Search Results (6,404)

The conventional microstepping driving method suffers from significant periodic speed oscillations under ultra-low-speed conditions, which fail to meet the stringent demand for smooth operation of ultrasonic motors in semiconductor packaging. Most existing theories and simulations of ultrasonic motors adopt a macroscopic mechanical perspective; after extensive linearization and idealization, they can only provide preliminary mechanism analysis and fail to achieve precise quantitative computation. Moreover, they neglect critical factors such as the microstructure of contact surfaces, preload distribution, and vibration mode transmission, making it difficult to reflect the true characteristics of the motor—including strong nonlinearity, multiphysics coupling, and complex interface behavior—resulting in considerable discrepancies between theory and experiment. In this paper, a macro-micro multi-scale finite element model of a traveling-wave ultrasonic motor is established using ADINA and HyperMesh, fully accounting for the strong nonlinearity and multiphysics coupling effects. Based on the ultrasonic friction reduction theory and the beat traveling wave mechanism, the stator deformation, interface zoning characteristics, and torque output of the superimposed pulse driving method and the microstepping driving method are systematically compared. The simulated stator mode shapes are validated by laser scanning vibrometry experiments, and multiple speed tests ranging from 200 to 320 arcsec/s are conducted. Simulation results show that at a target speed of 900 arcsec/s, the superimposed pulse driving method reduces the speed fluctuation rate from 228% to 32%. Experimental results confirm that the speed fluctuation rate of the superimposed pulse driving method is consistently much lower than that of the microstepping driving method across the entire tested speed range. This study reveals the low-speed smooth operation mechanism of the superimposed pulse driving method, characterized by single-peak dominance and smooth alternation between the driving and braking zones, thereby fundamentally overcoming the inherent shortcomings of the traditional microstepping driving method. The proposed model can effectively replace costly direct interface measurements, providing a new method and reference for ultra-low-speed precision control of ultrasonic motors and for investigating the driving mechanisms of similar motors. Full article

This study examines how decision uncertainty shapes consumers’ Fear of Better Options (FOBO), and subsequently is associated with ditto consumption, while assessing FOBO’s mediating role and the moderating effects of emotional state (Fear of Missing Out, FOMO/Joy of Missing Out, JOMO) and cultural differences (China/Korea). Using survey data from 682 new energy vehicle consumers in China and Korea, structural equation modeling was applied to test the proposed framework. The results reveal that choice overload and price fluctuation significantly increase both FOBO and ditto consumption, while obsolescence risk does not show a significant direct effect. Notably, time pressure negatively influences FOBO but positively affects ditto consumption, suggesting a dual-path mechanism in decision-making under time constraints. FOBO partially mediates the effects of choice overload and price fluctuation on ditto consumption. Moreover, emotional state and cultural differences moderate these relationships: FOMO amplifies, whereas JOMO mitigates the transmission effect of FOBO. Chinese consumers display stronger overall effects compared with their Korean counterparts. This study expands upon uncertainty avoidance theory by incorporating FOBO into consumer decision-making models, providing insights into how decision uncertainty, along with cultural and emotional factors, can inform marketing strategies. Full article

With the rapid development of wireless communications, electromagnetic interference (EMI) in complex environments has become a critical factor affecting communication quality. Addressing the EMI issues caused by multi-band coexistence in indoor scenarios, traditional metallic resonant structures, while effective in filtering, often compromise optical transparency due to light blockage. To resolve this trade-off, this paper proposes a dual-ring resonant frequency-selective surface (FSS) based on Indium Tin Oxide (ITO) films. This design aims to achieve efficient transmission in specific C-band frequencies and suppress out-of-band interference, realizing excellent optical transmittance while ensuring electromagnetic shielding effectiveness. The designed metasurface targets a passband of 5.35–5.40 GHz for sub-6 GHz indoor communications. Experimental results confirm superior transmission in this range and significant out-of-band suppression. Furthermore, featuring high optical transparency, the structure can be directly integrated onto glass surfaces. It is not only suitable for optically transparent devices but also provides a compact passive solution for anti-EMI applications in smart buildings and sub-6 GHz indoor communications. Full article

