Characteristic Width Research Articles

Response of boreal songbird communities to the width of linear features created by the energy sector in Alberta, Canada

Response of boreal songbird communities to the width of linear features created by the energy sector in Alberta, Canada

A model for the rapid prediction of small feature width producible by Metal AM

In this paper, an analytical parametric model is presented for the swift prediction of small features producible in the X-Y plane through the Metal AM Laser Powder Bed Fusion (LPBF) process. This model can be employed to design and create surface textures on Additive Manufactured parts without the need for costly post-processing steps. The Rosenthal equation is the basis for the model, which considers both the build parameters of the LPBF process and the thermo-physical properties of the materials. The initial model was constructed and assessed using one LPBF machine followed by the implementation of a tuning method utilizing the Limited Memory Algorithm for Bound Constrained Optimization to enhance the model’s accuracy. Overall, the findings suggest that with a simple optimization step based on a single printed tuning sample, precise analytical models can be established for specific LPBF machines and materials combinations.

Exploring the phase diagrams of multidimensional Kuramoto models

The multidimensional Kuramoto model describes the synchronization dynamics of particles moving on the surface of D-dimensional spheres, generalizing the original model where they are characterized by a single phase. Particles are represented by D-dimensional unit vectors and the coupling constant can be extended to a coupling matrix acting on the vectors. The system has a large number of independent parameters, given by the characteristic widths of the distributions of natural frequencies and the D2 entries of the coupling matrix. Moreover, as the coupling matrix breaks the rotational symmetry, the average values of the natural frequencies also play a key role in the dynamics. General phase diagrams, indicating regions in parameter space where the system exhibits different behaviors, are hard to derive analytically. Here we obtain the complete phase diagram for D=2, for arbitrary coupling matrices and Lorentzian distributions of natural frequencies. We show that the system exhibits four different phases: disordered and static synchrony (as in the original Kuramoto model), rotation of the synchronized cluster (similar to the Kuramoto-Sakaguchi model with frustration) and active synchrony, a new phase where the module of the order parameter oscillates as it rotates on the sphere. We also explore the diagrams numerically for higher dimensions, D=3 and D=4, for particular choices of coupling matrices and frequency distributions. We find that the system always exhibits the same four phases, but their location in the space of parameters depends strongly on the dimension D being even or odd, on the coupling matrix and on the shape of the distribution of natural frequencies.

Multisoliton interactions approximating the dynamics of breather solutions

AbstractNowadays, breather solutions are generally accepted models of rogue waves. However, breathers exist on a finite background and therefore are not localized, while wavefields in nature can generally be considered as localized due to the limited sizes of physical domain. Hence, the theory of rogue waves needs to be supplemented with localized solutions, which evolve locally as breathers. In this paper, we present a universal method for constructing such solutions from exact multisoliton solutions, which consists in replacing the plane wave in the dressing construction of the breathers with a specific exact N‐soliton solution converging asymptotically to the plane wave at large number of solitons N. On the example of the Peregrine, Akhmediev, Kuznetsov–Ma, and Tajiri–Watanabe breathers, we show that constructed with our method multisoliton solutions, being localized in space with characteristic width proportional to N, are practically indistinguishable from the breathers in a wide region of space and time at large N. Our method makes it possible to build solitonic models with the same dynamical properties for the higher order rational and super‐regular breathers, and can be applied to general multibreather solutions, breathers on a nontrivial background (e.g., cnoidal waves), and other integrable systems. The constructed multisoliton solutions can also be generalized to capture the spontaneous emergence of rogue waves through the spontaneous synchronization of soliton norming constants, though finding these synchronization conditions represents a challenging problem for future studies.

