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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]

Both spontaneous Raman scattering and stimulated Raman scattering (SRS) are cornerstones of modern photonics, spectroscopy, and imaging. However, a unified understanding of the ultimate detectability of Raman scattering is lacking, due to both historical and technical reasons. Starting from quantum electrodynamics, we formulate the fundamental detectability for both spontaneous Raman scattering and SRS. The key concept is recognizing spontaneous Raman scattering as stimulated Raman process driven by vacuum field fluctuation. A simple and unified expression, Eq. (17), is derived, which can be depicted on a two-dimensional phase-diagram-like graph with inherent symmetry. It turns out that the particle nature of light dictates the ultimate detectability of spontaneous Raman scattering, which can be represented by a line on this detectability diagram. Importantly, if provided with a reasonably strong Stokes photon flux, SRS can breach this fundamental limit and open uncharted territory of drastically accelerated measurement speed and much lower detection concentration relevant to biological imaging. Such new territory in the detectability diagram is otherwise forbidden by the spontaneous counterpart. Diagrammatical analysis explains the empirical observations, provides quantitative insights, and makes new predictions. Notably, recent experimental applications of SRS microscopy can almost entirely be captured by this diagram, further supporting the explanatory power of the theory. Thus, this unified diagrammatic approach outlines a framework to understand all Raman-based measurement and provides a theoretical explanation for the remarkable utility of the emerging SRS microscopy. [ABSTRACT FROM AUTHOR]

Real-time temperature monitoring with high accuracy and spatiotemporal resolution is critical for many biological applications, including disease diagnosis, drug delivery, and biomedical research. However, traditional methods for measuring temperature in biological systems present difficulties for a variety of reasons, such as slow response time, limited spatial resolution, low amplitude, and susceptibility to electromagnetic interference. Most importantly, in many cases, the thermal mass of temperature probes limits the accuracy and speed of measurement significantly. Here, we show that photonic microring resonators (MRRs) can be used for sensitive, precise, and high spatiotemporal resolution measurement of temperature in the biological milieu. The high refractive index of Si MRR and negligible thermal mass enable sensitive, ultrafast, and accurate temperature transients. By using a double resonator circuit, we demonstrate that MRR sensors can measure temperature with a 1 mm spatial resolution. We then show that MRR yields more accurate results than fiber optic probes for measuring temperature transients. Finally, we demonstrate the localized temperature measurement capability of MRRs in mouse brain tissue heated by superparamagnetic nanoparticles in an alternating magnetic field. This compact, lab-on-chip photonic temperature sensing platform holds great promise for continuous monitoring of temperature in critical biological and biomedical applications. [ABSTRACT FROM AUTHOR]

We have recently demonstrated that the 3D shape of micro-parts can be measured using LED illumination based on speckle contrast evaluation in the recently developed SPICE profilometry (shape measurements based on imaging with spatially partially coherent illumination). The main advantage of SPICE is its improved robustness and measurement speed compared to confocal or white light interferometry. The limited spatial coherence of the LED illumination is used for depth discrimination. An electrically tunable lens in a 4 f -configuration is used for fast depth scanning without mechanically moving parts. The approach is efficient, takes less than a second to capture required images, is eye-safe and offers a depth of focus of a few millimeters. However, SPICE's main limitation is its assumption of a small illumination aperture. Such a small illumination aperture affects the axial scan resolution, which dominates the measurement uncertainty. In this paper, we propose a novel method to overcome the aperture angle limitation of SPICE by illuminating the object from different directions with several independent LED sources. This approach reduces the full width at half maximum of the contrast envelope to one-eighth, resulting in a twofold improvement in measurement accuracy. As a proof of concept, shape measurements of various metal objects are presented. [ABSTRACT FROM AUTHOR]

Laminar flame speeds of ammonia/hydrogen blends diluted in a mixture of 79% Ar and 21% O 2 (referred to as "airgon") were measured for the first time at high temperatures exceeding 500 K and atmospheric pressure using the shock tube flame speed method. Lean (ϕ = 0.8), stoichiometric (ϕ = 1) and rich (ϕ = 1.2) mixtures, with hydrogen fuel fractions x H 2 = 0.2, 0.4, and 0.6 were studied in the temperature range of 500–820 K behind reflected shock waves. A significant enhancement in flame speeds and improved flame morphology was observed with increasing concentrations of hydrogen. Equivalent fuel/air data were computed from fuel/airgon measurements using a mixture-scaling approach and compared against available literature data. Although current data do not overlap with the temperatures of data in the literature, the full 300–800 temperature range of experimental data remain consistent with a non-Arrhenius correlation, while a power-law fit does not capture the full data trend. 1-D flame speed simulations were conducted using five recent chemical kinetic models of ammonia combustion available in the literature. Large disagreement was found among the models, with the model by Zhou et al. agreeing well with experiments at all conditions studied in this work. Sensitivity analyses were performed, and the most relevant reactions involved in the computation of flame speed, according to the models, were identified. Overall, the experimental data and modeling demonstrate the value of using blends of ammonia and hydrogen to improve the combustion characteristics of ammonia as a carbon-free fuel. • First measurements of ammonia/hydrogen flame speeds at temperatures above 500 K. • Hydrogen fuel fraction varying from 0.2 to 0.6, with ϕ = 0.8, 1, and 1.2 were studied. • Inclusion of hydrogen significantly improves ammonia flame morphology. • Empirical correlations were constructed using measurements and literature data. • Significant differences in the predictions of chemical kinetic models were observed. [ABSTRACT FROM AUTHOR]

Ocean currents are one of the movements of horizontal or vertical mass movement of seawater that takes place continuously. The purpose of this study is to determine current conditions in open water close to narrow strait waters, as well as canal estuaries. Current data is the result of measurements that have been carried out using ADCP (Acoustic Doppler Current Profiler) mini type ADP-SONTEK equipment on May 16, 2018, while tidal data refers to the recording results of the Makassar BIG tidal station. The results showed that the total surface current speed ranged from 0.017 - 0.375 m/sec with a dominant direction to the west or to open water both at high tide and at low tide. While the result of separation, the speed of tidal currents ranges from 0.032 - 0.343 m / sec. [ABSTRACT FROM AUTHOR]

