scholarly journals A Survey of Electromagnetic Influence on UAVs from an EHV Power Converter Stations and Possible Countermeasures

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 701
Author(s):  
Yanchu Li ◽  
Qingqing Ding ◽  
Keyue Li ◽  
Stanimir Valtchev ◽  
Shufang Li ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Wide Spectrum ◽  
Electromagnetic Emission ◽  
Power Converter ◽  
Electromagnetic Environment ◽  
Communication Circuits ◽  
Electromagnetic Emissions ◽  
Surrounding Space ◽  
Extra High Voltage ◽  
The Impact

It is inevitable that high-intensity, wide-spectrum electromagnetic emissions are generated by the power electronic equipment of the Extra High Voltage (EHV) power converter station. The surveillance flight of Unmanned Aerial Vehicles (UAVs) is thus, situated in a complex electromagnetic environment. The ubiquitous electromagnetic interference demands higher electromagnetic protection requirements from the UAV construction and operation. This article is related to the UAVs patrol inspections of the power line in the vicinity of the EHV converter station. The article analyzes the electromagnetic interference characteristics of the converter station equipment in the surrounding space and the impact of the electromagnetic emission on the communication circuits of the UAV. The anti-electromagnetic interference countermeasures strive to eliminate or reduce the threats of electromagnetic emissions on the UAV’s hardware and its communication network.

Electromagnetic environment on extensive rail areas and the process of using electronic safety systems

2018 ◽  
Vol 121 ◽  
pp. 21-30
Author(s):  
Kamil Białek ◽  
Jacek Paś
Keyword(s):  
Magnetic Fields ◽  
Electromagnetic Interference ◽  
Electronic Equipment ◽  
Electromagnetic Environment ◽  
Security Systems ◽  
Electric And Magnetic Fields ◽  
Safety Systems ◽  
The Impact

The article presents the results of research electric and magnetic fields in the field of higher frequencies, which are produced by electronic security systems in large logistics areas. The paper also presents the background of the electromagnetic environment. Distorted electromagnetic environment can interfere with the operation of electrical and electronic equipment that are used in the railway area. Particular attention has been paid to the impact of electromagnetic interference on selected electronic security systems.

scholarly journals Investigations on the Use of the Power Transistor Source Inductance to Mitigate the Electromagnetic Emission of Switching Power Circuits

Signals ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 586-603
Author(s):  
Erica Raviola ◽  
Franco Fiori
Keyword(s):  
Electromagnetic Interference ◽  
Power Efficiency ◽  
Electromagnetic Emission ◽  
Optimization Method ◽  
Power Converter ◽  
Primary Concern ◽  
Power Transistor ◽  
Power Transistors ◽  
Power Switches ◽  
Oscillation Damping

With power designers always demanding for faster power switches, electromagnetic interference has become an issue of primary concern. As known, the commutation of power transistors is the main cause of the electromagnetic noise, which can be worsened by the presence of unwanted oscillations superimposed onto the switching waveforms. This work proposes a solution to mitigate the oscillations caused by the turn-on of a power transistor by exploiting its source inductance plus an external one. In this context, an optimization method is proposed to find the optimal value of the source inductance as a trade-off between oscillation damping and power dissipation. The experimental results performed on a prototyped power converter assess the proposed technique as the spectrum of the conducted emission is attenuated by 20 dB at the oscillation frequency. With respect to traditional solution based on snubbers, the proposed solution results in a similar oscillation damping, but with a 0.5% higher power efficiency.

scholarly journals The results of experimental studies of VLF–ULF electromagnetic emission by rock samples due to mechanical action

2014 ◽  
Vol 14 (6) ◽  
pp. 1383-1389 ◽  
Author(s):  
A. A. Panfilov
Keyword(s):  
Laboratory Experiments ◽  
Experimental Studies ◽  
Electromagnetic Emission ◽  
Mechanical Action ◽  
Impact Action ◽  
Rock Samples ◽  
Electric Component ◽  
Electromagnetic Emissions ◽  
Electromagnetic Signals ◽  
The Impact

