Mode Of Operation Research Articles

Access to the full three-dimensional Brillouin zone with time resolution, using a new tool for pump-probe angle-resolved photoemission spectroscopy.

Here, we report the first time- and angle-resolved photoemission spectroscopy (TR-ARPES) with the new Fermiologics "FeSuMa" analyzer. The new experimental setup has been commissioned at the Artemis laboratory of the UK Central Laser Facility. We explain here some of the advantages of the FeSuMa for TR-ARPES and discuss how its capabilities relate to those of hemispherical analyzers and momentum microscopes. We have integrated the FeSuMa into an optimized pump-probe beamline that permits photon-energy (i.e., kz)-dependent scanning, using probe energies generated from high harmonics in a gas jet. The advantages of using the FeSuMa in this situation include the possibility of taking advantage of its "fisheye" mode of operation.

The Effect of Senegal River Irrigation Water Quality on Soil Salinization: A Study of the Main Canal of the M’Pourie Plain in Mauritania

In this study, the Senegal River, being the main source of water, plays a crucial role in the area’s agricultural development. Irrigation on the M’Pourie plain using water from the Senegal River is carried out without any prior sanitation control. An evaluation of the quality of irrigation water and its impact on soil salinization in different agricultural plots soil salinity is crucial for the effective utilization of traditional irrigation water over extended periods. Comprehensive physico-chemical analyses were conducted across nine locations on the M’Pourie plain in Rosso during the dynamic seasons of 2021-2023. Nevertheless, a relatively small number of studies have employed soil salinity indexing methods to examine the consequences of river irrigation on soil salinity. The analysis and interpretation of the results obtained were based both on classic methods (average and correlations) and more advanced techniques such as principal component analysis (PCA) and the Piper diagram which allow characterization and a spatial typology of water. Analysis of the Piper diagram highlights the distinction between two groups of water, weakly and moderately mineralized, ranging from 52.22 μS.cm-1 in the dry season to 72.22 μS.cm-1 in the rainy season, presenting a sodium-potassium bicarbonate facies The variability of irrigation water supplies, proves to be important in the functioning of an agro-systems. Two modes of operation have become individualized: the dry phase mode, characterized by very strong mineralization of the water linked to a significant load of dissolved elements, and the wet phase mode, whose water quality is poorly mineralized but shows the impact that its irrigation water can represent in the loading of organic and mineral pollution and the need for strict control of these waters upstream before their agricultural use. The results of this study show the absence of risks of soil salinization in relation to the chemical nature of irrigation water and the impact of agriculture on the M’Pourie plain.

Modelling environmental life cycle performance of alternative marine power configurations with an integrated experimental assessment approach: A case study of an inland passenger barge

There is pressure on the global shipping industry to move towards greener propulsion and fuel technologies to reduce greenhouse gas emissions. Hydrogen and electricity are both recognised as pathways to achieve a net-zero. However, in the evaluation of the environmental performance of these alternative marine power configurations, conventional life cycle assessment (LCA) methods have limitations reflecting the varied nature of ship design and operational modes. The integration of LCA with experimental assessment could remedy the shortcoming of conventional approaches to data generation. The system energy demand data in this study was generated based on specific ship design and directly fed into life cycle assessment. To demonstrate the effectiveness and potential the approach was applied to a case study of inland waterway vessel. Suitable hybrid PV/electricity/diesel and hydrogen powered fuel cell systems for the case vessel were modelled; and hydrodynamic testing and dynamic system simulation was undertaken to provide ship performance data under various operational/environmental profiles. Lifecycle assessment (LCA) indicated hydrogen and electrical propulsion technologies have the potential for 85.7 % and 56.2 % emissions reduction against an MGO base case, respectively. The results highlight that implementation of both technologies is highly dependent on energy production pathways. Hydrogen systems reliant on fossil feedstocks risk an increase in emissions of up to 6.3 % against the MGO base case. Sensitivity analysis indicated an electrical system with electricity production from 79.5 % renewables could achieve savings of 82.2 % in GHG emissions compared to the MGO base case. Crucially, the results demonstrate a further development of the LCA approach which can enable a more accurate environmental performance evaluation of alternative marine power configurations considering specific ship design and operational characteristics. Ultimately this addition makes the results more meaningful for commercial operations and decision making in the selection of alternative marine power systems to support the transition to net-zero.

