scholarly journals Characteristic Study of Visible Light Communication and Influence of Coal Dust Particles in Underground Coal Mines

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 883
Author(s):  
Fawad Javaid ◽  
Anyi Wang ◽  
Muhammad Usman Sana ◽  
Asif Husain ◽  
Imran Ashraf
Keyword(s):  
Visible Light ◽  
Light Transmission ◽  
Coal Dust ◽  
Coal Mines ◽  
Visible Light Communication ◽  
Underground Mines ◽  
Dust Particles ◽  
Delay Spread ◽  
Underground Coal Mines ◽  
The Impact

The critical environment of the underground mines is a risky zone for mining applications and it is very hazardous to engage the miners without a sophisticated communication system. The existing wired networks are susceptible to damage and the wireless radio systems experience severe fading that restricts the complete access to the entire assembly of a mine. Wireless optical communication is a better approach that can be incorporated in the erratic atmosphere of underground mines to overcome such issues, as lights are already used to illuminate the mine galleries. This study is focused on investigating the characteristics of visible light communication (VLC) in an underground coal mine. The entire scope of VLC is elaborated along with the influence of coal dust particles and the scattering model. The impact of coal dust clouds on visibility and attenuation is analyzed for visible light transmission. The shadowing effect generated by the pillars and mining machinery is estimated by employing the bimodal Gaussian distribution (BGD) approach in coal mines. The characteristic model of VLC for underground coal mines is presented by classifying the area of the mine into mine gallery and sub-galleries. The transmission links of VLC are categorized as the line of sight (LOS) link for direct propagation and the non-LOS (NLOS) link for reflected propagation. The scenarios of LOS and NLOS propagation are considered for each evaluating parameter. Furthermore, the performance of the proposed framework is examined by computing the received signal power, path loss, delay spread (DS), and signal to noise ratio (SNR).

scholarly journals An Optimized Approach to Channel Modeling and Impact of Deteriorating Factors on Wireless Communication in Underground Mines

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5905
Author(s):  
Fawad Javaid ◽  
Anyi Wang ◽  
Muhammad Usman Sana ◽  
Asif Husain ◽  
Imran Ashraf
Keyword(s):  
Wireless Communication ◽  
Coal Mines ◽  
Channel Modeling ◽  
Signal Propagation ◽  
Underground Mines ◽  
Delay Spread ◽  
Physical Parameters ◽  
Multimode Waveguide ◽  
Underground Coal Mines ◽  
5 Ghz

The environment of underground coal mines has challenging properties that makes this zone inadaptable for a stable communication system. Additionally, various deteriorating physical parameters strongly affect the performance of wireless networks, which leads to limited network coverage and poor quality of data communication. This study investigates the communication capability in underground coal mines by optimizing the wireless link to develop a stable network for an underground hazardous environment. A hybrid channel-modeling scheme is proposed to characterize the environment of underground mines for wireless communication by classifying the area of a mine into the main gallery and sub-galleries. The complex segments of mine are evaluated by categorizing the wireless links for the line-of-sight (LOS) zones and hybrid modeling is employed to examine the characteristics of electromagnetic signal propagation. For hybrid channel modeling, the multimode waveguide model and geometrical optic (GO) model are used for developing an optimal framework that improves the accessibility of the network in the critical time-varying environment of mines. Moreover, the influence of various deteriorating factors is analyzed using 2.4 GHz to 5 GHz frequency band to study its relationship with the vital constraints of an underground mine. The critical factors such as path loss, roughness loss, delay spread, and shadow fading are examined under detailed analysis with variation in link structure for the mine.

COMBUSTION OF A GAS SUSPENSION OF COAL DUST IN A SWIRLING FLOW

2021 ◽  
pp. 139-147
Author(s):  
K.M. Moiseeva ◽  
◽  
A.Yu. Krainov ◽  
E.I. Rozhkova ◽  
◽  
...  
Keyword(s):  
Flow Velocity ◽  
Swirling Flow ◽  
Coal Dust ◽  
Combustion Efficiency ◽  
Dust Particles ◽  
Gas Temperature ◽  
Flow Swirl ◽  
Angular Component ◽  
Air Suspension ◽  
The Impact

Swirling combustion is currently one of the most important engineering problems in physics of combustion. There is a hypothesis on the increase in the combustion efficiency of reacting gas mixtures in combustion chambers with swirling flows, as well as on the increase in the efficiency of fuel combustion devices. In this paper, it is proposed to simulate a swirling flow by taking into account the angular component of the flow velocity. The aim of the study is to determine the effect of the angular component of the flow velocity on the characteristics of the flow and combustion of an air suspension of coal dust in a pipe. The problem is solved in a twodimensional axisymmetric approximation with allowance for a swirling flow. A physical and mathematical model is based on the approaches of the mechanics of multiphase reacting media. A solution method involves the arbitrary discontinuity decay algorithm. The impact of the flow swirl and the size of coal dust particles on the gas temperature distribution along the pipe is determined.

