• Title/Summary/Keyword: Wall-function

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Case Study on Application of PHC Pile to Earth Retaining and Retention Wall (옹벽겸용 흙막이벽으로 PHC말뚝의 적용 사례 연구)

  • Han, Jung-Geun;Hong, Ki-Kwon;Eo, Yun-Won;Kim, Sang-Kwi
    • Journal of the Korean Geosynthetics Society
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    • v.5 no.3
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    • pp.37-44
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    • 2006
  • The construction of earth retaining wall and structure which get environmental element have to appling at the same time, then construction period and construction cost increase. These system which is presented to overcomes shortcoming and have function of earth retaining wall and retention wall at the same time. However, because existing method has limit excavation depth, the advanced design pattern more than existing method, rows of pile was applied. The workability and stability of applied design method are evaluated through analyze of construction case. The results confirmed that application design method can solve displacement of pile and limit excavation depth in existing earth retaining wall.

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Identification of Sugar-Responsive Genes and Discovery of the New Functions in Plant Cell Wall

  • Lee, Eun-Jeong
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2007.04a
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    • pp.65-73
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    • 2007
  • The objective of this study is to understand how regulatory mechanisms respond to sugar status for more efficient carbon utilization and source-sink regulation in plants. So, we need to identify and characterize many components of sugar-response pathways for a better understanding of sugar responses. For this end, genes responding change of sugar status were screened using Arabidpsis cDNA arrays, and confirmed thirty-six genes to be regulated by sucrose supply in detached leaves by RNA blot analysis. Eleven of them encoding proteins for amino acid metabolism and carbohydrate metabolism were repressed by sugars. The remaining genes induced by sugar supply were for protein synthesis including ribosomal proteins and elongation factors. Among them, I focused on three hydrolase genes encoding putative $\beta$-galactosidase, $\beta$-xylosidase, and $\beta$-glucosidase that were transcriptionally induced in sugar starvation. Homology search indicated that these enzymes were involved in hydrolysis of cell wall polysaccharides. In addition to my results, recent transcriptome analysis suggested multiple genes for cell wall degradation were induced by sugar starvation. Thus, I hypothesized that enzyme for cell wall degradation were synthesized and secreted to hydrolyze cell wall polysaccharides producing carbon source under sugar-starved conditions. In fact, the enzymatic activities of these three enzymes increased in culture medium of Arabidopsis suspension cells under sugar starvation. The $\beta$-galactosidase encoded by At5g56870 was identified as a secretory protein in culture medium of suspension cells by mass spectrometry analysis. This protein was specifically detected under sugar-starved condition with a specific antibody. Induction of these genes was repressed in suspension cells grown with galactose, xylose and glucose as well as with sucrose. In planta, expression of the genes and protein accumulation were detected when photosynthesis was inhibited. Glycosyl hydrolase activity against galactan also increased during sugar starvation. Further, contents of cell wall polysaccharides especially pectin and hemicellulose were markedly decreased associating with sugar starvation in detached leaves. The amount of monosaccharide in pectin and hemicellulose in detached leaves decreased in response to sugar starvation. These results supported my idea that cell wall has one of function to supply carbon source in addition to determination of cell shape and physical support of plant bodies.

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A Study on the Condensation Performance of The Curtain-walls (커튼월 결로 성능평가에 관한 연구)

  • Lee, Sang-Jin;Ock, Jong-Ho;Kim, Sung-Keun
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2008.11a
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    • pp.808-812
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    • 2008
  • Recently, the buildings have been likely to shape Super Tall trend. Therefore, the exterior parts of the buildings come to be changed. Instead of early heavy wall structure, it is changed to light wall concept of curtain wall system. However, the curtain wall system causes lots of loads due to the external surrounding factors of building. In particular, due to the densely built-up condition in Korea, the generation of dew condensation is getting severer Since there has been no standardized process that reviews this generation of dew condensation, it is very urgent for us to prepare the reviewing process for the dew condensation for construction business managers. The purpose of this study is to assess dew condensation function of the curtain wall and provide the basic data for the provision of the future dew condensation review process by comparing and analyzing the range of generation of dew condensation as well as temperature distribution according to the change of relative humidity at the identical temperature by selecting the Unitized system and Stick system which are the representative types of curtain wall system.

