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Selecting the best mining method among many alternatives is a multicriteria decision making problem. The aim of this paper is to demonstrate the implementation of an integrated approach that employs AHP and PROMETHEE together for selecting the most suitable mining method for the "Coka Marin" underground mine in Serbia. The related problem includes five possible mining methods and eleven criteria to evaluate them. Criteria are accurately chosen in order to cover the most important parameters that impact on the mining method selection, such as geological and geotechnical properties, economic parameters and geographical factors. The AHP is used to analyze the structure of the mining method selection problem and to determine weights of the criteria, and PROMETHEE method is used to obtain the final ranking and to make a sensitivity analysis by changing the weights. The results have shown that the proposed integrated method can be successfully used in solving mining engineering problems.

This paper presents a conceptual framework for investigation of the factors influencing the failure of small and medium enterprises (SMEs) as well as the level of their recovery. Based on the review of literature, all the factors are classified either as individual characteristics of entrepreneurs or non-individual characteristics, that is, characteristics related to SMEs. Having in mind various factors identified by different researchers in their studies, the authors of this paper formed a basic hypothetical framework as well as a qualitative framework for evaluation of the most significant factors influencing SME failure and recovery. Accordingly, a preliminary questionnaire was designed in order to collect the attitudes of entrepreneurs regarding the impact of particular factors. The results of the survey were used for further quantitative analysis and as a base for the formation of a structural equation model for testing the proposed hypotheses. Using the structural equation model to derive results, the authors have found that all the analysed factors except the factors related to private time activities of entrepreneurs/owners of SMEs have a statistically significant influence on SME success, with external non-individual factors having the greatest influence. Furthermore, the results indicate that the level of recovery, business life cycle stage and the sector of a failed SME impact on the ranking of the factors leading to SME failure. The study points to the necessity of improving the conditions under which SMEs operate, primarily by removing the obstacles that hinder growth and development of SMEs as well as by developing the appropriate system of support for entrepreneurs. In addition, having a clear vision of the factors of failure can help SMEs to become more resistant to the adverse effects of these factors and deal with them more effectively.

This work was motivated by the need to better reconcile emission factors for fugitive dust with the amount of geologic material found on ambient filter samples. The deposition of particulate matter with aerodynamic diameter less than or equal to 10 m (PM 10 ), generated by travel over an unpaved road, over the first 100 m of transport downwind of the road was examined at Ft. Bliss, near El Paso, TX. The field conditions, typical for warm days in the arid southwestern United States, represented sparsely vegetated terrain under neutral to unstable atmospheric conditions. Emission fluxes of PM 10 dust were obtained from towers downwind of the unpaved road at 7, 50, and 100 m. The horizontal flux measurements at the 7 m and 100 m towers indicated that PM 10 deposition to the vegetation and ground was too small to measure. The data indicated, with 95% confidence, that the loss of PM 10 between the source of emission at the unpaved road, represented by the 7 m tower, and a point 100 m downwind was less than 9.5%. A Gaussian model was used to simulate the plume. Values of the vertical standard deviation z and the deposition velocity V d were similar to the U.S. Environmental Protection Agency (EPA) ISC3 model. For the field conditions, the model predicted that removal of PM 10 unpaved road dust by deposition over the distance between the point of emission and 100 m downwind would be less than 5%. However, the model results also indicated that particles larger than 10 m (aerodynamic diameter) would deposit more appreciably. The model was consistent with changes observed in size distributions between 7 m and 100 m downwind, which were measured with optical particle counters. The Gaussian model predictions were also compared with another study conducted over rough terrain and stable atmospheric conditions. Under such conditions, measured PM 10 removal rates over 95 m of downwind transport were reported to be between 86% and 89%, whereas the Gaussian model predicted only a 30% removal. One explanation for the large discrepancy between measurements and model results was the possibility that under the conditions of the study, the dust plume was comparable in vertical extent to the roughness elements, thereby violating one of the model assumptions. Results of the field study reported here and the previous work over rough terrain bound the extent of particle deposition expected to occur under most unpaved road emission scenarios. IMPLICATIONSThis work was motivated by the well-documented disagreement between estimates of road and other geological dust obtained by emissions inventory methods and the actual amount of inorganic minerals observed on filter samples at ambient monitoring sites. This study provides a basis for modeling the magnitude of PM 10 dust removal by deposition close to the emission source. The analysis focuses on emissions from unpaved roads, though the results may be pertinent to other sources of fugitive dust. TECHNICAL PAPER INTRODUCTIONFugitive dust is emitted from an unpaved road when a vehicle ...

