Operational Stability Research Articles

Simulation Optimization and Experimental Validation of Hydraulic Impact in Pruning Machines

Abstract This study addresses the instability caused by hydraulic shocks in fruit tree pruning machines during operation and proposes an optimization scheme that combines simulation with experimentation. We investigated the mechanisms of load shock in the hydraulic system through mathematical modeling and LS-DYNA simulation analysis. The optimal operating parameters were determined using mechanical and orthogonal analyses: a forward speed of 4 km/h, a pruning tool angle of 60°, and a saw blade rotation speed of 1200 r/min.Additionally, we employed AMESim simulation to optimize the hydraulic system of the pruning machine by designing a dual accumulator configuration to effectively suppress hydraulic shocks.We validated the optimized system through simulations and experimental tests, demonstrating significant reductions in pressure fluctuations, with cutting efficiency improved by 30% and pressure fluctuations reduced by 26.7%.This study not only presents an innovative dual accumulator design but also validates its effectiveness in pruning machines through simulations and experiments, thereby enhancing the operational efficiency and stability of agricultural machinery.

Influence of External Clearance Variation on Vibration Characteristics of Ship Electrically Assisted Turbocharger Rotor Bearing System

Electrically assisted turbocharging (EAT) technology is an important technical means to effectively solve the problems of insufficient intake air and poor transient response of traditional turbocharged engines at low speed or acceleration, and to realize the electrification of marine internal combustion engine power system. In the EAT design stage, the original rotor model of a marine turbocharger was established and verified. Subsequently, the EAT rotor dynamics design and analysis were carried out, and the influence of the unbalanced phase and external clearance on rotor vibration was discussed. The results show that when the external clearance is small, extensive sub-synchronous vibration occurs and bifurcation occurs at high speed. When the external clearance is large, the sub-synchronous vibration component almost disappears but high synchronous vibration occurs at a high speed. At the same time, the shaft is significantly affected by the gravity load at low speeds, and the rotor makes a balanced motion on the critical limit cycle at high speed. In order to minimize the vibration and noise of the same type of EAT, it is recommended to control the outer clearance of the EAT bearing in the range of 0.30–0.36[Formula: see text]mm. The research content provides a reference for the dynamic design and analysis of the EAT, which effectively helps the development of the original engine of the ship electric auxiliary turbocharger and improves the operation stability of the EAT.

X-Type Ligands Effect on the Operational Stability of Heavy-Metal-Free Quantum Dot Light-Emitting Diodes.

ZnSeTe quantum dots (QDs) offer an efficient avenue for realizing heavy-metal-free light-emitting diodes (LEDs) that meet the Rec.2100 blue standard. Synthetic core-shell engineering has enabled big advances in the external quantum efficiency (EQE) of ZnSeTe QD-LEDs. However, the mechanisms behind the degradation of the operational stability of ZnSeTe QD-LEDs remain relatively unexplored. In this study, we explore the impact of ligand density and composition on both material and device stability. We developed a solid-film ligand exchange utilizing an inorganic X-type ligand (zinc chloride), revealing that the substitution of inorganic ligands for organic counterparts significantly influences the stability of both materials and devices.

High-Performance Ultra-Broadband Photodetector Based on Fe3O4/CrSiTe3 Heterostructures.

Photodetectors based on advanced materials with a broad spectral photoresponse, high sensitivity, huge integration ability, room-temperature operation, and stable environmental stability are highly desired for diversified applications of imaging, sensing, and communication. Herein, a high-performance ultra-broadband photodetector based on an ultrathin two-dimensional (2D) Fe3O4 nanoflake heterostructure with high sensitivity was designed. The photodetector response light was from visible 405 nm to long-wave infrared (LWIR) 10.6 μm in ambient air. The competitive performances, including a high photoresponsivity (R) of 182.8 A W-1, fast speed with the rise time τr = 8.8 μs, and decay time τd = 4.1 μs, were demonstrated in the visible range. Notably, the device exhibits an excellent uncooled LWIR detection ability, with a high R of 1.4 A W-1 realized at a 1.5 V bias. In the full spectral range, the noise equivalent power is lower than 0.79 pW Hz-1/2, and specific detectivity (D*) is higher than 4.9 × 108 cm Hz1/2 W-1 in ambient air. This work provides alternative ultrathin 2D materials for future infrared optoelectronic devices.

