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Biomass gasification systems may be relevant for decentralized power generation from these residues in the isolated areas. This work deals with the analysis of both the technical and economic feasibility, and then the environmental and social impacts of a 95 kWe gasification plant project in order to generate electricity for Badara village in Burkina. Two biomasses feedstock: cotton stalk and rice husk are used. Mass and energy balances of the processes were performed to assess technical performance. Levelized cost of electricity (LCOE) analysis is used to estimate the production cost of the two biomasses options. The environmental impacts were assessed by using a Life Cycle Assessment (LCA) approach. The results show that the valorisation of the rice husk is the solution that offers the low production cost (0.34 €/kWh) compared to cotton stalk (0.38 €/kWh) despite its low electricity efficiency (11.9% against 12.6%). Nevertheless, the use of the cotton stalks is most interesting in terms of direct job creation (9.58 full-time equivalent jobs /year against 8 full-time equivalent jobs /year). Concerning the environmental issue, the gasification of cotton stalk generates consistently higher environmental burdens than the rice husks gasification. This assessment represents an important step that could assist the policy maker to make a relevant decision for this local conditions and available resources.

This paper presents the design of a high gain cross DRA array antenna (AXDRA) with a novel feeding method based on microstrip transmission line for millimeter-wave operation. Simulation results shows that the AXDRA achieves an impedance bandwidth from 57.5 GHz to 63 GHz covering ISM band, and gives an appreciable gain of 15.5 dBi, found to be stable within the passband. The size of the whole antenna structure is about 25mm×25mm and is therefore small enough to be used in underground communications systems. The simulation process was done using Computer Simulation Technology (CST) Microwave Studio.

In this paper, an overview of the overall channel characterizations for wireless communication systems in underground mines is presented. Such environments, because of the very nature of the mining operation, the complexity of the systems, and the procedures and extraction methods of the minerals are considered to be dangerous, hazardous and aggressive. Radio signals suffer from strong attenuations due to reflection, diffractions and scatterings in this complex transmission medium. The transmitted radio signals are therefore subject to different impairments and distortions. Moreover, for the deployment of a wireless network, the choice of the operation frequency band, which has a major impact on the planning and the dimensioning, is as important as the deploying environment. Propagation measurements were carried out at 2.4 GHz, 5.8 GHz and 60 GHz. These frequencies were targeted because they are commonly used for different wireless communication applications. This paper summarizes different findings on the propagation characteristic parameters such as the path loss, outage probability, delay spread and the coherence bandwidth. This the first time, to our knowledge, that a comparison of the operating frequency effects in an underground mine is reported.

A dielectric resonator antennas (DRA) is good candidate to achieve a performant millimeter band antennas. They can provide larger band smaller size, but their performances when used for circular polarisation are still limited. The proposed antenna XDRA is composed of a superstrate, an aperture feed and a cross dielectric resonator. This antenna is designed to cover the ISM frequency band at 60 GHz (57 GHz-65 GHz), is shown to deliver an impedance bandwidth ( S11

This paper presents impact of mechanical motor noise on channel propagation parameters in an underground mine. The reported results are based on experimental data obtained during a measurement campaign in the mine around 5.8 GHz. The measurements were performed in an experimental gold mine located in Val d'Or, Qc, Canada at 40m below ground level using two different scenarios. In the first case, the motor was turned off while, in the second case, the engine was running. Based on the measured data, the impact of mechanical motor noise on some channel propagation parameters in the underground mine are analyzed and discussed.

This paper presents an evaluation of the ultra-wideband (UWB) channel capacity in an underground mine. A measurement setup was established to measure the channel frequency response both in LOS and NLOS. The measurements were performed at level −70 m in an experimental gold mine. The SISO (single input single output) channel capacity was first determined, followed by the SIMO (single input multiple output) capacity with receiving antennas. The measurements results reveal that the channel capacity can support high data rates. Also, it decreases with the distance between transmitter and receiver. The result shows also that increase of the capacity of a SIMO channel is not linear with the number of receiving antennas.

In this paper, a comparative study of three high gain hybrid antennas with different superstrates is presented. The three superstrates are a dielectric slab, a frequency selective surface (FSS) with square ring elements and a dielectric slab, and a FSS with strip dipole. A hybrid Dielectric Resonator antenna (DRA) is the excitation source. This antenna gives a good impedance bandwidth over the entire ISM band (57 GHz- 64 GHz). CST Microwave Studio software package is used to investigate the antennas. The input impedance, the gain, and the far field patterns have been presented. It is observed that the electromagnetic characteristics of a dielectric resonator antenna (DRA) can be enhanced by using different superstrates. The gain can be improved to near 16 dBi. And a gain of 11 dB over the entire ISM band have been achieved.

