Distributed detection of hydrogen and deuterium diffusion into a single-mode optical fiber with chirped-pulse phase-sensitive optical time-domain reflectometry

For some infrastructures like oil and gas extraction boreholes or radioactive waste repositories, where distributed optical fiber sensors are employed to grant the safety of the facilities, the presence of gas species such as hydrogen or deuterium is one more relevant parameter to monitor. The possibility of employing the same kind of sensors for this purpose is of special interest, reducing the cost by employing a single interrogator, able to measure more than one parameter by simply employing an adequate sensing fiber. To meet this goal, we present here a sensor based on Chirped Pulse Phase sensitive Optical Time Domain Reflectometry, which is able to detect these species while they diffuse into the silica fiber core. Its ability to measure the induced change of its refractive index with a sensitivity around 10 8 has allowed determining hydrogen concentration in the silica core with precision in the order of 10 3 mol/m3 and spatial resolution ~6 m, while also providing an indirect measurement of the solubility of deuterium in a standard telecom-grade optical fiber.Commission of the European Communities JointMinisterio de Economía y CompetitividadMinisterio de Ciencia, Innovación y UniversidadesComunidad de Madri

Smart and sustainable urban logistic applications aided by intelligent techniques

[EN] CO2-free urban logistics is one of the 10 objectives to reach by 2030 as part of transport policy. What technologies can help to accomplish it? In this paper, we discuss the very complex situation that today¿s big and modern cities are facing with a tremendous environment of many urban logistics companies running in the same city. In the majority of cases, there is less or none coordination among them worsening traffic congestions. We believe that intelligent techniques are one of the key approaches that can aid to support smart and sustainable urban logistic applications. There are large open problems in the field of cooperative urban logistics that can greatly improve with the help of artificial intelligence. Some solutions are cited in this paper, but the overall conclusion is that there is still much work to be done.Giret Boggino, AS. (2019). Smart and sustainable urban logistic applications aided by intelligent techniques. Service Oriented Computing and Applications (Online). 13(3):185-186. https://doi.org/10.1007/s11761-019-00271-zS185186133Market reports (2019) Global last mile delivery market size, status and forecast 2019–2025. The Market reports. Report code : 1362721, pp 1–114Xiao Z, Wang JJ, Lenzer J, Sun Y (2017) Understanding the diversity of final delivery solutions for online retailing: a case of Shenzhen, China. In: World conference on transport research—WCTR 2016 Shanghai. Transportation Research Procedia, vol 25, pp 985–998, 2017. 10–15 July 2016Gonzalez-Feliu J, Semet F, Routhier JL (2014) Sustainable urban logistics: concepts, methods and information systems. Springer, BerlinMacharis C, Melo S (2011) City distribution and urban freight transport: multiple perspectives. Edward Elgar Publishing, CheltenhamPagell M, Wu Z (2009) Building a more complete theory of sustainable supply chain management using case studies of 10 exemplars. J Supply Chain Manag 45:37–56Morana J, Gonzalez-Feliu J (2015) A sustainable urban logistics dashboard from the perspective of a group of operational managers. Manag Res Rev 38(10):1068–1085Gunasekaran A, Kobu B (2007) Performance measures and metrics in logistics and supply chain management: a review of recent literature (1995–2004) for research and applications. Int J Prod Res 45:2819–2840Griffis SE, Goldsby TJ, Cooper M, Closs DJ (2007) Aligning logistics performance measures to the information needs of the firm. J Bus Logist 48:35–56Alonso-Mora J, Samaranayake S, Wallar A, Frazzoli E, Rus D (2017) On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment. Proc Natl Acad Sci 114(3):462–467Gentile G, Noekel K (2016) Modeling public transport passenger flows in the era of intelligent transport systems. Springer, BerlinNeirotti P, De Marco A, Cagliano AC, Mangano G, Scorrano F (2014) Current trends in smart city initiatives: some stylised facts. Cities 38:25–36Chatterjee R (2016) Optimizing last mile delivery using public transport with multiagent based control. Master thesis, pp 1–59Skiver RL, Godfrey M (2017) Crowdserving: a last mile delivery method for brickand—mortar retailers. Glob J Bus Res 11(2):67–77Brüning M, Schönewolf W (2011) Freight transport system for urban shipment and delivery. In: IEEE forum on integrated and sustainable transportation systems, Vienna, pp 136–14

