1,970 research outputs found
Sistemas de produção de grãos com pastagens anuais de inverno, para a região Sul do Brasil, sob sistema plantio direto.
bitstream/item/84153/1/CNPT-COM.-TEC.-1-97.pd
Sistemas de produção de grãos com pastagens anuais de inverno e de verão, sob plantio direto.
bitstream/CNPT-2010/40663/1/p-do45.pd
Silicon photomultiplier arrays - a novel photon detector for a high resolution tracker produced at FBK-irst, Italy
A silicon photomultiplier (SiPM) array has been developed at FBK-irst having
32 channels and a dimension of 8.0 x 1.1 mm^2. Each 250 um wide channel is
subdivided into 5 x 22 rectangularly arranged pixels. These sensors are
developed to read out a modular high resolution scintillating fiber tracker.
Key properties like breakdown voltage, gain and photon detection efficiency
(PDE) are found to be homogeneous over all 32 channels of an SiPM array. This
could make scintillating fiber trackers with SiPM array readout a promising
alternative to available tracker technologies, if noise properties and the PDE
are improved
Penetrating particle ANalyzer (PAN)
PAN is a scientific instrument suitable for deep space and interplanetary
missions. It can precisely measure and monitor the flux, composition, and
direction of highly penetrating particles (100 MeV/nucleon) in deep
space, over at least one full solar cycle (~11 years). The science program of
PAN is multi- and cross-disciplinary, covering cosmic ray physics, solar
physics, space weather and space travel. PAN will fill an observation gap of
galactic cosmic rays in the GeV region, and provide precise information of the
spectrum, composition and emission time of energetic particle originated from
the Sun. The precise measurement and monitoring of the energetic particles is
also a unique contribution to space weather studies. PAN will map the flux and
composition of penetrating particles, which cannot be shielded effectively,
precisely and continuously, providing valuable input for the assessment of the
related health risk, and for the development of an adequate mitigation
strategy. PAN has the potential to become a standard on-board instrument for
deep space human travel.
PAN is based on the proven detection principle of a magnetic spectrometer,
but with novel layout and detection concept. It will adopt advanced particle
detection technologies and industrial processes optimized for deep space
application. The device will require limited mass (~20 kg) and power (~20 W)
budget. Dipole magnet sectors built from high field permanent magnet Halbach
arrays, instrumented in a modular fashion with high resolution silicon strip
detectors, allow to reach an energy resolution better than 10\% for nuclei from
H to Fe at 1 GeV/n
A Scintillating Fiber Tracker With SiPM Readout
We present a prototype for the first tracking detector consisting of 250
micron thin scintillating fibers and silicon photomultiplier (SiPM) arrays. The
detector has a modular design, each module consists of a mechanical support
structure of 10mm Rohacell foam between two 100 micron thin carbon fiber skins.
Five layers of scintillating fibers are glued to both top and bottom of the
support structure. SiPM arrays with a channel pitch of 250 micron are placed in
front of the fibers. We show the results of the first module prototype using
multiclad fibers of types Bicron BCF-20 and Kuraray SCSF-81M that were read out
by novel 32-channel SiPM arrays from FBK-irst/INFN Perugia as well as
32-channel SiPM arrays produced by Hamamatsu. A spatial resolution of 88 micron
+/- 6 micron at an average yield of 10 detected photons per minimal ionizig
particle has been achieved.Comment: 5 pages, 7 figures, submitted as proceedings to the 11th Topical
Seminar on Innovative Particle and Radiation Detectors (IPRD08
In-orbit performance of the EPIC-MOS detectors on XMM-Newton
XMM-Newton was launched into space on a highly eccentric 48 hour orbit on
December 10th 1999. XMM-Newton is now in its fifth year of operation and has
been an outstanding success, observing the Cosmos with imaging, spectroscopy
and timing capabilities in the X-ray and optical wavebands. The EPIC-MOS CCD
X-ray detectors comprise two out of three of the focal plane instruments on
XMM-Newton. In this paper we discuss key aspects of the current status and
performance history of the charge transfer ineffiency (CTI), energy resolution
and spectral redistribution function (rmf) of EPIC-MOS in its fifth year of
operation.Comment: 8 pages, 10 figures, SPIE Glasgow 21-25 June 2004, Session 548
Análise de risco de sistemas de produção com pastagens anuais de inverno, sob sistema plantio direto.
Percolation, Morphogenesis, and Burgers Dynamics in Blood Vessels Formation
Experiments of in vitro formation of blood vessels show that cells randomly
spread on a gel matrix autonomously organize to form a connected vascular
network. We propose a simple model which reproduces many features of the
biological system. We show that both the model and the real system exhibit a
fractal behavior at small scales, due to the process of migration and dynamical
aggregation, followed at large scale by a random percolation behavior due to
the coalescence of aggregates. The results are in good agreement with the
analysis performed on the experimental data.Comment: 4 pages, 11 eps figure
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