602 research outputs found
A Robotic Solution for the Restoration of Fresco Paintings
In this paper, a service robot solution is presented for the
analysis, surveying and restoration of fresco paintings. The
proposed design approach integrates robot design and
restoration operation. It aims to merge them into a feasible
solution that can be both practical and feasible for restorers.
The simulation results are reported to show a successful
design solution, which has been conceived with the
constraints of a low-cost user-oriented design and the
consideration of cultural heritage
Understanding illnesses through a film festival: an observational study
Audio-visual materials play a fundamental role in the context of education, care and clinical treatment, as they seem to have a high impact on public awareness. This study aims to describe what messages are perceived by the society at an International Festival of Short Films and Art on Diseases that may help to understand difficult topics, such as illness, dying and suffering.
Through an observational, descriptive, cross-sectional study, using full participant observation and an open, self-administered questionnaire, 32 short films were analysed during a healthcare art festival. Categories were developed using inductive content analysis. The message perceived by the participants, after the viewing of the shorts and reflection of the debates among the attendees, were considered in four categories: i) creative and positive education is possible; ii) awareness of preconception and practical duties; iii) meaning of life changes the experience of illness; iv) family and caregivers also experienced suffering. The short films are considered as an excellent tool to generate social dialogue and debate. Public events can be understood as an opportunity to ac- quire, in an emotional and critical manner, other competencies for public awareness. Together, they are capable of communicating difficult messages through a fast, positive, and creative way
Probing the innermost regions of AGN jets and their magnetic fields with RadioAstron II. Observations of 3C 273 at minimum activity
RadioAstron is a 10 m orbiting radio telescope mounted on the Spektr-R
satellite, launched in 2011, performing Space Very Long Baseline Interferometry
(SVLBI) observations supported by a global ground array of radio telescopes.
With an apogee of about 350 000 km, it is offering for the first time the
possibility to perform {\mu}as-resolution imaging in the cm-band. We present
observations at 22 GHz of 3C 273, performed in 2014, designed to reach a
maximum baseline of approximately nine Earth diameters. Reaching an angular
resolution of 0.3 mas, we study a particularly low-activity state of the
source, and estimate the nuclear region brightness temperature, comparing with
the extreme one detected one year before during the RadioAstron early science
period. We also make use of the VLBA-BU-BLAZAR survey data, at 43 GHz, to study
the kinematics of the jet in a 1.5-year time window. We find that the nuclear
brightness temperature is two orders of magnitude lower than the exceptionally
high value detected in 2013 with RadioAstron at the same frequency (1.4x10^13
K, source-frame), and even one order of magnitude lower than the equipartition
value. The kinematics analysis at 43 GHz shows that a new component was ejected
2 months after the 2013 epoch, visible also in our 22 GHz map presented here.
Consequently this was located upstream of the core during the brightness
temperature peak. These observations confirm that the previously detected
extreme brightness temperature in 3C 273, exceeding the inverse Compton limit,
is a short-lived phenomenon caused by a temporary departure from equipartition.