The Planck clusters in the LOFAR sky

Context. It is well established that shock waves in the intracluster medium launched by galaxy cluster mergers can produce synchrotron emission, which is visible to us at radio frequencies as radio relics. However, the particle acceleration mechanism producing these relics is still not fully understood. It is also unclear how relics relate to radio halos, which trace merger-induced turbulence in the intracluster medium. Aims. We aim to perform the first statistical analysis of radio relics in a mass-selected sample of galaxy clusters, using homogeneous observations. Methods. We analysed all relics observed by the Low Frequency Array Two Metre Sky Survey Data Release 2 (LoTSS DR2) at 144 MHz, hosted by galaxy clusters in the second Planck catalogue of SZ sources (PSZ2). We measured and compared the relic properties in a uniform, unbiased way. In particular, we developed a method to describe the characteristic downstream width in a statistical manner. Additionally, we searched for differences between radio relic-hosting clusters with and without radio halos. Results. We find that, in our sample, ∼10% of galaxy clusters host at least one radio relic. We confirm previous findings, at higher frequencies, of a correlation between the relic-cluster centre distance and the longest linear size, as well as the radio relic power and cluster mass. However, our findings suggest that we are still missing a population of low-power relics. We also find that relics are wider than theoretically expected, even with optimistic downstream conditions. Finally, we do not find evidence of a single property that separates relic-hosting clusters with and without radio halos.

A maximum force perspective on black hole thermodynamics, quantum pressure, and near-extremality

I re-examined the notion of the thermodynamic force constructed from the first law of black hole thermodynamics. In general relativity, the value of the charge (or angular momentum) at which the thermodynamic force equals the conjectured maximum force F=1/4\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$F=1/4$$\\end{document} is found to correspond to Q2/M2=8/9\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$Q^2/M^2=8/9$$\\end{document} (respectively, a2/M2=8/9\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$a^2/M^2=8/9$$\\end{document}), which is known in the literature to exhibit some special properties. This provides a possible characterization of near-extremality. In addition, taking the maximum force conjecture seriously amounts to introducing a pressure term in the first law of black hole thermodynamics. This resolves the factor of two problem between the proposed maximum value F=1/4\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$F=1/4$$\\end{document} and the thermodynamic force of Schwarzschild spacetime F=1/2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$F=1/2$$\\end{document}. Surprisingly it also provides another indication for the instability of the inner horizon. For a Schwarzschild black hole, under some reasonable assumptions, this pressure can be interpreted as being induced by the quantum fluctuation of the horizon position, effectively giving rise to a diffused “shell” of characteristic width M\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sqrt{M}$$\\end{document}. The maximum force can therefore, in some contexts, be associated with inherently quantum phenomena, despite the fact that it is free of ħ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbar $$\\end{document}. Some implications are discussed as more questions are raised.

Investigating a Renewable-Resource-Targeting Mobile Aquaculture System Using Route Optimization Based on Optimal Foraging Theory

Aquaculture systems require careful consideration of location, which determines water conditions, pollution impacts, and hazardous conditions. Mobility may be able to address these factors while also supporting the targeting of renewable energy sources such as wind, wave, and solar power throughout the year. In this paper, a purpose-built mobile aquaculture ship is identified and modeled with a combination of renewable energy harvesting capabilities as a case study with the objective of assessing the potential benefits of targeting high renewable energy potentials to power aquaculture operations. A route optimization algorithm is created and tuned to simulate the mobility of the aquaculture platform and cost-basis comparisons are made to a stationary system. The small spatial variability in renewable energy potential when combining multiple resources significantly limits the benefits of a mobile, renewable-targeting aquaculture system. On the other hand, the consistent energy harvest from a blend of renewable energy types (13 kW installed wind capacity, 661 m2 installed solar, and 1 m characteristic width wave-energy converter) suggests that the potential benefits of a mobile platform for offshore aquaculture (mitigation of environmental and social concerns, any potential positive impact on yields, hazard avoidance, etc.) can likely be pursued without significant increases in energy harvester costs.

Aligned skeletal muscle assembly on a biofunctionalized plant leaf scaffold.

