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The permutation flow shop batch scheduling problem: an improved population-based iterative greedy algorithm with self-adaption and self-viewing
No full textTo address production scheduling difficulties, efforts in academia and industry focus on achieving a balance of economic, environmental, and societal growth through green manufacturing scheduling. In this paper, the multi-objective permutation flow shop batch scheduling problem (MOPFSBSP) is optimized by taking makespan and machine emission noise into account. As a result of evaluating other NEH-based algorithms, the enhanced NEH_PRSQ algorithm yields a favorable initial solution after evaluating other NEH-based algorithms. The improved population-based iterative greedy algorithm (IPBIG) is then given a self-adaptation and self-viewing strategies to make it better at exploring. Then, a local search algorithm is suggested to apply mutation and replacement to sub-batches and sub-lots of each product to achieve the best solution. The algorithms presented in this research are tested on the Car, Rec, and Hel standard database instances and compared with traditional and innovative algorithms. The experimental data shows that the IPBIG algorithm outperforms other algorithms in optimizing over 74.19% of instances, particularly medium- and large-scale instances. Undoubtedly, the IPBIG algorithm offers a superior solution to the MOPFSBSP problem, it also significantly diminishes production noise, enhances operational efficiency for enterprises, and provides a novel trajectory for the sustained advancement of manufacturing firms
A Neural-Network Framework for Tracking and Identifying Cosmic-Ray Nuclei in the RadMap Telescope
No full textThe detailed characterization of the radiation environment aboard spacecraft is a prerequisite for assessing shielding requirements and for minimizing the exposure of crew and equipment during future deep-space missions. The scintillating-fiber tracking calorimeter at the heart of the RadMap Telescope is designed for detailed studies of cosmic rays within the resource constraints of an operational radiation monitor.
We present a neural-network framework that can reconstruct the properties of cosmic-ray nuclei traversing the instrument. Employing the Geant4 simulation toolkit and a simplified model of the detector to generate training and test data, we achieve the spectroscopic capabilities required for an accurate determination of the biologically relevant dose that astronauts receive in space. We can reconstruct the trajectory of a particle with an angular resolution of better than 1.4° and achieve a charge separation of better than 95% for nuclei with Z ≤ 8; specifically, we reach an accuracy of 99.8% for hydrogen. The energy resolution is < 20% for energies below 1 GeV/n and elements up to iron. We also discuss the limitations of our detector, the reconstruction framework, and this feasibility study, as well as possible improvements
The ALMA survey to Resolve exoKuiper belt Substructures (ARKS)
No full textContext. Dusty discs detected around main-sequence stars are thought to be signs of planetesimal belts in which the dust distribution is shaped by collisional and dynamical processes, including interactions with gas if present. The debris disc around the young A-type star HD 131835 is composed of two dust rings at ∼65 au and ∼100 au, a third unconstrained innermost component, and a gaseous component centred at ∼65 au. New ALMA observations show that the inner of the two dust rings is brighter than the outer one, in contrast with previous observations in scattered light.
Aims. We explore two scenarios that could explain these observations: the two dust rings might represent distinct planetesimal belts with different collisional properties, or only the inner ring might contain planetesimals while the outer ring consists entirely of dust that has migrated outwards due to gas drag.
Methods. To explore the first scenario, we employed a state-of-the-art collisional evolution code. To test the second scenario, we used a simple dynamical model of dust grain evolution in an optically thin gaseous disc. In each case we identified the parameters of the planetesimal and the gaseous disc that best reproduce the observational constraints.
Results. Collisional models of two planetesimal belts cannot fully reproduce the observations by only varying their dynamical excitation, and matching the data through a different material strength requires an extreme difference in dust composition. The gas-driven scenario can reproduce the location of the outer ring and the brightness ratio of the two rings from scattered light observations, but the resulting outer ring is too faint overall in both scattered light and sub-millimetre emission.
Conclusions. The dust rings in HD 131835 could be produced from two planetesimal belts, although how these belts would attain the required extremely different properties needs to be explained. The dust-gas interaction is a plausible alternative explanation and deserves further study using a more comprehensive model
The impact of localized out-of-plane antisymmetric flows and Hall effect on the magnetic reconnection in a compressible plasma
No full textBased on a two-dimensional compressible magnetohydrodynamic (MHD) model, we systematically investigated the individual effects and combined influence of localized out-of-plane antisymmetric flows and the Hall effect on magnetic reconnection dynamics. The results reveal that both the localized out-of-plane antisymmetric flow and the Hall effect rapidly trigger magnetic reconnection, but the maximum achievable energy conversion rate is reduced, indicating that the nonlinear evolution of reconnection in later stages is suppressed. Additionally, the out-of-plane antisymmetric flow suppresses the magnetic island coalescence observed in purely resistive tearing modes. The introduction of the Hall effect can accelerate the merger of magnetic islands within the current sheet. When combined with the out-of-plane antisymmetric flow's influence, it is shown that the interplay between the Hall effect and the z-axis-aligned out-of-plane antisymmetric flow forms magnetic islands within elongated current sheets, thereby inducing additional plasma instabilities. These findings contribute significantly to the understanding of tearing mode instability development under the coupled influences of outflow dynamics and Hall physics in MHD systems
Rb vapour Zeeman optical spectroscopy in a self-calibrated magnetic field
No full textHigh-resolution optical spectroscopy of Rb atoms in an intermediate-Zeeman magnetic field regime is performed. Magnetic fields between 0.05 T and 0.13 T are measured. We introduce a measurement approach based on three-level systems where the open-loop frequency energy separation is determined by the applied magnetic field. Using this method an accuracy better than 100 ppm is reached in a measurement series. In parallel, on the basis of complementary measurements based on three-level V systems we obtain the first experimental value of the Landé g-factor of the first excited state for Rb, =0.66709(7), and for Rb, =0.6663(2). Our approach is unprecedented in the literature for Rb
An Enhanced EDBO-based Planning for Optimal Placement and Sizing of Wind Turbine-Based Distributed Generators in Unbalanced Radial Distribution System
No full textBackground: Researchers are actively addressing the environmental impact of fossil fuels by leveraging Renewable Energy Sources (RES), particularly wind power. However, the inherent variability of wind energy, driven by unpredictable wind speeds, presents challenges for ensuring the reliability of distribution systems.