Thus, the availability of interferometric baselines capable of providing
{\mu}as angular resolution does not systematically imply measured brightness
temperatures over the known physical limits for astrophysical sources.Comment: Accepted for publication in A&
Gamma-ray sources imaging and test-beam results with MACACO III Compton camera
Hadron therapy is a radiotherapy modality which offers a precise energy deposition to the tumors and a dose reduction to healthy tissue as compared to conventional methods. However, methods for real-time monitoring are required to ensure that the radiation dose is deposited on the target. The IRIS group of IFIC-Valencia developed a Compton camera prototype for this purpose, intending to image the Prompt Gammas emitted by the tissue during irradiation. The system detectors are composed of Lanthanum (III) bromide scintillator crystals coupled to silicon photomultipliers. After an initial characterization in the laboratory, in order to assess the system capabilities for future experiments in proton therapy centers, different tests were carried out in two facilities: PARTREC (Groningen, The Netherlands) and the CNA cyclotron (Sevilla, Spain). Characterization studies performed at PARTREC indicated that the detectors linearity was improved with respect to the previous version and an energy resolution of 5.2 % FWHM at 511 keV was achieved. Moreover, the imaging capabilities of the system were evaluated with a line source of 68Ge and a point-like source of 241Am-9Be. Images at 4.439 MeV were obtained from irradiation of a graphite target with an 18 MeV proton beam at CNA, to perform a study of the system potential to detect shifts at different intensities. In this sense, the system was able to distinguish 1 mm variations in the target position at different beam current intensities for measurement times of 1800 and 600 s.</p
Gamma-ray sources imaging and test-beam results with MACACO III Compton camera
Hadron therapy is a radiotherapy modality which offers a precise energy deposition to the tumors and a dose reduction to healthy tissue as compared to conventional methods. However, methods for real-time monitoring are required to ensure that the radiation dose is deposited on the target. The IRIS group of IFIC-Valencia developed a Compton camera prototype for this purpose, intending to image the Prompt Gammas emitted by the tissue during irradiation. The system detectors are composed of Lanthanum (III) bromide scintillator crystals coupled to silicon photomultipliers. After an initial characterization in the laboratory, in order to assess the system capabilities for future experiments in proton therapy centers, different tests were carried out in two facilities: PARTREC (Groningen, The Netherlands) and the CNA cyclotron (Sevilla, Spain). Characterization studies performed at PARTREC indicated that the detectors linearity was improved with respect to the previous version and an energy resolution of 5.2 % FWHM at 511 keV was achieved. Moreover, the imaging capabilities of the system were evaluated with a line source of 68Ge and a point-like source of 241Am-9Be. Images at 4.439 MeV were obtained from irradiation of a graphite target with an 18 MeV proton beam at CNA, to perform a study of the system potential to detect shifts at different intensities. In this sense, the system was able to distinguish 1 mm variations in the target position at different beam current intensities for measurement times of 1800 and 600 s.</p
Gamma-ray sources imaging and test-beam results with MACACO III Compton camera
Hadron therapy is a radiotherapy modality which offers a precise energy deposition to the tumors and a dose reduction to healthy tissue as compared to conventional methods. However, methods for real-time monitoring are required to ensure that the radiation dose is deposited on the target. The IRIS group of IFIC-Valencia developed a Compton camera prototype for this purpose, intending to image the Prompt Gammas emitted by the tissue during irradiation. The system detectors are composed of Lanthanum (III) bromide scintillator crystals coupled to silicon photomultipliers. After an initial characterization in the laboratory, in order to assess the system capabilities for future experiments in proton therapy centers, different tests were carried out in two facilities: PARTREC (Groningen, The Netherlands) and the CNA cyclotron (Sevilla, Spain). Characterization studies performed at PARTREC indicated that the detectors linearity was improved with respect to the previous version and an energy resolution of 5.2 % FWHM at 511 keV was achieved. Moreover, the imaging capabilities of the system were evaluated with a line source of 68Ge and a point-like source of 241Am-9Be. Images at 4.439 MeV were obtained from irradiation of a graphite target with an 18 MeV proton beam at CNA, to perform a study of the system potential to detect shifts at different intensities. In this sense, the system was able to distinguish 1 mm variations in the target position at different beam current intensities for measurement times of 1800 and 600 s.</p
