bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on an integrated control strategy for grid-connected and off-grid optical storage microgrids
Authors: Wang Xiulian , Zhang Junhe 
Published: April 2024

Abstract
In order to mitigate the volatility and randomness caused by the switching processes in a photovoltaic storage microgrid, and to enhance its stability, in this paper, the utilization of the PQ+PQ control strategy is proposed for grid-connected operation and the V/f+PQ integrated control strategy is proposed for off-grid operation. Through this approach, a smooth transition from the PQ control of the master inverter to the V/f control is achieved, enabling seamless switching between grid-connected and off-grid modes in the photovoltaic storage microgrid. The proposed integrated control strategy is validated for feasibility and accuracy using a simulation platform built in Matlab/Simulink.
Nanosecond photography observation of the discharge process across the 220 kV/500 kV insulators in lightning impulse
Authors: Liao Minchuan , Zhao Zicai , He Shaomin , Wu Rongrong , Qu Lu , Chen Huaifei 
Published: April 2024

Abstract
Long air gap discharge is the basis for the study of lightning protection and external insulation design of high voltage lines. However, there is a lack of detailed and comprehensive observation of the long air gap discharge process at the ns-level, as well as higher voltage insulator discharge observations. In this paper, the lightning impulse discharge/flashover tests are conducted on 220 kV glass insulators and 500 kV glass/composite insulators. Firstly, the U50% test is performed to determine the U50% value of each insulator under standard lightning impulse, and 1.1U50%, slightly higher than U50%, is applied to ensure the breakdown of the insulator. Subsequently, emICCD is utilized with a very short exposure time (minimum 10 ns) to obtain repeated single shots of discharge images under different delays, exposure times and light intensity gain. These images were spliced together based on time sequence to create a continuous discharge process. The discharge processes of 220 kV glass insulator and 500 kV glass/composite insulator are compared and analyzed. The results show that in the early stage of discharge, the discharge processes at the low voltage end of both 220 kV and 500 kV glass insulators are more intense. Additionally, the downward leader is faster than the upward leader in the discharge process of 500 kV composite insulators.
Semi-global Simulations of Star Formation in Nuclear Rings of Barred Galaxies
Authors: Kim Woong-Tae , Moon Sanghyuk 
Published: April 2024

Abstract
Nuclear rings at the centers of barred galaxies are active in star formation. To understand what determines the star formation rate (SFR) and structure of nuclear rings, we conduct semi-global, magnetohydrodynamic simulations of nuclear rings subject to various mass inflow rates with and without magnetic fields. We adopt the TIGRESS framework of Kim & Ostriker to handle radiative heating and cooling, star formation, and related supernova feedback. Our findings suggest that supernova feedback cannot destroy the nuclear ring completely or halt star formation within it, while both the mass inflow rate and supernova feedback affect the ring star formation rate. The supernova feedback is responsible for small-amplitude SFR fluctuations with a timescale of less than 40 million years, while the SFR variations over longer timescales are due to changes in the mass inflow rates. Magnetic fields seeded by the inflows are amplified in the ring due to rotational shear and supernova feedback, greatly reducing the SFR at late times. Strong magnetic tension in the ring drives radially inward accretion flows from the ring to form a circumnuclear disk in the central region, which is absent in the unmagnetized model.
Achieving Higher Order Accuracy in Space in Hydrodynamic Simulations of Self-Gravitating Gas
Authors: Hanawa Tomoyuki , Mullen Patrick Dean 
Published: April 2024

