Electrodynamics of balanced charges

In this work we modify the wave-corpuscle mechanics for elementary charges introduced by us recently. This modification is designed to better describe electromagnetic (EM) phenomena at atomic scales. It includes a modification of the concept of the classical EM field and a new model for the elementary charge which we call a balanced charge (b-charge). A b-charge does not interact with itself electromagnetically, and every b-charge possesses its own elementary EM field. The EM energy is naturally partitioned as the interaction energy between pairs of different b-charges. We construct EM theory of b-charges (BEM) based on a relativistic Lagrangian with the following properties: (i) b-charges interact only through their elementary EM potentials and fields; (ii) the field equations for the elementary EM fields are exactly the Maxwell equations with proper currents; (iii) a free charge moves uniformly preserving up to the Lorentz contraction its shape; (iv) the Newton equations with the Lorentz forces hold approximately when charges are well separated and move with non-relativistic velocities. The BEM theory can be characterized as neoclassical one which covers the macroscopic as well as the atomic spatial scales, it describes EM phenomena at atomic scale differently than the classical EM theory. It yields in macroscopic regimes the Newton equations with Lorentz forces for centers of well separated charges moving with nonrelativistic velocities. Applied to atomic scales it yields a hydrogen atom model with a frequency spectrum matching the same for the Schrodinger model with any desired accuracy.Comment: Manuscript was edited to improve the exposition and to remove noticed typo

Brewster-angle measurements of sea-surface reflectance using a high resolution spectroradiometer

This paper describes the design, construction and testing of a ship-borne spectroradiometer based on an imaging spectrograph and cooled CCD array with a wavelength range of 350-800 nm and 4 nm spectral sampling. The instrument had a minimum spectral acquisition time of 0.1 s, but in practice data were collected over periods of 10 s to allow averaging of wave effects. It was mounted on a ship's superstructure so that it viewed the sea surface from a height of several metres at the Brewster angle (53 degrees) through a linear polarizing filter. Comparison of sea-leaving spectra acquired with the polarizer oriented horizontally and vertically enabled estimation of the spectral composition of sky light reflected directly from the sea surface. A semi-empirical correction procedure was devised for retrieving water-leaving radiance spectra from these measurements while minimizing the influence of reflected sky light. Sea trials indicated that reflectance spectra obtained by this method were consistent with the results of radiance transfer modelling of case 2 waters with similar concentrations of chlorophyll and coloured dissolved organic matter. Surface reflectance signatures measured at three locations containing blooms of different phytoplankton species were easily discriminated and the instrument was sufficiently sensitive to detect solar-stimulated fluorescence from surface chlorophyll concentrations down to 1 mg m−3

Quantum Zakharov Model in a Bounded Domain

We consider an initial boundary value problem for a quantum version of the Zakharov system arising in plasma physics. We prove the global well-posedness of this problem in some Sobolev type classes and study properties of solutions. This result confirms the conclusion recently made in physical literature concerning the absence of collapse in the quantum Langmuir waves. In the dissipative case the existence of a finite dimensional global attractor is established and regularity properties of this attractor are studied. For this we use the recently developed method of quasi-stability estimates. In the case when external loads are $C^\infty$ functions we show that every trajectory from the attractor is $C^\infty$ both in time and spatial variables. This can be interpret as the absence of sharp coherent structures in the limiting dynamics.Comment: 27 page

Relativistic dynamics of accelerating particles derived from field equations

In relativistic mechanics the energy-momentum of a free point mass moving without acceleration forms a four-vector. Einstein's celebrated energy-mass relation E=mc^2 is commonly derived from that fact. By contrast, in Newtonian mechanics the mass is introduced for an accelerated motion as a measure of inertia. In this paper we rigorously derive the relativistic point mechanics and Einstein's energy-mass relation using our recently introduced neoclassical field theory where a charge is not a point but a distribution. We show that both the approaches to the definition of mass are complementary within the framework of our field theory. This theory also predicts a small difference between the electron rest mass relevant to the Penning trap experiments and its mass relevant to spectroscopic measurements.Comment: A few typos were correcte

Some qualitative properties of the solutions of the Magnetohydrodynamic equations for nonlinear bipolar fluids

In this article we study the long-time behaviour of a system of nonlinear Partial Differential Equations (PDEs) modelling the motion of incompressible, isothermal and conducting modified bipolar fluids in presence of magnetic field. We mainly prove the existence of a global attractor denoted by \A for the nonlinear semigroup associated to the aforementioned systems of nonlinear PDEs. We also show that this nonlinear semigroup is uniformly differentiable on \A. This fact enables us to go further and prove that the attractor \A is of finite-dimensional and we give an explicit bounds for its Hausdorff and fractal dimensions.Comment: The final publication is available at Springer via http://dx.doi.org/10.1007/s10440-014-9964-

Mode decomposition method for investigating the nonlinear dynamics of a multimode beam

