bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal design of low frequency rubber vibration isolator
Authors: Li Xinyu
Published: August 2024

Low frequency vibration isolator is a common structure vibration control device, widely used in transportation and machinery manufacturing fields. This paper is centered around enhancing the optimization design of rubber isolators operating at low frequencies. In the initial section, the paper introduces the structural framework and operational principles of rubber isolators. Furthermore, it delves into the analysis of their significance and potential applications within engineering contexts. Subsequently, the paper narrows its focus to address the design challenges concerning rubber isolators with low-frequency capabilities. A comprehensive three-dimensional model is constructed using ANSYS software, employing finite element analysis techniques. The paper employs a multi-objective optimization algorithm through a direct optimization module to facilitate the optimization design process. Within this study, the NSGA-II algorithm was employed to drive the optimization of design, with the objective of achieving a 10 Hz frequency for a series of dual rubber isolators, while simultaneously constraining static deformation to within 8 mm. The outcomes of this investigation emphasize the successful attainment of optimization goals by meticulously fine-tuning the structural dimensions of the isolators.
Research on the path of low-carbon construction of multimodal logistics parks under the background of “carbon peak” and “carbon neutrality”
Authors: Liu Yajie , Chen Ningning , Cui Weihua , Zhuang Qingxu
Published: August 2024

The construction of intermodal logistics parks in China is developing rapidly, but most of them are in the bad mode of high energy consumption. While polluting the environment, it also affects the cost reduction and efficiency of the whole logistics industry, which is not conducive to the healthy development of the logistics industry. Therefore, under the goals of “carbon peak” and “carbon neutral”, the planning of multimodal logistics parks must seek the development path of low-carbon transformation. This is not only a responsibility, but also a necessary path for the healthy and sustainable development of the logistics industry in the future, which has far-reaching strategic significance. Therefore, based on this background, the paper describes the opportunities and challenges of low-carbon construction of China’s multimodal logistics parks. According to the above analysis, combined with the relevant policies, it puts forward the low-carbon construction path of multimodal logistics parks. It is intended to provide support for the promotion of low-carbon construction of multimodal logistics parks and help the practice of the “carbon peak” and “carbon neutral” strategic goals in practice.
Structural design of a novel rotary platform 3D printer
Authors: Liu Shengrui
Published: August 2024

Stair-stepping defects in 3D printing processes can be caused by various reasons, such as the quality of the printing material, the position of the print head, printing speed, printing temperature, and so on. To improve the issue of stair-stepping effects in thin-walled revolving parts during the 3D printing process, this project aims to design a 3D printer that enables the print head to move in the X, Y, and Z axes while the heated bed platform can rotate. This will significantly reduce the stair-stepping effect’s impact and greatly enhance the printing’s quality and accuracy.
A prediction method for salt frost resistance of carbon-glass mixed fiber concrete based on improved BP neural network
Authors: Wu Yang , Huang Shenjiang
Published: August 2024

Low temperature and freeze-thaw can greatly reduce the service life of concrete, leading to serious safety hazards. Salt frost resistance is one of the important characteristics of concrete. Therefore, in order to more accurately evaluate the salt frost resistance of carbon glass hybrid fiber reinforced concrete. This article proposes a prediction method using measured data based on an improved BP neural network. Firstly, conduct freeze-thaw cycle tests on fiber reinforced concrete with different proportions. Studied the variation law of concrete quality loss rate and dynamic elastic modulus. Then, based on BP neural network and particle swarm optimization algorithm, a salt frost damage prediction model for carbon glass hybrid fiber reinforced concrete was established. Finally, conduct optimization based on the learning samples and compare and analyze the prediction errors of the model. The simulation results demonstrate that the proposed method has good accuracy and stability.
Effectively planning waterfront public place affected by the ecological environment
Authors: Wang Jing
Published: August 2024

Urban waterfront area planning is a very important part to improve the quality of the urban ecological environment. Research effective planning paths of urban waterfront guided by ecological environment effect can promote landscape diversity index and other indicators are selected as the relevant indicators of the ecological environment which establish comprehensive evaluation index system of urban waterfront public place planning path. Use the fuzzy statistical path to determine the evaluation index weight, establish the waterfront public place planning path evaluation model according to the waterfront public place planning evaluation index weight, and use the model evaluation results to determine the effective planning paths of urban waterfront guided by the ecological environment effect. The experimental results show that the evaluation score of urban waterfront planning path 2 is the highest, which verifies that planning path 2 is an effective planning path of waterfront public places guided by considering the ecological and environmental effects.
Impact of drought on vegetation over inner Mongolia autonomous region
Authors: Zhang Ziti
Published: August 2024

