Bound state techniques to solve the multiparticle scattering problem

Solution of the scattering problem turns to be very difficult task both from the formal as well as from the computational point of view. If the last two decades have witnessed decisive progress in ab initio bound state calculations, rigorous solution of the scattering problem remains limited to A$\leq$4 case. Therefore there is a rising interest to apply bound-state-like methods to handle non-relativistic scattering problems. In this article the latest theoretical developments in this field are reviewed. Five fully rigorous methods will be discussed, which address the problem of nuclear collisions in full extent (including the break-up problem) at the same time avoiding treatment of the complicate boundary conditions or integral kernel singularities. These new developments allows to use modern bound-state techniques to advance significantly rigorous solution of the scattering problem.Comment: To appear in Progress in Particle and Nuclear Physic

Four-nucleon scattering: Ab initio calculations in momentum space

The four-body equations of Alt, Grassberger and Sandhas are solved for \nH scattering at energies below three-body breakup threshold using various realistic interactions including one derived from chiral perturbation theory. After partial wave decomposition the equations are three-variable integral equations that are solved numerically without any approximations beyond the usual discretization of continuum variables on a finite momentum mesh. Large number of two-, three- and four-nucleon partial waves are considered until the convergence of the observables is obtained. The total \nH cross section data in the resonance region is not described by the calculations which confirms previous findings by other groups. Nevertheless the numbers we get are slightly higher and closer to the data than previously found and depend on the choice of the two-nucleon potential. Correlations between the $A_y$ deficiency in \nd elastic scattering and the total \nH cross section are studied.Comment: Corrected Eq. (10

Context-aware mobile app for the multidimensional assessment of the elderly,

Rural areas in Europe are presenting a decreasing population density and an increasing age index. These elders usually present multiple diseases that require complex tools to identify the exact cares that they need. Currently, different frameworks can evaluate their functional status and identify the required cares to maintain their Quality of Life, together with the associated cost to the health system. Nevertheless, these frameworks are usually questionnaires that have to be performed by already overloaded professionals. In this paper, we make use of mobile technologies to build a system capable of monitoring the activities of the elderly and analysing these data to assess their functional status. The experiments carried out show us that it correctly evaluates these patients and reduces the effort required by health professionals

Ising Field Theory on a Pseudosphere

We show how the symmetries of the Ising field theory on a pseudosphere can be exploited to derive the form factors of the spin fields as well as the non-linear differential equations satisfied by the corresponding two-point correlation functions. The latter are studied in detail and, in particular, we present a solution to the so-called connection problem relating two of the singular points of the associated Painleve VI equation. A brief discussion of the thermodynamic properties is also presented.Comment: 39 pages, 6 eps figures, uses harvma

A re-evaluation of the Fourier descriptor approach to quantifying sand particle geometry

This paper describes an evaluation of the use of Fourier descriptors to characterize soil particle shape. The approach proposed by Bowman et al (2001) was implemented in a MATLAB code, taking advantage of the MATLAB Image Processing Toolbox. The method uses a discrete Fourier transform, to obtain a series of descriptors. Bowman et al proposed that the first four descriptors be used to quantify elongation, triangularity, squareness and asymmetry; altogether a measure of particle shape or ‘morphology’. In the current study, this approach was first fundamentally examined using simple, ideal geometries. Two granular quartz soils, Ham River Sand and Toyoura Sand, with mean particle sizes of 170m and 300m respectively, were then analysed. Attention was paid to determining a minimum population of particles to obtain consistent data. The results indicated a significant shortcoming in this approach to quantify particle geometry. While the elongation descriptor was in agreement with measurements of particle elongation obtained from other approaches, the remaining descriptors exhibited significant scatter. Based upon the particle types considered, it was concluded that this approach has limited potential for use in soil shape characterization. Further research is needed to establish whether the method may indeed be useful for quantifying roughness

Contributions to the ontology of aging, the sensitive indicators of rehabilitation nursing care, in terms of self-care, in people with respiratory disorders

With the increase in the average life expectancy, the appearance of chronic diseases and, in particular, in the respiratory forum and its disadvantages in the autonomy and self-care of patients, brought an important paradigm for health care and, in particular, rehabilitation nursing, with implications for the development of ontologies of aging. Thus, it is imperative to systematize them in scientifically measurable indicators to demonstrate the benefit that rehabilitation nursing brings to improve patients' quality of life, thus ensuring excellence. Each area of scientific health should contribute to the construction of aging ontology. Objective: to identify indicators sensitive to nursing care of rehabilitation, in terms of self-care, in relation to those with respiratory pathology, to be integrated into the ontology of aging. Methods: A systematic review of the literature was performed using the EBSCO (full-text MEDLINE, CINAHL, Full-Text Plus, British Nursing Index), using the PI [C] O method with 6 emergent articles. Results: A total of 20 indicators were identified, including: Ability to perform activities, increase physical and functional independence, symptom management, reduction of complications, increase in quality of life, which can be allocated as a proposal for classes of the aging ontology. Conclusion: Knowledge of indicators sensitive to nursing care recognition of the importance of rehabilitation nursing in increasing self-care and autonomy for people with respiratory pathology, and research in this area is fundamental for its effectiveness and efficiency, and its integration in the ontologies of aging is fundamental

A global simulation for laser driven MeV electrons in 50μm50\mu m-diameter fast ignition targets

The results from 2.5-dimensional Particle-in-Cell simulations for the interaction of a picosecond-long ignition laser pulse with a plasma pellet of 50-$\mu m$ diameter and 40 critical density are presented. The high density pellet is surrounded by an underdense corona and is isolated by a vacuum region from the simulation box boundary. The laser pulse is shown to filament and create density channels on the laser-plasma interface. The density channels increase the laser absorption efficiency and help generate an energetic electron distribution with a large angular spread. The combined distribution of the forward-going energetic electrons and the induced return electrons is marginally unstable to the current filament instability. The ions play an important role in neutralizing the space charges induced by the the temperature disparity between different electron groups. No global coalescing of the current filaments resulted from the instability is observed, consistent with the observed large angular spread of the energetic electrons.Comment: 9 pages, 6 figures, to appear in Physics of Plasmas (May 2006