Single Rod Research Articles

Fuel performance modelling of Cr-coated Zircaloy cladding under DBA/LOCA conditions

Chromium coatings are being developed for advanced technology fuel (ATF) claddings, offering negligible corrosion during normal operation, improved resistance to high-temperature steam oxidation, and superior high-temperature strength, the latter two being of utmost relevance during design basis accidents (DBAs). Demonstrating the improved response of Cr-coated Zircaloy requires the development or extension of fuel performance codes to coating simulations.In this work, material models and correlations for Cr-coated Zircaloy cladding have been derived or obtained from the literature and implemented into TRANSURANUS and the FRAPTRAN-TUmech suite. These extended tools have been used to simulate two complementary LOCA tests: QUENCH-L1 rod 4 (out-of-pile bundle test on fresh Zircaloy cladding) and IFA-650.10 (in-pile single rod test on high-burnup Zircaloy-UO2 fuel), enabling a gradual cross-verification of results between codes and a comparative performance analysis between coated and uncoated cladding.The results indicate negligible impact of coating properties other than creep on the burst time. While the superior high-temperature creep resistance of coated cladding slightly delays the burst time, additional burst data would be necessary to draw sound conclusions on the balloon size. Regarding the modelling approach, treating the coated cladding as a composite material through the definition of effective properties might result in worse performance relative to uncoated cladding, contradicting experimental observations. Therefore, the separate modelling of the coating and the cladding is recommended.

Numerical investigation of drag reduction effects on a track bicycle fork using wings with a wavy leading edge

AbstractReynolds‐averaged Navier–Stokes (RANS) and large‐eddy simulations (LES) of the flow around wings with a wavy leading edge (WLE) are conducted in order to assess the capabilities of a passive flow control strategy for drag reduction. The intended application is indoor track cycling with controlled flow conditions. A section of a single fork rod is investigated in order to make the numerical simulations feasible. The present study reveals that net drag reduction is possible by a nonsinusoidal modification of the leading edge of the wing. However, the drag reduction effect remains limited to a few percent. While RANS and LES yield the same drag coefficient for a reference case, RANS underestimates the drag reduction effect for a longer wing and the WLE cases, but exhibits otherwise a qualitatively similar trend as the LES. With the aid of RANS, an optimal geometry is obtained defined by the wavelength‐to‐chord length ratio of and the amplitude‐to‐chord length ratio of . Corresponding LES results give an indication of the origin of drag reduction by a hampered vortex shedding. The generation of smaller and more streamwise oriented vortical flow structures at the trailing edge and behind the WLE wing is correlated with significantly reduced lift fluctuations and drag reduction.

Validity of machine learning algorithms for automatically extract growing rod length on radiographs in children with early-onset scoliosis.

The magnetically controlled growing rod technique is an effective surgical treatment for children who have early-onset scoliosis. The length of the instrumented growing rods is adjusted regularly to compensate for the normal growth of these patients. Manual measurement of rod length on posteroanterior spine radiographs is subjective and time-consuming. A machine learning (ML) system using a deep learning approach was developed to automatically measure the adjusted rod length. Three ML models-rod model, 58mm model, and head-piece model-were developed to extract the rod length from radiographs. Three-hundred and eighty-seven radiographs were used for model development, and 60 radiographs with 118 rods were separated for final testing. The average precision (AP), the mean absolute difference (MAD) ± standard deviation (SD), and the inter-method correlation coefficient (ICC[2,1]) between the manual and artificial intelligence (AI) adjustment measurements were used to evaluate the developed method. The AP of the 3 models were 67.6%, 94.8%, and 86.3%, respectively. The MAD ± SD of the rod length change was 0.98 ± 0.88mm, and the ICC[2,1] was 0.90. The average time to output a single rod measurement was 6.1s. The developed AI provided an accurate and reliable method to detect the rod length automatically.

