Search Results (91)

Cataracts are the leading cause of reversible blindness worldwide; this condition results from the aggregation of lens proteins. Currently, surgery remains the only treatment; however, there is growing interest in non-surgical approaches, including the use of bioactive compounds incorporated into nanostructured systems designed to enhance solubility, enable controlled release, and improve bioavailability and bioactivity. Among the bioactive compounds investigated, curcumin has attracted considerable attention due to its antioxidant and anti-inflammatory properties, positioning it as a potential anticataractogenic agent. In the present study, curcumin-loaded nanoemulsion was developed via ultrasonication and characterized by average particle size, D90 percentile, ζ potential, and rheological behavior. In addition, its anti-cataract efficacy was evaluated both using an in vivo model in rats and an ex vivo model employing human cataract samples. The resulting curcumin-loaded nanoemulsion exhibited an average particle size of 152 ± 19.79 nm with a monomodal distribution, along with good physical stability over time. The nanoemulsion exhibited apparent viscosity between 30 and 25 mPa·s, at shear rate values (100 to 0 s⁻¹), indicating slight shear-thinning behavior. Regarding the effect on cataracts, in the in vivo model, cataract reversal was observed. Furthermore, ex vivo isothermal titration calorimetry (ITC) analyses indicated exothermic heat exchange between the curcumin nanoemulsions and cataract fragments, consistent with binding interactions occurring within lens components, likely involving crystallin proteins. These findings provide biophysical and in vivo evidence that intravitreally administered curcumin-loaded nanoemulsions not only prevent but actively reverse lens opacity, positioning them as a promising non-surgical therapeutic approach for cataract treatment. Full article

Reliable indoor localization is required for automated guided vehicles (AGVs), robot validation, and industrial digital-twin applications, but ultrasonic positioning can degrade sharply when acoustic visibility changes. This paper evaluates Marvelmind Super-Beacon localization in controlled laboratory experiments involving both AGV tracking and UR10 robot-arm positioning. The non-inverse architecture (NIA) and inverse architecture (IA) configurations are included as parallel validation scenarios to assess the robustness of the proposed mitigation framework across different Marvelmind deployment modes. The baseline analysis identifies the dominant acoustic failure modes, including multipath-induced scatter, crossover-zone handover jumps, update-rate degradation, complete non-line-of-sight (NLoS) outages, and height-dependent 3D jitter. To mitigate these effects, an embedded ultrasonic–inertial pipeline is implemented on an ESP32-S3-WROOM-1 module. The system combines UART packet validation, interrupt-driven ICM-20948 inertial acquisition at 500 Hz, sliding-window kinematic outlier rejection, and a 15-state error-state Kalman filter (ESKF). The embedded estimator logic is designed to maintain motion continuity during intermittent or corrupted acoustic positioning while reintroducing validated ultrasonic absolute corrections. Using recorded AGV and UR10 datasets, mitigation performance was quantitatively assessed through a firmware-consistent replay of the recorded measurements, using the same gating, inertial propagation, and measurement-update logic as the real-time ESP32-S3 implementation. Across ten trials per configuration, the replay-based trial-mean RMSE in the 2D AGV scenarios decreased from 101.2–104.1 mm for raw ultrasonic data to 47.2–48.7 mm after fusion, while peak failure-interval errors were reduced by 64.2–65.7%. In the 3D UR10 scenarios, replay-based trial-mean RMSE decreased from 157.6–158.4 mm to 80.2–80.5 mm, and peak height-sensitive 3D errors were reduced by 58.8–60.0%. The results demonstrate the feasibility of embedded ultrasonic–inertial robustness enhancement for localization in controlled laboratory AGV and robot-arm scenarios. While the proposed approach shows promising performance under the investigated conditions, further validation is required before extending the conclusions to larger-scale and dynamically changing industrial environments. Full closed-loop online robot localization and control based directly on the fused localization output remain subjects for future investigation. Full article

Ceramic Matrix Composite (CMC) are widely used in aerospace due to the advantages such as high-temperature resistance and lightweight properties. Detecting defects within these materials is crucial for ensuring the safety of corresponding structures. In this paper, a finite element model of CMC model for layered structures is established for the ultrasonic non-destructive testing. Based on the computed tomography (CT) scan images and porosity of the material, a randomly distributed pore model is constructed to investigate the effect of pores on the ultrasonic signals. Random pores are also introduced in the simulation to ensure that the model corresponds as closely as possible to reality. Moreover, the feasibility of utilizing air-coupled ultrasonic excitation to generate specific frequency Lamb waves is verified. The effect of pore presence on the signal propagation is analyzed, and the effects of layered structures at different positions and lengths on the signal propagation are investigated. The results demonstrate that the Lamb waves with a specified frequency can be excited using the method described in this paper, and the presence of pores and delamination defects can affect the propagation of the Lamb wave in CMC, in which the signal attenuation can reach up to 7.6 dB. Full article

