Search results for "formation [jet]"
showing 10 items of 6317 documents
Investigation of Coating Impact on OFDR Optical Remote Fiber-Based Sensors Performances for Their Integration in High Temperature and Radiation Envir…
2016
The response of optical frequency-domain reflectometry-based temperature sensors is here investigated in harsh environments (high temperature, high radiation dose) focusing the attention on the impact of the fiber coating on the sensor performances in such conditions. Our results demonstrate that the various coating types evolve differently under thermal treatment and/or radiations, resulting in a small (<5%) change in the temperature coefficient of the sensor. The identified procedure, consisting of a prethermal treatment of the fiber at its maximum coating operating temperature, is here verified up to 150 °C for higherature acrylate and up to 300 °C for polyamide coating. This method allo…
A universal optical all-fiber omnipolarizer
2012
International audience; Wherever the polarization properties of a light beam are of concern, polarizers and polarizing beamsplitters (PBS) are indispensable devices in linear-, nonlinear- and quantum-optical schemes. By the very nature of their operation principle, transformation of incoming unpolarized or partially polarized beams through these devices introduces large intensity variations in the fully polarized outcoming beam(s). Such intensity fluctuations are often detrimental, particularly when light is post-processed by nonlinear crystals or other polarization-sensitive optic elements. Here we demonstrate the unexpected capability of light to self-organize its own state-of-polarizatio…
Simultaneous polarization attraction and Raman amplification of a light beam in optical fibers
2012
International audience; In this paper, we demonstrate that it is possible to combine both Raman amplification and polarization attraction of a signal wave in a single optical fiber by means of a counterpropagating scheme. Experiments were performed near 1550 nm in a continuous wave regime and by means of a 10 Gbit ∕ s return-to-zero signal injected in a 20 kmlong low polarization mode dispersion optical fiber. Complete repolarization and 6.7 dB amplification of the signal wave was achieved by injecting a 850 mW, 1480 nm counterpropagating polarized pump wave.
Near‐IR Radiation‐Induced Attenuation of Aluminosilicate Optical Fibers
2021
The X-ray radiation-induced attenuation (RIA) growth kinetics are studied online in different single-mode aluminosilicate optical fibers in the near-IR (NIR) domain to evaluate their potential in terms of dosimetry. The optical fibers differ by Al contents, core sizes, drawing parameters, and also by a preform deposition process. The data show no dependence of the RIA on all these parameters, a positive result for the design of point or distributed radiation detectors exploiting RIA to monitor the dose. The RIA growth rate is unchanged for dose rates changing from 0.073 to 6.25 Gy(SiO2) s−1, and the RIA linearly increases with the dose up to 2 kGy(SiO2). Small but noticeable RIA changes are…
Surrogate-assisted multicriteria optimization: Complexities, prospective solutions, and business case
2017
Complexity in solving real-world multicriteria optimization problems often stems from the fact that complex, expensive, and/or time-consuming simulation tools or physical experiments are used to evaluate solutions to a problem. In such settings, it is common to use efficient computational models, often known as surrogates or metamodels, to approximate the outcome (objective or constraint function value) of a simulation or physical experiment. The presence of multiple objective functions poses an additional layer of complexity for surrogate-assisted optimization. For example, complexities may relate to the appropriate selection of metamodels for the individual objective functions, extensive …
An Oral History of Programming Practices: Gender and Age Dynamics and Digital (Dis)Engagement Among Computer Programmers in Finland
2015
Since the 1980s, educational policies in many countries have aimed at improving the computer literacy and programming competencies of the population. Over the same period, the possibilities that people have seen regarding programming and everyday programming practices have emerged as an area of strong interest within historical scholarship. The paper contributes to these discussions by drawing on techniques of oral history to focus on programming hobbies and practices in Finland. Examining data from a massive survey of computer hobbyists (N = 1,453) and their recollections about personal computer use (largely during the 1980s), the paper gathers new information on what leads to people’s pur…
ORAL EXPRESSIVE COMPETENCE’S DEVELOPMENT BY USE OF MINDTOOLS
2015
The aim of this work is to verify the efficacy of a training programme focused on the enhancement of oral expressiveness (the generation of ideas and planning, pragmatic awareness), realized with a group of children between 10 and 12 years, in the last year of primary school and in the first year of secondary school in the Palermo area. The educational activities were conducted from January to June 2014. Action learning provided a learning environment based on real problem solving with team work; the active search for information, discussion and reflection, as well as decision-making, were assisted by semantic networks (concept maps) and knowledge construction tools. Oral presentation, or p…
Expectations and Experiences of Implementing a Mobile Secure Communication Application
2020
The privacy and security of communication in corporations and governmental organizations has increased enormously over the years. At the same time, a growing amount of technological solutions to support this have emerged. This study examines user expectations before and use experiences during the implementation phase of a mobile secure communication application. These are investigated from the expectation–confirmation perspective and its influence on continued adoption. The study has an exploratory approach for this investigation. To guide the investigation, the study draws from the expectation–confirmation theory (ECT) and the unified theory of acceptance and use of technology (UTAUT). Emp…
Towards Measuring the Agility of Software Business
2018
Agile development methods have been employed across the software industry. However, it is not always clear if the used methods actually help the software firms in being more agile and if agility has a positive influence in the software firm performance. Studying these questions may turn out impossible since good measurements for assessing the overall agility of software firms do not yet exist. A need is therefore detected to measure the differences in agility between firms and finding the means to evaluate the differences in agility in reliable manner. This article examines how to measure the agility of a software firm and reports initial steps in the process of developing measurement instr…
Multi-marginal entropy-transport with repulsive cost
2020
In this paper we study theoretical properties of the entropy-transport functional with repulsive cost functions. We provide sufficient conditions for the existence of a minimizer in a class of metric spaces and prove the $\Gamma$-convergence of the entropy-transport functional to a multi-marginal optimal transport problem with a repulsive cost. We also prove the entropy-regularized version of the Kantorovich duality.