516 research outputs found

    Measurements of the Secondary Electron Emission from Rare Gases at 4.2K

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    Dependence of the secondary electron yield (SEY) from the primary beam incident energy and the coverage has been measured for neon, argon, krypton and xenon condensed on a target at 4.2K. The beam energy ranged between 100 eV and 3 keV, the maximal applied coverage have made up 12000, 4700, 2500 and 1400 monolayers correspondingly for neon, argon, krypton and xenon. The SEY results for these coverages can be considered as belonging only to investigated gases without influence of the target material. The SEY dependencies versus the primary beam energy for all gases comprise only an ascending part and therefore, the maximal measured SEY values have been obtained for the beam energy of 3keV and have made up 62, 73, 60.5 and 52 for neon, argon, krypton and xenon correspondingly. Values of the first cross-over have made up 21 eV for neon, 14 eV for argon, 12.5 eV for krypton and 10.5 eV for xenon. An internal field appearing across a film due to the beam impact can considerably affect the SEY measurements that demanded the beam current to be reduced till 9.0E-10A. Duration of the beam impact varied between 500 \mu sec and 250 \mu sec. It was found that reliable SEY measurements can also be taken on a charged surface if the charge was acquired due to beam impact with electrons of higher energy. All SEY measurements for once applied coverage have been carried out for whole range of incident energies from 3 keV down to 100 eV without renewing the film. Developing of pores inside of a deposited film can significantly increase the SEY as it was observed during warming up the target.Comment: 10 Pages - 25 figure

    Measurements of the Secondary Electron Emission of Some Insulators

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    Charging up the surface of an insulator after beam impact can lead either to reverse sign of field between the surface and collector of electrons for case of thick sample or appearance of very high internal field for thin films. Both situations discard correct measurements of secondary electron emission (SEE) and can be avoided via reducing the beam dose. The single pulse method with pulse duration of order of tens microseconds has been used. The beam pulsing was carried out by means of an analog switch introduced in deflection plate circuit which toggles its output between "beam on" and "beam off" voltages depending on level of a digital pulse. The error in measuring the beam current for insulators with high value of SEE was significantly reduced due to the use for this purpose a titanium sample having low value of the SEE with DC method applied. Results obtained for some not coated insulators show considerable increase of the SEE after baking out at 3500C what could be explained by the change of work function. Titanium coatings on alumina exhibit results close to the ones for pure titanium and could be considered as an effective antimultipactor coating.Comment: 8 pages, 13 figure

    International humanitarian law in cyberspace: Ratione materiae, ratione temporis and problem of cyber-attack qualification

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    The purpose of the article is to analyse problems arising from applying the rules of International Humanitarian Law in cyberspace, particularly the problems of ratione materiae and ratione temporis of this branch of Public International Law in cyberspace. The rapid development of cyber technologies that can be used within an armed conflict affirm the applicability of this research. The existence of “The Tallinn Manual 2.0” on International Law Applicable to Cyber Operations also confirms the impact of this topic on the modern world. The fact that parties in armed conflicts use new technologies in cyberspace does not affect the applicability of IHL rules to such military actions. In the context of this issue, a key question which instigates scientific discussion is that of which cyber operations are subject to the regulation of the law of cyber armed conflicts. The urgent need to study this problem stems from the fact that cyberspace is not an ordinary theatre of war, with the means and methods of warfare used in it being in no way related to the traditional use of armed force; given this quality of cyber operations, it is essential to understand which areas may be subject to IHL. The article analyses two main doctrinal points of view in relation to this problem; as this doctrine (in the context of this issue) also addresses the legal qualification of cyber-attacks, the article also raises this topical issue. Based on the results of this analysis, the author concludes that, despite all the evidence of theoretical conclusions regarding the problems under analysis, they still do not seem comprehensive due to the lack of relevant state practice, which needs to be developed

    Sentiment Analysis Based on Machine Learning Algorithms

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    This article reveals principles of sentiment analysis in text based on supervised learning algorithms. In particular, the Naive Bayes Classifier algorithm is chosen as an example. Also, the article considers steps of preparing data for the analysis.В статье рассмотрены принципы анализа тональности текста на основе алгоритмов обучения с учителем. Выбранным алгоритмом является наивный классификатор Байеса. Также, рассмотрен процесс подготовки данных к анализу

    ENIGMA-A centralised supervisory controller for enhanced onboard electrical energy management with model in the loop demonstration

