• 펄프종이기술
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• 제39권4호
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• pp.14-20
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• 2007

The effects of blending starches with different gelatinization temperatures on the development of ply-bond strength were systematically investigated using a three component mixture design technique. Oxidized corn starches with different gelatinization temperatures were blended with natural corn starch and sprayed for plybonding. Optimum blend ratio for maximizing plybond strength improvement for the starch blends was 40% of natural starch, 27% of oxidized starch with low gelatinization temperature and 33% of oxidized starch with high gelatinization temperature. Starch granules with the lowest gelatinization temperature gelatinizes at the lowest temperature, while the natural corn starch gelatinizes at later stage of drying. The improvement of plybond strength with starch blends were verified on machine trial as well. Plybond strength improvement obtained from the machine trial was lower than that achievable with handsheets, which was attributed to the lower internal bond strength of the linerboards made from recycled fibers.

• 펄프종이기술
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• 제33권3호
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• pp.69-74
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• 2001

Diaper rash is found on the skin inside of babys diaper area. Most diaper rashes are caused by prolonged contact with the moisture, germs, and ammonia of the stool and urine. Some diaper rashes are caused by fungi infection such as candida albicans and Preteus vulgaris. In this study, Candida albicans was used as a test microorganism and experiment was carried out to inhibit diaper rash. Handsheets were treated with chitosan oligosaccharide, bamboo extractives, as well as mixture of monolaurin as an emulsifier and bamboo extractives. Both shake flask method and halo test were applied in order to examine the antimicrobial activity of each sample. It was found from both results of the halo test and shake flask method that handsheets treated with chitisan oligosaccharide or bamboo extractives showed antimicrobial property. In the treatment of bamboo extractives without emulsifier, no distinct difference in antimicrobial effect was found between bamboo branch and bamboo leaves extractives. In case of mixture of bamboo extractives and emulsifier, the result also suggested that bamboo branch showed better syngergistic effect than bamboo leaves. Both chitosan oligosaccharide and bamboo extractive can be used as antifungal agents against Candida albicans for making diaper.

• Advances in nano research
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• 제16권5호
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• pp.445-458
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• 2024

The objective of this paper is to present free vibration and static stability analyses of rotating composite beams reinforced with carbon nanotubes (CNTs) under uniform thermal loads. Beam structural equations and CNT-reinforced composite (CNTRC) beam formulations are derived based on Timoshenko beam theory (TBT). The temperature-dependent properties of the beam material, such as the elastic modulus, shear modulus, and material density, are assumed to vary over the thickness according to the rule of mixture. The beam material is modeled as a mixture of single-walled carbon nanotubes (SWCNTs) in an isotropic matrix. The SWCNTs are aligned and distributed in the isotropic matrix with different patterns of reinforcement, namely the UD (uniform), FG-O, FG-V, FG- Λ and FG-X distributions, where FG-V and FG- Λ are asymmetric patterns. Numerical examples are presented to illustrate the effects of several essential parameters, including the rotational speed, hub radius, effective material properties, slenderness ratio, boundary conditions, thermal force, and moments due to temperature variation. To the best of the authors' knowledge, this study represents the first attempt at the finite element modeling of rotating CNTRC Timoshenko beams under a thermal environment. The results are presented in tables and figures for both symmetric and asymmetric distribution patterns, and can be used as benchmarks for further validation.

• 펄프종이기술
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• 제33권4호
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• pp.15-20
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• 2001

The function of the moisture-proof paper is to prevent moisture from adsorbing into the packed goods. Water-vapor transmission rate of the moisture-proof paper should be less than 100g/$m^2$.24hr and the optimum rate would be less than 50g/$m^2$.24hr. In general the moisture-proof paper has been made by laminating polyethylene or polypropylene on top of the base paper. However this kind of moisture-proof paper has a problem in recycling so that it brings about environmental pollution. In general the moisture-proof paper has been made by laminating polyethylene or polypropylene on top of the base paper. However this kind of moisture-proof paper has a problem in recycling so that it brings about environmental pollution. The purpose of this paper was to make moisture-proof paper using the mixture of SB latex and wax emulsion which was recyclable and environmentally friendly. Water vapor transmission rate showed less than 50g/$m^2$.24hr in mixture ratio of 85:15, 87:13, 90:10. Especially the mixture ratio of 87:13 showed the most favorable water-vapor transmission rate. However, the moisture-proof layer was destroyed slightly by folding in packing. It has been observed that there was no close relationship between water-vapor transmission rate of the moisture-proof paper and grammage of the base paper, but the density of base paper had influenced on water vapor transmission rate. It was also observed that the moisture-proof paper could be recycled. The moisture-proof paper was similar to base paper in degree of the pulping, and there was no significant difference in dispersion between moisture-proof paper and base paper. Most of wax particles which caused the spots during drying process could be removed by flotation process. Tensile strength and tear strength of both moisture-proof paper and base paper after pulping were measured to examine the fiber bonding, and no significant difference in physical properties was observed.

