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The extension of the seismic bandwidth to lower frequencies enhances impedance contrasts that can be poorly represented by the broadband acquisition wavelet. Furthermore, long filters that are used to shape the wavelet of processed data can cause issues with noise, phase and interference between seismic events. In this paper, we use a mathematical technique known as mollification to resolve impedance variations with the highest detail allowed by the bandwidth of the data. The mollifier is integrated and windowed to match the low‐frequency content of the data to yield a convenient conversion to relative impedance. Synthetic data created from wedge models show that the windowed mollifier provides an improved representation of the impedance profile. This is replicated by application to an acoustic well log and a regular seismic dataset recorded in the Southern North Sea as well as a broadband dataset recorded in the North Sea. [ABSTRACT FROM AUTHOR]

Through the optimization of tool parameters and the wedge shape, titanium alloy workpieces free of internal and external defects were formed by flat cross wedge rolling (CWR) adopting tools without surface grooves. Firstly, the thermomechanical coupled model of CWR for TC11 (Ti-6.5Al-3.5Mo-1.5Zr-0.3Si) titanium alloy was established in the finite element (FE) software DEFORM-3D, and the effects of forming angle α, stretching angle β, and section reduction Ψ were studied. The results showed that in the conventional empirical range of tool parameters, the defect-free workpiece is hard to be rolled by the typical tool structure. To optimize the forming quality of rolled workpieces, a modified tool structure was proposed by introducing an inclined plane with a width of λ (2–5 mm) on the top of the wedge shape and revising the side wedge plane α to a combination of two inclined planes α1 and α2 (α ≥ α1 > α2). Simulations and experiments demonstrated that the modified tools without surface grooves can achieve TC11 alloy workpieces with smooth surface. When the distance between the top and bottom tools is too large, the rolled workpiece axis is prone to being bent, and the gap from the top tool to the billet should be controlled in the range of 0–0.2 mm to ensure its straightness. Finally, the necking-free TC11 alloy rolled workpieces (Ψ = 67.9% and Ψ = 82.3%) with smooth surface and excellent internal quality were manufactured by IM500 flat CWR mill at 900 °C, 500 mm/s. [ABSTRACT FROM AUTHOR]

The installation of many pile foundations near slopes inevitably exposes them to the influence of the slopes on the stiffness and strength of the soil–pile system, which is a significant issue involving geomechanics and worthy of concern. Therefore, a modified failure wedge model with an optimal base angle is developed to address the impact of slopes on laterally loaded piles in sand, drawing insights from previous experimental results and finite-element analyses. The objective of this model is to provide a more comprehensive and universal analysis of the lateral behavior of piles while considering a limited height slope, compared with previous models applicable in relatively limited cases. In this modified model, factors such as edge distance from the slope crest and slope height are taken into consideration. The proposed theoretical method demonstrates its capability to accurately predict the lateral response of a pile. Based on this method, an analysis is conducted to examine how slope inclination, edge distance from the slope crest, and slope height affect the soil–pile system. [ABSTRACT FROM AUTHOR]

This investigation aimed to optimize gradient positioning for radiochromic film calibration to facilitate a uniform distribution of calibration points. The study investigated the influence of various parameters on gradient dose profiles generated by a physical wedge, assessing their impact on the field's dose dynamic range, a scalar quantity representing the span of absorbed doses. Numerical parameterization of the physical wedge profile was used to visualize and quantify the impact of field size, depth, and energy on the dynamic range of dose gradients. This concept enabled the optimization of the gradient positioning and estimation of the necessary number of exposures for the desired calibration dose range. An optimization algorithm based on histogram bin height minimization was developed and presented. The maximum dynamic range was achieved with a 20 ×$\times$ 20 cm2$\textrm {cm}^{2}$ field size at 5 cm depth. Optimization of wedge gradient positioning yielded the most uniform dose distribution with 7 exposures for the [1,10] Gy range and 8 exposures for the [1,20] Gy range. Film calibration using gradients centered at 1.6, 3, 3.5, and 7 Gy central axis (CAX), obtained through optimized gradient positioning, was showcased. The presented work demonstrates the potential for an improved film calibration process, with efficient material utilization and enhanced dosimetric accuracy for clinical applications. While the method was described for the use of a physical wedge, the methodology can be easily extended to the use of a more convenient dynamic wedge. [ABSTRACT FROM AUTHOR]

In the current study, wedge effects on a planing hull's friction and pressure resistance components have been numerically investigated. This study also assesses how the variation of pressure and friction resistance components can be predicted by trim angle variation. The obtained results indicate that at $Fr_b \lt 0.9$ F r b < 0.9 , stern wedges slightly increase the vessel's pressure resistance. By increasing the speed, pressure, and friction resistance components of the wedge-mounted model descends and increases, respectively, compared to the baseline model. The results indicate that the wedge-mounted planing hull experience a decrease in pressure resistance of up to 27% and an increase in friction resistance of up to 34%. After $Fr_b = 2.15$ F r b = 2.15 , some interaction effects between the wedge length and height on the total and pressure resistance appear. The findings also indicate that wedge effects on the planing hulls' pressure and friction resistance components are much different from those of displacement hulls. [ABSTRACT FROM AUTHOR]

AbstractUsing the Buchsbaum-Eisenbud structure theorem for a minimal free resolution of an arithmetically Gorenstein variety, we describe a structure theorem for the highest linear syzygies among quadrics defining a del Pezzo variety. Indeed, such syzygies can be represented as columns of a skew-symmetric matrix whose entries are wedge products of linear forms. [ABSTRACT FROM AUTHOR]

