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The motivation of the present study is to gain insights into the evolution of elastic properties of cemented tungsten carbides (WC) shock compressed to 100 GPa. Seven plate impact experiments—two front surface impact and five release wave overtake—are conducted to make simultaneous measurements of Hugoniot states and longitudinal sound speeds in shocked WC with 3.7wt.% cobalt binder. The sound speeds along with estimates for bulk sound speeds, obtained using the Birch–Murnaghan EoS, are analyzed to determine the elastic moduli—longitudinal, bulk, and shear—as a function of Hugoniot stress. The longitudinal and bulk sound speeds at Hugoniot states of interest are found to increase linearly with longitudinal stress. Consistent with the increase in sound speeds, the longitudinal and bulk moduli also increase with Hugoniot stress; however, the increase in longitudinal modulus is modest when compared to predictions of theoretical models that account for pressure and temperature dependence of elastic moduli, but with no damage. The shear moduli remain nearly constant at ∼ 318 GPa over the range of Hugoniot states investigated. These values are, however, much lower than those predicted by the Steinberg–Guinan model with no damage. Poisson's ratio decreases initially from its ambient value of 0.208 to ∼ 0.199 for Hugoniot stress ≤ 10 GPa indicating consolidation of the WC microstructure with low initial stress; however, with an increase in Hugoniot stress to ∼ 100 GPa, Poisson's ratio increases to ∼ 0.317, indicating degradation of shear moduli with increasing stress. The product of density and Grüneisen parameter (ρ Γ), after an initial spike, remains nearly constant for volumetric strains ≥ 0.07. The maximum average temperature rise is estimated to be ∼ 286 ° C at the highest Hugoniot stress employed in the study. [ABSTRACT FROM AUTHOR]

Background: Psychosocial rehabilitation in forensic psychiatric services requires sound measurement of patient and staff perceptions of psychosocial function. The recommended World Health Organisation Disability Assessment Schedule 2.0 (WHODAS), designed for this, has not been examined with offender patients. Aims: To examine patient and staff WHODAS ratings of secure hospital inpatients with psychosis, any differences between them and explore associations with other clinical factors. Methods: Seventy‐three patients self‐rated on the WHODAS after 3 months as inpatients. An occupational therapist interviewed the patient's primary nurse and care team at about the same time (staff ratings). Scores were calculated according to the WHODAS manual. WHODAS scores and interview‐rated symptom severity, cognitive measures, daily antipsychotic dose and duration of care were compared. Results: Patient ratings indicated less disability than staff ratings for total score and for the domains of understanding and communicating, getting along and life activities. Self‐care and participation ratings were similar. Patients were more likely to rate themselves as disabled in getting around (mobility). Only one‐fifth of patient‐ and staff‐ ratings (16, 22%) were similar, while for nearly a third of the patients (23, 32%) self‐ratings were higher than staff ratings. More severe positive symptoms were associated with higher self‐rated WHODAS disability after accounting for treatment duration, negative symptoms, cognitive score and antipsychotic dose. No variable accounted for the staff/patient differences in ratings. Conclusion: Our mean WHODAS score findings echoed those in other patient samples—of patient underestimation of disability, linked to severity of symptoms. In this study using the WHODAS for the first time in a forensic mental health secure inpatient service, however, we found that, by comparing individuals, half of the patients reported equivalent or greater disability than did staff. Future research should focus on elucidating from patients what contributes to their self‐ratings. Understanding their thought processes in rating may enhance rehabilitation planning. [ABSTRACT FROM AUTHOR]

A sonic anemometer targeted at wind speed measurements on the surface of Mars is described. This environment requires transducer operation in 4–10 mbar CO2 at temperatures between 143 and 293 K (–130 °C and 20 °C, respectively). Over these ranges, transducer pressure and temperature sensitivity could be a source of measurement error. To investigate this, four candidate transducers were tested using transmission mode ultrasonic testing and impedance measurements: two narrowband piezoelectric transducers, a broadband capacitive transducer, and a micromachined capacitive ultrasound transducer. A system model was used for comparison and interpretation, and implications for a sonic anemometer were examined. Variation of transducer characteristics, including diffraction effects, across 2–10 mbar in CO2 and 190–293 K (–83 °C–20 °C) result in ±2.3% error in wind speed measurement and ±1.1% error in speed of sound measurement for the worst case but only ±0.14% error in wind and ±0.07% error in speed of sound for the best transducer operated off resonance. The acoustic conditions on Mars are similar to those in Earth's stratosphere at 30–42 km of altitude. Hence, testing was also conducted in dry air over the same range of pressures and temperatures with relevance to a secondary application of the instrument as a stratospheric anemometer for high altitude balloon missions on Earth. [ABSTRACT FROM AUTHOR]

The existence of defective drilled lotus seeds will lead to problems such as plumule residue and lotus seed appearance damage, which decreases the quality of lotus seed food products. Therefore, it is vital to sort drilled lotus seeds. Since the drilled holes on defective seeds are not coaxial with the axis of the lotus seeds, blowing an air jet along the axial direction towards the end face of defective seeds will generate a different acoustic response than that of qualified ones. Based on this characteristic, this study proposes an intelligent sorting method for drilled lotus seeds based on air jet impact acoustic signal and one-dimensional convolutional neural network (1D-CNN) acoustic classification. The method directly extracts features from 1D acoustic signals and achieves automatic classification through the constructed 1D-CNN. First, the sorting principle, acoustic signal data acquisition and preprocessing, and dataset preparation methods were introduced. Then, the effect of hyper-parameters, including the number of convolutional layers, convolution kernel size, learning rate, and training epochs, on the performance of the 1D-CNN model was investigated. On this basis, the parameters were optimized to form the final 1D-CNN model – AudioLS (Audio of Lotus Seed). The accuracy, detection time, and parameters achieved by AudioLS were 98.04%, 25.12 ms, and 0.79 M, respectively. Compared with five classic 2D-CNN models, i.e., Residual Network (ResNet) 50, Visual Geometry Group (VGG) 16, VGG19, DenseNet121, and Extreme Inception (Xception), AudioLS achieved better performance. The accuracy increased by 1.82%, 1.30%, 1.28%, 1.83%, and 2.05%, respectively, and the detection time was shortened by 16.77%, 2.71%, 7.85%, 28.11%, and 11.92%, respectively. The research results verify the effectiveness of the proposed intelligent sorting method. [ABSTRACT FROM AUTHOR]

This paper presents a localization method for an underwater multitonal source by using a vertically distributed system in deep water. The system is composed of two kinds of nodes. One is a node at large depth, and the other is a node covering most of the water column. The former and latter are utilized to estimate the source range and depth, respectively. Specifically, the proposed method estimates the source range by matching the spatial arrival angle measured by the first kind of node with the replicas calculated by the acoustic model. Based on the estimation value of the source range, the second kind of node is utilized to estimate the source depth by using an incoherent time reversal method. The effectiveness of the proposed method is demonstrated through numerical simulations. The effects of the measurement error and the sound speed profile mismatch on the performance of the proposed method are also analyzed. [ABSTRACT FROM AUTHOR]