Design and Simulation of Adiabatic–Damping Dual–Function Strut for LH2 Storage Tank

In the process of the on–board transportation of liquid hydrogen storage and transportation tanks, apart from considering the support strength and adiabatic performance, it is imperative to take into account the vibration characteristics of the carrying platform. The present work introduces a versatile support structure comprising a damping module and a ball contact insulation structure, enabling effective isolation of external vibrations while simultaneously providing support and insulation. The first step involves describing the principle of a flexible support structure and designing the mechanical structure. Subsequently, a damping analysis is conducted based on dynamic theory to establish the relationship between the spring and damping. Finally, the structural parameters of the dual–function strut are determined, followed by simulation of heat transfer performance. The results demonstrate that the dual–function strut exhibits exceptional vibration damping performance by reducing the amplitude of external vibrations greater than 5 Hz to less than 6%. Moreover, owing to the compact linear diameter spring structure of the vibration damping module and its ball contact effect, the thermal resistance of the dual–function strut is significantly enhanced, resulting in a mere heat leakage of only 22 W/m2 in a single rod section.

Design and analysis of sensor structure based on ultrasonic temperature measurement

Abstract Based on the principle of ultrasonic temperature measurement, this paper designs the structure of a waveguide rod sensor with a reflective groove. Using multi-physics field simulation software to conduct acoustic thermal coupling parametric simulation analysis on six different high melting point materials, we obtain the curve functions of the relationship between sound velocity and temperature for the six materials and verify the feasibility of ultrasonic temperature measurement using waveguide rods. Analysis shows that the sensitivity of six alloys to temperature changes is as follows: Ti6Al4V titanium alloy > α-Al2O3 > Inconel693 nickel-based alloy > ThO2 > Tungsten-rhenium alloy > Ta8W2Hf. At the same time, three different shapes of waveguide rods were designed: single groove waveguide rod, multi-zone waveguide rod, and spiral waveguide rod to analyze the impact of temperature measurement accuracy. The research results have important theoretical guidance significance for solving the problem of temperature measurement in high-temperature environments.

Simulation of natural convection flow for vertical heated rod by using ANSYS/Fluent

The decay heat removal by natural convection is very important in case of Station blackout (SBO) of nuclear reactor. The computational fluid dynamic (CFD) is helpful to simulate the flow and temperature field. However, the CFD simulation models need to be validated by the experimental data. Thus, in this report, the Anslys/Fluent is applied to simulate the natural convection induced by single heater rod. The vertical heated rod with a diameter of 12 mm and a length of 225 mm is immersed at the center of a vertical pipe made of acrylic with a diameter of 146 mm and a height of 500 mm. In this simulation, the coupled scheme algorithm is also applied. Regarding to experimental method, the optical method such as Particle Image Velocimetry (PIV) was applied for 2-dimensional velocity distribution and pointwise temperature measurement. As a result, the predicted flow and temperature field are well agreed with experimental data. Accordingly, the thermal plumes are well estimated by ANSYS/Fluent, in which the buoyant plumes induced by different temperatures vertically go up along the heater rod's upper part until the container's isolated upper wall. The complicated flow occurs in the middle part of the container by mixing the downward flow on the top and the upward flow from the heater rod.

Threshold of Keulegan–Carpenter instability within a 6 × 6 rod bundle

The literature is rich in fluid–structure interaction studies of a single rod in oscillating fluid (or the reciprocate), however, there is a dearth of experimental data for rod bundle oscillation, particularly if the bundle is in a confined environment. The presence of the fluid surrounding the moving solid is modeled with force coefficients such as inertial and drag. In case of small amplitudes oscillating flow, these force coefficients depend non-linearly on the Keulegan–Carpenter number KC. The dependence present different regimes, separated by threshold KC numbers. At different regimes correspond different fluid dynamics, hence different force coefficients. The aim of this paper is to experimentally investigate the fluid dynamic for a rod bundle oscillating in a stagnant fluid. The velocity fields have been measured with Particle Image Velocimetry (PIV). Both the rod bundle and the fluid have the same refractive index, which allow to measure the velocity fields within the rod bundle in an non intrusive manner. The bundle is hosted in a double tank, immersed in a refractive index matched solution and placed on an earthquake shake table. The shake table sets the bundle into motion along a single direction.Data enable the identification of a threshold effect in the fluid response to the oscillating assembly. This threshold effect is due to the formation of vortexes in the fluid. Data show a clear trend on how the development of turbulence occurs firstly inside the rod assembly and then in the bypass between the assembly and the tank wall. The experimental results indicate the presence of a viscous boundary layer developed along the rod, above the threshold KC. The results presented in this paper represent a step forward the comprehension of the damping effect induced by the fluid at different oscillating amplitudes and frequencies, due to different KC regimes.

