Search results for " fiber"
showing 10 items of 1776 documents
Coupled theoretical and experimental studies for the radiation hardening of silica-based optical fibers
2014
International audience; We applied theoretical and experimental spectroscopy tools to ad hoc silica-based "canonical" samples to characterize the influence of several dopants and of some drawing process parameters on their radiation sensitivities. We present in this paper, the recent advances and results occurring from our coupled approach. On the experimental side, we studied the doping influence on the response of optical fibers and showed that changing the drawing parameters has a negligible influence on the fiber response in the case of specialty fibers. We focus mainly on the ${rm SiE}^prime$ defect that is observed through Electron Paramagnetic Resonance (EPR) measurements in all cano…
Design of dispersion-managed fiber systems for transmitting chirp-free Gaussian pulses
2008
International audience; We present a general method to analytically design a dispersion-managed (DM) fiber system for any desired fiber (dispersion, nonlinearity and losses) and pulse (width and energy) parameters. This analytical design allows one to transmit chirp-free Gaussian pulses (for very long distances) in almost all kinds of DM fiber systems that have appeared so far in the literature, including systems with dispersion map length greater, equal or shorter with respect to the amplification period.
Voltage gradient electrophoresis of nucleic acids on agarose gels.
1993
A very simple method is described which allows the separation of DNA molecules in a wide molecular weight range (from 0.6 to about 30 kb) in the same electrophoresis agarose gel. This is based on the achievement of a voltage gradient through a simple device consisting of a Plexiglas plate placed slantwise with respect to the gel surface plane, submerged in the electrophoretic running buffer. Further applications of our system are also described.
Identification of the cannabinoid receptor type 1 in serotonergic cells of raphe nuclei in mice.
2007
The endocannabinoid system (ECS) possesses neuromodulatory functions by influencing the release of various neurotransmitters, including GABA, noradrenaline, dopamine, glutamate and acetylcholine. Even though there are studies indicating similar interactions between the ECS and the serotonergic system, there are no results showing clear evidence for type 1 cannabinoid receptor (CB1) location on serotonergic neurons. In this study, we show by in situ hybridization that a low but significant fraction of serotonergic neurons in the raphe nuclei of mice contains CB1 mRNA as illustrated by the coexpression with the serotonergic marker gene tryptophane hydroxylase 2, the rate limiting enzyme for t…
Disorder-induced single-mode transmission.
2017
Localized states trap waves propagating in a disordered potential and play a crucial role in Anderson localization, which is the absence of diffusion due to disorder. Some localized states are barely coupled with neighbours because of differences in wavelength or small spatial overlap, thus preventing energy leakage to the surroundings. This is the same degree of isolation found in the homogeneous core of a single-mode optical fibre. Here we show that localized states of a disordered optical fibre are single mode: the transmission channels possess a high degree of resilience to perturbation and invariance with respect to the launch conditions. Our experimental approach allows identification…
Estimation of Purkinje trees from electro-anatomical mapping of the left ventricle using minimal cost geodesics
2015
The electrical activation of the heart is a complex physiological process that is essential for the understanding of several cardiac dysfunctions, such as ventricular tachycardia (VT). Nowadays, patient-specific activation times on ventricular chambers can be estimated from electro-anatomical maps, providing crucial information to clinicians for guiding cardiac radio-frequency ablation treatment. However, some relevant electrical pathways such as those of the Purkinje system are very difficult to interpret from these maps due to sparsity of data and the limited spatial resolution of the system. We present here a novel method to estimate these fast electrical pathways from the local activati…
Similar prediction of total mortality, diabetes incidence and cardiovascular events using relative- and absolute-component Mediterranean diet score: …
2013
Abstract Background and Aim Accumulated evidence supports the effectiveness of Mediterranean-type diets (MeDiet) in reducing mortality and preventing several chronic diseases. Widely used scores to assess adherence to MeDiet are based on specific sample characteristics; alternatively, they might be built according to absolute/normative cut-off points for the consumption of specific food groups (pre-defined servings/day or/week). The aim of this study was to compare sample-specific MeDiet adherence scores (MDS) versus absolute-normative scores (Mediterranean Diet Adherence Screener – MEDAS) on their association with macronutrient intake, total mortality and incidence of chronic diseases. Des…
An in vitro comparison of different adhesive strategies on the micro push-out bond strength of a glass fiber post
2010
Objectives: To evaluate in vitro the push-out bond strengths of a glass fiber post adhesively luted with self-etching resin based and self-adhesive luting cements, as well as modified application procedure of self-adhesive luting cements in combination with single step self-etch adhesives. Materials and methods: Fifty single-rooted human maxillary central incisor teeth were endodontically treated and divided into five groups (n=10). Glass fiber posts (RelyX Fiber Post) were cemented with the following materials: group 1: ED Primer II/Panavia F 2.0 (PAN); group 2: RelyX Unicem (RU); group 3: Maxcem (MC); group 4: Adper Prompt L-Pop (PLP)/RelyX Unicem; group 5: Optibond all-in-one (OB)/Maxcem…
Structural analysis of Gossypium hirsutum fibers grown under greenhouse and hydroponic conditions
2016
Cotton is the one of the world's most important crops. Like any other crop, cotton growth/development and fiber quality is highly dependent on environmental factors. Increasing global weather instability has been negatively impacting its economy. Cotton is a crop that exerts an intensive pressure over natural resources (land and water) and demands an overuse of pesticides. Thus, the search for alternative cotton culture methods that are pesticide-free (biocotton) and enable customized standard fiber quality should be encouraged. Here we describe a culture of Gossypium hirsutum ("Upland" Cotton) utilizing a greenhouse and hydroponics in which the fibers are morphological similar to conventio…
Study of new tellurite glasses in the TeO2-ZnO-La2O3 (TZL) system for the manufacturing of mid-infrared multimaterial optical fibers and specialty op…
2023
This thesis work was carried out using tellurite glasses from the TeO2-ZnO-La2O3 (TZL) ternary diagram for optical fibers manufacturing. The choice to use this system is motivated by the ambition to improve the transmission of optical signals within oxide glasses for which absorption bands related to OH groups are present in the transparency window. A structural study is first carried out on these glasses by Raman spectroscopy in order to understand the influence of the composition on physicochemical properties (especially on optical and thermal properties) but also to estimate the ability of a vitreous matrix to reorganize when subjected to a thermal solicitation such as the preform-to-fib…