| 1. |
- Ali, Faheem, et al.
(författare)
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Self-powered photo-thermo electrochemical sensor for harvesting of low photo thermal energy
- 2020
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Ingår i: Energy Sources, Part A: Recovery, Utilization and Environmental Effects. - : Informa UK Limited. - 1556-7036 .- 1556-7230.
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Tidskriftsartikel (refereegranskat)abstract
- An ecofriendly design of low-cost electrochemical sensor activated by low-grade photo-thermal energy can be a prime stepping-stone for the perspective developments of various renewable energy conversion and utilization schemes. In this study, an investigation of n-type indium arsenide (n-InAs)/aqueous solution of orange dye (OD)/Zinc (Zn) sensor was carried out at various molarities of 1, 2, and 3 mM of electrolytes under variable visible light illumination. OD was employed as a photo-active electrolyte, which is nontoxic and water-soluble organic semiconductor material. n-InAs was employed as a photoactive electrode while Zn was used as a counter metal electrode in our sensor configuration. The operation mechanism is based on the electrochemical-cell principle associated with photo-thermal energy splint. Photoinduced current-voltage characteristics, sensor stability, and a real-time transient characteristics were investigated using three different concentrations of electrolyte. A relatively improved response time was attained of 3 mM OD-electrolyte sensor with an inter-electrode distance of 3 mm under a light illumination of 95 mW/cm2 and a temperature gradient of 1.5°C.
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| 2. |
- Bahrami, Ataallah, et al.
(författare)
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The effect of grinding circuit efficiency on the grade and recovery of copper and molybdenum concentrates
- 2022
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Ingår i: Energy Sources, Part A. - : Taylor & Francis Group. - 1556-7036 .- 1556-7230. ; 44:3, s. 8121-8134
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Tidskriftsartikel (refereegranskat)abstract
- The efficiency of grinding and flotation process in copper-molybdenum processing circuit, largely affected by performance of thickeners and hydrocyclones devices. The goal of this paper is to investigate the effect of the rate-limiting factors on the performance of these devices and consequently on grinding and separation efficiency of the molybdenum processing circuit. So, a full process mineralogical study have been carried out on outputs of thickeners and hydrocyclone of the molybdenite flotation circuit. According to the results, coarse-grained fractions (>50 μm) of the planar molybdenite will not necessarily be recovered by thickener and hydrocyclones. This is especially true for hydrocyclones when the inlet-load rate is high, i.e., the erroneous discharge of planar molybdenite particles from the overflow of hydrocyclone, as well as their floatability in the thickener overflow, can be attributed to the effect of particle shape and size. This issue harms the grade and recovery of flotation due to the increase in the amount of circulating load (regrinding) and consequently the generation of fine particles (<10 μm) in the hydrocyclone-milling circuit. On the other hand, the almost spherical particles of copper minerals, as well as the nonplanar molybdenite fine-grained particles, are easily removed from the hydrocyclone underflow or settled in thickeners. The introduction of copper mineral particles into molybdenum concentrate and vice versa has reduced the quality of the produced concentrate and undesirable flotation performance.
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| 3. |
- Chelgani, Saeed Chehreh, et al.
(författare)
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Estimation of heavy and light rare earth elements of coal by intelligent methods
- 2021
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Ingår i: Energy Sources, Part A. - : Taylor & Francis. - 1556-7036 .- 1556-7230. ; 43:1, s. 70-79
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Tidskriftsartikel (refereegranskat)abstract
- Since last two decades, several investigations in various countries have been started to discover new rare earth element (REE) resources. It was reported that coal can be considered as a possible source of them. REE of coal occur in low concentrations, and their detection is a complicated process; therefore, their predictions based on conventional coal properties (proximate, ultimate and major elements (ME)) may have several advantages. However, few studies have been conducted in this area. This study examined relationships between coal properties and REE (HREE and LREE) for a wide range of coal samples (708 samples). Variable importance measure (VIM) by Mutual information (MI) as a new feature selection method was applied to consider the heterogeneous structure of coal and assess the individual relation between coal parameters and REE to select the compact subsets as input variables for modeling and improve the performance of prediction. VIM by MI showed that Si-Carbon, and Al-Hydrogen are the best subsets for the prediction of HREE and LREE concentrations, respectively. A boosted neural network (BNN) model as a new predictive tool was used for REE prediction. BNN can significantly reduce generalization of error. Results of BNN models showed that the HREE and LREE concentrations can satisfactory estimate (R 2 : 0.83 and 0.89, respectively). Results of this investigation were approved that MI-BNN can be used as a potential tool for prediction of other complex problems in energy and fuel areas.
