bluuebunny/crossref_metadata_2025 huggingface dataset:
The feasibility study of heavy ion-driven reactor-size double-shell target in inertial confinement fusion
Authors: Rezaie-Chamani Afsaneh , Khoshbinfar Soheil
Published: February 2025

In recent years, the design of double-shell targets has been investigated as an alternative approach to achieving ignition conditions at the National Ignition Facility. In this paper, we have numerically examined the parametric optimization of a double-shell spherical target in inertial confinement fusion driven by ion beams. Here, we have employed two deuterium-tritium (DT) fuel layers separated by low-density gas or foam. It facilitates the piston pressure on the central fuel at maximum compression, initiating the ignition there. The ignition and burn stage dynamics were studied numerically by the Deira-4 code, a one-dimensional, three-temperature code designed for heavy ion-driven fusion. We have assumed that Bi-209 ions were illuminated symmetrically on the outer surface of a reactor-sized target. The input power has a peak value of 175 TW and individual ion energies of 7 GeV (∼33.5 MeV/u). To attain proper hydrodynamics efficiency at the implosion stage, geometric optimization was performed on the two outermost layers, including the tamper and absorber layers. It was found that the released thermonuclear energy is sensitive to the outer DT fuel mass. More energetic ions result in a lower energy gain due to preheating. Finally, we compared the double-shell target with/without the density gradient effect. It was shown that the double-shell target with density gradient may manage the Rayleigh–Taylor instability during the implosion stage. In this case, the implosion velocity is reduced to 224 km/s. At stagnation, the ignition condition does not purely follow a volume ignition regime, and the average ion temperature over the fuel region arrives at 2.7 keV, and the optimized energy gain of 169 is achieved.
Feasibility validation of piezoelectric actuators under full-ocean-depth pressure conditions: A study based on M-shaped hybrid-mode design
Authors: Chen Di , Yu Pengpeng , Zhang Shiyu , Zhang Anti , Wang Liang , Jin Jiamei
Published: February 2025

Due to the extremely high pressures in the deep sea, traditional rigid actuators typically require protective vessels and pressure-compensation systems, leading to complex structures and increased risk of structural failure. The inherent adaptability of piezoelectric excitation and friction-coupling drive to high-pressure environments suggests that, theoretically, piezoelectric actuators can operate in full-ocean-depth pressure conditions with an open, direct-immersion structure without requiring bulky pressure-compensation systems. However, the feasibility of piezoelectric actuators operating in full-ocean-depth pressure environments (0–110 MPa) remains unvalidated. To address this, we designed an M-shaped hybrid-mode piezoelectric actuator to experimentally verify its performance under full-ocean-depth pressure conditions. The actuator’s structural dimensions were determined using the finite element method to meet the requirements of frequency degeneracy. We developed a high-pressure water simulation system and measured velocity to evaluate the actuator's performance in simulated full-ocean-depth pressure environments. Our results demonstrate that the actuator prototype operates successfully under pressures up to 110 MPa, equivalent to a depth of 11 000 m, the Earth's deepest point. In addition, the actuator’s velocity remains stable across hydrostatic pressures ranging from 0 to 110 MPa. Although our experiments focus on the M-shaped hybrid-mode design, this actuator embodies the core principles of piezoelectric excitation and friction-coupling drive, which are broadly applicable to various piezoelectric actuators. By validating this design, we broaden both the structural configurations and driving mechanisms available for piezoelectric actuators and provide key insights into the feasibility of piezoelectric actuators operating under full-ocean-depth pressure conditions.
Quantum evolution equations through statistical methods: From fluctuations to nonlinearity
Authors: Fuentes Miguel , Curilef Sergio
Published: February 2025

Various phenomenological generalizations of the foundational equation in quantum physics have been proposed in prior studies. This paper presents a rigorous analytical derivation, grounded in first principles, that elucidates the impact of quantum fluctuations on the evolution of quantum systems. Furthermore, it demonstrates how this essential generalization can be achieved through statistical methods. The paper reveals that standard linear equations of quantum mechanics are recovered under specific limits of the parameter that governs nonlinear behavior. It establishes a direct correlation between the decay of quantum waves and the magnitude of these fluctuations. This connection provides critical insights into the dynamic properties of quantum systems and their susceptibility to underlying stochastic influences. Moreover, this work successfully formulates a comprehensive approach to a complete family of nonlinear quantum evolution equations. This framework expands our theoretical arsenal and enhances our ability to model and predict the behavior of complex quantum systems under various conditions. This research represents a significant advancement in our understanding of quantum mechanics, offering a more nuanced view of how quantum systems evolve under the influence of intrinsic fluctuations. It paves the way for future explorations into the stability, coherence, and dynamical evolution of quantum states, potentially impacting quantum computing, information processing, and other applications in quantum technology.
Optimal conditions for first passage of jump processes with resetting
Authors: Radice Mattia , Cristadoro Giampaolo , Thapa Samudrajit
Published: February 2025