The reliable evaluation of the interfacial bonding quality of steel structures strengthened with carbon fiber-reinforced polymer (CFRP) is crucial to ensuring the long-term service safety of the structures. Focusing on the active and passive detection methods based on piezoelectric sensing, this paper takes numerical simulation as the core research method to provide theoretical verification and mechanism explanation for subsequent key experiments, thus supporting the accurate detection of interfacial damage in CFRP–steel plate joints. A 3D piezoelectric–structural coupling finite element model and a 2D ultrasonic guided wave propagation finite element model were established via COMSOL Multiphysics 6.2 to systematically simulate the electromechanical response characteristics of three piezoelectric sensors (PMN-PT, PZT and PVDF). The research focused on analyzing the potential output and voltage–load response of the three sensors, and simultaneously explored the propagation laws and energy evolution mechanisms of ultrasonic waves in the presence of different debonding damages and groove defects in CFRP plates. The simulation results show that the PMN-PT sensor exhibits the optimal detection performance, with its peak potential output reaching 2.66 times that of the PZT sensor and 4.69 times that of the PVDF sensor, with a load sensitivity of 484.3 mV/kN. In the ultrasonic active detection of interfacial debonding damage, the first-wave amplitude has a significant positive correlation with the debonding length, and this characteristic is attributed to the strong reflection effect and energy accumulation caused by the acoustic impedance mismatch at the CFRP–air interface. For the internal groove defects in CFRP plates, the simulation clarifies that the increase in groove length leads to energy trapping in the plate, while the increase in groove depth intensifies ultrasonic wave energy reflection. The numerical simulation results were compared and verified with data from companion experiments conducted by the authors’ team, showing a high degree of consistency, which confirms the accuracy and reliability of the established finite element models. Meanwhile, the physical essence of damage detection is elucidated from the perspective of wave theory, providing a solid numerical analysis foundation and theoretical support for the intelligent monitoring of interfacial damage in CFRP–steel structures. Full article

Moth auditory systems, evolutionarily adapted and structurally diverse with ultrasonic sensitivity, underpin the development of acoustic-based pest management strategies. Here, based on hypotheses derived from previous findings, we tested whether and how audible sounds (music, bird chirp, noise; 0.25–1 kHz, 80/120 dB) affect the development, survival, behavior and fecundity, as well as the molecular responses, using both short-term and long-term exposure (three successive generations) experimental designs. Behavioral assays showed dose-specific responses: high-intensity (120 dB) bird chirp and noise suppressed larval and adult activity, while low-intensity (80 dB) counterparts promoted larval crawling. Long-term exposure revealed that bird chirp and noise significantly impaired fitness, reducing larval/pupal body weight, pupation/eclosion rates, and egg hatching rate, with 120 dB noise exerting the strongest effects; 80 dB music showed neutral or positive impacts. Transcriptomic analysis identified 71–235 differentially expressed genes (DEGs) across treatment groups, with bird chirp and noise inducing more downregulated DEGs related to metabolism, immunity, and development. Notably, all cuticle-related DEGs in the 80 dB noise group and 53.2% in the 120 dB noise group were upregulated, suggesting stress-induced cuticular remodeling. GO/KEGG enrichment indicated distinct patterns: 80 dB music, bird chirp and 120 dB noise groups only had downregulated DEGs enriched in certain terms/pathways, mainly associated with cellular components; the 80 dB noise group had upregulated DEGs enriched in sensory, cuticle, metabolism and longevity-related terms/pathways, and downregulated DEGs in metabolism and human disease-related terms/pathways. Analysis of the expression patterns of all the longevity pathway-related genes suggested that sound stress induces lifespan regulation in this insect. These findings clarify S. frugiperda’s multidimensional responses to audible sound, providing a foundation for sound-based pest management. Full article

