We employ a simple effective nucleon-nucleon interaction for sd-shell model calculations derived from the Reid soft-core potential folded with two-body correlation functions which take account of the strong short-range repulsion and large tensor component in the Reid force. Shell model calculations for ground and low lying energy states of neutron rich oxygen isotopes 18-28O are performed using OXBASH code. Generally, this interaction predicts correct ordering of levels, yields reasonable energies for ground states of considered isotopes and predicts very well the newly observed excitation energy of
in 26O. Besides, it produces reasonable energy spectra for 23-27O and compressed energy spectra for 18-22O isotopes. This is mainly due entirely to defects in the
diagonal matrix elements of employed interaction. To improve the present calculations, we modify the interaction through replacing the 14 diagonal matrix elements of
with those of the USD interaction. Mostly, our modified interaction predicts well the ordering of levels, the ground state energies and low lying energy spectra for all selected oxygen isotopes. The modified interaction confirms the location of the neutron drip line at
and also identifies the presence of the shell gap at
and
which proves the doubly magic behavior of 22O and 24O. The spins in 24O of several excitation energies around 7.5 MeV are predicted by our interactions. The calculated results obtained with the modified interaction are very close to those obtained with the empirical interactions of USDB and WPN.
In the present work, the possibility of treating many types of radioactive sources was examined practically. Six types of sealed radioactive sources were selected: 137Cs, 133Ba, 90Sr, 152Eu, 226Ra, and 241Am. The sources were exposed to a neutron flux emitted from 241Am/Be source for 33 days. The results showed a measurable reduction of activity for 226Ra, 241Am, and 152Eu, while the other radionuclides, 137Cs, 133Ba, and 90Sr, showed less response to neutron incineration.
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This study focuses on CFD analysis in the field of the shell and double concentric tube heat exchanger. A commercial CFD package was used to resolve the flow and temperature fields inside the shell and tubes of the heat exchanger used. Simulations by CFD are performed for the single shell and double concentric tube.
This heat exchanger included 16 tubes and 20 baffles. The shell had a length of 1.18 m and its diameter was 220 mm. Solid Works 2014, ANSYS 15.0 software was used to analyze the fields of flow and temperature inside the shell and the tubes. The RNG k-ε model was used and it provided good results. Coarse and fine meshes were investigated, showing that aspect ratio has no significant effect. 14 million
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Heat exchanger is an important device in the industry for cooling or heating process. To increase the efficiency of heat exchanger, nanofluids are used to enhance the convective heat . transfer relative to the base fluid. - Al2O3/water nanofluid is used as cold stream in the shell and double concentric tube heat exchanger counter current to the hot stream basis oil. These nanoparticles were of particle size of 40 nm and it was mixed with a base fluid (water) at volume
concentrations of 0.002% and 0.004%. The results showed that each of Nusselt number and overall heat transfer coefficient increased as nanofluid concentrations increased. The pressure drop of nanofluid increased slightly than the base fluid because
TThe property of 134−140Neodymium nuclei have been studied in framework Interacting Boson Model (IBM) and a new method called New Empirical Formula (NEF). The energy positive parity bands of 134−140Nd have been calculated using (IBM) and (NEF) while the negative parity bands of 134−140Nd have been calculated using (NEF) only. The E-GOS curve as a function of the spin (I) has been drawn to determine the property of the positive parity yrast band. The parameters of the best fit to the measured data are determined. The reduced transition probabilities of these nuclei was calculated. The critical point has been determined for 140Nd isotope. The potential energy surfaces (PESs) to the IBM Hamiltonian have been obtained using the intrin
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The effective Skyrme type interactions have been used in the Haretree-Fock
mean-field model for several decades, and many different parameterizations of the
interaction have been realized to better reproduce nuclear masses, radii, and various
other data. In the present research, the SkM, SkM*, SI, SIII, SIV, T3, Sly4, Skxs15,
Skxs20 and Skxs25 Skyrme parameterizations have been used within Haretree-Fock
(HF) method to investigate some static and dynamic nuclear ground state properties
of 174-206Hg isotopes. In particular, the binding energy per nucleon, proton, neutron,
mass and charge densities and corresponding root mean square radii, neutron skin
thickness and charge form factor. The calculated results are comp
Over the last few decades the mean field approach using selfconsistent
Haretree-Fock (HF) calculations with Skyrme effective
interactions have been found very satisfactory in reproducing
nuclear properties for both stable and unstable nuclei. They are
based on effective energy-density functional, often formulated in
terms of effective density-dependent nucleon–nucleon interactions.
In the present research, the SkM, SkM*, SI, SIII, SIV, T3, SLy4,
Skxs15, Skxs20 and Skxs25 Skyrme parameterizations have been
used within HF method to investigate some static and dynamic
nuclear ground state proprieties of 84-108Mo isotopes. In particular,
the binding energy, proton, neutron, mass and charge densities
Background: Necrotizing fascitis is a progressive, rapidly spreading inflammatory infection located in the deep fascia, with secondary neerosis of the subcutaneous tissues polymicrobial infection is the most common finding in necrotizing fascitis rather than a single caustive organism.
The optical absorption data of Hydrogenated Amorphous Silicon was analyzed using a Dunstan model of optical absorption in amorphous semiconductors. This model introduces disorder into the band-band absorption through a linear exponential distribution of local energy gaps, and it accounts for both the Urbach and Tauc regions of the optical absorption edge.Compared to other models of similar bases, such as the O’Leary and Guerra models, it is simpler to understand mathematically and has a physical meaning. The optical absorption data of Jackson et al and Maurer et al were successfully interpreted using Dunstan’s model. Useful physical parameters are extracted especially the band to the band energy gap , which is the energy gap in the a
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In this research, the frequency-frequency interactions in chaotic systems has been experimentally and numerically studied. We have injected two frequencies on chaotic system where one of these frequencies is modulated with chaotic waveform and the other is untiled as a scanning frequency to find modulating frequency. It is observed that the Fast Fourier Transformation (FFT) peaks amplitude increased when the value of the two frequencies are matched. Thus, the modulating frequency could be observed, this leads to discover a new method to detect the modulating frequency without synchronization.
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Recently, the environmental isotopes are adopted to figure out the hydrological processes, recharge areas, flow paths, groundwater origin and the interaction between different watery bodies. Currently, five samples of the rainwater have been collected since January to April 2012, as well as December 2011. Those sampling periods have highest amounts of precipitation events. Meantime, 25 samples of groundwater, 5 of the Lesser Zab River and 3 of overland flow have been picked up during the wet period. The dry sampling of groundwater and the Lesser Zab River has been achieved in summer 2011. The Local Meteoric Water Line lies between Global Meteoric Water Line (GMWL) and East Mediterranean Water Line (EMWL). The lowest, highest and
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