Korteweg-de Vries description of Helmholtz-Kerr dark solitons

A wide variety of different physical systems can be described by a relatively small set of universal equations. For example, small-amplitude nonlinear Schrödinger dark solitons can be described by a Korteweg-de Vries (KdV) equation. Reductive perturbation theory, based on linear boosts and Gallilean transformations, is often employed to establish connections to and between such universal equations. Here, a novel analytical approach reveals that the evolution of small-amplitude Helmholtz–Kerr dark solitons is also governed by a KdV equation. This broadens the class of nonlinear systems that are known to possess KdV soliton solutions, and provides a framework for perturbative analyses when propagation angles are not negligibly small. The derivation of this KdV equation involves an element that appears new to weakly nonlinear analyses, since transformations are required to preserve the rotational symmetry inherent to Helmholtz-type equations

Delayed commutation in quantum computer networks

In the same way that classical computer networks connect and enhance the capabilities of classical computers, quantum networks can combine the advantages of quantum information and communications. We propose a non-classical network element, a delayed commutation switch, that can solve the problem of switching time in packet switching networks. With the help of some local ancillary qubits and superdense codes we can route the information after part of it has left the network node.Comment: 4 pages. 4 figures. Preliminar versio

Helmholtz bright and boundary solitons

We report, for the first time, exact analytical boundary solitons of a generalized cubic-quintic Non-Linear Helmholtz (NLH) equation. These solutions have a linked-plateau topology that is distinct from conventional dark soliton solutions; their amplitude and intensity distributions are spatially delocalized and connect regions of finite and zero wave-field disturbances (suggesting also the classification as 'edge solitons'). Extensive numerical simulations compare the stability properties of recently-reported Helmholtz bright solitons, for this type of polynomial non-linearity, to those of the new boundary solitons. The latter are found to possess a remarkable stability characteristic, exhibiting robustness against perturbations that would otherwise lead to the destabilizing of their bright-soliton counterpart

Energy Distribution of a Charged Regular Black Hole

We calculate the energy distribution of a charged regular black hole by using the energy-momentum complexes of Einstein and M{\o}ller.Comment: 6 pages, no figure

Wave envelopes with second-order spatiotemporal dispersion : I. Bright Kerr solitons and cnoidal waves

We propose a simple scalar model for describing pulse phenomena beyond the conventional slowly-varying envelope approximation. The generic governing equation has a cubic nonlinearity and we focus here mainly on contexts involving anomalous group-velocity dispersion. Pulse propagation turns out to be a problem firmly rooted in frames-of-reference considerations. The transformation properties of the new model and its space-time structure are explored in detail. Two distinct representations of exact analytical solitons and their associated conservation laws (in both integral and algebraic forms) are presented, and a range of new predictions is made. We also report cnoidal waves of the governing nonlinear equation. Crucially, conventional pulse theory is shown to emerge as a limit of the more general formulation. Extensive simulations examine the role of the new solitons as robust attractors

New Talent Signals: Shiny New Objects or a Brave New World?

Almost 20 years after McKinsey introduced the idea of a war for talent, technology is disrupting the talent identification industry. From smartphone profiling apps to workplace big data, the digital revolution has produced a wide range of new tools for making quick and cheap inferences about human potential and predicting future work performance. However, academic industrial–organizational (I-O) psychologists appear to be mostly spectators. Indeed, there is little scientific research on innovative assessment methods, leaving human resources (HR) practitioners with no credible evidence to evaluate the utility of such tools. To this end, this article provides an overview of new talent identification tools, using traditional workplace assessment methods as the organizing framework for classifying and evaluating new tools, which are largely technologically enhanced versions of traditional methods. We highlight some opportunities and challenges for I-O psychology practitioners interested in exploring and improving these innovations

Optical Purity Study of Citronellal present in the Essential Oils obtained from Citronella and of Lemon Eucalyptus

El objetivo del trabajo fue conocer la pureza óptica del citronelal presente en los aceites esenciales de citronela (Cymbopogon nardus (L.) Rendle) y eucalipto citriodora (Eucalyptus citriodora Hook), midiendo la rotación óptica específica. Los aceites esenciales se extrajeron por destilación por arrastre con vapor de agua a partir de variedades botánicas autenticadas. El citronelal, de ambos aceites esenciales fue separado por destilación fraccionada al vacío y el de Eucalyptus citriodora debió luego purificarse químicamente antes de realizar la medición de la rotación óptica específica. La identificación de los componentes de los aceites esenciales y la cuantificación del citronelal se realizaron por cromatografía gaseosa. La rotación óptica específica se determinó utilizando la Norma IRAM-SAIPA Nº18507-2002. En este estudio se obtuvo aproximadamente 95% de (+)-citronelal a partir de citronela, mientras que el citronelal del eucalipto citriodora es prácticamente racémico, lo cual está acuerdo con información de la literatura.The objective of the study was to determine the optical purity of citronellal present in the essential oils obtained from citronella (Cymbopogon nardus (L.) Rendle) and eucalyptus citriodora (Eucalyptus citriodora Hook), measuring the specific optical rotation. The essential oils are extracted by distillation by stripping with steam from authenticated botanical varieties. Citronellal from both essential oil was separated by fractional distillation under vacuum and the lemon eucalyptus product had to be chemically purified before measuring its specific optical rotation. The identification of the components of essential oils and the quantification of citronellal were performed by gas chromatography. The specific optical rotation was determined using the IRAM-SAIPA standard Nº18507-2002. In this study the citronellal obtained from citronella was about 95% of (+)-citronellal, while the citronellal obtained from eucalyptus citriodora was practically racemic, in agreement with information from the literature.Fil: Zambón, Silvia N.. Universidad Tecnológica Nacional. Facultad Regional Resistencia. Centro de Investigación En Química Orgánica Biológica; ArgentinaFil: Chamorro, Ester r.. Universidad Tecnológica Nacional. Facultad Regional Resistencia. Centro de Investigación En Química Orgánica Biológica; ArgentinaFil: Casuscelli, Sandra Graciela. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; Argentin