like limestone powder as it decreases the segregation and bleeding [ 1 ]. The soil is so far modeled on basis of plasticity theory [ 2, 3 ]. The relative displacement of small soil particles due to particle frictional resistance results in plastic
The research on automated stone machining processes was very significant in the last two decades. Sawing, cutting and grinding of different stones like granite, marble, limestone became cheaper and more productive because of the results of researches. When searching through international specialised literature in the topic of stone machining with machine centres, theoretical summaries or researches can hardly be found. The aim of the researchers writing this article is — as a pioneer in Hungary, but also among the first internationally — to examine the optimization and technological problems in the area of stone milling processes. The researchers have developed a complex research system with the collaboration of two departments of University of Technology and Economics and an industrial stone machining firm, Woldem Ltd. to solve the problems. This paper summarizes the parts of this system. General steps and results of research processes are demonstrated by reference experiments. Face milling operations were made on a granite block with five different cutting speeds and then the researchers measured slip safety and average surface roughness values in case of different samples. Finally, upcoming tasks of the research team are summarized.
Authors:S. M. El-Behery, W. A. El-Askary, M. H. Hamed, and K. A. Ibrahim
Heat transfer in gas-solid two-phase flow is investigated numerically and experimentally. The numerical computations are carried out using four-way coupling Eulerian-Lagrangian approach. The effects of particle rotation and lift forces are included in the model. The gas-phase turbulence is modeled via low Reynolds number k-ε turbulence models. The SIMPLE algorithm is extended to take the effect of compressibility into account. The experimental study is performed using crushed limestone to simulate the solid phase. The effects of Reynolds numbers, particles size and temperature on the pressure drop and the temperature of the phases are investigated. The model predictions are found to be in a good agreement with available experimental data for high speed gas-solid flow and present experimental data for low speed flow. The present results indicate that heat transfer in gas solid flow can be modeled using ideal gas incompressible flow model at low conveying speed, while for high speed flow, a full compressible model should be used.
specialist for Missan oil company (operator of the field), for review but not for publishing. 2.1 Mishrif formation The top is characterized by an unconformity. The formation is presented by limestone of white, light–brown, and brown color due to oil stain
Authors:G. Lizia Thankam, T.R. Neelakantan, and S. Christopher Gnanaraj
. Weerdt , M. B. Haha , G. L. Saout , K. O. Kjellsen , H. Justnes , and B. Lothenbach , “ Hydration mechanisms of ternary Portland cements containing limestone powder and fly ash ,” Cem. Concr. Res. , vol. 41 , no. 3 , pp. 279 – 291
Authors:Rayan Gh. Thannoun, Salim A. Fanoosh, and Hadeer Gh. M. Adeeb
ridge of the three anticlines. It consists of a terrain with a high altitude formed on the beds of limestone alternating with marl and clay of the Fatha formation (Middle Miocene). 4.1.4 Alluvial terraces, flood plain and valley filling Some parts of
stone, pillar base, corbels, column drums, – fired brick and lime-sand brick, fired clay, limestone and porous concrete wall block, – formwork block, ceramic and concrete lining, – wooden cube, small and large stone cube for pavement, – concrete paving