• Title/Summary/Keyword: Starting solution

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Effect of Starting Materials on the Characteristics of (La1-xSrx)Mn1+yO3−δ Powder Synthesized by GNP (GNP법에 의해 합성한 (La1-xSrx)Mn1+yO3−δ 분말의 출발물질에 따른 특성)

  • Lee, Mi-Jai;Kim, Sei-Ki;Jee, Mi-Jung;Choi, Byung-Hyun;Park, Sang-Sun;Lee, Kyung-Hee
    • Journal of the Korean Ceramic Society
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    • v.44 no.1 s.296
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    • pp.52-57
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    • 2007
  • We synthesized $(La_{1-x}Sr_x)MnO_3$ as a cathode for SOFC by glycine nitrate process (GNP) and knew the different properties of $(La_{1-x}Sr_x)MnO_3$ by using nitrate solution and oxide solution as a starting material. In case of using nitrate solution as a starting material, main crystal phase peak of $LaMnO_3$ increased as Sr content added up and a peak of $Sr_2MnO_4\;and\;La_2O_3$ was showed as a secondary phase. We added Mn excess to control a crystal phase. In this case, the electrical conductivity had a high value 210.3 S/cm at $700^{\circ}C$. On the other side, when we used oxide solution as a starting material, we found main crystal phase of $LaMnO_3$ to increase as Sr content added up and a peak of $La_2O_3$ as a secondary phase. Similary, we added Mn excess to control a crystal phase in this case. We knew $(La,Sr)MnO_3$ powder to sinter well and the electrical conductivity of the sintered body at $1200^{\circ}C$ for 4 h was 152.7 S/cm at $700^{\circ}C$. The sintered $(La,Sr)MnO_3$ powder at $1000^{\circ}C$ for 4 h got the deoxidization peak, depending on the temperature and in case of using nitrate solution as a starting material, the deoxidization peak was showed at $450^{\circ}C$ which is lower than used a oxide solution as a starting material. As a result, when $(La,Sr)MnO_3$ powder was synthesized to add Mn excess and to use nitrate solution as a starting material, we found it to have the higher deoxidization property and considered it as a cathode for SOFC properly. And we found it to have different electrical conductivity the synthesized $(La,Sr)MnO_3$ powder by using different starting materials like nitrate solution and oxide solution which influence a sintering density and crystal phase.

Effect of NH4F Flux on the Characteristics of Barium Strontium Silicate Phosphor Particles (NH4F 융제가 바륨 스트론튬 실리케이트계 형광체의 특성에 미치는 영향)

  • Kang Hee Sang;Koo Hye Young;Jung Dae Soo;Ju Seo Hee;Hong Seung Kwon;Kang Yun Chan;Jung Kyeong Youl;Park Seung Bin
    • Korean Journal of Materials Research
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    • v.15 no.6
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    • pp.408-412
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    • 2005
  • [ $Ba_{1.5}Sr_{0.5}SiO_4:Eu$ ] phosphor particles with high photoluminescence intensity under long wavelength ultraviolet were prepared by spray pyrolysis. We investigated the effect of $NH_4F$ flux added into starting solution on the morphology and photoluminescence intensity of $Ba_{1.5}Sr_{0.5}SiO_4:Eu$ phosphor prepared by spray pyrolysis. $Ba_{1.5}Sr_{0.5}SiO_4:Eu$ phosphor particles prepared from starting solution containing $NH_4F$ flux had the maximum photoluminescence intensity at the post-treatment temperature of $1200^{\circ}C$ and the maximum photoluminescence intensity of $Ba_{1.5}Sr_{0.5}SiO_4:Eu$ phosphor particles prepared from the starting solution containing $NH_4F$ flux was $137\%$ of that of the phosphor particles prepared from the starting solution without flux material. $Ba_{1.5}Sr_{0.5}SiO_4:Eu$ phosphor particles prepared from starting solution containing $NH_4F$ flux had larger size and more aggregated morphology than those prepared from starting solution without flux material. The photoluminescence intensity of $Ba_{1.5}Sr_{0.5}SiO_4:Eu$ phosphor particles prepared from starting solution containing $NH_4F$ flux above $3wt.\%$ had high photoluminescence intensities. The addition amount of $NH_4F$ flux showing the maximum photoluminescence intensity was $12wt.\%$. The optimum amount of $NH_4F$ flux was $5wt.\%$ when we considered the morphological and photoluminescence characteristics of $Ba_{1.5}Sr_{0.5}SiO_4:Eu$ ohosphor particles prepared by spray pyrolysis.