Abstract
Modern astrophysical simulation codes employ a variety of numerical algorithms capable of achieving higher-order accuracy in both space and time. Albeit they succeed in achieving an effective higher spatial resolution and in suppressing the numerical damping of waves, to our knowledge, all current astrophysical simulations invoking self-gravity are limited to second-order accuracy in space. If we can devise an algorithm to evaluate self-gravity with a higher-order spatial accuracy, we can better the evaluation of the gravitational acceleration and gravitational energy release which dictate the evolution of many astrophysical systems. Herein, we present a numerical algorithm for self-gravitating hydrodynamics capable of achieving fourth-order accuracy for a given density distribution on a Cartesian uniform grid. First, we derive the cell-averaged gravitational potential at fourth-order accuracy from the cell-averaged density by solving the Poisson equation. Next, we obtain the cell average of the product of the density and gravitational acceleration, which differs from the cell-averaged density multiplied by the cell-averaged gravitational acceleration. We then show the verification of the algorithm by applying it to critical test problems: (1) maintaining equilibria of self-gravitating slabs, even upon advection, (2) evolving a polytropic sphere with a massive power-law envelope, and (3) conservation of specific entropy during the propagation of a sound wave.
Natural Light Harvesting Materials: A Study on Optoelectronic Properties of Potential Natural Dyes
Authors: Harshitha D , Mahesh H M , Renuka C G 
Published: April 2024

Abstract
Natural dyes are being highlighted by research and industry trends; the majority of plant species offer abundant sources of colouring compounds. They can be harvested using affordable technology and used in cutting-edge applications. Hence, an examination of the optoelectronic characteristics of Carissa caranda fruit dye has been looked into in this paper. Anthocyanins present in Carissa caranda were extracted by solvent extraction of the fruits with ethanol and methanol solvents, maintaining pH at 7 under room temperature. UV-visible spectroscopy analyzed the dye extracts, and the optoelectronic properties such as optical energy band gap, extinction coefficient, and refractive index, are studied. UV-Vis investigations revealed large absorption peaks in the visible area and obvious band gaps. Carissa caranda natural dye had the lowest direct bandgap of 2.98eV and an indirect bandgap of 1.93eV for ethanolic extraction. It was found that the optical absorption in the dyes obeyed both direct and indirect transitions between the molecular energy levels. FTIR spectroscopy has been used to confirm the composition of the natural dyes. The findings here may be particularly significant for organic electronics applications, including O-LEDs and sensors.
Crystal structure, molecular mechanics and In silico analyses of piperizine derivative against human mammary carcinoma cells inhibition.
Authors: Keshav Kumar H , Ananda S , Dukanya  , Keerthikumara V , Basappa  , Mahendra M 
Published: April 2024

Abstract
In the present study, the single crystal of novel piperazine derivative4-(2, 3-chlorophenyl) piperazine-1-yl) (2-hydroxyphenyl) methanone (KDM) is grown by using the solvent evaporation method. The 3D structure of the molecule is confirmed by the single-crystal X-ray diffraction method. The study revealed that the molecular system is crystallized in the orthorhombic system with space group Pbca
. The supramolecular crystal architecture establishes the stability of a compound via short contacts and halogen-hydrogen interactions. The Hirshfeld surface analysis were performed to evaluate the numerous intermolecular interactions based on the anisotropy of the topology. The Frontier molecular orbital (FMO) analysis and Molecular electrostatic potential (MEP) plots are investigated to understand the electronic structure properties of compounds using Density Functional Theory (DFT). In silico molecular docking, analysis is carried out to predict the best binding pose of the compound in the active site pocket of the BCl-XL/BAK protein-protein interface. Further, in vitro cytotoxicity studies against human breast cancer (MCF-7) cell lines of similarly designed piperazine-based derivatives showed prominent results. The results of the current study revealed that the compounds under investigation possess potential anti-cancer properties.
Tailored Synthesis of CN-PPy Composite for Enhanced Electrochemical Functionality
Authors: Vijaykumar S P , Sapna S , Suresh D S , Ganesha H , Ba Shbil Abdullah 
Published: April 2024

Abstract
This study details the synthesis of pure carbon nitride (CN) and composite polypyrrole through an in-situ polymerization method. The prepared samples were comprehensively characterized using Fourier Transform Infrared Spectroscopy (FT-IR), Field Emission Scanning Electron Microscopy (FESEM), and X-ray Diffraction (XRD). These analyses confirmed the chemical bonding, structural, and morphological characteristics of the products. Electrochemical measurements, conducted through cyclic voltammetry (CV) and Linear Sweep Voltammetry (LSV), revealed significant current rates in both anodic and cathodic peaks, indicating superior electrochemical properties. This work not only details the synthesis process but also provides a thorough understanding of the structural, morphological, and electrochemical aspects, exhibiting the materials’ potential for various applications in electrochemical devices.
Determination of effective atomic number, electron density and Kerma of some ferroelectric materials using mass attenuation coefficients in the energy range 1 keV -100 GeV
Authors: Pushpa A. , Bhagyalaxmi I. B , Shivaleela B. , Shivraj G. G 
Published: April 2024

