bluuebunny/crossref_metadata_2025 huggingface dataset:
Universality of hydroxyl radical generation in irradiated nanoenhancer suspensions: Vital role of concentration
Authors: Yang Changfeng , Zhang Bowen , Lin Xiaoqian , Han Qinglin , Bao Hongze , Liu Yan
Published: May 2024

Concentration plays an essential role in generating hydroxyl radicals in irradiated nanoenhancer suspensions. In this paper, we used coumarin-3-carboxylic acid as a hydroxyl radical-specific probe to investigate the hydroxyl radical production of different concentration nanodiamonds (NDs) and CeO2 NPs in phosphate-buffered saline under x-ray irradiation. NDs significantly enhanced hydroxyl radical production, and the maximum enhancement of hydroxyl radical production was observed at a concentration of 10 µg/ml, with an enhanced factor of 1.398 ± 0.262. CeO2 NPs can increase and scavenge hydroxyl radicals at different concentration ranges, with the lowest and highest enhanced factors of 0.623 ± 0.069 and 1.738 ± 0.264, respectively. We tested the hydrodynamic diameter at various concentrations to explore the concentration effect further. We found that with increasing concentration, there might be factors, such as hydroxyl radical recombination and nanoparticle agglomeration, that lead to changes in the enhancement factor. Based on the data from previous and present studies, the experimental results indicate that the concentration factor is essential for hydroxyl radical generation in nanoenhancer suspensions under ionizing radiation. We also provide possible mechanisms for enhancing hydroxyl radical production by nanoenhancers in water under ionizing radiation and the decrease in enhancement factor at high concentrations of nanoenhancers.
Translocation of two-dimensional active polymers through nanopores using Langevin dynamics simulations
Authors: Hu Han-Xian , Shen Yi-Fan , Luo Meng-Bo
Published: May 2024

The translocation of polymers through nanopores is a complex process influenced by various factors. In this study, the translocation behavior of a two-dimensional active polymer chain, comprised of a head active Brownian particle (ABP) and a tail passive polymer chain, through a nanopore is studied using Langevin dynamics simulations. Results show that the effect of the self-propulsion force of the ABP on the translocation differs significantly from the driving force inside the pore for traditional polymer translocations. Specifically, the translocation time τ initially increases with increasing the magnitude fs of the self-propulsion force and then decreases with a further increase in fs. A small fs lowers the potential barrier for the translocation and thus promotes slow translocations, whereas a large fs directly pulls the polymer chain through the nanopore following the scaling relation τ ∝ fs−1. Moreover, two asymptotic scaling relations between τ and polymer length N, τ ∝ Nα, are found, with the exponent α of about 2.5 for small fs or long N and the exponent α of about 1.4 for short active polymers with large fs. We discover that the slow rotation of the ABP accelerates the translocation process.
Resilience of finite clusters of carbon flux network under localized attack
Authors: Qing Ting , Wang Fan , Du Ruijin , Dong Gaogao , Tian Lixin
Published: May 2024

The investigation into the resilience of the carbon flux network regarding its capability to sustain the normal flow and transformation of carbon under extreme climatic events, pollutant emissions, biological invasions, and other factors, and the stability of connections between its nodes, has not yet been deeply studied. In this study, we developed carbon flux network models for various regional lands using complex networks, percolation theory, and introducing time delay effects using carbon flux daily data from 2000 to 2019 for three regions: China, the mainland United States, and Europe, to measure the resilience of finite clusters with sizes greater than or equal to s of the carbon flux network under localized attack. The analysis revealed that the carbon flux networks in different regions are characterized by a degree distribution consistent with the Poisson distribution. The carbon flux network demonstrated continuous phase transition behavior under localized attack. Interestingly, numerical simulation revealed a consistent relationship between the carbon flux network and the theoretical Erdős–Rényi network model. Moreover, the carbon flux network becomes more vulnerable as s increases. In addition, we discovered that there is a general scaling relationship of critical exponent δ≈−2 between the fraction of finite clusters and s. Therefore, investigating the resilience of carbon flux networks can enable us to predict and respond to the various risks and challenges, which will help policy designers formulate appropriate response strategies and enhance carbon flux systems’ stability and resilience.
On the orientation dependence of the pressure and frictional drag experienced by spheroids in creeping flow
Authors: Ouchene R.
Published: May 2024

The present work deals with the creeping flow past a single oblate or prolate spheroid. On the basis of the investigations by Aoi [J. Phys. Soc. Jpn. 10, 119 (1955)] on the contributions of pressure and frictional drag to the total drag experienced by spheroids when the fluid streams with a speed parallel to the axis of symmetry, we find that the pressure contribution corresponds to half of the dimensionless shape factor γ0 provided by Happel and Brenner, Low Reynolds Number Hydrodynamics (Prentice-Hall Inc. Englewood Cliffs, NJ, 1965). Accordingly, we conjecture the validity of this finding when the fluid streams with a speed perpendicular to the axis of symmetry. Therefore, the formulations of dimensionless shape factors α0/2 and β0/2 are confronted with the numerical results at particle Reynolds number of 0.1. Furthermore, the formulations of the pressure and the frictional drag are deduced and extended to any orientation relative to the flow direction. These results give physical insight into the total drag experienced by spheroids in creeping flow and can be helpful for the validation of simulations of the flow past an obstacle.
How is enrolment with a general practice associated with subsequent use of the emergency department in Aotearoa New Zealand? A cohort study
Authors: Pledger Megan , Irurzun-Lopez Maite , Mohan Nisa , Cumming Jacqueline
Published: May 2024