Cathode Characteristics in the Synthesis of $(La,\;Sr)MnO_{3+{\delta}$ of Precursor ($(La,\;Sr)MnO_{3+{\delta}$ 합성에 있어서 출발물질에 따른 양극특성)

  • Lee, Mi-Jai;Kim, Sei-Ki;Ji, Mi-Jung;Choi, Byung-Hyun;Park, Sang-Sun
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.360-363
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    • 2006
  • We synthesized $(La,\;Sr)MnO_{3+{\delta}$ as a cathode for SOFC by glycine nitrate process(GNP) and knew the different properties of $(La_{1-x}Sr_x)MnO_3$ by using nitrate solution and oxide solution as starting material. In case of using nitrate solution as a starting material, main crystal phase peak of $LaMnO_3$ increased as Sr content added up and a peak of $Sr_2MnO_4\;and\;La_2O_3$ was showed as a secondary phase. We added Mn excess to control a crystal phase. In this case, the electrical conductivity had a high value 210.3S/cm at $700^{\circ}C$ On the other side, when we used oxide solution as a starting material, we found main crystal phase of $LnMnO_3$ to increase as Sr content added up and a peak of $La_2O_3$ as a secondary phase. Similary, we added Mn excess to control a crystal phase in this case. We knew $(La,\;Sr)MnO_3$ powder to sinter well and the electrical conductivity of the sintered body at $1200^{\circ}C$ for 4hrs was 152.7s/cm at $700^{\circ}C$. The sintered $(La,\;Sr)MnO_3$ powder at $1000^{\circ}C$ for 4hrs got the deoxidization peak, depending on the temperature md in case of using nitrate solution as a start ing material the deoxidization peak was showed at $450^{\circ}C$ which is lower than used a oxide solution as a starting material. As a result, when $(La,\;Sr)MnO_3$ powder was synthesized to add Mn excess and to use nitrate solution as a starting material, we found it to have the higher deoxidization property and considered it as a cathode for m properly. And we found it to have different electrical conduct ivity the synthesized $(La,\;Sr)MnO_3$ powder by using different start ing materials like nitrate solution and oxide solution which influence a sintering density and crystal phase.

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Exploring the Customization Decision Support System Using Waypoint Solutions

  • Ono, Akinori;Matsuura, Kiyokazu;Endo, Seiji;Nakagawa, Yuji
    • Asia Marketing Journal
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    • v.18 no.1
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    • pp.23-35
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    • 2016
  • Product customization has been popular since Internet shopping began. Many firms have introduced customization configuration systems, allowing customers to choose a wide range of product attributes, attracting them to participate in the shopping process, and increasing customer satisfaction. Paradoxically, the attribute-by-attribute (AbA) choice in the customization process requires a high-information processing load resulting in shopper confusion. To reduce this confusion, the CvSS (customization via starting solution) system has recently been developed. However, this system provides solution support only for the starting point of the configuration process. Thus, in this study, the authors proposes the CvWS (Customization via Waypoint Solutions) system, which would greatly reduce the customer effort needed to complete the configuration process by using a novel approach to solve the nonlinear knapsack problem. The newly proposed system is theoretically compared with the AbA customization as well as the CvSS system. Also, its feasibility is discussed in the context of the nonlinear multiconstraint knapsack problem.

The study on the Ways to Activation of the Youth Starting up a Business by Korea-China FTA (한·중 FTA 체결에 따른 청년창업 활성화방안에 관한 연구)

  • KIM, Dong-Ho
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.69
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    • pp.617-632
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    • 2016
  • After contracting of Korea-China FTA, we have expected the trade volume has mutually been increasing a lot. If we are using this contract, we would make an activation of Korea economy. Especially, Korea youngman has been caught a big chance to make a business in Korea & China. For example, Xian, which is one of center of silk road, has become big strategy area. As we need to focus on this area, we will be expected to indirect influences of consumer's industries like cosmetic, fishery products, food service, eco-friendly items. Recently, the youngman starting up a business has become a trend of kinds of alternative new job. Then, we have to provide practical solution for young man. One of this solution is 'starting up a business'. In this study, I empirically investigated the relation between Korea-China FTA and the youth starting up a business. So, I believe that this study can light up on the direction of effective starting up for making & success a business in China.

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Effect of Ca/P Mole Ratio on the Sintering of Hydroxyapatite Powders Synthesized by the Wet Method and its Microstructure (습식법으로 제조한 수산화아파타이트 분말의 소결과 그 미세구조에 미치는 Ca/P몰비의 영향)

  • 신용규;정형진;김병호
    • Journal of the Korean Ceramic Society
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    • v.26 no.1
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    • pp.123-131
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    • 1989
  • Hydroxyapatite powders were syntehsized by the reaction of Ca(NO3)2.4H2O and (NH4)2HPO4 in aqueous solution. The effect of the Ca/P mole ratio in the starting solution on the sintering of the powders and its microstructure was studied. When the Ca/P mole ratio in the starting solution was 1.69, the relative density of the sintered bodies was more than 95%. The sinterability was decreased as the Ca/P mole ratio in the starting solution was increased (Ca/P mole ratio >1.67). Hydroxyapatite sintered bodies obtained from the Ca/P mole ratio=1.69 had very excellent bending strength. The best bending strength was obtained at 110$0^{\circ}C$ and its value was 1220kg/$\textrm{cm}^2$. The average grain size was 0.277${\mu}{\textrm}{m}$. Most of sintered bodies were almost shown 100% hydroxyapatite phase. However, in case of the Ca/P mole ratio=1.64 hydroxyapatite was decomposed to $\alpha$-whitlockite above 120$0^{\circ}C$.