In recent years, remote sensing technology has become an important tool for monitoring vegetation changes in semi-arid regions. By using data collected by satellites to calculate vegetation indices, researchers can track changes in vegetation density and productivity over time. This can help identify areas of potential desertification or degraded land degradation and develop management strategies to restore degraded ecosystems. The objectives of this paper are to use multi-temporal MODIS data to extract vegetation distribution characteristics and dynamics in Inner Mongolia Autonomous Region. This study summarized the rainfall data of Inner Mongolia Autonomous Region from 2000 to 2019, and found the driest year 2001 and the wettest year 2012. The NDVI data of 4 districts of Xingan League in 2001 and 2012 were selected for analysis, and the average NDVI value and standard deviation of the 4 districts were obtained. NDVI data was combined with elevation data and vegetation data for analysis. The relationship between precipitation and NDVI is helpful to understand the impact of drought on vegetation in Inner Mongolia and provide reference for regional environmental management.
Technology of High-k/Metal-Gate Stack
Authors: Wang Mingshi
Published: August 2024

The High-k/Metal-Gate Stack (HKMG) technology represents a seminal advancement in semiconductor fabrication, predicated upon the substitution of SiO2 with high-k dielectric materials, coupled with the integration of metal gate materials. This technological paradigm shift has emerged as a transformative response to the intricate challenges encountered within the semiconductor industry, a sector perpetually engaged in the relentless pursuit of diminishing the critical dimensions of semiconductor devices. Issues such as increased power leakage, enhanced parasitic capacitance, and the escalating complexity of gate insulators have impeded the sustainable downscaling of traditional silicon dioxide-based devices. These challenges have necessitated a comprehensive re-evaluation of the materials and processes involved in semiconductor manufacturing, leading to the conception and evolution of the HKMG technology. This article’s analysis of the developmental trajectory of HKMG technology reveals a progression marked by the systematic exploration of alternative high-k dielectric materials, rigorous compatibility assessments with metal gate materials, and the concurrent refinement of manufacturing processes to ensure seamless integration. After that, elucidating the impediments encountered during its evolution and expounding upon the corresponding ameliorative measures instituted. Looking ahead, ongoing research focusing on the synthesis of advanced high-k dielectric materials, and the development of novel metal gate materials with superior compatibility to further enhance device performance and functionality makes HKMG technology a huge prospect. Such advancements are paving the way for the realization of more powerful, energy-efficient, and compact electronic devices.
The development of cloaking techniques based on phase-modulated metasurfaces
Authors: Yang Ganyu
Published: August 2024

More and more attention has been paid to explore the application background of cloaking techniques based on phase-modulated metasurfaces, which play an important role in modern engineering and military applications. Phase-modulated metasurfaces are an emerging field of research that explores how the propagation of electromagnetic waves can be manipulated by precisely controlling the phase on tiny elements. These tiny elements, usually nanoscale structures, are arranged on the metasurface to precisely control the propagation and scattering of electromagnetic waves in a specific frequency range. The thesis first reviews the development of metamaterial cloaking technology, introduces the realization of several mainstream metamaterial cloaking technologies, and points out the benefits of cloaking techniques based on phase-modulated metasurfaces compared with other cloaking technologies. Then the development history of cloaking techniques based on phase-modulated metasurfaces is introduced through four key time nodes. We can find that phase-modulated metasurfaces are not only getting thinner and thinner, but in addition to the stealth effect, i.e., the reduction of the RCS (Radar Cross Section), phase-modulated metasurfaces can also simulate different virtual shapes. Finally, the development and research progress of cloaking techniques based on phase-modulated metasurfaces are summarized, and personal opinions on its future development are put forward. This paper summarizes the advances in the field of phase-modulated metasurfaces over the last decade and presents some representative approaches to phase-modulated metasurfaces at various points in time, which can help readers better understand the field of metasurfaces and metamaterials.
Design and application of a radar target simulator
Authors: Zhou Hao , Xu Shujun , Xiong Feng , Tang Ying
Published: August 2024

To fulfill the need for debugging boundary scenes in radar data processing development, this paper proposes a simulator design method for the editing and simulation of diverse combat scenes as required. The simulator was developed based on the VPX platform, including external control equipment, resource scheduling, beam control, target simulation, and data processing. The motion model is based on linear and circular models, the clutter model algorithm is the zero memory nonlinear transformation method based on K distributions, and the noise model is designed as Gaussian white noise, characterized by a probability distribution in the Gaussian distribution and a constant power spectrum. The generated plots are condensed, and their quality is calculated, for which the rate of plot rejection can reach more than 50% by controlling the feature elements. Finally, the simulated target trajectory is visually verified through Matlab.
Research on AdHoc network routing algorithm for link stability prediction
Authors: Xu Xiaoling , Cui Wei
Published: August 2024

