bluuebunny/crossref_metadata_2025 huggingface dataset:
Comprehensive evaluation of light pollution based on AHP and EWM integrated model
Authors: Wang Chunxiang , Zhai Jianqiao , Li Ying , Pang Bin
Published: June 2023

With the rapid development of urban economy, the value of China's light resources has been explored, but its impact on ecological environment has also been gradually intensified. In order to establish a universal light pollution measurement standard model, this paper uses the combination of AHP and EWM to determine the index weight, and gives the calculation method and index evaluation standard of theoretical data.

In order to measure the risk level of light pollution numerically, this paper uses the PEST analysis model to construct the light Pollution Risk Index (LPI ) and establish the index group. The Fuzzy Delphi Method is utilized to screen the first-level indicators and the second-level indicators, and finally 4 first-level indicators and 14 second-level indicators are obtained. Using this evaluation model, the degree of light pollution in different areas was evaluated by questionnaires, and the results showed that urban areas had the most serious light pollution. Finally, based on the night sky brightness formula, this paper analyzed the sensitivity of the algorithm. The results showed that the selected quantitative indicators have strong stability and the model has strong robustness.
Research on Carbon Reduction Paths in Recycling Industrial Parks based on System Dynamics
Authors: Cao Guoliang , Li Ruixin , Qi Lei , Ning Chen
Published: June 2023

The “double carbon” target is a medium-to-long-term national strategy proposed by China to combat climate change. The industrial sector is one of the key areas for the implementation of the “double carbon” target. Therefore, studying the association between carbon emission factors and carbon emissions is crucial to reduce greenhouse gas emissions from industrial activities. In the present study, the association between factors affecting carbon emissions and carbon emissions in a circular economy were investigated for an industrial park in Northwest China. A carbon emission system dynamics model for this circular economy industrial park was constructed, in reference to the relevant national policies and the current condition of the park. Five different scenarios were utilized to dynamically simulate the impact of rapid economic development, energy restructuring, industrial restructuring, and technological development, and carbon emission reduction paths for industrial parks were explored. The results showed that, the park would peak at 1134.67 thousand tons of CO2 in 2032, according to the baseline scenario, with industrial energy consumption accounting for over 80% of the total emissions. A combined regulation scenario, with increased investment in research and development and environmental management, would achieve a peak in 2030, with a relatively lower peak of 1062.88 thousand tons of CO2. Our findings provides new insights into the paths of carbon emission reduction in recycling industrial parks.
Optimal Operation and Effect Research of Enhanced Denitrification AAO Process for Treating Rural Domestic Sewage
Authors: Chen Le
Published: June 2023

In view of the low concentration of organic matter in rural domestic sewage and the lack of carbon source in the biochemical denitrification process, resulting in excessive total nitrogen in the effluent, the traditional AAO process was improved to enhance the system's biochemical denitrification capacity. Through engineering demonstration, an improved process based on enhanced denitrification AAO process was constructed and applied to a village in Zhejiang Province. This process can ensure the complete separation of mixed liquid denitrification and sludge denitrification. While ensuring the denitrification efficiency, it can further reduce nitrate entering the anaerobic zone, so as to ensure a stable denitrification and phosphorus removal effect. The removal rates of the system for COD, NH3-N, TN, TP and SS are 95.6%, 99.5%, 75.1%, 97.6%, 91.6% respectively, in line with Zhejiang Province's "Water Pollution Discharge Requirements for Rural Domestic Sewage Centralized Treatment Facilities" (DB33 973-2021) Table 1 Level 1 Standard. In addition, the system energy consumption is 0.28 kwh/m³, which meets the requirements of low energy consumption system. This case can provide technical reference for the technical selection of rural domestic sewage treatment in my country.
Research on Remote Automatic Monitoring Method of Atmospheric Salt Fog Concentration Based on Optical Sensor
Authors: Shen Hao , Liu Hui , Jia Ran , Zhou Chao
Published: June 2023

The traditional automatic monitoring method of salt spray concentration has a weak anti-interference ability, which affects the monitoring accuracy. Therefore, a remote automatic monitoring method of atmospheric salt fog concentration based on optical sensor is designed. Determine the optical power loss of salt fog remote monitoring in atmospheric environment, and obtain the relationship between optical power loss and salt density, environmental humidity. Based on optical sensing, a quartz rod monitoring and early warning model under high salt fog environment is established to increase the surface area of the quartz rod, thus improving the anti-interference ability of the remote automatic monitoring device. The simulation experiment verifies that the monitoring method has higher monitoring accuracy and can be applied in real life.
The Impact of Green Credit Policies on Green Innovation in Heavily Polluting Firms: Evidence from China
Authors: Si-gen Song , Min Tian
Published: June 2023

Based on balanced panel data of listed companies from 2007-2017, this paper investigates the causal relationship between green credit policy and green innovation of heavily polluting enterprises. It finds that green credit policies can significantly promote green innovation among heavily polluting firms and that R&D investment mediates the relationship between the two, a finding that passes a series of robustness tests.
Exploration of treatment technology for heavy metal wastewater
Authors: Li Yunchu , Huang Ziyan , Lyu Chenxi , Yan Yijuan , Zhu Shengnan
Published: June 2023