Optimization and performance assessment of Ag@SiO2 core–shell nanofluids for spectral splitting PV/T system: Theoretical and experiment analysis

Ag@SiO2 nanofluid is widely used in spectral splitting PV/T system. Its core–shell structure has great influence on the optical properties. In this work, we focus on the comprehensive analysis and structure optimization of Ag@SiO2 nanofluid to achieve its optimal spectral performance. DDA method is used to predict the optical properties of Ag@SiO2 nanofluid and an optimization model based on filter efficiency is proposed. The effect of the SiO2 shell thickness and Ag core mass concentration is analyzed. It indicates that the spectral performance of Ag@SiO2 nanofluid can be improved with SiO2 shell thickness of 15–40 nm and Ag core mass concentration of 81–135 mg/L. To achieve the same theoretical merit function of 1.46, the usage of Ag mass can be reduced by 25/33/44/62 % with SiO2 coating of 10/20/40/70 nm. The optimal structure to achieve the highest filter efficiency η of 37.8 % is with a shell thickness of 20 nm and a mass concentration of 113.9 mg/L. An indoor PV/T operation testing is conducted to verify the optimization results. The merit function of Ag-based nanofluids increases from 1.58 to 1.598 and a reduction in Ag usage of 17 % is achieved with a SiO2 coating shell of 17.8 nm. Operation stability is also enhanced with no aggregation observed during the working cycle and 7-day static experiment.

Highly Active and Durable Nanostructured Nickel-Molybdenum Coatings as Hydrogen Electrocatalysts via Solution Precursor Plasma Spraying.

The increasing demand for green hydrogen is driving the development of efficient and durable electrocatalysts for the hydrogen evolution reaction (HER). Nickel-molybdenum (NiMo) alloys are among the best HER electrocatalysts in alkaline electrolytes, and here we report a scalable solution precursor plasma spraying (SPPS) process to produce the highly active Ni4Mo electrocatalysts directly onto metallic substrates. The NiMo coating coated onto inexpensive Ni mesh revealed an excellent HER performance with an overpotential of only 26 mV at -10 mA cm-2 with a Tafel slope of 55 mV dec-1. Excellent operational stability with minimum changes in overpotential were also observed even after extensive 60 hour high-current stability test. In addition, we investigate the influence of different substrates over the catalytic performance and operational stability. We also proposed that a slow, but consistent, dissolution of Mo is the primary degradation mechanism of NiMo-based coatings. This unique SPPS approach enables the scalable production of exceptional NiMo electrocatalysts with remarkable activity and durability, positioning them as ideal cathode materials for practical applications in alkaline water electrolysers.

Air-Processed Efficient Perovskite Solar Cells With Full Lifecycle Management.

Despite the outstanding power conversion efficiency of perovskite solar cells (PSCs) realized over the years, the entire lifecycle from preparation and operation to discarding of PSCs still needs to be carefully considered when it faces the upcoming large-scale production and deployment. In this study, bio-derived chitin-based polymers are employed to realize the full lifecycle regulation of air-processed PSCs by forming multiple coordinated and hydrogen bonds to stabilize the lead iodide and organic salt precursor inks, accelerating the solid-liquid reaction and crystallization of two-step deposition process, then achieving the high crystalline and oriented perovskites with less notorious charge defects in the open air. The air-prepared PSCs exhibit a decent efficiency of 25.18% with high preparation reproducibility and improved operational stability toward the harsh environment and mechanical stress stimuli. The modified PSCs display negligible fatigue behavior with keeping 92% of its initial efficiency after operating for 32 diurnal cycles (ISOS-LC-1 protocol). Meanwhile, closed-loop lead management of end-of-life PSCs including suppression of lead leakage, toxicity evaluation of broken devices, and recycling of lead iodide components are comprehensively investigated. This work sheds light on a promising avenue to realize the entire lifecycle regulation of air-processed efficient and stable PSCs.

The Impact of Inflation on Commercial Banks in China

Abstract: Inflation is an important issue that affects the profitability and operational stability of commercial banks. Conducting an in-depth analysis of these influences while putting forward effective countermeasures can be beneficial to ensuring the stable operation of commercial banks. This paper focuses on the period from 1937 to 1949 where the Second Sino-Japanese War and the Chinese Civil War, which had contributed to severe inflation and disrupted the banking sector, and the formation of the modern Chinese banking system. This study critically examines the main causes behind inflation, evaluates their implications on the functioning of commercial banks. It also assesses both the positive and negative impacts on commercial banks, pointing out the challenges commercial banks face during different periods. For example, the market turmoil and policy changes in the 1940s have made it difficult for commercial banks to retain normal operation; therefore are suffering from making profits and inflation has made the situation even worse. In addition, this paper provides short-run and long-run strategies for reducing the negative effects of inflation, with consideration of Chinas unique economic structure and historical context. By integrating insights from historical and contemporary perspectives, this analysis aims to offer valuable views on the micro and macro impacts inflation could bring.