Objective: Efficiently determining optimal locations and capacities for integrating RES into distribution networks is crucial for realizing benefits such as improved voltage profiles, congestion mitigation, enhanced reliability, and reduced emissions. Placing RES in suboptimal locations may yield undesirable outcomes.
Methodology: To address the issue a nature-based optimization approach called Enhanced Dung Beetle Optimisation (EDBO) is introduced for selecting the most suitable positions and sizes for Wind Turbines (WT) within distribution systems. The optimization considers technical constraints such as wind power output, voltage and power flow limits, and load balancing requirements.
Test system: This optimization approach is applied to optimize WT placement and sizing within distribution systems, showcasing its effectiveness through simulation tests on IEEE-13 and IEEE-34 bus systems.
Results and Conclusion: The proposed method significantly reduces power loss compared to all other conventional techniques used in the IEEE-13 bus system and the IEEE-34 bus systems. Additionally, the technique enhances sustainable and reliable energy distribution in the context of WT integration
Structure and ion transport in lithium silicates: insights from molecular dynamics simulations
No full textMolecular dynamics (MD) simulation is conducted to investigate the structure and diffusion in lithium silicate glasses. The density, atomic-pair distances, average partial coordination number, radial distribution function (RDF), and structure factor (SF) as obtained from simulation show a good agreement with experiment. The result shows that during 150 ps, unlike Si and O, Li atoms move between coordination cells (CCs). The average lifetime of LiNBO linkage is significantly larger than that of LiBO linkage. The diffusion constant (D) is expressed by the rate of creating linkages, mean square displacement (MSD) per oxygen, and correlation factor (, and )
Quantum chemical exploration of piperazinium nitrate: molecular stability, reactivity descriptors, electronic excitations, intermolecular interactions, and NLO activity
No full textSingle crystals of Piperazinium Nitrate were obtained by slow evaporation, crystallizing in a monoclinic system (P21/c), and stabilized by strong N–H···O hydrogen bonds in a three-dimensional network. structural integrity of the grown crystal was confirmed by X-ray diffraction (XRD) analysis. Experimental characterization using FT–IR and FT–Raman spectroscopy confirmed the presence of functional groups and characteristic vibrational modes corresponding to the molecular structure. Hirshfeld surface (HS) analysis and 2D fingerprint plots quantified the intermolecular contacts, highlighting the dominant role of hydrogen bonding in crystal packing and structural stability. HS analysis revealed that O···H interactions contribute 54.9% of the overall intermolecular contacts, confirming the dominance of hydrogen bonding in the crystal packing. Density Functional Theory (DFT) calculations at the B3LYP/6-311G (d, p) level were performed to optimize the molecular geometry and investigate the electronic structure, revealing a significant HOMO–LUMO energy gap of 5.391 eV, denoting the stability of molecule and low chemical reactivity. Time-Dependent DFT (TD-DFT) simulations of the UV–Visible (UV–Vis) spectrum provided insights into the electronic excitation behavior. The absorption peak at 255.76 nm, it exhibits the π → π* and n → π* electronic transitions in gas phase. Natural Bond Orbital (NBO) analysis indicated a strong intramolecular hyperconjugative interaction between the lone pair on LP(3) O2 and antibonding orbital of the N1–O4 bond, contributing 144.41 kJ mol−1 to molecular stabilization. Fukui function analysis identified the reactive sites susceptible to electrophilic and nucleophilic attack. Electron Localization Function (ELF) and Localized Orbital Locator (LOL) maps illustrated regions of electron localization and delocalization. Non-Covalent Interaction (NCI) analysis based on Reduced Density Gradient (RDG) plots revealed the presence of weak van der Waals forces and strong hydrogen bonding interactions. The calculated first-order hyperpolarizability (29.244 × 10⁻31 esu), which is 7.8 times greater than that of urea, and the calculated first-order hyperpolarizability confirms the strong NLO response and highlights the potential of the compound for nonlinear optical (NLO) and photonic applications
Study of Nitrogen Diffusion in Aluminum Containing Plasma-Nitrided Air-Hardening Medium Manganese Steels
No full textThis study explores the effects of plasma nitriding on the surface hardness and nitride compound layer thickness of AHD steels containing 4% manganese, with a focus on aluminium content and treatment temperature. A temperature range from 500-700°C was studied. Chemical analysis and nitrogen diffusion profiles were obtained via Electron Probe Micro-Analysis (EPMA). Results showed nitrogen diffusion during plasma nitriding is highly temperature-dependent. At 500°C, a compound layer comprising γ'-Fe4N or γ'/ɛ- phases was observed across all three investigated alloys. Elevated aluminum levels promote thicker nitride layers and higher diffusivity, whereas treatment duration has a comparatively minor influence on layer growth. Additionally, nitrogen diffusion induces a displacement effect on carbon within the alloys interior, affecting overall microstructural evolution. The nitrogen diffusion coefficient was calculated, revealing an increase with rising temperature. These findings underscore the significant roles of process temperature and alloy composition in tailoring microstructural modifications and enhancing mechanical properties through plasma nitriding of AHD steels