Sensitivity analysis of parameters impacting the performance of an energy ship using airborne wind energy

This study assesses the impact of different model parameters on the power performance of energy ship systems using point-mass models, focusing on two operational modes. The first mode involves a kite operating in a pumping mode with adjustable tether lengths, aided by additional propellers for ship propulsion. It utilizes a quasi-steady kite model coupled with ship motion’s drag force and velocity triangles. The second mode features a kite pulling the ship, while underwater hydraulic turbines harness energy from ship velocity. Derived from a sail-based model, calculations deploy the force balance equation in line with ship motion, considering the drag forces of the ship and hydraulic turbines, alongside the propulsive force resulting from the kite’s interaction with the ship. The investigated parameters influencing the power performance include kite surface, ship length, wind speed, the angle between the ship’s motion direction and wind direction, and, for the pumping mode, ship speed. The power production of the propulsion mode is generally lower, with differences of at least 72%, depending on the combination of considered parameters.

A novel dual condensers heat pipe photovoltaic/thermal (PV/T) system: Numerical dynamic modelling and effect factors analysis in dual-function operation mode

This paper presents a dual condensers heat pipe PV/T system with multiple operating modes, including hot water, space heating, and dual-function. To exploiting the system's potential of energy supply, this paper proposes a dynamic model of the system in dual-function mode on the basis of the verified dynamic heat transfer model and condenser distributed parameter model. Several effect factors on the system performance have been analyzed, including water tank capacity, air-cooled condenser area and the dual condensers installation height difference. The simulated results show that the above parameters have little effect on the system's total thermal efficiency but a significant effect on single condenser heat gain distribution. When the water tank capacity increases from 100 L to 200 L, the thermal efficiency of the water-cooled condenser increases from 10.68 % to 17.82 %, while the air-cooled condenser's decreases from 48.12 % to 40.72 %. As the air-cooled condenser area is changed from model 1 to 4, the total efficiency increase from 58.13 % to 71.41 %. The system's thermal efficiency falls from 58.66 % to 47.50 % and its overall efficiency falls from 71.41 % to 60.40 % when the height difference rises from 0 m to 0.7 m.

Sinusoidal Phase Shift Modulation for V2H Operational Mode in Current-Fed Bidirectional Onboard Charger

Sinusoidal Phase Shift Modulation for V2H Operational Mode in Current-Fed Bidirectional Onboard Charger

Optimization method for capacity configuration and power allocation of electrolyzer array in off-grid integrated energy system

Hydrogen production using renewable energy is in line with China's the goal of carbon peak and carbon neutrality. The construction of off-grid hydrogen energy industrial park can effectively achieve local utilization of renewable energy and develop the green hydrogen industry. However, off-grid hydrogen energy industrial park has not the compensation and sustentation from large power grid, the stable operation and economic production of electrolyzer are affected by significant factors, such as power fluctuation and frequent start stop. Therefore, this paper proposed the optimization method for capacity configuration and power allocation of electrolyzer array in off-grid integrated energy system. Firstly, based on units of energy supply, energy conversion, and energy storage, a structural model of off-grid integrated energy system was established. Then, by analyzing the operational characteristics of single electrolyzer and electrolyzer array, flexible mode of multiple electrolyzers operating in combination was proposed. Furthermore, considering the hydrogen production cost, the mean of hydrogen production volatility and penalty cost, the capacity configuration and power allocation methods for electrolyzer array were proposed, and the optimization problem is solved with multi-objective particle swarm optimization algorithm. Finally, the hydrogen energy industrial park in Zhangye is taken as example to verify the effectiveness of above research content. Compared to a single type of alkaline electrolyzer, the mean of hydrogen production volatility of multiple electrolyzers operating in combination has decreased by 43.2 %, the hydrogen production quantity has increased by 9.74 %. Compared to a single type of proton exchange membrane electrolyzer, the hydrogen production cost has been reduced by 14.16 %. Compared with the balanced running mode, the flexible operation mode can improve the cost-effective and quantity of hydrogen production.

