-
Evaluation Methodology for Pre-Mining Potentiaity for Mineral Deposits
Issue:
Volume 9, Issue 4, December 2021
Pages:
42-50
Received:
6 August 2021
Accepted:
19 August 2021
Published:
30 October 2021
Abstract: Here we introduce "Pre-mining potentiality of mineral deposit" and gets marked "Ppm" under this methodology, which comprehensively represents the mining and geological conditions in the crust, the geologic parameters, study and calculation of mineral reserves, mining method, moreover assessments of other studies such as for operation, location and marketing capabilities, a warning forecast of the economic viability and environmental impact on nature. The pre-mining potentiality evaluation of mineral deposits can be considered as the most comprehensive pre-production assessment of a deposit, which makes it possible to compare it with other same type deposits and to assess and determine the priorities of this field. External factors, the method of mining development, production productivity, the technique and technology of the extraction system, the amount of capital investment, the professionalism and the capacity of management and financial capacity of the project executor, show the main effects on the actual magnitude of the final social and economic benefits that result from the overall implementation of the project. And the internal factors in it, deposits, mining and production and economic as well as environmental conditions, are the main foundation for those external factors. These internal factors need to be examined before operational phase or during mine development, with detailed study in the framework of consistent scientific research and consider clearly the logical and expected results of future mining operations. The following research works are carried out to develop a mineral deposit. Including: reconnaissance studies, geophysics, hydrogeology, geotechnical studies, resource delineation, evaluation work - a scoping study, preliminary and detailed feasibility studies, detailed environmental impact assessment. In international practice these research and evaluation works are called in general in Russian “предэксплуатационные исследования месторождения полезного ископаемого” and in English “pre-production evaluation for mineral deposit”. These works of research and analysis for the development of a deposit are not feasible simultaneously for all similar deposits, which require a lot of time and cost, therefore, the possibilities of evaluation and comparison are not obtained, and their priorities are not well determined. So, here a scientifically methodological question is being considered to evaluate the pre-mining potentiality, which is based on the influences of the internal factors of a given deposit, regardless of time and cost, for evaluation, comparing and ranking in general.
Abstract: Here we introduce "Pre-mining potentiality of mineral deposit" and gets marked "Ppm" under this methodology, which comprehensively represents the mining and geological conditions in the crust, the geologic parameters, study and calculation of mineral reserves, mining method, moreover assessments of other studies such as for operation, location and ...
Show More
-
Unconventional Gases Between the Environmental and Energy Crises
Azmy Muhammad Abdul-Jalil Al-Ghaish,
Aliaa Mohammed Abdul Jalil Al Ghaish
Issue:
Volume 9, Issue 4, December 2021
Pages:
51-58
Received:
15 April 2021
Accepted:
4 June 2021
Published:
5 November 2021
Abstract: The sudden advancement in the technology of unconventional gas production, especially in the United States, has aroused the interest of those interested in energy affairs, as this technical progress allowed greater economic contact with the supply of conventional natural gas, especially with the achievement of large-scale production of unconventional gas pools. In spite of what the technological developments of that industry promise to advance its place in unconventional gas, and the economic effects that it can have, especially with the development of discoveries of its resources over time, on both energy producers and importers. However, opinions were divided between opponents and supporters of its exploitation, whether due to its economic effects. Especially since its exploitation will give many countries the opportunity to give up or reduce dependence on natural gas, especially the United States of America, China and the countries of the European Union; The matter will also negatively affect the countries producing natural gas due to the economic impacts resulting from the expansion of production of that alternative. Or because of its environmental impacts resulting from its use as a fossil fuel, or the technology used in its extraction and production and its harmful effects on water resources and land. This issue will be addressed by seeking to determine the effects resulting from the expansion of unconventional gas production, and whether the exploitation of unconventional gas gives satisfactory economic results that justify the cost that will be borne by society, and the question and what effects this type of energy can have. Through a research plan consisting of an introductory topic entitled What are non-conventional gases, the first topic titled Motives for Expansion in the Production of Non-Conventional Gases, the Second Study entitled the Importance of Non-Conventional Gases and the Controversy Around them, the Third Study entitled “Non-conventional Gas Production and the Strategy of Advanced Countries for Energy Security, Conclusion, Conclusions and recommendations.
Abstract: The sudden advancement in the technology of unconventional gas production, especially in the United States, has aroused the interest of those interested in energy affairs, as this technical progress allowed greater economic contact with the supply of conventional natural gas, especially with the achievement of large-scale production of unconvention...
Show More
-
Energetic Valorization of Eichhornia crassipes and Pistia stratiotes by Methane Production in an Anaerobic Co-digestion Process
Pierre Ntakiyiruta,
Bi Gouessé Henri Briton,
Pierre Claver Mpawenayo,
David Nahimana,
Christophe Niyungeko,
Kouassi Benjamin Yao,
Gaspard Ntakimazi
Issue:
Volume 9, Issue 4, December 2021
Pages:
59-69
Received:
13 October 2021
Accepted:
1 November 2021
Published:
10 November 2021
Abstract: Eichhornia crassipes and Pistia stratiotes are often used in phytoremediation of wastewater. Nevertheless, these macrophytes must be renewed after use to avoid recontamination of treated wastewater by dead plants. This study aims to produce of energy from a mixture of these two macrophyte es by anaerobic co-digestion in the presence of the activated sludge which acts as an inoculum. The study was carried out using a 4 L digesters batch under mesophilic conditions (35°C). The scenarios 3/1; 2/1 ratios between substrate and inoculum as well as control were used to evaluate the quantity biogas produced over a 25-day period. The pH, NH4+, BOD5 and COD were monitored to verify the stability of the process. The results of this study show that the pH varies from 6.39 to 7.31 while the NH4+, COD and BOD5 concentrations vary from 39.6 to 86.4 mg L−1, 1965.8 to 2940.4 mgO2 L-1 and 1200 to 1500 mgO2/L-1 respectively. The varying ranges of these parameters have no effect on methanogenesis. When the two macrophytes were mixed in a 3/1 ratio, a volume of 13797 mL of biogas was produced with a methane content of 70.53%, a value within the range of a good quality of biogas.
