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1.
Navid Hosseini Kamran Goshtasbi Behdeen Oraee-Mirzamani Mehran Gholinejad 《Arabian Journal of Geosciences》2014,7(5):1951-1956
The state of periodic loading and the interval of periodic roof weighting have an important role in geomechanical stability and, hence, in the continuity of longwall mining operations. In this paper, the mechanism of roof caving in longwall mining—together with the effect of engineering and geomechanical properties of surrounding rock masses on the magnitude and timing of periodic loading—is studied. For this purpose, a longwall mine is first modeled using Phase2 software, and then, by simulating the roof caving process, the periodic roof weighting intervals is calculated. Based on the numerical modeling, the first roof weighting interval and the periodic roof weighting interval are calculated as 27.2 and 12.1 m, respectively. Sensitivity analysis is then applied to determine the effect of changes in the mechanical properties of the rock mass, especially in the main roof and immediate roof. The results of the analysis show that as GSI and quality of the immediate roof increases, the periodic roof weighting interval also increases. Hence, the applied algorithm in this research study can effectively be utilized to calculate the periodic roof weighting interval in the longwall mining method. 相似文献
2.
Masoumeh NABILOU Peyman AFZAL Mehran ARIAN Ahmad ADIB Hassan KHEYROLLAHI Mohammad FOUDAZI Parviz ANSARIRAD 《《地质学报》英文版》2022,96(2):591-606
Multifractal modeling is a mathematical method for the separation of a high potential mineralized background from a non-mineralized background. The Concentration-Distance to Fault structures (C-DF) fractal model and the distribution of the known iron (Fe) deposits/mines seen in the Esfordi and Behabad 1:100,000 sheets from the Bafq region of central Iran are used to distinguish Fe mineralization based on their distance to magnetic basement structures and surface faults, separately, using airborne geophysical data and field surveys. Application of the C-DF fractal model for the classification of Fe mineralizations in the Esfordi and Behabad areas reveals that the main ones show a correlation with their distance from magnetic basement structures. Accordingly, the distances of Fe mineralizations with grades of Fe higher than 55% )43% < Fe ≤ 60%) are located at a distance of less than 1 km, whereas for surfacial faults with grades of 43% ≤ Fe ≤ 60%, the distances are 3162< DF ≤ 4365 m from the faults. Thus, there is a positive relationship between Fe mineralization and magnetic basement structures. Also, the proximity evidence of Precambrian high-grade Fe mineralization related to magnetic basement structures indicates syn-rifting tectonic events. Finally, this C-DF fractal model can be used for exploration of magmatic and hydrothermal ore deposits. 相似文献
3.
Nonlinear dust acoustic (DA) shock waves are studied in a nonextensive charge varying complex plasma. A burger-like equation the coefficients of which is significantly modified by nonextensivity and dust charge fluctuation is derived. It is found that the influence of particle (electrons and ions) nonextensivity and dust charge fluctuation affect the basic properties of the collisionless DA shock wave drastically. 相似文献
4.
Ashraf Samaneh AghaKouchak Amir Nazemi Ali Mirchi Ali Sadegh Mojtaba Moftakhari Hamed R. Hassanzadeh Elmira Miao Chi-Yuan Madani Kaveh Mousavi Baygi Mohammad Anjileli Hassan Arab Davood Reza Norouzi Hamid Mazdiyasni Omid Azarderakhsh Marzi Alborzi Aneseh Tourian Mohammad J. Mehran Ali Farahmand Alireza Mallakpour Iman 《Climatic change》2019,152(3-4):379-391
Climatic Change - By combining long-term ground-based data on water withdrawal with climate model projections, this study quantifies the compounding effects of human activities and climate change... 相似文献
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Regional long-term production modeling from a single well test, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope 总被引:1,自引:0,他引:1
7.
Weak ion-acoustic solitary waves (IASWs) in unmagnetized plasmas having two-fluid ions and kappa-distributed electrons are considered. The effects of electron suprathermality, warm ion temperature and polarity on the nonlinear properties of these IASWs are analyzed. It is found that our present plasma model may support compressive as well as rarefactive solitary structures. 相似文献
8.
Mehran Shahmansouri 《Astrophysics and Space Science》2013,344(1):153-160
Dust-acoustic (DA) solitary waves are investigated in a magnetized dusty plasma comprising cold dust fluid and kappa-distributed ions and/or electrons. The influence of suprathermal particles, obliqueness, and ion temperature on the DA solitary waves is investigated. We find that only negative DA solitary waves will be excited in this model. Also it is shown that the amplitude of the DA solitary wave decreases with deviation of electrons or ions from Maxwellian distribution via decrease of κ e or κ i . The effect of the temperature of the ion decreases with the amplitude and steepness of the solitary wave front. 相似文献
9.
During the last decade, a number of models have been developed to consider the conflict in dynamic reservoir operation. Most of these models are discrete dynamic models which are developed based on game theory. In this study, a continuous model of dynamic game and its corresponding solutions are developed for reservoir operation. Two solution methods are used to solve the model of continuous dynamic game, namely the Ricatti equations and collocation methods. The Ricatti equations method is a closed form solution, requiring less computational efforts compared with discrete models. The collocation solution method applies Newton's method or a quasi-Newton method to find the problem solution. These approaches are able to generate operating policies for dynamic reservoir operation. The Zayandeh-Rud river basin in central Iran is used as a case study and the results are compared with alternative water allocation models. The results show that the proposed solution methods are quite capable of providing appropriate reservoir operating policies, while requiring rather short computational times due to continuous formulation of state and decision variables. Reliability indices are used to compare the overall performance of the proposed models. Based on the results from this study, the collocation method leads to improved values of the reliability indices for total reservoir system and utility satisfaction of water users, compared to the Ricatti equations method. This is attributed to the flexible structure of the collocation model. When compared to alternative water allocation models, lower values of reliability indices are achieved by the collocation method. 相似文献
10.
Pourkerman Majid Marriner Nick Hamzeh Mohammad-Ali Lahijani Hamid Morhange Christophe Amjadi Sedigheh Vacchi Matteo Maghsoudi Mehran Shah-Hosseini Majid Afarin Mohammad 《Natural Hazards》2022,112(2):1823-1849
Natural Hazards - The western Makran subduction zone is capable of producing considerable tsunami run-up heights that penetrate up to 5 km inland. In this study, we show how climate change... 相似文献