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Sidawi K.,University of Ontario Institute of Technology | Pioro I.,University of Ontario Institute of Technology | Razumovskiy V.G.,National Technological University of Ukraine | Pis'mennyi Eu.N.,National Technological University of Ukraine | Koloskov A.Eu.,National Technological University of Ukraine
International Conference on Nuclear Engineering, Proceedings, ICONE | Year: 2015

There have been relatively few publications detailing correlations for heat-transfer in SuperCritical Water (SCW) flowing inside bundle geometry compared to SCW heat-transfer in bare-tubes. Since flow geometry is impeded by bundle geometry, heat-transfer to the coolant occurs differently in bundles than in bare tubes. In this paper, results of heat-transfer to supercritical water flowing upward in a vertical 1-rod annular channel and 3-rod bundle (rods are equipped with helical ribs) are discussed. The data obtained in this study could be applicable for a reference estimation of heat transfer in future designs of fuel bundles. The Jackson (2002) bare-tube heat-transfer correlation most accurately predicted Heat Transfer Coefficients (HTCs) in annular channel trials at heat fluxes less than 2.5 MW/m2. However, this correlation (along with others) did not predict HTCs accurately in annular channel trials at heat fluxes above 2.5 MW/m2 and in 3-rod bundle geometry at all values of heat flux tested. Changes in thermophysical properties of a coolant, especially, within the pseudocritical region, caused discontinuity in the calculated HTC profiles in most correlations. Copyright © 2015 by JSME.


Bessalov A.V.,National Technological University of Ukraine | Tsygankova O.V.,National Technological University of Ukraine
Telecommunications and Radio Engineering (English translation of Elektrosvyaz and Radiotekhnika) | Year: 2015

Modification of the law of addition of points on the Edwards curve over a simple field is offered. The necessary and sufficient condition of dividing of the point by 2 is obtained. The theorem about a degenerate pair of torsion curves when the curve parameter d = 2 is proved. The algorithm of finding all unknown points kP of the Edwards curve with 1/8 part of the known points is offered. © 2015 by Begell House, Inc.


Ye Ilchenko M.,National Technological University of Ukraine | Narytnyk T.M.,National Technological University of Ukraine | Radzikhovsky B.M.,National Technological University of Ukraine | Kuzmin S.E.,National Technological University of Ukraine | Lutchak O.V.,National Technological University of Ukraine
Telecommunications and Radio Engineering (English translation of Elektrosvyaz and Radiotekhnika) | Year: 2015

The results of design and experimental study of receiving and transmitting channels of the telecommunication systems with Gigabit throughput in the 130-134 GHz frequency band, containing subharmonically pumped frequency converters, a local oscillator using highly stable crystal oscillator, pandpass waveguide (1.6 õ0.8 mm channel) septum filter and a conical horn antenna, are provided. Laboratory studies of a sample terahertz band digital simplex relay system for the telecommunication range within 1 km under normal conditions with the possible bit error rate (BER) values of no more than 10-6 comprising: receiving and transmitting channels in the 130-134 GHz frequency bandwidth and a digital modem with the channel throughput of up to 1200 Mbps, are performed in terms of practical application for the first time. © 2015 by Begell House, Inc.


Narytnyk T.M.,National Technological University of Ukraine | Lutchak O.V.,National Technological University of Ukraine | Osypchuk S.O.,National Technological University of Ukraine | Uryvskyi L.O.,National Technological University of Ukraine
Telecommunications and Radio Engineering (English translation of Elektrosvyaz and Radiotekhnika) | Year: 2015

The principles of a signal-code sequence shaping are considered, the means and new technologies for selection of the type of the signal sequence are suggested in order to attain the best throughput and efficiency parameters in the telecommunication channel of a wireless data transmission system where the performance is determined by the signal-to-noise ratio at the input of the receiver. Based on the analysis of parameters and criteria recommended by IEEE 802.11a/n specifications for selection of the signal-code sequences, it is suggested the informational efficiency parameter for using the telecommunication channel resources. The telecommunication line was tested to the range of 1.7 km with the help of MikroTik R52n-M wireless interfaces. There were defined the signal-code sequences, which were selected for data transmission by the software-defined radio systems. It was determined that judging upon the signal level at the input of the receiver, types of the signal-code sequence and the obtained data transmission rate, the software-defined radio system using the MikroTik R52n-M equipment is fully compliant with the recommendations provided in IEEE 802.11?/n specifications. Realization of the concept for creation of a Wi-Fi-based software-defined radio systems is demonstrated on the example of a developed gigabit data transmission system in the 130...134 GHz bandwidth of the terahertz band. The system was tested in vitro where it attained the data transmission rate of up to 1.2 Gbps. It is demonstrated that the above data transmission system can be potentially used in transportation and distribution networks for the next generation mobile communication networks providing for the required bitrate, reliability and protection. ©2015 by Begell House, Inc.


Narytnik T.N.,National Technological University of Ukraine
Telecommunications and Radio Engineering (English translation of Elektrosvyaz and Radiotekhnika) | Year: 2014

The results of investigation of basic trends and promising of development for the mobile backhaul are provided. On the basis of performed theoretical estimations, computations and physical simulation it is designed a THz band radio communication channel with the possibility of building super high-rate (over 1 Gbps) backhauls. ©2014 by Begell House Inc.

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