bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on “three places and four fields” airline resource cooperative allocation based on decision tree algorithm
Authors: Luo Dingfa
Published: April 2024

In view of the disharmony development status of Beijing Tianjin Hebei region, the paper puts forward a route optimization Principle of cooperative allocation of route resources of airport group from the angle of flight punctuality, airlines share and function orientation. An optimal model of airline resources cooperative allocation is established to maximize the overall operational benefit of regional airports and the modified decision tree C4.5 algorithm was applied to solve the problem. Since this algorithm combined with constraint condition of model as pruning standard, the efficiency of the algorithm was greatly improved. Finally, the problem find the optimal solution could be found by comparing the profit and loss value of the program. The analysis example showed that the overall benefit of multi-airport system increased by 7.03%. This model was useful to optimize airline network and conformed to the actual situation, and the research results can provide a reference for civil aviation authorities in planning the airline network of multi-airport system.
Podemos dispensar o uso do torniquete nas artroplastias totais do joelho?
Authors: Guerreiro João Paulo Fernandes , Janeiro Caio Winch , Zarpelon Bruno , Calzavara Paulo Mazzo , Bignardi Paulo Roberto , Danieli Marcus Vinicius
Published: April 2024

Objetivo Analisar se há mais sangramento em pacientes submetidos a artroplastia total do joelho (ATJ) sem a utilização do torniquete. Os objetivos secundários foram analisar os tempos cirúrgico e de internação, a necessidade de transfusão e a taxa de complicações.

Métodos Estudo retrospectivo por meio da análise de prontuários. Os pacientes foram divididos em dois grupos: ATJ com e sem a utilização de torniquete. Foram comparados os valores das quedas da hemoglobina e do hematócrito 24 h e 48 h após a cirurgia, os tempos cirúrgico e de internação, a necessidade de transfusão e a taxa de complicações até 5 meses de pós-operatório.

Resultados No período, foram operados 104 pacientes, sendo 94 incluídos no estudo. Não houve diferença entre as médias dos valores da hemoglobina e do hematócrito entre os grupos no pré-operatório (p = 0,675 e p = 0,265, respectivamente), 24 h (p = 0,099 e p = 0,563, respectivamente) e 48 h (p = 0,569 e p = 0,810, respectivamente) após a cirurgia. O tempo cirúrgico e o tempo de internação também não foram diferentes entre os grupos (p = 0,484 e p > 0,05, respectivamente). Não houve diferença com relação à necessidade de transfusões, nem com relação à taxa de complicações analisadas.

Conclusão Podemos dispensar o uso do torniquete nas cirurgias de ATJ sem alteração significativa no valor dos níveis de hemoglobina e de hematócrito 24 h e 48 h após a cirurgia quando comparado ao grupo com uso de torniquete. Não houve diferenças significativas no tempo total das cirurgias, no tempo de internação, na necessidade de transfusões e nas taxas de complicações analisadas.
Acesso à coluna lombossacral: Visão atual
Authors: Araujo Ono Allan Hiroshi de , Pereira Filho Aécio Rubens Dias , Araujo Fernando Flores de , Marcon Raphael Marthus , Cristante Alexandre Fogaça , Barros Filho Tarcisio Eloy de Pessoa
Published: April 2024

A abordagem cirúrgica da coluna lombossacral tem sido objeto de estudos anatômicos experimentais e científicos desde a era hipocrática. Contudo, foi no século XX que, com a evolução da assepsia e da antibioticoterapia, a cirurgia da coluna começou a evoluir em velocidade vertiginosa e as diversas possibilidades de vias de acesso tornaram-se objetos de desenvolvimento e discussão. Desta forma, as doenças da coluna lombossacral podem ser acessadas de diferentes maneiras e posições, desde a abordagem posterior tradicional em decúbito ventral até as abordagens anterior, oblíqua, lateral e endoscópica. O presente artigo traz vias de acesso de última geração para a coluna lombossacral. O objetivo deste artigo é elucidar as possibilidades de acesso à coluna lombar para quaisquer finalidades, como descompressão, fusão, ressecções tumorais, reconstrução ou correção de deformidades, independentemente do tipo de implante ou seu posicionamento.
Fraturas do rádio distal associadas à fratura do escafoide
Authors: Nogueira Caio Kzan Geyer , Moraes Vinícius Ynoe de , Sarmento Lucas Pereira , Nakachima Luís Renato , Santos João Baptista Gomes dos , Belloti João Carlos
Published: April 2024

Objetivo Avaliar os resultados epidemiológicos e funcionais dos pacientes que apresentaram fraturas concomitantes do rádio distal e do escafoide e foram tratados em um único centro especializado em cirurgia da mão, através de instrumentos validados para analisar os desfechos funcionais desses pacientes.

Métodos Foram avaliados os pacientes com diagnóstico de fratura do rádio distal e escafoide tratados de janeiro de 2011 até dezembro de 2021, através dos questionários Disabilities of the Arm, Shoulder and Hand (DASH), Patient Rated Wrist Evaluation (PRWE) e Escala Visual Analógica da dor (EVA); goniometria; consolidação radiográfica; complicações em seis meses de pós-operatório.