In 2023, ASF was recognized in Lombardy in wild boars, but shortly thereafter the disease was also identified in pig farms, with serious economic repercussions for the entire national pig sector. To identify factors related to the introduction of the infection into pig farms, a case–control study was conducted with the aim of gaining knowledge on the risk and protective factors involved in the introduction of the ASF virus into intensive pig farms. To this end, a questionnaire was developed on risk factors related to ASFV transmission into pig farms and on good management and biosecurity practices. The results of the study showed that measures aimed at strengthening the segregation of the farm from the external environment (external biosecurity), such as the mandatory passage through a hygiene lock upon entry, the presence of a hygiene lock for farm personnel and external visitors, the presence of special equipment and disinfection points at the entrance to the sheds, the loading of dead pigs outside the animal housing area and the ownership of non-adjacent agricultural land, were associated with a reduced risk. This information, if effectively communicated, could be of direct practical value to farmers to ensure the successful implementation of farm biosecurity. Full article

Cable-driven minimally invasive surgical robots suffer from significant motion inaccuracies due to nonlinear transmission effects such as friction, elasticity, and hysteresis. These factors lead to strong nonlinear and direction-dependent behaviors, making accurate modeling and compensation challenging. To address this issue, this study investigates the error characteristics of a cable-driven surgical robot prototype based on its structural features. A kinematic model is first established, and geometric errors are corrected through Denavit–Hartenberg (DH) parameter identification using a least-squares method. To further characterize nonlinear effects, the LuGre friction model and equivalent stiffness theory are introduced to analyze friction and cable deformation behaviors. Since physics-based models alone cannot accurately capture the coupled nonlinear errors, a radial basis function (RBF) neural network is employed to approximate the residual errors. To enable real-time implementation, the predicted errors are further simplified using equivalent polynomial functions for efficient compensation. Experimental results demonstrate that the proposed method significantly improves the motion accuracy of the cable-driven system, effectively reducing both tracking error and hysteresis effects. By integrating mechanism-based modeling with data-driven compensation, this approach provides a practical and effective solution for precision enhancement in cable-driven surgical robotic systems. Full article

Although hantaviruses have traditionally been considered geographically restricted rodent-borne pathogens, globalization, climate change, ecosystem disruption, and environmental contamination may collectively favor novel transmission scenarios and altered epidemiological patterns. The experience gained during the SARS-CoV-2 pandemic showed the importance of environmental determinants, airborne exposure, and host susceptibility factors in emerging viral diseases. In this context, increasing but still indirect evidence suggests that environmental toxicants and the exposome may modulate susceptibility to hantavirus infection and influence disease severity. The proposed mechanisms include oxidative stress, endothelial dysfunction, pulmonary inflammation, and immune dysregulation, rather than direct causal effects of toxicants on infection itself. This article discusses current knowledge regarding interactions among toxic environmental exposures, climate change, and hantavirus disease, with special emphasis on Andes orthohantavirus (ANDV), the principal hantavirus known to exhibit person-to-person transmission. The article integrates recent evidence within the One Health framework and highlights future research priorities linking environmental toxicology, zoonotic disease ecology, and global environmental change. Full article

This study investigates whether stock market volatility of the Indonesian Composite Index (IHSG) during presidential elections is predominantly driven by global or domestic factors. Using an event study framework covering four election cycles (2009, 2014, 2019, and 2024), we examine three transmission channels, macroeconomic conditions (interest rate, inflation, exchange rate), trading activity (volume, frequency, traded value), and global risk sentiment (VIX), across a five-month pre- and post-election window, with the election month excluded to avoid short-term shock distortion. Channel variables are constructed using Principal Component Analysis (PCA) and tested through multiple linear regression with dummy interaction terms. To address autocorrelation in the initial OLS model (Durbin–Watson = 1.189), the Cochrane–Orcutt procedure is applied, which resolves the issue (Durbin–Watson = 1.990) and yields the primary results. The corrected model explains 55.8% of variation in IHSG volatility (Adjusted R² = 0.558, F = 7.862, p < 0.001). Results consistently show that global risk sentiment (VIX) is the only significant positive driver of volatility (β = 0.003, p < 0.001), while macroeconomic and trading activity channels show no robust significance. No significant interaction effects are found, indicating that the influence of these channels does not differ statistically between pre- and post-election periods. We conclude that stock market volatility around Indonesian presidential elections is more strongly associated with global risk sentiment than with domestic macroeconomic or trading activity factors. The VIX consistently emerges as the dominant explanatory variable in the estimated model. Full article

