bluuebunny/crossref_metadata_2025 huggingface dataset:
Flexible organic optoelectronic devices: Design, fabrication, and applications
Authors: Wang Yuanhe , Wen Yanlong , Zhuang Xiaoxiao , Liu Shihao , Zhang Letian , Xie Wenfa
Published: September 2024

Flexible organic optoelectronic devices (FOODs) are rapidly emerging as a transformative technology in consumer electronics due to their exceptional bendability, lightweight, and seamless integration capabilities. This review provides a comprehensive overview of FOODs, including flexible organic light-emitting devices, organic photodetectors, and organic solar cells. We delve into their structural design, fundamental operating principles, and the unique advantages and challenges they present for applications requiring flexibility. Following this, the review explores the critical components of FOODs, with a particular focus on transparent conductive electrodes (TCEs) and innovative substrate materials. We discuss various TCE types, including carbon-based, metal network, and composite designs. Additionally, we explore the use of novel substrates like fibers, fabrics, and paper. Finally, the review examines current fabrication and encapsulation techniques employed for these flexible devices. We conclude by highlighting promising applications of FOODs in diverse fields, including biomedical science and intelligent interactive technologies.
The effects of metal oxides doping on the surface stability of In2O3 for CO2 hydrogenation
Authors: Xu Xingtang , Li Yanwei , Sun Guang , Cao Jianliang , Wang Yan , Qin Xulong
Published: September 2024

The significance of maintaining the surface stability of the In2O3 catalyst in the conversion of CO2 to methanol through hydrogenation cannot be overstated. To improve surface stability, doping with metal oxides is usually employed. To explore high-efficiency In2O3 based catalysts, density functional theory calculations were utilized to explore the effects of doping CuO, Co2O3, NiO, TiO2, HfO2, Nb2O3, Ta2O5, and CeO2 on the stability of the In2O3(110) surface. It was found that in a CO atmosphere, the crucial step in determining the creation of oxygen vacancies on the In2O3 plane occurred during the desorption of CO2 from the vacancy location. The results indicate that doping CuO, Co2O3, NiO, Nb2O3, Ta2O5, and CeO2 on the In2O3(110) surface promotes the reduction process through the reaction of CO with the O atoms on the surface, resulting in reduced surface stability. Conversely, the doping of Ti and Hf can raise the reaction energy barriers for CO reacting with the O atoms on the surface and enhance CO2 molecule adsorption on vacant sites, thereby suggesting the potential of TiO2 and HfO2 as effective modifiers to improve the efficiency and durability of the In2O3 catalyst. Furthermore, it is crucial to enhance its stability by modifying the density of the electron cloud or Fermi level of the In2O3 catalyst.
Study on the migration characteristics of temporary plugging agents in hot dry rock fractures considering ambient temperature field variations
Authors: Li Zongze , Yang Zirui , Wu Yue , Yu Bo , Wang Daobing , Wang Yueshe
Published: September 2024

An enhanced geothermal system (EGS) is a crucial method for extracting geothermal resources. Enhancing the efficiency and recovery capacity of EGS hinges on the essential use of temporary plugging and diversion fracturing technology. Consequently, studying the migration patterns of temporary plugging agents within hot dry rock (HDR) fractures is crucial. However, existing research on the movement of temporary plugging agents in HDR fractures often neglects the influence of ambient temperature changes. These variations significantly impact the degradation and migration of particles. This study uses computational fluid dynamics and the discrete element method to analyze how changes in the ambient temperature field affect the temperature within fractures and the movement of temporary plugging agents. The study introduces three dimensionless numbers: dimensionless temperature change T, dimensionless time t, and dimensionless position X, to evaluate the migration behavior of temporary plugging agents. It also explores the effects of temporary plugging fracturing fluid injection rate, viscosity, and branch fracture structure on the migration of temporary plugging agents. Results indicate that when t = 2 and X = 1, the temperature change T without considering HDR temperature field changes is 13.55%; with temperature field changes, T is 7.44%, resulting in a simulation difference of 82.12%; Within the simulation parameter range, as the injection rate of temporary plugging fracturing fluid increases, the dimensionless temperature change T decreases; as the viscosity of temporary plugging fracturing fluid increases, the dimensionless temperature change T initially decreases and then stabilizes; the branch fracture structure has a great influence after the branch.
General practice registrars’ practice in outer metropolitan Australia: a cross-sectional comparison with rural and inner metropolitan areas
Authors: Tran Michael , Ralston Anna , Holliday Elizabeth , Tapley Amanda , Fielding Alison , Moad Dominica , Ledger Jocelyn , Wearne Susan , Davey Andrew , van Driel Mieke , Ball Jean , Moran Vanessa , Dizon Jason , Magin Parker
Published: September 2024