Resultados Vinte e três pacientes foram incluídos no estudo, sendo 73,9% homens e 26,1% mulheres; 56,5% das fraturas ocorreram à direita e 43,5% à esquerda. A maioria das fraturas do rádio distal foi tratada com placa volar bloqueada, totalizando 56%. Na avaliação funcional pelo PRWE, obteve-se média de 35,9 pontos (variação de 14 a 71 pontos) e pelo DASH média de 37,8 pontos (variação de 12 a 78 pontos). A EVA apresentou uma média de 2,33 durante a atividade (variação de 0,6 a 6,2).

Conclusão Verificou-se que as fraturas do rádio distal associadas a fraturas do escafoide foram causadas por traumas de alta energia, com o sexo masculino mais acometido. Houve baixo índice de complicações com tratamento cirúrgico e os pacientes tiveram evolução funcional satisfatória, com baixo índice de dor.
Parametric simulations of fractal-fractional non-linear viscoelastic fluid model with finite difference scheme
Authors: Murtaza Saqib , Ismail Emad A. A. , Awwad Fuad A. , Bonyah Ebenezer , Hassan Ahmed M. , Khan Muhammad Saad , Khan Razi , Ahmad Zubair
Published: April 2024

Fractal-fractional derivatives are more general than the fractional derivative and classical derivative in terms of order. Fractal-fractional derivative is used in those models where the classical continuum hypothesis theory fails. More precisely, these derivative operators are used where the surface or space is discontinuous, e.g., porous medium. Fractal-fractional derivative is considered advance tool to analyze the fluid dynamic model more than fractional and classical model. Given the extensive applicability of fractal-fractional derivatives, the current analysis focuses on investigating the behavior of a non-linear Walter’s-B fluid model under the influence of time-varying temperature and concentration During the simulation process, we have also taken into account the effects of first-order chemical reactions, Soret numbers, thermal radiation, Joule heating, and viscous dissipation of energy. A magnetic field with a strength of B0 was applied to the left plate in the transverse direction. The classical mathematical model was first developed using relative constitutive equations and later generalized with the fractal-fractional derivative operator. Numerical solutions to the generalized model have been obtained using the finite difference method. Various graphs are drawn from the obtained numerical solutions to study the influence of physical parameters on the rheology of Walter’s-B fluid. It has been observed that by varying the fractional and fractal order of the generalized model, one can easily derive fractal, fractional, and classical models.
Inviscid analysis of horizontal axis wind turbines using distributed vorticity elements
Authors: Basom Blair J. , Miller Mark A. , Kandias Constantinos S. , Coder James G. , Schmitz Sven , Maughmer Mark D.
Published: April 2024

The primary tool currently used for a wind turbine preliminary design is the blade element momentum method, which lacks a detailed wake model and relies on an assumption of non-interacting streamtubes. These simplifications limit the designer's ability to tailor the blade shape to minimize the induced power loss of the rotor. Improved prediction of the induced velocity distribution on the blades can be achieved through the use of vortex-based models at a computational cost low enough for use in design processes requiring many iterations. This paper presents the implementation of a potential flow, lifting-surface methodology using elements of distributed vorticity. The use of such elements provides several advantages including higher resolution than filament-based methods, simulation of non-planar blade planforms, and avoids the need for empirical corrections. Because the wake has a strong influence on the flow at the rotor, the accurate prediction of its geometry is highly important for wind turbine analysis. To this end, a force-free relaxed-wake model is presented as well as less numerically intensive fixed-wake and hybrid-wake models. Comparison is made to the blade element momentum method and Goldstein's theoretical solution for the ideal lightly loaded rotor.
Non-contact, portable, and stand-off infrared thermal imager for security scanning applications
Authors: Khor WeeLiam , Chen Yichen Kelly , Roberts Michael , Ciampa Francesco
Published: April 2024

In this article, we demonstrated the physical application of a portable infrared (IR) security scanning system for the non-contact and stand-off detection of target objects concealed underneath clothing. Such a system combines IR imaging and transfer learning with convolutional neural networks (CNNs) to enhance the detection of weak thermal signals and automate the classification of IR images. A mid-wavelength IR detector was used to record the real-time heat emitted from the clothing surface by human subjects. Concealed objects reduce the transmissivity of IR radiation from the body to the clothing surface, generally showing lower IR intensity compared to regions without objects. Due to limited resources for training data, the transfer learning approach was applied by fine-tuning a pre-trained CNN ResNet-50 model using the ImageNet database. Two image types were investigated here, i.e., raw thermal and Fuzzy-c clustered images. Receiver operating characteristic curves were built using a holdout set, showing an area-under-the-curve of 0.8934 and 0.9681 for the raw and Fuzzy-c clustered image models, respectively. The gradient-weighted class activation mapping visualization method was used to improve target identification, showing an accurate prediction of the object area. It was also found that complex clothing, such as those composed of materials of different transmissivity, could mislead the model in classification. The proposed IR-based detector has shown potential as a non-contact, stand-off security scanning system that can be deployed in diverse locations and ensure the safety of civilians.
Diagnosis of a rotor imbalance in a wind turbine based on support vector machine
Authors: Chen Mingyang , Guo Shanshan , Xing Zuoxia , Folly Komla Agbenyo , Liu Yang , Zhang Pengfei
Published: April 2024