We investigate the first passage time beyond a barrier located at b≥0 of a random walk with independent and identically distributed jumps, starting from x0=0. The walk is subject to stochastic resetting, meaning that after each step the evolution is restarted with fixed probability r. We consider a resetting protocol that is an intermediate situation between a random walk (r=0) and an uncorrelated sequence of jumps all starting from the origin (r=1) and derive a general condition for determining when restarting the process with 0<r<1 is more efficient than restarting after each jump. If the mean first passage time of the process in the absence of resetting is larger than that of the sequence of jumps, this condition is sufficient to establish the existence of an optimal 0<r∗<1 that represents the best strategy, outperforming both r=0 and r=1. Our findings are discussed by considering two important examples of jump processes for which we draw the phase diagram illustrating the regions of the parameter space where resetting with some 0<r∗<1 is optimal.
CUT-E as a 1/N expansion for multiscale molecular polariton dynamics
Authors: Pérez-Sánchez Juan B. , Koner Arghadip , Raghavan-Chitra Sricharan , Yuen-Zhou Joel
Published: February 2025

Molecular polaritons arise when the collective coupling between an ensemble of N molecules and an optical mode exceeds individual photon and molecular linewidths. The complexity of their description stems from their multiscale nature, where the local dynamics of each molecule can, in principle, be influenced by the collective behavior of the entire ensemble. To address this, we previously introduced a formalism called collective dynamics using truncated equations (CUT-E). CUT-E approaches the problem in two stages. First, it exploits permutational symmetries to obtain a substantial simplification of the problem. However, this is often insufficient for parameter regimes relevant to most experiments. Second, it takes the exact solution of the problem in the N → ∞ limit as a reference and derives systematic finite-N corrections. Here, we provide a novel derivation of CUT-E based on recently developed bosonization techniques. We lay down its connections with 1/N expansions that are ubiquitous in other fields of physics and present previously unexplored key aspects of this formalism, including various types of approximations and extensions to high-excitation manifolds.
Mixing characteristics of transverse jets in an annular supersonic flow
Authors: Wang Jiaoru , An Bin , Sun Mingbo , Li Peibo , Wang Taiyu , Liang Changhai , Chen Jikai , Li Menglei , Xie Yu , Yang Kai , Zhang Decong , Yi Zechuan
Published: February 2025

The supersonic combustor with an annular cross section has the potential to enhance fuel/air mixing because the height of an annular flow path is relatively low. However, the efforts that have been dedicated to this topic are exiguous. In this study, numerical simulations were conducted to reveal the fuel/air mixing process in annular flow paths. The Mach number, total temperature, and total pressure of the entrance flow were 2.35, 300 K, and 101.325 kPa, respectively. The height of the annular flow path (H) varied from 7.5 to 12.5 mm, but the equivalent diameter was 37.74 mm for all the cases. In the cases with a jet orifice number (Nj) of 8, an orifice diameter of 0.5 mm, an equivalence ratio of 0.25, and a flow path height of 7.5 mm, the low flow path height significantly enhanced the shock reflection and fuel air mixing in the annular flow path. Therefore, the mixing efficiency in the annular flow path was higher than that of the circular flow path. However, when the equivalence ratio increased to 0.50, the penetration height of the fuel jet was limited by the height of the annular flow path. As a consequence, the mixing efficiency in the circular flow path overpassed the annular flow path. The influence of the annular flow path height (H = 7.5∼12.5 mm) was studied under the condition with an equivalence ratio of 0.5 and Nj = 8. As the flow path height increased from 7.5 to 12.5 mm, the jet penetration height enjoyed a growth but the shock wave reflection was weakened. Consequently, the mixing efficiency in the annular flow path experienced an increase followed by a decrease and reached the maximum at H = 10 mm. The investigation of Nj (from 8 to 32) suggested that the increase in Nj could distribute the fuel jet more evenly along the circumference of the annular flow path but it also reduced the jet penetration height. Therefore, there was an optimum Nj for a certain annular flow path. Under the present condition, the optimum Nj for the case with H = 7.5, 10, and 12.5 mm were 32, 20, and 16, respectively. The optimum mixing efficiencies of these three cases were higher than the circular flow path. Compared to the annular flow path height and orifice number, the impact of the orifice diameter (d = 0.25 to 1.41 mm, H = 10 mm) on mixing efficiency was not significant.
A dualization approach to the ground state subspace classification of abelian higher gauge symmetry models
Authors: Espiro J. Lorca
Published: February 2025

In the literature, abelian higher gauge symmetry models are shown to be valid in all finite dimensions and exhibit the characteristic behavior of symmetry protected topological phases models. While the ground state degeneracy and the entanglement entropy were thoroughly studied, the classification of the ground state space still remained obscure. Based on differentio-geometric approach and, anticipating the notation of the current paper, if C•,∂•Cis the chain complex associated to the geometrical content of these models, while G•,∂•Gis its symmetries counterpart, we show that the ground state space is classified by a H0(C, G) × H0(C, G) group, where H0(C, G) is the 0th cohomology and H0(C, G) is the corresponding 0th homology group with coefficients in the chain complex.
Diffusion in comb-structured surfaces coupled to bulk processes
Authors: Lenzi E. K. , Rosseto M. P. , Gryczak D. W. , de Souza P. A. , Lenzi M. K. , Ribeiro H. V. , Zola R. S.
Published: February 2025