Background General practice training in outer metropolitan (OM) areas contributes to patients’ access to care. Differences in clinical practice and training in rural versus urban areas have been established, but less is known about OM versus inner metropolitan (IM) differences – whether they offer a trainee learning experience of populations with distinct demographics and healthcare characteristics. This study sought to identify the characteristics and associations of general practice training in New South Wales and Australian Capital Territory OM areas, compared to IM and rural areas. Methods Cross-sectional analyses of data (2016–2020) from the Registrar Clinical Encounters in Training (ReCEnT) study, an ongoing cohort study of Australian GP registrars’ in-consultation clinical and educational experience and behaviours, were performed. Multinomial logistic regression assessed associations of rural/OM/IM practice location with registrar and practice factors, patient factors, consultation content factors and consultation action factors. Results Overall, 1308 registrars provided data from 177,026 consultations. For several variables, there was a pattern in the differences of associations across rural/OM/IM areas. Experience of care of older patients and Aboriginal and/or Torres Strait Islander health were more likely in OM than IM areas. Care of patients from non-English speaking background was more likely in OM than in rural areas. Possible markers of healthcare access (specialist referrals, and pathology and imaging requests) were less likely in OM than in both IM and rural areas. Conclusions OM areas are distinct (and educationally rich) clinical learning environments, with distinct demographic characteristics and seeming healthcare access limitations. This finding has implications for workforce support and health resource allocation.
Causal interpretations of family GWAS in the presence of heterogeneous effects
Authors: Veller Carl , Przeworski Molly , Coop Graham
Published: September 2024

Family-based genome-wide association studies (GWASs) are often claimed to provide an unbiased estimate of the average causal effects (or average treatment effects; ATEs) of alleles, on the basis of an analogy between the random transmission of alleles from parents to children and a randomized controlled trial. We show that this claim does not hold in general. Because Mendelian segregation only randomizes alleles among children of heterozygotes, the effects of alleles in the children of homozygotes are not observable. This feature will matter if an allele has different average effects in the children of homozygotes and heterozygotes, as can arise in the presence of gene-by-environment interactions, gene-by-gene interactions, or differences in linkage disequilibrium patterns. At a single locus, family-based GWAS can be thought of as providing an unbiased estimate of the average effect in the children of heterozygotes (i.e., a local average treatment effect; LATE). This interpretation does not extend to polygenic scores (PGSs), however, because different sets of SNPs are heterozygous in each family. Therefore, other than under specific conditions, the within-family regression slope of a PGS cannot be assumed to provide an unbiased estimate of the LATE for any subset or weighted average of families. In practice, the potential biases of a family-based GWAS are likely smaller than those that can arise from confounding in a standard, population-based GWAS, and so family studies remain important for the dissection of genetic contributions to phenotypic variation. Nonetheless, their causal interpretation is less straightforward than has been widely appreciated.
The Core Metadata Schema for Learner Corpora (LC-meta)
Authors: Paquot Magali , König Alexander , Stemle Egon W. , Frey Jennifer-Carmen
Published: September 2024

Metadata is critical throughout the research process, from study design to corpus selection/compilation, result
interpretability and cumulative research. To date, however, learner corpus research has not developed community standards or best
practices for metadata collection and sharing. In this article, we present the results of a collaborative project aimed at
addressing this issue by developing a standardised metadata schema for learner corpora. We first describe the procedure
implemented to design the schema, including the ways in which we continuously involved learner corpus researchers in this
initiative. We then introduce the Core Metadata Schema for Learner Corpora (LC-meta, Version 2), which consists
in a set of obligatory and optional variables that encapsulate crucial information about L2 data (administrative details, corpus
design, text-related variables, learner-related variables, annotations, annotators, or transcribers). Finally, we discuss future
developments and emphasise the importance of continued maintenance and further refinement of this schema by the research
community.
Non-past and past verb stems in Tangut
Authors: Beaudouin Mathieu
Published: September 2024