This study discusses acoustic dissipation, which contributes to inaccuracies in impedance tube measurements. To improve the accuracy of these measurements, this paper introduces a transfer function model that integrates diverse dissipation prediction models. Bayesian inference is used to estimate the important parameters included in these models, describing dissipation originating from various mechanisms, sound speed, and microphone positions. By using experimental measurements and considering a hypothetical air layer in front of a rigid termination as the material under test, Bayesian parameter estimation allows a substantial enhancement in characterization accuracy by incorporating the dissipation and sound speed estimates. This approach effectively minimizes residual absorption coefficients attributed to both boundary-layer effects and air medium relaxation. The incorporation of dissipation models leads to a substantial reduction (to 1%) in residual absorption coefficients. Moreover, the use of accurately estimated parameters further enhances the accuracy of actual tube measurements of materials using the two-microphone transfer function method. [ABSTRACT FROM AUTHOR]

In late March 2011, landfast sea ice (hereafter, "fast ice") formed in the northern Larsen B embayment and persisted continuously as multi-year fast ice until January 2022. In the 11 years of fast-ice presence, the northern Larsen B glaciers slowed significantly, thickened in their lower reaches, and developed extensive mélange areas, leading to the formation of ice tongues that extended up to 16 km from the 2011 ice fronts. In situ measurements of ice speed on adjacent ice shelf areas spanning 2011 to 2017 show that the fast ice provided significant resistive stress to ice flow. Fast-ice breakout began in late January 2022 and was closely followed by retreat and breakup of both the fast-ice mélange and the glacier ice tongues. We investigate the probable triggers for the loss of fast ice and document the initial upstream glacier responses. The fast-ice breakup is linked to the arrival of a strong ocean swell event (>1.5 m amplitude; wave period waves >5 s) originating from the northeast. Wave propagation to the ice front was facilitated by a 12-year low in sea ice concentration in the northwestern Weddell Sea, creating a near-ice-free corridor to the open ocean. Remote sensing data in the months following the fast-ice breakout reveals an initial ice flow speed increase (>2 -fold), elevation loss (9 to 11 m), and rapid calving of floating and grounded ice for the three main embayment glaciers Crane (11 km), Hektoria (25 km), and Green (18 km). [ABSTRACT FROM AUTHOR]

Objectives: The objectives were to present the real-time estimated values of cochlear implant (CI) electrode insertion speed (IS) during intraoperative sessions using the Cochlear Nucleus SmartNav System to assess whether this measure affected CI outcomes and to determine whether real-time feedback assists expert surgeons in achieving slow insertion. Methods: The IS was measured in 52 consecutive patients (65 implanted ears) using the CI632 electrode. The IS values were analyzed in relation to procedure repetition over time, NRT ratio, and CI audiological outcomes. Results: The average IS was 0.64 mm/s (SD = 0.24); minimum and maximum values were 0.23 and 1.24 mm/s, respectively. The IS significantly decreased with each array insertion by the operator (p = 0.006), and the mean decreased by 24% between the first and last third of procedures; however, this reduction fell within the error range of SmartNav for IS (+/−0.48 mm/s). No correlation was found between IS and the NRT ratio (p = 0.51), pure-tone audiometry (PTA) at CI activation (p = 0.506), and PTA (p = 0.94) or word recognition score (p = 0.231) at last evaluation. Conclusions: The estimated IS reported by SmartNav did not result in a clinically significant reduction in insertion speed or an improvement in CI hearing outcomes. Real-time feedback of IS could potentially be used for training, but its effectiveness requires confirmation through additional studies and more accurate tools. Implementation of IS assessment in clinical practice will enable comparisons between measurement techniques and between manual and robot-assisted insertions. This will help define the optimal IS range to achieve better cochlear implant (CI) outcomes. [ABSTRACT FROM AUTHOR]

A fully differential lumped linear driver for Mach–Zehnder modulator has been presented and assessed in 130‐nm SiGe BiCMOS technology. Multitopology peaking techniques, especially T‐coil peaking method, have been employed to flatten the frequency response and increase the bandwidth. Degeneration resistors have been used to enhance circuit linearity. Simultaneously, improvements have been made to the output stage of the conventional single emitter follower push–pull) circuit to enhance the output eye diagram quality at higher transmission rates. The fabricated driver achieved a differential gain of 16.2 dB with a bandwidth of over 50 GHz, corresponding to a fixed output swing of over 3.2 Vppd within the automatic gain control loop. Time domain measurements, limited in speed by the measurement setup, reported a data rate up to 56 Gb/s none return to zero and 40‐GBaud 4‐levels pulse amplitude modulation with a bit error rate less than 10−12. [ABSTRACT FROM AUTHOR]

Coherent Doppler wind lidar (CDWL) uses transmitted laser pulses to measure wind velocity distribution. However, the echo signal of CDWL is easily affected by atmospheric turbulence, which can decrease the signal-to-noise ratio (SNR) of lidar. To improve the SNR, this paper proposes a pulse accumulation method based on the cross-correlation function to estimate the phase of the signal. Compared with incoherent pulse accumulation, the proposed method significantly enhances the correlation between signals from different periods to obtain high SNR gains that arise from pulse accumulation. Using simulation, the study evaluates the effectiveness of this phase estimation method and its robustness against noise in algorithms which analyze Doppler frequency shifts. Furthermore, a CDWL is developed for measuring the speed of an indoor motor turntable and the outdoor atmospheric wind field. The phase estimation method yielded SNR gains of 28.18 dB and 32.03 dB for accumulation numbers of 500 and 1500, respectively. The implementation of this method in motor turntable speed measurements demonstrated a significant reduction in speed error—averaging 9.18% lower than that of incoherent accumulation lidar systems. In experiments that measure atmospheric wind fields, the linear fit curve slope between the measured wind speed and the wind speed measured via a commercial wind-measuring lidar can be reduced from 1.146 to 1.093. [ABSTRACT FROM AUTHOR]

This study illustrates at‐line application of hyperspectral imaging in the visible range for quality control of large‐scale offset printing. In particular, the measurement stability of a competitive device is assessed and compared to traditional handheld and desktop spectrophotometers. The performance of the commercially available instruments was assessed based on collected spectra and their corresponding L*, a*, and b* values. The printing process was described by hyperspectral images (in visible range) of selected regions from template color fields acquired at 17 sampling occasions. Spectra constituting hyperspectral images were visualized and evaluated in the space of significant principal components obtained from the principal component analysis. Furthermore, confidence ellipses were constructed for each set of spectra characterizing a specific moment of the printing process. Comparing their mutual locations, shapes, orientations, and sizes enabled effective visualization of process variability and was more comprehensive regarding the classic approach based on information provided by desktop and handheld spectrometers. This study demonstrates the effectiveness of hyperspectral imaging for real‐time quality control in large‐scale offset printing, in particular by studying sampling distributions. By assessing measurement stability and comparing competitive devices with traditional spectrophotometers, it reveals the advantages of hyperspectral imaging in measurement speed, spatial dimension inclusion, and process variability visualization. Chemometric analysis aids in effective color assessment, while local segmentation can offer insights into color perception, crucial for process monitoring and detection of various sources of variation. [ABSTRACT FROM AUTHOR]

