The Reactivity of Azidonitrobenzofuroxans towards 1,3-Dicarbonyl Compounds: Unexpected Formation of Amino Derivative via the Regitz Diazo Transfer and Tautomerism Study

Herein, we report on the reaction of nitro-substituted azidobenzofuroxans with 1,3-dicarbonyl compounds in basic media. The known reactions of benzofuroxans and azidofuroxans with 1,3-dicarbonyl compounds in the presence of bases are the 1,3-dipolar cycloaddition and the Beirut reaction. In contrast with this, azidonitrobenzofuroxan reacts with 1,3-carbonyl compounds through Regitz diazo transfer, which is the first example of this type of reaction for furoxan derivatives. This difference is seemingly due to the strong electron-withdrawing effect of the superelectrophilic azidonitrobenzofuroxan, which serves as the azido transfer agent rather than 1,3-dipole in this case.     

Properties of flame synthesized germanium oxide nanoparticles

Germanium oxide (GeOx) nanoparticles in the size range from 1.5 to 10 nm were synthesized in a low-pressure premixed H2/O2/Ar flame in the pressure range 25-55 mbar. The flame was doped with different amounts of tetramethylgermanium (Ge(CH3)4) ranging from 500 to 2000 ppm. The influence of process parameters such as pressure, flame coordinate, and cold gas flow velocity with respect to growth of germanium oxide particles were investigated. The formed particles were analyzed in-situ according to their mass and charge by means of a particle mass spectrometer (PMS). The specific surface area was determined ex-situ by the BET method. The crystal structure and chemical composition of the produced nanopowder was characterized by EDX and XRD measurements. Additionally, the particles were analyzed by means of FT-IR spectroscopy.     

Calculation of the time for establishing radiation equivalence of high-level wastes

The potential harm of long-lived radionuclides estimated as the product of the activity of a radionuclide and the dose coefficient is examined. The potential harm of actinides in high-level wastes is calculated taking account of the harm due to their decay products. At the same time, an analogous calculation is performed for the uranium isotopes ²³⁸U, ²³⁵U, and ²³⁴U consumed in the reactor. The value obtained, which depends on the time, can be regarded as the averted harm. The time for establishing radiation equivalence between the high-level wastes and the consumed uranium is determined as the time in which the potential harm from actinides becomes equal to the averted harm. It depends on the holding time of the spent fuel before radiochemical reprocessing. For a 5 yr holding period, it is 49000 yr.__________Translated from Atomnaya Énergiya, Vol. 98, No. 2, pp. 123–129, February, 2005.     

Increasing the measurement accuracy of digital automatic scan converter compensators

Conclusions On the basis of what has been proposed it is possible to conclude that the allowable errors in comparisons of two time functions do not depend on the levels of the switching thresholds of balance indicators. It is possible to design digital measuring instruments having high measurement sensitivity and accuracy by using ordinary balance indicator circuits.The methods considered permit us to take instruments of certain accuracy classes, and, without reducing the quality of their information indicators, reduce the number of quantization steps with respect to level and thereby increase, by many times, the measurement speed with the same response speed of the commutation elements.Translated from Izmeritel'naya Tekhnika, No. 8, pp. 48–51, August, 1971.     

Manufacture of small bearings from atomized powders

Conclusions Processes have been developed for the manufacture of atomized copper, tin, and bronze powders suitable for the bearings of the electric motors of domestic air conditioners. A technique has been developed for the production of small instrument journal bearings possessing good operating characteristics.Translated from Poroshkovaya Metallurgiya, No. 8(224), pp. 48–52, August, 1981.     

Extinction coefficient of thyroglobulin

The extinction coefficient at 280 nm of the solution (pH 7,2-7,4) of thyroglobulin from normal thyroid and nodular euthyroid goiter was measured with the values of 0,6-0,7 to 0,9 ml.mg-1.cm-1. The value of E1%280 as function of the iodoamino acid content depends on the morphological state of the thyroid gland. A simple method for determination of the E1%280 value by measuring of the protein absorption spectrum is proposed.