Rotor imbalances in wind turbines present safety risks and lead to economic losses, and a method to diagnose rotor imbalances is urgently needed. A diagnostic method for rotor imbalances is proposed in this paper. First, a signal reconstruction method is proposed, and a novel index is used to determine the number of components used in signal decomposition in order to effectively address the interference by noise on the sensor. Second, an entropy calculation method is proposed, and the Gaussian kernel function is used to replace the fuzzy functions. The results indicate significant differences for different types of rotor imbalances. Moreover, it exhibits good noise robustness and a low dependence on the data length. Third, a support vector machine with multiscale kernels is proposed, and kernel functions with various characteristics and scales are combined. It has a well-distributed hyperplane and better classification performance, and it is robust to wind conditions. Finally, the method is tested and verified with varying levels of noise and turbulence. The results demonstrate satisfactory performance because the proposed method can effectively identify rotor imbalances under different noise and wind conditions.
Flow across a circular cylinder in an inclined channel stabilized by buoyancy
Authors: Zhang Wei , Samtaney Ravi
Published: April 2024

In this study, flow across a circular cylinder confined in an inclined channel is considered, with account taken of mixed convection. Cases with opposing or aiding buoyancy that is not in alignment with the incoming flow are considered, and it is found that the flow around and in the wake of the cylinder is affected. The effects of inclination and buoyancy on the flow and heat transfer patterns are investigated, with a focus on the stabilization and destabilization of flow by these two factors. Simulation results are analyzed with regard to the flow field, lift and drag forces, heat transfer, the deviation of separation and through-flow in the channel, and the temperatures on the channel walls. The flow is more strongly destabilized by an opposing buoyancy, but can be fully stabilized by an aiding buoyancy in an inclined channel. The drag on the cylinder is minimized around a critical Richardson number Ricr. The inclination of the channel has significant effects on the local heat transfer on the cylinder and on the characteristics of the through-flow. The pattern of the wake flow, i.e., whether it is steady or unsteady, affects the heating of the channel walls.
Giant magnetoimpedance effect and spin accumulation in conjugated polymeric networks with inhomogeneity
Authors: Singh Sukhjot , Rampur Mallikarjun , Chetty Anjali , Joshi Rajeev Shesha
Published: April 2024

The magnetoimpedance effect allows us to estimate the extent of spin dependent scattering in disordered solids. The change in impedance with respect to applied magnetic field manifests through local change in permeability on the surface and it amplifies at defect sites. The local electrical inhomogeneities are expected to aid this effect through spin dependent scattering. The organic conjugated electrical networks provide scope for producing such inhomogeneities formed by path defects and protonic charge accumulation leading to spin dependent scattering. This hypothesis is investigated in the present work taking polyaniline as a prototype network. The electrical inhomogeneities in the network were controlled by selective oxidation and aging in polyaniline. The Giant Magnetoimpedance (GMI) was observed in the electrically inhomogeneous network with the change in electrical impedance of the order of 50%–60% for lower frequencies with prominent capacitive coupling and a change of the order of 200% at higher frequencies with prominent inductive coupling with the application of magnetic field. However, no spin accumulation was observed in the insulating networks formed by a modified oxidative process. This study is expected to serve as a tool to develop frequency selective spin accumulation based magnetic field sensors and oscillator networks.
Australian Fire Danger Rating System: implementing fire behaviour calculations to forecast fire danger in a research prototype†
Authors: Kenny B. J. , Matthews S. , Sauvage S. , Grootemaat S. , Hollis J. J. , Fox-Hughes P.
Published: April 2024

Background The Australian Fire Danger Rating System (AFDRS) was implemented operationally throughout Australia in September 2022, providing calculation of fire danger forecasts based on peer-reviewed fire behaviour models. The system is modular and allows for ongoing incorporation of new scientific research and improved datasets. Aims Prior to operational implementation of the AFDRS, a Research Prototype (AFDRSRP), described here, was built to test the input data and systems and evaluate the performance and potential outputs. Methods Fire spread models were selected and aligned with fuel types in a process that captured bioregional variation in fuel characteristics. National spatial datasets were created to identify fuel types and fire history in alignment with existing spatial weather forecast layers. Key results The AFDRSRP demonstrated improvements over the McArthur Forest and Grass Fire Danger systems due to its use of improved fire behaviour models, as well as more accurately reflecting the variation in fuels. Conclusions The system design was robust and allowed for the incorporation of updates to the models and datasets prior to implementation of the AFDRS.
TL1A is an epithelial alarmin that cooperates with IL-33 for initiation of allergic airway inflammation
Authors: Schmitt Pauline , Duval Anais , Camus Mylène , Lefrançais Emma , Roga Stéphane , Dedieu Cécile , Ortega Nathalie , Bellard Elisabeth , Mirey Emilie , Mouton-Barbosa Emmanuelle , Burlet-Schiltz Odile , Gonzalez-de-Peredo Anne , Cayrol Corinne , Girard Jean-Philippe
Published: April 2024

