Main Plane Research Articles

Unveiling deformation behavior and damage mechanism of irradiated high entropy alloys

The oxide dispersion strengthening (ODS) high entropy alloy (HEA) exhibits the high elevated temperature performance and radiation resistance due to severe atomic lattice distortion and oxide particles dispersed in matrix, which is expected to become the most promising structural material in the next generation of nuclear energy systems. However, microstructure and damage evolution of irradiated ODS HEA under loading remain elusive at submicron scale using the existing simulations owing to a lack of atomic-lattice-distortion information from a micromechanics description. Here, the random field theory informed discrete dislocation dynamics simulations based on the results of high-resolution transmission electron microscopy are developed to study the dislocation behavior and damage evolution in ODS HEA considering the influence of severe lattice distortion and nanoscale oxide particle. Noteworthy, the damage behavior shows an unusual trend of the decreasing-to-increasing transition with the continuous loading process. There are two main types of damage micromechanics generated in irradiated ODS HEA: the dislocation loop damage in which the damage is controlled by irradiation-induced dislocation loops and their evolution, the strain localization damage in which the damage comes from the dislocation multiplication in the local plastic region. The oxide particle hinders the dislocation movement in the main slip plane, and the lattice distortion induces the dislocation sliding to the secondary slip plane, which promotes the dislocation cross-slip and dislocation loop annihilation, and thus reduces the material damage in the elastic damage stage. These findings can deeply understand atomic-scale damage mechanism and guide the design of ODS HEA with high radiation resistance.

Analysis and research on polarized radiation characteristics of ship targets at sea

The traditional ship infrared detection method cannot solve the edge details when the ship target interacts flexibly with the sea surface background. Polarization detection technology has gradually become an important research direction for high-precision detection of marine targets because of its advantages of acquiring the intrinsic characteristics of targets. This paper selects the typical part panels and scaled models of ships as experimental research object, focusing on the analysis of the polarized radiation characteristics of marine ship targets. Starting from the principle of polarization detection, we extended the application of the bidirectional polarization reflection distribution function that can obtain the polarization spectral characteristics of the target. According to the principle of time-sharing polarization detection, we designed a simulation experiment scheme for the polarization characteristics of the typical parts of the ship and the overall model related to the sea surface background. Finally, we implemented the measurement experiment of multi-angle polarization characteristics in the field and performed data analysis. The results show that: (1) The polarization reflectivity and polarization degree of the typical parts of the ship tend to be consistent with the changes of the observation geometric conditions, both increase with the increase of the observation zenith angle, and the forward scattering area is larger than the back scattering area. (2) The observation direction has a great influence on the overall detection results of the ship. When using the 30°zenith angle of the forward scattering area of the main plane for observation, the contrast between the ship and the water body is obvious, and it is easy to detect the ship.

The interaction between Pd/CeO2 crystal surface and electric field: Application to complete oxidation of methane

Pd/CeO2 with different crystal faces can significantly affect the methane oxidation process, but the catalytic behavior in electric field is not clear yet. The supported Pd/CeO2 with rod, octahedral and cubic morphologies were synthesized by hydrothermal method, and their methane oxidation efficiency in electric field was measured. The structure of Pd/CeO2 and reaction mechanism in electric field were investigated by XRD, BET, XPS, H2-TPR, TEM and in situ DRIFTs. Studies show that the synergistic effect between electric field and (111) crystal plane in octahedral CeO2 is the strongest and (110) in rod CeO2 is the main active restraint crystal plane. The Pd atoms on the surface of Pd/CeO2-oct are exposed to the most amount of Pd atoms and the main Pd nanoparticles are present. Pd species on CeO2-cube and CeO2-rod surface with relatively low activity exist mainly in the form of Pd2+ and Pd4+, whereas Pd0 and Pd2+ on the Pd/CeO2-oct surface are more favorable for CH4 oxidation in the catalytic cycle. Pd4+ is inactive for CH4 oxidation. In addition, H migration from Pd active site to the support induced by hydrogen spillover can enhance the oxidation activity of CH4 in electric field. The conversion of carbonate/hydrogencarbonate to formate is an advantageous step in the methane oxidation process, with the active sequence being octahedral (111) > cubic (100) > rod (110) faces in/without electric field.

