Low-cost Energy Research Articles

New stable rare earth Ti-based semiconductor pyrochlore oxides for low-cost energy applications

New stable rare earth Ti-based semiconductor pyrochlore oxides for low-cost energy applications

Synergistic enhancement in hydrodynamic cavitation combined with peroxymonosulfate fenton-like process for bpa degradation: New insights into the role of cavitation bubbles in regulation reaction pathway

The combination of hydrodynamic cavitation (HC) and Fenton-like oxidation technology can dramatically enhance the pollutant removal capacity, however, the synergistic effect of cavitation and catalysts on reactive oxygen species (ROS) generation remained enigmatic. In this study, we established a combined system based on HC and Ce-MnFe2O4 activated peroxymonosulfate (PMS) for BPA removal, and attentions were paid on the role of cavitation bubbles. The results show that the combination of HC in Ce-MnFe2O4 activated PMS could mediate the degradation of BPA from the non-radical pathway dominated by 1O2 to •O2− dominated radical pathway. Both controlled experiments and theoretical calculations revealed that the cavitation bubbles with different sizes play the dominant role in ROS generation. The microjets produced by the collapse of cavitation bubbles could create a large number of oxygen vacancy defects on Ce-MnFe2O4 surface, which modify the activation barrier of PMS and facilitate the generation of •O2− thermodynamically. The stable existing cavitation bubbles with the size of 100∼400 nm could create considerable gas-liquid interface. The molecular dynamics simulations show that the nano bubbles can concentrate the BPA and increase the probability of contacts between BPA and Ce-MnFe2O4, hence effectively solve the issues of short lifetime of •O2− radicals and limited mass transfer distance to strengthen the reaction. In addition, the PMS/Ce-MnFe2O4/HC system not only achieves the satisfied COD (95 %) and TOC (65 %) removal efficiency but also enabled the BPA-contaminated water with a low energy cost of 0.065 kWh·m−3 and oxidant cost, highlighting the application potential of the HC technology for contaminated water.

Neutral Ligand Triggered Low-Dimensional Reconstruction for Improving the Efficiency and Stability of Perovskite Solar Cells.

Perovskite solar cells (PSCs) offer a potentially large-scale method for producing low-cost renewable energy. However, stability challenges currently limit their practical application. Consequently, alternative methods for increasing the PSC stability are urgently needed. Compared with three-dimensional (3D) perovskites, low-dimensional (LD) perovskites have been shown to have higher stability. In this study, a LD/3D hybrid perovskite strategy is used that involves post-treating the Cs0.05(FA0.98MA0.02)0.95Pb(I0.98Br0.02)3 perovskite with a neutral allyl 1H-imidazole-1-carboxylate (AImC) ligand. We show that this neutral organic spacer molecule has two key roles. AImC acts as a solvent and triggers localized reconstruction to produce a LD capping layer in one postprocessing step. AImC prolongs the carrier lifetime and reduces trap-assisted recombination. As a result, the PSCs containing AImC achieve a maximum power conversion efficiency (PCE) of 21.42% compared to 20.27% for the control device and show significantly decreased hysteresis. AImC also greatly increased the stability of the films and devices to air, moisture, and heat. The results of this study imply that neutral amine liquids that have the correct solvating and ligating properties have good potential to improve the PCE and stability of the PSCs.

Performance‐Oriented Understanding and Design of a Robotic Tadpole: Lower Energy Cost, Higher Speed

Performance‐Oriented Understanding and Design of a Robotic Tadpole: Lower Energy Cost, Higher Speed

Multifunctional Self-Assembled Bio-Interfacial Layers for High-Performance Zinc Metal Anodes.

Rechargeable aqueous zinc-ion (Zn-ion) batteries are widely regarded as important candidates for next-generation energy storage systems for low-cost renewable energy storage. However, the development of Zn-ion batteries is currently facing significant challenges due to uncontrollable Zn dendrite growth and severe parasitic reactions on Zn metal anodes. Herein, we report an effective strategy to improve the performance of aqueous Zn-ion batteries by leveraging the self-assembly of bovine serum albumin (BSA) into a bilayer configuration on Zn metal anodes. BSA's hydrophilic and hydrophobic fragments form unique and intelligent ion channels, which regulate the migration of Zn ions and facilitate their desolvation process, significantly diminishing parasitic reactions on Zn anodes and leading to a uniform Zn deposition along the Zn (002) plane. Notably, the Zn||Zn symmetric cell with BSA as the electrolyte additive demonstrated a stable cycling performance for up to 2400 hours at a high current density of 10 mA cm-2. This work demonstrates the pivotal role of self-assembled protein bilayer structures in improving the durability of Zn anodes in aqueous Zn-ion batteries.