Introduction Around 5% of the people in Aotearoa New Zealand (NZ) are not enrolled with a general practice. Aim This study aimed to explore the utilisation of general practice by enrolment status and subsequent use of an emergency department. Methods We compared a cohort of respondents from New Zealand Health Surveys (2013/14–2018/19) on self-reported general practice utilisation and their substitutes, according to their enrolment status (enrolled and not enrolled). They were then followed up to examine their subsequent use of an emergency department. Time to an emergency department presentation was modelled with proportional hazards regression models with enrolment status as the explanatory variable. Confounding variables used were sex, age group, prioritised ethnicity, the New Zealand Deprivation Index and self-rated health. Results Those not enrolled were more likely to be young, male, Asian, more socioeconomically deprived and with better health status than those enrolled. Generally, those not enrolled utilised general practice services less. Those not enrolled who had used an emergency department were more likely to have used it as a substitute for general practice (40% vs 26%). Modelling showed that those not enrolled took longer to access an emergency department. Adjusting for confounding variables did not change that interpretation. Discussion Those not enrolled were younger and healthier and may have a perception that enrolment isn’t necessary. As a group, they were more likely to be socioeconomically deprived and to use an emergency department, which is free at a public hospital in NZ, as a substitute for primary care which suggests that cost may influence their choices.
Boosting thermal energy transport across the interface between phase change materials and metals via self-assembled monolayers
Authors: Shan Zi-Yu , An Meng , Zhang Xing , Zhang Hai , Ma Wei-Gang
Published: May 2024

Thermal energy storage using phase change materials (PCMs) has great potential to reduce the weather dependency of sustainable energy sources. However, the low thermal conductivity of most PCMs is a long-standing bottleneck for large-scale practical applications. In modifications to increase the thermal conductivity of PCMs, the interfacial thermal resistance (ITR) between PCMs and discrete additives or porous networks reduces the effective thermal energy transport. In this work, we investigated the ITR between a metal (gold) and a polyol solid–liquid PCM (erythritol) at various temperatures including temperatures below the melting point (300 and 350 K), near the melting point (390, 400, 410 K, etc) and above the melting point (450 and 500 K) adopting non-equilibrium molecular dynamics. Since the gold-erythritol interfacial thermal conductance (ITC) is low regardless of whether erythritol is melted or not (<40 MW m−2 K−1), self-assembled monolayers (SAMs) were used to boost the interfacial thermal energy transport. The SAM with carboxyl groups was found to increase the ITC most (by a factor of 7–9). As the temperature increases, the ITC significantly increases (by ∼50 MW m−2 K−1) below the melting point but decreases little above the melting point. Further analysis revealed that the most obvious influencing factor is the interfacial binding energy. This work could build on existing composite PCM solutions to further improve heat transfer efficiency of energy storage applications in both liquid and solid states.
Synthesis and high-frequency magnetoelectric characterization of the 0–3 particulate lead-free multiferroic composite KNN/CFO
Authors: Gualdi Alexandre José , Dos Santos Batacline Leonardo , Correia Espírito Santo Gustavo , Alkathy Mahmoud S , Zabotto Fabio Luis
Published: May 2024

The research for lead-free magnetoelectric (ME) multiferroic composite materials has increased considerably because they are environmentally friendly. For composites with 0–3 connectivity, synthesis with lead-free phase has proven challenging to obtain high values of ME coupling. This work reports the successful synthesis of the KNN/CFO composite (K0.5N0.5NbO3/CoFe2O4) by conventional synthesis process. XRD and SEI showed two well-defined, also presenting good electric polarization values. The ME coefficient was very high, reaching values close to 2850 mV cm−1·Oe at the electromechanical resonance frequency. The dipolar interaction between the electric charges and magnetic moments of the KNN and CFO phases was responsible for the high value and the behavior of dependence on the applied magnetic field.
Absolute measurement of vacuum ultraviolet fluxes from inductively coupled plasmas via metal surface photoemission currents
Authors: Richmond Josef L , Machacek Joshua R , Davoodianidalik Mahdi , Tsifakis Dimitrios , Charles Christine , Boswell Roderick W
Published: May 2024

Quantifying vacuum-ultraviolet (VUV) fluxes typically requires vacuum-compatible spectrometers and is often associated with significant cost and effort. A simple technique for the absolute measurement of local VUV fluxes from plasmas using the photoemission from a set of coated metal plates, is described. The radiant power from a 13.56 MHz hydrogen plasma operating at 40–87 mTorr and with an radio frequency (RF) input power from 100 to 120 W was investigated by irradiating a set of 2 cm diameter Au, Ag and Cu plates. The variation in photoemission currents was compared with the photoelectric yield curves to estimate the absolute flux incident on the surfaces in the 113–190 nm range. The measured fluxes were found to have an uncertainty of 5%–30% when compared with the VUV spectrometer measurements. The VUV output power was found to have a maximum at a pressure of 70–80 mTorr and to increase with RF power. In all cases, the VUV output power was measured to be approximately 12%–16% of the RF input power to the matching network, in good agreement with spectroscopy results.
Reply to comment on ‘Composition-based aluminum alloy selection using an artificial neural network’
Authors: Fatriansyah Jaka Fajar , Rizqillah Raihan Kenji , Suhariadi Iping , Federico Andreas , Kurniawan Ade
Published: May 2024

