نتایج جستجو برای: historical quarries
تعداد نتایج: 108953 فیلتر نتایج به سال:
Many of the grindstones used in Nigerian homes are quarried from sandstone in a small group of villages near Kano in the extreme north of the country. Of an unselected group of 126 stonecutters from two of these villages 49 were found to have radiographic evidence of silicosis, with progressive massive fibrosis in 17. Those with silicosis had worked longer in the quarries than 77 whose radiogra...
Block volumes are generally estimated by analyzing the discontinuity spacing measurements obtained either from the scan lines placed over the rock exposures or the borehole cores. Discontinuity spacing measurements made at the Mesozoic limestone quarries in Karaburun Peninsula were used to estimate the average block volumes that could be produced from them using the suggested methods in the lit...
This paper describes the application of simulation techniques in the forecast behavior of a material handling system, which takes place in Pedro de Valdivia Nitrate Mine in Chile. The main goal of the study was to determine the way a change in the size of loading and carrying fleets would affect the total production of the system which is measured in term of the quantity of material that is mon...
The provenance of flint artefacts found in archaeological excavations is very important for archaeologists to better understand artefact displacement, exchange networks, mobility patterns, prehistoric migrations and various cultural processes such as commerce, procurement strategies, territorial boundaries, etc. Reflectance Spectroscopy an analytical technique that measures the radiation reflec...
The purpose of this study was to determine the lung impact from working within the Libyan quarry industry, and if the length of work impacted the degree of degradation. Eighty three workers from eight silica quarries in the Nafusa Mountains of Libya opted to participate. These quarries were working the upper cretaceous geological structure. Eighty-five individuals who lived in Gharyan City with...
This work has evaluated the effects of a thermally dried or composted dewatered sewage sludge on glucosidase activity, total (TCH) and extractable (ECH) carbohydrate content, microbial biomass carbon (MBC) and basal respiration (BR) of soils from limestone quarries under laboratory conditions. Two doses (low, L and high, H) of the dewatered sludge (DS), or of the respective thermally dried (TD...
In this paper, problem of short-term production planning for dimension stone quarries was mathematically modeled using a binary integer programming. The model includes an objective function, which was founded as the minimization of the costs due to the total cutting planes of the blocks. This objective may cause to maximization of the net present value (NPV) in dimension stone quarries. During ...
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