Phase Relations and Properties of Phases in the TlInSe2–TlPrSe2 System

The phase diagram of the TlInSe₂–TlPrSe₂ system was mapped out using differential thermal analysis and x-ray diffraction data. The system was found to contain a partial solid-solution series (0–10 mol % TlPrSe₂) and a quaternary compound of composition Tl₂InPrSe₄. The electrical conductivity, Hall coefficient, and thermoelectric power of TlPrSe₂ and Tl₂InPrSe₄ were measured in the temperature range 300–1100 K. The charge carriers in these compounds were shown to be scattered mainly by longitudinal acoustic phonons.     

The effect of welded boundaries on the response of rectangular hot-rolled mild steel plates subjected to localised blast loading

A series of experiments examining the effects of welded boundaries on the localised blast load response of mild steel plates is presented in this short communication. Two types of welding are examined, TIG and MIG welding. The welded boundary response is compared with clamped boundary and straight and chamfer machined boundary responses. The overall trend of midpoint deflection–thickness ratio versus dimensionless damage number for all the plates follows previously reported empirical trends. The tearing threshold (Mode II*) in terms of the damage number is lowest for the machined plates followed by the welded plates with the clamped plates having the highest resistance to tearing.     

Caffeine attenuates CNS oxygen toxicity in rats

We tested the effect of caffeine, on hyperoxia-induced seizures. Thirty-seven rats with chronic cortical electrodes were injected i.p. with caffeine (1.25, 2.5, and 10 mg/kg) or vehicle before exposure to 0.5 MPa oxygen and 17 rats to oxygen with 5% CO2 at 0.5 MPa. EEG monitoring and spectral analysis of EEG activity were carried out. Caffeine significantly prolonged the latent period to the onset of seizures (P < 0.05 in ANOVA), in a dose-related manner. Our results suggest that caffeine may be used in low doses for protection against hyperoxia-induced seizures.     

AN improved method of optimization for electrical machines

Methods of optimizing the design of electrical machines are discussed. The augmented Lagrangian multiplier method is described, and an algorithm for this method is introduced. The method is compared with the more familiar exterior penalty function method using, as an example, the cost optimization of permanent magnetic variable-speed drive motors. The improved method is shown to be superior, both in its ability to reach an optimum consistently and in the number of required iterations     

Adjuvant chemotherapy in early breast cancer: optimal and suboptimal anthracycline-containing regimens

We hypothesized that the advantage of adjuvant anthracycline-containing regimens over the conventional CMF combination found by the Early Breast Cancer Trialists' Collaborative Group overview may depend on the 'additive' or 'substitutive' nature of the administration of anthracycline in the experimental arm. The aim of this study was to explore this hypothesis. By means of computerized and hand searches, we identified 21 published randomized trials comparing early breast cancer adjuvant chemotherapies with and without anthracycline, and divided them into those in which the use of anthracycline was substantially 'additive' or substantially 'substitutive'. The trial results were then judged 'positive' or 'negative' depending on whether they showed statistically significant differences in disease-free or overall survival in favor of the anthracycline-containing regimen. Anthracycline was substantially 'additive' in 14 trials, eight of which were 'positive', and substantially 'substitutive' in seven, all of which were 'negative': this difference is statistically significant (P = 0.018). In conclusion this trial classification, an attempt to test a very simple unifying concept with the aim of explaining the different results of trials involving the administration of anthracyclines in the adjuvant setting of early breast cancer, significantly correlated with patient outcome. It therefore seems that anthracycline-containing chemotherapeutic regimens can be considered optimal or suboptimal depending on whether or not they reflect the potential benefit offered by anthracycline administration.     

An over 2200-km coherent transmission experiment at 2.5 Gb/s usingerbium-doped-fiber in-line amplifiers

A 2223 km transmission distance was achieved with a 2.5-Gb/s heterodyne detection system that used erbium-doped-fiber in-line amplifiers and dispersion-shifted single-mode fibers. Twenty-five amplifiers, placed at approximately 80-km intervals, offered a total gain of more than 440 dB. Receiver sensitivity was -42.0 dBm, with only a 4.2-dB penalty from the initial sensitivity achieved by the back-to-back configuration