Electrical discharges in the atmosphere of Venus

Data received from Venera 11 and 12 experiments involving the electrical activity of the atmosphere of Venus show that the electrical discharges occur in the cloud layer. Their energy is roughly the same as in terrestrial lightning, but with a pulse repetition frequency of the discharges which is much greater

Beam test results of 3D fine-grained scintillator detector prototype for a T2K ND280 neutrino active target

An upgrade of the long baseline neutrino experiment T2K near detector ND280 is currently being developed with the goal to reduce systematic uncertainties in the prediction of number of events at the far detector Super-Kamiokande. The upgrade program includes the design and construction of a new highly granular fully active scintillator detector with 3D WLS fiber readout as a neutrino target. The detector of about $200\times 180\times 60~cm^3$ in size and a mass of $\sim$2.2~tons will be assembled from about $2\times10^6$ plastic scintillator cubes of $1\times1\times1~cm^3$. Each cube is read out by three orthogonal Kuraray Y11 Wave Length Shifting (WLS) fibers threaded through the detector. A detector prototype made of 125 cubes was assembled and tested in a charged particle test beam at CERN in the fall of 2017. This paper presents the results obtained on the light yield and timing as well as on the optical cross-talk between the cubes.Comment: 5 pages, 8 figure

Економічна безпека суб’єктів господарювання в умовах пандемії COVID-19: характеристика загроз

Суворов Н. О. Економічна безпека суб’єктів господарювання в умовах пандемії COVID-19: характеристика загроз / Н. О. Суворов // Сучасні проблеми правового, економічного та соціального розвитку держави : тези доп. Міжнар. наук.-практ. конф. (м. Харків, 27 листоп. 2020 р.). – Харків, 2020. – С. 233 - 234.В статті зазначається, що загрози економічній безпеці суб’єктів господарювання, які спричинені введенням протиепідемічного карантину, мають об’єктивний характер, пов’язані з форс-мажорними обставинами, виникли раптово і не могли бути передбачені. Оскільки карантин є адміністративним заходом державного регулювання, держава має розділити з суб’єктами господарювання ті втрати, що вони понесли у зв’язку з його введенням. В статье отмечается, что угрозы экономической безопасности субъектов хозяйствования, вызванные введением противоэпидемического карантина, имеющих объективный характер, связанные с форс-мажорными обстоятельствами возникли внезапно и не могли быть предусмотрены. Поскольку карантин является административной мерой государственного регулирования, государство должно разделить с субъектами хозяйствования потери, которые они понесли в связи с его введением. The article states that the threats to the economic security of economic entities that are caused introduction of anti-epidemic quarantine, are objective in nature, related to force majeure, arose suddenly and could not be foreseen. Because quarantine is an administrative measure of state regulation, the state must divide with business entities the losses they have incurred in connection with its introduction

Comparative performance of MRI-derived PRECISE scores and delta-radiomics models for the prediction of prostate cancer progression in patients on active surveillance

Objectives: To compare the performance of the PRECISE scoring system against several MRI-derived delta-radiomics models for predicting histopathological prostate cancer (PCa) progression in patients on active surveillance (AS). // Methods: The study included AS patients with biopsy-proven PCa with a minimum follow-up of 2 years and at least one repeat targeted biopsy. Histopathological progression was defined as grade group progression from diagnostic biopsy. The control group included patients with both radiologically and histopathologically stable disease. PRECISE scores were applied prospectively by four uro-radiologists with 5–16 years’ experience. T2WI- and ADC-derived delta-radiomics features were computed using baseline and latest available MRI scans, with the predictive modelling performed using the parenclitic networks (PN), least absolute shrinkage and selection operator (LASSO) logistic regression, and random forests (RF) algorithms. Standard measures of discrimination and areas under the ROC curve (AUCs) were calculated, with AUCs compared using DeLong’s test. // Results: The study included 64 patients (27 progressors and 37 non-progressors) with a median follow-up of 46 months. PRECISE scores had the highest specificity (94.7%) and positive predictive value (90.9%), whilst RF had the highest sensitivity (92.6%) and negative predictive value (92.6%) for predicting disease progression. The AUC for PRECISE (84.4%) was non-significantly higher than AUCs of 81.5%, 78.0%, and 80.9% for PN, LASSO regression, and RF, respectively (p = 0.64, 0.43, and 0.57, respectively). No significant differences were observed between AUCs of the three delta-radiomics models (p-value range 0.34–0.77). // Conclusions: PRECISE and delta-radiomics models achieved comparably good performance for predicting PCa progression in AS patients

