[1] We show that the spatial coherency of the ambient seismic field can be used for attenuation tomography in the western United States. We evaluate the real portion of the spatial coherency with an elastic geometric spreading term (a Bessel function) and a distance dependent decay (an attenuation coefficient). In order to invert the spatial coherency, a weight stack inversion technique is appl...

ABSTRACT  Introduction: Recently uses of medium and high energy x-rays has been increased in Iran and radiotherapy centers along with a variety of accelerators have been installed in some provinces. In the other hand there is no sufficient skill in designing and making radiotherapy treatment rooms. This study was conducted to evaluate the efficacy of different m...

Several recent studies have used the coherence of seismic noise between stations to retrieve the phase slowness and attenuation. However, there is considerable debate on the feasibility of attenuation retrieval, its interpretation, and its dependence on the noise directionality and has been the subject of several analytical and numerical studies. In this article, we perform a detailed analysis ...

OBJECTIVES Aluminum step wedge (ASW) equivalent radiodensity (eRD) has been used to quantify restorative material's radiodensity. The aim of this study was to evaluate the effects of image acquisition control (IAC) of a digital X-ray system on the radiodensity quantification under different exposure time settings. MATERIALS AND METHODS Three 1-mm thick restorative material samples with variou...

Sugar-mill wastewaters have potential to support microalgal biomass production for use as a biofuel feedstock (lipid source). Growth kinetics, light dynamics, and lipid production in multispecies-microalgae cultures collected from a sugar-mill pond are reported in this paper. Lipid content of the microalgae collected from the pond water was 14.5 % (w/w). Culturing the same microalgae in a photo...

Background: Photon attenuation as an inevitable physical phenomenon influences on the diagnostic information of SPECT images and results to errors in accuracy of quantitative measurements. This can be corrected via different physical or mathematical approaches. As the correction equation in mathematical approaches is nonlinear, in this study a new method of linearization called ‘Piece ...