From the analytical perspective, we investigate the diffusion processes that arise from a system composed of a surface with a backbone structure coupled to the bulk via the boundary conditions. The problem is formulated in terms of diffusion equations with nonlocal terms, which can be used to model different processes, such as sorption–desorption and reactions on the surface. For the backbone structure, we consider the comb model, which imposes constraints on the diffusion processes in different directions on the surface. The results reveal a broad class of behaviors that can be connected to anomalous diffusion.
Spherical shock wave modulation induced by interaction with homogeneous isotropic turbulence
Authors: Tanaka K. , Watanabe T. , Suzuki H. , Kouchi T.
Published: February 2025

In this study, we have performed direct numerical simulations (DNSs) of the interaction between a spherical shock wave and homogeneous isotropic turbulence to investigate shock wave modulation. We considered two parameters, the central pressure of the initial high-energy region that generates the shock wave and the turbulent Mach number Mt. DNSs were performed under five conditions. A polar coordinate system (r,θ,ϕ) was then defined for the analyses, with the center of the high-energy region as the origin. The local position of the shock wave rs was defined as the position of the maximum value PM of the radial pressure distribution P(r) at two declinations (θ,ϕ) in the polar coordinate system. Specifically, rs and PM were functions of (θ,ϕ), and their statistics were computed using data over all (θ,ϕ) at each time. The standard deviation of the fluctuation of rs increased monotonically with the shock-wave front propagation in turbulence. This shows that the shock-wave front deformation grew monotonically. The mean pressure distribution conditioned by the fluctuations of rs and joint probability density function of fluctuation of rs and PM show that there is a negative correlation between the deformation of the shock-wave front and the local intensity of the shock wave. This indicates that the deformed shock-wave front tends to return to its original shape. However, the monotonous growth of the deformation indicates the presence of a counter-effect that allows it to grow.
Analytical solution for the hydrodynamic resistance of a disk in a compressible fluid layer with odd viscosity on a rigid substrate
Authors: Daddi-Moussa-Ider Abdallah , Vilfan Andrej , Hosaka Yuto
Published: February 2025

Chiral active fluids can exhibit odd viscosity, a property that breaks the time-reversal and parity symmetries. Here, we examine the hydrodynamic flows of a rigid disk moving in a compressible 2D fluid layer with odd viscosity, supported by a thin lubrication layer of a conventional fluid. Using the 2D Green’s function in Fourier space, we derive an exact analytical solution for the flow around a disk of arbitrary size, as well as its resistance matrix. The resulting resistance coefficients break the Onsager reciprocity, but satisfy the Onsager–Casimir reciprocity to any order in odd viscosity.
Turbulent flow and heat transfer of superhydrophobic cylinders with measured slip length
Authors: Saadatbakhsh Mohammad , Jadidi Mohammad
Published: February 2025

This study investigates the impact of surface-engineered wall slip on flow dynamics and heat transfer in tandem cylinder configurations at a subcritical Reynolds number (Re = 3900). Utilizing large eddy simulation (LES) with experimentally calibrated slip lengths, the research examines how the slip conditions modify boundary layer behavior, wake structures, turbulence characteristics, and overall thermal performance. LES predictions reveal significant modifications in flow physics and heat transfer characteristics. Slip conditions lead to thinner boundary layers on both cylinders and delayed flow separation. This modification enhances aerodynamic performance by reducing drag and lift forces, particularly for the upstream cylinder. The wakes become narrower and more elongated, increasing the vortex-shedding frequencies while attenuating the energy associated with vortex shedding. Furthermore, the implementation of slip boundary conditions significantly alters turbulence characteristics toward one-component “cigar-shaped” turbulence in the Lumley triangle. Both spatial and temporal turbulence scales undergo substantial modifications, with integral length scales typically reducing. Heat transfer performance quantified through Nusselt number distributions exhibits a nuanced response to slip conditions. While the upstream cylinder consistently shows enhanced heat transfer, the downstream cylinder's thermal response strongly depends on the center-to-center ratio. The research highlights the potential for optimizing heat transfer and aerodynamic performance through the strategic application of surface-engineered wall slip, opening new avenues for innovation in various engineering applications, including heat exchangers and thermal management systems.
Tunnel shaft impact on smoke transport in fire-induced high-speed train stopping
Authors: Du Hao , Tang Zitong , Meng Shuang , Zhou Dan
Published: February 2025

When a moving high-speed train experiences a sudden fire and is forced to stop in a tunnel with a shaft, the smoke transport characteristics become complex due to the coupled effects of the train's piston effect and natural smoke extraction through the shaft, posing significant risks to personnel safety and tunnel infrastructure. This study numerically reproduces the above fire scenario to analyze the impact of the tunnel shaft on smoke transport characteristics following a fire-induced train stoppage. The research utilizes the renormalization group (RNG) k-ε turbulence model with buoyancy correction and the volume heat source model, utilizing a sliding mesh technique to simulate the movement of a fire-affected high-speed train in a tunnel with a shaft. The reliability of the numerical approach is validated through moving model test results. The study examines the evolution of smoke flow velocity and temperature during the uniform speed–deceleration–stopping phase and for 360 s after the train halts. Additionally, the effects of the distance between the fire source and the shaft (Df-s), the shaft height (H), and the shaft area (S) on smoke flow velocity and temperature are analyzed. Finally, orthogonal range analysis identifies Df-s as the most significant factors influencing peak temperature and the high-temperature smoke zone in the tunnel, with a markedly stronger effect than the other two parameters. The results can provide guidance for the escape and evacuation of personnel in the event of a fire on a high-speed train inside a tunnel.
High-resolution three-dimensional flow measurement through dual-frame light field particle tracking velocimetry
Authors: Zhu Xiaoyu , Xu Chuanlong , Hossain Md. Moinul , Khoo Boo Cheong
Published: February 2025

