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Number of results: 4
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Abstract

CFD technique was used to determine the effect of a stent-graft spatial configuration and hematocrit value on blood flow hemodynamic and the risk of a stent-graft occlusion. Spatial configurations of an endovascular prosthesis placed in Abdominal Aortic Aneurysm (AAA) for numerical simulations were developed on the basis of AngioCT data for 10 patients. The results of calculations showed that narrows or angular bends in the prosthesis as well as increased hematocrit affects blood flow reducing velocity and WSS which might result in thrombus development.

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Authors and Affiliations

Andrzej Polańczyk
Marek Podyma
Ludomir Stefańczyk
Ireneusz Zbiciński
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Abstract

Considering that the clay content in the western Liaoning region is high, the dominant fraction is <0.045 mm high ash in fine-grained low thermal coal and coal slurry. Self-developed CMC (Cone type Multi-stage Cyclone) multiple multistage small cone angle hydrocyclone groups are used for desliming flotation experiment research, product particle size analysis, hydrocyclone underflow product order evaluation tests and flotability evaluation. The results showed that 150 mm hydrocyclones with small cone angles are more suitable as the main desliming equipment before flotation than those with 75 mm and 50 mm hydrocyclones with small cone angles, but the bottom abortion rate is lower, and the phenomenon of “overflow running” is more serious. In the deslime-flotation process of the CMC multistage and small-cone angle hydrocyclone groups, the removal rate of fine particles with ash contents of 69.82% <0.045 mm in the original coal slime reaches 64.43%, basically solved the problem of “overflow and coarse running” of cyclones, and high ash fine clay minerals such as kaolin were enriched in the overflow. The group of three kinds of CMC hydrocyclone underflow products due to their different size widths shows that the flotability of the three underflows can be mixed into the float. Compared with raw coal direct flotation plants, the yield and combustible recovery rate can increase 2-3 times, and the floatability level is increased from extremely difficult to float to difficult to float, which can also be used for the underflow product floatability. The flotation process is different, strengthening the graded plant recycling process and providing a technological reference for better realization of narrows lime flotation.
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Authors and Affiliations

Sun Dezhi
1
Li Caixia
2
Guan Zhihao
1
Zhao Tianyang
3
Zhou Hongbo
4
Wang Xingfeng
2
Ning Qin
2

  1. National Energy Group Shendong Coal Group Company, Yulin, Shanxi, China
  2. School of Mining, Liaoning Technical University, Fuxin, China
  3. National Energy Group Yulin Energy Co., Ltd, Washing Center, Yulin, Shanxi, China
  4. Liaoning Nonferrous Investigation Research Institute Company, Shenyang 110013, China
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Abstract

The article describes and compares two OFDM based communications schemes for reducing the effects of the combination of Narrowband Interference (NBI) and Impulsive Noise (IN), which are noise types typical in Power Line Communication (PLC). The two schemes are Modified BPSK-OFDM (called MBPSK, for brevity) and QFSK-OFDM (called QFSK, for brevity), which are non-conventional OFDM schemes. We give a description of the two schemes, showing how they are derived and also show their similarities and eventually compare their performances. Performance simulation results, in terms of bit error rate, are given to compare the systems under the effect of IN and NBI. The popular Middleton Class A model is used for modelling IN. The results show that MBPSK scheme outperforms the QFSK scheme in terms of minimum distance, and hence in terms of bit error probability when no preprocessing is performed. However, under clipping/nulling, both schemes eventually reach the bit error rate floor.

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Authors and Affiliations

Abiola G. Bolaji
Thokozani Shongwe
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Abstract

Nowadays, there is a trend to employ adaptive solutions in mobile communication. The adaptive transmission systems seem to answer the need for highly reliable communication that serves high data rates. For efficient adaptive transmission, the future Channel State Information (CSI) has to be known. The various prediction methods can be applied to estimate the future CSI. However, each method has its bottlenecks. The task is even more challenging while considering the future 5G/6G communication where the employment of sub-6 GHz and millimetre waves (mmWaves) in narrow-band, wide-band and ultra-wide-band transmission is considered. Thus, author describes the differences between sub-6 GHz/mmWave and narrow-band/wide-band/ultrawide- band channel prediction, provide a comprehensive overview of available prediction methods, discuss its performance and analyse the opportunity to use them in sub-6 GHz and mmWave systems. We select Long Short-Term Memory Recurrent Neural Network (RNN) as the most promising technique for future CSI prediction and propose optimising two of its parameters - the number of input features, which was not yet considered as an opportunity to improve the performance of CSI prediction, and the number of hidden layers.
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Authors and Affiliations

Maciej Soszka
1

  1. Institute of Radioelectronics and Multimedia Technology, Warsaw University of Technology, Warsaw, Poland

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