Abstract. The paper presents the results of laboratory experiments on electromagnetic emissions excitation (the electric component of electromagnetic fields) by rock samples due to different forms of mechanical stress applications. It was shown that samples generate electric impulses with different spectra when the impact action, gradual loading or dynamic friction is applied. It was ascertained that level and spectral compositions of signals, generated by rock samples, change with an increasing number of hits. It was found that strong electromagnetic signals, generated while rock samples were fracturing, were accompanied by repetitive weak but perceptible variations in the electric field intensity in short frequency ranges.

scholarly journals Analysis of the electromagnetic environment in an extensive railway area

2018 ◽  
Vol 67 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Kamil Białek ◽  
Jacek Paś
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Interference ◽  
High Frequency ◽  
Electronic Devices ◽  
Capacitive Coupling ◽  
Electronic Systems ◽  
Electromagnetic Environment ◽  
Frequency Spectra ◽  
Electric And Magnetic Fields ◽  
The Impact

The paper presents the results of testing the electric and magnetic fields across a wide frequency spectrum as unintentionally generated in an extensive railway area. High levels of electromagnetic interference generated in a railway area can cause the malfunction of electrical and electronic devices. The paper presents an electromagnetic environment in the low and high frequency spectra that prevail in an extensive railway area. Special attention was paid to the impact of electromagnetic interference on specific electronic systems. Keywords: electromagnetic field, spectrum, interference, induction and capacitive coupling

scholarly journals The Impact of Fluid Loss and Carbohydrate Consumption during Exercise, on Young Cyclists’ Fatigue Perception in Relation to Training Load Level

2021 ◽  
Vol 18 (6) ◽  
pp. 3282
Author(s):  
Leonardo Cesanelli ◽  
Berta Ylaitė ◽  
Giuseppe Messina ◽  
Daniele Zangla ◽  
Stefania Cataldi ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Wide Spectrum ◽  
Load Level ◽  
Training Load ◽  
Fluid Loss ◽  
Young Athletes ◽  
Carbohydrate Consumption ◽  
Significant Difference ◽  
Training Impulse ◽  
The Impact

High-level young athletes need to face a wide spectrum of stressors on their journey to élite categories. The aims of the present study are (i) to evaluate session rate of perceived exertion (sRPE) at different training impulse (TRIMP) categories and the correlations between these two variables and, (ii) evaluate the correlations between sRPE, fluid loss, and carbohydrate consumption during exercise. Data on Edward’s TRIMP, sRPE, body mass loss pre- and post- exercise (∆), and carbohydrate consumption (CHO/h) during exercise have been acquired from eight male junior cyclists during a competitive season. One-way ANOVA and correlation analysis with linear regression have been performed on acquired data. sRPE resulted in a significant difference in the three TRIMP categories (p < 0.001). sRPE resulted in being very largely positively associated with TRIMP values (p < 0.001; R = 0.71). ∆ as well as CHO/h was largely negatively related with sRPE in all TRIMP categories (p < 0.001). The results confirmed the role of fluid balance and carbohydrate consumption on the perception of fatigue and fatigue accumulation dynamics independently from the training load. Young athletes’ training load monitoring and nutritional-hydration support represent important aspects in athlete’s exercise-induced fatigue management.

scholarly journals Influence of Aircraft Power Electronics Processing on Backup VHF Radio Systems

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 777
Author(s):  
Jan Leuchter ◽  
Radim Bloudicek ◽  
Jan Boril ◽  
Josef Bajer ◽  
Erik Blasch
Keyword(s):  
Power Electronics ◽  
Electromagnetic Interference ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Intermediate Frequency ◽  
Radio Communication ◽  
Very High Frequency ◽  
Switching Power ◽  
Radio Systems ◽  
The Impact