To address the challenge of detecting internal defects in medium-thick titanium alloy laser welds, a combined simulation and experimental study on ultrasonic testing was conducted. A finite element model employing a 5 MHz shear wave angle transducer for inspecting titanium alloy welds was established. An ultrasonic testing system was developed, incorporating a DPR300 pulser-receiver (JSR Ultrasonics, Pittsford, NY, USA) and an MSO5204 oscilloscope (RIGOL, Suzhou, China), and was calibrated using standard reference blocks. The inspection results for four prefabricated internal defects at various depths demonstrated that all defects were effectively detected, with the minimum detectable equivalent defect size reaching 1 mm. The measured signal-to-noise ratio (SNR) averaged 17.6 dB, validating the high sensitivity of the proposed system. The mean absolute error for defect localization was 0.438 mm, achieving a positioning accuracy better than 0.5 mm. This study indicates that the pro-posed method enables effective detection and accurate localization of internal defects in titanium alloy laser welds, providing critical technical support for laser welding quality assessment. Full article

While Saccharomyces cerevisiae (baker’s yeast) offers a safe, non-animal source of chitin-glucan (CG), its potential as a functional cosmetic ingredient has been overshadowed by industrial sources like Aspergillus niger. This study advances the existing literature by establishing a critical structure–function relationship for CG micro/nano particles extracted via three physical disruption methods: ultrasonic bath, ultrasonic probe, and autoclaving. The obtained CG was systematically characterized by physicochemical and biological tests. A significant trade-off was identified: while autoclaving (40 min) resulted in lower mass yield compared to ultrasonication, it produced particles with the highest crystallinity, an enriched chitin/glucan ratio, and the smallest particle size (~70% of particles with mean diameter of 480 ± 33 nm). Structurally, these sub-micron particles demonstrated superior colloidal stability and a physical “barrier effect” for sustained hydration, outperforming the amorphous structures typically associated with mild extraction. The anti-wrinkle efficacy was validated through a specific “triad” mechanism: (1) the insoluble 3D network ensures prolonged water retention, (2) the particles exhibit robust free radical scavenging activity (~67%), and (3) most notably, the specific nano-structure significantly upregulated Collagen Type I-α1 expression in human dermal fibroblasts (HDF) and human skin fibroblasts (HSF), surpassing commercial chitin controls. These findings prove that the extraction-induced nano-structure, rather than mass yield, is the determinant factor for bioactivity, positioning S. cerevisiae CG as a high-performance, multi-target ingredient for anti-aging formulations. Full article

Extensively drug-resistant (XDR) bacteria pose a serious global public health threat due to their high levels of resistance to multiple classes of antibiotics. This study aimed to characterize bacterial isolates obtained from clinical samples, evaluate their antibiotic resistance patterns, and investigate the antimicrobial and anticancer potential of essential oils (EOs) and their nanoemulsions (NEs). A total of 175 bacterial isolates were collected from various clinical sources, identified, and subjected to antibiotic susceptibility testing using both conventional methods and the VITEK^® 2 system. Among these, nine isolates were identified as extensively drug-resistant. Among the tested EOs, carvacrol exhibited the strongest antibacterial activity, with minimum inhibitory concentrations (MICs) ranging from 14 to 35 µg/mL, compared to 8 to 19 µg/mL for meropenem. To enhance its stability and efficacy, carvacrol nanoemulsions (CANE) were prepared via ultrasonication and characterized using zeta potential measurements, which indicated a positive surface charge of +14.2 mV, while dynamic light scattering (DLS) analysis revealed a narrow size distribution with a mean hydrodynamic diameter of 411.3 nm. High-resolution transmission electron microscopy (HR-TEM) showed spherical droplets ranging from 18 to 144 nm in size, with an average diameter of 69 ± 28 nm. The nanoemulsion formulation significantly enhanced antibacterial activity, with MICs reduced to 11 ± 0.0–23 ± 0.21 µg/mL, compared to 14 ± 0.13–35 ± 0.11 µg/mL for pure carvacrol oil. Gas chromatography–mass spectrometry (GC–MS) analysis identified major active constituents, including thymol, methoxyphenyl, estragole, and D-limonene, which are likely contributors to the observed antimicrobial and anticancer effects. In addition, carvacrol nanoemulsions demonstrated potent cytotoxicity against multiple human cancer cell lines (HepG2, MCF-7, PC-3, and Caco-2) while showing minimal toxicity toward normal cells. Confocal microscopy further confirmed apoptosis induction in treated cancer cells, suggesting a mitochondria-mediated apoptotic pathway. In conclusion, this study highlights the strong therapeutic potential of essential oils—particularly carvacrol and its nanoemulsion formulation—as dual-action agents exhibiting broad-spectrum antibacterial activity against XDR pathogens and selective cytotoxicity against cancer cells. Full article

