NES (Slovakia)

This paper discusses the issue related to the switching regulators operated at high switching frequencies, where it is necessary to eliminate the influence of parasitic components of the converter's main circuit. In more detail it deals with the node-ringing phenomena, which is typical for synchronous buck converters. The existence of the parasitic inductances arising from the printed circuit board conductive paths, induce voltages, which are several times higher than nominal input voltage, thus it increases the risk of damage of the power transistors. Therefore, optimization of the circuit is required to reduce the voltage spikes and therefore improve safety margin related to nominal operation. In this paper, node-ringing phenomena is introduced, while the optimization methodologies for its reduction are described and verified by experimental analysis.

In this paper, experimental measurements of four parallel-connected three-phase inverters of railway auxiliary converters were carried out. The purpose of this measurement was to verify the ability of parallel co-operation of four threephase inverters connected to a common three-phase bus, verifying the starting sequence of the inverters and power sharing by individual converters. The converters were powered by a common high voltage AC source and the outputs were interconnected to form a common three-phase network. The ability to uniform power sharing was tested during 15 kW and 137 kW motor acceleration. The results showed that all inverters were able to synchronize and connect to the common bus and stable operate in parallel connection. Furthermore, the power sharing was uniform and stable under these conditions.

Abstract Chinese researchers just confirmed that patients can transmit the coronavirus without showing symptoms. A woman passed it to 5 relatives. A 20-year-old woman from Wuhan, China, transmitted the coronavirus to her family members without ever showing any symptoms, a new study found. The woman tested positive for the virus, but her CT scans were clear and she never became physically ill. Five of her family members, however, came down with a fever. Two developed severe pneumonia. The case is evidence that the coronavirus can be transmitted when someone is asymptomatic.

A revolution, Napoleon said, can be neither started nor stopped. In medicine it happens over decades. The emergence of cardiac stents, for example, revolutionized the use of coronary bypass..

Chinese scientists won a major victory, by proving that the Majorana fermions – a particle we’ve found tantalizing hints for years – genuinely exists. This discovery has huge implications for quantum computing, and it might change the world. Don Lincoln, a senior physicist at Fermi lab, does research using the Large Hadrons Collider. He is the author of “The Large Hadrons Collider: The Extraordinary Story of the Higgs Boson and Other Stuff That Will Blow Your Mind”, and produces a series of science education videos. To the question: Why is there (in our Universe) something including cancer, rather than nothing? He is giving the simplest scientific answer: We shouldn’t exist at all.

Developmental biologists at Tufts University, using a tadpole model, that bioelectrical signals from distant cells control the incidence of tumors arising from cancer-causing genes and that this process is impacted by levels of a common fatty acid produced by bacteria found in the tadpole and also in humans.Bile acids and oxidative stress decrease DNA repair proteins, an increase in DNA damage and increased genomic instability through this mechanism of metastases caused by Quantum Entanglement Entropy.This process provides a mechanistic explanation for the important QEE link between a Western-style diet and associated increased levels of colon cancer.

Almost every public transport vehicle includes the battery pack. For it's charging is necessary that the vehicle dispose with charger. These vehicles are usually operated in different parts of the world and in many areas there are extreme conditions. To ensure operational reliability and a long operating time without maintenance. The charger was designed and created with natural cooling for extreme conditions (deserts). The charger is supplied by three phase AC voltage 400 V/50 Hz. At the output of the charger is adjustable charging voltage 0–30 V and output current 0–250 A. The charger has been implemented with all modern functions used in the current chargers as thermal correction of the output voltage, measuring capacity of the battery pack and the like.

It is known that the management of chronic gout in relation to serum uric acid (SUA) monitoring, allopurinol dosing, and lifestyle advice is often sub-optimal in primary care.[1] A quality improvement project in the form of a criterion based audit was carried out in an urban general practice to improve the care of patients being treated for gout.Baseline searching of EMIS confirmed that management of patients with gout who were taking allopurinol was not in line with current guidance. 51(40%) had a SUA checked in the past 12 months, 88(25%) had a SUA below target level, and gout lifestyle advice was not being recorded.An audit was performed to measure and improve the following criteria:• Monitoring of SUA levels in the past 12 months• Titration of urate lowering therapy to bring the SUA below target level• Lifestyle advice in the past 12 monthsAn audit standard of 60% achievement at 2 months and 80% achievement at 4 months was set.The intervention consisted of a custom electronic template within EMIS which allowed guidance of gout management to be displayed and for data to be entered. All members of the team including GPs and administrative staff were educated regarding the intervention. This resulted in a sustained improvement over a 6 month period in all 3 components of the audit with 112(84%) having a SUA level checked, 79(51%) having a SUA below target level and 76(57%) receiving lifestyle advice. Although the improvement did not reach the audit standard in 2 of the criteria it would be expected that outcomes would continue given the systems changes which have been made.

This paper presents an application of deadbeat control theory in control of the DC/AC single-phase voltage source PWM inverter (VSI PWM). The main object of the article is to ensure a high quality of the inverter output voltage under different types of load (linear and nonlinear). One of the main criteria of the quality of the output voltage is total harmonic distortion (THD). It should be kept as small as possible. This article describes a detailed modelling of the plant and controller design. A novel multi-loop control technique based on deadbeat theory is proposed in order to achieve sinusoidal output voltage. The proposed control scheme consists of current and voltage loop. Theoretical analysis, simulation and practical results have been given to verify the proposed digital control scheme. Proposed control scheme was implemented into the TMS320F28335 DSC controller and tested on 1 kW PWM inverter.

The paper presents an implementation of a discontinuous space vector modulation of three phase inverter. The modulation is implemented in a DSC (Digital Signal Controller) using only one PWM module. Phases of the inverter work in a complementary mode. This implementation gives an assumption to use one DSC for simultaneous controlling of several three phase inverters. Furthermore, a simulation comparison of discontinuous and continuous space vector modulation is made.