The paper describes the influence of power electronics, energy processing, and emergency radio systems (ERS) immunity testing on onboard aircraft equipment and ground stations providing air traffic services. The implementation of next-generation power electronics introduces potential hazards for the safety and reliability of aircraft systems, especially the interferences from power electronics with high-power processing. The paper focuses on clearly identifying, experimentally verifying, and quantifiably measuring the effects of power electronics processing using switching modes versus the electromagnetic compatibility (EMC) of emergency radio systems with electromagnetic interference (EMI). EMI can be very critical when switching power radios utilize backup receivers, which are used as aircraft backup systems or airport last-resort systems. The switching power electronics process produces interfering electromagnetic energy to create problems with onboard aircraft radios or instrument landing system (ILS) avionics services. Analyses demonstrate significant threats and risks resulting from interferences between radio and power electronics in airborne systems. Results demonstrate the impact of interferences on intermediate-frequency processing, namely, for very high frequency (VHF) radios. The paper also describes the methodology of testing radio immunity against both weak and strong signals in accordance with recent aviation standards and guidance for military radio communication systems in the VHF band.

scholarly journals System Level Simulation of Microgrid Power Electronic Systems

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 644
Author(s):  
Michal Frivaldsky ◽  
Jan Morgos ◽  
Michal Prazenica ◽  
Kristian Takacs
Keyword(s):  
Smart Grid ◽  
Simulation Model ◽  
Real Time ◽  
Power Converter ◽  
System Level ◽  
Time Behavior ◽  
Operational Parameters ◽  
System Level Simulation ◽  
Time Operation ◽  
The Impact

In this paper, we describe a procedure for designing an accurate simulation model using a price-wised linear approach referred to as the power semiconductor converters of a DC microgrid concept. Initially, the selection of topologies of individual power stage blocs are identified. Due to the requirements for verifying the accuracy of the simulation model, physical samples of power converters are realized with a power ratio of 1:10. The focus was on optimization of operational parameters such as real-time behavior (variable waveforms within a time domain), efficiency, and the voltage/current ripples. The approach was compared to real-time operation and efficiency performance was evaluated showing the accuracy and suitability of the presented approach. The results show the potential for developing complex smart grid simulation models, with a high level of accuracy, and thus the possibility to investigate various operational scenarios and the impact of power converter characteristics on the performance of a smart gird. Two possible operational scenarios of the proposed smart grid concept are evaluated and demonstrate that an accurate hardware-in-the-loop (HIL) system can be designed.

scholarly journals Acute Management Should Be Optimized in Patients with Less Specific Stroke Symptoms: Findings from a Retrospective Observational Study

2021 ◽  
Vol 10 (5) ◽  
pp. 1143
Author(s):  
Simona Halúsková ◽  
Roman Herzig ◽  
Dagmar Krajíčková ◽  
Abduljabar Hamza ◽  
Antonín Krajina ◽  
...  
Keyword(s):  
Wide Spectrum ◽  
Intravenous Thrombolysis ◽  
National Institutes Of Health ◽  
Vascular Territory ◽  
Anterior Circulation ◽  
Point Increase ◽  
Single Center Study ◽  
Mouth Corner ◽  
Specific Symptoms ◽  
The Impact

Anterior circulation stroke (ACS) is associated with typical symptoms, while posterior circulation stroke (PCS) may cause a wide spectrum of less specific symptoms. We aim to assess the correlation between the initial presentation of acute ischemic stroke (AIS) symptoms and the treatment timeline. Using a retrospective, observational, single-center study, the set consists of 809 AIS patients treated with intravenous thrombolysis (IVT) and/or endovascular treatment (EVT). We investigate the impact of baseline clinical AIS symptoms and the affected vascular territory on recanalization times in patients treated with IVT only and EVT (±IVT). Regarding the IVT-only group, increasing the National Institutes of Health Stroke Scale (NIHSS) score on admission and speech difficulties are associated with shorter (by 1.59 ± 0.76 min per every one-point increase; p = 0.036, and by 24.56 ± 8.42 min; p = 0.004, respectively) and nausea/vomiting with longer (by 43.72 ± 13.13 min; p = 0.001) onset-to-needle times, and vertigo with longer (by 8.58 ± 3.84 min; p = 0.026) door-to-needle times (DNT). Regarding the EVT (±IVT) group, coma is associated with longer (by 22.68 ± 6.05 min; p = 0.0002) DNT, anterior circulation stroke with shorter (by 47.32 ± 16.89 min; p = 0.005) onset-to-groin time, and drooping of the mouth corner with shorter (by 20.79 ± 6.02 min; p = 0.0006) door-to-groin time. Our results demonstrate that treatment is initiated later in strokes with less specific symptoms than in strokes with typical symptoms.

