The modelling of equilibrium data for the liquid-liquid extraction of metals : Part II. Models for the copper/LIX 64N and chromate/Aliquat 336 systems

The equilibrium data for two examples of metal extraction are considered. The copper/LIX 64N system is an important one in that category involving the solvent extraction of acid leach liquors. In the case of alkali leach liquors the chromate/Aliquat 336 system provides the example. The data for each of these systems have been tested against various models. For the copper/LIX 64N system it has been shown that a polynomial gives the best fit, a modified chemical model is however only slightly worse. In the case of the chromate/Aliquat 336 system the chemical model is better than the polynomial.Parameters are reported for the best fits to each of the models tested and a computer display of a copper/LIX 64N surface is given.     

Excess-noise and receiver sensitivity measurements of In0.53Ga0.47As/InP avalanche photodiodes

We report the results of excess-noise and normalised receiver sensitivity measurements for In0.53Ga0.47As/InP avalanche photodiodes for use in the ?=0.95 ?m to 1.65 ?m spectral region. The excess-noise measurements are consistent with a hole-to-electron ionisation rate ratio in InP of ~ 0.4. The receiver sensitivity, measured at 45 Mbit/s and 10?9 bit-error-rate, was ?53.2 dBm at a gain of 20 assuming unity quantum efficiency for the detector. This sensitivity is the highest reported at ?=1.3 ?m and represents an improvement over a PIN detector using the same amplifier.     

Morphological effects in rats following a 22-day space flight

A morphological examination of 27 rats flown onboard the biosatellite and sacrificed on the 1st-2nd and 26-27th postflight days demonstrated no significant changes in the structural organization of the vital organs and systems of the animal body. It was, however, found that the space exposure induced morphologically detectable changes in the musculo-skeletal system, hemo- and lymphopoiesis, hypothalamic-pituitary-adrenal system and the juxtaglomerular apparatus of the kidneys. The changes were reversible and nonspecific, and could be seen in animals exposed to ground-based hypokinetic and other stress experiments. Postflight the animals developed some reactions that were similar to those in humans. This helps to identify the morphological substrate of certain changes in the human body and to investigate their pathogenesis.     

Peer acceptance and school-related variables in an integrated junior high school.

Interracial peer acceptance at the junior high school level was related to 9 predictor variables: grade point average (GPA), IQ, attendance, self-concept of academic ability, sex, race, age, years in the school, and classroom racial composition. 322 7th- and 8th-grade students from predominantly lower-middle-class backgrounds were administered modified Syracuse Scales of Human Relations, measuring academic and social acceptance. Analysis of variance results show that White Ss slightly preferred Whites for the satisfaction of their academic and social needs. However, with stepwise multiple regression analysis, race was not a significant predictor variable for academic or social acceptance by White Ss. GPA and sex were the most prominent predictors of acceptance. Black Ss accepted both Black peers and White peers equally for academic interaction but preferred Blacks for social interaction. Race was a significant predictor variable for academic and social acceptance by Black Ss. However, race was secondary to GPA and/or sex for academic acceptance by Black females and Black males. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Digital correlation for noise radar systems

A recently developed radar system using a c.w. microwave noise spectrum from an impatt oscillator as the transmitted signal has shown useful performance. The application of a digital correlator to measure, essentially in real time, the autocorrelation function of the noise spectrum and provide a radar display of targets at ranges of up to at least 1 km is now described.