Cryogenic electron tomography is a technique for imaging biological samples in 3D. A microscope collects a series of 2D projections of the sample, and the goal is to reconstruct the 3D density of the sample called the tomogram. Reconstruction is difficult as the 2D projections are noisy and can not be recorded from all directions, resulting in a missing wedge of information. Tomograms conventionally reconstructed with filtered back-projection suffer from noise and strong artefacts due to the missing wedge. Here, we propose a deep-learning approach for simultaneous denoising and missing wedge reconstruction called DeepDeWedge. The algorithm requires no ground truth data and is based on fitting a neural network to the 2D projections using a self-supervised loss. DeepDeWedge is simpler than current state-of-the-art approaches for denoising and missing wedge reconstruction, performs competitively and produces more denoised tomograms with higher overall contrast. The authors propose DeepDeWedge, a deep learning method to improve the visual quality of 3D images obtained with cryogenic electron tomography. DeepDeWedge effectively removes noise and artefacts due to missing data. [ABSTRACT FROM AUTHOR]

In this paper, we consider locally wedge-shaped manifolds, which are Riemannian manifolds that are allowed to have both boundary and certain types of edges. We define and study the properties of free boundary minimal hypersurfaces inside locally wedge-shaped manifolds. In particular, we show a compactness theorem for free boundary minimal hypersurfaces with curvature and area bounds in a locally wedge-shaped manifold. Additionally, using Schoen–Simon–Yau's estimates, we also prove a Bernstein-type theorem indicating that, under certain conditions, a stable free boundary minimal hypersurface inside a Euclidean wedge must be a portion of a hyperplane. As our main application, we establish a curvature estimate for sufficiently regular free boundary minimal hypersurfaces in a locally wedge-shaped manifold with certain wedge angle assumptions. We expect this curvature estimate will be useful for establishing a min-max theory for the area functional in wedge-shaped spaces. [ABSTRACT FROM AUTHOR]

In the midst of an intensifying US–China competition, China has adopted various policies to deal with the expanding US-led security network encircling it. As one endeavour, China has implemented a wedge strategy to weaken the US-led security coalition. This study focuses on one case of China's wedging against South Korea to disturb the US-South Korea alliance. This wedging strategy against the Park Geun-hye Administration was composed of two distinct approaches: a reward-based general wedging to prevent South Korea from tilting toward the US, and a coercion-based issue-specific wedging to divide them primarily by disturbing the deployment of THAAD in Korea. [ABSTRACT FROM AUTHOR]

Gate valves provide sealing with metal-to-metal friction. When the right interior parts are selected, and the production is not made according to the proper design criteria, internal leaks occur in the valves in the medium term. Considering the ideal pressure, velocity equations and designs suitable for the process can be realized by determining the nominal pressure and velocity curves. This study designed a standard gate valve with 8-inch connection dimensions. Computational Fluid Dynamics (CFD) method investigated split, flexible, and solid wedge types of the designed valve, 0.5, 1, and 2 m/s flow velocities for zero, four and five-degree wedge closing angles and 20 mm, 40 mm, 60 mm, 90 mm, and 120 mm opening wedge positions. Ansys Fluent software was used for the analyses. Mesh optimization was performed for the ideal mesh number and analyzed according to the ideal mesh number. The k-Epsilon turbulence model was used for simulations. The same situations were repeated for a parallel wedge (0-degree wedge seating angle). The lowest pressure distribution and pressure loss occurred in the parallel wedge compared to the opening position of other types of wedges. The best gate type obtained from the analysis results was determined, and an experimental tightness test was performed. It can be said that the soft seat gate valve, designed according to the results of the sealing test, gives approximately 2.5 times more opening-closing life than the metal gate valve, thus reducing the maintenance-repair costs. [ABSTRACT FROM AUTHOR]

Shock–shock interactions (SSIs) are widespread in hypersonic vehicles. The mutual interaction between multiple shock waves can result in severe pressure loads and increase the thermal load. The SSI induced by a double wedge configuration is a classical problem. This paper describes a novel U-electrode surface arc actuator that produces a supermultichannel array surface arc discharge under hypersonic conditions. High-speed schlieren measurements are used to investigate the SSI induced by the hypersonic double wedge and plasma control under Mach 8 flow conditions. The results show that the shock wave array induced by the plasma forms a virtual compression surface. This surface deforms the shock wave induced by the first wedge, and the oblique shock wave in front of the secondary wedge and the SSI region disappear due to the uplift and hot gas mass disturbance from the impact. Because the applied actuation frequency is higher than the characteristic frequency of the base flow field, the high-frequency pulsations of the shock wave are controlled by the plasma actuation. Additionally, the low-frequency instability is suppressed. Thus, the aerodynamic load and low-frequency instability of the double wedge configuration under high-Mach-number conditions are effectively regulated. [ABSTRACT FROM AUTHOR]

Serial wedge pattern has garnered significant interest for its potential applications in rapid and long-distance liquid transport. However, the occurrence of droplets being blocked at junctions of the serial wedge pattern poses a critical challenge to droplet transport. In this paper, the blocking of droplets is introduced in detail, and the condition of the blocking is systematically investigated. The threshold of blocking is quantitatively represented by the width difference between the wide and narrow ends of wedge (ld). Pinning resistance encountered by droplets when detaching from junctions is a primary cause of blocking. The pinning resistance leads to the droplet tails being torn off. It has been observed that ld plays a crucial role in ensuring smooth droplet transport on the serial wedge pattern and preventing blocking. Larger volume of droplets negatively influences passage by reducing the transport velocity. Conversely, increasing the volume of droplets helps restrain the torn-off tail. Optimizing the curvature at junctions mitigates blocking by not only increasing transport velocity but also decreasing the volume of the torn-off tail. A systematic understanding of the mechanism of blocking can significantly advance the practicality of pumpless droplet transport on the serial wedge pattern. [ABSTRACT FROM AUTHOR]

In the present study the acoustic field around rigid wedges is investigated. The acoustic field consists of diffraction contributions (from the edge) and of geometrical acoustics contributions (the incident signal and signals reflected on the wedge faces). A new depiction, called the polarity plot, is proposed that depicts the polarity of the diffracted impulse response, as well as the number of the geometrical acoustics contributions around a given wedge. Based on the observed patterns of the polarity plots, a set of measurements around a wedge is described which (if experimentally feasible) could be used in order to determine the wedge angle. [ABSTRACT FROM AUTHOR]

