bluuebunny/crossref_metadata_2025 huggingface dataset:
A cost-effective and high efficient Janus membrane for the treatment of oily brine using membrane distillation
Authors: Liu Lang , Wang Wei , Hong Ye
Published: April 2024

Membrane distillation technology could utilize low-grade heat to desalinate brine, but the membrane material often suffers from disadvantages of low permeation flux and weak robustness to contaminants. To address these issues, the commercial polytetrafluoroethylene (PTFE) membrane was modified by cost-effective chemicals of tannic acid and (3-Aminopropyl)-triethoxysilane (APTES) to construct hydrophilic/underwater superoleophobic nano-rough structures on the surface to enhance its flux and oil-fouling resistance in direct contact membrane distillation. The results show that a high underwater oil contact angle of 180° is observed to the membrane surface due to the rough nanostructures functionalized by abundant hydroxyl groups. Despite the additional mass transfer resistance provided by the rough nanostructures, the flux was increased noticeably. This is mainly attributed to the strong interactions between the abundant hydroxyl groups of hydrophilic layer surface and water molecules, leading to a part of free water staying at intermediate transition state (IW). The mass transfer resistance of the hydrophilic layer itself is reduced as a consequence of decreased evaporation enthalpy of water, thereby increasing the flux. Moreover, while the flux of the pristine membrane is reduced by 84.18%, the flux of Janus membrane remains the same when treating mineral oil brine emulsions with oil concentration up to 1500 ppm in comparison with the result for 35 g l−1 brine solution, indicating that the Janus membrane is safe from the oil contamination. Our work provides a fine guidance for membrane distillation to treat high oily brine.
Silicon-based transient electronics: principles, devices and applications
Authors: Zhao Haonan , Liu Min , Guo Qinglei
Published: April 2024

Recent advances in materials science, device designs and advanced fabrication technologies have enabled the rapid development of transient electronics, which represents a class of devices or systems that their functionalities and constitutions can be partially/completely degraded via chemical reaction or physical disintegration over a stable operation. Therefore, numerous potentials, including zero/reduced waste electronics, bioresorbable electronic implants, hardware security, and others, are expected. In particular, transient electronics with biocompatible and bioresorbable properties could completely eliminate the secondary retrieval surgical procedure after their in-body operation, thus offering significant potentials for biomedical applications. In terms of material strategies for the manufacturing of transient electronics, silicon nanomembranes (SiNMs) are of great interest because of their good physical/chemical properties, modest mechanical flexibility (depending on their dimensions), robust and outstanding device performances, and state-of-the-art manufacturing technologies. As a result, continuous efforts have been made to develop silicon-based transient electronics, mainly focusing on designing manufacturing strategies, fabricating various devices with different functionalities, investigating degradation or failure mechanisms, and exploring their applications. In this review, we will summarize the recent progresses of silicon-based transient electronics, with an emphasis on the manufacturing of SiNMs, devices, as well as their applications. After a brief introduction, strategies and basics for utilizing SiNMs for transient electronics will be discussed. Then, various silicon-based transient electronic devices with different functionalities are described. After that, several examples regarding on the applications, with an emphasis on the biomedical engineering, of silicon-based transient electronics are presented. Finally, summary and perspectives on transient electronics are exhibited.
The weak mixing property on negatively curved manifolds
Authors: Coudène Yves
Published: April 2024

Given a complete manifold of negative curvature, we show that weak mixing is a generic property in the set of all probability measures invariant by the geodesic flow, as soon as the flow is topologically weakly mixing in restriction to its non-wandering set.
Dual-space disentangled-multimodal network (DDM-net) for glioma diagnosis and prognosis with incomplete pathology and genomic data
Authors: Qiu Lu , Zhao Lu , Zhao Wangyuan , Zhao Jun
Published: April 2024

Objective. Effective fusion of histology slides and molecular profiles from genomic data has shown great potential in the diagnosis and prognosis of gliomas. However, it remains challenging to explicitly utilize the consistent-complementary information among different modalities and create comprehensive representations of patients. Additionally, existing researches mainly focus on complete multi-modality data and usually fail to construct robust models for incomplete samples. Approach. In this paper, we propose a dual-space disentangled-multimodal network (DDM-net) for glioma diagnosis and prognosis. DDM-net disentangles the latent features generated by two separate variational autoencoders (VAEs) into common and specific components through a dual-space disentangled approach, facilitating the construction of comprehensive representations of patients. More importantly, DDM-net imputes the unavailable modality in the latent feature space, making it robust to incomplete samples. Main results. We evaluated our approach on the TCGA-GBMLGG dataset for glioma grading and survival analysis tasks. Experimental results demonstrate that the proposed method achieves superior performance compared to state-of-the-art methods, with a competitive AUC of 0.952 and a C-index of 0.768. Significance. The proposed model may help the clinical understanding of gliomas and can serve as an effective fusion model with multimodal data. Additionally, it is capable of handling incomplete samples, making it less constrained by clinical limitations.
The application of impulse oscillometry system based on machine learning algorithm in the diagnosis of chronic obstructive pulmonary disease
Authors: Zhao Dongfang , Mou Xiuying , Li Yueqi , Yao Yicheng , Du Lidong , Li Zhenfeng , Wang Peng , Li Xiaoran , Chen Xianxiang , Li Xiaopan , Li Yong , Fang Zhen , Xia Jingen
Published: April 2024

