181,606 research outputs found
Giovanni Gentile as moral philosopher
This essay assesses Gentile's contributions to practical philosophy, showing how a distinctive but idiosyncraticmoral theory emerges over the course of his systematic works. Wakefield argues that Gentile's thoroughgoing anti-realism does not, as some critics have thought, leave him unable to distinguish reasonable from unreasonable arguments or good from bad reasons for action. While actual idealism veers too close to implausible relativism to have much use as an all-purpose philosophical outlook, argues Wakefield, it retains real power as a practical theory
Near-threshold electron injection in the laser-plasma wakefield accelerator leading to femtosecond bunches
We gratefully acknowledge the support of the UK EPSRC (grant no. EP/J018171/1), the EU FP7 programmes: the Extreme Light Infrastructure (ELI) project, the Laserlab-Europe (no. 284464), and the EUCARD-2 project (no. 312453).The laser-plasma wakefield accelerator is a compact source of high brightness, ultra-short duration electron bunches. Self-injection occurs when electrons from the background plasma gain sufficient momentum at the back of the bubble-shaped accelerating structure to experience sustained acceleration. The shortest duration and highest brightness electron bunches result from self-injection close to the threshold for injection. Here we show that in this case injection is due to the localized charge density build-up in the sheath crossing region at the rear of the bubble, which has the effect of increasing the accelerating potential to above a critical value. Bunch duration is determined by the dwell time above this critical value, which explains why single or multiple ultra-short electron bunches with little dark current are formed in the first bubble. We confirm experimentally, using coherent optical transition radiation measurements, that single or multiple bunches with femtosecond duration and peak currents of several kiloAmpere, and femtosecond intervals between bunches, emerge from the accelerator.Peer reviewe
Medicine and society in Wakefield and Huddersfield, 1780-1870
The thesis examines the formation and evolution of medical
provisions in Wakefield and Huddersfield between circa 1780 and
1870. The survey covers 'institutional' facilities, namely hospital and dispensary provisions and Poor Law medical services,
friendly society facilities for the sick and the development of
'fringe' or 'peripheral' medical practices. The thesis also
discusses the structural, professional and social development of
medical communities in the two towns.
A wide range of source material was utilised, to include
Poor Law material (pre- and post-1834), the records of friendly
societies and medical charities census returns, newspapers, trade
and medical directories and parliamentary reports and returns.
The use of such a combination of material gives a better indication
of the range of facilities available and their relative importance.
It will be suggested that the emphasis medical historians have
put on institutional provisions has been misplaced. The importance
of previously neglected options, the friendly society and 'peripheral'
forms of treatment, will be stressed. Leading on from this,
it is possible to suggest that self-help forms of medical relief
(compared with those 'provided' by the wealthy classes for the poor)
were of greater significance-than has previously been assumed.
An attempt has been made to place the development of medical
services against the backdrop of the communities that they evolved in.
The growth of institutional provisions and the progress of self-help
forms are linked to the organisation of the two communities, their
class structure and social, civic and economic developments. The
leading role of laymen in creating a demand for, and in the setting
up and evolution of, medical provisions has also been stressed.
It is hoped an analysis of these factors will lead to a clearer
understanding of how and why medical facilities developed-as they
did, and to a greater insight into the relationships between medicine
and society
Wakefield Or Wakeland, R, [No Service Number]
This record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/423343Surname: WAKEFIELD OR WAKELAND. Given Name(s) or Initials: R. Military Service Number or Last Known Location: [No Registration Number]. Missing, Wounded and Prisoner of War Enquiry Card Index Number: 32581.249858
Item: [2016.0049.55604] "Wakefield Or Wakeland, R, [No Service Number]
An ultrashort pulse ultra-violet radiation undulator source driven by a laser plasma wakefield accelerator
Narrow band undulator radiation tuneable over the wavelength range of 150–260 nm has been produced by short electron bunches from a 2 mm long laser plasma wakefield accelerator based on a 20 TW femtosecond laser system. The number of photons measured is up to 9 × 106 per shot for a 100 period undulator, with a mean peak brilliance of 1 × 1018 photons/s/mrad2/mm2/0.1% bandwidth. Simulations estimate that the driving electron bunch r.m.s. duration is as short as 3 fs when the electron beam has energy of 120–130 MeV with the radiation pulse duration in the range of 50–100 fs
Pepper-pot emittance measurement of laser-plasma wakefield accelerated electrons
The transverse emittance is an important parameter governing the brightness of an electron beam. Here we present the first pepper-pot measurement of the transverse emittance for a mono-energetic electron beam from a laser-plasma wakefield accelerator, carried out on the Advanced Laser-Plasma High Energy Accelerators towards X-Rays (ALPHA-X) beam line. Mono-energetic electrons are passed through an array of 52 mu m diameter holes in a tungsten mask. The pepper-pot results set an upper limit for the normalised emittance at 5.5 +/- 1 pi mm mrad for an 82 MeV beam
Letter from R. A. Carroll, Jr., Principal of Wakefield-Zebulon School, to S. B. Simmons
Letter from R. A. Carroll, Jr., Principal of Wakefield-Zebulon School, to S. B. Simmons, requesting advice for the school year
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