• Title/Summary/Keyword: reducing agents

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Comparison of Quality Standards of Chemical Admixtures for Concrete between Korea and China (한국과 중국의 콘크리트용 화학 혼화제 품질 규정 비교)

  • Hu, Yun-Yao;Lim, Gun-Su;Kim, Jong;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.97-98
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    • 2023
  • In this study, comparison of the quality standard of chemical admixtures between Korea and China is conducted. It is classified into three types of water reducing agents: standard, delayed, and accelerated according to the sensitivity and strength improvement of the sensitivity and strength of the agent. However, Chinese standards classify reducing agents only as standard, high efficiency, and high performance, and do not add AE agents into water reducing agent. On the other hand, that of Korea has a classification regulation for reducing agents added with AE agents.

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Effects of Reducing Agents on Textural Changes and Protein Modification in Extruded Wheat Gluten (압출성형시 환원제 첨가에 의한 밀가루 글루텐의 조직 변화와 단백질의 변성)

  • 고봉경
    • Journal of the East Asian Society of Dietary Life
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    • v.6 no.2
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    • pp.213-219
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    • 1996
  • Addition of reducing agents during extrusion markedly affected physical and chemical properties of wheat flour and gluten extrudates. Expansion at the die was increased for wheat flour and gluten extrudates. Organic materials containing sulfur were evaporated as a flavor from gluten at the die and total sulfur contents were decreased. Physical shape was different for gluten extrudates without reducing agents. It was difficult to form the long strand of gluten extrudate without cooling die. Hydroquinone accelerated cell breakdown and produced more irregular shape of extrudate. However, addition of cysteine decreased the cell breakdown and produced the long strand of gluten extrudates. Chemical reactions of reducing agents such as cysteine and hydroquinone were different for high content (<80%) of wheat gluten. It was assumed that reducing agents donated hydrogen to inhibit the formation of disulfide crosslinking, decreased the dough strength and produced the broken cell and irregular shape of extrudates. Whereas, cysteine reacted as a binder as well as reducing agent and formed long strands. The evidence of reaction of reducing agents was shown from the fact that non-protein disulfide was increased and protein disulfide was slightly decreased from cysteine added gluten extrudate.

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An Experimental Study on the Fluidity Evaluation of Mortar in accordint to kinds of Cements and High Range Water Reducing Agents (시멘트 및 고성능감수제의 종류에 따른 유동성평가에 관한 실험적 연구)

  • 김규용;여동구;이정률;우영제;강석표;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.23-26
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    • 1999
  • The properties of concrete can be affected by high range water reducing agent and cement. The data for compatibility and effect of fluidity is reported already according to the mixing proportion of kinds of cements and high range water reducing agents. Moreover, the international market of construction has been opened, the international standard of capability has been promoted and the international exchange of construction materials has been brisked. This study investigated fluidity properties of mortar due to kinds of cements and high range water reducing agents which are producted in different nations. Also studied were the compatibility effect of cements and high range water reducing agents.

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Effect of horseradish, mushroom waste and almond hull on the concentrations of odorous compounds in swine manure for spreading on grassland in spring

  • Hwang, Ok-Hwa;Han, Deug-Woo;Lee, Sang-Ryoung;Kwag, Jeong-Hoon;Lim, Joung-Soo;Cho, Sung-Back
    • Korean Journal of Agricultural Science
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    • v.43 no.4
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    • pp.589-594
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    • 2016
  • The objective of the current study was to investigate the effect of odor reducing agents on the levels of pH, total carbon, total nitrogen, and odorous compounds [phenols, indoles, short chain fatty acid (SCFA), branched-chain fatty acid (BCFA), and ammonium nitrogen] of swine manure during the spring season (temperature around $20^{\circ}C$). Odor reducing agents included horseradish powder, mushroom waste powder, and almond hull powder. A manure sample (15 L) was taken from the pit under the pens of a swine feeding operation and incubated with 0.03% horseradish powder, 1% mushroom waste powder, and 1% almond hull powder, respectively, in acryl chambers for 14 days. Addition of almond hull powder showed the lowest pH (p < 0.05) and the highest level of total carbon (p < 0.05) among treatments of odor reducing agents. Although addition of odor reducing agents increased the level of phenols (p < 0.05), addition of almond hull powder decreased the level of indoles (p < 0.05). Levels of SCFA and BCFA were higher in almond hull powder than those in control (p < 0.05). Taken together, the results from our current study showed that odor reducing agents can be used for reducing the odor of swine manure by providing fermentable carbohydrates. At $20^{\circ}C$, however, the function of odor reducing agents might be decreased due to lower microbial activity.

