• Title, Summary, Keyword: mixing ratio

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Experimental Studies on the Characteristics of Foaming Mortar(II) -Part 2 Characteristics of Strength and Air Content- (기포모르터의 제특성에 관한 실험적 연구 (II) -제2보 강도와 공기량 특성-)

  • 성찬용
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.30 no.3
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    • pp.106-113
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    • 1988
  • This study was performed to obtain the basic data which can be applied to use of foamihg mortars. 1. At the mixing ratio 1:1, the highest strengths were showed by foaming mortam, respec - tively. But, it. gradually was decreased in poorer mixing ratio and more addition of foam- ing agent. The decreasing rates of strengths were incresed in poorer mixing ratio and more addition of foaming agent. 2. The strengths were decreased up to 77.0-92.8% by mix-foaming type and 36.7-74.4% by pre-foamed type than cement mortar. 3. At the mixing ratio of 1:1, the lowest air contents were showed by foaming mortars, respectively. But, it gradually was increased in poorer mixing ratio and more addition of foaming agent. The increasing rates of air contents were increased in richer mixing ratio and more addition of foaming agent. 4. Air contents were showed up to 26.0-63.8 times by mix-foaming type and 5.8-17.7 times by pre-foamed type than cement mortar, respectively. 5. The correlations between compressive strength and air content were highly significant, respectively. The multiple regression equations of strengths and air content were computed depending on a fuction of mixing ratio and addition of foarning agent. It was highly significant, respectively.

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Experimental Studies on the Characteristics of Foaming Mortar(I)- Part 1 characteristics of bulk density and absorption rate - (기포모르터의 제특성에 관한 실험적 연구-제1보 밀도와 흡수율 특성)

  • 성찬용
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.30 no.1
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    • pp.73-80
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    • 1988
  • This study was performed to obtain the basic data which can be applied to use of foaming mortars. The results obtained were Summarized as follows; 1.At the mixing ratio of 1:1, the highest bulk densities were showed by foaming mortars, respectively. But, it gradually was decreased in poorer mixing ratio and more addition of foaming agent. The decreasing rates of bulk densities were increased in richer mixing ratio and more addition of foaming agent. 2.The bulk densities were decreased up to 38.8-55.9% by mix-foaming type and 9.7-23.6% by pre-foamed type than cement mortar. 3.At the mixing ratio of 1:1, the lowest absorption rates were showed by foaming mortars, respectively. But, it gradually was increased in poorer mixing ratio and more addition of foaming agent. The increasing rates of absorption rates were increased in richer mixing ratio and more addition of foaming agent. 4.Absorption rates when immersed in 72hours were showed up tp 3.41-5.85 times by mix-foaming type and 1.05- 1.S5times by pre -foamed type than cement mortar, it was significantly higher at the early stage of immersed time than cement mortar. 5.The correlations between bulk density and absorption rate were highly singnificant, respectively. The multiple regression equations of bulk density and absorption rate were computed depending on a fuction of mixing ratio and addition of foaming agent. it was highly significant respectively.

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Fundamental Study on Evaluation method of Activity Factor of Fly Ash (플라이애시의 활성도지수 평가에 관한 기초적 연구)

  • Park, Sang-Joon
    • Journal of the Korea Institute of Building Construction
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    • v.8 no.5
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    • pp.59-65
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    • 2008
  • In the evaluation method of KS on the activity factor of fly ash, same amount of cement should be replaced with fly ash. Therefore, contradictory effects on concrete strength exist, i. e. strength decease due to low content of cement and strength increase of strength due to filling-pore-function of fly ash. European Committee for Standardization (CEN) specifies the method 1 to 4. adding fly ash without reducing the content of cement, for the evaluation method on activity factor of fly ash. This study investigates the applicability of the method 2 of CEN to mix design of concrete. The followings are derived ; There is a key ratio of f)y ash mixing which enhances the incremental ratio of mixing water to improve fluidity of mortar. The incremental ratio of mixing water is maximized about 11% ratio of fly ash mixing. Compressive strength most slightly increases at that ratio of fly ash mixing. Activity factor of fly ash increases as water-cement ratio becomes low and contents of fly ash becomes high. Moreover, quality of fly ash and condition of mix design affect the applicable amount of fly ash and available range of water-cement ratio. However, this method has some problems for practical purpose because activity factors of fly ash for some cases are over 1.0. Further research should be conducted to develop more useful method of evaluating activity factor of fly ash.

