Use of aluminum nitride in melting a V-Al-N master alloy

The possibility to use aluminum nitride as a nitriding agent for out-of-furnace aluminothermic melting of V-Al-N master alloys is studied and tested. It has been found that the replacement of nitrided vanadium by aluminum nitride in a charge for melting does not change the phase composition of the master alloy and the uniformity of the distribution of nitride inclusions in the ingot volume. The nitrogen-containing phase of the V-Al-N master alloy is represented by aluminum nitride. The mean values of the structural parameters of the master alloys melted from charges containing nitrided vanadium or aluminum nitride are identical.     

The Effect of Nitrogen Pressure on the Synthesis of CdS From [Cd(NH2C(S)NHNH2)2](NO3)2 Complex Compound Using Combustion Method

A precursor method of obtaining sulfide materials by combustion of metal nitrate complex compounds with sulfur-containing organic derivatives of hydrazine as ligands has been proposed. A possibility of maintaining morphology and dispersity of the obtained products by changing external pressure at which the combustion is carried out has been demonstrated for the synthesis of cadmium sulfide as an example.     

The role of recombination and RAD52 in mutation of chromosomal DNA transformed into yeast

While transformation is a prominent tool for genetic analysis and genome manipulation in many organisms, transforming DNA has often been found to be unstable relative to established molecules. We determined the potential for transformation-associated mutations in a 360 kb yeast chromosome III composed primarily of unique DNA. Wild-type and rad52 Saccharomyces cerevisiae strains were transformed with either a homologous chromosome III or a diverged chromosome III from S. carlsbergensis. The host strain chromosome III had a conditional centromere allowing it to be lost on galactose medium so that recessive mutations in the transformed chromosome could be identified. Following transformation of a RAD+ strain with the homologous chromosome, there were frequent changes in the incoming chromosome, including large deletions and mutations that do not lead to detectable changes in chromosome size. Based on results with the diverged chromosome, interchromosomal recombinational interactions were the source of many of the changes. Even though rad52 exhibits elevated mitotic mutation rates, the percentage of transformed diverged chromosomes incapable of substituting for the resident chromosome was not increased in rad52 compared to the wild-type strain, indicating that the mutator phenotype does not extend to transforming chromosomal DNA. Based on these results and our previous observation that the incidence of large mutations is reduced during the cloning of mammalian DNA into a rad52 as compared to a RAD+ strain, a rad52 host is well-suited for cloning DNA segments in which gene function must be maintained.