• Title/Summary/Keyword: Alkaline material

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Mercury Ion Removal Using a Packed-Bed Column with Granular Aminated Chitosan

  • JEON, CHOONC
    • Journal of Microbiology and Biotechnology
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    • v.15 no.3
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    • pp.497-501
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    • 2005
  • This study deals with the removal of mercury species using a packed-bed column with spherical aminated chitosan material. These adsorbents revealed a high adsorption capacity for mercury species. Experiments with feed solutions of 10 ppm Hg dissolved in distilled water showed an excellent removal with a sharp increase of the filter effluent concentration after a total throughput of 900 bed volumes of feed water. Up to $95\%$ desorption was reached by using 3 bed volumes of 0.01 N EDTA solution. EDTA could be recovered by means of sulfuric acid with about $75\%$ efficiency. Almost the same results were obtained in repeated sorption and desorption experiments at identical conditions. The experiments demonstrated that the sorbents possessed practically no sorption capacity for alkaline earth ions ($Ca^{2+}\;and\;Mg^{2+}$). Their influence on the sorption of mercury was negligible. In experiments with spiked tap water of the Karlsruhe Research Centre and a feed mercury concentration of 0.01 mg/l, the breakthrough of Hg was observed only after a total throughput of about 6,000 bed volumes of feed water.

Effects of Environmental Variables on Hydrogen Generation from Alkaline Solutions using used Aluminum Cans (알칼리 용액에서 알루미늄 재활용 캔을 이용한 수소생산에 미치는 환경 인자의 영향)

  • Yun, Kwi-Sub;Park, Chan-Jin
    • Journal of Hydrogen and New Energy
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    • v.22 no.1
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    • pp.29-34
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    • 2011
  • This study examined the effect of environmental variables, such as the NaOH concentration and solution temperature, on the rate of hydrogen generation from NaOH solutions through the corrosion of used aluminum cans as a potential candidate material for the safe and economic production of hydrogen. Corrosion of the used aluminum cans was promoted by increasing the NaOH concentration and solution temperature because of the loss of aluminum passivity. The measured rate of hydrogen generation from the NaOH solutions increased with increasing NaOH concentration due to the catalytic activity of NaOH in the hydrolysis process. However, at higher solution temperatures, the rate of hydrogen generation rate was less affected by the NaOH concentration than that at lower temperature.

Wet-Etching Characteristics of Inorganic GeSbTe Films for High Density Optical Data Storage (고밀도 광기록을 위한 GeSbTe 박막의 Wet-Etching 특성연구)

  • Kim, Jin-Hong;Kim, Sun-Hee;Lee, Jun-Seok
    • Transactions of the Society of Information Storage Systems
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    • v.2 no.3
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    • pp.196-200
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    • 2006
  • We are developing a phase change etching technology using an inorganic photoresist of GeSbTe film which is the recording material of the phase change disc. A selective etching phenomenon between amorphous and crystalline states can be utilized with an alkaline etchant. Phase-change pits could be formed using this technique, in which the etching selectivity is strongly dependent on the concentration of the etchant. The degree of etching was investigated by the transmittance between crystalline and amorphous films after the wet-etching. The pits patterned on the disc could be observed by AFM after wet-etching.

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Positive Type Photoresist for Patterning of Interdielectric Layer of TFT Array

  • Lee, Hyo-Jung;Kim, Hyo-Jin;Kim, Soon-Hak;Park, Lee-Soon;Lee, Yun-Su;Song, Gab-Deuk
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.564-566
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    • 2007
  • Synthesis of two photoactive compounds containing core imide moiety was carried out for an application to interdielectric layer in TFTLCD array. An aqueous alkaline developable polymer matrix was synthesized by free radical copolymerization. A positive photoresist formulation was developed utilizing synthesized UV monomers, photoactive compound, binder polymer, sulfactant and alkali developable polymer matrix. It was found that via-holes with good resolution, high transmittance and thermal resistance could be obtained by photolithographic process utilizing the new positive interdielectric material with high thermal stability.

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A Study of Mechanical Properties in Compression on High density Graphite Products with Expanded Graphite (고밀도 팽창흑연 성형품의 압축 특성에 관한 연구)

  • Shin, Y.W.
    • Journal of Power System Engineering
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    • v.10 no.1
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    • pp.52-59
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    • 2006
  • Graphite is well known as a material which has high-temperature thermostable property, chemical resistance against acid and alkaline state also is very easy to environment. Nowadays the need of graphite product is increasing rapidly because of its advantages. In this paper, the mechanical property of newly developed graphite products with high density is investigated with especially in compression test. I introduced the graphite specimens for this study by NGF method with two expandable graphite and compared to the specimens of commercial graphite sheet from expanded graphite which made by the rolling process. I investigated the characteristics of these materials by measuring specific weight, hardness, compressive strength and investigating structures by SEM, It is verified that the graphite products with NGF method has superior properties for using gasket materials than that of commercial graphite sheet.

