559 research outputs found
Development of a DMILL radhard multiplexer for the ATLAS Glink optical link and radiation test with a custom Bit ERror Tester
A high speed digital optical data link has been developed for the front-end readout of the ATLAS electromagnetic calorimeter. It is based on a commercial serialiser commonly known as Glink, and a vertical cavity surface emitting laser. To be compatible with the data interface requirements, the Glink must be coupled to a radhard multiplexer that has been designed in DMILL technology to reduce the impact of neutron and gamma radiation on the link performance. This multiplexer features a very severe timing constraints related both to the front-end board output data and the Glink control and input signals. The full link has been successfully neutron and proton radiation tested by means of a custom bit error tester. (7 refs)
Auto-zero stabilized CMOS amplifiers for very low voltage or current offset
In this paper, we present two amplifiers designed in CMOS technology and including an auto-zero architecture for very low offset control
Early signs of infection in Cacao swollen shoot virus (CSSV) inoculated cocoa seeds and the discovery of the cotyledons of the resultant plants as rich sources of CSSV
Despite the huge efforts and funds expended to try and bring Cacao swollen shoot virus (CSSV) disease under control, the disease has remained largely intractable. Inspired by the need to inject newideas into the current breeding programmes for CSSV resistance, the interactions between cocoa and the virus in CSSV-infected plants from 3 days post inoculation (dpi) to about 30 dpi were studied using both microscopic and molecular methods. Cellular modifications such as nucleic acid-rich inclusion bodies, apoptosis, and the in situ localisation of the virus in novel tissues that is cotyledons and hypocotyl, were discerned by microscopic examinations. These cellular modifications were observed incotyledons of seedlings as young as 8 dpi. By validating these microscopic results using PCR it was also discovered that the cotyledons of the inoculated plants were virus-rich. CSSV was amplified or detected in total DNAs extracted from all 4 CSSV-isolates studied, and in some cases the detection was from as early as 3dpi plants. Compared to cocoa leaves, the traditional source from which CSSV or its DNA is usually extracted, the cotyledons were much easier to process and analyse. The significance ofthese findings to the CSSV-resistant breeding programmes, and to CSSV research in general is discussed
A low power 12-bit and 25-MS/s pipelined ADC for the ILC/Ecal integrated readout
International audienc
Cocoa swollen shoot virus in Ghana: A review of diagnostic procedures
A quick and more reliable diagnostic method has for a long time been identified as one input that will greatly enhance the control of the cocoa swollen shoot disease in Ghana. Many diagnostic procedures have beendeveloped for detecting the virus that causes the disease; yet, the detection of latent infections is still unpredictable. This paper reviews work done indiagnosing swollen shoot disease to develop a quicker, more reliable, and cost-effective method that could be applicable in programmes for controlling cocoa swollen shoot disease. Enzyme-linked immunosorbent assay(ELISA), virobacterial agglutination tests (VBA), and other biochemical analyses have been discussed as diagnostic tools that could be developed to effectively replace the use of visible symptom expressions as theonly method for field detection of the disease
Constrained stochastic blackbox optimization using a progressive barrier and probabilistic estimates
This work introduces the StoMADS-PB algorithm for constrained stochastic
blackbox optimization, which is an extension of the mesh adaptive direct-search
(MADS) method originally developed for deterministic blackbox optimization
under general constraints. The values of the objective and constraint functions
are provided by a noisy blackbox, i.e., they can only be computed with random
noise whose distribution is unknown. As in MADS, constraint violations are
aggregated into a single constraint violation function. Since all functions
values are numerically unavailable, StoMADS-PB uses estimates and introduces
so-called probabilistic bounds for the violation. Such estimates and bounds
obtained from stochastic observations are required to be accurate and reliable
with high but fixed probabilities. The proposed method, which allows
intermediate infeasible iterates, accepts new points using sufficient decrease
conditions and imposing a threshold on the probabilistic bounds. Using Clarke
nonsmooth calculus and martingale theory, Clarke stationarity convergence
results for the objective and the violation function are derived with
probability one
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