Reconstruction of lateral coherence and 2D emittance in plasma betatron X-ray sources

X-ray sources have a strong social impact, being implemented for biomedical research, material and environmental sciences. Nowadays, compact and accessible sources are made using lasers. We report evidence of nontrivial spectral-angular correlations in a laser-driven betatron X-ray source. Furthermore, by angularly-resolved spectral measurements, we detect the signature of spatial phase modulations by the electron trajectories. This allows the lateral coherence function to be retrieved, leading to the evaluation of the coherence area of the source, determining its brightness. Finally, the proposed methodology allows the unprecedented reconstruction of the size of the X-ray source and the electron beam emittance in the two main emission planes in a single shot. This information will be of fundamental interest for user applications of new radiation sources.

Small extracellular vesicles' enrichment from biological fluids using an acoustic trap.

Small extracellular vesicles (sEVs), a form of extracellular vesicles, are lipid bilayered structures released by all cells. Large-scale studies on sEVs from clinical samples are necessary, but a major obstacle is the lack of rapid, reproducible, efficient, and low-cost methods to enrich sEVs. Acoustic microfluidics have the advantage of being label-free and biocompatible, which have been reported to successfully enrich sEVs. In this paper, we present a highly efficient acoustic microfluidic trap that can offer low and large volume compatible ways of enriching sEVs from biological fluids by flexible structure design. It uses the idea of pre-loading larger seed particles in the acoustic trap to enable sub-micron particle capturing. The microfluidic chip is actuated using a piezoelectric plate transducer attached to a silicon-glass bonding plate with circular cavities. Each cavity works as a resonant unit, excited at the frequency of both the half wave resonance in the main plane and inverted quarter wave resonance in the depth direction, which has the ability to strongly trap seed particles at the center, thereby improving the subsequent nanoparticle capture efficiency. Mean trapping efficiencies of 35.62% and 64.27% were obtained using 60 nm and 100 nm nanobeads, respectively. By the use of this technology, we have successfully enriched sEVs from cell culture conditioned media and blood plasma at a flow rate of 10 μL min-1. The isolated sEV subpopulations are characterized by NTA and TEM, and their protein cargo is determined by WB. This acoustic trapping chip provides a rapid and robust method to enrich sEVs from biofluids with high reproducibility and sufficient quantities. Therefore, it can serve as a new tool for biological and clinical research such as cancer diagnosis and drug delivery.

