Peculiarities of primary and secondary structure of phage FI-1 DNA

The composition of nitrous bases of phage FI-1 DNA was studied. As is evidenced from the values of buoyant density in CsCl (p=1,7093 g/cm(3)), melting temperature (T degrees m=86,05 degrees), spectral parameters and direct chromatographic determination, the DNA analysed contains 41,5 mole% pairs of guanine-cystosine. 5-hydroxymethylcytosine and other anomalous bases were not found. Chemical identification and jaxtposition of data of buoyant density in CsCl and Cs2SO4 (p=1,4466 g/cm(3)) and T degrees m. showed the presence of the extra-sugar component in DNA, most likely in the form of hentibiose. Spectral character of thermal denaturation of DNA in different solvents is indicative of the double helixity of its structure. DNA is characterized by enthalpies of conformational transitions "helix coil" (deltaH=12,3 kcal/g) and (deltaH=10 kcal/g) for the solvents, 1 x SSC, and 0,1 x SSC, correspondingly. The presence of extra-sugar in DNA with standard set of nitrous bases is discussed.     

Raw materials for the production of pigments in the system ZrO2---SiO2---Fe2O3

The authors show that (FeZr)-pigments may be obtained from coarse-sized materials (μ-ZrO₂ and -SiO₂) having a lower degree of chemical purity. The quantity of -Fe₂O₃ introduced should not exceed 8% (by weight). Mixing of batch components in a ball mill lined with porcelain plates is an indispensable condition for obtaining high-quality (FeZr)-pigments from the said raw materials. Steel taper rollers should be used as the grinding media.     

Experience with uranium-erbium fuel at the Ignalinsk Atimic Power Plant

Conclusions Experience with uranium-erbium fuel assemblies at the Ignalinsk Atomic Power Plant confirms the possibility of removing additional absorbers and considerably increasing the depth of fuel burnup, while maintaining permissible values of the steam reactivity and other characteristics important for reactor safety. Conversion of the reactor to uranium-erbium fuel permits not only the maintenance of α_ϕ within specified limits but also compensation for its growth on account of replacement of the control rods. The effectiveness of uranium-erbium fuel up to degrees of burnup close to the design value (∼20 MW·day/kg) has been demonstrated. The good agreement of the theoretical predictions and the actual characteristics offers hope that the complete conversion of reactors to uranium-erbium fuel and appropriate removal of additional absorbers will yield high fuel burnup and considerable improvement in the economic performance of atomic power plants. Other means of increasing the fuel burnup in RBMK-1500 reactors might be to increase the fuel enrichment and erbium content, to use zirconium spacers, and to reduce the operational reserve of reactivity. Ignalinsk Atomic Power Plant. Kurchatovskii Institute Russian Scientific Center. Mashinostroitel'nyi Zavod Joint Stock Company. Scientific-Research and Design Institute of Energy Technology. A. A. Bochvar All-Russian Scientific-Research Institute of Nonferrous Materials. Translated from Atomnaya énergiya, Vol. 85, No. 2, pp. 91–97, August, 1998.     

Catalytic plasma anodization of single-crystal 6H-SiC structures

The use of catalytic plasma anodization to obtain oxides on the surface of SiC is an original method, hitherto unused. This method can significantly reduce the process temperature, increase the oxide growth rate, and improve the properties of the structures, giving a low density of surface states and a small fixed charge in the oxide. Pis’ma Zh. Tekh. Fiz. 25, 5–7 (August 12, 1999)     

Investigation of Ti-Ge/GaAs Schottky barrier contacts

The effect of germanium content in a titanium film, as well as treatment methods and conditions, on the Schottky barrier height (φ_b) and the ideality factor (n) for Ti-Ge / GaAs contacts were investigated. It is shown that photon treatment provides better contacts than thermal treatment.