Search Results (1,973)

To reveal the damage–seepage coupling mechanism of delayed floor water inrush induced by small fault activation under mining-induced stress, a cubic cement mortar specimen containing a persistent small fault was prepared based on similarity theory. Systematic triaxial loading–seepage tests were conducted under different fault fracture zone particle gradations, fracture zone widths, and fault angles, with simultaneous monitoring of stress–strain behavior, acoustic emission (AE) characteristics, and seepage flow evolution. The results show that: ① The peak strength decreases with increasing fracture zone width, but increases with increasing Talbot gradation coefficient (a fractal grading method) and fault angle. The failure mode transitions from shear-dominated to tension–shear composite failure. The spatial localization of AE events corresponds well with macroscopic fracture surfaces, and the AE source amplitude is positively correlated with compressive strength. ② The seepage flow exhibits a nonlinear evolution pattern of “compaction stabilization—stepwise rise—plateau stabilization” during loading. In the early loading stage, compaction of the fracture zone causes a slight decrease in flow. Approaching peak strength, the initiation and propagation of through-going fractures create interconnected seepage channels, leading to a stepwise jump in flow. In the post-peak stage, accompanied by fine particle erosion and framework reconfiguration, the flow tends to stabilize. A larger fracture zone width, smaller gradation coefficient, and smaller fault angle result in a more significant post-peak seepage surge, with the maximum flow rate reaching 3.6 times that of the specimen with a 2 mm wide fracture zone. ③ Grey relational analysis indicates that the fault angle is the most sensitive factor affecting the risk of delayed water inrush (correlation degree 0.788), followed by particle gradation and fracture zone width. The study demonstrates that under monotonic loading conditions, the damage evolution and seepage response of small faults are jointly controlled by their geometric parameters and internal structure, with the fractal grading method effectively quantifying the role of particle gradation. The findings provide a theoretical basis for risk assessment of delayed water inrush from small faults in working faces above confined aquifers. Full article

Insulated concrete sandwich panels (ICSPs) are widely utilized in modern building structures due to their excellent combination of energy efficiency and structural load-bearing capacity. However, compared to their mechanical and thermal properties, the sound insulation characteristics of ICSPs remain insufficiently studied, presenting a scientific deficit. In practical engineering, insufficient consideration of these acoustic properties—particularly the “acoustic bridging” induced by connectors—often leads to unpredictable noise transmission, making it difficult for building envelopes to meet stringent modern acoustic codes. To further investigate their acoustic characteristics, this paper extends existing theories on infinite periodic ICSPs to study the airborne sound insulation performance of finite-sized ICSPs. First, analytical models for ICSPs under simply supported on all edges (SS) and clamped on all edges (CC) boundary conditions are derived, wherein the connectors are equivalently modeled as elastic media and discrete elastic springs, respectively. Subsequently, the accuracy and applicability of the analytical models are verified through finite element (FE) models and an airborne sound insulation experiment. Finally, based on the analytical models, a parametric study is conducted to explore the effects of the stiffness of connectors, boundary conditions, and the thickness of the core layer on the sound insulation performance of the ICSPs. The results indicate that connector stiffness has a non-monotonic influence on the sound insulation performance of ICSPs. As the connector stiffness increases, the R_w first decreases and then increases, and the sound insulation performance gradually stabilizes when the connector stiffness becomes sufficiently high. Boundary conditions have a significant effect on the acoustic response. For the reference ICSPs, changing the boundary condition from SS to CC increases the R_w from 49 dB to 62 dB, corresponding to an increment of 13 dB and an approximately 95.0% reduction in the equivalent sound transmission coefficient. When the total panel thickness is kept constant, reducing the core layer thickness from 80 mm to 40 mm increases the R_w from 49 dB to 55 dB under SS boundary conditions and from 62 dB to 66 dB under CC boundary conditions, corresponding to increments of 6 dB and 4 dB, respectively. These improvements are equivalent to reductions of approximately 74.9% and 60.2% in the sound transmission coefficient, though this must be weighed against the inevitable reduction in thermal insulation capacity. Although the sound insulation performance of ICSPs is inferior to that of solid concrete panels (SCPs) of equivalent thickness, with reasonable parameter optimization, their sound insulation indices can significantly exceed the latest requirements of current building codes. By fully accounting for boundary effects in practical engineering, this study provides an analytical basis for the acoustic performance prediction and engineering-oriented optimization of finite-sized ICSPs. Full article

