Search Results (7,279)

Conventional pneumatic precision planters still face challenges in combining high-speed operation with accurate seed placement and embryo protection under zero-velocity seeding conditions. This study presents a dual-motor rotating–throwing seed-metering device that simultaneously overcomes these challenges. Instead of relying on conventional imprecise airflow to generate initial velocity, seeds are accelerated and released by a motor-driven spoon with precisely defined kinematic profiles. By accurately controlling seed-throwing velocity and angle, the system compensates for the forward motion of the machine to achieve zero-velocity seeding and accurate landing point control across the full speed range. The elimination of seed tubes prevents frictional embryo damage, particularly benefiting fragile seeds such as cotton or peanuts. High-speed imaging (1000 fps) verified uniform initial seed ejection conditions, stable trajectories, and landing position errors below 1.5 cm at 7–13 km/h. The proposed electromechanical approach provides accurate metering, zero-velocity seeding, and seed protection under high-speed conditions, overcoming the inherent limitations of airflow-dependent systems and offering a robust alternative for precision agriculture. Compared with conventional pneumatic meters, the proposed system reduced seed landing variation by over 50%, demonstrating superior robustness under 7–13 km/h operation. Full article

Under China’s “Dual Carbon” strategy, carbon transparency has become a critical determinant of corporate competitiveness. Using a dataset of Chinese A-share listed companies from 2010 to 2023, this study constructs an integrated theoretical framework combining signaling theory and the “real effects” hypothesis to investigate the impact of carbon information disclosure (CID) on firm value. The results demonstrate a significant positive relationship between CID quality and firm value, a finding that remains highly robust against the exogenous macro-policy shock of the 2020 Dual Carbon goals. A primary conceptual contribution lies in identifying Green Mergers and Acquisitions (M&A) as a vital mediating strategic mechanism. High-quality CID acts as a credible commitment device that triggers internal problemistic search, compelling firms to undertake substantive green M&A to fulfill environmental claims, thereby establishing a “transparency-to-strategy-to-value” continuum. Furthermore, heterogeneity analysis indicates that the valuation premium is markedly more pronounced in non-state-owned enterprises (Non-SOEs) and non-heavily polluting industries, reflecting their reliance on transparency to alleviate capital constraints and signal “green competitiveness.” These findings confirm that the capital market prices carbon disclosure as a high-quality strategic asset rather than a mere compliance cost, offering targeted empirical evidence for policymakers to refine standardized disclosure frameworks and for investors to screen for substantive “Green Alpha.” Full article

Digital literacy has become central to educational participation and social inclusion worldwide. Yet significant disparities persist in low-resource schooling contexts, where unequal access to digital infrastructure may shape learners’ confidence in engaging with technology. This study examines the relationship between socioeconomic access and digital self-efficacy among underserved high school students in South Africa through the lens of the UNESCO Digital Literacy Global Framework (DLGF). Data were collected from 286 learners in three Eastern Cape secondary schools in South Africa using a structured questionnaire measuring constructs derived from the DLGF. Focusing on two core constructs, socioeconomic access and digital self-efficacy, a partial PLS-SEM model was estimated with SmartPLS 4. The reflective measurement model showed acceptable reliability and convergent validity (CR = 0.83, AVE = 0.51 for socioeconomic access; CR = 0.79, AVE = 0.65 for digital self-efficacy). Socioeconomic access was positively associated with digital self-efficacy ($\beta$ = 0.38, t = 7.04, p < 0.001), explaining 15% of its variance ($R^2$ = 0.15). These findings suggest that policies aimed at improving device availability and reliable connectivity in underserved schools may strengthen learners’ confidence in performing foundational digital literacy tasks, particularly information search and source evaluation. Full article

Objectives: To analyze speech perception outcomes of a cohort of experienced adult cochlear implant (CI) users to explore whether there is a correlation with electrical dynamic range (EDR) parameters, and to describe speech intelligibility curve morphology according to the degree of CI performance. Methods: A bicentric retrospective observational study. Data were extracted from a cochlear implantation database from a total of 36 CI users implanted with Advanced Bionics devices. Results: Mean age at implantation was 56.61 years. In the majority of cases, hearing loss onset was more than 15 years before implantation (80.55%), and only 11.11% of cases preserved residual hearing. This resulted in a significant relationship between speech therapy and better speech recognition (p = 0.044). At the same time, no correlation was found between age, duration of deafness before implantation, and maximum speech perception achieved (p > 0.05). Mean speech audiometry curves displayed a roll-over phenomenon in poor performers and a plateau effect in average performers. In contrast, the mean curve of high performers exhibited a steeper morphology (p < 0.0001). Speech recognition threshold (SRT) and word recognition score (WRS) were predictors of speech audiogram curves (p = 0.006). No direct correlation was found between the mean T-level, M-level, dynamic range, and maximum recognition score, even after clustering electrodes by position along the cochlea (p > 0.05). Conclusions: EDR parameters did not emerge as independent predictors of speech recognition outcomes within this specific cohort. Speech therapy and rehabilitative efforts showed a significant relationship with improved performance, and speech audiogram curve morphology may offer a more specific clinical tool for assessing global CI performance. Further prospective studies with larger, more homogenous populations are required to validate these findings. Full article

