Search Results (26,990)

During this research, an automatic monitoring system was developed to monitor the working parameters in a solar power plant consisting of two flexible silicon modules. The first stage of the monitoring system relies on a microcontroller, which collects data from wattmeter modules made using a microcontroller. This tier also includes DC/DC converter and RS232-TCP converter modules for data transfer. The second stage, the industrial PLC, receives data from the first stage and transmits them to the PC, where the information is stored and the processes are visualized on the HMI screen. During this study, the charging process was analyzed using PWM- and MPPT-type charging controllers, as well as the power supply of Fito LED strips for lighting plants. Using the created monitoring system, the parameters of the solar power plant with flexible PV modules were monitored. This study compared PWM and MPPT battery charging methods, finding that MPPT is more efficient, especially under unstable solar conditions. MPPT technology optimizes energy usage more efficiently, resulting in faster battery charging compared to PWM technology. Full article

Anode-free lithium batteries (AFLBs) present an opportunity to eliminate the need for conventional graphite electrodes or excess lithium–metal anodes, thus increasing the cell energy density and streamlining the manufacturing process. However, their attributed poor coulombic efficiency leads to rapid capacity decay, underscoring the importance of achieving stable plating and stripping of Li on the negative electrode for the success of this cell configuration. A promising approach is the utilization of lithiophilic coatings such as silver to mitigate the Li nucleation overpotential on the Cu current collector, thereby improving the process of Li plating/stripping. On the other hand, inkjet printing (IJP) emerges as a promising technique for electrode modification in the manufacturing process of lithium batteries, offering a fast and scalable technology capable of depositing both thin films and patterned structures. In this work, a Fujifilm Dimatix inkjet printer was used to deposit Ag sites on a Cu current collector, aiming to modulate the interfacial electrochemistry of the system. Samples were fabricated with varying areas of coverage and the electrochemical performance of the system was systematically evaluated from bare Cu (non-lithiophilic) to a designed pattern (partially lithiophilic) and the fully coated thin film case (lithiophilic). Increasing lithiophilicity resulted in lower charge transfer resistance, higher exchange current density and reduced Li nucleation overpotential (from 55.75 mV for bare Cu to 13.5 mV for the fully coated case). Enhanced half-cell cyclability and higher coulombic efficiency were also achieved (91.22% CE over 76 cycles for bare Cu, 97.01% CE over 250 cycles for the fully coated case), alongside more uniform lithium deposition and fewer macroscopic irregularities. Moreover, our observations demonstrated that surface patterning through inkjet printing could represent an innovative, easy and scalable strategy to provide preferential Li nucleation sites to guide the subsequent Li deposition. Full article

This paper presents an 8 × 8 channel optoelectronic readout array (ORA) realized in the TSMC 180 nm 1P6M RF CMOS process for the applications of short-range light detection and ranging (LiDAR) sensors. We propose several circuit techniques in this work, including an amplitude-to-voltage (A2V) converter that reduces the notorious walk errors by intensity compensation and a time-to-voltage (T2V) converter that acquires the linear slope of the output signals by exploiting a charging circuit, thus extending the input dynamic range significantly from 5 μA_pp to 1.1 mA_pp, i.e., 46.8 dB. These results correspond to the maximum detection range of 8.2 m via the action of the A2V converter and the minimum detection range of 56 cm with the aid of the proposed T2V converter. Optical measurements utilizing an 850 nm laser diode confirm that the proposed 8 × 8 ORA with 64 on-chip avalanche photodiodes (APDs) can successfully recover the narrow 5 ns light pulses even at the shortest distance of 56 cm. Hence, this work provides a potential CMOS solution for low-cost, low-power, short-range LiDAR sensors. Full article

