[en] Manet steel is one of the martensitic I 2%Cr-I%Mo-v steels family. These steels are used extensively in highly thermally stressed components, such as superheater tubing and main steam pipe systems in power stations, due to their adequate strength at high temperatures. In the present work the effect of ageing at 550 degree C for 1000 h on the impact properties of manet II steel was investigated. Two different Charpy V-notch impact specimens were used: full-size and sub size ones. Tests were carried out on two instrumental impact machines appropriate for the two specimen sizes. Both microstructure and fracture surface were examined using optical and scanning electron microscopy (SEM). The results showed that ageing produced little embrittling effect on MANET II steel. Both the ductile-to-brittle transition temperature (DBTT) and the brittleness transition temperature (T_D) were increased by bout 15 degree C. The local fracture stress was also slightly reduced due to the ageing treatment. The results were discussed in the light of the chemical composition and the fracture surface morphology. 12 figs., 3 tabs

[en] This work deals with the application of the proposed method for U extraction from the primary ore of El-Atshan locality, Eastern Desert, Egypt. This ore shows the presence of two U mineralization stages. The late stage carry some 85% of the U present in the ore (represented by coffinite and pitchblende). The early U stage is represented by a graphitic Nb - Ti - Zr - U refractory mineral representing some 15% of U in the ore. Study of relevant extraction factors revealed that about 87% as the maximum extraction of U was attained. Failure to attain 100% U extraction could be explained as due to locking of the undissolved amount in the refractory mineral. To recover U from the obtained pregnant leach liquors, the technique followed in the previous study is herein applied. This involved the precipitation of NH₄(UO₂ SaL₃)4 H₂O by adjusting the pregnant leach liquor by ammonia to ph 5-6.5 after its concentration by its recycle for uranium extraction from new ore batches. The precipitated ammonium uranyl tri salicylate is calcined at 500 degree for obtaining pure orange-yellow trioxide (UO₃) powder

[en] A solid state nuclear track detector Cr-39 has been used for measuring the radon concentration in the soil air and indoor concentration. The bulk etch rate, C_B of Cr-39 has been measured in various concentrations of NaOH in the range (6-8 mole) at temperature 70 degree C. In addition, the track etch rate, V_T, and the ratio V = V_T/V_B, of alpha particles emitted from radon gas exists in nature have been measured in a similar range of etching conditions. This study shows that 8 M NaOH at 70 degree C represent the optimum etching conditions for Cr-39, with the range of the present study. The equilibrium factor and gamma-dose equivalent were calculated by using the track densities of open and filtered solid state nuclear track detectors

[en] As the next logical step in the evolution of programmable devices, Field programmable interconnect components (FPIC) bring the benefits of programmability to the system-level by enabling totally ^programmable hardware^. Continuing what was started by programmable memories twenty years ago and then enhanced by programmable logic ten years later, programmable interconnect holds the key to complete system programmability. History has shown that flexibility is the key benefit realized by programmable technologies (see figure 1). Initially used in a lab environment for design verification purposes, programmable technologies enhance development and ease of experimentation. As experience by more users is accumulated, performances improves and component prices are reduced, applications rapidly expand to address highly flexible and quickly implemented final manufactured products. With similar attributes of it's programmable predecessors, FPIC technology provides an attractive solution to the design verification problems of today and the manufacturing challenges of tomorrow

[en] The radiometric dating of the peralkaline volcanics of the greater wadi El-Kareim area gave an average Rb-Sr isochron age of 290+-15 m.Y. This includes the age of El Atshan volcanics known for their radioactive mineralization. A minor group of dykes and sills at wadi Kareim gave an isochron age of 74+-12 m.y. Two episodes of igneous activity seem thus to have accurred in this area, an earlier and major one at the late Carboniferous Early permian and a minor pulse at the Late Cretaceous-Early Tertiary time

[en] Effects of gamma irradiation from Co⁶⁰ on larval and pupal stages of the saw-toothed grain beetle. Oryzaephilus surinamensis L. were determined. Larval and pupal sensitivity depended on age at treatment, the older the larvae or pupae, the less susceptible. No adults emerged in the 10- to 12-day larvae and 4-day old pupae when irradiated at 10 and 100 Krad. respectively. Irradiation of larvae and pupae especially at high doses, resulted in reduced percent adult emergence in incomplete emergence, and in structural deformities. The percentage sterility for both sexes at each dosage used were determined. Males and females irradiated asl-d and 4-d-old pupae, then mated with normal unmated adults of the opposite sex laid infertile eggs when irradiated at 12 Krad. Adult mortality from irradiated pupae (1- or 4-d-old) was increased with the increase of the dose

[en] The basis of the unitary scheme model is used to calculate energy spectra and charge nuclear radius of ⁶Li. Central-interparticle interaction with a Gaussian radial dependence is used in the calculation. The inclusion of high configurations corresponding to number of quanta of excitation N=4 with ground configuration N=2 has been considered. Good fitting for the low-lying levels of ⁶Li with experiment is obtained except for the level (2⁺,1)

[en] Excitation functions for elastic scattering of protons on Sr⁸⁸ target has been measured in the energy region of the opening of the neutronanalogue (10.0-12.4 MeV). An anomaly is observed at the (p,n) threshold in the energy averaged excitation function at theta=150. The anomaly is analyzed in terms of lane model for threshold phenomena

[en] The effect of low-temeprature (less than or equal to 100⁰C) fast neutron irradiation on the room-temperature tensile and hardness properties of zirconium-2.5 wt.%Nb alloy was investigated up to a fluence of 1.43 x 10²⁰ n.cm^-2 (E greater than or equal to 1 MeV). Considerable irradiation hardening and loss of ductility were observed. Below saturation fluence of 6.3 x 10²⁰ n.cm^-2 (E greater than or equal to 1 MeV) the irradiation induced change in yield strength Δ delta was found to be proportional to (0t)1/2 in agreement with Seeger's dispersed barrier hardening model. It was concluded that this model is obeyed when irradiation and material conditions lead to the formation of small defect clusters. Inverse exponential relationship was found to describe irradiation hardening in the entire fluence range used. The relation between irradiation induced change in Vicker's hardness, Δ Hv, and yield strength Δ delta, for several zirconium alloys was described by: Δ Hv = 2.2 Δ delta. The irradiation hardening behaviour of zirconium-2.5 wt.%Nb was compared to that of zircaloy-2 and related to irradiation induced defect configuration

[en] Fertilized eggs of Gallus domesticus have been exposed before incubation at different levels of gamma radiation: 660 r., 910 r., 1040 r., and 1170 r. The dose levels 1040 r. and 1170 r. have been found lethal. The dose 910 r. has been found inhibitory on the development of embryos in 85.7% of the treated eggs. The dose level 660 r. has caused 50% mortality of the embryos of the treated eggs. The commonest deformity resulting from the two dose levels 910 r. and 660 r. has been shown in the legs (paralysis, twisting of tarsometatarsus and reduction of fingers). Other anomalies have been shown as unsymmetrical wings, twisted trunk, compressed neck and depressed head. The results have been discussed in view of the relevant literature in the field of radiobiology