4,948 research outputs found
Quantum erasure in the presence of a thermal bath: the effects of system-environment microscopic correlations
We investigate the role of the environment in a quantum erasure setup in the
cavity quantum electrodynamics domain. Two slightly different schemes are
analyzed. We show that the effects of the environment vary when a scheme is
exchanged for another. This can be used to estimate the macroscopic parameters
related to the system-environment microscopic correlations.Comment: 10 pages, 2 figure
Biofilm growth and hydrodynamic behaviour in the biological plate tower (BPT) with and without hanging biomass (BPT-HB)
Deodorization and volatile organic compound abatement from polluted air streams can be
accomplished with the biological plate tower (BPT), which has proved to be a reliable alternative to
biofilters and biotrickling filters. Unlike those, the BPT is a non-clogging device, with constant active
surface, and steady performance, making it ideal for scale-up and modelling. The initial BPT design
needed improvement for better performance. The cylindrical body (circular plates) was replaced by a
rectangular cuboid (rectangular plates). Holes in the plates did augment the amount of active
biomass (hanging from the holes and under the plates), without reducing the transfer of toluene from
the gaseous to the liquid phase. The diminished distance between plates was well tolerated in cocurrent
flow, allowing much higher quantities of biomass in the same reactor volume. With 18 and
14 mm spacing between adjacent plates, the BPT, with and without holes, was tested for flooding,
holdup and pressure drop. Several gas and liquid flows were tested, both in co-current and countercurrent.
In hydrodynamic terms, the BPT-HB with co-current flow was clearly the best option. Higher
stability with higher flow rates, and lower pressure drops were observed. The inoculum was obtained
from wastewater plant activated sludge (petrochemical industry)
Urachal Tumor: A Case Report of an Extremely Rare Carcinoma
The urachus is a tubular structure that connects the bladder to the allantois in the embryonic development, involuting after the third trimester. The urachus carcinoma is an extremely rare tumor that accounts for <1% of all bladder cancers. We report a case of a 46-year-old woman, with no past medical history, complaining of hematuria with 6-month duration and a physical exam and an abdominal computed topographic scan revealing an exophytic mass of 6.8 cm longer axis that grew depending on the anterior bladder wall, invading the anterior abdominal wall. Cystoscopy detected mucosal erosion. The biopsy showed structures of adenocarcinoma of enteric type. The surgical specimen showed urachus adenocarcinoma of enteric type with stage IVA in the Sheldon system and stage III in the Mayo system. This case has a 3-year follow-up without disease recurrence.info:eu-repo/semantics/publishedVersio
Atomic detection in microwave cavity experiments: a dynamical model
We construct a model for the detection of one atom maser in the context of
cavity Quantum Electrodynamics (QED) used to study coherence properties of
superpositions of electromagnetic modes. Analytic expressions for the atomic
ionization are obtained, considering the imperfections of the measurement
process due to the probabilistic nature of the interactions between the
ionization field and the atoms. Limited efficiency and false counting rates are
considered in a dynamical context, and consequent results on the information
about the state of the cavity modes are obtained.Comment: 12 pages, 1 figur
Control of state and state entanglement with a single auxiliary subsystem
We present a strategy to control the evolution of a quantum system. The novel
aspect of this protocol is the use of a \emph{single auxiliary subsystem}. Two
applications are given, one which allows for state preservation and another
which controls the degree of entanglement of a given initial state
Network of recurrent events for the Olami-Feder-Christensen model
We numerically study the dynamics of a discrete spring-block model introduced
by Olami, Feder and Christensen (OFC) to mimic earthquakes and investigate to
which extent this simple model is able to reproduce the observed spatiotemporal
clustering of seismicty. Following a recently proposed method to characterize
such clustering by networks of recurrent events [Geophys. Res. Lett. {\bf 33},
L1304, 2006], we find that for synthetic catalogs generated by the OFC model
these networks have many non-trivial statistical properties. This includes
characteristic degree distributions -- very similar to what has been observed
for real seismicity. There are, however, also significant differences between
the OFC model and earthquake catalogs indicating that this simple model is
insufficient to account for certain aspects of the spatiotemporal clustering of
seismicity.Comment: 11 pages, 16 figure
Superdiffusion of massive particles induced by multi-scale velocity fields
We study drag-induced diffusion of massive particles in scale-free velocity
fields, where superdiffusive behavior emerges due to the scale-free size
distribution of the vortices of the underlying velocity field. The results show
qualitative resemblance to what is observed in fluid systems, namely the
diffusive exponent for the mean square separation of pairs of particles and the
preferential concentration of the particles, both as a function of the response
time.Comment: 5 pages, 5 figures. Accepted for publication in EP
Kinetics of fluorene biodegradation by a mixed culture
The present study intended to determine the kinetics of biological degradation of fluorene by a mixed culture of microorganisms. Batch experiments were performed, being the inoculum an enriched mixed culture from a contaminated wastewater. Fluorene was quantified in the aqueous phase by solid phase micro-extraction (SPME), and analyzed in a GC-FID. The mixed culture was able to degrade fluorene and experimental results showed that biosorption had no influence on fluorene removal. The kinetic parameters, maximum reaction rate (kmax) and half saturation constant (Ks), respectively, 3.20×10–4 h–1 ± 0.93×10–4 h–1 and 126 μg L–1, were calculated
- …