Search Results (1,073)

Solar-driven irrigation, a promising clean technology for agricultural water conservation, is constrained by mismatched photovoltaic (PV) pump outflow and irrigation demand, alongside unstable PV output. While compressed-air energy storage (CAES) shows mitigation potential, existing studies lack systematic explorations of pump water-lifting characteristics and supply capacity under coupled meteorological and air pressure effects, limiting its practical promotion. This study focuses on a solar-coupled compressed-air energy storage regulated sprinkler irrigation system (CAES-SPSI). Integrating experimental and theoretical methods, it establishes dynamic flow models for three DC diaphragm pumps considering combined PV output and outlet back pressure, introduces pressure loss and drop coefficients to construct a nozzle pressure dynamic model via calibration and iteration, and conducts a 1-hectare corn field case study. The results indicate the following: pump flow increases with PV power and decreases with outlet pressure (model deviation < 9.24%); nozzle pressure in pulse spraying shows logarithmic decline; CAES-SPSI operates 10 h/d, with hourly water-lifting capacity of 0.317–1.01 m³/h and daily cumulation of 6.71 m³; and the low-intensity and long-duration mode extends irrigation time, maintaining total volume and optimal soil moisture. This study innovatively incorporates dynamic air pressure potential energy into meteorological-PV coupling analysis, providing a universal method for quantifying pump flow changes, clarifying CAES-SPSI’s water–energy coupling mechanism, and offering a design basis for its agricultural application feasibility. Full article

In view of the problems of high weed regeneration rate in traditional mechanical weeding and environmental risk in chemical weeding, a synergetic strategy of “mechanical damage + wound spraying mechanism” was proposed, and an intelligent weeding device combining synchronous cutting and spraying was designed to enhance the efficacy of herbicides and reduce their use. Focusing on the physical characteristics of weeds and the cutting mechanism, the analysis of the weed-cutting system and the force characteristics of the cutting tool were conducted. Key factors affecting cutting quality were identified, and their respective value ranges were determined. A targeted spraying system was developed, featuring a conical nozzle, DC diaphragm pump, and electromagnetic control valve. The Delta parallel manipulator, equipped with both the cutting tool and nozzle, was designed, and a kinematic model was established for both its forward and inverse movements. Genetic algorithms were applied to optimize structural parameters, aiming to ensure effective coverage of typical weed distribution areas within the working space. A simulated environment measurement was built to verify the motion accuracy of the manipulator. Field experiments demonstrated that the equipment achieved an 81.5% wound weeding rate on malignant weeds in the seedling stage at an operating speed of 0.6 m/s, with a seedling injury rate below 5%. These results validate the high efficiency of the integrated mechanical cutting and targeted spraying system, offering a reliable technical solution for green and intelligent weed control in agriculture. This study fills the blank of only focusing on recognition accuracy or weeding rate under a single weeding method, but lacks a cooperative weeding operation. Full article

Background: Interscalene brachial plexus block (ISB) remains the gold standard anesthesia method in shoulder surgery. However, risk of diaphragm paralysis is a major concern among anesthesiologists. Recent studies on anterior suprascapular nerve block (ASB) and costoclavicular brachial plexus block (CCB) have given promising results for preventing diaphragm paralysis and providing sufficient analgesia. Methods: Forty-six patients who underwent arthroscopic shoulder surgery under one of three regional anesthesia techniques, including ISB (n = 15), ASB (n = 15), and CCB (n = 16), were included in the study. Diaphragmatic excursion was measured by ultrasonography 30 min after the block. Postoperative pain was assessed with a numerical rating scale. The groups were compared in terms of diaphragm paralysis and postoperative pain status. Results: The groups were similar in basic patient and surgical characteristics as well as motor and sensory block scores. There was no difference in analgesic use between the groups. Diaphragm measurements in the ISB group were found to be significantly lower compared to the ASB and CCB groups (p < 0.001). In addition, diaphragm measurements in the ASB group were found to be lower than in the CCB group (p = 0.036). When comparing diaphragm measurements between the initial and 30th min of block, significant decreases were observed in the ISB and ASB groups (p < 0.001), whereas no difference was found in the CCB group. Conclusions: Postoperative pain scores and analgesic use were similar between the three blocks. In terms of diaphragm paralysis, the best blocks appeared to be CCB followed by ASB. CCB and ASB can be considered as safe and effective alternative blocks in arthroscopic shoulder surgery, particularly for patients without serious obstructive or restrictive pulmonary disease. Full article

