Electric Source Research Articles

МОРСЬКИЙ БЕЗПІЛОТНИЙ УДАРНИЙ ДРОН-КАТЕР ІЗ УЛЬТРАЗВУКОВИМ ПРИШВИДШУВАЧЕМ РУХУ

A description of the design scheme of a marine unmanned attack drone-boat with an ultrasonic accelerator is given. Its increase in speed at the final stage of reaching a target pre-selected by the operator is provided by an ultrasonic generator of high-frequency electromagnetic waves installed in the hull of the drone-boat, the emitters of which are placed on the hull below its waterline to irradiate the water in which the hull moves and disturb its cavitation. It was found that the use of an ultrasonic generator, which includes a high-frequency pulse generator with an electrical power source, an amplifier with a resonator, and an emitter of ultrasonic high-frequency electromagnetic waves, is optimal for disturbing cavitation in offshore water. The emitters are washed with onboard water and are arranged in a staggered pattern on the boat's hull and bottom below its waterline. It has been proven that the disturbance of the cavitation field under the bottom of the moving hull of the boat in offshore water reduces the viscosity of water by 30-40%, thereby reducing the hydrodynamic resistance of water by moving solid bodies in it. It was found that lowering the hydrodynamic resistance of the water on board contributes to increasing the speed of the boat's hull from its cruising speed of 75-80 km/h in the final section of the approach to the target to 95-100 km/h. It is noted that increasing the boat's speed contributes to a proportional increase in the kinetic energy of its impact on a previously selected target, increasing the degree of damage and destruction caused to the target. It is estimated that increasing the speed of the drone-boat by 25-30% guarantees a 25-26% reduction in the duration of its stay in the affected area and, accordingly, proportionally lowers the probability of it being hit by the enemy's automated small arms. It is recommended to choose the design scheme and structure of powerful typical devices for ultrasonic welding as an ultrasonic generator of ultrasonic pulsating electromagnetic wave radiation. Their cheap parts and assemblies are mass-produced by industrial enterprises.

KELURAHAN PETANI HIJAU MODERN: SMART FARMING MENGGUNAKAN TEKNOLOGI PANEL SURYA UNTUK MEWUJUDKAN KAWASAN PERTANIAN MODERN DI KELURAHAN BAKUNG JAYA

The development of automatic plant watering devices has become a major focus in increasing efficiency and effectiveness in plant cultivation. In this context, automatic plant watering devices that use electrical energy sources from solar panels have shown great potential in saving energy and reducing environmental impacts. This tool is designed to replace manual work in watering plants, both in hydroponic systems and sprinkler systems. In hydroponic systems, automatic plant watering devices use soil moisture sensors to detect soil moisture and send commands to the water pump to water periodically. This allows hydroponic plants to receive nutrients continuously and maintain air humidity with automatic fogging. Meanwhile, in sprinkler systems, automatic plant watering devices use solar panels as a source of electrical energy. These solar panels generate electrical energy that is used to power the water pump and sprinkler, thus watering plants automatically without the need for human intervention. The advantages of using solar panel in automatic plant watering devices include the use of renewable energy, easy maintenance, and no greenhouse gas emissions. However, this tool also has disadvantages, such as dependence on sunlight intensity. Thus, the development of automatic plant watering devices using solar panel can help increase plant productivity, save energy, and reduce environmental impacts. This tool can also be integrated with various types of plant cultivation systems, thus providing many benefits in the development of modern agricultural technology.

Quantifying and enabling the resiliency of a microgrid considering electric vehicles using a Bayesian network risk assessment

With the increase in the number of natural disasters, caused by climate change, the role of emission and resilience has become more outstanding. In this paper, a novel model for quantifying and enabling the resiliency of a microgrid, using a Bayesian network risk assessment approach is presented. The three objective functions of cost, pollution, and resilience are optimized simultaneously using an improved lexicographic augmented ɛ-constraint method. It should be mentioned that these items are included in the proposed model due to the irreplaceable role of electric vehicles (EVs) and renewable energy sources (RESs) in distribution systems. Moreover, with the Bayesian network, the interaction between random variables is considered and a graphic view of casual relationships between stochastic and probabilistic variables is investigated in this study. The Monte Carlo scenario-based technique has handled the uncertainties of EVs and RESs. The proposed mixed integer linear programming (MILP) is implemented in the GAMS software environment under the CPLEX solver and finally, the results are discussed.

