Evaluation of magnetic properties of electrical steel is vital in improving the quality of electrical machinery since it is used as magnetic cores for transformers, motors and generators. A double yoke single sheet tester (ssT) was modeled using two identical C-cores wound with copper wires at limb side in horizontal arrangement. The magnetic properties for electrical steels, grade M4 and M19 were tested under a frequency of 50 Hz with the current ranging from 02 to 2.4A. The effects of the sample dimension and anisotropy on magnetic measurements were investigated. Evaluation on specimen dimensions indicate that the non-uniformity of sample magnetization in overhang sample can attribute to the flux leakage between the yoke legs. The stray flux is also increased with the overhang sample. However, the so-called fit-in sample which is fitted nicely between the yoke end poles can minimize the effect of stray flux. One way ANOVA and T-test were used as statistical methods and executed at the 5% significance level. It is statistically proven that the magnetic properties of both magnetic materials are influenced by their anisotropy.
The effects of strontium doping on the electrical and magneto-transport properties of magneto resistive La0.7Ca0.28Sr0.02MnO3 at different sintering temperatures have been studied. The samples were prepared by the co-precipitation technique (COP) and sintered at 1120, 1220 and 1320 oC. XRD patterns revealed that the samples have an orthorhombic structure and the diffraction patterns can be indexed with the Pbnm space group. The insulator metal transition, TIM increased linearly from 261 K to 272 K with the increase in sintering temperature. The magnetoresistance (MR) measurements were made in magnetic fields from 0.1 to 1 T at room temperature. The percentage of MR increased with increasing of magnetic field and sintering temperature for all samples. The electrical resistivity data were fitted with several equations in the metallic (ferromagnetic) and insulator (paramagnetic) regime. The density of states at the Fermi level N(EF) and the activation energy (Ea) of electron hopping were estimated by using variable range hopping and small polaron hopping model.
Catanionic system using anionic sodium bis-(2ethylhexyl)sulfosuccinate (Am) and cationic cetyltrimethylammonium bromide (cTAB) is studied. The system is prepared by addition of CTAB solution to a prepared AOT solution until slight anionic-rich catanionic phase is produced. Catanionic system consists of the mixture of different types of surfactants and counterion due to electrostatic interaction between the oppositely charged surfactant. Both of these products affect the in surface activity of the surfactant. Hydrodynamic diameters decrease and clearer solution were seen with the increase of CTAB concentration in solution mixture. As a result, mixed surfactant with larger hydrophobic region and the presence of counterion will induce smaller vesicle to form in catanionic system.
A combined similarity-numerical solution of the magnetohydrodynamic boundary layer slip flow of an electrically conducting non-Newtonian power-law nanofluid along a heated radiating moving vertical plate is explored. Our nanofluid model incorporates the influences of the thermophoresis and the Brownian motion. The basic transport equations are made dimensionless first and then suitable similarity transformations are applied to reduce them into a set of nonlinear ordinary differential equations with the associated boundary conditions. The reduced equations are then solved numerically. Graphical results for the non-dimensional flow velocity, the temperature and the nanoparticles volume fraction profiles as well as for the friction factor, the local Nusselt and the Sherwood numbers are exhibited and examined for various values of the controlling parameters to display the interesting aspects of the solutions. It was found that the friction factor increases with the increase of the magnetic field (M), whilst it is decreased with the linear momentum slip parameter (a). The linear momentum slip parameter (a) reduces the heat transfer rates and the nanoparticles volume fraction rates. Our results are compatible with the existing results for a special case.
To identify the potential zones for gold mineralization at the Felda Chiku 3, Gua Musang, Kelantan, East coast Malaysia, twenty-one (21) geophysical survey lines were conducted at the proposed mineral exploration site using the pole - dipole of the electrical resistivity and induced polarization arrays to get the maximum depth of 150 m with 400 m survey length. From the resistivity and chargeability concentration maps, the potential mineralized zones as delineated, was observed to be dominantly concentrated towards the southwest and northern part of the area. The 3D resistivity and chargeability slice model present low resistivity values and high chargeability values that are well correlated which is palpable especially at the depths of 25 m and 50 m respectively. The data showed that the potential mineralized zones are trending approximately north-south directions. Forty (40) drilling locations were proposed for follow-up drilling based on the resistivity and chargeability models.
