Examination of the impact of design of a residual current protective device on the release frequency range

2017 ◽  
Author(s):  
Pawel Czaja
Keyword(s):  
Residual Current ◽  
Protective Device ◽  
Frequency Range ◽  
The Impact

Study on the Residual Current Protection Device Technology

2014 ◽  
Vol 8 (1) ◽  
pp. 404-411 ◽  
Author(s):  
Guo Rongyan ◽  
Zhang Honghui
Keyword(s):  
Distribution System ◽  
Low Voltage ◽  
Residual Current ◽  
Electrical Safety ◽  
Protective Device ◽  
Protection Device ◽  
Voltage Distribution ◽  
The People ◽  
Safety Protection ◽  
Device Technology

As an important electrical safety protection device in low voltage distribution system, residual current protection device is to protect the insulation line leakage fault; the electric shock of the people plays an important role in fault. From the protection characteristics of residual current protective device to points, those can be divided into, residual current protection device for residual pulsating direct current and residual dc, according to the residual sinusoidal alternating current.

scholarly journals Aspects of Strength Testing of Tank Containers in Compliance with the Requirements of the UN Navigation Rules and Regulations

2021 ◽  
Vol 9 (3) ◽  
pp. 349
Author(s):  
Andrii Sulym ◽  
Pavlo Khozia ◽  
Eduard Tretiak ◽  
Václav Píštěk ◽  
Oleksij Fomin ◽  
...  
Keyword(s):  
Natural Frequencies ◽  
Response Spectrum ◽  
Experimental Curve ◽  
Bulk Liquid ◽  
Frequency Range ◽  
Test Configuration ◽  
Shock Response ◽  
Shock Response Spectrum ◽  
Spectrum Curve ◽  
The Impact

This article deals with the method of computer-aided studies of the results of tank container impact tests to confirm the ability of portable tanks and multi-element gas containers to withstand the impact in the longitudinal direction on a specially equipped test rig or using a railway flat car by impacting a flat car with a striking car, in compliance with the requirements of the UN Navigation Rules and Regulations. It is shown that the main assessed characteristic of the UN requirements is the spectrum of the shock response (accelerations) for the interval natural frequencies of the shock pulse. The calculation of the points of the shock response spectrum curve based on the test results is reproduced in four stages. A test configuration of the impact testing of the railway flat car with a tank container is presented, and the impact is performed in such a way that, under a single impact, the shock spectrum curve obtained during the tests for both fittings subjected to impact repeats or exceeds the minimum shock spectrum curve for all frequencies in the range of 2 Hz to 100 Hz. Formulas for determining the relative displacements and accelerations for the interval natural frequencies of the shock wave are given. The research results are presented in graphical form, indicating that the experimental values of the shock response spectrum exceed the minimum permissible values; the equation of the experimental curve of the shock response spectrum in the frequency range 0–100 Hz is described by power-law dependence. The coefficients of the equation were determined by the statistical method of maximum likelihood with the determination factor being 0.897, which is a satisfactory value; a comparative analysis showed that the experimental curve of the impact response spectrum in the frequency range 0–100 Hz exceeds the normalized curve, which confirms compliance with regulatory requirements. A new test configuration is proposed using a tank car with a bulk liquid, the processes in which upon impact differ significantly from other freight wagons under longitudinal impact loads of the tank container. The hydraulic impact resulting from the impact on the tank container and the platform creates an overturning moment that causes the rear fittings to be unloaded.

scholarly journals Experimental on the protective performance of column bridge pier anti-scouring device

2021 ◽  
Vol 248 ◽  
pp. 01015
Author(s):  
Zhejiang Chen ◽  
Liang Liu ◽  
Yonglin Hu ◽  
Nan Ye ◽  
Xiaoli Shen ◽  
...  
Keyword(s):  
Optimal Parameter ◽  
Reduction Rate ◽  
Local Scour ◽  
Bridge Pier ◽  
Design Parameters ◽  
Water Tank ◽  
Protective Device ◽  
Measuring Point ◽  
Test Range ◽  
The Impact