Abstract
The effective atomic number Zeff and the corresponding effective electron density Nel of ferroelectric materials (BaCoF4, LiNbO3, KNbO3, BaTiO3, PbZrO3, PbTiO3, KNbO3, Bi4Ti3O12, KHPO4, PbBi2Nb2O9, SrBi2Ta2O9, Ba0.73Sr0.27TiO3 and Mg3B7O13Cl) has been calculated in the extended energy region from 1 keV – 100 GeV using WinXCom program. The total photon interaction with coherent and incoherent one can distinguish three energy regions are approximately E<1 keV, 10 keV<E<1 GeV and E>10 GeV. The main photon interaction processes in these regions are photoelectric absorption, incoherent (Compton) scattering and pair production. Zeff and Nel values also have been obtained for different processes such as coherent and incoherent scattering pair production in nuclear and electric field, photoelectric absorption and the variations are shown graphically. The variations are due to the presence of different elements in a compound. The behaviour of the energy dependence of electron density is similar to the energy dependence of effective atomic number. The photoelectric absorption is dominant for total coherent process for Kinetic energy released per unit mass (Kerma). Direct method is one of the method helpful to calculate effective atomic number for all types of materials, for all energies greater than 1 keV.
Ftir, uv-vis and conductivity studies in a copolymer of indole and carbazole
Authors: Raghavendra B , Sankarappa T , Malge Amarkumar , Heerasingh Mohansingh , Devidas Ashwini 
Published: April 2024

Abstract
The copolymer containing different wt% of indole and carbazole were synthesized by following in situ copolymerization method using ammonium persulfate as oxidizer, at room temperature. Crystalline and amorphous phases were noted from XRD patterns of the samples. Structural and optical studies were carried out by FTIR and UV-Vis spectroscopy. Different functional groups in the prepared copolymer have been identified and optical band gaps were determined to vary from 3.83 eV to 3.96 eV and 3.98 eV to 4.13 eV corresponding to direct and indirect transitions. Dc conductivity measured in the temperature range of 300 K to 423 K is observed to be semiconducting type. Two different regions of variation of conductivity with temperature have been observed and the corresponding activation energy was determined. The increase in conductivity and decrease in activation energy with increase of wt% of Cz content in PInCz copolymer is observed. This may be due to decrease of hopping distance of polarons with increase of Cz contents in the copolymer.
Structural, Physical and Optical studies of Sc3+ doped Lithium Aluminum Borate glasses
Authors: Nagaraju J , Eraiah B 
Published: April 2024

Abstract
Optically transparent lithium aluminum borate containing scandium glasses with composition 70B2O3 – 20Li2O – (10 – x) Al2O3 – xSc2O3 (where x= 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 and 0.7 in mol %) were fabricated by conventional melt quenching technique. The non-crystalline nature of the samples was monitored by X-ray diffraction and it confirms non-crystalline nature. Structure of the fabricated glasses are assessed using the Fourier transform infrared spectra. The absorption spectra of these glasses have been recorded in the wavelength range 200 nm – 1100 nm. Direct and indirect optical energy band gaps were calculated from Tauc’s plots. The physical parameters such as refractive index (RI), optical basicity and interaction parameters were determined using proper formulas to know the characteristics of fabricated glass matrix. The results obtained indicate that 0.3 mol% Sc2O3-containing BLASc glass is more suitable for w-LEDs and lasers applications.
Switching Behavior of the Composite Low Dimensional Structural Hybrids of Carbon After UV Exposure
Authors: Saini Sonia , Bhattacharjee Kuntala , Gouda Girish M 
Published: April 2024