Decellularized plant scaffolds have drawn attention as alternative tissue culture platforms due to their wide accessibility, biocompatibility, and diversity of innate microstructures. Particularly, in this work, monocot leaves with innate uniaxial micropatterned topography were utilized to promote cell alignment and elongation. The leaf scaffold was biofunctionalized with poly(PEGMEMA-r-VDM-r-GMA) copolymer that prevented non-specific protein adsorption and was modified with cell adhesive RGD peptide to enable cell adhesion and growth in serum-free media. The biofunctionalized leaf supported the adhesion, growth, and alignment of various human cells including embryonic stem cells (hESC) derived muscle cells. The hESC-derived myogenic progenitor cells cultured on the biofunctionalized leaf scaffold adopted a parallel orientation and were elongated along the leaf topography. These cells showed significant early myogenic differentiation and muscle-like bundled myotube formation. The aligned cells formed compact myotube assemblies and showed uniaxial muscle contraction under chemical stimulation, a critical requirement for developing functional skeletal muscle tissue. Polymer-functionalized plant leaf scaffolds offer a novel human cell culture platform and have potential in human tissue engineering applications that require parallel alignment of cells. STATEMENT OF SIGNIFICANCE: Plant scaffolds are plentiful sources in nature and present a prefabricated construct to present topographical cues to cells. Their feature width is ideal for human cell alignment and elongation, especially for muscle cells. However, plant scaffolds lack proteins that support mammalian cell culture. We have developed a polymer coated leaf scaffold that enables cell adhesion and growth in serum-free media. Human muscle cells cultured on the biofunctionalized leaf, aligned along the natural parallel micro-patterned leaf topography, and formed muscle-like bundled myotube assemblies. These assemblies showed uniaxial muscular contraction, a critical requirement for developing functional skeletal muscle tissue. The biodiversity of the plant materials offers a novel human cell culture platform with potential in human tissue engineering.

Transformation of a fully nonlinear breather-like package of internal waves over a bottom step in a layered fluid

In this paper, we study the process of transformation of a localized wave packet over a bottom step in a three-layer fluid, in which the height of the step is equal to or exceeds the thickness of the lower layer; therefore, density stratification becomes two-layer in the shallow water zone. In numerical experiments, both the height of the step and the width of the step were varied. The problem is solved in the framework of a fully nonlinear model of hydrodynamics of an inviscid incompressible stratified fluid. The primary analysis consisted in estimating the values of dimensionless parameters used, as a rule, in runup problems: the Froude and Iribarren numbers, the ratio of the characteristic wavelength to the characteristic slope width, the ratio of the topographic slope to the characteristic wave beam angle. Since the “cutoff” line for the lower pycnocline is partially or completely located on a step, one could expect the effects of run-up, breaking or reflection of waves propagating along the lower pycnocline, but this doesn’t happen. It is shown that the reflection of the wave packet from the step is minimal in all cases considered, a strong steepening of the wave is observed, but no breaking occurs in this case — the wave then just quickly decays on the lower pycnocline. An analysis of the spectral amplitudes and energy fields allows us to conclude that there is a transfer of energy from the lower pycnocline to the upper one. The breather in a two-layer fluid cannot exist, but the wave packet formed in the upper pycnocline after its destruction has much higher energy than it has before the step.

Energy-resolved pulse profiles of accreting pulsars: Diagnostic tools for spectral features

