441 research outputs found
Effect of deposition parameters on TiAlN coating using pulsed DC CFUBMS
This paper aims to investigate the parametric effect of deposition and target frequency on the mechanical properties and machining performance of the TiAlN coatings deposited in a dual cathode pulsed dc CFUBMS system. Coating composition is not directly dependent on deposition temperature or target frequency individually but increase in both the parameters has led to Al rich coating. The coating thickness is influenced by target frequency only. The fatigue fracture resistance of the TiAlN coating has been evaluated by the nanoimpact test and it has been found to be at least as good as commercial Ti0.5Al0.5N coating deposited on cemented carbide. In dry machining SAE 1037 steel, it has been observed that the resistance to crater wear is influenced by target frequency. Simultaneous increase in the deposition temperature and target frequency has provided improved resistance to crater wear due to their favourable influence on the coating thickness and Al percentage
Clinical problems with the performance of euthanasia and physician-assisted suicide in The Netherlands
BACKGROUND AND METHODS: The characteristics and frequency of clinical
problems with the performance of euthanasia and physician-assisted suicide
are uncertain. We analyzed data from two studies of euthanasia and
physician-assisted suicide in The Netherlands (one conducted in 1990 and
1991 and the other in 1995 and 1996), with a total of 649 cases. We
categorized clinical problems as technical problems, such as difficulty
inserting an intravenous line; complications, such as myoclonus or
vomiting; or problems with completion, such as a longer-than-expected
interval between the administration of medications and death. RESULTS: In
114 cases, the physician's intention was to provide assistance with
suicide, and in 535, the intention was to perform euthanasia. Problems of
any type were more frequent in cases of assisted suicide than in cases of
euthanasia. Complications occurred in 7 percent of cases of assisted
suicide, and problems with completion (a longer-than-expected time to
death, failure to induce coma, or induction of coma followed by awakening
of the patient) occurred in 16 percent of the cases; complications and
problems with completion occurred in 3 percent and 6 percent of cases of
euthanasia, respectively. The physician decided to administer a letha
Physician reports of terminal sedation without hydration or nutrition for patients nearing death in the Netherlands
BACKGROUND: Terminal sedation in patients nearing death is an important
issue related to end-of-life care. OBJECTIVE: To describe the practice of
terminal sedation in the Netherlands. DESIGN: Face-to-face interviews.
SETTING: The Netherlands. PARTICIPANTS: Nationwide stratified sample of
482 physicians; 410 responded and 211 of these reported characteristics of
their most recent terminal sedation case. MEASUREMENTS: Physician reports
of frequency of terminal sedation (defined as the administration of drugs
to keep the patient in deep sedation or coma until death, without giving
artificial nutrition or hydration), characteristics of the decision-making
process, drugs used, the estimated life-shortening effect, and frequency
of euthanasia discussions. RESULTS: Of respondents, 52% (95% CI, 48% to
57%) had ever used terminal sedation. Of the 211 most recent cases,
physicians used terminal sedation to alleviate severe pain in 51% of
patients (CI, 44% to 58%), agitation in 38% (CI, 32% to 45%), and dyspnea
in 38% (CI, 32% to 45%). Physicians reported discussing with patients th
Low-lying quadrupole collective states of the light and medium Xenon isotopes
Collective low lying levels of light and medium Xenon isotopes are deduced
from the Generalized Bohr Hamiltonian (GBH). The microscopic seven functions
entering into the GBH are built from a deformed mean field of the Woods-Saxon
type. Theoretical spectra are found to be close to the ones of the experimental
data taking into account that the calculations are completely microscopic, that
is to say, without any fitting of parameters.Comment: 8 pages, 4 figures, 1 tabl
Liquid-Solid Transition of Hard Spheres Under Gravity
We investigate the liquid-solid transition of two dimensional hard spheres in
the presence of gravity. We determine the transition temperature and the
fraction of particles in the solid regime as a function of temperature via
Even-Driven molecular dynamics simulations and compare them with the
theoretical predictions. We then examine the configurational statistics of a
vibrating bed from the view point of the liquid-solid transition by explicitly
determining the transition temperature and the effective temperature, T, of the
bed, and present a relation between T and the vibration strength.Comment: 14 total pages, 4 figure
The long term effects of sports concussion on retired Australian football players: a study using Transranial Magnetic Stimulation