• 한국식품조리과학회지
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• 제6권4호통권13호
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• pp.27-32
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• 1990

Triglyceride는 구성지방산의 종류에 따라 분자종이 다양하게 존재하여 식품의 가공, 저장중에 있어서 유지의 물성변화 및 산화특성을 효과적으로 규명하기 위해서는 구성 triglyceride 분자종의 상세한 해석이 요구된다고 하겠다. 율무 지질의 triglyceride를 reverse phase HPLC UV detector 210nm에서 분석한 결과 6개의 peak로 분획되었다. 각 획분을 GC로 acycl 탄소수별로 분획하고, 다시 DEGS column을 이용하여 fatty acid 조성을 분석하였다. 이 세가지 결과로부터 triglyceride 조성을 산정한 결과 11개의 TG 조성을 추산하였으며, 그 중 주요 triglyceride로는 C18 : 1 C18 : 2 C18 : 2(OLL)이 38.2%, C16 : 0 C18 : 2 C18 : 3(PLLn)이 15.7%, C18 : 1 C18 : 1 C18 : 2(OOL)이 12.6%였다. 한편 capillary GC와 GC-MS로 같은 시료를 분석하여 분자종을 확인하는 작업을 계속하고 있으며 위의 결과와 비교하여 다음에 보고하고자 한다.

• 한국전기전자재료학회논문지
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• 제27권12호
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• pp.820-824
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• 2014

TiNOx multi-layer thin films on aluminum substrates were prepared by DC reactive magnetron sputtering method. 4 multi-layers of $TiO_2$/TiNOx(LMVF)/TiNOx(HMVF)/Ti/substrate have been prepared with ratio of Ar and ($N_2+O_2$) gas mixture. $TiO_2$ of top layer is anti-reflection layer on double TiNOx(LMVF)/TiNOx(HMVF) layers and Ti metal of infrared reflection layer. In this study, the crystallinity and surface properties of TiNOx thin films were estimated by X-ray diffraction(XRD) and field emission scanning electron microscopy(FE-SEM), respectively. The grain size of TiNOx thin films shows to increase with increasing sputtering power. The composition of thin films has been investigated using electron probe microanalysis(EPMA). The optical properties with wavelength spectrum were recorded by UV-Vis-NIR spectrophotometry at a range of 200~1,500 nm. The TiNOx multi-layer films show the excellent optical performance beyond 9% of reflectance in those ranges wavelength.

• 한국식품영양과학회지
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• 제41권3호
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• pp.320-326
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• 2012

본 연구에서는 홍삼분말과 커피분말의 혼합비율에 따른 추출물에서의 항균효과와 항산화성을 알아보기 위해 물과 에탄올로 추출하여 그람 음성균 3종과 그람 양성균 3종 및 진균 1종에 대한 항균활성 및 항산화력을 측정하였다. 각각의 추출물을 이용하여 항균 효과를 측정한 결과 열수 추출물은 모든 균주에서 항균활성을 보였으나 비교적으로 약한 항균효과를 보였고, 에탄올 추출물은 그람음성 균주 E. coli와 진균인 C. albicans 2종에서는 항균효과를 보이지 않았지만 나머지 균주에서는 열수 추출보다 우수한 항균효과를 보였다. B. cereus 균주에서는 모든 샘플에서 항균효과가 나타났고, ES2 샘플은 P. aeruginosa와 S. Typhimurium 균주에서 각각 19 및 20 mm의 clear zone을 형성하였고, 0.25 및 0.125 mg/mL의 농도로 MIC를 나타내어 가장 우수한 항균효과를 보였다. 또한 항균성을 보인 대부분의 시료에서 0.5~1.0 mg/mL의 MIC 농도를 나타내었다. 그리고 DPPH 자유기 소거효과를 이용한 항산화력 측정에서는 열수 추출물에서 55.38~60.01%, 에탄올 추출물에서 59.37~70.50%로 AA보다는 약하지만 BHT의 결과와 비슷하여 비교적 높은 자유기 소거효과를 보였다. 총 폴리페놀화합물 함량은 열수 추출물에서 93.57~109.18 mg/g으로 커피와 홍삼의 혼합비율이 9:1일때 가장 높은 함량을 보였고, 에탄올 추출물에서는 105.16~119.79 mg/g으로 혼합비율이 7:3일 때 가장 높은 함량을 보였다. 열수 추출물과 에탄올 추출물의 총 페놀화합물의 함량을 비교하였을 때, 대체로 에탄올 추출물에서 총 페놀화합물 함량이 높은 경향을 보였다. 혼합 비율에 따라 각 시료의 항균 효과와 항산화력 역시 변화를 보였다. 따라서 홍삼의 일반 식품 이용가능성으로 커피와의 함량 조절로 커피의 항균효과와 항산화력을 변화시킬 수 있다는 가능성을 알 수 있었다. 이 연구를 바탕으로 추후 특정 생리활성물질의 분석과 생리활성기능을 연관 지어 연구를 진행한다면 기존의 기호음료로서의 커피에서 기능성 음료로서의 커피로 발전할 수 있을 것으로 기대된다.

