• 제목/요약/키워드: water additives

검색결과 613건 처리시간 0.03초

New Water-soluble Cutting Fluids Additives Derived from the Thermal Reaction Products of Unsaturated Fatty Acids with Acrylic Acid and Maleic Anhydride

  • Watanabe, Shoji
    • 한국응용과학기술학회지
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    • 제20권4호
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    • pp.372-376
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    • 2003
  • Water-soluble cutting fluids are used for processing of aluminium materials. This short article describes properties of new additives of water-soluble cutting fluids for aluminium materials. Various Diels-Alder adducts of unsaturated fatty acids with acrylic acid of maleic anhydride were prepared by thermal reactions. Triethanolamine salts of Diels-Alder adducts of dehydrated castor oil fatty acids with acrylic acid or maleic anhydride showed excellent anti-corrosion property of aluminium materals. These thermal adducts showed anti-rust property for cast-iron chips, too.

단위 팽창재량 및 양생 환경요인 변화에 따른 콘크리트의 팽창 특성 (Expansion Properties of Concrete under Various Unit Contents of Expansion Admixture and Curing Conditions)

  • 한천구;류현기;홍상희;김정진
    • 콘크리트학회논문집
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    • 제12권1호
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    • pp.79-88
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    • 2000
  • Usually, the expansive additives is used to prevent the occurrence of drying shrinkage in concrete. However it may sometimes be over-added in field due to the insufficient cognition of constructor's, which may cause the serious problems in concrete structures. In this study the experiments are performed to present the expansion properties of concrete by varying the water to binder ratios, unit contents of expansive additives and curing conditions. By the results, the strength showed an increase with the addition of expansion additives from 30kg/㎥ up to 50kg/㎥, and a great decrease by contraries if the larger amount are added. Also the more the expansion additives were used, the more length change occurred in concrete. In view of the curing conditions, the concrete by air cured appeared a little expansion even the unit expansion additives increased, which showed an opposite inclination of that with standard curing. This could be explained by the less occurrence of hydration in air condition which also lead to the little expansion of concrete. Hence the expansion concrete to be cured in water or moisture condition became an especial important thing. concrete using expansive additives showed that high expansion was taken place with the rise of temperature.

팽창재량 및 양생방법에 따른 시멘트 모르터의 특성에 관한 연구 (A Study on the Properties of Cement Mortar with the Content of Expansive Additives Under Various Curing Method)

  • 한성수;김정진;김효구;홍상희;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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    • pp.181-186
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    • 1999
  • When the expansive additives are used in concrete to reduce the shrinkage cracking, it shows variable properties with the curing method and curing temperature. Therefore, in this study, the experiments are perfomed to present the expansion of cement mortar by varying the unit additions of expansive additives and the curing method. According to the test results, the order of expansion by curing method, which is caused by hydration heat of cement, is follows ; curing at water > curing at air after curing at water for 7 days > curing at air. Cement mortar using expansive additives shows that high expansion is place with rise of temperature.

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각종 혼합재를 첨가한 콘크리트의 중성화에 관한 실험적 연구 (An Experimental Study on the Carbonation of concrete using various Admixture Additives)

  • 최광윤;배수환;장재동;이도헌;윤재환
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.787-792
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    • 2003
  • The purpose of this study is to suggest the fundamental data of durability which effects on the Carbonation of concrete by adding various admixture additives. Thus, We have experimented the accelerated test on the concrete blending which was admixed by blast furnace slag, fly-ash, silica fume , durability amelioration and it was cured 7weeks after twenty eight days water curing. The result of this experiment is that Carbonation speed increased extremely when water cement ratio went up, and by growing of replace cement ratio of admixture additives. The specimen which was added fly-ash, blast furnace slag, silica fume has the faster Carbonation speed than the specimen which was not added admixture additives. All of these specimen, fly-ash has the fastest progress speed.

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물유리의 농도와 첨가제 종류에 따른 방염제의 성능 (Flame Retardancy of Plywood Treated with Various Water Glass Concentration and Additives)

  • PARK, Sohyun;HAN, Yeonjung;SON, Dong Won
    • Journal of the Korean Wood Science and Technology
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    • 제49권1호
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    • pp.44-56
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    • 2021
  • 소방청의 방염성능기준에 제시된 45°멕켈 버어너법을 이용하여 물유리 농도와 첨가제 종류에 따른 합판의 탄화길이 및 면적 등의 방염성능을 측정하였다. 합판에 농도 20-50%의 물유리를 처리한 결과, 방염성능은 물유리의 농도와 비례하는 경향을 나타냈다. 그러나 30%를 넘는 고농도의 물유리로 처리된 합판의 표면에서 백화현상과 끈적임이 발생하여 농도 30%를 최적 조건으로 결정하였다. 농도 30%의 물유리에 서로 다른 비율의 첨가제를 추가하여 실험을 수행한 결과, 수산화칼륨 15% 조건과 수산화알루미늄 1-10%의 조건에서 방염성능 기준을 만족하였다. 반면에 황산마그네슘은 방염성능에 크게 영향을 미치지 않았다. 물유리와 첨가제에 따른 방염성능의 결과는 방염제를 활용한 불연재에 대한 기초자료로 활용될 것으로 기대된다.