Small‐angle‐scattering tensor tomography is a technique for studying anisotropic nanostructures of millimetre‐sized samples in a volume‐resolved manner. It requires the acquisition of data through repeated tomographic rotations about an axis which is subjected to a series of tilts. The tilt that can be achieved with a typical setup is geometrically constrained, which leads to limits in the set of directions from which the different parts of the reciprocal space map can be probed. Here, we characterize the impact of this limitation on reconstructions in terms of the missing wedge problem of tomography, by treating the problem of tensor tomography as the reconstruction of a three‐dimensional field of functions on the unit sphere, represented by a grid of Gaussian radial basis functions. We then devise an acquisition scheme to obtain complete data by remounting the sample, which we apply to a sample of human trabecular bone. Performing tensor tomographic reconstructions of limited data sets as well as the complete data set, we further investigate and validate the missing wedge problem by investigating reconstruction errors due to data incompleteness across both real and reciprocal space. Finally, we carry out an analysis of orientations and derived scalar quantities, to quantify the impact of this missing wedge problem on a typical tensor tomographic analysis. We conclude that the effects of data incompleteness are consistent with the predicted impact of the missing wedge problem, and that the impact on tensor tomographic analysis is appreciable but limited, especially if precautions are taken. In particular, there is only limited impact on the means and relative anisotropies of the reconstructed reciprocal space maps. [ABSTRACT FROM AUTHOR]

Following Bump and Hoffstein in [2] , the orbits in Γ ∞ (3) ﹨ Γ (3) are in bijection with sets of invariants satisfying certain relations. We explain how wedge product matrices give an alternative definition of the invariants of matrix orbits. This new method provides the possibility of performing similar computations with other congruence subgroups and arbitrary n × n matrices. Using Steinberg's refined version of the Bruhat decomposition, we construct an explicit choice of coset representative for each orbit in the orbit space Γ ∞ (3) ﹨ Γ (3) of 3 × 3 matrices over the PID of Eisenstein integers. [ABSTRACT FROM AUTHOR]

What drives recessions and expansions? Since it was introduced in 2007, there have been hundreds of business cycle accounting (BCA) exercises, a procedure aimed at identifying classes of models that hold quantitative promise to explain economic fluctuations. This paper contributes with a software—a graphical user interface that allows practitioners to perform BCA exercises with minimal effort—and exemplifies the procedure by studying the U.S. recessions in 1973 and 1990 and reflecting upon the critiques BCA has been subject to. We look into the many equivalence theorems that the literature has produced and that allow BCA practitioners to identify the theories that are quantitatively relevant for the economic period under study. The methodological extensions that have been brought forth since BCA's original inception are addressed as well as conclusions regarding the relative contribution of each wedge: GDP and investment are usually driven by an efficiency wedge, hours worked are closely related to the labor wedge and, in an open economy extension, the investment wedge helps to explain country risk spreads on international bonds. Finally, larger changes in interest rates and currency crises are usually associated with the investment and/or the labor wedge. [ABSTRACT FROM AUTHOR]

Purpose: The IC Profiler (ICP) manufactured by Sun Nuclear Corporation (SNC) is an ionization chamber (IC) array used for linear accelerator dosimetry measurements. Previous work characterized response of the ICP under various conditions, but there is limited work of its implementation into monthly QA measurement procedures. This work quantifies ICP accuracy and variables that affect accuracy for beam output measurements, and demonstrates feasibility of using the ICP for all recommended monthly dosimetry measurements. Methods: A total of 1985 output measurements on six Varian TrueBeam and Edge linear accelerators were performed using three ICP with quad wedges (QWs) and were compared with conventional IC measurements. The accuracy of the ICP for beam output was characterized as the difference between the ICP and IC. Variables that affect ICP accuracy, including gain settings, calibrations, and template baselining as well as machine or energy‐specific bias were investigated. Measurements of profile constancy, energy, dose rate constancy, wedge factors, and gating were performed. Results: The initially observed mean output difference between the ICP and IC was 0.16% (0.61%). When gain settings were optimized, the output difference accuracy improved to −0.02% (0.38%). The output accuracy of the ICP was not dependent on array, dose, temperature and pressure calibrations, or template baselining. Statistically, ICP output accuracy was dependent on machine and beam energy, but clinically, all measurements fell within 0.5% of unity. ICP measurements of energy, dose rate constancy, and wedge factors matched passing results with conventional IC in water measurements. Gating and beam profile constancy measurements demonstrated good stability using the ICP. Finally, monthly dosimetry QA using ICP was completed in an average of 33 min compared to 66 min using the IC. Conclusion: This work demonstrated the feasibility and efficiency of using the ICP, with specific considerations, as a measurement device for dosimetric linear accelerator monthly QA. [ABSTRACT FROM AUTHOR]

Schur rings are subrings of the group ring of the group G afforded by a partition of G into finite sets. In this paper, Schur rings over a free abelian group of rank two are classified under the assumption that one of the direct factors is a union of some basic sets. There are eight different types, and all but one type of which are traditional. [ABSTRACT FROM AUTHOR]