Over the past decade, the documentation of Gyalrongic languages has shed light on grammatical phenomena which were
poorly understood in Tangut, a language of critical importance in the field of Sino-Tibetan comparative linguistics. This paper
provides an explanation for the last remaining unelucidated verbal alternation in Tangut
(-ɨ1
/-i2
), which, as I will demonstrate, encodes a non-past/past
distinction. By doing so, it also gives fresh arguments for placing Tangut and the Horpa languages together within one clade.
Finally, methodologically speaking, it offers an example of grammatical reconstruction from above, i.e. employing sister languages
to better understand the grammar of an extinct language through their common ancestor, revealing a rare example of complex
distributional retention uncorrelated with regular phonetic correspondences.1
Language learning from watching cartoons in the primary EFL
classroom
Authors: Casulleras Montserrat , Miralpeix Imma
Published: September 2024

This chapter presents the results of a study in which two
groups of primary
school English as a Foreign Language (EFL) learners watched one
episode a week of the animated TV series Curious George –
with L1
subtitles or L2 subtitles – over a period of five months. These beginner
students were tested on comprehension and vocabulary recognition
immediately after watching each episode and in two special episodes without
subtitles (middle and end of treatment). Although significant differences
were not always present, the L1-subtitles group tended to score higher in
comprehension, and the L2-subtitles group in L2 word recognition. The
findings also emphasize the central role of language aptitude and vocabulary size for L2
learning through audiovisual materials in instructional settings.
Temperature of a steady system around a black hole
Authors: Kim Hyeong-Chan
Published: September 2024

We study the issue of temperature in a steady system around a black hole event horizon, contrasting it with the appearance of divergence in a thermal equilibrium system. We focus on a spherically symmetric system governed by general relativity, particularly examining the steady state with radial heat conduction. Employing an appropriate approximation, we derive exact solutions that illuminate the behaviors of number density, local temperature, and heat in the proximity of a black hole. We demonstrate that a carefully regulated heat inflow can maintain finite local temperatures at the black hole event horizon, even without considering the back-reaction of matter. This discovery challenges conventional expectations that the local temperature near the event horizon diverges in scenarios of thermal equilibrium. This implications shows that there’s an intricate connection between heat and gravity in the realm of black hole thermodynamics.
Dark matter and dark energy in combinatorial quantum gravity
Authors: Trugenberger C A
Published: September 2024

We point out that dark matter and dark energy arise naturally in a recently proposed model of combinatorial quantum gravity. Dark energy is due to the ground-state curvature at finite coupling, dark matter arises from allotropy in the discrete structure of space-time. The stable structure of the space-time ‘crystal’ represents the curved background, the coexisting metastable allotropes of higher curvature and energy are natural candidates for dark matter. We thus suggest that dark energy and dark matter are two manifestation of quantum gravity.
Boosting gravitational waves: a review of kinematic effects on amplitude, polarization, frequency and energy density
Authors: Cusin Giulia , Pitrou Cyril , Bonvin Camille , Barrau Aurélien , Martineau Killian
Published: September 2024

We review the kinematic effects on a gravitational wave due to either a peculiar motion of the astrophysical source emitting it or a local motion of the observer. Working in the context of general relativity, we show at fully non-linear order in velocity, that the amplitude of the wave is amplified by the Doppler factor in the case in which the source moves with respect to a reference frame, while it is invariant if the observer moves (with respect to a reference observer). However, the observed specific intensity transforms in the same way under a boost of the source or of the observer. We also show at fully non-linear order that under a boost (of either source or observer), the polarization tensor is rotated in the same way the wave direction is rotated by aberration, such that the only net effect of a boost on polarization is to change the phase of the helicity components. We apply these results to a wave emitted by a binary system of compact objects in the cosmological context.
Plasma synthesis of Pt/C catalysts and their electrocatalytic performance
Authors: Zhu Xiangmiao , Zhang Xu , Tao Yunming , Wang Wei , Wang Cong , Zhang Shiru , Shen Jie , Starostin Sergey A , Lin Liangliang
Published: September 2024