Unveiling the 3D structure of nova shells with MUSE: The case of RR Pic

Context. Nova eruptions occur in cataclysmic variables when enough material has been accreted onto the surface of the white dwarf primary. As a consequence, the material that has been accumulated until then is expelled into the interstellar medium, forming an expanding nova shell around the system. Understanding the physical process that shapes the morphology of nova shells is essential to fully comprehend how the ejection mechanism operates during nova eruptions. Because of its closeness and age, the nova shell around the classical nova RR Pic (Nova Pic 1925) is an ideal target for studying the evolving morphology of nova shells. Aims. The use of integral field spectroscopy (IFS) is a technique that has received little attention in the study of nova shells, despite the advantages in using it when studying the morphology and kinematics of nova shells. In this work, we present an IFS study of the RR Pic nova shell, with a particular emphasis on the extraction of the 3D morphology of the shell. Methods. The nova shell was observed by the Multi-Unit Spectroscopic Explorer (MUSE) instrument placed at the ESO-VLT. By measuring the extension of the nova shell in these new observations, and comparing it against previous measurements, we were able to determine the expansion history of the ejected material. We used this information, together with the distance to the system based on Gaia EDR3 parallaxes, and the systemic velocity of the system reported in the literature to obtain the physical 3D view of the shell. Results. The MUSE datacube confirms the presence of the nova shell in Hα, Hβ and [OIII], and very faintly in [NII]. A comparison with previous observations suggests that the shell continues in its free-expansion phase but with the different parts of the shell apparently expanding at different rates. The data analysis corroborates the previous vision that the shell is composed of an equatorial ring and polar filaments traced by Hα. At the same time, the new data also reveal that [OIII] is confined in gaps located in the tropical regions of the shell where no Hydrogen is observed. The flux measurements indicate that ~99% of the shell flux is confined to the equatorial ring, while the polar filaments show a flux asymmetry between the NE and SW filaments, with the latter being ~2.5 times brighter. We have estimated the mass of the shell to be ~5 × 10−5 M⊙. From the analysis of the 3D-extracted data, we determine that the ring structure extends ~8000 au from the central binary, and has a position angle of ~155 deg and an inclination of ~74 deg. The analysis of the equatorial ring reveals it is composed of a main ring and several small clouds, extending up to a height of ~4000 au above and below the main plane of the equatorial ring. The radial profile of the whole ring structure is reminiscent of a bow shock. Conclusions. Our data have proven the capabilities of observing nova shells using IFS, and how the nova shell around RR Pic is an interesting object of study. Further and continuous observations of the shell across the electromagnetic spectrum are required to confirm the results and ideas presented in this work.

Penerapan Metoda High Pressure Jet Cooling (HPJC) untuk Mengurangi Keausan Tepi Pahat pada Proses Membubut dengan Kecepatan Rendah

High Pressure Jet Cooling (HPJC) is an alternative method to the ineffective and environmentally friendly flooding method for coolant distribution at the cutting contact area. This method is widely utilized in the machining process of materials that are difficult to cut or have superior mechanical properties using various tools that have high cutting speeds. At high cutting speeds, it will be difficult for coolant to penetrate the contact area. For this reason, in this study HPJC is used to turn low carbon steel material with a tool that has a low cutting speed. By using a tool capable of providing pressure variation in coolant delivery, flank wear as a result of the turning process was observed. The results were validated using ANOVA and Fisher Least Significant Differences methods. The results show that pressure variation can reduce the tool wear rate. However, the tools used were not sufficient to distinguish the change in applied pressure from the reduction in tool life. This is because the coolant is only concentrated on the main plane of the tool. As a result, other types of wear, namely nose wear, have increased.

EPR of LiNaGe4O9:Mn crystal

EPR spectra of manganese ions were studied in lithium-sodium tetragermanate LiNaGe4O9 crystal. The observed spectrum was typical for doping ions in tetravalent Mn4+ state (3d 3, S=3/2) and for main orientations of static magnetic field along the crystal axes (T=296 K) consisted of hyperfine sextuplet from electronic transition Ms= +1/2 ↔ – 1/2. Transitions Ms= ±3/2 ↔±1/2 were not detected owing to strong interaction of the spin system with crystal field as compared with electron Zeeman interaction in the X frequency range of EPR registration. The angular variations of the spectrum were measured for static field B rotated in three main crystal planes. Since only central transition (Ms= +1/2 ↔ – 1/2) was detected and the splitting of the fine structure remained unknown, the spectrum was described in the approximation of effective spin Seff=1/2. The parameters of the spin Hamiltonian, including electron Zeeman and hyperfine interactions, were calculated. The magnetic multiplicity of the spectrum (km=2) evidenced that paramagnetic centers occupied the sites with monoclinic C2 point symmetry. Taking into consideration the positional symmetry as well ionic charges and radii of the guest ion and the hosts, it was concluded that paramagnetic Mn4+ centers substituted for Ge4+ within oxygen octahedral complexes in the crystal lattice of LiNaGe4O9.