Adaptive-DMPC based energy management and pre-installation techno-economic analysis of a grid-tied cyber-physical community microgrid

The trends for creating smart cities is increasing as it gives assurance of high-quality living standards, however, converting an existing city into a smart one needs more time, investments and is highly tedious. Another concept of community based sustainable living that can be installed in and around outskirts of any city. All the features of smart cities can be brought in by most economical, sustainable, and environmental friendly way. A cyber-physical Community Microgrid (CMG) can have various loads such as heating, cooling, security and lighting purposes. The dependency on grid supply can be reduced by using renewable sources of electricity. Solar water heaters and biogas plant can take care of heating loads. Handling uncertainties in generation, time-varying load scenarios, and dynamics of supply grid are crucial for smooth operation of cyber-physical CMG. In this work, an Energy Management Strategy (EMS) for CMG is proposed using an adaptive Distributed Model Predictive Control (DMPC) that improves scalability with modular architecture, allow enhanced flexibility and adaptability, robustness and reliability, enhanced optimization and predictive capabilities. All possible intermittencies types due to renewables, time-variable demand profiles, smooth charging/discharging cycles and longevity of storage batteries, curtailing of noncritical loads, and dynamic price of grid consumption are applied. Further, use of EMS outcomes is done to develop pre-installation techno-economic analysis for establishing a CMG with optimal component sizing. The given DMPC scheme for CMG is verified by conducting comprehensive test case studies over 24 hrs interval on the Matlab/Simulink and hardware-in-loop testing.

Dynamic characteristics analysis and vibration control of coupled bending-torsional system for axial flow hydraulic generating set

Aiming at the vibration problems of shaft system for axial flow hydraulic generating sets caused by complex excitations, the coupled bending-torsional dynamic equations of rotor-runner system are established considering multi-effect including hydraulic, mechanical, electrical and other external vibration sources. Whether taking the torsional degree of freedom into account, the stability and disparate destabilization laws of system periodic solutions are analyzed using the shooting method combined with Floquet theory. On this basis, the influence of coupling bending-torsional effect on system dynamic behaviors is discussed through bifurcation diagrams, Poincaré maps, trajectories, time domains and frequency spectrums. Furthermore, in order to alleviate the unsteady vibration of rotor as well as runner, the magnetorheological fluid damper is introduced into the shaft system, and numerical simulations are performed on models of coupled bending-torsional systems with or without the magnetorheological fluid damper. The analyses indicate that the interaction between bending and torsional vibration of the shaft system will expand the chaotic sustained range for rotor. Meanwhile, the amplitude of the rotor-runner system is magnified owing to the torsional vibration, which leads to local rubbing faults of the system under specific operating conditions, while the intervention of the magnetorheological fluid damper can significantly suppress the nonlinear motion of rotor and runner, reduce the amplitude of system vibration, so as to avoid the occurrence of friction defects effectively. The above research results can provide conducive references for fault diagnosis, optimized design, and vibration control of axial flow hydraulic generating sets.

Technoeconomic analysis of solar PV electrification to remote areas of Dera Ghazi Khan: A case study