Single-camera light field particle image velocimetry (LF-PIV) shows potential for three-dimensional (3D) flow measurements in scenarios with limited optical access but faces challenges of low spatial resolution. To address this issue, we propose a dual-frame light field particle tracking velocimetry (LF-PTV) method that enhances spatial resolution in volumetric velocimetry. This approach combines line-of-sight estimation with a customized deep neural network to reconstruct particle volumes while suppressing elongation artifacts. A gradient-fitting localization technique is employed to pinpoint particle centers, and a motion predictor coupled with a topology-feature matching method facilitates accurate trajectory tracking between successive frames. The performance of the dual-frame LF-PTV method is systematically evaluated through numerical simulations of Gaussian vortex flows and experimental measurements of wake flow behind a circular cylinder. Comparative analyses are conducted to benchmark the proposed method against other PTV and conventional LF-PIV techniques. Results indicate that the deep neural network effectively refines coarse line-of-sight reconstructions, significantly reducing particle elongation. The deep neural network reconstruction using a single light field camera (LFC) achieves approximate accuracy with the traditional Simultaneous Multiplicative Algebraic Reconstruction Technique using dual LFCs. The gradient-fitting algorithm can achieve superior particle localization, especially in high-density seeding, by reducing outliers and enhancing coverage. Furthermore, the integration of motion prediction with the topology-feature matching approach minimizes tracking errors, yielding superior accuracy and spatial resolution in synthetic vortex flow reconstructions. Experimental results further confirm the method's capability to resolve finer wake flow structures, correcting LF-PIV inaccuracies and delivering a three times enhancement in spatial resolution.
Hydrodynamic characteristics of sequential water entry for two structures under different time intervals
Authors: Qi Xiaobin , Yang Zhe , Lu Lin , Shi Yao
Published: February 2025

To investigate the high-speed water entry problem of sequential structures, a three-dimensional numerical calculation model for the high-speed water entry of sequential structures was established based on solving the Reynolds-averaged Navier–Stokes equations. The volume of fluid multiphase flow model and 6 degrees of freedom rigid body motion model were employed, and the Schnerr–Sauer cavitation model was introduced, combined with overlapping grid technology. Numerical simulations of sequential water entry for two structures under different water entry time interval were carried out, and the influence laws of different water entry time interval on the cavity evolution, vortex evolution, and motion characteristics during the water entry of sequential structures were obtained. Results show that the influence of sequential water entry on cavity evolution is mainly reflected in three aspects: disrupting cavity formation, influencing surface closure of the cavity, and inducing curvature in the cavity wall. Simultaneously, the conventional vortex evolution has been modified, with impact dissipation emerging as a novel mode of vortex evolution within the small water entry time intervals. Moreover, in comparison to the water entry of the first structure, the second structure experiences significantly less resistance upon immersion in the flowing water, leading to a more gradual deceleration.
Buffeting response analysis and vibration damping strategies for steel truss arch bridges in the maximum cantilever state
Authors: Liu Jun , Li Hongzhi , Xu Di , Ni Zhifu , Wen Yufen , Qiu Enxi
Published: February 2025

To enhance wind resistance safety for construction personnel and structural integrity, this study investigates the buffeting response and vibration damping measures of a steel truss stiffened arch bridge with a main span of 400 meters during its maximum cantilever construction state. A finite element model was developed, and a three-dimensional pulsating wind field was simulated using the harmonic synthesis method. Time-domain analysis was applied to compute buffeting displacement responses at the cantilever end of the arch rib and the top of the construction buckle tower. Numerical results were compared with wind tunnel tests of a full-bridge model under varying wind speeds, revealing similar buffeting response patterns. At the bridge reference wind speed, predicted peak buffeting displacements were 22.157 and 21.778 cm in the lateral and vertical directions of the arch rib cantilever end, and 16.994 cm laterally at the buckle tower top, with deviations from wind tunnel tests of 13.2%, 10.2%, and 6.9%, respectively. To mitigate these displacements, lateral wind-resistant cables and flexible connections were analyzed. Lateral cables reduced displacements by up to 84.8% at the arch rib cantilever end and 61.0% at the buckle tower top, while flexible cables further reduced responses by up to 76.8%, ensuring enhanced construction safety. The agreement between numerical and experimental results validates the proposed methods, providing a strong basis for wind-resistant design and vibration damping strategies in similar large-span bridges.
Gas transport in double bifurcation subjected to asymmetric reciprocating flow
Authors: Wanigasekara Chandrika , Jacob Chinthaka , Manasseh Richard , Leontini Justin S.
Published: February 2025