Flow and heat transfer characteristics in adaptive latticework structure designed using shape memory alloys

In this study, numerical simulation and particle image velocimetry experiments were performed to investigate an adaptive flow and heat transfer control structure based on shape memory alloy operating in the range of Reynolds number 100 to 2000. The adaptive structure could operates with low drag coefficient in the flat state, and actively enhance heat transfer with a latticework channel structure in the warping state. Different warping heights and Reynolds numbers were investigated to analyze the flow patterns and heat transfer enhancement mechanism. The warping of the shape memory alloy leads to flow deflection and generates a z-direction velocity component around the gap, which is the main reason for local heat transfer enhancement. The average velocity in the main stream plane (XY plane) close to the heat transfer surface increases sharply with warping. This study found significant increase in normal velocity and in-plane velocity (up to 0.17 and 0.94 times reference inlet velocity uin) in the plane at a distance of 0.1 times hydraulic diameter Dh from the wall due to warping, which strengthens the disturbance near the wall and thus enhances heat transfer. The longitude vortices generated in the structure are divided into the main vortex in the center of the channel and the corner vortex in the sub channel. The corner vortex is mainly caused by the gap flow between the shape memory alloy and the wall surface. In the warping state, the average value of the main stream velocity components near the wall is relatively close to the numerical simulation results (by deviation of 0.04 uin). In numerical results, the structure can achieve a heat transfer regulation ratio of 2.5–3.3 times and a resistance regulation ratio of 5.2–14.6. The performance parameters are not monotonous with the increase of the warping height or the Reynolds number. When the warping height is 0.6 Dh and Reynolds number equals to 400, maximum performance factor (1.34) is achieved.

A Method Probing High-Temperature Oxidation Behavior of Crystalline Materials.

To date, the oxidation behavior of crystal materials is not fully understood; additional research is needed to understand the oxidation of materials. Herein, density functional theory (DFT) calculations and a 3D kinetic Monte Carlo (KMC) model are used to investigate the infiltration and diffusion behaviors of oxygen atoms within the crystal. Oxygen molecules readily adsorbes on crystal surfaces of the material and rapidly dissociates, verified by both first-principles calculations and energy-dispersive spectrometer (EDS) results. The infiltration ability of oxygen atoms into the inner crystal layers is affected by the surrounding oxygen atom, lattice compactness, and other factors. Energy-barrier calculations show that crystal thin/dense layers have significant effects on the crystal oxidation process, so high-pressure technology is used to investigate this correlation experimentally. KMC calculations and thermogravimetric analyses (TGA) show the infiltration behavior of oxygen atoms in the main crystal plane (211) toward the inner layers has the highest proportion to the actual high-temperature oxidation behavior of the title material. The results of both the KMC calculations and thermal experiments show the material peeled off upon further oxidation, which accelerates oxidation. At the same time, high-pressure treatment increases the oxidation resistance of materials at lower temperatures (<600°C).

Biomechanics of internal fixation in Hoffa fractures – A comparison of four different constructs

ObjectiveCompare the biomechanical effectiveness of four different bone-implant constructs in preventing fracture displacement under axial loading. MethodsTwenty artificial femora had a standardized coronally oriented fracture of the lateral femoral condyle, representing a Hoffa fracture classified as a Letenneur type I. Four different fixation constructs were applied to the synthetic bones for biomechanical testing. The constructs consisted of a posterolateral (PL) buttressing locking plate in conjunction with two cannulated lag screws inserted from posterior to anterior (PA) – Group 1; Two cannulated screws inserted from anterior to posterior (AP) without plating– Group 2; A posterolateral (PL) buttressing locking plate in isolation – Group 3; and a combination of two lag screws from anterior to posterior (AP) in addition to a horizontal one-third tubular locking plate – Group 4. An axial load was applied to the fracture site with a constant displacement speed of 20 mm/min, and the test was interrupted when a secondary displacement was detected determining a fixation failure. We recorded the maximum applied force and the maximum fracture displacement values. ResultsGroup 1 demonstrated the highest overall bone-implant axial stiffness with the lowest secondary displacement under loading. Groups 3 and 4 showed equivalent mechanical behavior. Group 2 presented the lowest mechanical stiffness to axial loading. The combination of the one-third tubular locking plate with anterior-to-posterior lag screws (Group 4) resulted in 302 % increase in fixation stiffness when compared to anterior-to-posterior lag screws only (Group 2). ConclusionsThis study confirms the mechanical superiority of having a plate applied parallel to the main fracture plane in the setting of coronally oriented femoral condyle fractures. The addition of a horizontal plate, perpendicular to the main fracture plane, significantly increased the resistance to shearing forces at the fracture site when compared to constructs adopting just cannulated screws. Level of evidenceBiomechanical study