Techno – economic and environmental design of a three – phase hybrid renewable energy system for UNVDA Ndop Cameroon using meta-heuristic and analytical approaches

A three – phase hybrid renewable energy system have been proposed in this study as an alternate current grid power supply for an agro – company in the North – West Region of Cameroon. In this study, an industrial load profile with an energy demand of 383.45 kWh/day, 72.79 kWp peak and a residential load with energy demand of 33.26 kWh/day, 2.7 kWp peak have been considered in solving the economic, technical and environmental aspects of the optimization problem. To achieve the best results, a two step methodology has been implored to design the system. The first method requires an analytical approach used to determine the required battery, inverter, diesel generator capacities and the number of three phase PV arrays (NF). The second methodology is a techno – economic and environmental analysis conducted for different number of NF using three meta-heuristic algorithms; ABC, GA and PSO. The obtained results from these methodologies showed that for different values of NF, the REF was in the range 62.9–99.8 % in the Photovoltaic hybrid system (PVHS). The lowest cost of energy was 0.1441 €/kWh at a final REF of 99.8 % compared to a standalone system with an energy cost of 0.1655 €/kWh. The PVHS consist of a 117 kW PV array, 30 kW inverter, 160 kW diesel generator operating at a load factor of 75 % and a battery bank capacity of 43.2 kWh. The Standalone option consist of a 126 kW PV array, 135 kW inverter and a battery bank capacity of 475.2 kWh. The large inverter capacity and battery bank in the standalone system accounts for the high energy cost compared to the PVHS. This study can be used to evaluate and validate the performance of hybrid renewable energy systems for agro – companies whose load profile lack time series data and require a three – phase supply for industrial applications.

Synthesis of chemical bath deposited Manganese oxide thin films for high performance supercapacitor

The present study addresses the growing need for high-performance supercapacitors, emphasizing the benefits of Manganese oxide (MnO2) thin film as a promising electrode material. Thin film deposition of MnO2 is achieved through Chemical Bath Deposition (CBD) method by varying the deposition time on the stainless steel substrate. In order to investigate impact of deposition time on various physico-chemical properties of MnO2 thin films, different characterizations were carried out like X-ray diffraction, Scanning electron microscopy, Energy dispersive X-ray analysis, X-ray photoelectron spectroscopy, cyclic voltammetry, Galvanostatic charge–discharge analysis. The deposited MnO2 thin films are subsequently studied for their electrochemical properties in a 1 M KOH electrolyte solution. Remarkably, the best specific capacitance is obtained about 296.5 F/g at current density of 0.5 A/g, with 86.42 % retention after 5000 cycles, highlighting the excellent electrochemical performance of the MnO2 thin films deposited at 6 hrs of reaction time. This work highlights valuable insights into the CBD deposited MnO2 thin films for supercapacitor applications, providing a foundation for the development of an efficient, low-cost, and scalable energy storage devices.

Investigating the structural, electronic, optical and thermodynamic properties of ATiO3 (A = Ba, Ca, Ra) for low-cost energy applications

The structural, optoelectronic, and thermodynamic characteristics of ATiO3 (A = Ba, Ca, Ra) perovskites have comprehensively been investigation first-principles based DFT calculations. The GGA method was employed to handle exchange and correlation potentials. The analysis of the E-V plots indicates that RaTiO3 exhibits the highest level of stability in comparison to BaTiO3 and CaTiO3. The direct band-gap characteristic of the ATiO3 (A = Ba, Ca, Ra) perovskites is apparent in the band structure plots. The band gaps for BaTiO3, CaTiO3, and RaTiO3 are 2.48, 3.15, and 1.91 eV, respectively. The analyzed materials exhibit the highest level of photon absorption in the near UV area, as demonstrated in the ε2(ω) plots. The refractive index n(ω) values reveal that ATiO3 (A = Ba, Ca, Ra) are active optical materials as their n(ω) values are between 1 and 2. These perovskite oxides have optical features that make them promising prospects for anti-reflecting coatings over entire energy span as these materials exhibits a very low reflection (∼20 %) of incident photons. The thermodynamic properties of ATiO3 (A = Ba, Ca, Ra) are assessed to determine their dynamical stability and suitability for thermal applications. The results of the investigation demonstrate that these perovskite oxides have the potential to be used in optoelectronic devices.