Compressive Strength and Optimal Mixing Ratio of Alkali Activated Cement Concrete Containing Fly Ash (플라이 애쉬를 활용한 알칼리 활성시멘트 콘크리트의 압축강도와 최적혼합비)

  • Han, Sang-Ho;Park, Sang-Sook;Kang, Hwa-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.4
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    • pp.152-158
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    • 2007
  • This is a fundamental research to utilize alkali activated cement(AAC) in concrete. The compressive strength of AAC concrete were measured for the various mixing ratios of activator/fly ash, and the mixing ratios of water glass, NaOH, and water among the activators. The mixing ratio of fine and coarse aggregates was maintained constantly. The relationships between the compressive strength and mixing ratios were analyzed to find the optimal mixing ratio of AAC concrete. As the results, the optimal mixing ratio of activator/fly ash in AAC concrete was 0.7, and that of water glass, NaOH, water among the activator was 4.0:1.0:2.5 for the maximum compressive strength.

Effects of Mixing of Recycled Newspaper and Rice Straw on Physical Properties of Packaging Trays (신문고지와 볏짚의 혼합이 포장 트레이의 물성에 미치는 효과)

  • Ahn, Byoung-Kuk
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.3 no.2
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    • pp.17-23
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    • 1996
  • Packaging trays were manufactured with recycled newspaper and rice straw to investigate the effect of mixing ratio of rice straw pulp on physical properties of the trays. The apparent density of the trays increased gradually with increasing mixing ratio of rice straw pulp and the bursting strength increased at the mixing ratio of above 40%. The results showed that the trays made from 100% rice straw pulp had the highest bursting strength and the trays with the mixing ratio of 20% and 100% had high compression strength. The air resistance of the trays decreased with increasing mixing ratio until 80%. As the mixing ratio of rice staw pulp in the trays increased, L value in color decreased and b value increased.

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Characteristics of Microfauna in Biological Treatment of Landfil Leachate with Reactor Including Porous Media (다공성 Media가 조여된 반응조를 이용한 매립지 침출수의 호기성 생물학적 처리시 미소생물상의 특성)

  • 홍성철;박연규
    • Journal of Environmental Science International
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    • v.5 no.1
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    • pp.61-69
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    • 1996
  • The combined wastewater of municipal landfill leachate and municipal sewage was treated using several sets of bench-scale aerated circulating system including porous media. Investigated items in this experiment were the dominant protozoa and metazoa in this system, the variation of microfauna relationship between operating condition and dominant genera. Also considered the factors determining dominant genera and their role. The outcome of this research is as follows; 1. Aspidisca, Vorticella, Truhellophyllum, Lecane, Philodina, Cyclops were mainly appeared prior to combinding leachate, while Trachelocerca, Bodo, Glaucoma were the dominant genera after combinding leachate. 2. As to metazoa, Nematode and Philodina were not influenced by 5oA leachate mixing ratio, meanwhile Crustacea has high sensitivity for increased leachate mixing ratio and it was not appeared in 5% leachate mixing ratio. 3. The appropriate treatability could'nt be expected at the above 10% leachate mixing ratio. Especially, in the condition of 20% leachate mixing ratio, all of the microfauna were affected damage seriously on their existence. Meanwhile hydraulic retention time, substrate loading rate and slut자e production rate didn't give notable influence on increasing the number of microfauna. 4. As to protozoa, saprozoic and holozoic species were appeared commonly and polysaprobic species were dominent. 5. Filamentous organsms were nearly not affected by leachate mixing. It seems that they could live without any trouble at the 10% leachate mixing ratio, if the substrate is sufficient. 6. Diversity of microfauna had a reducing trernd as the sewage was mixed with leachate.