Comprehensive performance evaluation on a transcritical CO2 ejector-expansion heat pump system

In order to reduce irreversible loss and recover expansion work for improving automotive thermal system performance, this study experimentally evaluated the performances and characteristics of a CO2 ejector-expansion (EJE) heat pump system for electric vehicles under typical cooling and heating operating modes, examined the adaptability of the EJE system with a fixed-dimension ejector, and compared the EJE system with the basic-regenerative (REG) and vapor-injection (INJ) systems in the − 30 °C to 50 °C range. The results show that the increasing electronic expansion valve (EXV) opening leads to an increasing entrainment ratio and a decreasing lift ratio in both two modes. The maximum COP is 2.00 at 35 °C/27 °C (out-cabin/in-cabin air temperature) and 1.85 at 0 °C/20 °C. The COP improvement reaches a maximum of 21.6 % and 31.0 % at the ejector design temperature of 45 °C, compared to the REG and INJ systems, respectively. However, the heating performance of the ejector designed at a high temperature significantly decreases as the ambient temperature goes down. At − 30 °C/20 °C, the EJE system performs worse with a COP degradation of 6.1 % compared to the REG system.

Operation Modes of an Optically Pumped 6H SiC Quantum/Solid-State Magnetometer

Operation Modes of an Optically Pumped 6H SiC Quantum/Solid-State Magnetometer

Void closure in a pulsed complex plasma in microgravity

A new experimental method for creating void-free complex (dusty) plasmas under microgravity conditions is presented. The method is based on a pulsed operation mode of a four-channel radio frequency generator for plasma sustainment. A dust cloud of micrometer-sized particles can be immersed in the bulk of a low temperature plasma under microgravity conditions. It typically contains a central volume depleted of particles—the void—that prevents the generation of large, continuous clouds. Experiments performed at different neutral gas pressures and discharge volumes during the microgravity phase of a parabolic flight show that the central void is closed completely once the pulsed operation mode is applied. The particle cloud shape and the density distribution within the cloud are practically independent of the pulse period within the investigated parameter range and mainly depend on the overall discharge parameters neutral gas pressure and discharge volume. This indicates that the pulsed operation of the plasma source does not introduce new physical effects on the particles aside from the void closure. The proposed method has great potential for future application in experimental facilities dedicated to fundamental studies of large three-dimensional, homogeneous complex plasma systems in microgravity.

Literature Review on Fabrication of Quad Cycle for Handicapped Person

Abstract: In our daily life, we have seen various types of tri-cycles and tri-wheeled vehicles used by the disabled peoples for their locomotion from one place to another. There are several newly developed tri-wheeled vehicles for physically challenged people, which will be operated by manual, electrical and motorized modes. The most commonly used handicapped wheelchair are driven by the manual mode of operation by the use of pedal, but this vehicle provides discomfort to the handicapped persons through weakness in their body and due to their lack of physical fitness in all period of time. Hence, in order to reduce those difficulties various types of moped and modified scooter like vehicles are introduced, which are in the form of semi or fully automated mode of construction and working for their better increase in the comfort for their transportation. This paper overviews the implementation of new conceptual ideas and technologies on handicapped vehicles for the betterment in the preexisting vehicle models for differently abled people and we hope this will be helpful for the further manipulation in developments and provide the guide line for the new innovations in automotive for the physically challenged people.

High-frame-rate contrast-enhanced ultrasound to differentiate between clear cell renal cell carcinoma and angiomyolipoma