전력케이블 절연층용 원재료의 특성비교 (Characteristic Comparison of Raw Materials Used for Power Cable Insulation)

  • 오우정;고정우;김종은;서광석;이건주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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    • pp.302-304
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    • 1997
  • Chemical structure and electrical properties such as water treeing and space charge accumulation of various raw materials(XLPE) used for power cable insulation were investigated. It was found that chemical structure was changed after crosslinking reaction and every materials have different amounts of DCP and antioxidant. Electrical properties were also changed after extraction using $CHCl_3$ and xylene. Water tree length was smaller with additives such as DCP and antioxidant and bigger with low molecular weight components of polyethylene than that of extracted samples. Heterocharge was changed into homocharge after extraction. This shows that additives and low molecular weight components of polyethylene cause the heterocharge.

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An Experimental Study on Friction Reduction by Additives in a Water Channel

  • Kim Wu-Joan;Kim Hyoung-Tae
    • Journal of Ship and Ocean Technology
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    • 제9권1호
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    • pp.27-37
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    • 2005
  • An experimental study has been carried out as a basic research for the development of the friction drag reduction technology for water-borne vehicles by injecting microbubbles or polymer solution. Experimental apparatus and procedures have been devised and prepared to measure the changes of the wall friction with the injection of additives and the basic experimental data on friction drag reduction are obtained for fully developed channel flows. The effects of key controlling parameters were investigated for higher drag reduction with varying the concentration and the injection rate of additives. The frictional drag has been reduced up to $25\%$ with the microbubble injection and $50\%$ with the polymer solution injection.

Effect of Spirulina platensis and Probiotics as Feed Additives on Growth of Shrimp Fenneropenaeus chinensis

  • Kim Choong-Jae;Yoon Sook-Kyung;Kim Hong-Ik;Park Yong-Ha;Oh Hee-Mock
    • Journal of Microbiology and Biotechnology
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    • 제16권8호
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    • pp.1248-1254
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    • 2006
  • The effect of Spirulina platens is and probiotics as feed additives on the growth of the shrimp Fenneropenaeus chinensis was investigated in comparison with a control. The shrimp were cultured in rearing tanks in a seawater pond for 35 days from September 1, 2004. As regards the water quality, the probiotic treatment (T2, commercial diet and 3% probiotics) produced a lower TDN (total dissolved nitrogen) and TDP (total dissolved phosphorus), making it effective in water quality improvement. Nonetheless, the phytoplankton flora succeeded from diatoms to cyanobacteria, regardless of the feed additives. Treatment T3, including 3% S. platensis, produced the highest mean body weight, which was 39% higher than that for all the other treatments (P<0.05). Accordingly, it was found that the use of Spirulina and probiotics as feed additives increased the shrimp body weight and improved the water quality, respectively.

Modification of polyethersulfone hollow fiber membrane with different polymeric additives

  • Arahman, Nasrul;Mulyati, Sri;Lubis, Mirna Rahmah;Razi, Fachrul;Takagi, Ryosuke;Matsuyama, Hideto
    • Membrane and Water Treatment
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    • 제7권4호
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    • pp.355-365
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    • 2016
  • The improvement of fouling resistance of porous polymeric membrane is one of the most important targets in membrane preparation for water purification in many process like wastewater treatment. Membranes can be modified by various techniques, including the treatment of polymer material, blending of hydrophilic polymer into polymer solution, and post treatment of fabricated membrane. This research proposed the modifications of morphology and surface property of hydrophobic membrane by blending polyethersulfone (PES) with three polymeric additives, polyvinylpyrrolidone (PVP), Pluronic F127 (Plu), and Tetronic 1307 (Tet). PES hollow fiber membranes were fabricated via dry-wet spinning process by using a spinneret with inner and outer diameter of 0.7 and 1.0 mm, respectively. The morphology changes of PES blend membrane by those additives, as well as the change of performance in ultrafiltration module were comparatively observed. The surface structure of membranes was characterized by atomic force microscopy and Fourier transform infra red spectroscopy. The cross section morphology of PES blend hollow fiber membranes was investigated by scanning electron microscopy. The results showed that all polymeric additives blended in this system affected to improve the performances of PES membrane. The ultra-filtration experiment confirmed that PES-PVP membrane showed the best performance among the three membranes on the basis of filtration stability.

Pozzolanic reaction of the waste glass sludge incorporating precipitation additives

  • You, Ilhwan;Choi, Jisun;Lange, David A.;Zi, Goangseup
    • Computers and Concrete
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    • 제17권2호
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    • pp.255-269
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    • 2016
  • The waste glass sludge is a waste produced in the glass industry. It is in a dust form and disposed with water. In the disposal process, various cohesive agents are incorporated in order to precipitate the glass particles efficiently. In this paper, we investigate the pozzolanic reaction of the waste glass sludge incorporating precipitation additives experimentally. The consumption of calcium hydroxide, the setting time and the compressive strength and the pore structure were tested for two different types of the waste glass sludge depending on whether precipitation additives were used. It was found that the waste glass sludge incorporating the precipitation additives had a higher pozzolanic potential than the reference waste glass sludge without precipitation additives.