Observations of 21 cm line from neutral hydrogen promise to be an exciting new probe of astrophysics and cosmology during the Cosmic Dawn and through the Epoch of Reionization (EoR) to when dark energy accelerates the expansion of our Universe. At each of these epochs, separating bright foregrounds from the cosmological signal is a primary challenge that requires exquisite calibration. In this paper, we present a new calibration method called nucal that extends redundant-baseline calibration, allowing spectral variation in antenna responses to be solved for by using correlations between visibilities measuring the same angular Fourier modes at different frequencies. By modelling the chromaticity of the beam-weighted sky with a tunable set of discrete prolate spheroidal sequences, we develop a calibration loop that optimizes for spectrally smooth calibrated visibilities. Crucially, this technique does not require explicit models of the sky or the primary beam. With simulations that incorporate realistic source and beam chromaticity, we show that this method solves for unsmooth bandpass features, exposes narrow-band interference systematics, and suppresses smooth-spectrum foregrounds below the level of 21 cm reionization models, even within much of the so-called wedge region where current foreground mitigation techniques struggle. We show that this foreground subtraction can be performed with minimal cosmological signal loss for certain well-sampled angular Fourier modes, making spectral-redundant calibration a promising technique for current and next-generation 21 cm intensity mapping experiments. [ABSTRACT FROM AUTHOR]

Translation abstract Report of the working group for recommendations on excavations: current and future worksThe working group for excavations of the German Geotechnical Society (DGGT) has since 1968 regularly published recommendations for analysis, design and construction of excavations. The present report provides an overview of current works of the working group. In the reporting period, the focus has been on the participation in commenting on the drafts of the new Eurocode 7 and the design of struts. Further points to discuss were a supplement to Eurocode 0 and questions how to design soldier pile walls with a supporting wedge. [ABSTRACT FROM AUTHOR]

Employing direct numerical simulations, we investigate water and water-glycerol (85 wt%) droplets (∼ 25 µL) moving on smooth surfaces, with contact angles of around 90 ∘ , at varying inclinations. Our focus is on elucidating the relative contribution of local viscous forces in the wedge and bulk regions in droplets to the total viscous force. We observe that, for fast-moving droplets, both regions contribute comparably, while the contribution of the wedge region dominates in slow-moving cases. Comparisons with existing estimates reveal the inadequacy of previous predictions in capturing the contributions of wedge and bulk viscous forces in fast-moving droplets. Furthermore, we demonstrate that droplets with identical velocities can exhibit disparate viscous forces due to variations in internal fluid dynamics. [ABSTRACT FROM AUTHOR]

Spin^h manifolds are the quaternionic analogue to \text {spin}^c manifolds. We compute the \text {spin}^h bordism groups at the prime 2 by proving a structure theorem for the cohomology of the \text {spin}^h bordism spectrum \mathrm {MSpin^h} as a module over the mod 2 Steenrod algebra. This provides a 2-local splitting of \mathrm {MSpin^h} as a wedge sum of familiar spectra. We also compute the decomposition of H^*(\mathrm {MSpin^h};\mathbb {Z}/2\mathbb {Z}) explicitly in degrees up through 30 via a counting process. [ABSTRACT FROM AUTHOR]

In marine engineering, fluid–structure interaction (FSI) problems caused by wave impact are prevalent and often accompanied by violent free-surface changes. To accurately capture the free-surface and optimize the solution strategy for FSI problems, this study proposes a solver (overInterISODyMFoam) that combines isoAdvector and overset for refined free-surface capturing and a partitioned approach that couples finite volume and modal superposition (FVMS) based on the preCICE platform for solving FSI wave impact problems. The performance of solver and the FVMS method are verified by comparing them to the experimental results of a 20° wedge entering the water. The results indicated that the free-surface capturing method proposed can achieve a sharper interface than the Multidimensional Universal Limiter with Explicit Solution method and exhibits less numerical dissipation at the spray front. As a three-dimensional two-way coupled method, the calculations of FVMS method are in good agreement with the experimental results. The average error for the pressure and stress peaks is approximately 5.60% and 4.52%, respectively. The FVMS method shows better applicability than the two-dimensional (2D) one-way coupled method. Due to the ignored elasticity effect, the slamming pressure peak and stress peak calculated by the 2D one-way coupled method are approximately 4%–11% and 6%–23% higher than the experimental results, respectively. [ABSTRACT FROM AUTHOR]

In the work i tis investigated the intense coudition of lirnear viscoelastic (Maxwell type) thread at a cross-section blow by wedge havig flat frontal part. I tis supposed that a defeectiv part of the thread fits the surface of the blowing body. The problem is solved at a subsonic mode with the condition on threads break. In many fields of modern industry, materials having elastic as well as viscous properties are used. The given thesis is dedicated to one of such questions, i.e. there is studied a behavior of a viscous-elastic fiber (Maxwells model) at a normal blow on it with a rigid wedge and a wedge with a flat front part and constant velocity. [ABSTRACT FROM AUTHOR]

The Molucca Sea subduction zone is unique for its active divergent double‐subducted slab located in the north of the Java and Banda subduction zones. The spatial proximity of these subduction zones would cause a complex mantle flow field. To clarify the mantle dynamics, here we present P‐wave tilting‐axis anisotropic tomography obtained by inverting a large number of local and teleseismic travel‐time data recorded at 254 seismic stations in eastern Southeast Asia. Our results suggest that the mantle structure and dynamics of the western Molucca Sea subduction zone may be remotely controlled by the Java and Banda subduction zones. Mantle convection in the big mantle wedge west of the Molucca Sea subduction zone is possibly influenced by east‐west mantle flow associated with compression of the Indo‐Australian slab as well as north‐south mantle flow related to rollback of the Indo‐Australian slab. In contrast, the eastern Molucca Sea subduction zone is virtually unaffected by other subduction zones, probably due to the ongoing slab subduction there. Plain Language Summary: This study focuses on the Molucca Sea subduction zone, situated north of the Java and Banda subduction zones, which is well known for its active divergent double‐subducted slab. Interactions of these subduction zones lead to a complex mantle flow field. To understand the mantle dynamics, we present high‐resolution P‐wave tilting‐axis anisotropic tomography of the Molucca Sea subduction zone obtained by jointly inverting local and teleseismic travel‐time data recorded at 254 local seismic stations. Our results indicate that the mantle structure and dynamics of the western Molucca Sea subduction zone are influenced by remote control of the Java and Banda subduction zones. In contrast, the structure and dynamics of the eastern Molucca Sea subduction zone are virtually unaffected by other subduction zones. Key Points: Complex mantle dynamics are revealed by tilting‐axis anisotropic tomographyMantle flows and multiple subducting slabs influence each otherThe Indo‐Australian slab remotely controls mantle dynamics under the western Molucca Sea [ABSTRACT FROM AUTHOR]