BackgroundTo investigate the diagnostic efficacy of high-frame-rate contrast-enhanced ultrasound (H-CEUS) in differentiating between clear cell renal cell carcinoma (CCRCC) and angiomyolipoma (AML).MethodsA retrospective study was performed on the clinical data of 79 patients diagnosed with CCRCC and 31 patients diagnosed with AML at the First Affiliated Hospital of Nanchang University between October 2022 and December 2023. Conventional ultrasound (US) and H-CEUS examinations were conducted on all patients prior to surgery, dynamic images were recorded from the US, and the qualitative and quantitative parameters of H-CEUS were collected. The t-test, χ² test and non-parametric Mann-Whitney test were employed to assess differences in clinical data, US characteristics, and qualitative and quantitative parameters of H-CEUS between the CCRCC and AML groups. The independent risk factors of CCRCC were identified using binary logistic regression. The receiver operator characteristic (ROC) curve was constructed to evaluate the diagnostic effectiveness of clinical + US and H-CEUS in differentiating between CCRCC and AML.ResultsThe CCRCC group and the AML group exhibited significant differences in patient gender, operation mode, nodular echo, and nodule blood flow (χ²=11.698, -, -,=10.582; P<0.001, <0.001, <0.001, and = 0.014, respectively). In addition, the H-CEUS qualitative analysis demonstrated significant differences between the AML group and the CCRCC group with respect to enhancement mode, regression mode, peak intensity, enhancement uniformity, no enhancement, and presence or absence of pseudocapsule (χ²=41.614, -, -, = 2.758, = 42.099, -; P<0.001, <0.001, <0.001, 0.097, <0.001, and <0.001, respectively). The Arrival time (AT) in the CCRCC group was significantly shorter than that in the AML group, as determined by quantitative analysis of H-CEUS (Z=-3.266, P = 0.001). Furthermore, the Peak intensity (PI), Ascent slope (AS), and The area under the curve (AUC) exhibited significantly higher values in the CCRCC group compared to the AML group (Z=-2.043,=-2.545,=-3.565; P = 0.041, = 0.011, and <0.001, respectively). Logistic regression analysis indicated that only gender, nodule echo, the pseudocapsule, AS, and AUC of H-CEUS were independent risk factors of CCRCC. The ROC curve revealed that combining gender and nodule echo yielded a sensitivity of 92.4%, specificity of 64.5%, and an AUC of 0.847 in distinguishing between CCRCC and AML. When combining the H-CEUS parameters of pseudocapsule, AS, and AUC, the sensitivity, specificity, and AUC for distinguishing between CCRCC and AML were 84.8%, 96.8%, and 0.918, respectively. No statistically significant difference was observed in the diagnostic effectiveness of the two methods (Z=-1.286, P = 0.198). However, H-CEUS demonstrated better AUC and specificity.ConclusionsH-CEUS enhances the sensitivity and specificity of differentiating between CCRCC and AML by improving the temporal resolution, offering a more precise diagnostic foundation for identifying the most appropriate therapy for patients.

Investigation of Mazidagi phosphate ore in wet flue gas desulphurization

The employment of Mazidagi phosphate ore for wet flue gas desulphurization was investigated. The ore was exposed to sulfation processes in a three-phase double-stirred reactor to determine the effects of certain parameters on SO2 absorption. The absorption rate significantly increased with inlet SO2 concentration, gas flow rate, stirring speeds, and solid concentration but not with temperature. The absorption rate increases as the mass transfer coefficients and interface area value increase with stirring speeds. These parameters have also a prominent impact on the absorption rate depending on the dissolution rate of CaCO3. Based on these, the most effective parameters on SO2 absorption are liquid-phase stirring speed and suspension concentration, and the process is diffusion-controlled in the liquid phase. In addition, optimum conditions were determined, and then the ore was exposed to sulfation processes via a semi-batch operation mode. A comparison between raw and sulfated ore was examined for the changes in physical structure and chemical composition. Although the ratios of fluorapatite and carbonate-fluorapatite remained nearly constant, the ratio of calcite decreased significantly. It was determined from these investigations that the calcite in the phosphate ore has been converted into the CaSO3∙½H2O compound. Consequently, both the calcite in the phosphate ore was utilized effectively for wet flue gas desulphurization, and a phosphate-rich industrial product was obtained.

Detuning piezoelectric receivers by resistive load adjustment for electrodynamic wireless power transfer

This article investigates electrical detuning techniques for low-frequency electrodynamic wireless power transfer (EWPT) systems. This study focuses on protecting the receiver from potential damage when quick increases in magnetic fields occur due to transmitter–receiver distance variation or in-rush transmitter coil currents. In the case of such event, to avoid damaging the mechanical receiver, the solution investigated in this article is to adjust the electrical load connected to the receiver. This adjustment enables precise tuning and detuning of the receiver’s resonant frequency and damping characteristics, thereby allowing to reduce its mechanical displacement amplitude and protecting it from damage. Based on well-known models of EWPT systems, we develop an analysis of two key operational modes of the proposed tuning/detuning approach: maximum transmitted power (MTP) mode, where the receiver circuitry’s input impedance is optimized for peak power transfer, and minimum displacement (MD) mode, which involves electrically detuning the receiver’s resonant frequency to limit its mechanical displacement. We establish transition conditions between MD and MTP modes based on the receiver voltage amplitude, enabling automated monitoring and adjustment of the receiver’s detuning. Experimental validation has been conducted with an EWPT experimental setup and a custom piezoelectric receiver. The results, in good agreement with the proposed analytical model predictions, confirm the effectiveness of the proposed detuning algorithm, which successfully reduces the receiver displacement by 60% in response to sudden magnetic field increases.