This study investigates the effects of post-fabrication annealing on polymer-based capacitive micromachined ultrasonic transducers (polyCMUTs). These devices comprise microscopic diaphragms produced via photolithographic patterning of polymer layers. Critical point drying, required to release the diaphragms, can cause significant plastic deformation, thereby reducing electromechanical coupling. Post-fabrication annealing, carried out in incremental steps up to 190 °C, led to an effective increase in coupling by a factor of 5.4. Atomic Force Microscopy showed that the initial upward deflection of 162.7 nm decreased to 6.2 nm after annealing at 190 °C, while also improving surface uniformity. In parallel, the transducer’s resonance frequency rose from 2.33 MHz (unannealed) to 2.60 MHz, and the input impedance phase angle at resonance increased from −68.1° to −4.3°. Together, these changes indicate a significant improvement in resonator behavior and, consequently, device performance. Thus, post-fabrication annealing is an effective measure to achieve the designed performance while enhancing manufacturing yield, thereby increasing the applicability of polyCMUTs. Full article

Electromagnetic pumps are developed for industrial, medical and scientific applications, moving electrically conductive liquids and molten solder in electronics manufacturing using electromagnetism instead of mechanical parts. This study presents a comprehensive thermal analysis of an electromagnetic diaphragm pump, focusing on the influence of operating current, permanent magnet switching speed, and cooling conditions on pumping performance. The pump utilizes a flexible diaphragm embedded with a permanent neodymium magnet, which interacts with time-varying magnetic fields generated by electromagnets to drive fluid motion. Temperature monitoring is conducted using a waterproof DS18B20 sensor and an uncooled FLIR A325sc infrared camera, allowing accurate mapping of thermal distribution across the pump surface. Experimental results demonstrate that higher current and increased magnet switching speed lead to faster temperature rise, impacting the volume of fluid pumped. Incorporation of an automatic cooling fan effectively reduces coil temperature and stabilizes pump performance. Polynomial regression models describe the relationship between temperature, pumped liquid volume, and magnet switching speed, providing information to optimize pump operation and cooling strategies. The novel relationship between temperature and the volume of the pumped liquid is considered as a fourth-degree polynomial. In particular the model describes a quantitative evaluation of the effect of heating on pumping efficiency. An initial increase in temperature correlates with a higher pumped volume, but excessive heating leads to efficiency saturation or even decline. Indeed, mathematical dependencies are crucial in mechanical pump engineering for analyzing physical phenomena; this is achieved by using a mathematical equation to define how different physical variables are related to each other, enabling engineers to calculate performance and optimize the pump design. Full article