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| 4. |
- Chelgani, Saeed Chehreh
(författare)
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Prediction of specific gravity of Afghan coal based on conventional coal properties by stepwise regression and random forest
- 2023
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Ingår i: Energy Sources, Part A. - : Taylor & Francis. - 1556-7036 .- 1556-7230. ; 45:2, s. 4323-4334
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Tidskriftsartikel (refereegranskat)abstract
- Coal can be considered as the main fuel for electricity generation in Afghanistan. However, there is a quite limited data available about the overall quality, distribution, and character of coals in Afghanistan. Specific gravity (S.G) of coal as a key factor can be used for the estimation of potential tonnage production and be a fundamental parameter for the selection of coal washery process method. However, there is no investigation which comprehensively explores relationships between S.G and coal properties. In this investigation, the potential of S.G prediction based on conventional properties for Afghan coal samples was explored by stepwise regression and random forest. Pearson correlation (r) and variable importance measurement (VIM) of random forest (RF) were applied to select the most effective variables among conventional parameters for the S.G prediction. Results of VIM indicated that ash and carbon content of coal samples had the highest importance for the S.G prediction. Stepwise regression and RF models were developed based on these two coal variables. Testing the generated models indicated that S.G of Afghan coals can quite accurately predict by these models (R2 > 0.90). Modeling outcomes showed that the highest S.G (S.G > 2) for Afghan coal occurred when ash was higher than 40% and carbon was lower than 30%.
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| 5. |
- Cuvilas, Carlos Alberto, et al.
(författare)
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The Characterization of Wood Species from Mozambique as a Fuel
- 2014
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Ingår i: Energy Sources, Part A. - : Informa UK Limited. - 1556-7036 .- 1556-7230. ; 36:8, s. 851-857
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Tidskriftsartikel (refereegranskat)abstract
- The efficient utilization of fuelwood as a source of energy is strongly dependent on the properties of the biomass. This study characterizes common hardwood species from Mozambique and evaluates their quality as a fuel. Disc samples, taken at breast height, from Afzelia quanzensis Welwn, Millettia stuhlmannii Taub, Pterocarpus angolensis DC, Sterculia appendiculata K. Schum, Pericopsis angolensis Meeuwen, Acacia nigrescens Oliv., Pseudolachostylis maprounaefolia Pax, and Icuria dunensis Wieringa, were collected from three provinces in Mozambique. Chemical and physical properties were analyzed. The raking of the species as fuel was performed using fuelwood value index. The higher heating value varied between 19.38 and 21.50 MJ/kg dry weight. The concentration of lignin ranged from 21.96 up to 36.69% weight dry basis (wt% d.b.), and ash free. All studied species showed very low concentrations of Si, S, and Cl. Ash content varied between 0.76-3.71 wt% (d.b.), while the basic density ranged from 536 to 1,111 k gm(-3). Heavy metals were also determined and their concentrations were below the values reported in the literature. The species Acacia nigrescens had the highest fuelwood value index and it was closely followed by Icuria dunensis and Millettia stuhlmannii. The worst ranked was Sterculia appendiculata.
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| 6. |
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| 7. |
- Han, Jen-Yu, et al.
(författare)
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Impact of temperature and solar irradiance in shadow covering scenarios via two-way sensitivity analysis for rooftop solar photovoltaics
- 2024
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Ingår i: Energy Sources, Part A. - : Taylor & Francis. - 1556-7036 .- 1556-7230. ; 46:1, s. 3165-3176
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Tidskriftsartikel (refereegranskat)abstract
- Solar irradiance and temperature are two primary factors that affect the energy generation efficiency of solar photovoltaic (PV) systems, meaning that climate change may significantly impact the production of solar energy in the future. In this study, a two-way sensitivity analysis is carried out to determine the energy generation potential under future climate change conditions, and conditions of shadow covering are also considered. The simulation results indicate that the impact of solar irradiance causes the most variation in energy generation, and that shadow covering has a weak impact on the output. In the one-way sensitivity analysis, solar irradiance makes a +/- 18% difference in energy generation, whereas shadow covering represents about +/- 2%. In the future trend of climate change in the world and Taiwan, the energy generation potential can decrease up to 21% and increase 8%, respectively, mainly corresponded by solar irradiance. We suggest that compared with the issue of temperature, the efficiency of solar irradiance usage is more important, especially in view of the global trend toward solar irradiance loss. Taiwan also suffers the issue, but the different trend of climate change impact may make the challenge different.