• Transactions on Electrical and Electronic Materials
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• 제16권5호
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• pp.264-267
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• 2015

AlCrNO cermet films were prepared on aluminum substrates using a DC-reactive magnetron sputtering method and a water-cooled Al:Cr target. The Al₂O₃/AlCrNO (LMVF)/AlCrNO (MMVF)/AlCrNO (HMVF)/Al/substrate of the 5 multi-layers was prepared according to the Ar and (N₂ + O₂) gas-mixture rates. The Al₂O₃ of the top layer is the anti-reflection layer of triple AlCrNO (LMVF)/AlCrNO (MMVF)/AlCrNO (HMVF) layers, and an Al metal forms the infrared reflection layer. In this study, the crystallinity and surface properties of the AlCrNO thin films were estimated using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM), while the composition of the thin films was systematically investigated using Auger electron spectroscopy (AES). The optical properties of the wavelength spectrum were recorded using UH4150 spectrophotometry (UV-Vis-NIR) at a range of 0.3 μm to 2.5 μm.

• Preventive Nutrition and Food Science
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• 제8권3호
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• pp.253-259
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• 2003

Conjugated linoleic acid (CLA) is a class of positional, geometric conjugated dienoic isomers of linoleic acid (LA). CLA activates the immune system, protects against tumorigenesis, and reduces the incidence of atherosclerosis. Trans-10, cis-12 CLA has specific effects on lipid metabolism, it has been shown to reduce body fat gain and regulates some adipocyte secreted proteins in vivo and in vitro. Here we report that a CLA mixture affects cytokine secretion from rat primary adipocytes. Rat primary adipocytes were treated with 1 mM, 100 $\mu$M, 1 $\mu$M or 100 nM CLA mixture doses; and leptin, tumor necrosis factor alpha (TNF a ), interleukin-6 (IL-6) and glycerol levels in the medium were measured. Leptin secretion was lower, TNF $\alpha$ secretion higher and IL-6 secretion did not change in response to the CLA mixture. Leptin and TNF $\alpha$ secretions did not change with CLA mixture treatment in a dose-dependent manner. In addition, the CLA mixture did not appear to enhance lipolysis in rat primary adipocytes. In conclusion, our study demonstrates that the decrease in leptin and increase in TNF $\alpha$ secretion in adipocytes treated with CLA mixture may be due to the apoptotic effect and to a reduction in peroxisome proliferator-activated receptor gamma (PPAR ${\gamma}$ ) ligands.

• 한국농공학회논문집
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• 제49권6호
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• pp.87-92
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• 2007

Strain-stress behavior of soil is of importance in dealing with geo-techniques which relate to bearing capacity, slope stability, earth pressure and many geo-technical problems. So understanding mechanism of the behavior and reinforcing soil to the required state has been an issue for many years. This paper presents the possibility of magnetic force in enhancing shear strength. To analyze the reinforcing effect, triaxial compression tests were performed on two sets of steel-sand mixtures, one of which is influenced by permanent magnet, NdFeB. With magnetic force under 50 kPa confining pressure, maximum shear strengths increased according to steel percentages but under 100 kPa, no significant changes in maximum shear strengths occurred. Therefore the analysis by Mohr's circles indicates that magnetic force converts the shearing characteristics of sand into those of clay.