Among the current pollutants in our water bodies, the one that has the greatest degree of pollution and impact on the water environment is heavy metal wastewater. Various heavy metal ions in water bodies can seriously disrupt the ecological balance of water bodies and spread throughout the biosphere through the natural material cycle and other means. Excess heavy metal ions not only seriously endanger the health of aquatic organisms, but can also enrich in animals and even humans, posing a serious threat to human health and causing failure or damage to vital organs such as the human internal organs and brain. The common heavy metal ions in existing water bodies are Cu2+, Hg2+, Pb2+ etc. Due to their inherent difficulty in degradation, enrichment and persistence, heavy metal ions make heavy metal wastewater treatment different from other traditional pollutant treatment methods. This paper examines the two main techniques currently used to remove heavy metals from water bodies: physical, chemical and biological techniques, and summarises the advantages and disadvantages of both methods. It is proposed that future treatment methods for heavy metal wastewater should develop an environmentally friendly and efficient systematic approach based on biotechnology and synergistic multi-technologies.
Study on Adsorption of Heavy Metals Cu and Zn by Microplastics Under Different Aged Factors
Authors: Teng Wenxi , Zhang Xiang , Yang Yalin , Zeng Jinfeng , Lian Junfeng , Qin Xinxin
Published: June 2023

Microplastics are widely distributed in a variety of environments, absorbing heavy metals in the environment while aging due to various environmental factors. In this paper, the effects of different aging factors (pH, DOM, and H2O2) on the adsorption capacity of heavy metals Cu and Zn on polyethylene microplastics (PE-MPs) were investigated, and the changes in physical and chemical properties of PE microplastics were analyzed. The results demonstrate that H2O2 aging bears the greatest effect on the adsorption effect of PE microplastics, dissolved organic matter (DOM) aging has the least effect on the adsorption effect of PE microplastics, and the adsorption effect of microplastics aged with pH=9 is stronger than that aged with pH=4; the adsorption kinetics model of microplastics fitted to the pseudo-second-order kinetic model, and the thermodynamic model fitted to Langmuir model; aging mainly changed the surface structure of microplastics, increased the Zeta potential of microplastics, introduced more oxygen-containing functional groups, and finally affected the ability of microplastics to adsorb heavy metals. The research provides data reference for understanding the influence of different aging on the adsorption capacity of heavy metals in microplastics.
Preparation of sodium alginate-polyvinyl alcohol@PVDF hybrid membrane for efficient oil-water separation
Authors: Peng Huiting , Lin Jiaopan , Xia Mengsheng , Xu Guangying , Gao Junkai
Published: June 2023

Oily sewage is widespread in petrochemical and machinery manufacturing industries. Direct discharge not only wastes water and oil resources, pollutes the ecological environment, but also affects the survival and health of humans and other organisms. The traditional oil-water separation method has strong limitations, poor economy and low separation efficiency. Sodium alginate (SA) and polyvinyl alcohol (PVA) were uniformly coated on the surface of PVDF membrane, and superhydrophilic SA-PVA@PVDF hybrid membrane was prepared by multiple cyclic self-assembly. The oil-water separation experiment was carried out by using the membrane. The initial separation efficiency was 99.8%, and the overall separation efficiency remained above 98.3% after 10 cycles of regeneration experiments. This study provides a new idea for the low-cost, green and simple preparation of superhydrophilic-underwater superoleophobic separation materials.
Study on boron removal performance of covalent organic skeleton membrane by hydroxyl groups
Authors: Xing Yan , Lyu Qiang , Hu Songqing , Sun Shuangqing
Published: June 2023

Growing demand for water desalination promoted the vigorous development of reverse osmosis (RO) membrane. How to effectively remove boron from seawater is the key problem to be solved by RO membrane. It is important to select suitable membrane materials for experimental design before complicated and expensive experimental attempts. In this paper, we demonstrate that pore chemistry plays a key role in boron removal capability of RO membranes via nonequilibrium molecular dynamics simulations. This study shows that the introduction of hydroxyl (-OH) groups into the Covalent organic frameworks (COFs) pore allows for better boron removal without changing water permeability. The optimal boron rejection of AB-COF membranes is 76.67%, and that of ATFG-COF membranes with hydroxyl groups can achieve 90%. This is caused by the hydrophilic pore of ATFG-COF that will preferentially adsorb water molecules to prevent the passage of boric acid molecules through membrane zone. Additionally, -OH groups on the pore will also adsorb a part of boric acid in the membranes, reducing the amount of boric acid entering into the permeate side. The results obtained in this paper can provide guidance for the rational design of RO membranes to achieve more efficient boron removal.
Comprehensive Review of Machine Learning-Based Methods for Electricity Load Forecasting
Authors: Zhao Zixu
Published: June 2023

