Summary: The aim of this research is stability analysis of coal pillars in inclined coal seams (the variable pillar width and the variable seam dip) using the finite difference method software (FLAC2D). This aim is achieved by assessing the vertical and shear stresses distribution and their influence on the coal pillar.Introduction: In some mining method such as longwall, room and pillar and stope and pillar, the design of mine is done in such a way that the pillars are left in the seam gradient. Therefore in this case the effect of seam dip must be considered on the stability of pillar. Pillars in dipping strata are under in compression and shear load and therefore require consideration of a failure criterion that accounts for compression and shear load. The stability analysis of coal pillar can be performed by empirical, analytical, statistical and numerical methods.Since the existing empirical methods developed to pillar design have some limitations, the application of numerical methods was widely increasing to optimize pillar size in all mining methods. Applying numerical methods, it is possible to consider seam dip on the stability of coal pillar.Methodology and Approaches: In this study, six numerical models were analyzed in FLAC2D software for 30, 45 and 60 degree steeply coal seams with 10 and 15 m pillar width. It should be noted that 90 m width are considered for stopes in all numerical models. Moreover, exploitation has been started at the first stope and then continued to the second stope. In each step of the analyses, the model is run to equilibrium before creating the second stope.Results and Conclusions: The numerical modeling result on 30, 45 and 60 degree steeply coal seams with 10 and 15 m pillar width showed that the vertical stresses on the pillar decreased by increase of coal seam dip and coal pillar width. Moreover, the shear stresses increased by increases of coal seam dip. Finally, according to the numerical modeling result the pillar width of 15 m on a dip of 30 degree is stable.

Subsidence is an undesirable consequence of underground mining in many countries. It can cause environmental damage and harm surface structures in the mine area. There are many methods for prediction of surface subsidence due to mining activities. Prediction of subsidence due to inclined coal seam working is complicated for non-symmetric nature of the subsidence curve trough. In this research, a new two-conditional function is developed to predict non-symmetric curve of subsidence profile above an inclined long wall face. The results are compared to the subsidence profiles obtained from the Lizhuizi coalmine in China. The coefficient of deviations between calculated and measured data is 0.997. This comparison shows that mining subsidence can be predicted with a reasonable degree of accuracy using the proposed new method.    

Seam carving is one of content aware image retargeting techniques. In this method, a path of pixels with lowest energy, called seam, crossing from top to bottom or from left to right in an image is extracted. By removing or inserting seams, size of the image can be changed. Speed and quality are two main parameters in seam carving. In this paper a new method for speed enhancement of seam carving is proposed. The input image is decomposed into odd and even subimages and searching for seams is performed in parallel in these subimages. Compared to the original seam carving, the proposed method improves the speed at least by two times while maintain image’s quality unchanged. Previous seam searching algorithms can be utilized in our method or it can be combined with other parallel processing schemes. Finally, image quality of the proposed seam carving is improved.

In this paper the geometrical relationship of the folds which exist in the Folded Zagros Mountains, including Asef Mountain (northern Iran), were studied. The southern and western zones of the Zagros Mountains are called the Folded Zagros. These zones extend approximately 1,375 km in length with a width ranging from 120 to 250 km. Asef Mountain is located in northern Shiraz (from northern Sarda to the vicinity of Zarghan) and is part of the southwestern zone of the Folded Zagros. In this area, Cenozoic formations are folded due to the effects of the tectonic process. This study was done in order to identify these folding features. The results of this research indicate that the axial surface of the folding has a dominant northwest-southeast trend which does not conform to the general trend of the Zagros. The folds are placed into the classes: upright gently plunging, steeply inclined gently plunging, steeply inclined moderately plunging, upright moderately plunging, upright sub horizontal, moderately inclined sub horizontal and moderately inclined gently plunging with respect to their geometry and floating divisions (Fluety,1964), on the basis of axial surface and hinge line trends of the Cenozoic formations. Additionally, these folds are categorized in close and open fold classes on the basis of limb inclination (Fluety, 1964).

