• 제목/요약/키워드: Fresh Material

검색결과 519건 처리시간 0.024초

원전 시설용 콘크리트의 압축강도 및 건조밀도 특성 평가 (Evaluation for Mechanical Properties of Compress Strength and Dry Density of Concrete at NPP)

  • 이영대;김규용;신경수;남정수;이태규;최경철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 추계 학술논문 발표대회
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    • pp.53-54
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    • 2011
  • The facilities producing the nuclear energy chosen for resolving the recent global energy problem have been increasingly constructed, and hence more frequent durability tests on radiation shielding concrete are required due to NPP(Nuclear Power Plant) life extension and increase of radioactive waste repositories. Bulk dry density is one of the critical factors ensuring the durability and performance of the radiation shielding concrete because the design of the radiation shielding reinforced concrete structures for NPPs is based on the bulk dry density of the concrete. Bulk density of unconsolidated shielding concrete can be calculated utilizing a test assuring to satisfy the bulk dry density, or existing credible data set. This study evaluated correlation between bulk density and bulk dry density of the concrete used for Korean NPPs (y=1.0913X-0.2458) and developed a correlation expression considering standard deviation of bulk dry density (y=1.0913X-0.3358).

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스티치 트랜스퍼 니트 조직의 조형적 적용 - 여성 니트웨어 제작과정을 중심으로 - (Formative Application using Stitch Transfer Knitting Structure - Focused on Making Process of Women's Knitwear -)

  • 김성달
    • 한국의류산업학회지
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    • 제8권5호
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    • pp.562-570
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    • 2006
  • Knit industry requires versatile knit designers who have to control whole process such as material select, color, type of machine, technique, structure and shape. In other words, knit designers urgently need to interplay between technology and design aesthetics. It becomes essential to learn and master basic principles of knitting in order to design and develop effectively for innovative knitwear design. The main purpose of this study is to show fresh methodology through examining the various applications of 'Stitch transfer knitting structure' used in women's knitwear design development. Stitch transfer knitting structure is one of the most popular techniques among various basic knitting methods. Eight knitwears were designed and produced with various types of formative applications which differ from existent stitch transfer knitwears of flat and simple style in the market. These are produced by computer knitting machine 'Shima Seiki 122S' and programmed by 'Knit CAD' software. Among various basic stitch transfer pattern, 'Leaf' pattern is selected as a most effective example for this study. This fabric applied to collar, sleeves, body pattern and accessories as formative decoration. It is expected that this study of methodology helps to get open mind and to indicate possibility to develop and show creative and innovative knitwear and knitted textile design.

영화와 공학의 소통 방식 (The Communication Aspect of Film and Engineering)

  • 함종호
    • 공학교육연구
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    • 제18권6호
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    • pp.88-97
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    • 2015
  • This is paper aims to figure out the way movies and engineering have communicated and the right direction for better communication between them. Engineering no longer should be treated as playing a key role when it comes to film making. Engineering is essential in making films look real. It means that movies gain credibility from utilizing engineering, which all other types of arts also seek after. Films can be resonated better through mutual communication with engineering. The paper takes a close look at emotional aspects to figure out what the new direction of communication between movies and engineering is. People's lives shown in films and the material world that engineering represents are mingled to attain the emotional oneness between the two. This can be easily observed in Japanese movies where robots and humans have a close relationship or recent films whose theme is emotional exchange among humans and robots. This kind of contact leads us to explore newly found humans' position that was brought about in the wake of development in engineering and existential conditions that humans need to have accordingly. Artificial intelligence and neurology sectors that the engineering field is today earnestly working on are in line with it. Therefore, this article seeks to find out the meaning and value of communication between movies and engineering when establishing the fresh mankind model based on emotions and pursuit of diversity.

녹화와 식생조성을 위한 샐비어와 금잔화 종자의 펠렛처리 (Seed Pelletizing of Salvia splendens and Calendula officinalis for the Greening and Re-vegetating)

  • 김승현;이병룡;최병곤
    • 한국환경복원기술학회지
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    • 제10권5호
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    • pp.67-75
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    • 2007
  • The purpose of this study was to pelletize to calendula and salvia seeds with peat moss as basic material for the efficient greening and vegetating of slopes and damaged areas. Also the pelletizing was compressed by spherical types that mixed basic fertilizer of N.;300 mg/l, P.;200 mg/l, K.;400 mg/g and plant growth regulator of A and NAA each 300PPM. Soil and soil surface seeding methods were researched to find the growing state of germination percent, germination date, germination force, length of leaf, number of leaf, width of leaf, length of plant, and etc. Comparing with controlled pelletizing, peat moss and +GA pelletizing treatments resulted in higher from two to three times as following growing states : length of leaves, number of leaves, width of leaves, length of plants, length of roots, fresh weights, and ratio of germination. Especially the two treatments above showed four more times effects than the +NNA treatment. Also their germinating date germinating force were earlier and stronger. The surface seeding method was superior to soil seeding.