Experimental study of saturation by visible light transmission in dual-scale fibrous reinforcements during composite manufacturing

2017 ◽  
Vol 36 (23) ◽  
pp. 1693-1711 ◽  
Author(s):  
F LeBel ◽  
É Ruiz ◽  
F Trochu
Keyword(s):  
Visible Light ◽  
Light Transmission ◽  
Void Formation ◽  
In Situ Monitoring ◽  
Injection System ◽  
Computer Assisted ◽  
Liquid Composite Molding ◽  
Composite Molding ◽  
The Impact ◽  
Dual Scale

A new in situ monitoring strategy is proposed to study void formation during real-time impregnation of dual-scale fibrous reinforcements in liquid composite molding. Void content data from burn-off tests are used to calibrate a refractive index matching approach based on two optical principles: Beer–Lambert and Fresnel laws. Once calibrated, this approach based on visible light transmission is used to study the impact of key process parameters on the saturation footprint of dual-scale fibrous reinforcements during and after mold filling. The injection parameters investigated are the flow front velocity, the pressure distribution inside the mold cavity, the bleeding flow rate, and the mold packing pressure. The experimental setup is a computer-assisted injection system and a transparent resin transfer molding mold is used to perform unidirectional injections. A vinyl ester resin is injected through E-glass bidirectional non-crimp fabrics under various manufacturing conditions. This investigation not only confirms the decreasing trend in void formation by mechanical entrapment of air with the decrease in impregnation velocity, as it converges toward the optimal impregnation conditions for this fibrous reinforcement reported in previous studies, but it also brings insights on void dissolution and transport in liquid composite molding.

scholarly journals Sistem Komunikasi Suara Bawah Air dengan Metoda Simplex menggunakan Visible Light Communication (VLC)

2019 ◽  
Vol 7 (2) ◽  
pp. 253
Author(s):  
LUCIA JAMBOLA ◽  
ARSYAD RAMADHAN DARLIS ◽  
LITA LIDYAWATI ◽  
DZIKRI FACHRI HUSAENI
Keyword(s):  
Visible Light ◽  
Communication Systems ◽  
Light Transmission ◽  
Visible Light Communication ◽  
Color Filter ◽  
Underwater Communication ◽  
Test Results ◽  
Voice Communication ◽  
Yellow Color ◽  
Long Time

ABSTRAKSistem komunikasi suara bawah air telah dikenal sejak lama, diantaranya sonar dan akustik. Seiring perkembangan zaman dan kemajuan teknologi, kini hadir komunikasi dengan media transmisi cahaya tampak yaitu Visible Light Communication (VLC) yang dapat diterapkan pada komunikasi bawah air. Pada penelitian ini telah dilakukan komunikasi suara bawah air (simplex) menggunakan VLC, dengan media akuarium berisi air dan beberapa pengujian diantaranya menggunakan color filter, didapat hasil pengujian terbaik yaitu tegangan 4,4 Vpp dan frekuensi 3,003 kHz untuk color filter yellow, pengujian menggunakan lensa didapat hasil pengujian terbaik yaitu tegangan 4,4 Vp-p dan frekuensi 3,051 kHz untuk lensa (+50), dan pengujian terakhir menggunakan lampu UV didapat hasil pengujian terbaik dengan tegangan 4,4 Vp-p dan frekuensi 3,010 kHz. Implementasi sistem VLC ini menunjukkan hasil yang baik dan layak untuk diterapkan pada komunikasi suara bawah air (simplex).Kata kunci: VLC, Komunikasi Suara Bawah Air, Simplex. ABSTRACTUnderwater voice communication systems have been known for a long time, including sonar and acoustics. Along with the development and advancement of technology, now there is communication with visible light transmission media, namely Visible Light Communication (VLC) which can be applied to underwater communication. Under this study underwater voice communication (simplex) has been carried out using VLC, with aquarium media containing water and several tests including using a color filter, the best test results obtained are voltage 4.4 Vp-p and frequency 3.003 kHz for yellow color filter, testing using the lens obtained the best test results namely voltage 4.4 Vp-p and frequency 3.051 kHz for lenses (+50), and the last test using UV lights obtained the best test results with a voltage of 4.4 Vp-p and a frequency of 3.010 kHz. The implementation of the VLC system shows good and feasible results to be applied to underwater voice communication (simplex).Keywords: VLC, Underwater Voice Communication, Simplex.