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Sensorless Starting of Direct Drive Horizontal Axis Washing Machines

  • Dianov, Anton;Kim, Nam Su;Lim, Seung Moo
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.2
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    • pp.148-154
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    • 2014
  • This paper describes problems of the sensorless starting of horizontal axis washing machines with direct drive and suggests solution, which was experimentally verified. Horizontal axis washing machines have very difficult conditions for the drive starting, especially at full load. Inertia of the tub and water, torque from the laundry make load torque at starting higher than rated one and sometimes even higher than the maximum torque of the motor, which makes sensorless starting extremely challenging task. This paper suggests modified open-loop starting, where control system is closed shortly after beginning at low speed and rotates the drum until laundry restructuring. To ensure proper work of the sensorless algorithm at low speed additional measures for increasing of the estimation algorithm performance have been taken. These measures include special algorithm for the drive parameters estimation, which has been developed and verified by the experimental results.

Eco-friendly Indigo Dyeing using Baker's Yeast: Reducing Power according to Alkaline Solution Type (효모를 사용한 친환경 인디고 염색: 알칼리수용액 종류에 따른 환원력)

  • Son, Kyunghee;Shin, Younsook
    • Textile Coloration and Finishing
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    • v.31 no.4
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    • pp.249-257
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    • 2019
  • Baker's yeast(Saccharomyces cerevisiae) was used as a biocatalyst for eco-friendly indigo dyeing and the reducing power of yeast according to the alkaline solution type was compared. NaOH solution, lye, and buffer solution were used as alkaline solutions. The reducing power(K/S value, oxidation/reduction potential(ORP), pH) was monitored according to the elapsed time including the initiation of reduction, peak reduction, and the end of reduction. In all alkaline solutions, it was confirmed that yeast can be used reducing agent in indigo reduction dyeing. The pH stability and reducing power of buffer solution was better than that of NaOH alone. Although, pH and ORP stability of the reduction bath in lye were better than that of buffer solution, K/S value in buffer solution was higher compared to lye. The reducing power was different depending on the starting pH of the dye bath, and it was better when starting at pH 10.70 than at pH 11.30. Fastnesses to washing, rubbing, and light were relatively good with above rating 4. There was no significant difference in colorfastness depending on the type of alkaline solutions.

The Characteristics and Formation of Tungsten Nano-Powder by Ultrasonic Spray Pyrolysis Method (초음파분무열분해법에 의한 나노 텅스텐 분말의 형성 및 특성에 관하여)

  • Lee, Ho-Jin;Yoon, Jung-Hyun;Choe, Jean-Il
    • Journal of Surface Science and Engineering
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    • v.41 no.4
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    • pp.174-179
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    • 2008
  • Nanosize tungsten powder was synthesized by ultrasonic spray pyrolysis method through a solution containing ammonium metatungstate hydrate $[(NH_4)_6W_{12}O_{39}{\cdot}H_2O]$ and reduction treatment. It was expected the improvement of mechanical properties due to increasing surface free energy and surface activity. Starting solutions with each concentration, reaction temperature and reduction treatment were significantly influenced on the formation of tungsten size and phase. It was found that particle size was decreased with concentration of starting solution and surface tension were decreased. The particle size was increased at thermal decomposition temperature above $600^{\circ}C$ by neck growth of interparticles. Tungsten particles were formed by reduction reaction in atmosphere of hydrogen gas at the temperature above $700^{\circ}C$.

Y-TZP Sintered with Spherical Fine Powders Prepared by Ultrasonic Spray Pyrolysis (초음파 분무 열분해 구형 미립자를 이용한 Y-TZP 소결체의 제조)

  • 김복희;이정형
    • Journal of the Korean Ceramic Society
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    • v.32 no.5
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    • pp.575-581
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    • 1995
  • Zr0.94Y0.06O1.97 powder was synthesized by the ultrasonic spray pyrolysis with various concentrations of starting solution and the influence of powder characteristics on sintering behavior was investigated. Powders prepared at 75$0^{\circ}C$ were characterized as narrowly distributed submicron spherical particles, which were crystalline, nonagglomerated, and compositionally homogeneous. The changes in concentration from 0.01 to 01. mol/ι increased mean particle size from 0.24 to 0.38${\mu}{\textrm}{m}$ and decreased the specific surface area from 14.2 to 2.9$m^2$/g. The relative density of the specimen from the powders, prepared with the solution concentration of 0.01 mol/ι, was 98% after sintering for 2 hr at 1,45$0^{\circ}C$ and the monoclinic phase was observed after sintering at 1,55$0^{\circ}C$. As the concentration of starting solution was increased, the formation temperature of monoclinic phase was lowered.

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