Line Junction Research Articles

A new method for the prediction of vibration responses of thin plates coupled with discontinuous connections

Due to the limitation caused by the assumption of ideal continuous line junctions between plates or the high computation cost, the existing methods cannot provide reliable prediction solutions of vibration responses of coupled plates with real connections, such as bolts and corner irons. To this end, a discontinuous energy finite element analysis (dEFEA) method with high accuracy is proposed to predict the vibration responses of discontinuously connected plates, which can revert the real connection. This method developes the coupling loss factors (CLFs) on the steady-state energy flow technique to characterize vibration transmission between plates with different connections. In addition, a discontinuous energy finite element equation of coupled plates is established to obtain the vibration responses of those. The efficacy of the dEFEA method is demonstrated by experiments and the method can improve the prediction accuracy of vibration, which is verified by the comparison between discontinuous and ideal continuous connections. To sum up, vibration transmission of connected structures varies greatly depending on the way of connection and cannot be simplified to a line connection.

On the Water Jet Quality at Part-Load Operation of Pelton turbines

Abstract Pelton turbines with multiple nozzles are characterised by their excellent performance over a wide operating range of mass flow rates. Thus, Pelton turbine manifolds must also be designed to deliver good flow quality to the nozzles at part-load operating conditions to accomplish the expectations. A reduced number of nozzles are opened at low mass flow rate operating conditions, where the choice of the open nozzles depends on the water jet quality generated at the individual nozzles. We investigate the flow phenomena occurring in the manifold with the operation of a reduced nozzle number employing numerical simulations to analyse beneficial nozzle opening selections. The turbulent two-phase flow is predicted by the Volume-Of-Fluid (VOF) approach and the k–ω SST turbulence closure model. Different nozzle operating scenarios are simulated, and the implications on the water jet quality, i.e. deviation and shape deformation, are reported. The results show that the free water jet quality criteria can change drastically at individual nozzle operating conditions because of the velocity changes at the branch line junctions.

Characterization of two distinct immortalized endothelial cell lines, EA.hy926 and HMEC-1, for in vitro studies: exploring the impact of calcium electroporation, Ca2+ signaling and transcriptomic profiles

BackgroundDisruption of Ca2+ homeostasis after calcium electroporation (CaEP) in tumors has been shown to elicit an enhanced antitumor effect with varying impacts on healthy tissue, such as endothelium. Therefore, our study aimed to determine differences in Ca2+ kinetics and gene expression involved in the regulation of Ca2+ signaling and homeostasis, as well as effects of CaEP on cytoskeleton and adherens junctions of the established endothelial cell lines EA.hy926 and HMEC-1.MethodsCaEP was performed on EA.hy926 and HMEC-1 cells with increasing Ca2+ concentrations. Viability after CaEP was assessed using Presto Blue, while the effect on cytoskeleton and adherens junctions was evaluated via immunofluorescence staining (F-actin, α-tubulin, VE-cadherin). Differences in intracellular Ca2+ regulation ([Ca2+]i) were determined with spectrofluorometric measurements using Fura-2-AM, exposing cells to DPBS, ionomycin, thapsigargin, ATP, bradykinin, angiotensin II, acetylcholine, LaCl3, and GdCl3. Molecular distinctions were identified by analyzing differentially expressed genes and pathways related to the cytoskeleton and Ca2+ signaling through RNA sequencing.ResultsEA.hy926 cells, at increasing Ca2+ concentrations, displayed higher CaEP susceptibility and lower survival than HMEC-1. Immunofluorescence confirmed CaEP-induced, time- and Ca2+-dependent morphological changes in EA.hy926’s actin filaments, microtubules, and cell–cell junctions. Spectrofluorometric Ca2+ kinetics showed higher amplitudes in Ca2+ responses in EA.hy926 exposed to buffer, G protein coupled receptor agonists, bradykinin, and angiotensin II compared to HMEC-1. HMEC-1 exhibited significantly higher [Ca2+]i changes after ionomycin exposure, while responses to thapsigargin, ATP, and acetylcholine were similar in both cell lines. ATP without extracellular Ca2+ ions induced a significantly higher [Ca2+]i rise in EA.hy926, suggesting purinergic ionotropic P2X and metabotropic P2Y receptor activation. RNA-sequencing analysis showed significant differences in cytoskeleton- and Ca2+-related gene expression, highlighting upregulation of ORAI2, TRPC1, TRPM2, CNGA3, TRPM6, and downregulation of TRPV4 and TRPC4 in EA.hy926 versus HMEC-1. Moreover, KEGG analysis showed upregulated Ca2+ import and downregulated export genes in EA.hy926.ConclusionsOur finding show that significant differences in CaEP response and [Ca2+]i regulation exist between EA.hy926 and HMEC-1, which may be attributed to distinct transcriptomic profiles. EA.hy926, compared to HMEC-1, displayed higher susceptibility and sensitivity to [Ca2+]i changes, which may be linked to overexpression of Ca2+-related genes and an inability to mitigate changes in [Ca2+]i. The study offers a bioinformatic basis for selecting EC models based on research objectives.