Aims. We introduce a method for extracting spectral information from energy-resolved light curves folded at the neutron star spin period (known as pulse profiles) in accreting X-ray binaries. Spectra of these sources are sometimes characterized by features superimposed on a smooth continuum, such as iron emission lines and cyclotron resonant scattering features. We address here the question on how to derive quantitative constraints on such features from energy-dependent changes in the pulse profiles. Methods. We developed a robust method for determining in each energy-selected bin the value of the pulsed fraction using the fast Fourier transform opportunely truncated at the number of harmonics needed to satisfactorily describe the actual profile. We determined the uncertainty on this value by sampling through Monte Carlo simulations a total of 1000 faked profiles. We rebinned the energy-resolved pulse profiles to have a constant minimum signal-to-noise ratio throughout the whole energy band. Finally we characterize the dependence of the energy-resolved pulsed fraction using a phenomenological polynomial model and search for features corresponding to spectral signatures of iron emission or cyclotron lines using Gaussian line profiles. Results. We apply our method to a representative sample of NuSTAR observations of well-known accreting X-ray pulsars. We show that, with this method, it is possible to characterize the pulsed fraction spectra, and to constrain the position and widths of such features with a precision comparable with the spectral results. We also explore how harmonic decomposition, correlation, and lag spectra might be used as additional probes for detection and characterization of such features.

Laser Beam Quality of Airy Beam in the Jet Engine Exhaust Induced Turbulence

Theoretical predictions of laser beam interactions with jet-engine-exhaust-induced turbulence are of importance for optimization of various optical systems, including LIDARs and airborne laser measurement systems. This paper is based on the extended Huygens–Fresnel diffraction integral and the Wigner distribution function, combined with the recently proposed power spectral density function of atmospheric turbulence induced by jet engine exhaust, to derive the formula for the quality factor of a partially coherent Airy beam in turbulent media induced by jet engine exhaust. Numerical calculations based on the analytical formula show that the smaller the structure constant and outer scale of the atmospheric turbulence induced by jet engine exhaust, the smaller the quality factor of a partially coherent Airy beam, indicating better laser beam quality. At the same time, the larger the generalized parameter and inner scale of the jet-engine-exhaust-induced turbulence and the longer the wavelength of the laser beam, the smaller the corresponding quality factor. The numerical results also show that reducing the coherence length of a partially coherent Airy beam and increasing its characteristic width are beneficial for reducing the quality factor in the atmospheric turbulence induced by jet engines. However, the numerical results show that increasing the coherence length of a partially coherent Airy beam and reducing its characteristic width are beneficial for reducing the quality factor in vacuum. This situation demonstrates significant differences between the interaction mechanisms of an Airy beam in vacuum and in the jet-engine-exhaust-induced turbulence. The results of our discussion contribute to clarifying the mechanism of interaction between an Airy laser beam and random media, as well as the application of a curved Airy laser beam in practical situations.

Utilization of multi-pass laser processing strategy for enhancing the capability of low power ns laser for machining of Ti-6Al-4V alloy

The present study aims to investigate the deep machining of Ti-6Al-4V alloy using a nanosecond (ns) laser through multi-pass and gas pressure. Experiments were conducted based on Full factorial design (FFD) by varying gas pressure and laser process parameters (LPP). Results showed that deeper grooves could be achieved through multi-pass laser scanning support with appropriate gas flow rate and laser parameters. A higher gas flow rate leads to more efficient removal of material and a faster machining rate. Further, the present findings revealed the substantial influence of laser power on the depth and width of the machined features, accounting for 41.28% and 7.11% of the variations, respectively. Moreover, power exhibited a significant impact on the taper angle (20.69%) and the heat-affected zone (HAZ) (12.04%) during the machining process. Additionally, the utilization of a multi-pass laser scan demonstrated a remarkable effect on the depth (1.89%), width (3.3%), HAZ (9.96%), and taper angle (8.78%). Furthermore, the assisted gas flow rate displayed a significant influence on the machined groove profile, that is, depth (41.97%), width (67.6%), HAZ (65.48%), and taper angle (30.15%). To achieve optimized results for high-depth machining with minimal defect, the present study recommends employing an average power of 40 W, an assisted gas flow rate of 25 L/min, and conducting four passes. These parameters develop laser machined surface with a high depth (~1499 µm) while simultaneously minimizing Taper (1.87°) and narrow HAZ (83 µm). Further, these conditions are suitable for laser cutting, trepanning, and surface texturing using a low-power laser system of Ti-6Al-4V alloy.