Evidence is analyzed that indicates that the material universe, in which the Earth and Milky Way Galaxy reside, does not have a high speed net expansion or translational velocity. The velocity of planet Earth in the solar system is used to correct data carefully obtained by Albert Michelson from 1926 to 1933 for the speed of light measured directly from c = d/t for round trips of travel in differing directions on Earth. When light source and target move together in lateral motion with respect to Earth orbit velocity, synchronous aberration of light is incorporated to correct the computations. All data are then in close agreement with the intrinsic speed that light must have from its own instantaneous position in space, derived by James Maxwell. The relative velocity between a light front and a moving target depends on the velocity of the target and causes light to travel a different distance than the simple ground distance between source and target, all while light speed remains fixed at c. The close agreement of observed speed with true light speed in all cases indicates that the difference between total velocity of the Earth and its solar orbit velocity is not relatively large. It is possible that the universe of matter may exist in a rotating dynamic equilibrium state in which regional irregularity exists with overall order. • The direct measurements of light speed by Michelson are corrected for earth orbit velocity. • All light speed measured values agree to high accuracy with the Maxwell derived formula. • The total velocity of the Earth in space is not consistent with rapid motion. • The unjverse of galaxies including the Milky Way may not be expanding from a central location. • The correlation of red shifts with star distances are explained by mechanisms other than Doppler motion. [ABSTRACT FROM AUTHOR]

Laminar flame speeds of methanol/air mixtures at 338–398 K are measured by the heat flux method, extending the range of equivalence ratio up to 2.1. And a new optimized methanol mechanism with 94 reactions is proposed by using the particle swarm algorithm, adjusting 20 Arrhenius pre‐exponential factors in their uncertainty domains. The optimized model is compared with eight methanol combustion mechanisms and experimental data published in recent years, covering a wide range of initial temperatures (298–1537 K), pressures (0.04–50 atm) and equivalence ratios (0.5–2.1). The results show that the optimized mechanism not only improves the accuracy of ignition delay time with rapid compression machine at low temperature but also moderately improve the description of laminar flame speed in lean and stoichiometric conditions. Meanwhile, the optimized model significantly enhances the prediction accuracy of CH3 and CH2O radical, and perfectly captures the evolution trend of HCO radical in laminar flat flame. Overall, the optimized mechanism provides the best overall description of the currently available measurements, leading to more accurate and comprehensive prediction of ignition delay time, laminar flame speed and species concentration. [ABSTRACT FROM AUTHOR]

To measure the parallel interactive development of latent ability and processing speed using longitudinal item response accuracy (RA) and longitudinal response time (RT) data, we proposed three longitudinal joint modeling approaches from the structural equation modeling perspective, namely unstructured-covariance-matrix-based longitudinal joint modeling, latent growth curve-based longitudinal joint modeling, and autoregressive cross-lagged longitudinal joint modeling. The proposed modeling approaches can not only provide the developmental trajectories of latent ability and processing speed individually, but also exploit the relationship between the change in latent ability and processing speed through the across-time relationships of these two constructs. The results of two empirical studies indicate that (1) all three models are practically applicable and have highly consistent conclusions in terms of the changes in ability and speed in the analysis of the same data set, and (2) additional analysis of the RT data and acquisition of individual processing speed measurements can reveal the parallel interactive development phenomena that are difficult to detect using RA data alone. Furthermore, the results of our simulation study demonstrate that the proposed Bayesian Markov chain Monte Carlo estimation algorithm can ensure accurate model parameter recovery for all three proposed longitudinal joint models. Finally, the implications of our findings are discussed from the research and practice perspectives. [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]

Fringe projection profilometry (FPP) is widely used for high-accuracy 3D imaging. However, employing multiple sets of fringe patterns ensures 3D reconstruction accuracy while inevitably constraining the measurement speed. Conventional dual-frequency FPP reduces the number of fringe patterns for one reconstruction to six or fewer, but the highest period-number of fringe patterns generally is limited because of phase errors. Deep learning makes depth estimation from fringe images possible. Inspired by unsupervised monocular depth estimation, this paper proposes a novel, weakly supervised method of depth estimation for single-camera FPP. The trained network can estimate the depth from three frames of 64-period fringe images. The proposed method is more efficient in terms of fringe pattern efficiency by at least 50% compared to conventional FPP. The experimental results show that the method achieves competitive accuracy compared to the supervised method and is significantly superior to the conventional dual-frequency methods. [ABSTRACT FROM AUTHOR]

In this paper, we proposed a stepping equivalent range-gate method (S-ERG method) to measure the speed and the distance of the moving target for range-gated imaging lidar. In this method, the speed is obtained by recording the time at which the moving target passes the front and back edges of the range gate, the distance information can also be obtained by the front and back edges of the range gate at the same time. To verify the feasibility of this method, a stationary target and a moving target with different speeds were measured by the S-ERG method. By using the S-ERG method, we not only obtained the distance information of the stationary target and the moving target at the front and back edges of the range gate, respectively, but also obtained the speed of the moving target. Compared to speeds measured by rotational displacement sensors, the speed measurement error of the S-ERG method is less than 5%, whether the target is far away or close to the range-gated lidar system, and this method is almost independent of the delay step time. The theoretical analysis and experimental results indicate range-gated imaging lidar using the S-ERG method has high practicality and wide applications. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to develop a seven-link dynamic model of the operator's body while working with a motorized backpack sprayer. This model includes the coordinates of the sprayer relative to the body, the rotational inertia of the sprayer, the muscle moments acting on the joints, and a kinematic coupling that keeps the body balanced between the two legs. The constraint functions were determined and the non-linear differential equations of motion were derived using Lagrangian equations. The results show that undesirable fluctuations in the ankle force are noticeable at the beginning and end of a swing phase. Therefore, injuries to the ankle joint are more likely due to vibrations. The effects of engine speed and sprayer mass on the hip and ankle joint forces were then investigated. It is found that the engine speed and sprayer mass have significant effects on the hip and ankle forces and can be used as effective control parameters. The results of the analysis also show that increasing the engine speed increases the frequency of the hip joint force. However, no significant effects on the frequency of the ankle joint force are observed. The results of this study may provide researchers with insight into estimating the allowable working hours with the motorized backpack sprayers, prosthesis design, and load calculations of hip implants in the future. [ABSTRACT FROM AUTHOR]

