Search results for "Modula"
showing 10 items of 1481 documents
NEUROMODULAZIONE DELLA CORTECCIA PREFRONTALE:VERSO UN’APPLICAZIONE CLINICA PER I DISTURBI DEL COMPORTAMENTO ALIMENTARE.
Neuropeptide Y: una overview sugli effetti di neuro- ed immuno-modulazione
2002
Olfactory neurons activity and olfactory perception are modulated by anorectic peptides, insulin and leptin
2010
International audience; Cf. www.achems.org/files/public/BookmarkedAbstractsFINAL.pdf
Modification of a commercial atomic force microscopy for low-noise, high-resolution frequency-modulation imaging in liquid environment.
2011
A key issue for high-resolution frequency-modulation atomic force microscopy imaging in liquids is minimizing the frequency noise, which requires a detailed analysis of the corresponding noise contributions. In this paper, we present a detailed description for modifying a commercial atomic force microscope (Bruker MultiMode V with Nanoscope V controller), aiming at atomic-resolution frequency-modulation imaging in ambient and in liquid environment. Care was taken to maintain the AFMs original stability and ease of operation. The new system builds upon an optimized light source, a new photodiode and an entirely new amplifier. Moreover, we introduce a home-built liquid cell and sample holder …
Non-linear analysis of a modified QPSK Costas loop
2019
A Costas loop is one of the classical phase-locked loop based circuits, which demodulates data and recovers carrier from the input signal. The Costas loop is essentially a nonlinear control system and its nonlinear analysis is a challenging task. In this article for a modified QPSK Costas loop we analyze the hold-in, pull-in and lock-in ranges. New procedure for estimation of the lock-in range is considered and compared with previously known approach. peerReviewed
Critical Exploration of Flexible Delivery
2020
This work-in-progress research article presents an introductory qualitative study on students' perceptions of a flexibly delivered, modular computer science course. Many contemporary approaches to education rely in various ways on flexible delivery of course content. This is often done to capitalize on modern technology and the web, and to put the student ‘in the center.' However, it is becoming manifest that these approaches may challenge both the students and the equity between them, making it important to understand the effects of flexible delivery in terms of the students. In the voice of our students, flexible delivery was seen as a largely positive approach, reducing stress, promoting…
Measurement of nonlinear and chromatic dispersion parameters of optical fibers using modulation instability
2006
International audience; We present a simple method for the measurement of Kerr, second- and third-order dispersion coefficients in optical fibers using power and dispersion dependences of modulation instability near the zero-dispersion wavelength. We also complete the analysis by the accurate determination of the zero-dispersion wavelength of the fiber using the phase-matched four wave mixing process which occurs near this specific wavelength.
Measurement of the soliton number in guiding media through continuum generation.
2020
No general approach is available yet to measure directly the ratio between chromatic dispersion and the nonlinear coefficient, and hence the soliton number for a given optical pulse, in an arbitrary guiding medium. Here we solve this problem using continuum generation. We experimentally demonstrate our method in polarization-maintaining and single-mode fibers with positive and negative chromatic dispersion. Our technique also offers new opportunities to determine the chromatic dispersion of guiding media over a broad spectral range while pumping at a fixed wavelength. (C) 2020 Optical Society of America
Polarisation attraction and incoherent modulation instability in optical fibers
2006
This thesis, entitled « Polarisation attraction and incoherent modulation instability in optical fibers », presents a theoretical and experimental study of two new processes from the nonlinear optic in optical fibers domain. We introduce in the first chapter some theoretical notions useful for the comprehension of this work. Then, we demonstrate in the second chapter that it is possible to generate some modulation instability in optical fibers using a partially coherent optical beam. We highlight and observe the main properties of the phenomenon. We study the polarisation attraction in isotropic fibers process in the third chapter. Our work proves the existence of the phenomenon, and permit…
Even harmonic pulse train generation by cross-polarization-modulation seeded instability in optical fibers
2012
International audience; We show that, by properly adjusting the relative state of polarization of the pump and of a weak modulation, with a frequency such that at least one of its even harmonics falls within the band of modulation instability, one obtains a fully modulated wave at the second or higher even harmonic of the initial modulation. An application of this principle to the generation of a 80-GHz optical pulse train with high extinction ratio from a 40-GHz weakly modulated pump is experimentally demonstrated using a nonzero dispersion shifted fiber in the telecom C band.