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Keywords = PA resonant enhancers

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16 pages, 1308 KiB  
Review
Multimodality Imaging in Aldosterone-Induced Cardiomyopathy: Early Detection and Prognostic Implications
by Francesca Zoccatelli, Gabriele Costa, Matteo Merlo, Francesca Pizzolo, Simonetta Friso and Luigi Marzano
Diagnostics 2025, 15(15), 1896; https://doi.org/10.3390/diagnostics15151896 - 29 Jul 2025
Viewed by 412
Abstract
Primary aldosteronism (PA), the most common cause of secondary hypertension, is increasingly recognized as an independent driver of adverse cardiac remodeling, mediated through mechanisms beyond elevated blood pressure alone. Chronic aldosterone excess leads to myocardial fibrosis, left ventricular hypertrophy, and diastolic dysfunction via [...] Read more.
Primary aldosteronism (PA), the most common cause of secondary hypertension, is increasingly recognized as an independent driver of adverse cardiac remodeling, mediated through mechanisms beyond elevated blood pressure alone. Chronic aldosterone excess leads to myocardial fibrosis, left ventricular hypertrophy, and diastolic dysfunction via mineralocorticoid receptor activation, oxidative stress, inflammation, and extracellular matrix dysregulation. These changes culminate in a distinct cardiomyopathy phenotype, often underrecognized in early stages. Multimodality cardiac imaging, led primarily by conventional and speckle-tracking echocardiography, and complemented by exploratory cardiac magnetic resonance (CMR) techniques such as T1 mapping and late gadolinium enhancement, enables non-invasive assessment of structural, functional, and tissue-level changes in aldosterone-mediated myocardial damage. While numerous studies have established the diagnostic and prognostic relevance of imaging in PA, several gaps remain. Specifically, the relative sensitivity of different modalities in detecting subclinical myocardial changes, the long-term prognostic significance of imaging biomarkers, and the differential impact of adrenalectomy versus medical therapy on cardiac reverse remodeling require further clarification. Moreover, the lack of standardized imaging-based criteria for defining and monitoring PA-related cardiomyopathy hinders widespread clinical implementation. This narrative review aims to synthesize current knowledge on the pathophysiological mechanisms of aldosterone-induced cardiac remodeling, delineate the strengths and limitations of existing imaging modalities, and critically evaluate the comparative effects of surgical and pharmacologic interventions. Emphasis is placed on early detection strategies, identification of imaging biomarkers with prognostic utility, and integration of multimodal imaging into clinical decision-making pathways. By outlining current evidence and highlighting key unmet needs, this review provides a framework for future research aimed at advancing personalized care and improving cardiovascular outcomes in patients with PA. Full article
(This article belongs to the Section Pathology and Molecular Diagnostics)
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30 pages, 34072 KiB  
Article
ARE-PaLED: Augmented Reality-Enhanced Patch-Level Explainable Deep Learning System for Alzheimer’s Disease Diagnosis from 3D Brain sMRI
by Chitrakala S and Bharathi U
Symmetry 2025, 17(7), 1108; https://doi.org/10.3390/sym17071108 - 10 Jul 2025
Viewed by 418
Abstract
Structural magnetic resonance imaging (sMRI) is a vital tool for diagnosing neurological brain diseases. However, sMRI scans often show significant structural changes only in limited brain regions due to localised atrophy, making the identification of discriminative features a key challenge. Importantly, the human [...] Read more.