AbstractThis article aims to develop a teachers’ perception scale regarding the artificial intelligence use in education. The scale development study was carried out in two stages during the 2023–2024 academic year, covering 597 teachers who stated that they used different artificial intelligence applications. Literature was thoroughly reviewed and focus group interviews were held with teachers who used artificial intelligence applications in education while pooling scale items. Field expert faculty members were consulted in evaluating face and content validity of the scale. Exploratory factor analysis was performed on the data obtained from the first sample group (n = 424), and a three-factor structure was determined in the first stage. It was observed that the factors of the first draft scale, consisting of 18 items, revealed 57.8% of the total variance. The first confirmatory factor analysis was conducted on the data collected from the second sample group (n = 173) in the second stage. It was confirmed that the structure consisting of 18 items and three factors (teaching perception, learning perception, and ethical perception) was compatible with the data. After the first-level confirmatory factor analysis for the Teachers’ Perception Scale Regarding Artificial Intelligence Use in Education, a second-level confirmatory factor analysis was conducted to determine whether the factors that made up the scale revealed the variable. The final scale, consisting of 15 items and three dimensions, was determined to be compatible with the data obtained. Reliability analysis presented that the Cronbach alpha internal consistency coefficient was calculated as .87 for the whole scale, .82 for learning perception, .79 for teaching perception, and .79 for ethical perception. The results show that the teachers’ perception scale regarding artificial intelligence use in education is valid and reliable, and a sound measurement tool to determine the perception regarding artificial intelligence use in education. [ABSTRACT FROM AUTHOR]

Objectives The critical problem to be solved in the construction of a high-precision seafloor control network is to reduce the influence of systematic errors on the coordinate accuracy of seafloor control points during acoustic positioning.Methods First, we analyze two positioning models: Non-difference and difference between epochs. Second, due to the change of sound velocity in seawater is affected by the long period term error and the short period term error, the system error caused by the shift in sound velocity in the measurement also has the characteristics of periodic change.Results and Conclusions Based on this premise, a symmetric epoch differential positioning model was constructed. The results of simulation analysis and measured data analysis show that when the observation duration is an even multiple of the system error variation period, the symmetric differential positioning model can effectively reduce the influence of the system error on the positioning results. Still, when the observation duration is not an even multiple of the system error variation period, the model is no longer applicable. [ABSTRACT FROM AUTHOR]

Here, we present observations of temporal variability of sub-ice platelet layer over seasonal and diurnal timescales under Ice Shelf Water-influenced fast ice in McMurdo Sound. Electromagnetic induction (EM) sounding time-series measurements of the thicknesses of fast ice and sub-ice platelet layer were made in winter and late spring of 2018. Winter objectives were to measure the seasonal growth of fast ice and sub-ice platelet layer near the McMurdo Ice Shelf in the east, while in late spring we assessed the diurnal variability of sub-ice platelet layer with coincident EM time-series and oceanographic measurements collected in the main outflow path of supercooled Ice Shelf Water in the west. During winter, we observed when the sub-ice platelet layer formed beneath consolidated ice. Episodes of rapid sub-ice platelet layer growth (∼ 0.5–1 m) coincided with strong southerly wind events and polynya activity, suggesting wind-enhanced Ice Shelf Water circulation from the McMurdo–Ross Ice Shelf cavity. In late spring, we investigated how the tides and ocean properties influenced the sub-ice platelet layer. Over a 2-week neap–spring tidal cycle, changes in sub-ice platelet layer thickness were observed to correlate with the tides, increasing more during neap than spring tide cycles, and on diurnal timescales, more on ebb than flood tides. Neap and ebb tides correspond with stronger northward circulation out of the cavity, indicating that sub-ice platelet layer growth was driven by tidally enhanced Ice Shelf Water outflow. The observed variability indicated that wind-driven circulation and the tides influence Ice Shelf Water outflow in McMurdo Sound and, consequently, sub-ice platelet layer evolution over a range of timescales. [ABSTRACT FROM AUTHOR]

The in situ acoustic measurement of seafloor sediment is an important technical means to obtain the acoustic parameters of seafloor. The time‐of‐flight method is commonly used to calculate the sound speed in seafloor sediment. Accurate identification of signal feature points is essential for determining travel time or travel time difference of acoustic signals. However, the precise identification of feature points, such as the take‐off point of the first wave of a sound wave signal, is challenging. The conventional manual identification method is inefficient and prone to errors. The development of a feature point auto‐identification method is imperative for accurately calculating the travel time of acoustic signals. In this study, we employed the cross‐correlation method, the level threshold method and the short window‐long window energy ratio method to extract the acoustic travel time differences and calculate the sound speeds in seawater and in seafloor sediment. We then analysed the effectiveness of these calculated results. The sound speeds in seawater obtained through the aforementioned methods were compared with the sound speeds measured using a sound velocity profiler. The comparison revealed that these processing methods exhibit a high level of accuracy. The sound speed results in sediments show that the programme‐based auto‐identification methods significantly reduce the standard deviation compared to the manual identification method. This study successfully assessed the processing accuracy of different methods and expanded the processing methods for in situ acoustic signals of seafloor sediments. [ABSTRACT FROM AUTHOR]

We outline techniques for the control and measurement of the nucleation of crystalline materials. Small angle x-ray scattering/wide angle x-ray scattering x-ray diffraction measurements are presented that demonstrate the impact of low power, continuous, non-cavitational ultrasound on the nucleation and crystallization of a wax—n-eicosane dissolved in a heptane/toluene solvent. A mathematical-physical approach based on the rectification of heat and mass transport by such a low power oscillating pressure field is outlined, and it is suggested that this approach be combined with dissipative particle dynamics computational modeling to develop a predictive method capable of modeling the impact of low power oscillating pressure fields (acoustics and ultrasonics) on a wide range of nucleating systems. Combining the ultrasound pitch and catch speed of sound measurements with low power harmonically oscillating pressure fields to monitor and control nucleation presents the prospect of entirely new industrially significant methods of process control in crystallization. It also offers new insights into nucleation processes in general. However, for the acoustic control technique to be widely applied , further theoretical and modeling work will be necessary since, at present, we are unable to predict the precise effect of low power ultrasound in any given situation. [ABSTRACT FROM AUTHOR]

The heavy global demand for sand in various sectors of the economy subjects the Vietnamese Mekong Delta to correspondingly high amounts of sand mining—a process that started in the early 1990s contributing significantly to the Vietnamese economy. The impacts of intensive sand mining and mining-related industries damage the integrity of the river and local communities. Much of the literature focuses on the former, exposing people to the deleterious implications of sand mining on the physical environment. This study aims to fill the gap on the less explored latter through the lenses of place and landscape per human geography tradition, using qualitative methods of thirty-five interviews with locals, video recordings, and sound measurements to highlight the impacts of sand mining and mining-related industries. This study revealed that sand mining and its associated activities are responsible for people’s perceptions of notable air, land, and noise pollution, as well as substantial harm to the urban environment. Over 80 percent of interviewed locals acknowledged the disruptions to their daily lives and a substantial loss of their sense of place. These findings shed light on narratives frequently overlooked by policymakers, emphasizing the urgency of addressing these issues for a sustainable future. [ABSTRACT FROM AUTHOR]