This reply is addressed to comments on our paper entitled ‘Composition-based Aluminum Alloy Selection Using an Artificial Neural Network.’ There are six main comments, and we addressed the comments carefully. This machine learning (ML) modeling is only part of the development of a broader material selection (or material screening) system. Consideration of other material properties can certainly be included through the integration of ML systems.
Tunable deformation design of porous Al2O3 based on the Direct FE2 method
Authors: Zhao Ang , Liu Kui , Li Pei , Cui Yehui
Published: May 2024

The tunable deformation design of porous ceramics has raised many interests in many engineering and manufacturing fields, where its corresponding design methodologies still suffer from the lower efficiency and higher computational cost. To handle this problem, a novel optimization and design methodology based on the Direct FE2 method has been proposed in this study, and several numerical examples of the porous Al2O3 tunable deformation design has been performed by this novel methodology. Compared with the traditional methodologies, the proposed method is more convenient to conduct the tunable deformation design and improves the optimization efficiency. Based on this method, the distribution and assembly of the microscale representative volume element could be tailored along the space dimension to handle the sinusoidal deformation and variable Poisson’s ratio ceramic design at the macroscale. By comparing the simulation results with the direct numerical simulation model, the effectiveness and accuracy of this methodology is well validated. Meanwhile, the simulation results based on the proposed methodology found that the predictability of porous Al2O3 deformation could be enhanced by changing the micro structure parameters such as the elliptical hole angle and aspect ratio. This methodology holds great potential for applications in the design and optimization of porous ceramics with tailored deformation characteristics.
Experimental sharing of Bell nonlocality with projective measurements
Authors: Xiao Ya , Xin Rong Yan , Wang Shuo , Hong Han Xin , Shi Xu Jin , Yong Jian Gu
Published: May 2024

In the standard Bell experiment, two parties perform local projective measurements on a shared pair of entangled qubits to generate nonlocal correlations. However, these measurements completely destroy the entanglement, rendering the post-measurement state unable for subsequent use. For a long time, it was believed that only unsharp measurements can be used to share quantum correlations. Remarkably, recent research has shown that classical randomness assisted projective measurements are sufficient for sharing nonlocality (Steffinlongo and Tavakoli 2022 Phys. Rev. Lett.
129 230402). Here, by stochastically combining no more than two different projective measurement strategies, we report an experimental observation of double Clauser–Horne–Shimony–Holt inequality violations with two measurements in a sequence made on each pair of maximally and partially entangled polarization photons. Our results reveal that the double violation achieved by partially entangled states can be 11 standard deviations larger than that achieved by maximally entangled ones. Our scheme eliminates the requirement for entanglement assistance in previous unsharp-measurement-based sharing schemes, making it experimentally easier. Our work provides possibilities for sharing other types of quantum correlations in various physical systems with projective measurements.
Spectral and timing analysis of NGC 7314
Authors: Kalli Siham , Zoghbi Abderahmen , Costantini Elisa
Published: May 2024

The analysis of X rays observations from the active galactic nuclei is a good tool to study the properties of the supermassive black hole, the physics of the accretion disk and the corona, and to model their geometries. We present a detailed spectral and timing analysis of the Seyfert galaxy NGC 7314, we used all available public XMM-Newton and NuSTAR observations from 2001 to 2016. In order to improve the spectral modeling, we used both relativistic and non relativistic reflection models. We confirmed the presence of narrow and Broad Iron lines and we obtained constraints for other spectral proprieties. For the timing analysis, we first studied the behaviour of the power density spectrum, then we studied the time delays between the direct X rays emission and the reflected emission from the accretion disk, we measure reverberation in at least one observation, but we do not see it in others, suggesting it may be a transient phenomenon.
Relativistic atomic structure calculations of Li-like ions used for plasma diagnostic studies
Authors: Singh Gajendra , Singh A K , Chowdhuri M B , Nandi T
Published: May 2024

We have carried out atomic structure calculations using systematically enlarged multiconfiguration Dirac-Fock wavefunctions of Li-like ions of the most prominent plasma impurities (Ar, Ti, Fe, Ni, Kr and W) found in presently working tokamaks. Relativistic Breit interaction and quantum electrodynamic (QED) corrections such as vacuum polarization and self-energy corrections are also included in the calculations prior to the evaluation of low lying energy levels, transition probabilities, oscillator strengths and line strengths. Selective radiative data for electric dipole and magnetic quadrupole transitions are also reported. Special emphasis is given in the computations of fundamental quantities such as oscillator strengths as they are widely used in atomic data and analysis structure (ADAS) databases to evaluate quantities such as effective collision strengths. Present computed values are compared with existing available results on NIST database and few similar earlier computations and a good agreement has been found. We believe that the detailed atomic data with the relativistic and QED corrections will assist in spectroscopic studies such as accurate line identification and plasma modelling work in tokamak plasma, laser induced breakdown spectroscopy (LIBS), highly charged ions clocks and astrophysical observations.
Pressure effects on the structural, electronic, elastic, optical, and vibrational properties of YMg intermetallic compounds: a first-principles study
Authors: Ciftci Yasemin O , Çatıkkaş Berna
Published: May 2024

