Schwannomas account for about 8% of intracranial tumors and 90% are vestibular schwannomas. Oculomotor schwannoma without neurofibromatosis is extremely rare. A 41-year-old female presented with complaints of blurred vision, and the neurologic examination revealed afferent pupillary defect and decreased visual acuity of the left side. Brain magnetic resonance image showed an extra axial mass in...

We report a study of the 3E excited-state structure of single negatively charged nitrogen-vacancy (NV) defects in diamond, combining resonant excitation at cryogenic temperatures and optically detected magnetic resonance. A theoretical model is developed and shows excellent agreement with experimental observations. In addition, we show that the two orbital branches associated with the 3E excite...

First-principles calculations are presented for the phosphorus vacancy VP in ZnGeP2, using full-potential linearized muffin-tin orbital supercell local density functional theory calculations. We find the VP to have a high energy of formation compared to the GeZn antisite donor in Zn-poor material. Including a band gap correction to the Hamiltonian, the defect is predicted to be amphoteric with ...

The electronic behavior of metallic carbon nanotubes under the influence of atomistic vacancy defects present in the channel is theoretically investigated using non-equilibrium Green’s function method self-consistently coupled with three-dimensional electrostatics. A nearest neighbor tight binding model based on a single pz orbital is used for the device Hamiltonian. A single vacancy defect in ...

Relativistic Quantum Defect Orbital (RQDO) calculations, with and without explict account for core-valence correlation, have been performed on dipole-allowed transitions between the levels belonging to the 3s2 3p2, 3s2 3p nd (n = 3, 4, 5), 3s2 3p ns (n = 4, 5) and 3s2 3p 4p configurations of the Si-like ion SIII in the LS-coupling scheme. The present oscillator strengths, which are of considera...

We propose a mechanism of photostructural changes in amorphous As2S3 ( a-As2S3) on the basis of ab initio molecular orbital calculations on clusters of atoms modeling the local structure of the amorphous system. We have found that trigonal AsS3 pyramidal units can be transformed into a fivefold coordinated As site having four As-S bonds and one As-As bond via a photoionization process. This pho...

Using the orbital-free density functional theory as a model theory, we present an analysis of the field theoretic approach to quasi-continuum method. In particular, by perturbation method and multiple scale analysis, we provide a formal justification for the validity of numerical coarse-graining of various fields in the quasi-continuum reduction of field theories by taking the homogenization li...

The electronic behavior of metallic carbon nanotubes under the influence of externally applied electric fields is investigated using the Non-Equilibrium Green’s function method self consistently coupled with three-dimensional (3D) electrostatics. A nearest neighbor tight binding model based on a single pz orbital for constructing the device Hamiltonian is used. The 3D Poisson equation is solved...

Sino-nasal mycosis is a known complication in patients with immunological or metabolic compromise. Mainstay of treatment includes reversal of the compromised state, systemic antifungals and repeated radical debridements assisted by serial imaging. Salvage is possible provided no cerebral extension exists on presentation. The resultant deformity following debidement causes gross morbidity and ps...