Background and Objectives: Pelvic ring injuries with symphyseal disruption are classically associated with high-energy mechanisms such as motor vehicle collisions. Recently, waterslides have emerged as an underrecognized but distinct source of severe pelvic trauma. Waterslide-related pelvic trauma represents a distinct biomechanical entity characterized by a supine or semi-supine body position at splashdown, extreme forced hip abduction, asymmetric lower-limb positioning, and abrupt hydrodynamic deceleration. The high descent velocity, abrupt hydrodynamic deceleration, and forced hip abduction at water entry may combine to generate open-book-type pelvic injuries. Evidence guiding diagnosis and surgical management in this setting remains scarce. Materials and Methods: We retrospectively analyzed a consecutive series of adult patients sustaining waterslide-related anterior–posterior compression type II (APC2) pelvic ring injuries. Demographic data and the body mass index (BMI), fracture classification, surgical strategy, complications, and functional outcomes were reviewed. Only patients with complete imaging, operative records, and follow-up were included. Results: Four patients (38–72 years) met the inclusion criteria. All sustained rotationally unstable open-book pelvic injuries and were classified as APC2; three were AO/OTA 61B2.3 and one 61B3.3. All patients were overweight or obese (BMI 27.2–31.2). Pelvic binders provided an effective acute reduction in symphyseal diastasis; however, in one bilateral injury, CT imaging obtained with the binder in situ masked posterior ligamentous instability. Definitive surgical fixation was performed in all cases. Early mechanical failure occurred in two patients treated with short anterior symphyseal plate constructs. In the bilateral injury, isolated anterior fixation failed repeatedly until posterior sacroiliac stabilization was added. No deep infections or thromboembolic events occurred. Although two patients required short observational ICU stays, none were admitted for hemodynamic instability or pelvic bleeding. Conclusions: At 12-month follow-up, three patients achieved pain-free ambulation without assistive devices, while one patient required intermittent use of a single crutch; all patients regained independence in daily activities. Waterslide accidents represent a high-energy injury mechanism capable of producing severe APC2 pelvic disruptions, particularly in patients with an elevated BMI. Awareness of this mechanism and meticulous assessment of posterior stability are essential to avoid under-treatment and mechanical failure. Full article

Background/Objectives: Reproducible evaluation of aerosol dispersibility remains a key challenge in the development of dry powder inhalers (DPIs), where small variations in particle cohesion, morphology, or device resistance can lead to large differences in aerodynamic performance. In passive DPIs, the forces required for powder fluidization and aerosolization arise from the interaction of patient inspiratory airflow with device geometry and must overcome strong interparticle cohesive forces to enable effective lung delivery. Cascade impaction is the gold standard for determining aerodynamic particle size distribution (APSD), but its low throughput and experimental burden limit its utility for systematic formulation and device screening. Prior studies have explored laser diffraction-based particle sizing under varying dispersion energies as indirect metrics of powder dispersibility. Here, we extend this approach by introducing a mathematically rigorous, distribution-based framework that applies the first-order Wasserstein distance (Earth Mover’s Distance) to quantify relative dispersibility with respect to a material-specific maximally dispersed reference state. Methods: Mannitol, trehalose, and inulin were spray-dried under matched conditions to generate model dry powders. Particle size distributions were measured by laser diffraction (Sympatec HELOS/R) using both a RODOS dry dispersion module to define a maximally dispersed reference state and an INHALER module to generate aerosols under clinically relevant dispersion conditions spanning multiple device resistances and pressure drops. For each condition, the Wasserstein-1 distance (W₁) was computed between cumulative volume-based size distributions obtained under reference and inhaler-based dispersion. Cascade impaction was used as an orthogonal method to characterize aerodynamic performance under a representative dispersion condition. Results: W₁ captured formulation-, device-, and flow-dependent differences in dispersibility that were not readily separable by visual inspection of particle size distributions alone. Crystalline mannitol exhibited the largest and most flow-rate-dependent W₁ values, whereas amorphous trehalose and polymeric inulin showed smaller W₁ values with distinct, non-monotonic pressure responses that depended on device resistance. W₁ qualitatively aligned with cascade impaction metrics, exhibiting a positive association with mass median aerodynamic diameter and an inverse association with fine particle fraction, while also demonstrating that efficient dose emission can occur despite incomplete deagglomeration. Conclusions: This study establishes the Wasserstein distance as a physically interpretable, formulation-agnostic metric for quantifying aerosol dispersibility relative to a material-specific reference state. This framework enables systematic comparison of dispersion efficiency across devices and operating conditions using standard laser diffraction data and provides a reproducible basis for mechanistic optimization of DPI formulations and inhaler designs. Full article

