• 제목/요약/키워드: Powder Flow

검색결과 611건 처리시간 0.029초

해조류를 이용한 Cu(II) 및 Zn(II) 이온의 흡착 및 회수 (Adsorption and Recevery of Cu(II) and Zn(II) Ions by Algal Biomass)

  • 박광하;전방욱;김한수;김영하
    • 분석과학
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    • 제9권4호
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    • pp.373-381
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    • 1996
  • 몇 가지 금속을 제거하기 위한 목적으로 건조된 해조류를 이용하였다. 금속 흡착제로 사용하기 위하여 40~60 mesh의 해조 분말을 칼럼에 충진시킨 후, 금속 용액을 1mL/min의 속도로 흘려 보내면서 금속이온을 흡착시켰다. Cu(II), Zn(II) 이온 모두 갈조류인 Sargassum horneri(Turner) C. Agarch보다 녹조류인 Ulva pertusa Kjellman에서 더 많은 흡착량을 보였고 두 해조류 모두 Zn(II) 이온보다 Cu(II) 이온이 더 많이 흡착하였다. 금속의 회수율은 산성 또는 중성일 경우에 켰으며 Zn(II) 이온보다 Cu(II) 이온의 회수율이 다소 높았다.

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'LTCC를 소재로 하는 마이크로 리포머의 최적 설계에 관한 연구: (다양한 채널구조에 따른 성능변화 고찰)' (A Study on the Optimum Design for LTCC Micro-Reformer: (Performance Evaluation of Various Flow Channel Structures)

  • 정찬화;오정훈
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.551-552
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    • 2006
  • The miniature fuel cells have emerged as a promising power source for applications such as cellular phones, small digital devices, and autonomous sensors to embedded monitors or to micro-electro mechanical system (MEMS) devices. Several chemicals run candidate at a fuel in those systems, such as hydrogen. methanol, ethanol, acetic acid, and di-methyl ether (DME). Among them, hydrogen shows most efficient fuel performance. However, there are some difficulties in practical application for portable power sources. Therefore, more recently, there have been many efforts for development of micro-reformer to operate highly efficient micro fuel cells with liquid fuels such as methanol, ethanol, and DME In our experiments, we have integrated a micro-fuel processor system using low temperature co-fired ceramics (LTCC) materials. Our integrated micro-fuel processor system is containing embedded heaters, cavities, and 3D structures of micro- channels within LTCC layers for embedding catalysts (cf. Figs. 1 and 2). In the micro-channels of LTCC, we have loaded $CuO/ZnO/Al_2O_3$ catalysts using several different coating methods such as powder packing or spraying, dipping, and washing of catalyst slurry.

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한류기용 Bi2212 튜브의 특성 (Bi2212 Tube Characteristics for SCFCL)

  • 이남일;장건익;오일성;박권배
    • Progress in Superconductivity
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    • 제7권2호
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    • pp.174-178
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    • 2006
  • For the practical application on SCFCL, Bi2212 tubes were fabricated by Centrifugal Forming Process (CFP) in terms of many different processing parameters. Typical sizes of tubes were 60, 150 mm in length and 2.5, 3.5, 4.8 mm in thickness. Initially powder was melted by induction heating. The optimum range of melting temperatures and preheating temperature were $1100^{\circ}C$ and $500^{\circ}C$ for 30min respectively. The nominal mold rotating speed was around 1000 RPM. A tube was annealed at $840^{\circ}C$ for 80 hours in oxygen atmosphere. The tube of 50mm x 70mm x 2.5mm, rotated with 1000 RPM showed $I_c=890\;A\;and\;T_c=80$. It was found that the tube processed with faster rate of mold rotation speed, thinner tube thickness and shorter tube length shows better electric characteristics as compared with the tube normally processed. In order to study the uniformity heat and fluid flow analysis tool was adopted along tube.