Abstract
Low dimensional multi structural components of carbon are of great interest currently owing to their applications in developing flexible plastic electronics. In this work, we discuss emergence of different structural hybrids of carbon from as-prepared HiPCO SWCNTs subjecting them to oxidative acid purification and covalent functionalization process. Transmission electron microscopy (TEM) investigations reveal single wall carbon nanotubes (SWCNTs) serve as a building block to obtain multi wall carbon nanotubes (MWCNTs), graphene sheets (GS), carbon nano scrolls (CNS) structures which coexist in the sample. These structures when grafted with polymer binder and spray coated on Si substrate provide highly sustainable thin film coatings that are stable even in adverse space conditions [1]. These CNT and CNS based composite coatings are promising candidates for stray light control space applications exhibiting a low reflectance of the order of 2-3% in the visible spectral range [1]. Electrical switching behaviour of these films were investigated by capturing current(time) (I(t)) response, displaying promising switching character with distinct ON-OFF cycle. These coatings offer opportunities for the development of facile, cost-effective carbon-based devices without going into the nontrivial task of separating different the structures.
Influence of Zirconium substitution on electrical properties of Nickel-Zinc Ferrites
Authors: Sajjan Soumya , Kulkarni Ananda , Gounhalli Shivraj G. 
Published: April 2024

Abstract
The Zirconium substituted Nickel Zinc Ferrite nano particles with chemical composition of Ni(0.5-x)Zn(0.5-x)ZrxFe2O4, where the value of x varies from 0 to 0.2, have been synthesized by the sol-gel auto combustion method, using high purity nitrates and fuelling agent citric acid. The structural property was studies from X-ray diffraction spectra. The crystallite size decreases with increase in Zirconium substitution. The electrical property of the same was investigated by studying the dielectric constant, and AC conductivity. There are fluctuations in these properties with variation in Zirconium substitution in Ni-Zn Ferrite.
Predicting shock hugoniot and equation of state of single-crystal molybdenum by molecular dynamics simulation
Authors: Singla Anuradha , Ray Aditi 
Published: April 2024

Abstract
In the present paper, we employ non-equilibrium molecular dynamics approach to simulate impact-induced shock propagation in single-crystal Molybdenum. Shock hugoniot, generated by simulation of impact with varied strength shows excellent agreement with experimental data in the strong shock regime. The resulting hugoniot parameters obtained by linear fitting of shock velocity vs. particle velocity data are then used to estimate ambient pressure Grüneisen coefficient. Finally Mie-Grüneisen equation of state (EOS) with hugoniot as reference state, is employed to express pressure-volume-energy relationship for [001] single-crystal Mo. The influence of different analytical forms for volume dependence of Grüneisen parameter on EOS is investigated.
Influence of Zr-doping on the structure and transport properties of rare earth high-entropy oxides
Authors: Kante Mohana V , Lakshmi Nilayam Ajai R , Kreka Kosova , Hahn Horst , Bhattacharya Subramshu S , Velasco Leonardo , Tarancón Albert , Kübel Christian , Schweidler Simon , Botros Miriam 
Published: April 2024

Abstract
Fluorite-type ceria-based ceramics are well established as oxygen ion conductors due to their high conductivity, superseding state-of-the-art electrolytes such as yttria-stabilized zirconia. However, at a specific temperature and oxygen partial pressure they occasionally exhibit electronic conduction attributed to polaron hopping via multivalent cations (e.g. Pr and Ce). (Ce, La, Pr, Sm, Y)O2−δ
is a high-entropy oxide with a fluorite-type structure, featuring low concentrations of multivalent cations that could potentially mitigate polaron hopping. However, (Ce, La, Pr, Sm, Y)O2−δ
undergoes a structural transition to the bixbyite-type structure above 1000 °C. In this study, we introduce Zr doping into (Ce, La, Pr, Sm, Y)O2−δ
to hinder the structural transition at elevated temperatures. Indeed, the fluorite structure at elevated temperatures is stabilized at approximately 10 at.% Zr doping. The total conductivity initially increases with doping, peaking at 5 at.% Zr doping, and subsequently decreases with further doping. Interestingly, electronic conductivity in (Ce, La, Pr, Sm, Y)1−x
Zr
x
O2−δ
under oxidizing atmospheres is not significant and is lowest at 8 at.% Zr. These results suggest that ceria-based high-entropy oxides can serve as oxygen ion conductors with a significantly reduced electronic contribution. This work paves the way for new compositionally complex electrolytes as well as protective coatings for solid oxide fuel cells.
Investigating nano-SiC reinforced WE43 magnesium matrix surface composites
Authors: Kang Amardeep Singh , Singh Ravinder Pal , Singla Shivali 
Published: April 2024

