Search results for "current"
showing 10 items of 2224 documents
Current Status of Nanoclay Phytotoxicity
2018
The use of nanotechnology in several fields has created a great interest and its rapid development with application in material science, nanomedicine, medical diagnosis, computer chips, catalysis and so on. The use of nanomaterials represents various advantages, including size, highly active surfaces, unique physico-chemical properties, and in some cases a controlled release of chemicals. In this context phyto-nanotechnology is growing and has promising application in agricultural aspects, such as use of soil remediation, antioxidants, adsorbents, nano-sensor for detection of soil quality, delivery of fertilizers and many others. Plants are very important components of the terrestrial eco-s…
Optimum design of two-level MCML gates
2008
In this paper, we address the problem of the optimum design of two-level MOS Current Mode Logic (MCML) gates. In particular, we describe a design methodology based on the concept of crossing-point current already introduced for the optimum design of single-level MCML gates. This methodology is suited both for automated implementation and graphic estimate of the optimum design. Moreover, it clearly shows how some important design parameters affect the optimum values of delay and power consumption. Several gates were designed in an IBM 130 nm CMOS technology. The results of SPICE simulations, reported here, demonstrate the effectiveness of the proposed design methodology.
A statistic approach of cables ageing in MV lines on thermal and electrical combined stress
2006
The paper introduces a methodology that through a probabilistic characterisation of load for MV network, and implementing a life model for combined electric and thermal stresses, simulates the process of ageing of the insulating materials evaluating the expected life time of the cable. Such evaluation is necessary to the possibility of assuming less restrictive thermal overloading limits on electrical cables, with the consequential increase on reserve that cables could offer. A numerical example is reported to better explain the methodology
The Current State of Industrial Practice in Artificial Intelligence Ethics
2020
As Artificial Intelligence (AI) systems become increasingly widespread, we have begun to witness various failures highlighting issues in these systems. These incidents have sparked public discussion related to AI ethics and further accelerated the on-going academic discussion in the area. High-level guidelines and tools for managing AI ethics have been introduced to help industry organizations make more ethical AI systems, but we currently know little about the state of industrial practice. Have these guidelines been adopted by the software industry for developing AI solutions? Are these failures that make the news just the tip of the iceberg? We provide insights into the current state of p…
Diagnosis of mechanical unbalance for double cage induction motor load in time-varying conditions based on motor vibration signature analysis
2013
This paper investigates the detectability of mechanical unbalance in double cage induction motor load using motor vibration signature analysis technique. Rotor imbalances induce specific harmonic components in electrical, electromagnetical, and mechanical quantities. Harmonic components characteristic of this category of rotor faults, issued from vibration signals analysis, are closely related to rotating speed of the rotor, which complicates its detection under non-stationary operating conditions of the motor. Firstly, experimental results were performed first under healthy and mechanical load unbalance cases, for different load levels under steady-state operating conditions to evaluate th…
Control of solid-state fault current limiter for DG-integrated distribution systems
2017
Fault current limier (FCL) is a device that limits the system current under fault conditions without disconnecting the system and affecting the power system protection components such as circuit breakers. Many types of FCLs have been proposed to limit the magnitude of the fault current. Solid-state fault current limiters (SSFCLs) can limit the peak value of the fault current by applying several methods, such as controlling the system impedance or controlling the voltage that appears across the fault. In this paper, a new control scheme for the SSFCL circuit is presented. The control method is based on controlling the duty cycle of solid state switches to control the rms value of the system …
Current and Voltage Behaviour During a Fault in a HV/MV System: Methods and Measurements
2015
When a single line to ground fault happens on the MV side of a HV/MV system, only a small portion of the fault current is injected into the ground by the ground-grid of the faulty substation. In fact the fault current is distributed between grounding electrodes and MV cables sheaths. In systems with isolated neutral or with resonant earthing this may be sufficient to provide safety from electric shock. Experimental measurements were performed on a real MV distribution network: a real single line to ground fault was made and fault currents were measured in the faulty substation and in four neighbouring substations. In this paper the problem of fault current distribution is introduced, the te…
Design and characterization of the SiPM tracking system of NEXT-DEMO, a demonstrator prototype of the NEXT-100 experiment
2013
NEXT-100 experiment aims at searching the neutrinoless double-beta decay of the Xe-136 isotope using a TPC filled with a 100 kg of high-pressure gaseous xenon, with 90% isotopic enrichment. The experiment will take place at the Laboratorio Subterraneo de Canfranc (LSC), Spain. NEXT-100 uses electroluminescence (EL) technology for energy measurement with a resolution better than 1% FWHM. The gaseous xenon in the TPC additionally allows the tracks of the two beta particles to be recorded, which are expected to have a length of up to 30 cm at 10 bar pressure. The ability to record the topological signature of the beta beta 0 nu events provides a powerful background rejection factor for the bet…
Mean flow, secondary currents and bed shear stress at a 180-degree laboratory bend with and without enhanced permeable groins as an Eco-friendly rive…
2022
River restoration aims to apply environmentally-friendly structures for bank protection in meandering rivers to restore their natural habitat. Enhanced Permeable Groin (EPG) is a novel river restoration technique that can improve the fish habitat environment in a river system by creating a series of eco-friendly scour pools. This study reports the results of two groups of 3D velocity measurements in a 180-degree channel bend in cases with and without an EPG for clear water conditions to characterize the mechanisms leading to the primary stages of the scouring phenomenon. The analysis revealed that the presence of an EPG amplified the velocity magnitude in the regions near the tip of the van…
Current state of water management in Japan
2014
Financial sustainability of water utilities is essential to guarantee the provision of high quality services. The aims of this paper are to review the current state of water management in Japan and to identify the main difficulties which confront Japanese water utilities. As the facilities built when the country expanded water utilities rapidly are drawing near the renewal period concurrently, water operators must quickly accelerate facility renewal work. The statistical data from the Japan Water Works Association illustrate that one of the most significant challenges facing Japanese water utilities is to finance investments to renew facilities and to prepare them for earthquakes. Difficult…