• Title/Summary/Keyword: Concetration

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A Study on the PVA Particle Manufacturing for Polymerization Type Fine Toner (중합형 미세토너 합성을 위한 PVA입자 제조에 관한 연구)

  • 전재우;우화령;이난형;류원석;김삼수
    • Textile Coloration and Finishing
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    • v.15 no.6
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    • pp.8-17
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    • 2003
  • In order to investigate the possibility of PVA particle as toner, PVA/PVAc particle was manufactured. Fine spherical PVAc particle with emulsifier SDS(sodium Dodecyl Sulfate) and initiator V-50(2,2'- azo bis(2-amidinopropane) dihydrochloride) was manufactured by emulsion polymerization. And then, the PVAc was carried with surface saponification. PVA/PVAc skin core structured particle was obtained under optimum saponification condition. PVA skin side in manufactured PVA/PVAc particles was dyed with 1:2 metal complex type C. I. Acid Yellow 235 and then the dyed PVA particles were observed with a optical microscope. Under given polymerization condition such as SDS concentration, $1.62\times{10}^{-2} \;mol/lH_2O$, V-50 concetration, $3.7\times{10}^{-3}\;mol/lH_2O$ and temperature $50^\circ{C}$ , the high molecular weight of PVAc with Pn 13,900 and PVA with Pn 3,400 was produced. The particle distribution of obtained PVAc microspheres was appeared highly at 60 and $100\mu{m}$, respectively.

A Study on Nitric Oxide Formation & Reduction in Industrial Burner (I) -NO Concetration-Distribution in Double Swirling Diffusion Flame by LIF- (산업용 고부하버너 연소에서의 $NO_x$ 형성 및 저감에 관한 연구(I)-레이저 유도 형광법(LIF)를 이용한 이중선회 확산화염의 NO 농도 분포 측정-)

  • 박경석;김경수
    • Journal of Energy Engineering
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    • v.10 no.4
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    • pp.379-386
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    • 2001
  • This experimental study deals with on Nitric Oxide Formation & Reduction in Industrial Bunner. In this study, Laser-induced fluorescence (LIF) techniques have been used for quantitative measurements of Nitric Oxide. The NO A-X (0, 0) Vibrational band around 226 nm was excited using a XeCl excimer-pumped dye laser. And on-line excitation used $P_{21}+Q_1(14.5)/R_{12}+Q_2(20.5)/P_1(23.5)$ transition, for minimizing the other interferential effect. The measurements were taken NO concentration distribution in double swirling diffusion flame. In this swirl burner, NO concentration in downstream fo the flame decrease as primary/secondary air ratio increases.

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Surface Activities of Carboxybetaine Derivatives (카르복시베타인 유도체(誘導體)의 계면활성(界面活性))

  • Shon, Joo-Hwan;Kim, Yu-Ok
    • Journal of the Korean Applied Science and Technology
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    • v.4 no.2
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    • pp.43-48
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    • 1987
  • Isoelectric point and surface tension of twelve of the alkylcarboxy betaines such as 2-(trimethylammonio) dodecanoate, 2-(trimethyammonio) tetradecanoate, 2-(trimethylammonio) hexadecanoate, (dimethyldodecylammonio)ethanoate, (dimethyltetradecylammonio)ethanoate, (dimethylhexadecylammonio) ehtanoate, 2-(dimethylododecylammonio) propanoate, 2-(dimethyltetradecylammonio)proopanoate, 2-(dimethylhexadecylammonio)propanoate, 2-(dimethyltetradecylammonio)-3-phenyl propanoate, 2-(dimethyltetradecylammonio)-3-phenyl propanoate are tested. From the measurement of the isoelectric point, it was found that the isoelectric point were leaned toward the alkaline zone for c-alkylarbrxybetaines, and toward the acidic zone for N-alkylcarboxybetaines. At the range of the carboxybetaine concentration $2\;{\times}\;10^{-2}{\sim}2\;{\times}\;10^{-5}$mole/l, the surface tension of the aqueous solution were decreased to 30-38 dyne/cm, showing the tendency that the ability of lowering the surafce tension was depending on the increase of carbon atom number in the lipophilic alkyl chain. The critical micelle concetration measured by the surface tension and concentration curves have been found at the range of $10^{-2}{\sim}10^{-5}$mole/l.