Crystal growth, characterization and electronic band structure of TiSeS

Layered semimetallic van der Waals materials TiSe2 has attracted a lot of attention because of interplay of a charge density wave (CDW) state and superconductivity. Its sister compound TiS2, being isovalent to TiSe2 and having the same crystal structure, shows a semiconducting behavior. The natural rises what happens at the transition point in TiSe2-xSx, which is expected for x close to 1. Here we report the growth and characterization of TiSeS single crystals and the study of the electronic structure using density functional theory (DFT) and angle-resolved photoemission (ARPES). We show that TiSeS single crystals have the same morphology as TiSe2. Transport measurements reveal a metallic state, no evidence of CDW was found. DFT calculations suggest that the electronic band structure in TiSeS is similar to that of TiSe2, but the electron and hole pockets in TiSeS are much smaller. The ARPES results are in good agreement with the calculations.Comment: 22 pages, 9 figure

Dynamics of the Free Surface of a Conducting Liquid in a Near-Critical Electric Field

Near-critical behavior of the free surface of an ideally conducting liquid in an external electric field is considered. Based on an analysis of three-wave processes using the method of integral estimations, sufficient criteria for hard instability of a planar surface are formulated. It is shown that the higher-order nonlinearities do not saturate the instability, for which reason the growth of disturbances has an explosive character.Comment: 19 page

Development Of Software–Hardware System for Real Time Simulation of Electric Power System with Smart Grids

The design and research of electric power system (EPS) with smart grids (SG), which are the current world trend of modern electric power industry, requires solving a large number of non-trivial tasks. The developed technical solutions and used equipment are novel for the world practice. Therefore, their implementation requires carefulanalysis and an individual approach to research that provides an assessment of the impact of new network elements on the power system. All of this puts requirements on the tools and methods of research used to solve such problems. At present, digital systems for modelling EPS with SG based on the application of numerical methods are used as such tools. However, despite the high level of these developments, it has drawbacks. The use of incomplete and invalid information obtained by digital tools can lead to the wrong design and operational decision in real power system, which can cause blackouts. The alternative approach for solving the problem of detailed simulation of EPS with SG is the creation of hybrid system based on the principle of combining different modelling methods. Hybrid Real-Time Power System Simulator (HRTSim) is developed based on this approach and presented in the paper

Hybrid interventions on aorto-iliac segment and arteries of lower limbs

Department of Vascular Surgery, Department of Endovascular Surgery, Mariinsky Hospital, Saint Petersburg, Russia, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroduction: Current progress in endovascular methods and techniques makes possible its effective combination with open surgical procedures. Material and methods: The following hybrid procedures were performed in our department: 34 interventions on aorto-iliac segment (iliac arteries stenting combined with reconstruction of deep femoral artery – 16 cases, loop-endarterectomy from external iliac artery combined with iliac arteries stenting – 18 cases); 25 interventions on femoral-popliteal segment (loop-endarterectomy from superficial femoral artery – 15 cases, iliac stenting combined with loop-endarterectomy from superficial femoral artery – 7 cases, above-knee femoral-popliteal bypass combined with popliteal artery stenting – 3 cases); and 21 interventions on popliteal-tibial segment (loopendarterectomy from popliteal artery with angioplasty of tibial arteries – 8 cases, femoral-peroneal bypass combined with angioplasty of tibial arteries – 13 cases). Completion angiography was routinely performed in all patients for quality control of revascularization. Chronic ischemia grade II Fontaine was diagnosed preoperatively in 19 (23,75%) patients, grade III - in 40 (50%) and grade IV – in 21 (26,25%) patients. Results: Complete regression of ischemic pain, initial signs of healing of superficial defects of soft tissues as well as primary healing of wounds after debridement of necrotic lesions were observed in the postoperative period. Mean duration of hospital stay was 7 days. Conclusion: Thus, implementation of hybrid procedures contributes to the reduction of the volume of open vascular reconstructions. Hybrid interventions represent the optimal approach for treatment of occlusive lesions of aorto-iliac segment and arteries of lower limbs