A simple, green, and scalable approach, utilizing dielectric barrier discharge (DBD) plasma in lieu of chemical reductants, is presented for producing Pt/C catalysts. The results revealed crystalline well-dispersed Pt nanoparticles of small sizes were generated on the surface of carbon support, where the Pt loading can be regulated by adjusting the H2PtCl6 concentration. The resulting Pt/C catalysts demonstrated excellent catalytic activity in both acidic and alkaline electrolytes for hydrogen evolution reactions (HER) and methanol oxidation reactions (MOR). With the rise of the Pt loading, the catalytic activity gradually improves. Specifically, for HER, an overpotential value of 120 mV was measured for the 8 wt% Pt/C-modified electrode at a geometric current density of −10 mA cm−2, with a Tafel slope of 45.4 mV dec−1 in acidic electrolyte. The values became 208 mV and 83.7 mV dec−1 in alkaline electrolyte. Same phenomenon was also observed in MOR, where the increase of the Pt loading results in faster electron transport rate and stronger methanol oxidation peak. Besides, the catalytic activity of the plasma-prepared Pt/C catalysts is better than the commercial samples with the same Pt loading. This work demonstrates a DBD plasma-assisted strategy for the preparation of Pt/C catalysts in an efficient and environmentally friendly manner.
Brain-inspired computing with self-assembled networks of nano-objects
Authors: Vahl Alexander , Milano Gianluca , Kuncic Zdenka , Brown Simon A , Milani Paolo
Published: September 2024

Major efforts to reproduce functionalities and energy efficiency of the brain have been focused on the development of artificial neuromorphic systems based on crossbar arrays of memristive devices fabricated by top-down lithographic technologies. Although very powerful, this approach does not emulate the topology and the emergent behavior of biological neuronal circuits, where the principle of self-organization regulates both structure and function. In materia computing has been proposed as an alternative exploiting the complexity and collective phenomena originating from various classes of physical substrates composed of a large number of non-linear nanoscale junctions. Systems obtained by the self-assembling of nano-objects like nanoparticles and nanowires show spatio-temporal correlations in their electrical activity and functional synaptic connectivity with nonlinear dynamics. The development of design-less networks offers powerful brain-inspired computing capabilities and the possibility of investigating critical dynamics in complex adaptive systems. Here we review and discuss the relevant aspects concerning the fabrication, characterization, modeling, and implementation of networks of nanostructures for data processing and computing applications. Different nanoscale electrical conduction mechanisms and their influence on the meso- and macroscopic functional properties of the systems are considered. Criticality, avalanche effects, edge-of-chaos, emergent behavior, synaptic functionalities are discussed in detail together with applications for unconventional computing. Finally, we discuss the challenges related to the integration of nanostructured networks and with standard microelectronics architectures.
Experimental progress in Eu(Al,Ga)4 topological antiferromagnets
Authors: Shang Tian , Xu Yang , Gao Shang , Yang Run , Shiroka Toni , Shi Ming
Published: September 2024

The non-trivial magnetic and electronic phases occurring in topological magnets are often entangled, thus leading to a variety of exotic physical properties. Recently, the BaAl4-type compounds have been extensively investigated to elucidate the topological features appearing in their real- and momentum spaces. In particular, the topological Hall effect and the spin textures, typical of the centrosymmetric Eu(Al,Ga)4 family, have stimulated extensive experimental and theoretical research. In this topical review, we discuss the latest findings on the Eu(Al,Ga)4 topological antiferromagnets and related materials, arising from a wide range of experimental techniques. We show that Eu(Al,Ga)4 represents a suitable platform to explore the interplay between lattice-, charge-, and spin degrees of freedom, and associated emergent phenomena. Finally, we address some key questions open to future investigation.
Freezing of short-range ordered antiferromagnetic clusters in the CrFeTi2O7 system
Authors: Kumar Arun , Panja Soumendra Nath , Keller Lukas , Nair Sunil
Published: September 2024

We report on the CrFeTi2O7 (CFTO) system using a combination of x-ray diffraction, dc magnetization, ac susceptibility, specific heat and neutron diffraction measurements. CFTO is seen to crystallize in a monoclinic P21
/a symmetry. It shows a glassy freezing at T
f∼22 K, characterized by the observation of bifurcation between ZFC and FC χ (T) curves, frequency dispersion across T
f in ac susceptibility, and follows Vogel–Fulcher and power law type critical dynamics, very slow relaxation of iso-thermal remanent magnetization with time and a linear temperature dependence of magnetic contribution to specific heat C
m below T
f. The microscopic neutron diffraction analysis of CFTO not only confirms the absence of long-range antiferromagnetic (AFM) ordering but also exhibits diffuse scattering due to the presence of short-range ordered AFM correlated spin clusters.
Elucidating correlation-driven insulating state in an effective spin—½ antiferromagnet NdVO4
Authors: Ranaut Dheeraj , Sihi Antik , Saravanan M P , Deepshikha Jaiswal-Nagar , Mukherjee K
Published: September 2024