Objective. Diagnosing chronic obstructive pulmonary disease (COPD) using impulse oscillometry (IOS) is challenging due to the high level of clinical expertise it demands from doctors, which limits the clinical application of IOS in screening. The primary aim of this study is to develop a COPD diagnostic model based on machine learning algorithms using IOS test results. Approach. Feature selection was conducted to identify the optimal subset of features from the original feature set, which significantly enhanced the classifier’s performance. Additionally, secondary features area of reactance (AX) were derived from the original features based on clinical theory, further enhancing the performance of the classifier. The performance of the model was analyzed and validated using various classifiers and hyperparameter settings to identify the optimal classifier. We collected 528 clinical data examples from the China–Japan Friendship Hospital for training and validating the model. Main results. The proposed model achieved reasonably accurate diagnostic results in the clinical data (accuracy = 0.920, specificity = 0.941, precision = 0.875, recall = 0.875). Significance. The results of this study demonstrate that the proposed classifier model, feature selection method, and derived secondary feature AX provide significant auxiliary support in reducing the requirement for clinical experience in COPD diagnosis using IOS.
Modelling of power exhaust in TCV positive and negative triangularity L-mode plasmas
Authors: Tonello E , Mombelli F , Février O , Alberti G , Bolzonella T , Durr-Legoupil-Nicoud G , Gorno S , Reimerdes H , Theiler C , Vianello N , Passoni M ,   the TCV Team,   the WPTE Team
Published: April 2024

L-mode negative triangularity (NT) operation is a promising alternative to the positive triangularity (PT) H-mode as a high-confinement edge localised mode-free operational regime. In this work, two TCV Ohmic L-mode core density ramps with opposite triangularity

δ
≃
±
0.3

are investigated using SOLPS-ITER modelling. This numerical study aims to investigate the power exhaust differences between NT and PT focusing, in particular, on the geometrical effect of triangularity. To disentangle the latter from differences related to cross-field transport, anomalous diffusivities for particle (

D
n

A
N

) and energy (

χ

e

/

i

A
N

) transport are fixed to the same values in PT and NT. The simulation results clearly show dissimilar transport and accumulation of neutral particles in the scrape-off layer for the two configurations. This gives rise to different ionization sources in the edge and divertor regions and produces differences in the poloidal and cross-field fluxes, ultimately leading to different power and particle divertor fluxes in the two configurations. Simulations recover the experimental feature of a hotter and attached outer target (

T

e
,
OSP

NT

≳
5

eV

) in the NT scenario compared to the PT counterpart.
Study of optical float-zone grown gallium oxide Schottky barrier diode
Authors: Sahoo Jyotiranjan , Vijayakumar P , Saquib Taha , Suganya M , Ganesamoorthy S , Muralidharan Rangarajan , Nath Digbijoy N
Published: April 2024

β
−

Ga
2

O
3

based lateral Schottky barrier diodes are fabricated using Ni/Au as Schottky contact and Ti/Au as Ohmic contact. The Sn-doped

β
−

Ga
2

O
3

sample is grown by the optical float-zone technique. The effect of trenches, which are used for mesa isolation, on breakdown voltage is investigated. The device shows near-ideal characteristics in terms of built-in potential. The parasitic series and shunt resistances are extracted, and their dependency on temperature is established. Modeling of temperature-dependent reverse leakage current is demonstrated using the thermionic emission model, Poole–Frenkel emission model, and Fowler-Nordheim tunneling mechanism. The procedure to extract relevant parameters is explained in terms of bias and temperature dependency. The combined model shows excellent agreement with experimental data over a wide range of bias and temperature. The maximum electric field of 2.3 MV cm−1 is achieved.
The kink-antikink single waves in dispersion systems by generalized PHI-four equation in mathematical physics
Authors: Sahu Itishree , Jena Saumya Ranjan
Published: April 2024

An essential aspect of mathematical physics is the PHI-four equation, which is a specific version of the Klein–Gordon equation that predicts particle physics phenomena. The present paper addresses numerical approaches to generalized PHI-four equation based on Laplace Adomian Decomposition Technique (LADT) which is governed by coupling of Laplace transform and Adomian decomposition method to determine the kink-antikink single waves in dispersion systems arises in mathematical physics. The nonlinear terms in the PHI-four equation are handled using the accelerated polynomial i.e., Adomian polynomial. The approach is extremely interesting computationally and is straightforward to execute. The accuracy and robustness of the current scheme are demonstrated by four test problems. To demonstrate the efficacy of our suggested approach, the current result is contrasted with both the analytical solution and existing solutions in literature. Stability and convergence analysis are well developed to justify the applicability of the current approach.
A dual band CPW-fed MIMO antenna for fifth generation application
Authors: Kansal Parul , Mandpura Anup Kumar , Kumar Narendra
Published: April 2024

