• 한국응용과학기술학회지
• /
• 제31권4호
• /
• pp.584-594
• /
• 2014

고분자 필름의 표면에 친수성의 증가시키는 것은 그 자기 세정 및/또는 방담 특성을 가지게 하는데 중요한 접근 방법이다. 일반적으로 친수성 표면은 비이온 계면활성제를 코팅하거나 표면에너지를 증가시킴으로써 제조할 수 있다. 본 연구에서는 가격이 저렴하고 톨루엔 용제에 잘 용해될 뿐 만아니라 커플링제와 반응할 수 잇는 하이드록시기를 가지고 있는 Tween, Span 및 PEG-PPG 블록공중합체를 선택하여 실험을 수행하였다. 배합 조건에 따라 PET 필름 표면의 친수도에 큰 영향을 미침을 확인하였다. 그러나, PET 필름의 표면상에 단순히 이들 계면활성제의 도입은 수세 후에는 높은 내구성을 보여주지 않았다. 내구성을 높이기 위해 에폭시 및 이소시아네이트와 같은 두 종류의 커플링제를 사용하였다. 코팅액에 6 중량 %isophrone 디이소시아네이트 (IPDI)를 함유한 코팅액으로 코팅된 PET 필름 표면의 물에 대한 접촉각은 $8.7^{\circ}$까지 낮아졌으며, 이는 매우 높은 친수성에 대한 간접적인 증거이다. 또한, 코팅된 PET 필름의 광 (파장 500 nm) 투과율 값은 높은 투명 특성을 유지하면서 87%에서 85%로 약간 감소하였다. 이 PET 필름은 자기 세정 특성이 필요한 필름산업에 적합한 소제로 사용될 수 있다.

• 한국수소및신에너지학회논문집
• /
• 제22권1호
• /
• pp.1-12
• /
• 2011

To improve the mechanical properties, such as durabilities and antioxidative characteristics, the covalently cross-linked (CL-) SPEEK (sulfonated polyether ether ketone)/Cs-substituted HPA (heteropoly acid) organic-inorganic composite membranes (CL-SPEEK/Cs-HPAs), have been intensively investigated. The composite membrane were prepared by blending cesium-substituted HPAs (Cs-HPAs), including tungstophosphoric acid (TPA), molybdophosphoric acid (MoPA), and tungstosilicic acid (TSiA) with cross-linking agent content of 0.01 mL. And composite electrolytes composed of Cs-HPAs, prepared by immersion (imm.) and titration (titr.) methods to increase the stability of HPAs in water, were applied to polymer electrolyte membrane electrolysis (PEME). As a result, the proton conductivity of Cs-substituted composite membranes increased rapidly over $60^{\circ}C$ but mechanical properties, such as tensile strength, decreased in accordance with added Cs content. The bleeding-out of Cs-TPA membranes by titration method (50 vol.% Cs) decreased steadily to 2.15%. In the oxidative stability test by Fenton solution, the durability of membranes with Cs-HPA significantly increased. In case of CL-SPEEK/ Cs-TPA membrane, duration time increased more than 1200 hours. It is expected that even though CL-SPEEK/Cs-MoPA membrane shows the high proton conductivity, electrocatalytic activity and cell voltage of 1.80 V for water electrolysis, the CL-SPEEK/Cs-TPA (imm.) is more suitable as an alternative membrane in real system with the satisfactory proton conductivity, mechanical properties, anti-oxidative stability and cell voltage of 1.89 V.

• Asian-Australasian Journal of Animal Sciences
• /
• 제23권11호
• /
• pp.1503-1509
• /
• 2010

Forty-eight 40-wk-old Hi-sex laying hens were individually caged in an environmentally controlled house to evaluate the effect of garlic (Allium Sativum) juice administration on egg production, egg quality, and yolk cholesterol. Garlic juice was prepared by blending pealed garlic cloves with distilled water (1:1, w/w). Hens were randomly divided into four equal groups; one served as a control and the other three groups were individually gavaged, 3.75 ml, 7.5 ml, or 15 ml garlic juice, three times a week, which respectively represented 0.25, 0.50 and 1% of body weight. Egg production was recorded on a daily basis; egg weight, albumen height, albumen and yolk pH, Haugh unit, and bacterial count of E. coli-challenged eggs were recorded at day of oviposition (day-1) and after 5 and 10 days of storage at room temperature. Yolk cholesterol content was analyzed for five successive weeks. Garlic juice increased (p<0.05) egg weight and mass with no change in egg production intensity. Garlic juice administration recorded higher (p<0.05) albumen height and improvement in Haugh unit. Also, eggs from garlic-treated hens recorded lower (p<0.05) albumen and yolk pH when compared to eggs collected from control hens. Garlic reduced (p<0.05) the $log_{10}$ of bacterial count in egg contents linearly when challenged with E. coli. Egg-yolk cholesterol content was not influenced by garlic juice administration. It is concluded that garlic juice improved performance characteristics and may increase egg shelf life as indicated by egg quality improvement and lower bacterial count of E. coli-challenged eggs. The levels of garlic juice used in this study were insufficient to influence egg yolk cholesterol.