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Effect of KGD1 Deletion on Cell Wall Biogenesis in Saccharomyces cerevisiae (Saccharomyces cerevisiae의 KGD1 유전자 결손이 세포벽 생합성에 미치는 영향)

  • Kim, Sung-Woo;Ahn, Ki-Woong;Park, Yun-Hee;Park, Hee-Moon
    • The Korean Journal of Mycology
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    • v.38 no.1
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    • pp.29-33
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    • 2010
  • KGD1 gene was cloned by functional complementation of defects in $\beta$-1,3-glucan synthase activity of the previously isolated Saccharomyces cerevisiae mutant LP0353, which displays a number of cell wall defects at restrictive temperature. We performed the gene disruption experiment to characterize the function of KGD1 gene, which encodes $\beta$-ketoglutarate dehydrogenase, in cell wall biosynthesis. The disruption of KGD1 showed the decreased growth rate, the increase of chitin synthases activity, alterations in cell wall composition, and increase of susceptibility to cell wall inhibitors such as Calcofluor white and Nikkomycin Z. These results suggested that KGD1 might be involved in cell wall biogenesis, especially the biosynthesis of $\beta$-1,6-glucan and chitin in S. cerevisaie.

A Parameter Study on the Frequency Characteristics of the Structural-acoustic Coupled System (구조-음향 연성계의 경계값 변화에 따른 방사음 변화)

  • 김양한;서희선
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.7
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    • pp.604-611
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    • 2004
  • It is well known that wall impedance essentially determines how sound wave transmits from one place to another. The wall impedance is related with its dynamic properties : for example, the mass, stiffness, and damping characteristics. It is noteworthy, however, that the wall impedance is also function of spatial characteristics of two spaces that is separated by the wall. This is often referred that the wall is not locally reacting. In this paper, we have attempted to see how the acoustic characteristics of the two spaces is affected by various structure parameters such as density, applied tension, and a normalized length of the wall. Calculations are conducted for two different modally reacting boundary conditions by modal expansion method. The variation of the Helmholtz mode and the structural-dominated mode are analyzed as the structure parameters vary. The displacement distribution of the structure, pressure and active intensity of the inside and outside cavity are presented at the Helmholtz mode and the structure-dominated mode. It is shown that the frequency characteristics are governed by both structure-and fluid-dominated mode. The results exhibit that the density of the structure is the most sensitive design parameter on the frequency characteristics for the coupling system as we could imagine in the beginning. The Helmholtz mode frequency decrease as density increases. However. it increases as applied tension and an opening size increase. The bandwidth of the Helmholtz mode is mainly affected by density of the structure and its opening size.

A study on Design for Radiation Element of Slotted Waveguide by the Method of Moment (모멘트법을 이용한 도파관 복사소자의 설계에 관한 연구)

  • 민경식;박세현;김동철;임학규
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2000.05a
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    • pp.135-138
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    • 2000
  • This paper presents design for radiation element of slotted waveguide by the method of moment. The piecewise sinusoidal function as the basis function is used for the Moment Method. From the analytically results based on the Galerkin's moment method, frequency characteristics and radiation power is investigated for the design parameter such as the slot length, offset and angle. This paper also discusses that the radiation power is controled by the slot offset and angle. The thickness of the waveguide wall is also discusses in the analysis.

