The fact that mines have to be established at the place where they are located without having a chance to choose a location brings out area usage conflicts with areas that need to be protected. In fact, forestlands are most common in these overlapping areas in Turkey. In order to perform mining activities in this overlapping forestlands, mining enterprises in Turkey receive forest land permit fees (FLPF), reforestation fees, rehabilitation fees + security deposit of conformity to the environment (SDCE), and other fees. In order to determine the share of these costs in mining investments and operating costs (OC) and to bring a solution proposal so that these costs do not pose a risk of loss of the investment in the mining enterprises, questions have been asked to mining enterprises within Turkey using the “Survey Monkey” program. The averages of all forest fees determined from the answers are proportioned to the mining investment amounts (MIA) and the annual average OC of each mining company responding to the Survey.
Thus, the distribution criteria of different forest fees that are required to be paid by the mining enterprises in order to carry out mining operations in the forestlands in Turkey and their distribution on the basis of mineral groups were analyzed. In this calculation, it was suggested that all the fees in Turkey should be reduced to a more reasonable degree by suggesting solutions regarding the calculation method envisaged by the FLPF, which has a very high share. Otherwise, the result of these rates shows that the costs of forest land-use for mining stipulated by the legislation in Turkey are quite high compared to other countries, and that the current mining investments can have difficulty in maintaining their economic operability in the presence of these required costs.
To design breast ultrasound scanning systems or to test new imaging methods, various computer models are used to simulate the acoustic wave field propagation through a breast. The computer models vary in complexity depending on the applied approximations. The objective of this paper is to investigate how the applied approximations affect the resulting wave field. In particular, we investigate the importance of taking three-dimensional (3-D) spatial variations in the compressibility, volume density of mass, and attenuation into account. In addition, we compare four 3-D solution methods: a full-wave method, a Born approximation method, a parabolic approximation method, and a ray-based method. Results show that, for frequencies below 1 MHz, the amplitude of the fields scattering off the compressibility or density contrasts are at least 24 dB higher than the amplitude of the fields scattering off the attenuation contrasts. The results also show that considering only speed of sound as a contrast is a valid approximation. In addition, it is shown that the pressure field modeled with the full-wave method is more accurate than the fields modeled using the other three methods. Finally, the accuracy of the full-wave method is location independent whereas the accuracy of the other methods strongly depends on the point of observation.
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