• Title/Summary/Keyword: reductant

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A Study on Permanent Wave Form According to the Reductant (퍼머넨트 웨이브의 형태 변화에 미치는 환원제의 영향)

  • Bea, Young-Sil
    • Fashion & Textile Research Journal
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    • v.7 no.6
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    • pp.641-649
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    • 2005
  • This study is to make pH 9 reduction by adding NaOH to 1, 3, 5, 7, 9, 11% solution of thioglycollic acid, cysteine, cysteamin, to add it on helically winded natural hair and colored hair and leave them for 20, 40, 60 minutes, to add $NaBrO_3$ oxidant for 15 minutes and to compare and analyze the wave form. This study showed the results of permanent using thioglycollic acid, cysteine, cysteamin. In the permanent wave form according to the kind of reductant, concentration, and processing time, there were a little difference between thioglycollic acid and cysteine. But cysteamine not only showed apparent difference but also formed strong and elastic wave. The permanent wave is affected by the diagonosis of hair, the choice of permanent solution and the processing time. Therefore the scientific diagonosis of hair is to be considered first of all. By choosing the kind of solution, the concentration and the processing time according to the results of hair diagonosis and wave form, we can prevent the lengthening and damage of hair.

Preparation and Optical Properties of Ag-Coated Cu Powder by Dropping Method of Coating Agent (피복제 적하법에 의한 Ag 피복 Cu 미립자의 제조 및 광학적 특성)

  • Yu, Yeon-tae
    • Korean Journal of Materials Research
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    • v.13 no.9
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    • pp.555-560
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    • 2003
  • Ag-coated Cu particles were prepared by dropping method of coating agent and were evaluated by scanning electron microscope and color difference meter. The shape of Cu particles having obvious crystal plan and edge was changed spherically according to the increase of Ag coating amount. When the Ag coating amount was 50 wt% to Cu particles, the whiteness of Ag-coated Cu particles was almost similar to that of pure Ag particles. Adding $NH_4$OH in reductant solution could increase effectively the whiteness of the Ag-coated particles. The Ag-coated particles having the highest whiteness was obtained when the content of hydrazine in reductant solution was 0.48 M.

Synthesis of Ag-Pd Alloy Nanoparticles by Chemical Reduction Method (화학환원법을 이용한 Ag-Pd 합금 나노분말의 합성)

  • Seo, Won-Sik;Kim, Yun-Do;Choung, Il-Yeop;Lee, Ho-Seok;Song, Ki-Chang
    • Journal of the Korean Ceramic Society
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    • v.43 no.4 s.287
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    • pp.224-229
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    • 2006
  • Ag-Pd alloy nanoparticles were prepared by a chemical reduction method using hydrazine $(N_2H_4)$ as a reductant in $AgNO_3\;and\;Pd(NO_3)_2$ aqueous solutions. Characterization of these particles by X-ray powder diffraction revealed a bimetallic and crystalline silver-palladium alloy. The average size of the particles was influenced not by the reductant $(N_2H_4)$ concentration, but the concentration of the starting materials $(AgNO_3\;and\;Pd(NO_3)_2)$.

Facile Preparation of Silver Nanoparticles and Application to Silver Coating Using Latent Reductant from a Silver Carbamate Complex

  • Kim, Kyung-A;Cha, Jae-Ryung;Gong, Myoung-Seon
    • Bulletin of the Korean Chemical Society
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    • v.34 no.2
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    • pp.505-509
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    • 2013
  • A low temperature ($65^{\circ}C$) thermal deposition process was developed for depositing a silver coating on thermally sensitive polymeric substrates. This low temperature deposition was achieved by chemical reduction of a silver alkylcarbamate complex with latent reducing agent. The effects of acetol as a latent reducing agent for the silver 2-ethylhexylcarbamate (Ag-EHCB) complex and their blend solutions were investigated in terms of reducing mechanism, and the size and shape of silver nanoparticles (Ag-NPs) as a function of reduced temperature and time, and PVP stabilizer concentration were determined. Low temperature deposition was achieved by combining chemical reduction with thermal heating at $65^{\circ}C$. A range of polymer film, sheet and molding product was coated with silver at thicknesses of 100 nm. The effect of process parameters and heat treatment on the properties of silver coatings was investigated.

