• 제목/요약/키워드: Green body

검색결과 683건 처리시간 0.033초

건조법, 파쇄법, 성형법에 따른 인공경량골재의 파쇄율 비교 (A comparison of fracture rate of artificial light-weight aggregates by various drying, breaking, and forming methods)

  • 박지윤;김유택;이기강;강승구;김정환
    • 한국결정성장학회지
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    • 제15권1호
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    • pp.39-44
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    • 2005
  • 적점토 60 wt%, 석탄회 20 wt%, 석분오니 20 wt%를 혼합하여 제작한 sheet 형태의 소지에 인덴트(indent)를 주고 건조방법, 파쇄방법, 성형방법을 변화시켜 1~5 mm 골재의 파쇄율을 알아보았다. 소지를 건조할 때 실내와 실외에서의 자연건조, 건조기건조, 마이크로웨이브(microwave)건조, 급속건조로 분류하여 비교실험 하였고, 파쇄방법은 볼밀 Ⅰ 파쇄, 볼밀 Ⅱ 파쇄, 낙하파쇄, 기계식 파쇄(롤러밀사용)법으로 변화를 주었다. 성형방법은 인덴트의 간격과 깊이를 변화시키면서 동시에 소지의 두께를 변화시켜 실험하였다. 건조방법에 의한 비교실험 결과는 210초까지 건조시킨 마이크로웨이브건조가 약 42%로. 파쇄방법에서는 볼밀 Ⅱ 파쇄법이 약 65 %로 가장 높은 파쇄율을 보였고, 성형방법에서는 인덴트의 깊이가 깊어질수록(3mm의 소지에서만), 소지의 두께가 증가할수록 크기가 Ф=5 mm보다 큰 골재의 수율은 감소했고 Ф=5 mm 이하인 골재의 수율은 증가했다. 각각의 실험 후 파쇄 된 1~5mm 골재의 aspect ratio를 비교해본 결과 3mm 두께의 소지를 급속건조법에 의해 건조하고 볼밀 Ⅱ법을 이용해 파쇄 한 경우 가장 균일한 골재의 모양으로 파쇄 되었음을 알 수 있었다.

네일의 토압분담 효과를 고려한 Green Wall 시스템의 설계 (Design of the Green Wall System considering Distribution Effect of Earth Pressure by Soil Nail)

  • 박시삼;조성한;유찬호;김홍택;김용언
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2006년도 춘계 학술발표회 논문집
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    • pp.1038-1045
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    • 2006
  • The Green Wall is highest eco-system among a segmental retaining wall systems. Recently, the demand of high segmental retaining wall (SRW) is increased in domestic. The soil nailing system is applied in order to maintain the high SRW stability for steeper slope. However, the proper design approach that can consider the earth pressure reduction effects in soil nailing system has not been proposed. This study was performed to introduce the design case by 'Two-Body Translation mechanism' to be able to consider distribution of earth pressure in the soil nailing when designing the green wall using soil nailing system. Also, this study attempts to evaluate the earth pressure change when advanced soil nailing system is constructed using $FLAC^{2D}$ ver. 3.30 program and 'Two-Body Translation mechanism'. Also in this study, various parametric studies using numerical methods as shear strength reduction (SSR) technique and limit equilibrium technique were carried out. In the parametric study, the length ratio and the bond ratio of the soil nailing were changed to identify the earth pressure reduction effect of the retaining wall reinforced by soil nailing.

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Collection and Characteristics of the Wild Silkmoth, Samia cynthia pryeri, in Korea

  • Kim, Bo-Youn;Park, Young-Whan;Park, Nam-Sook;Lee, Sang-Mong
    • International Journal of Industrial Entomology and Biomaterials
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    • 제3권1호
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    • pp.101-103
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    • 2001
  • The wild silkmoth, Samia cynthia pryeri, was firstly collected at Miryang, Korea. The development and quantitative characters of S. cynthia preyri in the laboratory condition were analysed. The larval body color of dark yellow green or light yellow green of the S. cynthia pryeri was changed into white color during the molting period, and the yellowish bristles in younger larvae were changed into fade green color in advanced stage larvae. Aralia elata and Zanthoxylum piperitum were newly identified as host plants to S. cynthia pryeri. Cocoon weight and cocoon shell percentage were average 2.14 g and 12.3 %, respectively. In addition, the morphology of the silkgland was different from that of the domestic silkworm,Bombyx mori, but was identical with that of the wild silkmoth, Antheraea yamamai.