A mechanical analysis of variable angle-tow composite plates through variable kinematics models based on Carrera’s unified formulation

Variable Angle-Tow (VAT) laminates offer a promising alternative to straight fiber composites. By varying fibers orientation within the structure plane, ambitious design and performance goals can be achieved. However, the wider design space results in a more complex problem with more parameters to consider. Carrera’s Unified Formulation (CUF) has been used in previous works performing buckling, vibrational and stress analyses of VAT plates. Usually, one-dimensional (1D) CUF beam models are used, while two-dimensional (2D) plate models are obtained as a particular case of shells by considering a null curvature. In most cases, a linear law is considered to describe the variation of fibers orientation in the main plane of the structure. The purpose of this article is to extend the CUF 2D plate finite elements family to the mechanical analysis of composite laminated plate structures with curvilinear fibers. The main contribute consists in the development of a CUF FE model within the Reissner’s Mixed Variational Theorem (RMVT) context for an improved calculation of the out-of-plane stress components. Results show that RMVT can predict in-plane stresses and satisfy the though-the-thickness transverse stresses continuity due to inter-layer equilibrium. The accuracy of RMVT-based models is also investigated using two different approximation points distributions along the plates thickness.

A Family of Oscillations Connecting Stable and Unstable Permanent Rotations of a Heavy Solid with a Fixed Point

The rotation of a heavy rigid body around a fixed point is investigated if the center of gravity belongs to the main plane of the ellipsoid of inertia. A reduction of the system of Euler–Poisson equations to a reversible conservative system with two degrees of freedom is given, and a bifurcation analysis of permanent rotations is carried out. Global families of periodic motions are found that connect stable and unstable permanent rotations of the same frequency. It is proved that non-degenerate symmetric periodic motion in a reversible mechanical system always continues to the global family.

Construction of a 3D Distribution Network Environment Based on Multi-source Data Fusion

Traditional distribution networks are designed using two-dimensional drawings. Its expression is abstract, the accuracy of manually measured elevation data could be higher, and complex sections are difficult to measure. To solve this problem, a three-dimensional environment for digital planning and design of the distribution network is proposed by combining laser point cloud and oblique photography modelling. Firstly, a rough registration method based on the main material plane is proposed to improve the registration efficiency. The GICP method is used to accurately register the point cloud and build a refined model of distribution equipment; Then, the UAV tilt photography technology is used to model the distribution line corridor, and the elevation model is obtained at the same time. The experimental results show that the model error after precise registration is 3.75 cm, which meets the requirements of high-precision modelling. The average error between the elevation model obtained by the tilt photography of the distribution line corridor and the measured elevation is 0.112 m, which meets the accuracy requirements of mapping.

Milling Force Modeling Methods for Slot Milling Cutters

The slot milling cutter is primarily used for machining the tongue and groove of the steam turbine rotor, which is a critical operation in the manufacturing process of the steam turbine rotor. It is challenging to predict the milling force of a groove milling cutter due to variations in rake, rake angles and cutting speeds of the main cutting edge. Firstly, based on a limited amount of experimental data on turning, we have developed an equivalent turning force model that takes into account the impact of the rounded cutting edge radius, the tool’s tip radius and the feed rate on tool’s geometric angle. It provides a more accurate frontal angle for the identification method of the Johnson–Cook material constitutive equation. Secondly, the physical parameters, such as shear stress, shear strain and strain rate on the main shear plane, are calculated through the analysis of experimental data and application of the orthogonal cutting theory. Thirdly, the range of initial constitutive parameters of the material was determined through the split Hopkinson pressure bar (SHPB) test. The objective function was defined as the minimum error between the theoretical and experimental values. The optimal values of the Johnson–Cook constitutive equation parameters A, B, C, n and m are obtained through a global search using a genetic algorithm. Finally, the shear stress is determined by the governing equations of deformation, temperature and material. The axial force, torque and bending moment of each micro-segment are calculated and summed using the unit cutting force vector of each micro-segment. As a result, a milling force prediction model for slot milling cutters is established, and its validity is verified through experiments.