Noise pollution is one of the consequences of urbanization that can cause environmental disturbances in urban areas. Urban ecosystems provide noise reduction services through Urban Green infrastructures (UGIs). Many studies have been conducted to evaluate and model traffic noise, but none have addressed the flow, supply, and demand of noise reduction ecosystem services. The main purpose of this paper is to present a new methodology for estimating flow, supply, and demand for noise reduction in Hamadan city that has not been mentioned in any paper so far. UGIs were classified into six main categories: agricultural lands, gardens, parks, abandoned lands, single trees, and street trees. A total of 57 sampling stations for sound measurement were made in August 2018. The current map of noise pollution (flow) was created using the Kriging method. The amount of supply was measured up to a distance of 50 meters from the main roads based on two approaches (the distance effect and the sound barrier effect). To quantify the demand, the current sound intensity level in the noise-sensitive land uses was compared with standards. Zonal statistics was used for spatial analysis of supply-demand in the urban neighborhood as a working unit. Results showed that at distances of 5m, 10m, 15m, and 20m, the average noise reduction was found to be 1.61, 2.83, 3.92, and 5.33 dB, respectively. Sound barriers at distances of 5m and 10m resulted in an average sound reduction of 1.61 and 2.83 dB, respectively. Individual trees, strip trees, abandoned lands, parks, and gardens led to a decrease in traffic noise by 0.3, 1, 0.1, 3.5, and 4.5 dB, respectively. The clustering analysis revealed a significant spatial clustering of noise pollution in Hamedan. The results and new methodology of this research can be used in similar areas to estimate the supply and demand of noise reduction and also for decision-makers to take management actions to increase supply and meet the demand for noise reduction service. [ABSTRACT FROM AUTHOR]

Those with visual impairments, including complete blindness or partial sight loss, constitute a significant global population. According to estimates by the World Health Organization (WHO), there are at least 2.2 billion people worldwide who have near or distance vision disorders. Addressing their needs is crucial. Introducing a smart cane tailored for the blind can greatly improve their daily lives. This paper introduces a significant technical innovation, presenting a smart cane equipped with dual ultrasonic sensors for obstacle detection, catering to the visually impaired. The primary focus is on developing a versatile device capable of operating in diverse conditions, ensuring efficient obstacle alerts. The strategic placement of ultrasonic sensors facilitates the emission and measurement of high-frequency sound waves, calculating obstacle distances and assessing potential threats to the user. Addressing various obstacle types, two ultrasonic sensors handle overhead and ground-level barriers, ensuring precise warnings. With a detection range spanning 2 to 400 cm, the device provides timely information for user reaction. Dual alert methods, including vibrations and audio signals, offer flexibility to users, controlled through intuitive switches. Additionally, a Bluetooth-connected mobile app enhances functionality, activating audio alerts if the cane is misplaced or too distant. Cost-effective implementation enhances accessibility, supporting a broader user base. This innovative smart cane not only represents a technical achievement but also significantly improves the quality of life for visually impaired individuals, emphasizing the social impact of technology. The research underscores the importance of technological research in addressing societal challenges and highlights the need for solutions that positively impact vulnerable communities, shaping future directions in research and technological development. [ABSTRACT FROM AUTHOR]

Thin and light design, picture quality and sound quality are important factors in TVs and monitors. Recently, a monitor speaker has been developed that provides a new sound experience combining an electrostatic thin actuator to vibrate the OLED display and an electrodynamic woofer. However there are limitations in evaluating sound quality of this technology because the existing international standards are speaker unit evaluation method based on an anechoic chamber environment. In this study, we propose a sound quality measurement method that can reflect the listening environment of monitor customers based on the new IEC standard and share the results of OLED thin actuator panel speaker. [ABSTRACT FROM AUTHOR]

We performed in situ X‐ray diffraction and ultrasonic sound velocity measurements on hcp‐Fe up to 15 GPa, 873 K in a multi‐anvil apparatus. The elastic moduli and their pressure and temperature derivatives were determined by fitting the velocity and density data to the third‐order finite strain equations, yielding KS0 = 169.0(57) GPa, KS0′ = 5.4(6), (∂KS/∂T)P = −0.031(3) GPa/K, G0 = 104.5(27) GPa, G0′ = 1.7(2), (∂G/∂T)P = −0.060(2) GPa/K. Within the experimental P‐T range, we find significant temperature effect on the density‐velocity (ρ − VPor S) relations and caution the use of the temperature‐independent Birch's law for extrapolation to core conditions. Furthermore, temperature‐induced velocity decrease is more significant in VS than in VP, offering a possible explanation for the high Poisson's ratio in the core. Extrapolations based on our results together with previous experimental data suggest that VP of hcp‐Fe aligns with PREM at Earth's core conditions, while Vs and density are approximately 10% and 2.7% higher than PREM, respectively. Plain Language Summary: Iron is believed to be the predominant constituent of the Earth's core. Comparing the physical properties of Fe at high P‐T conditions with the seismological observations provides a strong constraint on the composition of Earth's core and thus aids our understanding of the dynamics and evolution of the Earth. In this study, we measured the density, compressional and shear velocities of iron simultaneously at high pressure and high temperature conditions. We found that temperature plays a significant role in decreasing the velocity of iron, especially for the shear wave velocities. We modeled the velocity profiles of Earth's inner core based on elasticity data from this study and previous studies. Our results suggest that while the compressional velocity of hcp‐Fe demonstrates a good match, the density is slightly heavier, and the shear velocity is faster than the seismic observations. A comprehensive explanation of the seismic observations necessitates considering other light elements in the core. Key Points: Direct measurements of sound velocities of hcp‐Fe at simultaneous high P‐TLarge temperature‐induced shear softening in hcp‐Fe help explain the high Poisson ratio in the Earth's inner coreVelocity profiles of hcp‐Fe at Earth's inner core are faster than PREM [ABSTRACT FROM AUTHOR]

Personalized Sound Zone (PSZ) is the ultimate sound space that enables a world in which one hears only the sounds one wants to hear and others hear only the sounds that one wants them to hear. It will enable new lifestyles in which people can enjoy work and entertainment experiences regardless of location, provide a new acoustic experience by merging real space and virtual sound space, enable selfdriving cars in which people seated apart from each other can comfortably have conversations in a space as quiet as a living room, and improve the quality of life by enhancing hearing ability. These Feature Articles introduce the challenges involved in achieving PSZ. [ABSTRACT FROM AUTHOR]

This paper replies to a research note outlining a method for the conversion of weights and measures in the Danish Sound Toll registers. Whereas Yrjö Kaukiainen argues that the use of values for Danish units of measurement is sufficient, Werner Scheltjens highlights the complexity of pre-modern weights and measures, and raises concerns about the simplification of the measurement and taxation procedures at the customs office in the Danish Sound. [ABSTRACT FROM AUTHOR]

