Computer telephony architectures: MVIP, H-MVIP, and SCbus

The author discusses the objectives of a computer-telephony integration (CTI) bus for the PC, TDM, network synchronization, digital switching, multichassis connections, MVIP bus technologies, SCbus technology, and CTI client server architectures     

An overview of electric vehicle technology

An overview of the present status and future trends in electric vehicle technology is provided. The emphasis is on the impact of rapid development of electric motors, power electronics, microelectronics, and new materials. Comparisons are made among various electric drive systems and battery systems. The market size of electric vehicles in the coming years and the potential electric vehicle impacts are discussed     

Magnetic markers as a noninvasive tool to monitor gastrointestinaltransit

A novel method to monitor gastrointestinal transit of solid oral dosage forms or nutrients is presented, providing a simultaneous recording of gastrointestinal motility of the traversed section. Based on the measurement of the magnetic field of an ingested magnetized marker, its location is found by fitting a magnetic dipole field to the measured data     

Experimental demonstration of step-like dispersion profiling inoptical fibre for soliton pulse generation and compression

Generation of 100 GHz trains of 500-700 fs pulses using dual-frequency beat conversion in a step-like dispersion profiled fibre is reported. The authors believe that this is the first time the generation and compression of soliton pulses using such a fibre has been demonstrated. The fabrication of such fibre assemblies does not require any special facilities and relies only on conventional optical fibre technology. They believe that the use of profiling the fibre dispersion by fibre segments instead of continuously dispersion-decreasing fibre is not only possible but preferable in many applications     

Performance implications of the thermal-induced frequency drift infast wavelength switched systems with heterodyne detection

The frequency modulation response and tuning dynamics of a two-section DFB laser are determined by carrier and thermal modulation of the active layer refractive index. In response to a step change in the injection current for switching between channels in a wavelength division multiplexed system, the optical frequency changes rapidly due to the carrier effect, and then slowly drifts toward a steady state value due to the thermal effect. For wavelength switched applications with heterodyne detection, the drifting of the optical frequency broadens the spectrum of the IF signal and may impose a limit on the time that the signal remains within the IF passband (residency time). The IF spectral broadening and residency time are investigated theoretically and experimentally. Based upon a minimum mean square error fit between experimental and theoretical FM responses, the dependence of the spectral broadening and residency time on the bias condition of the laser and the optical frequency switching interval is characterized     

Making broadband-ISDN successful

It is argued that the technology needed to support the emerging broadband integrated services digital network technology (B-ISDN) is on the horizon, but the deployment of this technology in the telecommunication plant will not be sufficient to make B-ISDN a commercial success. Two corequisites for ensuring the long-term success of the emerging B-ISDN include stimulating the demand for bandwidth by inventing and promoting new telecommunication applications, and enabling the interconnection or convergence of the emerging high-speed network and the existing cable television infrastructure. The author believes that this is necessary because no alternative seems to offer a workable base for financing the transition to B-ISDN and for reaching the needed economy of scale, and because the intrinsic value of the public network grows combinatorially with the number of subscribers     

Origin of satellite structures of high field epr in Cd1−xMnxTe

The electron paramagnetic resonance (EPR) of Mn²⁺ in Cd_1?x Mn _x Te was examined at low temperatures and high magnetic fields with the Mn concentration ranging fromx=0.01 tox=0.65. A far infrared laser was used as a radiation source. The structure of the resonance is strongly influenced by electromagnetic propagation effects. By variation of the sample thickness it was clearly shown that the satellite structures besides the main EPR peak, formerly explained as originating from transitions in the Mn²⁺ pair energy level scheme, are solely due to interference effects.     

Evaluation of atomic fluorescence, absorption and emission techniques for the determination of mercury

Summary Atomic fluorescence (AFS), absorption (AAS) and emission (AES) systems were evaluated for the determination of inorganic mercury. Identical vapour generation and amalgamation procedures were used to permit direct comparison of the performance of a commercial long-path AAS instrument to laboratory constructed non-dispersive AFS as well as He-MIP based AES instruments. Instrumental noise-limited detection limits (LOD) were 0.94, 2.4, 2.8 pg for AAS, AES and AFS techniques, respectively. Methodological LOD's were found to be blank controlled and similar for all three instruments, viz. 9, 25 and 16 pg for AAS, AFS and AES, respectively. All three systems produced accurate results at the low ng/l concentration, as verified by the analysis of a certified river water reference material (NRCC ORMS-1).