High-resolution observations of SN 2001gd in NGC 5033
We report on 8.4 GHz VLBI observations of SN2001gd in the spiral galaxy
NGC5033 made on 26 June 2002 and 8 April 2003. Our data nominally suggests a
relatively strong deceleration for the expansion of SN2001gd, but we cannot
dismiss the possibility of a free supernova expansion. From our VLBI
observations on 8 April 2003, we inferred a minimum total energy in
relativistic particles and magnetic fields in the supernova shell of E_min
=(0.3-14) 10^{47} ergs, and a corresponding equipartition average magnetic
field of B_min = (50--350) mG. We also present multiwavelength VLA measurements
of SN2001gd, which are well fit by an optically thin, synchrotron spectrum,
partially absorbed by thermal plasma. We obtain a supernova flux density of
(1.02 +/- 0.05) mJy at the observing frequency of 8.4 GHz for the second epoch,
which results in an isotropic radio luminosity of (6.0 +/- 0.3) * 10^{36} ergs
between 1.4 and 43.3 GHz, at an adopted distance of 13.1 Mpc. Finally, we
report on an XMM-Newton X-ray detection of SN2001gd on 18 December 2002. The
supernova X-ray spectrum is consistent with optically thin emission from a soft
component (associated with emission from the reverse shock) at a temperature
around 1 keV. The observed flux corresponds to an isotropic X-ray luminosity of
L_X = 1.4 +/- 0.4 * 10^{39} ergs/s in the (0.3-5) keV band. We suggest that
both radio and X-ray observations of SN2001gd indicate that a circumstellar
interaction similar to that displayed by SN1993J in M81 is taking place.Comment: 9 pages, 6 figures, 2 tables, accepted for publication in MNRA
Gamma-ray sources imaging and test-beam results with MACACO III Compton camera
Hadron therapy is a radiotherapy modality which offers a precise energy deposition to the tumors and a dose reduction to healthy tissue as compared to conventional methods. However, methods for real-time monitoring are required to ensure that the radiation dose is deposited on the target. The IRIS group of IFIC-Valencia developed a Compton camera prototype for this purpose, intending to image the Prompt Gammas emitted by the tissue during irradiation. The system detectors are composed of Lanthanum (III) bromide scintillator crystals coupled to silicon photomultipliers. After an initial characterization in the laboratory, in order to assess the system capabilities for future experiments in proton therapy centers, different tests were carried out in two facilities: PARTREC (Groningen, The Netherlands) and the CNA cyclotron (Sevilla, Spain). Characterization studies performed at PARTREC indicated that the detectors linearity was improved with respect to the previous version and an energy resolution of 5.2 % FWHM at 511 keV was achieved. Moreover, the imaging capabilities of the system were evaluated with a line source of 68Ge and a point-like source of 241Am-9Be. Images at 4.439 MeV were obtained from irradiation of a graphite target with an 18 MeV proton beam at CNA, to perform a study of the system potential to detect shifts at different intensities. In this sense, the system was able to distinguish 1 mm variations in the target position at different beam current intensities for measurement times of 1800 and 600 s.</p
Gamma-ray sources imaging and test-beam results with MACACO III Compton camera
Hadron therapy is a radiotherapy modality which offers a precise energy deposition to the tumors and a dose reduction to healthy tissue as compared to conventional methods. However, methods for real-time monitoring are required to ensure that the radiation dose is deposited on the target. The IRIS group of IFIC-Valencia developed a Compton camera prototype for this purpose, intending to image the Prompt Gammas emitted by the tissue during irradiation. The system detectors are composed of Lanthanum (III) bromide scintillator crystals coupled to silicon photomultipliers. After an initial characterization in the laboratory, in order to assess the system capabilities for future experiments in proton therapy centers, different tests were carried out in two facilities: PARTREC (Groningen, The Netherlands) and the CNA cyclotron (Sevilla, Spain). Characterization studies performed at PARTREC indicated that the detectors linearity was improved with respect to the previous version and an energy resolution of 5.2 % FWHM at 511 keV was achieved. Moreover, the imaging capabilities of the system were evaluated with a line source of 68Ge and a point-like source of 241Am-9Be. Images at 4.439 MeV were obtained from irradiation of a graphite target with an 18 MeV proton beam at CNA, to perform a study of the system potential to detect shifts at different intensities. In this sense, the system was able to distinguish 1 mm variations in the target position at different beam current intensities for measurement times of 1800 and 600 s.</p
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