Epithelium-derived cytokines or alarmins, such as interleukin-33 (IL-33) and thymic stromal lymphopoietin (TSLP), are major players in type 2 immunity and asthma. Here, we demonstrate that TNF-like ligand 1A (TL1A) is an epithelial alarmin, constitutively expressed in alveolar epithelium at steady state in both mice and humans, which cooperates with IL-33 for early induction of IL-9high ILC2s during the initiation of allergic airway inflammation. Upon synergistic activation by IL-33 and TL1A, lung ILC2s acquire a transient IL-9highGATA3low “ILC9” phenotype and produce prodigious amounts of IL-9. A combination of large-scale proteomic analyses, lung intravital microscopy, and adoptive transfer of ILC9 cells revealed that high IL-9 expression distinguishes a multicytokine-producing state-of-activated ILC2s with an increased capacity to initiate IL-5-dependent allergic airway inflammation. Similar to IL-33 and TSLP, TL1A is expressed in airway basal cells in healthy and asthmatic human lungs. Together, these results indicate that TL1A is an epithelium-derived cytokine and an important cofactor of IL-33 in the airways.
Interstitial macrophages are a focus of viral takeover and inflammation in COVID-19 initiation in human lung
Authors: Wu Timothy Ting-Hsuan , Travaglini Kyle J. , Rustagi Arjun , Xu Duo , Zhang Yue , Andronov Leonid , Jang SoRi , Gillich Astrid , Dehghannasiri Roozbeh , Martínez-Colón Giovanny J. , Beck Aimee , Liu Daniel Dan , Wilk Aaron J. , Morri Maurizio , Trope Winston L. , Bierman Rob , Weissman Irving L. , Shrager Joseph B. , Quake Stephen R. , Kuo Christin S. , Salzman Julia , Moerner W.E. , Kim Peter S. , Blish Catherine A. , Krasnow Mark A.
Published: April 2024

Early stages of deadly respiratory diseases including COVID-19 are challenging to elucidate in humans. Here, we define cellular tropism and transcriptomic effects of SARS-CoV-2 virus by productively infecting healthy human lung tissue and using scRNA-seq to reconstruct the transcriptional program in “infection pseudotime” for individual lung cell types. SARS-CoV-2 predominantly infected activated interstitial macrophages (IMs), which can accumulate thousands of viral RNA molecules, taking over 60% of the cell transcriptome and forming dense viral RNA bodies while inducing host profibrotic (TGFB1, SPP1) and inflammatory (early interferon response, CCL2/7/8/13, CXCL10, and IL6/10) programs and destroying host cell architecture. Infected alveolar macrophages (AMs) showed none of these extreme responses. Spike-dependent viral entry into AMs used ACE2 and Sialoadhesin/CD169, whereas IM entry used DC-SIGN/CD209. These results identify activated IMs as a prominent site of viral takeover, the focus of inflammation and fibrosis, and suggest targeting CD209 to prevent early pathology in COVID-19 pneumonia. This approach can be generalized to any human lung infection and to evaluate therapeutics.
Experimental study and numerical simulation of morphing characteristics of bistable laminates embedded with 3D printed shape memory polymers
Authors: Zhang Zheng , Yang Guoquan , Pan Baisong , Sun Min , Zhang Guang , Chai Hao , Wu Huaping , Jiang Shaofei
Published: April 2024

Bistable laminates have potential applications in areas such as buffer and soft robotics due to their two stable states and ability to deform through both snap-through and snap-back processes. However, conventional orthotropic bistable laminates with two stable state configurations and snap loads are similar in magnitude. There is a problem that the deformation cannot be easily driven when the laminate stiffness is high. To solve this problem, a clever design is needed to reduce the snap-back load and increase the snap-through load so that the driven deformation can be realized more easily. In this paper, we propose a design method to suppress and control the deformation of bistable laminates by utilizing the shape memory of 3D-printed shape memory polymers (SMP), which enables the laminates to increase the stiffness while reducing the driving force. First, a numerical model of viscoelasticity of the laminate is established to study its deformation characteristics, and the numerical results are compared with experimental results with good agreement. The effect of SMPs on the snap load and principal curvature of bistable laminates is also investigated. Finally, the interlayer interface bonding of the bistable laminates is examined in microscopic perspective. The results demonstrate that 3D printed SMPs can effectively enhance the snap-through load and reduce the snap-back load of bistable laminates, achieving deformation suppression and control while maintaining good interlaminar bonding with carbon fiber composites. This study provides new insights and practical significance for the deformation suppression and active control of bistable structures.
Constraining gamma-ray lines from dark matter annihilation using Fermi-LAT and H.E.S.S. data
Authors: Angel Lucia , Gambini Guillermo , Guedes Leticia , Queiroz Farinaldo S. , de Souza Vitor
Published: April 2024

Using 14 years of Fermi-LAT data and 10 years of H.E.S.S. observations in the direction of the galactic center, we derive limits on gamma-ray lines originated from dark matter annihilations for fermionic and scalar fields. We describe the dark matter annihilation into γγ or γZ final states in terms of effective operators and place limits on the energy scale as a function of the dark matter mass, taking into account the energy resolution of the instruments. For the Fermi-LAT data, we considered an NFW and a contracted NFW dark matter density profile, the latter being preferred by the Fermi GeV excess. For the H.E.S.S. observation, we used NFW and Einasto profiles. Fermi-LAT yields the most stringent constraints for dark matter masses below 300 GeV, whereas H.E.S.S. has the strongest ones for dark matter masses above 1 TeV. The telescopes share similar sensitivities for dark matter masses between 300 GeV and 1 TeV. We conclude that Fermi-LAT (H.E.S.S.) can probe energy scales up to 10(20) TeV for scalar and fermionic dark matter particles.
One-loop infrared rescattering by enhanced scalar fluctuations during inflation
Authors: Fumagalli Jacopo , Bhattacharya Sukannya , Peloso Marco , Renaux-Petel Sébastien , Witkowski Lukas T.
Published: April 2024