Structural magnetic resonance imaging (sMRI) is a vital tool for diagnosing neurological brain diseases. However, sMRI scans often show significant structural changes only in limited brain regions due to localised atrophy, making the identification of discriminative features a key challenge. Importantly, the human brain exhibits inherent bilateral symmetry, and deviations from this symmetry—such as asymmetric atrophy—are strong indicators of early Alzheimer’s disease (AD). Patch-based methods help capture local brain changes for early AD diagnosis, but they often struggle with fixed-size limitations, potentially missing subtle asymmetries or broader contextual cues. To address these limitations, we propose a novel augmented reality (AR)-enhanced patch-level explainable deep learning (ARE-PaLED) system. It includes an adaptive multi-scale patch extraction network (AMPEN) to adjust patch sizes based on anatomical characteristics and spatial context, as well as an informative patch selection algorithm (IPSA) to identify discriminative patches, including those reflecting asymmetry patterns associated with AD; additionally, an AR module is proposed for future immersive explainability, complementing the patch-level interpretation framework. Evaluated on 1862 subjects from the ADNI and AIBL datasets, the framework achieved an accuracy of 92.5% (AD vs. NC) and 85.9% (AD vs. MCI). The proposed ARE-PaLED demonstrates potential as an interpretable and immersive diagnostic aid for sMRI-based AD diagnosis, supporting the interpretation of model predictions for AD diagnosis. Full article
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16 pages, 1441 KiB  
Article
Effects of Tricholoma Matsutake-Derived Insoluble Fiber on the Pasting Properties, Structural Characteristics, and In Vitro Digestibility of Rice Flour
by Qin Qiu, Jing Chen, Dafeng Sun, Yongshuai Ma, Yujie Zhong, Junjie Yi, Ming Du, Man Zhou and Tao Wang
Foods 2025, 14(12), 2143; https://doi.org/10.3390/foods14122143 - 19 Jun 2025
Viewed by 498
Abstract
This study explores the effects of Tricholoma matsutake-derived insoluble dietary fiber (TMIDF) on the pasting behavior, structural properties, and in vitro digestibility of rice flour. The incorporation of 5% TMIDF significantly increased the peak viscosity (from 2573.21 to 2814.52 mPa·s) by competitively [...] Read more.
This study explores the effects of Tricholoma matsutake-derived insoluble dietary fiber (TMIDF) on the pasting behavior, structural properties, and in vitro digestibility of rice flour. The incorporation of 5% TMIDF significantly increased the peak viscosity (from 2573.21 to 2814.52 mPa·s) by competitively adsorbing water and forming a dense transient network, while simultaneously reducing the final viscosity (from 1998.27 to 1886.18 mPa·s) by inhibiting amylose recrystallization. Multi-scale structural analyses revealed that TMIDF enhanced V-type crystallinity and limited enzyme access via a porous fibrous matrix. Fourier-transform infrared spectroscopy and low-field nuclear magnetic resonance analyses confirmed that hydrogen bonding and water redistribution were key interaction mechanisms. TMIDF significantly lowered in vitro starch digestibility and increased resistant starch content by 16% (from 14.36% to 30.94%) through synergistic effects, including physical encapsulation of starch granules, formation of enzyme-resistant amylose-lipid complexes, and α-amylase inhibition (31.08%). These results demonstrate that TMIDF possesses a unique multi-tiered modulation mechanism, involving structural optimization, enzyme suppression, and diffusion control, which collectively surpasses the functional performance of conventional plant-derived insoluble dietary fibers. This research establishes a theoretical basis for applying fungal insoluble dietary fibers to develop low glycemic index functional foods, highlighting their dual role in improving processing performance and nutritional quality. Full article
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21 pages, 564 KiB  
Article
Sounding Identity: A Technical Analysis of Singing Styles in the Traditional Music of Sub-Saharan Africa
by Alfred Patrick Addaquay
Arts 2025, 14(3), 68; https://doi.org/10.3390/arts14030068 - 16 Jun 2025
Viewed by 991
Abstract
This article presents an in-depth examination of the technical and cultural dimensions of singing practices within the traditional music of sub-Saharan Africa. Utilizing an extensive body of theoretical and ethnomusicological research, comparative transcription, and culturally situated observation, it presents a comprehensive framework for [...] Read more.