Stepped wedge trials (SWTs) are a type of cluster randomized trial that involve repeated measures on clusters and design‐induced confounding between time and treatment. Although mixed models are commonly used to analyze SWTs, they are susceptible to misspecification particularly for cluster‐longitudinal designs such as SWTs. Mixed model estimation leverages both "horizontal" or within‐cluster information and "vertical" or between‐cluster information. To use horizontal information in a mixed model, both the mean model and correlation structure must be correctly specified or accounted for, since time is confounded with treatment and measurements are likely correlated within clusters. Alternative non‐parametric methods have been proposed that use only vertical information; these are more robust because between‐cluster comparisons in a SWT preserve randomization, but these non‐parametric methods are not very efficient. We propose a composite likelihood method that focuses on vertical information, but has the flexibility to recover efficiency by using additional horizontal information. We compare the properties and performance of various methods, using simulations based on COVID‐19 data and a demonstration of application to the LIRE trial. We found that a vertical composite likelihood model that leverages baseline data is more robust than traditional methods, and more efficient than methods that use only vertical information. We hope that these results demonstrate the potential value of model‐based vertical methods for SWTs with a large number of clusters, and that these new tools are useful to researchers who are concerned about misspecification of traditional models. [ABSTRACT FROM AUTHOR]

We consider the problem of equilibrium of an elastic half plane with a semiinfinite crack on its boundary. At a certain distance from the crack tip, the crack edge is in contact with a rigid semiinfinite wedge and, in the vicinity of the tip, the crack edge is in contact with the rigid base. Frictional forces are taken into account in the zone of contact between the crack edge and the rigid base. The analytic solution of the problem is obtained by the Wiener–Hopf method. The boundaries of the contact zones, the distributions of stresses in these zones and on the boundary of the half plane outside the crack are determined, as well as the mode II stress intensity factors. [ABSTRACT FROM AUTHOR]

Questions surrounding the labour wedge and the tax wedge in the United States are complicated by the fact that, historically, there is a lack of coherent relationship between the series of hours worked (based on standard measurements) and that of the tax wedge. This has been cited as grounds for discounting the tax wedge as a viable explanation for the behaviour of the labour wedge. In this paper, I explore an alternative measurement of labour hours in the United States in a bid to clear up some of the morass surrounding the tax wedge and hours worked. In the process, I show that, the labour wedge is rather more aligned with available labour hours over the business cycle than it does actual hours worked. Moreover, cyclical properties of the available hours series, however puzzling, are explained by the presence of a government transfer scheme which I introduce in the household side of the market. Also, the presence of the transfer scheme alters the marginal rate of substitution (MRS) between consumption and leisure, and by doing so, reverses the cyclical properties of the tax wedge. This puts the tax wedge in alignment with the labour wedge over the business cycle. [ABSTRACT FROM AUTHOR]

The effects of the composition and angle of the subducting slab and mantle wedge flow on tectonic and magmatic processes in island arcs and associated back-arcs are poorly understood. Here we analyse the ages and compositions of submarine lavas from the flanks and the floor of the back-arc Futuna Trough some 50 km east of Tanna Island in the New Hebrides arc front. Whereas >2.5 Ma-old back-arc lavas formed from an enriched mantle source strongly metasomatized by a slab component, the younger lavas show less slab input into a depleted mantle wedge. The input of the slab component decreased over the past 2.5 million years while the enriched mantle was replaced by depleted peridotite. The change of Futuna Trough lava compositions indicates rapid (10 s of km/million years) replacement of the mantle wedge by corner flow and slab steepening due to rollback, causing extensional stress and back-arc rifting in the past 2.5 million years. A compositional change in lavas from the Futuna trough at 2.5 Ma suggest a change in mantle source, attributed to slab rollback and the opening of the back-arc basin. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the article is to determine the impact of changes in the tax-free amount on the tax wedge in Poland and to assess the proposed changes in the tax system. Design/methodology/approach: In order to determine changes the development of the tax wedge, it was measured twice for 2024. The tax wedge analysis was performed for salaries in the range of PLN 4,242 - PLN 19,000 gross per month. The impact of the proposed changes on state budget revenues was adopted as a criterion for assessing changes in the tax system. Findings: Increasing the tax-free amount to PLN 60,000 in 2024 would the will reduce the tax wedge by between 1.3 and 4 percentage points and reduce state budget revenues by approximately PLN 48 billion. The current situation of local government units, in particular municipalities, is difficult and requires subsidization from the state budget, and the proposed changes in the tax system will further reduce their own income and pose a serious threat to their independence. Research limitations/implications: The subject of further research may be the tax wedge taking into account the degressive tax-free amount and its impact on budget revenues. Originality/value: The article was written in response to the work carried out by the Ministry of Finance on increasing the tax-free amount and is an attempt to assessment the proposed changes. [ABSTRACT FROM AUTHOR]

Multilevel interventions (MLIs) hold promise for reducing health inequities by intervening at multiple types of social determinants of health consistent with the socioecological model of health. In spite of their potential, methodological challenges related to study design compounded by a lack of tools for sample size calculation inhibit their development. We help address this gap by proposing the Multilevel Intervention Stepped Wedge Design (MLI-SWD), a hybrid experimental design which combines cluster-level (CL) randomization using a Stepped Wedge design (SWD) with independent individual-level (IL) randomization. The MLI-SWD is suitable for MLIs where the IL intervention has a low risk of interference between individuals in the same cluster, and it enables estimation of the component IL and CL treatment effects, their interaction, and the combined intervention effect. The MLI-SWD accommodates cross-sectional and cohort designs as well as both incomplete (clusters are not observed in every study period) and complete observation patterns. We adapt recent work using generalized estimating equations for SWD sample size calculation to the multilevel setting and provide an R package for power and sample size calculation. Furthermore, motivated by our experiences with the ongoing NC Works 4 Health study, we consider how to apply the MLI-SWD when individuals join clusters over the course of the study. This situation arises when unemployment MLIs include IL interventions that are delivered while the individual is unemployed. This extension requires carefully considering whether the study interventions will satisfy additional causal assumptions but could permit randomization in new settings. [ABSTRACT FROM AUTHOR]

