• 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.

• 한국수소및신에너지학회논문집
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• 제24권1호
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• pp.1-11
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• 2013

Additives such as glycerol, methanol, acetone, and ethanol were used to prevent $NaBO_2$ from precipitation, and their effects on hydrogen generation properties of $NaBH_4$ hydrolysis were investigated. When the concentration of additives was 5 wt%, the additives such as methanol, acetone, and ethanol could not prevent $NaBO_2$ precipitation. Although glycerol prevented $NaBO_2$ precipitation, conversion efficiency decreased to 78.0% due to its viscosity. Based on test results, hydrogen generation tests were also performed at various concentration of glycerol and methanol to investigate the concentration effects on hydrogen generation properties. As the concentration of glycerol increased from 1 wt% to 3 wt%, conversion efficiency increased owing to additive effect. When its concentration increased to 5 wt%, conversion efficiency decreased due to its viscosity. As the concentration of methanol increased from 5 wt% to 10 wt%, conversion efficiency increased owing to additive effect. When its concentration increased to 15 wt%, conversion efficiency decreased due to $NaB(OCH_3)_4$ precipitate. Although conversion efficiency decreased about 1% when 3 wt% glycerol was added, $NaBO_2$ precipitation was prevented. Consequently, addition of 3 wt% glycerol to $NaBH_4$ solution improves stability of hydrogen generation system.

• Applied Biological Chemistry
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• 제38권4호
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• pp.330-333
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• 1995

알코올처리 찰가자미류껍질 젤라틴을 식용단백소재로 이용하기 위한 기초자료를 얻을 목적으로 첨가제에 의한 알코올처리 젤라틴의 물리적 특성치의 변화를 검토하였다. 겔강도, 졸화온도, 겔화온도 및 점도와 같은 물리적 특성치는 에탄올처리의 유무에 관계없이 두 젤라틴 모두가 철이온, 당 및 에탄올을 첨가한 경우는 증가하였으나, 염화나트륨 및 유기산을 첨가한 경우는 감소하는 경향을 나타내었고, 첨가물에 의한 물리적 특성치의 증감폭은 에탄올 처리 유무에 따라 차이가 없었다.

• International Journal of Safety
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• 제4권2호
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• pp.24-29
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• 2005

An experimental study was presented for extinguishing characteristics of liquid fuel fire by water mist($Dv_{0.99}{\leq}200{\mu}m$) containing potassium acetate and sodium acetate trihydrate. To evaluate the extinguishing performance of water mist containing additives, the evaporation characteristics of a water droplet on a heated surface was examined. The evaporation process was recorded by a charge-coupled-device camera. Also, small-scale extinguishing tests were conducted for n-heptane pool fire in ventilated space. During the experiments, flame temperatures were measured, and concentrations of oxygen and carbon monoxide were analyzed by a combustion gas analyzer. The average evaporation rate of water droplet containing additives was lower than that of pure water at a given surface temperature and decreased with the concentration increase due to the precipitation of salt in the liquid-film and change of surface tension. In case of using additives, the fire extinguishing times was shorter than that of pure water at a given discharge pressure and it was because the momentum of a water droplet containing additives was increased. And also dissociated metal atoms, potassium or sodium, were reacted as a scavenger of the major radical species OH, H which were generated for combustion process. Moreover, at a high pressure of 4 MPa, the fire was extinguished through blowing effect as well as primary extinguishing mechanisms.

• 분석과학
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• 제13권3호
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• pp.282-290
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• 2000

본 연구는 390nm 이하에서 자외선 흡수가 완벽한 폴리카보네이트(광학용)에 첨가된 각종 첨가제를 아세톤으로 추출하거나 용해-침전 방식으로 분리하여 분석하는 것이다. 분리된 첨가제를 정성적으로 분석하기 위해 자외선흡광광도계, FT-IR 및 HPLC로 분석하였다. 분리된 물질은 광안정제 및 산화방지제(1차 및 2차)등의 첨가제와 단량체 및 올리고머가 함유된 복잡한 혼합물로 추정할 수 있다. 분리된 첨가물을 Bondapak $C_{18}$ 칼럼, 메탄올 이동상, PDA (Photodiode Array) 검출기를 사용한 역상(reversed phase, RP) HPLC 분석을 통해 비스페놀 A, Irganox 1010, Cyasorb UV-5411 성분들을 확인할 수 있있다. 또한, 자외선 흡광도를 이용한 정량분석을 통해 폴리카보네이트에 광안정제인 Cyasorb UV-5411가 0.12중량% 함유된 것을 알 수 있었다.