Development and Testing of a System Thermal-Hydraulics Model for a 50-MWel-Class Pressurized Water Reactor–Small Modular Reactor

Abstract This paper describes the development, analysis, testing of a RELAP5-3D system thermal-hydraulics model for a 50-MWel-class pressurized water reactor–small modular reactor (PWR–SMR), similar to that by NuScale Power. This study focuses on a series of sensitivity tests to investigate the impacts of model changes. Parameters considered in the sensitivity study included the surge line junction resistance (SLJR), steam generator (SG) heat transfer area (SGHTA), SG primary flow area (SGPFA), SG secondary pressure (SGSP), and SG secondary flowrate (SGSF). Results for the reference and sensitivity simulations are compared with available design data. The flow in the primary circuit of the PWR–SMR is driven by natural circulation and can be sensitive to changes in hydraulic resistance and pressure drop in system components. Initial analysis results demonstrated significant flow oscillations. As a result of sensitivity studies, it was found that the surge line junction resistance needed to be increased by increasing the form loss coefficient from 4.9 to 30.0, to reduce mass flow oscillation amplitude to less than ±2%. Modifications to the steam generator heat transfer area, primary flow area, or secondary pressure have very little impact in reducing flow oscillations. However, it was found that the steam generator secondary flowrate will affect primary circuit flow oscillations, and when the SGSF was artificially increased from 68 kg/s (design data) to 91 kg/s (a 36% increase), the oscillations were eliminated, along with better matching with design data for core flowrate and inlet/outlet temperatures. Further improvements to the model for the steam generator will be required.

Holistically-Attracted Wireframe Parsing: From Supervised to Self-Supervised Learning.

This article presents Holistically-Attracted Wireframe Parsing (HAWP), a method for geometric analysis of 2D images containing wireframes formed by line segments and junctions. HAWP utilizes a parsimonious Holistic Attraction (HAT) field representation that encodes line segments using a closed-form 4D geometric vector field. The proposed HAWP consists of three sequential components empowered by end-to-end and HAT-driven designs: (1) generating a dense set of line segments from HAT fields and endpoint proposals from heatmaps, (2) binding the dense line segments to sparse endpoint proposals to produce initial wireframes, and (3) filtering false positive proposals through a novel endpoint-decoupled line-of-interest aligning (EPD LOIAlign) module that captures the co-occurrence between endpoint proposals and HAT fields for better verification. Thanks to our novel designs, HAWPv2 shows strong performance in fully supervised learning, while HAWPv3 excels in self-supervised learning, achieving superior repeatability scores and efficient training (24 GPU hours on a single GPU). Furthermore, HAWPv3 exhibits a promising potential for wireframe parsing in out-of-distribution images without providing ground truth labels of wireframes.

A novel parallel constrained extended Kalman filter for improving navigation algorithm – case study: gas pipeline

In many real navigation problems, moving objects may have some state or measurement constraints along their way. Using these constraints in conventional Extended Kalman Filter (EKF) equations results large matrices which are computationally time-consuming. In this paper, a new Constrained Navigation Filter (CNF) is proposed as a parallel to reduce the computational burden of the conventional EKF algorithm while increasing the positioning accuracy. So a methodology has been developed for Strap-down Inertial Navigation System (SINS) based on MEMS IMU applied on Pipeline Inspection Gauge (PIG) to sense data at constant sampling rate of 108 km of the pipeline. The results verified that using such a hybrid approach has improved positional accuracy 8.97% in comparison with that of the latest methods like EKF/ Pipe Line Junctions (PLJ). Also, the proposed method is 2.277 times better than EKF/PLJ in the algorithm runtime.

