scholarly journals Nondestructive Measurement of Momentum Transfer Collision Frequency for Low Temperature Combustion Plasma

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Douglas Letsholathebe ◽  
Kgakgamatso M. Mphale ◽  
Samuel Chimidza
Keyword(s):  
Momentum Transfer ◽  
Communication Systems ◽  
High Performance ◽  
Collision Frequency ◽  
Direct Method ◽  
Low Temperature Combustion ◽  
Fire Plume ◽  
Fire Plumes ◽  
Wildfire Suppression ◽  
Measured Momentum

Accurately measured momentum transfer collision frequency and electron density for fire plasma enable correct simulation of electromagnetic wave propagation in the medium. The simulation is essential for designing high-performance systems suitable for the environment. Despite this, momentum transfer collision frequency for fire plumes has always been an estimated quantity and/or crudely determined. There are anecdotal reports of severe line-of-sight (LOS) radio frequency signal degradation on firegrounds. The problem has implications on safety of fire-fighters during wildfire suppression hence the need of high performance communication systems. In the experiment, a nonintrusive and direct method for measuring momentum transfer collision frequency in a fire plume was carried out. Using an automatic network analyser,x-band microwaves were caused to propagate combustion zones of eucalyptus and grass litter fires to measure the flames, scattering parameters. The parameters were then used to determine average collision frequencies for the plumes. The average collision frequencies for the eucalyptus and grass fire plumes were measured to be5.84×1010and5.92×1010 rad/s, respectively.

scholarly journals A Study of the Magneto?Kerr and Other Effects at a Plasma Surface

1967 ◽  
Vol 20 (1) ◽  
pp. 29 ◽  
Author(s):  
LC Robinson
Keyword(s):  
Momentum Transfer ◽  
Kerr Effect ◽  
Collision Frequency ◽  
Absolute Measurement ◽  
High Electron ◽  
Surface Phenomena ◽  
Density Region ◽  
Plasma Surface ◽  
Microwave Reflection

The role of microwave reflection observations and particularly the magneto. microwave Kerr effect in the study of plasma surface phenomena is discussed. The method makes possible the absolute measurement of high electron surface densities in a density region not readily accessible to other experimental techniques, and it gives an indication of the collision frequency for momentum transfer.

scholarly journals Advanced Hybrid Beamforming Technique in MU-MIMO Systems

2020 ◽  
Vol 10 (17) ◽  
pp. 5961
Author(s):  
Seong-Joon Shim ◽  
Seulgi Lee ◽  
Won-Seok Lee ◽  
Jae-Hyun Ro ◽  
Jung-In Baik ◽  
...  
Keyword(s):  
Communication Technology ◽  
Communication Systems ◽  
High Performance ◽  
Mimo Systems ◽  
Error Performance ◽  
Fifth Generation ◽  
New Radio ◽  
Sum Rate ◽  
Hybrid Beamforming ◽  
Beam Patterns

This paper proposes a high performance wireless commmunication technology in MU-MIMO systems. The millimeter wave (mmWave) communication technology was considered for the future wireless communication systems such as the fifth-generation new radio (5G NR). In 5G NR, the mmWave communication technology was studied to increase the use of wide bandwidth and the data rate. Therefore, MU-MIMO systems can be used in mmWave. To decrease the complexity of conventional digital beamforming system, the hybrid beamforming system was studied. In particular, the proposed hybrid beamforming system improves the error performance and average sum rate in partially connected structure (PCS) hybrid beamforming system. The proposed PCS hybrid beamforming system forms variously combined beam patterns using the information of azimuth and elevation angles for the multi-paths according to the number of bits. In addition, the azimuth and elevation angles among the formed beam patterns are estimated according to the received signal strength (RSS). In the simulation results, the proposed PCS hybrid beamforming system has better error performance and the average sum rate than the conventional hybrid beamforming system.

scholarly journals SPINET: A Parallel Computing Approach to Spine Simulations

1996 ◽  
Vol 5 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Peter G. Kropf ◽  
Edgar F. A. Lederer ◽  
Thomas Steffen ◽  
Karl Guggisberg ◽  
Jean-Guy Schneider ◽  
...  
Keyword(s):  
Finite Element ◽  
Parallel Computing ◽  
Functional Programming ◽  
High Performance ◽  
Dynamic Models ◽  
Spinal Injury ◽  
Direct Method ◽  
Finite Element Program ◽  
Biomechanical Models ◽  
Interdisciplinary Approaches