We show that, whenever the perturbations of some field are excited during inflation by a physical process on sub-horizon scales, they unavoidably generate, even through gravitational interactions alone, a significant resonant IR cascade of power down to scales that are of the order of the horizon at that time (we denote these scales as near IR). We provide general analytic one-loop results for the enhancement of the IR power of the curvature perturbation generated by this effect, highlighting the role played by the resonance. We then study a number of examples in which the excited state is: (i) an isocurvature field, (ii) the curvature perturbation itself, (iii) a mixture of curvature and isocurvature fluctuations driven to an excited state by their coupled dynamics. In the cases shown, the cascade significantly modifies the near IR part of the power spectrum of the curvature perturbation with respect to the linear theory, indicating that this effect can impact the phenomenology associated with a variety of mechanisms considered in the literature, notably concerning primordial black holes and gravitational waves.
On the transition radiation interpretation of anomalous ANITA events
Authors: Ammerman-Yebra Juan , Alvarez-Muñiz Jaime , Zas Enrique
Published: April 2024

The Antarctic Impulsive Transient Antenna (ANITA) detector has observed several radio pulses coming from the surface of the ice cap at the South Pole. These pulses were attributed to upward-going atmospheric particle showers instead of the downward-going showers induced by cosmic rays that exhibit a characteristic polarity inversion of the radio signal due to reflection in the ice. Coherent transition radiation from cosmic-ray showers developing in the atmosphere and intercepting the ice surface has been suggested as a possible and alternative explanation of these so-called “anomalous” events. To test this interpretation, we have developed an extension of ZHS, a program to calculate coherent pulses from electromagnetic showers, to deal with showers that transit a planar interface between two homogeneous and dielectric media, including transition radiation. By considering different geometries, it is found that all pulses from air showers intercepting the ice surface and detected at the height of ANITA, display the same polarity as pulses emitted by ultra-high-energy cosmic-ray showers that fully develop in the atmosphere and are reflected on the ice. We find that transition radiation is disfavored as a possible explanation of the anomalous ANITA events.
Scalar gravitational waves can be generated even without direct coupling between Dark Energy and ordinary matter
Authors: Chou Li-Ying , Chu Yi-Zen , Liu Yen-Wei
Published: April 2024

We point out, the scalar sector of gravitational perturbations may be excited by an isolated astrophysical system immersed in a universe whose accelerated expansion is not due to the cosmological constant, but due to extra field degrees of freedom. This is true even if the source of gravitational radiation did not couple directly to these additional fields. We illustrate this by considering a universe driven by a single canonical scalar field. By working within the gauge-invariant formalism, we solve for the electric components of the linearised Weyl tensor to demonstrate that both the gravitational massless spin-2 (transverse-traceless) tensor and the (Bardeen) scalar modes are generated by a generic astrophysical source. For concreteness, the Dark Energy scalar field is either released from rest, or allowed to asymptote toward the minimum in a certain class of potentials; and we compute the traceless tidal forces induced by gravitational radiation from a hypothetical compact binary system residing in such a universe. Though their magnitudes are very small compared to the tensors', spin zero gravitational waves in such a canonical scalar driven universe are directly sensitive to both the Dark Energy equation of state and the eccentricity of the binary's orbit.
Research on the Design and Application of Anti-wind devices for Seismically Isolated Buildings
Authors: Lin Yejian
Published: April 2024

Specialized anti-wind devices were designed and applied to seismically isolated buildings to solve the problem that seismic isolation buildings in areas with high wind loads could not simultaneously meet the requirements of the seismic damping objectives and the wind bearing capacity calculation. Taking an actual project as an example, anti-wind devices are added to the seismic isolation interface, a finite element analysis model of the structure is established and a time-distance analysis calculation is performed, and a synergistic design is carried out for the seismic damping effect and wind-resistant calculation. The results of the study show that the addition of anti-wind devices to reduce the number of lead rubber bearings can simultaneously satisfy the expected seismic damping effect and wind bearing capacity requirements; Numerical analysis of static loading verifies the effectiveness of anti-wind devices; This anti-wind device can be popularized for use in seismically isolated buildings in areas with high wind loads.
Flow discharge coefficient of crest weirs with covered vegetation
Authors: Yan Zhou , Bai Ruidi
Published: April 2024

The flow data of mountainous rivers is very important in hydrological forecasting. Crest weirs with smooth surface have been widely used and studied, while there is little information on the weir covered with vegetation. In this experiment, the flow coefficient reduction are systematically investigated by different density flexible artificial vegetation, in addition to the changes of discharge, crest length and height. The equivalent roughness height of vegetation on the weir was calculated. It was found that the flow coefficient with vegetation is smaller than smooth crest. According to the ratio of upstream water head to the length of vegetation weir crest, the experimental flow can be divided into broad-crested weir flow rate of H/L < 0.4 and narrow-crested weir flow rate of H/L > 0.4. The flow coefficient reduction rate of both types of weir flow rates varies to a certain extent. Experimental data showed that the crest weir height H/P played a different law for the broad-crested weir and narrow-crested weir. Taking into account the influence of vegetation, crest length and height, empirical formula for flow coefficient was proposed for flow estimation correction.
Analysis of Surrounding Rock Stability and Supporting Structure Effect Based on a Hydropower Station Underground Cavern
Authors: Pu Cheng , Han Bin , Li Chao , Lv Qingchao
Published: April 2024

