The role of a photospheric component and of pair breakdown is examined in the internal shock model of gamma-ray bursts. We discuss some of the mechanisms by which they would produce anomalously steep low energy slopes, X-ray excesses and preferred energy breaks. Sub-relativistic comptonization should dominate in high comoving luminosity bursts with high baryon load, while synchrotron radiation ...

The present study was carried out to determine the possible origins of sediments entering Taleghan Dam in northern part of Iran, in order to avoid further sedimentation and helping in extension of the useful life of the proposed dam. This was performed by XRD analysis. To do so, first of all, sediment sampling points were positioned along the Taleghan River. The collected samples, after coding,...

cients. Normalizing to a unit plot of length 22.13 m, both the USLE and RUSLE use the equation Empirical soil erosion models continue to play an important role in soil conservation planning and environmental evaluations around L 5 (l/22.13) [2] the world. The effect of hillslope length on soil loss, often termed the where L is soil loss normalized to the 22.13-m-long slope length factor, is one...

frequency to retain the triangular shape of the inductor current. It will be assumed in the following, therefore, that.the output signal of amplifier A, includes a remnant of the inductor current triangular waveform (except for possible curvature of the corners) multiplied by a constant (kJ. In CM realisation (Fig. 2), the output of the error amplifier V;, modified by a 'compensation slope' Mc ...

the objective of the current study was to determine the anatomical features of the auditory ossicles inhamster. twenty temporal bones from 10 adult hamsters, weighing 275-300 g were used. after dissectingthem, the features of the ossicles were assessed with an ocular micrometer and photographed by astereomicroscope. finally, all data were evaluated and analysed using the sigma statt software. t...