• 한국연초학회지
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• 제32권1호
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• pp.12-18
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• 2010

The parcel wrapper for cigarettes has been used as the package and media materials for protection and design of product brands. The design of parcel wrapper has been contributed to the delivery of brand image and motivated consumer to purchase the brand. Therefore, the properties of parcel wrapper have been paid attention to highlight the design image, and increasing opacity of media materials has been one of the effective ways to obtain clear design on the paper surface. This study was carried out to improve the opacity of parcel wrapper for cigarettes. The effects of pulp composition and inorganic fillers in the furnish on the optical and mechanical properties were investigated. The use of hardwood in the stock preparation gave the increased opacity of paper than that of softwood. The application of higher refractive indices of fillers was effective to improve opacity. Brightness, tensile strength and stiffness were affected by the retained filler amount on the paper. Increase of filler contents decrease the tensile strength and stiffness due to the lesser bonding ability of fibers.

• 펄프종이기술
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• 제31권2호
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• pp.15-24
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• 1999

A new technique for recycling of white water was developed in order to reduce the calcium hardness in a closed OCC recycling system. Calcium ions present in the white water were precipitated as calcium carbonate by reacting with sodium carbonate, and the precipitated $CaCO_3$ was removed from the system using a flotation fractionation method, which has been commonly used in deinking process. In the flotation stage, a mixed gas of $CO_2$-air was purged into the flotation cell because the pH of $Na_2CO_3$-treated white water was reduced to neutral by $CO_2$ gas. Since $CaCO_3$ precipitate tends to stick onto fine fiber surface and then selectively removed from the white water, a proper amount of suspended solid in white water acts as an important factor for deciding the removal efficiency. By the application of $Na_2CO_3$ addition-$CO_2$ flotation to the short circulated white water, the calcium hardness was significantly reduced by 87% and more. Removal of calcium ions with fine fibers led to a drainage improvement, reduction of fresh water consumption, and enhanced efficiency of wet-end chemicals.

• 펄프종이기술
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• 제40권2호
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• pp.8-15
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• 2008

Wastewoods (logging residues) generated in Korea were used to make lignocellulosic fillers for papermaking. Lignocellulosic fillers could play great roles to increase retention efficiency and thus decrease turbidity of white water in papermaking process. In addition, lignocellulosic fillers could be used to improve physical properties of paper through their high affinity to cellulosic fibers, leading to the less use of chemical additives like retention aids. Wastewoods including Pinus densiflora and Quercus variabilis were chemically and mechanically treated for making fine particles passing through 100 mesh wire. The newly generated fillers showed larger particle size distribution than ground calcium carbonates but similar distribution to talc. In particular, pretreatment by hot water was more effective to generate smaller particle size than by alkali treatment. Lignocellulosic particles mixed with ground calcium carbonates under intense hybridizing condition greatly contributed to surface coverage of organic fillers in addition to filling to lumen and pits.

• Carbon letters
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• 제8권4호
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• pp.285-291
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• 2007

Carbon materials of various morphologies were synthesized by pyrolysis of Soap-nut seeds (Sapindus mukorossi), Jack Fruit seeds (Artocarpus heterophyllus), Date-seeds (Phoenix dactylifera), Neem seeds (Azadirachta indica), Tea leaves (Ehretia microphylla), Bamboo stem (Bambusa bambus) and Coconut fiber (Cocos nucifera), without using any catalyst. Carbon materials thus formed were characterized by SEM XRD and Raman. Carbon thus synthesized varied in size (in ${\mu}m$) but all showed highly porous morphology. These carbon materials were utilized as the anode in Lithium secondary battery. Amongst the various precursors, carbon fibers obtained from Soap-nut seeds (Sapindus mukorossi) and Bamboo stem (Bambusa bambus), even after $100^{th}$ cycles, showed the highest capacity of 130.29 mAh/g and 92.74 mAh/g respectively. Morphology, surface areas and porosity of carbon materials obtained from these precursors were analyzed to provide interpretation for their capacity to intercalate lithium. From the Raman studies it is concluded that graphitic nature of carbon materials assist in the intercalation of lithium. Size of cavity (or pore size of channels type structure) present in carbon materials were found to facilitate the intercalation of lithium.

• Carbon letters
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• 제15권2호
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• pp.125-128
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• 2014

In this study, the effect of stacking sequence on the flexural and fracture properties of carbon/basalt/epoxy hybrid composites was investigated. Two types of carbon/basalt/epoxy hybrid composites with a sandwich form were fabricated: basalt skin-carbon core (BSCC) composites and carbon skin-basalt core (CSBC) composites. Fracture tests were conducted and the fracture surfaces of the carbon/basalt/epoxy hybrid composites were then examined using scanning electron microscopy (SEM). The results showed that the flexural strength and flexural modulus of the CSBC specimen respectively were ~32% and ~245% greater than those of the BSCC specimen. However, the interlaminar fracture toughness of the CSBC specimen was ~10% smaller than that of the BSCC specimen. SEM results on the fracture surface showed that matrix cracking is a dominant fracture mechanism for the CSBC specimen while interfacial debonding between fibers and epoxy resin is a dominant fracture process for the BSCC specimen.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.103-105
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• 2005