Recent advances in radiation-hardened fiber-based technologies for space applications

International audience; In this topical review, the recent progress on radiation-hardened fiber-based technologies is detailed, focusing on examples for space applications. In the first part of the review, we introduce the operational principles of the various fiber-based technologies considered for use in radiation environments: passive optical fibers for data links, diagnostics, active optical fibers for amplifiers and laser sources as well as the different classes of point and distributed fiber sensors: gyroscopes, Bragg gratings, Rayleigh, Raman or Brillouin-based distributed sensors. Second, we describe the state of the art regarding our knowledge of radiation effects on the performance of these devices, from the microscopic effects observed in the amorphous silica glass used to design fiber cores and cladding, to the macroscopic response of fiber-based devices and systems. Third, we present the recent advances regarding the hardening (improvement of the radiation tolerance) of these technologies acting on the material, device or system levels. From the review, the potential of fiber-based technologies for operation in radiation environments is demonstrated and the future challenges to be overcome in the coming years are presented

Radiation resistant single-mode fiber with different coatings for sensing in high dose environments

A radiation resistant single-mode optical fiber has been specifically developed for distributed sensing in harsh environments associated with MGy(SiO2) dose radiation. Different types of coating have been used: acrylate, polyimide, aluminum that allow extending the range of accessible temperatures up to 400°C. Various characterizations were performed: radiation inducted attenuation (offline and online), fiber mechanical strength and coating thermal degradation post irradiation. Safe operation is demonstrated for almost all coating types up to the MGy(SiO2) range of cumulated dose

Investigation of Coating Impact on OFDR Optical Remote Fiber-Based Sensors Performances for Their Integration in High Temperature and Radiation Environments

The response of OFDR-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 environments. 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. We identified a procedure allowing improving the sensor performances in harsh environments. This procedure consists in a pre-thermal treatment of the radiation tolerant fibers at its maximum coating operating temperature. This allows stabilizing the temperature coefficients when the fiber is exposed to the harsh constraints. Finally, we show that radiation does not affect scattering phenomenon, CT coefficients remain identical within 1% fluctuations up to 10 MGy, and that permanent RIA reached values stands for the development of high-spatial resolved distributed temperature for harsh environment associated with high temperature (up to 300 °C) and ionizing radiation up to the MGy dose level

Reading and Writing Practices with a Potential for Transformation: Collaborative Research in School, Hospital, Community and Working-Class Neighborhood Environments