Research in scientitic programming enables us to realize more and more complex applications, and on the other hand, application-driven demands on computing methods and power are continuously growing. Therefore, interdisciplinary approaches become more widely used. The interdisciplinary SPINET project presented in this article applies modern scientific computing tools to biomechanical simulations: parallel computing and symbolic and modern functional programming. The target application is the human spine. Simulations of the spine help us to investigate and better understand the mechanisms of back pain and spinal injury. Two approaches have been used: the first uses the finite element method for high-performance simulations of static biomechanical models, and the second generates a simulation developmenttool for experimenting with different dynamic models. A finite element program for static analysis has been parallelized for the MUSIC machine. To solve the sparse system of linear equations, a conjugate gradient solver (iterative method) and a frontal solver (direct method) have been implemented. The preprocessor required for the frontal solver is written in the modern functional programming language SML, the solver itself in C, thus exploiting the characteristic advantages of both functional and imperative programming. The speedup analysis of both solvers show very satisfactory results for this irregular problem. A mixed symbolic-numeric environment for rigid body system simulations is presented. It automatically generates C code from a problem specification expressed by the Lagrange formalism using Maple.

Performance Evaluation of Elliptical-Cylindrical Antenna Array using SaDE Optimized Hyper Beam

2017 ◽  
Vol 7 (1) ◽  
pp. 178 ◽  
Author(s):  
Gebrehiwet Gebrekrstos Lema
Keyword(s):  
Communication Systems ◽  
High Performance ◽  
Optimization Technique ◽  
Analytical Techniques ◽  
Side Lobe ◽  
Optimization Techniques ◽  
Side Lobe Level ◽  
Pattern Synthesis ◽  
Improved Performance ◽  
The Individual

<p>For high performance communication systems, Side Lobe Level (SLL) reduction and improved directivity are the goal of antenna designers. In the recent years, many optimization techniques of antenna design are occupying demanding place over the analytical techniques. Though they have contributed attractive solutions, it is often obvious to select one that meets the particular design need at hand. In this paper, an optimization technique called Self-adaptive Differential Evolution (SaDE) that can be able to learn and behave intelligently along with hyper beam forming is integrated to determine an optimal set of excitation weights in the design of EcAA. Non-uniform excitation weights of the individual array elements of EcAA are performed to obtain reduced SLL, high directivity and flexible radiation pattern. To evaluate the improved performance of the proposed SaDE optimized hyper beam, comparison are done with uniformly excited, SaDE without hyper beam and Genetic Algorithm (GA). In general, the proposed work of pattern synthesis has resulted in much better reduction of SLL and FNBW than both the uniformly excited and thinned EcAA. The results of this study clearly reveal that the SLL highly reduced at a very directive beamwidth.</p>

Low-temperature combustion synthesis and UV treatment processed p-type Li:NiOx active semiconductors for high-performance electronics

2018 ◽  
Vol 6 (46) ◽  
pp. 12584-12591 ◽  
Author(s):  
Jun Yang ◽  
Bowen Wang ◽  
Yongpeng Zhang ◽  
Xingwei Ding ◽  
Jianhua Zhang
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Combustion Synthesis ◽  
High Performance ◽  
Low Temperature Combustion ◽  
Uv Treatment ◽  
Temperature Combustion ◽  
P Type

The p-type Li:NiOx thin films were successfully fabricated through the SUV route at 150 °C.

A Multistage High Performance Amplification Approach for Improving WDM Communication System

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Hardeep Singh Saini ◽  
Dinesh Arora ◽  
Amit Wason ◽  
Deepak Sharma
Keyword(s):  
Quality Factor ◽  
Communication Systems ◽  
High Performance ◽  
Optical Amplifiers ◽  
Traditional Approach ◽  
Signal Transmission ◽  
Fiber Amplifier ◽  
Optical Amplifier ◽  
Erbium Doped Fiber Amplifier ◽  
Eye Diagram

AbstractOptical amplifiers are developed to boost up the performance of the communication systems. Amplifiers such as erbium doped fiber amplifier (EDFA), RAMAN and semiconductor optical amplifier (SOA) are used for this purpose. It is mandatory to use optical amplifiers for signal transmission to long distances. In this paper, the hybrid optical amplifier EDFA-RAMAN-EDFA is proposed to enhance the signal quality received at receiver end and to initiate the efficient transmission of 8 × 10 Gbps transmission speed for wavelength division multiplexed (WDM) system. The proposed mechanism is evaluated with respect to various parameters such as quality factor, eye-height, and bit error rate (BER) and eye diagram considering various values of transmission distance ranging from 100 to 200 km. The analysis shows that the proposed mechanism has better quality factor value and minimum BER value than the traditional approach. Wider eye opening for proposed technique represents that the distortions produced in the system are least.

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