High-frequency oscillatory ventilation is a medical ventilation technique that aims to be lung-protective by only moving small volumes of air in and out of the airway per cycle; these small tidal volumes mean that gas transport must be achieved by mechanisms other than bulk advection. Nonlinear mean streaming is one such mechanism. This paper uses direct numerical simulations to study the generation of nonlinear mean streaming in a double bifurcation, a geometry representative of the bifurcating structure of the airway. Specifically, the impact of an asymmetric waveform (where the inflow time is shorter than the outflow time) and the base frequency of reciprocation is measured. We show that the streaming flow strength is nearly independent of the waveform asymmetry at high Reynolds numbers representative of the large upper airways. However, the streaming flow strength can be significantly enhanced by asymmetry at low Reynolds numbers representative of the smaller lower airways. We show that there is an optimal outflow to inflow time ratio in the vicinity of 1.4, and confirm that the impact of asymmetry on the streaming strength occurs for a range of base frequencies spanning an order of magnitude.
Wholesale flat subduction of the Indian slab and northward mantle convective flow: Plateau growth and driving force of the India–Asia collision
Authors: Ma Jincheng , Song Xiaodong , Bunge Hans-Peter , Fichtner Andreas , Tian You
Published: February 2025

The tectonic evolution of the Tibetan Plateau has been influenced by continental collision and postcollisional convergence of Indian and Eurasian plates, both of which have undoubtedly imposed their imprints on the lithosphere and upper-mantle structures beneath the collision zone. However, the mode by which the Indian Plate has subducted beneath Tibet, and its driving forces, have been highly uncertain. Here, we present seismic evidence from a full-waveform tomographic model that reveals flat subduction of the Indian Plate beneath nearly the entire plateau at

∼

300 km depth, implying that the slab may have transitioned to positive/neutral buoyancy and is no longer capable of supporting steep-angle deep subduction. The horizontal distance over which the flat slab slides northward increases from west (where it collides with the Tarim lithospheric keel) to east (where it has resided approximately north of the Songpan-Ganzi Fold Belt beyond the Qiangtang Block). The Asian lithosphere is subducting beneath northeastern Tibet without colliding with the Indian slab. The low-velocity zone, with a thickness of 50 to 110 km, sandwiched between the Tibetan crust and Indian slab, is positively correlated with the high-elevation, low-relief topography of Tibet, suggesting partial melting of the uppermost mantle that has facilitated the growth and flatness of the plateau by adding buoyant material to its base. We propose that deep mantle convective currents, traced to the Réunion plume and imaged as large-scale low-velocity anomalies from the upper mantle under the Indian Plate downward toward the uppermost lower mantle under the Baikal-Mongolia Plateau, are the primary force driving the ongoing India–Asia postcollisional convergence.
Early colonization of the deep-sea bottom—The protracted build-up of an ecosystem
Authors: Buatois Luis A. , Mángano M. Gabriela , Paz Maximiliano , Minter Nicholas J. , Zhou Kai
Published: February 2025

Our understanding of the patterns and processes behind the evolution of deep-marine ecosystems is limited because the body-fossil record of the deep sea is poor. However, that gap in knowledge may be filled as deposits are host to diverse and abundant trace fossils that record the activities of benthic deep-marine organisms. Here, we built a global dataset of trace-fossil occurrences from a comprehensive survey of 720 Ediacaran–Devonian units and show that the establishment of a modern-style deep-marine benthic ecosystem was protracted and coincident with global cooling and increase in oxygenation during the Ordovician. The formation of open burrows may have increased bioirrigation in the uppermost sediment zone, promoting ventilation and generating an ecosystem engineering feedback loop between bioturbation and pore-water oxygenation. Sharp changes in deep-marine bioturbation during the Devonian may have originated from oxygen variations resulting from climate-controlled oceanic circulation.
Spherically symmetric and static black bounces with multiple horizons, throats, and anti-throats in four dimensions
Authors: Rodrigues Manuel E , de S Silva Marcos V
Published: February 2025

Black bounce (BB) spacetimes usually arise from the Simpson–Visser regularization method. This type of metric presents a wormhole throat inside an event horizon. In this paper, we presented new classes of BB spacetime solutions, which have multiple horizons, throats, and anti-throats. These solutions are variants of black holes and wormholes, based on modifications of the Schwarzschild and Simpson–Visser metrics. The metric function allows for multiple horizons and throats, and the asymptotic behavior recovers the Schwarzschild solution. The article considers a scalar field coupled to nonlinear electrodynamics, generating solutions with a partially phantom scalar field and a magnetic monopole. The energy conditions can be satisfied or violated depending on the region of spacetime, analyzed through an anisotropic fluid. The regularity of the spacetime is ensured by the analysis of the Kretschmann scalar.
A federated learning based intelligent fault diagnosis framework for manufacturing processes with intraclass and interclass imbalance
Authors: Ma Liang , Shi Fuzhong , Peng Kaixiang
Published: February 2025