Periodontitis is closely linked to atherosclerosis; however, the role of the keystone periodontal pathogen Porphyromonas gingivalis (P. gingivalis), particularly its virulence factor, outer membrane vesicles (OMVs), in vascular smooth muscle cell (VSMC) dysfunction remains unclear. This study aimed to explore the effects of P. g-OMVs on mouse aortic smooth muscle cells (MOVAS) and the potential involvement of cytoskeleton-associated protein 4 (CKAP4) in this process. OMVs were isolated by ultracentrifugation and characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting. MOVAS cells were treated with OMVs; cellular functions were evaluated using CCK-8, colony formation, scratch wound-healing, ELISA, and Western blotting assays. Lentiviral vectors were used to construct CKAP4 overexpression and knockout cell models. Results showed that after P. g-OMVs were internalized by MOVAS cells, the cells showed cytoskeletal disorganization, promoting cell proliferation, wound closure, and contractile-to-synthetic phenotypic switching (decreased α-SMA and increased OPN expression), and enhancing extracellular matrix (ECM) remodeling (upregulated expression of type I collagen, type III collagen, fibronectin, matrix metalloproteinase-2 and -9, and tissue inhibitor of metalloproteinase-1). At the protein level, P. g-OMV treatment was associated with upregulated expression of CKAP4, integrin α5, and integrin β1; CKAP4 overexpression synergized with OMV stimulation to amplify these phenotypic alterations, whereas CKAP4 knockout attenuated these cellular changes. These findings suggest an association between CKAP4 upregulation and P. g-OMV-induced MOVAS dysfunction, indicating that CKAP4 may serve as a potential target in periodontitis-associated atherosclerosis. Full article

Metal accumulation in cacao (Theobroma cacao L.) cultivation represents an important agronomic and food-safety concern, particularly in acidic tropical soils where cadmium (Cd) and other trace metals can become bioavailable and translocate to plant tissues. Green magnetic nanomaterials offer a potential strategy for reducing metal mobility in agricultural substrates, but their performance depends on surface chemistry, dose, and plant genotype. In this study, we synthesized and evaluated MCRES, defined here as a maghemite–Citrus reticulata extract system, a biofunctionalized γ-Fe₂O₃-based nanosystem prepared by coupling iron oxide nanoparticles (NPs) with a 3% (w/v) Citrus reticulata peel extract. The objective was to determine whether citrus-mediated biofunctionalization could produce a scalable magnetic nanoamendment capable of modifying Cd and naturally occurring Ni partitioning in cacao seedlings. MCRES was recovered magnetically and dried, yielding 8.44 g of product from 10 g of precursor. Rietveld analysis performed in X ray diffractograms confirmed phase-pure cubic γ-Fe₂O₃ with a lattice parameter of 0.8332 nm, a crystallite size of 11.3(1) nm, and satisfactory refinement quality (χ² ≈ 1.34). Transmission electron microscope images showed quasi-spherical NPs with a log-normal size distribution centered at 7.5 nm. Magnetic measurements showed superparamagnetic-like behavior at 300 K, high saturation magnetization values of 62 emu g⁻¹ at 300 K and 71 emu g⁻¹ at 5 K, and elevated effective anisotropy values obtained from the Law of Approach to Saturation fitting. MCRES was applied at 0, 1, 2, 4, and 6 g pot⁻¹ to cacao seedlings containing Cd-amended Ultisol with naturally occurring Ni. Plant responses were genotype and dose dependent: TSH-1188 genotype showed limited dose sensitivity for most biometric variables, whereas ICS-95 genotype showed significant dose effects, with maximum growth at the 2 g pot⁻¹ treatment. Metal-partitioning results indicated that Cd remained comparatively mobile toward shoots, whereas Ni was preferentially retained in roots. In TSH-1188 genotype, the Ni translocation factor decreased from 3.07 in the control to 0.85–1.00 at higher MCRES doses. Compared with previous work on non-biofunctionalized nanomaghemite, these results suggest that citrus-mediated biofunctionalization produces a distinct Cd/Ni partitioning response. Overall, MCRES is recommended as a promising nursery-scale green nanoamendment for reducing metal mobility in cacao cultivation, but its agronomic use should be optimized according to genotype and dose. Future work should include side-by-side comparisons with unfunctionalized γ-Fe₂O₃, Citrus reticulata extract alone, and non-contaminated controls under field conditions to validate its long-term effectiveness and environmental safety. Full article