Microphone array-based beamforming algorithms are widely used in sound source identification, fault diagnosis, and radar communication because of their excellent performance. However, their limited spatial resolution and high dynamic side flap level seriously affect the recognition accuracy. To explore a high-performance beamforming sound source identification algorithm, the microphone array compressed beamforming underdetermined equation is solved by extending the iterative threshold. A sound source identification model is established, and a new compressed beamforming (CSB-II) algorithm is proposed. Numerical simulations show that the CSB-II algorithm can effectively reduce the starting frequency of sound source identification and has high sound source identification accuracy. The effects of signal-to-noise ratio, sound source distance, and array number on sound source identification accuracy are analyzed separately. The laws affecting sound source identification accuracy are derived from guiding actual sound source measurements. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the psychometric properties of the Greek version of the Jefferson Scale of Empathy—Student version (JSE-S) and its association with potential predictors among Greek-speaking undergraduate medical students. This study adopted a cross-sectional, comparative–descriptive research design. The study was conducted during October and November 2023. Cronbach's α values for the JSE-S and the factors "perspective taking", "compassionate care", and "standing in the patient's shoes" showed internal consistency. The intraclass correlation coefficient for the JSE-S score in the test–retest study indicated a high level of reliability. The participants showed moderate empathy levels. Females scored higher than males in the Greek version of the JSE-S. Moreover, students enrolled in the fourth academic year showed higher empathy mean scores than those enrolled in the first year. Statistically significant empathy differences by specialty preferences or faith in God/supreme power were not found. The present study provided satisfactory evidence that the Greek JSE-S is a psychometrically sound measurement instrument. Empathy differences by gender were found in line with prior literature. [ABSTRACT FROM AUTHOR]

A new method is described for calculating flare combustion efficiency (CE) and destruction and removal efficiency (DRE) using a numerical parametric model. The method combines key variables that affect flare performance including the flare vent gas net heating value (NHV), flare design, flow rate, exit velocity, and inert gas composition, alongside the environmental influence of crosswind speed. Each effect is characterized using a parametric model derived from experimental testing data and computational fluid dynamics (CFD). The inclusion of CFD allows the model to be extended into the high-wind conditions that cannot be adequately controlled for in empirical testing yet represent some of the most challenging conditions in which to maintain good combustion. This new parametric model method (PMM) is coupled with ultrasonic flowmeters from which the molecular weight and net heating value of the flare gas can be derived using the vent gas speed of sound measurement. In doing so, this method provides a reliable continuous flare combustion efficiency measure that can be deployed at scale with minimum hardware updates. The system was verified using an extractive sampling method with tests conducted on three full-scale industrial flares including non-assisted, single-arm pressure-assisted, and multi-arm pressure-assisted flare designs. A total of seventy valid test points were carried out with varying flow rate and flare gas heating value, covering a CE range from 46–100%. The uncertainty of the method was assessed using both traditional error propagation and Monte Carlo methodology. The results from the new method agree with the extractive method to within 0.8% in the ≥98% DRE region where flares are expected to operate to limit the impacts of flaring as a source of methane as a greenhouse gas. Uncertainty analysis revealed that the larger DRE discrepancy for DRE ≤ 98% correlates to the measurement uncertainties for both methods. [ABSTRACT FROM AUTHOR]

Mindfulness is defined inconsistently, and its various measures resemble established personality self-report scales. Therefore, jingle and jangle fallacies are likely to undermine the construct's utility. To address these issues, we conducted two studies to test three hurdles of validity: 1) a sound definition and measurement model, 2) empirical distinctiveness, and 3) incremental criterion validity. We established an overarching and inclusive mindfulness definition covering twelve aspects. Based on this definition, we used an item sampling algorithm to select items from eight mindfulness scales. We established an eclectic bi-factor and a single-factor model, both fitting the data well. Bivariate latent variable correlations between a single mindfulness factor and big-five/six personality factors reached up to.68. Although 50% of mindfulness' variance was unaccounted for by the personality factors, it provided no meaningful incremental criterion validity over personality factors. Our results indicate that mindfulness has little or no incremental utility above established personality factors. [ABSTRACT FROM AUTHOR]

An investigation has been carried out to gain insight of the micellization behavior of streptomycin sulfate, a surface-active drug, in aqueous medium for six amino acids (proline, glutamic acid, asparagine, glycine, histidine, and aspartic acid) at 0.01 mol·kg−1. The thermodynamic aspects were analyzed using three techniques: conductivity, density, and speed of sound measurements at various temperatures (293.15–313.15 K) along with UV–Vis spectroscopy at a specific temperature of 298.15 K. By employing conductometry, valuable data on micellization and the degree of ionization of the drug were obtained. The impact of amino acids on two essential parameters, the critical micellar concentration (CMC) and thermodynamic aspects of drug micellization, have been examined. Interestingly, the presence of amino acids was found to enhance the drug tendency to form micelles, as depicted by the CMC variations. The study also investigated the suitability of UV–Vis spectroscopy with pyrene as a probe to explore the interactions between amino acids and the drug. Further, density and speed of sound analysis provides information about strong interactions in streptomycin sulfate-amino acids-water system. The results revealed significant changes in the micropolarity and micelle assembly due to these interactions in aforesaid system. [ABSTRACT FROM AUTHOR]

Sound power, a standard metric used to quantify product noise, is determined through the vibration-based sound power (VBSP) method. This method involves measuring surface velocities and utilizing an acoustic radiation resistance matrix, R, dependent on the structure's geometry. While R matrix expressions have been established for baffled flat plates, fully closed cylinders, and fully closed spheres, this work presents the first analytical expression tailored for baffled simply curved plates with uniform curvature. This development, based on eigenfunction expansion and the uniform theory of diffraction, extends the VBSP method's capabilities for accurate sound power assessment from these structures. Experimental validation involved testing three plates of varying curvature in a reverberation chamber, comparing the VBSP method with the ISO 3741 pressure-based standard. One of the curved plates underwent additional testing in an anechoic chamber following the ISO 3745 standard, confirming the VBSP method's accurate sound power measurements down to the 160 Hz one-third octave band. The same plate was tested in uncontrolled acoustic environments -- a busy hallway and an outdoor location. The VBSP results showed strong agreement with ISO 3741, affirming the method's robustness for measuring sound power from baffled simply curved plates in acoustically challenging real-world conditions. This underscores the practicality of the VBSP method, enabling accurate sound power measurements of baffled curved plates in the presence of substantial background noise and environmental variability. [ABSTRACT FROM AUTHOR]

Noise pollution has become a public health problem in several countries worldwide. Noise maps are tools used in many cities, mainly on the European continent. In other regions, they are used in smaller areas, and few studies focus on hospital areas, considered noise-sensitive zones. In this context, this study aimed to perform sound measurements and noise maps for the day and night periods in the surroundings of three hospitals in Sorocaba, Brazil. Sound measurements occurred around the three hospitals based on NBR 10151 and ISO 1996 standards. The noise maps were drawn up using a calculation model based on ISO 9613–2. Results showed that the sound measurement points around the hospitals had levels above those recommended by the Brazilian standard for sensitive areas (LAeq 50 and 45 dB for day and night, respectively). The acoustic maps showed high sound levels on all faces of the hospital buildings, both during the day and at night. The worst scenario concerned the vicinity of the roads with the highest flow and speed of vehicles. We concluded that three different hospitals in the city have high sound levels in their surroundings above the recommended for sensitive areas. [ABSTRACT FROM AUTHOR]

