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Background: Control of humeral torsion can present a challenge, especially intraoperatively during closed reduction and fixation of humeral shaft fractures or 2-part surgical neck fractures of the proximal humerus. The objective of this study is to develop and validate an indirect method for the assessment of humeral torsion using an index that is linearly correlated with rotational arm position and can be derived from only a single plain radiographic image of the proximal humerus. Methods: The Humeral Head Offset Index (HHOI) is calculated as the ratio of the medial and lateral offset of the humeral head measured from the outer cortices of the shaft on a plain radiographic or fluoroscopic image. The relationship of HHOI with humeral torsion was first verified on a sawbone model with radiopaque characteristics under fluoroscopic control. Different degrees of retroversion were simulated through manual rotation of the humerus with a digital protractor in 5° increments until 40° internally rotated and then in 5° increments until 40° externally rotated from the neutral position. The same procedure was subsequently performed digitally on Digitally Reconstructed Radiographs (DRRs) from computed tomography (CT) dataset of the sawbone. Next, the HHOI index was applied to eight randomly selected patients with total humerus CT using the same method. Spearman's rho was calculated for the bivariate analysis of correlation between the simulated degree of retroversion and the HHOI. Strength of correlation was classified according to Koo and Li. Interrater and intrarater reliability of three blinded observers with repetition of measurement after three months were analyzed by assessing the intraclass correlation coefficient (ICC). Results: Both in the sawbone model and in DRRs, we demonstrated a high to very high significant linear correlation between simulated retroversion and the HHOI. ICC values demonstrated excellent interrater reliability and excellent intrarater reliability for measurement of the HHOI. Conclusions: The HHOI is a new, simple, reliable index that has a linear relationship to the rotation of the humerus and can therefore allow an indirect control of humeral torsion in comparison to the contralateral side. [ABSTRACT FROM AUTHOR]

Cosmological reconstruction is a powerful technique in modified gravity invented to find the analogy of different cosmological epochs in modified gravity. In this paper, I present the modified holographic reconstruction scheme for f(T,풯 ) theory of gravity where T and 풯 are the torsion scalar and trace of energy–momentum tensor in the context of flat FRW universe. For this reconstruction, I consider Hubble horizon as an infrared cutoff and focus on a particular model f(T,풯 ) = T + γg(풯 ) (a correction to the teleparallel action depending on the matter content). Within this framework, I consider both the power law scale factor as well as the well-established cosmological bouncing scenario. Further, I explore various gravitational Lagrangians that can be reconstructed to yield analytical solution for symmetric, superbounce, oscillatory, singular bounce and matter bounce settings. The viability of these reconstructed models is then assessed through the EoS parameter ωDE and the ωDE − ωDE′ plane (ωDE′ = dωDE dln a ). Notably, all the results align well with recent observational data. [ABSTRACT FROM AUTHOR]

We develop an abstract theory of flows of geometric 퐻-structures, i.e., flows of tensor fields defining 퐻-reductions of the frame bundle, for a closed and connected subgroup H ⊂ SO ⁢ ( n ) H\subset\mathrm{SO}(n) , on any connected and oriented 푛-manifold with sufficient topology to admit such structures. The first part of the article sets up a unifying theoretical framework for deformations of 퐻-structures, by way of the natural infinitesimal action of GL ⁢ ( n , R ) \mathrm{GL}(n,\mathbb{R}) on tensors combined with various bundle decompositions induced by 퐻-structures. We compute evolution equations for the intrinsic torsion under general flows of 퐻-structures and, as applications, we obtain general Bianchi-type identities for 퐻-structures, and, for closed manifolds, a general first variation formula for the L 2 L^{2} -Dirichlet energy functional ℰ on the space of 퐻-structures. We then specialise the theory to the negative gradient flow of ℰ over isometric 퐻-structures, i.e., their harmonic flow. The core result is an almost-monotonocity formula along the flow for a scale-invariant localised energy, similar to the classical formulas by Chen–Struwe [M. Struwe, On the evolution of harmonic maps in higher dimensions, J. Differential Geom. 28 (1988), 3, 485–502; Y. M. Chen and M. Struwe, Existence and partial regularity results for the heat flow for harmonic maps, Math. Z. 201 (1989), 1, 83–103] for the harmonic map heat flow. This yields an 휀-regularity theorem and an energy gap result for harmonic structures, as well as long-time existence for the flow under small initial energy, relative to the L ∞ L^{\infty} -norm of initial torsion, in the spirit of Chen–Ding [Y. M. Chen and W. Y. Ding, Blow-up and global existence for heat flows of harmonic maps, Invent. Math. 99 (1990), 3, 567–578]. Moreover, below a certain energy level, the absence of a torsion-free isometric 퐻-structure in the initial homotopy class imposes the formation of finite-time singularities. These seemingly contrasting statements are illustrated by examples on flat 푛-tori, so long as the set [ S n , SO ⁢ ( n ) / H ] [\mathbb{S}^{n},\mathrm{SO}(n)/H] of homotopy classes of maps S n → SO ⁢ ( n ) / H \mathbb{S}^{n}\to\mathrm{SO}(n)/H contains more than one element and the universal cover of SO ⁢ ( n ) / H \mathrm{SO}(n)/H is a sphere, e.g. when n = 7 n=7 and H = G 2 H=\mathrm{G}_{2} , or n = 8 n=8 and H = Spin ⁢ ( 7 ) H=\mathrm{Spin}(7) . [ABSTRACT FROM AUTHOR]