Phase-modulated continuous wave (PMCW) has emerged as a promising waveform candidate for next-generation integrated sensing and communication systems due to its favorable sensing performance and multiplexing capability. In multiple-input and multiple-output (MIMO) PMCW systems, fast-time code-division multiplexing enables simultaneous transmission from multiple transmitters but causes inter-transmitter code interference due to non-ideal cross-correlation properties. The interference is observed to manifest as a low-rank component in the range–Doppler domain while target echoes appear as sparse components. This structural distinction motivates the use of robust principal component analysis (RPCA) for interference mitigation. In practice, conventional RPCA incurs high computational complexity due to the singular value decomposition (SVD) required at every iteration. To address this limitation, we propose an unfolded RPCA network in which each iterative step is mapped to a network stage and SVD is replaced by a factorized low-rank approximation. The proposed network also incorporates stage-wise learnable parameters for adaptive interference mitigation in MIMO PMCW systems. Simulation results demonstrate that the proposed method achieves interference mitigation performance comparable to conventional RPCA with 21.2 times lower inference latency. These results confirm the effectiveness and computational efficiency of the proposed method for real-time mitigation of inter-transmitter code interference in MIMO PMCW systems. Full article

Green synthesis of gold nanoparticles is an effective approach to create biocompatible nanomaterials. In this study, gold nanoparticles (BC-AuNPs) were prepared by reducing chloroauric acid with black corncob (BC) extract at relatively low temperatures. The optimal preparation conditions were obtained through a single-factor experiment, which included 5 mL of black corncob extract and 0.12 mL of 3% HAuCl₄ solution at a pH of 5.0, and the reaction was carried out at 50 °C in a water bath for 3 h. The prepared BC-AuNPs were characterized by ultraviolet–visible (UV-Vis) spectroscopy, Fourier-transform infrared (FTIR) analysis, transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), and Zeta-potential measurement, which showed that they were dispersed spherical particles with an average size of approximately 23.0 nm and their surfaces were covered with various black corncob active components. The photothermal performance test indicated a good photothermal effect with a conversion efficiency of 41.3%. Antibacterial experiments revealed that BC-AuNPs had excellent antibacterial activity. The minimum inhibitory concentrations (MICs) for E. coli and Salmonella were 25.00 and 50.00 µg/mL, respectively. Overall, this study proved a potential application for gold nanoparticles in photothermal antibacterial fields. Full article

In the framework of mean-field approximation, the influence of social contacts on the spread of an epidemic in a population of constant size is discussed. The key feature of the proposed model is that it includes two infection–transmission mechanisms depending on the physical nature of the contact between people. We separate the transfer mechanism related directly to the movement of people (the so-called transport processes) from the one occurring when the relative velocity between individuals is negligible (the so-called social contacts). Based on the developed physicochemical analogy, this approach allows us to derive, in a unified manner, expressions for the rate constants of infection–transmission of different nature. The resulting transmission rate constants are used to modify the SEIS model to examine the influence of social activity on the formation of an endemic equilibrium in the population under consideration. The frequency of social contacts is estimated using Dunbar’s approach and a direct statistical calculation based on the binomial distribution. These relations are then used to discuss the formation of quasi-stationary states, which can be interpreted as endemic equilibria. A qualitative analysis of the resulting dynamical regimes is carried out. The necessary conditions for the existence of this equilibrium, depending on both social and medical–biological factors, are also derived. The analytical results are illustrated by numerical simulations. The present results should be interpreted as a necessary step to establish a link between purely transport and social mechanisms of epidemic development. Full article