This article presents an in-depth examination of the technical and cultural dimensions of singing practices within the traditional music of sub-Saharan Africa. Utilizing an extensive body of theoretical and ethnomusicological research, comparative transcription, and culturally situated observation, it presents a comprehensive framework for understanding the significance of the human voice in various performance contexts. The study revolves around a tripartite model—auditory clarity, ambiguous auditory clarity, and occlusion—that delineates the varying levels of audibility of vocal lines amidst intricate instrumental arrangements. The article examines case studies from West, East, and Southern Africa, highlighting essential vocal techniques such as straight tone, nasal resonance, ululation, and controlled (or delayed) vibrato. It underscores the complex interplay between language, melody, and rhythm in tonal languages. The analysis delves into the influence of sound reinforcement technologies on vocal presence and cultural authenticity, positing that PA systems have the capacity to either enhance or disrupt the equilibrium between traditional aesthetics and modern requirements. This research is firmly rooted in a blend of African and Western theoretical frameworks, drawing upon the contributions of Nketia, Agawu, Chernoff, and Kubik. It proposes a nuanced methodology that integrates technical analysis with cultural significance. It posits that singing in African traditional music transcends mere expression, serving as a vessel for collective memory, identity, and the socio-musical framework. The article concludes by emphasizing the enduring strength and flexibility of African vocal traditions, illustrating their capacity for evolution while preserving fundamental communicative and artistic values. Full article
20 pages, 5421 KiB  
Article
Effects of Water-Soluble and Fat-Soluble Antioxidant Combinations in Oil-in-Water Emulsions on the Oxidative Stability of Walnut Kernels
by Ying Jing, Rongrong Wang, Huiliang Wen and Jianhua Xie
Foods 2025, 14(11), 1967; https://doi.org/10.3390/foods14111967 - 31 May 2025
Viewed by 637
Abstract
Walnuts, which are rich in unsaturated fatty acids (UFAs), are highly susceptible to oxidation during storage, leading to quality degradation. Consequently, antioxidant technologies for the oxidative stability of walnuts have garnered significant attention. The addition of antioxidants remains the most cost-effective and efficient [...] Read more.
Walnuts, which are rich in unsaturated fatty acids (UFAs), are highly susceptible to oxidation during storage, leading to quality degradation. Consequently, antioxidant technologies for the oxidative stability of walnuts have garnered significant attention. The addition of antioxidants remains the most cost-effective and efficient method currently available, with synergistic effects enhancing the efficacy of mixed antioxidant combinations compared to single antioxidants. In this study, four lipophilic antioxidants—tert-butylhydroquinone (TBHQ), butylated hydroxytoluene (BHT), dilauryl thiodipropionate (DLTP), and propyl gallate (PG)—were paired with four hydrophilic antioxidants—rosemary extract (RE), phytic acid (PA), tea polyphenols (TPs), and sodium ascorbate (SA)—resulting in 16 experimental groups to investigate synergistic effects. The effects of water-soluble and fat-soluble antioxidant combinations on walnut oxidation were systematically evaluated through peroxide value, acid value, thiobarbituric acid reactive substances, and DPPH radical scavenging capacities. Additionally, fatty acid composition analysis was employed to assess the preservation of beneficial UFAs. Mechanistic insights were obtained via thermogravimetric analysis and electron paramagnetic resonance spectroscopy. Notably, two combinations, 0.03% TBHQ + 0.03% TPs (w/w) and 0.03% DLTP + 0.03% SA (w/w), exhibited good oxidative stability of walnut kernels. These formulations demonstrated superior antioxidant performance and effectively inhibited oxidative pathways while maintaining UFA integrity, demonstrating their potential as advanced preservation strategies for lipid-rich foods. Full article
(This article belongs to the Special Issue Preservation and Shelf Life Extension of Food Products)
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15 pages, 3559 KiB  
Article
Evaluation of the Shear Modulus Degradation by a Modified Hyperbolic Function for Unconventional Geomaterials
by Hernán Patiño, Fausto Molina-Gómez and Rubén Ángel Galindo-Aires
Geosciences 2025, 15(5), 176; https://doi.org/10.3390/geosciences15050176 - 14 May 2025
Cited by 1 | Viewed by 400
Abstract
The characterisation of shear modulus degradation is essential for understanding the dynamic response of geomaterials. This article presents a modified hyperbolic model that evaluates the shear modulus for various angular strains and effective confining stresses. The model has been calibrated and validated using [...] Read more.
