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[en] S. paratyphi was exposed to single and fractionated doses of gamma irradiations i.e. 0; 0.15; 0.30; and 0.45 kGy. The fractionated doses were given in various intervals i.e. 0.1 and 3 hours. The doses rate was 0.65 kGy/hour. The optimum growth temperature was 30 celcius centigrade and the concentration of cell suspension to be irradiated was 3 exp.8 cells/ml. It seemed that nutrition and fractionated doses had a synergism action on the resistance of Salmonella. The comparison among interval time of irradiation of 0, 1, and 3 hours at the dose of 0.15 kGy were 83:87:91; at the dose of 0.30 kGy were 72:74:74 and at the dose of 0.45 kGy were 64:67:70. When we compared the interval time of irradiation of 1 and 3 hours the cell resistance was decrease in the cell suspension without nutrition. The comparison among interval time of irradiation of 0, 1, and 3 hours at the dose of 0.15 kGy were 79:82:77; at the dose of 0.30 kGy were 58:65:63 and at the dose of 0.45 kGy were 35:46:43. (author). 11 refs, 5 tabs
[en] It is known that microbes obtained in the rock having sulfur and uranium have the highly ability in extraciting uranium (21-24 %). An experiment was carried out in the leaching process using those microbes and T. ferrooxodans 402 which has the capability in extracting uranium on 28 %. Four combination treatments has been done in this research using ATCC suspension for the medium of microbes as well as the solution for the process. From the data obtained, the extracting ability of microbe for uranium shows no statistical significant difference between treatments. Generally, the combination treatment tends to decrease the capability of uranium extraction which being possessed by the microbe. The highly yield uranium extraction was found on the combination treatment used TP-4/1 with CB-17/3, T.ferrooxidans 10435, or with T. ferrooxidans 402, while other treatment only gave yield around 6 to 10 % uranium. (authors). 11 refs, 2 figs, 4 tabs
[en] Molecular plating is a widely used technique for the preparation of lanthanide and actinide targets. We have studied the growth and surface morphology of uranium films during the molecular plating process using atomic force microscopy, scanning electron microscopy, Raman and IR spectroscopy and X-ray fluorescence. During deposition of U films on 10 μm Al backings by molecular plating, the RMS roughness increased from 17 to 446 nm for deposition times up to 45 min and then decreased to 223 nm for deposition times of 120 min, which gave the smoothest films with a fractal dimension of 2.10.
[en] The atomic force microscopy (AFM) has been used to study the microstructure damage of thin aluminum film surfaces induced by bombardment of alpha particles and fission fragments from 252Cf source. Different types of defects (dislocations lines, loops, voids, and blisters) and their complex morphologies appeared under both the beam of alpha particles and a mix of alpha particles and fission fragments. The first surface damage became clearly visible only after 250 hr irradiation of a mix of alpha particles and fission fragments (8.65 x 108 ff/cm2 and 1.36 x 1010 α/cm2). The number of voids and dislocation lines created on the aluminum surface were (3.8 ± 0.8) x 107 cm-2 and (2.1 ± 0.8) x 106 cm-2, respectively. Single blisters were observed with the mean diameter of (933 ± 22) nm and the mean height of (102 ± 15) nm. The first ellipsoidal dislocation loops appeared at the fluence of (1.03 x 109 ff/cm2 and 1.62 x 1010 α/cm2). However, these ellipsoidal loops were not seen with low energetic alpha particles at the same fluence. Our results suggest that the fission fragments might maximize large voids and dislocations and increase the degradation in depth resolution. (authors)
[en] A stack of titanium foils was irradiated with 136 MeV 136Xe to study microstructure damage and phase stability of titanium upon irradiation. X-ray diffraction, scanning electron microscopy/energy dispersive spectroscopy and atomic force microscopy were used to study the resulting microstructure damage and phase stability of titanium. We observed the phase transformation of polycrystalline titanium from alpha-Ti (hexagonally closed packed (hcp)) to face centered cubic (fcc) after irradiation with 2.2 × 1015 ions/cm2. Irradiation of Ti with 1.8 × 1014–2.2 × 1015 ions/cm2 resulted in the formation of voids, hillocks, dislocation loops, dislocation lines, as well as polygonal ridge networks
[en] Radiation damage caused by fission fragments to metal surfaces is an important research topic. Thin titanium foils were irradiated with a continuous wave beam of 132 MeV 132Xe+29 at the current intensity of 2 pnA. Pre- and post-irradiated surface topologies were investigated using atomic force microscopy and the observed defects were quantified by root mean square roughness, depth profile of the disordered zones, size and areal density of the voids, and discussed as a function of the applied fluencies (1–9) × 1013 Xe/cm2. The first ellipsoidal dislocation loops appeared at the fluence of 3.0 × 1013 Xe/cm2 with the areal density of 1.56 × 106/cm2 that increased to 2.0 × 107 cm−2 when the dose rose to 9.0 × 1013 Xe/cm2. At this point also the first dislocation lines with the density of 1.3 × 107 cm−2 were seen. Our results suggest that the fission fragments might maximize large voids and dislocations and increase the degradation in depth resolution.