The use of journal bearings instead of rolling bearings as planetary bearings in wind turbine (WT) gearboxes is advantageous for the power density of the drive train. In addition, they can increase the reliability of the gearboxes as they can be operated wear-free in hydrodynamic operation, i.e. with fluid friction. The dynamic loading conditions in wind turbines, as well as special conditions such as insufficient lubrication and particle contamination, can lead to mixed friction operation and consequently to wear in the journal bearings. If mixed friction is not detected, damage and failure of the journal bearing and consequently of the WT gearbox may occur. Therefore, it is required to develop a Condition Monitoring System (CMS) to detect mixed friction in the journal bearings during operation of the WT. Preliminary investigations have shown that various friction conditions can be detected by acoustic measurements in combination with machine learning classifiers. Current investigations on CMS methods for journal bearings using acoustic measurement methods are limited to component level applications. A condition monitoring methodology for wind turbine gearbox journal bearings does not currently exist. A major challenge for CMS development for journal bearings in WT gearboxes is the transfer of methods already proven at component level to gearbox applications. In preparation for CMS application at the gearbox level, this paper presents an approach for monitoring different friction conditions of journal bearings based on acoustic measurements at a component test rig. For the classification of the friction state, different machine learning (ML)-based approaches trained on the acquired acoustic measurement data are compared with respect to the achieved classification accuracy. Knowledge of the robustness of the classification method, e.g. with respect to the distance of the sensor to the bearing, provides the necessary basis for the use of the CMS at the gearbox level. The investigations are carried out under operating conditions typical for planetary bearings in wind turbines. Classification performance is evaluated using a validated elasto-hydrodynamic simulation model. The aim of the work is to develop a method that detects friction classes in the journal bearing based on structure-borne sound measurements. Here, simulation results are used to train the algorithms. Finally, the demonstrated method will be successfully applied to a test rig for wind turbine gearbox journal bearings. Bas- ed on the results, an ML approach will be selected for application in gearboxes. [ABSTRACT FROM AUTHOR]

Over the past decade, a substantial body of research exploring soundscapes in religious historical buildings has emerged, yet a comprehensive summary of this work is lacking. This paper selects 74 typical studies of soundscapes in religious historical buildings published between 2011 and 2022 to conduct quantitative statistics and visualization analysis from a bibliometric perspective. The selected literature is categorized based on the type of religious building, Christian, Islamic, or Buddhist. The literature is further segmented according to the research subject, including sound field studies, sound analyses, and evaluations of the acoustic environment. The research methods employed are also differentiated and include sound field measurements, acoustic simulations, questionnaires and auralization procedures. The analysis reveals pronounced disparities in research foci depending on the type of religious historical building. For instance, studies on the soundscape in Christian churches tend to focus on objective sound field attributes and frequently employ sound field simulations to analyse the acoustic parameters of diverse church spaces and materials. Conversely, research on the soundscape in Islamic mosques prioritizes speech intelligibility and acoustic comfort, while studies of the soundscape of Buddhist temples gravitate towards the impact of natural and religious sounds on individuals. This paper anticipates the future direction of soundscape research on religious historical buildings. [ABSTRACT FROM AUTHOR]

The excess molar volume, excess isentropic compressibility, and deviation in viscosity have been investigated from density, speed of sound and viscosity measurements of three binary mixtures of 2-methyl-1-butanol (B) with 1,2–disubstituted ethanes (1,2–dichloroethane(B1), ethylenediamine (B2) and monoethanolamine (B3) over entire composition range at various temperatures of 303.15 K −313.15 K. The excess / deviation has been fitted by a Redlich-Kister equation and the results are discussed in terms of attractive forces and chemical forces. The excess properties are found to be either negative or positive depending on the physical and chemical forces and the nature of the liquid mixtures. These systems studied exhibit very strong cross-association through hydrogen bonding. Prigogine-Flory-Patterson (PFP) theory is applied to identify the predominant molecular interaction. Jouyban-Acree model, results are discussed in terms of mean relative deviation (MRDs) and individual relative deviation (IRD) between calculated and experimental densities, speeds of sound, and viscosities as an accuracy criterion. [ABSTRACT FROM AUTHOR]

Owing to the dependence of algorithms on the measurement of ship soundings and geophysical parameters, the accuracy and coverage of topography still need to be improved. Previous studies have mostly predicted topography using gravity or gravity gradient, However, there is a relative lack of integrated research combining or comparing gravity and gravity gradient. In this study, we develop observation equations to predict topography based on vertical gravity anomalies (VG; also called gravity anomalies) and vertical gravity gradient (VGG) anomalies generated by a rectangular prism. The sources of interference are divided into medium- to high-frequency errors and low-frequency errors, and these new methods reduce these errors through regularization and error equations. We also use numerical simulations to test the efficiency of the algorithm and error-reduction method. Statistics show that VGG anomalies are more sensitive to topographic fluctuations; however, the linear correlation between VG anomalies and topography is stronger. Additionally, we use the EIGEN-6C4 model of VG and VGG anomalies to predict topography in shallow and deep-sea areas, with maximum depths of 2 km and 5 km, respectively. In the shallow and deep-sea areas, the root mean square (RMS) errors of VGG anomalies prediction are 93.8 m and 233.8 m, and the corresponding accuracies improved by 7.3% and 2.3% compared with those of VG anomaly prediction, respectively. Furthermore, we use cubic spline interpolation to fuse ship soundings and improve the accuracy of the final topography results. We develop a novel analytical algorithm by constructing an observation equation system applicable to VG and VGG anomalies. This will provide new insights and directions to refine topography prediction based on VG and VGG anomalies. [ABSTRACT FROM AUTHOR]

Polar boundary layers are difficult to model due to the existence of intermittent turbulence within stable layers. Here we present a case study evaluation of coherent structures in a stable boundary layer observed during a series of flights with an uncrewed aircraft system (DataHawk2) on 19 October 2016 at Oliktok Point, Alaska as part of the ERASMUS (Evaluation of Routine Atmospheric Sounding Measurements using Unmanned Systems) field campaign. During a sequence of five flights over a nine-hour period, 57 profiles of atmospheric properties (0–400 m a.g.l) were collected. Turbulence was identified using derived Richardson Number, temperature structure function parameter, and turbulence kinetic energy dissipation. Throughout all flights on this strongly stable day, intermittent turbulence was observed. These turbulent layers showed well-mixed potential temperature profiles embedded within otherwise stable potential temperature profiles; often resulting in a characteristic staircase pattern. Turbulent layers ranged from 1 to 30 m deep, with most individual layers being 1–2 m deep. Vertical propagation velocities of layers in the lower atmosphere were on the order of a few cm s−1, typical of non-convective environments. In different regions of the profile, turbulence was driven by a different balance of buoyancy and shear forces, with turbulence in the near surface environment driven by strong shear forces overcoming strong resistance to buoyancy, while turbulence in elevated layers characterized by weaker shear forces overcoming weaker resistance to buoyancy. We discuss the potential of such datasets for improving subgrid parameterizations of small-scale turbulence embedded within stable boundary layers. [ABSTRACT FROM AUTHOR]