Characteristics of Nickel-Diamond Composite Powders by Electroless Nickel Plating (무전해 니켈 도금법으로 제조된 니켈-다이아몬드 복합분체의 특성)

  • ;;Hoang Tri Hai
    • Journal of Powder Materials
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    • v.11 no.3
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    • pp.224-232
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    • 2004
  • Ni-diamond composite powders with nickel layer of round-top type on the surface of synthetic diamond (140/170 mesh) were prepared by the electroless plating method (EN) with semi-batch reactor. The effects of nickel concentration, feeding rates of reductant, temperature, reaction time and stirring speeds on the weight percentage and morphology of deposited Ni, mean particle size and specific surface area of the composite powders were investigated by Atomic Adsortion Spectrometer, SEM-EDX, PSA and BET. It was found that nucleated Ni-P islands, acted as catalytic sites for further deposition and grown into these relatively thick layers with nodule-type on the surface of diamond by a lateral growth mechanism. The weight percentage of Ni in the composite powder increased with reaction time, feeding rate of reductant and temperature, but decreased with stirring speed. The weight percentage of Ni in Ni-diamond composite powder was 55% at 150 min., 200 rpm and 7$0^{\circ}C$ .

A Study on the Reduction of Iron Oxide from Slag in the EAF Process (전기로 공정에서 슬래그 중 산화철의 환원 회수에 관한 연구)

  • Kim, Young-Hwan;Yoo, Jung-Min
    • Resources Recycling
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    • v.25 no.4
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    • pp.54-59
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    • 2016
  • EAF processed slag which contains about 20 ~ 35 weight percent FetO is poured to slag pot and cooled. If we recover Fe from molten slag by the reduction, we will improve steel yield rate and reduce slag quantity poured from the furnace. Usually, carbon is used as a reductant and slag foaming agent in the EAF process. In this experiment, after melt the metal in induction furnace and then add slag with carbon and Al dross powder as a reductant, we investigated the reduction of FetO from slag and change of Phophorus content. As the result, when we use Al dross as a reductant, recovery rate is two times more than carbon. Phosphorus pick up is less than 50ppm with reduction of EAF slag.

Effects of Oxidant, Reductant Treatment and Its Phosphorylation on Qualities and Functional Properties of Defatted Rice Bran Protein Isolates (산화.환원제처리 및 인산화가 분리탈지미강단백의 품질 및 기능적 성질에 미치는 영향)

  • Park, Wan-Kyu;Kim, Seung-Yeol;Lee, Ka-Sun
    • Korean Journal of Food Science and Technology
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    • v.20 no.1
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    • pp.106-111
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    • 1988
  • Comparative effects of oxidant, reductant treatment and its phosphorylation on qualities and functional properties of defatted rice bran protein isolates were investigated. Effects of oxidant and reductant treatment were that essential amino acid content of protein isolates was high and its color, pepsin digestibility were good. The phosphorylated defatted rice bran protein isolated was taken by incubating sodium trimeta phosphate in aqueous solution at pH 10.5 and $35^{\circ}C$ for 3 hours and its protein score was 55. Functional properties such as solubility, whipping activity and foam stability were much improved. But color, pepsin digestibility, bulk density and fat absorption were not affected by phosphorylation.

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A Study on the Optimal Analytical Method for the Determination of Urinary Arsenic by Hydride Generation-Atomic Absorption Spectrometry (HG-AAS법에 의한 요중 비소의 최적 분석법에 관한 연구)

  • Lee, Jong-Wha;Lee, Ui-Seon;Hong, Sung-Chul;Jang, Bong-Ki
    • Journal of Environmental Health Sciences
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    • v.35 no.5
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    • pp.402-410
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    • 2009
  • This study was carried out to examine the optimal analytical method for determination of urinary toxic arsenic (inorganic arsenic and its metabolites) by HG-AAS (hydride generation-atomic absorption spectrometry). In the analysis of SRMs (standard reference materials), method E (addition of 0.4% L-cysteine to pre-reductant and use 0.04M HCl as carrier acid) showed the most accurate results compared with the reference values. In the analysis of 30 urinary samples, analytical results were significantly different depend on the component of pre-reductant and the concentration of carrier acid. When the concentration of carrier acid was higher, the analytical result was lower. The recovery rates of MMA (monomethylarsonic acid) and DMA (dimethylarsenic acid) were varied by the concentration of pre-treatment acid and carrier acid and hydride generation reagents. When the concentration of carrier acid was 1.62 M (5% HCl), the recovery rates of DMA was 1%. The recovery rates of MMA and DMA in method E (=V) were 102% and 100%, respectively. The results of this study suggest that the component and concentration of pre-reductant and carrier acid must be carefully adjusted in the analysis of urinary arsenic, and method E is recommendable as the most precise analytical method for determination of urinary toxic arsenic.