• 제목/요약/키워드: Unit Weight

검색결과 2,361건 처리시간 0.028초

석탄회 인공경량골재를 사용한 고강도 콘크리트의 역학적 특성 (Mechanical Properties of Reinforced High-Strength Concrete Using Fly-ash Artificial lightweight Aggregate)

  • 박완신;한병찬;성수용;윤현도;정수용
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.151-156
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    • 2001
  • Concrete has excellent characteristics as building material and functions relatively well; but it has many problems concerning too heavy weight of the structures. Accordingly, it is the assignment for study in the part of building materials to lighten and high strengthen the weight of concrete structures in order to improve those weak Points; and it seems one of the representative solutions to develop the high strength lightweight aggregate concrete. Based on the experimental results presented, the following conclusions are drawn. The concrete with unit weight of 1.96~2.03t/$m^{2}$, compressive strength of 322~431kgf/$cm^{2}$ was gained. So, it appears that the lightweight aggregate concrete will be useful for low unit weight and high strength lightweight aggregate concrete. In the end, to manufacture artificial lightweight aggregate concrete for construction work is necessary to develope artificial aggregate which has improved performances physically.

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Variability in Specific Leaf Weight in Mulberry Germplasm and Its Inheritance Pattern

  • Sarkar, A.;Mogili, T.;Chaturvedi, H.K.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제7권1호
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    • pp.69-73
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    • 2003
  • Specific leaf weight (SLW), defined as the mass of tissue per unit leaf area has been found to be an important physiological parameter as it indicates the relative thickness of leaves. Greater SLW provides more photosynthetic potential per unit area of leaf and hence it is frequently been considered as correlated with photosynthesis in several plant species. Collections of 165 mulberry (Morus sp.) germplasm accessions, both Indian and exotic in origin were evaluated for their variability with respect to SLW. The mean specific leaf weight ranged from 35.3 to $72.3 g/m^{-2}$. The distribution of SLW was found to be normal. High heritability (97.08%) and a small difference between genotypic and phenotypic variance demonstrates the genetic control over SLW. Significant heterotic effect with respect to SLW was observed in crosses when parents with high and low SLW were chosen.

섬유소 분해효소의 단백질 분자량이 다른 조합처리가 펄프의 고해도 변화 및 습지 보수도에 미치는 영향 (The effect of Several Pulp properties and freeness treated with different sized cellulase)

  • 김병헌;양이석
    • 한국인쇄학회지
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    • 제19권1호
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    • pp.64-74
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    • 2001
  • This study is to find the effect of the molecular weight distribution of components on the freeness and physical properties of paper by observing the change of properties according the modification of fibers by using production technology and process technology together to develop additives which can effectively control according to the purpose of paper-making process and by combining low molecular weight cellulase (below MW 20,000; CMC activity 400 unit) with different enzyme's molecular weight and activity and high molecular weight cellulase(MW 20,000∼80,000;CMC activity 90,000 unit) and then process them in Sw-BKP(Softwood Bleached Kraft Pulp) and Hw-BKP(Hardwood Bleached Kraft Pulp) and Cotton Linter Pulp and OCC(Old Corrugated Container) with different properties of pore of surface of fibers respectively, since it is judged that making the appropriate composition ratio of components is necessary in consideration of the properties of fibers and paper-making process.

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산란 주령 및 중량 규격에 따른 계란의 주요 성분 및 내부 품질 비교 (Comparison of Principle Components and Internal Quality of Eggs by Age of Laying Hens and Weight Standard)

  • 이재청;김선효;선창완;김창호;정사무엘;이준헌;조철훈
    • 한국가금학회지
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    • 제40권1호
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    • pp.49-55
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    • 2013
  • 본 연구는 산란 주령과 중량에 따른 계란의 주요 성분과 내부 품질의 변화를 확인하기 위하여 수행되었다. Hy-Line Brown 품종의 18주령에서 63주령으로부터 계란을 주령별로 약 50개씩 총 2,140개를 수거하여 난각, 난황 및 난백의 중량과 난백 높이 그리고 Haugh unit을 측정하였다. 중량 규격이 높아짐에 따라 난각, 난황 및 난백의 중량은 증가하였으나, 난백 높이와 Haugh unit은 낮아짐을 나타내었다. 또한, 산란 주령이 경과함에 따라 난황은 증가하고, 난백 비율은 감소하는 경향을 나타내었으며, 산란 주령은 난각, 난황, 난백 및 전체 계란 중량과 정의 상관관계를 보였으나, 난백 높이와 Haugh unit과는 부의 상관관계를 나타내었다. 또한 계란 중량이나 주요 구성 성분의 중량이 증가함에 따라 난백 높이 및 Haugh unit은 감소하는 것으로 나타났다.