DCAE-UNET: IMPROVED OPTIC DISC SEGMENTATION MODEL USING SEMI-SUPERVISED DEEP DILATED CONVOLUTION AUTOENCODER-BASED MODIFIED U-NET

An accurate assessment of the morphological characteristics of the Optic Disc (OD) is essential for the diagnosis of various retinal disorders. It is necessary to segment the OD precisely to detect structural OD changes associated with visual field loss. Although deep learning models are effective for this task, they require extensive labeled datasets, which can be time-consuming and costly. Furthermore, fundus images have multi-scale features, making segmentation challenging. In this study, we present a semi-supervised and transfer learning approach for OD segmentation. Our approach utilizes an improved Dilated Convolutional AutoEncoder (DCAE) and a pre-trained modified U-Net to segment the OD. The DCAE segments the OD using feature similarity from unlabeled images in the Messidor dataset and saves the learned weights. Transfer learning is then applied to reuse the model weights in the U-Net, accelerating training on small datasets such as Drions-DB and Drishti-GS. The network architecture was modified by increasing the layers from 8 to 128 and halving the feature map length and width. To address the multi-scale challenge without inflating the model parameters, we introduce the Dilated Hierarchical Feature Extraction Module (DHFEM), a convolutional module capable of achieving multi-scale feature extraction without increasing model parameters. Additionally, DHFEM incorporates convolutional layers with varying receptive fields, further enhancing the network ability to extract features across multiple scales. Our OD segmentation method outperforms existing algorithms with reduced parameter quantities of 0.4 M. The mean Intersection over Union (mIoU) values are 0.9383 and 0.9629 and inference times of 45 ms and 40 ms for the Drions-DB and Drishti-GS datasets, respectively.

Experimental investigation on two-dimensional aerodynamic admittances of rectangular cylinders in various turbulent flows

This paper conducts an experimental investigation of two-dimensional aerodynamic admittances (2D AAFs) for rectangular 5:1 cylinders within various turbulent flow fields. The determination of 2D AAF is achieved by removing the influence of the three-dimensional effect (3D effect) from the traditional AAF, wherein the traditional AAF can be straightly derived based on the ratio of the one-dimensional fluctuating force spectrum to the one-dimensional turbulent wind spectrum. In line with prior research, the values of traditional AAFs show variations in response to the 3D effect in different turbulent flow fields. Moreover, within homo-turbulence conditions, or more specifically, under similar turbulence intensity, the traditional AAFs differ depending on the turbulent integral scale to the model characteristic width ratios (dimensionless turbulent integral scale). Compared to the traditional AAF, the 2D AAF effectively cuts down on the discrepancies arising from the dimensionless turbulent integral scale. In cases where different dimensionless turbulent integral scales are present but the turbulence intensity remains constant, the 2D AAFs are almost consistent. Nevertheless, it can be observed that the 2D AAF of the rectangular 5:1 cylinder is still affected by turbulence intensity. For different turbulence intensities, the 2D AAFs have certain changes. When there is less turbulence intensity, it frequently approaches the quasi-steady value, and as the turbulence intensity increases, it gradually approaches the Sears function.

A strategy for regulation of gas–liquid microflow patterns by changing gas kinetic energy

Controllable regulation of gas–liquid microflow pattern and bubble size is significant to bubble-based microfluidics, but it is hard to be realized with the existing technologies. Accordingly, this work reports a convenient strategy that changes the gas kinetic energy to controllably regulate the microflow patterns from Taylor flow to short bubble flow and bubbly flow. Results exhibit that the desired flow patterns and bubble size can be effectively obtained by varying the gas inlet size to change gas kinetic energy, and a much wider bubbly flow regime which could not be reached normally in conventional T-junction microchannels is easily obtained. Besides, from the bubble’s characteristic width and length, the behaviors of the bubble generation in different T-junctions were compared to reveal the mechanism behind the generation of bubbles. Importantly, as the hydraulic diameter of the gas inlet decreases from 365.0 to 50.0 μm, the dominative factors on the bubble generation transfer mainly from the liquid phase to both the two-phases because the gas–liquid Weber number ratio increases from 6.6 × 10−5–5.4 × 10−3 to 4.2 × 10−2–3.4. Finally, the parameter of the two-phase Weber number ratio is the first time introduced to the unified prediction model for bubble generation frequency.

