Charge oscillation-induced light transmission through subwavelength slits and holes

We present a concrete picture of spoof surface plasmons (SSPs) combined with cavity resonance to clarify the basic mechanism underlying extraordinary light transmission through metal films with subwavelength slits or holes. This picture may indicate a general mechanism of metallic nanostructure optics: When light is incident on a non-planar conducting surface, the free electrons cannot move homogeneously in response to the incident electric field, i.e., their movement can be impeded at the rough parts, forming inhomogeneous charge distributions. The oscillating charges/dipoles then emit photons (similar to Thomson scattering of x rays by oscillating electrons), and the interference between the photons may give rise to anomalous transmission, reflection or scattering.Comment: 4 pages, 4 figures, are "surface plasmons" true for conducting structures? Answere is here. Also see the new arXiv:0903.3565v1, the expansion of this pape

Development and validation of a numerical tool for the simulation of the temperature field and infrared radiance rendering in an urban scene

International audienceWe present a numerical tool aimed at simulating infrared images of an urban environment, by solving the direct heat transfer problem, and then computing the radiance rendering at the sensor level. SOLENE (Cerma, Nantes) was coupled with two software packages developed at ONERA: SUSHI (Simulation in Urban Scene of Heat dIffusion) and MOHICANS (MOdélisation Hyperspectrale d'Images en entrée Capteur pour l'ANalyse et l'inversion du Signal) for realizing this task. SUSHI is also used for computing the surface temperatures: either a 1D model or a 2D model is used. We present the whole software chain, its validation by software and experimental analysis

Degeneracy analysis for a super cell of a photonic crystal and its application to the creation of band gaps

A method is introduced to analyze the degeneracy properties of the band structure of a photonic crystal making use of the super cells. The band structure associated with a super cell of a photonic crystal has degeneracies at the edge of the Brillouin zone if the photonic crystal has some kind of point group symmetry. Both E-polarization and H-polarization cases have the same degeneracies for a 2-dimensional (2D) photonic crystal. Two theorems are given and proved. These degeneracies can be lifted to create photonic band gaps by changing the transform matrix between the super cell and the smallest unit cell. The existence of the photonic band gaps for many known 2D photonic crystals is explained through the degeneracy analysis.Comment: 19 pages, revtex4, 14 figures, p

Indicators related to BMP performances: operational monitoring propositions Suivi opérationnel des performances des techniques alternatives, quelles mesures ?

RÉSUMÉ Depuis de nombreuses années, les techniques alternatives se sont multipliées en France comme dans de nombreux pays. Ces techniques offrent des performances très intéressantes du point de vue du traitement des pollutions et sur le plan hydrologique. Cependant, ces techniques permettent également de rendre de nombreux services tout aussi importants : préservation de l'environnement, amélioration du microclimat local, valorisation de l'eau pour la vie urbaine (activités sociales et récréatives), etc. Cette communication cible plus particulièrement les praticiens en proposant une synthèse des performances à évaluer et des indicateurs utilisables pour ces évaluations. L'évaluation des performances doit permettre de suivre dans le temps chaque technique alternative. La communication propose également des protocoles de suivi en fonction des performances à suivre. ABSTRACT This communication proposes a review on performance indicators related to the assessment of Sustainable Urban Drainage Systems (SUDS). The proposed indicators aims practitioners who want to monitor the performance of their technologies. A broad range of indicators related to hydraulic performance, hydrologic performance, economical aspects, others environmental and sanitary, social aspects, lifespan and long-term effectiveness are proposed. Indeed, the performance of sustainable drainage systems should not be limited to pollution and hydrology. Such systems play a broader role within integrated urban water management, providing benefits such as landscape amenity and amelioration of the biodiversity. This communication also proposes the construction of survey terms and data acquisition methods whose goal will be to assess the delivered service. The survey may be used to obtain feedback to assist in improving the design or the management of SUDS

Study of 2 beta-decay of Mo-100 and Se-82 using the NEMO3 detector

After analysis of 5797 h of data from the detector NEMO3, new limits on neutrinoless double beta decay of Mo-100 (T-1/2 > 3.1 x 10(23) y, 90% CL) and Se-82 (T-1/2 > 1.4 x 10(23) y, 90% CL) have been obtained. The corresponding limits on the effective majorana neutrino mass are: 1.4 x 10(22) y (90% CL) for Mo-100 and T-1/2 > 1.2 x 10(22) y (90% CL) for Se-82. Corresponding bounds on the Majoron-neutrino coupling constant are < (0.5-0.9) x 10(- 4) and <(0.7-1.6) x 10(- 4). Two-neutrino 2beta-decay half-lives have been measured with a high accuracy, (T1/2Mo)-Mo-100 = [7.68 +/- 0.02(stat) +/- 0.54(syst)] x 10(18) y and (T1/2Se)-Se-82 = [10.3 +/- 0.3(stat) +/- 0.7(syst)] x 10(19) y. (C) 2004 MAIK "Nauka/Interperiodica"

Possible background reductions in double beta decay experiments

The background induced by radioactive impurities of $^{208}\rm Tl$ and $^{214}\rm Bi$ in the source of the double beta experiment NEMO-3 has been investigated. New methods of data analysis which decrease the background from the above mentioned contamination are identified. The techniques can also be applied to other double beta decay experiments capable of measuring independently the energies of the two electrons.Comment: 15 pages, 13 figures, accepted in the Nuclear Instruments and Methods

Measurement of double beta decay of ¹⁰⁰Mo to excited states in the NEMO 3 experiment

The double beta decay of ¹⁰⁰Mo to the 0_{1}^{+} and 2_{1}^{+} excited states of ¹⁰⁰Ru is studied using the NEMO 3 data. After the analysis of 8024 h of data the half-life for the two-neutrino double beta decay of ¹⁰⁰Mo to the excited 0_{1}^{+} state is measured to be T_{1/2}^{2v} = [5.7_{-0.9}^{+1.3} (stat.) ± 0.8 (syst.)] x 10²⁰ y. The signal-to-background ratio is equal to 3. Information about energy and angular distributions of emitted electrons is also obtained. No evidence for neutrinoless double beta decay to the excited 0_{1}^{+} state has been found. The corresponding half-life limit is T_{1/2}^{0v} (0⁺→0_{1}^{+}) > 8.9 x 10²² y (at 90% C.L.). The search for the double beta decay to the 2_{1}^{+} excited state has allowed the determination of limits on the half-life for the two neutrino mode T_{1/2}^{0v} (0⁺→2_{1}^{+}) > 1.1 x 10²¹ y (at 90% C.L.) and for the neutrinoless mode T_{1/2}^{0v} (0⁺→2_{1}^{+}) > 1.6 x 10²³ y (at 90% C.L.)