Compact microstrip diplexer design using new octagonal resonators for 5G and Wi-Fi applications

The present paper sheds light on designing a new and high performance microstrip diplexer. The latter is based on new octagonal meandrous resonators combined with the connected common port, without adding any transmission line junction, in order to get a miniaturized structure. The suggested compact resonator is formed through combining the octagonal meandrous lines and coupled lines, which create a bandpass filter. These filters operate at 3.5 GHz and 5 GHz which make them suitable for 5G and Wi-Fi applications. Accordingly, an approximated equivalent LC model of the presented octagonal meandrous resonator is suggested and analyzed so as to validate the simulation results. On top of that, the suggested diplexer is compact, as it occupies only 0.0768 λ g × 0.024 λ g. Thus, it attained excellent performance in terms of S-Parameters as the transmission coefficients are about -1 dB and the reflection coefficient is about -20 dB at both channels, whereas the isolation is about -25 dB. Hence, the validation of theoretical and simulated results is carried out through measurements of the manufactured prototype.

Role of line junctions in expert object recognition: The case of musical notation.

Line junctions are well-known to be important for real-world object recognition, and sensitivity to line junctions is enhanced with perceptual experience with an object category. However, it remains unclear whether these very simple visual features are involved in expert object representations at the neural level, and if yes, at what level(s) they are involved. In this EEG study, 31 music reading experts and 31 novices performed a one-back task with intact musical notation, musical notation with line junctions removed and pseudo-letters. We observed more separable neural representations of musical notation from pseudo-letter for experts than for novices when line junctions were present and during 180-280 ms after stimulus onset. Also, the presence of line junctions was better decoded in experts than in novices during 320-580 ms, and the decoding accuracy in this time window predicted the behavioral recognition advantage of musical notation when line junctions were present. These suggest that, with perceptual expertise, line junctions are more involved in category selective representation of objects, and are more explicitly represented in later stages of processing to support expert recognition performance.

PLJ-SLAM: Monocular Visual SLAM With Points, Lines, and Junctions of Coplanar Lines

Existing monocular visual simultaneous localization and mapping (SLAM) mainly focuses on point and line features, and the constraints among line features are not fully explored. In this paper, a multi-feature monocular SLAM with ORB points, lines, and junctions of coplanar lines is proposed for indoor environments. To create 3D junctions of coplanar lines, an adaptive coordinate confidence is designed to describe the coordinate stability of 2D junctions on the image plane. Based on the matched 2D junctions between the current keyframe and other two associated keyframes, a multi-view coplanarity verification is performed for 3D junction creation. Moreover, reprojection verification is conducted to update the observation of 3D junction, which is used to dynamically update the confidence of coplanarity for confidence-based local bundle adjustment. The camera pose is optimized through multiple constraints of ORB points, lines, and junctions of the coplanar lines. As a result, the performance of monocular SLAM is improved. The experiment verification shows the effectiveness of the proposed method.

Expansion of Spinal Canal with Lift-Open Laminoplasty: A New Method for Compression Cervical Myelopathy.