This study investigated corticomotor excitability and inhibition, cognitive functioning, and fine motor dexterity in retired elite and amateur Australian football (AF) players who had sustained concussions during their playing careers. Forty male AF players who played at the elite level (n=20; mean age 49.7±5.7 years) or amateur level (n=20; mean age 48.4±6.9 years), and had sustained on average 3.2 concussions 21.9 years previously, were compared with 20 healthy age-matched male controls (mean age 47.56±6.85 years). All participants completed assessments of fine dexterity, visuomotor reaction time, spatial working memory (SWM), and associative learning (AL). Transcranial magnetic stimulation (TMS) was used to measure corticospinal excitability: stimulus-response (SR) curves and motor evoked potential (MEP) 125% of active motor threshold (aMT); and intracortical inhibition: cortical silent period (cSP), short-interval intracortical inhibition (SICI), and long-interval intracortical inhibition (LICI). Healthy participants performed better in dexterity (p=0.003), reaction (p=0.003), and movement time (p=0.037) than did both AF groups. Differences between AF groups were found in AL (p=0.027) and SWM (p=0.024). TMS measures revealed that both AF groups showed reduced cSP duration at 125% aMT (p>0.001) and differences in SR curves (p>0.001) than did healthy controls. Similarly, SICI (p=0.012) and LICI (p=0.009) were reduced in both AF groups compared with controls. Regression analyses revealed a significant contribution to differences in motor outcomes with the three measures of intracortical inhibition. The measures of inhibition differed, however, in terms of which performance measure they had a significant and unique predictive relationship with, reflecting the variety of participant concussion injuries. This study is the first to demonstrate differences in motor control and intracortical inhibition in AF players who had sustained concussions during their playing career two decades previously
Resonant nonstationary amplification of polychromatic laser pulses and conical emission in an optically dense ensemble of neon metastable atoms
Experimental and numerical investigation of single-beam and pump-probe
interaction with a resonantly absorbing dense extended medium under strong and
weak field-matter coupling is presented. Significant probe beam amplification
and conical emission were observed. Under relatively weak pumping and high
medium density, when the condition of strong coupling between field and
resonant matter is fulfilled, the probe amplification spectrum has a form of
spectral doublet. Stronger pumping leads to the appearance of a single peak of
the probe beam amplification at the transition frequency. The greater probe
intensity results in an asymmetrical transmission spectrum with amplification
at the blue wing of the absorption line and attenuation at the red one. Under
high medium density, a broad band of amplification appears. Theoretical model
is based on the solution of the Maxwell-Bloch equations for a two-level system.
Different types of probe transmission spectra obtained are attributed to
complex dynamics of a coherent medium response to broadband polychromatic
radiation of a multimode dye laser.Comment: 9 pages, 13 figures, corrected, Fig.8 was changed, to be published in
Phys. Rev.
Euthanasia, physician-assisted suicide, and other medical practices involving the end of life in the Netherlands, 1990-1995
Questions of fairness and anti-doping in US cycling: The contrasting experiences of professionals and amateurs
The focus of researchers, media and policy on doping in cycling is often limited to the professional level of the sport. However, anti-doping test results since 2001 demonstrate that banned substances are also used by US cyclists at lower levels of the sport, necessitating a broader view of the patterns and motivations of substance use within the sport. In this article, we describe and explain the doping culture that has emerged in domestic US cycling among amateur and semi-professionals. Through analysis of records from sports governing bodies and journalistic reports, we assess the range of violation types and discuss the detection and punishing of riders who were not proven to have intended to cheat but became "collateral damage" in the war on doping. We argue that the phenomenon of doping is more complex than what has been shown to occur in elite sport, as it includes a wider variety of behaviours, situations and motivations. We develop fresh insights by examining cases where doping has been accidental, intrinsically motivated, non-performance enhancing or the result of prescribed medical treatments banned by anti-doping authorities. Such trends call into question the fairness of anti-doping measures, and we discuss the possibility of developing localised solutions to testing and sanctioning amateur athletes
Spectroscopy of the proton emitter 109I
Excited states in the proton-unbound nucleus 109I were populated using the 54Fe(58Ni,p2n) reaction at a
beam energy of 220 MeV. Gamma rays in 109I were identified using the recoil-decay tagging technique. The
analysis of proton-correlated gg coincidence data produced the yrast decay sequence in 109I, which can be
tentatively assigned as built on the h11/2 proton state based on systematic trends in the neighboring isotopes.
This sequence is completely different from that reported previously. A comparison of the h11/2 band in 109I
with those in heavier iodines shows that 109I continues the trend of decreasing quadrupole deformation with
decreasing neutron number
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