The kidney, an essential excretory organ of the body, performs a series of crucial physiological functions such as waste removal, maintenance of electrolyte and acid–base balance, and endocrine regulation. Due to its rich blood flow and high metabolic activity, the kidney is susceptible to damage. Currently, kidney injury is classified into acute kidney injury (AKI) and chronic kidney disease (CKD), both of which are associated with high rates of morbidity and mortality on a global scale. The current clinical diagnosis of renal injury relies on the assessment of renal filtration function using creatinine and urea nitrogen as “gold-standard” markers. However, the delayed response time, limited specificity, and reduced accuracy of creatinine and urea nitrogen in evaluating kidney injury have significantly hindered advancements in diagnostic methods for kidney injury. Urinary protein is widely utilized as a biomarker for the early diagnosis of kidney injury due to the selectivity of the glomerular filtration system determining whether proteins can pass through the filtration barrier based on their size and charge. Therefore, as a complex biological sample with varying charges and particle sizes, urinary protein is considered an ideal indicator for monitoring the progression of kidney disease. Exploring the relationship between urinary protein and the advancement of kidney injury based on differences in particle size and charge offers a new perspective for assessing and treating such injuries. Hence, we conducted a comprehensive review of 74 relevant studies to gain a thorough understanding of the physiological mechanism and significance of proteinuria production. The aim was to explore the challenges and opportunities in clinical urine protein detection, as well as to discuss strategies targeting glomerular filtration barriers in order to effectively reduce urine protein levels and treat kidney injury, which could provide a new perspective for identifying the progression of kidney injury. Full article

A new family of symmetrical fluorene derivatives with different types of substituents attached to the C-2 and C-7 positions of the fluorene core synthesized by the Sonogashira coupling reactions is reported. The electronic structures and the properties of the compounds investigated by means of photoelectron emission spectroscopy, UV–Vis absorption and photoluminescent spectroscopy as well as by DFT and TD-DFT theoretical calculations are discussed. It is shown that the nature of substituents influences the π-conjugation of the molecules. No intermolecular charge transfer within the investigated wavelength range is observed. The applicability of the synthesized compounds in organic light-emitting diodes (OLEDs) based on exciplex emission is demonstrated. The advanced co-deposition technique with the tuned OLED architecture was applied and resulted in improved OLED parameters. Full article

Electric vehicles (EVs) are rapidly replacing fossil-fuel-powered vehicles, creating a need for a fast-charging infrastructure that is crucial for their widespread adoption. This research addresses this challenge by improving the control of dual active bridge converters, a popular choice for high-power EV charging stations. A critical issue in EV battery charging is the smooth transition between charging stages (constant current and constant voltage) which can disrupt converter performance. This work proposes a novel feedforward control method using a combination of droop-based techniques combined with a sophisticated linear active disturbance rejection control system applied to a single-phase shift-modulated dual active bridge. This combination ensures a seamless transition between charging stages and enhances the robustness of the system against fluctuations in both input voltage and load. Numerical simulations using MATLAB/Simulink R2024a demonstrated that this approach not only enables smooth charging but also reduces the peak input converter current, allowing for the use of lower-rated components in the converter design. This translates to potentially lower costs for building these essential charging stations and faster adoption of EVs. Full article

The use of Moore’s law appears to be coming to an end due to technological and physical constraints, as complementary metal-oxide semiconductor (CMOS) transistors become smaller and closer to the atomic scale. Therefore, various emerging technologies are being researched as potential successors to traditional CMOS transistors, and one of the most exciting candidates is the magnetoelectric spin-orbit (MESO) device. The MESO device comprises two portions (input and output) and it cascades charge/voltage as input and output signals. In the MESO device’s output portion, ferromagnetic (FM) and high-spin-orbit-coupling layers are employed to provide spin-polarized current and charge/voltage output. In this paper, we offer a description and analysis of the operating mechanism of the MESO device’s output portion using a spin flow approach and propose a double-FM-layer structure. In the double-FM-layer structure, we implement two FM layers with antiparallel magnetization directions, instead of using a single-FM-layer structure to increase the output charge/voltage. The proposed structure is verified through the Verilog-A compact model. Full article

The reversible photo-induced conformation transition of a single molecule with a [5]helicene backbone has garnered considerable interest in recent studies. Based on such a switching process, one can build molecular photo-driven switches for potential applications of nanoelectronics. But the achievement of high-performance reversible single-molecule photoswitches is still rare. Here, we theoretically propose a 13,14-dimethylcethrene switch whose photoisomerization between the ring-closed and ring-open forms can be triggered by ultraviolet (UV) and visible light irradiation. The electronic structure transitions and charge transport characteristics, concurrent with the photo-driven electrocyclization of the molecule, are calculated by the non-equilibrium Green’s function (NEGF) in combination with density functional theory (DFT). The electrical conductivity bears great diversity between the closed and open configurations, certifying the switching behavior and leading to a maximum on–off ratio of up to 10³, which is considerable in organic junctions. Further analysis confirms the evident switching behaviors affected by the molecule–electrode interfaces in molecular junctions. Our findings are helpful for the rational design of organic photoswitches at the single-molecule level based on cethrene and analogous organic molecules. Full article

