Nonlinear Schrodinger Equations and N=1 Superconformal Algebra

By using AKNS scheme and soliton connection taking values in N=1 superconformal algebra we obtain new coupled super Nonlinear Schrodinger equations.Comment: 12 pages, no figures, LaTex fil

Implications of a Quantum Mechanical Treatment of the Universe

We attempt to treat the very early Universe according to quantum mechanics. Identifying the scale factor of the Universe with the width of the wave packet associated with it, we show that there cannot be an initial singularity and that the Universe expands. Invoking the correspondence principle, we obtain the scale factor of the Universe and demonstrate that the causality problem of the standard model is solved.Comment: LaTex, 5 pages, 1 figure, to be published in Mod. Phys. Lett.

A Numerical Study to Investigate the Hydrodynamic Properties of Nanowire Motion in Liquid

Manipulating micro(nano)-sized entities in liquid environment is a challenging yet necessary task in nanoscience and nanotechnology development. Due to the small dimensions, viscous behavior dominates the micro(nano)-sized obejcts motion. In this study, a computational fluid dynamic (CFD) approach has been used to investigate hydrodynamic effects on a nanowire (NM) translating an rotating about its long and short axis. Several numerical methods dealing with solid motion in fluid, including some CFD methods and Finite element analysis (FEA), have been compared. The change in drag coefficient with NW length, NW diameter, translational velocity, rotation speed, and wall effects has been researched. As a model, nanowires with 1-10 µm dimensions and 50 nm-250 nm diameters were investigated in liquid, with velocities of 0.5-500 µm/s. Nanowire is rotated about its long axis with an angular velocity of ω=0.25π, 0.5π, 1.0π, 2.0π rad/s, and about its short axis with a fluid flow allow the rotation of the nanowire whose one end is contsrained to a rotational motion around x and y axis. These models were also compared with the existing analytical models. Good agreement was observed between the numerical results and analytical calculations. The FEA model is also repeated in the closed boundary to investigate the wall effects on the nanowire’s motion in liquid environment

Efficacy of letrozole versus clomiphene citrate for infertile women with polycystic ovary syndrome

Background: The aim was to compare ovulation induction protocols in anovulatory patients, who make up a significant percentage of infertility patients, and to determine the most appropriate treatment for patients in the clinic based on the findings.Methods: The effectiveness of clomiphene citrate (CC) and letrozole (aromatase inhibitor) in ovulation induction treatments were retrospectively compared in patients who applied for infertility in the last 5 years and were found to be anovulatory. 20 of these patients were being treated with clomiphene citrate, while the 18 were being treated with letrozole.Results: The study included a total of 38 anovulatory infertile patients. The mean age of the patients was found to be 29.3. When the endometrial thicknesses (ET) after the treatment were compared, the first group's mean EC was 6.1, while that of the second group was 9.05. The endometrial thicknesses measured after the treatments were found to be significantly different, which were consistent with other studies in the literature. Post-treatment ovulation responses were similar with 55% in both groups. In the evaluation of pregnancy outcomes, 20% of pregnancy was achieved in the first group and 33% in the second group.Conclusions: The use of letrozole, an aromatase inhibitor, may be suggested as an alternative to CC in the ovulation induction protocol in our clinical practice, particularly in obese patients

An Upper Bound on the Higgs Boson Mass from a Positivity Condition on the Mass Matrix

We impose the condition that the eigenvalues of the mass matrix in the shifted Lagrangian density be positive at \phi=\phi_{0}, the vacuum expectation value of the scalar field. Using the one-loop effective potential of the standard model, this condition leads to an upper bound on the Higgs boson mass m_{H}: m_{H}<230GeV, for a top quark mass of 175GeV.Comment: LaTex, 5 page

Ab initio investigation of BCS-type superconductivity in LuNi2 B2 C -type superconductors

Journal ArticleAb initio pseudopotential calculations have been made to calculate the structural, electronic, vibrational, and superconducting properties of the borocarbide superconductors RM2B2C(R=Lu,La,Y;M=Ni,Pd,Pt). Using the electronic and vibrational spectra, the average electron-phonon coupling parameter is calculated to be 0.78, 0.83, 0.96, and 1.48 for LaPt2B2C, LuNi2B2C, YPt2B2C, and YPd2B2C, respectively. From a detailed spectral analysis throughout the irreducible Brillouin zone (IBZ), we found that the highest contribution to the electron-phonon coupling parameter for these materials comes from the acoustic and low-frequency optical modes characterized with anomalous dispersion, instead of the A1g optical-phonon mode claimed in previous studies. Using the calculated electron-phonon coupling parameter values, the superconducting critical temperatures for LaPt2B2C, LuNi2B2C, YPt2B2C, and YPd2B2C are found to be 10.40, 15.94, 11.30, and 20.60 K, respectively, which are in good accordance with their experimental values of 10.50, 16.10, 10.00, and 21.00 K.This work was supported by the Scientific and Technological Research Council of Turkey (TÜBİTAK) (Project No. MFAG-114F192). Some of the calculations for this project were carried out using the computing facilities on the Intel Nehalem (i7) cluster (ceres) in the School of Physics, University of Exeter, United Kingdom