• Title/Summary/Keyword: NSC

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Study on Mock-up test for field application of High Strength Concrete using Non-Sintered Cement (비소성시멘트를 사용한 고강도 콘크리트의 현장적용을 위한 모의부재에 관한 연구)

  • Kim, Han-Sik;Han, Da-Hee;Kim, Kwang-Ki;Paik, Min-Su;Mun, Kyoung-Ju;Jung, Sang-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2006.11a
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    • pp.33-36
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    • 2006
  • This Study is based on manufacture non-sintering cement(NSC) by adding phosphogysum and waste lime to GBFS as sulfate and alkali activators. This study also investigates the basic physical properties and duality of NSC, and evaluates its reusing possibility as construction materials. Therefore, we design 40MPa and 60MPa for compressive strength using OPC and NSC by binder. And There is a purpose to present fundamental data, applying in field and analyzing quality control of concrete using NSC according to rate of replace between OPC and NSC.

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Improving design limits of strength and ductility of NSC beam by considering strain gradient effect

  • Ho, J.C.M.;Peng, J.
    • Structural Engineering and Mechanics
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    • v.47 no.2
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    • pp.185-207
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    • 2013
  • In flexural strength design of normal-strength concrete (NSC) beams, it is commonly accepted that the distribution of concrete stress within the compression zone can be reasonably represented by an equivalent rectangular stress block. The stress block it governed by two parameters, which are normally denoted by ${\alpha}$ and ${\beta}$ to stipulate the width and depth of the stress block. Currently in most of the reinforced concrete (RC) design codes, ${\alpha}$ and ${\beta}$ are usually taken as 0.85 and 0.80 respectively for NSC. Nonetheless, in an experimental study conducted earlier by the authors on NSC columns, it was found that ${\alpha}$ increases significantly with strain gradient, which means that larger concrete stress can be developed in flexure. Consequently, less tension steel will be required for a given design flexural strength, which improves the ductility performance. In this study, the authors' previously proposed strain-gradient-dependent concrete stress block will be adopted to produce a series of design charts showing the maximum design limits of flexural strength and ductility of singly-and doubly-NSC beams. Through the design charts, it can be verified that the consideration of strain gradient effect can improve significantly the flexural strength and ductility design limits of NSC beams.

Effect of Dietary Intake of Ultra-fine or Nano-Scale Pulverized Cornstarch on the Growing Performance and Gut Function in Rats (Nano-Scale Pulverizer (NSP)와 Ultra-Fine Pulverizer (UFP)로 물리적 변성된 옥수수전분 섭취가 흰쥐의 성장능력 및 장기능에 미치는 영향)

  • Lee, Hye-Sung;Ju, Da-Nim;Kim, Bo-Ram;Kim, Sun-Hee;Han, Myung-Ryun;Kim, Myung-Hwan;Chang, Moon-Jeong
    • Journal of Nutrition and Health
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    • v.42 no.8
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    • pp.740-749
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    • 2009
  • The objectives of this study was to determine whether a new physically modified cornstarch by ultra-fine- or nanoscale pulverizer to reduce particle size offers better bioactive function than native cornstarch in weanling Sprague-Dawley rats. Male weaning Sprague-Dawley rats were fed diets containing native cornstarch (NAC), ultra fine pulverized cornstarch (UFC) or nano-scale pulverized cornstarch (NSC) for 4 weeks. In vitro rate of starch hydrolysis, growth performance, organ weight, intestine length intestinal proliferation and the fermentation by Bifidobacterium of rat cecum were evaluated. The diet with reduced particle size (UFC or NSC) significantly increased body weight gain and organ weight. Feed efficiency was increased in NSC fed rats and was not affected in UFC fed rats. Intestinal proliferation was decreased in NSC group. Reduction of particle size also increased cecal short chain fatty acid concentration and the growth and acidifying activity of Bifidobacterium. It is concluded that a reduction of particle size of starch granules by physically modification may increase growing performance and gut function.

Predicting shear capacity of NSC and HSC slender beams without stirrups using artificial intelligence

  • El-Chabib, H.;Nehdi, M.;Said, A.
    • Computers and Concrete
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    • v.2 no.1
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    • pp.79-96
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    • 2005
  • The use of high-strength concrete (HSC) has significantly increased over the last decade, especially in offshore structures, long-span bridges, and tall buildings. The behavior of such concrete is noticeably different from that of normal-strength concrete (NSC) due to its different microstructure and mode of failure. In particular, the shear capacity of structural members made of HSC is a concern and must be carefully evaluated. The shear fracture surface in HSC members is usually trans-granular (propagates across coarse aggregates) and is therefore smoother than that in NSC members, which reduces the effect of shear transfer mechanisms through aggregate interlock across cracks, thus reducing the ultimate shear strength. Current code provisions for shear design are mainly based on experimental results obtained on NSC members having compressive strength of up to 50MPa. The validity of such methods to calculate the shear strength of HSC members is still questionable. In this study, a new approach based on artificial neural networks (ANNs) was used to predict the shear capacity of NSC and HSC beams without shear reinforcement. Shear capacities predicted by the ANN model were compared to those of five other methods commonly used in shear investigations: the ACI method, the CSA simplified method, Response 2000, Eurocode-2, and Zsutty's method. A sensitivity analysis was conducted to evaluate the ability of ANNs to capture the effect of main shear design parameters (concrete compressive strength, amount of longitudinal reinforcement, beam size, and shear span to depth ratio) on the shear capacity of reinforced NSC and HSC beams. It was found that the ANN model outperformed all other considered methods, providing more accurate results of shear capacity, and better capturing the effect of basic shear design parameters. Therefore, it offers an efficient alternative to evaluate the shear capacity of NSC and HSC members without stirrups.

