Search results for "Discharge"
showing 10 items of 424 documents
Dynamic regimes of cyclotron instability in the afterglow mode of minimum-B electron cyclotron resonance ion source plasma
2016
The paper is concerned with the dynamic regimes of cyclotron instabilities in non-equilibrium plasma of a minimum-B electron cyclotron resonance ion source operated in pulsed mode. The instability appears in decaying ion source plasma shortly (1–10 ms) after switching off the microwave radiation of the klystron, and manifests itself in the form of powerful pulses of electromagnetic emission associated with precipitation of high-energy electrons along the magnetic field lines. Recently it was shown that this plasma instability causes perturbations of the extracted ion current, which limits the performance of the ion source and generates strong bursts of bremsstrahlung emission. In this artic…
Partial Discharges in HVDC Cables - The Effect of the Temperature Gradient During Load Transients
2021
The paper investigates the role of the space charge accumulation phenomena in the inception of Partial Discharges (PD) in a defect within the bulk of the dielectrics of a High Voltage Direct Current (HVDC) cable. It is widespread accepted that the number of PD occurring in an HVDC cable during its lifetime is largely less than that under AC voltage stress. This is essentially due to higher values of the voltage between the conductor and the screen needed to trigger PD under a steady DC voltage than the same value under AC stress. Nevertheless, due to the dependency of the electrical conductivity of the insulation on the electric field and temperature, PD in HVDC cables is strongly influence…
Evaluation and improvement of the quality of the discharge prescription in Cystic Fibrosis children hospitalised for intravenous antibiotic therapy
2017
1.Antecedentes. La Fibrosis Quística (FQ) es una enfermedad conocida desde la edad media, aunque durante esa época no estaba descrita como tal sino más bien como un hechizo maligno. En 1943, Farber propuso el término mucoviscidosis y este término se sigue utilizando en la actualidad. La FQ es la enfermedad hereditaria autosómica recesiva grave más frecuente en la población blanca, con una incidencia en Europa que oscila entre 1:1.353 en Irlanda y entre 1:25.000 en Finlandia, y una frecuencia de portadores de 1 por cada 2527. Es una enfermedad de las células epiteliales exocrinas, que se caracteriza por la producción de un moco espeso y viscoso que obstruye los conductos del órgano donde se …
Pressure support ventilation + sigh in acute hypoxemic respiratory failure patients: Study protocol for a pilot randomized controlled trial, the PROT…
2018
Background Adding cyclic short sustained inflations (sigh) to assisted ventilation yields optimizes lung recruitment, decreases heterogeneity and reduces inspiratory effort in patients with acute hypoxemic respiratory failure (AHRF). These findings suggest that adding sigh to pressure support ventilation (PSV) might decrease the risk of lung injury, shorten weaning and improve clinical outcomes. Thus, we conceived a pilot trial to test the feasibility of adding sigh to PSV (the PROTECTION study). Methods PROTECTION is an international randomized controlled trial that will be conducted in 23 intensive care units (ICUs). Patients with AHRF who have been intubated from 24 h to 7 days and under…
ELECTRICAL DISCHARGE MACHINING - A HIGH FUTURE NONCONVENTIONAL PROCESSING PROCESS
2021
Electrical discharge machining is one of the most common processes for processing metallic materials. This process is characterized by the lack of mechanical pressure on the object that ensures the macroscopic location of the erosive agent. This scientific paper highlights a study based on experimental data processing as well as modeling the most important technological parameters for dimensional processing by electrical discharge machining with and without magnetic activation. In this context, the modeling and optimization of process parameters is approached, which can lead to the quality increasing of the processed surface, to an increase of the processing productivity and to a reduction …
Radiofrequency and 2.45 GHz electron cyclotron resonance H− volume production ion sources
2016
The volume production of negative hydrogen ions (H-) in plasma ion sources is based on dissociative electron attachment (DEA)to rovibrationally excited hydrogen molecules(H2), which is a two-step process requiring both, hot electrons for ionization, and vibrational excitation of the H2 and cold electrons for the H- formation through DEA. Traditionally H- ion sources relying on the volume production have been tandem-type arc discharge sources equipped with biased filament cathodes sustaining the plasma by thermionic electron emission and with a magnetic filter separating the main discharge from the H- formation volume. The main motivation to develop ion sources based on radiofrequency (RF) o…
Closure to "Assessing stage-discharge relationships for circular overflow structure" by M. Bijankhan and V. ferro
2018
The paper is a closure to a previous article.
Simple flume with a central baffle
2016
Abstract In this paper the stage-discharge relationship of a flume with a central baffle is theoretically deduced using the Buckingham-Theorem of the dimensional analysis and the self-similarity theory. The new stage-discharge equation is calibrated by the measurements carried out by Peruginelli and Bonacci using a baffle having a given throat length and five different values of the contraction ratio. Finally, for a given throat length, a relationship linking the discharge with the upstream water depth, the contraction ratio and the contracted width is deduced.
New Stage–Discharge Relationship for Triangular Broad-Crested Weirs
2022
Simple hydraulic structures, such as weirs, allow measuring flow discharge by using the upstream flow depth and a stage–discharge relationship. In this relationship, a discharge coefficient is introduced to correct all the effects neglected in the derivation (viscosity, surface tension, velocity head in the approach channel, flow turbulence, non-uniform velocity profile, and streamline curvature due to weir contraction). In this paper, the dimensional analysis and the incomplete self-similarity theory are used to investigate the outflow process of triangular broad-crested weirs, characterized by different values of the ratio between crest height p and channel width B, and to theoretic…
A concept for the extraction of the most refractory elements at CERN-ISOLDE as carbonyl complex ions
2021
The European physical journal / A 58(5), 94 (2022). doi:10.1140/epja/s10050-022-00739-1