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| 8. |
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| 9. |
- Hussain, M., et al.
(författare)
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Optimization of lithium adsorption from seawater via aluminum chloride as adsorbent using response surface methodology
- 2024
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Ingår i: Energy Sources, Part A. - : Informa UK Limited. - 1556-7036 .- 1556-7230. ; 46:1, s. 2907-2921
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Tidskriftsartikel (refereegranskat)abstract
- Lithium extraction from natural resources is an accelerating field of research owing to its growing demand in the medical, nuclear, battery, and air conditioning industries. Lithium compounds are used in various industries, including ceramics, glass, lubricant gases, rocket propellant, and aluminum production. The extraction of lithium from seawater via adsorption using AlCl3.6 H2O as an adsorbent is investigated in this study. The effect of process parameters such as pH, temperature, contact time, the molar ratio ([Al3+]/[Li+]), and stirring rate on process efficiency is investigated and optimized. The response surface methodology (RSM) is used to investigate the effects of operating parameters and choose the optimal configuration. A standard synthetic solution containing 50 ppm lithium is prepared and experimented with facilitating comprehension of the procedure. The adsorption efficiency of a synthetic solution is 88% at optimized values, while that of seawater is 78.5%. Seawater has a lower efficiency because it contains ions such as Mg2+, Ca2+, K+, and Na+ that compete for active points/sites during adsorption with lithium ions (Li+).
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| 10. |
- Lohani, Sunil Prasad, et al.
(författare)
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Anaerobic co-digestion of food waste, poultry litter and sewage sludge : seasonal performance under ambient condition and model evaluation
- 2021
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Ingår i: Energy Sources, Part A. - : Taylor & Francis Group. - 1556-7036 .- 1556-7230. ; , s. 1-16
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Tidskriftsartikel (refereegranskat)abstract
- With the increasing population, food waste, sewage sludge, and poultry litter management problem are scaling up even in low-income countries. The management of these wastes has therefore been challenging. Anaerobic digestion of food waste alone is not very stable due to its acidic nature and high degradability whereas sewage sludge and poultry litter have low biochemical methane potential and a high nitrogen concentration. Co-digestion of suitably selected substrate leads to enhanced biogas production potential, system stability due to synergetic effects, and resolving the problem of waste management in the vicinity in a holistic approach. However, these wastes have varying characteristics and composition, in terms of carbon-to-nitrogen (C/N) ratio, pH, and alkalinity. In addition, millions of the rural household bio- digesters operating in low-income countries are working under ambient conditions and are primarily unheated. Therefore, there is a need of research to assess the viability of biogas production of co-digestion of all above substrates in an optimal mixing ratio operating in an ambient temperature condition. In this study, food waste (FW), sewage sludge (SS), and poultry litter (PL) were co-digested at ratios (SS: PL: FW: 3:2:1, 2:1:1, 1:1:1) with 8% total solid (TS) content at ambient temperature in summer and winter seasons. Biogas yield was highest with mixing ratio of 2:1:1 with the values of 640 L/kgVS in summer while it gave extremely low biogas yield of 106 L/ kgVS in winter. The 2:1:1 mixture also had the highest methane composition of nearly 65% as well as the highest VS removal efficiency of 60%, making it the most viable option for increasing biogas production. Mathematical modeling results using Gompertz model and first-order model predicted well with R2 value ranging from 0.91 to 0.98, which upheld the experimentally obtained values. Findings from this study suggest that co-digestion substrates (SS:PL:FW) mixing ratio of 2:1:1 is an optimized ratio among the studied co-substrate ratio for enhanced biogas production. Furthermore, winter biogas yield is almost one sixth of summer biogas yield, which means use of temperature enhancement techniques to anaerobic digesters operating at ambient conditions would be essential to increase the biogas yield during winter.
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