Criteria for Core-Collapse Supernova Explosions by the Neutrino Mechanism

We investigate the criteria for successful core-collapse supernova explosions by the neutrino mechanism. We find that a critical-luminosity/mass-accretion-rate condition distinguishes non-exploding from exploding models in hydrodynamic one-dimensional (1D) and two-dimensional (2D) simulations. We present 95 such simulations that parametrically explore the dependence on neutrino luminosity, mass accretion rate, resolution, and dimensionality. While radial oscillations mediate the transition between 1D accretion (non-exploding) and exploding simulations, the non-radial standing accretion shock instability characterizes 2D simulations. We find that it is useful to compare the average dwell time of matter in the gain region with the corresponding heating timescale, but that tracking the residence time distribution function of tracer particles better describes the complex flows in multi-dimensional simulations. Integral quantities such as the net heating rate, heating efficiency, and mass in the gain region decrease with time in non-exploding models, but for 2D exploding models, increase before, during, and after explosion. At the onset of explosion in 2D, the heating efficiency is $\sim$2% to $\sim$5% and the mass in the gain region is $\sim$0.005 M_{\sun} to $\sim$0.01 M_{\sun}. Importantly, we find that the critical luminosity for explosions in 2D is $\sim$70% of the critical luminosity required in 1D. This result is not sensitive to resolution or whether the 2D computational domain is a quadrant or the full 180$^{\circ}$. We suggest that the relaxation of the explosion condition in going from 1D to 2D (and to, perhaps, 3D) is of a general character and is not limited by the parametric nature of this study.Comment: 32 pages in emulateapj, including 17 figures, accepted for publication in ApJ, included changes suggested by the refere

Nuclear incompressibility using the density dependent M3Y effective interaction

A density dependent M3Y effective nucleon-nucleon (NN) interaction which was based on the G-matrix elements of the Reid-Elliott NN potential has been used to determine the incompressibity of infinite nuclear matter. The nuclear interaction potential obtained by folding in the density distribution functions of two interacting nuclei with this density dependent M3Y effective interaction had been shown earlier to provide excellent descriptions for medium and high energy $\alpha$ and heavy ion elastic scatterings as well as $\alpha$ and heavy cluster radioactivities. The density dependent parameters have been chosen to reproduce the saturation energy per nucleon and the saturation density of spin and isospin symmetric cold infinite nuclear matter. The result of such calculations for nuclear incompressibility using the density dependent M3Y effective interaction based on the G-matrix elements of Reid-Elliott NN potential predicts a value of about 300 MeV for nuclear incompressibility.Comment: 4 Page

Continuous phase transition and negative specific heat in finite nuclei

The liquid-gas phase transition in finite nuclei is studied in a heated liquid-drop model where the nuclear drop is assumed to be in thermodynamic equilibrium with its own evaporated nucleonic vapor conserving the total baryon number and isospin of the system. It is found that in the liquid-vapor coexistence region the pressure is not a constant on an isotherm indicating that the transition is continuous. At constant pressure, the caloric curve shows some anomalies, namely, the systems studied exhibit negative heat capacity in a small temperature domain. The dependence of this specific feature on the mass and isospin of the nucleus, Coulomb interaction and the chosen pressure is studied. The effects of the presence of clusters in the vapor phase on specific heat have also been explored.Comment: 18 pages, 13 figures; Phys. Rev. C (in press

Service-based survey of dystonia in Munich

We performed a service-based epidemiological study of dystonia in Munich, Germany. Due to favourable referral and treatment patterns in the Munich area, we could provide confident data from dystonia patients seeking botulinum toxin treatment. A total of 230 patients were ascertained, of whom 188 had primary dystonia. Point prevalence ratios were estimated to be 10.1 (95% confidence interval 8.4-11.9) per 100,000 for focal and 0.3 (0.0-0.6) for generalised primary dystonia. The most common focal primary dystonias were cervical dystonia with 5.4 (4.2-6.7) and essential blepharospasm with 3.1 (2.1-4.1) per 100,000 followed by laryngeal dystonia (spasmodic dysphonia) with 1.0 (0.4-1.5) per 100,000. Copyright (C) 2002 S. Karger AG, Base

Nuclear matter incompressibility coefficient in relativistic and nonrelativistic microscopic models

We systematically analyze the recent claim that nonrelativistic and relativistic mean field (RMF) based random phase approximation (RPA) calculations for the centroid energy E_0 of the isoscalar giant monopole resonance yield for the nuclear matter incompressibility coefficient, K_{nm}, values which differ by about 20%. For an appropriate comparison with the RMF based RPA calculations, we obtain the parameters for the Skyrme force used in the nonrelativistic model by adopting the same procedure as employed in the determination of the NL3 parameter set of an effective Lagrangian used in the RMF model. Our investigation suggest that the discrepancy between the values of K_{nm} predicted by the relativistic and nonrelativistic models is significantly less than 20%.Comment: Revtex file (13 pages), appearing in PRC-Rapid Com

