• 제목/요약/키워드: water additives

검색결과 613건 처리시간 0.033초

수성막포 약제를 첨가한 미분무수의 식용유 화재 소화특성 (Extinguishing Characteristics of Cooking Oil Fire by Water Mist added with AFFF Agent)

  • 신창섭;김성룡
    • 한국안전학회지
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    • 제24권5호
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    • pp.21-27
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    • 2009
  • Effective way of cooking oil fire extinguishment is using water mist system which has cooling and smothering effects. Low pressure water mist system has advantage because it is compatible with existing sprinkler systems. To increase the effectiveness of low pressure water mist system, additives can be used which increase the momentum of water particle and the chemical effect. In this experiment, aqueous film forming form(AFFF) agent is used as additive and the effect of additive concentration and water pressure are experimented. For the extinguishment of cooking oil fire such as soybean and olive oils, AFFF agent is effective and can decrease the fire extinguishing time and water consumption.

도로포장 구조물에서의 스트리핑 현상과 스트리핑 방지제의 이용방안 (Stripping of Asphalt Pavements and Antistripping Addities)

  • 윤현희
    • 대한교통학회지
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    • 제8권2호
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    • pp.119-131
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    • 1990
  • 물 또는 습기에 의하여 도로포장 구조물의 아스팔트와 자갈(aggregate)사이의 결합력이 손실되어 아스팔트가 자갈로부터 분리되는 현상 즉 스트리핑(stripping)에 의하여 많은 도로포장이 파괴되고 있다. 이러한 스트리핑 현상을 방지하기 위하여 여러가지 방법이 개발 사용되고 있는데 흔히 스트리핑 방지제(antistripping additive)를 아스팔트에 섞어서 사용하고 있다. 본 연구의 목적은 스트리핑 현상의 원인을 규명하고 이것을 바탕으로 효율적인 스트리핑 방지제의 조건과 사용방법을 제시하는 것이다. 도로포장용 자갈의 물리화학적 성질을 관찰하여 스트리핑과의 관계를 검토한 결과 스트리핑 현상은 아스팔트와 자갈 사이의 전기적 반발력에 의해 일어날 수 있으며, 자갈 표면의 전기화학적 성질이 스트리핑에 중요한 역할을 함을 알 수 있었다. 또한 현재 사용되고 있는 스트리핑 방지제는 IR 분석결과 대부분이 아민(amine) 계통의 양이온 계면활성제 이었다. 이러한 스트리핑 방지제는 0.5에서 1.0%정도 아스팔트에 섞어서 사용하면 스트리핑을 현저히 줄일 수 있으나, 장시간 (약 24 시간 이상) 뜨거운 상태에서 방치하면 그 성능이 감소되는 것을 알 ? 있었다.

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화학약액에 의한 표층혼합공법에 관한 연구 (A Study on Surface Mixing Method by Chemical Stabilizer)

  • 진병익;유재일
    • 한국지반공학회지:지반
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    • 제1권2호
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    • pp.55-66
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    • 1985
  • 본 연구는 석회계 및 물유리계 약액을 사용하여 대상토의 토성변화에 따른 혼합고결토의 차수효과 및 전단강도증대 등 약액혼합핵과에 대해 구명한 것으로, 경제적이고 합리적인 공법을 개발발전시키는 데 주목적을 두었다. 주요 연구내용은 다음과 같다. (1) 사용된 화학약액으로는 가고계 및 물유리계 그리고 2차첨가재를 사용하여 혼합고결토에 대한 제보험을 하고, (2) 화학약액의 종류 및 혼합기에 따른 혼합고결토의 공학적 특성을 비교.검토하였으며, (3) 혼합고결토의 강도증대, 차빙효과, 익밀특성 등 공학적 특성에 의한 개양동과를 구명하였다.

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Effects of Different Additives on Fermentation Characteristics and Protein Degradation of Green Tea Grounds Silage

  • Wang, R.R.;Wang, H.L.;Liu, X.;Xu, C.C.
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권5호
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    • pp.616-622
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    • 2011
  • This study evaluated the fermentation characteristics and protein degradation dynamics of wet green tea grounds (WGTG) silage. The WGTG was ensiled with distilled water (control), or lactic acid bacteria (LAB), enzyme (E), formic acid (FA) and formaldehyde (FD) prior to ensiling. Three bag silos for each treatment were randomly opened at 0, 3, 7, 14, 28 and 60 days after anaerobic storage. For all the treatments, except for FA, there was a rapid decline in pH during the first 7 days of ensiling. LAB treatment had higher lactic acid content, lower ammonia-N ($NH_3$-N) and free-amino nitrogen (FAA-N) contents than other treatments (p<0.05). E treatment had higher lactic acid, water-soluble carbohydrates (WSC) and non-protein nitrogen (NPN) content than the control (p<0.05). FA treatment had higher $NH_3$-N and FAA-N content than the control (p<0.05). FD treatment had lower NPN and FAA-N content than the control, but it did not significantly inhibit the protein degradation when compared to LAB treatment (p>0.05). Results indicate that LAB treatment had the best effect on the fermentation characteristics and protein degradation of WGTG silage.

