With the advent and wide spread use of computers a number of algorithms have been developed to determine the optimum ultimate pit limits in open pit mining. The main objective of these algorithms is to find groups of blocks that should be removed to yield the maximum overall mining profit under specified economic conditions and technological constraints. The most common methods are: Lerchs and ...

Planning and design procedure of an open pit mining project just can be started after ultimate pit determination. In the carried out study in this paper it was shown that the most important factor in ultimate pit determination and in consequence in the whole planning and design procedure of an open pit mine is the metal price. Metal price fluctuations in recent years were exaggerated and impose...

The hypothesis that greater safety from cavitation by airseeding through inter-vessel pits comes at the cost of less porous pit membranes with greater flow resistance was tested . Sixteen vessel-bearing species were compared: 11 from the Rosaceae, four from other angiosperm families, and one fern. Unexpectedly, there was no relationship between pit resistance (and hence the prevailing membrane ...

BACKGROUND To report a rare condition of bilateral optic disc pit in a child. CASE DESCRIPTION A ten-year-old female was admitted with a complaint of headache. Visual acuity was 20/20 in both eyes (OU). Anterior segment examination was normal in OU. Fundus examination revealed optic disc pit (ODP) located temporally with a diameter of 1/5 disc diameter in OU. Intraocular pressure was within n...

in this study, a hybrid intelligent model has been designed to predict groundwater inflow to a mine pit during its advance. novel hybrid method coupling artificial neural network (ann) with genetic algorithm (ga) called ann-ga, was utilised. ratios of pit depth to aquifer thickness, pit bottom radius to its top radius, inverse of pit advance time and the hydraulic head (hh) in the observation w...

abandoned surface mine excavations can be a major environmental, social and/or human healthproblem for the mining industry as well as for the community living nearby. this problem is exacerbated by therapidly growing population encroaching on areas of historic mined lands. the aim of this studywas to assess thesafety status of the historic nyala mine excavation with the purpose of coming up wit...

BACKGROUND AND AIMS The lack of triangulation has restricted the growth of flexible endoscopic surgical techniques. In addition, endoscope channel size limits the type of tools that can be used. A novel percutaneous intragastric trocar (PIT) has been developed to address these issues. The aim of this study was to evaluate the procedural characteristics of PIT placement and removal, as well as i...