The J
eff = ½ state: a result of interplay of strong electronic correlations (U) with spin–orbit coupling (SOC) and crystal field splitting, offers a platform in the research of quantum materials. In this context, 4f rare-earth based materials offer a fertile playground. Here, strong experimental and theoretical evidences for a J
eff = ½ state is established in a three-dimensional spin system NdVO4. Magnetic measurements show the signatures of a SOC driven J
eff = ½ state along with the presence of antiferromagnetic (AFM) interaction between Nd3+ moments, whereas, heat capacity reveals the presence of an AFM ordering around 0.8 K, within this state. An entropy of Rln2 (equivalent to J = ½) is released around 4 K which implies the presence of J
eff = ½ state at low temperatures. Total energy calculations within the density functional theory (DFT) framework reflect the central role of SOC in driving the Nd3+ ions to host such a state with AFM correlations between them, which is in agreement with experimental results. Further, DFT + SOC calculations with and without the inclusion of U, points that electron–electron correlations give rise to the insulating state making NdVO4 a potential candidate for U-driven correlated Mott insulator.
An optimal goose lithium-ion batteries accurate and rapid RUL prediction method with automatic initial hyperparameters settings
Authors: Li Gang , Huang Yiyi , Sun Caitang , Pang Ying
Published: September 2024

Machine learning has emerged as a highly effective tool for addressing complex data problems, garnering significant attention in the field of equipment degradation and remaining service life prediction. Existing prediction models typically exhibit two primary shortcomings: on the one hand, the accuracy of life prediction reaches the desired level of precision while failing to achieve a sufficiently fast prediction speed, and on the other hand, generalization is not guaranteed while requiring the model to be robust. These two aspects present a significant challenge to the field of machine learning. In light of the aforementioned issues, we propose a prediction model based on the goose algorithm. Initially, we set the goose algorithm using adaptive initialization of the goose population to guarantee that the goose population is set at the appropriate interval, and we incorporate it into the extreme learning machine model through the improved goose algorithm. goose algorithm is used to predict the service life. Finally, we utilize different types of lithium batteries with varying operational conditions to conduct pertinent case studies to validate the proposed prediction model. The results demonstrated that the average accuracy was above 98% in all validated datasets. The shortest computation time was 0.19 s.
A composite power quality disturbance detection method based on extremum extension optimized SVMD and Teager Energy Operator
Authors: Xiang Wu , Anqi Jiang , Shuqing Zhang , Haitao Liu , Shanshan Song
Published: September 2024

The growth of nonlinear loads and distributed generation in power grids has increased the frequency and complexity of power quality disturbances (PQDs). To improve PQ, it is necessary to accurately detect disturbance parameters, identify the causes of disturbances, and formulate corresponding management measures. Traditional disturbance detection methods primarily target single disturbances. As a contribution to complex disturbances, this paper proposes a composite PQD detection method based on extremum extension successive variational mode decomposition and Teager Energy Operator (EE-SVMD-TEO). Briefly, the SVMD method is utilized to decompose PQD signals. This method is further improved using an EE approach to reduce the influence of endpoint effects. Subsequently, the TEO is applied to the disturbance components obtained from the SVMD for disturbance detection. The results from composite disturbance detection simulation experiments show that the proposed method can differentiate disturbances in composite PQD signals. Combined with TEO, it successfully recognizes the start and end times of each disturbance, achieving a detection accuracy of over 97.5% at a signal-to-noise ratio of 30 dB Gaussian white noise. By comparing the modal decomposition results, the detection accuracy of disturbance time points, and the detection result stability, our method is more suitable for detecting composite PQD events than EEMD-TEO and EWT-TEO.
Temperature compensation method for impedance signals of bolt loosening under temperature varying conditions using TransUnet
Authors: Huang Xin , Qu Wenzhong , Xiao Li
Published: September 2024

