6,640 research outputs found
Cooperação técnica e produção familiar sustentável de hortaliças: análise dos condicionantes e determinantes para a formulação de uma política nacional de segurança alimentar e nutricional para o Haiti.
bitstream/CNPH-2010/36452/1/doc-129.pd
Aspectos metodológicos da análise de viabilidade econômica de sistemas de produção.
Tem por finalidade promover mecanismo de levantamento de dados e análises econômicas, de forma sistemática, que possibilitem a realização de inferências quanto aos retornos econômicos de sistemas de produção agropecuários, em especial aqueles que incorporam tecnologias ou práticas indicadas pela Embrapa
DT Sector Collector electronics design and construction
The CMS detector at LHC is equipped with Drift Tubes (DT) chambers for muon detection and triggering in the barrel region. The Sector Collector (SC) modules collect the track segments reconstructed by on-chamber trigger electronics. Data from different chambers are aligned in time and sent to the subsequent reconstruction processors via optical links. Several FPGA devices performing the processing of the data were designed in VHDL, including spy features to monitor the trigger data flow. A test jig was set up with custom hardware and software in order to fully validate final production boards. Installation and commissioning in CMS provided first experience with the synchronization and monitoring tools
Design and Test of the Off-Detector Electronics for the CMS Barrel Muon Trigger
Drift Tubes chambers are used in the CMS barrel for tagging the passage of high Pt muons generated in a LHC event and for triggering the CMS data read out. The Sector Collector (SC) system synchronizes the track segments built by trigger modules on the chambers and deliver them to reconstruction processors (Track Finder, TF) that assemble full muon tracks. Then, the Muon Sorter (MS) has to select the best four candidates in the barrel and to filter fake muons generated by the TF system redundancy. The hardware implementations of the Sector Collector and Muon Sorter systems satisfy radiation, I/O and fast timing constraints using several FPGA technologies. The hardware was tested with custom facilities, integrated with other trigger subsystems, and operated in a beam test. A test beam on a 40 MHz bunched beam validated the local trigger electronics and off-detector prototype cards and the synchronization tools. The CMS Magnet Test and Cosmic challenge in 2006 proved stable and reliable operation of the Drift Tubes trigger and its integration with other trigger systems and with the readout system. Constraints, design, test and operation of the modules are presented
Positron Production and Capture based on Low Energy Electrons for SuperB
TUPEB057International audienceProviding a high quality and sufficient high current positron beam for the ultra high luminosity B-factory SuperB is a major goal. In this paper a proposition for positrons production and capture scheme based on low energy electrons up to1 GeV is presented. For this technique, several types of flux concentrator used to capture the positrons are being studied. The following accelerating section bringing the positrons up to 280 MeV and the total yield for L-band and S-band type accelerators are given. Also the result of the benchmark between ASTRA and a LAL code based on Geant4 toolkit simulation is discussed
Low emittance muon accelerator studies with production from positrons on target
A new scheme to produce very low emittance muon beams using a positron beam
of about 45~GeV interacting on electrons on target is presented.
One of the innovative topics to be investigated is the behaviour of the
positron beam stored in a low emittance ring with a thin target, that is
directly inserted in the ring chamber to produce muons. Muons can be
immediately collected at the exit of the target and transported to two
and accumulator rings and then accelerated and injected in muon
collider rings. We focus in this paper on the simulation of the e beam
interacting with the target, the effect of the target on the 6-D phase space
and the optimization of the e ring design to maximize the energy
acceptance. We will investigate the performance of this scheme, ring plus
target system, comparing different multi-turn simulations. The source is
considered for use in a multi-TeV collider in ref.[1]Comment: accepted for publication in Physical Review Accelerators and Beam
Eficiência econômica do uso de sistemas de irrigação para a produção de tomate orgânico nas condições de Brasil Central.
Avaliou-se a eficiência econômica do uso de diferentes sistemas de irrigação na produçaõ de tomate orgânico. A análise foi realizada com dados obtidos em unidades demonstrativas conduzidas em 2011, no Distrito Federal.Suplemento. Trabalho apresentado no 52. Congresso Brasileiro de Olericultura, Salvador, 2012
The Injection System of the INFN-SuperB Factory Project: Preliminary Design
THPEA007International audienceThe ultra high luminosity B-factory (SuperB) project of INFN requires a high performance and reliable injection system, providing electrons at 4 GeV and positrons at 7 GeV, to fulfill the very tight requirements of the collider. Due to the short beam lifetime, continuous injection of electrons and positrons in both HER and LER rings is necessary to keep the average luminosity at a high level. Polarized electrons are required for experiments and must be delivered by the injection system, due to the beam lifetime shorter than the polarization build-up: they will be produced by means of a SLAC-SLC polarized gun. One or two 1 GeV damping rings are used to reduce e+ and e- emittances. Two schemes for positron production are under study, one with electron-positron conversion at low energy (<1 Gev), the second at 6 GeV with a recirculation line to bring the positrons back to the damping ring. Acceleration through the Linac is provided by a S-band RF system made of traveling wave, room temperature accelerating structures. An option to use the C-band technology is also presented
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