CHARACTERIZATION AND STABILIZATION OF WASTE DUSTS FROM SHREDDED AUTOMOBILES INDUSTRIES

  • Takashi, Furuyama;Abel, Bissombolo;Sukeyuki, Mori;Masamichi, Hata;Yoshitsugu, Koga;Tetsuo, Ikejiri
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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    • pp.699-704
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    • 2001
  • Until recently, disposal to landfill has been the most convenient way to deal with the increasing amount of residues the shredding industries produce. But the shortage of such disposal sites and the risk that liquid drained from these waste dusts may pollute ground water have increased the environmental pressures to find more effective solutions. The present study is an alternative approach that suggests identifying waste dusts characteristics and selecting an appropriate binder for hazardous materials to reduce the amount of contaminants (mainly lead) that were leaking into the soil. Investigations on the characteristics of automobiles waste dusts show that these materials are composed mainly of cottons and sponge like substances, plastics, rubber, glasses and gravel, metals, and electric wires. Besides, the percentage in weight of organic (inflammable) materials is about 70% and the lead contamination, which has not a ionic but a particulate nature, is particularly remarkable in cottons and sponge like materials. Binding additives such as K-20 and sodium carbonate were not effective but the addition of 5 % of cement (in weight of the investigated sample) followed by a 3-minute stirring and a 4-hour storage could drastically reduce the run off of lead below the maximum authorized level. No addition of water was necessary in this method.

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R141b 포접화합물을 이용한 축냉시스템의 성능에 관한 실험적 연구 (An Experimental Study on the Performance of Cool Storage System using R141b Clathrate)

  • 정인성;김양규;이준식;노승탁
    • 설비공학논문집
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    • 제6권4호
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    • pp.354-364
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    • 1994
  • Experiments have carried out to investigate the effects of parameters, such as mass ratio of R141b-to-water, stirrer speed, brine inlet temperature, brine flowrate, and additives, on the performance of the cool storage system using R141b clathrate. The cool storage system in this experiment was composed of storage tank, refrigerator, and heater. The results show that the mass ratio of R141b-to-water, 1 : 3~1 : 3.5 gives the best performance and the stirring speed has optimum point as 600rpm. At this speed impeller Reynolds number is $1.01{\times}10^5$. The lower the inlet brine temperature and the highter the brine flowrate, the better performance. The addition of metal powder turned out to reduce the degree of supercooling. The supercooling reduction was proportional to the amount of the metal power. However when metal powder was added more than 0.1 wt%, there was no additional supercooling reduction. The surfactants shortened the time consumed for cool storage to the half of no surfactant added case.

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녹차에서 카테킨 화합물의 초임계 유제 추출 (Supercritical Fluid Extraction of Catecnin Compounds from Green Tea)

  • 나영진;이윤우;김재덕;노경호
    • KSBB Journal
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    • 제16권4호
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    • pp.327-331
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    • 2001
  • 전라남도 보성산 녹차로부터 유용성분인 카테킨 화합물을 초임계 이산화 탄소와 첨가제를 사용하여 추출하고 역상 고성능 액체 크로마토그래피(RP-HPLC)를 사용하여 분석하였다. LiChrospher 100RP-18(15 $\mu$m)로 충진된 column을 이용하여 0.05% phosphoric acid가 포함된 물과 acetonitrile을 이동상으로 사용하였으며 구배용매 조성법을 적용하였다. 이동상의 조성에 따른 체류인자의 조절을 통해 EGCG를 분리하였다. 각각의 초임계 추출법에 따른 EGCG의 추출량을 비교한 결과, 초임계 유체에 극성물질을 포함하는 경우가 녹차의 유용 성분인 EGCG의 추출량이 가장 많았다. 그러나 ethanol에 의한 용매 추출법은 초임계 유체에 의한 추출법보다 EGCG에 대해 많은 추출양과 선택적인 고순도 분리가 가능하였다.

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Effect of Steam Explosion Condition on the Improvement of Physicochemical Properties of Pine Chips for Feed Additives

  • JUNG, Ji Young;HA, Si Young;YANG, Jae-Kyung
    • Journal of the Korean Wood Science and Technology
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    • 제50권1호
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    • pp.59-67
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    • 2022
  • Dietary fiber is considered a feed ingredient with high nutritional value in the broiler feed industry. Pine chips contain a large amount of dietary fiber and require some modification for use as broiler feed. In this study, pine chips were subjected to steam explosion under different severity factor (Ro) conditions to improve the chemical and physical properties of dietary fiber. The highest water-holding capacity, oil-holding capacity, and swelling capacity were found for Ro 4.0, followed by Ro4.5 and 3.5. The optimal condition for the steam explosion was determined to be Ro 4.0 (reaction temperature of 210℃, and reaction time of 6.0 min). Under these conditions, the water-holding capacity, oil-holding capacity, and swelling capacity of steam-exploded pine chips were 8.3 g/g, 6.5 g/g, and 5.0 mL/g, respectively. This study may contribute to the application of lignocellulose and related products in the broiler feed industry.