Bismuth-based photocatalytic materials have been widely used in the field of photocatalysis in recent years due to their unique layered structure. However, single bismuth-based photocatalytic materials are greatly limited in their photocatalytic performance due to their poor response to visible light and easy recombination of photogenerated charges. At present, constructing semiconductor heterojunctions is an effective modification method that improves quantum efficiency by promoting the separation of photogenerated electrons and holes. In this study, the successful preparation of an In₂O₃/Bi₂WO₆ (In₂O₃/BWO) II-type semiconductor heterojunction composite material was achieved. XRD characterization was performed to conduct a phase analysis of the samples, SEM and TEM characterization for a morphology analysis of the samples, and DRS and XPS testing for optical property and elemental valence state analyses of the samples. In the II-type semiconductor junction system, photogenerated electrons (e⁻) on the In₂O₃ conduction band (CB) migrate to the BWO CB, while holes (h⁺) on the BWO valence band (VB) transfer to the In₂O₃ VB, promoting the separation of photoinduced charges, raising the quantum efficiency. When the molar ratio of In₂O₃/BWO is 2:6, the photocatalytic degradation degree of rhodamine B (RhB) is 59.4% (44.0% for BWO) after 60 min illumination, showing the best photocatalytic activity. After four cycles, the degradation degree of the sample was 54.3%, which is 91.4% of that of the first photocatalytic degradation experiment, indicating that the sample has good reusability. The XRD results of 2:6 In₂O₃/BWO before and after the cyclic experiments show that the positions and intensities of its diffraction peaks did not change significantly, indicating excellent structural stability. The active species experiment results imply that h⁺ is the primary species. Additionally, this study proposes a mechanism for the separation, migration, and photocatalysis of photoinduced charges in II-type semiconductor junctions. Full article

The growing integration of renewable energy sources, such as photovoltaic and wind systems, into energy grids has underscored the need for reliable control mechanisms to mitigate the inherent intermittency of these sources. According to the Brazilian grid operator (ONS), there have been cascading disconnections in renewable energy distributed systems (REDs) in recent years, highlighting the need for robust control models. This article addresses this issue by presenting the validation of an active power ramp rate control (PRRC) function for a PV plant coupled with a Battery Energy Storage System (BESS) using WECC generic models. The proposed model underwent rigorous validation over an extended analysis period, demonstrating good accuracy using the Root Mean Squared Error (RMSE) and an R-squared (R²) metrics for the active power injected at the Point of Connection (POI), PV active power, and BESS State of Charge (SOC), providing valuable insights for medium and long-term analyses. The ramp rate control module was implemented within the plant power controller (PPC), leveraging second-generation Renewable Energy Systems (RES) models developed by the Western Electricity Coordination Council (WECC) as a foundational framework. We conducted simulations using the Anatem software, comparing the results with real-world data collected at 100 ms to 1000 ms intervals from a PV plant equipped with a BESS in Brazil. The proposed model underwent rigorous validation over an extended analysis period, with the presented results based on two days of measurements. The positive sequence model used to represent this control demonstrated good accuracy, as confirmed by metrics such as the Root Mean Squared Error (RMSE) and R-squared (R²). Furthermore, the article underscores the critical role of accurately accounting for the power sampling rate when calculating the ramp rate. Full article

As modern civilization’s energy demands continue to rise, the need for efficient renewable energy solutions becomes increasingly critical. In addressing this challenge, our research explores the potential of newly developed iron (Fe)-doped molybdenum disulfide (MoS₂) thin-film electrodes, synthesized through a simple hydrothermal method, as a promising energy storage device. By systematically varying the Fe doping levels, we aim to elucidate the relationship between Fe content and the structural, morphological, and electrochemical properties of the MoS₂ electrodes. The optimized FM-3 electrode exhibited a remarkable areal capacitance of 8.25 F/cm² at a current density of 10 mA/cm² with an energy density of 0.22 mWh/cm² and a power density of 2.2 mW/cm². Furthermore, the FM-3 demonstrated impressive long-term cycling stability, retaining 85.58% of its initial capacitance after 10,000 charge–discharge cycles. To further explore practical applicability, an asymmetric pouch-type supercapacitor device was assembled using an FM-3 electrode and activated carbon. The device achieved an impressive areal capacitance of 0.43 F/cm² at a current density of 20 mA/cm², delivering an energy density of 0.133 mWh/cm² and a power density of 7.5 mW/cm². The exceptional performance of the FM-3 electrode can be attributed to the enhanced diffusion rate, charge transfer efficiency, and better carrier mobility induced by Fe doping. This work not only highlights the significant electrochemical performance improvements of Fe-doped MoS₂ electrodes but also demonstrates their potential for scalable energy storage solutions, making a valuable contribution to the field of next-generation energy storage technologies. Full article