This study aims to improve network communication efficiency and reliability by researching routing algorithms for predicting link stability in AdHo networks. AdHoc network is a self-organizing, decentralized network structure in which nodes establish temporary connections through wireless communication, making the network resilient and flexible. However, due to the continuous changes in network topology and the instability of wireless links, routing problems in AdHoc networks have become particularly complex. This article proposes a backup path routing algorithm LS-BPR based on link stability prediction. This mechanism takes the path with the minimum delay as the main path, uses the cost function as the standard for selecting backup paths, and then uses the ARIMA model to predict links with good link stability as backup paths. We simulate and compare LS-BPRAODV and AODV protocols using the QualNet simulation platform. The simulation results show that the LS-BPRAODV, with the addition of a prediction mechanism, improves network performance, reduces the number of source node routing discoveries, reduces the number of route breaks, significantly reduces the packet loss rate and information reception delay in the network, and improves the average throughput of the network. This study provides new theoretical and empirical support for the routing algorithm for link stability prediction in AdHo networks, which is of great significance for promoting the development of wireless self-organizing networks.
A stable satellite routing algorithm based on a-star algorithm in dynamic networks
Authors: Sun Xiaohui , Shen Yuefeng , Zhang Huibin
Published: August 2024

This paper focuses on solving the routing optimization problem under the dynamic topology of the satellite communication network. With the rapid development of low-earth-orbit (LEO) satellite network communication technology, the dynamically changing topology of satellite networks has brought about frequent link switching and triggered a large number of routing updates. This paper proposes an improved routing algorithm named the Stable A-Star Routing (SASR) algorithm. The SASR algorithm is based on the A-star algorithm and aims to reduce path-switching frequency and enhance path stability by optimizing the path selection strategy. Through detailed simulation experiments and performance evaluation, we verified the performance advantages of the SASR algorithm in terms of the number of path switches, the number of path hops, the route convergence time, and the occurrences of congestion in business under different business volumes, and conducted comparative studies with classic algorithms. The results show that the SASR algorithm offers obvious advantages in key performance indicators. Compared with the Dijkstra algorithm and the A-star algorithm, the average number of path switches can be reduced by 22% and 10%, respectively. It shows more prominent advantages under a larger business volume, providing an efficient and reliable solution for routing optimization under the dynamic topology of satellite communication networks.
Application of an improved simulated annealing algorithm in satellite network routing
Authors: Liu Haojiang , Zhang Huibin
Published: August 2024

Satellite communication is integral to modern communication systems, yet navigating the intricacies of routing in networks characterized by high loads and dynamic evolution poses a significant challenge. This research is dedicated to enhancing satellite communication routing algorithms, with the goal of bolstering network efficiency and amplifying the success rate of business transmissions. Our approach introduces an improved simulated annealing algorithm incorporating adaptive temperature control and innovative path neighborhood exploration strategies. This novel algorithm is adept at adjusting to ever-shifting network topologies and meeting various business requirements. Our simulation results reveal that this refined algorithm outperforms traditional annealing methods in several critical aspects. It elevates the success rate of business transmissions, reduces the average number of forwardings by 6.546% across various load scenarios, and diminishes system response time by 15.05%, thereby marking a substantial improvement in network performance.
Dual-Branch feature fusion residual neural network for individual radar signal recognition in low SNR environments
Authors: Jing Zehuan , Li Peng , Yan Erxing , Chen Yingchao , Zhang Jiamiao , Wu Bin , Gao Youbing
Published: August 2024

To address the challenge of radar emitter signal individual recognition, where single-dimensional radar fingerprint features are susceptible to noise interference and neural networks exhibit low recognition accuracy in low signal-to-noise ratio (SNR) environments, this study introduces a residual neural network predicated on a two-branch feature fusion. This approach amalgamates two-dimensional time-frequency domain features with one-dimensional intermediate-frequency signal features. Unlike existing algorithms, our proposed method integrates the knowledge gleaned from features learned across different dimensions. This integration enables the neural network to utilize features from multiple dimensions for recognition, thereby mitigating the impact of noise on a single feature. Experimental results demonstrate that our proposed algorithm outperforms others under various low SNRs, achieving an average recognition rate of 88.39%.
FPGA-based tiling scheme and on-chip memory scheduling scheme for multi-branch semantic segmentation neural network accelerator
Authors: Li Hui , He Pengyu , Lu Shengli
Published: August 2024

According to the characteristics of a multi-branch semantic segmentation neural network with a large amount of intermediate data during the inference process, we reduce the requirement of off-chip memory access and the redundant calculation due to tiling through better blocking scheme, better on-chip memory partitioning scheme, and on-chip memory scheduling scheme, improving the energy efficiency to 77.4 GOPS/W.
Implementation of turbo decoding for VDES signal data segments
Authors: Zhang Haotian , Wang Jianxin
Published: August 2024

The International Telecommunication Union (ITU) mandates the use of turbo coding for VDES signal data segments. Previous studies primarily focused on turbo decoding for a specific link in VDES, often neglecting its applicability to all links. This paper proposes an FPGA-based implementation method for turbo code decoding, aiming to achieve fast and accurate turbo decoding of VDES signal data segments, while also ensuring compatibility with different links. The resulting turbo decoder can adapt to the different code rates and data segment lengths specified in the VDES. A comparison of the decoding speeds between DSP and FPGA confirms that the parallel computing capability of FPGA can significantly improve the decoding speed. Finally, the main onboard resources required for FPGA implementation of turbo decoding were provided.
Research on signal equalization technology based on visible light communication
Authors: Wang Hetao , Weng Qing , Liu Hao
Published: August 2024

