Abstract
We formulate a computational method to evaluate the overlap integral of the shell-model and cluster-model wave functions. The framework is applied to the system of the core plus two ...neutrons, and the magnitude of the overlap of the shell-model configuration (core + $n$ + $n$) and the di-neutron cluster one (core + $2n$) is explored. We have found that the magnitude of the overlap integral is prominently enhanced when two neutrons occupy shell-model orbits with low orbital angular momenta, such as $s$- and $p$-wave orbits. The shell–cluster overlap is calculated in systems with $jj$-closed cores plus two neutrons, and the enhancement due to occupation of the $s$ or $p$ orbit also occurs in the systematic calculation. The effect of the configuration interaction on the shell–cluster overlap integrals is also discussed.
γ softness in atomic nuclei is investigated in the framework of energy density functionals. By mapping constrained microscopic energy surfaces for a set of representative nonaxial medium-heavy and ...heavy nuclei to a Hamiltonian of the proton-neutron interacting boson model (IBM-2) containing up to three-body interactions, low-lying collective spectra and transition rates are calculated. Observables are analyzed that distinguish between the two limiting geometrical pictures of nonaxial nuclei: the rigid-triaxial rotor and the γ-unstable rotor. It is shown that neither of these pictures is realized in actual nuclei, and that a microscopic description leads to results that are almost exactly in between the two geometrical limits. This finding points to the optimal choice of the IBM Hamiltonian for γ-soft nuclei.
Power semiconductor devices, such as insulated-gate bipolar transistors, metal-oxide-semiconductor field-effect transistors, and static-induction thyristors, are used in different kinds of pulsed ...power generators developed for different applications. In addition, the semiconductor opening switch is found to have very effective applications in pulsed power generation by inductive energy storage. Semiconductor switches have greatly extended the scales of pulsed power parameters, especially in repetition rate and lifetime. They have also enabled new areas of pulsed power applications, such as accelerators, flue-gas treatment, and gas lasers.
Situated in the so-called “island of inversion,” the nucleus 32Mg is considered as an archetypal example of the disappearance of magicity at N=20. We report on high statistics in-beam spectroscopy of ...32Mg with a unique approach, in that two direct reaction probes with different sensitivities to the underlying nuclear structure are employed at the same time. More specifically, states in 32Mg were populated by knockout reactions starting from 33Mg and 34Si, lying inside and outside the island of inversion, respectively. The momentum distributions of the reaction residues and the cross sections leading to the individual final states were confronted with eikonal-based reaction calculations, yielding a significantly updated level scheme for 32Mg and spin-parity assignments. By fully exploiting observables obtained in this measurement, a variety of structures coexisting in 32Mg was unraveled. Comparisons with theoretical predictions based on shell-model overlaps allowed for clear discrimination between different structural models, revealing that the complete theoretical description of this key nucleus is yet to be achieved.
To describe an ultrasound-guided transurethral bladder biopsy technique using endoscopic forceps and its results in dogs of different sizes with different lesion locations.
Medical records of dogs ...that underwent ultrasound-guided transurethral bladder biopsy with endoscopic forceps were retrospectively reviewed. Patient signalment, lesion location, use of urinary catheter as a guide, outcome of the procedure and histopathology results were retrieved.
Twenty-seven dogs underwent this procedure. Biopsy samples were successfully obtained in 23 dogs. Insertion of the endoscopic forceps without a urinary catheter allowed the procedure to be performed in patients with a small urethral diameter without complication. The procedure was unsuccessful in dogs with a urethral diameter smaller than the outer diameter of the biopsy forceps (i.e. 1.8 mm), either due to small patient size or obstructive urethral lesion. All biopsy samples allowed histopathological diagnosis. No complications were reported after the procedure.
This non-invasive biopsy technique should be considered in patients with bladder lesions in which histopathological diagnosis is needed, especially when endoscopic examination is not feasible. By use of the Doppler mode, biopsy retrieval was safe also when the lesion was highly vascularised.
Objectives
To describe an ultrasound‐guided transurethral bladder biopsy technique using endoscopic forceps and its results in dogs of different sizes with different lesion locations.
Materials and ...Methods
Medical records of dogs that underwent ultrasound‐guided transurethral bladder biopsy with endoscopic forceps were retrospectively reviewed. Patient signalment, lesion location, use of urinary catheter as a guide, outcome of the procedure and histopathology results were retrieved.
Results
Twenty‐seven dogs underwent this procedure. Biopsy samples were successfully obtained in 23 dogs. Insertion of the endoscopic forceps without a urinary catheter allowed the procedure to be performed in patients with a small urethral diameter without complication. The procedure was unsuccessful in dogs with a urethral diameter smaller than the outer diameter of the biopsy forceps (i.e. 1.8 mm), either due to small patient size or obstructive urethral lesion. All biopsy samples allowed histopathological diagnosis. No complications were reported after the procedure.
Clinical Significance
This non‐invasive biopsy technique should be considered in patients with bladder lesions in which histopathological diagnosis is needed, especially when endoscopic examination is not feasible. By use of the Doppler mode, biopsy retrieval was safe also when the lesion was highly vascularised.
Michel parameters are kinematic values defined as bilinear combinations of the coupling terms in the general matrix element of the Fermi interaction where all possible Lorentz-invariant scalar, ...vector and tensor terms are included. The leptonic τ decays provide an excellent laboratory in which to measure the Michel parameters. Any deviation of these parameters from the Standard Model expectation would indicate New Physics. Two Michel parameters, η¯ and ξκ, can only be measured in the radiative leptonic decay. These parameters have previously been measured in the radiative decay of the muon but as yet have not been measured in τ decays. We report the results of a feasibility study of the measurement of η¯ and ξκ in radiative leptonic τ decays at Belle and Belle II.
The atomic masses of ^{55}Sc, ^{56,58}Ti, and ^{56-59}V have been determined using the high-precision multireflection time-of-flight technique. The radioisotopes have been produced at RIKEN's ...Radioactive Isotope Beam Factory (RIBF) and delivered to the novel designed gas cell and multireflection system, which has been recently commissioned downstream of the ZeroDegree spectrometer following the BigRIPS separator. For ^{56,58}Ti and ^{56-59}V, the mass uncertainties have been reduced down to the order of 10 keV, shedding new light on the N=34 shell effect in Ti and V isotopes by the first high-precision mass measurements of the critical species ^{58}Ti and ^{59}V. With the new precision achieved, we reveal the nonexistence of the N=34 empirical two-neutron shell gaps for Ti and V, and the enhanced energy gap above the occupied νp_{3/2} orbit is identified as a feature unique to Ca. We perform new Monte Carlo shell model calculations including the νd_{5/2} and νg_{9/2} orbits and compare the results with conventional shell model calculations, which exclude the νg_{9/2} and the νd_{5/2} orbits. The comparison indicates that the shell gap reduction in Ti is related to a partial occupation of the higher orbitals for the outer two valence neutrons at N=34.
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