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Spurred by the global pandemic, research in health monitoring has pivoted towards the development of smart garments, enabling long-term tracking of individuals’ cardiovascular health by continuously monitoring the electrocardiogram (ECG) and detecting any abnormality in the signal morphology. Many types of dry electrodes have been proposed as alternatives to gold standard Ag/AgCl wet electrodes, and they have been integrated into clothes capable of acquiring only a limited number of the different ECG traces. This limitation severely diminishes the diagnostic utility of the collected ECG data and obstructs the garment’s potential for clinical-level evaluation. Here, we demonstrate a special ECG upper armband with a glove component which houses graphene-textile electrodes, where a fully mobile, exploring electrode located at the index finger enables the user to strategically position the electrode on-demand to desired body areas and measure the different ECG traces that are bipolar limb and unipolar chest leads. Based on measurements with and without employing the well-known Wilson Central Terminal (WCT) arrangement, the correlation ratio of unipolar ECG chest leads acquired with the graphene textile-based armband and Ag/AgCl electrodes both in “WCT-less” configuration reach up to %99.65; and up to %99.54 when Ag/AgCl electrodes are utilized “with WCT” while the graphene-based armband in “WCT-less” configuration. To the authors’ best knowledge, this study reports the first multilead on-demand “touch-and-measure” ECG recording from a fully wearable textile garment. Moreover, owing to the human-centered armband design, we achieved a more than three-fold reduction in electrode count from 10 in clinical ECG practice down to 3.
This investigation examines the dynamic response of an accelerating turbulent pipe flow using direct numerical simulation data sets. A low/high-pass Fourier filter is used to investigate the contribution and time dependence of the large-scale motions (LSM) and the small-scale motions (SSM) into the transient Reynolds shear stress. Additionally, it analyses how the LSM and SSM influence the mean wall shear stress using the Fukagata–Iwamoto–Kasagi identity. The results reveal that turbulence is frozen during the early flow excursion. During the pretransition stage, energy growth of the LSM and a subtle decay in the SSM is observed, suggesting a laminarescent trend of SSM. The transition period exhibits rapid energy growth in the SSM energy spectrum at the near-wall region, implying a shift in the dominant contribution from LSM to SSM to the frictional drag. The core-relaxation stage shows a quasisteady behaviour in large- and small-scale turbulence at the near-wall region and progressive growth of small- and large-scale turbulence within the wake region. The wall-normal gradient of the Reynolds shear stress premultiplied energy cospectra was analysed to understand how LSM and SSM influence the mean momentum balance across the different transient stages. A relevant observation is the creation of a momentum sink produced at the buffer region in large- and very large-scale (VLSM) wavelengths during the pretransition. This sink region annihilates a momentum source located in the VLSM spectrum and at the onset of the logarithmic region of the net-force spectra. This region is a source term in steady wall-bounded turbulence.
This paper discusses the propagation of coastal currents generated by a river outflow using a 1 ${1}/{2}$-layer, quasigeostrophic model, following Johnson et al. (2017) (JSM17). The model incorporates two key physical processes: Kelvin-wave-generated flow and vortical advection along the coast. We extend JSM17 by deriving a fully nonlinear, long-wave, dispersive equation governing the evolution of the coastal current width. Numerical solutions show that, at large times, the flow behaviour divides naturally into three regimes: a steady outflow region, intermediate regions consisting of constant-width steady currents and unsteady propagating fronts leading the current. The widths of the steady currents depend strongly on dispersion when the constant outflow potential-vorticity anomaly is negative. Simulations using contour dynamics show that the dispersive equation captures the full quasigeostrophic behaviour more closely than JSM17 and give accurate bounds on the widths of the steady currents.
