Search results for "UF"
showing 10 items of 4385 documents
The effect of plasma instabilities on the background impurities in charge breeder ECRIS
2017
International audience; Experimental observations of plasma instabilities in the 14.5 GHz PHOENIX charge breeder ECRIS are summarized. It has been found that the injection of 133Cs+ or 85Rb+ into oxygen discharge of the CB-ECRIS can trigger electron cyclotron instabilities, which results to sputtering of the surfaces exposed to the plasma, followed by up to an order of magnitude increase of impurity currents in the extracted n+ charge state distribution. The transition from stable to unstable plasma regime is caused by gradual accumulation and ionization of Cs/Rb altering the discharge parameters in 10 - 100 ms time scale, not by a prompt interaction between the incident ion beam and the EC…
An investigation into the fracture behaviour of honeycombs with density gradients
2020
International audience; In this study we perform an experimental and computational investigation about the fracture behaviour of polymer honeycombs presenting gradients in terms of lattice density. Such lattice relative density variations are introduced with the aim of mimicking the micro-morphology encountered in some natural materials, such as several kinds of woods, which seems related to the ability of the corresponding macro-material to delay the propagation of fracture under certain conditions. Starting from the conclusions of previous computational analyses, we perform a few experimental tensile tests on ABS model honeycombs obtained by additive manufacturing, with the aim of getting…
Cold gas dynamic spray technology: A comprehensive review of processing conditions for various technological developments till to date
2018
Abstract Today, cold gas dynamic spray (CGDS) technology has thrived with considerable capabilities for manufacturing various technological depositions. The deposition conditions have been developed through many years and that have led to produce ample experimental data which is available in the literature. But, recent research and development activities also reveal innovative findings regarding various deposition conditions. This paper contains a review of experimental deposition procedures for the cold spray additive manufacturing. Details of processing conditions are reported and classified into various categories of baseline working conditions, specific processing including deposition o…
The Role of Right Interpretation of Space Charge Distribution for Optimized Design of HVDC Cables
2019
In the field of high-voltage transmission systems, different degradation phenomena affect the reliability of the employed components. In particular, under dc stress, the space charge accumulation phenomenon is believed to be the most responsible of the dielectrics lifetime reduction. To measure the accumulated space charges in flat specimens, the pulsed electro-acoustic (PEA) method is one of the most used techniques. The working principle of the PEA cell is based on the acoustic waves propagation and detection. As is well known, the acoustic waves propagating in different means are partially transmitted and partially reflected. Therefore, the piezoelectric sensor of the PEA cell is subject…
Addressing Manufacturing Challenges with Cost-Efficient Fault Tolerant Routing
2010
The high-performance computing domain is enriching with the inclusion of Networks-on-chip (NoCs) as a key component of many-core (CMPs or MPSoCs) architectures. NoCs face the communication scalability challenge while meeting tight power, area and latency constraints. Designers must address new challenges that were not present before. Defective components, the enhancement of application-level parallelism or power-aware techniques may break topology regularity, thus, efficient routing becomes a challenge.In this paper, uLBDR (Universal Logic-Based Distributed Routing) is proposed as an efficient logic-based mechanism that adapts to any irregular topology derived from 2D meshes, being an alter…
Synergistic effect of fiber content and length on mechanical and water absorption behaviors of Phoenix sp. fiber-reinforced epoxy composites
2016
Phoenix sp. fiber-reinforced epoxy composites have been manufactured using compression molding technique. The effect of reinforcement volume content (0%, 10%, 20%, 30%, 40%, and 50%) and size (300 µm particles, 10 mm, 20 mm, and 30 mm fibers) on quasi-static and dynamic mechanical properties was investigated. Moreover, the water absorption properties of composites were analyzed at different environmental conditions (10℃, 30℃, and 60℃). For each reinforcement size, composites loaded with 40% in volume show highest tensile and flexural properties. Furthermore, composites with 300 µm particles present the best impact properties and the lowest water absorption, regardless of the environmental …
Optical study for springback prediction, thickness reduction and forces variations on single point incremental forming
2019
Abstract The goal of the present work is to present an experimental study regarding the influence of the main technological influence factors such as the vertical step and the punch diameter on the single point incremental forming process (SPIF). In this paper we estimate the influence of these two factors on springback, thickness reduction and forces. Both parameters were varied on two levels: (d) punch diameter 6 and 10 mm and (s) vertical step 0,1 and 0,5 mm. The experiments were done on experimental layout composed by a robot, a clamping system that contains the die’s lower part and the optical system.
Opening of New Synthetic Routes Using Segmented Microflow in Multistep Syntheses
2017
The application of microfluidics in organic chemistry is a valuable tool to access new synthesis pathways and to break limitations set by traditional batch chemistry. In the past, the majority of research focused on solving problems associated with individual reactions. It is necessary to advance the field by incorporating flow chemistry in longer multistep syntheses to open more direct paths towards complicated compounds. Several strategies were developed to meet the demands of a four-step synthesis, which includes biphasic nitrations, gaseous substrates, and very fast reactions on multifunctional molecules. A unique micro flow setup was applied in each reaction to meet its specific requir…
Influence of Wind on Suspended Matter in the Water of the Albufera of Valencia (Spain)
2021
Wind is one of the factors that has a great influence on suspended matter in lakes, especially in shallow lagoons. In order to know how wind affects the water in Albufera of Valencia, a shallow coastal lagoon, the measured variables of turbidity and transparency have been correlated with the estimates by processing Sentinel-2 satellite images with the Sen2Cor processor. Data from four years of study show that most of them are light to gentle easterly breezes and moderate to fresh westerly breezes. The results obtained show significant correlations between the measured variables and those obtained from the satellite images for total suspended matter and water transparency and with the averag…
Estimating Missing Information by Cluster Analysis and Normalized Convolution
2018
International audience; Smart city deals with the improvement of their citizens' quality of life. Numerous ad-hoc sensors need to be deployed to know humans' activities as well as the conditions in which these actions take place. Even if these sensors are cheaper and cheaper, their installation and maintenance cost increases rapidly with their number. We propose a methodology to limit the number of sensors to deploy by using a standard clustering technique and the normalized convolution to estimate environmental information whereas sensors are actually missing. In spite of its simplicity, our methodology lets us provide accurate assesses.