579 research outputs found
Asymmetric Architecture for Heralded Single Photon Sources
Single photon source represent a fundamental building block for optical
implementations of quantum information tasks ranging from basic tests of
quantum physics to quantum communication and high-resolution quantum
measurement. In this paper we investigate the performance of a multiplexed
system based on asymmetric configuration of multiple heralded single photon
sources. {To compare the effectiveness of different designs we introduce a
single-photon source performance index that is based on the value of single
photon probability required to achieve a guaranteed signal to noise ratio.} The
performance and scalability comparison with both currently existing
multiple-source architectures and faint laser configurations reveals an
advantage the proposed scheme offers in realistic scenarios. This analysis also
provides insights on the potential of using such architectures for integrated
implementation.Comment: 11 pages, 13 figure
Bi-photon propagation control with optimized wavefront by means of Adaptive Optics
We present an efficient method to control the spatial modes of entangled
photons produced through SPDC process. Bi-photon beam propagation is controlled
by a deformable mirror, that shapes a 404nm CW diode laser pump interacting
with a nonlinear BBO type-I crystal. Thanks to adaptive optical system, the
propagation of 808nm SPDC light produced is optimized over a distance of 2m.
The whole system optimization is carried out by a feedback between deformable
mirror action and entangled photon coincidence counts. We also demonstrated the
improvement of the two-photon coupling into single mode fibers
Imperforate hymen causing congenital hydrometrocolpos.
A 3-day-old girl in good health was referred to our department for the evaluation of an abdominal mass detected at birth. Prenatal ultrasound (US) examinations had shown no anomaly. US examination revealed the presence of a hypoechoic and corpusculated cystic formation of about 8Â Ă—Â 5Â Ă—Â 4Â cm located in the mid region of the abdomen. The uterus was not visible and the kidneys were normal with no sign of hydronephrosis. The ovaries were normal. Physical examination confirmed US findings revealing the presence of a curved membrane which covered the vaginal opening. Based on these findings, the patient was diagnosed to have hydrometrocolpos. Hymenectomy was performed and about 100Â ml of milky fluid was subsequently removed by aspiration. The patient presented no other congenital anomalies and US follow-up showed a normal structure of the uterus
Impact of turbulence in long range quantum and classical communications
The study of the free-space distribution of quantum correlations is necessary
for any future application of quantum as classical communication aiming to
connect two remote locations. Here we study the propagation of a coherent laser
beam over 143 Km (between Tenerife and La Palma Islands of the Canary
archipelagos). By attenuating the beam we also studied the propagation at the
single photon level. We investigated the statistic of arrival of the incoming
photons and the scintillation of the beam. From the analysis of the data, we
propose the exploitation of turbulence to improve the SNR of the signal.Comment: 5 Pages, 5 figures, 1 Table, revtex
Experimental Realization of Optimal Noise Estimation for a General Pauli Channel
We present the experimental realization of the optimal estimation protocol
for a Pauli noisy channel. The method is based on the generation of 2-qubit
Bell states and the introduction of quantum noise in a controlled way on one of
the state subsystems. The efficiency of the optimal estimation, achieved by a
Bell measurement, is shown to outperform quantum process tomography
Application of Precision Agriculture for the Sustainable Management of Fertilization in Olive Groves
Olive tree growing (Olea europaea L.) has considerably increased in the last decades, as has the consumption of extra virgin olive oil in the world. Precision agriculture is increasingly being applied in olive orchards as a new method to manage agronomic variability with the aim of providing individual plants with the right input amount, limiting waste or excess. The objective of this study was to develop a methodology on a GIS platform using GEOBIA algorithms in order to build prescription maps for variable rate (VRT) nitrogen fertilizers application in an olive orchard. The fertilization plan was determined for each tree by applying its own nitrogen balance, taking into account the variability of nitrogen in soil, leaf, production, and actual biometric and spectral conditions. Each olive tree was georeferenced using the S7-G Stonex instrument with real-time kinematic RTK positioning correction and the trunk cross section area (TCSA) was measured. Soil and leaves were sampled to study nutrient variability. Soil and plant samples were analyzed for all major physical and chemical properties. Spectral data were obtained using a multispectral camera (DJI multispectral) carried by an unmanned aerial vehicle (UAV) platform (DJI Phantom4). The biometric characteristics of the plants were extracted from the achieved normalized vegetation index (NDVI) map. The obtained prescription map can be used for variable rate fertilization with a tractor and fertilizer spreader connected via the ISOBUS system. Using the proposed methodology, the variable rate application of nitrogen fertilizer resulted in a 31% reduction in the amount to be applied in the olive orchard compared to the standard dose
Effetti cardiorespiratori degli sprint ripetuti in giovani calciatori
Scopo: Nel calcio la performance dipende da attività caratterizzate da sforzi di breve durata, talora ad alta intensità , con ridotti tempi di recupero. Questo tipo di sforzo può avere maggiore potenzialità aritmogena rispetto a sforzi, anche massimali, iniziati e terminati in modo graduale. Gli sprint ripetuti permettono di valutare la performance e lo stato di allenamento in giovani calciatori. Scopo del nostro lavoro è stato quello di valutare gli effetti degli sprint ripetuti sul sistema cardiorespiratorio in giovani calciatori delle rappresentative regionali siciliane della FIGC.
