AEGIS – Mobile Device for Generating Electromagnetic Curtain for Special Applications and Countering the Threats of RCIED

In the article the concept, design and realization of the technological demonstrator of a mobile device for generating an electromagnetic curtain (with a name AEGIS) were presented, both in the hardware and software areas. The device is designed to block the radio communication which allow detonating the Radio Controlled Improvised Explosive Devices (RCIEDs). The preliminary laboratory tests of the demonstrator for generating the jamming signal, that were presented in the paper, aimed at assessing the correctness of the device operation and verification of generated signal parameters. On the basis of the obtained results, the ability to jam the cellular systems as well as other radio devices operating in the frequency band from 400 MHz to 2700 MHz was assessed

Właściwości dyfuzyjne fasadowych membran EPDM

This research aimed to investigate the water vapour transmission properties of chosen EPDM membranes applied in façade and window systems under laboratory tests. The applied procedure included in national and international standards utilized for the laboratory tests of water vapour transmission properties of EPDM membrane is described. Two main types (outside and inside types) of EPDM membranes are laboratory tested. The authors indicated that the EPDM membranes should differ in surface factures. Nevertheless, some manufacturers mark EPDM membranes on each roll (on the package only) without different permanent denotations on the EPDM membranes surfaces. This form of denotations can cause using problems - using the wrong types of the EPDM aprons in building partitions, because when the package is removed there is impossible to visually identify the type of EPDM membrane (outside or inside type) from the texture of the membrane surface. The experimental results of laboratory tests indicated using the wrong type of EPDM membrane in the inside aprons in building partitions in the investigated façade window system. The designed proportion of the sd values (the resistance to movement of water vapour) of inside and out-side EPDM façade membranes should be designed equally to about 3.0 (recommended value 4) to provide proper diffusion properties of partitions around windows in façade systems. The paper can provide scientists, engineers, and designers an experimental basis in the field of the EPDM membranes water vapour transmission properties applied to façades and windows systems.Celem badań było określenie właściwości przepuszczalności pary wodnej wybranych membran elewacyjnych EPDM stosowanych w systemach fasadowych i okiennych w ramach testów laboratoryjnych. Omówiono zastosowaną procedurę zawartą w normach krajowych i międzynarodowych stosowanych do badań laboratoryjnych właściwości przepuszczalności pary wodnej membrany EPDM. Dwa główne typy (zewnętrzne i wewnętrzne) membran EPDM zostały poddane badaniom laboratoryjnym. Proces określania właściwości przepuszczalności pary wodnej dla membran EPDM jest długotrwałym badaniem laboratoryjnym. Projektowana proporcja wartości sd (oporu na ruch pary wodnej) wewnętrznych i zewnętrznych membran elewacyjnych EPDM powinna być równa około 3,0 (zalecana wartość 4), aby zapewnić odpowiednie właściwości dyfuzyjne przegród wokół okien w systemach elewacyjnych. Eksperymentalne wyniki badań laboratoryjnych wskazały na zastosowanie niewłaściwego rodzaju membrany EPDM w fartuchach wewnętrznych przegród budowlanych w badanym systemie okien fasadowych. Autorzy mają nadzieję, że opisane testy laboratoryjne wzbudzą żywe zainteresowanie środowiska inżynierów i naukowców, aby uwzględnić tematykę właściwości przepuszczalności pary wodnej membran EPDM stosowanych w systemach elewacjach i okiennych

Development and Evaluation of a Tethered Class C3 Hexacopter in Maritime Conditions on the Helipad of a Ferry

Various unmanned aerial vechicle (UAV) applications, especially those based on reconnaissance and observation missions, often require an unlimited time of flight. This is possible only when a UAV is continuously supplied with power from a ground-based power source, which is why tethered UAV systems were developed. Tethered UAV systems are based on multicopters, which can hover above a landing pad or track its position if it is movable. The presented research concerned the development of a large C3 class hexacopter with a maximal payload of about 1 kg and a takeoff mass of 16 kg, which was tested in maritime conditions during a ferry’s cruise. The main purpose of the hexacopter was to continuously observe the area ahead of the vessel to detect and localize obstacles in the water. During the experimental tests, critical phases of flight were identified, the AC/DC power supply unit and power cord unwinder were tested, and the power required by six brushless direct current (BLDC) motors was registered. The obtained results could be useful in future work on tethered UAV systems applied in windy maritime conditions

Depolarisation model for a BAN indoor scenario

Abstract In this paper, an analysis of depolarisation in Body Area Networks for Body-to-Infrastructure communications based on a measurement campaign in the 5.8 GHz band in an indoor environment is performed. Measurements were made with an off-body antenna transmitting linearly polarised signals and dual-polarised receiving antennas carried by the user on the body. A Normal Distribution with a mean of 2.0 dB and a standard deviation of 4.3 dB is found to be the best fit for modelling cross-polarisation discrimination. The average correlation between the signals received by the orthogonally polarised antennas is below 0.5, showing that polarisation diversity can be used. A model is proposed for the average value of the standard deviation of the cross-polarisation discrimination ratio as a function of the transmitted polarisation, the mobility of users and link dynamics