In this study, we developed a scale to assess employee perceptions of the presence of workplace health promotion (WHP) programs within their organizational environment. After reviewing the literature and following the social-ecological model of health, 14 scale items were generated and initially tested with university staff and students. From these analyses and feedback from reviewers, six items were removed. The remaining eight items were completed by an independent sample of employees in various companies. A two-factor model fit the data well, assessing the perceived support provided by the organization, such as financial support for health improvements at work, and the strategic approach of the organization in addressing workplace health, such as holding meetings and training about improving health. The sub-scales and total score were found to be internally consistent/reliable (α = 0.85 and 0.79, respectively), and correlated significantly with a work performance measure in one of the samples. The new Workplace Health Promotion Perception (WHPP) scale demonstrates initially sound measurement properties for use in organizations, although further research is suggested, and examples provided. [ABSTRACT FROM AUTHOR]

Mitigating low-frequency noise poses a significant challenge for acoustic engineers, due to their long wavelength, with conventional porous sound absorbers showing limitations in attenuating such noise. An effective strategy involves combining porous materials with micro-perforated plates (MPP) to address this issue. Given the significant impact of structural variables like panel thickness, hole diameter, and air gap on the acoustic characteristics of MPP, achieving the optimal condition demands numerous sample iterations. The impedance tube's considerable expense for sound absorption measurement and the substantial cost involved in fabricating each sample using a 3D printer underscore the advantage of utilizing simulation methods to attain the optimal state. This study focuses on optimizing low-frequency enhancement by investigating key parameters. Using the Finite Element Numerical Method (FEM) in COMSOL software, a composite panel was constructed comprising date palm fiber layers, an intervening air layer, and MPP. The study explored the arrangement of these layers and the impact of parameters like hole diameter, plate thickness, and perforation ratio on acoustic behavior. The selected optimal parameter at each stage was consistently maintained for subsequent steps. Results revealed that layer arrangement significantly influenced acoustic characteristics. Placing the MPP layer before the porous material yielded superior low-frequency performance. Optimizing low-frequency behavior involved reducing hole diameter and perforation ratio while increasing plate thickness. Elevating the porous material's thickness relative to the air layer behind the MPP enhanced absorption peak and resonance frequency. In conclusion, halving the porous layer's thickness while incorporating an air layer and single MPP proved more effective than using a thick porous material. This approach not only reduces costs and space requirements but also enhances low-frequency performance. The study highlights the precision of numerical methods like FEM, reducing the need for resource-intensive direct methods and associated laboratory expenses. Graphic Abstract [ABSTRACT FROM AUTHOR]

Purpose: Traditional management models are no longer viable in this complex era, with fast-pacing markets and various emergent properties affecting organizational success. The present study acknowledges the need for developing a coherent framework that leaders may use to evaluate their organizational adaptive ability. Design/methodology/approach: This paper uses theoretical analysis. Findings: This paper proposes the CAL-R framework, which identifies key characteristics of complex adaptive systems (CAS). These actionable elements, manifested in respective behaviors, will increase organizational adaptability. Adaptability is then suggested to be the mediating factor between complex adaptive leadership practice and organizational performance. Research limitations/implications: The suggested actionable elements are developed based on a theoretical, non-measurable approach; however, the need for statistical rigorousness is also acknowledged. Further research and a quantitative approach are also suggested for the development of a sound measurement scale. Practical implications: Applying effective complex adaptive leadership will potentially provide organizations with a competitive advantage by making them more innovative, able to transform and adapt to environmental needs and changes and eventually meet their goals and reach their vision. Leaders may use the identified actionable elements as benchmarks against which they can evaluate their organizations' complex adaptive leadership readiness (CAL-R). Originality/value: The CAL-R framework may be used by leaders in order to evaluate their organization's current adaptive maturity level (ability) and identify the elements they need to focus on more and develop in order to become more adaptive and competitive. [ABSTRACT FROM AUTHOR]

Numerous factors influence the acoustic characteristics of seafloor sediments, necessitating a comprehensive study that combines theoretical analysis, laboratory measurements and in situ measurements to support acoustic prediction and inversion. In this study, a porosity-based effective density fluid model (P-EDFM) is established to analyze the variation of acoustic properties with the porosity of seafloor sediments. On the biases of P-EDFM, the attribute of measured sound velocity and acoustic attenuation coefficient of seafloor sediment in Series 9B of the SAX99 was well interpreted within the frequency range of 25-100 kHz. The in situ measured sound velocity ratio was well predicated by the P-EDFM in the East China Sea and Yellow Sea. It reveals that the in situ sound velocity ratio decreases with increasing bulk porosity and with decreasing bulk density. The scattering and differences in the acoustic attenuation coefficient measured in situ in seafloor sediments are found to be greater than those observed for sound velocity. After considering the influence of temperature in the P-EDFM, the prediction of in situ sound velocity aligns well with the measured dataset. While, the acoustic attenuation coefficient exhibits an inflection point, increasing initially and then decreasing with changes in porosity, similar to the observed pattern in Hamilton’s observation and estimation. By incorporating temperature and frequency influences, the in situ measurements of sound velocity of seafloor sediments are corrected into laboratory sound velocities by using the P-EDFM. The result reveals the sediment samples’ sampling and transmitting process has a much greater impact on the sound velocity of sandy sediment in the East China Sea compared to muddy sediment. Overall, P-EDFM can predict the in situ sound velocity and sound attenuation coefficient under different temperatures and frequencies, with a lower prediction error for sound velocity compared to sound attenuation coefficient. [ABSTRACT FROM AUTHOR]

Here, we present observations of temporal variability of sub-ice platelet layer over seasonal and diurnal timescales under Ice Shelf Water-influenced fast ice in McMurdo Sound. Electromagnetic induction (EM) sounding time-series measurements of the thicknesses of fast ice and sub-ice platelet layer were made in winter and late spring of 2018. Winter objectives were to measure the seasonal growth of fast ice and sub-ice platelet layer near the McMurdo Ice Shelf in the east, while in late spring we assessed the diurnal variability of sub-ice platelet layer with coincident EM time-series and oceanographic measurements collected in the main outflow path of supercooled Ice Shelf Water in the west. During winter, we observed when the sub-ice platelet layer formed beneath consolidated ice. Episodes of rapid sub-ice platelet layer growth (~0.5–1 m) coincided with strong southerly-wind-events and polynya activity, suggesting wind-enhanced Ice Shelf Water circulation from the McMurdo-Ross Ice Shelf cavity. In late spring, we investigated how the tides and ocean properties influenced the sub-ice platelet layer. Over a two-week neap-spring tidal cycle, changes in sub-ice platelet layer thickness were observed to correlate with the tides, increasing more during neap than spring tide cycles, and on diurnal timescales, more on ebb than flood tides. Neap and ebb tides correspond with stronger northward circulation out of the cavity, indicating that sub-ice platelet layer growth was driven by tidally-enhanced Ice Shelf Water outflow. The observed variability indicated that wind-driven circulation and the tides influence Ice Shelf Water outflow in McMurdo Sound, and consequently, sub-ice platelet layer evolution over a range of timescales. [ABSTRACT FROM AUTHOR]