Visible Light Communication (VLC) transmits signals through visible light and realizes the two functions of lighting and communication at the same time without the need for other hardware equipment. There are still some shortcomings in the visible light communication system. The optical signal propagated indoors is affected by inter-symbol interference (ISI) and external light noise at the receiving end. The signal will be severely distorted. These factors will significantly reduce the accuracy of the received signal decision, thereby seriously affecting the performance of the visible light communication system. Given the problems of intersymbol interference and optical noise in indoor visible light systems, this article studies adaptive equalization technology and modulation and demodulation technology suitable for visible light communication systems and improves the signal-receiving end equalization. Based on the existing equalizer structure, we combined the advantages of two different equalizers and optimized their combined structure parameters. On this basis, we added the MAP algorithm and proposed a hyperbolic tangent function to improve the traditional error function. The defects speed up the convergence speed without changing the mean square error. Experimental results show that the algorithm has improved in convergence performance. The algorithm’s convergence speed is 53.6% higher than the traditional algorithm, the steady-state error is reduced by about 6 dB, and the steady-state error of the algorithm is reduced by about 5 dB respectively.
Design and Analysis of Gas Cyclone with Arc-Shaped Cone Using Bézier Curve for Improved Performance
Authors: Abdo Toka A , Elnady Abdelrady O , Elsayed Khairy , El-shaer Yasser I
Published: August 2024

The research investigates novel gas cyclone separators with curved conical sections, comparing eight configurations with varying curvature sizes. Gas cyclones are traditionally used as particle separators to remove dust from gas streams, aiming to achieve a dust-free gas flow at the exit pipe while recovering particles to the dust outlet. Computational fluid dynamics (CFD) was employed to model the gas cyclone using the Reynolds stress turbulence model (RSM); the study examines flow fields and pressure losses. It finds that increased curvature correlates with reduced pressure drop. The curved profile is derived from the Bézier curve, characterized by a set of control points determining its shape. This study examines eight cyclone configurations with the intermediate point placed at varying fractions of the main radius: 1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 7/8, and the main radius itself. The investigation focuses on the impact of different conical segment shapes on cyclone performance, highlighting how convex variants outperform others at higher flow rates while concave variants exhibit higher pressure drop. The pressure drop in the convex variant with an intermediate point position equal to the main radius decreased by 50%. These findings suggest the potential of the convex variant in certain operating conditions over traditional designs with improved particle capture efficiency.
Modelling stress-strain curves and forming limit curves using deep learning
Authors: Eldin Salem Hossam , Elatriby Sherif A. , Mohamed Mohamed
Published: August 2024

The sheet metal forming process stands one of the most principal applications in production engineering with the goal of producing defect free products possessing the mechanical properties that met the working conditions requirements. The efficient metal forming process relies on a deep understanding of the material behaviour during the forming process. To achieve this, feasibility studies for new incoming components helps determine if a part is feasible for manufacturing or if design modifications are required. This simulation requires an accurate material card to replicate the real material behaviour, requiring extensive material testing data such as stress-strain curves and forming limit curves (FLC). Artificial intelligence, specifically deep learning, is a promising tool to overcome such challenges. In this study, one of the deep learning algorithms, the artificial neural network (ANN), is utilized to create material testing data for building the material cards for feasibility simulation.
A developed products’ families commonality Index based on variants’ similarity.
Authors: Hesham Fatma , Zamzam N. , Shedid GE , El-Kharbotly A.K.
Published: August 2024

Commonality indices used to assess the shared features of product families are crucial tools for benchmarking and redesigning these families. They also play a significant role in optimizing manufacturing systems by adding or removing components/modules to product platforms during delayed customization stages. Although several indices have been developed by researchers to measure commonality across product family variants, these indices are often only suitable for specific applications with specific configurations. In the present research, a new commonality index has been developed based on the similarity features of each pair of variants within a product family. The developed index is useful for clustering family variants into subfamilies, each with high components’ sharing ratio, facilitating the design of necessary product platform/s for delayed customization manufacturing systems. The results of applying this developed index to determine commonality across product family variants were compared with those obtained from several known commonality indices. The new index proved to be effective and sensitive in distinguishing between the commonalities of different product families. Additionally, the index was found to be effective in categorizing products into homogeneous families, grouping variants that share certain similarities and commonality features.
Virtual power plant optimization with demand response and multi-complementary energy planning
Authors: Jia Dongsheng , Bai Di
Published: August 2024

