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The paraconductivity of a number of c-axis-oriented YBa2Cu3Ox thin films, with a range of c-axis lattice parameters and Tc-values, has been determined as a function of temperature and analysed in terms of the paraconductivity due to direct and indirect fluctuation contributions. We present results on the c-axis coherence length and the phase-relaxation time at 100 K obtained from the fit to the paraconductivity data. The paraconductivity results for optimally doped films were: c-axis coherence length: ξc(0) = 1.25 Å; pair-breaking parameter: δ = 0.05; phase-relaxation time at 100 K: τϕ = 0.066 ps; and two-three-dimensional crossover temperature: T+ = 96.6 K. These values are in good agreement with those from other published work. There was considerable scatter in the coherence length and phase-relaxation time for films with different critical temperatures and oxygen contents. These results were process dependent but appear to be related to the 60 K phase transition in the Tc-x phase diagram.

The design of an ac magnetic induction susceptometer is described and results given for bulk YBCO samples in parallel and perpendicular applied fields and thin film YBCO samples in perpendicular applied fields. The susceptometer employs a double-differential technique designed to accept bulk or thin film samples mounted parallel or perpendicular to the applied field. Theoretical details are given regarding the particular methods used to calculate the complex external and internal susceptibility, flux density and magnetization and the validity of the quadrature detection technique. Performance details of the susceptometer are provided regarding the system sensitivity for frequencies 20, 50 and 100 Hz. Complex susceptibility results are given as a function of applied field magnitude and frequency for the various specimens analysed. The results obtained are compared with Bean plate theory and the critical currents for intergranular and intragranular regions are determined.

The effect of the alcoholic extract of Arbutus andrachne on certain biochemical parameters and the histology of the visceral organs in nonpregnant adult female rats was studied. The lethal dose 50% (LD) 50 was estimated, and three different doses (1/10th , 1/15th and 1/20th ) of the LD 50 extracts were injected intra-peritoneally for 14 consecutive days into three groups of animals (n ¼ 5 in each group), with one group used as a control and injected with distilled water through the same route. Blood was collected after sacrificing the animals and the following biochemical parameters were detected: glutamate pyruvate transaminase (GPT), glutamate oxaloacetate transaminase, alkaline phosphatase, cholesterol, glucose, triglycerides, creatinine and bilirubin. In addition, the total white blood (WBC) and red blood cells (RBC) were estimated in the blood of all groups. The gross and microscopic findings were reported after the collection of specimens from the animals, and processed routinely for standard histological procedures. The results showed an increase in the number of WBC, which indicated a defence response; while the RBC were decreased because of damage in tissues or organs. The gross and the microscopic changes seemed to be dosedependent, as very little or no effects were noticed in the lowest treated group, and more obvious changes were detected in the highest-dose group of animals. In addition, changes were observed in almost all biochemical parameters under investigation, with the exception of creatinine and GPT, which reflect the general effect of the material used on the animal health.

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