DEPENDENCE OF TEMPERATURE DETERMINATION ACCURACY ON THE BANDWIDTH OF THE INTERFERENCE FILTER IN OPTICAL PYROMETRY SYSTEMS

Some general issues common to all reactors for gas-phase epitaxy of A3B5 metal-organic compounds include large temperature gradients in the reactor, leading to the formation of convection loops, high gas flow rates that can result in turbulence instead of the expected laminar flow, and the need for good uniformity and precision in temperature control of the semiconductor substrate surface. Since the deposition process for many complex semiconductor devices (such as infrared laser diodes or heterojunction bipolar transistors) is highly temperature-dependent, a system for precise temperature control of the process at the substrate surface directly in the deposition zone is necessary to obtain high-quality heterostructures with reproducible parameters.
 This article describes the features of the epitaxial growth process in MOCVD reactors, as well as highlights the tasks facing the temperature control system. The feasibility of using a radiation compensation system is explored in comparison to measurement methods using a thermocouple and classical pyrometry. Transformation of the input optical signal into a proportional output current in this system is performed by a sensitive photodetector, namely a silicon photodiode. The selection of the wavelength range of the radiation is determined by the optical parameters of the semiconductor substrates and compounds used in the system. The measurement spectrum is determined by the parameters of the interference filter in the system.
 The research was conducted to determine the effect of the interference filter width on the accuracy of determining the real temperature of a pyrometric control system with radiation compensation. The dependence of the interference filter characteristic width and shape on the correction value of the temperature of pyrometric systems after calibration is analyzed. Based on the results obtained, recommendations are made for selecting the optimal working wavelength and interference filter bandwidth of the optical system as a compromise between the determination error and the magnitude of the optical signal. The results can be used for the design of modern precision pyrometric systems.

Spatial variations in aromatic hydrocarbon emission in a dust-rich galaxy.

Dust grains absorb half of the radiation emitted by stars throughout the history of the universe, re-emitting this energy at infrared wavelengths1-3. Polycyclic aromatic hydrocarbons (PAHs) are large organic molecules that trace millimetre-size dust grains and regulate thecooling of interstellar gas within galaxies4,5. Observations of PAH features in very distant galaxies have been difficult owing to the limited sensitivity and wavelength coverage of previous infrared telescopes6,7. Here we present James Webb Space Telescope observations that detect the 3.3 μm PAH feature in a galaxy observed less than 1.5 billion years after the Big Bang. The high equivalent width of the PAH feature indicates that star formation, rather than black hole accretion, dominates infrared emission throughout the galaxy. The light from PAH molecules, hot dust and large dust grains and stars are spatially distinct from one another, leading to order-of-magnitude variations in PAH equivalent width and ratio of PAH to total infrared luminosity across the galaxy. The spatial variations we observe suggest either a physical offset between PAHs and large dust grains or wide variations in the local ultraviolet radiation field. Our observations demonstrate that differences in emission from PAH molecules and large dust grains are a complex result of localized processes within early galaxies.

