423 research outputs found
Influence of the gate leakage current on the stability of organic single-crystal field-effect transistors
We investigate the effect of a small leakage current through the gate
insulator on the stability of organic single-crystal field-effect transistors
(FETs). We find that, irrespective of the specific organic molecule and
dielectric used, leakage current flowing through the gate insulator results in
an irreversible degradation of the single-crystal FET performance. This
degradation occurs even when the leakage current is several orders of magnitude
smaller than the source-drain current. The experimental data indicate that a
stable operation requires the leakage current to be smaller than $10^{-9} \
\mathrm{A/cm}^2$. Our results also suggest that gate leakage currents may
determine the lifetime of thin-film transistors used in applications.Comment: submitted to Appl. Phys. Let
Highlights from the Faraday discussion on new directions in porous crystalline materials, Edinburgh, UK, June 2017
A lively discussion on new directions in porous crystalline materials took place in June 2017, with the beautiful city of Edinburgh as a backdrop, in the context of the unique Faraday Discussions format. Here, 5 minute presentations were given on papers which have been submitted in advance of the conference, with copious time allocated for in-depth discussion of the work presented. Professor Mircea Dincă (MIT), chair of the scientific committee, opened the conference by welcoming the many different nationalities attending, and outlining the format of discussions
High precision beam momentum determination in a synchrotron using a spin resonance method
In order to measure the mass of the eta meson with high accuracy using the
d+p -> 3He+eta reaction, the momentum of the circulating deuteron beam in the
Cooler Synchrotron COSY of the Forschungszentrum Juelich has to be determined
with unprecedented precision. This has been achieved by studying the spin
dynamics of the polarized deuteron beam. By depolarizing the beam through the
use of an artificially induced spin resonance, it was possible to evaluate its
momentum p with a precision of dp/p < 10-4 for a momentum of roughly 3 GeV/c.
Different possible sources of error in the application of the spin resonance
method are discussed in detail and its possible use during a standard
experiment is considered.Comment: 10 pages, 6 figures, 2 tables, published versio
What factors influence training opportunities for older workers? Three factorial surveys exploring the attitudes of HR professionals
The core research questions addressed in this paper are: what factors influence HR professionals in deciding whether to approve training proposals for older workers? What kind of training are they more likely to recommend for older employees and in which organizational contexts? We administered three factorial surveys to 66 HR professionals in Italy. Participants made specific training decisions based on profiles of hypothetical older workers. Multilevel analyses indicated that access to training decreases strongly with age, while highly-skilled older employees with low absenteeism rates are more likely to enjoy training opportunities. In addition, older workers displaying positive performance are more likely to receive training than older workers who perform poorly, suggesting that training late in working life may serve as a reward for good performance rather than as a means of enhancing productivity. The older the HR professional evaluating training proposals, the higher the probability that older workers will be recommended for training.
keywords: training; older workers; HR professionals; factorial survey; multilevel model
Spin tune mapping as a novel tool to probe the spin dynamics in storage rings
Precision experiments, such as the search for electric dipole moments of
charged particles using storage rings, demand for an understanding of the spin
dynamics with unprecedented accuracy. The ultimate aim is to measure the
electric dipole moments with a sensitivity up to 15 orders in magnitude better
than the magnetic dipole moment of the stored particles. This formidable task
requires an understanding of the background to the signal of the electric
dipole from rotations of the spins in the spurious magnetic fields of a storage
ring. One of the observables, especially sensitive to the imperfection magnetic
fields in the ring is the angular orientation of stable spin axis. Up to now,
the stable spin axis has never been determined experimentally, and in addition,
the JEDI collaboration for the first time succeeded to quantify the background
signals that stem from false rotations of the magnetic dipole moments in the
horizontal and longitudinal imperfection magnetic fields of the storage ring.