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Abnormal Discharge Characteristics of Fluorescent Lamp

  • Lee, Chang-Ho;Kang, Jae-Kyung;Jang, Eun-Seok;Kim, Jae-Bum;Park, Joon-Ha;Shin, Jong-Keun;Chung, In-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.1425-1427
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    • 2009
  • In this paper, we investigated influence of gas pressure and gas mixing ratio on the abnormal discharge characteristics of fluorescent lamp. Abnormal discharge characteristics have been examined by changing inner gas pressure and mixing ratio. As the inner gas pressure and mixing ratio increase, the occurrence of abnormal discharge was delayed. It was found out that the occurrence of abnormal discharge is sufficiently delayed at the optimized inner gas pressure and mixing ratio.

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A Study on Strength and Permeability of Cooper Slag mixed Porous Concrete (동제련 슬래그를 혼입한 포러스 콘크리트의 강도 및 투수성능에 관한 연구)

  • Shim, Byung-Ju;Kim, Young-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • pp.69-72
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    • 2011
  • The purpose of this study is to identify basic property of porous concrete using cooper slag as fine aggregate. The specimens were made with cooper slag with various mixing ratio(10, 20, 30, 50%), porous concrete and porous concrete containing river fine aggregate and crushed fine aggregate, which W/B ratio fixed 0.25. Compressive strength, Flexural strength, coefficient of permeability. From the test results, various fine aggregate mixing ratio improves compressive strength and flexural strength, but cooper slag fine aggregate mixing ratio over 20%, concrete indicates trend to decrease performance of permeability. Concrete containing fine aggregate is improved the performance of permeability and strength compared to other specimen, when age 28days, and cooper slag mixing ratio less than 20% concrete indicates better performance than cooper slag mixing ratio 20% over.

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Relationship between Mixing Ratio by DNA Analysis and Rice Palatability on Commercial Brands of Rice (브랜드쌀의 DNA 판별에 의한 혼용율과 식미와의 연관성 분석)

  • Kim, Chae-Eun;Nam, Yean-Ju;Kang, Mi-Young
    • Korean journal of food and cookery science
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    • v.25 no.2
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    • pp.260-265
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    • 2009
  • The influence of mixing ratio of 25 commercial rice varieties was evaluated by DNA analysis and Toyo value palatability. No relationship was evident between rice palatability and various grain quality properties, or between palatability and mixing ratio. A positive relationship was evident between palatability and texture and between palatability and chalky rice ratio. A negative relationship was evident between mixing ratio and amylose content.

Performance and Feasibility Evaluation of Straight-Type Mixing Head in High-Pressure Resin Transfer Molding Process of Carbon Fiber Reinforced Composite Material (탄소 섬유강화 복합소재의 고압 수지이송 성형공정에서 직선형 믹싱헤드의 성능 및 유용성 평가)

  • Han, Beom Jeong;Jeong, Yong Chai;Hwang, Ki Ha;Kang, Myung Chang
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.5
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    • pp.157-165
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    • 2017
  • The high-pressure resin transfer molding (HP-RTM) technology has been commercialized for fast production of fiber reinforced composite materials. The high-pressure mixing head was one of the most core component of the HP-RTM process. In this study, a mixing head was systematically designed, manufactured and evaluated. This mixing head was composed of a nozzle, a mixing chamber, a cleaning piston part, and an internal mold release part. In actual, a straight-type structure was newly designed instead of the conventional L-type structure for improving the maximum mixing pressure and mixing ratio precision. The performance of mixing head was showed maximum mixing pressure of 15.22MPa and mixing ratio precision of 0.12%. CFRP molding experiments were successfully obtained a 6~11 laminating carbon sheet using HP-RTM presses and specimen molds.