Abstract: Eichhornia crassipes and Pistia stratiotes are often used in phytoremediation of wastewater. Nevertheless, these macrophytes must be renewed after use to avoid recontamination of treated wastewater by dead plants. This study aims to produce of energy from a mixture of these two macrophyte es by anaerobic co-digestion in the presence of the activate...
Show More
-
Simulation of the Power Flow State of the Main Electrical Distribution Grid of Abomey-Calavi (BENIN) and Lomé Golfe (TOGO)
Yendoubé Lare,
Koffi Sagna,
Alphonse Déssoudji Gboglo,
Pidenam Takouda,
Kossi Napo
Issue:
Volume 9, Issue 4, December 2021
Pages:
70-78
Received:
23 October 2021
Accepted:
13 November 2021
Published:
27 November 2021
Abstract: This work consists in a simulation study of the power flow state of the electricity distribution grid of Abomey-Calavi and the Lome Golfe. For this purpose, the CYME software was used to construct the single line diagrams of each grid based on the actual modeled parameters and data of the generators, busbars, transformers, lines and loads of the network. This power flow resulted in determining the power transits on the sections and the technical losses along the cables and in the transformers. It appears that the distribution grid of Abomey-Calavi and that of Lome Golfe respectively comprise a set of power plants totaling 127MW and 130 MW, a medium voltage system of 93 km spread over three (03) departures and 930 km spread over twenty-eight (28) departures, at the end of 2019. These grids respectively experience technical losses of 12.16% and 9.09% of the total transit power. The purpose of this work is first of all to show the effective existence of enormous losses in the electrical distribution grids in TOGO and BEBIN, then to give some recommendations necessary to reduce these losses. The reduction of these technical losses requires a study of the behavior of the existing grid and a better optimization of the design of subsequent grids.
Abstract: This work consists in a simulation study of the power flow state of the electricity distribution grid of Abomey-Calavi and the Lome Golfe. For this purpose, the CYME software was used to construct the single line diagrams of each grid based on the actual modeled parameters and data of the generators, busbars, transformers, lines and loads of the ne...
Show More
-
Short-Circuit Photocurrent Density Determination of Chalcopyrite Solar Cells and Study of Basic Parameters Under AM0, AM1, AM1.5 Spectra
El Hadji Mamadou Keita,
Abdoul Aziz Correa,
Issa Faye,
Chamsdine Sow,
Cheikh Sene,
Babacar Mbow
Issue:
Volume 9, Issue 4, December 2021
Pages:
79-89
Received:
28 October 2021
Accepted:
30 November 2021
Published:
11 December 2021
Abstract: In this work we present a method to evaluate the short-circuit photocurrent density delivered by a solar cell by and study basic parameters which are at the origin of the latter by considering the solar spectra AM0, AM1 and AM1.5. This photocurrent density is the greatest current density that the cell can supply according to the considered parameters for a given illumination. We apply this method to a 4-layer model composed of absorber materials based on chalcopyrite semiconductors (CuInSe2 and CuInS2) and based on a wide band gap window layers (ZnO and CdS) according to the model ZnO(n+)/CdS(n)/CuInS2(p)/CuInSe2 (p+) (model n+/n /p/p+). For this model the CuInS2 and CuInSe2 layers are named respectively base and substrate. We exploit continuity equation that governing charge carriers transport in semiconductor materials and use Newton's quadrature integration method over the entire solar spectrum ranging from 1 eV to 4 eV. For this calculation, we have found values of the short-circuit photocurrent density equal to 24.5 mA.cm-2, 19.3 mA.cm-2, 17.5 mAcm-2 respectively for the spectra AM0, AM1 and AM1.5 for the used parameters. The same principle of calculation and reasoning is used to determine and study under a given solar spectrum some intrinsic basic parameters such as the generation rate of carriers, the densities of minority carriers generated and the resulting photocurrents versus the junction depth. The study of these parameters shows a low penetration depth of photons for the considered materials CuInS2/CuInSe2, losses of charge carriers due to recombination phenomena in surface and interface, bulk recombinations, and losses which are also due to the natural phenomenon of diffusion of carriers in the material under a concentration gradient. This study tries to show that the optimization of the growth conditions of layers, a good choice of material arrangement and a good geometric dimensioning are essential to improve collection efficiency of charge carriers and the short-circuit photocurrent of a photovoltaic cell.
Abstract: In this work we present a method to evaluate the short-circuit photocurrent density delivered by a solar cell by and study basic parameters which are at the origin of the latter by considering the solar spectra AM0, AM1 and AM1.5. This photocurrent density is the greatest current density that the cell can supply according to the considered paramete...
Show More