The stepped wedge design is often used to evaluate interventions as they are rolled out across schools, health clinics, communities, or other clusters. Most models used in the design and analysis of stepped wedge trials assume that the intervention effect is immediate and constant over time following implementation of the intervention (the "exposure time"). This is known as the IT (immediate treatment effect) assumption. However, recent research has shown that using methods based on the IT assumption when the treatment effect varies over exposure time can give extremely misleading results. In this manuscript, we discuss the need to carefully specify an appropriate measure of the treatment effect when the IT assumption is violated and we show how a stepped wedge trial can be powered when it is anticipated that the treatment effect will vary as a function of the exposure time. Specifically, we describe how to power a trial when the exposure time indicator (ETI) model of Kenny et al. (Statistics in Medicine, 41, 4311–4339, 2022) is used and the estimand of interest is a weighted average of the time-varying treatment effects. We apply these methods to the ADDRESS-BP trial, a type 3 hybrid implementation study designed to address racial disparities in health care by evaluating a practice-based implementation strategy to reduce hypertension in African American communities. [ABSTRACT FROM AUTHOR]

The design of retaining walls depends on the amount of driving pressure from the backfill of the wall. Therefore, estimating this pressure is an essential factor in its design. In this research, the changes in the slope of failure, the place of the failure wedge, and the reduction of the failure line along the length and depth of the embankment were investigated on the retaining wall embankment reinforced with geotextile during ten tests in a laboratory study. The parameters under investigation in this article are the number of layers and the distances between the geotextile layers. The results showed that the presence of geotextile layers reduced the length of the fracture line up to 41%. It has also improved the value of the fracture angle and reduced the formation of the rupture wedge in the lower depths up to a maximum of 16%. The translational movement of the wall in the actuation state has a greater distinction between the fixed point and the failure zone, and the reinforcing layers are also effective in increasing the bearing capacity and stability of the retaining wall. [ABSTRACT FROM AUTHOR]

The water-impacting behavior of a wedge is often studied in the slamming phenomenon of ships and aircraft. Many scholars have proposed theoretical models for studying the water-impacting problem of a wedge, but these models still have some shortcomings. This study combines Von Karman's method, the Generalized Wagner Model (GWM), and Modified Logvinovich Model (MLM) to establish a converged theoretical Von Karman-GWM-MLM (VGM) model. The VGM model utilizes added mass to replace the fluid influence, which is derived from the velocity potential and boundary conditions. Considering the influence of impulse, the velocity is determined by the momentum theorem. Subsequently, the pressure, resultant force, and acceleration of the wedge can be calculated. By comparing with the published test data of other scholars, it is found that the velocity, acceleration, pressure, and force of the wedge obtained by the VGM model reached a consensus with experiments. The validity and accuracy of the VGM model are also verified. The efficiency and accuracy of problem-solving are both balanced when using the VGM model. The establishment of the VGM model is significant for solving water-impacting problems related to wedges. [ABSTRACT FROM AUTHOR]

Relict frost wedges are widespread and valuable indicators of past environmental conditions that have been extensively dated across central and western European lowlands over the past few decades, but their timing in the Czech Republic is poorly known. Here, we present optically‐stimulated‐luminescence (OSL) ages for seven relict frost wedges situated at four study sites in north–central Bohemia, Czech Republic (49.9992–50.4956°N, 13.3736–16.0011°E, 230–350 m above sea level). The OSL ages indicate that the frost wedges developed during two phases in marine isotope stage 2: an older phase that peaked at 23.6 ± 2.9 ka and a younger phase that peaked at 16.1 ± 1.3 ka. Both phases probably experienced cold, dry and windy conditions that were mostly associated with <0°C mean annual air and ground temperatures and the presence of at least discontinuous permafrost, which is in line with similar central and western European records and other paleo‐environmental archives. The new OSL ages constitute the first extended dataset on the timing of frost wedges in this undersampled area between the Fennoscandian and Alpine ice sheets, which is essential for reconstructing past permafrost extents and climate conditions, as well as for validating models of past permafrost dynamics in central Europe. [ABSTRACT FROM AUTHOR]

