• 제목/요약/키워드: deterioration ratio

검색결과 447건 처리시간 0.024초

친환경 감물가공 소재의 자외선 조사에 의한 물리적 특성변화에 대한 연구 -견 및 나일론 직물- (Effects of U.V. Irradiation on the Physical Properties of Fabrics Treated with Eco-friendly Persimmon Juice -Silk and Nylon Fabrics-)

  • 김지민;김종준
    • 패션비즈니스
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    • 제19권4호
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    • pp.120-134
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    • 2015
  • This study aimed to determine the physical properties of silk and nylon fabrics that are treated with persimmon juice in accordance with irradiation time of ultraviolet spectrum. Persimmon juice dyeing has the advantage of using the tannin component of the persimmon. Tannin plays an important role in inhibiting photodegradation of fibers or polymers. Among fibrous materials, silk and nylon are prone to deterioration by light. Hence, this study aimed to reduce these weaknesses of silk and nylon by applying persimmon juice treatment. We accordingly carried out investigation and experiments on ultraviolet irradiation, and physical characteristics of treated fabrics. The persimmon juice treatment process led to increased weight and thickness. In addition, the air permeability of silk fabric was increased, as compared to the control specimen; whereas, that of nylon fabric was decreased. Both drape stiffness and flex stiffness of silk and nylon tended to be high in textiles processed with persimmon juice treatment, as compared to the control textile. Peak load and elongation at peak load of untreated samples clearly decreased in both silk and nylon fabrics with the increase of ultraviolet irradiation time, while those of persimmon juice treated samples increased. Furthermore, ultraviolet blocking ratio measurement indicated that the fabric specimens treated with persimmon juice blocked U.V. spectrum better than the control specimen.

염화물이 함유된 동결수의 동결융해 작용에 따른 콘크리트의 내동해성과 표면열화 평가 (The Evaluation of Surface Scaling and Resistance of Concrete to Frost Deterioration with Freezing-Thawing Action by Salt Water)

  • 김규용;김무한;조봉석;이승훈
    • 한국구조물진단유지관리공학회 논문집
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    • 제11권6호
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    • pp.143-151
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    • 2007
  • 본 연구에서는 염화물이 함유된 동결수에 의한 콘크리트의 내동해성을 검토하기 위하여 동결융해 및 표면스케일링 저항성을 평가하고자 하였으며, 이를 위한 배합으로서 물결합재비는 0.37, 0.42, 0.47의 3수준, 결합재 방식은 일반 OPC 콘크리트, 고로슬래그 미분말 50%의 2성분계 콘크리트 및 플라이애시 15%와 고로슬래그 미분말 35%의 3성분계 콘크리트로 설정하였다. 그 결과, 고로슬래그 미분말 50% 및 플라이애시 15%와 고로슬래그 미분말 35%의 혼합 시멘트계 콘크리트의 경우 일반 OPC 콘크리트에 비하여 동결융해 및 표면스케일링 저항성이 상대적으로 우수하게 나타났으며, 이를 통해 내구성 저하가 우려되는 해양 환경 하에서 비래염분 및 비말 등의 해수의 작용에 의한 콘크리트의 내구성 저하현상을 억제하기 위한 방안으로서 슬래그의 활용이 유효함을 확인할 수 있었다.

팽창재와 수축저감제를 사용한 HPFRCC의 수축 저감 성능 (Shrinkage Reduction Performance of HPFRCC Using Expansive and Srhinkage Reducing Admixtures)

  • 박정준;문재흠;박준형;이장화;김성욱
    • 한국구조물진단유지관리공학회 논문집
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    • 제18권5호
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    • pp.34-40
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    • 2014
  • HPFRCC는 물-결합재비 (W/B)가 20%로 상당히 낮고 굵은 골재를 사용하지 않으며, 고분말 혼화재료를 혼입하기 때문에 자기수축이 상당히 크게 발생하여 구조물 적용 시 균열저감대책이 필요하다. 따라서 이 연구에서는 HPFRCC의 수축을 효율적으로 저감시키기 위한 방법으로 수축저감제와 팽창재의 사용을 검토하기 위하여 이들의 단독 또는 병행 혼입률에 따른 역학적 특성과 구속 수축특성을 평가하였다. 구속수축 실험 중에서 링-테스트 (Ring-test)를 통하여 HPFRCC에 사용되는 시멘트에 대하여 중량비로 수축저감제 1%와 팽창재를 7.5%를 병행 사용하였을 경우 압축강도와 인장강도가 크게 저하되지 않으면서도 수축을 가장 효율적으로 저감시킬 수 있는 최적 배합임을 도출하였고 수정된 건조수축 균열실험을 통하여 이를 검증하였다.

