Effective moment of inertia for several fission reaction systems induced by nucleons, light particles and heavy ions

Compound nucleus effective moment of inertia has been calculated for several fission reaction systems induced by nucleons, light particles, and heavy ions. Determination of this quantity for these systems is based upon the comparison between the experimental data of the fission fragment angular distributions as well as the prediction of the standard saddle-point statistical model (SSPSM). For the systems, the two cases, namely with and without neutron emission corrections were considered. In these calculations, it is assumed that all the neutrons are emitted before reaching the saddle point.It should be noted that the above method for determining of the effective moment of inertia had not been reported until now and this method is used for the first time to determine compound nucleus effective moment of inertia. Hence, our calculations are of particular importance in obtaining this quantity, and have a significant rule in the field of fission physics. Afterwards, our theoretical results have been compared with the data obtained from the rotational liquid drop model as well as the Sierk model, and satisfactory agreements were found. Finally, we have considered the effective moment of inertia of compound nuclei for the systems that formed similar compound nuclei at similar excitation energies.Comment: 9 pages, 2 Figures, 2 Table

The frequency of ovarian masses and lesions in different age categories in Khorram Abad (1381-1391)

Introduction: Ovarian cancer is the second most common cancer of the reproductive organs and the most common cause of death from malignancy of reproductive organs. Ovarian tumors are very different in terms of histology. The studies showed a large variation in prevalence and types of ovarian tumors at different ages. This study was performed with the aim to evaluate the frequency of the ovarian lesions at different age categories. Methods: this descriptive study was performed on 350 ovarian pathology samples of women referred to Pathology Center of Khorram Abad Shohadaye Ashayer during 2002-2012. Data related to physical examination and demographic data and chief complain of patients obtained from archival records and if necessary contact with them. The vague pathology specimens and insufficient records were excluded. Data was analyzed by SPSS statistical software (version 16). P< 0.05 was considered significant. Results: 83.4 of masses were related to reproductive ages that 91.4 of them were benign and the malignant tumors were predominantly observed in pre and post menopausal ages. Many masses were discovered and removed during other abdominal surgeries such as appendectomy that mostly were in reproductive ages andmost of them were benign. Conclusions: despite functional cysts are more common in reproductive ages, the highest prevalence of ovarian malignant lesions are seen in pre and post menopausal ages that Cerocyst adenocarsinoma is the most common. According to the increased prevalence of ovarian malignancies in these age categories, follow up of the masses in these age groups is very important. Therefore, it is recommended that this subject be given more importance in the annual examinations. © 2015-Journal Management System

A novel method for the prediction of pre-saddle neutrons in heavy-ion induced fission reaction systems

The number of neutrons emitted by compound nucleus before reaching the saddle-point ( ν pre) is calculated for 16 8 O+20882Pb , 12 6 C+23692U , 11 5 B+23793Np and 18 8 O+19779Au , h eavy-ion induced fission reaction systems. The behavior of angular anisotropies of fission fragments is normal for 16 8 O+20882Pb and 18 8 O+19779Au reaction systems, since the targets have spherical shapes. For these systems, the agreement between the angular anisotropies experimental data, as well as the predictions of standard saddle-point statistical model is high. And as the mass asymmetry, parameters is greater than the Businaro-Gallone asymmetry parameters α BG for the other two systems, the behavior of angular anisotropies of fission fragments is expected to be normal. Overall, an anomalous behavior in the angular anisotropies for these systems and the contributions of non compound nucleus events are observed

Prediction of fission barrier height for induced fission reactions with 16O at several energies

We have calculated the fission barrier height for 16O+208Pb, 16O+209Bi, 16O+232Th, 16O+238U and 16O+248Cm systems in energy range between 90 MeV to 215 MeV. This method is based on the experimental data for angular anisotropies of fission fragments. In present work, we have used the transition state model (STM) for two different cases: the first case is without neutron emission correction and the second case is with neutron emission correction. In this paper, we have predicted the fission barrier for the two super heavy nuclei that were not reported previously with experimental methods

Fission fragment angular distribution in heavy ion induced fission

  We have calculated the fission fragment angular anisotropy for 16O + 232Th,12C + 236U , 11B + 237 Np , 14 N + 232 Th , 11B + 235U , 12C + 232Th systems with the saddle point statistical model and compared the fission fragment angular anisotropy for these systems. This comparison was done with two methods a) without neutron correction and b) with neutron correction. Also we studied normal and anomalous behavior of the fission fragment angular anisotropy. Finally, we have predicted the average emitted neutron from compound nuclei considering the best fit for each system

Large-Scale Experimental and Numerical Study of Blast Acceleration Created by Close-In Buried Explosion on Underground Tunnel Lining

Despite growing demands for structures in water transportation tunnels, underground installations, subsurface dams, and subterranean channels, there is limited field knowledge about the dynamic behavior of these structures in the face of near-fault earthquakes or impulse excitations. This study conducted a large-scale test on underground tunnel excited by two close-in subsurface explosions. The horizontal and vertical acceleration were recorded on the vertical wall of the tunnel and the free field data including the acceleration on the ground surface at 11-meter distance from the tunnel. The frequency domain analysis of recorded results determined the frequency 961 Hz and 968 Hz for 1.69 kg and 2.76 kg equivalent T.N.T., respectively. Then, finite element analysis results were compared with the test data. The comparisons demonstrated a good correlation and satisfied the field data. Finally, based on numerical modeling, a parametric study was applied to determine the effects of shear wave velocity distance of the crater with respect to the tunnel on impulse response of the tunnel