Data based fault diagnosis technologies are important measures to improve the operation safety, stability, and reliability of manufacturing processes, which are key entry points and innovation powers to promote the intelligent manufacturing as well as improve the operation efficiency. Class-balanced datasets are often used for modeling and fault diagnosis by the traditional data based methods. However, in practical engineering applications, manufacturing processes often produce multiple classifications of imbalance data, bringing great challenges to the promotions and applications of the classical data based methods. To this end, an intelligent fault diagnosis framework is proposed for manufacturing processes, of which the issues on the intraclass and interclass imbalance have been specially focused. Specifically, considering the non-independently identically distribution characteristics among different fault data and the low recognition rates of minority fault samples, a new cost sensitive convolutional neural network is constructed as a base classifier by coordinating the cross entropy loss function with a specific cost sensitive index. Subsequently, a federated learning based aggregation algorithm is designed to optimize the participation weights of local classifiers with the purpose of cooperating with multiple classifiers to improve the model generalization performance. Finally, the validity of the proposed framework is demonstrated by a typical hot rolling process with different forms of imbalance fault data. The simulation results show that superior diagnosis performance can be achieved compared with some comparative algorithms in each scenario.
Balance energy savings with indoor comfort – an ANN-based energy management controller for flexible loads
Authors: Miow Xie Cherng , Lim Yun Seng , Hau Lee Cheun , Wong Jianhui , Chin Wai Meng
Published: February 2025

Flexible loads are common building demands that have gathered attention in demand-side management. However, further study is still required in applying machine learning-based methods on flexible loads to provide energy savings in practical studies. Thus, this article introduces an Artificial Neural Network (ANN)-based energy management controller for flexible loads, particularly VRV X AC and refrigerators. The controller balances energy savings and indoor comfort by controlling temperature set points for VRV X AC and duty cycles for refrigerators. Experimental data from the Daikin Research & Development building in Malaysia shows that the ANN-based controller can achieve energy savings of up to 27% while maintaining indoor comfort at an average temperature of 26.76°C with a Desired Energy Saving Coefficient (DESC) of 0.95. It is important to note that DESC represents the trade-off between energy savings and indoor comfort, with higher DESC values offering more significant savings at the potential cost of reduced comfort. Although maximum DESC settings have demonstrated up to 36% energy savings on-site, they have led to some compromise in comfort, evident from the higher average temperature of 27°C. This article highlights the fine balance between energy savings and indoor comfort during high building power demand.
Physical Properties Investigation of Bi2O3-PbO-B2O3-P2O5 Glasses
Authors: Ariyanti S , Marzuki A , Cari  , Ramelan A H , Fausta D E , Harjana  , Sutomo A D
Published: February 2025

Bismuth-lead glasses incorporated with different concentrations of P2O5 have been synthesized. The composition of the glasses is 53Bi2O3-28PbO-(19-x)B2O3-xP2O5 (BPBP) (x = 0, 0.25, 0.5, 0.75, 1.0, 1.25, and 1.5 mol%). All glasses were melted at 900°C for 40 minutes and subsequently annealed at 275°C for 8 hours and then cooled to room temperature at a cooling rate of 1°C/minute. Density measurements were carried out at room temperature using a pycnometer. It was shown that the density increases with increasing P2O5 concentration, that is, from 7.42 g/cm3 to 8.20 g/cm3. From the glasses composition and density data, several important physical properties of glasses were derived, i.e., P3+ ions concentration (Np), polar radius (rp), inter-ionic distance (ri), field strength (F), and oxygen packing density (OPD). With increasing P2O5 concentration, the Np value increases from 0 to 22.73 x 1021 ions/cm3the rp decreases from 0.2461 to 0.0383 Å, and the ri decreases from 0.9408 to 0.1446 Å. It was also shown that the OPD decreased from 56.10 mol/L to 62.19 mol/L, indicating that increasing P2O5 concentration raises the portion of Bridging Oxygen (BO) in the glass matrix.
Effect of various fluids on insulated seamless pipelines on Corrosion Under Insulation (CUI) level in Remaining Life Assessment (RLA) determination using Lixi Profiler
Authors: Fadhilah Syah Nikmatul , Mulyono Tasih , Ismail
Published: February 2025

Enhanced Oil Recovery involves two types of seamless pipes with different fluids: steam and crude oil. The pipes using certain standards, even pipes with different fluids have different standards, methods, and results. The pipes are insulated so CUI can appear. This research analyses the effect of various fluids in insulated seamless pipelines on the corrosion rate to determine the pipe’s RLA using Lixi Profiler. By analysing the minimum thickness of Gadolinium153’s photons can verification by pitting gauge and get CUI. Inspections on a 8-inch steam pipeline and a 6-inch crude oil pipeline. Lixi Profiler scanning results showed the steam pipe which was more stable than the crude oil pipe due to the radiation absorption quantity. It is found that the RLA of the steam pipe tends to be safe, while the crude oil pipe has the lowest RLA in the range of 0 to 2.7 years and is recommended to repair immediately. The identification results of external corrosion on crude oil pipelines and steam pipelines are pitting corrosion with depths 0.26 mm to 2.95 mm and CUI on 0.39 mm to 1.68 mm. This proves that corrosion rate of crude oil pipelines is higher than steam pipelines because they have more fittings, smaller pressures, and lower operating temperatures.
Evaluation of post-excavation engineering geological condition at the diversion tunnel of Tiga Dihaji Dam Construction, South Sumatera, Indonesia
Authors: Krisdianto Panji , Setiawan Hendy , Budianta Wawan
Published: February 2025