Because of the problem of local scour caused by the change of the flow structure caused by the water-resistance of the column bridge pier, the theoretical analysis, and indoor water tank test were used to study the effect of installing a new anti-scouring device in front of the bridge pier on the local scour reduction effect; the influence of the main design parameters such as the height of the protective device, the angle of the protective device and the distance from the protective device to the bridge pier on the local scour of the bridge pier was selected, and the optimal parameter design combination was selected. The test results show that: under the same water flow conditions, the maximum scour depth reduction rate of the measuring point under the protection of the protective device is 48.4% to 74.2% compared with the unprotected scour; the reduction rate of the bridge pier is relative to the relative height of the device and the device equivalent. The angle and the distance between the device and the bridge pier are related, and the shock reduction rate decreases with the increase of the flow intensity. In the test range, the ratio of the device height to the water depth is 2/3, the device angle is 60 °, and the distance from the bridge pier is 3. When the diameter of the pier is doubled, the effect of reducing the impact on the pier is the best.

Preparation of Magnetically Soft, Highly-Densified Fe Cluster-Assembled Films by Impact Cluster Deposition

2006 ◽  
Vol 11-12 ◽  
pp. 595-598
Author(s):  
Dong Liang Peng ◽  
K. Sumiyama ◽  
H. Yamada ◽  
Takehiko Hihara ◽  
T. Uchida
Keyword(s):  
Room Temperature ◽  
Magnetic Behavior ◽  
Cluster Beam ◽  
Frequency Range ◽  
Soft Magnetic ◽  
Size Change ◽  
Gas Condensation ◽  
Cluster Deposition ◽  
The Impact ◽  
High Cluster

Highly-densified Fe cluster-assembled films were obtained at room temperature by an energetic cluster deposition. Fe clusters were produced using a plasma-gas-condensation (PGC)-type cluster deposition apparatus with a high cluster productivity. Ionized clusters in a cluster beam were electrically accelerated and directly deposited onto a substrate together with neutral clusters from the same cluster source. By increasing the impact energy of the ionized clusters up to about 1 eV/atom, the obtained cluster-assemblies have packing fractions higher than 0.8 without any serious size change, and result in a soft magnetic behavior up to a frequency range of few hundred MHz.

scholarly journals Selected aspects of numerical modelling in prediction of building vibrations due to traffic

2018 ◽  
Vol 196 ◽  
pp. 01055
Author(s):  
Sławomir Dudziak ◽  
Zofia Kozyra
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modelling ◽  
The Finite Element Method ◽  
Frequency Range ◽  
Mass Estimation ◽  
Structure Response ◽  
Dynamic Analyses ◽  
Transportation Routes ◽  
The Impact

Dynamic analyses play an important role in the process of designing buildings in the vicinity of transportation routes. The Finite Element Method is the most popular modelling technique, because it allows to simulate the structure response in the higher frequency range properly. However, the results of such analyses depend on many factors and can differ a lot. This paper discusses the impact of the building mass estimation and neglecting or including damping in the analysis on the assessment of influence of vibrations due to traffic on people.

scholarly journals A new era for low frequency Galactic center transient monitoring

2013 ◽  
Vol 9 (S303) ◽  
pp. 458-460
Author(s):  
N. E. Kassim ◽  
S. D. Hyman ◽  
H. Intema ◽  
T. J. W. Lazio
Keyword(s):  
Radio Astronomy ◽  
Galactic Center ◽  
Monitoring Program ◽  
Low Frequency ◽  
Frequency Range ◽  
New Era ◽  
The Impact ◽  
New System