The characterisation of shear modulus degradation is essential for understanding the dynamic response of geomaterials. This article presents a modified hyperbolic model that evaluates the shear modulus for various angular strains and effective confining stresses. The model has been calibrated and validated using data from 108 resonant-column tests conducted on three different types of tailings from the Riotinto mines in Huelva, Spain. These tests were conducted on saturated samples that were consolidated at effective stresses of 50, 100, 150, 200, 250, and 300 kPa, accompanied by various combinations of torsional excitations to induce distinct angular strains. The results show that the hyperbolic model effectively predicts the shear modulus degradation in unconventional geomaterials, characterising the shear modulus under the testing conditions for the three types of Riotinto tailings. Additionally, the model can identify and confirm both the initial (or maximum) shear modulus and the reference angular strain as functions of the effective confining stress. The findings and model presented in this article contribute to enhancing the stability and resilience of geotechnical structures, including tailings storage facilities, that are subjected to dynamic loading, leading to safer designs and improved infrastructure performance. Full article
(This article belongs to the Section Geomechanics)
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14 pages, 4011 KiB  
Article
The Optimization of a T-Cell Resonator: Towards Highly Sensitive Photoacoustic Spectroscopy for Noninvasive Blood Glucose Detection
by Thasin Mohammad Zaman, Md Rejvi Kaysir, Shazzad Rassel and Dayan Ban
Biosensors 2025, 15(4), 254; https://doi.org/10.3390/bios15040254 - 16 Apr 2025
Viewed by 565
Abstract
Noninvasive blood glucose monitoring is crucial for diabetes management, and photoacoustic spectroscopy (PAS) offers a promising solution by detecting glucose levels through human skin. However, weak acoustic signals in PAS systems require optimized resonator designs for enhanced detection sensitivity. Designing such resonators physically [...] Read more.
Noninvasive blood glucose monitoring is crucial for diabetes management, and photoacoustic spectroscopy (PAS) offers a promising solution by detecting glucose levels through human skin. However, weak acoustic signals in PAS systems require optimized resonator designs for enhanced detection sensitivity. Designing such resonators physically is complex, requiring the precise identification of critical parameters before practical implementation. This study focused on optimizing a T-shaped photoacoustic resonator using finite element modeling in a COMSOL Multiphysics environment. By systematically varying the geometric design parameters of the T-cell resonator, a maximum increase in the pressure amplitude of 12.76 times with a quality factor (Q-factor) of 47.5 was achieved compared to the previously designed reference acoustic resonator. This study took a significant step forward by identifying key geometric parameters that influence resonator performance, paving the way for more sensitive and reliable noninvasive glucose monitoring systems. Full article
(This article belongs to the Section Optical and Photonic Biosensors)
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18 pages, 10372 KiB  
Article
Acoustic Fabry–Perot Resonance Detector for Passive Acoustic Thermometry and Sound Source Localization
by Yan Yue, Zhifei Dong and Zhi-mei Qi
Sensors 2025, 25(8), 2445; https://doi.org/10.3390/s25082445 - 12 Apr 2025
Viewed by 461
Abstract
Acoustic temperature measurement (ATM) and sound source localization (SSL) are two important applications of acoustic sensors. The development of novel acoustic sensors capable of both ATM and SSL is an innovative research topic with great interest. In this work, an acoustic Fabry-Perot resonance [...] Read more.