A symmetry-aware alignment method for photogrammetric 3D models

Despite the rapid development of crowd-sourced photogrammetric reconstruction, a huge database of 3D models is still given in arbitrary scale, position, and orientation. To alleviate the issue, model alignment methods have been proposed to identify good viewpoints for 3D models. This work introduces a symmetry-aware alignment method for photogrammetric 3D models. Our key idea is to associate the best orientation with global symmetry and place objects in a way they commonly appear in our surroundings. Compared to the previous alignment methods that only infer upright orientation, we also determine frontal orientation. The proposed method works in four steps. First, we compute symmetry features using point global symmetry descriptors (PGSD). Second, a set of reflective symmetry planes are generated by feature aggregation. Third, we extract global symmetry and the principal axis based on a subset of symmetry planes with smaller detection errors. Finally, upright and frontal orientations are determined by the principal axis and information entropy successively. We evaluated the proposed method on synthetic and real photogrammetric datasets. Experiments show that the proposed PGSD has achieved higher efficiency and accuracy than curvature, FPFH, and deep learning-based frameworks. Our method outperforms the existing symmetry detection and upright orientation methods, where the average recall of main symmetry plane is 71.13%, and 78.50% of the models are well-aligned.

Numerical simulation on the mechanical and fracture behavior of bedding argillaceous sandstone containing two pre-existing flaws

The overlying strata will move and generate flaws as the coal mining workings advance, and the development of flaws can affect the collapse process of the overlying strata, studying the fracture behavior under different pre-existing flaws conditions is crucial to maintain the stability of coal mining workings. In this work, a series of bedding argillaceous sandstone models containing two pre-existing flaws (i.e. bottom flaw length, included angle between upper and bottom flaw, and loading rate) were simulated under uniaxial compression experiments based on the discrete element method (DEM) under the moment tensor theory. The research results show that the increasing in included angle and loading rate lead to an increase in peak strength and a decrease in the angle of the main fracture plane. The variation of peak strength and b-value decreases with the bottom flaw length, with smaller tensile acoustic emission (AE) event and larger shear AE event for interlayer and bedding cracking, respectively. The crack-in-matrix presents a concave tendency with bedding angle, leading to a failure pattern change from matrix-dominated, matrix-bedding to bedding-dominated in a lower b-value. Loading rate promotes the change of AE event from tensile to shear mode with a wider fracture plane. In terms of brittleness, the range of brittleness is mainly between moderate brittleness and brittleness, and decreases and increases as the bottom flaw length and the included angle, respectively, exhibit a linear correlation in strength, independent of the loading rate to models. The research results could contribute to the comprehension of cracking mechanisms and improve safe production at coal mine workings of bedding strata.

The 28 October 2022 Mw 3.8 Goesan Earthquake Sequence in Central Korea: Stress Drop, Aftershock Triggering, and Fault Interaction