Lung diseases are among the leading global causes of morbidity and mortality, and existing reviews on deep learning (DL) for pulmonary diagnosis rarely integrate imaging, acoustic, and electronic health record (EHR) modalities within a single framework. We aimed to synthesize the state of the art (2019–2024) in multimodal DL for lung disease detection and classification, identifying dominant architectures, performance benchmarks, and translational barriers across chest X-rays, CT scans, respiratory sounds, and EHRs. A structured narrative review was conducted using PubMed, Scopus, IEEE Xplore, and Web of Science, applying explicit inclusion criteria for peer-reviewed studies; performance metrics, dataset characteristics, and reported limitations were extracted. Research involving convolutional neural networks (CNNs) and more recent models such as Transformers have reported high performance in chest X-ray classification, whereas acoustic approaches based on spectrograms and self-supervised representations (e.g., Wav2Vec 2.0) show promising but dataset-dependent results. Full article

The acoustics and soundscapes of historical religious places (HRPs) have been investigated in the literature. Some of these places are still used for their original functions and for tourism purposes. Being susceptible to alterations and renovations that directly affect the auditory environment, assessing users’ perceptions under these changes becomes important. To clarify users’ experience in HRPs, this study conducted a systematic review by following the PRISMA guidelines. Two phases of literature review were followed. The first phase focused on acoustics-related studies. The results indicated that they address the physical and architectural acoustics of HRPs without including perceptual or experiential assessment. This led to the second phase which used perceptual and soundscape-related keywords. The results showed that there were 24 studies that included subjective evaluation and perceptual descriptors. Based on these results, perceptual attributes (indicators) and assessment scopes were thematically synthesized. The findings revealed a significant gap in linking objective acoustics conditions with subjective experience in HRPs, calling for an integration of both approaches in future studies. Full article

Fish Aggregating Devices (FADs), traditionally used to attract and concentrate fish, can also serve as effective environmental enrichment tools in reservoirs, particularly in those with homogeneous characteristics and scarce refuge habitat, enhancing structural complexity and promoting recreational fishing opportunities. This study aimed to evaluate patterns in the use of prototype fish aggregation devices (FADs) in small size reservoirs. It was conducted at the Nascentes Reservoir (Crato), a small Mediterranean reservoir (ca. 10 ha) located in southern Portugal. These FADs were installed to enhance refuge habitat for fish species of interest to recreational fisheries, particularly largemouth bass (Micropterus salmoides Lacepède, 1802), thereby promoting the occurrence of trophy specimens. Two types of FADs were deployed and tested: (1) bank FADs (TREES), used in shallow waters near the margins; and (2) pelagic FADs (DAPs), suspended in the water column in deeper areas at the center of the reservoir. To monitor movement patterns and habitat use, an acoustic telemetry receiver array was deployed with a design to secure a three-dimensional fine-scale positioning with high accuracy. A total of 20 largemouth bass were tagged with acoustic transmitters equipped with pressure (i.e., depth) sensors. A before–after approach was used with 10 fish tracked before FAD deployment and 10 after. Results of fish behavior analysis provide strong evidence of fish using DAPs, but not TREES. In the presence of FADs, fish reduced their home ranges and movement amplitudes, becoming closely associated with these artificial habitats. Several environmental predictors explained fish behavior in the presence of artificial refuges, namely, diel period, moonlight intensity, and fish depth. The findings of this study are expected to contribute to the development of guidelines for refuge habitat enhancement in small- to medium-sized Mediterranean reservoirs, thereby increasing their recreational fishing attractiveness. Full article

The detection and localization of large underwater targets are important for maritime security, marine resource exploration, and underwater situational awareness, while the increasing acoustic stealth of underwater vehicles has limited conventional acoustic methods. This review provides a systematic overview of non-acoustic detection and localization technologies for large underwater targets, with emphasis on their relevance to unmanned aerial, surface, and underwater platforms. Wake-based detection, magnetic anomaly detection (MAD), and gravity anomaly detection (GAD) are reviewed as three representative non-acoustic routes. A bibliometric analysis is first conducted to summarize research trends, major contributors, and emerging hotspots. Wake-based methods are discussed in terms of wake signatures, modeling approaches, sensing platforms, and localization potential. MAD is analyzed from the perspectives of magnetic dipole modeling, target-based detection, noise-based detection, artificial intelligence (AI)-based detection, and magnetic localization. GAD is discussed with respect to physical feasibility, gravity-gradient target modeling, inversion methods, and engineering constraints. The review shows that wake-based methods are suitable for wide-area search and trajectory inference, MAD is relatively mature for short-range confirmation and localization, and GAD remains promising but less mature. Future research should focus on onboard sensors, platform stability, weak-signal extraction, background suppression, quantitative evaluation metrics, multi-source fusion, autonomous mission planning, and multi-platform collaboration. Full article