High throughput automated characterization of enamel microstructure using synchrotron tomography and optical flow imaging

The remarkable damage-tolerance of enamel has been attributed to its hierarchical microstructure and the organized bands of decussated rods. A thorough characterization of the microscale rod evolution within the enamel is needed to elucidate this complex structure. While prior efforts in this area have made use of single particle tracking to track a single rod evolution to various degrees of success, such a process can be both computationally and labor intensive, limited to the evolution path of a single rod, and is therefore prone to error from potentially tracking outliers. Particle image velocimetry (PIV) is a well-established algorithm to derive field information from image sequences for processes that are time-dependent, such as fluid flows and structural deformation. In this work, we demonstrate the use of PIV in extracting the full-field microstructural distribution of rods within the enamel. Enamel samples from a wild African lion were analyzed using high-energy synchrotron X-ray micro-tomography. Results from the PIV analysis provide sufficient full-field information to reconstruct the growth of individual rods that can potentially enable rapid analysis of complex microstructures from high resolution synchrotron datasets. Such information can serve as a template for designing damage-tolerant bioinspired structures for advanced manufacturing. Statement of significanceThorough characterization and analysis of biological microstructures (viz. dental enamel) allows us to understand the basis of their excellent mechanical properties. Prior efforts have successfully replicated these microstructures via single particle tracking, but the process is computationally and labor intensive. In this work, optical flow imaging algorithms were used to extract full-field microstructural distribution of enamel rods from synchrotron X-ray computed tomography datasets, and a field method was used to reconstruct the growth of individual rods. Such high throughput information allows for the rapid production/prototyping and advanced manufacturing of damage-tolerant bioinspired structures for specific engineering applications. Furthermore, the algorithms used herein are freely available and open source to broaden the availability of the proposed workflow to the general scientific community.

Microstructure, mechanical properties, and fracture behavior of multi-core through steel wire reinforced brass composite rod produced by a solid-liquid continuous casting and composite technique

A multi-core through steel wire reinforced brass composite rod was fabricated using a solid-liquid continuous casting and composite technique. Microstructure evolution, interface, mechanical properties, and deformation behavior of the composite rod during the room temperature tensile process were studied. The results showed that the steel wires in the composite rod were distributed in a regular hexagonal shape, forming a brass/steel interface with good metallurgical bonding. After annealing at 700 °C for 1h, the tensile strength of the composite rod was 376 MPa, and the elongation to failure was 46.3 %, whose tensile strength was 21 % higher than that of the brass cladding single steel wire composite rod with the same steel percentage. During uniform tensile deformation, each steel wire in the composite rod experienced a consistent and uniform tensile stress. When the tensile deformation became unstable, the central steel wire experienced the highest level of tensile stress, initially leading to the occurrence of necking and fracture. As the tensile strain increased, the brass grains underwent twisting and rotation. In addition, the steel grains were elongated along the tension direction, and the number of low-angle boundaries increased. The straight brass/steel interface was transformed into a wavy pattern with a good bonding interface, indicating that the composite rod exhibited excellent synergetic deformation capability. The mixing laws based on hybrid effects have good applicability to multi-core through steel wire reinforced brass composite rod, with a strength error of less than 7 %.

Torque‐tuned I‐V characteristics in a piezoelectric semiconductor composite fiber

AbstractThis paper studies the multi‐physical fields in a torsional composite fiber composed of a non‐piezoelectric semiconductor (PS) core coated with a piezoelectric dielectric shell. Based on the three‐dimensional framework of piezoelectricity and drift‐diffusion theory, we develop a nonlinear one‐dimensional model that incorporates the warping deformation, shear deformation, and axial variations of the electric field and charge transportations. A One‐dimensional model is linearized for small perturbations of charges, and we obtain the analytical solutions for single rods or PN junctions when torques are applied, which explicitly illustrates the electromechanical fields and redistribution of mobile charges. We also examine how the thickness of the composite rods affects the interaction between the piezoelectric and semiconductor components in the model. The optimal thickness ratio for maximizing the overall mobility of carriers has been discovered. This enables us to modify the thickness ratio to achieve the greatest PS interaction performance. Based on the nonlinear equations, we analyze the relationships between electric currents and applied voltages on the end of rods. Finally, we examine how twisting moments influence the characteristics of this I‐V relationship. The presented study provides a potential application for mechanical switches or sensors for PSs.