ObjectiveThis study is to introduce lift‐open laminoplasty and verify the increase of the spinal canal area following this surgical technique according to the preoperative anatomical measurement.MethodsThere are 82 patients (43 male and 39 female) analyzed in our study from January 2019 to December 2020. The average age was 63.2 ± 3.21 years (from 41 to 84 years). All of them were treated with open‐door laminoplasty, with a decompression segment range from C3 to C6. The increase of the spinal canal area after open‐door laminoplasty was measured on postoperative CT images of the patients, and the distances between both lamina‐facet junctions and lamina length was measured on preoperative CT images. Using the Pythagorean theorem for the equation of calculation area after the expansile open‐door laminoplasty. Based on previous measurement parameters, spinous process length, lateral mass width, distance between osteotomy line and lamina‐facet junctions line were additionally measured on preoperative CT images. Pythagorean theorem was used for calculating the area after the expansile lift‐open laminoplasty. The results were recorded and a statistical analysis was undertaken. Then, there were six patients (five male and one female) treated with lift‐open laminoplasty on C6, open‐door on C3–C5, who suffer from cervical spondylotic myelopathy from December 2020 to January 2021. The average age was 60.3 ± 1.7 years (from 56 to 71 years). Operation time, blood loss, and Japanese Orthopaedic Association (JOA) score recovery rate were recorded. Intraoperative and postoperative complications were observed.ResultsThe increase of the spinal canal area after open‐door laminoplasty measured on postoperative CT images was 123.01 ± 17.06 mm2 and the calculation of the increase of the spinal canal areausing the Pythagorean theorem after open‐door laminoplasty was 122.86 ± 15.86 mm2. A comparison of the actual value with calculative value showed no significant difference (T value = 0.057, P value = 0.955). The calculation of the increase of the spinal canal area after lift‐open laminoplasty was 183.57 ± 62.99 mm2, which was larger than that after open‐door laminoplasty (T value = 8.462, P value < 0.001). Mean operation time was 153.3 min and operative blood loss was 600 mL of the six patients treated with lift‐open laminoplasty. At 1 month follow‐up, all patients had recovered well. JOA score recovery rate was 37.6% and no intraoperative and postoperative complications occurred.ConclusionLift‐open laminoplasty could preserve nearly 100% of extensor muscle, avoid damaging C7 paraspinal muscles and C6‐7 posterior muscle‐ligament complex, reconstruct the spinous process firmly in the midline, and expand adequate spinal canal area after operation. These advantages could reduce the incidence rate of complications and bring better clinical results than traditional laminoplasty.

Majorana bound state manipulation by current pulses

Majorana bound states (MBSs) can occur in Josephson junctions of conventional s-wave superconductors coupled via a strong topological insulator. In configurations of multiple line junctions meeting at a point, the criterion for the MBS to exist coincides with the presence of a fractional Josephson vortex with 2π phase winding. We investigate the dynamic stability of such vortices in arrays of tri- and quad-junctions. The existence of fractional vortices in arrays is demonstrated, but the dynamic stability is found to depend critically on the current-phase relation and the inductance. We propose the idea, and study the feasibility, of manipulating the location of the vortices in arrays by using current pulses, compatible with rapid single flux quantum technology. It is shown theoretically, using a modified resistively shunted junction model, that braiding operations can be achieved using current pulses injected from the edge of the array. It is necessary to use vortex sites with elevated critical current as traps.

Application of cranioplasty with three-dimensional plastic titanium mesh in the repair of skull defects

Objective To study the effect of cranioplasty with three-dimensional plastic titanium mesh in the repair of skull defects. Methods A total of 45 patients with frontotemporal skull defects were randomly divided into observation group (n=29) and control group (n=16). The observation group was treated with three-dimensional plastic titanium mesh for cranioplasty, while the control group was treated with two-dimensional titanium mesh artificial shaping for skull repair. Beauty satisfaction related indicators in the two groups were compared. Results At three months of follow-up after surgical treatment, there were 29 cases of symmetrical cephalic patterns on the cranial repair side and the undamaged side as well as 1 case of temporalis muscle collapse in the observation group. There were 12 cases of symmetrical cephalic patterns on the cranial repair side and the undamaged side, 4 cases of temporalis muscle collapse, 6 cases of scalp infection, 5 cases of line junction exposure, 3 cases of titanium mesh upturned or exposed, and 3 cases of subcutaneous hydrops in the control group. There were statistically significant differences between the two groups in terms of beauty satisfaction and the number of patients with common complications (P Conclusion The incidence of common complications of cranioplasty with three-dimensional plastic titanium mesh is low, and the aesthetic satisfaction of the patients is high.