Underwater communication is essential for marine research, yet saline environments pose significant challenges as electromagnetic waves suffer from severe attenuation and optical systems face scattering. Consequently, acoustic transmission remains the most practical method for medium- to long-range communication. This study investigates the impact of salinity, transmission frequency, and propagation distance on signal integrity, specifically focusing on the feasibility of using a square-wave carrier with On-Off Keying (OOK) modulation as a simpler, low-cost alternative to traditional sinusoidal frequency-shift keying (FSK). Experiments were conducted in a custom glass tank and analyzed via MATLAB. The results reveal that increased salinity and higher frequencies led to greater signal distortion and attenuation, which complicates reliable binary recovery. However, despite these environmental hurdles, the study demonstrates that square-wave OOK allows for successful binary data recovery over short distances. The findings suggest that simplified modulation schemes could potentially be used for short-range underwater communication in controlled environments, particularly where minimizing system complexity is of concern. Ultimately, the work provides valuable insights into how environmental factors influence acoustic signal integrity, offering a preliminary basis for future development of accessible and efficient underwater communication platforms targeted to shallow water communication. Full article

The spatial organization of microscale fillers is critical for macroscopic performance, yet precise control over their distribution and orientation remains a major challenge in direct ink writing. Here, we present an acoustofluidic capillary nozzle that integrates acoustic manipulation into direct ink writing, enabling programmable in situ assembly of functional fillers during extrusion. By coupling a piezoelectric transducer with a commercial glass capillary, stable acoustic standing waves are established within the flow channel, driving suspended filler particles toward pressure nodes via acoustic radiation forces. Simulations and experiments systematically investigate how capillary geometry and material properties influence acoustic energy distribution and particle assembly behavior. In particular, rectangular capillaries generate stable multi-node standing waves, inducing periodic alignment of nickel-coated carbon fibers into ordered conductive bundles. This acoustically programmed microstructure reduces the percolation threshold from 8 wt% to 2 wt% and enhances electrical conductivity by up to 32.1-fold at identical filler contents. Meanwhile, the composites exhibit pronounced anisotropic conductivity and maintain excellent mechanical flexibility, with stable electromechanical performance under 16% bending strain and cyclic loading. This work demonstrates a simple and scalable acoustofluidic nozzle platform for programmable microstructure engineering in direct ink writing, offering new opportunities for fabricating high-performance multifunctional composites. Full article

This study investigates the impact of internal muffler geometry on flow-related dissipation characteristics potentially relevant to acoustic behavior using steady-state Computational Fluid Dynamics (CFD) simulations. Four variants were analyzed: an empty tube, considered to be a baseline model, a three-chamber baffle system, a single spiral channel, and a complex multi-channel insert manufacturable only via advanced additive technologies. Simulations were conducted in SimScale using a compressible flow model with the k-ω SST turbulence formulation. Key outputs included static pressure distribution and turbulent kinetic energy (TKE), both of which were evaluated as qualitative surrogate indicators associated with flow-induced energy dissipation phenomena. The results indicate that geometries incorporating spiral features modify flow redistribution patterns, pressure gradients and localized turbulence intensity, suggesting potential applicability for future acoustic optimization studies. The study highlights how additive manufacturing enables the integration of geometrically complex internal structures otherwise unattainable through conventional methods. By comparing pressure drop and TKE patterns with internal design features, the research offers a preliminary CFD-based framework for geometry screening and conceptual evaluation of muffler insert designs for automotive exhaust systems. This approach provides computational support for rapid comparative assessment prior to experimental validation and detailed acoustic analysis. Full article