The importance of protecting people from harsh weather conditions cannot be over-emphasized and the way to. do so should be sought vigorously. The most well known and widely used weather protection fabric in the current industry is $Gor-Tex.^1$ However, the Gore-Tex membrane cannot be attached to cotton or other natural fibers so it's use is not suitable for clothing such as underwear. If the exterior of cotton fabric can be made to be hydrophobic without sacrificing the comfort and breathability, the result will be a cotton fabric with the weather protection capability equivalent to Gore-Tex as well as the ability to provide the best wear comfort. However, this should be done without using toxic and expensive gases to be environmentally friendly and cost effective. Therefore, our approach for hydrophobic treatments of fabric and metal surfaces is to utilize a plasma-based technique. In general, plasma processes do not produce chemical wastes or waste disposal problems and they are fully automated.

• 한국수산과학회지
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• 제9권4호
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• pp.239-244
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• 1976

건조옥돔의 유지산화방지를 목적으로 몇가지 항산화제처리를 행하고 지방의 이동 및 분포 그리고 조직세포의 변화 등을 조직학적으로 관찰하여 다음과 같은 결과를 얻었다. 옥돔 건조중 초기단계에서는 피하지방의 일부가 결체조직이나 근절을 통하여 내부로 침투하여 들어가나 기간이 길어지면 나머지 지방은 외부로 삼출하였다. 피하지방이이 없어진 조직은 근세포가 서로 밀착하여 집을 볼 수 있었다. .항산화제 처리에 따른 조직상의 효과는 지방이 잔재하고 조직에도 변화가 적어 Tenox-II와 BHA 처리때가 가장 좋았다.

• 대한의생명과학회지
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• 제11권2호
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• pp.243-248
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• 2005

The present study was conducted to determine whether skin spread of Myrrha and Tending Diancibo Pu (TDP) irradiation have a remarkable effect on the cell regeneration as well as wound healing following dermal scald burn injury. Burn injury was induced on dorsal surface $(TBSA\;15\~20\%)$ by scald burn in rats. Postburn concentration of serum protein was significantly decreased compared with sham-treated, double treatment with Myrrha and TDP was significantly increased the protein concentration compared with that of burn control. The content of keratinocyte growth factor (KGF) at 48 h is higher than that of at 24 h, and double treatment with Myrrha and TDP was the most effective to increase the production of KGF in all experimental groups. Morphologically, epithelial regeneration and dermal collagen synthesis by fibroblasts were accelerated in Myrrha and TDP treated group compared with bum control at same time postburn. At 48 h after burn, all dermal connective tissues are recovered to new collagen fibers in case of Myrrha and TDP double treated group. The data suggest that double treatment with skin spread of Myrrha and TDP radiation have a remarkable effect of to accelerate cell regeneration and wound healing in case of scald burn skin.

• 대한기계학회논문집A
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• 제24권7호
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• pp.1697-1702
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• 2000

This study has been performed to investigate the effects of glass fiber characteristics on the mechanical properties of thermoplastic composite. The surface of glass fiber was coated with the silan e to enhance the bonding strength between fiber and matrix. A micro-droplet pull-off test was performed to investigate the influence of the silane concentration on the bonding strength. The maximum bonding strength was observed around 10.8% silane concentration. In order to examine the influence of the fiber length and fiber content on the properties of the composite, the composite materials involving tile fiber lengths of 5mm, 10mm, 15mm 20mm, and 25mm were tested. The composites used contain 20%, 30%, and 40% by weight of glass fibers. Tension and flexural tests were performed to investigate their mechanical properties of the composites. The tensile strength and tensile modulus of the composite increase with increasing the glass fiber content. The tensile modulus increases slightly with increasing the fiber length. The maximum tensile strength is observed around the fiber length of 15-20mm. The flexural modulus and strength also increase slightly with increasing the fiber length.

• KIEAE Journal
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• 제6권4호
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• pp.11-16
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• 2006

This work has carried out some preliminary studies for the utilization of a solar mini-dish system capable of concentrating solar rays to higher densities. A typical mini-dish system considered employs an array of solar mini-dishes where major components are light and compact. It consists of small mini-dishes, optical fiber bundles and diffusers at the end. Each mini-dish (typically has a 20 to 30 cm in diameter) is designed with a simple parabolic profile, concentrating sunlight (after the glass glazing cover to avoid dust deposition on the reflector and facilitate cleaning) onto a centrally-located small mirror which is placed on the bottom side of the transparent glass cover. The focused sunlight is reflected by the mirror surface onto a focal point where the receiving aperture of a homogenizer is located. Optical fibers are used to carry high-density solar rays to the other end where diffusers are mounted for indoor illumination. The proposed high density mini-dish system could make an efficient daylighting system as it excludes large moving parts and expandable if necessary. Each component of the system could be made from the off-the-shelf technology and thus, make the generic unit inexpensive to manufacture. Depending on spatial demand or characteristics, the amount of introducing daylight could be controlled. Preliminary tests have been carried out for a trial system to check any functional problems when in operation. Suggestions are also made to improve the design enhancing its performance and applicability.