A Novel High-Voltage Transmission Line Joint Temperature Monitoring System Using Hybrid Communication Networks

Line joint temperature monitoring is used in high-voltage transmission lines to improve the reliability and safety of power lines. However, traditional monitoring methods (e.g., manual inspection, UAV inspection, short-range wireless technology, etc.) cannot realize real-time monitoring of line joint temperature in remote areas. In this paper, we proposed a novel real-time monitoring system, which adopted a communication method combining ZigBee and LPWAN technology (LoRa and NB-IoT) for long-distance transmission. In this system, each power tower was regarded as a communication node that contained a main node and multiple subnodes. First, each node collected temperature data of the transmission line junctions by ZigBee and microprocessor processed and analyzed the data. Second, the LoRa multihop communication technology was used for transmission of the data between adjacent nodes to achieve wider coverage and a longer transmission distance. Finally, the end of the network was a main node, i.e., an LoRa-NB-IoT gateway. The temperature data of all nodes were transmitted to the “USR Cloud” by the NB-IoT technology. By conducting a system test, the system can meet the requirements of long-distance communication outside and reduce power consumption. After calculation, the system communication packet loss rate is approximately 3.3%, and the average power consumption of the system is about 21.19 mA. The PC can monitor the transmission line junction temperature in real time, transmission is stable, and the alarm function can be also realized. Therefore, the system is more suitable for temperature monitoring of line junctions in remote areas, achieving long-distance data acquisition and transmission through low power consumption and high transmission rate.

Modeling and Parameter Identification of a Cooling Fan for Online Monitoring

In many industrial fields, cooling fan systems have been widely implemented in electronic equipment such as network hosts, product line junction boxes, manufacturing facilities, computer numerical control (CNC) machine systems, cooling units of array servers, and many other power systems. These systems usually require high computation power and release high heat. Once the cooling fan systems malfunction or the cooling efficiency degrades, it could result in lower system performances or even cause serious damage to the core systems. Thus, there is a growing interest in monitoring and detecting the cooling fan operation status. As a result, the status of the cooling fan systems needs to be monitored in real-time. In this article, dynamics modeling, parameter identification, and online fan speed monitoring of a cooling fan system are presented. First, the nonlinear model of the cooling fan system is derived from blade aerodynamics with a driving motor. Next, a discrete model is applied based on the bilinear transformation of the description of the dynamic behavior and is further used for the least-square (LS) parameter estimation. To suppress the measurement noise, a regulation filter (RF) is further presented to improve the parameter identification precision. In addition, a Levenberg–Marquardt (LM) optimization is further applied for parameter refinement. Simulation comparison studies are considered to validate the proposed method. Moreover, many experiments are conducted to verify the feasibility and reliability for different types of fans. Unlike common conventional monitoring methods, the proposed framework does not apply constant threshold or need any training stages. The alarm threshold is adjusted automatically according to the current operation status. Finally, an embedded measurement and monitoring instrument is developed for demonstrating the effectiveness of the proposed method. Experiments firmly verify the novelty of the model-reference-based online cooling fan monitoring techniques.

Design of Ku-band High Directivity Directional Coupler

This paper introduces a method to improve the directivity of directional coupler. Adding open-stub to each section of the parallel coupling line. The open-stub is equivalent to a capacitance element to compensate the discontinuity of two adjacent coupled line junction. The simulation results show that this method can effectively improve the directivity of stripline directional coupler. In this paper, a Ku-band stripline directional coupler is designed, the directivity value of the directional coupler is -17dB without open-stubs. However, the directivity of the directional coupler improves 13dB with open-stubs.

Topologically derived dislocation theory for twist and stretch moiré superlattices in bilayer graphene

We develop a continuum dislocation description of twist and stretch moire superlattices in 2D material bilayers. The continuum formulation is based on the topological constraints introduced by the periodic dislocation network associated with the moire structure. The approach is based on solving analytically for the structural distortion and displacement fields that satisfy the topological constraints, and which minimize the total energy. The total energy is described by both the strain energy of each individual distorted layer, and a Peierls-Nabarro like interfacial contribution arising from stacking disregistry. The dislocation core emerges naturally within the formalism as a result of the competition between the two contributions. The approach presented here captures the structure and energetics of twist and stretch moire superlattices of dislocations with arbitrary direction and character, without assuming an analytical solution a priori, with no adjustable parameters, while accounting naturally for dislocation-dislocation image interactions. In comparisons to atomistic simulations using classical potentials, the maximum structure deviation is 6%, while the maximum line energy deviation is 0.019 eV/Angstrom. Several applications of our model are shown, including predicting the variation of structure with twist angle, and describing dislocation line tension and junction energies.

Evaluation of Lefort I Osteotomy Line and Pterygomaxillary Junction Region in Patients With Cleft Lip and Palate.

