Bisensors for amino acids

Two kinds of biosensors for amino acids (one with nonspecific enzyme as bioelement, the other with specific enzyme(s) as bioelement), including their principles, applications, recent researches and future trends were discussed in detail. 61 references were given. A part of work for gaining Ph. D in chemical and biochemical application at FPMs (Mons, Belgique) Synopsis of the first author Xia Jinlan, Male, born in 1963, now at Facult’e Polytechnique de Mons, Belgique     

Measuring probe for fast transients monitoring in gas insulatedsubstation

This paper describes the construction of four probes adjusted for fast transient monitoring in 123 kV SF₆ insulated substations. The primary requirement was the ability to monitor without distortion very fast transients containing frequencies up to 200 MHz. The measuring system was tested and calibrated with the help of computer modeling techniques. The verified experimental apparatus was then used for testing and calibrating the measuring probes. During the test, various effects on the measuring system characteristics were analyzed with respect to materials used for the components of the system     

Low-dimensional modelling of dynamics via computer algebra

I describe a method, particularly suitable to implementation by computer algebra, for the derivation of low-dimensional models of dynamical systems. The method is systematic and is based upon centre manifold theory. Computer code for the algorithm is relatively simple, robust and flexible. The method is applied to two examples: one a straightforward pitchwork bifurcation, and one being the dynamics of thin fluid films.     

Novel miniature integrated optical goniometers

A new principle and arrangement for directly determining the angle of incidence of an optical beam on an object are proposed and demonstrated. The novelty of the approach lies in the realization of a ‘smart object’, which extracts a portion of the incident beam's power into an optical waveguide attached to the object's surface or embedded in its body for converting the angle of incidence into the position of a guided beam with finite lateral extent. This ‘integrated optical light pointer’ beam is accomplished by means of creating additional degrees of freedom on the target in two different ways. While a first type is based on introducing spatial variations of the waveguide thickness, a second type makes use of a chirp of the grating periodicity. The feasibility for practical applications has been experimentally demonstrated by a direct comparison with a commercial high-resolution encoder, resulting in an r.m.s. error of <30′'. Measurements have been performed for chips fabricated based on replicated polycarbonate substrates and with no external optics, showing the great potential of this approach for realizing low-cost yet high-performance miniature goniometers.     

Computer interface design: A user-centered approach

Enhancing the way people use computers to perform tasks has become a very important issue in interface design and human-computer interactions. When the concept of human-computer interaction first began to emerge it was commonly understood as the hardware and software through which a human and computer could effectively communicate (Laurel, 1990). This effective communication is also know as user-friendliness. The concept of user friendliness has recently been expanded to include various attributes and cognitive aspects of the user's needs and experiences. Focus should be on the user's experiences, expectations, preferences, and cognitive aspects in developing efficient and effective computer interface designs. It is the basic premise of this paper to emphasize using a user-centered design in developing computer interfaces.     

Transient behavior of subthreshold characteristics of fullydepleted SOI MOSFETs

It has been found that the subthreshold currents of fully depleted silicon-on-insulator (SOI) MOSFETs show a transient behavior under certain front-gate and back-gate voltage conditions. The cause of this anomaly is explained, and applications for the phenomenon are pointed out. Particularly, a simple way to measure the silicon film thickness is suggested     

A mixed-signal RAM decision-feedback equalizer for disk drives

A mixed-signal RAM decision-feedback equalizer (DFE) that operates at 90 Mb/s is described. In the analog domain, the DFE subtracts intersymbol interference caused by the past four outputs. The equalized signal is fed into a nonuniform flash analog-to-digital converter (ADC) to produce the decision output and error signal used to adapt the RAM contents in the digital domain. With a 5 V supply voltage, the power dissipation is 260 mW during steady-state operation. The active area is 4.5 mm² in a 1 μm CMOS process     

Theoretical analysis of acceleration-induced central nervous systemischemia

The mechanism responsible for the +G(z)-induced loss of consciousness (G-LOC) experienced by fighter pilots is investigated. The nature of a G-LOC episode is described formcases of rapid onset. Evidence suggests that the G-LOC mechanism might be closely related to the mechanism for sleep. A theory of G-LOC that treats it as a protective physiological mechanism is proposed.