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Reducing the ratio of box girders' span to their height reduces bending moments and makes them deep members that are controlled by shear behavior. The presence of horizontal curvature generates torsional moments and different deflection between the outer and inner web as a result of twisting. Two experimental specimens with the same dimensions were cast and tested, one straight and the other horizontally curved. The two specimens were numerically modeled using the ABAQUS software for the purpose of verifying the numerical model to study more parameters. The finite element analysis showed a good agreement with the experimental values with a difference of (98-99) %, (94-97)% and 103% of the experiment for ultimate loading, deflection and twisting angle, respectively. It also showed stress paths that match the experimental and theoretical results that explain the behavior of deep beams, such as the Strut and Tie method (STM). The effect of compressive strength, whole width, and the width of the bearing and supporting plates was studied. Results showed that increasing the concrete's compressive strength by about 40-120%, increased the load capacity and decreased its deflection by approximately 6-14% and 3-15%, respectively. The deep box section torsional resistance increased when its width was increased by approximately 17–50%, although this had no significantly affect on the load capacity level. A reduction of 17-33% in the width of the loading and supporting bearing plates caused a 6-16% drop in load capacity besides a notable decrease in stiffness.

BackgroundPediatric supracondylar humeral fractures present considerable surgical challenges due to the difficulty of achieving proper fracture alignment and stable fixation while avoiding injury to the ulnar nerve. This study assesses the biomechanical performance of a novel Kirschner wire (K-wire) fixation device (KFD), designed to enhance stability and reduce complications linked to traditional K-wire configurations.MethodsUsing finite element analysis (FEA), we evaluated four fixation strategies for treatment of pediatric supracondylar humeral simple transverse fractures: crossed pin fixation, crossed pin fixation with KFD, two lateral pin fixation, and two lateral pin fixation with KFD, under various mechanical loads. The analysis focused on the stress and strain experienced by the K-wires at the fracture site during torsional and bending forces.ResultsFEA revealed that the KFD significantly reduced the stress and strain on the K-wires in all configurations. In both crossed pin and two lateral pin fixation methods, the addition of the KFD showed lower stress and strain levels compared to setups without the KFD.ConclusionThis study demonstrates the potential of the KFD to enhance fracture stability and reduce mechanical stress at the fracture site, suggesting a promising improvement in the treatment of pediatric supracondylar humeral fractures. This innovation may contribute to safer and more reliable outcomes in pediatric orthopedic surgery.

Signal beam combiners play a pivotal role in enhancing the output power of fiber lasers, which have wide-ranging applications from industrial processing to medical and military uses. This paper explores the influence of fiber twist angle and non-uniform symmetric arrangement on the performance of 19 × 1 fiber signal combiners. A simulation model was developed to analyze the impact of these parameters under adiabatic tapering conditions and the principle of brightness conservation. The model allowed for a systematic investigation of how varying twist angles and non-uniform spacings affect the combiner's performance metrics, such as transmission efficiency and beam quality. The study found that an optimal balance between high transmission efficiency (up to 98.5%) and good beam quality (minimum M2 factor of 1.06) can be achieved when the twist angle is kept below 60° and the non-uniform spacing is maintained within 10–30 μm. These conditions ensure minimal degradation of the beam quality while maximizing the transmission efficiency of the combiner. These findings offer valuable insights into the optimization of signal combiner design, which is critical for advancing high-power fiber laser systems. By carefully controlling the fiber twist angle and non-uniform spacing, designers can achieve superior performance in fiber laser applications, thereby enhancing the overall efficiency and reliability of these systems. This research contributes to the broader field of optical engineering by providing a deeper understanding of the underlying principles that govern the performance of signal combiners.

Acute appendicitis commonly presents with right iliac fossa pain. However, it may present with right scrotal pain and swelling, which may be confused with other scrotal pathologies such as orchitis, scrotal abscess, and testicular torsion. Acute appendicitis in children and adolescents may present with scrotal pain due to inflammatory intraperitoneal fluid tracking down into the scrotal sac via a patent processus vaginalis. In rare cases, acute appendicitis may present concurrently with testicular torsion, making the diagnosis much more challenging. Herein, we present an even rarer case of acute appendicitis with right testicular torsion and concurrent right inguinoscrotal hernia.

An epididymal cyst (EC) is a benign lesion. It arises due to cystic degeneration of the epididymis. The torsion of it is extremely rare. The usual presentation of the cyst is asymptomatic scrotal swelling. The swelling has a lobulated surface and feels like a bunch of grapes. The huge EC is rare and moreover, it is associated with torsion-rarest presentation.

