A Short duration Industrial Project Scheme

The aims and implementation of a short-duration industrial project program run at the University of Sheffield is discussed. The project is designed for second-year undergraduates studying electronic and electrical engineering and lasts for seven days. Topics covered include the selection of suitable projects, the project briefing, the investigation of a problem, the project presentation, report, and project appraisal. Examples of specific problems that have been tackled are included, and the future of the program is examine

A Short duration Industrial Project Scheme

The aims and implementation of a short-duration industrial project program run at the University of Sheffield is discussed. The project is designed for second-year undergraduates studying electronic and electrical engineering and lasts for seven days. Topics covered include the selection of suitable projects, the project briefing, the investigation of a problem, the project presentation, report, and project appraisal. Examples of specific problems that have been tackled are included, and the future of the program is examine

Library Cartoons: A Literature Review of Library-themed Cartoons, Caricatures, and Comics

To understand differing views of past events, historians, political science scholars, and sociologists have analyzed political and editorial cartoons with themes ranging from elections to fiscal policy to human rights. Yet scant research has been dedicated to cartoons with library themes. The author of this paper examines peer-reviewed literature on the subject of library cartoons, including historical background, analysis of recent themes, and arguments for promoting library-themed cartoons, caricatures, and comics. The author finds a significant gap in the literature on this topic and concludes that information professionals would benefit from a comprehensive content analysis of library-themed cartoons to enhance understanding of the significance of libraries during historic events, assess public perception of libraries, and identify trends over time

Psychrometric chart for physiological research

Chart facilitates use of graphical techniques for solving problems involving thermodynamic properties of moist air. The properties are presented, and their units of measurement are listed. Chart presenting conditions at standard atmosphere pressure at sea level is most useful

A single-layer tuneable microwave absorber using an active FSS

An experimental single-layer active microwave absorber in described. The absorber is a planar structure based upon the topology of a Salisbury screen, but in which the conventional resistive layer is replaced by an active frequency selective surface (FSS) controlled by pin diodes. The resulting structure has superior reflectivity-bandwidth characteristics compared to conventional passive absorbers of corresponding thickness. Measured data are presented and show that the reflectivity response of the absorber can be controlled over the frequency band from 9 to 13 GHz

Measurement of Nonplanar Dielectric Samples Using an Open Resonator

Conventional microwave methods for measuring permittivity often utilize samples in flat sheet form. In practice, however, it is sometimes desirable to measure samples having curved surfaces, for example, parts of lenses or small radomes. This paper describes an open resonator technique for achieving this and compares measurements made at 11.6 GHz on samples of polymethyl methacryIate in both curved and flat sheet form

A smart radar absorber based on the phase-switched screen

Although conventional (i.e., passive) radar absorbers are widely used for modifying the radar cross-section (RCS) of current military platforms, such absorbers may not have adequate performance to satisfy future requirements. Active absorbers, however, offer the potential to overcome the so-called Rozanov performance limit and to enable additional smart functionality such as monitoring damage, adaptive control of RCS or target appearance, identification-friend-or-foe, and absorb-while-scan. This paper outlines the concept and basic properties of a novel type of active radar absorber, the so-called phase-switched screen (PSS). The basic PSS topology is then modified so as to enable it to operate as a smart radar absorber when used together with an external sensor and feedback control loop. System implementation issues and the optimum choice of design parameters for a range of operational scenarios are discussed, and theoretical predictions are supported by measured performance data

Influence of switching-waveform characteristics on the performance of a single-layer-phase switched screen

Conventional microwave-absorbing materials rely on the absorption and conversion into heat, of the electromagnetic energy incident upon them. In an alternative approach, the phase-switched screen (PSS) applies phase modulation to the reflected signal so that the energy is redistributed into sidebands with, ideally, none remaining at the original incident carrier frequency f/sub c/. Hence, by adjusting the frequency and shape of the waveform that controls the PSS reflection coefficient, these sidebands may be positioned outside the pass-band of a receiver tuned to f/sub c/. An investigation has been carried out to determine how the choice of control waveform and switching frequency influence the PSS performanc

The phase-switched screen

Conventional (passive) radar-absorbent materials operate either by phase cancellation or by absorbing incident electromagnetic energy and converting it into heat. This paper examines a new type of active "absorber," called the phase-switched screen (PSS). The PSS operates quite differently from passive absorbers in that it exhibits an apparently low value of reflectivity by redistributing the electromagnetic energy incident upon it over a bandwidth that is wide enough to ensure that little reflected energy falls within the pass-band of the receiver. The discussion considers the basic temporal and spectral properties of several PSS topologies, and includes measured data on both planar and cylindrical PSS structures

FDTD modeling of heatsink RF characteristics for EMC mitigation

Due to their size and complex geometry, large heatsinks such as those used in the power electronics industry may enhance the radiated emissions produced by the circuits employing them. Such enhancement of the radio frequency (rf) radiation could cause the equipment to malfunction or to contravene current EMC regulations. In this paper, the electromagnetic resonant effects of heatsinks are examined using the finite-difference time-domain (FDTD) method and recommendations are made concerning the optimum geometry of heatsinks and the placement of components so as to mitigate potential EMC effects