• 한국대기환경학회지
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• 제15권4호
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• pp.475-483
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• 1999

A lab-scale test was carried out to study the reduction of electrical energy consumption in the pulsed corona discharge process for nitrogen oxides removal. The experiment was mainly focused on 1) the activation of pollution removal reactions by chemical additives and 2) the optimization of electrical circuit for the efficient energy transfer from the power supply to the corona reactor. Hydrocarbon chemical additives used in the experiment are thought to be responsible for the enhancement of the NO conversion through the chain reactions of free radicals such as, R, RCO, and RO. Electrical energy consumption per converted NO molecule has a minimum value of 17 eV when pentanol is injected. When ethylene and propylene are injected, 30 eV and 22 eV of electrical energy consumption is required for the conversion of NO molecule respectively. The ratio of the pulse forming capacitance$(C_e)$ to the reactor capacitance$(C_R)$ plays an important role in the energy transfer efficiency to the reactor. Maximum energy transfer efficiency of approximately 72% could be obtained by using the pulse forming capacitance which is 3.4 times larger than the reactor capacitance, and also the maximum NO conversion efficiency was observed with the same condition.

• 한국응용과학기술학회지
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• 제28권4호
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• pp.455-463
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• 2011

The average sulfur content of crude oil is 2.2%. Coal is about 0.3 to 4.0 percent of the sulfur gases or particles being discharged into the atmosphere through the chimney as 1 to 2% $SO_3$(Sulfur trioxide) and about 95% of the $SO_2$ is reported. $SO_3$ gas, which has many different causes of, as the combustion of sulfur containing fuel during the air due to the excess $SO_2$ gas is oxidized to $SO_3$ gas. Sulfur trioxide emitted from high sulfur heavy oil fired boiler caused white plume in stack and high temperature and cold end corrosion of facilities. So, in order to control sulfur trioxide concentration of Fuel gas in boiler, various of additives are used in other foreign. They are injected to Fuel Oil and consumed in boiler and reduce ash and the conversion rate of sulfur trioxide. In domestic, MgO compounds are used as additives but the total volume of them are made from other foreign company. In this study, MgO compounds were developed with liquid MgO compounds and field application was accomplished. The effect of newly developed chemicals and process were nearly equal to foreign products. In Consequent, the chemicals and process produced by newly developed technology can be substituted for foreign products and reduce the cost of plant operation.

• 한국세라믹학회지
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• 제44권7호
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• pp.349-353
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• 2007

2D SiC fiber-SiC (SiC/SiC) composites were fabricated via slurry infiltration and a stacking process. The effects of the additive composition and content in SiC slurries and the effect of the sintering time on the sintered density and strength of SiC/SiC composites were investigated. A slurry containing $Al_2O_3-Y_2O_3-MgO$ (AYM) additives led to a higher strength compared to a slurry containing $Al_2O_3-Y_2O_3-CaO$ (AYC) additives. The sintered density increased as the sintering time increased and showed a maximum (>98%) at 4 h. In contrast, the flexural strength increased as the sintering time increased and showed a maximum (615 MPa) at 6 h. The relative density and flexural strength increased as the additive content increased.

• Journal of Ceramic Processing Research
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• 제19권5호
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• pp.413-418
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• 2018

All-solid-state lithium batteries (ASSBs) using inorganic sulfide-based solid electrolytes are considered prospective alternatives to existing liquid electrolyte-based batteries owing to benefits such as non-flammability. However, it is difficult to form a favorable solid-solid interface among electrode constituents because all the constituents are solid particles. It is important to form an effective electron conduction network in composite cathode while increasing utilization of active materials and not blocking the lithium ion path, resulting in excellent cell performance. In this study, a mixture of fibrous VGCF and spherical nano-sized Super P was used to improve rate performance by fabricating valid conduction paths in composite cathodes. Then, composite cathodes of ASSBs containing 70% and 80% active materials ($LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$) were prepared by a solution-based process to achieve uniform dispersion of the electrode components in the slurry. We investigated the influence of binary carbon additives in the cathode of all-solid-state batteries to improve rate performance by constructing an effective electron conduction network.

• 한국식품과학회지
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• 제33권1호
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• pp.33-39
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• 2001