With the increase in population at an immense rate, electricity demand is growing exponentially. Researchers and policymakers are seeking alternating means of power generation to meet the load demand. These resources should be cost-effective, environmentally friendly and least carbon emissions. To mitigate the load demand Renewable Energy Sources (RES) are integrated into electrical networks. In this work, an off-grid solar photovoltaic (PV) system is designed for rural areas of Dera Ghazi Khan (DG Khan), Pakistan. These areas often lack access to reliable grid power. Installing PV systems in these areas can help provide a reliable source of electricity, reduce reliance on fossil fuels, and improve living conditions. This case study is simulated using PVsyst 7.2. of Roonghan village such as hospitals, shops, and residential houses for techno-economic analysis of off-grid solar PV. The economic viability shows that installing off-grid solar PV in DG Khan is much cheaper. The electricity taken from the grid that's almost 80.01%is expensive. This case study helps other researchers and policymakers to mitigate the electricity requirement of remote areas located far away from the national grid. To install a transmission line, having cost $26.98 corer but using an off-grid to provide electricity to the same area is $2.16 corer. Additionally, it integrates Battery Energy Storage (BES) with Renewable Energy Sources (RES) to achieve a 5 % annual energy cost reduction and enhanced self-sufficiency, filling a gap in existing literature.

High strength low alloy steel joint fabricated by laser welding with real-time high-frequency resistance heating

The balance between softening and hardening is still a great challenge for the laser welding of the high strength low alloy steel. For example, welding with low heat input was commonly used to avoid softening, but it would inversely harden the joint and introduce the undesired welding defects such as hydrogen-induced cracks. This work proposed a simple and robust processing technique, denominated High Frequency electric cooperated Laser Welding. Laser heat source was combined with high-frequency electric heat source to balance heat input distribution and reconcile the contradiction between softening and hardening in the welding of high strength low alloy steel. As a structural material sensitive to welding softening and hardening, S690QL steel was adopted to show the fundamental advancement of the new process. Benefitted from the skin effect and proximity effect of high-frequency current that improve the heat input distribution and the regulation of the high-frequency heat input proportion, the martensite content in the heat affected zone was greatly reduced, whilst the grain size was limited to a low value. Under the high-frequency heat input proportion of 47.1 %, lower bainite distributed throughout the heat affected zone. The softening and hardening issues of the joint therefore have been improved simultaneously: the tensile strength of the joint was almost equal to that of the base material, the impact energy of weld seam and the heat affected zone reached 77.6 J and 66.2 J respectively.

Electricity supply configurations for green hydrogen hubs: A European case study on decarbonizing urban transport

In this study, a techno-economic analysis tool for conducting detailed feasibility studies on the deployment of green hydrogen hubs for fuel cell bus fleets is developed. The study evaluates and compares five green hydrogen hub configurations' operational and economic performance under a typical metropolitan bus fleet refuelling schedule. Each configuration differs based on its electricity sourcing characteristics such as the mix of energy sources, capacity sizing, financial structure, and grid interaction. A detailed comparative analysis of distinct green hydrogen hub configurations for decarbonising a fleet of fuel-cell buses is conducted. Among the key findings is that a hybrid renewable electricity source and hydrogen storage are essential for cost-optimal operation across all configurations. Furthermore, bi-directional grid-interactive configurations are the most cost-efficient and can benefit the electricity grid by flattening the duck curve. Lastly, the paper highlights the potential for cost reduction when the fleet refuelling schedule is co-optimized with the green hydrogen hub electricity supply configuration.

Utilizing Amniotic Membrane Allograft as regenerative therapy for Treating Burns

Burn injuries are prevalent among all age groups and can result from thermal, scald, or electrical sources. Currently, various scaffolds are employed to enhance the healing process and minimize scar formation. Collagen serves as a scaffold, facilitating tissue regeneration and promoting the formation of new blood vessels. Additionally, scaffolds such as amniotic membrane aid in proper epithelialization and scar reduction, boasting unique anti-inflammatory and bacteriostatic properties. In our study, we utilized amniotic membrane allograft as a biological dressing for burn wounds on an adult patient's right thigh.

Cryptocarbon: How much is the corrective tax?

With increasing awareness of past environmental damage from crypto mining, questions arise as to how persistent the problem will be in the future and how taxation can help in addressing this negative externality. We estimate that the global demand for electricity by crypto miners reached that of Australia or Spain, resulting in 0.28% of global CO2 emissions in 2022. Projections suggest sustained future electricity demand and indicate further increases in CO2 emissions if crypto prices significantly increase and the energy efficiency of mining hardware is low. To address global warming damages, we estimate the corrective excise on the electricity used by crypto miners to be USD 0.045 per kWh, on average. Considering also air pollution costs raises the tax to USD 0.085 per kWh. Country-specific estimates vary depending on their electricity sources. Other new electricity reliant technologies are also driving up CO2 emissions. In our calculation, the corrective tax on electricity used by data centers is USD 0.048, on average.