En este escrito desarrollamos el marco conceptual de un proyecto de investigación colaborativa denominado Prácticas de Lectura y Escritura con Potencial (Trans)Formativo, para lo cual explicamos primero la perspectiva que se asumió al inicio del proyecto y sus transformaciones a lo largo de tres años de trabajo exploratorio. A continuación, analizamos cuatro prácticas (trans)formativas, ubicadas en ámbitos diversos de la Ciudad de Buenos Aires. Hemos identificado estas prácticas porque, tomadas en su conjunto, nos permiten: a) mostrar la noción de potencial transformativo cuando se lo piensa ligado a prácticas de lectura y escritura; b) describir y analizar la centralidad que ocupan el leer y el escribir en espacios, organizaciones e institucionalidades muy diferentes entre sí, pero que tienen en común un potencial para interpelar el orden dado y transformarlo, y c) hacer visible cómo estas prácticas fueron apelando a diversos formatos, soportes, disciplinas y lenguajes, y al hacerlo, reconfiguraron el mismo sentido de leer y escribir. En la sección final subrayamos los alcances de nuestro estudio en tanto los análisis de experiencias singulares nos permiten arribar a conclusiones en relación con el potencial transformativo de la lectura y la escritura. Asimismo, dejamos planteadas algunas limitaciones del estudio realizado e interrogantes para desarrollo futuro.In this paper we develop a conceptual framework for a collaborative research project called Literacy Practices and their Potential for Transformation. We first explain our theoretical and methodological approach, describing how we constructed a relevant framework over three years of exploratory work. We then analyze four different experiences currently being conducted in the City of Buenos Aires, Argentina. We have identified this set of practices because, taken together, they allow us to a) show the notion of a potential for transformation when linked to reading and writing practices, b) to describe and analyze the central role of reading and writing in very different spaces, organizations and institutions with a common potential to question the established order and transform it, and c) to make visible how these practices appealed to different formats, supports, disciplines, and languages, and in doing so reshaped the very meaning of reading and writing. We conclude by underscoring the scope of our study insofar as the analysis of specific experiences leads us to insights on the transformational potential of reading and writing practices, and point out some of the limitations of our study and possible lines of further research.Fil: Heras Monner Sans, Ana Ines. Universidad Nacional de San Martin. Escuela de Humanidades. Laboratorio de Investigacion En Ciencias Humanas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Laboratorio de Investigacion En Ciencias Humanas.; ArgentinaFil: Miano, María Amalia. Universidad Nacional de San Martin. Escuela de Humanidades. Laboratorio de Investigacion En Ciencias Humanas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Laboratorio de Investigacion En Ciencias Humanas.; ArgentinaFil: Moyano, Ana Rosa. Universidad Nacional de San Martín; ArgentinaFil: Ferreira, Mariel Lucía. Universidad Nacional de San Martín. Escuela de Humanidades. Centro de Estudios Desigualdades, Sujetos e Instituciones; ArgentinaFil: Soto, Eliana Verónica. Universidad Nacional de San Martín. Escuela de Humanidades. Centro de Estudios Desigualdades, Sujetos e Instituciones; ArgentinaFil: Cárdenas, Horacio. Universidad Nacional de San Martín; ArgentinaFil: Esposito, Silvina Adriana. Universidad Nacional de San Martín; ArgentinaFil: Del Valle Martínez, Judith. Universidad Nacional de San Martín; ArgentinaFil: Mori, María Inés. Universidad Nacional de San Martín; ArgentinaFil: Galli, María Laura. Universidad Nacional de San Martín; ArgentinaFil: Morana, María Victoria. Universidad Nacional de San Martín; ArgentinaFil: Schneider, Ana Patricia. Universidad Nacional de San Martín; Argentin

Coating impact and radiation effects on optical frequency domain reflectometry fiber-based temperature sensors

Temperature response of radiation-tolerant OFDR-based sensors is here investigated, with particular attention on the impact of coating on OFS. By performing consecutive thermal treatments we developed a controlled system to evaluate the performances of our distributed temperature sensor and to estimate the radiation impact. We show an important evolution of the temperature coefficient measurements with thermal treatments for non-irradiated fiber and that the amplitude of this change decreases increasing radiation dose. As final results, we demonstrate that sensor performances are improved if we performed a pre-thermal treatment on the fiber-based system permitting to monitor temperature with an error of 0.05°C

Neutron-induced defects in optical fibers

We present a study on 0.8 MeV neutron-induced defects up to fluences of 1017 n/cm² in fluorine doped opticalfibers by using electron paramagnetic resonance, optical absorption and confocal micro-luminescence techniques. Our results allow to address the microscopic mechanisms leading to the generation of Silica-related point-defects such as E’, H(I), POR and NBOH Center

Radiation Vulnerability of Fiber Bragg Gratings in Harsh Environments

The difficulties encountered in the implementation of a temperature or strain sensor based on fiber Bragg grating (FBG) in a harsh radiative environment are introduced. We present the choices made to select both a radiation-resistant fiber in terms of transmission and also the grating inscription conditions necessary to write radiation tolerant FBGs in such fibers with a femtosecond laser. The radiation response of these gratings was also studied under radiation at dose up to 1 MGy. The comparison between Ge-free and Ge-doped fibers was highlighted

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