Authors:M. R. Seyfi Abad Shapouri, M. Mayahi, K. Assasi and S. Charkhkar
. P. and Britton, P. (1998): Sequence analysis of strains of the 793/B genotype (CR88, 4/91) of IBV isolated between 1985 and 1997. Proceedings of the International Symposium on Infectious Bronchitis and Pneumovirus Infections in Poultry
Absolute thick-target -ray yields have been measured for a great variety of elements using an activation method. The data are used to discuss the possibilities of impurity activation analysis by means of 9.1 MeV proton-induced nuclear reactions. The most favourable absolute yields from nuclear reactions and absolute intensity values of main -lines are listed in the table. The tabulated results allow one to associate the impurity content in the irradiated sample with the intensity of the corresponding peaks in the gamma-ray spectrum, to determine the measurement sensitivity and to choose optimum analysis conditions.
Authors:G. Lewison, A. Fawcett-Jones and C. Kessler
Results are presented of a study covering 1986–91 of the scientific output of Latin American nations. The distribution of the output within the countries is shown: in most countries there is a high concentration in the national capital. The papers co-authored with scientists from other countries are also examined. There has been a notable rise in both the number and proportion of papers co-authored within the region, with the USA and Canada, and, especially, with the countries of the European Community, where a programme of International Scientific Co-operation, to promote just such links, has been active since the mid-1980s in many Latin American countries.
Crystallization kinetics of Al91La5Ni4 amorphous ribbons produced by a melt-spinning method were studied by DSC analysis and X-ray diffraction. The effect of heating
rate (from 4 to 200C min-1) was investigated in the temperature range from 298 to 700 K. Increases the heating rate from 4 to 200C min-1 resulted in increases of the temperature difference between the two stages of the transformation process: crystallization
of Al and crystallization of the Al compounds from 148.9 to 167.4 K. The apparent activation energies for the first step,
related to Al crystallization, and to the second step related to crystallization of Al4La and Al3Ni, were found to be 1619 and 19910 kJ mol-1, respectively. The results indicate the possibility of tailoring the heating treatment to produce the required fraction of
the amorphous phase.
Simultaneous production of carrier free89Zr and90,91m,92mNb through the (, pxn) and (,xn) nuclear reactions has been performed by -particle activation of Y2O3 target. The sequential separation of the produced radioisotopes from the bulk target matrix has been achieved through LLX using TOA as a liquid anion exchanger. Formation of the carrier free radionuclides in the target matrix and their purity in different stages of separation have been verified by -ray spectrometry.
Authors:Žaneta Mesíková, Petra Šulcová and M. Trojan
Synthesis of the green
spinel pigment Co0.46Zn0.55(Ti0.064Cr0.91)2O4 by a novel two-step method of preparation have
been investigated. Inorganic pigments are almost always prepared by a solid
state reaction. It is classical ceramic method which used oxides, hydroxides
or carbonates as precursors. The reaction is performed at temperature higher
than 1300C and an agent of mineralization is usually present. The presented
novel method of preparation decreases the calcining temperature necessary
for reaching of bright and clear hue of the pigments prepared. Main attention
was focused on the influence of two types of titanium raw materials on the
temperature region of the spinel structure formation and on the colour properties
of the pigments. The mixture of precursors with TiO2
gives a one-phase system when calcining at 1100C but the colour properties
are more interesting at 1150C. Thermal stability of this pigment is limited
by temperature 1300C. This temperature is connected with partial oxidation
of Cr(III) to Cr(VI). Thermal analysis provided the first information about
the temperature region of the pigment formation and determined the thermal
stability of pigment.
Authors:Hildrun Kretschmer, Ramesh Kundra, Donald deB. Beaver and Theo Kretschmer
% Participation of men in % Contribution of women, in% Number of female authors in % Naldi et al. 45.8 94.7 19.5 22.2 COLLNET bibliometric 65.3 76 45 47.9 14 Journals of gender studies 91.6 17.3 87.5 85.6 ‐ Naldi et al. ( 2004 )—Science and Technological