ABSTRACT We identified the causative fault of the 2022 Goesan, Korea, earthquake sequence based on the precise relocation of the sequence that revealed a 0.8 km-long fault plane striking east-southeast–west-northwest. The fault plane encompasses the largest foreshock, the mainshock, and the majority of the aftershocks. The orientation of the fault plane is consistent with the left-lateral strike-slip motion along the east-southeast (106°) striking nodal plane of the focal mechanism. The Jogok fault system recently mapped in the source area runs through the mainshock epicenter with a consistent strike and left-lateral strike-slip motion, which suggests that it is the likely causative fault of the 2022 Mw 3.8 Goesan earthquake sequence. It is a rare case of assigning a causative fault for a small-sized (Mw 3.8) earthquake with some confidence in a typical stable continental region setting, albeit no surface break observed due to deep focal depth (~13 km) and the small size of the event. Aftershocks on the main fault plane, and on the adjacent subparallel fault patches seemed to be triggered by the increase in Coulomb stress caused by the mainshock. Two large aftershocks on the subparallel fault patches show slightly higher stress drops than the large foreshock and mainshock on the main fault plane, likely due to high frictional strength on those fault patches. Events of the 2022 Goesan earthquake sequence progressed rapidly in time and appear to be high stress-drop events compared with other earthquakes that occurred in other regions in Korea, probably due to the long quiescent period in the Goesan earthquake epicentral region.

Three-dimensional echocardiographic evaluation of longitudinal and non-longitudinal components of right ventricular contraction: results from the World Alliance of Societies of Echocardiography study.

Right ventricular (RV) functional assessment is mainly limited to its longitudinal contraction. Dedicated three-dimensional echocardiography (3DE) software enabled the separate assessment of the non-longitudinal components of RV ejection fraction (EF). The aims of this study were (i) to establish normal values for RV 3D-derived longitudinal, radial, and anteroposterior EF (LEF, REF, and AEF, respectively) and their relative contributions to global RVEF, (ii) to calculate 3D RV strain normal values, and (iii) to determine sex-, age-, and race-related differences in these parameters in a large group of normal subjects (WASE study). 3DE RV wide-angle datasets from 1043 prospectively enrolled healthy adult subjects were analysed to generate a 3D mesh model of the RV cavity (TomTec). Dedicated software (ReVISION) was used to analyse RV motion along the three main anatomical planes. The EF values corresponding to each plane were identified as LEF, REF, and AEF. Relative contributions were determined by dividing each EF component by the global RVEF. RV strain analysis included longitudinal, circumferential, and global area strains (GLS, GCS, and GAS, respectively). Results were categorized by sex, age (18-40, 41-65, and >65 years), and race. Absolute REF, AEF, LEF, and global RVEF were higher in women than in men (P < 0.001). With aging, both sexes exhibited a decline in all components of longitudinal shortening (P < 0.001), which was partially compensated in elderly women by an increase in radial contraction. Black subjects showed lower RVEF and GAS values compared with white and Asian subjects of the same sex (P < 0.001), and black men showed significantly higher RV radial but lower longitudinal contributions to global RVEF compared with Asian and white men. 3DE evaluation of the non-longitudinal components of RV contraction provides additional information regarding RV physiology, including sex-, age-, and race-related differences in RV contraction patterns that may prove useful in disease states involving the right ventricle.

Hypocenter relocation of the Mw 5.9 eastern Manggarai earthquake 2022 and its aftershocks based on BMKG seismic network

The moderate earthquake (Mw 5.9) struck eastern Manggarai and its surroundings on February 21, 2022, at 12:36:00 UTC. Although this earthquake was classified as a moderate earthquake, it produced a significant number of aftershocks. The aftershocks could be observed as the post-seismic activity, which was still well recorded until March 31, 2022. The hypocenter location of the aftershocks is updated by applying the double-difference method. The aftershock distribution is striking in west-east orientation and dipping to the south, emphasizing a geometry of faults. The strike and dip directions are consistent with the focal mechanism determined by the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG). Most aftershocks after the relocation are distributed at a depth of < 25 km; the depth of the mainshock is 21.5 km. The aftershock distribution in this study shows that the earthquake sequence propagates toward the up-dip direction. The aftershock relocation also reveals that most aftershocks are situated slightly off the main fault plane in the complex splay faults. Therefore, we conjecture that the co-seismic activity may trigger the aftershocks. In addition, this study also shows that the fault system consists of several fault segments. Our study benefits earthquake disaster mitigation, especially in mapping the segment faults of the Flores backarc thrust.