Sensorless fuzzy-sliding mode control of five phases permanent magnet synchronous motor using MRAS: in three different operating modes

This paper presents a comprehensive study on sensorless control techniques for five-phase permanent magnet synchronous motors (5P-PMSMs). To optimize the speed control performance of (5P-PMSM), which has more advantages than its counterpart three-phase PMSM system, we utilized a combination of fuzzy logic and sliding mode control techniques to optimize the proposed sliding mode control. Additionally, the Model Reference Adaptive System (MRAS) is employed to estimate the speed and rotor position of the 5P-PMSM to enhance the robustness and adaptability of the control system. The modelling of the machine, detailed with a robust nonlinear strategy based on the sliding control, is introduced to track the system until the desired sliding surface is achieved first. To guarantee that the tracking errors converge, the sliding mode control has a chatter due to the discontinuous term. To mitigate the drawback, the proposed control is designed by combining SMC with fuzzy logic, enhancing the performance in a steady state. Examining the control performance of the integrated control fuzzy-SMC with MRAS in different operating modes, including three tests in reversal speed operation, open phase fault mode, and the low-speed operating mode under load torque. The main aim is to assess and analyze the robustness and performance of the proposed control strategy. The stability of the overall control system is examined using the Lyapunov theorem and Popov’s theory analysis of MRAS observer stability. The simulation results of the suggested control displayed by MATLAB-Simulink illustrate the effectiveness and adaptability of the sensorless control scheme across different operating conditions, offering promising prospects for practical implementation in industrial applications.

How to Reduce the Number of Inspectors: Operation Mode and Modeling Simulation of Centralized Image Recognition in Railway Passenger Security Inspection

Security inspection is an essential step for passengers entering railway stations in China. Under the existing security inspection operation mode, each X-ray machine needs an image inspector to recognize the X-ray image, which poses the issue of resource optimization for inspectors. Based on the networking of security inspection X-ray machines, an innovative centralized image recognition (CIR) operation mode for railway security inspections is proposed, and it is worth noting that network and device failures are risk factors for this mode. The method for assigning image recognition personnel is designed to reduce labor force needed for security inspection. Using a combination of agent-based modeling method and computer simulation technology, the four elements of passengers, security inspection X-ray machines, X-ray image inspectors, and secondary baggage inspection personnel are modeled, and CIR indicators to study the effectiveness of the operation are designed. Based on the real departing passenger data of the Zhangjiakou section of the Beijing Zhangjiakou Line in China, simulation is conducted in two scenarios: large passenger flow and small passenger flow. The research is conducted from three aspects: operational efficiency, travel experience, and system complexity. Experiments have shown that, with a slight increase in passenger waiting time, the average number of X-ray image inspectors is reduced by more than 70% compared with the existing operation mode. The best pick-up location for passengers is related to passenger flow. The proposed model can analyze the effectiveness of CIR operation mode and provide decisive support for the application of CIR operation mode.

Metadata and feature importance analyses of membrane capacitive deionization models: Is a water treatment artificial intelligence panacea possible?

Membrane capacitive deionization (MCDI) is an emerging technology for water purification and desalination. Artificial intelligence (AI) techniques using machine learning (ML) and deep learning (DL) have been widely applied to overcome the drawbacks of conventional numerical models in predicting effluent concentrations, an important parameter to estimate the energy consumption and degree of desalination of the MCDI process. However, despite the remarkable progress of these ML/DL models, relevant studies have only been conducted with limited datasets, leading to a substantial controversy regarding model accuracy. Therefore, in this study, we comprehensively evaluated the performances and applicability of multiple ML/DL models for MCDI using metadata (i.e., performance indices) and feature importance analyses. One MCDI dataset containing both constant-current and constant-voltage operations was reconfigured uniformly or unevenly depending on operation modes. Subsequently, six ML models and one DL model were used to execute the analyses using performance indices. Collectively, this study suggests that a perfect ML/DL model for the water treatment process may not exist, and understanding data types is as important as selecting appropriate models to build a data-driven AI model when process performance is greatly affected by specific input variables (i.e., current and voltage).

