Any ll-state solutions of the Hulth\'en potential by the asymptotic iteration method

In this article, we present the analytical solution of the radial Schr\"{o}dinger equation for the Hulth\'{e}n potential within the framework of the asymptotic iteration method by using an approximation to the centrifugal potential for any $l$ states. We obtain the energy eigenvalues and the corresponding eigenfunctions for different screening parameters. The wave functions are physical and energy eigenvalues are in good agreement with the results obtained by other methods for different $\delta$ values. In order to demonstrate this, the results of the asymptotic iteration method are compared with the results of the supersymmetry, the numerical integration, the variational and the shifted 1/N expansion methods.Comment: 14 pages and 1 figur

Fracturing ranked surfaces

Discretized landscapes can be mapped onto ranked surfaces, where every element (site or bond) has a unique rank associated with its corresponding relative height. By sequentially allocating these elements according to their ranks and systematically preventing the occupation of bridges, namely elements that, if occupied, would provide global connectivity, we disclose that bridges hide a new tricritical point at an occupation fraction $p=p_{c}$, where $p_{c}$ is the percolation threshold of random percolation. For any value of $p$ in the interval $p_{c}< p \leq 1$, our results show that the set of bridges has a fractal dimension $d_{BB} \approx 1.22$ in two dimensions. In the limit $p \rightarrow 1$, a self-similar fracture is revealed as a singly connected line that divides the system in two domains. We then unveil how several seemingly unrelated physical models tumble into the same universality class and also present results for higher dimensions

A primer on qualitative research synthesis in TESOL

Secondary research in the form of literature reviews facilitates consolidation and transfer of knowledge. In the field of TESOL, the majority of secondary research is conducted in the form of narrative reviews, which rely on the Plonsky’s selection and interpretation of primary studies and findings. Systematic reviews, which can be broadly categorized into meta-analysis (focusing on quantitative data) and qualitative research synthesis (focusing on qualitative data), are gaining popularity (see Plonsky, 2017) but are still less common. In particular, qualitative data collected from language classrooms, which are often criticized because of their lack of generalizability, are seldom synthesized in a systematic fashion. Against this backdrop, this article first attempts to make a case for conducting qualitative research synthesis in the field of TESOL. Second, this article provides a methodological framework and an example of how qualitative research synthesis can be conducted. The article closes with recommendations to promote qualitative research synthesis in the field of TESOL.Publisher PDFPeer reviewe

Elastic, electronic, and vibrational properties of RhN compound

WOS: 000278029900005The structural, electronic, mechanical, and vibrational properties of 4d transition metal mononitride, RhN, are investigated using the norm-conserving pseudopotentials within the local density approximation (LDA) in the frame of density functional theory. The calculated lattice parameters and the bulk modulus almost agree with the previous theoretical values. The second-order elastic constants have been calculated and the other related quantities such as Young's modulus, shear modulus, anisotropy factor, sound velocities, and Debye temperature also estimated. Charge distributions and density of states are reported to understand the bonding character in the stable phases. We have also obtained the phonon dispersion curves without LO/TO splitting.Gazi University [05/2009-55]This work is supported by Gazi University Research-Project Unit under Project No: 05/2009-55. Finally, we kindly acknowledge Dr. Savas Berber for helping on the charge-density calculations

Electronic and mechanical properties of the PdN: A first-principles study

WOS: 000282741400003The structural, electronic, and mechanical properties of 4d transition-metal mononitride, PdN, are investigated using the norm-conserving pseudopotentials within the local density approximation in the framework of the density-functional theory. We have considered four different crystal structures of PdN: (i) zinc-blende (ZB), (ii) rock-salt, (iii) cesium chloride, and (iv) wurtzite, and we have found the most stable structure to be ZB. The elastic constants, Zener anisotropy factor, Poisson's ratio, Kleinman parameter, Young's modulus, shear modulus, Debye temperature, longitudinal, transverse, and average sound velocities are calculated for the most stable structure. Charge distributions and density of states are reported to understand the bonding character in the stable phases. The obtained results are compared with the other available theoretical data. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimGazi University Research-Project Unit [05/2009-55]This work is supported by the Gazi University Research-Project Unit under project no: 05/2009-55

Phonon dispersion and thermodynamical properties in ZrB2, NbB2, and MoB2

WOS: 000275520000006The structural and lattice dynamical calculations are performed on ZrB2, NbB2, and MoB2 compounds using the first-principles of total energy calculations. Generalized gradient approximations (GGA) are used to model exchange-correlation effects. Structural results of these calculations are consistent with past experimental data and other theoretical findings. Our lattice dynamical results regarding phonon dispersion curves and temperature-dependent behavior of thermodynamical properties (entropy, heat capacity, internal energy, and free energy) contribute to the existing literature on these compounds. (C) 2009 Elsevier Ltd. All rights reserved.Gazi University Research-Project Unit [05/2009-55]This work is supported by Gazi University Research-Project Unit under Project No: 05/2009-55

A first-principles studies on TIX (X=P, As)

WOS: 000259560300008We present an ab initio study of the structural, electronic and thermodynamic properties of TIX(X=P,As). The plane-wave pseudopotential approach to the density-functional theory within the LDA and GGA approximations implemented in VASP (Viena Ab-initio Simulation Package) is used. The calculated lattice parameter, elastic constants, and band structures are compared with other available theoretical results, and good agreement is obtained. In addition, we have calculated the transition pressure (P(t)) from zinc-blende (ZB) to (rock-salt) NaCl structures, and have examined some thermodynamic properties.Gazi University Research Project [05/2007-23]This work is supported by Gazi University Research Project unit under Project No: 05/2007-23