A module over a ring R is pure projective provided it is isomorphic to a direct summand of a direct sum of finitely presented modules. We develop tools for the classification of pure projective modules over commutative noetherian rings. In particular, for a fixed finitely presented module M, we consider Add ⁡ ( M ) {\operatorname{Add}(M)} , which consists of direct summands of direct sums of copies of M. We are primarily interested in the case where R is a one-dimensional, local domain, and in torsion-free (or Cohen–Macaulay) modules. We show that, even in this case, Add ⁡ ( M ) {\operatorname{Add}(M)} can have an abundance of modules that are not direct sums of finitely generated ones. Our work is based on the fact that such infinitely generated direct summands are all determined by finitely generated data. Namely, idempotent/trace ideals of the endomorphism ring of M and finitely generated projective modules modulo such idempotent ideals. This allows us to extend the classical theory developed to study the behaviour of direct sum decomposition of finitely generated modules comparing with their completion to the infinitely generated case. We study the structure of the monoid V * ⁢ ( M ) {V^{*}(M)} , of isomorphism classes of countably generated modules in Add ⁡ ( M ) {\operatorname{Add}(M)} with the addition induced by the direct sum. We show that V * ⁢ ( M ) {V^{*}(M)} is a submonoid of V * ⁢ ( M ⊗ R R ^ ) {V^{*}(M\otimes_{R}\widehat{R})} , this allows us to make computations with examples and to prove some realization results. [ABSTRACT FROM AUTHOR]

This study is based on a theory for analyzing non-uniform torsion in thin-walled beams made of homogeneous elastic material with arbitrary cross-sections by incorporating the effect of the shear deformation of a cross-section. Utilizing the Finite Element Method (FEM), the proposed numerical approach addresses non-uniform torsion by breaking down a 3D analysis into 2D cross-sectional and 1D modeling components. Initially, the geometric constants of the cross-section were computed using a 9-node isoparametric element in 2D FEM. Subsequently, a 1D FEM employing a linear isoparametric element calculated the twist angle, torsion warping parameters, and stress results. The stress field was determined through a local analysis of the 2D cross-section. Notably, the 2D FEM component aligns with contemporary trends in commercial software, thereby bolstering the potential and practical applicability of the proposed numerical approach. Its verification and validation through numerical analyses using MATLAB underscore the efficacy and reliability of the method in analyzing non-uniform torsion behavior in structural design, particularly under diverse boundary conditions. [ABSTRACT FROM AUTHOR]

In this paper, we present two different ways for computing the Kauffman bracket skein module of S 1 × S 2 , KBSM S 1 × S 2 , via braids. We first extend the universal Kauffman bracket type invariant V for knots and links in the Solid Torus ST, which is obtained via a unique Markov trace constructed on the generalized Temperley–Lieb algebra of type B, to an invariant for knots and links in S 1 × S 2 . We do that by imposing on V relations coming from the braid band moves. These moves reflect isotopy in S 1 × S 2 and they are similar to the second Kirby move. We obtain an infinite system of equations, a solution of which is equivalent to computing KBSM S 1 × S 2 . We show that KBSM S 1 × S 2 is not torsion free and that its free part is generated by the unknot (or the empty knot). We then present a diagrammatic method for computing KBSM S 1 × S 2 via braids. Using this diagrammatic method, we also obtain a closed formula for the torsion part of KBSM S 1 × S 2 . [ABSTRACT FROM AUTHOR]

Inertial sensors act as inertial references in space gravitational wave detection missions, necessitating that their internal test mass (TM) maintains minimal residual acceleration noise. High-energy particles and cosmic rays in space, along with ion pumps in ground-based torsion pendulum experiments, can cause charge accumulation on the TM surface, leading to increased residual acceleration noise. Consequently, a charge management system was introduced to control the TM's charge. The complex light path propagation within the electrode housing (EH) makes the TM's charging and discharging process difficult to theoretically calculate and fully simulate. To address this issue, we propose a simulation method for charging and discharging inertial sensors within ultraviolet (UV) charge management systems. This method innovatively considers the impact of photoelectron emission angle and the TM's position offset from symmetry on performance. The method also simulates charging and discharging rates over time under conditions of symmetry and preliminarily examines factors affecting the TM's equilibrium potential. Simulation results indicate that this method effectively models the charge management system's operation, providing a valuable reference for system design. [ABSTRACT FROM AUTHOR]

In this case report, we described a rare complication—lung torsion after esophageal atresia repair in a newborn. Torsion of the lung is a critical condition in which either the entire lung or a lung lobe twists, leading to occlusion of blood vessels and airways. The patient's clinical condition was poor after the primary operation. An emergency thoracotomy showed 180° torsion of the right upper lobe (RUL) and right middle lobe (RML). After detorsion, perioperatively, the lung was gradually reperfused and had a normal appearance. After surgery, the patient was unstable, which culminated in a fatal end (bradycardia, reperfusion injury). Immediate intervention can preserve the affected lung or lung lobe. However, pulmonary torsion typically has a poor prognosis due to misdiagnosis and delayed treatment. Additionally, diagnosis in the neonatal period is even more challenging because the clinical symptoms are nonspecific. In any case, the question is whether detorsion is the right solution or whether a segmentectomy is necessary. [ABSTRACT FROM AUTHOR]

Pulmonary sequestration with torsion is a rare condition. We describe a seven‐month‐old baby presenting excessive crying for pulmonary sequestration with torsion. Contrast‐enhanced chest computed tomography demonstrated an oval‐shaped mass in the posteromedial right lower chest, no systemic arterial supply was evident. The edge of the mass showed slight linear reinforcement, and its interior had no reinforcement. Thoracoscopic segmentectomy was carried out and histology confirmed pulmonary sequestration with torsion. [ABSTRACT FROM AUTHOR]

This study examines the impact of high-pressure torsion (HPT) processing at various temperatures on the precipitation behavior of Cu-Cr alloys. The introduction of defects through HPT is observed to promote the precipitation of Cr atoms. Unlike the traditional large-scale precipitation that typically occurs around 400 °C, HPT can induce the precipitation of solute atoms even at room temperature. Furthermore, the temperature at which HPT is performed significantly influences the behavior of the precipitated phase during subsequent aging, ultimately affecting the alloy's overall properties. At elevated temperatures (ETs) and room temperature (RT), Cr atoms tend to aggregate, forming Guinier–Preston (GP) zones or precipitates, which coarsen into incoherent precipitates after annealing. In contrast, when HPT is conducted at liquid nitrogen temperature (LNT), Cr atoms are retained in their original positions, leading to the formation of uniformly distributed, high-density small precipitates post-annealing. This phenomenon results in superior properties for HPT-LNT-treated samples, evidenced by a microhardness of 191.8 ± 3.2 HV and an electrical conductivity of 84.6 ± 1.8% IACS. [ABSTRACT FROM AUTHOR]