This paper presents a simple and efficient method for decoupling two closely spaced cylindrical DRAs over the ISM band (57 GHz–64GHz). This technique consists of a combination of an etched slot defected ground plane and a simple metallic strip on the second substrate of an aperture coupled DRA array. Good results are obtained. The maximum gain and the isolation (S21) have increased over the whole ISM band. The study of the current distribution on the ground plane and on the metallic strip can explain these results. We have also used a superstrate to enhance the gain to compensate the loss due to the millimeter-wave propagation characteristics. CST simulations of S parameters are performed and presented.

In this paper, a novel design of a new broadband and high gain hybrid antenna is presented. The proposed antenna structure consists of a Dielectric Resonator (DR), an intermediate substrate a microstrip fed slot, and a circular soft surface. With the integration of these different elements, a wide bandwidth response and a high gain are achieved. The cylindrical soft structure is composed of a single metallic strip that is shorted to the ground through two sets of periodic vias. CST Microwave Studio software package is used to investigate the antenna. The input impedance, the gain, and the far field patterns have been analyzed. Furthermore, the proposed antenna is compared to another one which has three rings ant three sets of vias. It is accessed that the electromagnetic characteristics of a dielectric resonator antenna (DRA) can be improved by adding an intermediate substrate and a circular soft surface. The gain can be enhanced to near 6 dBi.

This paper deals with several aspects relative to the Multiple-Input Multiple-Output (MIMO) propagation channel. Measurement campaigns, made in former gold mine at 2.4 GHz, have been analyzed to obtain the relevant statistical parameters of the channel. These results make it possible the use of MIMO techniques in real underground mine gallery for wireless communication systems.

This paper presents a new broadband and high gain dielectric resonator antenna for millimeter-wave underground communications systems. The proposed antenna is composed of a microstrip feed, a cylindrical dielectric resonator, and multiple metallic strips stacked to a superstrate. This antenna is dedicated for the 60 GHz frequency band. Results show that the antenna has great performances especially in terms of bandwidth and gain. A bandwidth of 12.69 % at the centered frequency of 59.55 GHz and a gain of 15.40 dBi over the entire band (57 GHz to 64 GHz) are obtained. A maximum gain of 16.71 dBi has been achieved at 58 GHz. This antenna provides an improvement of 10.71 dBi compared to the conventional single DRA. With these performances, this antenna is suitable for wireless underground communication systems.

In this paper, a channel characterization of MIMO system for Long term Evolution LTE in underground mine at 2.4 GHz is presented and discussed. It was shown that the MIMO exploit the multipath propagation in rich scattering environment using multiple transmit and receive antennas to increase the capacity. The obtained results show a good performance in terms of capacity. Therefore, the MIMO system is useful for mining communication.

A design of millimeter-wave cylindrical dielectric resonator antenna operate at 60 GHz mounted on a hollow conformal ground plane is presented and analyzed. The effect of the radius curvature on the resonant frequency, the radiation pattern and antenna efficiency are discussed. The numerical results was performed using CST Microwave studio employing the Finite Integration Technique (FIT). Simulation results of the proposed antenna show a good performance in terms of bandwidth which is about 7.9% with (S11< −10 dB) at 60 GHz. On other hand, the obtained gain and efficiency are 5.4 dBi and 98% respectively. This antenna is suitable for millimeter-wave underground communication.

This paper presents a new broadband and high gain dielectric resonator for millimeter-wave underground communications systems. The proposed antenna is composed of a superstrate, a coplanar waveguide feed, and a rectangular dielectric resonator. This antenna is designed to cover the ISM frequency band at 60 GHz (57 GHz–65 GHz). This antenna was numerically designed using CST microwave Studio simulation software package. Simulated results show that the antenna has good performances especially in terms of bandwidth and gain. A bandwidth of 17.4% at the centered frequency of 60.98 GHz and a gain of 11 dB over the entire ISM band have been achieved. A maximum gain of 14.44 dB is obtained at 60 GHz. This is an enhancement of 9 dB compared to a single DRA.