Acoustic temperature measurement (ATM) and sound source localization (SSL) are two important applications of acoustic sensors. The development of novel acoustic sensors capable of both ATM and SSL is an innovative research topic with great interest. In this work, an acoustic Fabry-Perot resonance detector (AFPRD) and its cross-shaped array were designed and fabricated, and the passive ATM function of the AFPRD and the SSL capability of the AFPRD array were simulated and experimentally verified. The AFPRD consists of an acoustic waveguide and a microphone with its head inserted into the waveguide, which can significantly enhance the microphone’s sensitivity via the FP resonance effect. As a result, the frequency response curve of AFPRD can be easily measured using weak ambient white noise. Based on the measured frequency response curve, the linear relationship between the resonant frequency and the resonant mode order of the AFPRD can be determined, the slope of which can be used to calculate the ambient sound velocity and air temperature. The AFPRD array was prepared by using four bent acoustic waveguides to expand the array aperture, which combined with the multiple signal classification (MUSIC) algorithm can be used for distant multi-target localization. The SSL accuracy can be improved by substituting the sound speed measured in real time into the MUSIC algorithm. The AFPRD’s passive ATM function was verified in an anechoic room with white noise as low as 17 dB, and the ATM accuracy reached 0.4 °C. The SSL function of the AFPRD array was demonstrated in the outdoor environment, and the SSL error of the acoustic target with a sound pressure of 35 mPa was less than 1.2°. The findings open up a new avenue for the development of multifunctional acoustic detection devices and systems. Full article
(This article belongs to the Special Issue Recent Advances in Optical and Optoelectronic Acoustic Sensors)
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15 pages, 20353 KiB  
Article
Study on the Preparation and Properties of Thermally Conductive Semi-Aromatic Heat-Resistant PA5T-CO-10T/ Hexagonal Boron Nitride Composites
by Bingxiao Liu, Yunzhen Zhu, Chen Yang, Liqun Ma, Fuchun Zhang, Mingzheng Hao, Zhongqiang Wang, Lizhen Bai, Jiale An and Dongqi Xiao
Polymers 2025, 17(8), 1031; https://doi.org/10.3390/polym17081031 - 10 Apr 2025
Viewed by 432
Abstract
In this paper, we report a novel thermally conductive semi-aromatic heat-resistant PA5T-CO-10T/hexagonal boron nitride (PA5T-CO-10T/BN) composite, based on as-synthesized PA5T-CO-10T, which is a copolymer of poly (pentamethylene terephthalamide) (PA5T) and poly (decamethylene terephthalamide) (PA10T). We confirmed the structure of PA5T-CO-10T through a nuclear [...] Read more.
In this paper, we report a novel thermally conductive semi-aromatic heat-resistant PA5T-CO-10T/hexagonal boron nitride (PA5T-CO-10T/BN) composite, based on as-synthesized PA5T-CO-10T, which is a copolymer of poly (pentamethylene terephthalamide) (PA5T) and poly (decamethylene terephthalamide) (PA10T). We confirmed the structure of PA5T-CO-10T through a nuclear magnetic resonance carbon spectrometer (13C-NMR). The differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) results indicate that PA5T-CO-10T demonstrates a processing window (greater than 90 °C) which is suitable for melt processing and injection molding. Moreover, the PA5T-CO-10T composites with different BN contents were tested by scanning electron microscopy (SEM), a thermal conductivity meter, a rotational rheometer and X-ray diffraction (XRD). The results indicate that as the content of h-BN increases, the thermal conductivity of the PA5T-CO-10T/BN composites is significantly enhanced. When the mass of h-BN reaches 30 wt%, the thermal conductivity of the composite material is 2.5 times that of the original matrix resin. Simultaneously, there is a notable upward trend observed in the storage modulus, loss modulus, complex viscosity and orientation degree of h-BN. This is attributed to the high thermal conductivity and the high orientation degree of h-BN, which ensure the continuous enhancement of the material’s thermal conductivity. Additionally, the introduction of h-BN enhances the degree of connection between the material’s molecular chains. PA5T-CO-10T/BN possesses excellent heat resistance and thermal conductivity, presenting significant application prospects in the fields of electronics, electrical appliances and automobiles. Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites II)
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12 pages, 2631 KiB  
Article
Exciton-Resonance-Enhanced Two-Photon Absorption in Three-Dimensional Hybrid Organic–Inorganic Perovskites
by Xing Ran, Xin Xiang, Feng Zhou and Shunbin Lu
Photonics 2025, 12(3), 261; https://doi.org/10.3390/photonics12030261 - 13 Mar 2025
Cited by 1 | Viewed by 782
Abstract
Three-dimensional (3D) hybrid organic–inorganic perovskites (HOIPs) have attracted tremendous interest due to strong excitonic effects and large optical nonlinearities. Taking the advantages, 3D HOIPs show great potential for applications in excitonic and nonlinear devices. However, understanding the relevant mechanisms of exciton-associated nonlinear optical [...] Read more.