수중불분리성 콘크리트의 해양공사 적용에 관한 기초적 연구 (A Fundamental Study on the Antiwashout Underwater Concrete for the Underwater Work of Ocean)

  • 김명식;윤재범;박세인
    • 콘크리트학회논문집
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    • 제12권5호
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    • pp.25-34
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    • 2000
  • When concrete is placed underwater, it is diluted with separating cementitious material and as a result the quality of concrete becomes poor. To solve this problem, antiwashout underwater concrete is increasingly used for the construction and repair of the concrete structure underwater. The objective of this study is to investigate the characteristics of antiwashout underwater concrete as to the mix proportion, casting and curing water through experimental researches. The unit weight of water and cement, water-cement ratio, fine aggregate ratio, unit weight of antiwashout underwater agent and superplasticizer, and casting and curing water were chosen to measure the suspended solids, pH, air contents, slump flow, unit weight of hardened concrete, and compressive strength. From this study, the incremental modulus at mix proportion design and unit weight of antiwashout underwater agent were increased more than fresh water, and it is a optimum mix proportion that the unit weight of water(and cement) is 230kg/$\textrm{m}^3$(460kg/$\textrm{m}^3$), waterOcement ratio is 50%, fine aggregate ratio is 40%, unit weight of antiwashout underwater agent is 1.2% of water contents per unit weight of concrete, and unit weight of supeplasticizer is 2.5% of cement contents per unit weight of concrete when the antiwashout underwater concrete is used for the underwater work of ocean.

Incorporation of marble waste as sand in formulation of self-compacting concrete

  • Djebien, Rachid;Hebhoub, Houria;Belachia, Mouloud;Berdoudi, Said;Kherraf, Leila
    • Structural Engineering and Mechanics
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    • 제67권1호
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    • pp.87-91
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    • 2018
  • Concrete is the most widely used building material all over the world, because of its many technical and economic qualities. This pressure on the concrete resource causes an intensive exploitation of the quarries of aggregates, which results in a exhaustion of these and environmental problems. That is why recycling and valorization of materials are considered as future solutions, to fill the deficit between production and consumption and to protect the environment. This study is part of the valorization process of local materials, which aims to reuse marble waste as fine aggregate (excess loads of marble waste exposed to bad weather conditions) available in the marble quarry of Fil-fila (Skikda, East of Algeria) in the manufacture of self-compacting concretes. It consists of introducing the marble waste as sand into the self-compacting concrete formulation, with variable percentages (25%, 50%, 75% and 100%) and to study the development of its properties both in fresh state (air content, density, slump flow, V-funnel, L-box and sieve stability) as well as the hardened one (compressive strength and flexural strength). The results obtained showed us that marble wastes can be used as sand in the manufacture of self compacting concretes.

Strength enhancement of concrete incorporating alccofine and SNF based admixture

  • Reddy, Panga Narasimha;Jindal, Bharat Bhushan;Kavyateja, Bode Venkata;Reddy, A. Narender
    • Advances in concrete construction
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    • 제9권4호
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    • pp.345-354
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    • 2020
  • Cement is the most significant component in concrete. Large scale manufacturing of cement consumes more energy and release harmful products (Carbon dioxide) into the atmosphere that adversely affect the environment and depletes the natural resources. A lot of research is going on in globally concentrating on the recycling and reuse of waste materials from many industries. A major share of research is focused on finding cementitious materials alternatives to ordinary Portland cement. Many industrial waste by-products such as quartz powder, metakaolin, ground granulated blast furnace slag, silica fume, and fly ash etc. are under investigations for replacement of cement in concrete to minimize greenhouse gases and improve the sustainable construction. In current research, the effects of a new generation, ultra-fine material i.e., alccofine which is obtained from ground granulated blast furnace slag are studied as partial replacement by 25% and with varying amounts of sulfonated naphthalene formaldehyde (i.e., 0.3%, 0.35% and 0.40%) on mechanical, water absorption, thermal and microstructural properties of concrete. The results showed moderate improvement in all concrete properties. Addition of SNF with combination of alccofine showed a significant enhancement in fresh, hardened properties and water absorption test as well as thermal and microstructural properties of concrete.