During the spring and summer of 2000, 2001, and 2002, gaseous and particulate matter (PM) fuel-based emission factors for ϳ150,000 low-tailpipe, individual vehicles in the Las Vegas, NV, area were measured via on-road remote sensing. For the gaseous pollutants (carbon monoxide, hydrocarbons, and nitrogen oxide), a commercial vehicle emissions remote sensing system (VERSS) was used. The PM emissions were determined using a Lidar-based VERSS. Emission distributions and their shapes were analyzed and compared with previous studies. The large skewness of the distributions is evident for both gaseous pollutants and PM and has important implications for emission reduction policies, because the majority of emissions are attributed to a small fraction of vehicles. Results of this Las Vegas study and studies at other geographical locations were compared. The gaseous pollutants were found to be close to those measured by VERSS in other U.S. cities. The PM emission factors for spark ignition and diesel vehicles are in the range of previous tunnel and dynamometer studies. INTRODUCTIONThe first fuel-based (pollutant emission per quantity of fuel burned) emission distributions for particulate matter (PM) determined by cross-plume light detection and ranging (Lidar) backscatter measurements are presented here and compared with carbon monoxide (CO), nitrogen oxide (NO), and hydrocarbon (HC) emission distributions

Abstract:The aim of this article is to evaluate the quality of the Danube River in its course through Serbia as well as to demonstrate the possibilities for using three statistical methods: Principal Component Analysis (PCA), Factor Analysis (FA) and Cluster Analysis (CA) in the surface water quality management. Given that the Danube is an important trans-boundary river, thorough water quality monitoring by sampling at different distances during shorter and longer periods of time is not only ecological, but also a political issue. Monitoring was carried out at monthly intervals from January to December 2011, at 17 sampling sites. The obtained data set was treated by multivariate techniques in order, fi rstly, to identify the similarities and differences between sampling periods and locations, secondly, to recognize variables that affect the temporal and spatial water quality changes and thirdly, to present the anthropogenic impact on water quality parameters.Unauthenticated Download Date | 8/30/18 8:07 AM

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This study highlights the consequences on soil pollution of one hundred years of manufacturing in the Copper Mining and Smelting Complex RTB--Bor (Serbia). Soil sediments were taken via a probe from the surface layer of the soil at twelve different measuring points. The measuring points were all within 20 km of the smelting plant, which included both urban and rural zones. Soil sampling was performed using a soil core sampler in such way that a core of a soil of radius 5 cm and depth of 30 cm was removed. Subsequently, the samples were analyzed for pH and heavy metal concentrations (Cu, Pb, As, Cd, Mn, Ni and Hg) using different spectrometric methods. The obtained results for the heavy metal contents in the samples show high values: 2,540 mg kg -1 Cu; 230 mg kg -1 Pb; 6 mg kg -1 Cd; 530 mg kg -1 Ni; 1,300 mg kg -1 Mn; 260 mg kg -1 As and 0.3 mg kg -1 Hg. In this study, critical zones of polluted soil were identified and ranked according to their metal contents by the multi-criteria decision method Preference Organization Method for Enrichment Evaluation/Geometrical Analysis for Interactive Assistance -PROMETHEE/GAIA, which is the preferred multivariate method commonly used in chemometric studies. The ranking results clearly showed that the most polluted zones are at locations holding the vital functions of the town. Therefore, due to the high bioavailability of heavy metals through complex reactions with organic species in the sediments, consequences for human health could drastically emerge if these metals enter the food chain.