344 research outputs found
Petroleum-hydrocarbons biodegradation by Pseudomonas strains isolated from hydrocarbon-contaminated soil
Many indigenous microorganisms in water and soil are capable of degrading hydrocarbon contaminants. In this study, two bacterial strains were isolated from a contaminated soil of a refinery of Arzew (Oran). The isolated strains were identified as Pseudomonas aeruginosa (P3) and Pseudomonas fluoresens (P4). The capability of these isolates to degrade petroleum was performed by measuring the optical density, colony forming unit counts (CFU/ml) and concentration of total petroleum hydrocarbons (TPH). Degradation of Isomerate by these isolates was analyzed by gas chromatography with flame ionization detector (FID). Results indicated that the isolates can use petroleum as carbon source. Isolates P3 has the highest capability of hydrocarbons degradation (80.86% of biodegradation).Keywords: Biodegradation, contaminated soil, Petroleum, Isomerate, Pseudomonas sp
Antiresonance phase shift in strongly coupled cavity QED
We investigate phase shifts in the strong coupling regime of single-atom
cavity quantum electrodynamics (QED). On the light transmitted through the
system, we observe a phase shift associated with an antiresonance and show that
both its frequency and width depend solely on the atom, despite the strong
coupling to the cavity. This shift is optically controllable and reaches 140
degrees - the largest ever reported for a single emitter. Our result offers a
new technique for the characterization of complex integrated quantum circuits.Comment: 5 pages, 5 figure
Continuous parametric feedback cooling of a single atom in an optical cavity
We demonstrate a new feedback algorithm to cool a single neutral atom trapped
inside a standing-wave optical cavity. The algorithm is based on parametric
modulation of the confining potential at twice the natural oscillation
frequency of the atom, in combination with fast and repetitive atomic position
measurements. The latter serve to continuously adjust the modulation phase to a
value for which parametric excitation of the atomic motion is avoided. Cooling
is limited by the measurement back action which decoheres the atomic motion
after only a few oscillations. Nonetheless, applying this feedback scheme to a
~ 5 kHz oscillation mode increases the average storage time of a single atom in
the cavity by a factor of 60 to more than 2 seconds. In contrast to previous
feedback schemes, our algorithm is also capable of cooling a much faster ~ 500
kHz oscillation mode within just microseconds. This demonstrates that
parametric cooling is a powerful technique that can be applied in all
experiments where optical access is limited.Comment: 7 pages, 5 figure
The Fringe Detection Laser Metrology for the GRAVITY Interferometer at the VLTI
Interferometric measurements of optical path length differences of stars over
large baselines can deliver extremely accurate astrometric data. The
interferometer GRAVITY will simultaneously measure two objects in the field of
view of the Very Large Telescope Interferometer (VLTI) of the European Southern
Observatory (ESO) and determine their angular separation to a precision of 10
micro arcseconds in only 5 minutes. To perform the astrometric measurement with
such a high accuracy, the differential path length through the VLTI and the
instrument has to be measured (and tracked since Earth's rotation will
permanently change it) by a laser metrology to an even higher level of accuracy
(corresponding to 1 nm in 3 minutes). Usually, heterodyne differential path
techniques are used for nanometer precision measurements, but with these
methods it is difficult to track the full beam size and to follow the light
path up to the primary mirror of the telescope. Here, we present the
preliminary design of a differential path metrology system, developed within
the GRAVITY project. It measures the instrumental differential path over the
full pupil size and up to the entrance pupil location. The differential phase
is measured by detecting the laser fringe pattern both on the telescopes'
secondary mirrors as well as after reflection at the primary mirror. Based on
our proposed design we evaluate the phase measurement accuracy based on a full
budget of possible statistical and systematic errors. We show that this
metrology design fulfills the high precision requirement of GRAVITY.Comment: Proc. SPIE in pres
PCR5 and Neutrosophic Probability in Target Identification
In this paper, we use PCR5 in order to fusion the information of two sources providing subjective probabilities of an event A to occur in the following form: chance that A occurs, indeterminate chance of occurrence of A, chance that A does not occur
PCR5 and Neutrosophic Probability in Target Identification
In this paper, we use PCR5 in order to fusion the information of two sources providing subjective probabilities of an event A to occur in the following form: chance that A occurs, indeterminate chance of occurrence of A, chance that A does not occur
Lattice-shifted nematic quantum critical point in
We report the evolution of nematic fluctuations in single crystals as a function of Sulfur content x across the nematic quantum critical point (QCP) ~ 0.17 via Raman scattering. The Raman spectra in the nematic channel consist of two components, but only the low energy one displays clear fingerprints of critical behavior and is attributed to itinerant carriers.
Curie–Weiss analysis of the associated nematic susceptibility indicates a substantial effect of nemato-elastic coupling, which shifts
the location of the nematic QCP. We argue that this lattice-induced shift likely explains the absence of any enhancement of the
superconducting transition temperature at the QCP. The presence of two components in the nematic fluctuations spectrum is
attributed to the dual aspect of electronic degrees of freedom in Hund’s metals, with both itinerant carriers and local moments
contributing to the nematic susceptibility
Lattice-Shifted Nematic Quantum Critical Point in FeSeS
We report the evolution of nematic fluctuations in FeSeS single
crystals as a function of Sulfur content across the nematic quantum
critical point (QCP) 0.17 via Raman scattering. The Raman spectra in
the nematic channel consist of two components, but only the low energy
one displays clear fingerprints of critical behavior and is attributed to
itinerant carriers. Curie-Weiss analysis of the associated nematic
susceptibility indicates a substantial effect of nemato-elastic coupling which
shifts the location of the nematic QCP. We argue that this lattice-induced
shift likely explains the absence of any enhancement of the superconducting
transition temperature at the QCP. The presence of two components in the
nematic fluctuations spectrum is attributed to the dual aspect of electronic
degrees of freedom in Hund's metals, with both itinerant carriers and local
moments contributing to the nematic susceptibility.Comment: 10 pages, 5 figure
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