광촉매-분산 실리카 함침 콘크리트의 내구성 및 정화성능 평가 (Evaluation of Durability and Self-clearing in Concrete Impregnated with Photocatalyst-colloidal Silica)

  • 김혁중;김영기;권성준
    • 한국구조물진단유지관리공학회 논문집
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    • 제22권5호
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    • pp.47-54
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    • 2018
  • 콘크리트는 장기간 사용환경에 노출되면서 다양한 표면열화과정을 거친다. 실리케이트 기반 함침제는 콘크리트 표면에 적용되어 불용성 수화물을 형성하는데, 이 과정에서 다양한 공학적 장점을 기대할 수 있다. 본 연구는 분산형 실리케이트를 사용하여 표면의 내구성능을 강화하고 이후 광촉매를 분무함으로서 표면 함침된 콘크리트의 자기정화능력을 평가하는 것이다. 이를 위해 실리케이트 함침 콘크리트에 대하여 압축강도 뿐 아니라, 흡수성, 건조 수축, 염소이온저항성, 황산저항성, 동결융해 저항성 등과 같은 내구성 실험이 수행되었다. 또한 아세트 알데이드 및 메틸렌블루 반응 평가를 통하여 독성카스의 제거와 자기정화성능을 평가하였다. 실리케이트 함침 후 광촉매 도포를 함으로서 광촉매의 부착성을 확보할 수 있었으며, 콘크리트의 내구성 개선과 광촉매 고유의 정화성능을 유지할 수 있었다.

천연가스 개조 승용차에 대한 실험적 연구(2) - 분사 시스템 평가 (Experimental Study on Natural Gas Conversion Vehicle(2) - Evaluation of Injection System)

  • 김형구;권순태;엄인용
    • 한국자동차공학회논문집
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    • 제23권4호
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    • pp.444-453
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    • 2015
  • In the previous study, several problems were observed in a NG conversion vehicle, which were fail of air-fuel ratio closed loop control, aggravated fuel economy, increased harmful emission and declined roadability. It was provisionally supposed that the mismatch of injection system with the engine caused these performance deterioration. In this context, the characteristics of fuel injection system of commercial conversion kit for NG were investigated experimentally varying the engine speed, fuel rail pressure and volume. The results are as follows; The injection quantity decreases as the engine speed increases due to the extremely small rail volume of the presenting system and flow rate of No. 2 injector are always lower than that of the other ones regardless of the speed under the dynamic operation condition. Furthermore the existing system does not meet the required fuel quantity for the normal engine operation over 3000 RPM. On the other hands, the large rail volume systems ease and/or eliminate the difference of injection quantity between the injectors according to the speed variation, however, these systems decrease injection flow rate and still cannot supply sufficient fuel. Finally, suitable combination of the higher rail pressure and the larger rail volume might be a solution about these problems.

어묵에 처리한 grapefruit 종자추출물의 보장효과 (Preservative Effect of Grapefruit Seed Extract on Fish Meat Product)

  • 조성환;주인생;서일원;김재욱
    • 한국식품위생안전성학회지
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    • 제6권1호
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    • pp.67-72
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    • 1991
  • 어묵에 grapefruit 종자 추출물의 농도별로, 침지 처리한 후 저장기간에 따른 물리, 화학적 변화를 검토하여 다음과 같은 결과를 얻었다. 1. 저장 기간 중 어묵의 조단백함량 변화는 대조구에 비하여 GFSE 의 처리 농도가 높을수록 더 작았다. 2. Texture 는 저장기간이 경과함에 따라 감소하는 경향을 나타내었으나 GFSE 용액 처리구에서는 감소율이 낮았다. 3 어묵 단백질의 SDS-PAGE pattern 변화는 저장기간이 경과함에 따라 분자량, 30,000-32,000의 protein은 점차 가수분해되어 소멸되는 현상을 보였으며 특히 대조군의 경우 2일 경과 후부터 급격한 분해라 이루어져 단백질 major band의 손실율이 크게 증가한 것으로 나타난 반면, GFSE처리 시험구의 경우 4일 경과시에야 비로소 뚜렷한 손실반응을 보여 GFSE처리에 의하여 어묵단백질의 변패 발생 시기를 상당 기간 연장함을 확인할 수 있다.

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숲 가꾸기 임지의 소나무좀 발생과 후식 피해 (Secondary Damage and Adult Emergence of Pine Bark Beetle (Blastophagus piniperda) in Tended Forests)