The diversion tunnel at Tiga Dihaji Dam used underground tunneling construction with a diameter of 7 meters and a tunnel length of 595 meters. The diversion tunnel was already excavated, and the support systems were installed. The underground condition of the tunnel depends on the rock mass characteristics. Hence, the engineering geological conditions must be evaluated after the excavation process. Five aspects were evaluated: geomorphology, lithology, geological structure, groundwater level, and rock mass quality. Two methods were used to evaluate all of the five aspects: geological surface mapping and core sample analysis. Geological surface mapping was conducted on a 1,3 x 1,5 kilometers area around the diversion tunnel to obtain the geomorphology, lithology, and geological structure data. Core sample analysis was conducted by analyzing four sample cores along the tunnel alignment to obtain groundwater level and rock mass quality data. Two kinds of rock mass classification were used to analyze the rock mass quality: Rock Mass Rating (RMR) and Geological Strength Index (GSI). The evaluation will be presented in the form of engineering geological maps. Results indicated that the geomorphological condition of the study area was classified into steep sloping hills, gently sloping hills, and very steep sloping river valley units. The lithology condition was classified into tuff, interbedded sandstone and carbonaceous siltstone, and colluvial sediment. Systematic shear joints at some observation stations were observed, indicating the presence of weak planes in the diversion tunnel. The groundwater level was at 241-243 meters above sea level, which was above the elevation of the diversion tunnel at 218-221 meters. In addition, the rock mass quality in the study area consists of good, fair, and poor quality rocks for both methods, with RMR values ranging between 37,00 to 61,60, and the GSI of 32,50 to 73,90. In conclusion, the rock mass classification depends on the lithological settings and the weathering conditions in the study area.
Nickel Oxide Photocatalyst derived from Leached Spent Ni-Mo Catalyst using Citric Acid Solution
Authors: Izza Dani Putra Rasya , Suci Novitasari Putri , Asto Putro Firman , Jumari Arif , Paramitha Tika , Satria Yudha Cornelius
Published: February 2025

Ni-Mo catalyst has been commercially employed in both petroleum and petrochemical industries. Due to poisoning, this catalyst becomes inactive; therefore, it must be recycled properly. In this research, the citric acid solution was employed to recover selectively nickel from the catalyst through an extractive metallurgy mechanism. The leached Ni was converted into nickel oxide via the solution combustion method (SCM). The leaching solution was analyzed using FTIR. The post-combustion powder and post-sintered powder were analyzed using FTIR, XRD, and SEM. Based on SEM-EDX analysis, the resulting NiO powder has a sub-micron size and high Ni and O content. XRD and FTIR analyses confirm the presence of cubic-structured NiO with a dominant Ni-O bond. The samples were used as a Fenton catalyst during the photodegradation of Crystal Violet (CV) under UV-C light irradiation, resulting in a degradation efficiency of 91.6% after 50 minutes of 20 ppm CV.
Removal of mercury and iron in water using reduced graphene oxide/zinc oxide composite
Authors: Wahyuni Dwiria , Nurhasanah  , Muhammad Arsyad Ya’ , Mariani
Published: February 2025

Mercury (Hg) and iron (Fe) contamination in the water is classified as water pollution. This study aims to synthesize and evaluate a reduced graphene oxide/zinc oxide (rGO/ZnO) composite as an efficient adsorbent for removing Hg and Fe in the water. The varied mass of GO was prepared by sonication, aiming to reduce particle size and the oxygen functional group of GO. The rGO/ZnO was prepared by mixing sonicated GO and Zinc (Zn) powder in distilled water, followed by hydrothermal treatment. The rGO/ZnO composite was characterized by scanning electron microscopy (SEM), showing the coverage of rGO layers by ZnO. The performance of the rGO/ZnO composite as an adsorbent for Hg and Fe removal was evaluated through adsorption experiments. The results in varied concentrations of GO showed that the composite rGO/ZnO exhibited high adsorption for Hg and Fe ions in the water, with the highest adsorption capacity of 126 mg/g and 22.95 mg/g, respectively. Meanwhile, the highest removal efficiency of the composite was 99.83% for Hg and 91.82% for Fe. The observed color in well water also changes qualitatively and quantitatively up to 92.26%. In conclusion, the rGO/ZnO composite is a promising adsorbent for removing Hg and Fe ions in the water and decolorizing water contaminated by Fe.
Investigation of the characteristic relation of Polyvinylidene Fluoride-Cellulose Acetate Membranes as Separator of Lithium Ion Battery
Authors: Dinastuti Ria , Retno Dyartanti Endah , Jumari Arif , Wahyu Widodo Diyan , Budi Utomo Albuni Sukma
Published: February 2025