The properties of YMg in B2 structure have been comprehensively analysed using the first-principles plane-wave pseudopotential method. Specifically, the structural, electronic, elastic, vibrational, and optical properties were investigated using the generalized gradient approximation (GGA) method in the context of density functional theory. The Vienna ab initio simulation package (VASP) was utilized for these calculations. The computed lattice parameter (3.803 Å) and bulk modulus (41.33 GPa) are consistent with the earlier data on ambient pressure. The electronic band structure and energy-dependent density of states reveal the metallic nature of the titled compounds. The Born stability requirements confirmed the mechanical stability. The analysis of Pugh’s and Poisson’s ratios and Cauchy’s pressure reveals that YMg is ductile under the pressures in consideration. According to several anisotropy indices, the compound is noticeably anisotropic both in ambient and under pressure. Our investigation includes an analysis of several fundamental mechanical parameters of the material, including the bulk modulus, the pressure derivative of the Zener anisotropy factor, Poisson’s ratio, isotropic shear modulus and Young’s modulus with a particular focus on their dependence on pressure. We have determined that the elastic constants obtained remain mechanically stable, satisfying the Born Stability conditions even at high pressures of up to 60 GPa. To explore the dynamic stability of YMg, we analysed the material’s phonon dispersion curves. The examined compound displays stability under dynamic conditions from 0 GPa to 30 GPa, as evidenced by its positive vibration frequencies. However, this stability is not sustained under higher pressure, as the compound becomes unstable after 30 GPa to 70 GPa. The electronic band structure and density of states diagrams demonstrate YMg’s metallic properties. At atmospheric pressure (0 GPa), the total density of states (TDOS) near the Fermi level is approximately 1.63 states/eV, with pressure application reducing DOS. The dielectric function, refractive index, and energy loss spectra are examined within the 0–20 eV energy range. YMg exhibits its highest absorption between 4 and 11 eV. The peak optical conductivity is observed around 0.78 eV (equivalent to 1589.5409 nm), while the most significant energy loss occurs at 11.90 eV, roughly corresponding to 2.8 Hz in the ultraviolet spectrum. Moreover, we extensively analyzed the material’s phonon thermodynamic and optical properties, providing insights into its behavior under various conditions. The outcomes acquired at zero pressure are generally coherent with the current theoretical values.
First-principles study on the structural, elastic, electronic, optical and thermophysical properties of NaNO3 and K-doped NaNO3
Authors: Mehra Vidya , Ahmad Tahir , Agrawal Anju , Jha P K , Nautiyal Arvind , Semalty P D
Published: May 2024

The current work illustrates the optical, thermophysical, electronic, elastic, and structural characteristics of pure and K-doped NaNO3 obtained using DFT calculations. Electronic characteristics such as band structure, projected and total density of states of pure and doped NaNO3 are analyzed where the calculated band gaps for pure and K-doped NaNO3 were discovered to be 3.05 eV and 2.90 eV, respectively. The Berry–phase calculations carried out on both systems showed the existence of ferroelectric polarization, where an enhanced spontaneous polarization value of 36 μC/cm2 for K-doped NaNO3, as compared to 20 μC/cm2 for intrinsic NaNO3 is obtained. The thermophysical properties such as bulk modulus (B0), Debye temperature (θ
D), and specific heat capacity (Cv) were calculated over a wide temperature range from 0 K to 800 K. The linear optical properties namely the dielectric constant, refractive index, electron energy loss function, absorption and extinction coefficient are calculated in wide energy range from 0 to 30 eV and discussed in detail.
A feature enhanced EEG compression model using asymmetric encoding–decoding network
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Authors: Wang Xiangcun , Zhang Jiacai , Wu Xia
Published: May 2024

Objective. Recently, the demand for wearable devices using electroencephalography (EEG) has increased rapidly in many fields. Due to its volume and computation constraints, wearable devices usually compress and transmit EEG to external devices for analysis. However, current EEG compression algorithms are not tailor-made for wearable devices with limited computing and storage. Firstly, the huge amount of parameters makes it difficult to apply in wearable devices; secondly, it is tricky to learn EEG signals’ distribution law due to the low signal-to-noise ratio, which leads to excessive reconstruction error and suboptimal compression performance. Approach. Here, a feature enhanced asymmetric encoding–decoding network is proposed. EEG is encoded with a lightweight model, and subsequently decoded with a multi-level feature fusion network by extracting the encoded features deeply and reconstructing the signal through a two-branch structure. Main results. On public EEG datasets, motor imagery and event-related potentials, experimental results show that the proposed method has achieved the state of the art compression performance. In addition, the neural representation analysis and the classification performance of the reconstructed EEG signals also show that our method tends to retain more task-related information as the compression ratio increases and retains reliable discriminative information after EEG compression. Significance. This paper tailors an asymmetric EEG compression method for wearable devices that achieves state-of-the-art compression performance in a lightweight manner, paving the way for the application of EEG-based wearable devices.
Uniqueness of the Eigenvalue Inverse Problem for a Class of X-type Matrices with Linear Relations
Authors: Yu Tong , Li Zhibin , Wang Lidong
Published: May 2024

