Optimum burden

The prediction equation with 1.5 times the optimum burden ... 

Figure 10. Measured and predicted vibrations versus scaled distance with increased burden by one and half times the optimum burden at WCL coal mine...

Both the coefficient and the negative power (slope) of the curves are increasing gradually from optimum burden to double the optimum burden. 

The vibration for the blasts of excess burden was calculated by using the burden based predictor equation (15), v = vf2B - 1). The general optimum vibration level (Vj) for different blasts is calculated by substituting the corresponding scaled distance in the in the equation (16), which was derived for the blast rounds with optimum burden (OB). The v so calculated is multiplied by the quantity (2B - 1) to get the predicted... 

Burden has significant influence on the resultant ground vibrations. The increase due to excess burden can be estimated by inserting a factor which consists of ratio of excess burden to optimum burden. 

The net vibration due to deviated burden is a function of vibration with optimum burden and ratio of excess burden to optimum burden. [v2=Vj(25° -l)]. 

The new prediction model was tested in the field conditions and validated successfully for the burden varying from optimum burden to 2.25 times the optimum burden. 

Optimum burden distance depends on elastic modulus and density of rock material. Effect on Poisson s ratio is negligible for such a case. 

It is worth mentioning here that comparisons between the efficiency of different MIP separation systems like two HPLC systems or two CEC systems, or an HPLC system with a CEC system, are quite difficult when the adsorption isotherms are nonlinear. One of the typical difficulties is that the phase ratios in the two systems may be different. The effect of phase ratio on the separation and particularly on the achievable optimum separation is a complex question even in linear chromatography. In nonlinear chromatography this is really difficult and also burdened by the differences between the isotherms of the two compounds to be separated. The complexity of this matter has been mostly overlooked in the MIP literature and the visual comparison of two separations in rather different systems, operated under very different conditions, has frequently lead to statements declaring one technique better than the other. 

The same idea is utilized in the L-curve method [42] where a burden between measurements and the a priori terms is visualized by plotting the a priori norm, i.e. the a priori term in the total (a), versus the measurements norm, i.e. the measurements term in the total (a), with as a function parameter. This plot has an L-shaped corner showing a point with a specific value of of optimum balance between measurement minimization and a priori terms. 

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