Abstract Background Torsion of the spiral colon (TSC) describes twisting of the spiral colon around its mesentery. The present study reviewed the medical records of 58 cows and heifers with TSC and described the findings, treatment and outcome. Results All cases had an abnormal general condition, and the main vital sign abnormalities were tachycardia (72.4%), tachypnoea (67.2%) and decreased rectal temperature (51.8%). Signs of colic were seen in 62.1% of the cows. The most common intestinal abnormalities were an empty or almost empty rectum (96.6%), reduced or absent rumen motility (93.2%), positive ballottement and/or percussion and simultaneous auscultation on the right side of the abdomen (87.9%), reduced or absent intestinal motility (84.5%) and dilatation of the large intestines (spiral colon and/or caecum, 70.7%) diagnosed by transrectal palpation. The main biochemical changes were hypermagnesaemia (70.8%), hypocalcaemia (70.8%), and acidosis (66.7%). Haemoconcentration was found in 63.8%. The main ultrasonographic findings were reduced to absent small intestinal motility (83.3%), dilated small intestines (69.6%) and ascites (66.7%). The spiral colon was dilated in 44.0% of the cows and the caecum in 24.0%. The actual site of torsion could not be visualised. Based on the clinical findings, TSC was diagnosed in 22.4% and caecal dilatation in 50.0% of the cows. A tentative diagnosis of small intestinal ileus was made in another 10.3% of the cows, and a definitive diagnosis of small intestinal ileus in 17.3%. Fifty-three cows underwent right flank laparotomy, and the TSC could be reduced in 26. Twenty-six of the 58 (44.8%) cows were discharged and 32 (55.2%) were euthanased before, during or after surgery. Conclusions Acute illness, a sparse amount of faeces in the rectum and dilated spiral colon and caecum are characteristic findings of TSC. The final diagnosis often relies on the surgical or postmortem findings. Cattle with TSC should be treated surgically without delay. The prognosis is guarded with a survival rate of 44.8%.

We report on electric, thermal, and optical properties of Si subjected to severe plastic deformation. Single-crystalline Si wafers were processed by high-pressure torsion (HPT) under a nominal pressure of 6 GPa. The HPT-processed samples consisted of metastable body-centered-cubic Si-III and rhombohedral Si-XII as well as diamond-cubic Si-I and amorphous phases. The metastable phases increased with increasing the number of anvil rotations (N). The resistivity of the single-crystalline Si (20 Ω cm) increased to 50 Ω cm after HPT processing for N = 10 and then it decreased to ∼0.7 Ω cm when increasing N to 100. Such an increase and a subsequent decrease in resistivity were attributed to the grain refinement and the increase in the volume fraction of semimetallic Si-III, respectively. The thermal conductivity was reduced by two orders of magnitude (∼3 W m−1 K−1) after HPT processing for N ≥ 50. A weak broad photoluminescence peak originating from Si-I nanograins appeared in the visible light region after annealing at 600 °C. These results indicate that the resistivity, thermal conductivity, and photoluminescence of the HPT-processed Si strongly depend on the formation of metastable phases and grain refinement, which are induced by shear strain under high pressure. [ABSTRACT FROM AUTHOR]

Hydrogen-enriched compressed natural gas (HCNG) technology is one of the most critical developments in the natural gas industry. To ensure the safe utilization of HCNG, the mixing effect of the two gases must be characterized and evaluated. In this paper, five types of static mixers were developed and numerically simulated. The results showed that the velocity, hydrogen blending ratio (HBR), mixer types, element aspect ratio, torsion angle, and number of elements affected the mixing effect to different degrees. Specifically, the increase in velocity and HBR improved the mixing uniformity of hydrogen and methane, but with a limited impact. Additionally, the mixing uniformity increased with the increase in the torsion angle and the number of elements, as well as the decrease in the element aspect ratio. Overall, the torsion angle had the most significant effect on mixing uniformity. Comparing the five types of static mixers, it was found that the new LPD static mixers yielded the best mixing effect, while the Y-type static mixers had the worst mixing effect. It is noted here that all the static mixers could satisfy the mixing uniformity requirements of industrial production. [Display omitted] • The influence of five models on the gas mixing effect is comprehensively analyzed. • The gas mixing effect is analyzed by three evaluation indexes. • The effects of operating conditions and spoilers on the mixing effect are studied. • The new LPD static mixer has the best effect on gas mixing. [ABSTRACT FROM AUTHOR]