scholarly journals Evaluating ‘homegrown’ research networks in Africa

2018 ◽  
Vol 114 (3/4) ◽  
Author(s):  
Camilla Adelle ◽  
Nico Elema ◽  
Ereck Chakauya ◽  
David Benson
Keyword(s):  
Wide Spectrum ◽  
Evaluation Framework ◽  
Evidence Based ◽  
Regional Research ◽  
Research Networks ◽  
Sustainable Resources ◽  
Science Policy Interface ◽  
Mere Existence ◽  
The Impact

Attempts to improve the policy environment have led to a growing pressure on governments in Africa to embark on policymaking that is more evidence based and considers a wide spectrum of scientific and indigenous knowledge. Local – or ‘homegrown’ – research networks on the continent can help strengthen the role of scientific knowledge in policymaking by increasing the capacity of researchers and by enhancing the visibility and communication of the research produced. While a large number of regional and sub-regional research networks have sprung up in Africa, the mere existence of networks does not guarantee their success. In reality, the impact of research networks on the science–policy interface depends on how well the networks operate in practice. We present a framework for evaluating the effectiveness of research networks in a way that is comparable across networks. The evaluation framework was used to evaluate two sub-regional research networks: the NEPAD Southern African Networks of Water Centres of Excellence (SANWACTE) and the NEPAD Southern African Network for Biosciences (SANBio). The evaluation revealed some shared constraints limiting the effectiveness of both networks, including uneven regional representation, asymmetry between network members, and difficulties in securing sufficient, diverse and sustainable resources. Further research into network design and funding models is suggested in order to enhance the role of these networks in providing locally appropriate knowledge for policymaking on the continent.

scholarly journals Developing fit-for-purpose self-report instruments for assessing consumer responses to tobacco and nicotine products: the ABOUT™ Toolbox initiative

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1878 ◽  
Author(s):  
Christelle Chrea ◽  
Catherine Acquadro ◽  
Esther F. Afolalu ◽  
Erica Spies ◽  
Thomas Salzberger ◽  
...  
Keyword(s):  
Public Health ◽  
Wide Spectrum ◽  
Medical Product ◽  
Consumer Perception ◽  
Self Report ◽  
Measurement Instruments ◽  
Patient Reported ◽  
Fit For Purpose ◽  
And Behavior ◽  
The Impact

Background. Determining the public health impact of tobacco harm reduction strategies requires the assessment of consumer perception and behavior associated with tobacco and nicotine products (TNPs) with different exposure and risk profiles. In this context, rigorous methods to develop and validate psychometrically sound self-report instruments to measure consumers’ responses to TNPs are needed. Methods. Consistent with best practice guidelines, including the U.S. Food and Drug Administration’s “Guidance for Industry Patient-Reported Outcome Measures: Use in Medical Product Development to Support Labeling Claims,” scientifically designed, fit-for-purpose, reliable, and valid instruments are now being applied to tobacco regulatory research. Results. This brief report presents the ABOUT™ Toolbox (Assessment of Behavioral OUtcomes related to Tobacco and nicotine products) initiative. This communication: (1) describes the methodological steps followed for the development and validation of the measurement instruments included in the ABOUT™ Toolbox, (2) presents a summary of the high-priority tobacco-related domains that are currently covered in the ABOUT™ Toolbox (i.e., risk perception, dependence, product experience, health and functioning, and use history), and (3) details how the measurement instruments are made accessible to the scientific community. Conclusions. By making the ABOUT™ Toolbox available to the tobacco research and public health community, we envision a rapidly expanding knowledge base, with the goals of (1) supporting consumer perception and behavior research to allow comparisons across a wide spectrum of TNPs, (2) enabling public health and regulatory communities to make better-informed decisions for future regulation of TNPs, and (3) enhancing surveillance activities associated with the impact of TNPs on population health.

Sign in / Sign up

Export Citation Format

Share Document