The surrounding rock stability is a main difficult problem in the hydropower station construction and operation. Taking one hydropower station as object, FLAC 3D numerical simulation software was used to calculate the changes in surrounding rock failure zone distribution, surrounding rock strain, and block safety factor before and after supporting. The stability of the surrounding rock after excavation was analyzed and effect of the supporting structure was also evaluated. Finding that: the supporting structure can effectively improve the stability of surrounding rock. After supporting, the failure zone range, the deformation of surrounding rock, and the internal force of the supporting structure all reduced, while the safety factor of the block improved. Due to the effect of bolt, the deformation of the surrounding rock transformed from plastic to elastic, and the rebound zone of the surrounding rock increased, while the plastic and failure zone reduced. The depth of the failure zone on the downstream side is greater than that on the upstream side, and a large number of cracking zones are distributed on the downstream side. At the same time, due to the influence of cracks and geological fracture, the failure of surrounding rock around the main powerhouse is higher than that around the tailgate chamber higher than that in the main transformer chamber. The safety factor of the key blocks distributed around the main transformer chamber and the main power house improved, the sliding form of some blocks transformed from collapse to single-surface sliding.
An Analysis of Two Case Studies on the Construction of Underground Caverns-A Focus on the Tiantai Pumped Storage Station
Authors: Jing Maogui , Cheng Yongjin , Li Zheng , Gong Chao , Yan Zhongluan
Published: April 2024

This paper presents a numerical analysis of two case studies on the construction of underground caverns by FLAC3D, with a specific focus on the Tiantai Pumped Storage Power Station. During the construction period, two main problems, which are crane beam stability and rock support, have been numerically analysed and addressed. The first case study examines the influence of rock wall crane beam support on excavation stability. It has been proven that The reinforcement of connected concrete enhances integrity but may lead to localized cracking. Moreover, over-excavation reinforcement marginally improves anchor safety. The second case study investigates abnormal anchor stress in a powerhouse resulting from excavation. Recommended measures include conducting timely stability evaluations, identifying weakened zones to control rock stress relaxation effects, and establishing effective feedback mechanisms. By enhancing the safety of pumped storage power stations, promoting sustainable energy infrastructure, and improving the design and construction processes of such stations, this research paper aims to contribute to the overall development and success of these projects. In conclusion, the paper has discussed the rock wall crane beam stability and rock support effect, which implement the lack of this type of numerical analysis in underground cavern group construction. Also, it is recommended to accurately determine the rock mass mechanics parameters and timely support the excavated spaces to prevent abnormal increases in anchor stress.
A Comparative Study of Fragility Model for RC Girder Bridges and Buildings
Authors: Li Hexuan
Published: April 2024

Field surveys and data on the earthquake reveal that RC (reinforced concrete) bridges and buildings have been widely found in engineering structures, with abundant samples at disposal. By taking actual seismically damaged samples in the Wenchuan Earthquake happened in 2008 as examples, the paper established probability models for fragility matrix within Intensity VH-X/XI for the said two engineering structures based on EMS-98, MSK-81 and CSIS-08, and analyzed the comparative models for failure ratio and exceedance probability curves defined by these three scales. The paper, according to these analytical findings, proposed relevant measures and methods for improving the earthquake resistance of RC bridges.
The influence of penetration and cutting speed of pipe-jacking disc cutter on its cutting force and rock-breaking efficiency
Authors: Huang Xiaoyu , Yang Dishan , Lin Shaoyuan , Jian Quanrong , Chen Xiaoxiang
Published: April 2024

The disc cutter, which is essential to pipe-jacking to break rock, is the main tool used in this crucial method of tunnel building. The present research is focused on the force of the disc cutter and how well it breaks rock. This paper uses the medium-weathered granite of the Xinjing Mountain Substation - Beifeng Substation as an example to study the effects of penetration and cutting speed on the force and rock-breaking efficiency of the disc cutter. It does this by using ABAQUS to analyze the disc cutter’s operating state under various penetration and cutting speeds and to find the ideal rock-breaking efficiency. The findings demonstrate that: (1) Breaking rock is a discontinuous process that advances continuously. The rock unit beneath the disc cutter ring will change from an elastic to an elastic condition as the disc cutter moves. The rock unit beneath the disc cutter ring will undergo continuous extrusion as the disc cutter moves, changing from an elastic to a plastic state until failing as a result of damage. (2) All of the cutting forces rise as penetration and cutting speed increase, but the rolling force is more affected by penetration and vertical force by cutting speed. When the disc cutter breaks in a straight line, the side force is little. (3) The rock-breaking efficiency increases with a 4 mm penetration and a faster cutting speed.
Research on the flexural capacity of corroded recycled aggregate concrete beams by finite elements method
Authors: Zou Zhenghao , Xiao Shixiong , Chen Fang , Yang Guojiao , Zhao Lin , Wu Jin , Yang Zhiwen
Published: April 2024