Metodi: Sono stati esaminati 12 calciatori, di età media di 15±1 anni. Per valutare lo stato di fitness cardiorespiratoria sono stati determinati, al test da sforzo incrementale massimale al treadmill (SI), il VO2max in ml.Kg-1.min-1 (VO2maxSI) e la FCmax in bpm (FCmaxSI). Per valutare gli effetti cardiorespiratori degli sprint ripetuti, gli atleti hanno eseguito un test da sforzo al cicloergometro a freno meccanico (SR) che prevedeva 10 sprint massimali “all-out” di 6 sec, intervallati da 30 sec di recupero passivo. Nella serie dei 10 sprint, sono stati determinati il valore più elevato di VO2 in ml.Kg-1.min-1 (VO2maxSR) e di FC in bpm (FCmaxSR).
Risultati: Il valore medio di VO2maxSI (56,22±3,93 ml.Kg-1.min-1) indica che i soggetti esaminati hanno un buon livello di potenza aerobica, raggiunta ad una FCmaxSI di 190±8 bpm. I dati di VO2maxSR rilevati al test degli sprint ripetuti evidenziano un valore medio di 42,67±5,57 ml.Kg-1.min-1 (70% del VO2maxSI), raggiunto ad una FCmaxSR di 175±11 bpm (92% della FCmaxSI).
Conclusioni: I dati del nostro studio indicano che nei soggetti esaminati gli sprint ripetuti determinano incrementi della frequenza cardiaca rapidi, elevati e persistenti nella fase di recupero. Questo dato deve essere preso in considerazione non solo per la valutazione della performance ma anche nella formulazione dell’idoneità a praticare la disciplina sportiva del calcio
Effects of the 6th September 2002 earthquake: damage amplification in the south-eastern sector of Palermo explained by GIS technology
During the 6th September 2002 earthquake the highest damage level in Palermo was observed in the SE sector.
This is a recent urbanization area where reinforced concrete structures predominate. A detailed analysis of soil
properties in Palermo was carried out by City-GIS to investigate a possible role of nearsurface geology on earthquake
effects. City-GIS is a tool dedicated to natural hazard evaluation in urban areas. The availability of high
density of well log data (stratigraphic and geotechnical) allowed a realistic modeling of surface geology and
physical-mechanical properties that control the seismic response. In wide zones of the above mentioned sector
of Palermo, outcropping terrains are composed of thin calcarenite layers, lying above remarkably thick siltyclayey
sands that overlay the Numidian Flysch, commonly considered the bedrock of Quaternary sediments.
Since silty-clayey sands feature greater deformability properties (Young's modulus) and smaller resistance properties
(undrained cohesion and shear resistance angle) than Numidian Flysch, these zones of the SE sector exhibit
high values of the acoustic impedance contrast. Moreover, a quite wide portion of the study area, crossed
by the Oreto River, is characterized by very thick alluvial deposits. Here, the significant lateral variations of the
lithostratigraphic geometry may be an additional cause of strong site effects
Honey Production with Remote Smart Monitoring System
The innovative technologies of precision agriculture can be applied to beekeeping, a very important sector both from an environmental and production point of view. Bees are responsible, through pollination, for the reproduction of numerous plants guaranteeing biodiversity and providing a final product, honey, highly energetic and with high health properties. Today, sensors applied to the hives can be used to obtain information on the colony phenology in the field, disturbing them as little as possible, allowing the construction of forecast models to control their health state and production increase. The Department of Agricultural, Food and Forest Sciences of the University of Palermo developed a WNS-type system for continuously monitoring and controlling the main environmental factors, both inside and outside the hive, in order to evaluate their influence on daily honey production. The novel system allows to identify any critical points in honey production recording environmental, sound and production data and real time transmitting them to the operators, accessing a specifically created web interface. The results of the study represent the basis for a precision hive management model that can be applied in different environmental conditions to optimize honey production
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