• 대한안전경영과학회지
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• 제23권4호
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• pp.55-60
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• 2021

This study is to check waterproof by number of twists of fire hose and measure the first waterproof time to analyze the relationship between twists of fire hose and first waterproof time and waterproof by position of twists so as to suggest the efficient plan to prevent twists of fire hose. Ordinary fire hose did not make waterproof in case that position of twists was near the nozzle with twists 5 times or more, while anti-twist fire hose had no problem for waterproof only with delayed time. Like ordinary fire hose, anti-twist fire hose also showed the tendency to increase the waterproof time in proportion to the number of twists. In case that the position of twists was near waterproof port even with 10 times of twists in anti-twist fire hose, the first waterproof time was increase by 0.63 seconds on average without any problem for waterproof, which was somewhat faster than that in ordinary fire hose. With respect to the position of twists, waterproof of anti-twist fire hose was affected more as the number of twists was increased more near the nozzle rather than near the waterproof port, like ordinary fire hose. In summary, anti-twist fire hose equipped with anti-twist tool at the middle connection port and the nozzle showed a good waterproof performance with delayed waterproof time regardless of number of twists, as a solution for the twist problem of ordinary fire hose.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.65-68
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• 2006

In this study, comparison of setting time, compressive strength, watertightness and durability of between reference mortar with mortar using waterproof admixtures based on natural inorganic minerals. Test results shows that waterproof admixtures does not change setting time of mortar, but strongly improve compressive strength, permeability, absorption and durability of mortar. Especially early strength of mortar increased about 40% of reference.

• 한국지반공학회논문집
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• 제18권6호
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• pp.43-59
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• 2002

본 연구에서는 국내에서 이용되고 있는 지하구조물 누수에 대한 지수공법과 재료에 대하여 이론적 고찰 및 실험을 실시하고 현장적용 자료의 수집을 통한 통계적인 분석.고찰을 통하여 지하구조물의 누수유형별 지수공법 선정을 위한 시스템을 구축하고자 하였다. 선정시스템의 구성은 데이터베이스 5개의 대구분과 73개 항목의 세분화된 체크리스트를 이용하여 다양한 현장 조건을 고려한 설문조사를 토대로 4개로 대분된 위계성 등급에 따른 26개의 주요 선정인자를 설정하였다. 지수공법 데이터베이스는 국내에 적용실적이 많은 10개의 공법으로 이루어졌다. 설계조건 데이터베이스에서는 10개의 지수공법에 대한 적용범위와 설계조건에 대한 자료를 제공한다. 연구결과에 의한 시스템은 선정인자 데이터베이스와 지수공법 데이터베이스 그리고 설계조건 데이터베이스에 의한 관계형 데이터베이스로 구성되었다. 본 선정시스템의 현장적용 결과, 설계단계에 적용할 경우 지수공법 선정을 위한 시간 단축과 지수공법 선정시의 오류를 감소시킬 수 있었다. 또한 시공단계에 적용할 경우에는 설계단계에서 선정된 지수공법을 현장조건에 따라 재확인함으로써 지수공법의 타당성 분석을 할 수 있고 향후 유지관리에도 활용될 수 있을 것으로 기대된다.

• 한국화재소방학회논문지
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• 제17권1호
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• pp.21-25
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• 2003

본 연구에서는 복사열에 노출된 소방용 방수복의 열적 특성에 대한 실험을 수행하였다. 실험결과 소방용 방수복의 노출시간에 따른 표면의 온도상승은 노출거리가 가까울수록 급격히 일어났다. 또한 복사열유속이 클수록 표면의 온도가 높으며, 정상상태 도달시간은 짧게 나타났다. 소방용 방수복의 노출거리가 멀어질수록 표면의 온도는 급격히 감소하며, 전면과 후면의 온도차도 감소하였다. 복사열유속이 증가할수록 안전노출거리가 증가하였다. 따라서 소방대원의 안전을 위해서는 복사열원으로부터 일정거리이상 떨어져 작업하여야 할 것으로 사료된다.

• 콘크리트학회지
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• 제8권1호
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• pp.138-144
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• 1996

현재 우리나라 교량의 겨우 상판의 열화현상을 극소화시키기 위하여 방수의 필요성이 절대적으로 요구되고 있다. 따라서 본 연구에서는 지금 현재 국내에서 시공되고 있는 교량 방수 공법 중 침투성 방수제를 실내실험을 통하여 자연적 및 인위적 조건에 저항하는 특성의 파악을 위한 실험을 수행하였다. 실험결과 방수제의 침투깊이의 감소로 인해서 고강도 콘크리트를 사용할 경우 이 공법의 적용은 재고할 필요가 있는 것으로 판단된다. 방수제를 사용하는 경우 콘크리트의 내산성이 우수하게 나타나므로 침투성 방수제는 산성비에 대한 저항성이 크다. 그러나 방수제의 성능은 자연상태로 노출되어 있는 경우 그 수명이 영구적이 아니므로 교량의 슬래브에는 반드시 아스팔트 콘크리트를 포장하여야 한다. 실험결과로 부터의 또다른 결론은 방수제로 인해 콘크리트의 내열성 및 내마모성이 증가됨을 알 수 있다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 춘계 학술논문 발표대회
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• pp.35-41
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• 2008

