Four wave mixing in 3C SiC Ring Resonators

We demonstrate frequency conversion by four wave mixing at telecommunication wavelengths using an integrated platform in 3C SiC. The process was enhanced by high-Q and small modal volume ring resonators, allowing the use of mW-level CW powers to pump the nonlinear optical process. We retrieved the nonlinear refractive index $n_{2}=(5.31\pm 0.04)\times 10^{-19} m^{2}/W$ of 3C SiC and observed a signal attributed to Raman gain in the structure.Comment: 4 pages, 3 figure

Reviewer acknowledgement 2012

CONTRIBUTING REVIEWERS: The Editors of Pediatric Rheumatology would like to thank all our reviewers who have contributed to the journal in Volume 10 (2012)

El crecimiento urbano no planificado y sus cobsecuencias sobre la sustentabilidad de los servicios

Se plantea evaluar e identificar las áreas de mayor vulnerabilidad urbana consecuencia de los desequilibrios generados por el crecimiento urbano espontáneo. Para ello se abordan el sector residencial y los servicios básicos de infraestructura. En el sector residencial se evalúa la ocupación en el territorio, y su evolución en cuanto al crecimiento, sus necesidades energéticas y sus respectivas emisiones de contaminantes. En cuanto a los servicios básicos de infraestructura, se analiza a partir de la utilización de un modelo de CVU, las redes de energía eléctrica y gas natural. Se relaciona la oferta a través de sus cualidades, con las coberturas de cada red y la opinión de los usuarios (la demanda). Con los resultados obtenidos, se conformaron mapas orientados a establecer zonas homogeneas de calidad tendientes a definir la insustentabilidad creciente de las areas de menor consolidación, estableciendose zonas urbanas con inequidades coincidentes con la zona de mayor crecimiento espontáneo.This paper looks to identify and evaluate major vulnerability areas produced by imbalanced spontaneous urban growth. In order to do so, residential areas and basic infrastructure services are taken into account. In relation to the first one, land occupation, energetic consume increase and its polluting emissions are evaluated. While infrastructure and services- electric supply and gas mains-, are measured through the use of CVU model. The quality of the offer is set in relation to the mains range and the demand. Results are transferred into maps oriented to build homogeneous quality areas in order to define growing unsustainability in recently built areas, and showing inequality urban areas in coincidence with major spontaneous growth zones.Fil: Discoli, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Grupo Vinculado al INENCO - Instituto de Investigaciones y Políticas del Ambiente Constituido | Universidad Nacional de Salta. Facultad de Cienicas Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional. Grupo Vinculado al INENCO - Instituto de Investigaciones y Políticas del Ambiente Constituido; ArgentinaFil: Martini, Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Grupo Vinculado al INENCO - Instituto de Investigaciones y Políticas del Ambiente Constituido | Universidad Nacional de Salta. Facultad de Cienicas Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional. Grupo Vinculado al INENCO - Instituto de Investigaciones y Políticas del Ambiente Constituido; Argentin

Coherent coupling between localised and propagating phonon polaritons

Following the recent observation of localised phonon polaritons in user-defined silicon carbide nano-resonators, here we demonstrate coherent coupling between those localised modes and propagating phonon polaritons bound to the surface of the nano-resonator's substrate. In order to obtain phase-matching, the nano-resonators have been fabricated to serve the double function of hosting the localised modes, while also acting as grating for the propagating ones. The coherent coupling between long lived, optically accessible localised modes, and low-loss propagative ones, opens the way to the design and realisation of phonon-polariton based quantum circuits

Elastodynamic Effects of Mass-Balancing: Experimental Investigation of a Four-Bar Linkage

This paper deals with static balancing of closed-loop mechanisms. The long-term goal of the research is enhancing the performance of parallel robots by means of effective static balancing strategies that take into account the system dynamic behaviour. In this contribution, the influence of mass-balancing on the elastodynamic performance of a four-bar linkage, intended as the simplest example of closed-loop mechanism, is experimentally investigated. The design of the experimental apparatus is discussed and the results of tests on both an unbalanced linkage and its balanced variant are presented. Base-transmitted forces and vibrations are monitored for constant-speed operations and for velocity ramp tests in order to characterize the elastodynamic behaviour of the linkages. The analysis is supported by implementing a flexible multibody model of the experimental apparatus that enhances the interpretation of the experimental data

Automatic Leak Detection in Buried Plastic Pipes of Water Supply Networks by Means of Vibration Measurements

The implementation of strategies for controlling water leaks is essential in order to reduce losses affecting distribution networks of drinking water. This paper focuses on leak detection by using vibration monitoring techniques. The long-term goal is the development of a system for automatic early detection of burst leaks in service pipes. An experimental campaign was started to measure vibrations transmitted along water pipes by real burst leaks occurring in actual water supply networks. The first experimental data were used for assessing the leak detection performance of a prototypal algorithm based on the calculation of the standard deviation of acceleration signals. The experimental campaign is here described and discussed. The proposed algorithm, enhanced by means of proper signal filtering techniques, was successfully tested on all monitored leaks, thus proving effective for leak detection purpose

Analysis of the Dynamic Behavior of a Counterbalance Forklift Truck through Multibody Modelling and Simulation

This work deals with the analysis of the dynamic response of a counterbalance forklift truck prototype when performing standard verification maneuvers, defined by the manufacturer’s testing protocols. The research aims at developing numerical tools based on multibody models to predict accurately the dynamic loads acting on the forklift in the conditions of interest. In particular, this study focuses on a specific test condition, namely the passage on a steel plate obstacle at constant speed, which is one of the most severe maneuvers of the reference cycle in terms of dynamic loads. A model of the complete forklift is developed inside a commercial multibody environment. It takes into account the ground/tire interactions, by means of a simplified nonlinear contanct model, and the load handling assembly dynamics. An experimental campaign is designed and conducted to asses the vehicle behavior when running on the obstacle, by measuring the vibrations of the chassis and of the mast, as well as the forces generated by the mast tilting actuators. The measured data are exploited for model update and validation. The numerical results provided by the updated model show a satisfactory accuracy