4,131 research outputs found
Following Weyl on Quantum Mechanics: the contribution of Ettore Majorana
After a quick historical account of the introduction of the group-theoretical
description of Quantum Mechanics in terms of symmetries, as proposed by Weyl,
we examine some unpublished papers by Ettore Majorana. Remarkable results
achieved by him in frontier research topics as well as in physics teaching
point out that the Italian physicist can be well considered as a follower of
Weyl in his reformulation of Quantum Mechanics.Comment: LaTeX, 15 pages, 1 ps figur
Ettore Majorana's course on Theoretical Physics: a recent discovery
We analyze in some detail the course of Theoretical Physics held by Ettore
Majorana at the University of Naples in 1938, just before his mysterious
disappearance. In particular we present the recently discovered "Moreno Paper",
where all the lecture notes are reported. Six of these lectures are not present
in the collection of the original manuscripts conserved at the Domus Galilaeana
in Pisa, consisting of only ten lectures.Comment: AMS-latex, 16 pages, 2 figure
A Review of Characteristics and Treatments of the Avoidant Personality Disorder. Could the DBT be an Option?
Maps for Electron Clouds: Application to LHC Conditioning
In this communication we present a generalization of the map formalism,
introduced in [1] and [2], to the analysis of electron flux at the chamber wall
with particular reference to the exploration of LHC conditioning scenarios.Comment: 3 pages, 4 figure
A 1.2V 10ÎŒW NPN-Based Temperature Sensor in 65nm CMOS with an inaccuracy of ±0.2°C (3s) from â70°C to 125°C
This paper describes a temperature sensor realized in a 65nm CMOS process with a batch-calibrated inaccuracy of ±0.5°C (3Ï) and a trimmed inaccuracy of ±0.2°C (3Ï) from â70°C to 125°C. This represents a 10-fold improvement in accuracy compared to other deep-submicron temperature sensors [1,2], and is comparable with that of state-of-the-art sensors implemented in larger-featuresize processes [3,4]. The sensor draws 8.3ÎŒA from a 1.2V supply and occupies an area of 0.1mm2, which is 45 times less than that of sensors with comparable accuracy [3,4]. These advances are enabled by the use of NPN transistors as sensing elements, the use of dynamic techniques i.e. correlated double sampling (CDS) and dynamic element matching (DEM), and a single room-temperature trim
Magnetic fields generated by r-modes in accreting millisecond pulsars
In millisecond pulsars the existence of the Coriolis force allows the
development of the so-called Rossby oscillations (r-modes) which are know to be
unstable to emission of gravitational waves. These instabilities are mainly
damped by the viscosity of the star or by the existence of a strong magnetic
field. A fraction of the observed millisecond pulsars are known to be inside
Low Mass X-ray Binaries (LMXBs), systems in which a neutron star (or a black
hole) is accreting from a donor whose mass is smaller than 1 . Here we
show that the r-mode instabilities can generate strong toroidal magnetic fields
by inducing differential rotation. In this way we also provide an alternative
scenario for the origin of the magnetars.Comment: 6 pages, 3 figures, Proceedings conference "Theoretical Nuclear
Physics", Cortona October 200
A 2.4GHz 830pJ/bit duty-cycled wake-up receiver with â82dBm sensitivity for crystal-less wireless sensor nodes
A 65 nm CMOS 2.4 GHz wake-up receiver operating with low-accuracy frequency references has been realized. Robustness to frequency inaccuracy is achieved by employing non-coherent energy detection, broadband-IF heterodyne architecture and impulse-radio modulation. The radio dissipates 415 ĂÂżW at 500 kb/s and achieves a sensitivity of -82 dBm with an energy efficiency of 830 pJ/bit.\u
Efficacy of Two Common Methods of Application of Residual Insecticide for Controlling the Asian Tiger Mosquito, Aedes albopictus (Skuse), in Urban Areas
After its first introduction in the 1980's the Asian tiger mosquito, Aedes albopictus (Skuse), has spread throughout Southern Europe. Ae. albopictus is considered an epidemiologically important vector for the transmission of many viral pathogens such as the yellow fever virus, dengue fever and Chikungunya fever, as well as several filarial nematodes such as Dirofilaria immitis or D. repens. It is therefore crucial to develop measures to reduce the risks of disease transmission by controlling the vector populations. The aim of the study was to compare the efficacy of two application techniques (mist vs. stretcher sprayer) and two insecticides (Etox based on the nonester pyrethroid Etofenprox vs. Microsin based on the pyrethroid type II Cypermetrin) in controlling adult tiger mosquito populations in highly populated areas. To test the effect of the two treatments pre- and post-treatment human landing rate counts were conducted for two years. After one day from the treatment we observed a 100% population decrease in mosquito abundance with both application methods and both insecticides. However, seven and 14 days after the application the stretcher sprayer showed larger population reductions than the mist sprayer. No effect of insecticide type after one day and 14 days was found, while Etox caused slightly higher population reduction than Microsin after seven days. Emergency measures to locally reduce the vector populations should adopt adulticide treatments using stretcher sprayers. However, more research is still needed to evaluate the potential negative effects of adulticide applications on non-target organisms
Enhancing the significance of gravitational wave bursts through signal classification
The quest to observe gravitational waves challenges our ability to
discriminate signals from detector noise. This issue is especially relevant for
transient gravitational waves searches with a robust eyes wide open approach,
the so called all- sky burst searches. Here we show how signal classification
methods inspired by broad astrophysical characteristics can be implemented in
all-sky burst searches preserving their generality. In our case study, we apply
a multivariate analyses based on artificial neural networks to classify waves
emitted in compact binary coalescences. We enhance by orders of magnitude the
significance of signals belonging to this broad astrophysical class against the
noise background. Alternatively, at a given level of mis-classification of
noise events, we can detect about 1/4 more of the total signal population. We
also show that a more general strategy of signal classification can actually be
performed, by testing the ability of artificial neural networks in
discriminating different signal classes. The possible impact on future
observations by the LIGO-Virgo network of detectors is discussed by analysing
recoloured noise from previous LIGO-Virgo data with coherent WaveBurst, one of
the flagship pipelines dedicated to all-sky searches for transient
gravitational waves
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