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On the Improved Green Integral Equation applied to the Water-wave Radiation-Diffraction Problem

  • Do-Chun,Hong
    • 대한조선학회지
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    • 제24권1호
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    • pp.1-8
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    • 1987
  • It is shown that irregular frequencies in the source and doublet distribution method, can be eliminated if the Green function associated with Kelvin's source of pulsating strength, is modified only in the region inside the body at the level of the undisturbed free surface. The system of the resulting Green integral equation is augmented without loss of the square-integrable property of its kernel so hat the discretisation yield N linearly independent equations for N unknown variables. From the solution, the potential and velocity at any point on the wetted surface of a surface-piercing body can be found using the properties of the double layer composed of the source and normal doublet distribution.

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Green Body Behaviour of High Velocity Pressed Metal Powder

  • Jonsen, P.;Haggblad, H.A.;Troive, L.;Furuberg, J.;Allroth, S.;Skoglund, P.
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.22-23
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    • 2006
  • High velocity compaction (HVC) is a production technique with capacity to significantly improve the mechanical properties of powder metallurgy (PM) parts. Investigated here are green body data such as density, tensile strength, radial springback, ejection force and surface flatness. Comparisons are performed with conventional compaction using the same pressing conditions. Cylindrical samples of a pre-alloyed water atomized iron powder are used in this experimental investigation. The HVC process in this study resulted in a better compressibility curve and lower ejection force compared to conventional quasi static pressing. Vertical scanning interferometry measurements show that the HVC process gives flatter sample surfaces.

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The Planning of Urban Green Space System and Sustainable Development

  • Wang, Bingluo
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • 제1호
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    • pp.37-42
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    • 2001
  • In order to answer the challenge that development gave to environment, Chinese cities are making up and putting into effect the green space system planning. The planning main keys are: set down standards and scope of green space; bring the characteristics of every types of green space in to full play and made into basic units of the system; formed powerful links of the system; make full use of the natural system of city, constituted the urban and countryside as a organic whole green space system, therefore give full play their function and ecological effect. In fact, this green space system is a complex system. It is the main body of city ecological system, a main container of the citizen activities of leisure and recreation and a leading factor for making characteristic city landscape. Therefore it is a system carrying city's environment sustainable development.

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성형체의 대기시간에 따른 ALC 표면 색상과 결정특성 (Colors and Crystals of ALC Surface with Green Body's Staying Time)

  • 추용식;서성관;박수현;송훈;이종규
    • 한국세라믹학회지
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    • 제49권6호
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    • pp.535-541
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    • 2012
  • ALC was fabricated using cement, lime, quartzite and a foaming agent via a hydrothermal reaction. ALC has various hydrothermal reaction products and many pores. The properties and colors of ALC surfaces were changed by various factors during ALC fabrication process. This study tested various staying times to analyze these phenomena. It was found that the staying time of green body influenced the properties of hydrothermal products and color of ALC surface. The longer staying time of green body, the lower tobermorite content and cumulative loss weight. An increase in holding time changed color and decreased whiteness of ALC surface. The relationship between whiteness and cumulative loss weight was very high (Coefficient, r = 0.95). It was surmised that tobermorite content was an important factor for enhancement of whiteness However, ettringite and quartzite did not contribute to whiteness.

Effect of Green Tea Probiotics on the Growth Performance, Meat Quality and Immune Response in Finishing Pigs