Background: Pneumothorax (PTX) develops in 1–2% of neonates, leading to significant morbidity and mortality and requiring providers to be comfortable with management. Our objective was to evaluate whether radiographic measurements of PTX size can be used to predict the need for procedural intervention in neonates in order to help guide the need for the availability of specific personnel. Methods: With the help of a data analyst, 62 patients diagnosed with neonatal PTX between March 2016 and October 2024 were identified. Most babies (46) were born in 2023–2024 when our new electronic health record could more easily identify these infants. PTX size was evaluated using radiographs by calculating the ratio of the widest transverse measurement of the PTX on both anteroposterior (AP) and, when available, lateral decubitus (DECUB) divided by the widest transverse measurement of the hemithorax above the diaphragm. Clinical data were collected, and statistical analysis was performed using need for intervention (thoracentesis (TC), chest tube (CT), or both). Results: We found that a larger PTX size ratio, measured in the AP (p < 0.0001) or DECUB view (p < 0.008), was highly associated with need for intervention in this cohort of infants with PTX. Only 33% of PTXs required intervention. Also, 13/14 (93%) cases who underwent TC ultimately required a CT. PTX was more prevalent in males in general, but sex was not associated with needing intervention. The average gestational age (GA) of the cohort was 36 5/7 weeks, with only 12% being < 34 weeks GA. Univariate analysis indicated that lower GA and birth weight were risk factors for intervention. There was a trend (p = 0.075, by Fisher’s exact test) suggesting that infants with both respiratory distress syndrome (RDS) and PTX may be more likely (60%) to require intervention (no RDS, 29% intervention). Finally, a receiver operator characteristic curve was derived from the AP ratio based on the yes/no intervention which resulted in an area under the curve statistic of 0.902 and the optimal AP ratio cutoff of 0.184. Conclusions: The ratio of the transverse measurement of the PTX/hemithorax size from radiographs was highly predictive for need for intervention in a cohort of primarily term infants with PTX. Smaller and lower GA infants were at a higher risk for requiring procedural intervention. Nearly all infants who had TC also needed a CT. These findings could inform clinical strategies for managing neonatal PTXs, especially in identifying appropriate needed personnel availability if a TC occurs. Full article

Pre-tensioned T-beams with polygonal tendons offer high load-bearing capacity and suitability for large spans, demonstrating broad application potential in bridge engineering. The cracking state of a prestressed beam is a crucial indicator for assessing its service state, while the ultimate bearing capacity is a key metric for structural safety. In this study, we designed a novel 30 m pre-tensioned T-beam with polygonal tendons and investigated its shear cracking performance and ultimate bearing capacity under a shear-span ratio of 2.5 through a full-scale test. A graded loading protocol was employed. The results indicate that during the initial loading stage, the shear cracking load of the inclined section was 1766 kN. A distinct inflection point appeared on the load–displacement curve, accompanied by a significant reduction in stiffness. Cracks initially developed at the junctions between the web and the top flange, as well as the diaphragm, and subsequently propagated towards the shear–flexural region, exhibiting typical shear–compression failure characteristics. During the secondary loading to the ultimate state, the beam demonstrated good ductility and stress redistribution capability. The ultimate shear capacity reached 3868 kN. Failure occurred by crushing of the concrete in the compression zone after the critical inclined crack penetrated the web, with the member ultimately reaching its ultimate capacity through a plastic hinge mechanism. Strain analysis revealed that the polygonal tendons effectively restrained the premature development of inclined cracks, thereby enhancing the overall shear performance and deformation capacity. This study verifies the mechanical performance of the new T-beam under a shear span-to-depth ratio of 2.5 through calculations based on different codes and finite element numerical analysis, providing experimental evidence and theoretical references for its engineering application. Full article

As an emerging construction method, the lateral launching technique for shield tunneling can ensure launching safety while significantly reducing disturbances to urban traffic. However, the influence of its design parameters on construction stability and economic performance has not yet been systematically investigated, thereby limiting its broader application in complex urban environments. To address this gap, this study proposes a comprehensive analytical framework integrating field monitoring, numerical modeling, orthogonal experiments, and regression-based optimization. Relying on a shield lateral launching project in a central urban district of Guangzhou, a systematic investigation is conducted. Field monitoring data are used to verify the reliability of the three-dimensional finite element model, confirming that deformations of both the retaining structures and the surrounding ground remain within a stable and controllable range. On this basis, the orthogonal experimental method is, for the first time, introduced into the parameter sensitivity analysis of the shield lateral launching technique. The analysis reveals the influence ranking of support parameters on surface settlement. Key parameters are then selected for optimization design according to the sensitivity order, followed by a comprehensive evaluation of deformation control effectiveness and economic performance of the optimized scheme. The results show that the deformation of both the retaining structures and the ground during construction remains below the control limits, indicating good structural stability. Among the supporting parameters, the sensitivity coefficients from high to low are the diaphragm wall thickness H_W, the grouting reinforcement range H_G, the initial support thickness of the lateral-shifting tunnel H₁, the initial support thickness of the advance launching tunnel H₂, and the elastic modulus of the diaphragm wall E_W. Based on the sensitivity ranking, the highly sensitive parameters are selected for optimization, and the optimal parameter combination is determined to be a diaphragm wall thickness of 1000 mm, a grouting reinforcement range of 1600 mm, and an initial support thickness of 100 mm for the lateral-shifting tunnel. This combination meets the safety requirements for surface settlement while effectively reducing material consumption and improving economic performance. The study provides technical and theoretical references for shield launching under complex conditions. Full article