EEG Cortical Sources of Theta, Beta and Gamma Frequencies Orchestrate Audio-Visual Interactions.

The fascinating ability of brain to integrate information from multiple sensory inputs has intrigued many researchers. Audio-visual (AV) interaction is a form of multisensory integration which we encounter to form meaningful representations of the environment around us. There is limited literature related to the underlying neural mechanisms. Quantitative EEG (QEEG), a tool with high temporal resolution can be used to understand cortical sources of AV interactions. EEG data was recorded using 128 channels from 30 healthy subjects using audio, visual and AV stimuli in 'object detection task'. Electrical source imaging was performed using s-LORETA across seven frequency bands (lower alpha 1, lower alpha 2, upper alpha, beta, delta, gamma, theta) during AV versus unimodal conditions across 66 gyri. The cortical sources were activated in the theta, beta, and gamma bands in cross modal versus unimodal conditions, which we propose, reflect neural communication for AV interaction network. The cortical sources constituted areas involved with visual processing, auditory processing, established multisensory (frontotemporal cortex, parietal cortex, middle temporal gyrus, superior frontal gyrus, inferior frontal gyrus, precentral gyrus) and potential multisensory areas (paracentral, postcentral and subcallosal). Together, these results offer an integrative view of cortical areas in frequency oscillations during AV interactions.

Untangling light in noisy luminous environments

Electric light sources, including displays and luminaires, often exhibit rapid light fluctuations called temporal light modulation (TLM). TLM can be seen as their electrical footprint. This work demonstrates that TLM can be remotely detected and used to perform in situ photometric and spectroradiometric measurements of very low light levels superimposed to intense backgrounds. Illuminance levels about 500 000 times smaller than the background were reliably measured by lock-in detection, allowing photometric measurements to be performed during daytime, even with sunny conditions. Using a new type of optical lock-in spectrometer, it becomes possible to retrieve spectral quantities through the TLM of the light source. The spectral distribution of an LED lamp was measured against a daylit background more than 1500 times brighter. Lock-in detection is an excellent technique to perform in situ measurements of electric light, even at very low level, in the presence of daylight and other background lights, opening interesting opportunities to characterize anthropogenic light pollution.

Robust Design of Electrical System for Nuclear Plants to Prevent a Nuclear Accident During an Emergency Situation

The Chernobyl accident taught us an important lesson regarding the significance of the emergency diesel generator (EDG), which is crucial for supplying a nuclear facility with emergency alternating-current power. A worst-case scenario would occur if the EDG failed to start functioning. In response to this problem, this research addresses the issue and suggests an optimal design for another alternative electrical source using solar energy. Until now, employing this technology presented a challenge as a solar energy system generates electrical harmonics that are transmitted from the photovoltaic (PV) grid to the electrical network. These harmonics can negatively impact the performance and operation of nuclear facilities. Consequently, this study proposes a comprehensive investigation that tackles this issue by implementing a LCL filter to mitigate the harmonics in the PV network. This paper not only provides an alternative solution in the event of a diesel generator breakdown, but also studies the effect of this solution on the station’s performance and how to improve it. A mathematical model based on the MATLAB program is developed to simulate the application of the LCL filter strategy. The proposed technique is tested through simulation with an actual case, demonstrating its reliability and high-quality outcomes.