With the evolution of new power systems, harmonic sources in distribution networks have become increasingly dispersed, thus requiring lower-cost harmonic mitigation devices suitable for large-scale deployment. With its simple control architecture, the one-cycle controlled active power filter (APF) is better adapted to meet the aforementioned requirements. That said, under non-ideal voltage conditions like voltage distortion or unbalance, the compensating target current of the APF that relies on traditional one-cycle control (OCC) will undergo distortion as well, resulting in a substantial reduction in the compensation effect. This paper introduces a modified OCC method based on a positive-sequence filter, which allows for the control of a reduced-switch three-phase APF. This control method eliminates the negative sequence and harmonic components in the target current of the APF, and makes the compensated current maintain a good sinusoidal waveform. A one-cycle control equation applied to the reduced-switch APF was derived. The modified one-cycle control method allows the active filter to retain a favorable compensation effect when operating under non-ideal voltage conditions. Meanwhile, it preserves the inherent advantages of traditional one-cycle control, including the elimination of a phase-locked loop (PLL), a fixed switching frequency, and a straightforward control structure. Finally, an APF simulation model and a dSPACE-based APF experimental circuit were built to verify the proposed control method. In simulation, with the adoption of the modified OCC, the THD of the current was reduced from 8.25% before improvement to 3.79% after improvement. In experiments, according to the spectrum analysis function of the oscilloscope, the third-order current harmonic caused by voltage distortion was decreased from 500 mA to 100 mA, representing a reduction of 80%. Both simulation and experimental results verify that the proposed modified one-cycle control method can effectively solve the problem that control performance is susceptible to voltage quality. Full article

Objectives: Physician-modified endografts (PMEGs) expand endovascular treatment options in urgent or cost-sensitive settings where industry-provided custom-made devices (CMDs) are not available. Current PMEG manufacturing techniques are time-consuming, lack standardization, and often require repeated adjustments to achieve strut-free fenestration positioning. Mixed reality (MxR) may streamline this process by overlaying virtual templates directly onto the physical stent graft guiding fenestration positioning. Methods: We developed a standardized MxR-assisted workflow for four-fenestrated PMEG preparations and compared it to a conventional marking technique. In this experimental set-up, between May 2025 and July 2025, three stent grafts were evaluated (Endurant II^® 28 mm, Valiant Captivia^® 30 mm, and Valiant Captivia^® 32 mm). Five observers performed fenestration marking on 20 grafts per device type (10 per method), resulting in 60 PMEGs and 240 fenestrations. Outcomes included absolute positional error, relative positional error, number of strut-free fenestrations, number of re-attempts to achieve strut-free configuration, time required, and usability assessed via the System Usability Scale (SUS). Results: Across 240 fenestrations, both methods achieved high accuracy. Median absolute errors ranged from 0 to 1.25 mm for the conventional method and 0 to 1.75 mm for MxR. Relative positional errors were similarly small, with no significant differences between methods. MxR achieved higher rates of strut-free fenestration in the 28 mm Endurant II^® device. Re-attempts were fewer with MxR. Median procedure time was significantly reduced for the MxR-assisted workflow in Valiant Captivia 30 mm (5.0 vs. 9.8 min, p = 0.049) and 32 mm (5.6 vs. 8.2 min, p = 0.049) while a trend was observed for Endurant II (7.5 vs. 15.6 min, p = 0.066). SUS scores favored MxR (76.2 vs. 62.6), though not significantly. Conclusions: The MxR-assisted PMEG production workflow seems promising in this pre-clinical, experimental study and warrants continued development and investigation. Full article