The crystal structure of trametinib dimethyl sulfoxide has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Trametinib dimethyl sulfoxide crystallizes in space group P-1 (#2) with a = 10.7533(4), b = 12.6056(5), c = 12.8147(6) Å, α = 61.2830(8), β = 69.9023(11), γ = 77.8038(10)°, V = 1,428.40(3) Å3, and Z = 2 at 298 K. The crystal structure contains hydrogen-bonded trametinib and dimethyl sulfoxide (DMSO) molecules. These are arranged into layers parallel to the (101) plane. There are two strong classical hydrogen bonds in the structure. One links the trametinib and DMSO molecules. Another is an intramolecular hydrogen bond. The powder pattern has been submitted to the International Centre for Diffraction Data for inclusion in the Powder Diffraction File™.
The crystal structure of niraparib tosylate monohydrate Form I has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Niraparib tosylate monohydrate Form I crystallizes in space group P-1 (#2) with a = 7.22060(7), b = 12.76475(20), c = 13.37488(16) Å, α = 88.7536(18), β = 88.0774(10), γ = 82.2609(6)°, V = 1,220.650(16) Å3, and Z = 2 at 298 K. The crystal structure consists of alternating double layers of cations and anions (including the water molecules) parallel to the ab-plane. Hydrogen bonds are prominent in the crystal structure. The water molecule acts as a donor to two different O atoms of the tosylate anion and as an acceptor from one of the H of the protonated piperidine ring. The other piperidyl N–H acts as a donor to the carbonyl group of another cation. Surprisingly, there are no cation–anion N–H···O hydrogen bonds. The amide group forms as a N–H···O hydrogen bond to the anion and an intramolecular N–H···N hydrogen bond to the indazole ring. The powder pattern has been submitted to the International Centre for Diffraction Data for inclusion in the Powder Diffraction File™.
The crystal structure of aprocitentan Form A has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Aprocitentan Form A crystallizes in space group P-1 (#2) with a = 11.7381(11), b = 10.6771(12), c = 9.6624(5) Å, α = 110.4365(13), β = 92.3143(13), γ = 113.513 (2)°, V = 1,017.53(5) Å3, and Z = 2 at 298 K. The crystal structure consists of layers of aprocitentan molecules, approximately along the 1,-7,7 plane. N–H···N hydrogen bonds link the molecules within these layers. The powder pattern has been submitted to the International Centre for Diffraction Data for inclusion in the Powder Diffraction File™.
We study the evaporation dynamics of non-thin non-spherical-cap (i.e. wavy) droplets. These droplets exhibit surface curvature that varies periodically with the polar angle, which profoundly influences their evaporation flux, internal flow dynamics, and the resultant deposition patterns upon complete evaporation. The droplet is considered quasi-static throughout its entire lifetime. The asymptotic expansions of the evaporation flux in the diffusion-limited model, and the induced internal inviscid flow of the droplets, are derived through asymptotic analysis. Under the assumption of small deformation amplitudes, the accuracies of these two expansions are validated numerically. Expanding upon these asymptotic results, we also investigate the surface density profile of the droplet deposition after it dries up. The results indicate that the freely moving contact line of the droplet leads to the deposited stain exhibiting a mountain-like morphology. The internal inviscid flow along with the non-spherical-cap shape eliminates the divergence of the deposited surface density profile at droplet’s centre. This work provides a theoretical basis for geometrically controlled sessile droplet evaporation, which may have practical applications in industry.
The integration of wearable smart garments with multiple sensors has gained momentum, enabling real-time monitoring of users’ vital parameters across various domains. This study presents the development and validation of an instrumented smart shirt for risk prevention in workplaces designed to enhance worker safety and well-being in occupational settings. The proposed smart shirt is equipped with sensors for collecting electrocardiogram, respiratory waveform, and acceleration data, with signal conditioning electronics and Bluetooth transmission to the mobile application. The mobile application sends the data to the cloud platform for subsequent Preventive Risk Index (PRI) extraction. The proposed SenseRisc system was validated with eight healthy participants during the execution of different physically exerting activities to assess the capability of the system to capture physiological parameters and estimate the PRI of the worker, and user subjective perception of the instrumented intelligent shirt.
