Study made of anodized aluminum circuit boards

Hard coated aluminum circuit boards demonstrate the feasibility of obtaining an electrical power circuit of high packaging density with very high thermal conductivity and mechanical strengths

Information Geometry, Inference Methods and Chaotic Energy Levels Statistics

In this Letter, we propose a novel information-geometric characterization of chaotic (integrable) energy level statistics of a quantum antiferromagnetic Ising spin chain in a tilted (transverse) external magnetic field. Finally, we conjecture our results might find some potential physical applications in quantum energy level statistics.Comment: 9 pages, added correct journal referenc

Jacobi multipliers, non-local symmetries and nonlinear oscillators

Constants of motion, Lagrangians and Hamiltonians admitted by a family of relevant nonlinear oscillators are derived using a geometric formalism. The theory of the Jacobi last multiplier allows us to find Lagrangian descriptions and constants of the motion. An application of the jet bundle formulation of symmetries of differential equations is presented in the second part of the paper. After a short review of the general formalism, the particular case of non-local symmetries is studied in detail by making use of an extended formalism. The theory is related to some results previously obtained by Krasil'shchi, Vinogradov and coworkers. Finally the existence of non-local symmetries for such two nonlinear oscillators is proved.Comment: 20 page

From Lagrangian to Quantum Mechanics with Symmetries

We present an old and regretfully forgotten method by Jacobi which allows one to find many Lagrangians of simple classical models and also of nonconservative systems. We underline that the knowledge of Lie symmetries generates Jacobi last multipliers and each of the latter yields a Lagrangian. Then it is shown that Noether's theorem can identify among those Lagrangians the physical Lagrangian(s) that will successfully lead to quantization. The preservation of the Noether symmetries as Lie symmetries of the corresponding Schr\"odinger equation is the key that takes classical mechanics into quantum mechanics. Some examples are presented.Comment: To appear in: Proceedings of Symmetries in Science XV, Journal of Physics: Conference Series, (2012

On a generalization of Jacobi's elliptic functions and the Double Sine-Gordon kink chain

A generalization of Jacobi's elliptic functions is introduced as inversions of hyperelliptic integrals. We discuss the special properties of these functions, present addition theorems and give a list of indefinite integrals. As a physical application we show that periodic kink solutions (kink chains) of the double sine-Gordon model can be described in a canonical form in terms of generalized Jacobi functions.Comment: 18 pages, 9 figures, 3 table

Analysing the sensitivity of Arctic large-scale circulation to the regional radiation forcing over Europe using deep learning

The Arctic large-scale circulation is governed by a wide range of factor. In order to investigate the sensitivity of the Arctic large-scale circulation to the regional radiative forcing over Europe, we conducted sensitivity experiments using a state-of-the-art atmosphere-land-ocean coupled model. Using advanced Deep Learning (DL) algorithms, we analyzed the Arctic circulation regimes response to negative radiative forcing anomalies over Europe. We examined different architectures for our DL algorithm to find the most suitable one for our analysis. We simultaneously layer Thickness (300-700-T) and their spatiotemporal patterns with the DL algorithm. The DL algorithm showed good skills in capturing the general structure of the large-scale circulation. The radiative forcing over Europe doesn't seem to induce the occurrence frequency of preferred circulation regimes.Die arktische großräumige Zirkulation wird von einer Vielzahl von Faktoren bestimmt. Um die Sensitivität der arktischen großräumigen Zirkulation auf den regionalen Strahlungsantrieb über Europa zu untersuchen, haben wir Sensitivitätsexperimente mit einem hochmodernen gekoppelten Atmosphäre-Land-Ozean-Modell untersucht. Unter Verwendung neuer Deep-Learning-Algorithmen (DL) analysierten wir die Reaktion der arktischen Zirkulationsregime auf negativen Strahlungsantriebsanomalien über Europa. Wir haben verhsciedene Architekturen für unseren DL-Algorithmus untersucht, um die am besten geeignete für unsere Analyse zu finden. Wir haben die Felder des mittleren Drucks auf Meeresspiegelniveau und der Schichtdicke von 700 bis 300 hPa und ihre raumzeitlichen Muster mit dem DL-Algorithmus analysiert. Die DL-Algorithmen zeigten gute Ergebnisse bei der Erfassung der allgmeinen Struktur der großräumigen Zirkulation. Der Strahlungsantrieb über Europa scheint der großräumigen Zirkulation keine neuen raumzeitlichen Muster zuzufügen, veränderte aber die Häufigkeit des Auftretens bevorzugter Zirkulationsmuster

Online prevention of disordered eating in at-risk young-adult women: A two-country pragmatic randomized controlled trial

This article has been published in a revised form in Psychological Medicine. This version is free to view and download for private research and study only. Not for re-distribution, re-sale or use in derivative works. © Cambridge University Press 2017. This author accepted manuscript is made available following 6 month embargo from date of publication (Dec 2017) in accordance with the publisher’s copyright policyDisordered eating (DE) is a widespread, serious problem. Efficacious prevention programs that can be delivered at-scale are needed. A pragmatic randomized controlled trial of two online programs was conducted. Participants were young-adult women from Australia and New Zealand seeking to improve their body image. Media Smart-Targeted (MS-T) and Student Bodies (SB) were both 9-module interventions released weekly, whilst control participants received positive body image information. Primary [Eating Disorder Examination–Questionnaire (EDE-Q) Global], secondary (DE risk factors) and tertiary (DE) outcome measures were completed at baseline, post-program, 6- and 12-month follow-up. Baseline was completed by 608 women (M age = 20.71 years); 33 were excluded leaving 575 randomized to: MS-T (N = 191); SB (N = 190) or control (N = 194). Only 66% of those randomized to MS-T or SB accessed the intervention and were included in analyses with controls; 78% of this sample completed measures subsequent to baseline. Primary intent-to-treat (ITT) analyses revealed no differences between groups, while measure completer analyses found MS-T had significantly lower EDE-Q Global than controls at 12-month follow-up. Secondary ITT analyses found MS-T participants reported significantly higher quality of life–mental relative to both SB and controls (6-month follow-up), while MS-T and controls had lower clinical impairment relative to SB (post-program). Amongst measure completers, MS-T scored significantly lower than controls and SB on 5 variables. Of those with baseline DE, MS-T participants were significantly less likely than controls to have DE at 12-month follow-up. Given both programs were not therapist-moderated, MS-T has potential to achieve reductions in DE risk at low implementation costs

Distortion of meteor count rates due to cosmic radio noise and atmospheric particularities

The determination of the meteoroid flux is still a scientifically challenging task. This paper focusses on the impact of extraterrestrial noise sources as well as atmospheric phenomena on the observation of specular meteor echoes. The effect of cosmic radio noise on the meteor detection process is estimated by computing the relative difference between radio loud and radio quiet areas and comparing the monthly averaged meteor flux for fixed signal-to-noise ratios or fixed electron line density measurements. Related to the cosmic radio noise is the influence of D-layer absorption or interference with sporadic E-layers, which can lead to apparent day-to-day variation of the meteor flux of 15–20%

Elliptic Phases: A Study of the Nonlinear Elasticity of Twist-Grain Boundaries

We develop an explicit and tractable representation of a twist-grain-boundary phase of a smectic A liquid crystal. This allows us to calculate the interaction energy between grain boundaries and the relative contributions from the bending and compression deformations. We discuss the special stability of the 90 degree grain boundaries and discuss the relation of this structure to the Schwarz D surface.Comment: 4 pages, 2 figure