The safety of belt conveyor operation is of great importance during coal conveyance. This paper proposes a multi-task-based GSSA-YOLOM algorithm for monitoring the state of belt conveyors, which utilizes segmentation head to detect foreign objects and belt deviation, thereby balancing the trade-offs among multiple tasks. The detection neck is responsible for multi-scale feature fusion by incorporating the Asymptotic Feature Pyramid Network (AFPN) to achieve enhanced spatial perception. Then, Groupwise Separable Convolution (GSConv) is further introduced to simplify the network architecture, reducing computational complexity while maintaining sufficient detection accuracy for edge device deployment. Moreover, the SlideLoss and Soft-NMS functions are integrated to reduce the rate of false positives and missed detections. Comparison experiments were conducted, and the results indicate that the proposed GSSA-YOLOM model can improve mAP@50 by 3.4% compared with the baseline model while reducing the number of parameters by 27%, thereby satisfying coal mine safety monitoring requirements. Full article

This study presents a high-performance MEMS accelerometer employing a symmetrical differential ‘sandwich’ capacitive structure. An orthogonal rectangular compensation method was integrated with wet anisotropic etching to achieve high structural symmetry. An innovative glass–silicon composite cover plate was adopted, and the upper and lower plates were encapsulated by a sensitive structure via anodic bonding, which effectively reduced the parasitic capacitance. Simulations confirmed sufficient separation between the sensitive-axis (Z-axis) resonant frequency and orthogonal/torsional modes, ensuring low cross-axis coupling. The fabricated device exhibits high sensitivity (0.2216 V/g) and excellent linearity (99.842%) within a 0–8 g range. Furthermore, it demonstrates outstanding noise (7.88 µg/√Hz) and bias-instability (6.39 µg) performance, positioning it competitively against commercial counterparts. The proposed design and process offer a viable technical route for high-precision inertial sensing applications. Full article

Background: PRKAG2 cardiac syndrome is a rare autosomal dominant glycogen-storage cardiomyopathy that mimics sarcomeric hypertrophic cardiomyopathy (HCM) but features ventricular pre-excitation, progressive conduction disease and concentric hypertrophy due to intracellular glycogen accumulation. The c.905G>A (p.Arg302Gln) variant is one of the most frequently reported pathogenic substitutions. Case summary: We describe a three-generation family carrying the heterozygous PRKAG2 p.Arg302Gln variant. The proband, a 41-year-old man, presented with paroxysmal atrial fibrillation, short PR interval and abnormal intraventricular conduction associated with concentric left ventricular hypertrophy and preserved ejection fraction. Holter monitoring disclosed episodes of high-grade atrioventricular block, prompting implantation of a primary-prevention dual-chamber ICD. Two gene-positive brothers exhibited milder hypertrophy but shared sinus bradycardia, ventricular pre-excitation and supraventricular arrhythmias; one underwent catheter ablation of a posteroseptal accessory pathway. The affected mother displayed a hypertrophic phenotype complicated by sick sinus syndrome and permanent atypical atrial flutter requiring pacemaker implantation. No relevant extracardiac involvement was detected in any family member. Review and novelty: Using this family as a starting point, we provide a concise narrative review of PRKAG2 syndrome with emphasis on the Arg302Gln genotype, molecular mechanisms and emerging treatment strategies. We highlight key multimodality imaging and tissue-characterization features that help distinguish diffuse, concentric glycogen-storage hypertrophy from the often-asymmetric pattern of sarcomeric HCM. Integration of our findings with published Arg302Gln cohorts illustrates the broad phenotypic variability in conduction disease, pre-excitation and atrial arrhythmias. Conclusions: PRKAG2 p.Arg302Gln-related cardiomyopathy should be suspected in patients with otherwise unexplained left ventricular hypertrophy associated with short PR interval, pre-excitation or early brady–tachy arrhythmias. Early recognition of red-flag features, systematic genetic testing, family screening and tailored arrhythmia/device management are crucial, while emerging gene- and pathway-targeted therapies may offer future disease-modifying potential. Full article