Abstract
Magnesium matrix surface composites have been garnering attention due to their superior mechanical and corrosion resistance properties. An idea of facile fabrication of surface composite composed of nano-SiC reinforced WE43 matrix through friction stir processing was explored in this study. Also, the effects of tool geometries, tool rotations, and tool feeds on resultant properties were comprehensively investigated. Uniform dispersion of SiC nanoparticles within stir zone was evident. Square tool demonstrated the most promising results. Processing at 1700 rev min−1 and 60 mm min−1 with a square tool produced finest grains in surface composites exhibited exceptional microhardness (180.8 HV), nanohardness (1.867 GPa), elastic modulus (41.69 GPa), and wear resistance (0.0254 mm3 min−1). Besides it, WE43 substrates also exhibited superior mechanical properties when processed with a square tool at 800 rev min−1 and 60 mm min−1. This research opens up new possibilities for the development of reliable magnesium matrix surface composites for multifunctional applications.
Rational load balancing in collaborated cloud computing environments
*
Authors: Joshi Narayan A 
Published: April 2024

Abstract
Optimum efficiency and fault tolerance are the most demanding and challenging issues in the domain of performance and reliability management in cloud computing environments. Optimized resource utilization is a key aspect for yielding efficiency in cloud platforms. Workload balancing through resource sharing is one of the key solutions for attaining performance in cloud environments. In addition, multiple cloud environments join hands to offer performance and fault tolerance through resource sharing. We provide a better and cloud-instances’ priority-based efficient load balancing method for collaborative cloud platforms. The recommended efficient load balancing method shortens the waiting timespan and overcomes the starvation problem of low priority instances in intercloud environments. A functional prototype of the recommended load balancing method was deployed on a physical cloud infrastructure which was setup with the OpenStack cloud software on the Fedora Linux operating system. The pilot project execution findings exhibit a reduction in the timespan borne by instances for executing load balancing. This technique is useful for attaining fault tolerance and efficient resource utilization in intracloud and intercloud environments.
Amplitude chimeras and bump states with and without frequency entanglement: a toy model
Authors: Provata A 
Published: April 2024

Abstract
When chaotic oscillators are coupled in complex networks a number of interesting synchronization phenomena emerge. Notable examples are the frequency and amplitude chimeras, chimera death states, solitary states as well as combinations of these. In a previous study (Provata 2020 J. Phys. Complex.
1 025006), a toy model was introduced addressing possible mechanisms behind the formation of frequency chimera states. In the present study a variation of the toy model is proposed to address the formation of amplitude chimeras. The proposed oscillatory model is now equipped with an additional 3rd order equation modulating the amplitude of the network oscillators. This way, the single oscillators are constructed as bistable in amplitude and depending on the initial conditions their amplitude may result in one of the two stable fixed points. Numerical simulations demonstrate that when these oscillators are nonlocally coupled in networks, they organize in domains with alternating amplitudes (related to the two fixed points), naturally forming amplitude chimeras. A second extension of this model incorporates nonlinear terms merging amplitude together with frequency, and this extension allows for the spontaneous production of composite amplitude-and-frequency chimeras occurring simultaneously in the network. Moreover the extended model allows to understand the emergence of bump states via the continuous passage from chimera states, when both fixed point amplitudes are positive, to bump states when one of the two fixed points vanishes. The synchronization properties of the network are studied as a function of the system parameters for the case of amplitude chimeras, bump states and composite amplitude-and-frequency chimeras. The proposed mechanisms of creating domains with variable amplitudes and/or frequencies provide a generic scenario for understanding the formation of the complex synchronization phenomena observed in networks of coupled nonlinear and chaotic oscillators.