We study processes in which neutrinos can be generated as a possible source for the neutron emission form neutron stars. In the high energy limit and in the range em < E < Mw the cross sention for ge →ev`v is analytically calculated. We also calculate the cross section for gg→v`v in the noncommutative space. The obtained results in comparison with the cross section for gg→v`v and gg→gv`v in the commutative space could be quite important in the astrophysics. As a result the cross section for gg→v`v in the noncommutative spaces, in the range A = 100- 300Ge V, is comparable with its counterpart in the commutative space.  

In this paper we intend to determine valence quarks distribution functions u, d in a wide range of x and Q 2 , with using experimental data groups such as CCFR, NuTeV, CHORUS and CDHSW, and determine their correlated errors using xFitter framework. We extracted the results for valence quarks distribution functions with their uncertainties and compared them with other models. Our results are in agreement with the results of other various models and recent PDG results for strong coupling constant in two approximations NLO and NNLO. The extracted results for valence-quark distributions are in good agreement with available theoretical models.

The effect of aftershocks on structures are not usually considered in seismic design codes. In addition to mainshock events, aftershocks can cause major damage to structures, especially to mainshock-damaged structures. Analysis of the characteristics of the mainshock, foreshocks, and aftershocks reveal differences in the ground motion parameters. Structures may undergo a variety of seismic waves with different characteristics that can increase the chance of seismic amplification. The present study examined the effects of aftershock as well as foreshocks events on the response of single degree-of-freedom (SDOF) systems with nonlinear behavior. This allowed inclusion of possible differences during calculation of the response spectrum for cases having foreshock and aftershock effects and those excluding these effects. To this end, 38 mainshocks from different seismic regions with moment magnitudes (Mw) greater than 3.5 were used. More than 168 time acceleration histories from mainshock, aftershock, and foreshock events were applied to evaluate the effects of aftershocks and foreshocks on the response spectrum. The parameters of post-yield stiffness ratio (hardening and softening), ductility factor, period, and site classification were taken into account during 121,000 nonlinear analyses on 60 SDOF models. The results show that the aftershocks as well as foreshocks have a significant effect on the response spectrum, increasing the structural response. Consequently, the effect of aftershocks must be considered in the development of design spectra in seismic codes and guidelines.

Jerk, or jolt, is defined as the time derivative of acceleration. This study investigates the jerk response of Inelastic single-degree-of-freedom (SDOF) systems subjected to pulse-like near-fault ground motions. Compared with ordinary non–pulse-like records, pulse-like motions can impose significantly higher demands on structures. In this work, constant-strength spectra for the jerk response of Inelastic SDOF systems are developed using a set of 91 pulse-like earthquakes. The influence of key structural parameters, including strength reduction factor, hysteretic behavior, and viscous damping ratio, is examined. The results show that jerk demands exhibit slightly higher sensitivity to viscous damping in the short, normalized period region than in the long-period region. Furthermore, an analytical equation is proposed to estimate jerk demand as a function of the ratio of elastic vibration period to pulse period and the strength reduction factor, for various hysteretic models and damping ratios.

Single crystals of Ba1-xKxBiO3 compound for 0 < x <0.6 from insulator to superconducting region have been grown by electrochemical method. The crystals have been characterized by powder x-ray diffraction and Laue x-ray to determine the crystal structure, formed phases and potassium concentration. Inelastic x-ray Scattering spectrum of the crystals has been studied to investigate the phonon properties of this system. The potassium concentration and momentum dependences of the phonon modes have been investigated. The low energy phonons are almost unchanged by increasing of potassium concentration, while the high energy modes are increased considerably by potassium concentration in agreement with Raman and reflection experiments. An anomalous and strong phonon softening has been observed for the high energy phonon modes when the system transitions from insulator to metallic and superconductor system. This anomalous effect suggests a strong electron-phonon interaction and a sign for phonon mechanism of superconductivity in Ba1-xKxBiO3 system.

Porous silicon (PS) layers come into existence as a result of electrochemical anodization on silicon. Although a great deal of research has been done on the formation and optical properties of this material, the exact mechanism involved is not well-understood yet. In this article, first, the optical properties of silicon and porous silicon are described. Then, previous research and the proposed models about reflection from PS and the origin of its photoluminescence are reviewed. The reflecting and Scattering, absorption and transmission of light from this material are then investigated. These experiments include: different methods of PS sample preparation; their photoluminescence, reflecting and Scattering of light; determining different characteristics with respect to Si bulk

For many years now, Conventional Transmission Electron Microscope (CTEM) has been used as an efficient tool to fulfill Nano scale analysis and imaging requirements of scientists and researchers of different areas. Despite the fact that CTEM is a very efficient tool, in some areas researchers must add specially designed equipment to this microscope in order to create desired conditions for observing and imaging their specific specimens. In this article, we introduce one of the most practical kind of CTEM that has been invented for over a decade namely, Energy-Filtering Transmission Electron Microscope (EFTEM). EFTEM has been designed by using physical principles of electron energy-loss spectrometry (EELS) and commercial in-column or post-column energy-filters introduced by companies like: ZEISS and GATAN. It can generate precise images from ultrastructure of different specimens belonging to different areas of research by using Inelastically scattered electrons. The operation of these kind of energy-filters is straightforward and because of that acquiring element specific images within only a few minutes has become possible. For obtaining best results, a fundamental knowledge of the underlying physics of EELS and a systematic development of the technical details is necessary. Also it is important that users be able to know with certainty that EFTEM is the optimal equipment for their experiments. For aforementioned reason, detailed structures of available energy filters and applications of EFTEM in various fields are reviewed in the next article titled “ Introduction to Energy-Filtering Transmission Electron Microscope structure and applications” that will be publish in the next issue of this journal.

In this paper, a new method is proposed for identification of Inelastic shear frame structures with hesteresis, using data collected on their dynamic response. It uses the Prandtl-Ishlinskii rate independent model for hysteresis, which was originally used in the field of plasticity and ferromagnetism. The proposed identification method is capable of identifying the mass, damping and restoring force of a frame structure, which can be used in forming the equations of motion of the frame. By solving the equations of motion, the dynamic response is predicted. The method is based on the combined use of Quadratic Programming (QP) and Genetic Algorithms (GA). First, assuming a set of Prandtl-Ishlinskii constants, the QP is used to find the best frame parameters that can be used in its equations of motion to predict its dynamic response with the minimum of error compared to the real data collected on its dynamic response, while the GA is used to find the best Prandtl-Ishlinskii constants for more reduction in error. The method has been applied to different frames with bilinear nonlinearity where the results show the high capability of the method. Two examples, a Single and a Multi Degree Of Freedom (SDOF and MDOF) frame, are included in the paper.