AbstractAn upgrade of the low frequency observing system of the VLA developed by NRL and NRAO, called low band (LB), will open a new era of Galactic center (GC) transient monitoring. Our previous searches using the VLA and GMRT have revealed a modest number of radio-selected transients, but have been severely sensitivity and observing time limited. The new LB system, currently accessing the 236--492 MHz frequency range, promises ≥5 × improved sensitivity over the legacy VLA system. The new system is emerging from commissioning in time to catch any enhanced sub-GHz emission from the G2 cloud event, and we review existing limits based on recent observations. We also describe a proposed 24/7 commensal system, called the LOw Band Observatory (LOBO). LOBO offers over 100 VLA GC monitoring hours per year, possibly revealing new transients and helping validate ASTRO2010's anticipation of a new era of transient radio astronomy. A funded LOBO pathfinder called the VLA Low Frequency Ionosphere and Transient Experiment (VLITE) is under development. Finally, we consider the impact of LB and LOBO on our GC monitoring program.

scholarly journals A Phantom Investigation to Quantify Huygens Principle Based Microwave Imaging for Bone Lesion Detection

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1505 ◽  
Author(s):  
Banafsheh Khalesi ◽  
Behnaz Sohani ◽  
Navid Ghavami ◽  
Mohammad Ghavami ◽  
Sandra Dudley ◽  
...  
Keyword(s):  
Bone Lesion ◽  
Microwave Imaging ◽  
Lesion Detection ◽  
Linear Scale ◽  
Frequency Range ◽  
Spatial Displacement ◽  
Artefact Removal ◽  
Huygens Principle ◽  
Transmitting Antenna ◽  
The Impact

This paper demonstrates the outcomes of a feasibility study of a microwave imaging procedure based on the Huygens principle for bone lesion detection. This study has been performed using a dedicated phantom and validated through measurements in the frequency range of 1–3 GHz using one receiving and one transmitting antenna in free space. Specifically, a multilayered bone phantom, which is comprised of cortical bone and bone marrow layers, was fabricated. The identification of the lesion’s presence in different bone layers was performed on images that were derived after processing through Huygens’ principle, the S21 signals measured inside an anechoic chamber in multi-bistatic fashion. The quantification of the obtained images was carried out by introducing parameters such as the resolution and signal-to-clutter ratio (SCR). The impact of different frequencies and bandwidths (in the 1–3 GHz range) in lesion detection was investigated. The findings showed that the frequency range of 1.5–2.5 GHz offered the best resolution (1.1 cm) and SCR (2.22 on a linear scale). Subtraction between S21 obtained using two slightly displaced transmitting positions was employed to remove the artefacts; the best artefact removal was obtained when the spatial displacement was approximately of the same magnitude as the dimension of the lesion.

Electromagnetic fields at work places experts of the cellular companies

10.12737/5019 ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 1-4
Author(s):  
Горохов ◽  
E. Gorokhov ◽  
Ляпкало ◽  
A. Lyapkalo
Keyword(s):  
Magnetic Fields ◽  
Electromagnetic Radiation ◽  
Electromagnetic Fields ◽  
Electric Fields ◽  
Working Conditions ◽  
Base Stations ◽  
Frequency Range ◽  
Magnetic Components ◽  
Electronic Computers ◽  
The Impact

The paper presents the results of instrumental studies by means of hygienic assessment of levels of electromagnetic fields (EMF) on the workplaces in cellular companies. Measurements of EFM were made on workplaces of 2 groups of employees during the studies: office administrative specialists and technical employees. Instrumental measurements of EMF levels were made by Personal Electronic Computers (PCs) and receivingtransmitting equipment of base cellular stations (BCS). Measurements of EMF from the PC´s screens based on electric and magnetic components were performed: a tension of electric fields with a frequency range of 5Hz-2 kHz and 2 kHz-4 kHz; a tension of magnetic fields in the frequency range of 5Hz-2 kHz and 2 kHz-4 kHz. Measurements of flux density of electromagnetic energy were performed at operating platforms of base stations and at control operating equipment rooms of cellular stations. There were about 150 workplaces of office administrative specialists with PCs surveyed and more 500 workplaces of technical specialists. The activities of administrations of cellular companies were estimated to ensure the safety of working conditions of employees under the influence of electromagnetic radiation (EMR). Literature data on the impact of EMR on human health and health of employees were presented.

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