9,382 research outputs found
The effect of the integration interval on the measurement accuracy of RMS values and powers in systems with nonsinusoidal waveforms
In this paper the possibility of errors in the measurement of average values (in particular rms values or active powers) in power systems under nonsinusoidal conditions are discussed. The errors considered are either due to the fact that the measurement time interval is not an exact multiple of the fundamental period of the voltage and current signals, or due to the presence of interharmonics or subharmonics. The errors are calculated and the results are illustrated by means of simple examples
Observation of enhanced optical spring damping in a macroscopic mechanical resonator and application for parametric instability control in advanced gravitational-wave detectors
We show that optical spring damping in an optomechanical resonator can be enhanced by injecting a phase delay in the laser frequency-locking servo to rotate the real and imaginary components of the optical spring constant. This enhances damping at the expense of optical rigidity. We demonstrate enhanced parametric damping which reduces the Q factor of a 0.1-kg-scale resonator from 1.3×10^5 to 6.5×10^3. By using this technique adequate optical spring damping can be obtained to damp parametric instability predicted for advanced laser interferometer gravitational-wave detectors
The canonical controller and its regularity
This paper deals with properties of canonical controllers. We first specify the behavior that they implement. It follows that a canonical controller implements the desired controlled behavior if and only if the desired behavior is implementable. We subsequently investigate the regularity of the controlled behavior. We prove that a canonical controller is regular if and only if every controller is regular. In other words, canonical controllers are maximally irregular
Marinomonas brasilensis sp. nov., isolated from the coral Mussismilia hispida, and reclassification of Marinomonas basaltis as a later heterotypic synonym of Marinomonas communis
A Gram-negative, aerobic bacterium, designated strain R-40503(T), was isolated from mucus of the reef-builder coral Mussismilia hispida, located in the Sao Sebastiao Channel, Sao Paulo, Brazil. Phylogenetic analyses revealed that strain R-40503(T) belongs to the genus Marinomonas. The 16S rRNA gene sequence similarity of R-40503(T) was above 97% with the type strains of Marinomonas vaga, M. basaltis, M. communis and M. pontica, and below 97% with type strains of the other Marinomonas species. Strain R-40503(T) showed less than 35% DNA-DNA hybridization (DDH) with the type strains of the phylogenetically closest Marinomonas species, demonstrating that it should be classified into a novel species. Amplified fragment length polymorphism (AFLP), chemotaxonomic and phenotypic analyses provided further evidence for the proposal of a novel species. Concurrently, a close genomic relationship between M. basaltis and M. communis was observed. The type strains of these two species showed 78% DDH and 63% AFLP pattern similarity. Their phenotypic features were very similar, and their DNA G+C contents were identical (46.3 mol%). Collectively, these data demonstrate unambiguously that Marinomonas basaltis is a later heterotypic synonym of Marinomonas communis. Several phenotypic features can be used to discriminate between Marinomonas species. The novel strain R-40503(T) is clearly distinguishable from its neighbours. For instance, it shows oxidase and urease activity, utilizes L-asparagine and has the fatty acid C(12:1) 3-OH but lacks C(10:0) and C(12:0). The name Marinomonas brasilensis sp. nov. is proposed, with the type strain R-40503(T) (=R-278(T) =LMG 25434(T) =CAIM 1459(T)). The DNA G+C content of strain R-40503(T) is 46.5 mol%
Real-time detection of single electron tunneling using a quantum point contact
We observe individual tunnel events of a single electron between a quantum
dot and a reservoir, using a nearby quantum point contact (QPC) as a charge
meter. The QPC is capacitively coupled to the dot, and the QPC conductance
changes by about 1% if the number of electrons on the dot changes by one. The
QPC is voltage biased and the current is monitored with an IV-convertor at room
temperature. We can resolve tunnel events separated by only 8 s, limited
by noise from the IV-convertor. Shot noise in the QPC sets a 25 ns lower bound
on the accessible timescales.Comment: 3 pages, 3 figures, submitte
Improving the applicability of gauge-based radar rainfall adjustment methods to urban pluvial flood modelling and forecasting using local singularity analysis
Superconducting phase formation in random neck syntheses: a study of the Y-Ba-Cu-O system by magneto-optics and magnetometry
Magneto-optical imaging and magnetization measurements were applied to
investigate local formation of superconducting phase effected by a random neck
synthesis in Y-Ba-Cu-O system. Polished pellets of strongly inhomogeneous
ceramic samples show clearly the appearance of superconducting material in the
intergrain zones of binary primary particles reacted under different
conditions. Susceptibility measurements allows evaluation of superconducting
critical temperature, which turned out to be close to that of optimally doped
YBCO.Comment: 6 pages, 11 figure
Implication des modifications épigénétiques dans les cancers : développement de nouvelles approches thérapeutiques
Involvement of epigenetic modifications in cancers: development of new therapeutic approaches. Since cancer is the second cause of death after cardiovascular diseases in industrialized countries, it is urgent to elaborate new therapeutic approaches. Besides DNA mutations of essential genes, expansion of a cancer cell is frequently associated with epigenetic modifications i.e. not directly coded by the DNA sequence. Amongst epigenetic modifications, histones acetylation and DNA methylation are known to play important roles. In this context, a very promising anticancer therapy would be to correct epigenetic errors using compounds modulating histone acetylation and DNA methylation alone or in combination with other chemotherapeutic agents
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