• Title/Summary/Keyword: cohesive deposit

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Analysis of Characteristics of Cohesive Sediment Settling (점착성 퇴적물의 침전 특성 분석)

  • Kim, Jong-Woo;Yoon, Sei-Eui;Lee, Jong-Tae
    • Journal of Korea Water Resources Association
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    • v.38 no.2
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    • pp.133-142
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    • 2005
  • The settling concentration of fine suspended solid particles(alumina(Al$_2$O$_3$) and quartz(SiO$_2$)) is investigated with the physico-chemical effects(initial concentration, pH and NaCl). Laboratory tests have confirmed the significant influence of increasing initial concentration and salinity which can lead to flocculation due to the intermolecular attraction. Furthermore, the influence of the pH value on the concentration-time corves of alumina has been on firmed. Besides a numerical model to predict the behaviour of cohesive deposit under still water is analyzed by solving the unsteady one-dimensional diffusion-advection equation with a explicit, implicit, Crank-Nicolson and finite difference scheme. The model predicts the existence of an equilibrium concentration. Application of the model with implicit centered difference to data from settling experiments shows a similar distribution.

Lateral capacity of piles in layered soil: a simple approach

  • Mandal, Bikash;Roy, Rana;Dutta, Sekhar Chandra
    • Structural Engineering and Mechanics
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    • v.44 no.5
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    • pp.571-584
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    • 2012
  • Appropriate assessment of lateral capacity of pile foundation is known to be a complex problem involving soil-structure interaction. Having reviewed the available methods in brief, relative paucity of simple and rational technique to evaluate lateral capacity of pile in layered soil is identified. In this context, two efficient approaches for the assessment of lateral capacity of short pile embedded in bi-layer cohesive deposit is developed. It is presumed that the allowable lateral capacity of short pile is generally dictated by the permissible lateral displacement within which pile-soil system may be assumed to be elastic. The applicability of the scheme, depicted through illustration, is believed to be of ample help at least for practical purpose.

Measurement of the Slider-Disk Contact during Load/Unload process with AE and Electrical Resistance (Load/Unload 시 AE 와 전기저항을 이용한 슬라이더-디스크 충돌측정에 관한 연구)

  • Kim, Seok-Hwan;Lee, Yong-Hyun;Lim, Soo-Cheol;Park, Kyoung-Su;Park, No-Cheol;Park, Young-Pil
    • Transactions of the Society of Information Storage Systems
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    • v.3 no.4
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    • pp.160-166
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    • 2007
  • In this paper, the measured electrical resistance method is proposed to analyze the ramp-tab contact during the load/unload (L/UL) process. Since this method supplies the voltage change due to the resistance change, we can easily and conveniently identify the ramp-tab contact from the acoustic emission (AE) signal. At first, we carefully deposit the conductive material on the surface of the conventional ramp by sputtering method. The ratio frequency (RF) magnetron co-sputtering system is applied to accomplish the deposited double-layers on the ramp surface. One layer is the stainless steel for the conductive layer and the other is the titanium layer for the cohesive function between the ramp surface and the stainless steel layer. In order to guarantee the stiffness and damping properties of the original ramp, the deposited conductive layer is intended to have very thin thickness. After integration the proposed ramp device into the L/UL system and networking the electrical resistance circuit, the L/UL performance is experimentally evaluated by comparing the measured electrical resistance signal and AE signal.

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