6,596 research outputs found
Momentum space properties from coordinate space electron density
Electron density and electron momentum density, while independently tractable
experimentally, bear no direct connection without going through the
many-electron wave function. However, invoking a variant of the
constrained-search formulation of density functional theory, we develop a
general scheme (valid for arbitrary external potentials) yielding decent
momentum space properties, starting exclusively from the coordinate space
electron density. Numerical illustration of the scheme is provided for the
closed-shell atomic systems He, Be and Ne and for singlet
electronic excited state for Helium by calculating the Compton profiles and the
expectation values derived from given coordinate space electron
densities.Comment: 4 pages, 1 figur
Solve Non-Linear Parabolic Partial Differential Equation by Spline Collocation Method
This paper provides an overview of the formulation, analysis and implementation of Spline collocation method for the numerical solution of partial differential equation with two space variable which is of parabolic type. The method includes the solution of non-linear equation which can be expressed as in matrix form. The use of spline collocation methods in the solution of initial-boundary value problems for parabolic-type system id described, with emphasis on alternating direction implicit methods. Problem of vertical groundwater recharge solve by spline collocation method. Finally, recent applications of spline collocation method are outlined
Two-Layered Model of Blood Flow through Composite Stenosed Artery
In this paper a steady, axisymmetric flow, with a constricted tube has been studied. The artery has been represented by a two-layered model consisting of a core layer and a peripheral layer. It has been shown that the resistance to flow and wall shear stress increases as the peripheral layer viscosity increases. The results are compared graphically with those of previous investigators. It has been observed that the existence of peripheral layer is useful in representation of diseased arterial system
Leptonic decay of Heavy-light Mesons in a QCD Potential Model
We study the masses and decay constants of heavy-light flavour mesons D, Ds,
B and Bs in a QCD Potential model. The mesonic wavefunction is used to compute
the masses of D and B mesons in the ground state and the wavefunction is
transformed to momentum space to estimate the pseudoscalar decay constants of
these mesons. The leptonic decay widths and branching ratio of these mesons for
different leptonic channels are also computed to compare with the experimental
values. The results are found to be compatible with available data.Comment: 9 pages,3 table
Sensitivity Enhancement of a Concave Shaped Optical Fiber Refractive Index Sensor Covered with Multiple Au Nanowires
In the present paper, a new kind of concave shaped refractive index sensor (CSRIS) exploiting localized surface plasmon resonance (LSPR) is proposed and numerically optimized. The LSPR effect between polaritons and the core guided mode of designed CSRIS is used to enhance the sensing performance. The sensor is characterized for two types of sensing structures coated with gold (Au) film and Au nanowires (AuNWs), respectively. The influence of structural parameters such as the distance (D) of the concave shaped channel (CSC) from the core, the diameter of the nanowire (dn) and the size (s) of the CSC are investigated here. In comparison to Au film, the AuNWs are shown to significantly enhance the sensitivity and the performance of the designed sensor. An enhanced sensitivity of 4471 nm/RIU (refractive index unit) is obtained with AuNWs, for a wide range of analytes refractive index (na) varying between 1.33 to 1.38. However, for conventional Au film; the sensitivity of 808.57 nm/RIU is obtained for the same range of analytes
Drug-induced nephrotoxicity
Drug-induced nephrotoxicity is an extremely common condition and is responsible for a variety of pathological effects on the kidneys. Drug-induced acute renal failure (ARF) accounted for 20% of all ARF cases. Drugs showed to cause nephrotoxicity exert their toxic effects by one or more common pathogenic mechanisms. Although it is impossible to present all the drugs causing the nephrotoxicity, this article will summarize the mechanism of injury associated with particular common medications, discuss clinical presentations, renal markers, and evaluate strategies that prevent or minimize renal injury. Drug-induced nephrotoxicity tends to be more common among certain patients and in specific clinical situations. Therefore, successful prevention requires knowledge of pathogenic mechanisms of renal injury, patient-related risk factors, drug-related risk factors, and preemptive measures, coupled with vigilance and early intervention. General preventive measures include using alternative non-nephrotoxic drugs whenever possible; correcting risk factors, if possible; assessing baseline renal function before initiation of therapy, followed by adjusting the dosage; monitoring renal function and vital signs during therapy, and avoiding nephrotoxic drug combinations. Surprisingly, little information is available to guide us with respect to avoiding complications in critical illness; therefore, it is necessary to follow the guidelines
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