7 research outputs found
INFN Camera demonstrator for the Cherenkov Telescope Array
The Cherenkov Telescope Array is a world-wide project for a new generation of
ground-based Cherenkov telescopes of the Imaging class with the aim of
exploring the highest energy region of the electromagnetic spectrum. With two
planned arrays, one for each hemisphere, it will guarantee a good sky coverage
in the energy range from a few tens of GeV to hundreds of TeV, with improved
angular resolution and a sensitivity in the TeV energy region better by one
order of magnitude than the currently operating arrays. In order to cover this
wide energy range, three different telescope types are envisaged, with
different mirror sizes and focal plane features. In particular, for the highest
energies a possible design is a dual-mirror Schwarzschild-Couder optical
scheme, with a compact focal plane. A silicon photomultiplier (SiPM) based
camera is being proposed as a solution to match the dimensions of the pixel
(angular size of ~ 0.17 degrees). INFN is developing a camera demonstrator made
by 9 Photo Sensor Modules (PSMs, 64 pixels each, with total coverage 1/4 of the
focal plane) equipped with FBK (Fondazione Bruno Kessler, Italy) Near
UltraViolet High Fill factor SiPMs and Front-End Electronics (FEE) based on a
Target 7 ASIC, a 16 channels fast sampler (up to 2GS/s) with deep buffer,
self-trigger and on-demand digitization capabilities specifically developed for
this purpose. The pixel dimensions of mm lead to a very compact
design with challenging problems of thermal dissipation. A modular structure,
made by copper frames hosting one PSM and the corresponding FEE, has been
conceived, with a water cooling system to keep the required working
temperature. The actual design, the adopted technical solutions and the
achieved results for this demonstrator are presented and discussed.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
Overvoltage Mitigation Techniques for SiC-MOSFET based High-Speed Drives: Comparison of Active Gate Driver and Output dv/dt Filter
The high-speed drives can be supplied by the wideband-gap (WBG) power devices such as SiC-MOSFETs, as they offer the possibility to increase efficiency and reduce the size of passive components. Nontheless, HF operation of the SiC devices emphasizes the effect of parasitics generating reflected waves phoenomena across the interconnection cables and transient overvoltage on motor terminals, reducing the life time and the reliability of electric drives. In this paper, the two solutions for the overvoltage mitigation of SiC-MOSFET based 2L inverter have been compared: the solution with an active gate driver based on digital control and the solution with an output dv/dt filter. The filter has been designed in order to meet the NEMA standard on voltage stress. The complete parasitic model of SiC-MOSFET based inverter has been developed in the LTspice simulation tool, as resulting from the experimental prototype pcb board and tested with the high frequency models of the motor in order to determine the overvoltages on the motor terminals. The two solutions have been compared in terms of efficiency, cost and volume, in order to have the clearest picture possible when comes to the judicious choice that practitioners in the motor drive industry have to make. These comparisons were carried out by realistic dynamic models of power devices obtained from the manufacturer's experimental tests and verified both in the LTspice and PLECS simulation tools
A wireless telecommunications network for real-time monitoring of greenhouse microclimate
An innovative wireless monitoring system for measuring greenhouse
climatic parameters was developed to overcome the problems
related to wires cabling such as presence of a dense net of wires hampering
the cultivation practices, wires subjected to high temperature
and relative humidity, rodents that can damage wires. The system
exploits battery-powered environmental sensors, such as air temperature
and relative humidity sensors, wind speed and direction, and solar
radiation sensors, integrated in the contest of an 802.15.4-based wireless
sensors network. Besides, a fruit diameter measurement sensor
was integrated into the system. This approach guarantees flexibility,
ease of deployment and low power consumption. Data collected from
the greenhouse are then sent to a remote server via a general packet
radio service link. The proposed solution has been implemented in a
real environment. The test of the communication system showed that
0.3% of the sent data packed were lost; the climatic parameters measured
with the wireless system were compared with data collected by
the wired system showing a mean value of the absolute difference
equal to 0.6°C for the value of the greenhouse air temperature. The
wireless climate monitoring system showed a good reliability, while
the sensor node batteries showed a lifetime of 530 days
What to Do, and What Not to Do, When Diagnosing and Treating Breakthrough Cancer Pain (BTcP): Expert Opinion
Clinical management of breakthrough cancer pain (BTcP) is still not satisfactory despite the availability of effective pharmacological agents. This is in part linked to the lack of clarity regarding certain essential aspects of BTcP, including terminology, definition, epidemiology and assessment. Other barriers to effective management include a widespread prejudice among doctors and patients concerning the use of opioids, and inadequate assessment of pain severity, resulting in the prescription of ineffective drugs or doses. This review presents an overview of the appropriate and inappropriate actions to take in the diagnosis and treatment of BTcP, as determined by a panel of experts in the field. The ultimate aim is to provide a practical contribution to the unresolved issues in the management of BTcP. Five 'things to do' and five 'things not to do' in the diagnosis and treatment of BTcP are proposed, and evidence supporting said recommendations are described. It is the duty of all healthcare workers involved in managing cancer patients to be mindful of the possibility of BTcP occurrence and not to underestimate its severity. It is vital that all the necessary steps are carried out to establish an accurate and timely diagnosis, principally by establishing effective communication with the patient, the main information source. It is crucial that BTcP is treated with an effective pharmacological regimen and drug(s), dose and administration route prescribed are designed to suit the particular type of pain and importantly the individual needs of the patient