Qualitative enhancement of dwelling life has changing the recognition for the environment friendly wood which is being highlighted for its usage as an interior materials. This trend may prove the excellent performance of wood whose inherent characteristics has its comfortable, mild feeling of material, sound resistance and stabilities and the market of interior woods including floor, moulding and wooden panel as finishing interior materials is growing sustainably. However, since this materials is vulnerable to humidity and flame, waterproofing and flame retarding stability, an essential condition for interior materials, together with maintenance, are the main topics to be resolved. From the above-mentioned results, as a result of waterdrop contact angle, wood absorption volume and water content percentage test and the performance test of the processed materials after flame retardant, though there was some submerging time changes among types of woods for ensuring waterproofing performance improvement but as time passes, similar tendency was noticed to be formulated. As the submerging time is increased, so does the absorption volume and accordingly optimal level of range is judged to be drawn in order to ensure excellent performance, taking optimal economy into consideration. Therefore, it is considered that above-mentioned woods could be utilized for waterproof and flame retardant processed interior materials using uniform microwave and in order to put this technology into practical application, a research by way of diversified performance proving is required to be carried out.

• 한국안전학회지
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• 제28권4호
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• pp.43-47
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• 2013

The purpose of this paper is to evaluate the performance of a Plug-In MCCB developed for rapid power supply restoration when the MCCB is installed in a power system and to verify its reliability. Since the developed 3 ${\Phi}$ 3 W Plug-In MCCB can be installed on and removed from a bus bar by one touch using a plug housed at the rear, it can be replaced in a short period of time. Therefore, it can quickly respond to the normalization of a power system. When the Plug-In MCCBB is installed on a bus bar, the resistance between each phase and plug was measured to be 0.46 $m{\Omega}$ in average. When the Plug-In MCCB is installed, the tension in the vertical direction was measured to be 112.78 N in average, which is greater than the tension of 50 N specified in the related regulation. The withstanding voltage tests performed 5 times repeatedly by applying 6 kV to the developed Plug-In MCCB for 60 seconds shows good withstanding voltage characteristics. In addition, both the general waterproof test using a water injection method and the insulation resistance analysis using a Mega meter showed good waterproof and insulation characteristics.

• 생물환경조절학회지
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• 제25권4호
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• pp.288-293
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• 2016

본 연구는 복숭아 주간부 동해 예방을 위한 피복재의 보온성을 평가하기 위해 백색부직포, 황색일반지, 방수패드로 만들어진 피복재의 물리적 특성 및 보온성을 평가하고 실제 겨울철 복숭아 주간부 보온효과를 구명하여 피복재로서의 이용가능성을 검토하기 위해 수행하였다. 세 피복재 중 2겹방수패드 처리가 보온율과 열저항성이 가장 우수하였다. 2겹방수패드 처리의 주간단열효과는 $14.09^{\circ}C$ 만큼 온도상승을 차단하였고, 야간보온효과는 $7.23^{\circ}C$ 만큼 온도하강을 차단하여 보온효과가 가장 우수함을 확인하였다. 따라서 방수패드 재질을 보온피복재로 개발 보급할 경우 복숭아 주간부 동해 피해를 경감시키는데 도움을 줄 수 있을 것으로 생각되었다.

• Tribology and Lubricants
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• 제37권5호
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• pp.189-194
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• 2021

A straightforward, yet effective surface modification method of stainless steel mesh and its interesting anti-wetting characteristics are reported in this study. The stainless steel mesh is electrochemically etched, and the specimen has both micro and nano-scale structures on its surface. This process transforms the two types of mesh specimens known as the regular and dense specimens into hydrophobic specimens without applying any hydrophobic chemical coating process. The fundamental wettability of the modified mesh is analyzed through a dedicatedly designed experiment to investigate the waterproof characteristics, for instance, the penetration threshold. The waterproof characteristics are evaluated in a manner that the modified mesh resists as high as approximately 2.7 times the pressure compared with the bare mesh, i.e., the non-modified mesh. The results show that the penetration threshold depends primarily on the advancing contact angles, and the penetration stop behaviors are affected by the contact angle hysteresis on the surfaces. The findings further confirm that the inexpensive waterproof meshes created using the proposed straightforward electrochemical etching process are effective and can be adapted along with appropriate designs for various practical applications, such as underwater devices, passive valves, and transducers. In general, , additional chemical coatings are applied using hydrophobic materials on the surfaces for the applications that require water-repelling capabilities. Although these chemical coatings can often cause aging, the process proposed in this study is not only cost-effective, but also durable implying that it does not lose its waterproof properties over time.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.3172-3179
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• 2011

Several materials using polymer-portland-cement concrete have developed to have not only strength of attachment with body, but also waterproof function and strong anti-sodium chloride properties. Especially, in case of railway, unlike other public transportation, it is very difficult to doing the repair and reinforcement work of structure during service time. Therefore, the development and study of materials having characteristics of structural strength, unification behavior with body, and resistance of crack are very important. Accordingly, the characteristic of material of polymer based concrete is indicated compared with the experiment and analysis through this study, and suggested application to railway tunnel, bridge, and concrete track structure.