Purpose: An increased value of tibiofemoral rotation is frequently observed in patients with patellofemoral instability or maltracking. Nevertheless, the appropriate approach for addressing this parameter remains unclear so far. One potential approach for correcting tibiofemoral rotation is femoral rotational osteotomy. We hypothesized that femoral rotational osteotomy affects tibiofemoral rotation. Methods: All patients who underwent femoral rotational osteotomy between January 2018 and May 2022 were included in this study. Pre‐ and postoperative tibiofemoral rotation and the degree of femoral rotation were measured using two‐dimensional (2D) and three‐dimensional (3D) measurements. The effect of femoral rotation on tibiofemoral rotation was assessed. Results: Forty knees (18 right and 22 left) of 36 patients (28 females and 8 males) were included. Mean preoperative femoral torsion was 32.1 ± 10.1° in 2D and 30.8 ± 10.1° in 3D. Femoral rotation was performed by −14.1 ± 8.3° using 2D measurements and −15.0 ± 8.0° using 3D measurements. Tibiofemoral rotation changed from 9.9 ± 6.2° to 9.7 ± 6.0° (p = n.s.) in 2D, and from 10.2 ± 5.5° to 9.4 ± 5.4° (p = n.s.) in 3D. Conclusion: Tibiofemoral rotation showed no significant changes after femoral rotational osteotomy. Hence, femoral rotational osteotomy cannot be used to correct tibiofemoral rotation in addition to correcting the femoral version. Other surgical techniques need to be evaluated if correction of tibiofemoral rotation is required. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

The cochlea, situated within the inner ear, is a spiral-shaped, liquid-filled organ responsible for hearing. The physiological significance of its shape remains uncertain. Previous research has scarcely addressed the occurrence of transverse flow within the cochlea, particularly in relation to its unique shape. This study aims to investigate the impact of the geometric features of the cochlea on fluid dynamics by characterizing transverse flow induced by harmonically oscillating axial flow in square ducts with curvature and torsion resembling human cochlear anatomy. We examined four geometries to investigate curvature and torsion effects on axial and transverse flow components. Twelve frequencies from 0.125 Hz to 256 Hz were studied, covering infrasound and low-frequency hearing, with mean inlet velocity amplitudes representing levels expected for normal conversation or louder situations. Our simulations show that torsion contributes significantly to transverse flow in unsteady conditions, and that its contribution increases with increasing oscillation frequency. Curvature alone has a small effect on transverse flow strength, which decreases rapidly with increasing frequency. Strikingly, the combined effect of curvature and torsion on transverse flow is greater than expected from a simple superposition of the two effects, especially when the relative contribution of curvature alone becomes negligible. These findings may be relevant to understanding physiological processes in the cochlea, including metabolite transport and wall shear stress. Further studies are needed to investigate possible implications for cochlear mechanics. [ABSTRACT FROM AUTHOR]

Nowadays, piezoelectric micro-beam structures are used in various industries, and knowing and analysis of these smart microstructures is important. However, in the modeling of these electromechanical microbeams, the torsion during bending is generally omitted for simplicity. Considering that in some cases, twisting and bending cannot be omitted and must be modeled simultaneously. Therefore, this article presents a coupled bending-torsion model for the first time for static deflection and free vibration analysis of piezoelectric microbeams with nonclassical continuum theories. The governing equations of the motion and boundary conditions of the Timoshenko beam at the micro-scale have been obtained using size-dependent electromechanical theory and Hamilton's principle. In addition, the Laplace transform is used to solve the static equations, while the generalized differential quadratic (GDQ) method is used to discretize and solve the free vibration equations. In the following, the influence of various parameters, such as the effect of size and geometric conditions, on the static displacements and the natural frequency of the microbeam is discussed. [ABSTRACT FROM AUTHOR]

Background: Tissue stimulations greatly affect cell growth, phenotype, and function, and they play an important role in modeling tissue physiology. With the goal of understanding the cellular mechanisms underlying the response of tissues to external stimulations, in vitro models of tissue stimulation have been developed in hopes of recapitulating in vivo tissue function. Methods: Herein we review the efforts to create and validate tissue stimulators responsive to electrical or mechanical stimulation including tensile, compression, torsion, and shear. Results: Engineered tissue platforms have been designed to allow tissues to be subjected to selected types of mechanical stimulation from simple uniaxial to humanoid robotic stain through equal‐biaxial strain. Similarly, electrical stimulators have been developed to apply selected electrical signal shapes, amplitudes, and load cycles to tissues, lending to usage in stem cell‐derived tissue development, tissue maturation, and tissue functional regeneration. Some stimulators also allow for the observation of tissue morphology in real‐time while cells undergo stimulation. Discussion on the challenges and limitations of tissue simulator development is provided. Conclusions: Despite advances in the development of useful tissue stimulators, opportunities for improvement remain to better reproduce physiological functions by accounting for complex loading cycles, electrical and mechanical induction coupled with biological stimuli, and changes in strain affected by applied inputs. [ABSTRACT FROM AUTHOR]

The degeneracies of 1/4 BPS states with unit torsion in heterotic string theory compactified on a six torus are given in terms of the Fourier coefficients of the reciprocal of the Igusa cusp Siegel modular form Φ 10 of weight 10. We use the symplectic symmetries of the latter to construct a fine-grained Rademacher-type expansion which expresses these BPS degeneracies as a regularized sum over residues of the poles of 1 / Φ 10 . The construction uses two distinct SL (2 , Z) subgroups of Sp (2 , Z) which encode multiplier systems, Kloosterman sums and Eichler integrals appearing therein. Additionally, it shows how the polar data are explicitly built from the Fourier coefficients of 1 / η 24 by means of a continued fraction structure. [ABSTRACT FROM AUTHOR]