Recent developments in monolithic integration of InGaAsP/InP optoelectronic devices

Monolithically integrated optoelectronic circuits combine optical devices such as light sources (injection lasers and light emitting diodes) and optical detectors with solid-state semiconductor devices such as field effect transistors, bipolar transistors, and others on a single semiconductor crystal. Here we review some of the integrated circuits that have been realized and discuss the laser structures suited for integration with emphasis on the InGaAsP/InP material system. Some results of high frequency modulation and performance of integrated devices are discussed

Exploring the extended density-dependent Skyrme effective forces for normal and isospin-rich nuclei to neutron stars

We parameterize the recently proposed generalized Skyrme effective force (GSEF) containing extended density dependence. The parameters of the GSEF are determined by the fit to several properties of the normal and isospin-rich nuclei. We also include in our fit a realistic equation of state for the pure neutron matter up to high densities so that the resulting Skyrme parameters can be suitably used to model the neutron star with the "canonical" mass ($\sim 1.4 M_\odot$). For the appropriate comparison we generate a parameter set for the standard Skyrme effective force (SSEF) using exactly the same set of the data as employed to determine the parameters of the GSEF. We find that the GSEF yields larger values for the neutron skin thickness which are closer to the recent predictions based on the isospin diffusion data. The Skyrme parameters so obtained are employed to compute the strength function for the isoscalar giant monopole, dipole and quadrupole resonances. It is found that in the case of GSEF, due to the the larger value of the nucleon effective mass the values of centroid energies for the isoscalar giant resonances are in better agreement with the corresponding experimental data in comparison to those obtained using the SSEF. We also present results for some of the key properties associated with the neutron star of "canonical" mass and for the one with the maximum mass.Comment: 45pages, 16 figure

Dark open innovation in a criminal organizational context: the case of Madoff’s Ponzi fraud

Purpose The purpose of this paper is to investigate the processes of open innovation in the context of a fraudulent organization and, using the infamous Bernie L. Madoff Investment Securities fraud case, introduces and elaborates upon the concept of dark open innovation. The paper’s conceptual framework is drawn from social capital theory, which is grounded on the socio-economics of Bourdieu, Coleman and Putnam and is employed in order to make sense of the processes that occur within dark open innovation. Design/methodology/approach Given the self-evident access issues, this paper is necessarily based on archival and secondary sources taken from the court records of Madoff v. New York – including victim impact statements, the defendant’s Plea Allocution, and academic and journalistic commentaries – which enable the identification of the processes involved in dark open innovation. Significantly, this paper also represents an important inter-disciplinary collaboration between academic scholars variously informed by business and history subject domains. Findings Although almost invariably cast as a positive process, innovation can also be evidenced as a negative or dark force. This is particularly relevant in open innovation contexts, which often call for the creation of extended trust and close relationships. This paper outlines a case of dark open innovation. Research limitations/implications A key implication of this study is that organizational innovation is not automatically synonymous with human flourishing or progress. This paper challenges the automatic assumption of innovation being positive and introduces the notion of dark open innovation. Although this is accomplished by means of an in-depth single case, the findings have the potential to resonate in a wide spectrum of situations. Practical implications Innovation is a concept that applies across a range of organization and management domains. Criminals also innovate; thus, the paper provides valuable insights into the organizational innovation processes especially involved in relation to dark open innovation contexts. Social implications It is important to develop and fully understand the possible wider meanings of innovation and also to recognize that innovation – particularly dark open innovation – does not always create progress. The Caveat Emptor warning is still relevant. Originality/value The paper introduces the novel notion of dark open innovation

Shell Corrections for Finite-Depth Deformed Potentials: Green's Function Oscillator Expansion Method

Shell corrections of the finite deformed Woods-Saxon potential are calculated using the Green's function method and the generalized Strutinsky smoothing procedure. They are compared with the results of the standard prescription which are affected by the spurious contribution from the unphysical particle gas. In the new method, the shell correction approaches the exact limit provided that the dimension of the single-particle (harmonic oscillator) basis is sufficiently large. For spherical potentials, the present method is faster than the exact one in which the contribution from the particle continuum states is explicitly calculated. For deformed potentials, the Green's function method offers a practical and reliable way of calculating shell corrections for weakly bound nuclei.Comment: submitted to Phys. Rev. C, 12 pages, 7 figure