Radiation safety of a population inhabiting the area where a nuclear facility is situated

Translated from Atomnaya Énergiya, Vol. 67, No. 2, pp. 81–83, August, 1989.     

On the colour reactions of potato glycoalkaloids in strong acids in the presence of paraformaldehyde

The colour reaction of potato glycoalkaloids, containing solanidine as steroid, with strong acids and paraformaldehyde was examined to elucidate the kinetics and mutual relationship of the ‘Clarke’ and ‘Marquis’ reactions. It was found that the influence of time of addition of paraformaldehyde was the major factor in deciding the type of colour changes encountered. This factor and the specific absorption kinetics have important consequences for the use of these types of colour reactions as a quantitative assay. According to the structural similarity of the steroidal part of potato glycoalkaloids and cholesterol, colour reactions of both have been compared, indicating that both steroids react in strong acids in the presence of an oxidator, provided that the more lipophilic character of cholesterol is taken into account. Therefore a similar mechanism of a serial oxidation of carbonium ions as in the case of cholesterol, is suggested as the basis for these specific colour reactions of potato glycoalkaloids.     

Simultaneous a posteriori detection and identification of a predetermined number of quasi-periodic fragments in a sequence based on their segments

An a posteriori (off-line) approach to the simultaneous detection and identification of quasi-periodic fragments in a numerical sequence using their segments is analyzed. The solution of the problem is proposed for the case when the number of the desired fragments is known. The following assumptions are made. (i) Each desired fragment of the numerical sequence coincides with an element of the given alphabet of the reference sequences that have equal lengths (i.e., number of elements). (ii) Only a segment (part) of the desired fragment can be processed; unprocessable parts of the fragment are interpreted as lost data. (iii) The numbers of the elements in the sequence that correspond to the beginning of the desired fragment and the boundaries of the segment in the fragment represent deterministic (rather than random) quantities; the boundaries of the segments are different for different fragments; and the desired fragments are quasi-periodic in the sequence. (iv) Gaussian uncorrelated noise impedes the observation of the sequence that contains quasi-periodic segments of the reference sequences. It is demonstrated that the essence of the problem under study lies in the verification of a set of hypotheses on the mean value of a random Gaussian vector (the power of this set exponentially increases with an increase in the dimension of the vector—the sequence length). An effective a posteriori algorithm that provides for maximum-likelihood detection and identification is validated. The estimates of the time and space complexity are related to the parameters of the problem. The results of the numerical simulation are presented. This work was supported by the Russian Foundation for Basic Research, project no. 03-01-00036 and 06-01-00058. Aleksandr V. Kel’manov. Born April 25, 1952. Graduated from Izhevsk State Technical University in 1974. Received candidate’s degree in 1980 and doctoral degree in 1994. Leading researcher of the Sobolev Institute of Mathematics, Siberian Division, Russian Academy of Sciences. Scientific interests: mathematical methods for pattern recognition; discrete optimization; effective algorithms for the analysis and recognition of random sequences; algorithms for the solution of applied problems; and methods and algorithms for the processing, recognition, and synthesis of voice signals. Author of more than 120 papers. Sergei A. Khamidullin. Born March 28, 1952. Graduated from Novosibirsk State University in 1974. Received candidate’s degree in 1997. Senior researcher of the Sobolev Institute of Mathematics, Siberian Division, Russian Academy of Sciences. Scientific interests: mathematical methods for pattern recognition; discrete optimization; effective algorithms for the analysis and recognition of random sequences; algorithms for the solution of applied problems; and methods and algorithms for the processing, recognition, and synthesis of voice signals. Author of more than 80 papers.     

Simplified steady-state model of an SCR-inverter-basedload-commutated commutatorless series motor

This paper presents a simplified analytical model of a silicon-controlled-rectifier based, load-commutated inverter driven, commutatorless series motor to predict its speed-current, torque-current and torque-speed characteristics. The model has been formulated, keeping in view the steady state equivalent circuit of a conventional DC series motor. The proposed analytical expressions relating torque and current with speed are found to follow an inverse law and that relating torque and current is found to be parabolic, as is expected in a "series" machine. The drive has been implemented, loaded with a DC generator and experimentally similar characteristics have been obtained, as predicted by the analytical model. The characteristics obtained experimentally are seen to follow the ones, predicted by the analytical model closely     

A correlation between the microhardness and the mobility of twinning dislocations in bismuth crystals exposed to constant magnetic field and pulsed electric field

It is established that bismuth crystals under the simultaneous action of a constant magnetic field and current pulses exhibit a correlation between the microhardness and the mobility of twinning dislocations. It is shown that application of the external fields favors translation of the twinning dislocations along the twin-matrix boundaries.     

Operation of an experimental facility for fabrication of fuel elements and fuel assemblies of the bor-60 containing vibrocompacted fuel

Translated from Atomnaya Énergiya, Vol. 67, No. 5, pp. 320–323, November, 1989.     

Impact of structural steel flexibility and restraints gaps on the dynamic behaviour of piping

The effect of gaps present in the seismic supports of nuclear piping systems and of the flexibility of the steel structure to which intermediate supports are attached, is studied in this paper. An actual piping system is used to investigate the impact of structural steel and mechanical snubber gaps on the dynamic behaviour of piping. An evaluation is thus performed of the finite element modeling techniques employed by the designers in the dynamic analysis of piping systems.     

A Compositional Framework for Hardware/Software Co-Design

We describe a compositional framework, together with its supporting toolset, for hardware/software co-design. Our framework is an integration of a formal approach within a traditional design flow. The formal approach is based on Interval Temporal Logic and its executable subset, Tempura. Refinement is the key element in our framework because it will derivefrom a single formal specification of the system the software and hardware parts of the implementation, while preserving all properties of the system specification. During refinement simulation is used to choose the appropriate refinement rules, which are applied automatically in the HOL system. The framework is illustrated with two case studies. The work presented is part of a UK collaborative research project between the Software Technology Research Laboratory at the De Montfort University and the Oxford University Computing Laboratory.