To this end, we developed a new method based on the spin tune response of a
machine to artificially applied longitudinal magnetic fields. This novel
technique, called \textit{spin tune mapping}, emerges as a very powerful tool
to probe the spin dynamics in storage rings. The technique was experimentally
tested in 2014 at the cooler synchrotron COSY, and for the first time, the
angular orientation of the stable spin axis at two different locations in the
ring has been determined to an unprecedented accuracy of better than
rad.Comment: 32 pages, 15 figures, 7 table
Phase Measurement for Driven Spin Oscillations in a Storage Ring
This paper reports the first simultaneous measurement of the horizontal and
vertical components of the polarization vector in a storage ring under the
influence of a radio frequency (rf) solenoid. The experiments were performed at
the Cooler Synchrotron COSY in J\"ulich using a vector polarized, bunched
deuteron beam. Using the new spin feedback system, we
set the initial phase difference between the solenoid field and the precession
of the polarization vector to a predefined value. The feedback system was then
switched off, allowing the phase difference to change over time, and the
solenoid was switched on to rotate the polarization vector. We observed an
oscillation of the vertical polarization component and the phase difference.
The oscillations can be described using an analytical model. The results of
this experiment also apply to other rf devices with horizontal magnetic fields,
such as Wien filters. The precise manipulation of particle spins in storage
rings is a prerequisite for measuring the electric dipole moment (EDM) of
charged particles
Phase locking the spin precession in a storage ring
This letter reports the successful use of feedback from a spin polarization
measurement to the revolution frequency of a 0.97 GeV/ bunched and polarized
deuteron beam in the Cooler Synchrotron (COSY) storage ring in order to control
both the precession rate ( kHz) and the phase of the horizontal
polarization component. Real time synchronization with a radio frequency (rf)
solenoid made possible the rotation of the polarization out of the horizontal
plane, yielding a demonstration of the feedback method to manipulate the
polarization. In particular, the rotation rate shows a sinusoidal function of
the horizontal polarization phase (relative to the rf solenoid), which was
controlled to within a one standard deviation range of rad. The
minimum possible adjustment was 3.7 mHz out of a revolution frequency of 753
kHz, which changes the precession rate by 26 mrad/s. Such a capability meets a
requirement for the use of storage rings to look for an intrinsic electric
dipole moment of charged particles
The effect of milk production level on host resistance of dairy cows, as assessed by the severity of experimental Escherichia coli mastitis
The culturability of 10 strains of Campylobacter jejuni and Campylobacter coli was studied after the bacteria were exposed to acid conditions for various periods of time. Campylobacter cells could not survive 2 h under acid conditions (formic acid at pH 4). The 10 Campylobacter strains could not be recovered, even when enrichment media were used. Viable cells, however, could be detected by a double-staining (5-cyano-2,3-ditolyl tetrazolium chloride [CTC]-4',6'-diamidino-2-phenylindole [DAPI]) technique, demonstrating that the treated bacteria changed into a viable but nonculturable (VBNC) form; the number of VBNC forms decreased over time. Moreover, some VBNC forms of Campylobacter could be successfully resuscitated in specific-free-pathogen fertilized eggs via two routes, amniotic and yolk sac injecting
International Veterinary Epilepsy Task Force consensus report on epilepsy definition, classification and terminology in companion animals
Dogs with epilepsy are among the commonest neurological patients in veterinary practice and therefore have historically attracted much attention with regard to definitions, clinical approach and management. A number of classification proposals for canine epilepsy have been published during the years reflecting always in parts the current proposals coming from the human epilepsy organisation the International League Against Epilepsy (ILAE). It has however not been possible to gain agreed consensus, “a common language”, for the classification and terminology used between veterinary and human neurologists and neuroscientists, practitioners, neuropharmacologists and neuropathologists. This has led to an unfortunate situation where different veterinary publications and textbook chapters on epilepsy merely reflect individual author preferences with respect to terminology, which can be confusing to the readers and influence the definition and diagnosis of epilepsy in first line practice and research studies.
In this document the International Veterinary Epilepsy Task Force (IVETF) discusses current understanding of canine epilepsy and presents our 2015 proposal for terminology and classification of epilepsy and epileptic seizures. We propose a classification system which reflects new thoughts from the human ILAE but also roots in former well accepted terminology. We think that this classification system can be used by all stakeholders
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