Location-based services (LBSs) and positioning systems have spread worldwide due to the emergence of Internet of Things (IoT) and other application domains that require real-time estimation of the position of a person, tag, or asset in general in order to provide users with services and apps with added value. Whereas Global Navigation Satellite Systems (GNSSs) are well-established solutions outdoors, positioning is still an open challenge indoors, where different sensory technologies may be considered for that purpose, such as radio frequency, infrared, or ultrasounds, among others. With regard to ultrasonic systems, previous works have already developed indoor positioning systems capable of achieving accuracies in the range of centimeters but limited to a few square meters of coverage and severely affected by the Doppler effect coming from moving targets, which significantly degrades the overall positioning performance. Furthermore, the actual bandwidth available in commercial transducers often constrains the ultrasonic transmission, thus reducing the position accuracy as well. In this context, this work proposes a novel excitation and processing method for an ultrasonic positioning system, which significantly improves the transmission capabilities between an emitter and a receiver. The proposal employs a superheterodyne approach, enabling simultaneous transmission and reception of signals across multiple channels. It also adapts the bandwidths and central frequencies of the transmitted signals to the specific bandwidth characteristics of available transducers, thus optimizing the system performance. Binary spread spectrum sequences are utilized within a multicarrier modulation framework to ensure robust signal transmission. The ultrasonic signals received are then processed using filter banks and matched filtering techniques to determine the Time Differences of Arrival (TDoA) for every transmission, which are subsequently used to estimate the target position. The proposal has been modeled and successfully validated using a digital twin. Furthermore, experimental tests on the prototype have also been conducted to evaluate the system’s performance in real scenarios, comparing it against classical approaches in terms of ranging distance, signal-to-noise ratio (SNR), or multipath effects. Experimental validation demonstrates that the proposed narrowband scheme reliably operates at distances up to 40 m, compared to the 34 m limit of conventional wideband approaches. Ranging errors remain below 3 cm at 40 m, whereas the wideband scheme exhibits errors exceeding 8 cm. Furthermore, simulation results show that the narrowband scheme maintains stable operation at SNR as low as $-32$ dB, whereas the wideband one only achieves up to $-17$ dB, highlighting the significant performance advantages of the proposed approach in both experimental and simulated scenarios. Full article

This paper presents numerical and experimental investigations of acoustic agglomeration of solid particles in a chamber with three overlapping ultrasonic fields. The simultaneous generation of these fields produces an interference pattern with a greater number of pressure nodes, more evenly distributed across the chamber cross section. The chamber design is based on three piezoelectric transducers equipped with disc-shaped acoustic radiators and a cylindrical body. The transducers are evenly positioned around the cylinder’s horizontal axis of symmetry. Numerical simulations of their acoustic characteristics showed that, at a resonance frequency of 49.71 kHz and with a 125 V_p-p excitation, the system can generate up to 146 dB sound pressure level. The predicted interference field pattern indicated a high density of alternating pressure nodes across the chamber. Experimental results confirmed that, at a resonance frequency of 48.85 kHz and with the same excitation signal, the sound pressure in the chamber reached 144.8 dB. Particle agglomeration tests demonstrated effective performance: ultrafine particles in the 191–294 nm range decreased by 31.2%, while particles in the 0.75–1 µm range increased by up to 52.9%. These findings confirm the strong potential of interference acoustic fields for enhancing particle agglomeration and supporting air purification applications. Full article

This study addresses the high-precision requirements for liquid-level detection of propellants in aerospace rockets and optimizes the design parameters of an ultrasonic liquid-level measurement system based on the response surface method (RSM). Meanwhile, a quantitative correlation model between multiple physical parameters and output voltage is established through theoretical derivation. Firstly, the effects of piezoelectric ceramic sheet diameter, ultrasonic frequency, excitation voltage and liquid temperature on the output voltage are investigated. The optimum conditions were obtained by one-way tests, where the output voltage reached its maximum when the diameter of the piezoelectric ceramic sheet was 15 mm and the frequency was 1 MHz. The excitation voltage was positively correlated with the output voltage. Elevated liquid temperature enhanced the echo amplitude. The influence of law remained consistent across different liquid levels. Subsequently, under the liquid level of 12 cm (half-full operating condition), a three-factor, three-level response surface methodology (RSM) analysis experiment was conducted, focusing on three factors that significantly affect energy transfer efficiency: piezoelectric ceramic sheet diameter (D), ultrasonic frequency (f), and liquid temperature (T). The best parameter combination was obtained through model optimization: D = 14.773 mm, f = 0.878 MHz, T = 33.661 °C. The predicted U-value was 8.976 V. The validation experiments demonstrated that the error rates between the measured average voltage values and the predicted values under different liquid levels were all <1%, and the coefficient of variation (CV) of the output signal was reduced to 0.9%. This not only meets the error requirements for aerospace liquid-level measurement but also verifies the reliability of the optimized model. This study significantly enhances the output signal stability and measurement accuracy, providing support for the liquid-level detection of aerospace propellants and high-precision liquid-level measurement in industrial applications. Full article

