Exact Anisotropic Solutions of the Generalized TOV Equation

We explore gravitating relativistic spheres composed of an anisotropic, barotropic uid. We assume a bi-polytropic equation of state which has a linear and a power-law terms. The generalized Tolman-Oppenheimer-Volkoff (TOV) equation which describes the hydrostatic equilibrium is obtained. The full system of equations are solved for solutions which are regular at the origin and asymptotically flat. Conditions for the appearance of horizon and a basic treatment of stability are also discussed.Comment: 14 pages, 9 figure

Holographic Anisotropic Background in 5D Einstien-Gauss-Bonnet Gravity

In this paper, we extend the work on the AdS/QCD model to quadratic gravity to gain insight into the influence of gravity. We obtain an anisotropic black brane solution to a $5D$ Einstein-Gauss-Bonnet-two Maxwell-dilaton system. The background is specified by an arbitrary exponent, a dilaton field, a time component of the first Maxwell field, and a magnetic component of the second Maxwell field. The system in three cases has been investigated and in each case the effect of the parameter of theory, the anisotropic parameter has been considered. The blackening function supports the thermodynamical phase transition between small/large and AdS/large black brane for a suitable chemical potential and other parameters.Comment: 24 pages, 16 figures, accepted in EPJ

Sulfonic acid-functionalized silica: A remarkably efficient heterogeneous reusable catalyst for the one-pot multi-component synthesis of amidoalkyl naphthols

A novel, efficient and one-pot method for preparation of amidoalkyl naphthol derivatives is reported using sulfonic acid-functionalized silica as an effective heterogeneous catalyst under thermal solvent-free conditions. This method has the advantages of high yields, a cleaner reaction, simple methodology, easy work-up and greener conditions. The catalyst is easily prepared, stable (up to 300 C, reusable and efficient under the reaction conditions. Keywords: Amidoalkyl naphthols; Multicomponent synthesis; Solid acid; Sulfonic acid-functionalized silica; Heterogeneous recyclable catalys

MoO3-SiO2 as an efficient and reusable heterogeneous catalyst for the synthesis of 5-substituted 1H-tetrazoles

An efficient method for the preparation of 5-substituted 1H-tetrazole derivatives is reported using MoO3-SiO2 as an efficient heterogeneous catalyst. This method has the advantages of high yields, simple methodology and easy work-up. This catalyst could be recycledAn efficient method for the preparation of 5-substituted 1H-tetrazole derivatives is reported using MoO3-SiO2 as an efficient heterogeneous catalyst. This method has the advantages of high yields, simple methodology and easy work-up. This catalyst could be recycled very easily, which makes this methodology environmentally benign. Keywords: 5-substituted 1H-tetrazole, [2+3] cycloaddition, MoO3-SiO2, solid aci

Ultrabroadband single-cycle terahertz pulses with peak fields of 300 kV cm−1^{-1} from a metallic spintronic emitter

To explore the capabilities of metallic spintronic thin-film stacks as a source of intense and broadband terahertz electromagnetic fields, we excite a W/CoFeB/Pt trilayer on a large-area glass substrate (diameter of 7.5 cm) by a femtosecond laser pulse (energy 5.5 mJ, duration 40 fs, wavelength 800 nm). After focusing, the emitted terahertz pulse is measured to have a duration of 230 fs, a peak field of 300 kV cm$^{-1}$ and an energy of 5 nJ. In particular, the waveform exhibits a gapless spectrum extending from 1 to 10 THz at 10% of amplitude maximum, thereby facilitating nonlinear control over matter in this difficult-to-reach frequency range and on the sub-picosecond time scale.Comment: 7 pages, 4 figure

Effects of Peer Education and Orientation Tour on Anxiety in Patient Candidates for Coronary Angiography

Background: Coronary angiography is a stressful procedure for most patients. The physiological responses caused by anxiety during coronary angiography increase the likelihood of dysrhythmia, coronary artery spasm, and rupture. Objectives: This study compared the effects of peer education and an orientation tour on anxiety in patients who were candidates for coronary artery angiography. Patients and Methods: This single blind quasi-experimental study was conducted in 2014. A total of 177 patients who were candidates for coronary artery angiography were divided into three groups: a peer education group, an orientation tour group, and a control group. The patients in the peer education group were trained by a peer educator, and the patients in in the orientation tour group were trained by the researcher, who worked in the angiography unit. The DASS-21 questionnaire was used to measure the patients’ anxiety levels before the intervention and two hours before undergoing the coronary angiography. The data were analyzed using a Chi-square test, analysis of variance, the Kruskal-Wallis, Wilcoxon, Mann-Whitney U tests, and an interquartile range. Results: The three groups did not significantly differ regarding the mean anxiety scores before the intervention. However, a significant difference was observed between the mean anxiety scores of the three groups after the intervention (P = 0.0001). In the peer education group, the mean anxiety score was 5.34 ± 2.52 and decreased to 3.69 ± 2.87 after the intervention (P = 0.0001). In the orientation tour group, the mean anxiety was 5.53 ± 3.49, which and changed to 3.10 ± 2.22 (P = 0.0001). However, the mean anxiety score significantly increased in the control group (5.66 ± 2.94 vs. 6.53 ± 3.43, P = 0.017). Conclusions: Both methods of peer education and orientation tour decreased the anxiety levels in patients undergoing coronary artery angiography. Therefore, these approaches should be carried out according to the hospital condition and facilities