h. moomivand

Considering the consumption of more than 25% of energy by raw mill materials in cement plants, providing a suitable plan for blending different mining zones can be an effective approach in reducing the energy consumption. The purpose of this paper is optimizing the plan of blending limestone mining zones to reduce milling energy consumption raw mills (ball mill and HPGR). The geomechanical properties of different mine zones have been identified by performing the bond work index, drop weight, and uniaxial compressive strength (UCS) tests. Also, to comply with cement production standards, cementing modules including S.I.M, A.L.M, and L.S.F have been calculated for different mine zones. Mining production planning with the aim of achieving the minimum comminution energy and transportation costs has been developed by the Goal programming method. Planning constraint equations are also considered to regulate cement modules. Finally, utilizing windows Quantitative System for Business software, the necessary calculations have been carried out. Based on the results, the extraction order and blending values of different mine zones are adjusted regarding cement modules and minimizing transportation costs, leading to a reduction in energy consumption of raw mills.

Petrophysical and Geomechanical properties of rocks are important parameters in the design of engineering works and classification of rocks for engineering purposes. Recent studies indicate that geophysical methods, especially seismic and electrical, are able to estimate mechanical parameters and recognize spatial variations. In this research, to develop a predictive model for the uniaxial compressive strength (UCS), special electrodes were installed on the saturated core samples and simultaneously, the uniaxial compressive strength test and electric current flowing through the samples was done and variation of electrical resistivity during loading was measured in the laboratory. The results indicated that the structure and texture of rock had an important effect on the resistivity behavior during a mechanical loading.In this study, thirty core samples from the Fault breccias and Bimrocks (Block-in-matrix-rocks), were collected from different locations of Sabzkouh tunnel route in Chahar Mahal and Bakhtiari Provence. Regression analysis showed that there were generally strong correlations between the UCS and Resistivity in the samples having volumetric block proportion (VBP) of 25–75%. Multiple regression equations were derived for the prediction of UCS based on the resistivity and VBP values. The coefficient of determination (R2) and the root mean square error (RMSE) and the geometric mean error ratio (GMER) indices were calculated as 89.13%, 8.683 and 0.911, respectively, to characterize the prediction performance of the MLR model. The statistical test showed that the MLR model was valid and acceptable for predicting UCS.

The ability of organizations to manage crises and challenges has a significant impact on community resilience. Organizations provide essential services in times of crisis and play a very important role in the speed with which society returns to normal. Therefore, organizational resilience, which means the capacity of the organization to predict the crisis, respond appropriately to the crisis, reduce the impact and resistance to its damage, and finally recovery from the crisis, has become an important issue in organizational research. . In research organizations, the destructive innovations of competing organizations are a major and critical challenge that requires organizational resilience. This study examines the relationship between the dimensions of knowledge management and resilience in a research organization. The statistical population of the research is 60 researchers of the research organization. The data collection tool is a questionnaire distributed among the members of the statistical population and the completed questionnaires are the basis of the analysis of this research. The validity and reliability of the questionnaire were examined using expert opinion and Cronbach's alpha calculation, respectively. In addition, SPSS software was used to analyze the data and test the research hypotheses. Findings show that there is no significant relationship between innovation in knowledge management and knowledge transfer with organizational resilience, but between the dimensions of knowledge retention, application of knowledge, acquisition, documentation of management results. Knowledge and its creation have a significant relationship with organizational resilience, so the organization must review the processes of knowledge transfer and innovation in knowledge management to move towards organizational resilience.

Changing excavation from drilling and blasting to mechanical method has many advantges related to the environmental health, safety, and economic benefits. The rock mass weakness degree due to the possibility of excavation by a bulldozer can be the important basis for the changing the excavation method. In adition, the cost price of each method is also an important criterion. The rock mass weakness degree can be investigated using rock mass properties such as uniaxial compressive strength (UCS) and discontinuity spacing or relatively lower limit of blastability index (BI) or at the higher limit of rock fragmentation index (RFI). UCS=13.38 MPa, discontinuity spacing<0.1 m, BI=20.33 and RFI=42 were obtained in Sardar Bucan limestone mine. The powder factors were also obtained 0.18 kg/m3 and 0.253 kg/m3 for using BI and RFI respectively. Drilling and blasting operations were carried out for using different powder factors espacialy for minimum powder factor of 0.253 kg/m3 with burden to blasthole diameter ratio of 42 corresponding RFI=42. The cost price was assessed 14434 Rls/ m3 (6443 Rls/ton) for powder factor of 0.253 kg/m3. Mechanical excavation using a bulldozer was applied to replace the method of drilling and blasting, and the cost price of excavation by bulldozer was obtained equal to 8319 Rls/m3 (3713 Rls/ton), which was 58% of the cost of drilling and blasting method at the optimized conditions. The possibility of changing excavation from blasting to mechanical method can be an important development in the safety, economic and environmental benefits.