를 절약하여 구매할 수 있는 것으로 나타났다. 이상의 본 연구의 결과를 종합하여 볼 때 한국과 미국 모두 제품군별, 그리고 산업범주별로 상관관계가 차이를 보이고 있어, 양국의 소비자들이 패션제품 의 품질을 평가함에 있어 오로지 가격에 대한

• Journal of Korean Biological Nursing Science
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• v.5 no.1
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• pp.23-33
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• 2003

This morphological study was carried out to investigate the healing effect of open and occlusive dressing on rabbit skin wounds. The male white rabbits were given incision wound measuring 1.0cm in length and excision wound measuring $1.0{\times}0.2cm$ respectively on backs. Five rabbits among their received sterilization with beta dine twice a day and kept wound open. Another group of rabbits received sterilization and occlusive dressing with application of 1% sulfadiazine ointment and covering of gauze. The rabbits were observed at 5, 10, and 15 days after dressing with light microscope. The results were as follows. Both incision and excision wounds received open and occlusive dressing respectively revealed formation of scab and regeneration of epidermal epithelial cells at wound margin. The superficial dermis showed infiltration of neutrophils, monocytes, and lymphocytes, fibroblastic proliferation, and edema. On 10 days after opera and occlusive dressing the scab had disappeared and regeneration of epidermal epithelium was completed. The capillaries and inflammatory cells were decreased in number. However, edema and fibroblastic proliferation were more pronounced. On 15 days after opera and occlusive dressing, there were keratinization of regenerated epidermal epithelium, loss of inflammatory infiltration, edema, and capillary proliferation, and increase of fibroblastic proliferation and collagen fibers. The amounts of scars were less in incision wound than of excision one. There were no differences in healing processes between both dressing methods. According to the above results, it was conceived that sterilization of wound is more important in wound healing than dressing method in trivial wounds.

• Applied Microscopy
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• v.32 no.1
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• pp.57-66
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• 2002

The structures of sucker of two Cobiidae; Common freshwater goby and Triden goby were observed by light and electron microscopy. Scanning electron microscopy revealed the characteristic narrow ridges and grooves on the apical portion of sucker of Common freshwater goby, and hexagonal structures similar to a honeycomb representing the intercellular junctional area on the middle and basal portions. Some ridges were present on the epithelial surface on the middle and basal portions. The openings of several mucus-secreting cells were present between main epithelial cells. Light and transmission electron microscopy revealed the core of the fin; soft rays with a surrounding dense collagen fiber layer. Some loosely arranged fibers (collagen fiber) radiated toward the surface epithelium. The surface epithelium was cuboidal or columnar in shape. Scanning electron microscopy revealed the coiled irregular ridges and grooves, which was less developed and had sparser distribution than in Common freshwater goby, on the apical portion of sucker of Triden goby. The middle and basal portions had honeycomb structures as in Common freshwater goby. Fewer mucoussecreting cells were present. Light and transmission electron microscopy showed the core of soft rays, dense collagen fiber layer, however, the radiating fibers observed in the Common freshwater goby was rarely present. The sucker was thinner because the epithelium is squamous or polygonal in shape and rare presence of the radiating fibers.

• Composites Research
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• v.35 no.1
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• pp.42-46
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• 2022

In this study, when the carbon fiber composite was manufactured, the correlation between the porosity and mechanical properties according to the number of glass fiber felts laminated together and the stacking sequence was confirmed. The carbon fiber composite was manufactured by stacking glass fiber felts, which are highly permeable materials, and using vacuum assisted resin transfer molding (VARTM). Porosity was measured by photographing the cross-section of the specimen with an optical microscope and then using porosity calculation code of MATLAB, and mechanical properties were measured for tensile strength, modulus by tensile test. Furthermore, Pearson correlation coefficient between porosity and mechanical properties was calculated to confirm the correlation between two variables. As a result, the number of glass fiber felt increased and the distance from the center of laminated composites increased, the porosity increasing were confirmed. In addition, tensile strength/modulus showed a weak positive correlation with porosity. Also, in order to confirm the effect of only porosity on tensile strength and modulus, mechanical properties calculated by CLPT (Classical Laminate Plate Theory) and experimental values were compared, and the difference in tensile strength showed a strong positive correlation with porosity and the difference in modulus showed a weak positive correlation with porosity.

• Clean Technology
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• v.17 no.1
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• pp.48-55
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• 2011

