Coherent interaction of atoms with a beam of light confined in a light cage

Controlling coherent interaction between optical fields and quantum systems in scalable, integrated platforms is essential for quantum technologies. Miniaturise...     

Efficient allocation of elastic interfederation encrypted streaming sessions

Audio and video (A/V) collaboration platforms often use Internet cloud technologies to ensure elasticity. They generally operate on a best‐effort basis, without quality or delivery guarantees. However, such guarantees are a premise of business‐focused platforms, which often rely on static/dedicated infrastructure and hardware‐based components. This article presents results obtained in the final stage of the Elastic Media Distribution (EMD) project, which targets the migration of a business‐focused hardware‐based A/V collaboration tool towards a more elastic, reliable, and secure cloud‐based model. The use case under investigation is an educational scenario: teachers and students located at distributed sites collaborate under different data encryption policies. An existing model of collaboration streaming is extended to accommodate encryption‐enabled streaming components, and new resource allocation heuristics are proposed to deploy these components under stringent service level agreement (SLA) constraints. An extended version of our evaluation framework, based on the CloudSim simulator, manages encryption‐enabled components. A resource usage dataset was obtained by prototyping selected streaming components and evaluating their performance on the Virtual Wall large‐scale test bed. This dataset is fed into the extended simulation framework. Simulation results show longer than expected delays when loading streaming components, an issue that jeopardises the user experience that can be alleviated by the algorithms proposed in this article. Results show that the proposed algorithms enable policy‐based secured communications under bandwidth and virtual machine (VM) cost increases of 48% and 23%, respectively, if compared with a nonencrypted previous solution, and with set‐up times remaining under the required 2‐second deadline.     

A parametric study on supersonic/hypersonic flutter behavior of aero-thermo-elastic geometrically imperfect curved skin panel

In this paper, the effect of the system parameters on the flutter of a curved skin panel forced by a supersonic/hypersonic unsteady flow is numerically investigated. The aeroelastic model investigated includes the third-order piston theory aerodynamics for modeling the flow-induced forces and the Von Kármán non-linear strain-displacement relation in conjunction with the Kirchhoff plate hypothesis for the panel structural modeling. Structural non-linearities are considered and are due to the non-linear coupling between out-of-plane bending and in-plane stretching. The effects of thermal degradation and Kelvin??s model of structural damping independent on time and temperature are also considered. The aero-thermo-elastic governing equations are developed from the geometrically imperfect non-linear theory of infinitely long two-dimensional curved panels. Computational analysis and discussion of the finding along with pertinent conclusions are presented.     

Analysis of Iddq failures by spectral photon emission microscopy

In this work, a fast identification of I_ddq failures using spectroscopic photon emission microscopy (SPEMMI) is proposed. The spectra obtained from failure sites on the I_ddq failed chips were compared with the ones of known defective components. Four distinguishable spectra categories were identified. They were attributed to gate oxide breakdown, metal shorts, blackbody radiation, and ESD caused junction spiking. The focused ion beam (FIB) technique was used to look at the damage sites for confirmation of the SPEMMI results.     

The generation of shallow dopant layers by low-angle implantation

A simple arrangement for the generation of shallow dopant profiled by low-angle ion implantation is described. High resolution Rutherford backscattering has been employed to measure profiles of arsenic and antimony which have been obtained by implantation into (100) silicon at angles of incidence as low as 4° with respect to the wafer surface. These profiles have been compared with Monte Carlo calculations using the TRIM II code and found to be in good agreement. Electrical activity > 5 × 10¹⁹ cm^?3 has been achieved for dopant profiles with peak concentrations within 30 Å of the surface. The technique is amenable to the generation of tailored (e.g. uniform) implantation profiles at constant energy by variation of implant angle.     

Renewable energy for rural areas of Bolivia

This paper analyses the current status of rural renewable energy in Bolivia and provides and employs an analysis framework to study the network of stakeholders that determines the adoption, absorption and diffusion of renewable energy technology. The study, moreover, illustrates the impact and implications of traditional indigenous knowledge on the local entrepreneurial ecosystem.     

Mechanism and Kinetics of some Reactions on Silica-Alumina Catalysts

The dehydration of alcohol when its vapor is led over alumina, or some other heterogeneously acting catalysts, is already known from the end of the eighteenth century.     

HYDROGEN TRAIPB-NUUEAR MAGNETIC RESONANCE FOR INDUSTRIAL MOISTURE 8EN8MG

ABSTRACT

A procedure was developed based on a three-component physical model to simulate the drying characteristics of Laird lentils. In this model, the cotyledons were simplified as a homogeneous slab where moisture transfer was governed by a one-dimensional diffusion equation, and the hilum and seedcoat were considered as two parallel routes for moisture to escape from a seed. The simulation procedure was verified with the experimental data from thin-layer drying testing on samples of 19.0 to 24.5% initial moisture content at temperatures from 23 to 80°C and relative humidities from 5 to 70%. Using previously obtained information on the transport properties of the cotyledons, the seedcoat, and the hilum, the simulation followed the drying data closely over temperatures between 23 and 60°C.     

Production and characterization of transparent MgAl2O4 prepared by hot pressing

Hot pressing has been investigated for the production of transparent MgAl₂O₄ aimed at the scaling up of the process. Other assessed techniques (hot isostatic pressing, spark plasma sintering) can hardly be used for the production of flat components with large dimensions and good planarity.Hot pressing of stoichiometric Al₂O₃–MgO powder mixtures has been preferred to the direct pressing of spinel powder for the readily availability of pure powders and to exploit the thermodynamic driving force of the spinel formation. LiF has been used as sintering additive.A thermodynamic investigation of the reactions involving LiF, MgO and Al₂O₃ has helped in the comprehension of the densification mechanisms affecting the transparency of spinel. Transparencies up to 70% in the visible range (highest value 78% at 1100 nm) have been obtained. Suitable soakings have been added for promoting the initial liquid phase sintering and the release of LiF through formation of vapour phases.