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측면수직보조전계에 의한 전기영동전착 기술 (Electrophoretic Deposition Technique by Vertical Lateral Assisted Field)

  • 소대화;전용우;박정철;번점국
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 기술교육전문연구회
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    • pp.82-85
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    • 2003
  • This dissertation describes an optimization method for fabricating thick films with superconducting YBCO powders by electrophoresis technique. The lateral alternating applied voltage caused to shake the superconducting powder vertically to the deposition field during the process of the oriented deposition so that it was deposited along the c-axis on the silver tape with shaky-aligned EPD. As the result, the optimized thin film fabrication method was obtained to get more dense and uniform surface morphology as well as the improved critical current density. For commercial utilization and efficiency, in this dissertation, alternating voltage of 25-120 V/cm in frequency of 60Hz was proposed to apply it as a subsidiary source for shaky-flow deposition so that the fabricated thin film showed uniform surface morphology with less voids and cracks and $T_{c.zero}$ of 90 K and the critical current density of $3419A/cm^2$.

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Efficacy of Geru (red ochre) in controlling the bleeding in patients of Adolescent menorrhagia

  • Kotagasti, Tabassum
    • 셀메드
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    • 제5권2호
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    • pp.12.1-12.3
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    • 2015
  • Adolescent menorrhagia is defined as excessive menstrual bleeding from menarche to adolescents. It is a distressing condition both for the patient as well as for her parents. If it is not managed in time itmay pose significant health problems that may leads to blood transfusion. We determined the efficacy of Geru (Red ochre) in controlling the amount and duration of blood flow in patients of Adolescent menorrhagia. This study included 40 teenage girls, who presented with heavy bleeding during menstruation to Outpatient Department, Sameena Maternity Nursing Home, Hyderabad during the year of 2013. Assessment of each case was done by history and Pictorial Blood loss Assessment Chart (PBAC) score. Geru powder was given for 2 cycles and results were assessed. The data was analyzed statistically. The mean PBAC score before treatment was $497.04{\pm}389.92$ and after trial in $1^{st}$ and $2^{nd}$ it was found to be $471.13{\pm}162.18$ and $310.13{\pm}142.15$ respectively. On basis of results it was concluded that single unani drug Geru is enough in controlling bleeding and was found effective by its astringent and styptic properties.

Fabrication and Characterization of Titanate Nanotube Supported ZSM-5 Zeolite Composite Catalyst for Ethanol Dehydration to Ethylene

  • Wu, Liangpeng;Li, Xinjun;Yuan, Zhenhong;Chen, Yong
    • Bulletin of the Korean Chemical Society
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    • 제35권2호
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    • pp.525-530
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    • 2014
  • Titanium dioxide nanotube supported ZSM-5 zeolite composite catalyst was fabricated by decorating ZSM-5 zeolite on the hydrothermally synthesized titanium dioxide via hydrothermal process and subsequent annealing. The catalyst was characterized by X-ray powder diffraction (XRD), Transmission electron microscopy (TEM) and Nitrogen adsorption-desorption (BET). The surface acidity of the catalyst was measured by means of Fourier transform infrared (FT-IR) spectrum of pyridine adsorption. And the catalytic activity for ethanol dehydration to ethylene was evaluated in a continuous flow fixed-bed reactor. Attributed to the increase of the effective surface acid sites caused by titanium dioxide nanotube as electron acceptor, titanium dioxide nanotube supported ZSM-5 zeolite composite catalyst exhibits strongly enhanced activity for ethanol dehydration to ethylene.

경유 화염에서 왕겨를 이용한 바이오매스 재연소의 NOx 저감 효과 (The Effect of Biomass Reburning with Rice Husk on NOx Reduction in Light Oil Flame)

  • 김세원;신명철;이창엽
    • 한국연소학회지
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    • 제14권4호
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    • pp.17-24
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    • 2009
  • Reburning is one of the most useful technologies for reducing nitric oxide in economically and technically. The reburning process was demonstrated as an effective NOx reduction method through injection of a secondary hydrocarbon fuel. An experimental study has been conducted to evaluate the effect of biomass reburning on NOx and CO formation in a light oil flamed combustion furnace. Reburning tests on NOx reduction of air-carried rice husk powder as the reburn fuel and light oil as the main fuel were performed in flames stabilized by a co-flow swirl and fuel staged burner, which was mounted at the front of the furnace. The results included flue gas emissions and temperature distribution in the furnace for several kinds of experimental conditions. It was observed clearly that NOx concentrations in the exhaust have considerably decreased due to effect of biomass reburning. The maximum NOx reduction rate was 42% when the reburn fuel fraction was 0.18. The CO emissions were kept under 42 ppmv in all experimental tests. And this paper makes clear that in order to decrease NOx concentration in the exhaust when the biomass reburning system is adapted, the control of some factors such as reburn fuel fraction and reburn zone fraction is very important.