This paper presents an innovative integrated dual-band multiple-input multiple-output (MIMO) antenna for the global system for mobile communications band, fed by a coplanar waveguide. The distinctive aspect of this antenna design is its configuration, wherein all the MIMO antenna’s unit cells are placed orthogonal to one another. As a result, there is no need for additional isolation elements to achieve high isolation, simplifying the antenna’s fabrication process. The capability to operate in two frequency bands 3.5 GHz (Wi-Max) and 5.5 GHz (WLAN) is attained by integrating a curved form into the antenna’s radiator elements. Fabricated on an affordable FR-4 dielectric substrate measuring 64 × 64 × 1.6 mm3, the MIMO antenna demonstrates isolation exceeding 18 dB and an envelope correlation coefficient (ECC) of below 0.03. Experimental results from the fabricated four-port dual-band MIMO antenna configuration align with the outcomes of the simulations.
TDiff invariant field theories for cosmology
Authors: Maroto Antonio L.
Published: April 2024

We study scalar field theories invariant under transverse diffeomorphisms
in cosmological contexts. We show that in the geometric optics approximation, the corresponding particles move along geodesics and contribute with the same active mass (energy) to the gravitational field as in Diff invariant theories. However, for low-frequency (super-Hubble) modes, the contributions to the energy-momentum tensor differ from that of Diff invariant theories. This opens up a wide range of possibilities for cosmological model building. As an example, we show that the simplest TDiff invariant scalar field theory with only kinetic term could drive inflation and generate a nearly scale invariant (red-tilted) spectrum of density fluctuations. We also present a detailed analysis of cosmological perturbations and show that the breaking of full Diff invariance generically induces new non-adiabatic pressure perturbations. A simple scalar field dark matter model based on a purely kinetic term that exhibits the same clustering properties as standard cold dark matter is also presented.
Cosmological collider signatures of Higgs-R2 inflation
Authors: Ema Yohei , Verner Sarunas
Published: April 2024

We study the cosmological collider signatures in the Higgs-R
2 inflation model. We consider two distinct types of signals: one originating from the inflaton coupling to Standard Model fermions and gauge bosons, and another arising from the isocurvature mode interaction with the inflaton. In the former case, we determine that the signal magnitude is likely too small for detection by upcoming probes, primarily due to suppression by both the Planck scale and slow-roll parameters.
However, we provide a detailed computation of the signal which could be potentially applicable to various Higgs inflation variants. For the isocurvature mode signals, we observe that the associated couplings remain unsuppressed when the isocurvature mode is relatively light or comparable to the inflationary scale. In this case, we study the Higgs-R
2 inflation parameter space that corresponds to the quasi-single-field inflation regime and find that the signal strength could be as large as |f
NL| > 1, making Higgs-R
2 inflation a viable candidate for observation by future 21-cm surveys.
Numerical Simulation of Double-row Piles in Deep Foundation Pit Excavation
Authors: Wang Hui , Zhao Yujing , Liu Jialiang , Ma Jiaheng , Li Zhiyong
Published: April 2024

This paper aims to investigate the stress and deformation characteristics of double-row piles in deep foundation pit excavation by selecting representative strata in the Changchun area. The changes in bending moment, displacement, and earth pressure of double-row piles during the excavation are established using the FALC 3D software. The findings indicate that the deformation of the front pile is larger than that of the back pile, and the earth pressure distribution of the fornt pile deviates from the conventional Rankine earth pressure theory. Moreover, there are noticeable variations in earth pressure at the soil layer interface of the rear pile.
A Digital Twin Model of High-Pile Docks’ Structures based on Neo4j Knowledge Graph
Authors: Lu Shan , Jie Yaqi , Xu Xinyi , Tong Jiale
Published: April 2024

High-pile docks plays a vital role in modern civil engineering field. The operational efficiency and structural safety of these docks are paramount. However, structural damage to high-pile docks can lead to economic and human losses. To effectively manage structural health monitoring information for high-pile docks, this research utilizes knowledge graph technology to construct a visual knowledge repository for high-pile docks, named as the High-Pile Dock Knowledge Graph (DKG-Neo4j). For the construction of DKG-Neo4j, a plethora of literature, news, and standards related to health monitoring in the field of high-pile docks were gathered. Then, the collected information was organized hierarchically and categorized into tables, with CSV files exported using Python. Finally, this aggregated information was integrated into the Neo4j graph database to establish a comprehensive knowledge graph. The proposed High-Pile Dock Knowledge Graph (DKG-Neo4j) not only reflects the current state of the docks but also captures the connections between issues and maintenance strategies, empowering experts to engage in structural health monitoring and risk analysis. The DKG-Neo4j model boasts structural flexibility and scalability, contributing to smart cities and providing new approaches for the sustainable development of high-pile docks and the digital management of civil engineering.
Analysis of Displacement Influence of Span of Prestressed Fish-Belly Beam on Foundation Pit Plane
Authors: Pang Sen , Zhou Ziqing , Ma Kai , Wang Changjun , Wang Jian , Zhu Hongguang
Published: April 2024