Effect of Bee Venom on Glutamate-mediated Excitotoxicity in NSC-34 Motor Neuronal Cells (Glutamate 매개 흥분성 신경독성에 대한 봉독의 NSC-34 신경세포사멸 억제 효과)

  • Lee, Sang-Min;Choi, Sun-Mi;Jung, So-Young;Yang, Eun-Jin
    • YAKHAK HOEJI
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    • v.55 no.5
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    • pp.385-390
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    • 2011
  • Bee venom (BV), which is extracted from honeybees, has been used in traditional Korean medical therapy. Glutamate-mediated excitotoxicity contributes to neuronal death in neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) or Alzheimer's disease (AD). This study is to investigate the effect of BV on glutamate-induced neurotoxicity on NSC-34 motor neuron cells. To determine the viability of motor neuronal cells, we performed with MTT assays in glutamate-treated NSC-34 cell with BV or without. For the measurement of oxidative stress, DCF assay was used in glutamate-treated NSC-34 motor neuronal cells with BV or without. To investigate the molecular mechanism of BV against glutamate-mediated neurotoxicity in NSC-34 cells, western blot analysis was used. Glutamate significantly decreased cell viability by glutamate dose- or treatment time-dependent manner in NSC-34 cells. However, BV pre-treatment dramatically inhibited glutamate-induced neuronal cell death. Furthermore, we found that BV increased the expression of Bcl-2 protein that is anti-apoptotic protein and reduced the generation of oxidative stress. BV has a neuroprotective role against glutamate neurotoxicity by an increase of anti-apoptotic protein. It suggests that BV may be useful for the reduction of neuronal cell death in neuronal disease models.

Antifungal Activities of Crude Extractum from Camellia semiserrata Chi (Nanshancha) Seed Cake Against Colletotrichum musae, Colletotrichum gloeosporioides and Penicillium italicum in vitro and in vivo Fruit Test

  • Meng, Xiangchun;Li, Jun;Bi, Fangcheng;Zhu, Lixue;Ma, Zhiyu
    • The Plant Pathology Journal
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    • v.31 no.4
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    • pp.414-420
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    • 2015
  • Antifungal activities of crude extractum of Nanshancha Seed Cake (NSC), to inactivate postharvest pathogens were investigated. Highest inhibitory rate was found against C. musae, C. gloeosporioides and C. papaya P.Henn, which was much stronger than that by tea saponin. Compared to tea saponin, effects of NSC extractum was relatively weak and similar on C. gloeosporioides Penzig and P. italicum. In an in vivo study, best controlling effects by NSC extractum was found with banana anthracnose disease development, which showed no inhibitory effects by tea saponin. NSC extractum controlled in vitro C. musae growth through directly inhibiting germination rate and germ tube elongation, and causing distortation, rupture and indentation of C. musae mycelium. In banana fruit subject to C. musae inoculation, higher PAL, POD, GLU and CHT activity was observed in banana fruit treated with crude NSC extractum than that of water control fruits. Current study proved the best controlling effects of crude NSC extractum in C. musae in vitro and in vivo development, which through direct inhibition of C. musae growth and increasing defense system of the banana fruit.

A Study on Early Strength Estimation of High-strength Concrete Using Non-sintering Cement (NSC) (비소성시멘트를 사용한 고강도 콘크리트의 조기강도 추정 연구)

  • Kim, Han-Sik;Lim, Sang-Jun;Kang, In-Seuk;Park, Moo-Young;Mun, Kyung-Ju;Jung, Sang-Jin
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05b
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    • pp.609-612
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    • 2006
  • The quality of the concrete compression strength can be determined after the passage of 28 days, but if any defect is found the quality of concrete after that length of time, there can be serious problems in dismantling and repair. Thus, in response to the use of concrete using non sintering cement (NSC), the present study purposed to propose a method of managing the strength of high strength concrete using NSC in comparison with high strength concrete using ordinary Portland cement (OPC) through early strength estimation using microwave, which enables the quick estimation of the strength of high strength concrete using NSC.

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Pore Structure of Non-Sintered Cement Matrix (비소성 시멘트 경화체의 공극구조)

  • Mun Kyoung-Ju;Park Won-Chun;Soh Yang-Seob
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.329-332
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    • 2004
  • This study aims to manufacture non-sintering cement(NSC) by adding phosphogypsum(PG) and waste lime(WL) to granulated blast furnace slag(GBFS) as sulfate and alkali activators. This study also investigates the pore structure of NSC Matrix. The result of experiment of pore structure properties, showed no considerable difference for total pore volume by cement mixing ratio but shows a large distinction in distribution of pore diameter. On the whole, pore-diameter of paste of NSC show that occupation ratio of pore diameter below 10mm is larger and is smaller than OPC and BFSC at pore diameter of over 10nm. Such a reason is that the hydrate like CSH gel and ettringite formed dense pore structure of NSC matrix.

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The Characteristics of Chloride Fixation in Non-Sintering Cement Matrix (비소성 시멘트 경화체내 염화물 고정화 특성)

  • Mun, Kyoung-Ju;Hyoung, Won-Kil;Park, Won-Chun;So, Seung-Young;Soh, Yang-Seob
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.725-728
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    • 2006
  • This research investigates the characteristics of chloride fixation in non-sintering cement(NSC) matrix. NSC was manufactured by adding phosphogypsum and slack lime to granulated blast furnace slag as sulfate and alkali activators. As a result, the concentration of chloride ion in pore solution of NSC-solidified matrix is more low than that of OPC-solidified matrix containing the same chloride content in cement paste. Also, the concentration of chloride ion in pore solution of NSC-solidified matrix is similar with that of BSC-solidified matrix containing the same chloride content in cement paste.

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