Strain-dependent charge trapping and its impact on the operational stability of polymer field-effect transistors

Despite recent dramatic improvements in the electronic characteristics of stretchable organic field-effect transistors (FETs), their low operational stability remains a bottleneck for their use in practical applications. Here, the operational stability, especially the bias-stress stability, of semiconducting polymer-based FETs under various tensile strains is investigated. Analyses on the structure of stretched semiconducting polymer films and spectroscopic quantification of trapped charges within them reveal the major cause of the strain-dependent bias-stress instability of the FETs. Devices with larger strains exhibit lower stability than those with smaller strains because of the increased water content, which is accompanied by the formation of cracks and nanoscale cavities in the semiconducting polymer film as results of the applied strain. The strain-dependence of bias-stress stability of stretchable OFETs can be eliminated by passivating the devices to avoid penetration of water molecules. This work provides new insights for the development of bias-stable stretchable OFETs.

Surface Reaction Induced Compressive Strain for Stable Inorganic Perovskite Solar Cells

AbstractCesium‐based inorganic perovskites have emerged as promising light‐harvesting materials for perovskite solar cells (PSCs) due to their promising thermal‐ and photo‐stability. However, obstacles to commercialization remain regarding their phase instability. In this work, we report a facile and effective strategy to regulate the surface compressive strain via in situ surface reaction to stabilize CsPbI3 perovskite. The use of a chelating ligand with a molecular configuration closely matching the integer multiples of the unit cell lattice parameters of CsPbI3 induces compressive strain at the surface of CsPbI3. The chemical bonding and strain modulation synergistically not only passivate film defects, but also inhibit perovskite phase degradation, thus significantly improving the intrinsic stability of inorganic perovskite. Consequently, enhanced power conversion efficiency (PCE) of 21.0 % and 18.6 % were respectively achieved in 0.16‐cm2 lab‐scale devices and 25.3‐cm2 solar modules. Further, surface reaction enables PSCs with enhanced thermal and operational stability; these devices retain over 95 % of their initial PCE after damp‐heat tests (i.e., in 85 °C and 85 % R. H. air) for 2000 h, and remain 99 % of their initial PCE after operating for 2000 h, representing one of the most stable inorganic PSCs reported so far.

Iodide Management and Oriented Crystallization Modulation for High-Performance All-Air Processed Perovskite Solar Cells.

Halide-related defects at the buried interface not only cause nonradiative recombination, but also seriously impair the long-term stability of perovskite solar cells (PSCs). Herein, a bottom-up, all-in-one modification strategy is proposed by introducing a multisite antioxidant ergothioneine (EGT) at the buried interface to manage iodide ions and manipulate crystallization dynamics. The findings demonstrate that EGT not only passivates uncoordinated Sn4+/Pb2+ defects, but also firmly anchors iodide ions and inhibits their oxidation to I2. Additionally, the modification by EGT enhances the oriented crystallization of perovskite, improves the carrier dynamics, and releases residual stresses. Consequently, the optimized all-air processed device (Rb0.02(FA0.95Cs0.05)0.98PbI2.91Br0.03Cl0.06) achieves a remarkable power conversion efficiency (PCE) of 25.13%, which is among the highest values reported for devices fabricated in air, along with ultrahigh open-circuit voltage (VOC) of 1.191V and fill factor (FF) of 84.9%. The optimized device without encapsulation exhibits strong humidity, thermal, and operational stability under ISOS protocol. Specifically, the initial efficiency of the device is retained at 90.12% after 1512 h of thermal ageing at 65°C and 90.14% after 930 h of continuous maximum power point tracking (MPPT) under simulated AM1.5 illumination.

Stability Of Islamic Commercial Banks In Indonesia: Company Size, Profitability, And Efficiency

This study aims to analyze the effect of company size, profitability, and efficiency on the stability of Islamic commercial banks (ICB). This study uses a quantitative approach. The population of this study is Islamic commercial banks, and the sampling technique used is purposive sampling, obtained from four ICBs. The data source used is secondary data from each ICB's financial statements. The data analysis technique used is panel data regression analysis using e-views software version 13. The results of this study indicate that company size positively affects ICB's stability. However, profitability negatively affects ICB's stability. In contrast, efficiency does not affect ICB's stability. This study can complement existing theories, especially regarding the effect of size on company stability, and can be a reference for further research. Practically, this study can be a reference for banks in maintaining the stability of company operations in terms of company size and profitability.

π-Conjugation-Induced In Situ Nanoscale Ordering of Spiro-OMeTAD Boosts the Efficiency and Stability of Perovskite Solar Cells.