Piezoelectric transducer based electro-mechanical impedance technology is an effective and reliable detection method for bolt structure loosening under external load. However, temperature change usually causes some non-loosening factors to change the impedance spectrum of bolt structure. In order to reduce the misjudgment of loosening damage caused by temperature change, it is necessary to construct a temperature compensation model for impedance spectrum. In this paper, the convolutional structure in U-net and Transformer are effectively combined to form a TransUnet deep neural network structure suitable for input and output of one-dimensional data. Using impedance data between 10 °C and 50 °C and temperature as input to the network. After convolution operation, the convolutional block attention module is embedded in the U-net to optimize the encoder transmission characteristics and enhance the performance of the skip connection in the traditional U-shaped structure. The temperature compensation rate (TCR) is defined to measure the effect of temperature compensation. Then the lightweight convolutional neural network structure is used to recognize the bolt loosening damage of the compensated impedance signal. The generalization ability of the TransUnet was tested using impedance data that is not in the training dataset. The results show that the TransUnet proposed in the paper can realize the temperature compensation of multi-peak impedance signals. The TCR and recognition accuracy of bolt loose damage reaches reach 0.003 and 95.7%, respectively, which is 11% higher than that without temperature compensation. At 60 °C, the TCR and the identification accuracy of loosening damage can still reach 0.0055 and 90.2%, respectively, which show that the TransUnet has strong generalization ability.
Core-shell architecture and channel suppression: unleashing the potential of SC_RCS_DGJLFET
Authors: Himral Atul , Sharma Rajneesh , Agarwal Mohit
Published: September 2024

In this investigation, a suppressed channel-rectangular core–shell double gate junctionless field effect transistor (SC_RCS_DGJLFET) is simulated to enhance the junctionless device’s performance. This study leverages a core–shell architecture and channel suppression technique to improve the gate controllability over the channel region which helps in substantial depletion of the shells in the OFF state of the device. When compared to conventional double gate JLFETs (C_DGJLFET) and rectangular core–shell double gate JLFETs (RCS_DGJLFET), the performance of the SC_RCS_DGJLFET is superior in terms of IOFF, ION/IOFF ratio, DIBL and subthreshold slope (SS). The SC_RCS_DGJLFET achieves an ultra-low IOFF of 7.033 × 10−16 A, indicating a low leakage current with an impressive ION/IOFF = 5.092 × 1011 . Other performance parameters such as subthreshold slope and DIBL has also been improved for the SC_RCS_DGJLFET device. Subthreshold slope has been decresesd by 4.76% whereas the DIBL decreased by 33.82% when compared to existing RCS_DGJLFET. Additionally, to analyze the effect of doping on the device performance, the core doping in SC_RCS_DGJLFET is varied for fixed shell doping. The study found that fixing core doping to an appropriate value is a crucial parameter to achieve good device performance. The impact of variation of oxide extension towards the source and drain LextS/LextD in SC_RCS_DGJLFET is also studied for the first time in the core–shell architecture which has further improved the device’s performance. Finally, a CMOS inverter is designed using the proposed device that provides valuable insights into its suitability for digital circuit applications and verifies its performance benefits compared to existing transistor technologies. The SC_RCS_DGJLFET based CMOS inverter shows a sharp transition in voltage transfer characteristics (VTC), indicating fast switching speed and precise signal processing capabilities when compared to a CMOS inverter based on a conventional double gate junctionless field effect transistor (C_DGJLFET). Moreover, the transient characteristics of the SC_RCS_DGJLFET based CMOS inverter exhibit an improved output voltage swing, suggesting enhanced dynamic behaviour and stability during logic state transitions.
An exploration of enhanced characteristics and efficiency of dye-doped L-Threonine single crystal
Authors: Lakshmi S , Saravanan M
Published: September 2024