• 마이크로전자및패키징학회지
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• 제7권3호
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• pp.7-11
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• 2000

공침법을 이용하여 제조한 $SrTiO_3$분말에 $CuO-SiO_2$첨가물을 혼합하여 저전압구동형 SrTiO$_3$세라믹 바리스터 소자를 제조하였다. $CuO-SiO_2$첨가물을 이용한 $SrTiO_3$세라믹 바리스터제조 공정은 복잡한 공정을 단순화시킬 수 있을 뿐만 아니라, 일반적인 소결온도보다 100~$150^{\circ}C$ 낮은 온도에서도 소결이 되었다. 이 바리스터의 비직선계수($\alpha$) 값은 첨가물 5 wt% 혼합하여 $1350^{\circ}C$에서 하소한 시편에서 8.47의 최고값을 나타냈으며, 이때의 구동전압은 7 V 이하로 낮은 구동전압을 가진 바리스터를 제조할 수 있었다.

• 한국세라믹학회지
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• 제34권6호
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• pp.583-590
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• 1997

The effects of Mn2O3 and Y2O3 additives on the microstructure and dielectric properties of Sr(Zr, Ti)O3 have been investigated. Powders with Sr(Zr1-xTix)O3(0$\leq$x$\leq$0.1) composition were prepared by the conventional solid state processing from commercial TiO2 and precipitation-processed ZrO2. The powders containing sintering additives of Mn2O3 and Y2O3 were compacted and then sintered at 1,55$0^{\circ}C$ for 4 h to get>97% relative density. Mn2O3 suppressed the grain growth and Y2O3 enhanced the density of sintered body. The oxidation state of Mn ions were determined by a chemical wet method and EPR spectroscopy. Mn ions were present as Mn2+ and Mn4+ in SrZrO3, while as Mn3+ and Mn4+ in Ti-substituted Sr(Zr, Ti)O3. With the substitution of Ti, the lattice parameters of SrZrO3 decreased and its dielectric constant increased with remarkable decrease in Q value. The dielectric constant of Sr(Zr, Ti)O3 was in the range of 30 to 40, Q values 1,200~5,400 at 6 GHz and temperature coefficient of resonant frequency -67~100 ppm/K.

• 한국초전도ㆍ저온공학회논문지
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• 제21권2호
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• pp.15-21
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• 2019

In the mine exploration sites, sustainable treatment system of mine water with energy saving and minimized chemical additives is required. Since most of the mine water contains highly-concentrated ferrous ion, it is necessary to study on the removal method of iron ions. We propose the system consisting of two processes; precipitation process by air oxidation using solid catalyst-modified magnetite and separation process combining gravitational sedimentation and magnetic separation using a permanent magnet. Firstly, in the precipitation process (a former process of the system), we succeeded to prepare solid catalyst-modified magnetite. Air oxidation using solid catalyst-modified magnetite using $Fe_2(SO_4)_3$ as a starting material showed high iron removal capability. Secondly, in the separation process (latter process of the system), solid catalyst-modified magnetite using $Fe_2(SO_4)_3$ as a starting material can be separated by a superconducting bulk magnet and a permanent magnet.

• Applied Biological Chemistry
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• 제39권3호
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• pp.218-221
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• 1996

가공적성이 우수한 알코올처리 각시가자미껍질 젤라틴을 식품산업소재로 이용하기 위한 기초자료를 얻을 목적으로 가공시 많이 이용하거나 혼입될 우려가 있는 철이온, 식염, 당, 산 및 알코을 등에 의한 알코올처리 젤라틴의 물리적 특성의 변화를 무처리 젤라틴과 비교하여 검토하였다. 겔강도, 졸화온도, 겔화온도 및 점도와 같은 물리적 특성치는 에탄올처리의 유무에 관계없이 두 젤라틴 모두가 철이온 , 당 및 에탄올을 첨가한 경우 증가하였으나, 염화나트륨 및 유기산을 첨가한 경우는 감소하는 경향을 나타내었다. 첨가물에 의한 물리적 특성의 변화폭은 에탄올처리 젤라틴이 무처리 젤라틴에 비하여 식염, 당 및 에탄올을 가한 경우 차이가 없었으나 철이온 및 산을 가한 경우 적었다.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.130-137
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• 1997

Intumescent inorganic and organic coatings which dintr one from the other by the type of gas formers and the mechanisms of foam formation have been obtained and investigated. Inorganic intumescent coatings are the compositions based on water glass and mineral additives with different dispersity. Mineral additives contain adsorbed and absorbed water and carbonates which are destructed with the carbon dioxide and water evolution during the flame action on coating. The decreasing of mineral additives particle sizes under the mechanical milling with the fraction precipitation promotes the foam coke formation with less defects. Here the main structure of comparing compositions does not change. In organic coatings based on epoxy-polymers the polyammonium phosphate additive is used. It is the cabonization catalyst and the foam agent. The polyammonium phosphate of various dispersity employed is uniformly distributed on the polymeric matrix. The decreasing of the particle sizes leads to the increasing of the fire resistant properties of the intumescent coa-ting. The fire resistant analysis of the coating during more than an hour: the coating back side the temperature on plastic or wooden materials does not exceed 423K, and on metal-573K.