The preparation of underground-backfill material from CSW can be used for large-scale disposal of solid waste. The proportion of backfill material plays an important role in transportation and backfilling effect, and ...
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The preparation of underground-backfill material from CSW can be used for large-scale disposal of solid waste. The proportion of backfill material plays an important role in transportation and backfilling effect, and the mix-proportion optimization of backfill material is essentially a multi-factor and multi-objective optimization problem. In this paper, to obtain the mix proportion of backfill materials with optimal comprehensive-evaluation indexes, and suitable for the engineering application, the fluidity and strength of backfill material, mainly composed of coal gangue(CG), fly ash (FA), flue gas desulfurization gypsum (FGD gypsum), and gasification coarse slag (GCS), were tested by single-factor transformation method, and the effects of various solid wastes on the slump-flow, bleeding rate and early strength of backfill material were analyzed. The optimal mix proportion of CSW with the slump-flow, bleeding rate, and 3-day and 7-day strengths as the evaluation indicators is FA: GCS: FGD gypsum: CG = 25%:25%:25%:25%, according to the multi-objective decision model. Furthermore, the comprehensive evaluation index that meets the requirements of mine backfilling is obtained by changing the ordinary portland cement (OPC) content, that is, the optimal OPC content is 10% of the total solid waste, and the mass concentration is 78%. Finally, the pore structure, micromorphology, and composition of the backfill material with the optimal mix proportion were studied by Mercury Intrusion Porosimetry (MIP), X-ray Diffraction (XRD), and Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM-EDS). The research results provide a good reference for the field application of CSW for underground backfilling.
As the most developed city circle in northern China, allocating CO2 emission quotas at the Bohai Rim Economic Circle (BREC) city level is essential for developing specific abatement policies. Thus, with reflecting mul...
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As the most developed city circle in northern China, allocating CO2 emission quotas at the Bohai Rim Economic Circle (BREC) city level is essential for developing specific abatement policies. Thus, with reflecting multi-principles (fairness, efficiency, sustainability, and feasibility), this paper formulates the CO2 emission quota allocation among cities in BREC in 2030 based on the multi-objectivedecision approach. We first propose three allocation schemes based on the principles of fairness, efficiency, and sustainability, which are conducted by entropy method, zero-sum gains data envelopment (ZSG-DEA) model, and CO2 sequestration share method, respectively. Then, the CO2 allocation satisfaction is defined and used to measure the feasibility principle which is integrated as the objective function of the multi-objective decision model together with three allocation schemes to obtain the optimal allocation results. The results show that Beijing, Tianjin, Dalian, Shijiazhuang, Yantai, Weifang, and Linyi enjoy the largest CO2 emission quotas, having 1179.94 Mt in total and accounting for 31%. Beijing has the highest quotas, and Laiwu has the lowest emission quotas. Cities with large energy consumption and less CO2 sequestration capacity, such as Tianjin, Handan, and Tangshan, experience a decrease in the emission quota shares from 2017 to 2030, indicating that these cities would undertake large emission reduction obligations. Sensitivity analysis shows that Beijing, Zibo, and Jinan are more sensitive to minimum satisfaction changes, and the total satisfaction experiences an increase first and declines thereafter. Based on the results above, cities with large pressure to reduce CO2 emissions should not only promote economic development but also improve the capacity of CO2 sequestration by enhancing environmental protection to realize emission reduction targets.
Time, cost and quality are important objectives of each project, which project managers are always looking for completion of them in the shortest possible time, with the lowest cost and highest quality to be succeeded...
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Time, cost and quality are important objectives of each project, which project managers are always looking for completion of them in the shortest possible time, with the lowest cost and highest quality to be succeeded in the projects. One of the main challenges in this case is choosing the right approach to achieve these objectives. In this regard, the most commonly used approach is the use of balancing method. Indeed, using this method can be the most optimal mode of project implementation activities that the lowest and highest quality at the lowest cost, time has obtained. In this paper, a goal programming model is developed to find suitable solutions to manage the cost, time and quality of the project. In order to examine the developed model, a case study has been accomplished in the project implemented by Arak Machine Sazi Company. Computational results show the applicability of the model and the efficiency of proposed method.
Oil refinery production planning is a complex system and crucial. The optimization for production plan needs a mathematical model to represent the production system that can be used by the optimization model. This pap...
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ISBN:
(纸本)9781614999003;9781614998990
Oil refinery production planning is a complex system and crucial. The optimization for production plan needs a mathematical model to represent the production system that can be used by the optimization model. This paper presents a mathematical model of Master Production Scheduling (MPS) for Kalak Refinery System that can be used for future especially in optimizing its production system. In spite of the fact that MPS has been broadly studied but it has been very few in refinery system maybe because of its complexity in limited production capacity and flexible fabrication routings. In the mathematical model, steps in deriving the model are explained started from the block diagram of the production system, definition of all variables, list of constraints and lastly the final mathematical model with the objective and its general constraints. The model has been validated by comparing the actual production volume with the estimated volume calculated by the model. This paper successfully presents and validates a mathematical model for multi-objective decision model.
Large-scale emergency events bring a lot of effect to people's ordinary life, so it is necessary to provide fast and effective location-allocation analysis information for emergency traffic evacuation and succor. ...
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Large-scale emergency events bring a lot of effect to people's ordinary life, so it is necessary to provide fast and effective location-allocation analysis information for emergency traffic evacuation and succor. In this issue, some related models based on location-allocation analysis are introduced into emergency traffic evacuation field. Considering the actual situation and character of emergency traffic evacuation, we develop maximum covering models which are applied to emergency traffic evacuation and its optimized algorithm. Finally, we discuss some feasible solution strategies, and then get the large-scale emergency traffic evacuation plant provide dependable decision-making support for succor.
Large-scale emergency events bring a lot of effect to people’s ordinary life,so it is necessary to provide fast and effective location-allocation analysis information for emergency traffic evacuation and *** this iss...
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Large-scale emergency events bring a lot of effect to people’s ordinary life,so it is necessary to provide fast and effective location-allocation analysis information for emergency traffic evacuation and *** this issue,some related models based on location-allocation analysis are introduced into emergency traffic evacuation *** the actual situation and character of emergency traffic evacuation,we develop maximum covering models which are applied to emergency traffic evacuation and its optimized ***,we discuss some feasible solution strategies,and then get the large-scale emergency traffic evacuation plan provide dependable decision-making support for succor.
As a way of rearranging social economic resources, M&A (Merger and Acquisition) has been applied widely in corporate operating. It is assumed that the buyer has found a satisfied target company in past researches,...
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ISBN:
(纸本)7560323553
As a way of rearranging social economic resources, M&A (Merger and Acquisition) has been applied widely in corporate operating. It is assumed that the buyer has found a satisfied target company in past researches, but this assumption is not correspond with reality. Because of this reason, researches on searching and screening target companies are less, searching target companies with modem search theory is lack. In order to solve the realistic problems of selecting target companies in the process of M&A, the paper gives a search model of target companies to decide the bestsearching number by using the tool of search theory and Stigler decision method. And, the paper applies a decisionmodel of multi-objective to look for satisfied target companies, which may be. helpful to choose the best target companies of M&A more scientifically.
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