This accessible text is an introduction to the theory of phase transitions and its application to real materials. Assuming some familiarity with thermodynamics and statistical mechanics, the book begins with a primer on the thermodynamics of equilibrium phase transitions, including the mean-field and Ginzburg-Landau approaches. The general kinetic features and dynamics of phase transitions are explained, ensuring that readers are familiar with the key physical concepts. With the foundations established, the general theory is applied to the study of phase transitions in a wide range of materials including ferroic materials, caloric materials, liquid crystals and glasses. Non-equilibrium phase transitions, superconductors and quantum phase transitions are also covered. Including exercises throughout and solutions available online, this text is suitable for graduate courses as well as researchers in physics and materials science seeking a primer on popular and emerging research topics.
This research investigated the potential improvement of IVR on procedural practical knowledge in maritime safety education in a lifeboat case study. Participants were divided into three groups: a VR, control and VR+ group. A practical test exam with a real lifeboat was conducted to evaluate the differences in number of students passed/failed and overall performances in the execution of lifeboat launching procedures between groups. There was no evidence that the VR students had a higher success rate than students in the control group in correctly and safely performing a lifeboat drill. However, VR students’ overall performances on procedural correctness were significantly better than those of the control group, despite that the VR students never practiced with a physical lifeboat. Given the importance of safety in the maritime industry, it is worthwhile to further investigate to what extent IVR can provide a solution to the current limitations in maritime safety education.
The unmanned surface vehicle (USV) is deemed with significant potential to deal with the maritime search and rescue (SAR) missions. This paper investigates the path planning of the USV with SAR tasks, and proposes a novel algorithm based on combined convolutional neural network rapid-exploration random tree and improved artificial potential field (CRRT-IAPF). The proposed scheme can be divided into the global and the local path plannings. The rapid-exploration random tree (RRT) method is employed to generate the global path in the sea chart, which is further discriminated to be optimal or non-optimal through a well-trained convolutional neural network (CNN). The artificial potential field (APF) method is adopted to plan the local path in the environment with small obstacles and SAR task points. To facilitate the path convergence and avoid the oscillation, the potential field function is improved in a more efficient way. In addition, the evaluation functions of search success rate and rescue success rate are established to evaluate the completeness of SAR tasks. Through the simulation, it is verified that the proposed CRRT-IAPF scheme has the superiority over the others.
The article is devoted to the mathematical theories and algorithms necessary for the implementation of a software package that fully automates the calculations necessary in Nautical Astronomy. The article describes a method for calculating the equatorial and horizontal coordinates of the celestial bodies at any moment of time. The authors describe the calculation of the time of the apparent rising (setting) of the Sun, solar illumination and events of other celestial bodies. A formula for calculating astronomical refraction is proposed. A matrix method for implementing the method of least squares for determining the coordinates of a place along the lines of position is described. An algorithm for identifying navigational planets is also described and a method for estimating the error for it is proposed. Based on this, the results of the development of the software package ‘Astronomy Package’ for Nautical Astronomy are presented.
The need for Global Navigation Satellite System (GNSS) receiver testing increases with the advent of widespread Internet of Things (IoT) technologies and other electronic devices dependent on position determination. In this paper, a low-cost GNSS multiband L1+L5 signal recorder and replayer for equipment testing purposes is proposed. It is implemented using Software-Defined Radio (SDR) modules HackRF One with proper time and phase synchronisation. The recorder–replayer has been tested with GPS, GALILEO, BEIDOU and GLONASS satellites and several commercial GNSS receivers. Reduced GNSS signal bandwidth of approximately 10 MHz is sufficient for efficient reception of recorded signals. Performed tests with a driving car show applicability of this GNSS recorder–replayer in dynamic settings.
The first globalisation of the world occurred under the motivation of the Avis dynasty of Portugal, aimed at discovering new lands and wealth, exploring ocean routes, especially with the successful epic journey to India. The political decisions of the Avis dynasty kings, along with Christianity’s interest in expanding into Africa and Asia, were key factors in the success of these maritime explorations. However, the Coriolis force was a significant force of nature for the outcome of this journey. Here we investigate Caminha’s letter, the scribe of Pedro Álvares Cabral’s fleet when he found the lands of Brazil. This letter contains detailed scientific data, distances travelled, dates, geographical features, fauna and flora, initial anthropological information on indigenous peoples, and records of coastal depths. Analysis of these elements and facts lead to a new proposal for the location of Mount Pascoal and the so-called safe harbour, where Cabral’s fleet landed.
