Kerman-Klein-Donau-Frauendorf model for odd-odd nuclei: formal theory

The Kerman-Klein-Donau-Frauendorf (KKDF) model is a linearized version of the Kerman-Klein (equations of motion) formulation of the nuclear many-body problem. In practice, it is a generalization of the standard core-particle coupling model that, like the latter, provides a description of the spectroscopy of odd nuclei in terms of the properties of neighboring even nuclei and of single-particle properties, that are the input parameters of the model. A divers sample of recent applications attest to the usefulness of the model. In this paper, we first present a concise general review of the fundamental equations and properties of the KKDF model. We then derive a corresponding formalism for odd-odd nuclei that relates their properties to those of four neighboring even nuclei, all of which enter if one is to include both multipole and pairing forces. We treat these equations in two ways. In the first we make essential use of the solutions of the neighboring odd nucleus problem, as obtained by the KKDF method. In the second, we relate the properties of the odd-odd nuclei directly to those of the even nuclei. For both choices, we derive equations of motion, normalization conditions, and an expression for transition amplitudes. We also solve the problem of choosing the subspace of physical solutions that arises in an equations of motion approach that includes pairing interactions.Comment: 27 pages, Late

Three-Dimensional Computed Tomography Analysis of Airway Volume Changes Between Open and Closed Jaw Positions

Introduction Airway dimensions are closely linked to the bone and soft-tissue craniofacial anatomy. Reduction of the airway is seen with airway disorders and can impair function. The purpose of this retrospective study was to determine whether changing from open to closed jaw position affects the volume of the nasal cavity, nasopharynx, and oropharynx; the soft palate; the soft-tissue thickness of the airway; and the most constricted area of the airway. Methods Following reliability studies, in this retrospective study, we analyzed cone-beam computed tomography scans taken in both closed and open jaw positions of 60 subjects who were undergoing diagnosis and treatment of temporomandibular disorders. On each scan, condyle-fossa measurements, volumes of airway segments (nasal cavity, nasopharynx, oropharynx), soft palate areas, soft tissue thicknesses of the airway, and the most constricted area of the airway and its location were measured using Dolphin imaging software (version 11.5; Patterson Dental Supply, Chatsworth, Calif). Differences between the 2 jaw positions were analyzed with paired t tests, accepting P ≤0.05 as significant. Results Significant changes in airway dimensions were found between the closed and open jaw positions. With jaw opening, the nasopharynx volume increased, whereas the oropharynx volume decreased. Significant decreases were also found for measurements of basion to posterior airway wall, cervical vertebrae to posterior airway wall, most constricted area, nasal cavity volume, and soft palate area when the jaw was open. Conclusions Changing jaw position significantly affects airway dimensions

Kinematics and Preliminary FEMA P-695 Evaluation of the NewZ-BREAKSS Steel Boundary Frame with Buckling Restrained Brace Structural Fuses

Buckling Restrained Braced Frames (BRBFs) have become a popular seismic force resisting system (SFRS) due to their high ductility and energy dissipation. However, BRBFs are also susceptible to large residual drifts, which can make repair difficult. Efforts to reduce the residual drift of BRBFs typically involve special self-centering braces, or by using a dual system in tandem with the BRBF. This study proposes an alternative approach, in which a self-centering steel rocking frame is used as the boundary frame for the BRBF. The proposed system, called the NewZ-BREAKSS Buckling Restrained Braced Frame (NZ-BRBF) utilizes the recently proposed NewZ-BREAKSS (NZ) boundary frame to increase the post-yield stiffness of the system while concentrating all damage to the BRBs. The NZ-BRBF system is expected to behave similarly to conventional BRBF, but with smaller residual drifts and a boundary frame that remains essentially elastic, simplifying repair. This study presents a numerical investigation of the proposed low-damage SFRS, using the FEMA P-695 methodology as a guiding framework. The results suggest that the NZ-BRBF can exhibit better performance than conventional BRBFs and can be designed with the same response modification factor (R factor) as conventional BRBFs

Virtual Articulator – Aid Simulator at Diagnosis, Pre-Surgical Planning and Monitoring of Bucomaxilofacial Treatment

This work presents a system for use in dentistry and medicine, that allows advance in diagnosis and planning of treatments and surgical procedures, in cases that involves the Temporomandibular Joint, TMJ. Construction of Virtual Articulator includes related research areas of computer graphics, virtual reality and medicine and tends to become a new paradigm as a tool because it will simulate and reproduce the movements of the TMJ in a realistic way, allowing a complete analysis of the case under treatment. It is a software which comes to replace and increase in an innovative way the work done by mechanical articulators. Initially Virtual Articulator reconstructs the TMJ virtually, generating a 3D model, starting from exams such as Computed Tomography and Magnetic Ressonance. Once it is obtained a virtual copy of the TMJ, software simulates real mandible movements, with great flexibility and facility of parameterization. Virtual joints model is based on points captured from the motion curve of lower incisor point. Contribution of each muscle in temporomandibular movement is approached from Hill actuators model and the new concept of curves of insertion. It will be possible to analyze in depth a particular case in a diagnostic phase or predict the results of the surgical procedure

Modelling fast forms of visual neural plasticity using a modified second-order motion energy model

The Adelson-Bergen motion energy sensor is well established as the leading model of low-level visual motion sensing in human vision. However, the standard model cannot predict adaptation effects in motion perception. A previous paper Pavan et al.(Journal of Vision 10:1-17, 2013) presented an extension to the model which uses a first-order RC gain-control circuit (leaky integrator) to implement adaptation effects which can span many seconds, and showed that the extended model's output is consistent with psychophysical data on the classic motion after-effect. Recent psychophysical research has reported adaptation over much shorter time periods, spanning just a few hundred milliseconds. The present paper further extends the sensor model to implement rapid adaptation, by adding a second-order RC circuit which causes the sensor to require a finite amount of time to react to a sudden change in stimulation. The output of the new sensor accounts accurately for psychophysical data on rapid forms of facilitation (rapid visual motion priming, rVMP) and suppression (rapid motion after-effect, rMAE). Changes in natural scene content occur over multiple time scales, and multi-stage leaky integrators of the kind proposed here offer a computational scheme for modelling adaptation over multiple time scales. © 2014 Springer Science+Business Media New York