The Influence of Cuprum (II) Acetate (Cu (CH3COO)2) Dopant and Heating Temperature in The Fabrication of Thin Films of Barium Strontium Titanate (Ba0.4Sr0.6TiO3)

Abstract Barium Strontium Titanate (BST), or BaxSr1-xTiO3, is an excellent ferroelectric material that is widely used on thin film applications in microelectronic devices, making BST very essential to the tech industries. This research aims to fabricate Cuprum doped BST thin films at low temperature using the Chemical Solution Deposition (CSD) and spin coating technique, and then to analyze the thin film’s band gap energy from the UV-Vis curve, XRD Spectral and EDAX. The advantage lies in the use of low temperatures in which it allows a significant energy savings compared to other studies. Using the Kubelka-Munk method with the Tauc Plot relation, the bandgap energy values for each BST substrates were obtained. Without Cuprum (II) Acetate dopant, the Band Gap values of the thin film samples are 3.84 eV and 3.77 eV. With 3% concentration of Cuprum (II) Acetate dopant, we obtained smaller Band Gap values, which are 3.74 eV and 3.71 eV. Based on the XRD spectral analysis, the lattice parameters were determined with a tetragonal crystal structure. However, according to the EDAX analysis, the elemental composition obtained is not yet stoichiometric. This research is important to serve as a reference for other researchers and manufacturers to opt into fabrication of thin films with lower energy cost, provide guidance for researchers to have more flexibility in their own thin film fabrication.

Effect of concentration of aqueous alcohol solution and layer thickness on free convection due to local heating

This paper investigates the effect of point heating, ethyl alcohol concentration, and layer thickness on the convective behavior of the solution. Laser heating enhances heat and mass transfer at low energy costs. For the first time, the research determines boundaries of the transition to the chaotic behavior of the velocity field at a change in several parameters: the initial alcohol concentration and the initial thickness of the liquid layer. Simple estimated ratios are obtained to determine the critical value of the Bond number in a binary solution. The solution behavior is predominantly influenced by the solute Rayleigh and Marangoni numbers. A small alcohol concentration (about 10%) is shown to have a stabilizing effect on the velocity field. In the course of evolution, several flow patterns change sequentially, which is associated with changes in the gradient of surface tension, solution concentration and layer thickness with evaporation time.

Hybrid renewable hydrogen systems in Saudi Arabia: A techno-economic evaluation for three diverse locations

This study presents a techno-economic evaluation of hybrid renewable hydrogen systems in Al Jouf, Yanbu, and Riyadh, Saudi Arabia, using HOMER software to model and optimize grid-connected and off-grid configurations. Grid-connected systems consistently demonstrate superior cost-effectiveness, achieving lower hydrogen (COH) and energy (COE) costs, particularly in resource-rich regions like Yanbu. Off-grid systems, while more expensive, offer crucial energy independence for remote areas or where grid reliability is a concern. Sensitivity analyses reveal that increasing solar irradiance reduces COH, COE, and net present cost (NPC), along with optimal PV array sizes, especially in grid-connected systems. Wind resources play a significant role in Yanbu, where abundant wind reduces reliance on solar energy. This emphasis on the role of wind resources in Yanbu provides the audience with specific regional factors affecting system design. Off-grid systems exhibit greater sensitivity to demand fluctuations due to their dependence on battery storage. The study highlights the importance of tailoring system designs to local resource availability, climate, and demand. Policy recommendations include promoting grid integration, supporting off-grid solutions in areas with limited grid access, investing in climate-resilient technologies, and fostering regional collaboration for a sustainable hydrogen economy in Saudi Arabia and the Arab region.