Transport of Organic Acids through Porous Sulfonated Polystyrene Divinylbenzene Copolymer Membranes (다공성 술폰화 폴리스티렌-디비닐벤젠 공중합체 분리막을 통한 유기산의 이동)

  • 이광재;한정우;조영일
    • Membrane Journal
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    • v.1 no.1
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    • pp.44-54
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    • 1991
  • Sulfonated polystyrene-divinylbenzene(PS-DVB) copolymer membranes were prepared using different diluents (toluene, cyclohexane, cyclohexanol), various diluent ratio and DVB contents. And initial fluxes of organic acids were investigated by varying pH and initial concentration. As a results, water content and ion-exchange capacity decreased with increasing DVB concetration. Among used diluents, cyclohexanol was the most efficient for building up the highest water content and ion-exchange capacity. In the experiment of permeation, carboxylic acid such as formic acid and acetic acid showed higher fluxes when pH was lower than pKa and amino add such as L-alanine showed minimum flux when pH was isoelectric value. The relationaship between initial fluxes and initial concentrations has been expressed by saturation kinetics.

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Preparation and Characteristics of Ceramic Composite Powders Coated with $Al_2O_3$: (I) Hydrolysis of Mixed Aluminum Salt Solution for Coating ($Al_2O_3$로 피복시킨 세라믹 복합분체의 제조 및 특성 : (I) 피복용 혼합 알루미늄 염 용액의 가수분해)

  • 현상훈;정형구
    • Journal of the Korean Ceramic Society
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    • v.27 no.7
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    • pp.851-860
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    • 1990
  • The hydrolysis-precipitation reaction of mixed aluminum salt solutions of aluminum sulfate, aluminum nitrate, and urea has been investigated to obtain narrow-sized and unagglomerated fine spherical precipitates of aluminum hydroxide required for coating core particles. The hydrolysis-precipitatin reaction could be controlled to be appropriate to coating processes by usign urea as a pH control-agent. As the concetration of total Al3+ ion and the molar ratio of SO42-/Al3+ in starting solutions became smaller and also as the vol. ratio of water/solution for hydrolyzing mixed aluminum salt solution became larger, the morphology of precipitates tended to be more unagglomerated and spherical, while their size(0.5longrightarrow0.05${\mu}{\textrm}{m}$) to be smaller. The optimum hydrolysis condition for coating processes was to hydrolyze the mixed aluminum salt solution, in which the molar ratio of SO42-/Al3+ was 0.75, while the amount of water corresponding to the vol. ratio of water/solution of 15. The precipitate was the aluminum hydroxide which sulfate ions were strongly adsorbed on and the maximum yield in the hydrolysis-precipitation reaction was about 20%.

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Agglomeration of fine anthracite using oil and modified styrene (Oil과 Modified Styrene을 사용(使用)한 미립(微粒) 무연탄(無煙炭)의 응집(凝集))

  • Lee, Jae-Jang;Jang, Dong-Sung
    • Journal of Industrial Technology
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    • v.7
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    • pp.27-47
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    • 1987
  • Fine anthracite is very difficult to upgrade by conventional processes such as gravity concentration or froth flotation, because large quantities of fine coals are generated at the mining and preparation stages and a significant portion of these fine coals are mixed with gangue minerals. This study, therefore, was carried out for the purpose of improving recovery of low ash clean coal, effective beneficiation of low-grade coking coal and removal of sulphur from high-sulphur coals by employing the method of selective agglomeration using oil or polystrene flocculants, for coals which are generally hydrophobic in nature will be extracted by using flocculants. Studies were performed by varying solid concentration, concetration of bridging liquid, mixing speed and mixing time, balling speed and balling time, dispersant dosage, flocculant dosage, pulp pH, and particle size. The results were : when the methods of the oil agglomeration and selective flocculation were employ(in the two process the sample was ground to the size of -74 micron), 1) ash content of the agglomerated coal was 9.85, 7.83%, 2) combustibel recovery of it was 98.5%, 93.5%, respectively. It was observed in selective flocculation that polystyrene is an effective flocculant for coal, De-entrapment of shale from the concentrate flocculated by mechanical agitation was necessary for substantional reductions in final ash content.