Analysis of the Possibility of Rapid Quality Appraisal of Water-Reducing Agents Using the Liquid Densimeter and pH Meter (액체 밀도계 및 pH meter기를 이용한 감수제의 신속품질평가 가능성 분석)

  • Kim, Min-Sang;Hyun, Seong-Yong;Baek, Cheol;Jo, Man-Ki;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.210-211
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    • 2017
  • According to KS F 2560, water-reducing agents used when mixing concrete are to undergo quality evaluation testing slump, air contents, setting time, etc., when delivered from the admixture factory to the ready mixed concrete site. Yet in actual acceptance testing this could be substituted by the score report of the admixture company, in which a possibility of low reliability lies. Therefore this study sought to analyze whether by artificially changing the solid content rate of lignin- and naphthalene-based water-reducing agents and using a liquid densimeter evaluate the quality of the admixture. The results showed that the Type B liquid densimeter was most appropriate and 50cc the most appropriate capacity for the mass cylinder. Also, judging from the changes in density and pH according to the changes in solid content rate, it concludes that a rapid appraisal of the quality of lignin- and naphthalene-based water-reducing agents would be possible using a Type B liquid densimeter.

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Utilization of Tobacco Sucker Control Agents in China

  • Li, Hu-lin
    • Journal of the Korean Society of Tobacco Science
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    • v.25 no.2
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    • pp.154-159
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    • 2003
  • Using sucker agents for tobacco can lead some advantages including saving labor, increasing yield and reducing the spread of diseases. At present, the sucker control agents used in China mainly depended on importing. The agents includes two groups, systemics (Maleic hydrazide: MH, etc) and partial systemics (Butralin, Flumetralin, Pendimethalin, etc). Now, Pendimethalin(a.i. 33%, wp) was used extensively all over the tobacco field in China. Sucker control agents will also be used for tobacco production in China. Because of the high price of the imported agents, China has studied on the domestic production of tobacco sucker control agents and has made some progresses.

Effect of Reducing Agents on Bifidobacterium Fermentation of Saccharified Rice Solution (환원제 첨가가 쌀당화액의 Bifidobacterium발효에 미치는 영향)

  • 이주연;목철균;박종현;장학길
    • Microbiology and Biotechnology Letters
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    • v.27 no.3
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    • pp.230-235
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    • 1999
  • This study was intended to develop a new rice product by the fermentation of saccharified rice solution using Bifidobacterium and to select an appropriate reducing agent to provide the anaerobic condition for the growth of Bifidobacterium during fermentation. The enhancement of the growth of Bifidobacterium in saccharified rice solution was achieved by the treatment of reducing agents such as ascorbic acid and cysteine. The physical and chemical properties of the fermented product were evaluated, and the effect of the reducing agents were compared between ascorbic acid and cysteine. The fermented product with the addition of ascorbic acid shows the lower pH and the higher titratable acidity comparing the product with the addition of cysteine. This indicated that ascorbic acid was more appropriate reducing agent than cysteine for the fermentation of the saccharified rice solution. The number of viable Bifidobacterium in the fermented product with the addition of ascorbic acid(2.2$\times$108~3.4$\times$108CFU/ml) was greater than that with the addition of cysteine (8$\times$107~2.8$\times$108CFU/ml). Ascorbic acid supplement also contributed better sensory properties, such as flavor, taste and overall acceptibility than cysteine supplement did.

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Synthesis of ZnO:Zn Phosphors with Reducing Atmosphere and Their Luminescence Properties (환원분이기에 따른 ZnO:Zn 형광체의 합성 및 그 형광 특성)

  • 김봉철;백종봉;한윤수;이남양;이병교
    • Journal of the Korean Ceramic Society
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    • v.37 no.1
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    • pp.1-5
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    • 2000
  • Cathodoluminescence(CL) properties of ZnO:Zn green phosphor were investigated. ZnO:Zn phosphor was synthesized by varying reducing agents and firing temperatures. ZnS, charcoal and 5% H2 gas mixed with 95% N2 gas(5H2-95N2) were used as the reducing agent and atmosphere. The highest CL intensity of ZnO:Zn phosphor was observed under the condition of 5H2-95N2 atmosphere and firing temperature of 90$0^{\circ}C$ for 1h. Charocal and ZnO as reducing agents in the syntehsis of ZnO:Zn phosphor exhibited about 60% and 40%, respectively, of the CL intensity obtained with 5H2-95N2 atmosphere.

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Recent Progress in Electroless Plating of Copper

  • Sharma, Ashutosh;Cheon, Chu-Seon;Jung, Jae Pil
    • Journal of the Microelectronics and Packaging Society
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    • v.23 no.4
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    • pp.1-6
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    • 2016
  • In this article, the recent developments in electroless plating of copper, electroless bath formulation and effect of plating parameters have been reviewed. Cyanide free electroless baths are now being developed and studied due to the various environmental concerns. Various organic chemicals such as complexing agents, reducing agents, and additives such as poly-alcohols and aromatic ring compounds have been added to copper plating baths for promising results. The effects of various reducing and complexing agents, bath conditions like additives, bath pH, and composition have been summarized. Finally the applications of the electroless plating of copper and latest developments have been overviewed for further guidance in this field.