With the improvement of data processing power and the continuous development of modern power grids, there is an increasing demand for accuracy in predicting power load. To study the field of power load forecasting, this article summarizes and categorizes different models into three types: traditional models, single machine learning models, and hybrid models, based on previous literature. Firstly, a general overview is provided of the application of different models in power load forecasting. Secondly, typical models from three categories are selected for a detailed introduction. In traditional models, the ARIMA model is chosen, while in single machine learning models, CNN, and LSTM are chosen. For the hybrid model, the ResNet-LSTM mixed neural network is selected for the introduction. Finally, four different datasets were used to test different models. The differences and patterns of the models were summarized, and suggestions were proposed for future research directions in the field of power load forecasting.
Study on the Development Path of Green Low-Carbon Environmental Protection Industry under the New Situation
Authors: Wang Yin , Ding Yao
Published: June 2023

This paper aims to study the development path of green, low-carbon and environmental protection industries under the new situation. Currently, the green, low-carbon and environmental protection industry has become an important field for economic and social development. This paper proposes two key development paths, namely strengthening policy guidance and promoting technological innovation, by outlining the current status of the green, low-carbon and environmental protection industry. In terms of policy guidance, it is recommended that the government develop supportive policies and regulatory measures to guide and promote industry development. In terms of technological innovation, it is recommended that enterprises strengthen independent innovation and technological cooperation to promote the innovation and application of green, low-carbon and environmental protection technologies. Through comprehensive analysis and empirical research, new ideas and references can be provided for the development of the green, low-carbon and environmental protection industry.
Comprehensive treatment strategy for high water cut stage of medium and low permeability reservoir
Authors: Xue Hui
Published: June 2023

Maintaining good conditions for petroleum exploitation is an important basis for achieving better exploitation results. At present, the main reservoir conditions of our main oil fields are relatively good, and have entered high water cut, middle and late development. Due to long-term exploitation, the reservoir has suffered a certain degree of destruction, resulting in the rapid rise of aquifers and sharp reduction of production. It has certain influence on the output of oil and well and the final recovery efficiency of oil field. In order to alleviate the contradiction of rapid reduction of oil production pressure and output in high water cut stage of medium and low permeability reservoir, the development efficiency of reservoir can be improved. By analyzing the high water cut stage of medium and low permeability reservoir, this paper puts forward the comprehensive treatment measures, which provides the idea for realizing the increase of production.
Optimization method of ballistic blast fragmentation warhead striking aircraft in aircraft shelter
Authors: YANG Jie , ZHAN Jun , CHEN Zhixiang , LIU Xianyi , ZHOU Zhiqing , LI Zhi
Published: June 2023

For evaluating the economy and feasibility about blast fragmentation warhead striking aircraft in aircraft shelter, taking a typical aircraft and single/double aircraft shelter as study objects, based on the thought of simple/quadratic surface fitting, the 3D surface models of aircraft and shelter are built. According to the velocity and position model of fragment, combined with the transformation relationship of coordinate system, the missile-target encounter algorithm is given. The ruin tree model of aircraft is constructed to calculate the ruin probability algorithm of aircraft. For reducing the computation of missile-target encounter, a mean ruin probability algorithm of aircraft based on integration method is proposed, which slices target area to grids and takes grids as alternative aim point. Taking maximum to entire ruin effect of all aircrafts as target, the optimizing algorithm to strike scheme about minimum missile consumption and find best aim point based on advanced PSO algorithm are proposed. The striking scheme optimizing about fragmentation warhead striking aircraft in single/double aircraft shelter is simulated. The result shows that, low blast height, small CEP, combination strike strategy with multiply aim points can reduce the minimum missile consumption effectively.
A novel system for discovery and reuse of typical process route based on information entropy and PSO-Kmeans clustering algorithm
Authors: LI Chunlei , CHANG Zhiyong , LI Liang
Published: June 2023

Manufacturing enterprises will accumulate a large number of manufacturing instances as they run and develop. Being able to excavate and reuse the instance resources reasonably is one of the most effective ways to improve manufacturing and support innovation. To determine the reuse object scientifically and raise the reuse flexibility, a novel system for discovery and reuse of typical process route based on the information entropy and PSO-Kmeans clustering algorithm is proposed in this paper. In this system, a similarity measurement method of machining process routes based on the information entropy of multistage longest common subsequence is developed. Then a discovery method of typical process route based on the spectral clustering idea and PSO-Kmeans clustering algorithm is invented, and the two reuse approaches based on the typical process route are analyzed and discussed. Finally, the three case studies are rendered and the results reveal that the proposed system can provide better support for manufacture instance reuse.
Aeroelastic stability analysis of rotor blade with complex three-dimensional design
Authors: DENG Jinghui , YU Zhihao , ZHOU Yun , SONG Bin
Published: June 2023

A rotor dynamic analysis method for the complex three-dimensional design blade was developed and applied to analyzing its aeroelastic stability. Based on the medium-size deformation beam theory and Hamilton principle, the joint transfer matrix was used in the blade kinematic and the deformation compatibility principle was used in the assembled finite element matrix to develop the complex three-dimensional rotor structural dynamics model. The BO105 rotor was used to validate this method and the aeroelastic characteristic of the complex three-dimensional rotor was analyzed in detail. The results showed that the negative structural coupling of flap-torsion was appeared with tip sweep, and the 1/rev torsion modal frequency was decreased, and the 1/rev torsion modal damping ratio was maximally decreased about 90%. The positive structural coupling of lag-torsion was appeared with tip droop, the 2/rev lag modal frequency was decreased, the 1/rev torsion modal damping ratio was maximally decreased about 62%. The torsion stability was sharply decreased with tip sweep and droop design.
Calculation of flow turbulence and analysis on screens setting-up in continuous and transonic wind tunnel
Authors: PEI Haitao , CHEN Jiming , LIAO Daxiong , ZHU Bo , WU Shenghao
Published: June 2023