The separator membranes is one of the lithium ion battery components which functions to prevent short circuits in the battery cells and the lithium ion transfer medium. Types of polymers that can be used for separation membranes include polyethylene, polypropylene, polyvinylide fluoride (PVDF), polyacrylonitrile (PAN), polyvinyl alcohol (PVA), polyethylene oxide (PEO), and polymethyl methacrylate (PMMA). PVDF polymer was selected because it has the advantages of high polarity, high dielectric constant, and excellent electrochemical stability. However, the polymer has a weakness, namely a relatively high level of crystallinity, so it needs to be blended with Cellulose Acetate (CA) to reduce the degree of crystallinity and improve membranes performance. Fillers are used as additives to increase ionic conductivity. This research aims to determine the effect of nanoclay filler concentration on PVDF/CA membranes. The membranes solution was made by mixing CA, PVDF, nanoclay, and PVP addictive, with variations of nanoclay (0; 1.75; 3.59; 5.22; 6.94; and 8.46 %wt). The CA/PVDF membranes was then put through characterisation testing with FTIR, XRD, SEM, electrolyte uptake, and porosity. According to the test results, the best characterisation results are found in membranes with variations of nanoclay 6.94 %wt, which have electrolyte uptake values of 78.208% and porosity values of 97.520%.
Analysis of dose distribution and radiation source effectiveness in brachytherapy for right lung cancer using ORNL-MIRD 1996 Phantom with MCNP 6.2 software
Authors: Indah Purwati Inies , Purwanto Hery , Riyatun  , Anwar Fuad , Arianto Fajar
Published: February 2025

Brachytherapy is a form of radiation therapy that uses radiation to destroy cancer cells. Radiation can cause cells to ionize and deposit their energy. Brachytherapy simulations have been performed on right lung cancer using MCNP6.2. Organs at risk include the left lung, heart, pancreas, and liver. The therapy process uses a total of 60 seeds with varying amounts from 10, 20, 30, 40, 50 to 60 for each radiation source. The radiation sources used were Ir
192, Pd
103 and Cs
131 with gamma energy in MeV of 0.38; 0.021; and 0.0304, respectively. With the variation of seed number, the absorbed dose in right lung cancer and the optimal seed number for sources Ir
192, Pd
103 and Cs
131 are (31.326±0.013) Gy with the optimal seed number of 80, (6.925±0.038) Gy with the optimal seed number of 364, and (4.043±0.066) Gy with the optimal seed number of 623. For the results of the effective dose distribution in right lung cancer for each radiation source, Ir
192 is (1.5663±0.0072) Sv, Pd
103 is (0.3462±0.0071) Sv, and Cs
131 is (0.2021±0.0071) Sv. Based on this study, the absorbed dose in right lung cancer for a 10-year-old child is optimal at a dose of (31.326±0.013) Gy. The optimal effective dose for right lung cancer in a 10-year-old child is (1.5663±0.0072) Sv.
Screening and assessment of the chitosan-based nanoparticle formation through an ionic gelation method
Authors: Ainurofiq Ahmad , Wiyono Nanang , Vania Febrianti Marzuki Artha , Choiri Syaiful
Published: February 2025

The formation of a chitosan-based nano polymeric system through ionic gelation has been attractive for the past decade due to its cost eco-friendly and high drug loading. However, the formation of chitosan-based nanoparticles is affected by several undefined factors. This work aimed to understand the effect of those factors, namely, chitosan concentration, counter-charge type and concentration, drug solvent, and pH, on nanoparticle formation and screen the most considered factors for chitosan-based nanoparticle formation. A 26-2 fractional factorial design was utilized to assess and screen the most crucial factors in nanoparticle formation. In addition, a mixture of several natural polyphenol compounds was used as a drug model. The nanoparticle formation was measured by size and distribution, zeta potential, drug loading, and encapsulation efficiency. A multiple linear regression model was constructed according to the design, and the contribution was calculated based on the main effect, along with a confidence level of 95% (p=0.05). The results indicated that drug concentration determined the enlargement of particle size and the drug loading, and chitosan contributed to the increase of nanoparticle surface charge. The counter-charge and the solvent concentration affected the particle size distribution. Moreover, the pH system was slightly considered in broadening particle size distribution. The type of counter-charge contributed less to the response. Therefore, the concentration of chitosan, counter-charge, and drug loading were the most crucial factors to achieve lower particle size and higher encapsulation efficiency.
BridgeFinder: Enabling Predictive Optimisation Techniques for High-Level Design of Large Structures in Mechanical Engineering Development
Authors: Kessler Beatrice , Marzbani Hormoz , Jazar Reza , Kessler Jörg
Published: February 2025

In this study, we present BridgeFinder, a novel high-level design optimisation approach tailored to the demands of large-scale construction engineering. This method facilitates predictive design rather than relying on reverse calculations. BridgeFinder integrates SmilesMe, a newly devised notation and abstraction layer, with an evolutionary algorithm leveraging the specially developed Evolution Shape Function for fitness assessment. Our inspiration to develop BridgeFinder stems from MolFinder, a technique used in chemistry to forecast molecular structures. Current algorithm-based optimisation strategies primarily focus on the later stages of construction design, such as CAD/FEM. Alternatively, some methods lack definitive calculation guidance, leading to overly algorithm-driven outcomes that may not always align with the requirements of high-level design in large constructions (e.g., generative design techniques). BridgeFinder aims to bridge this gap, offering refined calculation guidance, thereby generating construction concepts more suited to the high-level phase of large-scale projects. We anticipate that our findings will illuminate new pathways for advancements in construction design methodologies.