In this paper, based on the experimental fitting method of recycled concrete beams with corroded rebar, finite element analysis by changing the values of factors affecting the flexural capacity was conducted. The results showed that the flexural capacity of recycled concrete beams increased with the increase of section width and height.
Seismic performance analysis of long-span continuous rigid frame bridge with Engineered Cementitious Composite at expansion joints
Authors: Yuan Jiaquan , Xiong Li , Feng Luyang , Jiang Weihong , Duan Wenhong , Li Guanrui , Li Huimei , Mou Lin , Yang Xiaohua
Published: April 2024

In this paper, OpenSees software is used to establish a numerical simulation analysis model of a long-span continuous rigid frame bridge with Engineered Cementitious Composite (ECC) expansion joint reinforcement scheme. The seismic response characteristics and laws of structures with ordinary concrete and ECC concrete at expansion joints are compared and analyzed, and their seismic performance is evaluated. The results show that the use of ECC material at the beam end position can effectively reduce the peak response of the structure under earthquake action and reduce the number of collisions. ECC material has a strong energy dissipation capacity and can reduce the collision damage of the beam section near the bridge expansion joint under earthquake action.
Simulation Analysis of Wind Collecting Device for A Vertical Axis Wind Turbine
Authors: Zhou Li , Long Yixin , Wang Fuzi , Yang Jiangfeng , Shou Zihe , Jia Qiubing , Sun Fengyan , Yang Hailu
Published: April 2024

In this paper, a wind collection device (WCD) is designed for vertical axis wind turbine, and the WCD and vertical axis wind turbine are modelled by SolidWorks software and numerically simulated by CFD software FLUENT for the WCD and vertical axis wind turbine before and after installing the WCD. The wind amplification effect of the WCD is demonstrated from different angles and the final results show that the WCD can amplify the wind speed from 5m/s to 8m/s and double the rotational speed of the wind turbine in a certain area, which is of certain reference significance in the field of wind power generation using traffic wind energy.
Damage Research of the Cut-and-Cover Tunnel under Static and Seismic Load
Authors: Wang Shupei , Li Sheng , Ma Li , Qiao Minglei , Wang Qicai , Chen Zhigang
Published: April 2024

This article uses the finite element software ABAQUS to establish an damage constitutive model for cut-and-cover tunnels, which studies the damage parameters for different filling heights under static load and damage evolution under seismic load. It is found that high filling has a significant impact on the damage of cut-and-cover tunnels, and earthquake waves affect the degree and distribution of lining damage. By studying the model of setting the LRL, it was found that it can effectively reduce the degree of damage. Therefore, it is necessary to set a LRL for high backfill cut-and-cover tunnels. And the damage parameters of different parts of the cut-and-cover tunnel are analyzed, and it was found that the arch crown and arch shoulder of the cut-and-cover tunnel were the most prone to damage. Therefore, reinforcement measures should be taken in the structural design.
Study on the Seismic Performance of High-Speed Railway Extradosed Cable-Stayed Bridge Considering CRTS III Slab Ballastless Track Structure
Authors: Quan Wei , Yu Hongming , Deng Lin , Liu Xuzheng , Wang Dongsheng
Published: April 2024

This paper explores the seismic damping mechanism and performance of CRTS III slab ballastless track on an isolation system extradosed cable-stayed bridge during rare earthquakes. It serves as a guide for designing slab ballastless tracks on high-speed railway extradosed cable-stayed bridges. Using a high-speed railway extradosed cable-stayed bridge as a case study, we established a Midas finite element model to optimize the track plate parameters by adjusting the fastener stiffness and plate joint length. The optimization process and method can be applied as a reference for similar bridge designs. The research findings reveal that, under rare earthquake conditions, the CRTS III slab ballastless track model (with a plate joint length of 90mm and fastener stiffness of 30kN/mm) has a minimal impact on increasing the longitudinal internal force at the pier’s base. It, at most, raises the earthquake internal force response by 5%. The model significantly reduces the overall relative displacement of the bridge pier and girder, with a notable 15.5% reduction in the relative displacement of pier 143# on the side pier. Therefore, when conducting internal force tests for the bridge, it is crucial to consider the influence of track plate restraint.
Shared pooled mobility: expert review from nine disciplines and implications for an emerging transdisciplinary research agenda
Authors: Creutzig Felix , Schmaus Alexander , Ayaragarnchanakul Eva , Becker Sophia , Falchetta Giacomo , Hu Jiawei , Goletz Mirko , Guéret Adeline , Nagel Kai , Schild Jonas , Schill Wolf-Peter , Schlenther Tilmann , Molkenthin Nora
Published: April 2024

Shared pooled mobility has been hailed as a sustainable mobility solution that uses digital innovation to efficiently bundle rides. Multiple disciplines have started investigating and analyzing shared pooled mobility systems. However, there is a lack of cross-community communication making it hard to build upon knowledge from other fields or know which open questions may be of interest to other fields. Here, we identify and review 9 perspectives: transdisciplinary social sciences, social physics, transport simulations, urban and energy economics, psychology, climate change solutions, and the Global South research and provide a common terminology. We identify more than 25 000 papers, with more than 100 fold variation in terms of literature count between research perspectives. Our review demonstrates the intellectual attractivity of this as a novel perceived mode of transportation, but also highlights that real world economics may limit its viability, if not supported with concordant incentives and regulation. We then sketch out cross-disciplinary open questions centered around (1) optimal configuration of ride-pooling systems, (2) empirical studies, and (3) market drivers and implications for the economics of ride-pooling. We call for researchers of different disciplines to actively exchange results and views to advance a transdisciplinary research agenda.
Ultra-low loss compact active TM mode pass polarizer using phase change material in silicon waveguide
Authors: V Nishanthika , Natesan Ayyanar , Sugesh R G Jesuwanth , Siva Rajaram
Published: April 2024