Turbulence intensity in test section is an important index to evaluate the flow-field performance of wind tunnel, and provide guarantee for model's dynamics and accurate test. The prediction model should be established to evaluate the effect of rectification design to ensure the turbulence-intensity index. Two methods are introduced and used to predict the turbulence-intensity of a continuous and transonic wind tunnel comparing with test results. It was found that the turbulence-intensity variation trend obtained from the two methods is basically same, turbulence-intensity attenuation is mainly concentrated in the first three screens, about 65%, the result calculated by model-one is 21% larger than the measured value and the model-two result is much closer. These two methods can be used to optimize the design of rectifying device effectively although the results obtained by two methods are slightly different form the measured value.
The first detection of an exoplanet that opened a new field in planetology
Authors: Marcelin Michel , Boisse Isabelle , Ferrari Marc , Hebrard Guillaume , Hugot Emmanuel
Published: June 2023

Periodic Radial Velocity oscillations of the star 51 Pegasi measured at OHP (Observatoire de Haute-Provence) in 1995 revealed a planet orbiting around it. This first detection of an exoplanet had been expected for a long time, since everyone was convinced that most of the stars were surrounded by planets. This success, leading to the Nobel Prize of physics in 2019, is the result of the evolution of technics for the measurement of radial velocities of stars during half a century at OHP.
On the prehistory of optical metasurfaces
Authors: Lalanne Philippe , Chavel Pierre
Published: June 2023

Before the word « metasurface » first appeared, optical elements that were thinner than a wavelength and deflected light in a direction incompatible with Snell’s law already existed. Based on three examples, we review the underlying concepts and their evolution in the past few decades.
Second order nonlinear optics in AlGaAs metasurfaces
Authors: Rocco Davide , Carletti Luca , Locatelli Andrea , Tognazzi Andrea , Franceschini Paolo , Gandolfi Marco , Cino Alfonso C. , Leo Giuseppe , De Angelis Costantino
Published: June 2023

Recently, nonlinear optics at the nanoscale level has emerged as a promising branch of nanophotonics. In this work, we focus our attention on Aluminum Gallium Arsenide (AlGaAs) nanoantennas and metasurfaces for efficient and controlled second harmonic photon emission. After a brief introduction concerning the main studies in this field, we present the latest results achieved in AlGaAs platforms both in the lossless and absorption regimes.
Filigranes Kartenhaus – Schmerzhafte Schulter
Authors: Albrecht Sindy
Published: June 2023

Schulterschmerzen sind komplex. Goldstandards fehlen aufgrund unzureichender Evidenzen. Ein zu enger Fokus etwa auf die Bildgebung vernachlässigt biopsychologische, biomechanische und neurowissenschaftliche Aspekte. Eine zu vage Anamnese übersieht mitunter die Schmerzursache. Sindy Albrecht erklärt, warum selbst (Mikro-)Traumata zu Schmerzen und pathologischen Bewegungsmustern führen und das filigrane Kartenhaus der Biomechanik zum Wanken bringen können. Das motorische Wiedererlernen gelingt durch sinnvolle und nicht schmerzende Aktivitäten.
Mobilität messen – Life-Space Assessment
Authors: Dietze Laura
Published: June 2023

Für ältere Menschen ist der Erhalt ihrer Mobilität häufig ein wichtiges Anliegen für die Therapie. Das Life-Space Assessment (LSA) lenkt den Fokus auf die Betätigungsperformanz und die relevanten Kontextfaktoren älterer Klient*innen, um ihre Mobilität zu erheben.
Das Gelungene hervorheben – Die potenzialfokussierte Haltung in der Ergotherapie
Authors: Junkers Anja , Hiebl Sara
Published: June 2023

Gelingt den Klienten in der Therapie etwas nicht, sorgt das in vielen Fällen für Frust. Ein potenzialfokussierter Blickwinkel lenkt die Aufmerksamkeit auf die kleinen bereits erzielten Fortschritte und die Aspekte, die schon funktionieren: die sogenannten positiven Unterschiede.
Myocardial Perfusion SPECT and ATTR imaging 2021 in Germany: Results of the 9th Survey
Authors: Lindner Oliver , Schaefer Wolfgang Michael , Silber Sigmund , Rischpler Christoph , Burchert Wolfgang
Published: June 2023

Aim This paper presents the results of the 9th survey of myocardial perfusion SPECT (MPS) from the reporting year 2021.

Methods 218 questionnaires (131 practices (PR), 58 hospitals (HO), 29 university hospitals (UH)) were evaluated. Results of the last survey 2018 are set in squared brackets.