Constraining a matrix by adding additional conditions to determine the matrix if given eigenpairs is called the eigenvalue inverse problem for matrices. The eigenvalue inverse problem of a matrix can be based on a given combination of different eigenvectors and real numbers to inverse a matrix method, and the method of inversion varies for different types of matrices. In this paper, we investigate the eigenvalue inverse problem for a class of X-type matrices characterized by linear relations, Invert the matrix based on its characteristics, determine eigenvalues and eigenvectors, and finally, prove that the solution of the problem exists and is unique, derive a series of expressions and recursive formulas, and we also check the algorithm’s accuracy correctness by giving different instances.
An Iterative Algorithm for Maximal and Minimal Solutions of a Class Matrix Equations
Authors: Li Lin , Su Dongqing , Zhao Xuejun
Published: May 2024

In the paper, the peak solutions of a class equation is studied, the peak solutions are the maximal and minimal solutions. There is an iterative algorithm given for the solutions of the class equation. First, the existence of the peak solutions of the class equations is obtained. Second, when the peak solutions exist, an iterative algorithm is established to converge to the peak solutions of the class equation. By an upper bound and a lower bound of the solutions of the equation solution as the initial matrix, the iterative algorithm of the paper converges to the peak solutions of the class equation. The convergence problem of the algorithm is proved by the mathematical induction in the paper. The above results are verified by the examples.
Optimal Transport Approaches for Cloud Fusion in 3D Reconstruction
Authors: Chen Duo
Published: May 2024

Cloud fusion plays a crucial role in achieving accurate 3D models. This paper introduces two optimal transport-based approaches, Gaussian Fusion and Cyclical Fusion, to showcase the effectiveness of optimal transport in establishing dense correspondence among incoming 3D point clouds. These approaches encompass several important components. Firstly, the fusion correspondences are derived from the optimal transport problem. The core principle of Gaussian Fusion and Cyclical Fusion involves manipulating points along geodesic curves to effectively leverage significant local geometric information. Secondly, this paper explores the fundamental concepts underlying Gaussian Fusion (displacement interpolation) and Cyclical Fusion (cyclical monotonicity), which greatly enhance the accuracy and completeness of the reconstruction process. And provides evidence for the uniqueness of displacement interpolation as geodesics on L2-Wasserstein space and the rationality of cyclical monotonicity in this context. Finally, the proposed approaches excel in capturing intricate surface details, particularly on small objects, when compared to the original fusion scheme which often introduces severe artifacts.
Rician Noise Removal in Low-noise Condition via a Deep Unfolding Network
Authors: Fei Tiancheng , Feng Xiangchu
Published: May 2024

Nuclear magnetic resonance (NMR) signals as the key role of research on denoising, are mainly influenced by Rician noise. Restoring clean Rician medical images from signal-related Rician noise is a challenging task with great practical significance. In this paper, an energy function based on MAP estimation is proposed, mainly for conditions of low noise, where the noise distribution is approximately Gaussian. Then the mathematical model is embedded into the network structure to realize the knot of knowledge-driven and network learning. The experiment shows that the proposed model only uses simple and lightweight network modules and a small amount of training data, which has a better denoising effect and has achieved satisfactory results under the two evaluation indexes.
Research on Expansion Coefficient Based on Water Temperature Density Regression Function
Authors: Wei Fengjun , Liu Chunhua , Zhang Fengxia , Guo Rendong , Hu Jilei , Che Chuanxun
Published: May 2024

Based on the regression function of water temperature and water density, two expressions of the thermal expansion coefficient function of water are obtained by integrating and differentiating the function. Compared with the measured data, the theoretical formula of the integral method is in good agreement with the measured accumulated thermal expansion coefficient of water obtained by the cumulative step size. The theoretical formula of the differential method is in good agreement with the measured cumulative thermal expansion coefficient of water obtained by equal step size and variable step size. Therefore, no matter the theoretical formula of the integral method or differential method, it can be used for the thermal expansion coefficient of water with cumulative step size or with finite equal step size or finite variable step size. The theoretical formula of the thermal expansion coefficient of water with integral method and differential method is of high precision and easy to use.
Numerical Simulation of Airflow Velocity and Temperature Distribution in an Aircraft Cabin
Authors: Tan Jingqi , Chen Lijun , Wang Lei , Guo Wenjun , Pan Jun , Wang Xiaoping
Published: May 2024

In this work, a computational fluid dynamics (CFD) model is established to calculate the airflow distribution in the cabin of a single-channel Boeing 737-800 airplane. The RNG k-ε model, considering the calculation of turbulence kinetic energy and its rate of dissipation, is adopted to solve turbulence problems in physical field simulation. The proposed three-dimensional model is able to consider the particular physical factors and spatial structures, which can simulate the detailed distributions of complex physical fields, compared with the one-dimensional lumped parameter model. The velocity and temperature fields under different air supply velocities are then numerically investigated. The calculation results show that when the air velocity at the top air supply inlet is 1.4 m/s, the velocity and temperature distribution inside the cabin can both meet the comfort requirements of humans in the airworthiness standards. The results from this work can help to design an aircraft environmental control system.
Effect of Chute on Gas Flow and Temperature of the Top of Blast Furnace
Authors: Cheng Xiaoman , Cheng Shusen
Published: May 2024