Numerical simulation of fluid-vegetation coupled dynamic using a promoted semi-resolved coupling model

Flexible vegetation is an important component of riverine and coastal ecosystems. The numerical simulation is difficult due to the complex motions of flexible vegetation and fluid. In this work, a semi-resolved numerical model coupling the computational fluid dynamics (CFD) and flexible rod dynamics (FRD) using a promoted two-way domain expansion method was proposed with the accuracy of the resolved model and the efficiency of the unresolved model. The governing equations of the flexible rod dynamics are solved by the finite element method (FEM). The effect of vegetation is added as source terms to the Reynolds-averaged Navier-Stokes equations, which are discretized and solved by the finite volume method (FVM). The anisotropic Gaussian kernel function is adopted to calculate the interactive forces between the fluid and the flexible rod with an anisotropic cross-section. The model was first validated by simulating the flow passing through a single flexible rod with a rectangular cross-section. Meanwhile, the main factors were calibrated. The engineering application of the model was further validated by simulating the flow passing through a finite patch of flexible vegetation. These results indicate that the proposed model could well simulate the open channel flows with the flexible vegetation.

삼국시대 복환판비의 전개 과정과 의미 —남원 두락리 고분군 출토품을 중심으로—

The double ring bit is a bit made of a single iron rod. In this paper, the current status and development of the double ring bits excavated from the southern part of the Korean Peninsula and the Japanese Archipelago are summarized. Based on this, the archaeological significance of the double ring bits of Durak-ri, Namwon, are examined. The double ring bits of the Korean Peninsula were mainly used in Silla and Gaya from the early fifth to the late seventh centuries. They can be classified into Silla or Gaya double ring bits according to the connection method (the presence or absence of a ring); the guard in the bit of the ‘Ga’ type double ring bit reflects the change over time. It seems that the technology for producing the ‘Ga’ and ‘Na’ types, which originated in Silla, spread to Gaya from the early 6th century to the first half of the 6th century, when Silla and Gaya maintained a friendly relationship. The double ring bits excavated from the Japanese Archipelago are not much different from those of Korea. The Japanese Archipelago double ring bits have many things in common with domestic examples, such as the use of the type ‘Ga’ to ‘Da’ types. However, in the Japanese Archipelago, ‘Da’ type examples were used from an early age, and the forms that were popular in Korea and their period of use were different. There is also the ‘Ra’ type that is not observed in Korea. The double ring bit excavated from the Durak-ri tombs, in Namwon, are of the ‘Ga-3’ type, used only around the early 6th century in East Asia. Therefore, the age of the ancient tomb can be estimated based on the double ring bits. Although the ‘Ga-3’ type is of Silla origin, the excavation of the Durak-ri tombs suggests that the artifacts may have been produced locally in the Unbong Plateau through the adoption of improved production technologies from Hapcheon, which was well equipped with a high-level ironmaking technological system. The bits not only demonstrate the friendly foreign relations between Silla and Gaya from the early to the first half of the 6th century, but also illustrate the acceptance process of the latest harness manufacturing technology from Hapcheon.

Pipe to annular flow conversion: Numerical study

Large Eddy Simulation (LES) of turbulent flow at the entrance to an annular pipe section has been performed. The flow over a single circular rod, coaxially immersed in a circular pipe is considered. The Reynolds number, based on mean velocity and hydraulic diameter of the annular section, is ReDh=40530. The study aims to gain insights into the turbulence characteristics of the primary and secondary separation bubbles, developing on a side surface of the rod. Key findings include tiny toroidal vortices in the primary bubble's front, forming a vortex train with intermittently shed vortex structures. Large-scale helical stripes have been reproduced at the entrance to the annular section. Tilting of the axially-oriented streaks was observed close to the rod surface. It resulted in a slight anisotropy of the normal Reynolds stresses. The LES data could refine classic Reynolds-averaged Navier-Stokes-based turbulence models.