ABOUT SOME PROBLEMS OF THE ELECTRIC ENERGY SECTOR OF GEORGIA

In the article - "About some problems of the electric energy sector of Georgia" - the issue of the country's electricity production potential and how it is used is discussed. The article mentions that out of all the energy resources, Georgia has the most electrical energy resources. These are hydropower (water resources), wind and solar resources. A retrospective analysis of both total and individual production and consumption of electricity in the period 1990-2023 concluded that a 47.5% increase in individual consumption was caused by the catastrophic population decrease in Georgia during the same period. The article also mentions that the average consumption of electricity in Georgia is half of the corresponding indicator of Germany, the USA - Mesa-Med, and Norway - one-sixth. The electricity balance of Georgia is negative. A significant part of electricity is imported from Russia and Azerbaijan. Among the problems faced by the electrical energy system, the article discusses the possibility of causing danger by depending on external sources of electricity, giving preference to the construction of large hydroelectric power plants (the construction of which destroys wild nature) and less attention to the study of the issue of regional production and consumption of electricity. The article provides conceptual solutions to each of these problems. Keywords: electric energy; hydropower; wind and solar energy; large and small hydropower plants; Electrical energy balance.

Environmental and social life cycle analysis of hydrogen-powered railway locomotives in Canadian context

Hydrogen locomotives offer a promising cleaner alternative to conventional diesel locomotives. However, hydrogen production methods and energy sources may introduce additional emissions. This paper evaluates the environmental and potential social impacts of hydrogen locomotives in Canada from a life cycle perspective, encompassing the locomotive's retrofitting components and the fuel life cycle. Results show varying emissions across different hydrogen production pathways and regions. Electrolysis has the highest emission reduction potential in provinces with cleaner electricity sources, such as Manitoba, Quebec and British Columbia, resulting in up to 47% reduction in life cycle emissions. Conversely, in Alberta and Saskatchewan, emissions are approximately three times higher than diesel due to reliance on fossil fuel-derived electricity. The social assessment underscores the imperative of considering emissions, costs, and technical implications to address potential social impacts. This positions hydrogen locomotives with significant challenges that necessitate resolution before they can be considered a superior alternative to diesel.

An AC and DC Electric Field Effect Based Charged Particle Focusing Scheme for Particle Beam Mass Spectrometer

Particle Beam Mass Spectrometer (PBMS) is a mass analyzer based particle sizer, features a few to hundreds of nanometer (nm) sizing capabilities in environmental pressures above hundreds of mTorr. The above feature makes the PBMS be used as in-situ process monitoring schemes for several kinds of semiconductor process equipment (e.g. Chemical Vapor Deposition). However, it still cannot be used in other process equipment (e.g. Plasma etching, Ion implantation) which requires lower process pressure conditions than the PBMS operation limits. The bottleneck of pressure limits comes from an aerodynamic lens component, which focuses incoming particles in background gas using repetitive fluidic contraction and expansion effects. These effects hard to be happened when the target particles are surrounded in molecular or transition background gas regions. In order to lower the operating pressure limits, other focusing schemes are required.In this study, an alternative particle focusing scheme which uses AC and DC electric field effects is proposed. The proposed scheme uses a stacked-ring ion funnel structure with variable AC and DC electric sources, for driving AC and DC potential variations along the funnel’s axial direction. While radial electric potential wells produced by AC frequency components induce particles’ radial position concentration to the funnel axis center, potential well depth and axial well depth steepness is controlled by AC amplitudes and DC source values.Simulation results show that with the proposed scheme, more than 50% of particle transmission efficiencies are obtained for 5 nm – 100 nm sized charged particles moving with Maxwellian velocities in molecular background region. The results come from AC electric sources with 200 Hz - 20 kHz frequency ranges and within 50 V amplitude ranges, and DC electric sources within 50 V ranges which are feasible values for hardware implementation.

(Invited) Electric-Driven Preconcentrating Microfluidic Device for Enhancing Biomolecular Sensing

Preconcentration of biomolecules for detection on microfluidic platforms based on electrical kinetic trapping (EKT) through ion concentration polarization (ICP) has been well developed in the past decade. Biomolecules can be entrapped due to the equilibrium of forces between electro-osmosis and ICP when applying a voltage to the system. In tis study, I will introduce different type of ICPs including theory, mechanism and their limitation. I will also clarify the experimental ICP results based on different microfluidic channel design. A triboelectric nanogenerator (TENG)-driven nanofluidic preconcentrating device that is able to trigger ICP and subsequently cause the EKT of the biomolecules without using a conventional electrical power source was also introduced. The EKT and electrical characteristics of the TENG-based nanofluidic preconcentrator were studied. The preconcentration factors of the device can be found to be ~1000 folds. Several examples of preconcentration device integrating to biosensing techniques are presented in this talk. Some biomarkers are also demonstrated. Further, I will also demonstrate that these biosensors, combining with preconcentrators, can be integrated to a smartphone reader.

