Search results for "manufacturing"
showing 10 items of 2299 documents
A Cost-Effective Solution for Clearing High-Impedance Ground Faults in Overhead Low-Voltage Lines
2019
Downed distribution conductors in overhead distribution systems may not be a concern for equipment but greatly challenge the safety of persons, as well as the integrity of properties. Standard overcurrent protective devices may not be able to detect the magnitudes of currents resulting from high-impedance ground faults. Sophisticated relays able to detect high-impedance ground faults have been available to electric utilities. However, their implementation is rather uncommon, especially in developing countries, most likely due to their costs. In this paper, the authors formalize the problem, and propose a possible cost-effective solution for low-voltage overhead lines with neutral wire. This…
Introduction. La paléomanufacture métallique : une nouvelle méthode d’étude
2007
The aim of this introduction to the third part of the specialist theme is to clarify the roles and the themes studied by each associate concerning the metal artefacts. It is divided into two parts:— the history of the study of metal artefacts and the presentation of a new method : metal paleo-manufacturing ;— research guidelines for this new speciality.
Mercury and Amino Acid Content Relations in Northern Pike (Esox Lucius) in Subarctic Lakes Along a Climate-Productivity Gradient
2023
Mercury is a highly toxic element for consumers, but its relation to amino acids and physiology of wild fish is not well known. The main aim of this study was to evaluate how total mercury content (THg) of northern pike (Esox lucius) is related to amino acids and potentially important environmental and biological factors along a climate-productivity gradient of ten subarctic lakes. Linear regression between THg and sixteen amino acids content [nmol mg−1 dry weight] from white dorsal muscle of pike from these lakes were tested. Lastly, a general linear model (GLM) for age-corrected THg was used to test which factors are significantly related to mercury content of pike. There was a positive r…
Chemical composition and microencapsulation suitability of sumac (Rhus coriaria L.) fruit extract
2021
Sumac (Rhus coriaria L.), a spice obtained by grinding whole sumac berries, is a complex natural product with a plethora of biological activities that can be favorably explored in nutraceutical and pharmaceutical fields. Sicilian sumac is herein chemically investigated by means of a combined NMR/HR MS-based profiling. A hydroalcoholic extract was prepared and its complexity unraveled following fractionation in an alcoholic and an aqueous fraction. The 1H-NMR spectrum of this latter fraction was dominated by the signals of gallic acid and its derivatives, whereas HR MS and HR MS/MS analyses highlighted the diversity in malic acid derivatives. Gallotannins and galloyl flavonol glycosides with…
Influence Des Conditions De Fabrication Sur Les Propriétés Mécaniques Et Physico-Chimiques D'un Composite Lin/Époxy Unidirectionnel
2017
This study focused on the development of a manufacturing process of laminated composites made from DGEBA epoxy matrix and flax fibers. The aim is to produce a material with good and low dispersed mechanical properties. Thermocompression is the chosen manufacturing method because it enables the production of composite with high fiber content. We used separated matrix and reinforcement, and not a prepreg, to fully control each component of our composites. Several curing cycle parameters have been tested in order to optimize mechanical properties and processing time. A multi-scale analyze has been carried on the produced composites in order to quantify the range of properties’ modifications. T…
: Effects of process conditions on mechanical and physicochemical properties of unidirectional flax/epoxy composite
2017
National audience; This study focused on the development of a manufacturing process of laminated composites made from DGEBA epoxy matrix and flax fibers. The aim is to produce a material with good and low dispersed mechanical properties. Thermocompression is the chosen manufacturing method because it enables the production of composite with high fiber content. We used separated matrix and reinforcement, and not a prepreg, to fully control each component of our composites. Several curing cycle parameters have been tested in order to optimize mechanical properties and processing time. A multi-scale analyze has been carried on the produced composites in order to quantify the range of propertie…
Design and Performance Evaluation of a High Power-Density EMI Filter for PWM Inverter-Fed Induction-Motor Drives
2016
This paper presents the design of an electromagnetic interference (EMI) filter for a low-voltage high-current induction-motor drives supplied by dc power grids. In order to effectively design the EMI filter, a suitable common-mode/differential-mode (CM/DM) separation technique has been used. Due to the high operating currents, the software-based separation technique using time-domain measurements has been applied. The proposed technique allows the CM and DM sections of the EMI filter to be properly selected in a more economical way, i.e., without the need of a dedicated hardware or costly radio frequency (RF) instrumentation. The design has been done according to a power-density criterion. …
Multinationals, R&D and productivity: Evidence for UK Manufacturing firms
2010
In this study, we analyze multinationality (domestic-based firms versus multinationals) and foreignness (foreign versus domestic firms) effects in the returns of R&D to productivity. We follow a two-step strategy. In the first step, we consistently estimate firm's productivity by GMM and numerically compute the sample distribution of the R&D returns. In the second step, we use stochastic dominance techniques to make inferences on the multinationality and foreignness effects. Results for a panel of UK manufacturing firms suggest that multinationality and foreignness effects operate in an opposite way: whilst the multinationality effect enhances R&D returns, the foreignness diminishes them. C…
Quasi-Fractional Models of Human Tendons Hereditariness
2018
In this study, the authors, after collecting a series of experimental evidences following a creep and relaxation tendon campaign, propose a non-linear model of the viscoelastic behavior of the tendons. The ligaments investigated are the patellars and the hamstrings. The analytical model proposed by the authors aims to explain the non-linear hereditary behavior of these tissues and proposes an approach with which to develop a hereditary fractional-order non-linear model.
Numerical experimental analysis of hybrid double lap aluminum-CFRP joints
2015
Abstract Due to their reliability and ease of assembly, both the adhesively bonded and the mechanical joints are commonly used in different fields of modern industrial design and manufacturing, to joint composite materials or composites with metals. As it is well known, adhesively bonded joints are characterized by high stiffness and good fatigue life, although delamination phenomena localized near the free edges may limit their use, especially for applications where corrosive environments and/or moisture can lead to premature failure of the bonding. In these cases, a possible alternative is given by the well-known mechanical joints. On the contrary, these last joints (bolted, riveted) requ…