Three-dimensional (3D) hybrid organic–inorganic perovskites (HOIPs) have attracted tremendous interest due to strong excitonic effects and large optical nonlinearities. Taking the advantages, 3D HOIPs show great potential for applications in excitonic and nonlinear devices. However, understanding the relevant mechanisms of exciton-associated nonlinear optical phenomena in 3D perovskites is still challenging. Here, we apply the quantum perturbation theory to calculate the exciton-associated degenerate 2PA spectra of 3D HOIPs. The calculated 2PA spectra of twelve 3D HOIPs are predicted to exhibit resonance peaks at both the sub-band and band edges. The exciton-resonance-associated 2PA coefficients are at least one order of magnitude larger than those of band-to-band transitions and are comparable to those of low-dimensional perovskites. To validate our model, we carried out measurements of the static light-intensity-dependent transmission on MAPbBr3 single crystals. Enhancements of 2PA coefficients are predicted theoretically and observed experimentally with a resonant peak at 1100 nm, indicating intrinsic two-photon transitions to excitonic states in MAPbBr3 single crystals. Full article
(This article belongs to the Special Issue Novel Two-Dimensional Materials Based on Nonlinear Photonics)
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26 pages, 15690 KiB  
Article
Testing Small-Strain Dynamic Characteristics of Expanded Polystyrene Lightweight Soil: Reforming the Teaching of Engineering Detection Experiments
by Ping Jiang, Xinghan Wu, Lejie Chen, Na Li and Erlu Wu
Polymers 2025, 17(6), 730; https://doi.org/10.3390/polym17060730 - 10 Mar 2025
Viewed by 566
Abstract
This study investigated the small-strain dynamic properties of expanded polystyrene (EPS) lightweight soil (ELS), a low-density geosynthetic material used to stabilize slopes and alleviate the subgrade settlement of soft soil. Resonant column tests were conducted to evaluate the effects of EPS’s granule content [...] Read more.
This study investigated the small-strain dynamic properties of expanded polystyrene (EPS) lightweight soil (ELS), a low-density geosynthetic material used to stabilize slopes and alleviate the subgrade settlement of soft soil. Resonant column tests were conducted to evaluate the effects of EPS’s granule content (20–60%), confining pressures (50 kPa, 100 kPa, and 200 kPa), and curing ages (3 days, 7 days, and 28 days) on the dynamic shear modulus (G) of ELS within a small strain range (10−6–10−4). The results indicate that ELS exhibits a high dynamic shear modulus under small strains, which increases with higher confining pressure and longer curing age but decreases with an increasing EPS granule content and dynamic shear strain, leading to mechanical property deterioration and structural degradation. The maximum shear modulus (Gmax) ranges from 64 MPa to 280 MPa, with a 60% reduction in Gmax observed as the EPS granule content increases and increases by 11% and 55% with higher confining pressure and longer curing ages, respectively. A damage model incorporating the EPS granule content (aE) and confining pressure (P) was established, effectively describing the attenuation behavior of G in ELS under small strains with higher accuracy than the Hardin–Drnevich model. This study also developed an engineering testing experiment that integrates materials science, soil mechanics, and environmental protection principles, enhancing students’ interdisciplinary knowledge, innovation, and practical skills with implications for engineering construction, environmental protection, and experimental education. Full article
(This article belongs to the Section Polymer Applications)
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13 pages, 7247 KiB  
Article
Reconfigurable ScAlN Piezoelectric Micromachined Ultrasonic Transducer Arrays for Range Finding
by Wenling Shang, Danrui Wang, Bin Miao, Shutao Yao, Guifeng Ta, Haojie Liu, Jinyan Tao, Xiaonan Liu, Xiangyong Zhao and Jiadong Li
Micromachines 2025, 16(2), 145; https://doi.org/10.3390/mi16020145 - 26 Jan 2025
Viewed by 1035
Abstract
Due to their compact sizes, low power consumption levels, and convenient integration capabilities, piezoelectric micromachined ultrasonic transducers (PMUTs) have gained significant attention for enabling environmental sensing functionalities. However, the frequency inconsistency of the PMUT arrays often leads to directional errors with the ultrasonic [...] Read more.