The application of fibrous activated carbon (FAC)-titanium dioxide ($TiO_2$) hybrid system has not been reported yet for the control of malodorous dimethyl sulfide (DMS) at residential environmental levels. Accordingly, the current study was designed not only to characterize this hybrid system using x-ray diffraction method, particulate surface measurement and Fourier transform Infrared (FTIR) method, but also to evaluate its adsorptional photocatalytic activity (APA) for the DMS removal. The physical/surface characteristics of FAC-$TiO_2$ which was prepared in this study suggested that the hybrid material might have certain APA for DMS. The Brunauer-Emmett-Teller (BET) specific area, total pore volume, micropore volume and mesopore volume decreased all as the $TiO_2$ amounts coated on FAC increased, whereas the reverse was true for average pore diameter. $TiO_2$ coated onto FAC did not influence the adsorptional activity of FAC for the DMS input concentration of 0.5 ppm. The APA test of the hybrid material presented that the initial removal efficiencies of DMS were 93, 78, 71 and 57% for the flow rates of 0.5, 1.0, l.5 and 2.0 L/min, respectively, and they decreased somewhat 2 h after the experiment started and kept almost constant for the rest experimental period. Under this pseudo-equilibrium condition, the DMS removal efficiencies were 78, 58, 53 and 36% for the four flow rates, respectively. Meanwhile, there were no significant byproducts observed on the surfaces of the hybrid material. Consequently, this study suggests that, under the experimental conditions used in the present study, the hybrid material can be applied for DMS at residential environment levels without being interfered by any byproducts.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.3
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• pp.57-65
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• 2015

Electronic packages consist of various materials, and as temperature changes, warpage occurs because of the difference in coefficient of thermal expansion. Shadow $moir{\acute{e}}$ is non-contact, whole field measurement technique for out-of-plane displacement. However, the technique has low sensitivity above $50{\mu}m/fringe$, it is not adequate for the warpage measurement in some circumstance. In this paper, by applying phase shifting process to the traditional shadow $moir{\acute{e}}$, measurement system having enhanced sensitivity of $12.5{\mu}m/fringe$ is constructed. Considering Talbot effect, the measurement is carried out in the half Talbot area. Shadow fringe pattern having four times enhanced sensitivity is obtained by the image process with four shadow fringes. The measurement technique is applied to the fibered package substrate and coreless package substrate for measuring warpages at room temperature and at about $100^{\circ}C$.

• The Journal of the Korea Contents Association
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• v.17 no.3
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• pp.666-674
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• 2017

Today, the term of fusion, such as technology convergence and industrial convergence, is emerging as one of the most important trends in our society. The purpose of this study is to analyze the convergence coefficient of each industry using patent data and to analyze the convergence phenomenon in industry based on convergence coefficient. To do this, 2011-2015 Korean patent data were utilized. The research findings revealed that the ICC by industry was the highest in order of man-made fibres, paints/varnishes, petroleum products/nuclear fuel and other chemicals. Also, according to the inter-industry convergence matrix, the number of convergence patents was the greatest in order of office machinery and computers, special purpose machinery industries and Measuring instruments. Added same analysis was conducted through Industry with high number of patents. As a result, the convergence has been actively carried out in the fields of optical instruments, Basic chemical, Fabricated metal products, Measuring instruments and special purpose machine manufacturing industries.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.1
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• pp.1-7
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• 2007

As fiber reinforced composite materials are widely used in aircraft, space structures and robot arms, the study on non-destructive testing methods has become an important research area for improving their reliability and safety. AE (acoustic emission) can evaluate the defects by detecting the emitting strain energy when elastic waves are generated by the initiation and growth of crack, plastic deformation, fiber breakage, matrix cleavage, or delamination. In the paper, AE signals generated under uniaxial tension were measured and analyzed using the $8{\times}8$ matrix piezo electric sensor. The electronic circuit to control the transmitting distance of AE signals was designed and constructed. The optical data storage system was also designed to store the AE signal of 64channels using LED (light emitting diode) elements. From the tests, it was shown that the source location and propagation path of AE signals in composite materials could be detected effectively by the $8{\times}8$ matrix piezo electric sensor.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.2
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• pp.221-227
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• 2021

Recently, interests in mask-type skin care devices using light-emitting diodes have been increasing and optical stimuli at certain wavelengths have been known to have various therapeutic effects, such as skin whitening, acne treatment, elasticity and wrinkle improvement by controlling the exposure to wavelengths of light and irradiation time. In particular, light sources of different wavelengths are applied in masks for the purpose of suppressing skin aging, inducing cell proliferation, and alleviating skin inflammation. In this paper, we developed a light-emitting diode control system that is actively used in skin regeneration masks using a microcontroller. Optical stimuli with different manners were applied to skin fibroblast cells in a single or complex wavelengths, and then confirmed how they are effective in the cell differentiation. In addition, we found a specific wavelength that has a positive effect on cell proliferation rates, and confirm the effectiveness of cell proliferation by image processing based quantitative analysis.

• Journal of the Korean Wood Science and Technology
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• v.32 no.1
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• pp.1-8
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• 2004

This study was carried out to investigate the sheet properties of Indian mallow Hanji, made by different pulping methods, such as alkali and sulfomethylated pulpings, and different stock compositions, various mixing ratios of bast fiber and woody core fibers. Indian mallow hanjis made from the sulfomethylated pulps had higher brightness and sheet strength than the alkali pulps. It was found that the brightness of sulfomethylated pulp was enough high without an extra-bleaching. In the mechanical properties of Indian mallow hanjis mixed with bast fiber and woody core stalk pulps, the sheet strength were decreased as wood core pulps contents were increased. The sheet formation were increased as the increase of woody core pulps contents, while the sheet strength decreased. Although the sulfomethylated pulping resulted in higher pulp yield, no morphological differences of fiber surfaces were shown as compared to the different pulping methods.