Introduction: Chemical pollution of water bodies constitutes a global problem with huge impacts on fish populations. Consequently, the assessment of the effects of contaminants, especially on the nervous system, has become essential. The zebrafish (Danio rerio) has emerged as a prominent vertebrate model in ecotoxicology and neuroscience, in large part owing to the availability of genetic resources, including a high level of genome sequencing and annotation, plus the similarity of its neuron types and neurotransmitters to other vertebrates, including humans, and its stereotyped behaviour. Objective: The main objective of this mini-review is to present a synthesis of the key behavioural assays used in zebrafish larvae to assess neurotoxicity, focusing on developmental neurotoxicity. Methodology: A literature review was conducted based on the ScienceDirect and PubMed databases, covering publications between 2000 and 2025, selecting relevant studies on larval (up to 120 hpf) behaviour and contaminant exposure. The methodology was based on the analysis of behavioural tests applied to larvae, which evaluate responses to various stimuli, including visual, acoustic, tactile, and social stimuli. Results: Established, commonly used key assays include the light/dark test and locomotor, touch, photomotor, acoustic, and social response tests. The literature results confirm that zebrafish larvae exhibit complex behavioural patterns comparable to those of higher vertebrates, making them suitable for neurobehavioural studies. Changes in locomotor behaviour, responses to stimuli, or social patterns are extremely sensitive indicators of early neurotoxic effects, often before morphological changes are observed. Furthermore, the developing nervous system is particularly sensitive to chemicals, with high potential for irreversible effects, even with short-term exposures. Conclusions: Overall, our findings demonstrate that behavioural assays in zebrafish larvae constitute an effective, sensitive, and economically viable tool for assessing the neurotoxicity of compounds, contributing to a better understanding of the mechanisms of action and advancing environmental protection and public health strategies, considering also the “one health” approach. Full article

Background: Tinnitus is a prevalent auditory disorder associated with maladaptive cortical plasticity and aberrant neural synchronization across auditory and non-auditory brain networks. Acoustic desynchronization-based sound therapies, such as coordinated reset neuromodulation, aim to counteract pathological oscillatory patterns but commonly require prolonged daily listening sessions and specialized delivery formats, which may limit their accessibility and practicality in routine clinical settings. To address this limitation, a modified desynchronization protocol embedding therapeutic tones within music was developed to improve tolerability and engagement. This study aimed to evaluate the clinical effects of modified Music-Integrated Desynchronization Sound Therapy (mMIDST) on tinnitus severity in patients with chronic tinnitus. Methods: In this prospective, randomized, controlled, single-blind pilot trial conducted at the Otolaryngology Department of Hospital Clínico Universidad de Chile (Santiago, Chile) between July 2024 and July 2025, adults aged 18–75 years with chronic non-pulsatile tinnitus were assigned to receive either mMIDST or an active control intervention consisting of low-frequency stimulation (LFS) embedded within identical music tracks. Participants listened to personalized sound files for one hour daily, five days per week. Tinnitus severity was assessed using the Tinnitus Handicap Inventory (THI), with audiometric evaluations performed at baseline and after one, two, and three months. Between-group differences were analyzed using the Mann–Whitney U test. Results: Twenty-five participants completed the study (15 mMIDST, 10 LFS). Baseline audiometric thresholds and THI scores were comparable between groups. The mMIDST group showed significantly greater reductions in THI scores than the LFS group at two and three months of treatment (p < 0.05). Conclusions: mMIDST was associated with time-dependent improvements in tinnitus-related distress compared with an active control condition. Embedding desynchronization-based tonal stimulation within music may represent a promising and well-tolerated non-invasive approach for chronic tinnitus management. Full article

Aiming at the technical bottleneck that traditional porous structures can hardly achieve mechanical load-bearing and acoustic regulation simultaneously, this study designs and fabricates three implicit surface porous structures (Gyroid, Diamond, Lidinoid) based on the bionic principle of trabecular bone. Experimental characterization and numerical analysis of their mechano-acoustic coupling performance are systematically carried out. Selective Laser Melting (SLM) technology is employed to realize the integrated forming of 316L bionic structures. Quasi-static compression experiments and finite element simulations are conducted to reveal the progressive deformation mechanism and energy absorption characteristics of different topological configurations. The results indicate that the Diamond structure exhibits the optimal comprehensive performance in terms of load-bearing capacity, specific energy absorption and isotropy. On this basis, the sound absorption and sound insulation performances of the structures are evaluated via an acoustic impedance tube test. The results show that the Diamond structure possesses a remarkably higher sound absorption coefficient and sound insulation value in the high-frequency range than other configurations, demonstrating excellent acoustic energy dissipation and sound wave isolation capability. The research indicates that the synergistic optimization of mechanical and acoustic performances can be achieved by regulating the Triply Periodic Minimal Surface (TPMS) topological configuration. Benefiting from its efficient stress transfer paths and intricate sound wave propagation channels, the Diamond structure realizes the coupling of high load-bearing capacity, superior energy absorption and favorable acoustic performance. This work provides a theoretical basis and technical support for the design of bionic porous structures in multifunctional scenarios such as bone implants and protective noise reduction. Full article

