Highly polarized injection luminescence in forward-biased ferromagnetic-semiconductor junctions at low spin polarization of current

We consider electron tunneling from a nonmagnetic $n$-type semiconductor ($n$-S) into a ferromagnet (FM) through a very thin forward-biased Schottky barrier resulting in efficient extraction of electron spin from a thin $n$-S layer near FM-S interface at low spin polarization of the current. We show that this effect can be used for an efficient polarization radiation source in a heterostructure where the accumulated spin polarized electrons are injected from $n$-S and recombine with holes in a quantum well. The radiation polarization depends on a bias voltage applied to the FM-S junction.Comment: 4 pages, 2 figure

Зміст принципу змагальності в кримінальному судочинстві України

Тітков К. С. Зміст принципу змагальності в кримінальному судочинстві України / К. С. Тітков // Актуальні проблеми політики : зб. наук. пр. / редкол. : С. В. Ківалов (голов. ред..), Л. І. Кормич (заст. голов. ред..), Ю. П. Аленін [та ін.] ; МОНмолодьспорт України ; НУ ОЮА. – Одеса : Фенікс, 2012. – Вип.. 46. – С. 358-366.In research both theoretical questions of criminal procedure and problem questions of application of principle of contentionness on different stages of criminal procedure of Ukraine are consistently examined, ways of their decision are specifi ed

Automatic selection of a subset size at vector fields construction

An algorithm for selection of the size of a correlation kernel at displacement vector field construction by the method of digital image correlation has been proposed. The algorithm has been tested on simulated and experimental optical images having different texture. The influence of the correlation kernel size and image texture on nose immunity at determining displacements has been studied. It is shown that the proposed algorithm allows to find this size providing the minimum error when determination of displacements and estimation of deformation

The algorithm of crack and crack tip coordinates detection in optical images during fatigue test

An algorithm of crack detection during fatigue testing of materials, designed to automate the process of cyclic loading and tracking the crack tip, is proposed and tested. The ultimate goal of the study is aimed at controlling the displacements of the optical system with regard to the specimen under fatigue loading to ensure observation of the 'area of interest'. It is shown that the image region that contains the crack may be detected and positioned with an average error of 1.93%. In terms of determining the crack tip position, the algorithm provides the accuracy of its localization with the average error value of 56 pixels

Application of Lucas-Kanade algorithm with weight coefficient bilateral filtration for the digital image correlation method

Application of bilateral filer weight coefficients for computing the weight function in Lucas-Kanade algorithm for optical flow determination is proposed. The obtained results based on processing different image types demonstrate the error reduction in optical flow determination. The approach to weight function parameters selection for bilateral filter is proposed and investigated

Mycoviruses are common among different species of endophytic fungi of grasses

8 páginas, 1 tabla, 1 figuraA survey of mycoviruses was made in a collection of 103 isolates belonging to 53 different species of endophytic fungi of grasses. DsRNA elements were detected in isolates of 12 of the species analyzed. The banding characteristics and sizes of some of the dsRNA elements suggest that they might belong to previously described mycovirus families. The observed incidence (22.6%) indicates that the presence of mycoviruses could be common among species of this group of ubiquitous fungi.This research was financed by project AGL2005-02839 granted by the Spanish Ministry of Science and Education. We thank Drs. Robert Coutts and Beatríz R. Vázquez de Aldana for reviewing the manuscript.Peer reviewe

Clinical efficacy of coronary angioplasty of chronic occlusion in patients with previous Q-myocardial infarction

Objective: to evaluate the clinical effects of delayed reperfusion of chronically occluded IRA in patients after Q-myocardial infarction (Q-MI), in relation to the general and local contractility of left ventricular ejection fraction (LVEF). Material and Methods. The study included 200 patients with previous Q-MI. PCI for chronic occlusion of the IRA was performed in an average period of 1-2 months after the documented Q-MI. Complete clinical and instrumental examination of patients was performed before the PCI and after 12 months. Symptoms of angina, left ventricular ejection fraction, prevalence areas of hypo-and akinesia infarction and functional class of chronic heart failure have been evaluated. Results. Statistically significant reduction in the number of patients with symptoms of angina: 41 (20.5%) versus baseline 94 (47%), p <0,0001; significant improvement in myocardial contractile function —the number of patients with LV EF <4076% reduction (38%) to 32 (16%), p <0.0001 have been revealed. An increase in the frequency of functional classes of heart failure has not reached the statistical significance. According to the ultrasound investigation of hypo-and akinesia areas of infarction there was a statistically significant increase in the incidence of myocardial hypokinesis prevalence of 152 (76%) versus baseline 103 (51.5%), p <0.0001. Conclusions. The late recanalization of chronic occlusion (after 8 weeks post-MI) with the restoration of optimum antegrade blood flow improves left ventricular function and long-term prognosis reducing the risk of cardiovascular disorders during the period of the 12-month follow-up

Ultrafast control of donor-bound electron spins with single detuned optical pulses

The ability to control spins in semiconductors is important in a variety of fields including spintronics and quantum information processing. Due to the potentially fast dephasing times of spins in the solid state [1-3], spin control operating on the picosecond or faster timescale may be necessary. Such speeds, which are not possible to attain with standard electron spin resonance (ESR) techniques based on microwave sources, can be attained with broadband optical pulses. One promising ultrafast technique utilizes single broadband pulses detuned from resonance in a three-level Lambda system [4]. This attractive technique is robust against optical pulse imperfections and does not require a fixed optical reference phase. Here we demonstrate the principle of coherent manipulation of spins theoretically and experimentally. Using this technique, donor-bound electron spin rotations with single-pulse areas exceeding pi/4 and two-pulses areas exceeding pi/2 are demonstrated. We believe the maximum pulse areas attained do not reflect a fundamental limit of the technique and larger pulse areas could be achieved in other material systems. This technique has applications from basic solid-state ESR spectroscopy to arbitrary single-qubit rotations [4, 5] and bang-bang control[6] for quantum computation.Comment: 15 pages, 4 figures, submitted 12/2008. Since the submission of this work we have become aware of related work: J. Berezovsky, M. H. Mikkelsen, N. G. Stoltz, L. A. Coldren, and D. D. Awschalom, Science 320: 349-352 (2008

Automatic selection of a subset size at vector fields construction

An algorithm for selection of the size of a correlation kernel at displacement vector field construction by the method of digital image correlation has been proposed. The algorithm has been tested on simulated and experimental optical images having different texture. The influence of the correlation kernel size and image texture on nose immunity at determining displacements has been studied. It is shown that the proposed algorithm allows to find this size providing the minimum error when determination of displacements and estimation of deformation

Security analysis of Cryptomator

Tato práce se zabývá problematikou šifrování datového úložiště a bezpečnosti dat. Poskytuje stručný přehled technologií a softwaru pro šifrování úložiště, které jsou aktuálně dostupné uživatelům. Práce poskytuje bezpečnostní analýzu Cryptomator, open-source aplikace pro šifrování souborů v cloudovém úložišti. Potenciální rizikové oblasti jsou dále prozkoumány a hodnoceny. Jsou uvedeny některé možné útoky.This thesis deals with the issue of storage encryption and data safety. It provides a brief overview of technologies and software for storage encryption currently available to users. The work provides a security analysis of Cryptomator, an open-source application for encrypting files in cloud storage. Potential risk areas are further explored and evaluated. Some of the possible attacks are shown