Electronic load for testing power generating devices

Instrument tests various electric power generating devices by connecting the devices to the input of the load and comparing their outputs with a reference voltage. The load automatically adjusts until voltage output of the power generating device matches the reference

Onset of η\eta-nuclear binding in a pionless EFT approach

$\eta NNN$ and $\eta NNNN$ bound states are explored in stochastic variational method (SVM) calculations within a pionless effective field theory (EFT) approach at leading order. The theoretical input consists of regulated $NN$ and $NNN$ contact terms, and a regulated energy dependent $\eta N$ contact term derived from coupled-channel models of the $N^{\ast}(1535)$ nucleon resonance plus a regulated $\eta NN$ contact term. A self consistency procedure is applied to deal with the energy dependence of the $\eta N$ subthreshold input, resulting in a weak dependence of the calculated $\eta$-nuclear binding energies on the EFT regulator. It is found, in terms of the $\eta N$ scattering length $a_{\eta N}$, that the onset of binding \eta\,^3He requires a minimal value of Re$\,a_{\eta N}$ close to 1 fm, yielding then a few MeV $\eta$ binding in \eta\,^4He. The onset of binding \eta\,^4He requires a lower value of Re$\,a_{\eta N}$, but exceeding 0.7 fm.Comment: v4 consists of the published Physics Letters B version [31] plus Erratum ([30], Appendix A here); main results and conclusions remain intac

Third Earth Resources Technology Satellite Symposium. Volume 3: Discipline summary reports

Presentations at the conference covered the following disciplines: (1) agriculture, forestry, and range resources; (2) land use and mapping; (3) mineral resources, geological structure, and landform surveys; (4) water resources; (5) marine resources; (6) environment surveys; and (7) interpretation techniques

Third Earth Resources Technology Satellite Symposium. Volume 2: Summary of results

Summaries are provided of significant results taken from presentations at the symposium along with some typical examples of the applications of ERTS-1 data for solving resources management problems at the national, state, and local levels

Cognitive Analytic Therapy in People with Learning Disability: An investigation into the common reciprocal roles found within this client group

Developments over the last twenty years have shown that, contrary to previous opinion, people with learning disabilities can benefit from psychotherapy (Sinason 1992; Kroese, Dagnan & Loumidia, 1997). Cognitive Analytic Therapy (CAT) has been adapted for use with a learning disability population (Ryle 2002). CAT collaboratively examines the Reciprocal Roles (RRs) a client plays in relationships. These are impacted by clients’ experiences of the world. The aim of this research is to identify which RRs may become apparent in working with people with learning disabilities. The therapy notes of participants (n=16) who had undergone CAT were examined and analysed using content analysis. Twenty-two different RRs were found. Four common Reciprocal Roles and two common idealised Reciprocal Roles were identified. Other observations about the data are presented. The limitations and clinical implications of the study are discussed

Reactions at Polymer Interfaces: Transitions from Chemical to Diffusion-Control and Mixed Order Kinetics

We study reactions between end-functionalized chains at a polymer-polymer interface. For small chemical reactivities (the typical case) the number of diblocks formed, $R_t$, obeys 2nd order chemically controlled kinetics, $R_t \sim t$, until interfacial saturation. For high reactivities (e.g. radicals) a transition occurs at short times to 2nd order diffusion-controlled kinetics, with $R_t \sim t/\ln t$ for unentangled chains while $t/\ln t$ and $t^{1/2}$ regimes occur for entangled chains. Long time kinetics are 1st order and controlled by diffusion of the more dilute species to the interface: $R_t \sim t^{1/4}$ for unentangled cases, while $R_t \sim t^{1/4}$ and $t^{1/8}$ regimes arise for entangled systems. The final 1st order regime is governed by center of gravity diffusion, $R_t \sim t^{1/2}$.Comment: 11 pages, 3 figures, uses poliface.sty, minor changes, to appear in Europhysics Letter

Eta-mesic nuclei

In this contribution we report on theoretical studies of $\eta$ nuclear quasi-bound states in few- and many-body systems performed recently by the Jerusalem-Prague Collaboration [1-5]. Underlying energy-dependent $\eta N$ interactions are derived from coupled-channel models that incorporate the $N^*(1535)$ resonance. The role of self-consistent treatment of the strong energy dependence of subthreshold $\eta N$ amplitudes is discussed. Quite large downward energy shift together with rapid decrease of the $\eta N$ amplitudes below threshold result in relatively small binding energies and widths of the calculated $\eta$ nuclear bound states. We argue that the subthreshold behavior of $\eta N$ scattering amplitudes is crucial to conclude whether $\eta$ nuclear states exist, in which nuclei the $\eta$ meson could be bound and if the corresponding widths are small enough to allow detection of these $\eta$ nuclear states in experiment.Comment: 7 pages, 5 figures; presented at HADRON2017, Sept. 25-29, 2017, Salamanca (Spain); prepared for Proceedings of Scienc

Occurrence of normal and anomalous diffusion in polygonal billiard channels

From extensive numerical simulations, we find that periodic polygonal billiard channels with angles which are irrational multiples of pi generically exhibit normal diffusion (linear growth of the mean squared displacement) when they have a finite horizon, i.e. when no particle can travel arbitrarily far without colliding. For the infinite horizon case we present numerical tests showing that the mean squared displacement instead grows asymptotically as t log t. When the unit cell contains accessible parallel scatterers, however, we always find anomalous super-diffusion, i.e. power-law growth with an exponent larger than 1. This behavior cannot be accounted for quantitatively by a simple continuous-time random walk model. Instead, we argue that anomalous diffusion correlates with the existence of families of propagating periodic orbits. Finally we show that when a configuration with parallel scatterers is approached there is a crossover from normal to anomalous diffusion, with the diffusion coefficient exhibiting a power-law divergence.Comment: 9 pages, 15 figures. Revised after referee reports: redrawn figures, additional comments. Some higher quality figures available at http://www.fis.unam.mx/~dsander

K−K^- - nucleus relativistic mean field potentials consistent with kaonic atoms

$K^-$ atomic data are used to test several models of the $K^-$ nucleus interaction. The t($\rho$)$\rho$ optical potential, due to coupled channel models incorporating the $\Lambda$(1405) dynamics, fails to reproduce these data. A standard relativistic mean field (RMF) potential, disregarding the $\Lambda$(1405) dynamics at low densities, also fails. The only successful model is a hybrid of a theoretically motivated RMF approach in the nuclear interior and a completely phenomenological density dependent potential, which respects the low density theorem in the nuclear surface region. This best-fit $K^-$ optical potential is found to be strongly attractive, with a depth of 180 \pm 20 MeV at the nuclear interior, in agreement with previous phenomenological analyses.Comment: revised, Phys. Rev. C in pres