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Background: An ideal synthetic spacer for medial opening wedge high tibial osteotomy (MOWHTO) has not yet been developed. The authors have developed a new β-tricalcium phosphate (β-TCP) spacer with 60% porosity (N-CP60) by modifying the micro- and macro-pore structures of a conventional β-TCP spacer (CP60) that is widely used in clinical practice. The purpose of this study was to compare the absorbability, osteoconductivity, and in vivo strength of the N-CP60 spacer with those of the CP60 spacer, when used in MOWHTO. Methods: First, the porosity, diameter distribution of macro- and micropores, and compressive strength of each β-TCP block were examined using methodology of biomaterial science. Secondly, a clinical study was performed using a total of 106 patients (106 knees) with MOWHTO, who were followed up for 18 months after surgery. In these knees, the N-CP60 and CP-60 spacers were implanted into 49 tibias and 57 tibias, respectively. The absorbability and osteoconductivity were radiologically evaluated by measuring the area of the implanted spacer remaining unabsorbed and assessing with the Hemert's score, respectively. The incidence of cracking in the implanted spacers was determined using computed radiography. Statistical comparisons were made with non-parametric tests. The significance level was set at p = 0.05. Results: The N-CP60 and CP60 blocks had almost the same porosity (mean, 61.0% and 58.7%, respectively). The diameter of macropores was significantly larger (p < 0.0001) in the N-CP60 block than in the CP60 block, while the diameter of micropores was significantly smaller (p = 0.019) in the N-CP60 block. The ultimate strength of the N-CP60 block (median, 36.8 MPa) was significantly greater (p < 0.01) than that of the CP60 block (31.6 MPa). As for the clinical evaluations, the absorption rate of the N-CP60 spacer at 18 months after implantation (mean, 48.0%) was significantly greater (p < 0.001) than that of the CP60 spacer (29.0%). The osteoconductivity of the N-CP60 spacer was slightly but significantly higher (p = 0.0408) than that of the CP60 spacer only in zone 1. The incidence of in vivo cracking of the posteriorly located N-CP60 spacer at one month (mean, 75.5%) was significantly lower (p = 0.0035) than that of the CP60 spacer (91.2%). Conclusions: The absorbability, osteoconductivity, and compressive strength of the new N-CP60 spacer were significantly improved by modifying the macro- and micro-pore structures, compared with the conventional CP60 spacer. The N-CP60 spacer is more clinically useful than the CP60 spacer. Trial registration number: H29-0002. [ABSTRACT FROM AUTHOR]

Introduction: The choice between a cementless taper wedge stem and a fit-and-fill stem in total Hip arthroplasty (THA) for various proximal femoral morphological types has not been thoroughly evaluated. This study aimed to compare the risk of stem-related complications between these two stem types in Dorr type A, B, and C femurs. Materials and Methods: From January 2015 through April 2021, we retrospectively reviewed 1995 cementless THA procedures. We stratified all procedures into three groups: Dorr type A (N = 360, 18.0%), B (N = 1489, 74.7%) and C (N = 146, 7.3%). The primary outcome domain was stem-related complications, including stem subsidence ≥ 3 mm, intraoperative fracture, periprosthetic fracture and aseptic stem loosening. We performed multivariate regression analysis to compare the risk of stem-related complication between the two stem types. Other factors included age, sex, body mass index, diagnosis, age-adjusted Charlson comorbidity index, stem alignment and canal fill ratio. Results: The incidence of stem-related complications in the taper wedge and fit-and-fill stem groups was 4.4% (N = 15) and 6.5% (N = 107), respectively. Fit-and-fill stems showed an increased risk of stem-related complications (aOR: 9.903, 95% CI: 1.567–62.597) only in Dorr type C femurs. No significant difference in risk was observed in Dorr type A and B femurs. Furthermore, the canal fill ratio at the lesser trochanter, 2 cm and 7 cm below the lesser trochanter, did not exhibit an association with stem-related complications in any Dorr type. Conclusions: Concerning the risk of stem-related complications, the taper wedge stem was a better choice in Dorr type C femurs. However, there was no difference in risk between the taper wedge stem and fit-and-fill stem in Dorr type A and B femurs. [ABSTRACT FROM AUTHOR]

The combined effect of wedge angle and melting energy transfer on the tangent hyperbolic magnetohydrodynamics nanofluid flow across a permeable wedge is numerically evaluated. Electronic gadgets produce an excessive amount of heat while in operation, so tangent hyperbolic nanofluid (THNF) is frequently used to cool them. THNF has the potential to dissipate heat more efficiently, thereby lowering the possibility of excessive heat and malfunctioning components. The effects of thermal radiation and heat source/sink are also examined on the flow of THNF. The flow has been formulated in the form of PDEs, which are numerically computed through the MATLAB solver BVP4c. The numerical results of BVP4c are relatively compared to the published work for validity purposes. It has been detected that the results are accurate and reliable. Furthermore, from the graphical results, it has been perceived that the rising impact of the Weissenberg number accelerates the velocity and thermal profile. The effect of the power-law index parameter drops the fluid temperature, but enhances the velocity curve. The variation in the wedge angle boosts the shearing stress and energy propagation rate, whereas the increment of Wi declines both the energy transfer rate and skin friction. [ABSTRACT FROM AUTHOR]

In this paper, a theoretical solution method for the post-wave parameters of detonation is proposed and developed with a series of analyses and applications. Based on Newton's method, the objective function for shock-coupled chemical reactions is constructed along with its derivative. Two verification examples demonstrate that the method can calculate accurate post-wave parameters quickly and is suitable for single-step and detailed mechanistic chemical reactions. In addition, the method provides sensitivities between various aerodynamic parameters to offer a fresh perspective for detonation, polar analysis with sensitivity is built as a result. Moreover, the method can predict the transition pattern of the detonation, and the validity is supported by the comparison of different examples. Rather than being limited to oblique detonation, the post-wave parameters of the curved detonation can also be calculated correctly, which indicates the excellent applicability of the method. This method can also be applied to the thermodynamic efficiency of detonation combustion and its sensitivity, which demonstrates the unique advantages of this method. Furthermore, the method can be rewritten as a solution for wedge angle under the given wave angle by changing the independent variable. This solution is validated by the simulation results, which implies that the method can be used as a simple inverse design method in oblique detonation engines. In general, the proposed method is an effective theoretical solution, analytical tool, and inverse design method for detonation. [ABSTRACT FROM AUTHOR]

The transition between Mach reflection (MR) and regular reflection (RR) of gaseous detonations in argon-diluted stoichiometric hydrogen–oxygen was investigated experimentally using a wedge with a concave–convex surface. The continuous MR triple-point trajectory was recorded using the smoked foil technique, from which the transition angles for MR ↔ RR transitions could be determined. Similar to the reflection of a non-reacting shock wave, the non-stationary hysteresis phenomenon was found for detonation reflection, i.e., the MR → RR transition angle was much larger than that for RR → MR transition. In addition, the RR → MR transition angle on the convex surface was smaller than that for detonation reflection over a single half-cylinder. This is opposite to what is found for non-reacting shock wave reflection. [ABSTRACT FROM AUTHOR]

