Search results for "POWER"
showing 10 items of 5099 documents
Solid–Liquid Suspensions in Top-Covered Unbaffled Vessels: Influence of Particle Size, Liquid Viscosity, Impeller Size, and Clearance
2014
Particle suspension in liquids is a unit operation commonly encountered in the process industry. Although it is usually carried out in baffled stirred tanks, there are some specific applications where the presence of baffles may be undesirable. In the present work solid-liquid suspensions are investigated in a radially stirred unbaffled tank provided with a top cover. The minimum impeller speed at which all solid particles get suspended (Njs) and the relevant power requirements (Pjs) are assessed. The dependence of these two parameters on physical properties (liquid viscosity, particle concentration, and size) and system geometrical configurations (impeller diameter and clearance) is invest…
Wireless power transfer system stability analysis for E-bikes application
2019
The present work reports the stability analysis of an Inductive Coupled Power Transfer (ICPT) System coupled to an electrical bike. The study has focused on two coupled coils with circular geometry and vertical disposition. In the first part of the work, the theoretical aspects related to the stability of wireless power systems are handled. In the second part, performing several simulations, varying the features of the considered configuration, the stability is looked for. In order to perform this process, the Ansys Maxwell software has been used, performing 3D simulations.
Heat to electricity conversion by cold carrier emissive energy harvesters
2015
This paper suggests a method to convert heat to electricity by the use of devices called cold carrier emissive energy harvesters (cold carrier EEHs). The working principle of such converters is explained and theoretical power densities and efficiencies are calculated for ideal devices. Cold carrier EEHs are based on the same device structure as hot carrier solar cells, but works in an opposite way. Whereas a hot carrier solar cell receives net radiation from the sun and converts some of this radiative heat flow into electricity, a cold carrier EEH sustains a net outflux of radiation to the surroundings while converting some of the energy supplied to it into electricity. It is shown that the…
Numerical study of photolithography system: electromagnetic differential method
2004
The R-matrix propagation algorithm is incorporated into the differential method to achieve an extended capability for modelling a photolithography systems. We show throughout this work the ability of the R-matrix algorithm and differential method to analyse gratings of arbitrary depth, profile, and conductivity without encountering numerical instabilities. We calculate the field intensity and the transmitted amplitudes in the 0 and −1 orders below different masks. We study also the influence of the various parameters (incidence, groove spacing, groove depth and index of refraction) on the field intensity maps and the transmittivity power. These results agree with the experimental patent: we…
Professional Agency, Identity, and Emotions While Leaving One’s Work Organization
2015
This study investigated the enactment of professional agency in an emotionally troubled work context emerging from a conflicted relationship between the professional and the work organization. Narrative interviews with Finnish educators were utilized. The findings indicate that the enactment of agency was in part framed by the educators’ rational interpretations of the relationship between themselves and their employer, plus their work history and future prospects. However, it was simultaneously embedded with contradictory emotions, such as a sense of being undervalued, fear, and a sense of empowerment. Within this framework, multifaceted professional agency was enacted particularly via lea…
The design of the DONES lithium target system
2019
Abstract In the framework of the EU fusion roadmap implementing activities, an accelerator-based Li(d,xn) neutron source called DONES (Demo-Oriented early NEutron Source) is being designed within the EUROfusion Work Package Early Neutron Source as an essential irradiation facility for testing candidate materials for DEMO reactor and future fusion power plants. DONES will employ a high speed liquid lithium jet struck by a 125 mA, 40 MeV deuteron beam to generate the intense neutron flux used to irradiate the material samples up to the desired level of displacement damage (˜10 dpa/fpy for iron in 0.3 l) and He production rates (˜10-13 appm He/dpa). In order to rapidly achieve a sound and stab…
Parametric study of the influence of First Wall cooling water on the Water Cooled Lithium Lead Breeding Blanket nuclear response
2019
Abstract In the framework of EUROfusion Work Package International Cooperation R&D activities, a close collaboration has been started among University of Palermo, ENEA Brasimone and ENEA Frascati for the development of the Water Cooled Lithium Lead (WCLL) Breeding Blanket (BB) concept. In this context, a research campaign has been carried out at the University of Palermo in order to investigate the influence of First Wall (FW) cooling water configuration on the nuclear response of the WCLL BB under irradiation in EU-DEMO, in order to gain useful indications for the WCLL BB pre-conceptual designs. To this end, three-dimensional nuclear analyses have been performed by MCNP5 v. 1.6 Monte Carlo…
Burnout syndrome among psychiatric trainees in 22 countries: Risk increased by long working hours, lack of supervision, and psychiatry not being firs…
2016
AbstractBackgroundPostgraduate medical trainees experience high rates of burnout, but evidence regarding psychiatric trainees is missing. We aim to determine burnout rates among psychiatric trainees, and identify individual, educational and work-related factors associated with severe burnout.MethodsIn an online survey psychiatric trainees from 22 countries were asked to complete the Maslach Burnout Inventory (MBI-GS) and provide information on individual, educational and work-related parameters. Linear mixed models were used to predict the MBI-GS scores, and a generalized linear mixed model to predict severe burnout.ResultsThis is the largest study on burnout and training conditions among p…
Work, power and learning in a risk filled occupation
2011
In this article we describe various ways in which power is exercised between personnel in a hospital operating theatre. We aim to investigate how the forms of discursive power and workplace learning are intertwined with each other by utilizing an ethnographic approach in the fieldwork. Our data were collected mainly through observations and interviews with surgical residents, physicians and nurses. In the article we describe the delicate ways in which power is exercised and resisted in everyday practices. We argue that there is a close relationship between learning and manifestations of power, together with the various forms of these manifestations and the restrictions that may be placed o…
Spatial fragmentation of, and US support for, the main multilateral institutions of the western order
2017
The growth of China-led minilateral initiatives mostly of a regional character has challenged the main multilateral institutions of the Western order and, ultimately, US authority. Faced with a progressive delegitimation of the institutional architecture that it promoted after World War II, the US, under the Obama administration, has acted to defend the existing main multilateral institutions of the order (UN, IMF, WB and WTO), attributing them with a strategic role. More than being radical, though, the reforms enacted have been incremental and pragmatic, but always imperfect. More importantly, they have not altered US influence, which is exercised mostly through informal means. This, howev…