The top gas temperature is an apparent indicator of the distribution state of gas flow, and it is an important parameter to judge the furnace condition. It is related to the top equipment in addition to the charge characteristics and bottom-up generation and distribution. Therefore, the fluid-solid heat transfer model from burden surface -chute-rising ducts is established in this paper. The finite element method is used to calculate the flow and heat transfer of the gas at the top of the blast furnace, and the influence of the chute on the top gas temperature is analyzed. The accuracy of the model is verified by the actual blast furnace top temperature. The results show that the chute has a guiding effect on the gas flow. As the chute rotates, the top gas temperature fluctuates. This research is helpful for actual blast furnace operators to understand the top temperature and make the condition judgment more accurate.
Experimental evaluation of a vapour compression refrigeration system using a nano-oil mixture of TiO2, Al2O3, and SiO2
Authors: Madyira D.M , Babarinde T.O
Published: May 2024

Nanolubricants were used to improve the performance of refrigeration systems in a household refrigerator. In this study, a pure lubricant is used as the base compressor lubricant, and nanoparticles of TiO2, Al2O3, and SiO2 at 0.4g/L concentrations are used as nanolubricants in 50g isobutane (R600a) refrigerants. Power consumption was investigated alongside the COP. TiO2 nanolubricant has the highest COP of 2.8 and the lowest power consumption of 11.3% when compared to based lubricant. However, in terms of power consumption, SiO2 and Al2O3-nanolubricant outperformed the based lubricant by 4.5% and 7.7%, respectively. This suggests that a nanolubricant could be used in a refrigeration system to replace a based lubricant with R600a refrigerant.
The role of Palm Fronds Charcoal Waste Particles On Mechanical, Thermal, and Acoustic Insulation Properties of Epoxy Composite
Authors: Ahmed Zainab W , Kadim Adil I
Published: May 2024

The main objectives of the current study are to improve the mechanical, thermal, physical and sound insulation properties of an epoxy composite, in addition to reducing environmental pollution resulting from the burning of palm kernel waste, which results from annual periodic cleaning of the palms trees, which have been disposed of by burning it. Charcoal Waste Particles of Palm Fronds Base have been used for epoxy matrix as a naturalistic reinforcement particulate material, risk-free, and non-toxic to enhance its features. The charcoal waste particles have been used in weight rates of 0, 2.5, 5, 7.5, and 10%. As stated by the results, the reinforcement process by charcoal waste particles increased the tensile strength value from 8.78 MPa to 13.64 MPa, with a 55%, and increased the elastic modulus value from 0.67MPa to 3.63MPa, with a rate 437%. Moreover, additionally, increased the bending strength from 0.1MPa to 0.64MPa, with a 540%, the hardness value increased from 58.87 to 74 (Shore D No) with a rate 26%, as well as the wear rate has been decreased. Thermal conductivity has dropped by 30% from the pure sample’s value of 0.15W/m. °C to 0.11W/m. °C. Concerning the Acoustic insulation’s, the results demonstrate that the specimens decreased the transferred acoustic energy levels from 103.3 to 95.2dB with rate 8%, with regard to the density of the prepared specimens it has been decreased from 1.55g/cm3 to 1.35g/cm3 and the results show that the liquid absorption rates have been decreased for all composite specimens.
Enhancement of swimming pool water quality by nanotechnology
Authors: Yousef Farman Halla , Hasan Al-Anbari Riyadh , Haider Adawiya J.
Published: May 2024

Because of the hazards associated with the use of chlorine in pool water treatment, a commercial polysulfone ultrafiltration membrane was utilized. These membranes were coated with varying concentrations of Ag-ZnO nanomaterial (0.05, 0.1, 0.2) and employed in a filter system designed to imitate the swimming pool water treatment process. The experiment lasted three months (April, May, and June) and was carried out for three days each month. The impact of nano-Ag-Zno on the UF nanocomposite membrane was investigated. To analyze the mechanical properties of the membranes, scanning electron microscopy (SEM), porosity, and contact angle were used. The findings reveal that treating the substrates with Ag-ZnO enhanced their hydrophilicity and porosity. Acommercial polysulfone membranes were coated with amixture of Ag-ZnO nanoparticles using the spray pyrolysis technique. The impact of nano-Ag-ZnO on the UF nanocomposite membrane was investigated. To analyze the mechanical properties of the membranes, SEM and contact angle were used. According to the findings, applying Ag-Zno in different concentration to the substrates boosted their hydrophilicity and porosity and aconcentration (2%) could achieve the goal of the research, which is to reduce the use of chlorine disinfection by eliminating Escherichia Coli bacteria, which considered acommon species in swimming pool water.
B-diketon Derived Ligands Metal Complexes, Synthesize, Characterization, and Bioactivity Studies
Authors: Rasheed Ali Fatima , Hassan Hasan A.
Published: May 2024