Traditional wooden granaries in rural Türkiye are disappearing at an accelerating rate due to agricultural abandonment, rural depopulation, and the absence of systematic documentation and conservation frameworks. In the Sındırgı district of Balıkesir, one of the richest concentrations of vernacular granary architecture in the Marmara Region, these structures remain largely unprotected and unstudied within a sustainable design framework, constituting an urgent conservation challenge. This study aims to assess the current preservation status of Sındırgı granaries, classify their typological diversity, and evaluate their sustainability performance against a defined set of ecological design criteria. A mixed methods approach was employed, combining a systematic literature review with extensive fieldwork across 33 neighborhoods. In total, 1411 granaries were identified and grouped into five typologies: evli, Simav, kabak, sandık, and üstü örtülü sandık. These typologies were systematically compared to five parameters: spatial distribution across neighborhoods, plan and section geometry, construction system and structural elements, material selection and condition, and preservation status. This comparison revealed that typological variation is not incidental but directly reflects differences in land ownership, agricultural production capacity, topography, and distance from the district center. Representative examples from each typology were documented through onsite measurements, photogrammetry, technical drawings, and interviews with local craftsmen. The sustainability performance of the granaries was then assessed across seven ecological design criteria: spatial organization, building form design, structural element design, material use and conservation, design with nature, urban design area planning, and nature interaction. The findings demonstrate that the long-term durability of these structures depends on an interrelated system of climate-responsive design decisions rather than any single factor. The study concludes by proposing a holistic conservation model comprising typology-based inventory, roof water moisture-focused intervention, periodic monitoring, and transmission of vernacular building knowledge, a framework applicable to comparable rural granary heritage across the region. Full article

The consumption of wild rodents in certain regions of Southwest China creates a potential interface for zoonotic pathogen exposure, yet the virome composition of edible rodents remains insufficiently characterized. In this study, we performed multi-organ RNA metatranscriptomic analysis of three commonly consumed rodent species (Niviventer andersoni, Berylmys bowersi, and Rattus losea) collected from Guizhou Province, analyzing five visceral organs per species. A total of 1198 viral contigs spanning 37 viral families were identified, revealing diverse viral communities across host species and tissues, with host identity emerging as a key factor shaping virome structure. Sequences related to Seoul virus were detected in the lungs of R. losea, showing high similarity to previously reported strains, and sequences closely related to porcine Rotavirus A were identified in the lung samples of N. andersoni, indicating a close phylogenetic relationship with livestock-associated viruses. While these findings do not confirm active infection or transmission, they may reflect potential environmental exposure or ecological links at the wildlife–livestock interface. Overall, this study provides a baseline characterization of the multi-organ virome of edible rodents and highlights the importance of integrated surveillance and risk assessment within a One Health framework. Full article

Pigs play a key role in the ecology of influenza A viruses (IAVs), particularly in avian influenza (AI)-endemic regions where co-circulation of viruses from different hosts increases reassortment risk. Between September 2023 and August 2024, we surveyed pigs from Lebanon and Egypt to study IAV ecology in AI-endemic countries. Nasal swabs and sera were collected and tested using real-time RT-PCR and hemagglutination inhibition assays against avian, swine, and human seasonal IAVs. Molecular analyses identified IAV-infections in both countries, including human H1 and avian H5 subtypes, which may reflect potential cross-species transmission from humans and birds. Serologic analyses revealed prior exposure to avian, swine, and human IAVs. Avian virus seropositivity reached 4.6% (H5N1) and 15.2% (H9N2) in Egypt and 8.6% (H5N1) and 4.3% (H9N2) in Lebanon. Antibodies against human H1N1 and H3N2 were prevalent in both countries. Serologic evidence exceeded molecular detection, indicating frequent past or transient infections not captured by PCR alone. Antibody responses were significantly associated with host-level factors such as housing type, age, shaping exposure risk. These findings demonstrate repeated multisource exposure of pigs to genetically distinct IAVs in AI–endemic countries, supporting the need for integrated virologic and serologic surveillance within a One Health framework. Full article