To effectively address the increasing complexity of system operation optimization and resource allocation caused by the continuous enrichment of supply-side resources and the flexible variability of demand-side loads in the energy system, a robust optimization model for virtual power plants considering demand response and multi-energy complementarity is proposed. Handling renewable energy and load uncertainty in virtual power plants by building a two-stage robust optimisation model. The introduction of robust coefficients allows for flexible adjustment of the conservatism of the optimized scheduling. Results indicate that considering demand response and multi-energy complementarity can effectively enhance the system’s robustness and flexibility.
Research on a transmission line defect identification method based on voiceprint recognition
Authors: Cheng Qi , Du Jikuan , Gao Yinghong , Li Lin , Li Junming , Yu Xin
Published: August 2024

With the continuous development and improvement of China’s power system, the length and coverage of transmission lines are getting larger and larger, making it inevitable that transmission lines will pass through areas with harsh environments and complex geographical environments. If defects are not discovered and handled properly, over time, serious losses will be caused. Traditional manual inspections can no longer meet actual requirements due to low efficiency. This paper proposes a transmission line defect identification method based on voiceprint recognition. First, the sound signal collected by the sensor is divided into frames and windowed for preprocessing. Then, feature extraction is performed based on the Mel frequency cepstral coefficient. Finally, the extracted vector is used to train the nearest neighbor classifier, and the trained classifier can identify defects in transmission lines.
Unified monitoring and online maintenance technology of substation secondary equipment
Authors: Su Faliang , Zheng Suisheng , Ji Rongrong , Ma Wei , Chai Changqing
Published: August 2024

To meet the needs of the promotion of “equipment ownership” and the implementation of a centralized monitoring mode in substations, a technical scheme of unified monitoring, online operation, and maintenance for secondary equipment in substations is proposed, considering the monitoring, operation, and maintenance requirements of secondary equipment such as protection devices and automation devices. A secondary equipment monitoring real-time gateway is arranged in Security Zone I. The comprehensive operation status data of various secondary equipment is collected, analyzed, processed, diagnosed, and applied through various apps, to realize heterogeneous access, on-demand deployment, and flexible expansion. The master station is designed with functions such as human-machine interaction and remote analysis for secondary device monitoring and operation. GSP, MQTT, and other service-oriented and message mechanism communication protocols are adopted between the substation and the master station to meet the diversified and easily expandable information exchange requirements. Through the factory test, it is verified that the scheme can realize the panoramic perception of the operation state of the secondary system and effectively improve the ability of abnormality diagnosis and processing.
An intelligent analysis method for power flow of bulk power grid based on fusion of indicator system feature and image feature
Authors: Cao Hongbo , Liu Jun , Ren Bixing , Chen Xinglei , Li Qiang
Published: August 2024

At present, the adjustment of power flow non-convergence in large power grid is still mostly based on manual trial and error, which relies heavily on expert experience and is inefficient. Therefore, an intelligent power flow analysis method based on index system and image feature fusion is proposed. Firstly, the power flow index system is constructed according to the actual demand, which can provide data support for the following power flow convergence judgment problems. Secondly, taking into account the constraints of similarity and ternary loss, the image feature information is used to guide the output of the information feature representation and to realize the organic interaction of the two modal features. On this basis, the calculation result of the index is correlated with the actual state of power flow to judge the convergence of power flow. Finally, the proposed method is verified on the CEPRI36 nodes system and a large power grid in China. The simulation results show that the accuracy of power flow convergence judgment is 100% for CEPRI36 nodes system and 99.83% for some domestic large power grid. It can effectively predict the convergence of the power flow before the calculation of the power flow required by the project and can provide the basis and theoretical support for the power flow optimization adjustment based on the indicator data.
On the contact of an absolutely rigid stamp with a half-plane taking into account static friction
Authors: Hakobyan V N , Amirjanyan H A , Grigoryan A H
Published: August 2024

The plane deformable state of an elastic half-plane into which an absolutely rigid stamp is pressed with friction is considered. It is assumed that the tangential stresses acting in the contact zone are related to normal pressure by the law of dry friction, the coefficient of which is a linear function of the coordinate of the contacting points of the contacting bodies. A determining singular integral equation for the stated problem is obtained, the solution of which is constructed in closed form. Numerical analysis is conducted, and regularities in the variation of contact stresses are determined depending on the ratios of horizontal and normal loads applied to the stamp.
Mechanical behavior of GFRP-Polymer sandwich composites with montmorillonite nanoclay
Authors: Sharma A P , Purusothaman M , Mohan T P , Kanny K , Velmurugan R
Published: August 2024