Results MPS data from a total of 133,057 [145,930] patients (–8.8%) with 131,868 [143,707] stress and 106,546 [121,899] rest MPS were analysed. A comparison with official data revealed that 54% all MPS were recorded. From 2018 to 2021, official data showed a every year an increase in MPS numbers. On average, 610 [502] MPS patients (+22%) were examined in each department. 74% [69%] of the responders reported an increase or no changes in their MPS patient numbers. Ambulatory care cardiologists represented as always, the mayor referral group (68% [69%]). For the first time, pharmacological stress was more frequently applied than ergometry (42% [51]). Regadenoson was mostly used. The use of the different protocols remained nearly unchanged. Two-day protocols were predominantly applied (49% [48%]). A shift from multi-headed cameras (58% [72%]) to SPECT-CT systems (24% [17%]) was found. Attenuation correction was performed in 33% [26%] of all MPS. 88% [86%] of all stress, 88% [87%] of all rest and 87% [83%] of all stress and rest MPS were acquired as gated SPECT. 72% [67%] of all departments performed scoring by default. The number of departments without scoring decreased to 13% [16%].

Conclusions The MPS Study 2021 shows that the long-term positive development of MPS imaging in Germany is continuing. The COVID-19 pandemia did not change this trend. The procedural and technical details of MPS imaging reveal a high level of guideline conformity.
Serum Uric Acid Levels and Recurrence Rate of Ischemic Stroke: A
Meta-Analysis
Authors: Li Min , Wang Hongmei , Gao Yanjun
Published: June 2023

The role of serum uric acid as a factor in the recurrence of ischemic stroke
stays unclear. Several studies have examined the relationship between serum uric
acid and recurrence of acute ischemic stroke, with various results. Therefore,
we carried out a meta-analysis to have a look at the relationship between serum
uric acid levels and the potential danger of stroke recurrence in patients with
ischemic stroke. Relevant experiments have been recognized via looking out the
electronic databases and conference sessions. This present study included a
case-control study of the impact of uric acid on the recurrence of ischemic
stroke. After the assessment of eligibility, this meta-analysis included four
articles in which 2452 patients with ischemic stroke were tested for their level
of serum uric acid. The results obtained from this meta-analysis confirmed that
improved uric acid concentrations were extensively and independently related to
an accelerated and higher risk of recurrent stroke. The pooled OR (95%
CI) was 1.80 (1.47, 2.20) (p<0.001). Overall, this meta-analysis shows a
relationship between uric acid concentration and stroke recurrence rate.
Furthermore, high uric acid levels could enhance the recurrence rate of ischemic
stroke.
Hybrid CMOS detectors for high-speed X-ray imaging
Authors: Porter J. L. , Looker Q. , Claus L.
Published: June 2023

Hybrid CMOS (hCMOS) x-ray framing cameras are a new and powerful detector option for experiments in the fields of Inertial Confinement Fusion (ICF) and High Energy Density Physics (HEDP). These digital cameras capture multiple images along a single line-of-sight with a time resolution as short as 1.5 ns and with high quantum efficiency. To manage the high data rate, an image sequence is acquired in a short burst of time and subsequently read out on a much longer time scale. The technology is well suited for operating in high radiation environments, including fusion ignition experiments. Diagnostics using hCMOS cameras are now deployed in experiments on major laser and pulsed-power ICF facilities around the world. Continued advances in microelectronics technologies will enable faster and more capable detectors well into the future. This paper reviews this detector technology with a focus on application to ICF and HEDP experiments.
An improved method for estimating the dissipation rate of turbulent kinetic energy using structure functions evaluated from the motion of finite-sized neutrally buoyant particles
Authors: Teixeira Miguel A. C. , Mériaux Catherine A.
Published: June 2023

Statistical relations used for estimating the dissipation rate of turbulent kinetic energy (TKE) in isotropic turbulence from the inertial subrange of Lagrangian temporal and spatial structure functions are extended here to the case of more realistic turbulence spectra that include low-frequency and low-wavenumber ranges. It is shown that using the traditional relations based only on the inertial subrange substantially underestimates the dissipation. The improved relations are better constrained by experimental data from which the dissipation is evaluated, enabling more accurate dissipation estimates. The concept is illustrated using laboratory data from water tank experiments of turbulence generated by an oscillating cylinder, where the dissipation is evaluated in three independent ways: from Lagrangian spectra and from Lagrangian temporal and spatial structure functions calculated from the motion of neutrally buoyant finite-sized particles. An additional correction to the relations for estimating the dissipation from the spatial structure functions is applied to take into account the filtering effect of the particles due to their finite size. It is found that, for these particular experiments, the TKE dissipation rate scales well with dimensionally consistent quantities built using the amplitude of the oscillation of the cylinder and the period of its motion, and the constant of proportionality in this scaling relation is determined using the method proposed here. Although the turbulence under consideration is quite anisotropic, the adopted theoretical framework, which assumes isotropic turbulence, seems to be applicable to the experimental data as long as the turbulence statistics are averaged over the three main flow directions.
Analysis of viscoelastic flow past a square cylinder in a channel with sudden contraction
Authors: Dhawan Sourabh , Das Malay Kumar , Panigrahi Pradipta Kumar
Published: June 2023