Influence of Fungicidal Spray on Powdery Mildew Epidemics and Major Yield-Attributing Characters of Mungbean

  • Saxen, Deep-Ratna;Moly Saxena
    • The Plant Pathology Journal
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    • 제18권2호
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    • pp.68-73
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    • 2002
  • The influence of fungicidal spray was assessed on powdery mildew epidemics caused by Erysiphe polygoni D.C. and on yield-attributing characters of mungbean [Vigna radiata (L.) Wilczek]. Mildew attack adversely affected the yield-attributing characters of mungbean and exhibited negative significant correlation with pod length (-0.57), pods/plant (-0.74), pod weight (-0.68), 100 seeds weight (-0.69), 100 seeds swell weight (-0.59), and seed germination (-0.71). These characters had direct or indirect effects on grain yield, which was also adversely affected due to mildew attack (-0.89). Powdery mildew was significantly retarded due to the single spray of carbendazim (0.05%) at 30-day-old crop, where the apparent rate of infection (r) was minimum at 0.0095/ unit/day and with low (11.44%) powdery mildew intensity. Other fungicides like tridemorph (0.075%) and penconazole (0.05%) were equally effective against the mildew disease where the disease intensity was less than 20% and the values of r were 0.0134 and 0.039/unit/day respectively, as compared with the control at 0.267/unit/day. Fungicide spray influenced the yield-attributing characters besides controlling the disease. Such effects were more pronounced in carbendazim (0.05%)-treated plots due to its phytotonic nature where pod length (7.59cm), pods/plant (29.75), pod weight (8.16 g), 100 grain weight (3.94 g), and swell weight of 100 seed (9.49 g) were maximum resulting to the highest yield (480 kg/ha) as compared with that of control (224 kg/ha). Spray of carbendazim also improved seed germination (74.5%). Spray of other fungicides like carbendazim with copper oxychloride in 1:1 ratio, tridemorph (0.075%), and penconazole (0.05%) was equally effective against powdery mildew of mungbean. These fungicides also exhibited positive effects on yield-attributing characters of the crop and finally increased yield. These systemic fungicides were more effective in controlling powdery mildew disease of V. radiata in the rainy season compared with wettable sulphur.

기존한약서의 현대적 용량 환산을 위한 도량형의 시대적 변천 고찰 (Historical Changes in Weights and Measures of Herbal Formulas in Medical Classics)

  • 한천희;이수연;김지훈;김윤경
    • 대한한의학방제학회지
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    • 제25권1호
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    • pp.103-113
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    • 2017
  • Objectives : Korea and China are applying different conversion standards for weight in traditional medicine books. This study aims to research and suggest how to convert the units of weight in old traditional medicine classics into the contemporary unit of grams. Methods : Historical documents of Korea and China were used to review the process in which weights and measures changed in each country and the manners in which the Chinese units of weight were introduced to Korea. Results : Weights and measures changed with time. They became almost standardized by the period of Song in China, when coins played the most crucial role, and it was introduced to Korea. Donggaryang, the standard container for weights and measures in ancient China, Gaewontongbo, a coin in Tang, Sangpyeongtongbo, a coin in Joseon, and a scale in Joseon were used as strong foundations for conclusion from literature review. Weight of a 1-don(coin) in the time a traditional medicine books were written was used as a unit of weight in those books. Sangpyeongtongbo, a 1-don coin in Joseon, weighs 4 grams on average. Conclusions : Since the current conversion of 1-don coin into 3.75 grams is not supported by literature review, it is suggested that 1-don(coin) as a unit of weight in traditional medicine books of Joseon, may be better converted into 4 grams, while that of China is converted to 3.73 grams.

고지방 식이를 섭취한 흰쥐에서 마황의 메탄올 추출물이 체지방조직 세포에 미치는 영향 (Effects of Methanol Extract of Ma-huang on Adipocyte of Epidiymal Fat in Rat Fed High Fat Diet)