Article: —This article describes the construction, principles of operating, and characteristics of the TOTEM- electron spectrometer developed for the Strannik complex of scientific instruments for the Resonance-MKA space project. In the article, analytical characteristics are presented of the qualification model of the instrument, which fully corresponds to the flight unit, and the procedure for functional tests of the instrument is described. The article also describes the structure and principles of functioning of the hardware and software laboratory facility developed for ground calibrations and tests of such a type of instruments. The design of the TOTEM-E instrument offers a new approach to measuring particle fluxes, which allows the accuracy and speed of measurements to be increased. A feature of the proposed scheme is the possibility of simultaneous measurement of electron fluxes in a plane section in the velocity space in the energy range from E0 to 6.5 × E0, where E0 is the minimum particle energy recorded by the instrument. This is achieved by using two conical electrostatic mirrors that take electrons from a flat 360° flow section for subsequent energy analysis and using a coordinate-sensitive detector for simultaneous particle registration. [ABSTRACT FROM AUTHOR]

A poro-elastic model for both sandy and muddy marine sediments is used to derive a visco-elastic approximation, and compared to the existing measurements of wave speeds, attenuations, and reflection. The poro-elastic model is the modified, corrected, Revil, extended Biot (mCREB) model. Its derivation, which includes a force chain approximation and a creep mechanism, is reviewed and equations for implementation are provided. It fits the existing measurements over a broad range of frequencies from a few Hertz to almost a megaHertz. Salinity is essential to the poro-elastic behavior of mud. A visco-elastic approximation is derived, based on the zero permeability condition. It is a simpler model with fewer input parameters, and practically identical to the popular viscous grain shearing (VGS) model, although their derivations are very different. Comparisons between the measurements, the poro-elastic model, and its visco-elastic approximation are made in order to identify the circumstances in which the latter may be used. Generally, the visco-elastic approximation may be used for frequencies below 1 kHz in mud and sand. At higher frequencies, poro-elastic effects dominate rendering the visco-elastic approximation inaccurate. [ABSTRACT FROM AUTHOR]

Road pavement monitoring represents the starting point for the pavement maintenance process. To quickly fix a damaged road, relevant authorities need a high-efficiency methodology that allows them to obtain data describing the current conditions of a road network. In urban areas, large-scale monitoring campaigns may be more expensive and not fast enough to describe how pavement degradation has evolved over time. Furthermore, at low speeds, many technologies are inadequate for monitoring the streets. In such a context, employing black-box-equipped vehicles to perform a routine inspection could be an excellent starting point. However, the vibration-based methodologies used to detect road anomalies are strongly affected by the speed of the monitoring vehicles. This study uses a statistical method to analyze the effects of speed on road pavement conditions at different severity levels, through data recorded by taxi vehicles. Likewise, the study introduces a process to overcome the speed effect in the measurements. The process relies on a machine learning approach to define the decision boundaries to predict the severity level of the road surface condition based on two recorded parameters only: speed and pavement deterioration index. The methodology has succeeded in predicting the correct damage severity level in more than 80% of the dataset, through a user-friendly real-time method. [ABSTRACT FROM AUTHOR]

The spectrum confocal displacement sensor is an innovative type of photoelectric sensor. The non-contact advantages of this method include the capacity to obtain highly accurate measurements without inflicting any harm as well as the ability to determine the object's surface contour recovery by reconstructing the measurement data. Consequently, it has been widely used in the field of three-dimensional topographic measuring. The spectral confocal displacement sensor consists of a light source, a dispersive objective, and an imaging spectrometer. The scanning mode can be categorized into point scanning and line scanning. Point scanning is inherently present when the scanning efficiency is low, resulting in a slower measurement speed. Further improvements are necessary in the research on the line-scanning type. It is crucial to expand the measurement range of existing studies to overcome the limitations encountered during the detection process. The objective of this study is to overcome the constraints of the existing line-swept spectral confocal displacement sensor's limited measuring range and lack of theoretical foundation for the entire system. This is accomplished by suggesting an appropriate approach for creating the optical design of the dispersive objective lens in the line-swept spectral confocal displacement sensor. Additionally, prism-grating beam splitting is employed to simulate and analyze the imaging spectrometer's back end. The combination of a prism and a grating eliminates the spectral line bending that occurs in the imaging spectrometer. The results indicate that a complete optical pathway for the line-scanning spectral confocal displacement sensor has been built, achieving an axial resolution of 0.8 μm, a scanning line length of 24 mm, and a dispersion range of 3.9 mm. This sensor significantly expands the range of measurements and fills a previously unaddressed gap in the field of analyzing the current stage of line-scanning spectral confocal displacement sensors. This is a groundbreaking achievement for both the sensor itself and the field it operates in. The line-scanning spectral confocal displacement sensor's design addresses a previously unmet need in systematic analysis by successfully obtaining a wide measuring range. This provides systematic theoretical backing for the advancement of the sensor, which has potential applications in the industrial detection of various ranges and complicated objects. [ABSTRACT FROM AUTHOR]

An accurate speed measurement method is a prerequisite for an electric-drive precision planter. However, the influence of speed measurement methods on planting quality under different field conditions is unclear. In this paper, an electric-drive precision planter compatible with different speed measurement methods was built. Then, an experimental study was conducted to compare the influence of real-time kinematic positioning global navigation satellite system, global navigation satellite system, rotary encoder, and Doppler radar on the planting quality under different field conditions (tillage and no-tillage fields) and operational speeds (4, 6, 8, 10 km h−1). The results indicated that the speed measurement method had a significant effect (p < 0.05) on quality of feed index and multiples index, but it had no significant effect (p > 0.05) on missing index and coefficient of variation. The real-time kinematic positioning global navigation satellite system is the best for the electric-drive precision planter under typical working conditions (tillage and no-tillage fields); the average quality of feed index was 98.4 %, and was 86.8 %, respectively in the tillage and no-tillage field. The rotary encoder is an alternative in tillage fields, and the global navigation satellite system is an alternative in no-tillage fields. The results of the study quantify the influence of speed measurement methods on planting quality under different field conditions, which can help promote the development and application of electric-drive planting technology to safeguard maize yields. • An electric-drive maize precision planting system was built. • The system was compatible with different speed measurement methods. • The influence of speed measurement methods on planting quality was assessed. • A selection procedure for speed measurement methods under different field conditions was provided. [ABSTRACT FROM AUTHOR]