As a new technology of antagonistic internal support, prestressed fish-bellied steel support system has been widely used in various foundation pit projects because of its advantages such as reutilization, effective displacement control and large mechanical operation space. But at present, the plane layout depends on experience, and has not yet formed a set of complete and reasonable plane layout methods. In the plane layout, the corner brace is arranged according to the condition of the plane stress balance of the corner brace, then the brace is arranged based on the corner brace balance theory, and finally the optimal span of the fish-belly beam is selected. The displacement diagram of supporting structure is obtained by using Midas/Gen with the span of fish-belly beam as the variable, the influence of the span of fish-belly beam on the horizontal displacement of foundation pit is analyzed, the relationship formula between the span of fish-belly beam and the size of foundation pit is obtained, and the plane layout method of prestressed fish-belly beam system is proposed.
Seismic Response Analysis of Continuous Beam Bridges with Engineered Cementitious Composite (ECC) in Plastic Hinge Region
Authors: Yuan Jiaquan , Xiong Li , Jiang Weihong , Duan Wenhong , Li Huimei , Li Xi , Mou Lin , Yang Xiaohua , Feng Luyang
Published: April 2024

This study investigates the seismic performance of potential plastic hinge regions in small and medium-sized bridges using Engineered Cementitious Composite (ECC) concrete. A 4×40m continuous beam bridge is used as an example, with time-history analysis conducted using the OpenSees finite element software, and the type of concrete material in the cross-section of the bridge pier’s plastic hinge region is varied to analyze the structural natural vibration characteristics and seismic responses of the bridge structure under earthquake action. The time-history analysis of seismic motion shows that after replacing the bridge pier’s plastic hinge region with ECC, the stiffness of the bridge pier significantly decreases, and the natural vibration period of the bridge increases. Under the action of longitudinal earthquakes, the energy dissipation capacity and seismic performance of the bridge pier increase with the increase in ECC content in the plastic hinge region at the bottom of the bridge pier. Furthermore, under earthquake action, the concrete at the edge of the cross-section using ordinary concrete throughout cracks under tension, while the tensile stress in the cross-sections using different proportions of ECC concrete remains the same and does not crack under tension, remaining elastic under compression, which also reflects the good seismic performance of ECC concrete.
Study on Influence of Tension Height of Steel Strand on Displacement of Foundation Pit Supported by Fish-bellied beams
Authors: Pang Sen , Ma Kai , Zhou Ziqing , Wang Changjun , Wang Jian , Zhu Hongguang
Published: April 2024

The steel support system of prestressed fish-bellied beams can reliably control the deformation of foundation pit and provide open excavation space for foundation pit excavation, in which the triangle plate plays an important role in the fish-bellied beams system. But the deformation of the triangle plate and the steel strand is too large is a common problem in the foundation pit support, through the analysis of the stability of the triangle plate, it is found that the tension point height is an important factor leading to the deformation of too large. Through MIDAS/GEN analysis, it is found that the increase of the tension point height of the strand is conducive to the control of the displacement of the connecting part, and with the increase of the tension point of the strand, the anti-impact stability of the fish-bellied beams system is gradually enhanced. Therefore, by changing the tension height of the steel strand, the supporting system of the fish-bellied beams is optimized.
Experimental Study on the Effect of Corrosion-inhibiting Admixtures on Chloride Corrosion Resistance of Concrete
Authors: Zeng Kelin , Sun Wenjin , Sun Lizhou , Liu Longlong
Published: April 2024

Compared to the different types of rust inhibitors, The effects of the internal and external coating corrosion inhibitors on the corrosion resistance of concrete were studied. The impact of the mixed rust inhibitor on the working performance, compressive strength and chloride ion permeability coefficient of concrete was investigated. The results show that the working performance, late mechanical properties, and resistance to chlorine salt erosion of concrete are better than those of reference concrete after adding the anti-rust agent. Comparing the effects of 2% and 4% internal rust inhibitors on the corrosion resistance of chloride ions, based on the control group, the chloride ion diffusion coefficient of concrete with 2% and 4% rust inhibitors decreases to the original 15.1% and 37.0%, respectively. Concrete’s chloride ion diffusion coefficient with external rust inhibitor decreases to 62.5%. In addition, the internal corrosion inhibitor has a specific water-reducing component, which reduces the water consumption of concrete and improves the compactness of concrete itself, thus improving the corrosion resistance of concrete.
Channeling of fluorescence photons from quantum dots into guided modes of an optical nanofiber tip
Authors: M Resmi , Bashaiah Elaganuru , Yalla Ramachandrarao
Published: April 2024

We demonstrate the channeling of fluorescence photons from quantum dots (QDs) into guided modes of an optical nanofiber tip (ONFT). We deposit QDs on the ONFT using micro/nano fluidic technology. We measure the photon-counting and emission spectrum of fluorescence photons that are channeled into guided modes of the ONFT. The measured emission spectrum confirms the deposition of QDs on the ONFT. We perform numerical simulations to determine channeling efficiency (η) for the ONFT and a single dipole source (SDS) system. For the radially oriented SDS at the center of the facet of the ONFT, we found the maximum η-value of 44% at the fiber size parameter of 7.16, corresponding to the ONFT radius of 0.71 µm for the emission wavelength at 620 nm. Additionally, we investigate the SDS position dependence in transverse directions on the facet of the ONFT in view of keeping experimental ambiguities. The present fiber inline platform may open new avenues in quantum technologies.
Wide-angle ultrabroadband absorption in black phosphorus/dielectric multilayer anisotropic metamaterials
Authors: Qing Ye Ming , Wang Hongfei , Lei Dangyuan
Published: April 2024

