3,799 research outputs found
The effect of the displacement damage on the Charge Collection Efficiency in Silicon Drift Detectors for the LOFT satellite
The technology of Silicon Drift Detectors (SDDs) has been selected for the
two instruments aboard the Large Observatory For X-ray Timing (LOFT) space
mission. LOFT underwent a three year long assessment phase as candidate for the
M3 launch opportunity within the "Cosmic Vision 2015 -- 2025" long-term science
plan of the European Space Agency. During the LOFT assessment phase, we studied
the displacement damage produced in the SDDs by the protons trapped in the
Earth's magnetosphere. In a previous paper we discussed the effects of the Non
Ionising Energy Losses from protons on the SDD leakage current. In this paper
we report the measurement of the variation of Charge Collection Efficiency
produced by displacement damage caused by protons and the comparison with the
expected damage in orbit.Comment: 17 pages, 7 figures. Accepted for publication by Journal of
Instrumentatio
X-ray follow-ups of XSSJ12270-4859: a low-mass X-ray binary with gamma ray FERMI-LAT association
XSSJ1227.0-4859 is a peculiar, hard X-ray source recently positionally
associated to the Fermi-LAT source 1FGLJ1227.9-4852/2FGLJ1227.7-4853.
Multi-wavelength observations have added information on this source, indicating
a low-luminosity low-mass X-ray binary (LMXB), but its nature is still unclear.
To progress in our understanding, we present new X-ray data from a monitoring
campaign performed in 2011 with the XMM-Newton, RXTE, and Swift satellites and
combine them with new gamma-ray data from the Fermi and AGILE satellites. We
complement the study with simultaneous near-UV photometry from XMM-Newton and
with previous UV/optical and near-IR data. The X-ray history of XSSJ1227.0-4859
over 7yr shows a persistent and rather stable low-luminosity (~6x10^33
d_{1\,kpc}^2 erg/s) source, with flares and dips being peculiar and permanent
characteristics. The associated Fermi-LAT source 2FGLJ1227.7-4853 is also
stable over an overlapping period of 4.7\,yr. Searches for X-ray fast
pulsations down to msec give upper limits to pulse fractional amplitudes of
15-25% that do not rule out a fast spinning pulsar. The combined
UV/optical/near-IR spectrum reveals a hot component at ~13\,kK and a cool one
at ~4.6\,kK. The latter would suggest a late-type K2-K5 companion star, a
distance range of1.4--3.6kpc and an orbital period of 7--9 h. A near-UV
variability (>6\,h) also suggests a longer orbital period than previously
estimated. The analysis shows that the X-ray and UV/optical/near-IR emissions
are more compatible with an accretion-powered compact object than with a
rotational powered pulsar. The X-ray to UV bolometric luminosity ratio could be
consistent with a binary hosting a neutron star, but the uncertainties in the
radio data may also allow an LMXB black hole with a compact jet. In this case
it would be the first associated with a high-energy gamma-ray source.Comment: 17 pages, 14 figures, 1 table; Accepted for publication in Astronomy
& Astrophysics Main Journa
IN-SHOE PRESSURE DISTRIBUTION DURING FENCING LUNGE
Fencing is a sport involving sharp backward and forward movements interspersed with several slower gliding steps in which lower limb agility is crucial to good movements and correct body positioning. Thus, while the upper extremity uses the weapon, the legs and feet work to get the fencer in position to it. From a biomechanical point of view, particularly stressed are the feet. Incidence of foot injury in fencing is high, and there have been many cases reported of metatarsal stress fractures, capsulitis, plantar fasciitis, and interdigital neuromas. Although it would be useful to accurately evaluate the high pressure points so that overall lower limb salvage may be improved, to our knowledge, no information about the force and pressure distribution beneath the foot of fencers performing technical actions is available. The purpose of this study was, therefore, to evaluate dynamic in-shoe plantar pressure during fencing lunge. Six right-handed foilists of national level (age: 24k5.5) were the subjects of this study. Each athlete was asked to perform the following technical actions: simple lunge; step forward-lunge; step backward-lunge; jump forward-lunge. Data for at least six trials per condition was collected. The Fscan in-shoe pressure measurement system was used to measure plantar pressure during all trials. The system uses an ultra-thin flexible and trimmable sensor with 960sensing locations distributed evenly across the entire plantar surface. These footsensors can be customized to the individual needs and sizing of each subject. The parameters examined included the centre of pressure path, time-pressure relationships, and the force and pressure in three regions of the foot (rear, mid, and forepart).Despite the apparent intersubject similarities in performing the actions, clear differences were observed in most of the examined parameters. In contrast to the above finding, the variability within-subject was low indicating a high consistency in movement execution, As expected, in all the technical actions, an asymmetrical load was placed on the lower extremities, with the right foot of the athletes particularly subjected to stress in the forward actions. The results showed that the majority of the right foot pressure was localized in the forefoot and especially over the head of the first and second metatarsal and hallux. High pressure levels, as those found here, applied too often and over a long periods of time can cause structural damage to the foot. Shoe and plantar orthosis designers should attempt to reduce such risks designing sager footwear and proper shoe inserts
Measurement of the effect of Non Ionising Energy Losses on the leakage current of Silicon Drift Detector prototypes for the LOFT satellite
The silicon drift detectors are at the basis of the instrumentation aboard
the Large Observatory For x-ray Timing (LOFT) satellite mission, which
underwent a three year assessment phase within the "Cosmic Vision 2015 - 2025"
long-term science plan of the European Space Agency. Silicon detectors are
especially sensitive to the displacement damage, produced by the non ionising
energy losses of charged and neutral particles, leading to an increase of the
device leakage current and thus worsening the spectral resolution.