Spiro-OMeTAD hole transport materials typically exhibit an amorphous state in perovskite solar cells. However, the lack of structural ordering leads to weak intermolecular interaction, inferior carrier transfer, and poor stability in devices. Herein, we developed a π-conjugation-induced short-range ordering strategy to modulate the stacking order of spiro-OMeTAD during film formation. A clear molecular ordering at the nanoscale is observed, which enhances intermolecular π-π stacking in spiro-OMeTAD and enables effective carrier extraction and favorable energy level alignment. The nanoscale-ordered spiro-OMeTAD allows the achievement of perovskite solar cells with a champion efficiency of 25.37%, surpassing devices utilizing amorphous spiro-OMeTAD (23.52%). The unencapsulated device demonstrates enhanced operational stability by retaining 98% of its initial efficiency under continuous 1 sun equivalent illumination at 60 °C for 840 h. This work establishes a significant and valid modulation concept for the stacking order of organic transport materials, paving the way for the development of efficient and stable perovskite solar cells.

Modulation of Charge Transport Layer for Perovskite Light-Emitting Diodes.

Perovskite light-emitting diodes (Pero-LEDs) have garnered significant attention due to their exceptional emission characteristics, including narrow full width at half maximum, high color purity, and tunable emission colors. Recent efficiency and operational stability advancements have positioned Pero-LEDs as a promising next-generation display technology. Extensive research and review articles on the compositional engineering and defect passivation of perovskite layers have substantially contributed to the development of multi-color and high-efficiency Pero-LEDs. However, the crucial aspect of charge transport layer (CTL) modulation in Pero-LEDs remains relatively underexplored. CTL modulation not only impacts the charge carrier transport efficiency and injection balance but also plays a critical role in passivating the perovskite surface, blocking ion migration, enhancing perovskite crystallinity, and improving light extraction efficiency. Therefore, optimizing CTLs is pivotal for further enhancing Pero-LED performance. Herein, this review discusses the roles of CTLs in Pero-LEDs and categorizes both reported and potential CTL materials. Then, various CTL optimization strategies are presented, alongside an analysis of the selection criteria for CTLs in high-performance Pero-LEDs. Finally, a summary and outlook on the potential of CTL modulation to further advance Pero-LED performances are provided.

20 years of the Bio-Analytic Resource for Plant Biology.

The Bio-Analytic Resource for Plant Biology ('the BAR', at https://bar.utoronto.ca) is celebrating its 20th year in operation in 2025. The BAR encompasses and provides visualization tools for large 'omics data sets from plants. The BAR covers data from Arabidopsis, tomato, wheat, barley and 29 other plant species (with data for 2 others to be released soon). These data include nucleotide and protein sequence data, gene expression data, protein-protein and protein-DNA interactions, protein structures, subcellular localizations, and polymorphisms. The data are stored in more than 200 relational databases holding 186 GB of data and are presented to the researchers via web apps. These web apps provide data analysis and visualization tools. Some of the most popular tools are eFP ('electronic fluorescent pictograph') Browsers, ePlantsand ThaleMine (an Arabidopsis-specific instance of InterMine). The BAR was designated a Global Core Biodata Resource in 2023. Like other GCBRs, the BAR has excellent operational stability, provides access without login requirement, and provides an API for researchers to be able to access BAR data programmatically. We present in this update a new overarching search tool called Gaia that permits easy access to all BAR data, powered by machine learning and artificial intelligence.

Visual-Inertial Fusion-Based Five-Degree-of-Freedom Motion Measurement System for Vessel-Mounted Cranes

Vessel-mounted cranes operate in complex marine environments, where precise measurement of cargo positions and attitudes is a key technological challenge to ensure operational stability and safety. This study introduces an integrated measurement system that combines vision and inertial sensing technologies, utilizing a stereo camera and two inertial measurement units (IMUs) to capture cargo motion in five degrees of freedom (DOF). By merging data from the stereo camera and IMUs, the system accurately determines the cargo’s position and attitude relative to the camera. The specific methodology is introduced as follows: First, the YOLO model is adopted to identify targets in the image and generate bounding boxes. Then, using the principle of binocular disparity, the depth within the bounding box is calculated to determine the target’s three-dimensional position in the camera coordinate system. Simultaneously, the IMU measures the attitude of the cargo, and a Kalman filter is applied to fuse the data from the two sensors. Experimental results indicate that the system’s measurement errors in the x, y, and z directions are less than 2.58%, 3.35%, and 3.37%, respectively, while errors in the roll and pitch directions are 3.87% and 5.02%. These results demonstrate that the designed measurement system effectively provides the necessary motion information in 5-DOF for vessel-mounted crane control, offering new approaches for pose detection of marine cranes and cargoes.