An ultrabroadband far-infrared absorber is achieved using an anisotropic metamaterial composed of alternating black phosphorus (BP) and dielectric films arranged in a trapezoidal structure. We numerically demonstrate that ultrabroad bandwidths (with >90% absorptivity) can be achieved with the strong anisotropic dielectric response of BP, namely 63.6 μm along the armchair direction and 53.6 μm along the zigzag direction. Importantly, the high absorption is maintained across a wide range of incident angles. Our simulation results align well with analytical calculations based on the effective medium theory, considering the multilayer structure as an effective homogeneous metamaterial with anisotropic permittivity. From the distribution profiles of magnetic fields, we observe tight trapping of different wavelengths at varying widths of the trapezoidal absorber, revealing the slow-light effect underlying the broadband absorption. Our study holds significant potential for device applications, such as BP-based broadband infrared photodetectors.
Specular transformation of electromagnetic partially coherent beams with a wave-folding interferometer
Authors: Tang Miaomiao , Dong Shijie , Yang Yunzhe , Zhou Yujie , Guo Mengwen , Li Xinzhong
Published: April 2024

We consider a class of specular or anti-specular vector beams, by illuminating stochastic vector beams into a prism-based wavefront-folding interferometer. Such transform is applied to various genuine model input beams, and then the properties of the resulting fields are discussed. Numerical results show that the specular nature of these vector fields not only creates sharp internal spectral density distribution, but also produces novel polarization patterns with oscillations or a central dip on the degree of polarization-profile. Such optical characteristics can be flexibly modulated by the correlation structure of the source. We also suggest that the specular transform could be efficiently employed in developing novel partially coherent vector beams.
Circular dichroism in nonlinear topological Weyl semimetals
Authors: Alomeare Helda , Nutku Ferhat , Sarısaman Mustafa
Published: April 2024

In recent years, the field of topological photonics has emerged as a promising area of research due to its potential for the development of new photonic devices with unique properties. Topological Weyl semimetals (TWSs), which are characterized by the presence of Weyl points in their electronic band structure, are one such example of a material with interesting topological properties. In this study, Kerr and Faraday rotations were used to determine the nonlinear characteristics of TWSs. We focused on surfaces where no Fermi arcs are involved, so that Maxwell’s equations would contain some peculiar topological terms. In Weyl semimetals with a specific topology, the distance between Weyl nodes aligned along the z-direction functions as a magnet. This results in a significant polar Kerr/Faraday rotation effect that is proportional to the separation distance, when light is directed onto the surface of the TWS that lacks Fermi arc states. Conversely, when the light is directed onto a surface with Fermi arc states, the Voigt effect is quadratically proportional to the separation distance. We considered electromagnetic wave propagation in a nonlinear Kerr-type medium. We have derived and solved the linear and nonlinear Helmholtz equations for TWSs using the tanh method. Our findings reveal that wave solutions could have some potentially significant implications for the design and optimization of photonic devices based on TWSs.
Emission current enhancement from quasi-freestanding epitaxial graphene microstructure electron emitters through surface layered silicon dioxide
Authors: Lewis Daniel , Swart Jason , Pedowitz Michael , DeMell Jennifer , Jordan Brendan , Myers-Ward Rachael L , Pennachio Daniel J , Hajzus Jenifer R , Daniels Kevin M
Published: April 2024

Enhanced electron emission from oxide-encapsulated quasi-freestanding bilayer epitaxial graphene devices is reported, including one emission current of 9.4 µA and successful emission even with oxide thicknesses of up to 1.25 µm. The low operating temperature (215 °C), and applied electric fields under which the devices operate indicate electron emission is due to phonon-assisted electron emission, wherein forward-scattering hot phonons impart the necessary energy for the electrons to escape the graphene as an emission current. A suite of device structures and behaviors are cataloged, and various emission behaviors are demonstrated through encapsulating oxide layers. Emission current enhancement due to electron multiplication in the oxide layers is observed across multiple devices and oxide thicknesses.
Effect on microstructure and mechanical properties of friction stir welded 5A06 aluminum alloy joints by deep cryogenic treatment
Authors: Du Jingjing , Qiao Mengke , Wang Jun , Zhang Liang , Bian Wenzhuo , Wang Huixia , Sun Rui , Zhang Yongdi , Su Shan
Published: April 2024