An active low-loss transverse magnetic (TM) pass polarizer, based on the phase change material (Ge2Sb2Te5), is proposed. The proposed polarizer is based on silicon-on-insulator technology that consists of a silicon waveguide that incorporates a thin layer of Si3N4 placed in-between GST. Enhancing the interaction between light and GST is achieved by strategically placing a double-layer GST adjacent to the slot waveguide. The polarizer’s tunability, on the other hand, depends on the shift in the refractive index (RI) of GST as it transitions between its crystalline and amorphous phases. By optimizing the structure, the polarizer exhibits negligible loss for both modes in the amorphous phase, and with the change of phase to crystalline, the loss of TE mode is more than 8 dB. In contrast, the loss of TM is less than 0.05 dB with a high ER of 21.82 dB, propagation length of 79.89 µm and Figure of merit reaches up to 108 at 1550 nm. Due to the combination of these performance parameters, the suggested active TM pass polarizer is an appealing and effective device for various photonic applications. In addition, the fabrication technique of the proposed active TM pass polarizer is explained.
Strong spin-phonon coupling in two-dimensional monolayer VS2 and the origin of its high-temperature magnetism
Authors: Zhang Shuo , Zhang Yunfei , Jia Minghao , Chang Pu , Guan Lixiu , Tao Junguang
Published: April 2024

Exploring intrinsic two-dimensional (2D) ferromagnetic (FM) semiconductors with high Curie temperatures (T
c) is an ongoing challenge. Herein, we found that the phonons of monolayer H-VS2 are strongly coupled to the magnetic ordering with the spin-phonon coupling constants (15.80 cm−1 for

A

1
g

and 78.72 cm−1 for

E

2
g

1

) an order of magnitude larger than most other 2D materials, which restricts structural reconstruction of FM ground state through spin interactions. Based on anharmonic model, the variation trend of phonon energy with temperature clearly demonstrates FM ground state at room temperature. The theoretically predicted high T
c of 303 K, closely in line with experimental observations, is correlated to the three lowest d-orbitals (i.e.

d

x
y

,

d

z
2

and

d

x
2

−

y
2

) split by the unique crystal field. The proximity of their energy levels facilitates efficient mutual virtual exchanges, which greatly prompts superexchange-driven FM coupling of adjacent spins, as confirmed by their orbital-resolved magnetic exchange coefficients. Our work validates the double-orbital model for the magnetic coupling mechanisms in 2D H-VS2, offers potentials to create novel high T
c spintronic semiconductors and paves a way for design of complex micro/nano-magnetoelectric devices.
Neural-network-designed three-qubit gates robust against charge noise and crosstalk in silicon
Authors: Kanaar David W , Kestner J P
Published: April 2024

Spin qubits in semiconductor quantum dots are a promising platform for quantum computing, however, scaling to large systems is hampered by crosstalk and charge noise. Crosstalk here refers to the unwanted off-resonant rotation of idle qubits during the resonant rotation of the target qubit. For a three-qubit system with crosstalk and charge noise, it is difficult to analytically create gate protocols that produce three-qubit gates, such as the Toffoli gate, directly in a single shot instead of through the composition of two-qubit gates. Therefore, we numerically optimize a physics-informed neural network to produce theoretically robust shaped pulses that generate a Toffoli-equivalent gate. Additionally, robust

π
2

X and Controlled-Z gates are also presented in this work to create a universal set of gates robust against charge noise. The robust pulses maintain an infidelity of 10−3 for average quasistatic fluctuations in the voltage of up to a few mV instead of tenths of mV for non-robust pulses.
Transferring predictions of formation energy across lattices of increasing size*
Authors: Lupo Pasini Massimiliano , Karabin Mariia , Eisenbach Markus
Published: April 2024

In this study, we show the transferability of graph convolutional neural network (GCNN) predictions of the formation energy of the nickel-platinum solid solution alloy across atomic structures of increasing sizes. The original dataset was generated with the large-scale atomic/molecular massively parallel simulator using the second nearest-neighbor modified embedded-atom method empirical interatomic potential. Geometry optimization was performed on the initially randomly generated face centered cubic crystal structures and the formation energy has been calculated at each step of the geometry optimization, with configurations spanning the whole compositional range. Using data from various steps of the geometry optimization, we first trained our open-source, scalable implementation of GCNN called HydraGNN on a lattice of 256 atoms, which accounts well for the short-range interactions. Using this data, we predicted the formation energy for lattices of 864 atoms and 2048 atoms, which resulted in lower-than-expected accuracy due to the long-range interactions present in these larger lattices. We accounted for the long-range interactions by including a small amount of training data representative for those two larger sizes, whereupon the predictions of HydraGNN scaled linearly with the size of the lattice. Therefore, our strategy ensured scalability while reducing significantly the computational cost of training on larger lattice sizes.