Terrain-aided navigation with a three-dimensional (3D) map has both high accuracy and high reliability, which is crucial for applications in the global navigation satellite system (GNSS)-denied scenarios. In this paper, a new terrain matching algorithm with 3D Zernike moments (3D ZMs) is proposed. The redundant items in the even-order 3D ZMs are analysed in theory. The 3D ZMs are also correlated with the standard deviations of terrain further to identify the redundant items. The new 3D ZM descriptors are proposed for the feature vector of the matching algorithm by excluding the redundant items from the descriptors. The simulation results demonstrate that the algorithm with the revised descriptors achieves a higher matching success rate than both that with the existing descriptors and that with the odd-order descriptors under the same conditions.
Maritime piracy represents a significant international challenge, impacting both economic stability and political dynamics. Researchers from diverse disciplines have been drawn to this multifaceted issue, each aiming to understand and address different aspects of piracy’s impact and implications. This study offers a comprehensive overview of maritime piracy research based on bibliographic analysis. Its objective is threefold. First, to delineate the key domains of inquiry within maritime piracy research. These domains encompass a wide range of topics, including the socio-economic drivers of piracy, the legal frameworks governing maritime security, and computer science to analyse piracy acts. Second, to identify major contributions in the field, recognising seminal works, influential authors and significant findings related to maritime piracy. Lastly, to discern emerging research trends within maritime piracy, and to identify novel areas of inquiry, innovative methodologies and promising avenues for future exploration. Furthermore, the most popular datasets from these studies that include relevant information are presented in this work.
This paper studies the probability of active navigational error events for use in ship–bridge allision risk analysis. To estimate the probability of these kinds of events, accident databases, incident reports and AIS data were studied; the case studies herein cover 6 years and 15 bridges in Scandinavia. The main findings of this paper show that there is great variation in the probability of ship–bridge allision due to active navigational errors, and it is not recommended to use the currently common practice of 2% uniform distribution of the number of ship passages on all bridges. Another important finding is that the probability of a ship striking a bridge due to the error type Wrong Course at a Turning point is not uniform along the length of the bridge, but is only likely to occur in a cone formation from the last turning point.
During a regatta, the influence of wind speed on the velocity of the boat, the distance covered and the manoeuvres carried out has not been clarified to date in the 49er and 49erFX classes. Therefore, the main aim of this study was to analyse how these variables are affected by wind speed during a regatta. The sample consisted of 39 Olympic sailors from the 49erFX and 49er classes, who participated in a World Cup. Velocity, velocity made good (VMG), distance and manoeuvres were evaluated in the upwind and downwind legs using global positioning system (GPS) devices. In both classes, it was observed that mean velocity, VMG and distance travelled increased as the wind velocity increased in upwind and downwind legs. The velocity, the distance travelled and the manoeuvres carried out are conditioned by wind speed in both upwind and downwind legs in the 49er and 49erFX classes.
Maritime navigation in low visibility presents a significant challenge, jeopardising seafarers’ situational awareness and escalating collision risks. This study introduces a maritime head-up display (mHUD) to address this issue. The mHUD, a 2-m diameter aluminium ring with dual rows of LEDs, enhances visibility for autonomous ships in adverse conditions on ship bridges and remote operating centres (ROCs). Displaying various modes such as shallow waters, land, lighthouses, beacons, buoys and maritime traffic, the mHUD was evaluated in a ship bridge simulator by 12 navigation students. Results revealed that the mHUD substantially improved situational awareness, proving more efficient and effective than navigating without it in poor visibility conditions. Participants found the mHUD easy to learn and expressed willingness to use it in real-world situations. The study highlights the mHUD’s potential to enhance situational awareness on ship bridges and ROCs for autonomous ships, while suggesting potential enhancements to increase usability and user satisfaction.