Summary: We present the Fast Assimilation‐Temperature Response (FAsTeR) method, a new method for measuring plant assimilation‐temperature (AT) response that reduces measurement time and increases data density compared with conventional methods.The FAsTeR method subjects plant leaves to a linearly increasing temperature ramp while taking rapid, nonequilibrium measurements of gas exchange variables. Two postprocessing steps are employed to correct measured assimilation rates for nonequilibrium effects and sensor calibration drift. Results obtained with the new method are compared with those from two conventional stepwise methods.Our new method accurately reproduces results obtained from conventional methods, reduces measurement time by a factor of c. 3.3 (from c. 90 to 27 min), and increases data density by a factor of c. 55 (from c. 10 to c. 550 observations). Simulation results demonstrate that increased data density substantially improves confidence in parameter estimates and drastically reduces the influence of noise.By improving measurement speed and data density, the FAsTeR method enables users to ask fundamentally new kinds of ecological and physiological questions, expediting data collection in short‐field campaigns, and improving the representativeness of data across species in the literature. [ABSTRACT FROM AUTHOR]

Bridge damage detection has attracted much attention recently. Most studies on damage detection of the high-speed railway (HSR) bridge neglect the effect of the interlayer connection between the railway track and bridge. This paper proposes a damage detection method for the HSR bridge using response-based sensitivity analysis of high-speed trains. The HSR bridge is modeled as a spatial track–bridge system, in which the fasteners, sleepers and track slabs are modeled as one viscoelastic layer. The responses of multiple vehicles are merged to overcome the critical issue that the length of response data recorded by a high-speed vehicle moving over the bridge is too short to perform the sensitivity analysis. Numerical studies demonstrate that the proposed method is capable to detect damages of the track–bridge system with different train speed, car-body mass, irregularity grade and the interlayer connection properties. By using the signal merging method and the averaged response from multiple train trips, the proposed method is robust to high speed and measurement noise. The damage on the bridge beam and the interlayer connection can be well-identified. It is also found that increasing the car-body mass, damping ratio of the track–bridge system, damping coefficient of interlayer connection could improve the efficiency of damage detection. [ABSTRACT FROM AUTHOR]

Engineering the admittance of external environments connected to superconducting qubits is essential, as increasing the measurement speed introduces spontaneous emission loss to superconducting qubits, known as Purcell loss. Here, we report a broadband Purcell filter within a small footprint, which effectively suppresses Purcell loss without losing the fast measurement speed. We characterize the filter's frequency response at 4.3 K and also estimate Purcell loss suppression by finite-element-method simulations of superconducting planar circuit layouts with the proposed filter design. The filter is fabricated with 200 nm-thick niobium films and shows the measured bandwidth over 790 MHz within 0.29 mm2 of compact size owing to densely packed spiral resonators. The estimated lifetime enhancement indicates the effective protection of the qubit from Purcell loss. The presented filter design is expected to be easily integrated on existing superconducting quantum circuits for fast and multiplexed readout without occupying large footprint. [ABSTRACT FROM AUTHOR]

The object of the research is the most important factors causing road accidents. This paper aimed to study the effects of this factors and their interactions on the stopping distance function. Understanding this function through simulation and comparing the results with mathematical models and experimental tests will help to reduce the number of road accidents. A large part of road accidents is linked to non-compliance with regulatory speed associated with vehicle braking system (grip, road and tires) and weather conditions. A speed measurement campaign on peri-urban roads was carried out to study driving behavior and compliance with speed limits in several Algerian cities. An experimental modelling of speed, anti-lock system, weather, grip and their interaction effects on the stopping distance of a vehicle using the experimental design method, combined with driving simulator tests was been conducted. The developments of experimental design with speed variation ranges (70 and 130 km/h) were necessary to study the influence of the various driving parameters on stopping distance. The mathematical model developed has been validated by the results obtained on the simulator. The experimental design method and simulator results were used to identify and define the important parameters that influence the braking distance. The results show that the stopping distance (SD) is mainly influenced by the vehicle speed (S), the weather conditions (M), and their interaction. The increase due to speed leads to an increase in the stopping distance with an estimated effect of 54.30 m. When the speed varies between its lower experimental level (70 km/h) and its higher level (130 km/h), it is estimated that the stopping distance will increase by 54.30 m. The analysis of the road speed measurement campaign, 55 % of road users do not obey the speed limits. The results obtained in this study can be applied to other countries, only the parameters need to be adjusted. [ABSTRACT FROM AUTHOR]

Terahertz tomography is a promising method among non-destructive inspection techniques to detect faults and defects in dielectric samples. Recently, image quality was improved significantly through the incorporation of a priori information and off-axis data. However, this improvement has come at the cost of increased measurement time. To aim toward industrial applications, it is therefore necessary to speed up the measurement by parallelizing the data acquisition employing multi-channel setups. In this work, we present two tomographic frequency-modulated continuous wave (FMCW) systems working at a bandwidth of 230–320 GHz, equipped with an eight-channel detector array, and we compare their imaging results with those of a single-pixel setup. While in the first system the additional channels are used exclusively to detect radiation refracted by the sample, the second system features an f-θ lens, focusing the beam at different positions on its flat focal plane, and thus utilizing the whole detector array directly. The usage of the f-θ lens in combination with a scanning mirror eliminates the necessity of the formerly used slow translation of a single-pixel transmitter. This opens up the potential for a significant increase in acquisition speed, in our case by a factor of four to five, respectively. [ABSTRACT FROM AUTHOR]

The channel in the marine environment is a time-varying and space-varying channel. Pulse-truncated continuous wave (PCW) speed measurement is often used in sonar, but the instability effect of PCW signal in the channel limits the effectiveness of speed measurement. Hyperbolic frequency modulation (HFM) signal is insensitive to Doppler; therefore, HFM signals are widely used in ranging and velocity measurement of sonar and radar. However, due to the filtering effect of the marine environment, the HFM signal of a single frequency band may cause excessive transmission loss, and the echo energy may be too weak to detect the target. Based on the analysis of the influence of speed on the distance measurement of HFM signal, a pulse sequence method based on HFM for speed measurement (PHS) is proposed, which uses HFM signals of different frequency bands and pulse widths in the pulse sequence to perform speed measurement. Extensive simulation results show that PHS method not only guarantees the speed measurement but also makes full use of the energy of the HFM sequence to improve the accuracy of the distance measurement. And PHS method is valuable to the practical application of engineering. [ABSTRACT FROM AUTHOR]