In order to improve the comprehensive mechanical properties of the welded joints of the 5A06 aluminum alloy, friction stir welded (FSW) joints were subjected to deep cryogenic treatment (DCT). The microstructure and mechanical properties were characterised using metallographic microscopy, x-ray diffractometer (XRD), energy spectrometer, microhardness tests, and tensile tests. The experimental results show that DCT refines the structure significantly due to the large temperature difference. This refinement results from an increase in Mg atoms within the α-Al solid solution through the precipitation of Al atoms, forming the Al3Mg2 phase. This enhancement in plasticity is achieved through dispersion distribution. Moreover, as the treatment time of DCT increases, the mechanical properties of the welded joint also improve significantly. The microhardness of the welding joint peaked at DCT3h, rising from 78.8 HV at DCT0h to 87.2 HV at DCT3h. Meanwhile, the tensile strength of the joint reached its maximum at DCT12h, rising from 358.7 MPa at DC0h to 385.3 MPa at DCT12h, representing a 7.4% increase. These experimental results underscore the significant impact of DCT on improving the welded joints.
Study on the tribological and rheological properties of magnetorheological fluids based on different base oils
Authors: Yu Long , Chen Fei , Li Hao-Peng
Published: April 2024

Base oil has great influence on the tribological and rheological properties of magnetorheological fluid. In this paper, four types of magnetorheological fluid are prepared respectively by silicone oil, mineral oil, synthetic oil (PAO) and castor oil, and their tribological and rheological properties are investigated. Firstly, the viscosity of the magnetorheological fluid is measured by a viscometer. Then the friction coefficient and wear scar diameter of the magnetorheological fluid is measured by a four ball friction testing machine. Next, the sedimentation rate of the magnetorheological fluids is calculated by the observation method. Finally, the shear yield stress of the magnetorheological fluid is measured by a rheometer. By analyzing the experimental data, it is concluded that the magnetorheological fluid prepared by white mineral oil and castor oil has excellent wear resistance. The magnetorheological fluid prepared by castor oil has better sedimentation stability and higher shear yield stress. Consequently, the magnetorheological fluid prepared by castor oil has better comprehensive properties.
Spectrally tunable phase-biased NALM mode-locked Yb:fiber laser with nJ-level pulse energy
Authors: Ebrahimzadeh Saeid , Adnan Sakib , Li Yishen , Pecile Vito F , Fellinger Jakob , Salman Sarper , Heyl Christoph M , Hartl Ingmar , Heckl Oliver H , Porat Gil
Published: April 2024

Applications of mode-locked fiber lasers benefit from robust and self-starting mode-locking, spectral tuning, high pulse energy and high average power. All-polarization-maintaining (PM) fiber lasers mode-locked with a phase-biased nonlinear amplifying loop mirror (NALM) have been shown to be very robust and reliably self-starting, and provide either spectral tuning or high pulse energy, but not both. We report on a simple method for concurrent spectral tuning and nanojoule-level pulse energy scaling of an all-PM phase-biased NALM mode-locked Yb:fiber laser, which we demonstrate over a 54 nm tuning range, reaching up to 1.67 nJ pulse energy and 126 mW average power. Unlike other laser configurations, our results show that net normal dispersion is not necessary or optimal for scaling the pulse energy of this type of mode-locked fiber laser.
Plasmonic tuning of nano-antennas for super-gain light amplification
Authors: Aşırım Özüm Emre , Kuzuoğlu Mustafa
Published: April 2024

Nanoscale conductive materials are often used for inducing localized free electron oscillations known as plasmons. This is due to their high electronic excitability under optical irradiation owing to their super-small volume. Recently, plasmons have been of interest for enhancing the gain-bandwidth product of optical amplifiers. There are currently two well-established mechanisms for light amplification. The first one is via stimulated emission of radiation (lasers) using a given energy source and often an optical feedback mechanism. The second one is based on the nonlinear coupling of a low-intensity input wave and a high-intensity pump wave for energy exchange (parametric amplifiers). Both techniques have shortcomings. Lasers have a small operation bandwidth and offer a limited gain, but require moderate energy pumping to operate. Whereas optical parametric amplifiers (OPAs) offer a high operation bandwidth along with a much higher optical gain, with the drawback of requiring intense pumping to be functional. The aim of this paper is to introduce a technique that combines the advantages and eliminates the drawbacks of both techniques in the nanoscale to allow for a better amplification performance in integrated optical devices. This is achieved by inducing a plasmonic chirp in conductive nanomaterials a.k.a nano-antennas, which enables the confinement of an enormous electric energy density that can be coupled to an input beam for amplification. Using the Finite Difference Time Domain numerical-method with the material parameters of well-known semiconductors, intramaterial condensation of electric energy density is observed in semiconductor nano-antennas for certain plasmonic chirp-frequencies which enables broadband high-gain optical amplification based on free-electron oscillations that is promising for small-scale optical devices requiring a high gain-bandwidth product. The results are in good agreement with semiempirical data.
Experimental investigation and optimization of heat pipe heat exchanger performance under two distinct heat transport mediums through TOPSIS approach
Authors: Sethuraman Ramasamy , Muthuvelan Thambidurai , Mahadevan Sivasubramanian , Raman Sakthisadhasivam
Published: April 2024