During the LOFT assessment phase, we irradiated two silicon drift detectors
with a proton beam at the Proton Irradiation Facility in the accelerator of the
Paul Scherrer Institute and we measured the increase in leakage current. In
this paper we report the results of the irradiation and we discuss the impact
of the radiation damage on the LOFT scientific performance.Comment: 21 pages, 7 figures, 2 tables. Accepted for publication by Journal of
Instrumentation (JINST
Rancang Bangun Purwarupa Sistem Rekam Medik Berbasis Android Untuk Situasi Darurat
Sistem Rekam Medik merupakan keterangan yang tertulis maupun yang terekam mengenai data-data pasien, beserta catatan riwayat pemeriksaan penyakit sebelumnya. Rekam medik pada umumnya dicatat atau didokumentasikan melalui media tertulis atau berbasis desktop. Tujuan dari penelitian ini adalah untuk merancang dan membangun suatu sistem rekam medik yang berbasis mobile yang dapat digunakan pada smartphone android menggunakan metodologi DAD (Disciplined Agile Delivery). Metode DAD terdiri dari 3 fase yaitu fase inception, fase construction, dan fase transition. Berdasarkan dengan hasil penelitian dapat disimpulkan bahwa aplikasi ini dapat membantu khususnya bagi tim medis sebagai sarana informasi mengenai data rekam medik pasien dan juga dapat menjadi media penyimpanan data rekam medik pribadi yang dapat diakses oleh pasien melalui login user
Diretrizes para escolha de um Sistema de Gerenciamento de Conteúdos.
O objetivo deste documento é apresentar as diretrizes básicas para escolha de um CMS tomando por base a experiência adquirida com o desenvolvimento do Agritempo.bitstream/CNPTIA/10192/1/comtec53.pdfAcesso em: 28 maio 2008
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A 3D printed drug delivery implant formed from a dynamic supramolecular polyurethane formulation
Using a novel molecular design approach, we have prepared a thermo-responsive supramolecular polyurethane as a matrix material for use in drug eluting implants. The dynamic supramolecular polyurethane (SPU) is able to self-assemble through hydrogen bonding and π-π stacking interactions, resulting in an addressable polymer network with a relatively low processing temperature. The mechanical properties of the SPU demonstrated the material was self-supporting, stiff, yet flexible thus making it suitable for hot-melt extrusion processing, inclusive of related 3D printing approaches. Cell-based toxicity assays revealed the SPU to be non-toxic and therefore a viable candidate as a biocompatible polymer for implant applications. To this end, the SPU was formulated with paracetamol (16 %w/w) and 4 wt% or 8 wt% poly(ethylene glycol) (PEG) as an excipient and hot melt extruded at 100 °C to afford a 3D printed prototype implant to explore the extended drug release required for an implant and the potential manipulation of the release profile. Furthermore, rheological, infra-red spectroscopy, powder X-ray diffraction and scanning electron microscopy studies revealed the chemical and physical properties and compatibility of the formulation components. Successful release of paracetamol was achieved from in vitro dissolution studies and it was predicted that the drug would be released over a period of up to 8.5 months with hydrophilic PEG being able to influence the release rate. This extended release time is consistent with applications of this novel dynamic polymer as a drug eluting implant matrix
Gamma-ray observations of Cygnus X-1 above 100 MeV in the hard and soft states
We present the results of multi-year gamma-ray observations by the AGILE
satellite of the black hole binary system Cygnus X-1. In a previous
investigation we focused on gamma-ray observations of Cygnus X-1 in the hard
state during the period mid-2007/2009. Here we present the results of the
gamma-ray monitoring of Cygnus X-1 during the period 2010/mid-2012 carried out
for which includes a remarkably prolonged `soft state' phase (June 2010 -- May
2011). Previous 1--10 MeV observations of Cyg X-1 in this state hinted at a
possible existence of a non-thermal particle component with substantial
modifications of the Comptonized emission from the inner accretion disk. Our
AGILE data, averaged over the mid-2010/mid-2011 soft state of Cygnus X-1,
provide a significant upper limit for gamma-ray emission above 100 MeV of
F_soft < 20 x 10^{-8} ph/cm^2/s, excluding the existence of prominent
non-thermal emission above 100 MeV during the soft state of Cygnus X-1. We
discuss theoretical implications of our findings in the context of high-energy
emission models of black hole accretion. We also discuss possible gamma-ray
flares detected by AGILE. In addition to a previously reported episode observed
by AGILE in October 2009 during the hard state, we report a weak but important
candidate for enhanced emission which occurred at the end of June 2010
(2010-06-30 10:00 - 2010-07-02 10:00 UT) exactly in coincidence with a
hard-to-soft state transition and before an anomalous radio flare. An appendix
summarizes all previous high-energy observations and possible detections of
Cygnus X-1 above 1 MeV.Comment: 16 pages, 12 figures, 1 table, accepted for publication in Ap
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