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    A centralised smart supervisor (CSS) controller with enhanced electrical energy management (E2-EM) capability has been developed for an Iron Bird Electrical Power Generation and Distribution System (EPGDS) within the Clean Sky 2 ENhanced electrical energy MAnagement (ENIGMA) project. The E2-EM strategy considers the potential for eliminating the 5 min overload capability of the generators to achieve a substantial reduction in the mass of the EPGDS. It ensures optimal power and energy sharing within the EPGDS by interfacing the CSS with the smart grid network (SGN), the energy storage and regeneration system (ESRS), and the programmable load bank 1 secondary distribution board (PLB1 SDU) during power overloads and failure conditions. The CSS has been developed by formalizing E2-EM logic as an algorithm operating in real time and by following safety and reliability rules. The CSS undergoes initial verification using model-in-the-loop (MIL) testing. This paper describes the EPGDS simulated for the MIL testing and details the E2-EM strategy, the algorithms, and logic developed for the ENIGMA CSS design. The CSS was subjected to two test cases using MIL demonstration, and based on the test results, the performance of the ENIGMA CSS is verified and validated

    Does it make sense to study heart rate variability in episodes of paroxysmal atrial fibrillation during the 24-hour electrocardiographic monitoring?

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    Aim. To study the characteristics of heart rate variability (HRV) in episodes of paroxysmal atrial fibrillation (AF) and sinus rhythm (SR) during the 24-hour Holter electrocardiographic (ECG) monitoring and to assess the presence and nature of their relationships. Material and methods. We analyzed 37 records of 24-hour Holter ECG monitoring obtained from patients with paroxysmal AF. For analysis, records were selected from the Long Term Atrial Fibrillation database (LTAFDB) (n=26), as well as from the long-term storage database “Myocard-holter” of the Sverdlovsk Regional Clinical Hospital № 1 (n=11). Each record contained at least 120 min of SR and at least 120 min of paroxysmal AF episodes. In addition, 48 HRV indices were calculated independently for SR and for AF episodes, after which the 96 HRV parameters obtained for each record were subjected to exploratory data analysis. Results. Analysis of HRV in AF paroxysm showed a significant increase in the RMSSD, SD1, pNN50 indices, which confirmed the great importance of para-sympathetic influence in the regulation of AF. Despite the fact that single HRV parameters in AF are not directly related to any single parameters in SR, we have shown that the AF is not completely chaotic and independent of the characteristics of baseline HR variability. We found that for some of the HRV indices determined during AF paroxysm (PAF_CVI, PAF_pNN20, PAF_pNN50, PAF_ApEn, PAF_SDNN, PAF_SD2), up to 74% of the variance of these indices can be explained using multivariate linear models, including 4 HRV indices for SR and taken as predictors. It was shown that among all the indices analyzed, only the PAF_HTI, calculated in paroxysmal AF, had a moderate negative correlation with the duration of AF episodes (r=0,60, p<0,01). Conclusion. It is shown that the study of HRV indices on AF paroxysm has a wide clinical and electrophysiological potential. The paper proposes statistical models that demonstrate the relationship between HRV in SR and in the rhythm of AF episode. The PAF_HTI index, assessed on episodes of AF, showed a relationship with the duration of AF episodes, which suggests the expediency of using HRV characteristics on AF to assess the possibility of SR recovery. © 2022, Silicea-Poligraf. All rights reserved

    Analysis of the possibility of fish and meat raw materials combination in products

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    Aspects for the use of regional raw materials in ground food technology require further study of functional and technological properties to be able to predict them depending on the chemical composition of raw materials and processing methods. The aim of our research was to comparatively study the chemical composition, functional-technological, rheological properties of fish raw materials, and duck meat in terms of their possible compatibility in meat-containing products. The subject of our research was representatives of the regional aquaculture Carassius gibelio and Hypophthalmichthys molitrix, as well as the meat of Muscovy duck (Cairina moschata). It has been established that the nutritional value of freshwater aquaculture objects Carassius gibelio and Hypophthalmichthys molitrix is virtually identical in protein and fat content, making them interchangeable in terms of nutritional balance when developing the combined product. The ratio of protein and fat to water for duck meat is higher 3.54 – 4.88 times that of aquaculture, which can be used in the selection of components of the formulation of emulsified products, taking into account the nutrient balance. It has been confirmed that the addition of salt enhances water holding capacity, water binding capacity, and fat holding capacity. Water holding and water-binding capacities of minced fish are higher due to higher water levels, which, combined with the low-watering duck meat, can be predicted to create a force meat system with high functional technological properties. The ability to emulsification and retain fat in the state of emulsion in minced duck meat has proved to be better, which when combined with fish minced meat can compensate for the ability to retain fat in the system of combined products. A combination of regional aquaculture with waterfowl meat will not only improve the functional and technological parameters of combined minced systems but also balance them by correcting the composition of proteins and fats
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