Radiological Outcomes of Magnetically Controlled Growing Rods for the Treatment of Children with Various Etiologies of Early-Onset Scoliosis-A Multicenter Study.

Background: The management of spinal deformities diagnosed before the age of 10 is critical due to the child's development, skeletal system, and growth mechanism. Magnetically controlled growing rods (MCGRs) are a surgical treatment option for the growing spine. The aim of this study was to analyze the radiological findings of patients treated with MCGRs for early-onset scoliosis (EOS) of various etiologies. We hypothesized that the MCGRs could provide acceptable long-term radiographic results, such as an increase in the T1-T12 and T1-S1 height and significant overall deformity correction. Methods: We retrospectively reviewed 161 EOS patients with a combined total of 302 MCGRs inserted at five institutions between 2016 and 2022 with a mean follow-up of at least two years. The Cobb angle of the major curve (MC), thoracic kyphosis (TK), lumbar lordosis (LL), and T1-T12 and T1-S1 height measurements were assessed before, after, and during the follow-up. Results: Among the 90 female and 71 male patients, there were 51 neurological, 42 syndromic, 58 idiopathic, and ten congenital scoliosis etiologies. Of the patients, 73 were aged under six years old. The mean follow-up time was 32.8 months. The mean age at placement of the MCGRs was 7 years and that at the last follow-up after fusion surgery was 14.5 years. The mean MC before the initial surgery was 86.2°; following rod implantation, it was 46.9°, and at the last follow-up visit, it was 45.8°. The mean correction rate among the etiology subgroups was from 43% to 50% at follow-up. The mean TK was noted as 47.2° before MCGR implantation, 47.1° after MCGR placement, and 44.5° at the last follow-up visit. The mean T1-T12 height increased by 5.95 mm per year, with a mean T1-S1 height of 10.1 mm per year. Conclusions: MCGR treatment allowed for an average correction of the curvature by 50% during the period of lengthening, while controlling any deformity and growth of the spine, with a significant increase in the T1-T12 and T1-S1 values during the observation period. MCGR treatment in EOS carries a risk of complications. While congenital and syndromic EOS often have short and less flexible curves in those groups of patients, single rods can be as effective and safe. Definitive fusion results in the mean final coronal correction between the start of MCGR treatment and after undergoing PSF of approximately 70%. The mean T1-T12 spinal height increased by 75 mm, while the T1-S1 spinal height gained a mean of 97 mm.

Light and electron microscopic observations on retinal neurons of red-tail shark (Epalzeorhynchos bicolor H. M. Smith, 1931).

The structure of photoreceptors (PR) and the arrangement of neurons in the retina of red-tail shark were investigated using light and electron microscopy. The PR showed a mosaic arrangement and included double cones, single cones (SC), and single rods. Most cones occur as SC. The ratio between the number of cones and rods was 3:1.39 (±0.29). The rods were tall that reached the pigmented epithelium. The outer plexiform layer (OPL) showed a complex synaptic connection between the horizontal and photoreceptor terminals that were surrounded by Müller cell processes. Electron microscopy showed that the OPL possessed both cone pedicles and rod spherules. Each rod spherule consisted of a single synaptic ribbon within the invaginating terminal endings of the horizontal cell (hc) processes. In contrast, the cone pedicles possessed many synaptic ribbons within their junctional complexes. The inner nuclear layer consisted of bipolar, amacrine, Müller cells, and hc. Müller cells possessed intermediate filaments and cell processes that can reach the outer limiting membrane and form connections with each other by desmosomes. The ganglion cells were large multipolar cells with a spherical nucleus and Nissl' bodies in their cytoplasm. The presence of different types of cones arranged in a mosaic pattern in the retina of this species favors the spatial resolution of visual objects. RESEARCH HIGHLIGHTS: This is the first study demonstrating the structure and arrangement of retinal neurons of red-tail shark using light and electron microscopy. The current study showed the presence of different types of cones arranged in a mosaic pattern that may favor the spatial resolution of visual objects in this species. The bipolar, amacrine, Müller, and horizontal cells could be demonstrated.

Finite Element Analysis of Bilateral Double Rod Constructs in Thoracolumbar Fractures.