Friction stir welding (FSW) can be defined as a green technology, because the consumption of energy during this process is less than other welding methods. In addition, during the process there is no gas, filler material or other consumables. It should be noted that, complex curved shapes are now commonly used in different industries in a bid to have lightweight structures. According to the above-mentioned descriptions, several investigations into the potential benefits of adopting Friction Stir Welding (FSW) in the production and joining different materials are being undertaken. The work presented in this paper is focused on thermal behavior of the curved FSW and its benefits for the green technology. Due to the robust nature of FSW process aluminum 6061-T6 alloy has been selected as the welding material. The results of the study showed that, the total peak temperature value of 300° C happened at time, t = 3 s at the plunge stage (outside of the welding seam). Meanwhile, at the dwell stage (between t = 3 s to t = 5 s), there is a stable situation in the amount of the generated heat from the plastic deformation as well as the contact shear stress at the tool-workpiece contact interfaces, thus the interfacial temperature is found to be stable. By the end of the dwelling step, the total generated heat is stable to the maximum value of 300° C. At the step time of t = 12. 8 s, the temperature is distributed asymmetrically across the workpiece until the time step of 19. 6 s which at this point the asymmetric contour expanded in the stir zone.

In order to meet the housing needs with the constraints of meager space available for development, new construction methodology is to be evolved. Soil Nailing is one of the emerging technologies which can help civil engineers for underground construction, slope stability, housing construction on inclined or vertical cuts etc. The literature available on this technique reveals findings based on experimental and empirical studies only. The empirical studies made by various investigators are mostly made by assuming circular, parabolic and straight line rupture surfaces only. In the present study an attempt has been made to develop design of nailed open cuts by assuming log-spiral rupture surface. In the study the tensile force in the nail material has been determined with strength property of nail material. All the possible variables e.g. nail angle, nail length, nail's structural geometry, nail's spacing (horizontal & vertical), method of nail installation, type of loading, nail materials etc have been incorporated in the study. It has been found that the optimum nail angle with the perpendicular to the face and excavation lies between 0 to 10° The optimum length is between 0.6 to 0.9 H, H being the height of cut. Grouted nails are found to exhibit more factor of safety as compared to driven nails. The plastic modulus of the nail material also plays an important role; higher the plastic modulus, more the factor of safety. For construction at the inclined cuts, design charts have also been developed in the present study.      

In the seismically active zones, pseudo-static and pseudo-dynamic approaches are widely used for designing the retaining wall with c-f backfill. However, the effect of soil amplification is neglected while considering propagation of waves from base. Soil amplification is crucial in the computation of seismic active earth pressure while analyzing the retaining walls of significant height. It should not be ignored in the seismic design of retaining wall. In this paper, soil amplification effects has been incorporated in the pseudo-dynamic approach for prediction of earth pressure on inclined retaining supporting inclined c-f soil backfill. Depth of tension crack has been obtained from derived seismic earth pressure distribution for soils having nonzero cohesion. Then total seismic earth pressure is computed from integration of earth pressure from depth of tensile crack to base. A parametric study is conducted to examine the effect of various parameters like cohesion value of soil backfill, wall friction, wall inclination, soil backfill inclination, soil amplification, horizontal and vertical seismic coefficients. The results obtained for seismic active earth pressure is clearly showing the non-linear behavior behind the inclined retaining wall, which is the requirement of the design of retaining wall in earthquake-prone regions.

From controversial view that has been flowing with regard to governmental interference and market freedom since three last centuries, two approaches can be identified: market-inclined and gvernment-inclined. This distinction is based on the weight that each approach assigns to one of these two institutions and its capacities for achievement of optimal economical efficiency. Controversy on this issue has a deep idealogic nature more than anything else and each approach tries to form historical evidence in their favors. In this paper, in addition to proposing the historical process of two approaches’ controversy and their internal varieties, we prove that in the shadow of achievements and failures of two approaches on one hand and proposing the alternative theoretical patterns and formation of developmental successful experience outside of conventional experiences that documented by two controversy parties on other hand, the grounds of the new pattern proposition of governmental interfernce extent have been provided since 1990 decade until now. The institution-inclined approach focusing on the topic of “quality” of interference instead of “quantity” of governmental interference is looking beyond the mentioned ideologic controversy and theorizing aboat the method and quality of positive governmental interaction with market institutions.