A sandwich composite consists of high stiffness and high strength outer layers called face sheets and low-density inner layers called core. In the present study, the sandwich composites comprising glass fabric/epoxy face sheets and epoxy modified with montmorillonite (MMT) nanoclay core are fabricated by a co-curing method. The sandwich panels show higher static tensile and three-point flexural properties such as ultimate strength, elastic modulus, and failure strain on adding up to 3 wt.% of MMT nanoclay contents than pristine sample. The former properties reduce at 4 and 5 wt.% of nanoclay contents owing to the formation of clustering of clay particles within the matrix. The stress-strain behavior of sandwich panels with 0–5 wt.% of MMT nanoclays obtained by laminated plate model follows experiments. The maximum lateral deflection of sandwich panels with nanoclays predicted by assuming them to be a simply supported beam is in-line with experimental results. For low-velocity single impact perforation load, the maximum force of sandwich panels improves on the infusion of up to 3 wt.% of clay while maximum displacement decreases. The ballistic limit velocity and energy absorption of panels improve on adding up to 3 wt.% of clay. Beyond the ballistic limit at different initial velocities, the residual velocity of sandwich panels decreases on addition of up to 3 wt.% of clay and energy absorption increases.
Dynamics of two cylinders in a cavity filled with liquid under modulated rotation
Authors: Vlasova O A
Published: August 2024

The dynamics of cylindrical bodies in a rotating horizontal cylinder filled with a high-viscosity fluid is experimentally studied. The cylinder rotation rate is modulated. When the cylinder rotates uniformly, the bodies are located near the cylindrical wall and rotate together with the cylinder. The dynamics of bodies depending on the amplitude and frequency of modulation of the cylinder rotation rate is studied in detail. It is found that the cylindrical bodies undergo azimuthal and rotational oscillations. When the critical amplitude of modulation is reached, the bodies repel from the wall and obtain a steady state position at some distance from the wall.
Response of the first POLAR-2 prototype to polarized beams
Authors: Kole Merlin , Angelis Nicolas De , Bacelj Ana , Cadoux Franck , Elwertowska Agnieszka , Hulsman Johannes , Li Hancheng , Łubian Grzegorz , Kowalski Tomasz , Koziol Gilles , Pollo Agnieszka , Produit Nicolas , Rybka Dominik , Stil Adrien , Sun Jianchao , Wu Xin , Zezuliński Kacper , Zhang Shuang-Nan
Published: August 2024

POLAR-2 is a dedicated gamma-ray polarimeter currently
foreseen to be launched towards the China Space Station around
2027. The design of the detector is based on the legacy of its
predecessor mission POLAR which was launched in 2016. POLAR-2 aims
to measure the polarization of the Gamma-ray Burst prompt emission
within the 30–800 keV energy range. Thanks to
its high sensitivity to gamma-ray polarization, as well as its large
effective area, POLAR-2 will provide the most precise measurements
of this type to date. Such measurements are key to improve our
understanding of the astrophysical processes responsible for
Gamma-Ray Bursts. The detector consists of a segmented array of
plastic scintillator bars, each one of which is read out by a
Silicon PhotoMultiplier channel. The flight model of POLAR-2 will
contain a total of 6400 scintillators. These are divided into 100
groups of 64 bars each, in so-called polarimeter modules. In recent
years, the collaboration has designed and produced the first
prototypes of these polarimeter modules and subjected these to space
qualification tests. In addition, in April 2023, the first of these
modules were calibrated using fully polarized gamma-ray beams at the
European Synchrotron Radiation Facility (ESRF) in France. In this
work, we will present the results of this calibration campaign and
compare these to the simulated performance of the POLAR-2
modules. Potential improvements to the design are also
discussed. Finally, the measurements are used, in combination with
the verified simulation framework, to estimate the scientific
performance of the full POLAR-2 detector and compare it to its
predecessor.
Detection and Mechanical Interpretation of Surface Displacement by Volcanic and Anthropogenic Interactions around Bandung Basin, through Multi Temporal Interferometric SAR (MT-InSAR) Technique
Authors: Sabrian P G , Saepuloh A , Septyandy M R , Heriyanto  , Putri A D
Published: August 2024

This study aims to evaluate capability of MT-InSAR (Multi Temporal interferometric synthetic aperture radar) technique for measuring the surface displacement caused by tectonic, volcanic, and anthropogenic activity around the Bandung Basin, West Java, Indonesia. For this, persistent scatterer (PS), small baseline subset (SBAS), and combined PS and SBAS techniques are adopted. The results reveal different displacement patterns within two areas anthropogenic-caused subsidence in the middle Bandung city and geothermal production field, and volcanic-caused uplift in the northern area around the Tangkuban Parahu volcano. In addition, each InSAR tehnique shows unique spatial deformation. A significant pattern is located around the Wayang Windu geothermal field that large displacements has been occurred around injection, production wells. Those detected displacements are crucial for mitigating geological hazards as well as geothermal production monitoring.
Structure Analysis Gunung Benau Karst Area by Using mSTA and FFD, North Kalimantan, Indonesia
Authors: Heriyanto  , Sabrain P G , Haryono E , Mahajana  , Magdalena H , Balfas M D , Hidayatullah Y , Habibah M F , Qomariah F R
Published: August 2024