One of the promising steps to improve the environment in various industrial sectors is the transfer of specialized technical means to alternative clean energy. Agriculture is not an exception, because the introduction of an electric drive on tractors of small traction classes, which are designed to perform traction, as well as small transport work, is relevant today. Such an implementation is implemented by replacing the internal combustion engine with an electric drive, in connection with this; the task of observing the traction properties of the tractor arises. Therefore, the material of this type aims to increase the traction efficiency of the wheeled lowpower tractor by optimizing its design features. The implementation of the outlined goal occurs due to the use of multi-criteria optimization when conducting a simulated numerical experiment of traction test cycles. When solving the set goal, the method of dynamic tests of the German Agricultural Society DLG-PowerMix is used, this includes 12 traction tests of an agricultural tractor. The result is a justified selection of the distribution of the total weight of the low-power tractor in combination with the tire pressure in conditions of compliance with the maximum average integral values of the speed and efficiency of the tractor, as well as the minimum average integral value of skidding, as those that should be implemented in an electric tractor. The practical significance of the work consists in providing specific values of weight distribution on the axle of the low-power tractor and tire pressure when aggregating with a plow, a cultivator, a rotary cutter and a hay mower, as well as taking into account the operation of a manure spreader and a hay baling. The scientific novelty of the work is the establishment of a relationship between the design parameters of the low-power tractor and the change in traction indicators during traction work, namely between the tractor weight distribution, tire pressure, speed, tractor efficiency and wheel slip. [ABSTRACT FROM AUTHOR]

Advancements in technology have recently enabled to assess soil aggregate stability (SAS) using digital devices. To address the need for a faster and more efficient method of measuring SAS, we have developed a simple yet effective approach using a specialized device. The innovative method named SlakeLight involves measuring the changes in light transmittance as aggregates undergo slaking. The device consists of the measuring chamber, which is placed on a LED light source with a surface-homogeneous distribution of luminosity. During the disintegration process of aggregates immersed in water, reduction in the light emitted to the photodiodes is proportional to SAS. The functionality of the device was tested using topsoil samples from two field fertilization trials. The recorded SAStrans values were compared with the wet sieving method (WSA) and SLAKE test. The new method showed a strong correlation with both reference methods (r = 0.89 for WSA, r = -0.86 for SLAKE). The device was able to detect a statistically significant differences in SAS between the grassland and the cropland at both sites. Although differences in SAStrans were not significant between different fertilization treatments unlike WSA, the simplicity and speed of the measurement increase the potential of the method for practical implementation in agriculture, surpassing the limitations of traditional and labor-intensive laboratory techniques. [ABSTRACT FROM AUTHOR]

Road agencies are looking for efficient pavement management tools to maintain adequate service levels and preserve the asset value. The traffic speed deflectometer (TSD) allows to continuously assess the structural condition of the pavement while moving at traffic speeds, thus overcoming the typical drawbacks of traditional non-destructive testing equipment. However, managing the huge amount of data deriving from TSD surveys is challenging, and there is no established method to use those data for identifying the remaining service life (RSL) of the pavement network. This study aimed at developing a new practical and reliable methodology to assess the RSL of motorway pavements at the network level from TSD measurements. The methodology is based on the use of the surface curvature index SCI300 and includes the temperature adjustment, the definition of a representative SCI300 value for each pavement section and the estimation of the residual fatigue resistance (considering bottom-up cracking as the critical distress). The methodology was implemented using the deflection data deriving from a TSD survey carried out on about 400 km of motorway pavement. The obtained RSL predictions can be used to identify the structural ranking of different pavement sections and guide budget forecasting, according to the actual maintenance and rehabilitation priorities. [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]

Indirectly driven shock-tube experiments were performed on the Omega Laser Facility to evaluate the relative importance of hohlraum x ray and radiative shock preheat sources on a low-density foam. X rays emitted from the hohlraum and a subsequent shock wave are channeled into a low-density foam sample, which contains a plastic preheat-witness disk placed downstream of the foam. Simultaneous radiographic measurements of the shock speed in the foam and the expansion rate of the witness disk due to preheat allow for the observation of effects from the hohlraum's low-energy and high-energy x-ray spectrum. We showed, from simulations, that low-energy x rays from the hohlraum are preferentially absorbed near the ablator surface (where the hohlraum and the shock tube meet), while higher-energy x rays largely pass through the ablator and foam and are volumetrically absorbed by the witness disk. Reproducing the experimentally measured shock speed and expansion of the witness disk simultaneously, we extracted the temperature evolution of preheated foam from the simulation and evaluated the relative importance of preheat sources on a low-density foam from hohlraum x-ray radiation and radiative shock. We found that radiation from the shock front was more effective at preheating the low-density foam than the high-energy x rays from the hohlraum. This shock-tube preheat experiment is important for understanding the results of the MARBLE experiments at the National Ignition Facility because initial conditions of foam-filled MARBLE capsules are sensitive to preheat. [ABSTRACT FROM AUTHOR]

The shortfin mako shark is a large‐bodied pursuit predator thought to be capable of the highest swimming speeds of any elasmobranch and potentially one of the highest energetic demands of any marine fish. Nonetheless, few direct speed measurements have been reported for this species. Here, animal‐borne bio‐loggers attached to two mako sharks were used to provide direct measurements of swimming speeds, kinematics and thermal physiology. Mean sustained (cruising) speed was 0.90 m s−1 (±0.07 s.d.) with a mean tail‐beat frequency (TBF) of 0.51 Hz (±0.16 s.d.). The maximum burst speed recorded was 5.02 m s−1 (TBFmax = 3.65 Hz) from a 2 m long female. Burst swimming was sustained for 14 s (mean speed = 2.38 m s−1), leading to a 0.24°C increase in white muscle temperature in the 12.5 min after the burst. Routine field metabolic rate was estimated at 185.2 mg O2 kg−1 h−1 (at 18°C ambient temperature). Gliding behaviour (zero TBF) was more frequently observed after periods of high activity, especially after capture when internal (white muscle) temperature approached 21°C (ambient temperature: 18.3°C), indicating gliding probably functions as an energy recovery mechanism and limits further metabolic heat production. The results show shortfin mako sharks generally cruise at speeds similar to other endothermic fish – but faster than ectothermic sharks – with the maximum recorded burst speed being among the highest so far directly measured among sharks, tunas and billfishes. This newly recorded high‐oxygen‐demand performance of mako sharks suggests it may be particularly vulnerable to habitat loss due to climate‐driven ocean deoxygenation. [ABSTRACT FROM AUTHOR]