Advanced alkaline water electrolysis (AWE) in “zero-gap” configuration is a promising approach for low-temperature hydrogen production, but its efficiency strongly depends on the design and surface chemistry of nickel-based electrodes. Here, we present a simple dip-and-drying method (DDM) to modify commercial nickel foam with a Ni–FeOOH/PTFE microporous catalytic layer and evaluate its electrochemical performance in 1 M KOH and in a laboratory zero-gap cell with a Zirfon^® Perl 500 UTP diaphragm, through circulating 25 wt.% KOH. The FeSO₄-assisted DDM treatment generates mixed Ni–Fe oxyhydroxide surface species, while PTFE imparts control hydrophobicity, enhancing both catalytic activity and gas-release behavior. Annealing the electrode (DDM-NF-CAT-A) results in a cell voltage of 2.45 V at 1 A·cm⁻² and 80 °C, demonstrating moderate performance comparable to other Ni-based electrodes prepared via low-complexity methods, though below that of optimized state-of-the-art zero-gap systems. Short-term durability tests (80 h at 0.5 A·cm⁻²) indicate stable operation, but long-term industrial performance was not assessed. These findings illustrate the potential of the DDM approach as a simple, low-cost route to structured nickel foam electrodes and provide a foundation for further optimization of catalyst loading, microstructure, and long-term stability for practical AWE applications. Full article

Valued above all others, the white truffle species (Tuber magnatum Picco) is highly dependent on the forest ecosystem and its underground biology. Despite its economic importance, knowledge of its biology and mycorrhizal symbioses remains limited; moreover, natural yields have sharply declined, and cultivation efforts have produced inconsistent results. This study evaluated various forest and mycorrhizal inoculation techniques to promote T. magnatum mycelium development in three Tuscan sites converted to truffle cultivation, using qPCR analysis. Alongside conventional practices like irrigation, mulching, and tillage, an experimental method with a sterile, spore-inoculated soil barrier was tested to improve host root establishment, enhance mycorrhization, and maintain long-term symbiosis for healthy truffle ecosystems. Soil analyses nine months after planting Quercus robur L. seedlings showed significant differences in Tuber magnatum mycelium abundance across sites and treatments. The MA treatment—mycorrhized seedlings combined with a sterile, inoculated substrate and separation diaphragm—produced the highest mycelial levels, underscoring the importance of initial mycorrhization and soil manipulation. These findings provide valuable insights for optimizing forest management and improving truffle cultivation by enhancing mycelial development, a key step toward increasing truffle production. Full article