The formation of Gunung Benau is associated to the geological structural process. This study uses remote sensing using DEMNAS data resampled at 10 meters. The DEMNAS data will be modeled using the modified Segment Tracing Algorithm (mSTA) and Fault Fracture Density (FFD) approaches. Surface geological mapping methods involve observations, descriptions, direct measurements, and field data recording of data appearances and geological conditions on the Gunung Benau. The structure which found in Gunung Benau is a shear joint with syncline and anticline folds and nine faults identified. The mSTA’s main lineament directions, Northeast-Southwest and Southeast-Northwest, are consistent with the area’s geological structure. The FFD shows that the highest density values occur in the central region of Gunung Benau, where faults are extensively exposed.
Groundwater well rehabilitation using hydropuls method: a case study in wonosobo groundwater well
Authors: Aryawicaksona S , Muhammad A S
Published: August 2024

Hydropuls is one of the groundwater well rehabilitation methods that involves pulsing highly compressed nitrogen gas through screen pipes at an adjustable interval. Nitrogen gas was chosen because of its colorless, odorless, and inert properties. The aquifer lithology of this groundwater well is sand, gravel and breccias (member of Sundoro Volcanics; Qsu) with silty clay as the impermeable layer that makes the aquifer type is confined aquifer. The following methods were used in this well rehabilitation: step tests before, borehole camera before, hydropuls, airlifting, borehole camera after and step test after well rehabilitation. Thin section analysis shows that sediment mostly consists of lithic fragments and plagioclase. The results of the polished section analysis reveal that most of the metallic minerals are magnetite and hematite. The XRF results show that the sediment mostly consists of SiO2, Al2O3 and Fe2O3. According to the XRD results, the sediment is mostly albite. The interpretation of sediment analysis shows that the clogging is caused by iron precipitation. The result is an average increase in specific capacity of 1.43 l/s/m (a 168% increase over the initial conditions) and an average drawdown improvement of 2.56 m (a 114% improvement compared to pre-hydropuls conditions). Borehole camera imaging confirmed that the precipitation on the screen was removed and the screen is in good condition.
Parameter identification by eigenfeature analysis: application to 2D Kuramoto-Sivashinsky surface models
Authors: Reiser D , Brenzke M , Wiesen S
Published: August 2024

We have developed a system that makes it possible to derive parameters of a Kuramoto-Sivashinsky (KS) model from a single given two-dimensional profile of surface structures, such as those produced by ion and plasma irradiation. The numerical method is inspired by well-known approaches to facial recognition. Starting from a scaled version of a KS Model to describe surface erosion, a training set of surface profiles is created. Each profile is assigned an appropriate feature in Fourier space and a Singular Value Decomposition is used to determine an orthogonal set of eigenfeatures that allow each profile to be assigned a point in the space of this basis and to determine the distances between them. It turns out that the profiles belonging to different model parameters are clearly separated from each other in this feature space, which enables very good identification. We explain the basic relationships using a synthetic data set and discuss the possibilities for applications to experimental results.
Improved corrosion resistance of hydroxyapatite-reinforced plasma electrolytic oxide coatings on AZ31 alloy from one-step and two-step fabrications
Authors: Anawati Anawati , Purnamasari Yuni , Khairunisa Alya Putri , Wulandari Meishinta Putri , Gumelar Muhamad Dikdik
Published: August 2024

The improved corrosion resistance of AZ31 alloy by plasma electrolytic oxidation (PEO) counteracts its apatite-forming ability. To overcome the issue, apatite-containing coatings were fabricated. One-step and two-step fabrications were compared to incorporate the nanoparticle hydroxyapatite (HA) in the coating and to evaluate their effect on the corrosion resistance. The corrosion resistance was evaluated by polarization test and EIS measurement in 0.9% NaCl solution. The electron microscopy and chemical analysis revealed that the HA particles were dispersed in the one-step coatings, while an interspersed HA distribution was observed in the two-step coatings. The dispersed particles enhanced the coating’s hardness from 490 to 554 HV. In the two-step coatings, the HA particles mainly accumulated inside the pores, reducing the coating porosity down to 3.9%. The one-step coatings were more stable in the corrosive solution, offering a remarkably higher corrosion resistance, than the two-step coatings. Moreover, the one-step coating required a shorter (half) processing time (10 min) than the two-step process (20 min) to achieve a similar order of corrosion current density of 10−7 A cm−2. The results demonstrated that the arrangement of reinforcement in the PEO coatings and its effect on the corrosion resistance can be adjusted.
Material circularity and environmental quality in the EU: what causes what and where?
Authors: Alola Andrew Adewale , Özkan Oktay , Uzuner Gizem
Published: August 2024