This paper presents a comprehensive thermal performance analysis of the heat pipe heat exchanger by varying the input process parameters and optimizing the best condition for waste heat recovery through the TOPSIS technique. In this work, the heat pipe is constructed with a copper tube and segmented into evaporator and condenser sections carrying hot and cold fluids with a half-fill ratio. The heat pipe is oriented in 0° horizontally with the wick material made from stainless steel and works based on the capillary principle. The efficiency of the HPHE is evaluated by varying the input operational parameters, namely heat input, mass flow rate of hot fluid, inlet temperature of hot fluid, and mass flow rate of cold fluid, on response variables, specifically thermal resistance, energy balance ratio, universal heat transfer coefficient, and effectiveness. The experiment was designed for four factors at three levels as per Taguchi’s L27 orthogonal array, and the best optimising condition was determined by employing the multi-objective technique for order preference by similarity to ideal solution (TOPSIS) approach. The best input condition found was A3B1C1D3, in which the heat input was at 90 W, the mass flow rate of hot fluid was at 0.2 kg min−1, the mass flow rate of cold fluid was at 0.1 kg min−1, and the inlet temperature was at 60 °C. The effect of process parameters and their significance on output responses was analysed by executing an analysis of variance (ANOVA) statistical method. The mathematical regression model was generated, and validation was made to investigate the prediction error percentage.
Toral band Fatou components for the Weierstrass ℘ function
Authors: Hawkins Jane , Koss Lorelei
Published: April 2024

We study the existence of unbounded Fatou components for the iterated Weierstrass

℘
\wp

function and discuss its dependence on lattice shapes. We show that there are open regions in shape space for lattices in

C

\mathbb {C}

for which scalings of the lattice (real and complex) yield unbounded toral band Fatou components.
The epidemiology of dying within 48 hours of presentation to emergency departments: a retrospective cohort study of older people across Australia and New Zealand
Authors: Sweeny Amy L , Alsaba Nemat , Grealish Laurie , Denny Kerina , Lukin Bill , Broadbent Andrew , Huang Ya-Ling , Ranse Jamie , Ranse Kristen , May Katya , Crilly Julia
Published: April 2024

Background

Emergency department (ED) clinicians are more frequently providing care, including end-of-life care, to older people.

Objectives

To estimate the need for ED end-of-life care for people aged ≥65 years, describe characteristics of those dying within 48 hours of ED presentation and compare those dying in ED with those dying elsewhere.

Methods

We conducted a retrospective cohort study analysing data from 177 hospitals in Australia and New Zealand. Data on older people presenting to ED from January to December 2018, and those who died within 48 hours of ED presentation, were analysed using simple descriptive statistics and univariate logistic regression.

Results

From participating hospitals in Australia or New Zealand, 10,921 deaths in older people occurred. The 48-hour mortality rate was 6.43 per 1,000 ED presentations (95% confidence interval: 6.31–6.56). Just over a quarter (n = 3,067, 28.1%) died in ED. About one-quarter of the cohort (n = 2,887, 26.4%) was triaged into less urgent triage categories. Factors with an increased risk of dying in ED included age 65–74 years, ambulance arrival, most urgent triage categories, principal diagnosis of circulatory system disorder, and not identifying as an Aboriginal or Torres Strait Islander person. Of the 7,677 older people admitted, half (n = 3,836, 50.0%) had an encounter for palliative care prior to, or during, this presentation.

Conclusions

Our findings provide insight into the challenges of recognising the dying older patient and differentiating those appropriate for end-of-life care. We support recommendations for national advanced care planning registers and suggest a review of triage systems with an older person-focused lens.
Second Language Learning Difficulty of Chinese Grammar: A Rasch Analysis of Teachers’ Perceptions
Authors: Lin Jia , Lu Yuan
Published: April 2024

This study examined second language (L2) learning difficulty of 13 Chinese grammatical constructions on the basis of teachers’ perceptions and associated the L2 learning difficulty of Chinese grammatical constructions with teacher-perceived learner grammatical competence and with the instructional levels. A total of 77 experienced teachers were invited to rate the learning difficulty of 13 Chinese grammatical constructions with reference to L2 learners at four instructional levels at college. Utilizing the Rasch rating scale model, this study established an L2 Chinese grammar learning difficulty hierarchy and revealed that the learning difficulty hierarchy mostly overlapped with the acquisitional order of Chinese grammar found in L2 Chinese research and with the instructional order in a widely used Chinese textbook. This study enriches our understanding of the multifaceted nature of L2 learning difficulty and the idiosyncratic learning difficulty and pattern associated with each Chinese grammatical construction in L2 development. Implications for Chinese instruction, material development, and assessment are provided.
‘Valuable Lives to Save’ vs. ‘Babysitting These People While They Try to Kill Themselves’: Changing Police Attitudes Towards Safe Consumption Sites
Authors: McNeilly Rebekah , Berardi Luca , Haggerty Kevin D , Bucerius Sandra M , Krahn Harvey
Published: April 2024