  • 구관효;이정환;김종갑
    • 한국농림기상학회지
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    • 제7권4호
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    • pp.258-264
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    • 2005
  • The objectives of this study were to study 1) emergence of pine bark beetles, 2) larval density in residual timber on Idlest land by each felling season, and 3) the secondary damage rates in the tended forest. Pine forest land which had undergone tending had a higher secondary damage ratio $(59.6\%)$ by pine bark beetles than forest land that was not tended $(2.8\%)$. The number of escape holes averaged 11.3 0.31 per $250 cm^2$ on the bark of leaf trees in the tended forest. The number of escape holes was higher in the Jinju site than in the Hamyang site. The larval habitat density of pine bark beetles as compared with each felling period was higher after mid-October than in forests tended early in October. Thus, forests should be tended before early October in order to prevent secondary damage from pine bark beetles. Secondary damage in the tended forest was higher in the upper part $(75.5\%)$ of the tree crown than in the lower part $(49.2\%)$. The damage was higher in terminal shoots $(80\%)$ than in lateral shoots $(48\%)$. Therefore, secondary damage by pine bark beetles can cause deterioration of the elongation growth of the forest trees. In conclusion, if by-products of tended pine forest forests are neglected, they will be utilized as a propagation site for pine bark beetles (Blastophagus piniperda L). The propagated adults will damage the tender shoots of the leaf trees and thus seriously limittheir elongation.

마늘 정유물의 향기성분 및 저장 안정성 (Flavor Compounds and Storage Stability of Essential Oil from Garlic Distillation)

  • 조길석;김현구;하재호;박무현;신효선
    • 한국식품과학회지
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    • 제22권7호
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    • pp.840-845
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    • 1990
  • 마늘에서 정유물을 증류하고 그 정유물의 휘발성 성분분석 및 저장안정성 시험을 실시하였다. 정유물을 포집하는데 사용한 pentane과 dichloromethane의 비는 2 : 1이었고, 정유물의 수율은 0.8 mm의 크기로 마쇄처리한 시료의 경우가 0.35%였고, 통마늘의 경우는 0.07%였다. 마늘 정유물에서 dimethyl sulfide, diallyl sulfide, methyl-1-propenyl disulfide, diallyl disulfide, allyl methyl sulfide, diallyl trisulfide 등의 6종류의 휘발성 물질이 동정되었고, diallyl trisulfide, diallyl disulfide, allyl methyl sulfide가 주요한 휘발성 성분이었다. 마늘 정유물을 $5^{\circ}C$$25^{\circ}C$에서 60일 동안 저장 중 품질 변화는 거의 일어나지 않았다.

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디젤기관에서의 경유-메탄올 혼합유의 연소 안전성과 연소특성에 관한 연구 (A Study on the Combustion Stability and Characteristics for D.O - Methanol Blending Oil in Diesel Engine)

  • 김상암;왕우경
    • 동력기계공학회지
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    • 제22권1호
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    • pp.48-55
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    • 2018
  • It has recently been reported that methanol fuel has been used in the product carrier with established duel fuel engine, which has been greatly reducing emissions of $CO_2$, NOx and SOx from the engine. However, to use methanol alone as fuel oil in a general diesel engine, design modification of cylinder head is needed because the ignition aid device or the duel fuel injection system is needed. On the other hand, only if the mixer is installed on the fuel oil supply line, diesel oil - methanol blending oil can be used as fuel oil for the diesel engine, but there is a problem of the phase separation when two fuels are mixed. In this study, diesel oil and methanol were blended compulsorily in preventing the phase separation with installing agitators and a fuel oil boost pump on fuel line of a test engine. Also, cylinder pressure and fuel consumption quantity were measured according to engine load and methanol blending ratio, and indicated mean effective pressure, heat release rate and combustion temperature obtained from the single zone combustion model were analyzed to investigate the effects of latent heat of vaporization of methanol on combustion stability and characteristics. As a result, the combustion stability and characteristics of 10% methanol blending oil are closest to the those of diesel oil, and it could be used as fuel oil in existing diesel engines without deterioration of engine performance and combustion characteristics.

낙동강수계 3단계 광역시·도 경계지점 목표수질 설정을 위한 관리권역 및 관리목표 설정 방법 연구 (Research on the Development Management Basin and Goal for 3th T.W.Q on the Boundary between Metropolitan Cities/Dos Specified in Nakdong River Basin)

  • 황하선;박지형;김용석;류덕희;최유진;이성준
    • 한국물환경학회지
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    • 제31권5호
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    • pp.569-575
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    • 2015
  • The current Total Pollution Load Control (TPLC) sets the Target Water Quality (TWQ) by utilizing the delivery ratio, unit loads, and water quality modeling, it also allocates the watershed's permitted discharge load. Currently, common target pollutants of every unit watershed in TPLC are BOD and T-P. This study has reviewed the 1th and 2th of TWQ setting process for the Nakdong River 3th TWQ setting in Total Pollution Load Control (TPLC). As a result of review, 1th and 2th were divided into one management basin (mulgeum) for setting management goals. However, 3th was divided into six management basins (mulgeum, gnagjeong, geumho river, nam river, miryang river, end of nakdong river). The principle of management goal setting were to achieve the objective criteria of Medium Areas for the linkage of the water environment management policy. And Anti-Degredation (principle of preventing deterioration) were applied to the 3th TWQ. Also, additional indicators were considered in accordance with the reduction scenarios for the final management goals.