  • Ko, S.Y.;Yang, C.J.
    • Asian-Australasian Journal of Animal Sciences
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    • 제21권9호
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    • pp.1339-1347
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    • 2008
  • The objective of this study was to determine the effects of green tea probiotics on growth performance, meat quality and immune response in finishing pigs, and to assess the possibility of substituting green tea probiotics for antibiotics in diets of finishing pigs. This green tea probiotics is made by mixing green tea powder and excipients (defatted rice bran and wheat bran) and fermenting the mixture with beneficial bacteria. A total of 90 crossbreed "Landrace$\times$Yorkshire" finishing pigs with an average body weight of $72.5{\pm}2.5kg$ were assigned to 5 dietary treatments in a completely randomized design. Each treatment had 3 replications with 6 pigs per replication. The five dietary treatments were control, antibiotic (0.003% chlortetracycline added) and 0.1, 0.5 and 1.0% of green tea probiotics. There were no significant differences in final body weight, daily weight gain, daily feed intake and feed conversion ratio in the green tea probiotics and antibiotic treatments (p>0.05). Crude protein content was significantly increased in the 0.1 and 1.0% green tea probiotics treatment groups (p<0.05) and there was no significant difference in crude fat content of the meat among the treatments. The TBA value of meat was significantly lowered with 0.5 and 1.0% green tea probiotics treatments compared to that of controls and statistically similar to the antibiotic treatment after 3 weeks of storage (p<0.05). The growth of spleen cells stimulated with Con A (0.1 and $1.0{\mu}g/ml$) was significantly increased with 1.0% green tea probiotics treatment compared to that of the control treatment (p<0.05). The growth of spleen cells stimulated with LPS (1.0, 3.0 and $10{\mu}g/ml$) was significantly increased in the 0.5% green tea probiotics group compared to the antibiotic group (p<0.05). In Con A ($1.0{\mu}g/ml$) medium, IL-6 production of spleen cells was significantly increased with 1.0% green tea probiotics treatment compared to that of the control (p<0.05). In LPS ($10.0{\mu}g/ml$) medium, TNF-${\alpha}$ production of spleen cells increased significantly in all green tea probiotics treatment groups compared to that of the control (p<0.05). Finally it can be summarized that addition of green tea probiotic has a positive effect similar to antibiotic and 0.5% is the suitable dietary supplementation dose for finishing pig production.

녹차가루가 당뇨 쥐의 골 대사 지표 및 골밀도에 미치는 영향 (Effects of Green Tea Powder on Bone Markers and Bone Mineral Density in STZ-Induced Diabetic Rats)

  • 최미자;조현주
    • 동아시아식생활학회지
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    • 제23권6호
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    • pp.713-722
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    • 2013
  • The purpose of this study was to examine the effects of dietary green tea powder supplementation on bone metabolism in streptozotocin-induced diabetic rats. Thirty-two male Sprague-Dawley rats (body weight $210{\pm}3g$) were divided into two groups, diabetic and non-diabetic groups. Each group was randomly divided into two subgroups which were fed with the control and 1% green tea powder diets. The serum and urine concentrations of calcium and phosphorus were determined. Serum osteocalcin and ALP and urinary DPD crosslinks value were measured in order to monitor bone formation and resorption. Bone mineral density (BMD) and bone mineral content (BMC) were estimated using PIXImus in the spine and femur. Body weight gain and FER were lower in the diabetic group than in the non-diabetic group regardless of diets. The serum concentration of calcium and phosphorus were not changed among all groups. Urinary calcium and phosphorus excretion were higher in the diabetic group than in the non-diabetic group regardless of diets; however, they were not significantly different by green tea powder intake. Serum alkaline phosphatase (ALP) was increased in the diabetic group than in thenon-diabetic group. Further, there were no significant differences in serum osteocalcin and urinary deoxypyridinoline crosslinks value among all groups. The levels of spine and femur bone mineral density of the diabetic group were significantly lower than that of the non-diabetic group. Within the diabetic group, spine BMD was significantly higher in rats fed with the green tea powder diet than in rats fed the control diet. Therefore, this study suggests that green tea powder has a beneficial effect on bone health, although it is not directly applicable to humans.

2차원 부유체 강제동요문제의 수치해석에 관하여 (On Numerical Method for Radiation Problem of a 2-D Floating Body)

  • 신영섭;이기표
    • 대한조선학회논문집
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    • 제30권2호
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    • pp.43-53
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    • 1993
  • 부유체 강제동요문제를 수치해석하는 데에는 두가지 어려움이 따른다. 첫째는 교차점주위의 급격한 유동이고 둘째는 무한원방처리이다. 본 논문에서는 무한원방처리에 주안점을 두어, 자유표면의 Taylor 전개 및 F.F.T. 적용으로 계산시간을 단축시켜 수치해석하였다. 즉 Green 정리를 이용하여 해를 표현한 후, 축차방법에 의하여 해를 구한다. 축차단계에서는 계산식을 자유표면 기울기에 대하여 Taylor 전개하여 Convolution 형태로 변형한 후 F.F.T. 를 적용함으로써 계산시간을 O(Nlog N)으로 유지할 수 있었다. 수치검증을 위하여 부유체 선형문제와 압력장의 비선형 문제를 수치해석하여 비교하였고, 이를 확장하여 부유체의 강제동요문제를 수치해석하였는데, 계산시간을 O(Nlog N)으로 유지하면서 수치해석할 수 있었다.

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