The present study examines the effectiveness of the geometric modification in stabilizing the viscoelastic (VE) fluid flow through a planar channel with 5:1 sudden contraction. The geometric modification employed in this study includes a square cylinder positioned in front of the contraction plane. The square cylinder pre-deforms the fluid before entering the contraction region. The cylinder causes elongational flow in the wake region as well as shear and elongational flow between the channel and cylinder walls, significantly changing the nature of the flow. We used the open-source software OpenFoam, which is based on the finite volume method, to solve the mass, momentum, and rheological stress-constitutive equations. The Oldroyd-B model mimics the rheological characteristics of the VE fluid. Our research demonstrates that the pre-deformation of VE fluid stabilizes flow in the Wi range of 0–4. Additionally, the salient corner vortex size in the Wi range of 6–10 is effectively reduced by the square cylinder with a blockage ratio of 0.30. Furthermore, the Pakdel–Mckinley stability criterion demonstrates that an increase in Wi beyond the critical value initiates elastic turbulence in the flow.
Reconfigurable localized effects in non-Hermitian phononic plate
Authors: Zhong Wenxin , Cai Runcheng , Zhuang Xiaoying , Rabczuk Timon , Pennec Yan , Djafari-Rouhani Bahram , Jin Yabin
Published: June 2023

Skin effect is one of the intriguing phenomena exhibited by non-Hermitian wave systems. It reflects the localization of the modes at the boundaries of the structure. We demonstrated the skin effect for elastic waves propagating in a non-Hermitian phononic plate containing piezoelectric components in their unit cells. The latter behave as sensors and actuators by using the direct and inverse piezoelectric effects. The demonstration is based on the calculation of the complex non-reciprocal dispersion curves and their analysis for any direction of the wavevector in the two-dimensional space. Therefore, localization phenomena at different boundaries and corners of a finite square structure are presented. Furthermore, by applying different levels of non-Hermiticity in different parts of a square structure, it is shown that the localized features can appear at different positions and with various shapes. These localized phenomena can be reconfigured by acting on the non-Hermiticity parameters. Our results provided a feedback control strategy to introduce the non-Hermitian skin effect in two-dimensional elastic systems for potential applications, such as vibration control, energy harvesting, and sensing.
Wavelet analysis of supersonic shock-boundary-layer interaction
Authors: Kokkinakis Ioannis W. , Khujadze George , Drikakis Dimitris , Spottswood S. Michael
Published: June 2023

We present a wavelet analysis of supersonic shock-boundary-layer interaction. We have used direct numerical simulation data for supersonic flow over a compression ramp and performed orthogonal anisotropic wavelets. The wavelet-based method of extracting coherent structures is applied to the flow vorticity field, decomposed into coherent and incoherent contributions using thresholding of the wavelet coefficients. The statistics of the coherent part of vorticity are close to the statistics of the total field. The study aims to improve our understanding of the shock-boundary-layer interaction, the role of vorticity, and the relationship between the flow's coherent and incoherent vorticity components with the near-wall sound. Our analysis shows a substantial correlation between the incoherent part of vorticity components and wall-pressure fluctuations.
Generalized uncertainty principle impact on nonextensive black hole thermodynamics
Authors: Çimdiker Ilim , Da̧browski Mariusz P , Gohar Hussain
Published: June 2023

The effect of the generalized uncertainty principle (GUP) on nonextensive thermodynamics applied to black holes, as well as the sparsity of the radiation at different temperatures associated with each nonextensive entropy, is investigated. We examine the Rényi, Tsallis–Cirto, Kaniadakis, Sharma Mittal, and Barrow entropies, temperatures, and heat capacities and show that, in each case, due to GUP corrections, the temperature and entropy have finite values, implying that the final state of the black hole is a remnant at the end of the evaporation process and that the sparsity of the radiation for massless bosons at each temperature depends on the mass of the black hole. We also find that GUP reduces the value of the sparsity profile for each case as compared to the sparsity parameter at Hawking temperature, which is always constant throughout the evaporation.
A unified deduction of the expressions of exergy and flow exergy
Authors: Zanchini Enzo
Published: June 2023

Exergy analysis is a branch of thermodynamics receiving an increasing interest in the scientific literature and in didactic presentations. Exergy represents the maximum useful work obtainable by a system that can interact with a reference environment. There exist two exergy functions: exergy, which refers to a collection of matter contained within the reference environment; flow exergy, which refers to a collection of matter flowing in a pipe, that can interact with the environment and diffuse into it. The usual derivations of the expressions of exergy and flow exergy are either complicated or not general. Moreover, two separate derivations are necessary, due to the different conceptual schemes employed in the definitions of these properties. As a consequence, the expressions of exergy and flow exergy are often reported without a derivation in didactic treatises. In this paper, we provide a simple and general unified deduction of the expressions of exergy and flow exergy. Moreover, we show that the logical scheme proposed, based on the concept of useful energy of a system contained in a pressure field, allows a simpler deduction and a deeper interpretation of the energy balance equation for a control volume in a steady state. Finally, in order to complete the didactic treatment, we rewrite the expression of the molar exergy of a pure substance at ambient temperature and pressure in a form applicable to reactive substances, and we present an application of this form.
Equivalent circuit model of GaN high electron mobility transistor with consideration of non-ideal effects using genetic algorithm
Authors: Li Fangqing , Wang Haodong , Chen Xin , Zhong Yaozong , Guo Xiaolu , Gao Hongwei , Cao Yunzhe , Zhi Gaofei , Li Qian , Zhou Yu , Sun Qian , Yang Hui
Published: June 2023