Due to their compact sizes, low power consumption levels, and convenient integration capabilities, piezoelectric micromachined ultrasonic transducers (PMUTs) have gained significant attention for enabling environmental sensing functionalities. However, the frequency inconsistency of the PMUT arrays often leads to directional errors with the ultrasonic beams. Herein, we propose a reconfigurable PMUT array based on a Sc0.2Al0.8N piezoelectric thin film for in-air ranging. Each element of the reconfigurable PMUT array possesses the ability to be independently replaced, enabling matching of the required frequency characteristics, which enhances the reusability of the device. The experimental results show that the frequency uniformity of the 2 × 2 PMUT array reaches 0.38% and the half-power beam width (θ−3dB) of the array measured at 20 cm is 60°. At a resonance of 69.7 kHz, the sound pressure output reaches 7.4 Pa (sound pressure level of 108.2 dB) at 19 mm, with a reception sensitivity of approximately 11.6 mV/Pa. Ultimately, the maximum sensing distance of the array is 7.9 m, and it extends to 14.1 m with a horn, with a signal-to-noise ratio (SNR) of 19.5 dB. This research significantly expands the ranging capability of PMUTs and showcases their great potential in environmental perception applications. Full article
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15 pages, 2050 KiB  
Article
Novel Treatment of 3D-Printed Short-Carbon-Fiber-Reinforced Polyamide (3D-SCFRPA66) Using Homogeneous Low-Potential Electron Beam Irradiation (HLEBI) and Ductility Enhancement
by Eiichi Miura, Helmut Takahiro Uchida, Taisuke Okazaki, Kohei Sagawa, Michael C. Faudree, Michelle Salvia, Hideki Kimura and Yoshitake Nishi
Polymers 2024, 16(23), 3408; https://doi.org/10.3390/polym16233408 - 3 Dec 2024
Cited by 1 | Viewed by 1609
Abstract
In short-carbon-fiber-reinforced polyamide 66 articles shaped by 3D printing (3D-SCFRPA66), the interfaces between printed layers are often susceptible to damage, and the composite is excessively brittle. Therefore, a novel treatment for 3D-printed short-carbon-fiber-reinforced polyamide (3D-SCFRPA66) using homogeneous low-potential electron beam irradiation (HLEBI) to [...] Read more.
In short-carbon-fiber-reinforced polyamide 66 articles shaped by 3D printing (3D-SCFRPA66), the interfaces between printed layers are often susceptible to damage, and the composite is excessively brittle. Therefore, a novel treatment for 3D-printed short-carbon-fiber-reinforced polyamide (3D-SCFRPA66) using homogeneous low-potential electron beam irradiation (HLEBI) to enhance tensile properties was investigated. In 3D-SCFRPA66 samples, ductility was measured based on the following parameters: strain at tensile strength (corresponding to homogeneous deformation) (εts) and resistance energy to homogeneous deformation, a measure of toughness (Ehd), which were both substantially increased. An HLEBI dose of 43.2 kGy at an acceleration potential of 210 kV for the finished 3D-SCFRPA66 samples increased the εts and Ehd values from 0.031 and 1.20 MPa·m for the untreated samples to 0.270 and 6.05 MPa·m for the treated samples, increases of 771% and 504%, respectively. Higher HLEBI doses of 86, 129, or 215 kGy also increased the εts and Ehd values to lesser degrees. Electron spin resonance (ESR) data in the literature show that HLEBI creates dangling bonds in Nylon 6. Since PA66 and Nylon 6 are constructed of C, N, and O and have similar molecular structures, HLEBI apparently severs the (-C-N-) bonds in the backbone of PA66, which have the lowest bond-dissociation energy (BDE) of ~326 to 335 kJ mol−1. This shortens the PA66 chains for higher ductility. In addition, for Nylon 6, X-ray photoelectron spectroscopy (XPS) data in the literature show that HLEBI reduces the N peak while increasing the C peak, indicating the occurrence of shortening chains via dangling bond formation accompanied by increases in crosslinking with carbon bonds. However, caution is advised, since HLEBI was found to decrease the tensile strength (σts) and initial elasticity ([dσ/dε]i) of 3D-SCFRPA66. This tradeoff can possibly allow the HLEBI dose to be adjusted for the desired ductility and strength while minimizing energy consumption. Full article
(This article belongs to the Special Issue Mechanical Characterization of Polymer Composites)
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23 pages, 4517 KiB  
Article
Rhamnolipid-Enriched PA3 Fraction from Pseudomonas aeruginosa SWUC02 Primes Chili Plant Defense Against Anthracnose
by Natthida Sudyoung, Siritron Samosorn, Kulvadee Dolsophon, Kwannan Nantavisai, Onanong Pringsulaka, Supaart Sirikantaramas, Akira Oikawa and Siriruk Sarawaneeyaruk
Int. J. Mol. Sci. 2024, 25(23), 12593; https://doi.org/10.3390/ijms252312593 - 23 Nov 2024
Cited by 1 | Viewed by 1321
Abstract
Chili anthracnose, caused by Colletotrichum truncatum, causes significant yield loss in chili production. In this study, we investigated the elicitor properties of a rhamnolipid (RL)-enriched PA3 fraction derived from Pseudomonas aeruginosa SWUC02 in inducing systemic resistance in yellow chili seedlings and antifungal [...] Read more.