We compute the Mordell–Weil groups of the modular Jacobian varieties of hyperelliptic modular curves X 1 (M , M N) over every composite field of some quadratic number fields. Also we prove criteria for the existence of elliptic curves over such number fields with prescribed torsion points generalizing the results for quadratic number fields of Kamienny and Najman. [ABSTRACT FROM AUTHOR]

Together with axial and flexural actions, modern-designed reinforced-concrete walls can also be subjected to torsion during rare loading events, such as large-magnitude earthquakes or strong winds. For certain widely used nonplanar open cross-section geometries, this torque is resisted primarily through warping. In some cases, the longitudinal stresses caused by torsional warping can be of the same order of magnitude as those caused by flexure, which postulates a reduction of the in-plane bending moment capacity of the section. This study explores the reduction of bending moment capacity of open reinforced-concrete U-shaped core walls due to the simultaneous application of flexural, axial, and torsional loading. Initial investigations focused on strain gradients through the wall segments of reinforced-concrete U-shaped walls. Using a refined data set from a recent experimental campaign, the commonly assumed linear strain gradient used in the design of reinforced-concrete walls is challenged. Numerical methods that intrinsically rely on the observed strain gradients are then employed to compute, for a range of torque-to-bending-moment ratios, the ultimate bending moment and torque capacities from combined loading scenarios. The numerical results corroborate existing experimental results, indicating a significant reduction (almost half) in ultimate bending moment capacity when a torque equal to approximately 20% of imposed bending is applied. Interaction diagrams between the ultimate torque and bending moment show that it is possible to derive a simple relationship between the two for the purposes of structural design. These results can help formulate guidelines for future international building codes, which in their current form cannot account for the design of open sections governed by warping torsion. [ABSTRACT FROM AUTHOR]

This study aims to develop an analytical model based on the curve beam theory to capture the mechanical response of a multihelix cable considering the internal contact displacements. Accordingly, a double-helix cable subjected to axial tension and torsion is analyzed, and both the line and point contacts between the neighboring wires and strands are considered via an equivalent homogenized approach. Then, the proposed theoretical model is extended to a hierarchical multihelix cable with mutual contact displacements by constructing a recursive relationship between the high- and low-level multihelix structures. The global tensile stiffness and torsional stiffness of the double-helix cable are successfully evaluated. The results are validated by a finite element (FE) model, and are found to be consistent with the findings of previous studies. It is shown that the contact deformations in multihelix cables significantly affect their equivalent mechanical stiffness, and the contact displacements are remarkably enhanced as the helix angles increase. This study provides insights into the interwire/interstrand mutual contact effects on global and local responses. [ABSTRACT FROM AUTHOR]

In a recent paper by A. A. Klyachko, V. Y. Miroshnichenko, and A. Y. Olshanskii, it is proven that the center of any finite strongly verbally closed group is a direct factor. In this paper, we extend this result to the case of finite normal subgroups of any strongly verbally closed group. It follows that finitely generated nilpotent groups with nonabelian torsion subgroups are not strongly verbally closed. [ABSTRACT FROM AUTHOR]

The Witt ring of a complex flag variety describes the interesting – i.e. torsion – part of its topological KO-theory. We show that for a large class of flag varieties, these Witt rings are exterior algebras, and that the degrees of the generators can be determined by Dynkin diagram combinatorics. Besides a few well-studied examples such as full flag varieties and projective spaces, this class includes many flag varieties whose Witt rings were previously unknown, including many flag varieties of exceptional types. In particular, it includes all flag varieties of types G_2 and F_4. The results also extend to flag varieties over other algebraically closed fields. [ABSTRACT FROM AUTHOR]

We introduce the notions of Gorenstein projective τ -rigid modules, Gorenstein projective support τ -tilting modules and Gorenstein torsion pairs and give a Gorenstein analog to Adachi–Iyama–Reiten's bijection theorem on support τ -tilting modules. More precisely, for an algebra Λ , we prove that there is a bijection between the set of Gorenstein projective support τ -tilting modules and the set of functorially finite Gorenstein projective torsion classes. As an application, we introduce the notion of CM- τ -tilting finite algebras and show that Λ is CM- τ -tilting finite if and only if Λ op is CM- τ -tilting finite. Moreover, we show that the Bongartz completion of a Gorenstein projective τ -rigid module need not be a Gorenstein projective τ -tilting module. [ABSTRACT FROM AUTHOR]

Evaluating building damage in mining areas using Interferometric Synthetic Aperture Radar (InSAR) has inherent challenges. This work presents a Delaunay Triangulation of Surface Deformation (DTSD) model that utilizes Permanent Scatter InSAR to analyze various types of deformations in villages. This model created a network of irregular triangles using Delaunay triangulation and PS points as the input. The calculation involved determining the inclination of triangular edges and the torsion of spatial Bezier curves fitted by these edges. The PS points' maximum inclination and curvature values were identified by solving over-determined equations. Results from a slurry injection mine in Huaibei, China, indicate that the various types of deformations in the neighboring communities were below 8 %, and the buildings experienced minimal damage. The DTSD model offers a theoretical framework for monitoring and assessing various types of surface deformation and designing essential zones for building protection. [ABSTRACT FROM AUTHOR]

