Hydro-Québec

About: Hydro-Québec is a government organization based out in Montreal, Quebec, Canada. It is known for research contribution in the topics: Electric power system & Dielectric. The organization has 2596 authors who have published 4433 publications receiving 100878 citations.

Motorized bracelet assembly for moving sensor modules around a pipe

Abstract: A motorized bracelet assembly for ultrasonic crack detection in a pipe. The bracelet has a motorized frame adapted for installation around the pipe and a sliding arrangement slideably mounted onto the frame. The sliding arrangement guides a displacement of sensor modules in periphery of the pipe. A first driving device controllably drives the sliding arrangement and thereby displacing the sensor modules in periphery of the pipe at desired operating positions. The bracelet comprises biasing devices for biasing the sensor modules against the pipe and a second driving device for controllably driving the frame along the axial direction of the pipe at a desired operating position.

Leached nanocrystalline materials process for manufacture of the same, and use thereof in the energetic field

Abstract: Leached nanocrystalline materials having a high specific surface are particularly useful for storing hydrogen or as catalysts or electrocatalysts in the manufacture electrodes, especially for fuel cells. Such materials can be manufactured by preparing a nanocrystalline material consisting of a metastable composite or alloy of at least two different chemical elements. To be nanocrystalline, this material must have a crystalline structure with the grain size lower than 100 nm. Then, the so prepared nanocrystalline material can be subjected to a leaching treatment in order to eliminate partially or totally one of the elements of the composite or alloy. This leaching results in nanocrystalline materials having a porous structure and, thereby, the requested high specific surface.

Particles comprising a non-conducting or semi-conducting core, which are coated with a hybrid conducting layer, production methods thereof and uses of same in electrical devices

Abstract: Particle mixture (I) comprises particles having a nonconducting or semiconducting core and a hybrid conductor coating, the particles being interconnected with hybrid conductor chains to form a network of electrical conductivity. Independent claims are also included for the following: (1) production of (I) by preparing a mixture of a nonconducting or semiconducting material with a conductive material and adding a second conductive material, preparing a mixture of a nonconducting or semiconducting material with at least two conductive materials, or preparing a mixture of conductive material and mixing it with a nonconducting or semiconducting material; (2) battery cathode and anode comprising (I); (3) lithium battery comprising a metallic lithium anode and a cathode comprising (I); (4) hybrid supercapacitor comprising an electrolyte, an anode comprising (I), and a high surface area carbon or graphite cathode.

Design of SFRC structural elements: post-cracking tensile strength measurement

Abstract: Utilisation of steel fibre reinforced concrete (SFRC) for designing structural members requires knowledge of the post-cracking tensile response. This paper reviews the experimental characterisation tests and subsequent analysis commonly used for determining the post-cracking tensile properties of SFRC. The experimental program supporting this investigation comprised five different SFRC mixes with fibre volumes ranging from 0.75 to 1.25% used to fabricate a set of characterisation specimens for uniaxial tension tests, notched beam tests and round panel tests carried out in parallel with an extensive experimental program on large scale beams. Characterisation test results allowed a comparison between direct stress–crack opening measurements and the stress–crack openings retrieved from the inverse analysis of bending tests. Discrepancies in post-cracking tensile results obtained with the three types of tests are analyzed and related mainly to test configurations, the presence of a predefined crack, support conditions, fibre orientation, and cracked surface size. Results obtained using material characterisations are then applied to the reproduction of the structural behaviour of large scale beams, documented in a companion paper.

Implementation of a ROV navigation system using acoustic/Doppler sensors and Kalman filtering

Abstract: Hydro-Que/spl acute/bec developed a new underwater ROV which is use to inspect its dams. Since 2000, the ROV has allowed Hydro-Que/spl acute/bec to save 5M$ in inspection costs. This paper presents the study of a Kalman filter and its performances. Kalman filtering is used to merge data from fiber gyros, DVL, accelerometers and global positioning system in order to have a better estimation of the position and orientation of the ROV. In real systems, sensors do not send data at the same rate and data acquisition is often intermittent. One innovative aspect of this approach is that it accepts asynchronous information and delay from the sensors. Experimental results in a real environment are presented.