This study aimed to evaluate the Le Fort I osteotomy line and pterygomaxillary junction via cone-beam computed tomography in individuals with cleft lip and palate (CLP). Retrospective study. Patients and Methods: The study included individuals older than 16 years with CLP, who were scheduled for repositioning of the maxilla by Le Fort I osteotomy, and those with class III malocclusion with maxillary hypoplasia, who were scheduled for Le Fort I osteotomy. The measurements made in the area of the cleft of individuals with CLP were compared with both the side with no cleft and those with class III malocclusion with maxillary hypoplasia. A total of 11 measurements were made on the axial section parallel to the Frankfurt Horizontal plane, corresponding to the lower 1/5 of the distance between the infraorbital foramen and the anterior nasal spine. There were significant differences both in the comparisons made between the individuals with CLP and those without CLP in terms of the canal-anterior alveolar crest (G) and sinus-anterior alveolar crest (L) measurements (P < .05). The mean measurement values showed that the measurement results were higher in individuals with CLP in general. In conclusion, we believe that there might be difficulties both in osteotomy and down fracture stages during Le Fort I osteotomies performed in individuals with CLP.

Phase diagram of grain boundary facet and line junctions in silicon

The presence of facets and line junctions connecting facets on grain boundaries (GBs) has a strong impact on the properties of structural, functional, and optoelectronic materials: They govern the mobility of interfaces, the segregation of impurities, as well the electronic properties. In the present paper, we employ density-functional theory and modified embedded atom method calculations to systematically investigate the energetics and thermodynamic stability of these defects. As a prototype system, we consider $\mathrm{\ensuremath{\Sigma}}3$ tilt GBs in Si. By analyzing the energetics of different faceted GBs, we derive a diagram that describes and predicts the reconstruction of these extended defects as a function of facet length and boundary inclination angle. The phase diagram sheds light upon the fundamental mechanisms causing GB faceting phenomena. It demonstrates that the properties of faceting are not determined solely by anisotropic GB energies but by a complex interplay between geometry and microstructure, boundary energies as well as long-range strain interactions.

Assessment of a novel stapler performance for laparoscopic sleeve gastrectomy.

Optimal stapler selection during laparoscopic sleeve gastrectomy requires careful balance between tissue compression, hemostasis, and mechanical integrity. Junctions along a staple line can further increase the risks of technical or mechanical staple line failures. The aim of this study was to compare two commonly utilized laparoscopic linear gastrointestinal staplers (Ethicon, Medtronic) with a novel linear stapler (Titan) designed to perform a sleeve gastrectomy with a single stapler firing. Excised gastric remnants from laparoscopic sleeve gastrectomy were utilized and tissue thickness was measured from fundus to antrum. An optimized experimental staple line was then created. The greater curve remnant was insufflated to determine the staple line burst pressure and location. The doubly stapled (clinical and experimental) gastric specimen underwent staple analysis for junctional location, malformation, and height. The Titan stapler withstood a significantly higher burst pressure than both Ethicon and Medtronic linear cutting staplers. While the Medtronic and Ethicon staplers had a similar percentage of staples in junctions, the Titan stapler has no junctions. In considering the formation of all staples outside of junctions, the Medtronic and Titan staplers had no difference in percentage of malformed staples, while the Ethicon stapler had a significantly higher percentage. Additionally, there were no differences in mismatch between staple height and tissue thickness between experimental groups. The Titan stapler conveys the mechanical benefits of higher burst pressure with the advantage of single load functionality. This single staple load eliminates staple line junctions without sacrificing the integrity of staple formation.

Integer‐Grid Sketch Simplification and Vectorization

AbstractA major challenge in line drawing vectorization is segmenting the input bitmap into separate curves. This segmentation is especially problematic for rough sketches, where curves are depicted using multiple overdrawn strokes. Inspired by feature‐aligned mesh quadrangulation methods in geometry processing, we propose to extract vector curve networks by parametrizing the image with local drawing‐aligned integer grids. The regular structure of the grid facilitates the extraction of clean line junctions; due to the grid's discrete nature, nearby strokes are implicitly grouped together. We demonstrate that our method successfully vectorizes both clean and rough line drawings, whereas previous methods focused on only one of those drawing types.