This article describes a new method for the design of rectangular foundations in cohesionless soil subject to a combination of vertical and horizontal loads, overturning moments, and torsional moments. It can be seen as a supplement to the general bearing capacity equation in which possible torsional effects of horizontal loads are not included. Torsional effects have had an increasing interest and are common in the design of offshore structures, but onshore structures, such as wind turbines and masts, may also be subject to torsional loads, which can have a substantial effect on the design. The method, which is suitable for hand calculations, applies an equation proposed by Finnie and Morgan for a Tresca material and it is shown that this equation can be used for cohesionless soil for the design of rectangular footings subject to vertical and horizontal forces, overturning moments, and torsional moments. The new method has been compared with those of DNV (DNV: global quality assurance and risk management company in the maritime industry) "Recommendations on offshore soil mechanics and geotechnical engineering" and it is shown that it produces results that are considerably more advantageous than the DNV method. In addition, comparisons have been made with results produced by OptumG3 software, and it is shown that the method leads to safe design. Charts and equations suitable for practical design have been prepared and the equations have been implemented into a computer program, which can be obtained at no cost by contacting the first author. [ABSTRACT FROM AUTHOR]

Flexural vibration (FV), torsional vibration (TV), static torsion (ST), longitudinal vibration (OAV), and tension (OAT) of 45° off-axis tests of flat pieces of cardboards were analyzed to determine the in-plane shear modulus (IPSM) using samples of various widths. The analyses were performed with simulations using the finite element method (FEM) for models with and without lamination and physical experiments using cardboard samples. For the FV, TV, and ST tests, the IPSM was calculated using binary search (BS) and linear regression (LR). The FEM results suggest that the IPSM values obtained from the TV and ST test simulations were affected by lamination. In contrast, the effect of lamination was not clear in the FV, OAV, and OAT test simulations. The coefficient of variation obtained from the FV experiments was often larger than that obtained from other tests. Despite this variation, the FV test is more attractive than the other tests because the experiments could be performed easily, and the effect of lamination could be reduced. [ABSTRACT FROM AUTHOR]

Designing or appraising framed concrete buildings exposed to high eccentric loads requires precise reinforced concrete (RC) torsional strength estimates. Unfortunately, semi-empirical formulae still fail to adequately predict the torsional capacity of RC beams, particularly over-reinforced and strong ones. To overcome this limitation, accurate Machine Learning (ML) models might replace more sophisticated and computationally intensive models. This work evaluates and determines the most effective tree-based machine learning algorithms to estimate the torsional capacity (7) of RC beams subjected to pure torsion. The objective of the present work is to provide innovative hybrid models that combine the concepts of the Adaptive neuro fuzzy inference systems (ANFIS) model with other optimization approaches, such as the Giant trevally algorithm (GTA) and Honey badger algorithm (HBA), to accurately forecast the Tr. A total of 202 RC rays were collected to form the data set. To facilitate the application of the ANFIS models, a training set and a testing set were created from the database. Out of the 202 samples in the database, 25 percent (51) were used for evaluation and 75 percent (151) were used for learning. ANFGTA demonstrated superior performance compared to ANF - HBA, with a 50% higher performance in the learning phase and an 80% higher performance in the evaluation stage, as measured by the MedSE index values. The ANF - GTA obtained lower SMAPE index values of 5.2192 and 5.39 compared to the values of 8.0622 and 9.3783 obtained by the ANF - HBA during the learning and assessment phases, respectively. [ABSTRACT FROM AUTHOR]

A tool for path following for a mobile manipulator is herein presented. The control algorithm is obtained by projecting a local frame associated with the robot onto the desired path, thus obtaining a non-orthogonal moving frame. The Serret–Frenet frame moving along the curve is considered as a reference. A curve resulting from the control points of a B-spline in 2D or 3D is investigated as the desired path. It is used to show how the geometric continuity of the path has an impact on the performance of the robot in terms of undesired force spikes. This can be understood by looking at the curvature and, in 3D, at the torsion of the path. These unwanted effects vanish and better performance is achieved thanks to the change of the B-spline order. The theoretical results are confirmed by the simulation study for a mobile manipulator consisting of a non-holonomic wheeled base coupled with a holonomic robotic arm with three degrees of freedom (rotational and prismatic). [ABSTRACT FROM AUTHOR]

The study presented the results of model experimental investigations on box structures made using additive manufacturing. The examined models had walls with reinforcements in the form of corrugations. An experiment was also conducted using a reference model without stiffeners. The aim of the study was to determine the influence of corrugation geometry on the shape and magnitude of structure deformations, as well as on the level of critical loads. The experiments were conducted using a dedicated research stand. Nonlinear numerical analyses of selected structure variations were also carried out using finite element method-based software. A comparison of the maximum displacement values obtained by experimental and numerical methods was made. [ABSTRACT FROM AUTHOR]

Work-related musculoskeletal disorders affect a large number of people, diminishing inter alia, their workplace efficiency. For this reason, rehabilitation procedures and equipment are called for, designed to expedite the swift reintegration of patients into daily activity. Within this context, this paper proposes a novel constructive solution of a device that ensures rehabilitation through the transverse passive mobilization of the neck joint. This paper introduces a torsion motor actuated by two pneumatic muscles that ensure sufficient adaptability of the device to, for example, conduct patient exercise within the boundaries of pain supportability. Based on the research results, recommendations are offered for the optimum operation of the rehabilitation equipment. [ABSTRACT FROM AUTHOR]

Objective: A female Rio Cauca caecilian Typhlonectes natans (estimated as between 10 and 18 years of age) housed at the Smithsonian National Zoological Park in Washington, D.C., developed progressive severe coelomic effusion over a 4‐week period. The coelomic effusion was diagnosed via radiographs and ultrasound, and a sample of the fluid was obtained for analysis, which revealed a low‐protein transudate suggestive of inflammation. As the coelomic effusion progressed, the caecilian became tachypneic, hyporexic, and lethargic. The caecilian was started on antibiotics and a diet trial, but signs continued despite therapy. Methods: An exploratory celiotomy was performed, which revealed adipose tissue torsion with local lymphangiectasia and a presumptive biliary cyst. Surgical correction was unable to be achieved due to concern for fatal hemorrhage, as the vasculature associated with the torsion was severely distended. Due to the severity of the torsion and associated risks, the caecilian was euthanized intraoperatively and subsequently necropsied for histologic evaluation. Result: After reviewing the caecilian's presentation and the progression of disease, it is suspected that the severe coelomic effusion was secondary to lymphangiectasia, which occurred subsequent to the adipose tissue torsion. Conclusion: This is the first reported case of adipose tissue torsion and associated clinical disease in an aquatic caecilian and should be a differential for progressive coelomic effusion in this species. Impact statementTo our knowledge, this is the first reported case of adipose tissue torsion and associated clinical disease in an aquatic caecilian and should be a differential for coelomic effusion in Rio Cauca caecilians. [ABSTRACT FROM AUTHOR]