North American police responses to the ‘drug issue’ have long been shaped by a crime control rather than a harm reduction imperative. Consequently, police officers’ responses to safe consumption sites (SCSs), where people who use illicit drugs can reduce personal health risks by administering previously obtained drugs in the presence of trained staff, were initially hostile. This paper draws on interview data from police officers in two western Canadian cities to highlight an apparent softening in attitudes, perhaps due to the current fentanyl-driven drug poisoning crisis. While some officers clearly recognized their public health benefits, others accepted SCSs, acknowledging the futility of a continued ‘war on drugs’. Some voiced reservations about SCSs, but not because of a generic ‘drugs are bad’ sentiment. Rather, they worried about specific downstream implications for communities and police work. These findings, reflecting apparent changes in police officers’ responses to SCSs, are discussed in the context of contemporary debates about police culture and the possibilities and desirability of pursuing police reform.
Impact of hospital volume on failure to rescue for complications requiring reoperation after elective colorectal surgery: multicentre propensity score–matched cohort study
Authors: Grönroos-Korhonen Marie T , Koskenvuo Laura E , Mentula Panu J , Nykänen Taina P , Koskensalo Selja K , Leppäniemi Ari K , Sallinen Ville J
Published: April 2024

Background

It has previously been reported that there are similar reoperation rates after elective colorectal surgery but higher failure-to-rescue (FTR) rates in low-volume hospitals (LVHs) versus high-volume hospitals (HVHs). This study assessed the effect of hospital volume on reoperation rate and FTR after reoperation following elective colorectal surgery in a matched cohort.

Methods

Population-based retrospective multicentre cohort study of adult patients undergoing reoperation for a complication after an elective, non-centralized colorectal operation between 2006 and 2017 in 11 hospitals. Hospitals were divided into either HVHs (3 hospitals, median ≥126 resections per year) or LVHs (8 hospitals, <126 resections per year). Patients were propensity score–matched (PSM) for baseline characteristics as well as indication and type of elective surgery. Primary outcome was FTR.

Results

A total of 6428 and 3020 elective colorectal resections were carried out in HVHs and LVHs, of which 217 (3.4%) and 165 (5.5%) underwent reoperation (P < 0.001), respectively. After PSM, 142 patients undergoing reoperation remained in both HVH and LVH groups for final analyses. FTR rate was 7.7% in HVHs and 10.6% in LVHs (P = 0.410). The median Comprehensive Complication Index was 21.8 in HVHs and 29.6 in LVHs (P = 0.045). There was no difference in median ICU-free days, length of stay, the risk for permanent ostomy or overall survival between the groups.

Conclusion

The reoperation rate and postoperative complication burden was higher in LVHs with no significant difference in FTR compared with HVHs.
Narrow mycorrhizal specialization and its effect on early development in the Mediterranean orchid Orchis italica
Authors: Balducci Marco G , Calevo Jacopo , Duffy Karl J
Published: April 2024

The contribution of individual orchid mycorrhizal (OrM) fungi to orchid germination is poorly understood. We isolated Tulasnella OrM fungi from 11 populations representing nine Italian regions associated with the orchid Orchis italica. We performed in vitro germination experiments using both single and two OrM isolate combinations of Tulasnella and Ceratobasidium isolates found in O. italica and co-occurring orchids. We performed an in situ reciprocal translocation experiment of O. italica seeds in two populations and we experimentally planted seeds into two unoccupied sites to test whether the presence of suitable OrM may limit its distribution. In vitro, Tulasnella isolates initiated germination, but only two isolates resulted in seedling development, while seeds did not germinate in the presence of Ceratobasidium isolates. Combinations of two Tulasnella isolates had lower germination rates compared to single isolates. Reciprocal translocations revealed that seeds from the same population had higher germination rates. Protocorms developed in one unoccupied site, with the associated fungus identified as Tulasnella spp. These results suggest that Tulasnella vary in their efficacy in seed germination and O. italica has a narrow specialization on Tulasnella. Such information is important for understanding the range limits of orchids and their ecological dependency on OrM fungi.
The subcortical default mode network and Alzheimer’s disease: a systematic review and meta-analysis
Authors: Seoane Sara , van den Heuvel Martijn , Acebes Ángel , Janssen Niels
Published: April 2024

The default mode network is a central cortical brain network suggested to play a major role in several disorders and to be particularly vulnerable to the neuropathological hallmarks of Alzheimer’s disease. Subcortical involvement in the default mode network and its alteration in Alzheimer’s disease remains largely unknown. We performed a systematic review, meta-analysis and empirical validation of the subcortical default mode network in healthy adults, combined with a systematic review, meta-analysis and network analysis of the involvement of subcortical default mode areas in Alzheimer’s disease. Our results show that, besides the well-known cortical default mode network brain regions, the default mode network consistently includes subcortical regions, namely the thalamus, lobule and vermis IX and right Crus I/II of the cerebellum and the amygdala. Network analysis also suggests the involvement of the caudate nucleus. In Alzheimer’s disease, we observed a left-lateralized cluster of decrease in functional connectivity which covered the medial temporal lobe and amygdala and showed overlap with the default mode network in a portion covering parts of the left anterior hippocampus and left amygdala. We also found an increase in functional connectivity in the right anterior insula. These results confirm the consistency of subcortical contributions to the default mode network in healthy adults and highlight the relevance of the subcortical default mode network alteration in Alzheimer’s disease.