Compound parabolic concentrator for LED-based underwater optical communication transmitter

Laser sources have been used at the transmitter unit of underwater wireless optical communication (UWOC) systems since their invention. In recent years, light-emitting diodes (LEDs) have begun to be used as UWOC transmitters due to their low cost, long lifespan, and high energy efficiency. However, data transmission distances in UWOC systems using bare LEDs and LED arrays with collimating lens are limited due to LED’s large divergence angles and insufficient gains provided by the low cost lens designs. In this paper, we propose to use a compound parabolic concentrator (CPC), whose transmission efficiency curve is very close to the ideal concentrator, as a collimator that narrows the divergence angle of LEDs to design low-cost UWOC transmitter with long communication distance. Using the Bouguer–Beer–Lambert channel model, we derived the received optical power expression at the receiver side for the LED-based UWOC system with CPC at the transmitter. Furthermore, unlike existing studies in the literature, the full spectrum of the LED has been taken into account when deriving the power expression. The results show that using the CPC collimator instead of a typical collimation lens in an LED-based UWOC system can narrow the divergence angle by approximately 10 times, resulting in a 70 dB increase in signal-to-noise ratio (SNR) at the receiver and up to a 20 times increase in the communication distance.

Optimizing hybrid renewable energy based automated railway level crossing in Bangladesh: Techno-economic, emission and sensitivity analysis

The railway system in Bangladesh, particularly the level crossing system, needs significant advancements, including a shift towards using renewable energy to power these crossings. As a solution, this study proposes optimal hybrid systems powered by renewable energy on an automated railway level crossing system, which is reliable, efficient, and sustainable. The main contribution of this study is to introduce an optimal hybrid renewable energy-based automated railway level crossing system in Bangladesh, focusing on technical and economic evaluation, emissions, and sensitivity assessment using HOMER Pro. The proposed system examines the optimal outcome for a 1 kW vertical-axis wind turbine and a 0.440 kW photovoltaic system at five selected locations. The results reveal satisfactory net present cost values amounting to USD 8495, USD 8505, USD 8564, USD 8262, and USD 8357 for Narayanganj, Cox’s Bazaar, Noakhali, Dinajpur, and Rajshahi respectively. Moreover, HOMER Pro indicates that the photovoltaic-wind turbine–grid-connected model offers a lower Cost of Energy which is around 0.03 USD/kWh compared to other configurations. The Internal Rate of Return for the selected locations are 20 %, 33.7 %, 31.5 %, 5.2 %, and 4.6 % for Narayanganj, Cox’s Bazaar, Noakhali, Dinajpur, and Rajshahi, respectively. The developed structure is projected to have a payback period ranging from 4.57 to 13.29 years across the five selected locations. Furthermore, the proposed systems reduce greenhouse gas emissions by up to 44.23 % compared to a grid-only system. Additionally, sensitivity analysis is performed by varying wind speed and solar irradiation to emphasize the robustness of the proposed systems.

Using break-even analysis to explore the cost and carbon reduction benefits of solar and wind energy integration in microgrids for convenience stores

In response to the increasing demands for net-zero carbon emissions in Taiwan and globally, this study explores the feasibility of implementing microgrid technologies in convenience stores to reduce carbon emissions. The study utilizes the commercial simulation tool HomerPro to evaluate the performance of integrating solar and wind power into microgrid systems, aligning with Taiwan's current priorities in renewable energy development. The analysis incorporates carbon pricing scenarios, grid reliability considerations, and financial variables such as discount and inflation rates. We simulated 256 system configurations to identify the most economically viable solutions under various conditions. The results indicate that integrating solar and wind energy into microgrid systems can significantly lower energy costs and carbon emissions, especially in high carbon-price scenarios. These benefits provide strong incentives for businesses to adopt carbon-neutral strategies. These findings provide valuable insights for policymakers and businesses, highlighting the critical role of reducing green power purchase prices in improving economic feasibility. Future research explores the impacts of integrating other renewable energy sources, offering broader technical support for achieving carbon neutrality.

