Entanglement entropy of dispersive media from thermodynamic entropy in one higher dimension

A dispersive medium becomes entangled with zero-point fluctuations in the vacuum. We consider an arbitrary array of material bodies weakly interacting with a quantum field and compute the quantum mutual information between them. It is shown that the mutual information in D dimensions can be mapped to classical thermodynamic entropy in D+1 dimensions. As a specific example, we compute the mutual information both analytically and numerically for a range of separation distances between two bodies in D=2 dimensions and find a logarithmic correction to the area law at short separations. A key advantage of our method is that it allows the strong subadditivity property---notoriously difficult to prove for quantum systems---to be easily verified.Comment: Corrected typos. Added reference

Induction motor control system with voltage controlled oscillator circuit

A voltage controlled oscillator circuit is reported in which there are employed first and second differential amplifiers. The first differential amplifier, being employed as an integrator, develops equal and opposite slopes proportional to an input voltage, and the second differential amplifier functions as a comparator to detect equal amplitude positive and negative selected limits and provides switching signals which gate a transistor switch. The integrating differential amplifier is switched between charging and discharging modes to provide an output of the first differential amplifier which upon the application of wave shaping provides a substantially sinusoidal output signal. A two phased version with a second integrator provides a second 90 deg phase shifted output for induction motor control

End-wall boundary layer measurements in a two-stage fan

Detailed flow measurements made in the casing boundary layer of a two-stage transonic fan are summarized. These measurements were taken at a station upstream of the fan, between all blade rows, and downstream of the last row. Conventional boundary layer parameters were calculated from the measured data. A classical two dimensional casing boundary layer was measured at the fan inlet and extended inward to approximately 15 percent of span. A highly three dimensional boundary layer was measured at the exit of each blade row and extended inward to approximately 10 percent of span. The steep radial gradient of axial velocity noted at the exit of the rotors was reduced substantially as the flow passed through the stators. This reduced gradient is attributed to flow mixing. The amount of flow mixing was reflected in the radial redistribution of total temperature as the flow passed through the stators. The blockage factors calculated from the measured data show an increase in blockage across the rotors and a decrease across the stators. For this fan the calculated blockages for the second stage were essentially the same as those for the first stage

General calculation of 4f−5d4f-5d transition rates for rare-earth ions using many-body perturbation theory

The $4f-5d$ transition rates for rare-earth ions in crystals can be calculated with an effective transition operator acting between model $4f^N$ and $4f^{N-1}5d$ states calculated with effective Hamiltonian, such as semi-empirical crystal Hamiltonian. The difference of the effective transition operator from the original transition operator is the corrections due to mixing in transition initial and final states of excited configurations from both the center ion and the ligand ions. These corrections are calculated using many-body perturbation theory. For free ions, there are important one-body and two-body corrections. The one-body correction is proportional to the original electric dipole operator with magnitude of approximately 40% of the uncorrected electric dipole moment. Its effect is equivalent to scaling down the radial integral \ME {5d} r {4f}, to about 60% of the uncorrected HF value. The two-body correction has magnitude of approximately 25% relative to the uncorrected electric dipole moment. For ions in crystals, there is an additional one-body correction due to ligand polarization, whose magnitude is shown to be about 10% of the uncorrected electric dipole moment.Comment: 10 pages, 1 figur

Extraction of crystal-field parameters for lanthanide ions from quantum-chemical calculations

A simple method for constructing effective Hamiltonians for the 4fN and 4fN-15d energy levels of lanthanide ions in crystals from quantum-chemical calculations is presented. The method is demonstrated by deriving crystal-field and spin-orbit parameters for Ce3+ ions doped in LiYF4, Cs2NaYCl6, CaF2, KY3F10 and YAG host crystals from quantum chemical calculations based on the DV-X{\alpha} method. Good agreement between calculated and fitted values of the crystal-field parameters is obtained. The method can be used to calculate parameters even for low-symmetry sites where there are more parameters than energy levels

Simplified diagrammatic expansion for effective operator

For a quantum many-body problem, effective Hamiltonians that give exact eigenvalues in reduced model space usually have different expressions, diagrams and evaluation rules from effective transition operators that give exact transition matrix elements between effective eigenvectors in reduced model space. By modifying these diagrams slightly and considering the linked diagrams for all the terms of the same order, we find that the evaluation rules can be made the same for both effective Hamiltonian and effective transition operator diagrams, and in many cases it is possible to combine many diagrams into one modified diagram. We give the rules to evaluate these modified diagrams and show their validity.Comment: 5 journal pages, 4 figure

RadOnc: An R Package for Analysis of Dose-Volume Histogram and Three-Dimensional Structural Data

Purpose/Objectives: Dose volume histogram (DVH) data are generally analyzed within the context of a treatment planning system (TPS) on a per-patient basis, with evaluation of single-plan or comparative dose distributions. However, TPS software generally cannot perform simultaneous comparative dosimetry among a cohort of patients. The same limitations apply to parallel analyses of three-dimensional structures and other clinical data. Materials/Methods: We developed a suite of tools ("RadOnc" package) using R statistical software to better compare pooled DVH data and empower analysis of structure data and clinical correlates. Representative patient data were identified among previously analyzed adult (n=13) and pediatric (n=1) cohorts and these data were used to demonstrate the performance and functionality of the RadOnc package. Results: The RadOnc package facilitates DVH data import from the TPS and includes automated methods for DVH visualization, dosimetric parameter extraction, statistical comparison among multiple DVHs, basic three-dimensional structural processing, and visualization tools to enable customizable production of publication-quality images. Conclusions: The RadOnc package provides a potent clinical research tool with the ability to integrate robust statistical software and dosimetric data from cohorts of patients. It is made freely available to the community for their current use and remains under active development