Acceleration of He3 up to 35 Mev in the one and one-half meter cyclotron

A method is described for accelerating He ₃ ²⁺ to 35 Mev in a cyclotron. A beam of 30 a with an energy spread of ± 0.3% was obtained on a target 12 m from the cyclotron. Due to the use of a gas recycling system, the loss of He₃ was decreased by two orders and was approximately 5 cm³/hr.The authors wish to express their deep appreciation to N. A. Vlasov and S. P. Kalinin for the continuing interest in the project; to V. I. Lamunin and N. N. Khaldin for constructing the gas recycling system; to N. V. Kartashov for tuning the pulsed ion source; to the staffs of the operating group and machine shop who assisted in the preparation of the apparatus and cyclotron inlet system.     

Double-doped YFeO3 as new electrodes for protonic ceramic fuel cells

Mixed ionic-electronic conductors (MIECs) based on YFeO₃ are positioned as one of the promising cathode materials for intermediate-temperature solid oxide fuel cells (so-called protonic ceramic fuel cells or PCFCs) based on proton-conducting electrolytes. Simultaneous modification of both basic cationic sublattices of YFeO₃ by calcium and iron was used to tailor the functionality of the obtained Y_0.9Ca_0.1Fe_1–хСo_хO_3–δ (x = 0.2, 0.3, 0.4 and 0.5) compounds. Following the successful synthesis of these oxides, such functional characteristics as structural, thermal, transport properties and electrochemical activity were extensively studied taking the composition (i.e. cobalt concentration, x) into account. The complex analysis carried out on the obtained data shows that Co-doping results in improved electrical conductivity and electrochemical polarisation resistance with no adverse effects on their thermal expansion, even at the highest cobalt content (x = 0.5). The performance of a single SOFC with the selected Y_0.9Ca_0.1Fe_0.5Сo_0.5O_3–δ electrode confirms the prospects of Y_0.9Ca_0.1Fe_1–хСo_хO_3–δ phases as modernized MIECs having good thermal properties and acceptable electrochemical activity.     

Effect of dispersed CdSe/ZnS quantum dots on optical and electrical characteristics of nematic liquid crystal cells

We have studied the electrical and optical characteristics of cells filled with nematic liquid crystal (NLC) based on cyanobiphenyls with positive dielectric anisotropy, containing dispersed 3.5-nm-sized CdSe/ZnS composite semiconductor nanoparticles (quantum dots, QDs) with a concentration of 0.1–0.2 wt %. In addition to a decrease in the threshold voltage of the electrooptical splay effect, the doping with QDs leads also to a decrease in the phase delay of light and the effective dielectric permittivity of NLC cells. These characteristics are reduced by half during the storage of NLC cells containing about 0.2 wt % QDs, which is related to the self-organization of QDs.     

Embedded TLS 1.2 Implementation for Smart Metering & Smart Grid Applications

Digital networked communications are the key to all Internet-of-Things applications, especially to smart metering systems and the smart grid. In order to ensure a safe operation of systems and the privacy of users, the transport layer security (TLS) protocol, a mature and well standardized solution for secure communications, may be used. We implemented the TLS protocol in its latest version in a way suitable for embedded and resource-constrained systems. This paper outlines the challenges and opportunities of deploying TLS in smart metering and smart grid applications and presents performance results of our TLS implementation. Our analysis shows that given an appropriate implementation and configuration, deploying TLS in constrained smart metering systems is possible with acceptable overhead.     

Connectivity of workflow nets: the foundations of stepwise verification

Behavioral models capture operational principles of real-world or designed systems. Formally, each behavioral model defines the state space of a system, i.e., its states and the principles of state transitions. Such a model is the basis for analysis of the system’s properties. In practice, state spaces of systems are immense, which results in huge computational complexity for their analysis. Behavioral models are typically described as executable graphs, whose execution semantics encodes a state space. The structure theory of behavioral models studies the relations between the structure of a model and the properties of its state space. In this article, we use the connectivity property of graphs to achieve an efficient and extensive discovery of the compositional structure of behavioral models; behavioral models get stepwise decomposed into components with clear structural characteristics and inter-component relations. At each decomposition step, the discovered compositional structure of a model is used for reasoning on properties of the whole state space of the system. The approach is exemplified by means of a concrete behavioral model and verification criterion. That is, we analyze workflow nets, a well-established tool for modeling behavior of distributed systems, with respect to the soundness property, a basic correctness property of workflow nets. Stepwise verification allows the detection of violations of the soundness property by inspecting small portions of a model, thereby considerably reducing the amount of work to be done to perform soundness checks. Besides formal results, we also report on findings from applying our approach to an industry model collection.     

Thermal diagnostics of friction in the system of sliding bearings at low rotation speeds of a common shaft

The problem of the thermal diagnostics of friction in the system of sliding bearings with a low rotational speed of the common shaft has been considered in which it is necessary to take into account its motion in the mathematical model of the thermal process in the system. It has been proposed to numerically solve the inverse problem of defining the functions of frictional heat generation by the temperature data in stationary bushings by the method of iterative regularization with a fairly small time step. Computational experiments have shown that the error of restoring the functions of frictional heat generation is commensurable with the accuracy of initial data setting.     

New high-spin bis-o-semiquinonato cobalt(II) complexes with neutral donor ligands

Two novel bis-o-semiquinonato cobalt complexes Co(3,6-SQ)₂L (1, L¹ = 2,6-dimethyl-N-(pyridin-2-ylmethylene)benzenamine; 2, L² = 2,6-dimethyl-N-(thiophen-2-ylmethylene)benzenamine; 3,6-SQ is 3,6-di-tert-butyl-o-benzosemiquinonato radical-anion) were synthesized. According to X-ray analysis, complex 2 adopts square pyramidal geometry with N-coordinated neutral ligand L² in the apical site. According to magnetic susceptibility measurements and spectroscopic studies, both complexes contain high-spin cobalt(II) (d⁷, S = 3/2) and two radical-anionic o-semiquinonato ligands. There is antiferromagnetic metal–ligand and ligand–ligand coupling in 1, while complex 2 demonstrates weak antiferromagnetic ligand–ligand coupling at low temperature and ferromagnetic metal–ligand exchange at 150–300 K.     

The role of fear and expectancies in capture of covert attention by spiders.

Fear-related stimuli are often prioritized during visual selection but it remains unclear whether capture by salient objects is more likely to occur when individuals fear those objects. In this study, participants with high and low fear of spiders searched for a circle while on some trials a completely irrelevant fear-related (spider) or neutral distractor (butterfly/leaf) was presented simultaneously in the display. Our results show that when you fear spiders and you are not sure whether a spider is going to be present, then any salient distractor (i.e., a butterfly) grabs your attention, suggesting that mere expectation of a spider triggered compulsory monitoring of all irrelevant stimuli. However, neutral stimuli did not grab attention when high spider fearful people knew that a spider could not be present during a block of trials, treating the neutral stimuli just as the low spider fearful people do. Our results show that people that fear spiders inspect potential spider-containing locations in a compulsory fashion even though directing attention to this location is completely irrelevant for the task. Reduction of capture can only be accomplished when people that fear spiders do not expect a spider to be present. (PsycINFO Database Record (c) 2011 APA, all rights reserved)