Hydrodynamics and operation of a multistage fluidized bed with particles of super-high density

High-density particles are commonly used in fluidized bed reactors in uranium recycling processes of nuclear industry, where high fluidization quality (i.e. low gas-solids contacting efficiency) is difficult to achieve, resulting in various problems such as reduced conversion, low product selectivity, stronger equipment vibration and bad operating stability, etc. The objective of this study was to validate the feasibility and advantages of a multistage fluidized bed in processing a super-high-density powder. Wolfram carbide powder of true density of 15630 kg/m3 was used in a cold-model counter-current three-stage fluidized bed with downcomers. Stability of operation, operating range and hydrodynamics were systematically studied. The fluidization quality and operating stability were also compared with a single-stage conical fluidized bed of similar diameter and same solids inventories. The experimental results demonstrated that this high-density wolfram carbide powder could be fluidized and circulated continuously at this multistage fluidized bed, but lower fluidization quality was observed and the stable operating range is narrow. Narrower stable operating range was observed at higher solids circulation rates. At corresponding operating conditions, the fluidization quality of multistage fluidized bed is significantly better than that of the conical fluidized bed with a similar solids inventory.

Modifying the buried interface by a sulfamate enable efficient perovskite solar cells with high stability

The buried interface between the pivotal perovskite layer and the electron transfer layer (ETL) greatly affects the photoelectric property of perovskite layer and the final performance of a perovskite solar cell (PSC). Effectively modifying the buried interface is feasible to improve the photoelectric conversion efficiency (PCE) and stability of PSCs. Herein, we employ a sulfamate sodium 4-aminoazobenzene-4′-sulfonate (SABS) with zwitterion to modify the SnO2 film surface to improve the performance of PSCs. The post-treatment makes the surface of SnO2 film smoother and also passivate the anion and cation vacancies of SnO2, which are benefit to the growth of perovskite crystals and strengthen the interface contact between SnO2 layer and perovskite layer. Furthermore, SABS molecules can passivate defects of perovskite layer at the buried interface. By using this post-treating method, the PCE of the final PSC is increased from 21.76 % to 23.86 %, and the storage and operational stability are also significantly improved. This promotion the buried interface via post-treating the SnO2 film with a zwitterion passivator provides a convenient strategy to effectively improve the performance and stability of PSCs.

Dynamics and stability analysis of unbalance responses in mid‐positioned electrically assisted turbocharger rotor

AbstractElectrically assisted turbochargers (EAT) improve intake efficiency by motor‐assisted compressor impeller rotation, enhancing the system's transient response. However, the addition of motor rotor components has increased the number of unbalanced positions in the shaft system, leading to problems such as excessive compressor end vibration and complex changes in oil film stability. To evaluate the effects of unbalance in the motor rotor, along with the parameters of floating ring bearings (FRB), on the dynamic response of EAT, a finite element model of an EAT rotor supported by nonlinear FRB is developed, and the vibration response of the compressor end bearing is obtained by numerical integration. The results indicate: (1) In contrast to the effect of compressor and turbine unbalance, proper motor rotor unbalance is more effective in suppressing oil whirl instability in the high‐speed operating range. However, a new inner oil film whirl “instability interval” is also induced in the low‐speed operating range, leading to an increase in the Y1 compressor‐end amplitude at low and medium speeds, and this “instability interval” increases with the amount of unbalance. (2) When an oil whirl occurs in the oil film, the maximum eccentricity of the bearing surges and is greater than 0.3, which can be used as an effective threshold for determining whether the oil film is unstable in engineering applications. (3) A suitable outer oil‐film clearance range should be , otherwise, a wide range of outer oil‐film whirl instability occurs. Controlling the amount of unbalance and oil‐film clearance to suppress the sub‐synchronous vibration of the EAT, provides a theoretical basis for the design of the dynamics of the nonlinear rotor bearing system and improves the stability of the turbocharger's operation.

Poliface: A Multi-pose Synchronous Imaging System

To enhance the accuracy of face recognition technology in real-world scenarios, it is necessary to train deep learning models on datasets that contain a large number of labeled human face images under multiple poses, lighting, and accessory variations. In this paper, we introduce a novel acquisition system named the Poliface. This system can capture multiple high-resolution images simultaneously around the human head. We designed this system with a well-built aluminum structure, control electronic circuits, and high-performing in-house software. The results demonstrate the precise operation and exceptional stability of this system. Using this Poliface system, we have collected over 6 million photos, which can be used to train and evaluate facial recognition models, and exploited for three-dimensional (3D) virtual face reconstruction.