Noise, vibration, and harshness (NVH) researchers spend inexhaustible resources of materials, time and money in determining the objective factors that are important in ensuring acoustic comfort in vehicles. In this paper, the factors that directly influence the interior acoustic pressure level in a heavy-duty vehicle were investigated. It was determined using specific descriptors and different units of measurement in assessment of sound levels and the impact generated by noise, the level of interior acoustic pressure and particular values of some prominent sources of noise in the operation of vehicles (engine, HVAC system), taking into account the factors of insurance and thermal comfort, with the aim of determining the cumulative impact at the board of heavy vehicles due to noise. [ABSTRACT FROM AUTHOR]

Sound absorption properties of clay surfaces At present, the historical building material clay is once again being used much more frequently in the construction industry. It is increasingly being used in residential and non‐residential buildings as plaster, building panels or design elements in the form of rammed earth or clay blocks. Because there are few reliable measurements of the sound absorption properties of clay surfaces, the frequency‐dependent sound absorption coefficients of a classic rammed earth wall and a surface plastered with clay were determined using the reverberation chamber method according to EN ISO 354 as part of the DBU‐funded EcoSights research project. Furthermore, a series of tests with measurements using the impedance tube (Kundt′s tube) according to DIN EN ISO 10534‐1 was carried out with rammed earth. The weight loss and the change in the surface structure of the samples were recorded. For the investigated clay surfaces, higher sound absorption coefficients than the design values for equivalent materials used for the purpose in building practice were obtained. [ABSTRACT FROM AUTHOR]

Comprehensive and accurate measurements of the speed of sound in liquid water are reported. The measurements were carried out by a double-path-length pulse-echo technique and cover the temperature range from 273.65 K to 368.15 K with pressures up to 100 MPa. The relative expanded ( k = 2 ) uncertainties are 2.1 mK in temperature, 45 parts-per-million (ppm) in pressure, and between 40 ppm and 70 ppm in speed of sound. Furthermore, values for the density and specific isobaric and isochoric heat capacities were derived from the speed of sound data in the measured temperature range up to 100 MPa by the method of thermodynamic integration. Very accurate values for the derived properties were obtained by using density data of Takenaka and Masui (Metrologia 27:165–171, 1990) and isobaric heat capacity data of Osborne et al. (J Res Natl Bur Stand 23:197, 1939) at ambient pressure as initial values in combination with an accurate correlation of our speed of sound. The relative expanded ( k = 2 ) uncertainties of the derived properties are 2 ppm in density, 0.11% in isobaric heat capacity, and 0.12% in isochoric heat capacity. The experimental speeds of sound and derived properties are compared with experimental data of other authors from the literature, the IAPWS-95 (International Association of the Properties of Water and Steam) formulation for the thermodynamic properties of water, and a recent equation of state for supercooled water. [ABSTRACT FROM AUTHOR]

Noise was among the most contested issues in the large open offices that proliferated after World War II in Europe and North America. The "landscape" offices that developed out of the German Bürolandschaft movement were known for large floor plates filled with misaligned desks. They were meant to improve employees' communication, but their acoustic design prompted worker anxieties about distraction and diminishing privacy. While early remediation efforts sought to quiet offices, in the 1960s designers began adding random, unintelligible noise to mask distractions and arranging employees according to their expected sound levels. This shift from eliminating noise to embracing it as a space-defining element reflected a powerful new acoustic paradigm. The Bürolandschaft movement waned in the 1970s, but the judicious spatial deployment of noise remains an invaluable technique as designers consider how architecture can help or hinder communication and collective intellectual activity. [ABSTRACT FROM AUTHOR]

Auditory localization plays an essential role in various tasks, including spatial orientation, locomotion, attention and memory. Optimization of experimental routine is important for preliminary assessment of the subject's sound localization ability. In the present study, a new quick technique for estimating the relative minimum audible distance (RMAD) using sound images is introduced. Twenty adults with normal hearing took part in six RMAD measurements in free field. The reference RMAD values were obtained using a method of constant stimuli by physically positioning a real sound source. The same method was used with stationary sound images created by superposition of signals emitted by two loudspeakers. To optimize the measurements, the RMADs were determined for the sound images using two adaptive psychoacoustic procedures known as one-down, one-up and two-down, one-up staircases. The group-average RMADs obtained by the method of constant stimuli for both types of stimuli and by two adaptive procedures were similar, 7% (SD = 2%). The effect of whether subjects were sighted or blindfolded was not significant for measurements of RMAD to sound images. The average measurement times were 373 s (SD = 20 s) for the method of constant stimuli, 85 s (SD = 9 s) for the one-down, one-up, and 124 s (SD = 14 s) for the two-down, one-up procedure. The results are consistent with the previous studies and confirm the validity of the measurements of RMAD using adaptive procedures with stationary sound images as a quick method. [ABSTRACT FROM AUTHOR]

The ultra-short baseline (USBL) positioning system has been widely used for autonomous and remotely operated vehicle (ARV) positioning in marine resource surveying and ocean engineering fields due to its flexible installation and portable operation. Errors related to the sound speed are a critical factor limiting the positioning performance. The conventional strategy adopts a fixed sound velocity profile (SVP) to correct the spatial variation, especially in the vertical direction. However, SVP is actually time-varying, and ignoring this kind of variation will lead to a worse estimation of ARVs'coordinates. In this contribution, we propose a two-step sound speed correction method, where, firstly, the deviation due to the acoustic ray bending effect is corrected by the depth-based ray-tracing policy with the fixed SVP. Then, the temporal variation of SVP is considered, and the fixed SVP is adaptively adjusted according to the in situ sound velocity (SV) measurements provided by the conductivity–temperature–depth (CTD) sensor equipped at the ARV. The proposed method is verified by semi-physical simulation and sea-trail dataset in the South China Sea. When compared to the fixed-SVP method, average positioning accuracy with the resilient SVP be improved by 8%, 21%, and 26% in the east, north, and up directions, respectively. The results demonstrate that the proposed method can efficiently improve the adaptability of sound speed observations and deliver better performance in USBL real-time positioning. [ABSTRACT FROM AUTHOR]