Gaia Data Release 3

Context. Diffuse interstellar bands (DIBs) are common interstellar absorption features in spectroscopic observations but their origins remain unclear. DIBs play an important role in the life cycle of the interstellar medium (ISM) and can also be used to trace Galactic structure. Aims. Here, we demonstrate the capacity of the Gaia-Radial Velocity Spectrometer (RVS) in Gaia DR3 to reveal the spatial distribution of the unknown molecular species responsible for the most prominent DIB at 862 nm in the RVS passband, exploring the Galactic ISM within a few kiloparsecs from the Sun. Methods. The DIBs are measured within the GSP-Spec module using a Gaussian profile fit for cool stars and a Gaussian process for hot stars. In addition to the equivalent widths and their uncertainties, Gaia DR3 provides their characteristic central wavelength, width, and quality flags. Results. We present an extensive sample of 476 117 individual DIB measurements obtained in a homogeneous way covering the entire sky. We compare spatial distributions of the DIB carrier with interstellar reddening and find evidence that DIB carriers are present in a local bubble around the Sun which contains nearly no dust. We characterised the DIB equivalent width with a local density of 0.19 ± 0.04 Å kpc−1 and a scale height of 98.60−8.46+11.10 pc. The latter is smaller than the dust scale height, indicating that DIBs are more concentrated towards the Galactic plane. We determine the rest-frame wavelength with unprecedented precision (λ0 = 8620.86 ± 0.019 Å in air) and reveal a remarkable correspondence between the DIB velocities and the CO gas velocities, suggesting that the 862 nm DIB carrier is related to macro-molecules. Conclusions. We demonstrate the unique capacity of Gaia to trace the spatial structure of the Galactic ISM using the 862 nm DIB.

Correlation between the morphological features of the biceps groove and injuries to the biceps pulley and the long head tendon of the biceps

PurposeThe morphometric features of the biceps groove were measured to investigate their correlation with the injury of the pulley and the long head of the biceps tendon (LHBT).MethodsA total of 126 patients undergoing arthroscopic rotator cuff repair surgery had their morphological features of bicipital groove evaluated on a 3D reconstruction model of the humeral head. The groove width, groove depth, opening angle, medial wall angle, and inclination angle of the bicipital groove were measured for each patient. During the surgery, the type of injury to the biceps pulley and the degree of long head of biceps tendon injury were assessed. The correlations of these injury assessments with bicipital groove measurements were analyzed.ResultsThe average groove width was(12.3 ± 2.1) mm. The average groove depth was(4.9 ± 1.4) mm. The average groove inclination angle was 26.3° ± 8.1°. The average opening angle was 89.8° ± 18.4°. The average medial groove wall angle was 40.6° ± 7.9°.Sixty six patients had injury of the biceps pulley structure, and their Martetschläger classifications were as follows: type I injury in 12 patients, type II injury in 18 patients, and type III injury in 36 patients. The Lafosse grades of Lesions of LHBT were as follows: 72 cases were grade 0 injury, 30 cases were grade I injury, and 24 cases were grade II injury. We found no significant correlation between the opening width, depth, inclination angle, opening angle, and medial wall angle of the morphological features of bicipital groove and injuries of the pulley and the LHBT. The correlation between pulley structure injury and lesions of LHBT was statistically significant.ConclusionLesions of LHBT show strong correlation with pulley injuries.This study does not find a correlation between the injury of the pulley or the LHBT and bicipital groove morphology.

Direct observation of spreading precursor liquids in a corner.

Precursor liquid is a nanoscale liquid creeping ahead of the macroscopic edge of spreading liquids, whose behaviors tightly correlate with the three-phase reaction efficiency and patterning accuracy. However, the important spatial-temporal characteristic of the precursor liquid still remains obscure because its real-time spreading process has not been directly observed. Here, we report that the spreading ionic liquid precursors in a silicon corner can be directly captured on video using in situ scanning electron microscopy. In situ spreading videos show that the precursor liquid spreads linearly over time ([Formula: see text]) rather than obeying the classic Lucas-Washburn law ([Formula: see text]) and possesses a characteristic width of ∼250-310nm. Theoretical analyses and molecular dynamics simulations demonstrate that the unique behaviors of precursor liquids originate from the competing effect of van der Waals force and surface energy. These findings provide avenues for directly observing liquid/solid interfacial phenomena on a microscopic level.