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An optimal control in cement kiln heat-up (시멘트 소성로 가열 단계에서의 최적 제어)

  • 김송호;이광순;이원규
    • 제어로봇시스템학회:학술대회논문집
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    • 1986.10a
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    • pp.468-470
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    • 1986
  • An optimal control in heat-up operation was formulated for minimizing the quadratic performance criterion which is a function of temperature, temperature gradient in the wall and fuel flow rate. For optimal control law computations mathematical model was simplified with assumptions and then linearized by use of orthogonal collocation in radial direction. Effects of weighting function assigned to temperature and temperature gradient and final time were compared with industrial data.

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Development of Design Program of Regeneratively Cooled Combustion Chamber (재생냉각 연소실 설계 프로그램 개발)

  • Cho, Won-Kook;Seol, Woo-Seok
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.3
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    • pp.102-110
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    • 2004
  • A design code validated against the thermal analysis results of CFD and published RTE code for a regeneratively cooled combustion chamber has been developed. The major function of the code is to predict the regenerative cooling performance and stress of the chamber wall. Adopted are the empirical correlation for the evaluation of the heat transfer coefficient of hot gas and coolant, and theoretical formula for the fin effect of the channel rib. The hot-gas-side wall temperature from the present code shows 100 K difference at most compared to RTE results. It shows less than 10 % difference for the heat flux thrall through the chamber wall and hot-gas-side convective heat transfer coefficient. The major cause of the wall temperature difference is due to the underestimation of the fin effect of the channel rib.

An Engineering Method for Non-Linear Fracture Mechanics Analysis of Circumferential Through-Wall Cracked Pipes Under Internal Pressure (내압이 작용하는 원주방향 관통균열 배관의 비선형 파괴역학 해석법)

  • Huh, Nam-Su;Kim, Yun-Jae;Kim, Young-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.6
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    • pp.1099-1106
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    • 2002
  • This paper provides engineering J-integral and crack opening displacement (COD) estimation equations for circumferential through-wall cracked pipes under internal pressure and under combined internal pressure and bending. Based on selected 3-D finite element calculations for the circumferential through-wall cracked pipes under internal pressure using the idealized power law materials, the elastic and plastic influence functions for fully plastic J-integral and COD solutions are found as a function of the normalized crack length and the mean radius-to-thickness ratio. These developed GE/EPRI-type solutions are then re-formulated based on the enhanced reference stress method. Such re-formulation not only provides simpler equations for J-integral and COD estimations, but also can be easily extended to combined internal pressure and bending. The proposed equations are compared with elastic-plastic finite element results using actual stress-strain data, which shows overall excellent agreement.

Numerical Study On Combined Natural Convection-Radiation In Partially Open Square Compartments with A Heater (발열체가 있는 열린 공간내에서의 자연대류-복사열전달 현상에 관한 수치적 연구)

  • 손봉세;한규익;서석호;이재효;김태국
    • Fire Science and Engineering
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    • v.9 no.1
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    • pp.10-19
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    • 1995
  • Study on combined natural convection-radiation In partially open square enclosures filled with absorbing-anisotropic scattering media is performed. A heater block located in the enclosure causes the natural circulation of the fluid in the enclosure which results In significant in-flow of the cold fluid through the partially open wall. Four different locations of the heater are considered to observe the effect of the heater locations on the resulting heat transfer. Results obtained from the combined convection-radiation analyses show much stronger circulation of t he fluid inside the enclosure as compared to those obtained from the pure convection analyses. As the ratio of the open area is Increased, the inflow of the cold fluid and the circulation of the fluid inside the enclosure is increased causing lower fluid temperature Inside the enclosure. It is shown that the location of the heater influences the circulation and heat transfer significantly by showing stronger circulations and more uniform temperature distributions for the cases where the heater is located on the bottom wall as compared to those for the cases where the heater is located on the upper part wall of the enclosure. For pure absorbing medium, the expected circulation in the fluid is relatively week as compared to those with absorbing-scattering medium due to the smaller wall heating as the radiant heat is used to heat the fluid instead. The forward anisotropic scattering phase function is shown to increase the fluid circulation further as compared to the isotropic scattering medium.

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