Search results for "HIF"

Measurement of temperature profile induced by the optical signal in fiber Bragg gratings using whispering-gallery modes.

2014

The temperature sensitivity of whispering-gallery mode resonances of an optical fiber is exploited to measure thermal effects induced by an optical signal of moderate power along a fiber Bragg gating (FBG). The UV inscription technique used for the fabrication of FBG introduces a permanent change in the absorption coefficient of the fiber; thus, thermal effects are expected. The resonance wavelength shift of whispering-gallery modes provides information about the temperature change in the fiber, point to point. We present the experimental characterization of the thermal effects in FBG as a function of the wavelength and the power of the launched optical signal through the grating.

Determination of the position of defects generated within a chirped fiber Bragg grating by analyzing its reflection spectrum and group delay

2016

We determinate the position of defects generated within a chirped fiber Bragg grating by analyzing its reflection spectrum and group delay. Simulations were performed by using the T-matrix method for different defect locations.

Fully automatic simultaneous fiber grating amplitude and group delay characterization

1997

Linearly polarized all-fiber laser using a short section of highly polarizing microstructured fiber

2007

A linearly polarized all-fiber erbium laser is presented in this work. The polarization selective element consists on a piece of a single-mode, polarizing microstructured fiber, which is placed within the laser cavity. The microstructured fiber shows a regular lattice of air-holes, in which four holes next to the core were enlarged. This fiber shows a polarization dependent loss of 16 dB/m around 1550 nm. The laser cavity presents different losses for each polarization and, as a consequence, a highly polarized emission is obtained. The polarization ratio of the emitted power was in excess of 20 dB.

Tunable dispersion device based on a tapered fiber Bragg grating and nonuniform magnetic fields

2003

We present a new variable dispersion device based on tuning the chirp of a tapered fiber Bragg grating by means of a magnetic transducer. By using a nonuniform magnetic field, we demonstrate a 188-472-ps/nm dispersion tuning range, suitable for tunable radio-frequency filters and dispersion compensation, among others.

Chromatic Dispersion Control in Mode-Locked Yb-Doped Fiber Lasers Based on a Microstructured Optical Fiber

2013

We present an experimental study on the use of solid core microstructured optical fibers (MOF) for managing the chromatic dispersion in an Yb-doped fiber laser passively mode-locked by a saturable absorber. The performance of the laser, in terms of pulse width and repetition rate, was investigated as a function of the net cavity dispersion.

Metilgrupu ietekme hifenadīna un sehifenadīna veidotajās sistēmās

2019

Metilgrupu ietekme hifenadīna un sehifenadīna veidotajās sistēmās. Iļjina N., darba vadītājs Dr. chem. Bērziņš, A., konsultans Mg. chem. Kons A. Maģistra darbs, 43 lappuses, 23 attēli, 8 tabulas, 42 literatūras avoti, 6 pielikumi. Latviešu valodā. Darbā apkopota informācija par cietvielu veidotajām formām, to pētīšanas un raksturošanas metodēm - pulvera rentgendifraktometriju, diferenciāli skenējošo kalorimetriju un termogravimetriju, kā arī aprakstītas darba izstrādei izmantotās vielas – hifenadīns un sehifenadīns. Eksperimentālajā daļā veikts cietvielu skrīnings pielietojot metodi, kas paredz paraugu amorfizēšanu, to suspendēšanu no dažādiem organiskajiem šķīdinātājiem un iegūto nogulšņu,…

2014

The taxon Syndermata comprises the biologically interesting wheel animals (“Rotifera”: Bdelloidea + Monogononta + Seisonidea) and thorny-headed worms (Acanthocephala), and is central for testing superordinate phylogenetic hypotheses (Platyzoa, Gnathifera) in the metazoan tree of life. Recent analyses of syndermatan phylogeny suggested paraphyly of Eurotatoria (free-living bdelloids and monogononts) with respect to endoparasitic acanthocephalans. Data of epizoic seisonids, however, were absent, which may have affected the branching order within the syndermatan clade. Moreover, the position of Seisonidea within Syndermata should help in understanding the evolution of acanthocephalan endoparas…

Gibellina, la città che visse due volte : terremoto e ricostruzione nella Valle del Belice

2019

Il passato di Gibellina Nuova non è Gibellina Vecchia. Le storie delle due città sono profondamente diverse: il terremoto del 1968, che colpì con un’intensità del IX grado della scala Mercalli la Valle del Belice, è stato additato come causa della loro soluzione di continuità, ma i veri fattori che hanno determinato una frattura nella continuità storica vanno ricercati nelle politiche di intervento e nelle utopie urbanistiche che hanno orientato la ricostruzione. Il dopo-terremoto del Belice è stato il banco di prova della Prima Repubblica di fronte alle calamità naturali; dal fallimento delle sperimentazioni urbanistiche operate in vivo nel tessuto sociale, dalla dicotomia tra ricostruzion…

Modulation of voltage-gated K(+) channels Kv11 and Kv1 4 by forskolin.

2002

Forskolin (FSK) affects voltage-gated K + (Kv) currents in different cell types, but it is not known which of the various subunits form FSK-sensitive Kv channels. We compared the effect of the compound at Kv1.1 and Kv1.4 channels ectopically expressed in HEK 293 cells. Low FSK concentrations induced a phosphorylation-dependent potentiation of Kv1.1 currents. At higher concentrations, this effect was superimposed by a fast, cAMP-independent channel block. Kv1.4 currents were inhibited with lower potency by FSK but were not modified by phosphorylation. The variable effect of the compound might help to distinguish between Kv subunits expressed by native cells.  2002 Elsevier Science Ltd. All …