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
Bugini , Roberto – Folli , Luisa : The use of „Aurisina limestone” in the roman architecture (Milan and Lombardy). VIII. Congresso Nazionale di Archeometria Scienze e Beni Culturali
The Kőbánya district of Budapest is situated on the eastern margins of the Hungarian capital city. Beneath Kőbánya there is an extensive limestone layer, in which tunnels and passages have been made, some of which appear to date from the 13th century. In the 19th century, the limestone caverns of Budapest-Kőbánya were used for the refrigeration of perishable goods in large quantities. The caverns represent one of Budapest’s historical industrial landmarks, although their architectural history has not been documented in full. This article analyses the architectural development of these evidently low-tech facilities, while also exploring their significant role in the city’s urbanisation. The technical functions and structure of the system of caverns may be useful as a resource for society in the future when the supply of fossil fuels runs out. The effectiveness of the caverns as places for refrigeration can be demonstrated through climatic calculations. The cavern system has significant energy capabilities, given that there is aconstant air temperature throughout the year. The vast amount of geothermal energy could be used to cool heat pumps or heat exchangers. The results of measurements taken in preparation for this article are presented.
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.
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.
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
Molli , Giancarlo – White , Joseph Clancy – Kennedy , Lori – Taini , Veronica : Low temperature deformation of limestone, Isola Palmaria, northern Apennine, Italy – The role of primary textures, precursory veins and intracristalline