• 한국염색가공학회지
• /
• 제20권3호
• /
• pp.31-38
• /
• 2008

Regenerated composite fibers were prepared from solution of styela clava tunics(SC) and poly vinyl alchol(PVA) using N-methylmorpholine-N-oxide(NMMO)/water(87/13)(wt%/wt%) as a solvent by dry jet-wet spinning. Structure and physical properties of regenerated composite fibers were investigated through birefrngence, x-ray diffratograms, tenacity, fibrillation and SEM. Optimal blend ratio of SC/PVA for mechanical properties of composite fibers was 70/30 and total weight was 4wt% concentrations in NMMO/$H_2O$ solvent system. Crystallinity index of composite fibers were decreased as the PVA contents increased. Fibrillation of $10{\sim}20wt%$ PVA blended fibers were occurred less than pure SC fiber. Shape of composite fibers were a circle cross section within 10wt% PVA content. But the cross section of fibers were changed as crushed flat with the PVA contents increased.

• 한국항행학회논문지
• /
• 제18권5호
• /
• pp.409-414
• /
• 2014

관광산업은 주 5일 근무제 시행 이후 여가시간이 증가함에 따라 양질의 성장을 보이고 있다. 관광산업은 전자 통신의 발달에 힘입어 다양한 형태의 문화와 결합하여 21세기 고부가가치 산업으로 각광받고 있다. 특히 삼면이 바다인 우리나라는 국민소득이 증가함에 따라 해양레저산업에 더욱 관심을 갖고 있다. 해양수산부는 막대한 정책지원을 통해 해양관광진흥계획을 수행하고 있으며, 어촌지역에 문화를 융합하여 타 지역 관광객 유치를 위해 노력하고 있다. 본 연구를 통한 콘텐츠를 활용하여 정책자금이 동원되는 활동을 바르게 모니터링하고, 고부가가치 관광 산업을 육성하기 위한 유용한 콘텐츠 활용 전략을 제시하였다.

• 한국염색가공학회지
• /
• 제28권1호
• /
• pp.40-47
• /
• 2016

As a coating material for loudspeaker dampers, resilient polyurethane/epoxy hybrid resins were synthesized to replace conventional phenol resin and examined the physical properties, which are not only environmentally friendly but also not harmful to human. Five types of polyurethane resins were synthesized in the step-shot method using methylene diisocyanate, three polyols such as poly tetramethylene ether glycol(PTMEG, MW:2000), poly(1,4-buthylene adipate(PBAP, MW:2000), and poly carbonatediol(PCD, MW:2000), and three chain extenders such as ethylene glycol(EG), neopentyl glycol(NPG), and 1,4-buthandiol(1,4-BD). The five types of synthesized polyurethane resins and commercially available bisphenol A type epoxy resin were blended in weight ratios of 90:10, 70:30, and 50:50 to synthesize 15 types of polyurethane/epoxy hybrid resins. Among the polyurethane resins, the one that was synthesized using PCD and 1,4-BD showed excellent tensile strength, 100% modulus, low extension, and relatively high viscosity. Polyurethane/epoxy hybrid resins with higher epoxy resin contents showed better thermal properties and water resistance while those with higher polyurethane contents showed higher flexibility. The polyurethane/epoxy hybrid resin made by blending the polyurethane based on PCD and 1,4-BD with a bisphenol A type epoxy resin in a weight ratio of 70:30 was identified to be the most suitable to be used in speaker dampers.

• 수산해양기술연구
• /
• 제53권1호
• /
• pp.89-97
• /
• 2017

Butanol has an ability to improve the ignition quality due to its lower latent heat of vaporization; it has an advantage to reduce a volume of a fuel tank because its energy density is higher than that of ethanol. Also, butanol-diesel oil blending quality is good because butanol has an effect to prevent the phase-separation between two fuels. Even if the blended oil contains water, it can reduce the corrosion of the fuel line. Thus, it is possible to use butanol-diesel oil blended fuel in diesel engine without modification, and it may reduce the environment pollution due to NOx and particulate and the consumption of diesel oil. Therefore, some studies are being advanced whether butanol is adequate as an alternative fuel for diesel engines, and the results of the combustion and exhaust gas emission characteristics are being presented. Though the injection and spray characteristics of butanol are more important in diesel combustion, the has not yet dealt with the matter. In this study, the influence in which differences of physical properties between butanol and diesel oil may affect the injection and spray characteristics such as injection rate, penetration, spray cone angle, spray velocity and process of spray development were examined by using CRDI system, injection rate measuring device and spray visualization system. The results exhibited that the injection and macroscopic spray characteristics of two fuels were nearly the same.