Measurements of compressed liquid density and speed of sound have been performed in cis -1-chloro-2,3,3,3-tetrafluoro-1-propene, also known as R-1224yd(Z). Density has been measured in the temperature range from 273.15 K to 353.15 K and for pressure up to 35 MPa. The relative expanded uncertainty (k = 2) for the obtained results has been estimated to be better than 0.05%. Speed of sound has been measured in the temperature range from 263 K to 353 K and for pressure up to 35 MPa. The expanded relative uncertainty (k = 2) for these measurements has been estimated to be better than 0.06%. Using the properties measured in this work and including measurements of vapor pressure and ideal gas specific heat capacity published in scientific literature, a Patel-Teja equation of state has been implemented for describing the properties of the refrigerant both in liquid and in vapor phase. An independent model for predicting the speed of sound has been proposed to allow to calculate the adiabatic compressibility of the fluid with an accuracy higher than that accessible from Patel-Teja formulation. • Density measurements of cis-1-chloro-2,3,3,3-tetrafluoro-1-propene (R-1224yd(Z)). • Speed of sound measurements of cis-1-chloro-2,3,3,3-tetrafluoro-1-propene (R-1224yd(Z)). • Implementation of the Patel-Teja equation of state for describing the properties of R-1224yd(Z) both in liquid and in vapor phase. • Comparison between experimental values and model predictions. [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]

Branches reduce stem quality, and the level of the effect is determined by the geometry, size, and number, of associated knots. Quantifying branchiness is difficult, as visual estimates are subjective, and mechanical measurements are impractical. Acoustic velocity (AV) is a relatively novel measurement capturing the speed stress travels through wood. AV is correlated with wood stiffness and is affected by internal characteristics like knots. This project tested AV as an indirect branchiness metric by measuring AV, height, diameter, and counting branches classified by diameter on 255 standing 8 year old longleaf pine (Pinus palustris). AV was highly correlated with height (r = 0.76, p < 0.0001) and slenderness (r = 0.52, p < 0.0001). AV was moderately correlated with large living branches (diameter > 2.54 cm) (r = −0.27, p < 0.0001), but not correlated with total branches. Height, slenderness, and the count of large living branches (diameter > 2.54 cm) were included in the selected model for AV. Inclusion of dead or small (diameter < 2.54 cm) branches reduced model power. The best model captured 11% of the variation in AV, of which branches explained 5%. We conclude that AV does not appropriately quantify individual tree branchiness, but may be suitable for comparing populations such as families or provenances. [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]

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]

The fundamental sensitivity limit of atomic force microscopy is strongly correlated to the thermal noise of cantilever oscillation. A method to suppress this unwanted noise is to reduce the bandwidth of the measurement, but this approach is limited by the speed of the measurement and the width of the cantilever resonance, commonly defined through the quality factor Q. However, it has been shown that optomechanical resonances in interferometers might affect cantilever oscillations resulting in an effective quality factor Q eff . When the laser power is sufficiently increased cantilever oscillations might even reach the regime of self-oscillation. In this self-oscillation state, the noise of the system is partially determined by the interaction with laser light far from equilibrium. Here, we show and discuss how tuning of laser power leads to nonlinear optomechanical effects that can dramatically increase the effective quality factor of the cantilever leading to out-of-equilibrium noise. We model the effects using a fourth order nonlinearity of the damping coefficient. [ABSTRACT FROM AUTHOR]

The solar‐only response nature limits the luminescent solar concentrators (LSCs) to solar harvesting rather than responding to other stimuli, which restricts the role of LSCs to energy supply in self‐powered internet of things (IoT) systems, and the application potential of LSCs in self‐powered devices has been seriously overlooked. In this work, LSCs with photovoltaic and piezoelectric features are proposed for the first time, extending the application scenario of LSCs to self‐powered sensors with pressure responsiveness. The luminescent layer of perovskite‐polymer composite film is prepared via in situ blade coating with the piezoelectric polymer matrix of poly(vinylidenefluoride‐trifluoroethylene) (P(VDF‐TrFE)). P(VDF‐TrFE) possesses stronger DMF adsorption capacity and higher electroactive phase content than a conventional piezoelectric matrix of poly(vinylidene fluoride) (PVDF), which not only reduces the residual‐solvent‐induced defects in perovskite luminophores, but also brings a sensitive pressure response to LSCs. The dual‐functional LSCs achieve a power conversion efficiency of 1.01% and a output piezoelectric voltage of 0.95 V can be obtained even at a low pressure of 0.16 kPa. A self‐powered speed measurement system is demonstrated, and the actual speed measurement is carried out. Such dual‐functional LSCs show great potential in self‐powered electrical devices, which can be applied to low‐energy‐consumption IoT systems and other commercial smart home products. [ABSTRACT FROM AUTHOR]

The market for unmanned aerial systems (UASs) has grown considerably worldwide, but their ability to transmit sensitive information poses a threat to public safety. To counter these threats, authorities, and anti-drone organizations are ensuring that UASs comply with regulations, focusing on strategies to mitigate the risks associated with malicious drones. This study presents a technique for detecting drone models using identification (ID) tags in radio frequency (RF) signals, enabling the extraction of real-time telemetry data through the decoding of Drone ID packets. The system, implemented with a development board, facilitates efficient drone tracking. The results of a measurement campaign performance evaluation include maximum detection distances of 1.3 km for the Mavic Air, 1.5 km for the Mavic 3, and 3.7 km for the Mavic 2 Pro. The system accurately estimates a drone's 2D position, altitude, and speed in real time. Thanks to the decoding of telemetry packets, the system demonstrates promising accuracy, with worst-case distances between estimated and actual drone positions of 35 m for the Mavic 2 Pro, 17 m for the Mavic Air, and 15 m for the Mavic 3. In addition, there is a relative error of 14% for altitude measurements and 7% for speed measurements. The reaction times calculated to secure a vulnerable site within a 200 m radius are 1.83 min (Mavic Air), 1.03 min (Mavic 3), and 2.92 min (Mavic 2 Pro). This system is proving effective in addressing emerging concerns about drone-related threats, helping to improve public safety and security. [ABSTRACT FROM AUTHOR]