Pervasive Environment for Gases Detection and Collapses in Underground Mines

2014 ◽  
Vol 875-877 ◽  
pp. 2056-2061
Author(s):  
Snider Molina ◽  
Ismael Soto ◽  
Lily Sun ◽  
Ke Cheng Liu
Keyword(s):  
Continuous Monitoring ◽  
Dynamic Assessment ◽  
Coal Mines ◽  
Underground Mines ◽  
Monitoring Networks ◽  
Application Development ◽  
Mining Operations ◽  
Technical Parameters ◽  
Pervasive Environment ◽  
Underground Coal Mines

Safety is an element of extreme priority in mining operations; currently many traditional mining countries are investing in the implementation of wireless sensors capable of detecting risk factors. The objective of this research is to contribute to the implementation of sensors for continuous monitoring inside underground mines providing technical parameters for the design of sensor networks applied in underground coal mines. The analyzed of applying these systems in terms of Benefit, Opportunity, Cost and Risk are discussed. Finally, a dynamic assessment of safety at underground mines it is proposed, this approach offers a contribution to design personalized monitoring networks, the experience developed in coal mines provides a tool that facilitates the application development of technology within underground coal mines.

Modulation and Demodulation Techniques in Indoor Visible Light Communication System

2014 ◽  
Vol 685 ◽  
pp. 306-309
Author(s):  
Hao Wang ◽  
Ze Yu Han
Keyword(s):  
Visible Light ◽  
Communication Technology ◽  
Communication System ◽  
High Speed ◽  
Data Transfer ◽  
Visible Light Communication ◽  
Communication Link ◽  
High Data ◽  
Modulation And Demodulation ◽  
The Impact

Visible light communication technology is a emerging wireless and optical communication technology developed after invention and application of white LED.In this paper, we have a research based on indoor visible light communication system of lighting white LED,discuss of the visible light communication channel characteristics,detailedly analysis of the indoor visible light communication link. This paper focuses on the modulation and demodulation method applied to visible light communication. In the past visible light communication is mainly used off keying modulation,however, the data transfer speed is limited due to the influence of ISI .This paper presents a solution based on OFDM modulation and demodulation, to reduce the impact brought from inter-symbol string under high data transfer speed.Based on data analysis and computer simulation,the program presented in this paper can be used as indoor lighting and high-speed data transmission.Finally, give scheme to achieve visible light communication modulation and demodulation,provide a theoretical basis for further experiments.

Real Time Entry Prohibition System for Coalmines

2020 ◽  
Vol 11 (2) ◽  
pp. 45-65
Author(s):  
Urmila Shrawankar ◽  
Rahul Neware ◽  
Pranay Mangulkar
Keyword(s):  
Wireless Communications ◽  
Real Time ◽  
Coal Mines ◽  
Well Being ◽  
Base Station ◽  
Wireless Transmission ◽  
Underground Mines ◽  
Software Systems ◽  
Underground Coal Mines ◽  
Favorable Conditions

This article focuses on the hazardous conditions prevailing in underground coal mines and the decision to prohibit entry, when conditions are adverse. Thus, the ongoing observation framework is helpful for ascertaining the conditions for working in underground coal mines and for essential safety and well-being measures. The advancements in WSN lead to advancements in wireless communications. The various sensors are deployed at the location and sense the environment and provide recent activities of the underground coal mines. The sensors transmit the procured information to the base station, principally the A-D transformation. The sensors can be considered a hub to the base station. Wireless transmission is used to send the data to the user. The designed hardware and software systems are used for the identification of the parameters and as per the thresholds, the decision and the prohibition of workers before entering into the mine is decided. The ML system helps in checking the favorable conditions for working in underground mines. While experimenting, real-time sensor generated data is used.

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