Soil Nutrient Analysis and Automatic Monitoring in Precision Agriculture

ABSTRACT The higher productivity from soil can be achieved through Wireless Sensor Networks (WSNs) technology; for this reason, the implementation of WSNs in precision agriculture is increasing day by day. Among the different technologies for crop monitoring, WSNs are recognized as a powerful option for collecting and processing data in the agricultural domain, with low cost and low energy consumption. The ultimate aim of this paper is to predict the precise values of soil nutrients nitrogen, phosphorus, and potassium (NPK) using a machine learning (ML)-based mathematical model formulation. The proposed system will use Global System for Mobile Communications (GSM) technology to automatically monitor soil parameters. It transfers soil data over the mobile network using a GSM modem. In the hardware part, sensor node units were developed to fetch and load data through the energy-efficient GSM, utilizing a bi-directional multi-level text messaging option to improve the alarm system’s efficiency. The system contains sensors such as potential of hydrogen and humidity (PH), which are used to monitor soil data collected from the sensors by the microcontroller. Additionally, as a novel contribution, machine learning based on regression models is applied to the NPK data. A novel data interpolation approach is proposed for data oversampling. The R2 values are compared, achieving nearly 99.5% accuracy in all cases. This paper focuses on various challenges and scalability issues encountered in research and discusses different results obtained by monitoring various soil parameters in a real-time agricultural environment.

Страх красоты

The article discusses the problem of rejecting the image of beauty in modern dance. It is indicated that the theme of despair, fear, violence and depression begins to dominate in modern dance since its inception in the 20s of the last century. The characteristic features of movements and plasticity in expressionist dance, in the school of M. Graham, are described: broken vertical, inwardly turned chest and feet, sharpness and convulsiveness of movements, blows aimed at oneself, etc. The article consistently examines the possible causes of this trend, such as technical ease and accessibility, lower energy cost of ‘sad dances’, as well as the opportunity to demonstrate originality, nonconformism, express social protest, etc. There is an opinion that the expression of pathological motives, negative feelings, fears in art contributes to the liberation from their destructive effect in real life. This approach is questioned, because there is also a reverse mechanism: as a result of viewing relevant plots (for example, scenes of violence), infection with emotions occurs, role models arise, and the thresholds of what is permissible decrease. Along with criticism of a number of trends in contemporary art, the importance of the concept of ugliness for culture is emphasized. Meeting one’s own infirmity and imperfection, be that physical, psychological or moral, plays an essential role in the spiritual development of a person. However, modern art, including the dance performances considered, follow the path of establishing ugliness as a new norm and cultivate the perverted reality of the ‘sick’ creativity of a disintegrating personality. The expression of beauty, on the contrary, is characteristic of an integral personality striving for perfection and praising life.

Production and research of tungsten carbide powder from VA grade tungsten metal waste in aviation kerosene

Purpose. Obtaining and studying the composition, structure and properties of tungsten carbide powder from VA grade tungsten metal waste in aviation kerosene. Methods. Tungsten carbide powder from tungsten metal waste of the VA brand was obtained in the following sequence. The reactor was filled with a working medium – aviation kerosene of the TS-1 brand, the waste was loaded into the reactor. Electrodes were mounted from the same waste tungsten of the VA brand. The mounted electrodes were connected to a pulse generator. The necessary electrical parameters of the installation were set: the capacitance of the condensers is 42.0–43.5 UF; the voltage on the electrodes is from 115–120 V; the pulse repetition rate is 50–55 Hz. The resulting tungsten powder was studied using: a scanning electron microscope QUANTA 600 FEG; a particle size analyzer Analysette 22 NanoTec; an energy-dispersed X-ray analyzer from the company EDAX; X-ray diffraction on a diffractometer Rigaku Ultima IV. Results. Based on the conducted experimental studies, a new method for producing tungsten carbide powder has been developed, characterized in that the powder is obtained by electroerosive dispersion of tungsten metal waste of the VA brand in aviation kerosene at a capacitor capacity of 42.0–43.5 UF, an electrode voltage of 115–120 V and a pulse repetition frequency of 50–55 Hz. It has been experimentally established that spherical and elliptical particles of tungsten carbide powder W2C have sizes from 2.26 microns to 90.72 microns with an average volumetric diameter of 20.2 microns and contain carbon on the surface. Conclusion. The production of tungsten carbide suitable for industrial use at low energy costs from metal waste has shown high efficiency of the technology of electroerosion dispersion.