Accurate estimates of the dynamical states of bicycles are crucial for many advanced rider assistance systems. However, systems that can provide an exact estimate of the system states (especially the system orientations) are often expensive and therefore cannot be used in mass production. In this work, a method is presented that estimates the dynamical states of a bicycle using measurements, provided by a cost-effective sensor configuration. The proposed method is based on a constrained extended Kalman filter and uses accelerometer, gyroscope and wheel speed measurements to estimate the vehicle dynamics. Since no bicycle model is required, the filter can be easily adapted for the use in a wide range of bicycles and other single-track vehicles like motorcycles. The filter is implemented on a rapid control prototyping platform and the results are compared to measurements of a reference sensor unit. Here, special attention is put on the roll angle and the velocity estimates, where the filter produces excellent results. In addition, the filter robustness to sensor errors and uncertain system parameters is evaluated. [ABSTRACT FROM AUTHOR]

Investigating the factors underlying perceived speed and risk is crucial to ensure safe driving. However, existing studies on this topic usually measure speed and risk perception indirectly after a driving session, which makes it difficult to trace dynamic effects and time points of potential misestimates. To address this problem, we developed and validated a novel continuous method for dynamically measuring risk and speed perceptions. To study the factors affecting risk and speed perception, we presented participants with videos captured on the same racing track from the same point of view but with different drivers who varied in their speed and risk profiles. During the experiment, participants used a joystick to continuously rate the subjectively perceived risk of driving in the first block and the perceived speed in the second block. Our analysis of these dynamic ratings indicates that risk and speed estimates were decoupled, with curves resulting in decreased speeds but increased risk ratings. However, a close distance to the car in front increased both speed and risk. Based on actual and estimated speed data, we found that overtaking cars on curves resulted in participants overestimating their own speed, whereas an increase in the distance to the car in front on a straight course led to underestimations of their own speed. Our results showcase the usefulness of dynamic rating profiles for in-depth investigations into situations that could result in drivers misjudging speed or risk and will thus help the development of more intelligent, human-centered driving assistance systems. [ABSTRACT FROM AUTHOR]

Individuals with peripheral vestibulopathy are known to have difficulty with volitional head turns. This leads to differences in head and body turning kinematics, compared to those without vestibular dysfunction. Multiple sclerosis (MS), a neuro-inflammatory disease affecting the central nervous system, can cause vestibular dysfunction (dizziness, unsteadiness, gaze instability). However, head and trunk turning kinematics in people with MS (PwMS) have not been assessed. Will PwMS, demonstrate head and body kinematics alterations similar to individuals with a peripheral dysfunction compared to vestibular healthy individuals? Eleven individuals with a recent vestibular schwannoma resection (VSR), fourteen PwMS, and 10 healthy control (HC) participants were fitted with head and trunk worn inertial measurement units (IMUs) and performed walking and turning tasks. Head and trunk peak turning speed and amplitude were extracted. Regression models controlling for gait speed were fit per outcome with post hoc corrections applied to significant models. Yaw plane head turn speed and amplitude were significantly less in the VSR group compared to HC. Pitch plane head turn amplitude was significantly smaller in PwMS compared to HC (p = 0.04), however pitch plane speed did not differ between the groups. There was no difference between PwMS and the VSR group in yaw or pitch plane speed and amplitude. Both PwMS and the VSR group turned significantly slower than HC during the 180d body turn as measured at the head and trunk (head speed model p = 0.009 and <0.001; trunk speed model p < 0.001 for both groups) however the MS and VSR groups did not differ from each other. Turning kinematics while walking in PwMS are altered compared to HC and are similar to individuals with unilateral vestibular hypofunction. Centrally mediated vestibular dysfunction in PwMS may alter movement kinematics and should be considered during examination and treatment. • People with MS have turning kinematics similar to people with vestibular loss (78). • Turning kinematics differ in people with multiple sclerosis compared to controls (81). • Centrally mediated vestibular dysfunction may alter movement kinematics (71). [ABSTRACT FROM AUTHOR]

The cold sintering process (CSP) is a low temperature processing technique that utilizes a transient phase to synthesize dense ceramics. However, some CSP parts contain microflaws that arise due to inhomogeneities in pressure, temperature, and transient phase. This work uses 20 MHz ultrasound to verify the presence of defects in CSP ZnO samples of varying densities (84%–97%). Acoustic metrics used in this work include wave speed, which is affected by differences in the effective elastic properties of the medium, and attenuation, which quantifies wave energy loss due to scattering from defects. Wave speed maps were inhomogeneous, suggesting density gradients which were verified with scanning electron microscopy. In addition, it was demonstrated that the pores produced by cold sintering are anisometric, which increases the anisotropy in the elastic properties. High attenuation regions (>300 Np/m) are present in all samples independent of relative density and correspond to defects identified in X‐ray computed tomography (XCT) which were as small as 38 µm in effective diameter. However, some high attenuation spots do not correspond to visible defects in XCT, which suggests the presence of features undetectable with XCT such as residual secondary phases at the grain boundaries. [ABSTRACT FROM AUTHOR]

In several studies, it has been suggested that task-switching performance is linked to processing speed. Here we argue that the relation between processing speed and high-level cognitive ability found in previous studies may be due to confounded measurements of processing speed and task-switching ability. In the present study, we required participants to complete an inspection time (IT) task to probe their processing speed. We employed conventional task-switching paradigms but applied a linear integrated speed-accuracy score (LISAS) which combines latency and accuracy scores to express task-switching ability. The results of regression analyses show that IT predicted average performance in task-switching paradigms. However, IT did not relate to any specific effects common in the task-switching task, which contradicts previous results. Our results suggest independent mechanisms of processing speed and tasks that require a high level of cognitive flexibility and control. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to investigate the influence of nonuniform gas speed across the build area on the melt pool depth during laser powder bed fusion. This study focuses on whether a nonuniform gas speed is a source of process variation within an individual build. Design/methodology/approach: Parts with many single-track laser scans were printed and characterized in different locations across the build area coupled with corresponding gas speed profile measurements. Cross-sectional melt pool depth, width and area are compared against build location/gas speed profiles, scan direction and laser scan speed. Findings: This study shows that the melt pool depth of single-track laser scans produced on parts are highly variable. Despite this, trends were found showing a reduction in melt pool depth for slow laser scan speeds on the build platform near the inlet nozzle and when the laser scans are parallel to the gas flow direction. Originality/value: A unique data set of single-track laser scan cross-sectional melt pool measurements and gas speed measurements was generated to assess process variation associated with nonuniform gas speed. Additionally, a novel sample design was used to increase the number of single-track tests per part, which is widely applicable to studying process variation across the build area. [ABSTRACT FROM AUTHOR]