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.

Etched colloidal LiFePO4 nanoplatelets toward high-rate capable Li-ion battery electrodes.

Abstract: LiFePO4 has been intensively investigated as a cathode material in Li-ion batteries, as it can in principle enable the development of high power electrodes. LiFePO4, on the other hand, is inherently “plagued” by poor electronic and ionic conductivity. While the problems with low electron conductivity are partially solved by carbon coating and further by doping or by downsizing the active particles to nanoscale dimensions, poor ionic conductivity is still an issue. To develop colloidally synthesized LiFePO4 nanocrystals (NCs) optimized for high rate applications, we propose here a surface treatment of the NCs. The particles as delivered from the synthesis have a surface passivated with long chain organic surfactants, and therefore can be dispersed only in aprotic solvents such as chloroform or toluene. Glucose that is commonly used as carbon source for carbon-coating procedure is not soluble in these solvents, but it can be dissolved in water. In order to make the NCs hydrophilic, we treated them with lith...

Book review: Knowledge-Based Systems Analysis and Design-A KADS Developer's Handbook by Stewart W. Tansley and Clive C. Hayball (Prentice Hall 1993)

Abstract: The acronym KADS (Knowledge Analysis and Design Support) has come to stand for a group of methods which can be applied to knowledge-based system development. KADS has become the de facto European standard and is being used with ever increasing frequency in North America as, for example, with the SOAR model [9]. As stated in the preface, the purpose of this book is to provide a full explanation of KADS plus a handbook for the use of KADS' methods. The authors' objective is to convince their target readers (practising computer professionals already well acquainted with the basic concepts of artificial intelligence) to adopt and use KADS. Note that although Prolog is the favored language in Europe, as well as that used by the developers of KADS, it is not used in this book, which simplifies the task of LISP users in applying the methods proposed.

Measurement of switching transients in 735 kV substations and assessment of their severity for transformer insulation

Abstract: An automatic measuring system that digitally records transients generated by EHV-transmission-system switching operations and lightning strokes has been developed. The severity of these transients was assessed by comparing them with test voltages applied to the transformers during acceptance tests. In order to quantify in-service transients with respect to the impulse-test voltages, the frequency spectra of the time-domain records were calculated and expressed as a percentage of the test level. The presence of high-frequency winding oscillations was revealed by simultaneous measurements of the bushing voltage and neutral current. The results of these measurements are presented in the form of a transfer function, which can also be used to detect winding displacements in service. >