To evaluate bilateral double rod contructs in thoracolumbar fractures in a Finite Element model MATERIAL and METHODS: A computed tomography of a 35-year old male have been chosen to create a vertebra model and 1/3 of the T12 was removed to create the burst fracture model. In model A, transpedicular polyaxial screws were inserted two levels above and two levels below the burst fracture. On each side the screws were connected with a single rod. In model B, the screws were connected with two rods on each side attached to two lateral connectors. A uniform 150 N axial load and 10 N/m torque was applied on the superior T10. ROM and von Mises stress nephrograms revealed that the bilateral double-rod construct is being the most rigid and that the force on the pedicle screws were significantly lower compared to model A. We believe that bilateral double-rod constructs for the stabilization of thoracolumbar fractures have a decreased load on pedicle screws and rods compared to the classic bilateral single rod stabilization system and can lower the risk of implant failure and the risk for secondary complications and revision surgery.

Design of an Asymmetric Damping Structure for a Single Cylinder and Single Rod MR Damper

Design of an Asymmetric Damping Structure for a Single Cylinder and Single Rod MR Damper

Experimental study on flow-induced vibration of single rod in axial flow

In this inquiry, a comprehensive experimental exploration delves into the flow-induced vibration traits of individual rods across varying circumstances. Utilizing a Laser Doppler Vibrometer (LDV), we measure vibration responses in diverse materials and structures of single rods, under varied constraint modes and inlet velocities ranging from 1 to 3 m/s. Statistical analyses, including root mean square and empirical mode decomposition (EMD), elucidate the acquired outcomes. Notably, results manifest an 84 % reduction in single-rod amplitude when under fixed support constraints compared to simple support. Varied vibration frequencies, attributed to distinct elastic moduli of materials, emerge as characteristics of these rods. A wire-wrapped configuration emerges as a consequential influencer on single-rod vibration, yielding a peak amplitude of 186.3 μm. This research sheds light on axial flow-induced vibration traits, thus furnishing a cornerstone for forthcoming explorations in this realm.

Interaction of Y and impurity P on the synergistic enhancement of elongation and electrical conductivity of single crystal copper rod

Single-crystal copper rods with high conductivity and mechanical properties are the decisive material for the production of microwires for chip bonding. To further improve the product of strength and elongation as well as electrical conductivity, rare earth Y is added to a single-crystal copper rod to adjust the microstructure and impurity state. The results show that Cu-0.03Y copper rods have excellent comprehensive properties. The electrical conductivity improves to 103.72 % IACS, and the product of strength and elongation improves to 8.772 GPa%. The precipitates in the Cu-0.03Y single crystal copper rod are nano-sized spherical particles composed of YP (NaCl type) and Cu5Y (Cu5Ca type) phases. The enthalpy of formation of Y and P is calculated using Miedema thermodynamics as ΔH = −173.45 kJ·mol−1. The precipitates formed by the preferential reaction of Y and P reduce the solid dissolved atoms in the copper, and the electrical conductivity increases accordingly. The 〈001〉 texture of a single-crystal copper rod decreases with the addition of Y, while the 〈101〉 texture increases with good plasticity, leading to an improvement in elongation.

Poster Session II: Investigating photoreceptor function in disease-affected retinas using optoretinography.

Assessing the functional response of photoreceptors is vital in understanding retinal disease progression. Traditional subjective methods like visual acuity and visual fields, and objective ones like electroretinography, have limitations. An ideal complement to these techniques is optoretinography (ORG), which images the retina and tests its function at once. ORG utilizes the phase of the optical coherence tomography (OCT) signal to quantify nanometer-scale changes, measuring subtle photoreceptor responses to stimuli. Efforts to observe stimulus-evoked responses in human cone photoreceptors began with adaptive optics (AO) and common path interferometry, enabling the resolution and tracking of individual cells. Advances in OCT systems with cellular resolution through AO or digital aberration correction successfully measured ORG responses from single cones and rods. This method tracks phase differences between outer segment tips (COST or ROST) and the inner-outer segment junction (IS/OS) to assess individual cell responses. A novel velocity-based method recently demonstrated the feasibility of measuring ORG signals with clinical-grade OCT systems. In the present work, we implemented this technique on disease-affected human retinas, revealing lower magnitudes of response compared to healthy retinas, and highlighting its potential clinical applications.