[en] A study is made of the overall optimisation of nuclear power systems; the basic criterion employed is the unit cost of electrical power output. The complexity of the problem leads to consideration of formal non-linear constrained optimisation methods and the use of high speed computers. It is shown that, despite the complex nature of nuclear power systems, realistic models can be constructed to represent the systems, that are solvable by the latest numerical optimisation techniques. (author)

[en] Published in summary form only

[en] Published in summary form only

[en] The phase transformation caused by high pressure torsion (HPT) of a cold rolled AISI 304L stainless steel was investigated. After cold rolling the steel has a microstructure of martensite α' (bcc) with a magnetization saturation of 136.0 A m^-2 kg^-1. The HPT processing with pressures of 2 and 5 GPa promoted the α' (bcc)→ε (hcp) partial transformation, as observed by X-ray diffraction. The magnetization saturation decreased by the increase of true deformation by HPT, which is in agreement to the α' decrease

[en] Published in summary form only

[en] The present work shows results on the surface effects produced by electrolytic hydrogenation and desorption of Ni-Pd alloys (60Ni-40Pd and 40Ni-60Pd, wt.%). The behaviour of these two alloys is rather similar to that of pure nickel rather than pure palladium. Intergranular and transgranular cracks were observed just after the electrolytic charging. During the natural aging the cracks become larger and propagate, as observed by scanning electron microscopy. The hydride phases formed are very unstable at room temperature and normal pressure. X-ray diffractograms were used to obtain a microstrain and microstress analysis of the NiPd solid solution and hydride phases. Magnetization curves of the Ni60-40Pd show that trapped hydrogen atoms remain in the NiPd phase after hydride decomposition and decrease the magnetization saturation and the magnetic permeability

[en] A computing program using Monte Carlo method for calculate the whole efficiency of distributed radiation counters in human body is developed. A simulater of human proportions was used, of which was filled with a known and uniform solution containing a quantity of radioisopes. The ^99mTc, ¹³¹I and ⁴²K were used in this experience, and theirs activities compared by a liquid scintillator. (C.G.C.)

[en] Magnetic properties of the Fe-20Mo-5Ni-xC (wt%, x varying from 0.016 to 0.14) alloys were studied after hot rolling, solution treatment, water quenching and magnetic aging at two different temperatures. Coercive force and maximum energetic product as high as 450 Oe and 1.8 MGOe, respectively, were obtained

[en] A duplex stainless steel was aged at 475 deg. C for different times up to 500 h. The thermal embrittlement was investigated by thermomagnetic analysis using a vibrating sample magnetometer and a thermomagnetic balance. The results obtained with the two equipment were similar and show that the Curie temperature increases with the ageing time. Relationships between T_c and mechanical properties (hardness and toughness) were proposed

[en] Copper rich compounds with YBaCu₁₂O₁₅ stoichiometry were synthesized at 900 deg. C under oxygen rich atmosphere and annealed at 350 deg. C in oxygen flow during 1, 3 and 60 days. Results of AC magnetic susceptibility, thermomagnetic analysis and electron paramagnetic resonance spectroscopy indicate multiphase materials containing the phases YBaCu-123 and YBaCu-247. Critical temperatures were determined by AC magnetic susceptibility and confirmed by EPR measurements