BiFeO3 nanoparticle decorated on flower-like ZnO (BiFeO3/ZnO) was fabricated through a facile hydrothermal-reflux combined method. This material was utilized as a composite photocathode for the first time in microbial fuel cell (MFC) to reduce the copper ion (Cu2+) and power generation concomitantly. The resultant BiFeO3/ZnO-based MFC displayed distinct photoelectrocatalytic activities when different weight percentages (wt%) BiFeO3 were used. The 3 wt% BiFeO3/ZnO MFC achieved the maximum power density of 1.301 W m-2 in the catholyte contained 200 mg L-1 of Cu2+ and the power density was greatly higher than those pure ZnO and pure BiFeO3 photocathodes. Meanwhile, the MFC exhibited 90.7% removal of Cu2+ within 6 h under sunlight exposure at catholyte pH 4. The addition of BiFeO3 nanoparticles not only manifested outstanding capability in harvesting visible light, but also facilitated the formation of Z-scheme BiFeO3/ZnO heterojunction structure to induce the charge carrier transfer along with enhanced redox abilities for the cathodic reduction. The pronounced electrical output and Cu2+ reduction efficiencies can be realized through the synergistic cooperation between the bioanode and BiFeO3/ZnO photocathode in the MFC. Furthermore, the developed BiFeO3/ZnO composite presented a good stability and reusability of photoelectrocatalytic activity up to five cyclic runs.
A double-negative metamaterial-inspired antenna is presented for mobile wireless applications. The antenna consists of a semi-circular radiating patch and a 3 × 4 hexagonal shaped metamaterial unit cell array in the ground plane. The antenna is fed with a 50 Ω microstrip feed line. The electric dimensions of the proposed antenna are 0.20λ × 0.26λ × 0.004λ, at the low-end frequency. The proposed antenna achieves a -10 dB impedance with a bandwidth of 2.29 GHz at the lower band and 1.28 GHz at the upper band and can operate for most of the mobile applications such as upper GSM bands, WiMAX, Bluetooth, and wireless local area network (WLAN) frequency bands. The focused novelties of the proposed antenna are its small size, multi-standard operating bands, and electromagnetic absorption reduction at all the operating frequencies using the double-negative metamaterial ground plane.
At present, the domotization of homes and public buildings is becoming increasingly popular. Domotization is most commonly applied to the field of energy management, since it gives the possibility of managing the consumption of the devices connected to the electric network, the way in which the users interact with these devices, as well as other external factors that influence consumption. In buildings, Heating, Ventilation and Air Conditioning (HVAC) systems have the highest consumption rates. The systems proposed so far have not succeeded in optimizing the energy consumption associated with a HVAC system because they do not monitor all the variables involved in electricity consumption. For this reason, this article presents an agent approach that benefits from the advantages provided by a Multi-Agent architecture (MAS) deployed in a Cloud environment with a wireless sensor network (WSN) in order to achieve energy savings. The agents of the MAS learn social behavior thanks to the collection of data and the use of an artificial neural network (ANN). The proposed system has been assessed in an office building achieving an average energy savings of 41% in the experimental group offices.
Solid-oxide fuel cells (SOFCs) are electricity generators that can convert the chemical energy in various fuels directly to the electric power with high efficiency. Recent advances in materials and related key components for SOFCs operating at ≈500 °C are summarized here, with a focus on the materials, structures, and techniques development for low-temperature SOFCs, including the analysis of most of the critical parameters affecting the electrochemical performance of the electrolyte, anode, and cathode. New strategies, such as thin-film deposition, exsolution of nanoparticles from perovskites, microwave plasma heating, and finger-like channeled electrodes, are discussed. These recent developments highlight the need for electrodes with higher activity and electrolytes with greater conductivity to generate a high electrochemical performance at lower temperatures.