This work proposes a semi-physical equivalent circuit model for GaN-based high electron mobility transistors (GaN HEMTs), taking into account the non-ideal effects of both the current source and resistance–capacitance components. The current source model is built based on both device operation and multiple model interfaces setup for important non-ideal effects, such as self-heating effects, channel length modulation, short channel effects, and so on. Moreover, according to the improved Meyer capacitance model with fringe capacitances, the non-linear capacitances of the GaN HEMT are modeled with a dependence on the bias voltages and gate geometry. The extraction of the model parameters is implemented accurately and efficiently in MATLAB through a genetic algorithm. Moreover, the capacitance model is established to be mathematically simple and Simulation Program with Integrated Circuit Emphasis (SPICE)-compatible for the design of GaN-based integrated circuits (ICs). The static and dynamic characteristics of GaN ICs were simulated and found to be in excellent agreement with the experimental results, validating that the established and well-packaged equivalent circuit model can be of great help to GaN HEMT development and IC design.
Unexpectedly high thermoelectric performance of anisotropic Zr2Cl4 monolayer
Authors: Wang Xiaoping , Qi Hangbo , Wang Ning , Wang Zishen , Tang Wenkai , Tan Zhihai , Zhu Zhe , Zhang Meng , Shen Chen
Published: June 2023

Recently, the Hf2Cl4-type materials as functional materials have attracted broad interest because of their enormous potential in thermoelectric (TE) applications. However, relevant investigations are still scarce up to now. To explore the Hf2Cl4-type materials with excellent TE properties, we focus on the TE properties of Zr2Cl4 monolayer and calculate the TE parameters based on first-principles calculations and Boltzmann transport equation. Although, as compared to some typical TE materials, it exhibits better heat transport and thus higher lattice thermal conductivity, the figure of merits (ZT) of both p-type and n-type Zr2Cl4 reach an unexpectedly high value of 3.90 and 3.60, respectively, owing to the larger electrical conductivity and higher power factor. Additionally, owing to the prominent difference in electrical conductivity between the x- and y-direction, strong anisotropy in ZT values is observed. Our study reveals that both n-type and p-type Zr2Cl4 monolayers have the potential for future TE applications.
Material jetting of carbon nano onions for printed electronics
Authors: Pinto Rui M R , Nemala Siva Sankar , Faraji Mohammadmahdi , Fernandes Joao , Ponte Clara , De Bellis Giovanni , Retolaza Aritz , Vinayakumar K B , Capasso Andrea
Published: June 2023

As an additive manufacturing process, material jetting techniques allow to selectively deposit droplets of materials in liquid or powder form through a small-diameter aperture, such as a nozzle of a print head. For the fabrication of printed electronics, a variety of inks and dispersions of functional materials can be deposited by drop-on-demand printing on rigid and flexible substrates. In this work, zero-dimensional multi-layer shell-structured fullerene material, also known as carbon nano-onion (CNO) or onion-like carbon, is printed on polyethylene terephthalate substrates using drop-on-demand inkjet printing. CNOs are produced using a low-cost flame synthesis technique and characterized by electron microscopy, Raman, x-ray photoelectron spectroscopy, and specific surface area and pore size measurements. The produced CNO material has an average diameter of ∼33 nm, pore diameter in the range ∼2–40 nm and a specific surface area of 160 m2.g−1. The CNO dispersions in ethanol have a reduced viscosity (∼1.2 mPa.s) and are compatible with commercial piezoelectric inkjet heads. The jetting parameters are optimized to avoid satellite drops and to obtain a reduced drop volume (52 pL), resulting in optimal resolution (220 μm) and line continuity. A multi-step process is implemented without inter-layer curing and a fine control over the CNO layer thickness is achieved (∼180 nm thick layer after 10 printing passes). The printed CNO structures show an electrical resistivity of ∼600 Ω.m, a high negative temperature coefficient of resistance (−4.35 × 10−2 °C−1) and a marked dependency on relative humidity (−1.29 × 10−2 RH%
−1). The high sensitivity to temperature and humidity, combined to the large specific area of the CNOs, make this material and the corresponding ink a viable prospect for inkjet-printed technologies, such as environmental and gas sensors.
Report on progress in physics: observation of the Breit–Wheeler process and vacuum birefringence in heavy-ion collisions
Authors: Brandenburg James Daniel , Seger Janet , Xu Zhangbu , Zha Wangmei
Published: June 2023

This report reviews the effort over several decades to observe the linear Breit–Wheeler process (

γ
γ
→

e
+

e
−

) and vacuum birefringence (VB) in high-energy particle and heavy-ion collider experiment. This report, motivated by the STAR collaboration’s recent observations, attempts to summarize the key issues related to the interpretation of polarized

