Search Results
You are looking at 1 - 4 of 4 items for
- Author or Editor: S. El-Nasr x
- Refine by Access: All Content x
Abstract
Normal motor oil have been analyzed by RNAA using thermal neutrons and single comparator method. The samples were taken from the oil carter of an engine. The concentration of trace elements have been measured as a function of running kilometers by 
-ray spectrometry. The trace elements which have been detected are Na, Mg, Al, Cl, V, Mn, Cu, Cr, Fe, Co, Zn, Br, Sb and Cd.
Abstract
Normal motor-oil was investigated by CPAA method using 12 and 18 MeV proton beams, which were extracted to the air. The samples were taken from the oil carter of a motor after different running times. The change of the amount of certain trace elements was detected with increasing time of use. By using this method the friction wear of the engine material can also be measured.
The influence of stoichiometric ratio on the phase transition of sodium potassium sulphate (NaxK1−x)2SO4 crystals is investigated in the temperature range 300–500 K. The stoichiometric ratiox is chosen to bex=0.2, 0.3, 0.4, 0.8 and 0.9. The study has been carried out by using differential scanning calorimetry, DSC technique. The value of the specific heat,C p, at the transition temperature,T c , increases asx is increased up tox=0.4 and then decreases for higher values ofx. The change in the specific heat, ΔC p, is following a relation of the form ΔC p ΔC p α(T−T c /T c )−α withα = 0.12 which is in a fair agreement with the 3d Ising model. Insertion of Cu2+ ions into the lattice of (NaxK1−x)2SO4 crystals leads to a multiple peak in the temperature dependence ofC p. The results are discussed from thermodynamical point of view.
Abstract
It is demonstrated that combined PIXE and PIGE measurements are suitable for the accurate determination of the elemental concentration of glass samples. Borosilicate glasses used as high voltage insulators in Van de Graaff accelerators and tested for the relevant physical properties have been analyzed. A correlation between concentrations and physical properties has been found, supporting the additivity rule.
