Search results for " cavi"
showing 10 items of 537 documents
Impairment of leaf hydraulics in young plants of Citrus aurantium (sour orange) infected by Phoma tracheiphila.
2007
Phoma trachephila (Petri) Kantschaveli et Gikachvili causes dieback of several Citrus species. The impact of this fungus on leaf hydraulics was studied in Citrus aurantium L. (sour orange) with the aim of identifying the primary mechanism of damage to leaves. Leaves inoculated with a conidial suspension were measured for conductance to water vapor (gL) and specific hydraulic conductance (Kleaf) every 3 days after inoculation. The earliest symptom of infection consisted of vein chlorosis. Functional vein density (FVD) was monitored and microscopic observations were made of major vein conduits. Impairment of vein hydraulics started 25 days after inoculation with a losses of Kleaf of 40% and g…
A new empirical method for extracting unloaded resonant frequencies from microwave resonant cavities
2003
Equivalent circuits traditionally used to model resonators and coupling networks in the vicinity of a resonance provide values of unloaded resonant frequencies which usually do not agree with experimental results. A new empirical method for the extraction of influence of coupling networks on resonant cavities is presented. The characterization of coupling structures is performed directly from measurements without the need of obtaining the electromagnetic fields inside the cavity, which is very interesting from a practical point of view. Results are validated with simulations and experimental measurements. The accuracy of some cavity applications, such as dielectric characterization techniqu…
Quasi-Normal Frequencies in Open Cavities: An Application to Photonic Crystals
2005
The electromagnetic field in an optical open cavity is analyzed in the framework of the Quasi-Normal Modes theory. The role of the complex quasi-normal frequencies in the transmission coefficient and their link with the density of quasi-modes function is clarified. An application to a quarter-wave symmetric one-dimensional photonic crystals is discussed to illustrate the usefulness and the meaning of our results.
Dental anatomy portrayed with microscopic volume investigations
1993
The clinical treatment of the root canal of teeth--called endodontics--assumes a precise idea of the spatial arrangement of the anatomy of teeth and their inner structure. By using computer-assisted data acquisition from filmed sequences of histologic serial sections and a special kind of magnetic resonance microscope--the Stray Field Imaging (STRAFI)--volume investigations were carried out using special functions of a newly developed 3D software. Possible applications and future perspectives are discussed.
A preliminary method for the numerical prediction of the behavior of air bubbles in the design of Air Cavity Ships
2016
Air-cavity ships (ACS) are advanced marine vehicles that use air injection under hull to improve the vessel’s hydrodynamic characteristics. Although the concept of drag reduction by supplying gas under the ship’s bottom was proposed in the 19th century by Froude and Laval, at this time there are not many systematic studies on this subject. This paper is a preliminary work with the purpose of being a basic tool for the design of the ACS with computational fluid dynamic methods. The study aims to conduct a series of computational tests to compare the numerical models of bubble with experimental data. The first step of this study was to investigate the behavior of free bubble in water, conside…
Cactus pear fruit extract exerts anti-inflammatory effects in carrageenin-induced rat pleurisy
2015
Nutritional research has recently shifted from alleviating nutrient deficiencies to chronic disease prevention. In this study activity of cactus pear fruit extract (CPFE) from Opuntia ficus-indica (L.) Mill. has been investigated in carrageenin-induced pleurisy, a rat model of acute inflammation. In our experimental design rat pleurisy was achieved by the injection of 0.2 ml of λ-carrageenin in the pleural cavity. At selected time points, rats were sacrificed; cells recruited in pleura were counted and exudates collected to analyse inflammatory parameters such as NO, PGE2, IL-1β, TNF-α. CPFE (in the range between 5 and 20 g fresh fruit equivalent/kg), orally given 30 min before the injectio…
Microreflectivity studies of wavelength control in oxidised AlGaAs microcavities
2003
Wet oxidation of GaAs/AlGaAs structures is an important technique in the processing of advanced devices such as vertical cavity surface emitting lasers (VCSELs). In one VCSEL application, the low-index and electrically-insulating AlxOy layers have been used to obtain high-reflectivity and broad bandwidth distributed Bragg reflector mirrors (DBRs). A further recent development has shown that combined lateral–vertical oxidation of intracavity AlGaAs layers can be used to tune the resonant wavelength of a semiconductor microcavity. The slow oxidation rate limits the lateral scale of practical wet oxidation to mesas structures of 50–100 μm in width. Therefore post-processing assessment of spect…
Role of CD36 in Oral and Postoral Sensing of Lipids
2011
Obesity and associated plethora of diseases constitute a major public health challenge worldwide. The conjunction of profound changes in our lifestyle and a thrifty genetic that evolved in an environment of food scarcity largely explains this epidemic situation. Food abundance promotes our specific appetite for the more palatable food generally rich in lipids. It is noteworthy that this attraction for fatty food is not specific to humans. Rats and mice also spontaneously prefer lipid-rich food in a free-choice situation. Detection of lipids in food requires the presence of specific sensors located in strategic places (e.g., oral cavity, small intestine, brain) whose activation results in a …
Pulse shaping in mode-locked fiber lasers by in-cavity spectral filter
2014
International audience; We numerically show the possibility of pulse shaping in a passively mode-locked fiber laser by inclusion of a spectral filter into the laser cavity. Depending on the amplitude transfer function of the filter, we are able to achieve various regimes of advanced temporal waveform generation, including ones featuring bright and dark parabolic-, flat-top-, triangular- and saw-tooth-profiled pulses. The results demonstrate the strong potential of an in-cavity spectral pulse shaper for controlling the dynamics of mode-locked fiber lasers.
Entanglement detection in hybrid optomechanical systems
2011
We study a device formed by a Bose Einstein condensate (BEC) coupled to the field of a cavity with a moving end-mirror and find a working point such that the mirror-light entanglement is reproduced by the BEC-light quantum correlations. This provides an experimentally viable tool for inferring mirror-light entanglement with only a limited set of assumptions. We prove the existence of tripartite entanglement in the hybrid device, persisting up to temperatures of a few milli-Kelvin, and discuss a scheme to detect it.