On a class of languages recognizable by probabilistic reversible decide-and-halt automata

We analyze the properties of probabilistic reversible decide-and-halt automata (DH-PRA) and show that there is a strong relationship between DH-PRA and 1-way quantum automata. We show that a general class of regular languages is not recognizable by DH-PRA by proving that two “forbidden” constructions in minimal deterministic automata correspond to languages not recognizable by DH-PRA. The shown class is identical to a class known to be not recognizable by 1-way quantum automata. We also prove that the class of languages recognizable by DH-PRA is not closed under union and other non-trivial Boolean operations.     

Analysis of the Possibility of Using Fuel Based on Reclaimed Uranium in VVÉR Reactors

A current problem is to show that reclaimed uranium can be, in principle, brought into the VVÉR fuel cycle. The possibility of using fuel based on reprocessed uranium in VVÉR is analyzed. The requirements for the initial isotopic composition of test batches of fuel pellets with 4% effective enrichment are determined, the compensation coefficient is calculated, the requirements for monitoring the isotopic composition are determined, and the technlogy for fabricating fuel pellets from relaimed fuel is determined. It is shown that the basic neutron-physical characteristics satisfy the restrictions adopted in the VVÉR-440 and -1000 designs. The effect of radiation on the public and the environment as a result of switching to fuel fabricated from reclaimed uranium is the same as for the standard oxide fuel.     

A Novel Photoswitchable Azobenzene-Containing Local Anesthetic Ethercaine with Light-Controlled Biological Activity In Vivo

Pain is a common symptom that impairs the quality of life for people around the world. Local anesthetics widely used for pain relief have a number of side effects, which makes the development of both new drugs and new ways to control their activity particularly important. Photopharmacology makes it possible to reduce the side effects of an anesthetic and control its biological activity in the body. The purpose of this work was to create a new light-controlled local anesthetic and study its biological activity in animals. A compound with a simple scheme of synthesis was chosen to shift the UV-Vis absorption band towards the visible range of the spectrum and was synthesized for the first time. Some computer calculations were performed to make sure that the aforementioned changes would not lead to loss of biological activity. The micellar form of the new compound was prepared, and in vivo biological studies were carried out in rabbits. The existence of a local anesthetic effect, which disappeared almost completely on irradiation with light (λ = 395 nm), was shown using the surface anesthesia model. Moreover, the possibility of multiple reversible changes in the biological activity of ethercaine under the action of light was demonstrated. The latter compound manifests no local irritating effect, either. The data obtained indicate the prospects for the development of new compounds based on azobenzene for light-controlled local anesthesia.     

Test Time Minimization for Hybrid BIST of Core-Based Systems

This paper presents a solution to the test time minimization problem for core-based systems. We assume a hybrid BIST approach, where a test set is assembled, for each core, from pseudorandom test patterns that are generated online, and deterministic test patterns that are generated off-line and stored in the system. In this paper we propose an iterative algorithm to find the optimal combination of pseudorandom and deterministic test sets of the whole system, consisting of multiple cores, under given memory constraints, so that the total test time is minimized. Our approach employs a fast estimation methodology in order to avoid exhaustive search and to speed-up the calculation process. Experimental results have shown the efficiency of the algorithm to find near optimal solutions.     

Comparative characterization of particle emissions from asbestos and non-asbestos cement roof slates

The first aim of this study was to characterise total and size-fractionated particulate matter (PM) aerosol, including fibres, released from the processing operations of cement roofing slates. The second aim was to compare particle emissions from asbestos-cement and non-asbestos cement sheets, with respect to total and size-fractionated particulate matter as well as fibres emissions. Asbestos and cellulose-based cement sheets were compared during slate treatment processes, namely crushing, rubbing, rasping and scrubbing. Generated PM and fibres were classified by a variety of methods (PM_2.5 and PM₁₀ cyclones, aerodynamic particle spectrometer and optical particle counter). A substantial variation in the mass of generated particles has been noticed, both within each PM fraction and between different treatment processes. The PM₁₀/PM_total concentration ratio ranged from 70 to 98% and PM_2.5/PM_total ratio equalled to ∼20%. The new generation non-asbestos sheets produced three times higher PM emissions than asbestos-cement sheets during crushing operation. Particle size distribution of number concentrations was mostly bimodal (two modes at 0.5 and 2.5 μm). With respect to fibres, the release of cellulose fibres from non-asbestos slates was from 1.8 to 13 times lower in comparison with asbestos fibres. At the same time, cellulose fibre length was 1.4–1.6 times lower. Hence, new generation non-asbestos roofing slates were proved to be less hazardous from the point of view of fibre release, but more hazardous with respect to total particle release.     

Oxidation-abrasion of TiC-based cermets in SiC medium

The aim of the current study was to investigate the effect of oxidation on abrasive wear behaviour of TiC based cermets at temperatures ranging from 20 to 900 °C. Three types of material performance maps were constructed: oxidation rate maps, wear rate maps and maps showing the effect of oxidation on abrasion. Discussion on the performance of different cermet grades is supported by the SEM images combined with EDS and XRD analysis. The results should facilitate the selection of TiC-based cermets providing optimum composition of cermets for high temperature applications.