Although the green and blue dividends associated with circular economy have been widely advocated, whether circular economy necessarily guarantee environmental quality remains unclear. To provide a more precise insight, in this case for a novel case of all the European Union countries, environmental effect of the share of used material resources from the reuse of waste materials is examined over the period 2010–2021. The results reveal that the reuse of waste materials statistically (i) increase CO2 emissions in most quantiles in Austria, Belgium, Denmark, France, Greece, Hungary, Lithuania, Malta, Netherlands, Poland, and Slovenia, (ii) mitigate CO2 emissions in most quantiles in Bulgaria, Croatia, Cyprus, Estonia, Finland, Italy, Portugal, Romania, Slovak Republic, Spain, and Ireland, and (iii) either increasing or reducing CO2 emissions depending on the quantile of material circularity use rate and CO2 emissions in Czech Republic, Germany, Luxembourg, Sweden, and Latvia. This result points to a more policy driven approach.
Racialized Commodities
Authors: Parmenter Christopher Stedman
Published: August 2024

Between circa 700 and 300 BCE, the ancient Greeks developed a vivid imaginary of the world’s peoples. Ranging from the light-skinned, “gray-eyed Thracians” of the distant north to the “dark-skinned Ethiopians” of the far south (as the poet Xenophanes would describe around 540 BCE), Greeks envisioned a world populated by human groups with distinct physiognomies. Racialized Commodities traces how Greece’s “racial imaginary”—a confluence of thinking about cultural geography, commodity production, and human physiognomy—emerged out of the context of cross-cultural trade between Greece and its Mediterranean neighbors over the Archaic and Classical Periods. For merchants, the racial imaginary might be used to play up the “exotic” provenance of their goods to consumers; it might also circulate practical information about customs, pricing, navigation, and doing business in foreign ports. Archaic Greek attempts to explain foreign bodies were rarely pejorative. But in the early Classical Period such images coalesced into the charged, idea of the barbaros, “barbarian.” Drawing from the historiography of trade in the eighteenth-century Atlantic world, Racialized Commodities adopts the model of “commodity biography” to investigate the entanglement of cultures, bodies, and things in Archaic and Classical Greece. Starting in the period circa 700–450 BCE, Part 1 focuses on the earliest images of African peoples, described by Greeks as Egyptians or Ethiopians, in Greek art. Part 2, which concentrates on the period between 550 and 300 BCE, seeks to explain how and why negative stereotypes of Thracians and Scythians were so widespread in ancient Greece.
A Short History of Natron
Authors: Parmenter Christopher Stedman
Published: August 2024

Part 1 of Racialized Commodities asks how and why Greeks began to see the bodies and cultures of Egyptians or Ethiopians as fundamentally different from their own. Chapter 1 begins with a structural analysis of the factors that drew a Greek merchant diaspora to Egypt in Late Period. An early fifth-century customs register (TAD C3.7) documents a high-volume export trade from Egypt to Greece in natron, a mineral evaporite used in textile production, bathing, and medicine. I propose that Egypt exported circa 27,000 kg natron annually to Greece in exchange for circa 125 kg silver and 3 kg gold. Doing so, Egyptian authorities mobilized a cheap, easily obtained mineral in exchange for precious Aegean silver. The author argues that the natron trade undergirded a broader cultural exchange between Greece and Egypt between circa 700 and 400 BCE.
Journeys into Slavery
Authors: Parmenter Christopher Stedman
Published: August 2024

The second half of Racialized Commodities argues that the earliest Greek stereotypes of people from the north—the “Thracians” and “Scythians” imagined as light-skinned, dim-witted, and enslavable in Greece’s racial imaginaire—dates to the expansion of the ancient Greek slave trade along the northern and western Black Sea coasts after circa 550 BCE. Chapter 4 uses an epigraphic corpus of thirty-seven letters, inscribed by slave traders onto lead tablets between circa 550 and 450 BCE, to reconstruct individual journeys taken by captives as they were conveyed from freedom north of the Pontic steppe to enslavement in Greece. Reconstructing the travels of individual slaves allows us to pursue a study in the spirit of what Joseph C. Miller has called the “biographical turn” in the study of slavery, privileging the experiences of enslaved people over the accounts of their masters. Although the lands around the distant Black Sea were never the leading source of enslaved labor for Aegean cities, the wealth of primary testimony from the region puts it at the forefront in the history of slavery in ancient Greece.
Slavery and the Balance of Trade
Authors: Parmenter Christopher Stedman
Published: August 2024

Chapter 5 explores the economics of the ancient Greek slave trade along the Black Sea coast. Classical Greek literary sources exaggerate its importance. In actuality, the Pontic slave trade in antiquity was mostly intra-regional. This chapter draws on three datasets—the distribution of coinage, amphorae, and shipwrecks—to reconstruct the paths of the long-distance slave trade in the ancient Black Sea, argue for its scale, and explain both its persistence and visibility in the literary record. In the fifth and fourth centuries BCE, Athens created a deliberate trade surplus that left cities along the Black Sea in constant need to export bulk commodities in exchange for Athenian silver. Enslaved captives were never the predominant export of Black Sea cities. Rather, mobilizing the “human resource” represented a fallback strategy, a resource mobilized in times when marketable commodities were in short supply.