Felix Jiri Weinberg. 2 April 1928 — 5 December 2012

Felix Weinberg's teenage years coincided with World War II. He spent much of the war in Nazi concentration camps, starting with Terezin in December 1942, followed by Auschwitz in December 1943, and finally Buchenwald, from which he was liberated on 11 April 1945. He joined Imperial College, London as a research assistant in 1951 and completed his PhD by 1954. He was appointed to a personal chair as professor of combustion physics in 1967, and he stayed at Imperial for his entire career. Weinberg was distinguished for his optical and electrical studies of flames and his pioneering development of innovative combustion methods. He invented a family of powerful optical tools in combustion, using both broad spectrum and laser light sources. His work on electrical diagnostics led to applications of electric fields to control combustion and to improved understanding of ionization and soot formation. He developed novel combustion devices that incorporated distinctive heat exchangers, thereby permitting the ignition and burning of very low calorific fuel–air mixtures. All of these works had a propelling influence on the global evolution of environmentally benign combustion furnaces. His wide-ranging service to academia, industry and scientific societies included visiting scholar appointments at universities around the world, consultancies for petroleum, chemical, aerospace and defence organizations, and active membership on committees and boards of governance for many scientific and professional bodies. He was author, co-author or editor of four books and well over 200 papers in the scientific literature.

Experimental investigations of a remote atmospheric pressure plasma by electrical diagnostics and related effects on polymer composite surfaces

Surface activation of Carbon Fiber Reinforced Polymers (CFRP) using Poly-EtherEtherKetone (PEEK) matrices is required to achieve strong and long-term adherent painting on the composite. Among the different techniques, an industrial atmospheric pressure remote plasma has been used in this work to treat PEEK CFRP surfaces. The characterization of this device by means of electrical diagnostics related to the effect of such post-discharge on the surface modifications is discussed. Firstly, electrical characteristics of the discharge show fairly high currents associated to high voltages which suggest a nonestablished and cold arc. Power consumed by the electrical supply associated to post-discharge length and surface temperatures allowed a better understanding of the industrial device. Secondly, the effects of plasma on surface chemistry and topography are analyzed by water contact angle measurements, X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM). Investigations showed that treated surfaces exhibited better hydrophilicity mainly due to an incorporation of oxygen containing groups (up to 8.4% more) under air plasma whereas an increase of the nanoroughness and specific surface is preponderant under nitrogen plasma. Different hydrophilic capabilities of the surface obtained in air and nitrogen gas plasma highlight a potential optimization of activation performances according to industrial specification.

The Equivalent Circuit Approach for the Electrical Diagnostics of Dielectric Barrier Discharges: The Classical Theory and Recent Developments

Measurements of current and voltage are the basic diagnostics for electrical discharges. However, in the case of dielectric barrier discharges (DBDs), the measured current and voltage waveforms are influenced by the discharge reactor geometry, and thus, interpretation of measured quantities is required to determine the discharge properties. This contribution presents the main stages of the development of electrical diagnostics of DBDs, which are based on lumped electrical elements. The compilation and revision of the contributions to the equivalent circuit approach are targeted to indicate: (1) the interconnection between the stage of development, (2) its applicability, and (3) the current state-of-the-art of this approach.

Analysis of Erosion Resistance of CuC Arcing Contacts Manufactured by Plasma Spraying Technology

Results of the erosion resistance study of the CuC electrodes manufactured by plasma spraying technology are presented. The diagnostics has have been performed by means of high-speed camera technique and optical emission spectroscopy which has been synchronised with electrical diagnostics. After the load material analyses, namely determination of mass loss and analysis of micro sections, have been done. It has been found that the erosion rate depends on conditions applied for the formation of coating layer, which was deposited either in air or in argon plasma. Furthermore, the erosion rate is significantly lower in the case of air plasma spraying.

Off-Line Field Diagnostics for MV and HV Oil-Paper Insulated Cables

<p>Focusing on off-line electrical diagnostics this paper presents a technical approach, including acceptance criteria options, for in-situ field condition assessment of <br />MV paper insulated lead covered (PILC) cable and HV/EHV self-contained fluid-filled (SCFF) cables. The proposed approach consists of a combination of off-line AC Hipot, partial discharge (PD) measurement and frequency domain dielectric spectroscopy. Case studies illustrate the successful practical application of this<br />technical approach for diagnostics and condition assessment, including replacement prioritization or ‘return to service’ decisions on critical cables.</p>

Development and characterization of a multi-electrode cold atmospheric pressure DBD plasma jet aiming plasma application

A novel APP jet was developed and extensively characterized using optical and electrical diagnostics to establish its capability for applications.