Introduction: This pilot randomized trial evaluated the feasibility of the Manual Diaphragm Release Technique (MDRT) in neurocritical patients on invasive mechanical ventilation (IMV) and explored its immediate effects on diaphragmatic kinematics to inform future trials. Methods: Adult neurocritical patients receiving IMV and ventilated in an assisted mode (pressure-support ventilation, PSV) at the time of enrollment were randomized to receive a single session of MDRT plus standard physiotherapy vs. a sham maneuver plus standard physiotherapy. The primary outcome was the feasibility of applying MDRT in neurocritical care patients under IMV, operationalized by the recruitment rate, protocol adherence, and incidence of intervention-related adverse events. The exploratory secondary outcomes were immediate diaphragmatic kinematics (contraction and relaxation velocities and inspiratory and expiratory excursions), which were measured by ultrasound to provide preliminary effect-size estimates for future trials. Results: Twenty neurocritical patients (10 in each group) were randomized and all completed the protocol. Baseline characteristics were comparable between groups. The study demonstrated high feasibility with 80% recruitment rate, 100% adherence, and a mean intervention time of 6.2 ± 1.1 min. No adverse events were observed during or after the intervention. Adjusted analyses revealed no detectable differences in diaphragmatic kinematics between groups after the single session. The adjusted mean differences were 0.1 mm/s (95% CI: −0.3 to 0.5; p = 0.50) for contraction velocity and 0.2 mm/s (95% CI: −0.05 to 0.45; p = 0.11) for relaxation velocity. For diaphragmatic excursion, the difference was 0.5 mm (95% CI: −1.2 to 2.2; p = 0.55) during inspiration and 1.0 mm (95% CI: −0.1 to 2.1; p = 0.08) during expiration. Conclusions: MDRT was found to be feasible for use in neurocritical patients under mechanical ventilation. Although no immediate effects on diaphragm kinematics were detected, these preliminary findings support the rationale for larger, adequately powered trials to further investigate cumulative or long-term effects. Trial registration: The trial is registered in ReBEC—Brazilian Registry of Clinical Trials under ID: RBR-3ngffwr. Full article

This study investigates the seismic retrofit of historic single-nave churches through the optimization of roof diaphragms designed to enhance energy dissipation. The proposed strategy introduces a deformable box-type diaphragm above the existing roof, composed of timber panels and steel connectors with a cover of steel stripes, where energy dissipation is concentrated in the connections. The retrofit design is guided by the estimation of Equivalent Damping Ratio (EDR) instead of the usually adopted resistance criterion, considering an energy-based approach to improve global seismic performance while preserving architectural integrity. In this way, the retrofitted configuration of the roof can be considered a damper. Three numerical phases are presented to assess the effectiveness of the equivalent damping-based intervention. In the first one, the seismic response of the initial non-retrofitted configuration is implemented using a 3D linear finite element model subjected to a response spectrum. Subsequently, nonlinear equivalent models subjected to spectrum-compatible accelerograms are implemented, simulating the possible retrofitted configurations of the roofs to detect the optimum damping and finding the corresponding roof diaphragm configuration. In the third one, the response of the detected retrofitted configuration is also evaluated by nonlinear 3D model subjected to accelerograms. The three phases with the relative numerical approaches are here applied to a case study, located in a high seismic hazard area. The results demonstrate that the EDR-based methodology can optimize the retrofitted roof diaphragm configuration; the nave transverse response is improved in comparison with that designed with the traditional approach, considering only the over-strength of the interventions. Comparisons about the approaches based on the EDR and the strength criteria are presented in terms of lateral displacements, in-plane shear acting on the roof diaphragm, and in-plane stresses on the façade. Full article