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상백피가 개의 신장 기능에 미치는 영향 (Influence of Mori Radicis Cortex on the Renal Function of Dog)

  • 고석태;이은화
    • 약학회지
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    • 제26권4호
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    • pp.197-208
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    • 1982
  • In this study attemps were made to obtain evidence as to the action of Mori Radicis Cortex on the renal' function of anesthetized mongrel dogs. 1. A light brown powder isolated from Mori Radicis Cortex (MRC) by a slight modification of Tanemura's method, when given intravenously in doses ranging 0.5 to 5.0mg/kg, elicited diuresis with the increase of positive water clearance and amounts of $Na^{+}$ and $K^{+}$ excreted in the urine. At this time the glomerular filtration rate, renal plasma flow and osmolar clearance were not observed to have any significant changes. This diuresis was augmented in process of time and its maximum effect was exhibited about 30 minutes after administration of MRC. 2. The MRC, when administered into a intra carotid artery, responded promptly with diuresis and natriuresis at a level too small to effect renal functions when administered intravenously. In this experiment the patterns of changes of renal function were the patterns of changes of renal function were the same as those of the above intravenously administered experiment. 3. When infused directly into a renal artery, the MRC exhibited little effect on either kidney. 4. During water diuresis, the MRC did not elicit diuretic action or significant changes in renal functions. The above observations suggest that the diuresis of MRC is brought about by the inhibition of the release of antidiuretic hormone with the mechanism facilitating the excretion of $Na^{+/}$ and $K^{+}$ in urine.

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메타카올린을 사용한 콘크리트의 유동특성 및 강도특성에 관한 실험적 연구 (An Experimental Study on the Flowing and Strength Properties of Concrete using Meta kaolin)

  • 이병수;이상수;송하영;김을용
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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    • pp.425-428
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    • 2005
  • In this study, the experiment was carried out to investigate and analyze the strength properties and flowability of concrete using meta kaolin. The main experimental variables were water/binder ratio 40.0$\%$, water content 170kg/$m^{3}$ and mineral admixtures such as slag powder, silica fume and meta kaolin. According to the test results, the principle conclusions are summarized as follows. 1) The flowing property of concrete that uses meta kaolin appears to be the same to that of the silica fume concrete, but the slump flow that evaluates the compaction ability of concrete shows the most favorable performance. 2) The air content of the concrete that uses meta kaolin can be effectively controlled for the target performance in compliance with the use of AE agent. 3) When it comes to the strength of concrete that uses meta kaolin, the most favorable development of strength occurs when the replacement rate is 10$\%$, in case of the silica fume, and the slag power. In addition, as the replacement rate increases, so becomes the development of concrete strength favorable.

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RF 마그네트론 스퍼터링에 의한 p형 투명 반도체 $SrCu_2O_2$ 박막의 제조 (Preparation of p-type transparent semiconductor $SrCu_2O_2$ thin film by RF magnetron sputtering)

  • 김세기;석혜원;이미재;최병현;정원희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.47-47
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    • 2008
  • P-type transparent semiconductor $SrCu_2O_2$ thin films have been prepared by RF sputtering using low-alkali glass for LCD and quartz as substrates. Single phase of $SrCu_2O_2$ powder was obtained by heating a stoichiometric mixture of CuO and $SrCO_3$ at 1223K for 96h under N2 gas flow, and target was fabricated at 1243K for 24h. Room temperature conductivity of the sintered body was about 0.02S/cm, and the activation energy in the temperature range of $-50^{\circ}C$~RT and RT~$150^{\circ}C$ were 0.18eV, 0.07eV, respectively. Effects of deposition pressure and post-annealing temperature on the electrical and optical properties of the obtained thin film have been investigated.

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