이온쌍고속액체크로마토그래피를 이용하여 현재 우리나라에서 식품에 사용이 허용된 타르색소 8종과 일본등 외국에서는 허용되어 있으나 우리나라에서 허용되어 있지 않은 11종 등 총 19종의 동시 및 계통분석법을 확립하였다. HPLC에 사용한 컬럼은 Symmetry $C_18$, 이동상은 0.01 M TBA-Br이 함유된 0.025 M 초산암모늄용액-아세토니트릴-메탄올(65 : 25 : 10)과 0.01 M TBA-Br이 함유된 0.025 M 초산암모늄용액-아세토니트릴-메탄올(40 : 50 : 10)를 구배용매조성법(gradient mode)으로 사용하였다. 자외선 검출기의 파장은 동시분석의 경우 254 nm, 계통분석은 황색계통 420 nm, 적색계통 520 nm 그리고 청색 및 녹색계통은 620 nm로 설정하였다. 이때 색소들의 검출한계는 적색계통이 $0.05\;{\mu}g/g$, 황색계통은 $0.03\;{\mu}g/g$, 청색 및 녹색계통은 $0.01\;{\mu}g/g$이었다. Sep-pak $C_18$을 이용한 색소의 정제 방법은 혼합색소표준용액의 pH를 $5{\sim}6$으로 조정하고 0.1% TBA-Br을 가하여 색소를 보유시킨 다음 0.1% 염산-메탄올로 색소를 용출하여 HPLC로 분석하였다. 19종의 타르색소를 동시분석하는데 35분이, 계통분석시에는 18분 정도가 소요되었고 두 경우 모두 양호한 분리를 보였다.

• Korean Chemical Engineering Research
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• 제54권1호
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• pp.108-113
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• 2016

A miniaturized lab-scale Cu plating cell for the metallization of electronic devices was fabricated and its deposit uniformity and profile were investigated. The plating cell was composed of a polypropylene bath, an electrolyte ejection nozzle which is connected to a circulation pump. In deposit uniformity evaluation, thicker deposit was found on the bottom and sides of substrate, indicating the spatial variation of deposit thickness was governed by the tertiary current distribution which is related to $Cu^{2+}$ transport. The surface morphology of Cu deposit inside photo-resist pattern was controlled by organic additives in the electrolyte as it led to the flatter top surface compared to convex surface which was observed in the deposit grown without organic additives.

• 펄프종이기술
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• 제34권4호
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• pp.7-15
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• 2002

It is of critical importance to understand the characteristics of papermaking additives and their reaction mechanisms to fully utilize the benefits they provide. Among the papermaking additives, retention aids play critical roles in improving productivity, product quality and process economy. Diverse research efforts to understand the reaction mechanisms between cationic polymers and anionic microparticles have been made since microparticle retention systems were introduced into the market. And it is most commonly accepted that flocs formed by the addition of cationic polymers are dispersed by shear force and the broken flocs are reflocculated instantly with the addition of microparticles. There are still many unanswered questions, however, on the reaction phenomena between cationic polymers and anionic microparticles. In this study, several cationic polymers including waxy maize starch, com starch and guar gum were used to investigate their retention efficiency when they were used along with anionic colloidal silica.

• 한국식품영양학회지
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• 제12권2호
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• pp.204-208
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• 1999

In order to obtain data for use of algin in drink making process solution properties of algin have been investigated at various condition of algin concentration temperature pH and various food additives. At same revolution velosity viscosities of algin were increased as algin concentration raised. Algin solution showed dilatnat type flow in concentration of 0.25% to 0.4% but pseudoplastic type flow in above 0.5% showed dilatant type flow in concentration of 0.25% to 0.4% but pseudoplastic type folw in above 0.5% A maximum viscosity of algin was observed at pH 5.5 and its viscosities were also decreased as the tem-perature increased and heating at 8$0^{\circ}C$ above. Organic acids affected on the viscosity of algin with pH dependently and gel formed in pH below 3.0 Sweetners have no effect to the viscosity of algin. How-ever addition of NaCl and KCL upto 1.0% decreased a little its viscosity and CACl2 MgCl2 and FeCl3 increased the viscosity of algin Glutamic acid decreased the viscosity of algin.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.163-166
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• 2009

알루미늄슬러리 연료 제조 시 알루미늄의 분산안정성에 미치는 공정변수의 영향을 조사하였다. 알루미늄슬러리연료의 분산안정성은 Laser의 산란 현상을 이용하여 물질의 분산 안정성을 파악하는 Turbiscan을 이용하여 확인하였다. 여러 종류의 첨가제 적용시 시간 경과에 따른 입자 크기 및 농도 변화를 측정한 결과, TPAB (Tetrapropyl ammonium bromide) 사용시 다른 첨가제보다 좋은 결과를 나타내었다.

• 한국세라믹학회지
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• 제43권6호
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• pp.351-357
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• 2006

The fabrication process of the honeycomb filter was investigated using synthesized cordierite with the addition of pore former and extrusion additives (either organic matter or graphite). Also, the effect of additives on the resultant properties of honeycomb filter such as porosity, thermal expansion coefficient and mechanical strength were investigated. With increasing the organic matter up to 10 wt%, porosity was increased but compressive strength was decreased. With increasing the graphite content, however, both porosity and compressive strength were increased. The specimen with an optimum processing condition (C-17A30G, sintering at $1150^{\circ}C$) was demonstrated 59% in porosity, 69 MPa in compressive strength, and $2.4{\times}10^{-6}/^{\circ}C\;(25{\sim}1000^{\circ}C$) in thermal expansion coefficient, which physical properties are appropriate for the honeycomb filter applications.