Shrimp meat is prone to autolysis and decay due to the abundance of endogenous enzymes and contamination from microorganisms. HVEF freezing can slow the spoilage of shrimp, producing small and uniform ice crystals, resulting in less damage to muscle tissue. In this study, HVEF technique was used to freeze the shrimp (Solenocera melantho), and the UPLC-MS metabolic technique was used to investigate the metabolites of frozen shrimp meat. Compared with the control group, 367 differential metabolites were identified in the HVEF group. Mapping them to the KEGG database, there were 108 with KEGG ID. Purine metabolism and pyrimidine metabolism were the most enriched pathways. In addition, phosphatidylcholines (PCs), inosine (HxR), and l-valine were identified as potential biomarkers associated with lipid, nucleotide, and organic acid metabolism, respectively. Overall, HVEF can improve freezing quality of shrimp meat by slowing down the metabolism of substances in the muscle of S. melantho.
Microbial fuel cells (MFCs) are the efficient and sustainable approach for the removal of toxic metals and generate energy concurrently. This article highlighted the effective use of rotten rice as an organic source for bacterial species to generate electricity and decrease the metal concentrations from wastewater. The obtained results were corresponding to the unique MFCs operation where the 510 mV voltage was produced within 14-day operation with 1000 Ω external resistance. The maximum power density and current density were found to be 2.9 mW/m2 and 168.42 mA/m2 with 363.6 Ω internal resistance. Similarly, the maximum metal removal efficiency was found to be 82.2% (Cd), 95.71% (Pb), 96.13% (Cr), 89.50% (Ni), 89.82 (Co), 99.50% (Ag), and 99.88% (Cu). In the biological test, it was found that Lysinibacillus strains, Chryseobacterium strains, Escherichia strains, Bacillus strains are responsible for energy generation and metal removal. Furthermore, a multiparameter optimization revealed that MFCs are the best approach for a natural environment with no special requirements. Lastly, the working mechanism of MFCs and future recommendations are enclosed.
The Southeast Asian countries have experienced significant degrees of economic growth over the years but have not managed to safeguard their environmental attributes in tandem. As a result, the aggravation of the environmental indicators across this region casts a shadow of doubt on the sustainability of the economic growth achievements of the Southeast Asian countries. Against this milieu, this study specifically explores the influence of renewable electricity generation capacity, technological innovation, financial development, and economic growth on the ecological footprints in five Southeast Asian countries namely Indonesia, Malaysia, the Philippines, Thailand, and Vietnam during the period 1985-2016. One of the major novelties of this study is in terms of its approach to assess the renewable energy use-ecological footprint nexus using the renewable electricity generation capacity as an indicator of renewable energy use in the selected Southeast Asian nations. The econometric analysis involves methods that are robust to handling cross-sectional dependency and slope heterogeneity issues in the data. Accordingly, the recently developed Cross-sectional Augmented Autoregressive Distributed Lag estimator is used to predict the short- and long-run impacts on ecological footprints. The major findings suggest that higher renewable electricity generation capacity and technological innovation reduce ecological footprints, while higher financial development and economic growth increase the ecological footprints. Therefore, these findings imply that in forthcoming years, the selected Southeast Asian countries will need to tackle the environmental adversities by enhancing their renewable electricity generation capacities, increasing investment in technological development, greening the financial sector, and adopting environmentally-friendly growth policies. Hence, the implementation of relevant policies, in this regard, can be expected to ensure complementarity between economic growth and environmental welfare across Southeast Asia.
Petroleum, coal, and natural gas reservoir were depleting continuously due to an increase in industrialization, which enforced study to identify alternative sources. The next option is the renewable resources which are most important for energy purpose coupled with environmental problem reduction. Microbial fuel cells (MFCs) have become a promising approach to generate cleaner and more sustainable electrical energy. The involvement of various disciplines had been contributing to enhancing the performance of the MFCs. This review covers the performance of MFC along with different wastewater as a substrate in terms of treatment efficiencies as well as for energy generation. Apart from this, effect of various parameters and use of different nanomaterials for performance of MFC were also studied. From the current study, it proves that the use of microbial fuel cell along with the use of nanomaterials could be the waste and energy-related problem-solving approach. MFC could be better in performances based on optimized process parameters for handling any wastewater from industrial process.
