Search results for "waves"
showing 10 items of 1766 documents
Calculation of Proton-Deuteron Elastic Scattering at 10 MeV with a Realistic Potential
1998
We present the first results of a calculation of the differential cross section and of polarization observables for proton-deuteron elastic scattering at 10thinspthinspMeV proton laboratory energy, for the Paris potential. The method used is the {open_quotes}screening and renormalization approach{close_quotes} which allows one to correctly take into account the Coulomb repulsion between the two protons. Comparison is made with the precise experimental data of Sagara {ital et al.}thinspthinsp[Phys.thinspthinspRev.thinspthinspC {bold 50}, 576 (1994)] and of Sperison {ital et al.}thinspthinsp[Nucl.thinspthinspPhys.thinspthinsp{bold A422}, 81 (1984)]. {copyright} {ital 1998} {ital The American …
The actual management of colorectal liver metastases
2020
Colorectal cancer is one of the most frequent cancers in the world and between 50% and 60% of patients will develop colorectal liver metastases (CRLM) during the disease. There have been great improvements in the management of CRLM during the last decades. The combination of modern chemotherapeutic and biological systemic treatments with aggressive surgical resection strategies is currently the base for the treatment of patients considered unresectable until few years ago. Furthermore, several new treatments for the local control of CRLM have been developed and are now part of the arsenal of multidisciplinary teams for the treatment of these complex patients. The aim of this review was to s…
An effective negative pressure cavitation-microwave assisted extraction for determination of phenolic compounds in P. calliantha H. Andr.
2013
A novel negative pressure and microwave assisted extraction technique (NMAE) was first proposed and applied for extraction of phenolic compounds from pyrola. [C₄MIM]BF₄ aqueous solution was selected as extraction solvent. Optimal extraction conditions were microwave power 700 W, negative pressure -0.07 MPa, temperature 40 °C, liquid-solid ratio 20 : 1, ionic liquid (IL) concentration 0.5 M, extraction time 15 min. The predominance of NMAE was investigated by comparing with microwave-assisted extraction (MAE) and negative pressure cavitation extraction (NPCE) using a first-order kinetics equation. The C∞ values of the target compounds by NMAE were from 0.406 to 5.977 mg g⁻¹ higher than these…
Oilseed treatment by ultrasounds and microwaves to improve oil yield and quality: An overview.
2016
International audience; Efficiency is a key point to ensure the profitability in the production of vegetable oils from oilseeds. To maximize the recovery yields of seed oils, the traditional process involves mechanical expression followed by subsequent chemical extraction using organic solvents (e.g. hexane). Besides health, environmental, and economic related issues to the use of organic solvents, thermal treatment of seeds during conventional oil extraction process inevitably leads to chemical changes (e.g. changes in macronutrients such as protein denaturation/degradation in the meal, oil oxidation, and changes in minor constituents such as fatty acids, sterols, phenolic compounds and to…
Design of a narrow-band filter based on the Brewster phenomenon for microwave applications
2017
A high-efficiency narrow-band filter based on a Dielectric Frequency-Selective Surface (DFSS) has been predicted theoretically for oblique plane-wave incidence. A DFSS showing total reflection at a frequency of 10.5 GHz, based on the Brewster phenomenon for TM polarization, has been designed with a single dielectric grating, showing extremely low-reflectance sidebands adjacent to the resonance peak. The angular and spectral response of the designed filter has been studied. In addition, dielectric ohmic losses have been accounted for in this structure. This work was supported by the Agencia Estatal de Investigación (AEI) and by the Unión Europea through the Fondo Europeo de Desarrollo Region…
Phase-conjugate emission of a two-mirror solid state laser
2002
We show that phase conjugation strongly contributes to the emission of a solid state laser in a two-mirror (Fabry-Perot) resonator , enabling dynamic correction of thermal lensing . Full correction of thermal effects is reached by vector phase conjugation .
Well-Balanced Adaptive Mesh Refinement for shallow water flows
2014
Well-balanced shock capturing (WBSC) schemes constitute nowadays the state of the art in the numerical simulation of shallow water flows. They allow to accurately represent discontinuous behavior, known to occur due to the non-linear hyperbolic nature of the shallow water system, and, at the same time, numerically maintain stationary solutions. In situations of practical interest, these schemes often need to be combined with some kind of adaptivity, in order to speed up computing times. In this paper we discuss what ingredients need to be modified in a block-structured AMR technique in order to ensure that, when combined with a WBSC scheme, the so-called 'water at rest' stationary solutions…
Discovery of hard phase lags in the pulsed emission of GRO J1744-28
2016
We report on the discovery and energy dependence of hard phase lags in the 2.14 Hz pulsed profiles of GRO J1744-28. We used data from XMM-Newton and NuSTAR. We were able to well constrain the lag spectrum with respect to the softest (0.3--2.3 keV) band: the delay shows increasing lag values reaching a maximum delay of $\sim$ 12 ms, between 6 and 6.4 keV. After this maximum, the value of the hard lag drops to 7 ms, followed by a recovery to a plateau at 9 ms for energies above 8 keV. NuSTAR data confirm this trend up to 30 keV, but the measurements are statistically poorer, and therefore, less constraining. The lag-energy pattern up to the discontinuity is well described by a logarithmic fun…
Attraction d'ondes pour des systèmes à résonance d'ondes contra-propagatives
2011
Wave attraction in counter-propagating waves systems is a general phenomenon that was first established in Physics in the context of the attraction of the polarization between two counter-propagating waves in optical fibers. This phenomenon has been observed experimentally, and its properties were studied through numerical simulations. The models are Hamiltonian hyperbolic systems of partial differential equations, with time-dependent boundary conditions on a finite interval. The underlying mechanism can be traced back to the existence of singular tori in the corresponding stationary equations. In this work we analyze in detail the simplest example in this family of models. We show that mos…
Tuning the Pseudospin Polarization of Graphene by a Pseudomagnetic Field.
2016
One of the intriguing characteristics of honeycomb lattices is the appearance of a pseudo-magnetic field as a result of mechanical deformation. In the case of graphene, the Landau quantization resulting from this pseudo-magnetic field has been measured using scanning tunneling microscopy. Here we show that a signature of the pseudo-magnetic field is a local sublattice symmetry breaking observable as a redistribution of the local density of states. This can be interpreted as a polarization of graphene's pseudospin due to a strain induced pseudo-magnetic field, in analogy to the alignment of a real spin in a magnetic field. We reveal this sublattice symmetry breaking by tunably straining grap…