Economic and low-carbon planning for interconnected integrated energy systems considering emerging technologies and future development trends

The integrated energy system facilitates the synergistic and efficient utilization of diverse energy. Establishing interconnected regional energy internets by linking multiple integrated energy systems enables the realization of cross-sector, cross-temporal, and cross-subject energy coupling, consequently enhancing economic benefits, driving profound decarbonization, and bolstering energy resilience. This study develops a multi-agent planning model grounded in an electricity-heat-hydrogen sharing framework, collaboratively optimizing capacity configurations and energy scheduling strategies across various integrated energy systems containing emerging technologies. Furthermore, this study integrates the trading volume and prices of various energy sources to distinguish the energy sharing contribution of each participant, then combines with the Nash bargaining game, forming a fair cooperative benefit allocation incentive mechanism. The proposed model is adeptly solved using the alternating directions method of multipliers, ensuring the protection of participants’ private information. To reflect seasonal characteristics of energy supply and demand, this study uses the daily data of three integrated energy systems across four seasons to simulate. The research results reveal an annual cost saving of 233.73 thousand RMB and a reduction of 290.85 tCO2. Additionally, the impact of variations in electricity operation modes, uncertainties, and emerging technical advances are evaluated to further validate the sustainability of the multi-energy trading mechanism.

RETRACTED: Optimizing energy and quantifying dispatchable potential of holistic HVAC systems

The increasing demand for flexible resources in power systems, coupled with the evolution of smart buildings, underscores the significance of optimizing energy use and quantifying dispatchable potential in heating, ventilation, and air conditioning systems. This work develops an energy optimization framework for these systems, accounting for external factors like solar radiation, temperature, and humidity. The goal is to minimize the energy consumption of holistic systems and devise optimal control strategies for each subsystem. The framework includes a mechanistic model that accurately describes the performance of cooling towers, a three-damper control strategy for air-side economizers, and three operational modes for air handling units. Furthermore, the relationship between the fresh air ratio and the supply/return air duct pressure drop obtained through analysis simplifies the optimization problem and reduces the difficulty of solving it. Subsequently, the framework utilizes indoor temperature and humidity ranges to ascertain optimal control strategies for both maximal and minimal energy consumption in the system. Simulation results for a hypothetical building reveal that dispatchable potential of the system can account for up to 13.055% of maximal energy consumption.

Extending the Digital Twin Ecosystem: A real-time Digital Twin of a LinuxCNC-controlled subtractive manufacturing machine

This research paper describes the design and implementation of a real-time data-driven Digital Twin Ecosystem (DTE) for a LinuxCNC-controlled subtractive manufacturing computer numerical control (CNC) machine. The DTE architecture integrates real-time data acquisition, processing, and synchronization with the physical CNC machine. Our architecture adopts and extends the methodology presented in previous work and utilizes two components, namely the data Acquisition, Processing, and Distribution Component (APDC), and the Virtual Representation Component (VRC), which is developed using the Unity real-time development platform. The DTE accurately models the CNC machine’s behavior under various operating conditions. The DTE is verified and validated through testing and experimentation, particularly focusing on response time, sequencing accuracy, and seamless integration. The DTE offers two modes of operation: the online mode allows for real-time process replication, ideal for process monitoring and remote management, while the offline mode supports asynchronous G-code simulation, enabling what-if analysis and exploration of process variables. In this work, we utilize the offline mode for predictive collision detection. Using the DTE, stakeholders could make informed decisions, optimize machining processes, and ensure cost-effective operations. This research contributes to the advancement of Digital Twin technology, particularly in CNC machining, fostering innovation in the manufacturing sector and promoting the development of practical, efficient, and reliable cyber–physical industrial systems, enhancing operational capabilities and productivity.