Introduction: Freshwater ecosystems are increasingly threatened by river fragmentation caused by the accumulation of small barriers such as weirs. These structures disrupt longitudinal connectivity and hinder fish movements, restricting access to essential habitats (e.g., spawning) and affecting biodiversity and ecological river functions. Though many of these structures are obsolete and their removal is increasingly promoted as a river restoration measure under the EU Biodiversity Strategy and the Nature Restoration Law, the ecological implications of barrier removal are not totally positive. One of the most pressing concerns is the unintended spread of Invasive Alien Species (IAS), which may expand upstream once a barrier is eliminated. In this context, selective barriers are gaining attention as a promising management tool to balance ecological restoration goals with IAS control. By carefully designing or adjusting hydraulic features such as head drops, it may be possible to allow passage for native species while restricting the movement of invasive fish. However, despite its potential, selective barrier design remains underexplored. Objective: This research aims to address this gap by testing how head drops influence the upstream movement of Iberian straight-mouth nase (Pseudochondrostoma polylepis), a native leuciscid, and the European perch (Perca fluviatilis), an IAS rapidly expanding across the Iberian Peninsula. Methodology: Laboratory experiments were conducted in an indoor ecohydraulic flume (6.5 × 0.7 × 0.7 m) at the Hydraulics Laboratory of IST. A single weir structure whose downstream water level was adjusted to create three distinct head drops—11, 18, and 25 cm (configurations A, B, and C, respectively)—was tested. Tests were performed using one specimen of each species that were allowed 15 min acclimation to the flume conditions followed by a 60 min trial. The number of approaches, attempts and successful upstream passages were recorded. Additionally, the flow-field characterization was performed using an Acoustic Doppler Velocimeter (ADV; Nortek-AS Vectrino 10 MHz). Results: Preliminary results indicate a strong capability of the native nase to overcome two of the tested head drops, with four and two successful passages recorded for configurations A and B, respectively. In contrast, the invasive species showed no successful passages under these conditions. For configuration C, no successful passages were observed for either species. Conclusions: These results highlight the potential of selective weir designs to promote river connectivity for native species while helping prevent the upstream expansion of invasive fish. Full article

With the increased application of porous asphalt, the recycling and reutilization of aged materials have become a critical issue for sustainable pavement engineering. This study investigates the evolution of the performance characteristics of porous asphalt mixtures under high-temperature heating conditions, with the aim of providing a theoretical basis for hot in-place recycling (HIR) technology in the rehabilitation of porous asphalt pavements. The heating states of asphalt, mortar and mixtures in HIR were simulated using controlled oven heating. Their microscopic, mechanical and thermal properties were evaluated under different aging conditions and with the incorporation of different rejuvenators. The results show that asphalt aging intensifies with the increasing heating temperature and time. The incorporation of bio-based rejuvenators significantly alleviates aging effects and demonstrates superior performance compared to conventional rejuvenators. Furthermore, aggregates and rejuvenators enhance the thermal conductivity of materials, while aging reduces the thermal conductivity coefficient and increases the risk of temperature gradient diseases. The rheological properties of asphalt are closely related to the degree of aging. While aging mitigation improves low-temperature cracking resistance and acoustic damping performance, it may compromise high-temperature deformation resistance. In conclusion, to achieve an optimal balance between performance recovery and aging control, it is recommended that the HIR of porous asphalt pavements be conducted at a heating temperature of 180 °C for 5 min, with the addition of 3% bio-based rejuvenator. Full article

The shift towards collaborative teaching practices and the development of Innovative Learning Environments (ILEs) have brought significant changes to educational settings, particularly regarding acoustic demands and classroom listening. The experiences of teachers and other professionals working within ILEs are under-researched. Therefore, the aim of this study was to explore how educators and professionals perceive and manage classroom listening and learning within these spaces. Using a qualitative approach, semi-structured interviews were conducted with eight primary school teachers and eight speech-language therapists working in various school ILEs. Transcripts were analysed using inductive thematic analysis. Three major themes were identified, namely experiences, creating order, and opportunities, with each theme encompassing two subthemes. Experiences included difficulties and positive experiences; creating order comprised teaching approaches and making it work; and opportunities involved collaboration and new roles. Key factors influencing the effectiveness of ILEs included collaboration, strategic resource use, use of scaffolding techniques, flexibility, and student engagement. The study highlighted the importance of mentorship for beginner teachers in order to foster a dynamic and supportive learning environment. Understanding these elements can help educators and professionals working together in ILE classrooms to shape their practices to enhance student outcomes. Full article