Large Language Models are increasingly used for high-level robotic reasoning, yet their latency and stochasticity complicate their direct use in low-level control. Moreover, extracting actionable navigation cues from multimodal context incurs inference costs that are challenging for embedded platforms. We present a plug-and-play framework that augments a finite-state machine with asynchronous velocity suggestions generated by a Large Language Model, using an off-the-shelf DistilGPT-2 model running on-device on a Jetson AGX Orin. The system extracts task-relevant cues from the current context and integrates them only if they satisfy deadline, schema, and kinematic validation, thereby preserving a deterministic 50 Hz control loop with a <5 ms fallback path. We compare multiple Large Language Models for embedded robot control and quantify trade-offs among model size, inference time, and output validity. To assess whether the Large Language Models add value beyond signal processing, we include an ablation against a standard smoothing baseline; the results indicate that the Large Language Models contribute anticipatory, context-dependent adjustments that are not captured by filtering alone. Experiments in Gazebo and on a real TurtleBot3 reduce the final position error from 0.246 m to 0.159 m and improve trajectory efficiency from 0.821 to 0.901 without increasing control-loop latency. Approximately 80% of the Large Language Models’ outputs pass validation and are applied. Overall, the framework reduces developer effort by enabling behavioral changes at the prompt level while maintaining interpretable, robust edge-based navigation. Full article

Safe drinking water and microbial inactivation from surfaces and devices are among the World Health Organization’s priorities. Plasma-activated water (PAW) inactivates microorganisms mainly by producing radicals (hydroxyl radicals, superoxide, nitrogen oxide, etc.), which form secondary reactive species like nitrates, nitrites, hydrogen peroxide, etc., from the air–liquid interface, where the plasma interacts with the water. A plasma arc device for water treatment with enhanced arc length was constructed at the Andronikashvili Institute of Physics (TSU) and used in the study. PAW’s antibacterial efficacy has been evaluated against Gram-negative E. coli and remarkably stress-resistant Gram-positive B. pumilus. This study identifies reactive oxygen (hydrogen peroxide and superoxide anions) and nitrogen species (total nitrate and nitrite ions) in plasma-activated water, analyzing their potential impact on antioxidant enzyme activity and their relationships with bacterial cell viability. B. pumilus exhibits greater resistance to plasma-activated water as a disinfectant compared to E. coli. Catalase is more effective than superoxide dismutase in protecting cells from external oxidative stress, based on the two antioxidant enzymes studied. Full article

This study examined the effects of environmental conditions, behavioral history, management practices, and personality traits on the operational performance of search and rescue (SAR) dogs and dogs admitted to SAR certification testing. Thirty-two handlers completed a questionnaire collecting demographic data, as well as information on their dogs’ behavioral history, management practices, and personality descriptors. Each dog–handler unit also undertook a search trial consisting of locating a hidden person in a wooded area, which was evaluated both by professional instructors and the handlers through ratings of critical behavioral indicators. Objective measurements were obtained through a weather station and GPS devices. Handlers described their dogs mainly in terms of work-relevant traits, such as socio-cognitive engagement, assertiveness, and arousal. The performance evaluation form was practical and efficient, though the Distraction parameter may require refinement, and handler ratings suggested a self-reporting bias. Temperature and wind speed were negatively associated with performance, whereas higher humidity was positively associated with it. Performance was also associated with litter size, age at adoption, dog experience, and management-related factors. Finally, speed, ground coverage, and a canine profile characterized by high arousal and reactivity were strong determinants of good search performance (|ρ| ≥ 0.3; p < 0.05). Although these findings require confirmation in larger samples, search performance appears to be a multifactorial construct shaped by the interplay of extrinsic and intrinsic factors. Defining the contribution of each factor could help optimize performance and dogs’ welfare. Full article

Unlike conventional positioning systems that rely on multiple sensors, the positioning system proposed in this study uses a single anisotropic magnetoresistive (AMR) sensor to measure the magnetic field of a target permanent magnet. This approach significantly reduces the system hardware cost and complexity, facilitating the miniaturization of positioning systems. Leveraging a BP neural network model, which is shown to be fast and accurate, the positioning system obtains the real-time magnetic field of the target magnet using a single sensor, subsequently converting three-axis magnetic field data into coordinate information to achieve real-time tracking and localization. The results show that the root mean square errors (RMSEs) for the X and Z axes in the simulation are 0.27 mm and 0.26 mm, respectively, while the RMSEs for the X, Y, and Z axes in the actual test are 0.83 mm, 1.15 mm, and 0.85 mm, respectively. It is also observed that the positioning error correlates with variations in the magnetic field with respect to position, which originate from the strong distance-dependent nonlinearity of the magnetic field. This method not only reduces hardware costs but also maintains accuracy. It is particularly well-suited to applications requiring high-precision positioning and tracking, achieving millimeter-level accuracy within a volume of 50 × 40 × 40 mm³. It has potential applications in aerospace intelligent connectors, medical devices and automation systems, where space and signal lines are limited. Full article