Use of e-plastic waste in concrete as a partial replacement of coarse mineral aggregate

  • Sabau, Marian;Vargas, Johnny R.
    • Computers and Concrete
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    • 제21권4호
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    • pp.377-384
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    • 2018
  • The accelerated increase of the population growth rate in the world and the current lifestyle based on consumerism considerably increased the amount of waste generated by the human activity. Specifically, e-plastic waste causes significant damage to the environment because of its difficult degradation process. This paper aims to establish the feasibility of using e-plastic waste in concrete as a partial replacement of coarse mineral aggregate. Considering a control mix without e-plastic waste designed for a compressive strength of 21 MPa, tests on concrete mixes with 40, 50 and 60% of e-plastic waste aggregate to determine the fresh and hardened properties were carried out. A reduction in the compressive strength as the percentage of e-plastic waste increases was observed, the maximum reduction being 44% with respect to the control mix. In addition, a significant reduction as much as 22% in the density of the concrete mixes with e-plastic waste was recorded, which means that lighter elements can be produced with this type of concrete. Two new equations based on regression analysis of the experimental data from this study were proposed. These equations estimate the reduction in the compressive strength of concrete mixes with e-plastic waste aggregate at 14 and 28 days. A cost analysis and a practical alternative to introduce this waste material into the market are also presented.

The Effects of Freezing and Supplementation of Molasses and Inoculants on Chemical and Nutritional Composition of Sunflower Silage

  • Konca, Y.;Buyukkilic Beyzi, S.;Ayasan, T.;Kaliber, M.;Bozkurt Kiraz, A.
    • Asian-Australasian Journal of Animal Sciences
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    • 제29권7호
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    • pp.965-970
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    • 2016
  • This study was conducted to determine the effects of freezing and supplementation of molasses (M), lactic acid bacteria (LAB) and LAB+enzyme mixture on chemical and nutritional composition of sunflower silage (SF). Sunflower crops were harvested (at about $29.2%{\pm}1.2%$ dry matter) and half of fresh sunflower was ensiled alone and half was frozen (F) at $-20^{\circ}C$ for 7 days. Silage additives were admixed into frozen SF material. All samples were ensiled in glass jars with six replicates for 90 days. The treatments were as follows: i) positive control (non-frozen and no additives, NF), ii) negative control (frozen, no additives, F), iii) F+5% molasses (FM), iv) F+LAB (1.5 g/tons, Lactobacillus plantarum and Enterococcus faecium, FLAB); v) F+LAB+enzyme (2 g/tons Lactobacillus plantarum and Enterococcus faecium and cellulase and amylase enzymes, FLEN). Freezing silage increased dry matter, crude ash, neutral detergent fiber, and acid detergent lignin. The organic matter, total digestible nutrient, non-fiber carbohydrate, metabolizable energy and in vitro dry matter digestibility were negatively influenced by freezing treatments (p<0.05). In conclusion, freezing sunflower plants prior to ensiling may negatively affect silage quality, while molasses supplementation improved some quality traits of frozen silage. Lactic acid bacteria and LAB+enzyme inoculations did not effectively compensate the negative impacts of freezing on sunflower silage.

상향류식 혐기성 입상슬러지 공법의 유기폐수 처리 효율에 미치는 온도의 영향 (Temperature Effect of the UASB Process for Treatment of Organic Waste)

  • 박철휘;정태학
    • 상하수도학회지
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    • 제10권4호
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    • pp.45-54
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    • 1996
  • Effects of temperature on the efficiency of the Upflow Anaerobic Sludge Blanket(UASB) process for treatment of wastewater from a starch and related products manufacturing industry were investigated using laboratory scale reactors equipped with two types of Gas-Solid Separator(GSS). Both fresh digested sludge and granular sludge stored nearly for one year at room temperature were good as a seeding material. The reactors seeded with aged granular sludge showed slow start-up, however, lowered activity at the initial period was recovered gradually. The GSS with an inner cylinder was proved to be effective in liquid-solid separation compared to the conventional type. Although the rate of organic removal and gas production per unit volatile suspended solids in the reactor reduced significantly as the temperature varied from 35 to $20^{\circ}C$, possibility of operation at low temperatures was shown as a result of gradual buildup of volatile suspended solids in the bed. Stable operation with a reduced efficiency was possible at a COD loading of $5-8kg/m^3/day$ at a temperature as low as $20^{\circ}C$.

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