High-entropy alloys (HEAs) have garnered significant attention for their exceptional properties, with eutectic high-entropy alloys (EHEAs) emerging as particularly notable due to their incorporation of eutectic structures comprising soft and hard phases. This study investigated the influence of shear strain on the microstructural refinement and mechanical properties of AlCoCrFeNi2.1 EHEAs, which were subjected to high-pressure torsion (HPT) at room temperature under a pressure of 6 GPa across 0.5 to 3 turns, compared to the initial material. After HPT treatment, significant grain refinement occurred due to strong shear strain, evidenced by the absence of B2 phase peaks in X-ray diffraction (XRD) analysis. Microhardness increased substantially post-HPT, reaching a saturation point at approximately 575 HV after three turns, significantly higher than that of the original sample. Moreover, the ultimate tensile strength of HPT-treated specimens reached around 1900 MPa after three revolutions, compared to approximately 1100 MPa for the as-cast alloy, with a mixed fracture mode maintained. This investigation underscores the efficacy of HPT in enhancing the mechanical properties of AlCoCrFeNi2.1 EHEAs through microstructural refinement induced by shear deformation, offering insights into the design and optimization of advanced HEAs for various engineering applications. [ABSTRACT FROM AUTHOR]

AbstractThis work describes the elastokinematic design and optimization for a new, package space saving rear suspension especially intended for small battery electric vehicles. Mainly for reasons of cost and weight efficiency, the twist-beam axle is widely used, especially in the A and B segments. One of the main disadvantages of twist-beam axles is that they limit the rear package space because of the torsion profile. The basic idea of this work was to reverse the installation direction of the twist-beam axle to create an additional package space for the battery. To obtain an optimized elastokinematic design, a new algorithm was introduced that allows modeling of the elastokinematic behavior of the new mechanism. A Pareto optimization of the body connecting bushing was performed, revealing that a specific spatial orientation enables effective compensation for camber compliance deficits. Finally, the Pareto-optimized elastokinematic design was compared to compliance measurement results of a prototype vehicle equipped with the new suspension concept. [ABSTRACT FROM AUTHOR]

The conformal nature of smooth curves in R 3 is characterised by conformal length, curvature and torsion. We present a derivation of these conformal parameters via a limiting process using inscribed polygons with circular edges. The procedure is based on elementary geometry in R 3 only and similar to the rectification of curves in the metrical case. It seems to be not available in the literature so far. [ABSTRACT FROM AUTHOR]

Background: Persistent truncus arteriosus is a rare congenital cyanotic heart defect characterized by a single ventricular outflow tract. Without surgical intervention, it has a poor prognosis in infancy. Here, we report an adult female patient with uncorrected truncus arteriosus type I, who presented with acute-onset abdominal pain due to torsion of a small bowel gastrointestinal stromal tumor (GIST). Case Report: A 41-year-old woman came to our Emergency Department with acute-onset lower abdominal pain for 2 days. Congenital heart disease, truncus arteriosus, had been diagnosed at birth, and there had been no surgical intervention. Abdominal computed tomography revealed a 10×9×12-cm mixed-density mass in the pelvic capacity. Transthoracic echocardiography revealed a 33-mm ventricular septal defect. The ascending aorta originated mainly from the right ventricle, and the pulmonary artery originated from the beginning of the aorta (type I truncus arteriosus, according to Collett and Edwards classification). After a quick and detailed preoperative workup, the patient underwent tumor resection by open surgery with general anesthesia. Conclusions: This is the first case to report emergency surgery for a patient with uncorrected persistent truncus arteriosus due to torsion of a small bowel GIST. A multidisciplinary team with deep understanding of the disease entity was crucial. By considering the fixed hemodynamic and respiratory physiology, overtreatment and unrealistic goals were avoided. Eventually, the patient was discharged after being hospitalized for 2 weeks. [ABSTRACT FROM AUTHOR]

This article, published in Seminars in Musculoskeletal Radiology, explores the relationship between ischiofemoral impingement, femoral torsion, and hip dysplasia. The study involved 101 hips of symptomatic patients with hip dysplasia undergoing periacetabular osteotomy. The researchers found that ischiofemoral edema and signs of ischiofemoral impingement were present in over a third of patients with hip dysplasia and increased femoral torsion. The findings highlight the importance of preoperative hip MRI in detecting these conditions in patients with hip pain and hip dysplasia. [Extracted from the article]

Introduction: Proximal humerus fractures are usually treated with locking plates, which could present recurrence, screw penetration, joint varization. The push–pull principle was introduced to prevent these risks and showed promising results; a dedicated design was then developed and this feasibility study aims to compare the biomechanical performances of such dedicated push–pull plate with the traditional locking plate using finite elements. Materials and methods: The humerus geometry was obtained from Sawbone CT-scans; the geometries of a traditional locking plate and of the dedicated push–pull one were used. A fracture was added below the humeral head and the plates were virtually implanted. The wire pulling mechanism was simulated connecting the plate to the humeral head apex, considering two levels of tension. Three testing set-ups (axial, torsion and compression bending) were simulated. Stress distributions on bone, plate and screws were measured. Results: Stress distribution on the distal humerus was similar for both plates. Stress distribution on the proximal humerus was more homogeneous for the push–pull model, showing less unloaded sections (up to 78%). The different levels of tension applied to the wire returned slight differences in terms of stress values, but the comparison with the traditional approach gave similar outcomes. Conclusions: More homogeneous stress distribution is found with the push–pull plate in all three testing set-ups, showing lower unloaded areas (and thus lower stress-shielding) compared to the traditional plate; the screws implemented returned to be all loaded in at least one of the set-ups, thus showing that they all contribute to plate stability. [ABSTRACT FROM AUTHOR]