This article presents a comparison of empirical and simulation studies and the parameters declared by the membrane manufacturer. The analysis concludes that these values differ at each stage. Therefore, a numerical and simulation analysis of an optimal flat membrane was undertaken, which will successfully perform measurement functions across the full pressure range without causing inelastic deformations based on a membrane made of 316 L stainless steel with the following mechanical parameters: Young’s modulus $\mathrm{E}=2\times {10}^{11} \mathrm{P}\mathrm{a}$, Poisson’s ratio $\mathsf{\nu }=0.28$, density $\mathsf{\rho }=7980 \mathrm{k}\mathrm{g}/{\mathrm{m}}^3$, and yield strength 2.8 × 10⁸ Pa. A diaphragm with an outer diameter of 25.4 mm, an inner diameter of $2.22\times {10}^{-4} \mathrm{m}$, and a thickness of t = $5.08\times {10}^{-5} \mathrm{m}$ was designed for a pressure sensor in vacuum extinguishing chambers of medium-voltage devices, with a pressure difference $\Delta \mathrm{p}$ from 7 × 10⁻⁴ Pa to 1.013 × 10⁵ Pa. Finite element method (FEM) simulations in the COMSOL Multiphysics environment showed maximum von Mises reduced stresses 1.96 × 10⁸ Pa below the yield strength, confirming operation in the linear-elastic range. The central deflection, described analytically by the equation $\mathrm{y}={\displaystyle \frac{3(1-{\mathsf{\nu }}^2)\mathrm{P}{\mathrm{r}}^4}{16\mathrm{E}{\mathrm{t}}^3}}$, increased fivefold with an increase in diameter to $3.81\times {10}^{-2} \mathrm{m}$ (active area A = 1.14 × 10⁻³ m² compared to 5.07 × 10⁻⁴ m²), achieving a metrological sensitivity of 9.1 × 10⁻¹⁰ m/Pa. Experimental studies integrated with Bragg FBG and epoxy adhesive (E = 5 × 10⁹ Pa, tensile strength $4.2\times {10}^7 \mathrm{P}\mathrm{a}$) revealed a significant deviation from the manufacturer’s catalog data (e.g., deflection of $2.0\times {10}^{-5} \mathrm{m}$ at $6.89\times {10}^2 \mathrm{P}\mathrm{a}$), resulting from uneven bonding and a lack of coaxiality. Corrugated membranes with t = $2.0\times {10}^{-5} \mathrm{m}$ exceeded plasticity, while the optimized configuration of a smooth membrane with rounded adhesive edges ($\mathrm{R}=1\times {10}^{-4} \mathrm{m}$) enabled precise pressure monitoring below ${10}^{-1} \mathrm{P}\mathrm{a}$, despite technological restrictions on assembly and miniaturization. Full article

Bamboo has evolved a highly optimized structural system in its culms, which this study transfers into lightweight fiber composite trusses fabricated by coreless filament winding. Focusing on the structural segmentation involving diaphragms of the biological role model, this design principle was integrated into the additive manufacturing process using a multi-stage winding, a tiling approach, and a water-soluble winding fixture. Through a FE-assisted analytical abstraction procedure, the transition to a carbon fiber material system was considered by determining a geometrical configuration optimized for structural mass, bending deflection, and radial buckling. Samples were fabricated from CFRP and experimentally tested in four-point bending. In mass-specific terms, integrating diaphragms into wound fiber composite samples improved failure load by 36%, ultimate load by 62%, and energy absorption by a factor of 7, at a reduction of only 14% in stiffness. Benchmarking against steel and PVC demonstrated superior mass-specific performance, although mōsō bamboo still outperformed all technical solutions, except in energy absorption. Full article

With the increasing functional and geometric complexity of modern steel buildings, irregular-shaped beam-to-column joints are becoming common in engineering practice. However, their seismic behavior remains insufficiently understood, particularly for configurations with geometric asymmetry and complex stress transfer mechanisms. This study experimentally investigates the seismic performance of irregular steel-beam-to-concrete-filled steel tube (CFST) column joints incorporating inclined internal diaphragms (IIDs), taking unequal-depth beam (UDB) and staggered beam (SB) joints as representative cases. Two full-scale joint specimens were designed and tested under cyclic loading to evaluate their failure modes, load-bearing capacity, stiffness/strength degradation, energy dissipation capacity, strain distribution, and panel zone shear behavior. Both joints exhibited satisfactory strength and initial stiffness. Although diaphragm fracture occurred at approximately 3% drift, the joints retained 45–60% of their peak load capacity, based on the average strength of several loading cycles at the same drift level after diaphragm failure, and maintained stable hysteresis with average equivalent damping ratios above 0.20. Final failure was governed by successive diaphragm fracture followed by the tearing of the column wall, indicating that the adopted diaphragm thickness (equal to the beam flange thickness) was insufficient and that welding quality significantly affected joint performance. Refined finite element (FE) models were developed and validated against the test responses, reasonably capturing global strength, initial stiffness, and the stress concentration patterns prior to diaphragm fracture. The findings of this study provide a useful reference for the seismic design and further development of internal-diaphragm irregular steel-beam-to-CFST column joints. Full article