The precursor in our study 2, 2’- ((1E,1’E) - (4,4’- diamino - 5, 5’- dimethyl - [1,1’-biphenyl]-3, 3’-diyl) bis(diazene-2,1-diyl) diphenol (W1) or (W2) 3,3’-dimethyl-5,5’-bis((E)-pyridin-3-yldiazenyl)-[1,1’-biphenyl]-4,4’-diamine were obtained from reaction of diazonium salt with tolidin. The both precursors used for synthesis of the ligands [H4L1] and [H2L2] by reaction with di benzyl methan to produce the ligands [H4L1]2,2’-((1E,1’E)-(4,4’-bis((3-hydroxy-1,3-diphenylpropylidene)amino)-5,5’-dimethyl-[1,1’-biphenyl]-3,3’-diyl)bis(diazene-2,1-diyl))diphenoland [H2L2] 3,3’-((3,3’-dimethyl-5,5’-bis((E)-pyridin-3-yldiazenyl)-[1,1’-biphenyl]-4,4’-diyl)bis(azaneylylidene))bis(1,3-diphenylpropan-1-ol). Elemental microanalysis, 1H and 13C-NMR, FT-IR, U.V, mass spectroscopies were used to describe the structure of the ligands. In this research we also reported the complexes synthesis via reaction of of [NiII, MnII, CoII, CdII, CuII] chloride salts with ligands, using KOH as a base and ethanol as a solvent, under reflux. Complexes were characterized by atomic absorption, (FT-I.R, U.V-Vis, 1H and 13C-NMR and mass) spectroscopies along with conductivity, magnetic susceptibility and melting point measurements. The presence of crystallized water molecule insured by thermal analysis in some complexes structure. Finally, the synthesized ligands and complexes biological activity studied against selected organisms.
The Simulation of Double Head Streamer Discharge in a 0.5 cm Air Gap
Authors: Abdulameer Maha. F. , Khalaf Thamir H.
Published: May 2024

The production and evolution of the double-head streamer discharge in air, as well as the characteristics of positive & negative streamers, were described in this work using a computer simulation method. Streamer discharge in a 0.5 cm air’ gap has been modeled and simulated by the fluid model. Under DC voltage, the model was tested using an axisymmetric plane-to-plane electrode layout in two dimensions. The model was implemented in commercial computation software COMSOL Multiphysics version 6.0 based on finite element method (FEM), in which a time-dependent solver was used. Results indicated that negative streamers travel more quickly than positive ones’, the charged particles (electrons and ions) density have the range of (1013 – 1014) cm−3 in both positive & negative streamer and the breakdown time for the gap (0.5cm) occurs in several nanoseconds.
Segmentation and quantitative analysis of optical coherence tomography (OCT) images of laser burned skin based on deep learning
Authors: Wu Jingyuan , Ma Qiong , Zhou Xun , Wei Yu , Liu Zhibo , Kang Hongxiang
Published: May 2024

Evaluation of skin recovery is an important step in the treatment of burns. However, conventional methods only observe the surface of the skin and cannot quantify the injury volume. Optical coherence tomography (OCT) is a non-invasive, non-contact, real-time technique. Swept source OCT uses near infrared light and analyzes the intensity of light echo at different depths to generate images from optical interference signals. To quantify the dynamic recovery of skin burns over time, laser induced skin burns in mice were evaluated using deep learning of Swept source OCT images. A laser-induced mouse skin thermal injury model was established in thirty Kunming mice, and OCT images of normal and burned areas of mouse skin were acquired at day 0, day 1, day 3, day 7, and day 14 after laser irradiation. This resulted in 7000 normal and 1400 burn B-scan images which were divided into training, validation, and test sets at 8:1.5:0.5 ratio for the normal data and 8:1:1 for the burn data. Normal images were manually annotated, and the deep learning U-Net model (verified with PSPNe and HRNet models) was used to segment the skin into three layers: the dermal epidermal layer, subcutaneous fat layer, and muscle layer. For the burn images, the models were trained to segment just the damaged area. Three-dimensional reconstruction technology was then used to reconstruct the damaged tissue and calculate the damaged tissue volume. The average IoU value and f-score of the normal tissue layer U-Net segmentation model were 0.876 and 0.934 respectively. The IoU value of the burn area segmentation model reached 0.907 and f-score value reached 0.951. Compared with manual labeling, the U-Net model was faster with higher accuracy for skin stratification. OCT and U-Net segmentation can provide rapid and accurate analysis of tissue changes and clinical guidance in the treatment of burns.
Effect of toroidal mode coupling on explosive dynamics of m/n = 3/1 double tearing mode
Authors: LU 路 Xingqiang 兴强 , GAO 高 Ge 歌 , MA 马 Zhiwei 志为 , GUO 郭 Wei 玮 , LI 李 Xin 鑫
Published: May 2024