Shape memory alloy (SMA) devices (utilizing wires/rods, springs or tubes) engage unique superelastic/pseudoelastic (SE) phenomenon for large stroke recovery, energy dissipation and damping applications. In particular, SMA components in torsion are also generally subjected to some pre-tension loads and hence understanding their combined effects on the torsional response is vital. In this work, some intricate internal loop and outer loop responses (large twists > 1500°) of SMA tubes under different twisting-untwisting scenarios are investigated to understand the effects of static pre-load on torsional responses. Key SMA hysteretic features like sink point memory (SPM) and return point memory (RPM) have not been well understood under torsion (with and without axial loads) have been investigated here. Further, a modified two variant thermodynamic Preisach modeling approach is proposed to simulate responses of twisted tubes with varying extents of twist and different axial loads. The central principle here is the use of a Gibbs Potential framework to separate the dissipative and thermoelastic parts of the SE responses using well established thermodynamic principles and then utilizing a non-ideal switching type disjunctive Preisach model to fit the nonlinear hysteretic dissipative section of the SE response. By using the outer loop response for model calibration, other complex loading unloading scenarios leading to intricate internal loops and effects of axial loads on these can be predicted. It is also shown that addition of a single interior loop detail for model calibration significantly enhances prediction of other more intricate internal loops. This approach dramatically simplifies the experimental data needed for the simulation of SMA components even under complex loading. [ABSTRACT FROM AUTHOR]

Introduction: Adnexal torsion is characterised by the rotation of the ovary and, occasionally, the fallopian tube around their supporting ligaments by more than 45 degrees. It predominantly occurs during the first and second trimesters of pregnancy, with an incidence of up to 0.1% in the third trimester. Dermoid and functional ovarian cysts, most commonly associated with benign serous cystadenomas, are frequently identified among the torted adnexal masses. Case Presentation: We report the case of a 32-year-old primigravida with a known ovarian cyst diagnosed in the first trimester, which was managed conservatively throughout the pregnancy. At 36 weeks of gestation, she presented with abdominal pain and was subsequently managed with an emergency caesarean section at 37 weeks due to the development of an acute surgical abdomen. During the procedure, a torted left tubo-ovarian complex was excised, with partial preservation of the healthy-appearing ovarian tissue. Histopathological examination identified the mass as a benign serous cystadenoma. Conclusions: Ovarian torsion during pregnancy poses a significant diagnostic challenge. The decision between conservative management and surgical intervention is primarily guided by a high index of suspicion for torsion. [ABSTRACT FROM AUTHOR]

This paper presents the torsional behavior of reinforced concrete beams strengthened with carbon fiber-reinforced polymer (CFRP) sheets. Assorted retrofit schemes are implemented with variable widths and number of single- and double-layer CFRP U-wraps. After loading 27 beams (three unstrengthened and 24 strengthened), test data were collected to investigate the efficacy of those U-wrap configurations. The width and layer of the bonded sheets dominate the capacity of the beams, whereas the number of the U-wraps in the longitudinal direction is an insignificant attribute. Although the CFRP retrofit decreases structural ductility, the placement of the U-wraps impedes stiffness-reduction rates, reduces twist angles, and redistributes torque-induced stresses. The identified characteristic effective shear modulus of the strengthened beams demarcates the pattern of energy drops, which are related to the degree of brittleness in failure. As far as effective strains are concerned, the applicability of existing equations is appraised, and a new expression is proposed through reliability theory and stochastic simulations. [ABSTRACT FROM AUTHOR]

Let K be a non-cyclotomic imaginary quadratic field with class number 1 and E/K an elliptic curve with E(K)[2] ≃ ℤ/2ℤ ⊕ ℤ/2ℤ. In this paper, we determine the torsion groups that can arise as E(L)tor where L is any quadratic extension of K. [ABSTRACT FROM AUTHOR]

In this paper, we will manifest how polytropic fluids produce effects on an alternate gravitational source, regardless of its features, for spherically symmetric and static spacetimes. For this purpose, we use f(T,풯) modified gravity, which is characterized by the trace of an energy–momentum tensor as 풯 and torsion scalar T, Additionally, using the polytropic equation of state, we will speculate about the distribution of energy among fluids within an astrophysical object. We offer a thorough methodology for identifying generic relativistic polytropes accompanied by the minimal geometric decoupling technique. Ultimately, a few tangible attributes of polytropes along with perfect fluids are observed using the Tolman IV solution, including total pressure, energy interchange, and thermal characteristics. [ABSTRACT FROM AUTHOR]

In this paper, some properties of finitely generated two-periodic modules over commutative Noetherian local rings have been studied. We show that under certain assumptions on a pair of modules (M,N) with M being two-periodic, the natural map M ⊗RN →HomR(M∗,N) is an isomorphism. As a consequence, we prove that Auslander’s depth formula holds for such a Tor-independent pair. Tor-independence plays a crucial role for the depth formula to hold. Under certain assumptions on the modules, we show that a pair of modules, over a one-dimensional local ring, is Tor-independent if and only if their tensor product is torsion-free. Celikbas et al. recently showed the Huneke–Wiegand conjecture holds for two-periodic modules over one-dimensional domains. We generalize their result to the case of two-periodic modules with rank over one-dimensional local rings. [ABSTRACT FROM AUTHOR]