We overview our recent experimental studies on the nonlinear spatial reshaping of multimode beams at the output of multimode optical fibers. We use a holographic mode decomposition technique, which permits to reveal the variation of the spatial mode composition at the fiber output, as determined by either conservative (the Kerr effect) or dissipative (Raman scattering) nonlinear processes. For the first case, we consider the effect of spatial beam self-cleaning, and we compare experimental mode decompositions with predictions based on the thermodynamic theory, including the case of beams carrying nozero orbital angular momentum. For the second case, we analyze the beam mode content at the output of a Raman laser based on a graded index multimode fiber

Does intraoperative neuromonitoring of recurrent nerves have an impact on the postoperative palsy rate? Results of a prospective multicenter study

BACKGROUND: The impact of intraoperative neuromonitoring on recurrent laryngeal nerve palsy remains debated. Our aim was to evaluate the potential protective effect of intraoperative neuromonitoring on recurrent laryngeal nerve during total thyroidectomy. METHODS: This was a prospective, multicenter French national study. The use of intraoperative neuromonitoring was left at the surgeons\u27 choice. Postoperative laryngoscopy was performed systematically at day 1 to 2 after operation and at 6 months in case of postoperative recurrent laryngeal nerve palsy. Univariate and multivariate analyses and propensity score (sensitivity analysis) were performed to compare recurrent laryngeal nerve palsy rates between patients operated with or without intraoperative neuromonitoring. RESULTS: Among 1,328 patients included (females 79.9%, median age 51.2 years, median body mass index 25.6 kg/m), 807 (60.8%) underwent intraoperative neuromonitoring. Postoperative abnormal vocal cord mobility was diagnosed in 131 patients (9.92%), including 69 (8.6%) and 62 (12.1%) in the intraoperative neuromonitoring and nonintraoperative neuromonitoring groups, respectively. Intraoperative neuromonitoring was associated with a lesser rate of recurrent laryngeal nerve palsy in univariate analysis (odds ratio = 0.68, 95% confidence interval, 0.47; 0.98, P = .04) but not in multivariate analysis (oddsratio = 0.74, 95% confidence interval, 0.47; 1.17, P = .19), or when using a propensity score (odds ratio = 0.76, 95% confidence interval, 0.53; 1.07, P = .11). There was no difference in the rates of definitive recurrent laryngeal nerve palsy (0.8% and 1.3% in intraoperative neuromonitoring and non-intraoperative neuromonitoring groups respectively, P = .39). The sensitivity, specificity, and positive and negative predictive values of intraoperative neuromonitoring for detecting abnormal postoperative vocal cord mobility were 29%, 98%, 61%, and 94%, respectively. CONCLUSION: The use of intraoperative neuromonitoring does not decrease postoperative recurrent laryngeal nerve palsy rate. Due to its high specificity, however, intraoperative neuromonitoring is useful to predict normal vocal cord mobility. From the CHU de Nantes, Clinique de Chirurgie Digestive et Endocrinienne, Nantes, France; CHU Lille, Université de Lille, Chirurgie Générale et Endocrinienne, Lille, France; CHU Nancy-Hôpital de Brabois, Service de Chirurgie Digestive, Hépato-Biliaire, et Endocrinienne, Nancy, France; CHU Angers, Chirurgie Digestive et Endocrinienne, Angers, France; CHU de Toulouse-Hôpital Larrey, Chirurgie Thoracique, Pôle Voies Respiratoires, Toulouse; CHU Saint-Etienne-Hôpital Nord, ORL et Chirurgie Cervico-Faciale et Plastique, Saint-Etienne, France; CHU de Limoges-Hôpital Dupuytren, Chirurgie Digestive, Générale et Endocrinienne, Limoges, France; CHU de Besançon-Hôpital Jean Minjoz, Chirurgie Digestive, Besançon, France; Centre Hospitalier du Mans, Service ORL et Chirurgie Cervico-Faciale, Le Mans, France; Centre Hospitalier Lyon-Sud, Chirurgie Générale, Endocrinienne, Digestive et Thoracique, Pierre Bénite, France; AP-HM-Hôpital de La Conception, Chirurgie Générale, Marseille, France; CHU de Rennes-Hôpital Pontchaillou, Service ORL et Chirurgie Maxillo-Faciale, Rennes, France; CHU de Caen, ORL et Chirurgie Cervico-Faciale, Caen, France; CHU d\u27Angers, ORL et Chirurgie Cervico-Faciale, Angers, France; CHU de Nantes, Service ORL, Nantes, France; AP HP URCEco île-de-France, hôpital de l\u27Hôtel-Dieu, Paris, France; DRCI, département Promotion, Nantes, France

Nonlinear multimode fiber optics: recent advances

We start by providing an overview of the emerging field of nonlinear optics in multimode optical fibers [1]. These fibers provide a simple testbed for observing complex wave propagation dynamics, in analogy with other fields of physics ranging from two-dimensional hydrodynamic turbulence and Bose-Einstein condensation. In addition, nonlinear multimode optical fibers enable new methods for achieving the ultrafast, light-activated control of temporal, spatial and spectral degrees of freedom of intense, pulsed light beams, for a range of different technological applications