The present work focused on the utilization of three local wastes, i.e., rambutan (Nephelium lappaceum), langsat (Lansium parasiticum), and mango (Mangifera indica) wastes, as organic substrates in a benthic microbial fuel cell (BMFC) to reduce the cadmium and lead concentrations from synthetic water. Out of the three wastes, the mango waste promoted a maximum current density (87.71 mA/m2) along with 78% and 80% removal efficiencies for Cd2+ and Pb2+, respectively. The bacterial identification proved that Klebsiella pneumoniae, Enterobacter, and Citrobacter were responsible for metal removal and energy generation. In the present work, the BMFC mechanism, current challenges, and future recommendations are also enclosed.
Microbial fuel cells (MFCs) are based on the biochemical reaction of microorganisms to decompose organic wastewater for converting chemical energy into power energy. MFCs are considered an environmentally friendly technology that is gaining popularity due to their simultaneous digestion and energy production abilities. To enhance its real application in wastewater treatment, this study proposes to use a non-woven material for replacing the usage of expensive membranes in MFCs. In addition, the study aims to consider a series of different aeration areas of cathode electrodes for finding an optional design. Results have shown that the adoption of non-woven with 0.45 μm can effectively prohibit the diffusion of oxygen into the anode chamber. Moreover, the non-woven material played an important role as an interface between the anode and cathode, enhancing the MFC performance. The usage of suitable non-woven material can replace the role of the membrane when applied in real wastewater applications. The results have shown that the case study where a combination of a 50% aeration area of the cathode electrodes with 25% exposure of the cathode plate in the air yielded relatively better aeration in terms of a higher current density of 250 mA/m2, higher power density of 220 mW/m2, and higher open voltage circuit of 0.4 V, compared to other case studies considered. These results indicate the optimal aeration configuration for MFCs applied in commercial wastewater treatment in the future.
Wind is a renewable energy source. Overall, using wind to produce energy has fewer effects on the environment than many other energy sources. Wind and solar energy provide public health and environmental benefits to the social. Wind turbines may also reduce the amount of electricity generation from fossil fuels, which results in lower total air pollution and carbon dioxide emissions. In order to better optimize the effect of social energy economic management and facilitate the multiobjective decision making of coordinated development of energy and socioeconomic environment, a modeling and analysis method of economic benefits of wind power generation based on deep learning is proposed. In this paper, based on the principle of deep learning, the evaluation indicators of wind power economic benefits are excavated, a scientific and reasonable economic benefit evaluation system is constructed, a wind power economic benefit analysis model supported by public management is constructed, and the steps of wind power economic benefit analysis are simplified. It is concluded that the modeling and analysis method of wind power economic benefits based on deep learning has high practicability in the actual application process, which is convenient for the prediction and analysis of energy demand for social and economic development.
Over the last three decades, the world has been facing the phenomenon of the ecological deficit as the ecological footprint is continuously rising due to the persistent decline of the per-capita bio-capacity. Moreover, there is a substantial increase in globalization and electricity consumption for the same period, and transportation is contributing to economic prosperity at the cost of environmental sustainability. Understanding the determinants of ecological footprint is thus critical for suggesting appropriate policies for environmental sustainability. As a result, this study analyzes the impacts of economic globalization, transportation, coal rents, and electricity consumption in ecological footprint in the context of the USA over the period 1995 to 2018. The data have been extracted from "Global Footprint Network," "Swiss Economic Institute," and "World Development Indicators." The current study has also applied the flexible Fourier form nonlinear unit root test to examine the stationarity among variables. For the empirical estimation, a novel technique, the "quantile auto-regressive distributive lag model," is applied in the study to deal with the nonlinear associations of the variables and to evaluate the long-term stability of variables across quantiles. The study's findings indicate that coal rents, transportation, and globalization significantly and positively contribute to the deterioration of ecological footprints at different quantile ranges in the short and long run. Electricity consumption is found to have a positive and significant impact at lower quantile ranges in the long run but not have a significant impact in the short run. The study suggested that lowering the dependence of the transport sector on fossil fuels, more use of hydroelectricity, and stringent strategies to curb coal consumption would be helpful to reduce the positive influence of these variables on ecological footprints in the USA.
