3,113 research outputs found
Classical and quantum quasi-free position dependent mass; P\"oschl-Teller and ordering-ambiguity
We argue that the classical and quantum mechanical correspondence may play a
basic role in the fixation of the ordering-ambiguity parameters. We use
quasi-free position-dependent masses in the classical and quantum frameworks.
The effective P\"oschl-Teller model is used as a manifested reference potential
to elaborate on the reliability of the ordering-ambiguity parameters available
in the literature.Comment: 10 page
Non-Hermitian von Roos Hamiltonian's -weak-pseudo-Hermiticity, isospectrality and exact solvability
A complexified von Roos Hamiltonian is considered and a Hermitian first-order
intertwining differential operator is used to obtain the related position
dependent mass -weak-pseudo-Hermitian Hamiltonians. Using a
Liouvillean-type change of variables, the -weak-pseudo-Hermitian von Roos
Hamiltonians H(x) are mapped into the traditional Schrodinger Hamiltonian form
H(q), where exact isospectral correspondence between H(x) and H(q) is obtained.
Under a user-friendly position dependent mass settings, it is observed that for
each exactly-solvable -weak-pseudo-Hermitian reference-Hamiltonian
H(q)there is a set of exactly-solvable -weak-pseudo-Hermitian isospectral
target-Hamiltonians H(x). A non-Hermitian PT-symmetric Scarf II and a
non-Hermitian periodic-type PT-symmetric Samsonov-Roy potentials are used as
reference models and the corresponding -weak-pseudo-Hermitian isospectral
target-Hamiltonians are obtained.Comment: 11 pages, no figures
Position-dependent-mass; Cylindrical coordinates, separability, exact solvability, and PT-symmetry
The kinetic energy operator with position-dependent-mass in cylindrical
coordinates is obtained. The separability of the corresponding Schr\"odinger
equation is discussed within radial cylindrical mass settings. Azimuthal
symmetry is assumed and spectral signatures of various z-dependent interaction
potentials (Hermitian and non-Hermitian PT-symmetric) are reported.Comment: 16 page
(1+1)-Dirac particle with position-dependent mass in complexified Lorentz scalar interactions: effectively PT-symmetric
The effect of the built-in supersymmetric quantum mechanical language on the
spectrum of the (1+1)-Dirac equation, with position-dependent mass (PDM) and
complexified Lorentz scalar interactions, is re-emphasized. The signature of
the "quasi-parity" on the Dirac particles' spectra is also studied. A Dirac
particle with PDM and complexified scalar interactions of the form S(z)=S(x-ib)
(an inversely linear plus linear, leading to a PT-symmetric oscillator model),
and S(x)=S_{r}(x)+iS_{i}(x) (a PT-symmetric Scarf II model) are considered.
Moreover, a first-order intertwining differential operator and an
-weak-pseudo-Hermiticity generator are presented and a complexified
PT-symmetric periodic-type model is used as an illustrative example.Comment: 11 pages, no figures, revise
d-Dimensional generalization of the point canonical transformation for a quantum particle with position-dependent mass
The d-dimensional generalization of the point canonical transformation for a
quantum particle endowed with a position-dependent mass in Schrodinger equation
is described. Illustrative examples including; the harmonic oscillator,
Coulomb, spiked harmonic, Kratzer, Morse oscillator, Poschl-Teller and Hulthen
potentials are used as reference potentials to obtain exact energy eigenvalues
and eigenfunctions for target potentials at different position-dependent mass
settings.Comment: 14 pages, no figures, to appear in J. Phys. A: Math. Ge
The Energy Eigenvalues of the Two Dimensional Hydrogen Atom in a Magnetic Field
In this paper, the energy eigenvalues of the two dimensional hydrogen atom
are presented for the arbitrary Larmor frequencies by using the asymptotic
iteration method. We first show the energy eigenvalues for the no magnetic
field case analytically, and then we obtain the energy eigenvalues for the
strong and weak magnetic field cases within an iterative approach for
and states for several different arbitrary Larmor frequencies. The
effect of the magnetic field on the energy eigenvalues is determined precisely.
The results are in excellent agreement with the findings of the other methods
and our method works for the cases where the others fail.Comment: 13 pages and 5 table
Part of the D - dimensional Spiked harmonic oscillator spectra
The pseudoperturbative shifted - l expansion technique PSLET [5,20] is
generalized for states with arbitrary number of nodal zeros. Interdimensional
degeneracies, emerging from the isomorphism between angular momentum and
dimensionality of the central force Schrodinger equation, are used to construct
part of the D - dimensional spiked harmonic oscillator bound - states. PSLET
results are found to compare excellenly with those from direct numerical
integration and generalized variational methods [1,2].Comment: Latex file, 20 pages, to appear in J. Phys. A: Math. & Ge
Bound - states for truncated Coulomb potentials
The pseudoperturbative shifted - expansion technique PSLET is generalized
for states with arbitrary number of nodal zeros. Bound- states energy
eigenvalues for two truncated coulombic potentials are calculated using PSLET.
In contrast with shifted large-N expansion technique, PSLET results compare
excellently with those from direct numerical integration.Comment: TEX file, 22 pages. To appear in J. Phys. A: Math. & Ge
First-order intertwining operators with position dependent mass and - weak-psuedo-Hermiticity generators
A Hermitian and an anti-Hermitian first-order intertwining operators are
introduced and a class of -weak-pseudo-Hermitian position-dependent mass
(PDM) Hamiltonians are constructed. A corresponding reference-target
-weak-pseudo-Hermitian PDM -- Hamiltonians' map is suggested. Some
-weak-pseudo-Hermitian PT -symmetric Scarf II and periodic-type models
are used as illustrative examples. Energy-levels crossing and flown-away states
phenomena are reported for the resulting Scarf II spectrum. Some of the
corresponding -weak-pseudo-Hermitian Scarf II- and
periodic-type-isospectral models (PT -symmetric and non-PT -symmetric) are
given as products of the reference-target map.Comment: 11 pages, no figures, Revised/Expanded, more references added. To
appear in the Int.J. Theor. Phy
INFLUENCE OF DRUG SOLUBILITY AND POLYMERS SUPPLY SOURCE ON THE PHYSICAL PERFORMANCE OF MATRIX TABLETS
Objective: The aim of this study is to explore the possible effects of drug solubility and commercial supply sources of HPMC and PVP on physical properties of matrix tablets.
Methods: Two different supply sources (A and B) for Hydroxy Propyl Methyl Cellulose (HPMC) as matrix forming polymer and Polyvinyl Pyrrilidone (PVP) as matrix supportive polymer were used with either Chlorphenaramine maleate (CPM), as a water soluble drug or Atenolol (ATN), as a water insoluble drug, to produce a series of matrix formulations using direct compression according to a 23 full factorial design. Matrices were then qualified for friability, hardness, and drug release attributes.
Results: Matrix hardness and friability properties demonstrated to be influenced by PVP supply source as an individual factor alone or in combination with drug solubility factor, moreover, both properties were found to be less affected by drug solubility and HPMC supply source, as individual factors. Compared to other factors, drug solubility was found to have a substantial influence on drug dissolution efficiency (DE) and diffusion exponent of the drug release (n) of different matrices.
Conclusion: Variation in commercial PVP supply source and drug solubility could possibly result in matrices with different physical performance
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