  • 임경아;박용구;조여원
    • 대한한의학회지
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    • 제22권3호
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    • pp.74-80
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    • 2001
  • Objectives : Ma-huang is a traditional Chinese medicinal herb, derived from Ephedra sinica Stapf and other Ephedra species, used to treat asthma, nose and lung congestion, and fever with anhidrosis. It contains 0.5-2.5% by weight of total alkaloids, of which ephedrine accounts for 30 to 90%. Recently, Ma-huang has been used as a source of ephedrine in many dietary supplements formulated for the treatment of obesity, since ephedrine has been found to be effective in inducing weight loss in the obese. In this study the effects of the methanol extract of Ma-huang on the adipocyte of epididymal and brown fat pads in rats fed a high fat diet for six weeks were studied. Methods : Male Sprague Dawley rats weighing an average 94g (4 weeks old) were fed either a regular diet (RE) or a high fat diet (HF), and the HF group was subdivided into a Ma-huang methanol extract (30mg/100g body weight) group (HF+MH). The weight of epididymal fat pad and brown adipose tissue were measured. The cell size and cell number per unit area of epididymal fat pad were investigated. Results : The yield weight of methanol extract of Ma-huang was 3.63mg per l00g of Ma-huang. The body weight gain of the HF group was similar with that of the HF+ MH but higher than that of the RE. The weights of the epididymal fat pads and brown adipose tissue of the RE group were lower than those of HF and HF+MH groups. The cell sizes and numbers per unit area of epididymal fat pads of the RE and HF+MH groups were larger than those of HF group. The cell numbers per unit area size of epididymal fat pads were the smallest in the RE group. Conclusions : It could be concluded that the Ma-huang extract has no effect on the epididymal fat pads in rats fed a high fat diet and the clinical application of Ma-huang for the treatment of obesity should be re-considered.

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전기적인 특성향상을 위한 리튬이온전지팩 개발 (Development of a new Li-Ion Pack-Battery for improving the electrical properties)

  • 강용구;권현규;서명수;박창용
    • 한국기계가공학회지
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    • 제8권2호
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    • pp.90-95
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    • 2009
  • This paper presents a new lithium ion unit-cell and pack battery by using a new formulation ratio of material. The three types of formulation ratio for the unit-cell were used. The life cycle and basic properties of the lithium ion unit-cell$({\Psi}18{\times}65(mm))$ about one of them were acquired by the charge-discharge experiment. The nominal voltage, nominal capacity and cycle life output of the lithium ion unit-cell is respectively 3.7V, 2.4Ah, and above 500cycle. Pack type lithium ion battery has the size of $29.5{\times}73.5{\times}115(mm)$ and the weight of 300g. As the results, the weight and bulk of lithium ion battery used to a safety lamp were decreased to 1/4 and 1/7. In addition, the comparison of the new lithium ion battery and lead storge battery for confirming the effectiveness of the new lithium ion battery have been performed.

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유리섬유 혼입 기포콘크리트의 배합변화에 따른 ,압축강도 특성에 관한 연구 (The Study on Compressive-Strength Property of the Aerated Concrete using Glass Fiber by Mixing Ratio)

  • 허재원;김효열;임남기
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
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    • pp.93-98
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    • 2005
  • The purpose of this study was to analyze the compression strength research by aerated concrete as mixing ratio This Study used foaming-agent and produced aerated concrete by pre-foam way that is used in construction site. An experiment changes unit cement amount, w/c and the glass fiber mixing rate and 'measured capacity change, unit capacity weight and compressive strength. The results obtained from experimental study are as following; Research to reduce unit capacity weight in condition more than unit cement amount 500kgf is considered should be gone side by side. The highest compressive strength result appeared in aerated concrete that cement amount 600kgf and w/c ratio $45\%$, $50\%$. compressive strength was increased maximum $34%$ when glass fiber $0.7\%$ addition cause by coherence enlargement to enlargement of cement paste and glass fiber addition per unit volume

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단위 구조 변경에 의한 알루미늄 압출재의 차음성능 개선 (Improvement Method of the Sound Insulation Performance of Aluminium Extruded Panels by the Unit Structure Modification)

  • 이현우;김석현;김정태;송달호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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    • pp.457-462
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    • 2009
  • In a high speed train, aluminium extruded panel is widely used in floor, side wall and roof structures for high bending stiffness and weight reduction. However, with some inevitable reasons, aluminium extruded panel shows inferior sound insulation performance compared with the flat panel having same weight. Especially, occurrence of local resonance modes in the particular frequency band, is one of the main reason in the deterioration of the sound insulation performance. Local resonance modes are generated in the structure which consists of periodic unit structure, such as the aluminium extruded panel. The local resonance frequency is determined by the specification of the unit structure. In this study, we predict the local resonance frequency band on the aluminium extruded panel used for the high speed train, and investigate how the design modification in the unit structure influences the local resonance frequency band and panel bending stiffness. The purpose of the study is to provide the design information for the effective unit structure in order to improve the sound insulation performance of the aluminium extruded panel.

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