We study curve-shortening flow for twisted curves in $\mathbb {R}^3$ (that is, curves with nowhere vanishing curvature $\kappa $ and torsion $\tau $) and define a notion of torsion-curvature entropy. Using this functional, we show that either the curve develops an inflection point or the eventual singularity is highly irregular (and likely impossible). In particular, it must be a Type-II singularity which admits sequences along which ${\tau }/{\kappa ^2} \to \infty $. This contrasts strongly with Altschuler's planarity theorem, which shows that ${\tau }/{\kappa } \to 0$ along any essential blow-up sequence. [ABSTRACT FROM AUTHOR]

In order to promote stirrup yielding prior to concrete crushing and avoid over-reinforcement failure modes in reinforced concrete (RC) members, current design codes stipulate limits on the maximum amount of shear and torsional reinforcement. Studies have shown that the shear strength limits introduced based on the plane-truss approach estimate the maximum shear strength and shear failure mode with reasonable accuracy. However, the torsional strength limits derived based on the space-truss analogy and thin-walled tube theory generally overestimate the maximum torsional strength. In this study, the difference between the limiting values introduced in current design codes on the maximum shear and torsional strengths was evaluated by analysing the test results of 406 shear and 153 torsional members. Additionally, experimental tests were conducted on 22 RC beams subjected to torsional moments in order to measure the strain rate of the web concrete directly and investigate the torsional strength limits. The torsional strength limits derived based on the space-truss model overestimated the actual maximum torsional strength. Based on these observations, a lower limit for the maximum torsional strength is proposed in order to avoid over-reinforced torsional failure. [ABSTRACT FROM AUTHOR]

Ocular torsion and vertical divergence reflect the brain's sensorimotor integration of motion through the vestibulo-ocular reflex (VOR) and the optokinetic reflex (OKR) to roll rotations. Torsion and vergence however express different response patterns depending on several motion variables, but research on their temporal dynamics remains limited. This study investigated the onset times of ocular torsion (OT) and vertical vergence (VV) during visual, vestibular, and visuovestibular motion, as well as their relative decay rates following prolonged optokinetic stimulations. Temporal characteristics were retrieved from three separate investigations where the level of visual clutter and acceleration were controlled. Video eye-tracking was used to retrieve the eye-movement parameters from a total of 41 healthy participants across all trials. Ocular torsion consistently initiated earlier than vertical vergence, particularly evident under intensified visual information density, and higher clutter levels were associated with more balanced decay rates. Additionally, stimulation modality and accelerations affected the onsets of both eye movements, with visuovestibular motion triggering earlier responses compared to vestibular motion, and increased accelerations leading to earlier onsets for both movements. The present study showed that joint visuovestibular responses produced more rapid onsets, indicating a synergetic sensorimotor process. It also showed that visual content acted as a fusional force during the decay period, and imposed greater influence over the torsional onset compared to vergence. Acceleration, by contrast, did not affect the temporal relationship between the two eye movements. Altogether, these findings provide insights into the sensorimotor integration of the vestibulo-ocular and optokinetic reflex arcs. [ABSTRACT FROM AUTHOR]

This article presents an elastic-gap free isotropic higher-order strain gradient plasticity theory that effectively captures dissipation associated to plastic strain gradients. Unlike conventional methods that divide the higher-order stress, this theory focuses on dividing the plastic strain gradient into energetic and dissipative components. The moment stress that arises from minimizing a dissipating potential demonstrates a nonlinear evolution over time, resembling the Armstrong-Frederick nonlinear kinematic hardening rule in classical plasticity. The thermodynamically consistent framework establishes additional dissipation in the dissipation inequality. The energetic moment stress saturates as the effective plastic strain increases during plastic flow. In contrast to the Gurtin-type nonincremental model, the proposed model smoothly captures the apparent strengthening at saturation without causing a stress jump. A passivated shear layer is analytically assessed to demonstrate that the proposed theory exhibits the same amount of dissipation as the existing Gurtin-type model when they show similar shear responses at saturation. It is also shown that the plastic flow remains continuous under nonproportional loading conditions using an intermediately passivated shear layer problem. Finally, the proposed theory is validated against a recent experiment involving combined bending torsion of an L-shaped beam using a 3D finite element solution. Overall, the proposed model provides an alternative approach to evaluating the size effect within the nonincremental isotropic strain gradient plasticity theory without introducing any stress jump. [ABSTRACT FROM AUTHOR]