Search results for "guide"
showing 10 items of 1478 documents
High-performance V-band Folded Waveguide TWT for satellite communication systems
2021
In this paper, the design of a V-band high-performance folded-waveguide Traveling Wave Tube amplifier for next-generation high data-rate satellite communication systems is presented. The folded waveguide shows a flat dispersion diagram and a high interaction impedance of about 5.95 Ω at the 49 GHz central frequency under a cathode voltage and a beam current of 20.6 kV and 300 mA, respectively. Good performance in terms of output gain with a maximal value of 45 dB at the lower frequency of 47 GHz is obtained. COSMIC 1D large-signal analysis results are in good agreement with the simulated 3D PIC results. The TWT reaching a 5 GHz bandwidth with an almost constant maximum output power of about…
Self-pumped phase conjugation in a BaTiO3:Rh waveguide
2002
We present a self-pumped phase conjugator originated by self-bending of the incident beam at λ = 515 nm in a BaTiO3:Rh waveguide elaborated by three successive He+ ion implantations. Phase conjugate reflectivity reached is 28 %.
Resonant Tunneling in 2D-Waveguides with Several Resonators
2021
In this chapter, we consider a two-dimensional waveguide that coincides with a strip having \(n+1\) narrows of small diameter \(\varepsilon \). All narrows are of the same shape and are spaced from each other by equal distances. Parts of the waveguide between two neighboring narrows play the role of resonators. The wave function of a free electron satisfies the Dirichlet boundary value problem for the Helmholtz equation in the waveguide. Near a simple eigenvalue of the closed resonator there are n resonant peaks of height close to 1. We let \(\varepsilon \rightarrow 0\) and obtain asymptotic formulas for the resonant energies and for the widths of the resonant peaks at their half-height. Th…
Predicting who fails to meet the physical activity guideline in pregnancy: a prospective study of objectively recorded physical activity in a populat…
2016
Background A low physical activity (PA) level in pregnancy is associated with several adverse health outcomes. Early identification of pregnant women at risk of physical inactivity could inform strategies to promote PA, but no studies so far have presented attempts to develop prognostic models for low PA in pregnancy. Based on moderate-to-vigorous intensity PA (MVPA) objectively recorded in mid/late pregnancy, our objectives were to describe MVPA levels and compliance with the PA guideline (≥150 MVPA minutes/week), and to develop a prognostic model for non-compliance with the PA guideline. Methods From a multi-ethnic population-based cohort, we analysed data from 555 women with MVPA recorde…
Management of hand osteoarthritis: from an US evidence-based medicine guideline to a European patient-centric approach.
2022
© Crown 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the per…
Spatial modulation of the electromagnetic energy transfer by excitation of graphene waveguide surface plasmons
2019
We theoretically study the electromagnetic energy transfer between donor and acceptor molecules near a graphene waveguide (WG). The surface plasmons (SPs) supported by the structure provide decay channels which lead to an improvement in the energy transfer rate when the donor and acceptor are localized on the same side or even on opposite sides of the WG. The modification of the energy transfer rate compared to its value in absence of the WG are calculated by deforming the integration path into a suitable path in the complex plane. Our results show that this modification is dramatically enhanced when the symmetric and antisymmetric SPs are excited. Notable effects on the spatial dependence …
IL VICERÉ GARÇIA DE TOLEDO E I CANTIERI REALI. UN LOGGIATO “ALLA GENOVESE” PER PALERMO
2014
The State Archive of Genoa keeps one of the few drawings related to the reconfiguration projects of the Royal Palace of Palermo in modern age. It's a pen drawing, partly in watercolor, depicting partially the front and the pavement of a long open gallery to be realized in the new eastern façade of the palace; the plan is attached to the contract, signed March 14th 1567 in Genoa, where the sculptors Giacomo Guidetti and Antonio Carabio were commissioned to supply all the necessary marbles and floor surfaces to realize the loggia.
Midbiotics: conjugative plasmids for genetic engineering of natural gut flora.
2019
ABSTRACT The possibility to modify gut bacterial flora has become an important goal, and various approaches are used to achieve desirable communities. However, the genetic engineering of existing microbes in the gut, which are already compatible with the rest of the community and host immune system, has not received much attention. Here, we discuss and experimentally evaluate the possibility to use modified and mobilizable CRISPR-Cas9-endocing plasmid as a tool to induce changes in bacterial communities. This plasmid system (briefly midbiotic) is delivered from bacterial vector into target bacteria via conjugation. Compared to, for example, bacteriophage-based applications, the benefits of …
The success (or not) of HUGO nomenclature.
2006
A literature search shows that biologists do not follow the official nomenclature guidelines for a substantial fraction of gene names.
Das schöne Lettland: seine Kurorte und Sommerfrischen
1926
Inhalt: Die Republik Lettland ; Riga : die schöne Hauptstadt Lettlands ; Die baltische Riviera : Ostseebad Riga-Strand ; Am Meeresstrande rechts der Düna : Vecāķis (Wezahken), Neibāde (Neubad), Pabāži (Pabbasch) ; Ostseebad Liepāja (Libau) ; Zwei heilkräftige Kurorte : Staatliches Moor- und Schwefelbad Ķemeri (Kemmern). Staatliches Moor- und Schwefelbad Baldone (Baldohn) ; Die Livländische Schweiz : Sigulda (Segewold), Krimulda (Kremon), Turaida (Treyden) ; Ogre (Oger) ; Eine Herzogsstadt als Sommerresidenz : Jelgava (Mitau) ; Eine schöne Flussfahrt : das Dünathal zwischen Pļaviņas (Stockmannshof) und Koknese (Kokenhusen) ; Wo Kurland am Schönsten ist! : die Kurische Schweiz ; Reiseziele in…