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A Comparative Investigation on Alkaline Peroxide Mechanical Pulp of Poplar Fast-Growing Clones and a Native Species

  • Ramezani, Omid
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06b
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    • pp.349-352
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    • 2006
  • The conventional pulping processes in Iran were reviewed in this paper. On account of forest resources restriction, a considerable extent of non-harvestable hardwood forests, the possibility of accessable non-wood resources and Poplar fast-growing species for using in pulp and paper industry was investigate. The cultivated area and abundance of each mentioned raw material (Wheat Straw, Sugarcane Bagasse, Poplars) were specified and the quality of their produced papers were compared in strength and opacity properties. Spruce species data was used for experiments comparisons. Regarding to environmental pollutions, low yield, inflexibility in wood and non-wood species resulted from the existent conventional processes of paper manufacturing, APMP is recommended due to high quality paper, desirable opacity properties, high yield and also the usage for all the raw materials.

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Mechanochemical Approach for Oxide Reduction of Spent Nuclear Fuels for Pyroprocessing

  • Kim, Sung-Wook;Han, Seung Youb;Jang, Junhyuk;Jeon, Min Ku;Choi, Eun-Young
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.19 no.2
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    • pp.255-266
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    • 2021
  • Solid-state mechanochemical reduction combined with subsequent melting consolidation was suggested as a technical option for the oxide reduction in pyroprocessing. Ni ingot was produced from NiO as a starting material through this technique while Li metal was used as a reducing agent. To determine the technical feasibility of this approach for pyroprocessing, which handles spent nuclear fuels, thermodynamic calculations of the phase stabilities of various metal oxides of U and other fission elements were made when several alkaline and alkali-earth metals were used as reducing agents. This technique is expected to be beneficial, not only for oxide reduction but also for other unit processes involved in pyroprocessing.

The Coating Performance of UV Curable Urethane Acrylate Coatings for Fancy Veneer Overlayed Plywood Flooring

  • Lee, Byoung-Hoo;Kim, Hyun-Joong;Lee, Young-Kyu
    • Journal of the Korean Wood Science and Technology
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    • v.32 no.6
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    • pp.23-35
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    • 2004
  • The goal of study was to investigate the influence of the acrylated urethane oligomer on mechanical properties, the chemical resistance and thermal resistance of the UV curable urethane acrylate coatings for fancy veneer overlayed plywood flooring. The pencil hardness and abrasion resistance of the coated fancy veneer overlayed plywood floorings increased with increasing the acrylate functionality of the acrylated urethane oligomer. In the case of the UV cured film containing hexa-functional acrylated aliphatic urethane oligomer, high discoloration of the coated fancy veneer overlayed plywood flooring was observed near the cracks at the beginning of the chemical treatment. In this study, it was found that the degradation of the UV cured film caused by an alkaline reagent was higher than that of the UV cured film caused by an acidic treatment.

INVESTIGATION OF "STEPPED" DISCHARGE CURVES IN SINTERED TYPE NICKEL-CADMIUM CELL

  • SASAKI, Y.;YAMASHITA, T.
    • Journal of the Korean institute of surface engineering
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    • v.32 no.3
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    • pp.360-362
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    • 1999
  • Formation of the nickel-cadmium alloy in the negative electrode of nickel-cadmium cell subjected to continuous charging at elevated temperatures ($40~45^{\circ}C$) is shown to be one of the causes of the 'stepped' discharge curves. The alloy has been characterized by electrode potential measurement and X-ray diffraction method. The potential lowering during discharge is related to discharge of the alloy. X -ray diffraction suggests that the nickel-cadmium alloy can be formed during charge in negative electrode by interaction of the two metals. Addition of Ni $(OH)_2$ into $Cd{\;}(OH)_2$ active material is found to form the alloy more readily than sintered negative electrode alone.ode alone.

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Mechanical Properties of Cement Paste according to the amount of Red mud Neutralized with Sulfuric Acid (황산 중화 레드머드 첨가량에 따른 시멘트 페이스트의 역학적 특성)

  • In, Byung-Eun;Kim, Sang-Jin;Kang, Suk-Pyo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.04a
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    • pp.21-22
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    • 2022
  • In order to improve the strength degradation of the cement-based material to which strong alkaline liquid red mud was added, the liquid red mud was neutralized with sulfuric acid and added to the cement paste to examine the mechanical properties according to the amount added. As a result of measuring the compressive strength, the strength was higher when the red mud was neutralized with sulfuric acid and added to the cement paste than the cement paste to which the liquid red mud was added. As a result of hydration heat measurement, when red mud was neutralized with sulfuric acid and added to the cement paste, an initial strength higher than that of liquid red mud was expressed.

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