γ
γ
→

l
+

l
−

measurements in high-energy experiments. To that end, we start by reviewing the historical context and essential theoretical developments, before focusing on the decades of progress made in high-energy collider experiments. Special attention is given to the evolution in experimental approaches in response to various challenges, to the demanding detector capabilities required to unambiguously identify the linear Breit–Wheeler process, and to the connections with VB. We close the report with a discussion, followed by a look at near-future opportunities for utilizing these discoveries and for testing quantum electrodynamics in previously unexplored regimes.
Measurement and gate-voltage dependence of channel and series resistances in lateral depletion-mode β-Ga2O3 MOSFETs
Authors: Maimon O , Moser N A , Liddy K J , Green A J , Chabak K D , Cheung K P , Pookpanratana S , Li Q
Published: June 2023

Lateral depletion-mode, beta-phase gallium oxide (β-Ga2O3) metal-oxide-semiconductor field-effect transistors (MOSFETs) with source-drain spacings of 3 µm, 8 µm, and 13 µm are studied using a modified transfer length method (TLM) to obtain sheet resistances in the gated and ungated regions as well as to observe their gate electric field dependence. The modified TLM requires the contact resistance to be independent of the gate-source voltage, or changing current density. We verify this by performing measurements on conventional TLM structures in dark and UV conditions and observe a changing current density with constant contact resistance, enabling the development of the proposed method. The conventional and modified TLM give sheet resistances of 20.0 kΩ sq−1 ± 1.0 kΩ sq−1 and 27.5 kΩ sq−1 ± 0.8 kΩ sq−1, respectively. Using a traditional method for determining the channel resistance, the modified TLM improves the convergence of the channel resistances between the three devices, showing higher accuracy than the conventional TLM structures. Gate-source voltage dependence of the sheet resistances is seen in the ungated regions, leading to non-ideal behavior which cannot be observed using the traditional method and conventional TLM structures. These results and analysis methods are important in improving MOSFET parameter extraction and understanding the gate electric field effects on the channel and series resistances in β-Ga2O3 MOSFETs.
Dexamethasone release pattern via a three-dimensional system for effective bone regeneration
Authors: Channey Hareet Singh , Holkar Ketki , Kale Vaijayanti , Ingavle Ganesh
Published: June 2023

For over a decade, dexamethasone (DEX) has been used for bone regenerative and anti-inflammatory purposes. It has also shown promise for inducing bone regeneration by using it as component of osteoinductive differentiation medium, particularly for in vitro culture models. Despite its osteoinductive properties, its use is limited due to its associated cytotoxicity, particularly when used at higher concentrations. DEX has adverse effects when taken orally; thus, it is best to use it in a targeted manner. Even when given locally, the pharmaceutical should be distributed in a controlled manner based on the needs of the wounded tissue. However, because drug activity is assessed in two-dimensional (2D) circumstances and the target tissue is a three-dimensional (3D) structure, assessing DEX activity and dosage in a 3D milieu is critical for bone tissue development. The current review examines the advantages of a 3D approach over traditional 2D culture methods and delivery devices for controlled DEX delivery, particularly for bone repair. Further, this review explores the latest advancement and challenges in biomaterial-based therapeutic delivery approaches for bone regeneration. This review also discusses possible future biomaterial-based strategies to study efficient DEX delivery.
Grain size trend analysis for sediment characteristic of Cirebon Waters
Authors: Agusta V C , Putri M R
Published: June 2023

This research aims to understand the sediment characteristic of Cirebon waters using a grain size trend analysis (GSTA). The GSTA can be used to determine sediment physical characteristics and demonstrate the sedimentary processes. A total of 32 seabed surface sediments were analyzed by measuring the size of sedimentary grains using the Mastersizer 2000 instrument and calculating grain size parameters such as mean grain size, sorting, skewness, and kurtosis using geometric methods in the Gradistat program. Analysis of grain size showed that sediments in the Cirebon Waters are dominated by silt with ranges from 7.765 to 33.43 µm (very coarse to fine silt). The mean grain size and skewness values indicated an increase in current energy and sediment transport rate from the southwest to the northeast part of Cirebon Waters. Sediments are poorly sorted, and kurtosis is predominantly mesokurtic type. All sediments were deposited by deposition mechanism in pelagic suspension and affected by slow deposition from quiet waters. Granulometric analyses become a good proxy to give fundamental information on sediment dynamics.
Comparison of Vs30 Based on SPT-N and CPT-u Data : Case Study of Semarang Coastal Zone
Authors: Shomim A F , Sarah D , Syahbana A J , Sari A M , Saputra O F , Satriyo N A , Trisnafiah S , Khaerani P , Martireni A P , Utari P A
Published: June 2023

Semarang coastal zone is one of the essential area in Indonesia. The area included ports and other land access that passes through the Semarang coast, the city’s central point of rapid development. The characteristic of the soil is one of the crucial parameters for base supporting regional planning, which is growing fast by the time. Currently, the capacity of the soil according to SNI 1706-2019 can refer through Vs30 data. As we know, Vs30 data provides an overview of the seismicity in an area. The main issue is that the empirical data of Vs30 is relatively expensive to acquire. Thus, many practitioners use a method by correlating data from CPT-u or SPT-N. The study approached the Vs30 data derived from the CPT-u then compared with the Vs30 data from SPT-N. The result shows that the value of Vs30 derived by CPT-u and N-SPT have a similar range of value to determining seismicity hazard particularly within the coastal area.