Carbon dots (CDs) are a recent addition to the nanocarbon family, encompassing both crystalline and amorphous phases. They have sparked significant research interest due to their unique electrical and optical properties, remarkable biocompatibility, outstanding mechanical characteristics, customizable surface chemistry, and negligible cytotoxicity. Their current applications are mainly limited to flexible photonic and biomedical devices, but they have also garnered attention for their potential use in intelligent packaging. The conversion of food waste into CDs further contributes to the concept of the circular economy. It provides a comprehensive overview of emerging green technologies, energy-saving reactions, and cost-effective starting materials involved in the synthesis of CDs. It also highlights the unique properties of biomass-derived CDs, focusing on their structural performance, cellular toxicity, and functional characteristics. The application of CDs in the food industry, including food packaging, is summarized in a concise manner. This paper sheds light on the current challenges and prospects of utilizing CDs in the packaging industry. It aims to provide researchers with a roadmap to tailor the properties of CDs to suit specific applications in the food industry, particularly in food packaging.
The lack of control in voltage overshoot, transient response, and steady state error are major issues that are frequently encountered in a grid-connected photovoltaic (PV) system, resulting in poor power quality performance and damages to the overall power system. This paper presents the performance of a control strategy for an inverter in a three-phase grid-connected PV system. The system consists of a PV panel, a boost converter, a DC link, an inverter, and a resistor-inductor (RL) filter and is connected to the utility grid through a voltage source inverter. The main objective of the proposed strategy is to improve the power quality performance of the three-phase grid-connected inverter system by optimising the proportional-integral (PI) controller. Such a strategy aims to reduce the DC link input voltage fluctuation, decrease the harmonics, and stabilise the output current, voltage, frequency, and power flow. The particle swarm optimisation (PSO) technique was implemented to tune the PI controller parameters by minimising the error of the voltage regulator and current controller schemes in the inverter system. The system model and control strategies were implemented using MATLAB/Simulink environment (Version 2020A) Simscape-Power system toolbox. Results show that the proposed strategy outperformed other reported research works with total harmonic distortion (THD) at a grid voltage and current of 0.29% and 2.72%, respectively, and a transient response time of 0.1853s. Compared to conventional systems, the PI controller with PSO-based optimization provides less voltage overshoot by 11.1% while reducing the time to reach equilibrium state by 32.6%. The consideration of additional input parameters and the optimization of input parameters were identified to be the two main factors that contribute to the significant improvements in power quality control. Therefore, the proposed strategy effectively enhances the power quality of the utility grid, and such an enhancement contributes to the efficient and smooth integration of the PV system.
In recent years, food waste has been a global concern that contributes to climate change. To deal with the rising impacts of climate change, in Hong Kong, food waste is converted into electricity in the framework of low-carbon approach. This work provides an overview of the conversion of food waste into electricity to achieve carbon neutrality. The production of methane and electricity from waste-to-energy (WTE) conversion are determined. Potential income from its sale and environmental benefits are also assessed quantitatively and qualitatively. It was found that the electricity generation from the food waste could reach 4.33 × 109 kWh annually, avoiding equivalent electricity charge worth USD 3.46 × 109 annually (based on US' 8/kWh). An equivalent CO2 mitigation of 9.9 × 108 kg annually was attained. The revenue from its electricity sale in market was USD 1.44×109 in the 1st year and USD 4.24 ×109 in the 15th year, respectively, according to the projected CH4 and electricity generation. The modelling study indicated that the electricity production is 0.8 kWh/kg of landfilled waste. The food waste could produce electricity as low as US' 8 per kW ∙ h. In spite of its promising results, there are techno-economic bottlenecks in commercial scale production and its application at comparable costs to conventional fossil fuels. Issues such as high GHG emissions and high production costs have been determined to be resolved later. Overall, this work not only leads to GHG avoidance, but also diversifies energy supply in providing power for homes in the future.