1,331 research outputs found
Enhanced and reduced transmission of acoustic waves with bubble meta-screens
We present a class of sonic meta-screens for manipulating air-borne acoustic
waves at ultrasonic or audible frequencies. Our screens consist of periodic
arrangements of air bubbles in water or possibly embedded in a soft elastic
matrix. They can be used for soundproofing, but also for exalting transmission
at an air/water interface or even to achieve enhanced absorption
Magnetization Modeling of Twisted Superconducting Filaments
This paper presents a new Finite Element numerical method to analyze the coupling between twisted filaments in a superconducting multifilament composite wire. To avoid the large number of elements required by a 3D code, the proposed method makes use of the energy balance principle in a 2D code. The relationship between superconductor critical current density and local magnetic flux density is implemented in the program for the Bean and modified Kim models. The modeled wire is made up of six filaments twisted together and embedded in a lowresistivity matrix. Computations of magnetization cycle and of the electric field pattern have been performed for various twist pitch values in the case of a pure copper matrix. The results confirm that the maximum magnetization depends on the matrix conductivity, the superconductor critical current density, the applied field frequency, and the filament twist pitch. The simulations also lead to a practical criterion for wire design that can be used to assess whether or not the filaments are coupled
Physicochemical and microbiological characteristics of kitoza, a traditional salted/dried/smoked meat product of Madagascar
Kitoza samples collected from producers in Madagascar were analyzed for their physicochemical and microbial properties. Lactic acid bacteria and coagulase‐negative staphylococci were the two codominant populations with average counts of 6–7 log cfu/g. Good hygienic practices were sometimes lacking but samples were not contaminated with Salmonella, Clostridium perfringens, and Bacillus cereus and only once with Listeria monocytogenes. Staphylococcus aureus was found occasionally with higher counts in salted/dried products than in salted/smoked products. Moisture, protein, fat, and salt contents varied considerably and were on average 41.5, 43.5, 14.3, and 3.3 g/100 g, respectively, and water activity was 0.893 on average. Smoked kitoza showed higher moisture content compared to dried kitoza. Most of the smoked kitoza had a water activity higher than 0.9 which is not in accordance with their storage at ambient temperatures. Benzo(a)pyrene content was above 2 µg/kg in 11 out of 30 smoked samples (17 ± 16.5 µg/kg on average)
Finite Element Model to Study the Deformations of NbSn Wires for the Next European Dipole (NED)
The Next European Dipole (NED) activity is aimed at the development of a large-aperture, high-field superconducting magnet relying on high-performances NbSn conductors. Part of the NED program is devoted to the mechanical study of a new generation of NbSn wires and to predict and describe their behavior under the severe loading conditions of the cabling process. The deformation resulting from the cabling process was simulated through mechanical analyses by Finite Elements (FE). The ensuing results of FE analyses are presented, allowing the wire behavior under simple uni-axial loads to be described. They are compared to cross section micrographs of deformed wires
Epidemiology, Prognosis, and Evolution of Management of Septic Shock in a French Intensive Care Unit: A Five Years Survey
Purpose. To evaluate the epidemiology, prognosis, and management of septic shock patients hospitalized in our intensive care unit (ICU). Materiel and Methods. Five-year monocenter observational study including 320 patients. Results. ICU mortality was 54.4%. Independent mortality risk factors were mechanical ventilation (OR = 4.97), Simplify Acute Physiology Score (SAPS) II > 60 (OR = 4.28), chronic alcoholism (OR = 3.38), age >65 years (OR = 2.65), prothrombin ratio <40% (OR = 2.37), and PaO2/FiO2 ratio <150 (OR = 1.91). These six mortality risk factors recovered allow screening immediately septic shock patients with a high mortality risk. Morbidity improved with time (diminution of septic shock complications, increase of the number of days alive free from mechanical ventilation and vasopressors on day 28), concomitant to an evolution of the management (earlier institution of all replacement and medical therapies and more initial volume expansion). There was no difference in mortality.
Conclusion. Our study confirms a high mortality rate in septic shock patients despite a new approach of treatment
FactoRing: Asynchronous TSN-compliant Network with low bounded Jitters for Industry 4.0
Time-Sensitive Networking (TSN) describes a set of features extending the functionalities and Quality of Service
(QoS) of standard Ethernet to enable determinism, reliability and reconfigurability, key requirements for Industry 4.0. The TSN profile for industrial automation (IEC/IEEE 60802 standard) defines specific options to favor reliability and reconfigurability.
Nevertheless, there are multiple possible options for scheduling to guarantee determinism. Today, the scheduling standards in TSN can be categorized according to the implemented communication paradigm: asynchronous or synchronous. This paradigm is of utmost importance to quantify the synchronization need and the reconfigurability effort. The main contribution of this work is the specification of an asynchronous TSN-compliant network for Industry 4.0, FactoRing, that bridges the gap between both paradigms to guarantee low bounded jitters and latencies, without the need of synchronization and complex network planning. Moreover, FactoRing supports ring-based topologies to significantly reduce installation wiring and costs. In this paper, we first present the main industry 4.0 requirements and assess the ability of recommended TSN mechanisms for industrial automation versus such requirements. Afterwards, we detail the main features of Factoring including QoS, reliability and reconfiguration management. Finally, preliminary results on
performance metrics like jitters, latencies and buffer usage are discussed and the first conclusions on the promises of Factoring to meet Industry 4.0 requirements are derived
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