The CLT code was used to quantitatively study the impact of toroidal mode coupling on the explosive dynamics of the m/n = 3/1 double tearing mode. The focus of this study was on explosive reconnection processes, in which the energy bursts and the main mode no longer dominates when the separation between two rational surfaces is relatively large in the medium range. The development of higher m and n modes is facilitated by a relatively large separation between two rational surfaces, a small q
min (the minimum value of the safety factor), or low resistivity. The relationships between the higher m and n mode development, explosive reconnection rate, and position exchange of 3/1 islands are summarized for the first time. Separation plays a more important role than q
min in enhancing the development of higher m and n modes. At a relatively large separation, the good development of higher m and n modes greatly reduces the reconnection rate and suppresses the development of the main mode, resulting in the main mode not being able to develop sufficiently large to generate the position changes of 3/1 islands.
Roadmap on methods and software for electronic structure based simulations in chemistry and materials
Authors: Blum Volker , Asahi Ryoji , Autschbach Jochen , Bannwarth Christoph , Bihlmayer Gustav , Blügel Stefan , Burns Lori A , Crawford T Daniel , Dawson William , de Jong Wibe Albert , Draxl Claudia , Filippi Claudia , Genovese Luigi , Giannozzi Paolo , Govind Niranjan , Hammes-Schiffer Sharon , Hammond Jeff R , Hourahine Benjamin , Jain Anubhav , Kanai Yosuke , Kent Paul R C , Larsen Ask Hjorth , Lehtola Susi , Li Xiaosong , Lindh Roland , Maeda Satoshi , Makri Nancy , Moussa Jonathan , Nakajima Takahito , Nash Jessica A , Oliveira Micael J T , Patel Pansy D , Pizzi Giovanni , Pourtois Geoffrey , Pritchard Benjamin P , Rabani Eran , Reiher Markus , Reining Lucia , Ren Xinguo , Rossi Mariana , Schlegel H Bernhard , Seriani Nicola , Slipchenko Lyudmila V , Thom Alexander , Valeev Edward F , Van Troeye Benoit , Visscher Lucas , Vlček Vojtěch , Werner Hans-Joachim , Williams-Young David B , Windus Theresa L.
Published: May 2024

This Roadmap article provides a succinct, comprehensive overview of the state of electronic structure (ES) methods and software for molecular and materials simulations. Seventeen distinct sections collect insights by 51 leading scientists in the field. Each contribution addresses the status of a particular area, as well as current challenges and anticipated future advances, with a particular eye towards software related aspects and providing key references for further reading. Foundational sections cover density functional theory and its implementation in real-world simulation frameworks, Green’s function based many-body perturbation theory, wave-function based and stochastic ES approaches, relativistic effects and semiempirical ES theory approaches. Subsequent sections cover nuclear quantum effects, real-time propagation of the ES, challenges for computational spectroscopy simulations, and exploration of complex potential energy surfaces. The final sections summarize practical aspects, including computational workflows for complex simulation tasks, the impact of current and future high-performance computing architectures, software engineering practices, education and training to maintain and broaden the community, as well as the status of and needs for ES based modeling from the vantage point of industry environments. Overall, the field of ES software and method development continues to unlock immense opportunities for future scientific discovery, based on the growing ability of computations to reveal complex phenomena, processes and properties that are determined by the make-up of matter at the atomic scale, with high precision.
Femtosecond laser-induced nanoparticle implantation into flexible substrate for sensitive and reusable microfluidics SERS detection
Authors: Hu Yongxiang , Zhou Yu , Luo Guohu , Li Dege , Qu Minni
Published: May 2024

Surface-enhanced Raman spectroscopy (SERS) microfluidic system, which enables rapid detection of chemical and biological analytes, offers an effective platform to monitor various food contaminants and disease diagnoses. The efficacy of SERS microfluidic systems is greatly dependent on the sensitivity and reusability of SERS detection substrates to ensure repeated use for prolonged periods. This study proposed a novel process of femtosecond laser nanoparticle array (NPA) implantation to achieve homogeneous forward transfer of gold NPA on a flexible polymer film and accurately integrated it within microfluidic chips for SERS detection. The implanted Au-NPA strips show a remarkable electromagnetic field enhancement with the factor of 9 × 108 during SERS detection of malachite green (MG) solution, achieving a detection limit lower than 10 ppt, far better than most laser-prepared SERS substrates. Furthermore, Au-NPA strips show excellent reusability after several physical and chemical cleaning, because of the robust embedment of laser-implanted NPA in flexible substrates. To demonstrate the performance of Au-NPA, a SERS microfluidic system is built to monitor the online oxidation reaction between MG/NaClO reactants, which helps infer the reaction path. The proposed method of nanoparticle implantation is more effective than the direct laser structuring technique. It provides better performance for SERS detection, robustness of detection, and substrate flexibility and has a wider range of applications for microfluidic systems without any negative impact.
Sustainable engineering of human hair fiber-composite in engineering application
Authors: S Dinesh , M Narasimharajan , R Ramadoss , C Elanchezhian
Published: May 2024

The hybrid composite material, resulting from the fusion of human hair and Kevlar 29 synthetic fiber in a 10:1 ratio, reinforced with epoxy resin using the hand layup technique, underwent meticulous mechanical and thermal testing. The investigation encompassed tensile, flexural, and impact property evaluations, elucidating a notable enhancement in mechanical strength with a diminishing synthetic fiber content. Concomitantly, the composite exhibited commendable heat resistance in heat deflection tests, making it potentially suitable for applications in elevated temperature environments. Water absorption properties were scrutinized, revealing a correlation between reduced synthetic fiber content and diminished water absorption, implying heightened durability in diverse conditions. Microstructure analysis through SEM provided intricate insights into the internal composition. In summation, the composite, featuring a higher proportion of natural fibers and a lower proportion of synthetics, demonstrated superior mechanical attributes, optimal heat resistance, and reduced water absorption, showcasing its applicability in automotive and engineering domains, particularly in the fabrication of vehicle panels and components. The aim of this research represents a significant advancement in composite materials, offering a cost-effective solution that balances mechanical strength and thermal resistance. It suggests the potential for high-performance materials by combining natural and synthetic fibers, promising versatility across various applications.