This paper presents a method to validate state of charge (SOC) estimations in batteries for their use in remotely manned aerial vehicles (UAVs). The SOC estimation must provide the mission control with a measure of the available range of the aircraft, which is critical for extended missions such as search and rescue operations. However, the uncertainty about the initial state and depth of discharge during the mission makes the estimation challenging. In order to assess the estimation provided to mission control, an a posteriori re-estimation is performed. This allows for the assessment of estimation methods. A reverse-time Kalman estimator is proposed for this task. Accurate SOC estimations are crucial for optimizing the utilization of multiple UAVs in a collaborative manner, ensuring the efficient use of energy resources and maximizing mission success rates. Experimental results for LiFePO4 batteries are provided, showing the capabilities of the proposal for the assessment of online SOC estimators. Full article

Using synchrotron radiation, a comparative VUV excitation study of YAG ceramics doped with Eu³⁺ and Cr³⁺ ions under VUV excitation (10.5–3.7 eV) at 9 K was conducted in this work. Both ceramics exhibit distinct excitation peaks in the VUV region, indicating high-energy transitions related to the internal electronic levels of the dopants and interband transitions within the YAG matrix. For YAG:Eu, the main excitation peaks at 6–7 eV correspond to transitions within the 4f-shell of Eu³⁺ and Eu³⁺-O²⁻ charge transfer states, showing weak dependence on the crystal field and high energy conversion efficiency. In contrast, YAG:Cr shows broad excitation bands due to transitions between levels influenced by strong crystal field interactions, resulting in lower luminescence efficiency. The study highlights the importance of crystal structure and dopant interactions in determining the spectral characteristics of YAG-based ceramics, offering potential for their application in advanced optoelectronic devices. Full article

This paper describes active battery balancing based on a bidirectional buck converter, a flyback converter, and battery cells by using the proposed chain-loop comparison strategy. The role of the bidirectional buck converter is to charge/discharge the battery pack. During the charging period, the converter is in buck mode, and its output is controlled by constant current/voltage; during the discharging period, the converter is in boost mode, and its output is controlled by constant voltage. The role of the flyback converter is voltage equalization of the battery pack, and its output is controlled by constant current. A chain-loop comparison strategy is used to control battery voltage equalization. In this work, three equalization modes, namely, charging balance, discharging balance, and static balance, were considered. The voltage difference between the maximum and minimum is 0.007 V after a balancing time of 19.75 min, 0.005 V after a balancing time of 24 min, and 0.007 V after a balancing time of 20 min for charging balance, discharging balance, and static balance, respectively. Full article

Electrochemical DNA sensors for DNA damage detection based on electroactive polymer poly(proflavine) (PPFL) that was synthesized at screen-printed carbon electrodes (SPCEs) from phosphate buffer (PB) and two natural deep eutectic solvents (NADESs) consisting of citric or malonic acids, D-glucose, and a certain amount of water (NADES1 and NADES2) were developed. Poly(proflavine) coatings obtained from the presented media (PPFL_PB, PPFL_NADES1, and PPFL_NADES2) were electrochemically polymerized via the multiple cycling of the potential or potentiostatic accumulation and used for the discrimination of thermal and oxidative DNA damage. The electrochemical characteristics of the poly(proflavine) coatings and their morphology were assessed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The working conditions for calf thymus DNA implementation and DNA damage detection were estimated for all types of poly(proflavine) coatings. The voltammetric approach made it possible to distinguish native and chemically oxidized DNA while the impedimetric approach allowed for the successful recognition of native, thermally denatured, and chemically oxidized DNA through changes in the charge transfer resistance. The influence of different concentrations of conventional antioxidants and pharmaceutical preparations on oxidative DNA damage was characterized. Full article