• Modified the experimental procedure or the sound-speed measurements of mixtures. • Reported the first set of gaseous speed of sound data for R1234yf(1) + R134a(2). • Established the method of determining the accurate component molar fraction. • Derived the molecular potential parameters and the interaction virial coefficient. • Reported a modified virial-coefficient correlation for the mixtures. The binary mixture 2,3,3,3-tetrafluoropropene (R1234yf) + 1,1,1,2-tetrafluoroethane (R134a) is commercially interesting and is widely studied in thermodynamics properties, but except for gaseous speed of sound. In this work, we modified the experimental procedure of the cylindrical fixed-path acoustic resonance method for the sound speed measurement of mixtures. Then we obtained the first two sets of gaseous sound speed data at the molar fraction of about (0.207/0.793) and (0.580/0.420) with a combined relative expanded uncertainty (k = 2) of 0.03%. The accurate molar fractions along each isotherm line were determined by extrapolating the experimental data with the absolute expanded uncertainty (k = 2) of 0.003. The interaction virial coefficients were derived from the experimental sound speed data and were used to establish a hard-core square-well molecular potential model. A previous virial coefficient correlation was modified to predict the virial coefficients for mixtures. The experimental results and model calculations agree well with each other, confirming the correctness of the experimental method. The data could provide references to test and develop the mixing model. [ABSTRACT FROM AUTHOR]

Many physical-layer security works in the literature rely on purely theoretical work or simulated results to establish the value of physical-layer security in securing communications. We consider the secrecy capacity of a wireless Gaussian wiretap channel using channel sounding measurements to analyze the potential for secure communication in a real-world scenario. A multi-input, multi-output, multi-eavesdropper (MIMOME) system is deployed using orthogonal frequency division multiplexing (OFDM) over an 802.11n wireless network. Channel state information (CSI) measurements were taken in an indoor environment to analyze time-varying scenarios and spatial variations. It is shown that secrecy capacity is highly affected by environmental changes, such as foot traffic, network congestion, and propagation characteristics of the physical environment. We also present a numerical method for calculating MIMOME secrecy capacity in general and comment on the use of OFDM with regard to calculating secrecy capacity. [ABSTRACT FROM AUTHOR]

• 3D ultrasonic sources were applied during the solidification of Mg-Zn-Y alloy. • Acoustic spectra were in-situ measured with cavitation intensities calculated. • Transient cavitation refines primary Mg 3 Zn 6 Y phase from petals to pentagon shape. • Anomalous (α-Mg+Mg 3 Zn 6 Y) eutectic structure occurs due to stable cavitation. • Mechanical properties and corrosion resistance were comprehensively improved. One dimensional (1D) and three dimensional (3D) ultrasound sources were applied to the solidification process of Mg 71.5 Zn 26.1 Y 2.4 alloy. The acoustic spectra were in-situ measured, based on which the cavitation intensities and dynamic solidification mechanism were further investigated. With the increase of ultrasonic dimension and amplitude, the primary Mg 3 Zn 6 Y phase was significantly refined from petals to nearly pentagonal shape. The sound field measurements showed that the transient cavitation played a decisive role in generating a high local undercooling, which facilitated the formation of icosahedral clusters and promoted the nucleation of primary Mg 3 Zn 6 Y phase. The morphological transition of (α-Mg+Mg 3 Zn 6 Y) eutectic from lamellar to anomalous structure occurred under 3D ultrasonic condition. The stable cavitation took the main responsibility because the high pressure excited by nonlinearly oscillating bubbles induced the preferential nucleation of α-Mg phase rather than Mg 3 Zn 6 Y phase. As compared with its static values, the tensile strength and compression plasticity of this alloy were increased by the factors of 1.9 and 2.1, and its corrosion resistance was also improved with the corrosion current density decreased by one order of magnitude. [ABSTRACT FROM AUTHOR]

The provision of quality healthcare relies on scales and measures with robust evidence of their psychometric properties. Using measurement instruments with poor reliability, validity, or feasibility, or those that are not appropriate for the target diagnostic group or construct/dimension under consideration, may be unfavorable for patients, unproductive, and hinder empirical advancement. Resources from the COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) group can assist in identifying and developing psychometrically sound measures. The COSMIN initiative is the only international, research-based practice taxonomy and methodological guidelines for measurement in healthcare. This manuscript aims to provide an accessible introduction to theories, principles and practices of psychometrics, instrument properties, and scale development, with applied examples from the COSMIN recommendations. It describes why measurement in healthcare is critical to good practice, explains the concepts of the latent variable and hypothetical construct and their importance in healthcare assessments, explores issues of flawed measurement and briefly explains key theories relevant to psychometrics. The paper also outlines a ten-step process to develop and validate a new measurement instrument, with examples drawn from a recently developed visuoperceptual measure for analysis of disordered swallowing to demonstrate key concepts and provides a guide for understanding properties of and terminology related to measurement instruments. This manuscript serves as a resource for healthcare clinicians, educators, and researchers who seek to develop and validate new measurement instruments or improve the properties of existing ones. It highlights the importance of using psychometrically sound measurement instruments to ensure high-quality healthcare assessments. [ABSTRACT FROM AUTHOR]

The shock wave response of [100] lithium fluoride (LiF) single crystals at high stresses is of long-standing interest due to their extensive use as optical windows in dynamic compression experiments. The report of melting in shock-compressed LiF single crystals between 134 and 152 GPa—based on a single sound speed datum [Liu et al., J. Appl. Phys. 117, 045901 (2015)]—was surprising because good optical transmission was previously demonstrated in LiF shock compressed to ∼200 GPa [Rigg et al., J. Appl. Phys. 116, 033515 (2014)]. To address these apparent differences, we report on plate impact experiments on [100] LiF single crystals shock compressed to 168 GPa. Wave profiles were measured using laser interferometry to determine Hugoniot states and longitudinal sound speeds in shock-compressed LiF. The measured Hugoniot states are in good agreement with those measured in previous studies. However, the measured sound speeds presented here show no evidence of melting up to 168 GPa. In particular, the abrupt drop reported previously in sound speed at 152 GPa was not observed in the present work. Our results establish a lower bound of 168 GPa for the onset of melting in shock-compressed LiF single crystals. [ABSTRACT FROM AUTHOR]

Ramp-compression experiments have been performed on the "Z" pulsed-power facility to investigate the strengths of Be and lead–antimony alloy. Yield strength and shear stress near peak pressure were obtained from measurements of the sound speed on release and using the Asay self-consistent method. Two S-65 grade Be samples, from batches that showed a significant difference in yield strength at ambient conditions, were found to have near identical yield strengths, which were also in agreement with similar earlier measurements on S-200 grade Be. Yield strength of the Pb4Sb alloy at ∼120 GPa was 1.35 GPa, while a National Ignition Facility experiment by Krygier et al. [Phys. Rev. Lett. 123, 205701 (2020)] found 3.8 GPa at ∼400 GPa pressure. Our result is intermediate between the ambient value and the one by Krygier et al., but the significantly increased strength is probably not associated with the transition to the high-pressure bcc phase of lead. [ABSTRACT FROM AUTHOR]

The heat capacity ratio or Laplace coefficient γ = C p / C V is determined at high pressure and high temperature by a numerical procedure from sound velocity measurements for a dozen liquids, including alkali metals and iron. The obtained data provide insight into this quantity that is difficult to measure experimentally. In addition, an analytical expression of the heat capacity ratio as a function of pressure is proposed, based on reasonable assumptions. This expression can be used for interpolation, extrapolation at high pressure, or to easily convert isothermal quantities into adiabatic ones or inversely. [ABSTRACT FROM AUTHOR]