In this paper, we present a new ultra wideband (UWB) antenna for UWB applications in underground mining environments. The proposed antenna is designed to operate from 3.1 to 10.6 GHz. It consists of a ring patch with a single layer metallic structure. The antenna is a printed-circuit patch using coplanar waveguide technology (CPW). The shape and the dimensions of the antenna are optimized to achieve a bandwidth of 124% and hence cover a frequency range from 2.8 GHz to 12 GHz. Experimental investigations are presented, and the obtained results confirm the antenna performances. With such characteristics, the antenna may find application in underground mining communications.

Efficient and reliable wireless communication in underground mining has experienced rapid development and is changing the mining industry in terms of safety, security and production. In this area, wireless communication is used to establish connections from inside mines to ground stations through voice and video transmission, control machinery remotely, and track down people and hazardous materials [1]. These communication systems must be able to maximize high data rates so that different applications and services can use the same bandwidth. The bandwidth available with millimeter wave is significantly larger than what is available with microwave band. Therefore, the unlicensed spectrum in the frequency band of 57 GHz to 65 GHz can be used for wireless communication in underground mines [2].

This paper presents a new broadband and high gain dielectric resonator for millimeter-wave underground communications systems. The proposed antenna is composed of a superstrate, an aperture coupled feed, an intermediate substrate and a cylindrical dielectric resonator. This antenna is designed to cover the ISM frequency band (57 GHz-65 GHz). This antenna was numerically designed using CST microwave Studio simulation software package. Simulated results show that the antenna has good performances especially in terms of bandwidth and gain. A bandwidth of 18.4% at the centered frequency of 59.83 GHz and a gain of 11 dB over the entire ISM bandwidth have been achieved. An enhancement of gain by 9 dB has been obtained at the frequency of 60 GHz compared to a single DRA. With these performances, this antennas is suitable for wireless underground communication systems.

The paper deals with high performance photovoltaic pumping system design. The design methodology is based on efficiency and de-rate adjustment factors related to system components. Solar energy and other requirement meteorological data are computed from satellite data. Finally the economic study is done based on the Life Cycle Cost method and technicoeconomic optimisation is added in the model.

In this paper, a new technique for the bandwidth and gain enhancement of dielectric resonator antennas using a cylindrical Electromagnetic Band Gap (EBG) structure has been proposed and demonstrated numerically. An aperture coupling scheme has been used to enable the isolation of the microstrip feed and the antenna. The EBG structure is based on the mushroom-like structure with a circular symmetry. It is composed of a periodic structure of metallic rings and of a periodic structure of vias. The periods of these two structures have been optimized using a full wave method to maximize the antenna gain. Numerical results have been presented showing that a gain enhancement of 6dB and an impedance bandwidth of 24 % are achieved with the new substrate. Experimental results will be presented during the conference.

In this paper, a novel technique for the gain enhancement of dielectric resonator antennas using a cylindrical EBG structure has been proposed and demonstrated numerically. The analysis and design of the structure has been based on the fact that the surface wave propagation is reduced in all radial directions thanks to the circular symmetry of the proposed EBG structure. The EBG structure is based on the mushroom-like structure with a circular symmetry. It is composed of a periodic structure of metallic rings and of a periodic structure of vias. The periods of these two structures have been optimized using a full wave method to maximize the antenna gain. Numerical results have been presented showing that a gain enhancement of 3 dB is achieved with the new substrate. Experimental results will be presented during the conference.

In this paper, a new hybrid resonator is proposed, the proposed design uses three parts, a dielectric resonator (DR), an intermediate substrate and an aperture coupled feed. Furthermore a matching circuit is designed in order to offer a wide bandwidth. The slot aperture is used as a radiator and as a mechanism to couple the DR to the microstrip line. The intermediate substrate is used to isolate the resonator from the slot leading to a structure that is robust to resonator placement and adhesive thickness. It is also used to lower the permittivity of the dielectric resonator antenna (DRA) which increases the bandwidth. Simulation and experimental results including return loss, and radiation patterns are presented and discussed

Broadband antennas have been increasingly investigated in recent years for wireless communication systems. Printed antennas fed by coplanar waveguide can provide a wide bandwidth and can be easily integrated with active circuits. In the same perspective, we proposed a new coplanar fed broadband antenna.. The investigated antenna uses printed monopole with two parasitic elements to widen the bandwidth. The design methodology is outlined. This antenna was numerically designed using Ansoft HFSS simulation software package. A parametric study using an electromagnetic simulator was performed. Based on the optimized design, an experimental prototype was fabricated and measured. Simulations and experimental measurements were carried out, and the comparison between them gives a good agreement. Using this approach, a fractional bandwidth of 47% at the center frequency of 2.35 GHz was achieved. This proposed antenna can be used for broadband wireless communications networks.