Chili anthracnose, caused by Colletotrichum truncatum, causes significant yield loss in chili production. In this study, we investigated the elicitor properties of a rhamnolipid (RL)-enriched PA3 fraction derived from Pseudomonas aeruginosa SWUC02 in inducing systemic resistance in yellow chili seedlings and antifungal activity against C. truncatum CFPL01 (Col). Fractionation of the ethyl acetate extract yielded 12 fractions, with PA3 demonstrating the most effective disease suppression, reducing the disease severity index to 4 ± 7.35% at 7 days post-inoculation compared with Col inoculation alone (83 ± 23.57%). PA3 also exhibited direct antifungal activity, inhibiting Col mycelial growth by 41 ± 0.96% at 200 µg/mL. Subfractionation revealed PA3 as a mixture of mono- and di-RLs, confirmed by 1H nuclear magnetic resonance and electrospray ionization mass spectrometry data. Additionally, PA3 enhanced seed germination and promoted plant growth without causing phytotoxicity. Transcriptomics revealed that PA3 pre-treatment prior to Col infection primed the defense response, upregulating defense-related genes involved in the phenylpropanoid, flavonoid, and jasmonic acid biosynthesis pathways, as well as those associated with cell wall reinforcement. Our findings highlight the potential of RL-enriched PA3 as both an antifungal agent and a plant defense elicitor, with transcriptome data providing new insights into defense priming and resistance pathways in chili, offering an eco-friendly solution for sustainable anthracnose management. Full article
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22 pages, 5925 KiB  
Article
Research on Energy Dissipation Mechanism of Cobweb-like Disk Resonator Gyroscope
by Huang Yi, Bo Fan, Feng Bu, Fang Chen and Xiao-Qing Luo
Micromachines 2024, 15(11), 1380; https://doi.org/10.3390/mi15111380 - 15 Nov 2024
Cited by 1 | Viewed by 2086
Abstract
The micro disk resonator gyroscope is a micro-mechanical device with potential for navigation-grade applications, where the performance is significantly influenced by the quality factor, which is determined by various energy dissipation mechanisms within the micro resonant structure. To enhance the quality factor, these [...] Read more.
The micro disk resonator gyroscope is a micro-mechanical device with potential for navigation-grade applications, where the performance is significantly influenced by the quality factor, which is determined by various energy dissipation mechanisms within the micro resonant structure. To enhance the quality factor, these gyroscopes are typically enclosed in high-vacuum packaging. This paper investigates a wafer-level high-vacuum-packaged (<0.1 Pa) cobweb-like disk resonator gyroscope, presenting a systematic and comprehensive theoretical analysis of the energy dissipation mechanisms, including air damping, thermoelastic damping, anchor loss, and other factors. Air damping is analyzed using both a continuous fluid model and an energy transfer model. The analysis results are validated through quality factor testing on batch samples and temperature characteristic testing on individual samples. The theoretical results obtained using the energy transfer model closely match the experimental measurements, with a maximum error in the temperature coefficient of less than 2%. The findings indicate that air damping and thermoelastic damping are the predominant energy dissipation mechanisms in the cobweb-like disk resonant gyroscope under high-vacuum conditions. Consequently, optimizing the resonator to minimize thermoelastic and air damping is crucial for designing high-performance gyroscopes. Full article
(This article belongs to the Special Issue Advances in MEMS Inertial Sensors)
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