Rings on MT-groups are investigated, a mixed Abelian group G is called an MT-group if every multiplication on the torsion part of G uniquely extends to a multiplication on G. The absolute Jacobson radical and the absolute nil-radical of MT-groups are described (Problem 94 in the book Infinite Abelian Groups by L. Fuchs). [ABSTRACT FROM AUTHOR]

We consider vector bundles of rank 2 with trivial generic fiber on the projective line over ℤ . For such bundles, a new invariant is constructed — the Reidemeister torsion, which is an analog of the classical Reidemeister torsion from topology. For vector bundles of rank 2 with trivial generic fiber and jumps of height 1, that is, for the bundles that are isomorphic to superscript 풪 2 in the fiber over ℚ and are isomorphic to superscript 풪 2 or direct-sum 풪 1 풪 1 over each closed point of Spec ℤ , we calculate this invariant and show that it, together with the discriminant of the bundle, completely determines such a bundle. [ABSTRACT FROM AUTHOR]

We compare two cycle class maps on torsion cycles and show that they agree up to a minus sign. The first one goes back to Bloch [ 6 ], with recent generalizations to non-closed fields. The second is the étale motivic cycle class map |$\alpha ^{i}_{X}\colon \operatorname{CH}^{i}(X)_{{\mathbb{Z}}_{\ell }}\to H^{2i}_{L}(X,{\mathbb{Z}}_{\ell }(i))$| restricted to torsion cycles. [ABSTRACT FROM AUTHOR]

In studying the effects of oxygen concentration and molecular structure on the morphologies of the soot particles produced by hydrocarbon fuels, ethylene and ethane were chosen as experimental fuels. With a Gülde laminar coaxial diffusion flame device, a soot particle device was used to sample soot particles at different oxygen concentrations (21%, 24%, 26%, 28%, and 31%) and at different heights above a burner (HABs = 10 mm, 20 mm, 30 mm, 40 mm, and 50 mm). High-resolution transmission electron microscopy (HRTEM) was used to scrutinize and analyze the soot particles at varying oxygen concentrations. The findings suggest that at the same oxygen concentration, ethylene produces brighter and taller flames. With an increase in the oxygen concentration, ethylene flames and ethane flames gradually decrease in height and become brighter. With an increase in the HAB, the average primary soot particle diameter (Dp) increases initially and then decreases, the fractal dimension (Df) increases, and the aggregates transition from strips and chains to clusters. At the same flame height (HAB = 30 mm), the Dp decreases, the Df increases, the carbon layer torsion resistance (Tf) and the carbon layer spacing (Ds) increase, and the carbon layer changes from a parallel arrangement to a curved arrangement to form denser network aggregations. [ABSTRACT FROM AUTHOR]

For any finitely generated module M with non-zero rank over a commutative one dimensional Noetherian local domain, the numerical invariant h (M) was introduced and studied in [25]. We establish a bound on it which helps capture information about the torsion submodule of M when M has rank one and generalizes the discussion in [25]. We further study bounds and properties of h (M) in the case when M is the canonical module ω R. This in turn helps in answering a question of S. Greco and then provides classifications in the Gorenstein, almost Gorenstein and far-flung Gorenstein setups. [ABSTRACT FROM AUTHOR]

AbstractThe connection of steel elements to concrete is typically achieved through embedded shear connectors (anchors) placed at the interface of concrete and steel. These shear connectors come in various types, such as headed studs, welded or coupled rebars, shear lugs, or a combination of these, designed to handle large shear forces. Shear connectors primarily resist shear forces and bending loads. However, when the load is not applied along the centroid of the shear connector, it generates a torsional moment in addition to shear- and flexure-induced moments, impacting the performance of shear connectors. To address this phenomenon, this experimental study assesses the behavior of shear connectors, including studs, shear lugs, and rebars, both individually and in combination, under three different load eccentricities relative to anchors spacing connectors (0, 0.25, 0.50, and 0.75). The results are then compared with the control specimen (without eccentricity). The findings revealed that vertical shear lugs can significantly enhance the shear capacity, and ACI 318-19 is conservative in this regard by 41.5% for a relative load eccentricity of 0.75. Nonetheless, it gives good estimations of the shear capacity of connectors without vertical shear lugs. HIGHLIGHTSContributing to the very limited data on the performance of anchors under the combined action of shear and torsion.ACI 318-19 [1] provides reliable estimations of shear strength for studs/rebars, both with and without eccentricity. However, it tends to be conservative by 41.5% (for a relative eccentricity of 0.75) when horizontal and vertical shear lugs are utilized.Contributing to the very limited data on the performance of anchors under the combined action of shear and torsion.ACI 318-19 [1] provides reliable estimations of shear strength for studs/rebars, both with and without eccentricity. However, it tends to be conservative by 41.5% (for a relative eccentricity of 0.75) when horizontal and vertical shear lugs are utilized. [ABSTRACT FROM AUTHOR]

Hummingbirds demonstrate remarkable robustness to wing defects by maintaining stable hovering during the molting process. However, mimicking these capabilities in flapping-wing robots presents significant challenges. To investigate the effectiveness of various controllers in maintaining the attitude of a hummingbird-mimetic flapping-wing robot against external disturbances under different wing defects, this study implemented a PD controller, a PID controller, and a three-loop feedback controller with a disturbance observer (3L-DOB controller). The flapping-wing robot features a pair of wings and controls its body's yaw, pitch, and roll rotations by modulating the tension of wing membranes and the neutral positions of wing torsion. The performance of these controllers was evaluated through semi-tethered experiments on a gimbal, employing three Wing Sets: intact wings, one wing was defective, and both wings were defective. The defective wing emulated hummingbird wing during molting, in which the wing area was cropped by 14.1%. As a result, the 3L-DOB controller showed the best performance in terms of responsiveness and accuracy across all Wing Sets, while the PID controller also achieved comparable performance. [ABSTRACT FROM AUTHOR]