Impact of Energy Crises on Income Inequality: An Application of Piketty’s Hypothesis to Pakistan

In Pakistan, the majority of people have access to energy supplies. However, people who are underprivileged, below the extreme poverty line, or part of the middle class often spend disproportionate portions of their income on energy supplies and services, to some extent because of higher upfront prices for energy supplies, expensive products, and expensive imported appliances. The nonavailability of low-cost energy supplies is mainly affecting underdeveloped regions that have mostly low-income households. We used the dynamic ordinary least squares method to look at the impact of the energy crisis on income inequality from 1997 to 2021. The results show that the energy crisis exacerbates income inequality as low-income groups end up spending more significant shares of their income on energy products, supplies, and services than higher-income groups. Fair and equal access to energy supplies and services is less likely to reduce income inequality if prices are not cost-efficient. Cautious deliberation regarding the structure of energy tariffs is inevitable; at the same time, safety nets and social security programs for the poorest groups need to be expanded. At this stage, the aim is to target energy prices that will achieve the objectives of reducing polarity and increasing real income.

Comparative Study of Steel Mill Dust Leaching with Phosphoric Acid and Sodium Hydroxide

Steel mill dust (SMD), produced by electric arc furnaces, is a highly polluting industrial waste due to its high content of metals (Zn, Fe, and Pb) and fine particle size (ca. 5.4 µm). This residue can be valorized to recover Zn using pyro and hydrometallurgical methods, with hydrometallurgy offering greater selectivity and lower energy costs. However, composition of SMD presents a challenge in identifying an optimal leaching agent. This study investigates the preferential extraction of Zn using two leaching agents, namely 150 g L−1 (1.5 M) phosphoric acid (H3PO4) and 240 g L−1 (6 M) sodium hydroxide (NaOH), in a two-stage leaching process (80 °C). Metallic Zn from the alkaline pregnant solution was recovered by electrodeposition (750 A/m2, graphite anode, stainless-steel cathode) and smelting (450 °C). The samples of SMD contained 26.3% Zn, 20.1% Fe, and 0.9% Pb, in compounds such as magnetite (Fe3O4), zincite (ZnO), and franklinite (ZnFe2O4). Each leaching agent successfully attained a 99% Zn recovery, demonstrating the proposed procedure’s high efficacy. However, H3PO4 leached also Fe and corroded the cathode during electrodeposition, thereby restricting the final recovery of metallic Zn. NaOH demonstrated greater selectivity for Zn over Fe and Pb, producing high-purity Zn deposits on the cathode by electrodeposition and 99% metallic zinc by smelting.

Research on the Energy Management Strategy of a Hybrid Tractor OS-ECVT Based on a Dynamic Programming Algorithm

The multi-degree-of-freedom characteristics of the planetary gear electronic continuously variable transmission (ECVT) configuration in series-parallel hybrid tractors impose more complex requirements for energy management strategies under variable load conditions. For a high-power hybrid tractor, this paper takes the hybrid tractor output-split (OS)-ECVT configuration as the research object and describes the principles of stepless transmission and power-splitting within the configuration. In order to improve the fuel economy of high-power hybrid tractors and the running status of power components, an energy management strategy focused on ploughing conditions based on the Bellman minimum dynamic programming (DP) algorithm is proposed in this paper. Second, equivalent fuel consumption is selected as the performance index for energy-saving control, and the solving principle of the energy management strategy based on the dynamic programming algorithm is established to facilitate the resolution process of the energy management strategy. Finally, the energy-saving control simulation is completed under ploughing conditions. The results show that compared with the energy management strategy based on the optimal operating line (OOL), the energy management strategy based on DP fully utilizes the benefits of low-cost electric energy and enables the hybrid power system to have a wider range of stepless transmission performance. In addition, the hybrid power system has the advantages of enhanced decoupling of speed and torque, higher efficiency, and more economical secondary energy conversion. As a result, the whole machine has enhanced power-split performance, greatly improving the running conditions of the power components. The equivalent fuel consumption values of the energy management strategies based on DP and OOL are about 3.1238 L and 4.2713 L, respectively. The equivalent fuel consumption based on DP is reduced by about 26.87%, which effectively improves the fuel efficiency of hybrid tractors.