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Directional Control of Radiation Heat Transfer from Solid Surface Using Grating Composed of Parallel Elliptical Cylinders -Directional Control of Energy Concetration- (타원주격자를 사용한 고체면에서의 복사열전달의 방향제어-에너지 집중 방향제어-)

  • Go, Heung;Hidetoshi Masuda;Jo, Byeong Su;Gang, Yeong Gyu
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.9
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    • pp.2933-2943
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    • 1996
  • A grating composed of elliptical cylinders (GEC), specially designed, is applicable to control of radiation heat transfer from a heated surface, as reported in our previous work. In this study, an analysis of radiation heat transfer is performed for a physical model in which the GEC is placed in front of a heated black-base surface and the major axes of the elliptical cylinders are inclined as a certain angle from the normal to the row of elliptical cylinders. Numerical solutions are obtained. Variations of the direction and the radiative energy concentration with slant angle of the major axis are shown for some parameters. It is verified that the GEC is able to widely change the direction of radiation heat transfer from the heated surface.

Auto-Bending Manufacturing System for Boiler Tubes (보일러 튜브 자동벤딩 생산시스템 개발)

  • Lee, Hyun-Soo;Kang, Moon-Hyun;Park, Jun-Kon;Hur, Kwan;Sung, Joon-Suk;Heo, Wang-Soon
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.450-454
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    • 1997
  • This system is the automatic boiler tube bending equipment which has four heads for bending the tube and the carriage for moving the tube. The system consists of two frames for transporting each moving parts, high-frequency heating equipment for heating the tube in hot bending, control panel for inputting the job data operating, remote control unit for concetration and distribution of input/output, and the monitoring system which can establish unmanned operationby receiving the bending job data via LAN form a design teamwhich produces the job data and schedule based on master production plan and diagnoses bending data change, input, whole system status, and system malfunctions. By employing this system, 30% of production improvement was achieved was achieved comparing to the existing bending system.

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Study on Rheological and Phermal Properties of Dioiscorea batatas DECAISNE Starch (마(Dioscorea batatas DECAISNE)전분의 Rheology 및 열적 특성에 관한 연구)

  • 최일숙;이임선;구성자
    • Korean journal of food and cookery science
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    • v.8 no.1
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    • pp.57-63
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    • 1992
  • The purpose of this study was to investigate the rheological and thermal properties of yam starch. Yam starch had a hydrodynamic volume with the intrinsic viscosity,[$\eta$], of 0.29dl/g deionized water. The values of the intrinsic viscosity of yam starch, determined to pH 2-11, varied between 0.07 to 0.18 dl/g. The highest intrinsic viscosity was obtained at pH 7. At salt concentrations 0-0.2 M NaCl, the intrinsic viscosity of yam starch was decreased up to 0.05 M NaCl concentration then increased to 0.07 M NaCl concentration and remained constant to reach 0.2 M NaCl concentration. The overlap parameter, calculated with the intrinsic vicosity data, was 3.45 g/dl in deionized water. The thermal properties of yam starch were investigated by Differential Scanning Calorimetry. Three endotherms were observed both pH solution and salt concentation. In the presence of pH 9, the onset temperature of gelatinization peak was the lowest temperature of 50.$32^{\circ}C$ and the enthalpy ($\Delta$H) was increased in this solution. The effect of salt on the thermal properties of yam starch was determined at salt concetration of 0-0.2 M NaCl. The enthalpy significantly decreased to salt concentration 0.07 M NaCl and the lowest onset temperature of this concentration was 52.$90^{\circ}C$.

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Influence of the process conditions for the amorphous silicon on the HSG-Si formation (비정질 규소막의 공정조건이 HSG-Si 형성에 미치는 영향)

  • Jeong, Jae-Young;Kang, Seong-Jun;Joung, Yang-Hee
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.11
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    • pp.1251-1256
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    • 2015
  • In this paper, the processing conditions of the amorphous silicon film growth were investigated the effect in forming the HSG-Si on the surface of the storage electrode. As a result, when the amorphous silicon film phosphorus concentration is greater than $5.5{\pm}0.1E19atoms/cm^3$, HSG-Si is not formed correctly and showed the concentration dependency of HSG formation. Also, the optimum condition of the phosphorus concentration for amorphous silicon and HSG thickness are $4.5E19atoms/cm^3$ and $450{\AA}$, respectively, because of the HSG thickness over the $500{\AA}$ create to bit failure according to a short of the electrodes and the electrode.