According to a number of astronomical studies, the universe is currently undergoing an accelerated expansion phase. We employed the recently proposed gravity, which holds that the current accelerated expansion phase of the universe is caused by a torsion scalar. The investigation is carried out using a parameterization of q (z) = − 1 + 3 2 ( (z + 1) q 2 q 1 + (z + 1) q 2 ) (where q 1 and q 2 are the model parameters) and the H (z) using H (z) = H 0 exp [ ∫ 0 z (1 + q (z)) d (ln (1 + z)) ] is obtained. The model shows good agreement with recent observations, such as the LCDM model at late times. Finally, we examined how the cosmological parameters behaved in for constrained values. [ABSTRACT FROM AUTHOR]

The geometrical properties of a helical ferromagnet are shown theoretically to control the critical temperature of a proximity-coupled superconductor. Using the Usadel equation for diffusive spin transport, we provide self-consistent analysis of how curvature and torsion modulate the proximity effect. When the helix is attached to a piezoelectric actuator, the pitch of the helix—and hence the superconducting transition—can be controlled electrically. [ABSTRACT FROM AUTHOR]

The production of Lycium barbarum L. is a labor-intensive industry. Multiple manual harvests are required during the harvesting season, which contributes to the high harvesting costs. The cultivation conditions of L. barbarum were investigated to increase efficiency and mitigate harvesting damage. A torsion harvester was designed according to the characteristic of infinite inflorescence and the distribution of detachment force, and the kinematics model of the harvester was established. The vibration responses of ripe and unripe fruit were obtained through ADAMS simulation of the branch model, and the influencing factors and value range of the torsion harvester were also determined. The mathematical models of ripe fruit harvesting rate, unripe fruit harvesting rate, ripe fruit damage rate and torsion angle, vibration rods distance, and vibration frequency were established by the Box-Behnken test. The influences of various factors on ripe fruit harvesting rate, unripe fruit harvesting rate, and ripe fruit damage rate were analyzed, and the best parameter combination was obtained: torsion angle 73.66°, vibration rods distance 35.51 mm and vibration frequency 19.12 Hz. Field experiment showed that the harvesting rate of ripe fruit is 95.67%, the harvesting rate of unripe fruit is 4.68%, and the damage rate of ripe fruit is 3.70%. The research results can promote the mechanization process of L. barbarum harvest, and provide a reference for vibration harvest of berries. [ABSTRACT FROM AUTHOR]

Series, 4 (Scuola Normale Superiore di Pisa, Pisa, 2007), 73-91] proved that, given two complex elliptic curves E1 and E2 along with even degree-2 maps πj: Ej → ℙ¹ having different branch loci, the intersection of the image of the torsion points of E1 and E2 under their respective πj is finite. They conjectured (also in works with Fu) that the cardinality of this intersection is uniformly bounded independently of the elliptic curves. The recent proof of the uniform Manin-Mumford conjecture implies a full solution of the Bogomolov-Fu-Tschinkel conjecture. In this paper, we prove a generalisation of the Bogomolov-Fu-Tschinkel conjecture whereby, instead of even degree-2 maps, one can use any rational functions of bounded degree on the elliptic curves as long as they have different branch loci. Our approach combines Nevanlinna theory with the uniform Manin-Mumford conjecture. With similar techniques, we also prove a result on lower bounds for ranks of elliptic curves over number fields. [ABSTRACT FROM AUTHOR]

The development of inelastic and plastic strains is studied for Ti49.3Ni50.7 (at.%) alloy samples with the structure of high-temperature B2 phase in the state as received from the manufacturer under torsion. It has been established that when the strain of the samples, specified by torsion, is equal to 10.6%, the value of the accumulated plastic strain is 0.35%. Therefore, the actual yield stress of the Ti49.3Ni50.7 (at.%) alloy samples is localized at the end of the pseudo-yield plateau on the stress-strain dependence rather than at the end of the strain hardening stage, as previously thought. The results presented in the work should be taken into account in the practical use of the alloy with this composition as products for technical and medical purposes that experience tensile, bending, and torsional deformations. [ABSTRACT FROM AUTHOR]

This research work aims to investigate experimentally the torsional behaviour of self-compacting reinforced concrete hollow beams with recycled concrete aggregate. Twelve beams were cast and tested. The beams have the same dimensions, and the variables that were investigated include, recycled aggregate content, longitudinal reinforcement, and transverse reinforcement. The test results revealed that for all beams no significant difference in behaviour was identified when comparing beams with recycled aggregate with those with normal aggregate. All the beams exhibited almost similar linear torque-rotation behaviour, but beams with RCA showed lower cracking torque and the twist angle depended on the replacement ratio of RCA. Beams without any reinforcement failed suddenly and separated into two parts, while beams with longitudinal bars showed brittle torsional failure, beams with both longitudinal and transverse reinforcement showed an increasing post-cracking behaviour with the formation of an increase in the number of helical and diagonal cracks. [ABSTRACT FROM AUTHOR]

Gerbes and higher gerbes are geometric cocycles representing higher degree cohomology classes, and are attracting considerable interest in differential geometry and mathematical physics. We prove that a 2-gerbe has a torsion Dixmier–Douady class if and only if the gerbe has locally constant cocycle data. As an application, we give an alternative description of flat twisted vector bundles in terms of locally constant transition maps. These results generalize to n-gerbes for n = 1 and n ≥ 3 , providing insights into the structure of higher gerbes and their applications to the geometry of twisted vector bundles. [ABSTRACT FROM AUTHOR]

We study a family of (possibly non topological) deformations of BF theory for the Lie algebra obtained by quadratic extension of so (3 , 1) by an orthogonal module. The resulting theory, called quadratically extended General Relativity (qeGR), is shown to be classically equivalent to certain models of gravity with dynamical torsion. The classical equivalence is shown to promote to a stronger notion of equivalence within the Batalin–Vilkovisky formalism. In particular, both Palatini–Cartan gravity and a deformation thereof by a dynamical torsion term, called (quadratic) generalised Holst theory, are recovered from the standard Batalin–Vilkovisky formulation of qeGR by elimination of generalised auxiliary fields. [ABSTRACT FROM AUTHOR]