Browsing by Publisher "Indian Academy of Sciences"
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Item An investigation of the influence of the pairing correlations on the properties of the isobar analog resonances in A = 208 nuclei(Indian Academy of Sciences, 2004) Kücükbursa A.; Salamov D.I.; Babacan T.; Aygör H.A.Within the quasi-particle random phase approximation (QRPA), the method of the self-consistent determination of the isovector effective interaction which restores a broken isotopic symmetry for the nuclear part of the Hamiltonian is given. The effect of the pairing correlations between nucleons on the following quantities were investigated for the A = 208 nuclei: energies of the isobar analog 0 + states, the isospin admixtures in the ground state of the even-even nuclei, and the differential cross-section for the 208 Pb( 3 He,t) 208 Bi reaction at E( 3 He) = 450 MeV. Both couplings of the excitation branches with T z = To ± 1, and the analog state with isovector monopole resonance (IVMR) in the quasi-particle representation were taken into account in our calculations. As a result of these calculations, it was seen that the pairing correlations between nucleons have no considerable effect on the T = 23 isospin admixture in the ground state of the 208 Pb nucleus, and they cause partially an increase in the isospin impurity of the isobar analog resonance (IAR). It was also established that these correlations have changed the isospin structure of the IAR states, and shifted the energies of the IVMR states to the higher values.Item Entropy generation in non-Newtonian fluid flow in a slider bearing(Indian Academy of Sciences, 2004) Pakdemirli M.; Yilbas B.S.; Yurusoy M.In the present study, entropy production in flow fields due to slider bearings is formulated. The rate of entropy generation is computed for different fluid properties and geometric configurations of the slider bearing. In order to account for the non-Newtonian effect, a special type of third-grade fluid is considered. It is found that the rate of entropy generation is influenced significantly by the height of the bearing clearance and the non-Newtonian parameter of the fluid.Item Assessment of retention basin volume and outlet capacity in urban stormwater drainage systems with respect to water quality(Indian Academy of Sciences, 2005) Yurdusev M.A.; Kumanlioǧlu A.A.; Soemaz B.The quality of river water or other surface waters is detrimentally affected by the contaminants carried by the rainfall runoff in urban areas. The control of pollution moved by rainfall runoff is achieved by installing outlets and small retention basins in stormwater collection systems, thereby allowing only a certain amount of rainfall water to overflow and leading the remaining to treatment plants. This study analyses the effect of concentration time on surface water pollution caused by rainfall runoff. For this purpose, a linear S-curve is assumed for the flow hydrograph arising from the collection system, based on parameters of rainfall considered and the catchment area. An independent code is developed to analyse such a system and this is applied to an urban area using nine-year single-discrete rainfall records of Izmir Station, Turkey. The system is capable of tackling situations where there is only a basin or a basin with outlet.Item Vibrations of stretched damped beams under non-ideal boundary conditions(Indian Academy of Sciences, 2006) Boyaci H.A simply supported damped Euler-Bernoulli beam with immovable end conditions are considered. The concept of non-ideal boundary conditions is applied to the beam problem. In accordance, the boundaries are assumed to allow small deflections and moments. Approximate analytical solution of the problem is found using the method of multiple scales, a perturbation technique.Item Entropy generation in a pipe due to non-Newtonian fluid flow: Constant viscosity case(Indian Academy of Sciences, 2006) Pakdemirli M.; Yilbas B.S.Non-Newtonian fluid flow in a pipe system is considered and a third grade non-Newtonian fluid is employed in the analysis. The velocity and temperature distributions across the pipe are presented. Entropy generation number due to heat transfer and fluid friction is formulated. The influences of non-Newtonian parameter and Brinkman number on entropy generation number are examined. It is found that increasing the non-Newtonian parameter reduces the fluid friction in the region close to the pipe wall. This in turn results in low entropy generation with increasing non-Newtonian parameter. Increasing Brinkman number enhances the fluid friction and heat transfer rates; in which case, entropy number increases with increasing Brinkman number.Item Determination of optimum welding parameters in connecting high alloyed X53CrMnNiN219 and X45CrSi93 steels by friction welding(Indian Academy of Sciences, 2011) Uzkut M.; Ünlü B.S.; Akdağ M.In this study, different welding parameters were applied to two different steels with high alloys and mechanical and metallographical investigations are performed. Thus, the optimum welding parameters were determined for these materials and working conditions. 12·30 diameter steel bars made up of 1·4871 (X53CrMnNiN219) and 1·4718 (X45CrSi93) steel were used as experimental material. The material loss increased with increase in friction and rotating pressure. No fracture at the welding region was observed and the highest fracture energy was identified in B5 group. Based on micro hardness investigation; the hardness profile reached its minimum value at the welding region. © Indian Academy of Sciences.Item Hydrophobic nano-carrier for lysozyme adsorption(Indian Academy of Sciences, 2016) Altunbaş C.; Ural F.Z.; Uygun M.; Avcibaşi N.; Avcibaşi U.; Uygun D.A.; Akgol S.In this work, poly(HEMA-APH) nanoparticles were synthesized by surfactant-free emulsion polymerization technique. Magnetic behaviour was introduced by simple addition of Fe3O4 into the polymerization medium. Characterization of the nanoparticle was carried out by FTIR, ESR, SEM, AFM and EDX analyses. These synthesized magnetic nanoparticles were used for adsorption of lysozyme. For this purpose, adsorption conditions were optimized and maximum lysozyme binding capacity was found to be 278.8 mg g-1 polymer in pH 7.0 phosphate buffer at 25°C. Desorption and reusability properties of the nanoparticles were investigated and lysozyme adsorption efficiency did not change significantly at the end of the 10 successive reuses. © 2016 Indian Academy of Sciences.