This research examines the Vajra-kīla made from khadira wood from a technological history perspective, focusing on the use of the kīla in Indian rituals and its contrasts with Indrakīla and other deified forms in various practices. The Indian prototype of the pronged instrument can be traced back to architectural tools. During Indian rituals, monks incorporated architectural customs into maṇḍala construction, including striking wedges made of khadira wood, tying five-colored strings, driving the kīla into the ground no more than four fingers deep, and never retrieving the wedges. Consequently, the majority of these disappeared without a trace. By exploring its early forms and materials, we can also understand the causes of the geographical imbalance in the remaining quantities of kīla. [ABSTRACT FROM AUTHOR]

A reliable initiation of oblique detonation is critical in oblique detonation engines, especially for oblique detonation engines under extreme conditions such as a high altitude and low Mach number, which may lead to excessive length of the induction zone and even the phenomenon of extinction. In this paper, surface ignition was applied to the initiation of oblique detonation, and a high-temperature region was set on the wedge to simulate the presence of a hot-spot induced by the laser heating. The two-dimensional multi-component Navier–Stokes equations considering a detailed H2 combustion mechanism are solved, and the oblique detonation wave accelerated by a hot-spot is studied. In this paper, hot-spots in the induction zone on the wedge, are introduced to explore the possibility of hot-spot initiation, providing a potential method for initiation control. Results show that these methods can effectively promote the accelerated initiation of the oblique detonation. Furthermore, the hot-spot temperature, size and position are varied to analyze their effects on the initiation position. Increasing the temperature and size of the hot-spot both can accelerate initiation, but from the perspective of energy consumption, a small hot-spot at a high temperature is preferable for accelerating ODW initiation than a large hot-spot at a low temperature. The initiated position of the oblique detonation is sensitive to the position of the hot-spots; if a 2000 K hotspot is at the beginning of the wedge, then the ODW's initiation distance will be reduced to about 30% of that without hotspot acceleration. [ABSTRACT FROM AUTHOR]

Background: The hallux dorsiflexion resistance test is a frequently employed clinical maneuver for assessing the initiation of the windlass mechanism This maneuver involves dorsiflexion of the phalanx of the hallux, thereby evaluating plantarflexion of the first metatarsal, elevation of the medial longitudinal arch, and supination of the rearfoot. The windlass mechanism plays a crucial role in gait, and orthopedic devices, such as a kinetic wedge, which aims to facilitate its activation by increasing the hallux dorsiflexion. Although it is believed that facilitating the windlass mechanism with the kinetic wedge should be directly correlated with a decrease in hallux dorsiflexion resistance, its effects have yet to be characterized. Thus, this study aimed to determine the influence of a kinetic wedge on hallux dorsiflexion resistance in asymptomatic individuals. Methods: The sample comprised thirty participants (14 women and 16 men). A digital force gauge measured the force required to perform the hallux dorsiflexion resistance test during two conditions: barefoot and with a kinetic wedge. The Wilcoxon signed-rank test was used to compare the hallux dorsiflexion resistance between conditions. Results: A statistically significant reduction in force (10.54 ± 3.16N vs. 19.62 ± 5.18N, p < 0.001) was observed when using the kinetic wedge compared to the barefoot condition during the hallux dorsiflexion resistance test. Conclusion: The use of a kinetic wedge reduces the required force for performing the passive hallux dorsiflexion resistance test in asymptomatic individuals. Future studies should determine to what extent the kinetic wedge can attenuate the required force to dorsiflex the hallux in individuals with musculoskeletal disorders such as plantar fasciopathy and functional hallux limitus. [ABSTRACT FROM AUTHOR]

Background: Stahl's ear deformity is characterized by disturbed normal anatomy of the ear. There is a third crus with distortion of the superior crus and a flat helix. Correction of Stahl's ear can be done non-surgically in the neonatal period but in elder patients the surgical correction is the only option. The present study aimed to use a simple excision method to treat this deformity and evaluate changes in auricular size following the excision. Methods: Ten auricles from July 2022 to October 2023 were included. Preoperative consultation and analysis of the deformity were done. Simple full thickness excision of the deformed cartilage with primary closure of the remaining defect and comparison of the size of the auricle to the preoperative measurements were done followed by assessment of the patient post-operative satisfaction. Results: There was no significant decrease in the ear height. No problems with the wounds were found. All patients were satisfied with the results except for the first patient who had some contour irregularity and needed to be re-operated on. Conclusions: Full thickness excision of the deformed cartilage is a simple method that eliminates the components of the deformity effectively. This method can be implemented when possible with pleasing aesthetic results and no significant changes in auricular size. Early discovery of the auricular deformities and correcting them may save the patient from a surgery later. An effective surgical technique is the one that eliminates the components of the defect and leaves the patient satisfied. Level of evidence: Level IV, therapeutic study. [ABSTRACT FROM AUTHOR]

We study self-similar viscous fingering for the case of divergent flow within a wedge-shaped Hele-Shaw cell. Previous authors have conjectured the existence of a countably infinite number of selected solutions, each distinguished by a different value of the relative finger angle. Interestingly, the associated solution branches have been posited to merge and disappear in pairs as the surface tension decreases. For the first time, we demonstrate how the selection mechanism can be derived based on exponential asymptotics. Asymptotic predictions of the finger-to-wedge angle are additionally given for different sized wedges and surface-tension values. The merging of solution branches is explained; this feature is qualitatively different to the case of classic Saffman-Taylor viscous fingering in a parallel channel configuration. Moreover, because the asymptotic framework does not highly depend on specifics of the wedge geometry, the proposed theory for branch merging in our self-similar problem likely relates much more widely to tip-splitting instabilities in time-dependent flows in circular and other geometries, where the viscous fingers destabilise and divide in two. [ABSTRACT FROM AUTHOR]