Investigating the Catalyst/Ionomer Interface in PEM Water Electrolysis Using Microelectrodes

Low temperature zero-gap PEM water electrolyzers are promising devices which are still in development. Water electrolyzers have the potential to be a critical part of the energy transition as a method to use renewable electricity to produce hydrogen which can feed into the hydrogen economy. When paired with renewable sources of electricity, electrolyzers will be subjected to variable power loads, which places a large stress on the systems. This stress causes increased degradation of many components, including the catalyst layers. It can be challenging to study the impact of degradation of the catalyst layer in an electrolysis cell, due to the many coupled degradation phenomenon occurring in the full cell system. Microelectrodes can be used to investigate the catalyst layer under electrolysis operating conditions, but in a simplified system which can more easily isolate the catalyst layer and kinetics. One of the limiting factors in water electrolyzer performance is the oxygen evolution reaction (OER) due to the sluggish kinetics. If the OER kinetics could be improved, it would greatly reduce the cost of the electrolyzer system. The ionomer forms a thin film in the catalyst layer, and controls the local conditions surrounding the catalyst. The local conditions and interactions of the ionomer with the active catalyst sites still aren't well understood, as well as the contribution of the ionomer to catalyst degradation. In this study, cavity microelectrodes will be used to investigate the impact of ionomer on IrOx catalyst OER performance and durability.

Understanding Mechanisms and Reversibility of Anode Degradation in PEM Water Electrolysis

Water electrolysis is an important route toward sustainable industrial production of hydrogen, as well as mitigation of the CO2 emissions associated with current hydrogen production from natural gas. The industrial deployment of clean electrolytic hydrogen will depend on long-term electrolyzer durability under the intermittent operating conditions associated with coupling with renewable sources of electricity. Thus, understanding cell degradation mechanisms is required to develop mitigation strategies and minimize performance degradation over extended periods of operation.Here, we investigate the effect of temperature and intermittent conditions on proton exchange membrane (PEM) water electrolyzer performance over a variety of timescales. Performance losses consisting of both reversible losses and irreversible degradation accelerate quickly during holds at high current densities and low temperatures, reaching high cell voltages within several hours. However, the cell can be returned to near beginning-of-test performance by interrupting these current holds with a variety of intermittent states of operation, such as interruption of the applied current or operation at higher temperatures. Reversible losses can harm the overall cell efficiency without being captured in short-term polarization curves, and may also contribute to stressors causing long-term degradation. The impact of different shut-down and idle states on the catalyst layers and cell degradation will also be discussed. The presented insights could contribute to the development of accelerated stress test protocols as well as performance recovery strategies for long-term operation of PEM water electrolyzers.

Magnetically Enhanced Electroconversion of CO2 to Valuable Products at High Current Densities

Carbon dioxide reduction has emerged as a highly promising area of focus, particularly considering the perpetual CO2 emissions from the industrial sector. The electrochemical reduction pathway stands out as one of the most auspicious methodologies for CO2 utilization, owing to its compelling attributes. These include, but are not limited to, operation under mild conditions, the ability to tailor CO2 conversion towards desired products, and the potential for seamless integration with renewable electricity sources (e.g., derived from solar and wind), thus offsetting the associated carbon footprint. Moreover, the application of magnetic fields has demonstrated effectiveness in numerous electrocatalytic reduction processes. Presently, there is a paucity of literature addressing the utilization of magnetic fields for CO2 reduction, as it represents a recently introduced concept. This presentation aims to contribute to the advancement of this novel idea, paving the way for its scalability in the near future. Our focus is on addressing mass transfer limitations and optimizing the process to handle high current density, thereby rendering it viable for large-scale CO2 reduction.