Vibro-thermography is an effective nondestructive testing technique for detecting closed defects like cracks and delaminations through frictional heat generated under ultrasonic excitation. However, its accuracy is often reduced by standing wave patterns that create periodic temperature artifacts in non-defective areas, leading to false positives. To overcome this, we propose an image processing approach using 2D Fourier Transform (2D-FFT) to reduce SW-induced patterns in the frequency domain. This enhances defect visibility by suppressing unwanted heat signatures. The method is evaluated on a cracked PMMA plate and a hollow tube of the same material. Full article

In order to measure the depth profile of the heat-treated case-hardened layer of linear guides, this paper proposes a B-scan imaging and 3D visualization method for detecting the depth profile of the case-hardened layer of linear guides based on the ultrasonic transverse wave backscattering technology. Firstly, by analyzing the generation mechanism of ultrasonic transverse waves and their advantages in material detection, and combining the differences in metallographic structure and hardness properties between the case-hardened layer and the base material, an ultrasonic transverse wave backscattering model for the case-hardened layer of linear guides was established. Then, an ultrasonic transverse wave detection experiment for the GH20 linear guide was designed and carried out to obtain the A-scan signals of the case-hardened layer depth at different positions on the cross-section of the linear guide. Finally, the A-scan signals obtained from the detection were used to generate the B-scan image of the case-hardened layer depth profile, and the 3D visualization of the case-hardened layer of the linear guide was achieved using Python and VTK tools. The experimental results show that the error between the measurement results of ultrasonic transverse waves and those of the metallographic method is 0.063 mm, and the detection results are within the allowable error range. This research provides an efficient, intuitive, and reliable technical method for detecting the depth of the case-hardened layer of linear guides in the industrial field. Full article

Due to the increasing interest in probiotic components to improve quality of life, this study aimed to investigate the bioactive potential of a paraprobiotic derived from a selected strain of probiotic lactic acid bacteria (Lacticaseibacillus paracasei MIUG BL80) on Saccharomyces cerevisiae MIUG D129, used as a cellular model organism. The paraprobiotics (inactivated cells) were obtained through a combination of ultrasonic and conventional heat treatments. It was observed that adding more than 10 % of the paraprobiotic suspension to the cultivation medium of yeast had a positive influence on the metabolic activity of the starter culture (S. cerevisiae). The specific growth rate increased from 0.227 in the control sample to 0.507 in the sample with 15% paraprobiotic supplementation (S3), while the generation time decreased from 4.403 h to 1.972 h. This suggests that adding probiotics to the cultivation medium enhances the metabolic performance of S. cerevisiae cells. Additionally, an improvement in yeast cell viability during wet biomass storage (from 48 h to 14 days at 4 °C) was observed. Full article

Tartary buckwheat hulls, a phenolic-rich by-product of buckwheat processing, offer great potential for resource utilization. In this study, ultrasound-assisted enzymatic extraction with two temperatures (40 °C and 50 °C) was employed to obtain phenolics from Tartary buckwheat hulls. Compared with the traditional extraction method (207 mg/100 g), ultrasound-assisted enzymatic extraction increased the total phenolic yield by 91.3% at 50 °C. Numerical simulations based on Fick’s law indicated that enzyme pretreatment concentration positively correlated with the effective diffusion coefficient ($D_e$), which increased from 9.15 × 10⁻⁷ to 2.00 × 10⁻⁶ m²/s at 40 °C. Meanwhile, the neuro-fuzzy inference system (ANFIS) successfully predicted the extraction yield under various ultrasonic conditions (R² > 0.98). Regarding quantitative analysis of phenolic compounds in extracts, the results revealed that catechins and epicatechins were the most abundant in Tartary buckwheat hull. Additionally, phenolic acids rapidly diffused at higher temperatures (50 °C), and flavonoids were highly sensitive to temperature and enzyme synergy. Phenolic extracts exhibit significant potential for value-added applications in food processing, particularly in improving antioxidative stability, prolonging shelf life. This study provides a theoretical basis for green, efficient phenolic extraction from plant residues. Full article