• Journal of Forest and Environmental Science
• /
• 제36권3호
• /
• pp.219-224
• /
• 2020

Urea formaldehyde resins are widely used in the manufacturing of wood composite and their usage is always combined with release of formaldehyde characterized to be hazardous to health during and after the manufacturing of the products. This study investigates the effectiveness of wood-based adhesive from oil of pyrolysed Triplochiton scleroxylon sawdust for the production of composite board. The wood-derived Pyrolytic Oil (PyO) was blended with Urea Formaldehyde (UF) resin to formed Pyrolytic Oil-Urea Formaldehyde (PyOUF). The obtained PyOUF called Wood-Based Adhesives at four blends and control (UF) viz; 1:1, 1:2, 1:3, 2:1, 1:3 were further employed to prepare the composite board and test for their bonding strength by physical (water absorption-WA and thickness swelling-Th.S) and mechanical properties (modulus of elasticity-MOE, modulus of rupture-MOR, and impact bending-IB). Data obtained was analysed using analysis of variance at α 0.05. The result of analysis of variance conducted on physical properties show significant difference (p≤0.05) between the WA values obtained when testing the different blending proportion of PyOUF and likewise between 2 and 24 h of immersion. PyOUF had significant effect (p≤0.05) on Th. S for 24 h but no significant different (p>0.05) for the 2 h period of soaking. The analysis of variance on mechanical properties of the composite board (MOE, MOR, and IB) show significance differences (p≤0.05) between the strength values obtained when testing the different ratios of PyO with UF. PyO content influenced the properties of the boards and it is evident that PyO can be used in the manufacture of composite board.

• 한국의류산업학회지
• /
• 제17권6호
• /
• pp.1030-1038
• /
• 2015

The purpose of this study is to investigate the dyeability of crabyon fiber contained cotton towels after dyeing with gallut. In this study, the colorants of gallnut were extracted with boiling water at 60℃ and 60min. Crabyon, composite fiber of Chitin/Chitosan and cellulose, is manufactured by uniformly blending Chitin/Chitosan and cellulose viscose and extruding the blended viscose into spin-bath. Cotton towels with crabyon fiber dyed with extracted solution from gallnut according to concentration, temperature and time. Crabyon fiber contained cotton towels dyed using gallnut were pre of post-mordanted using Al, Cu, and Fe. The dyeability(K/S) and color characteristics(L^*, a^*, b^*, C, and h(color angle)) of dyed crabyon fiber contained cotton towels were measured by computer color matching machine and photographs. The crabyon fiber composition of cotton towels was conformed by amide peak(-CONH-) of chitin or chitosan of FT-IR spectroscopy. The results obtained were as follows; The amide peak of crabyon fiber contained cotton towels appeared at about 1652 cm⁻¹. The dyeability of crabyon fiber contained cotton towel was increased gradually with increasing concentration of gallnut dyeing solution and saturated at about 150%(o.w.f). The optimum dyeing temperature and dyeing time were 90~100℃ and 80minutes expectively. The crabyon fiber contained cotton towels were dyed reddish yellow by non, Al, and Cu mordanting, reddish blue by Fe mordanting, respectively. The fastness to washing according to concentration of gallnut in and mordanting method indicated good grade result as more than 3~4 degree in all conditions.

• 한국구조물진단유지관리공학회 논문집
• /
• 제16권6호
• /
• pp.56-62
• /
• 2012

본 연구는 초고강도콘크리트의 배합에 사용되는 3성분계 혼합시멘트의 최적조합을 도출하기 위한 실험연구이다. 3성분계 혼합시멘트는 포틀랜드시멘트, 고로슬래브 미분말 0%, 30%, 40%, 50% 및 플라이애시 0%, 10%, 20%, 30%로 구성하였다. 물결합재비 0.18의 초고강도콘크리트를 대상으로 각 실험체의 압축강도와 공극구조를 조사한 결과, 플라이애시 10%, 고로슬래그 미분말 30%를 혼합한 3성분계 혼합시멘트를 사용한 콘크리트의 압축강도는, 50nm 이상의 공극량 감소에 의해, Plain 콘크리트에 비해 현저히 증가하였다.