The improved crystalline characteristics of a crystal doped with 0.5 mol% methylene blue dye was analyzed and compared using several techniques such as SXRD, FTIR, (Spectrum of absorption and Spectrum of optical transmittance), PXRD, and Second Harmonic Generation (SHG). The crystal was prepared using the slow evaporation method. The work hardening coefficient was evaluated for our synthesized crystal, indicating its soft nature. Additionally, we want to achieve similar levels of second harmonic Generation in both pure L-threonine materials and dye-doped crystals. Research on photoluminescence reveals that fully developed crystals have a reduced number of imperfections. Piezoelectric coefficients (d33) were also calculated for the as- grown Pure L-threonine crystal and L-threonine doped with dye Single crystal. The increased LDT value be attributed to the significantly decreased section, confinement, and mechanical stiffness of both the Pure L-threonine and dye-doped L-threonine Single crystal. The etching tests shown that both the as-grown Pure L-threonine crystal and the dye-doped L-threonine Single crystal had a better level of crystalline fineness and a smaller number of defects. These characteristics are essential for their use in nonlinear optics (NLO) applications.
Optimizing deposition parameters and characterizing TiO2 thin films for future memristor applications
Authors: Shivaram Shilpa , Paul Done Rinshun , S K Suresh Babu , B Vigneshwaran , V Haritha Sree , J Roshan Johns , D Nirmal
Published: September 2024

Titanium dioxide (TiO2) thin films were deposited on glass substrates using Spray Pyrolysis technique, with variations in multiple deposition parameters. The molarity of the precursor was altered within a small range from 0.09 M–0.15 M. The deposition temperature was systematically adjusted from 200 °C to 400 °C while the ratio between precursor and chelating agent varied between 1:1,1:2 and 1:3. The thickness of TiO2 films were found to be in the range of 216 nm to 14.9 μm. Structural analysis conducted by XRD confirmed the formation of anatase TiO2 thin films. Optical studies using UV-Visible spectrophotometer determined the absorption and indirect bandgap ranging from 299 nm to 326 nm and 3.08 eV to 3.44 eV respectively. Electrical studies carried out evaluated the leakage currents and DC resistivity for all individual films with the input voltage applied from ± 0.5 V to ± 5V. Impedance studies were conducted by varying input voltages from 0.2V–3V for each film, so as to examine the resultant impedance, dielectric constant, dielectric loss, conductivity, admittance and modulus spectra. The obtained results were analysed to optimise the deposition parameters for designing future memristors with specific individual or combined characteristics, such as high ON/OFF, switching speed, endurance and retention.
Fabrication of TiO2/CuTiO3/ sodium alginate nanocomposites of tuned structural, optical, fluorescence and dielectric properties
Authors: El Desouky Fawzy G , Abdel Rehim Mona H , Turky G
Published: September 2024

This study focuses on the fabrication of nanocomposites consisting of TiO2/CuTiO3/Sodium alginate, with an emphasis on investigating their structural, optical, fluorescent, and electrical properties. The composite TiO2/CuTiO3 (TO-CTO) was produced by chemical co-precipitation method then different ratios were blended with Sodium alginate (SA). Finally films of the obtained nanocomposite were prepared by casting technique. Characterization of (TO-CTO) powder using XRD diffraction revealed that there are rutile, and anatase TiO2 phases in the shape of a tetragonal hexagon. Moreover, CuTiO3 (CTO) structures in the shape of a rhombohedron could be assigned. TiO2/CuTiO3 (TO-CTO) nanocomposites were effectively integrated into sodium alginate (SA) polymers, as confirmed by XRD, ATR-FTIR, and SEM studies. The absorption spectra of the nanocomposites exhibit wide absorption bands that extend from the ultraviolet (UV) region at 260 and 389 nm to the visible spectrum and further into the very near infrared range. The optical band gap values decrease from (3.58 to 2.84 eV) as the weight fraction of TO-CTO increases in the nanocopmosite film. The photoluminescence (PL) emission intensity changes notably when nanofillers are added to the SA and PL spectra of both the rutile and anatase phases of TO appear. Moreover, emission spectra of SA in both the visible (2 to 2.8 eV) and near-infrared (1.4 to 1.54 eV) ranges could be observed, which could be ascribed to the intermolecular hydrogen bonding interactions within the alginate matrix. The rising proportions of TO-CTO oxides in the nanocomposites greatly affect the dielectric properties of the materials and the electrical properties of the TO-CTO/SA system demonstrated considerable variability. The obtained nanocomposites showed interesting UV, PL sensitivity and high dielectric constants can find applications in promising areas, such as photocatalysis, flexible emitting diodes, bio-imaging, and energy storage.
Decoherence-induced formation of sub-poissonian entangled and steerable states of collective fields
Authors: Xu Qing
Published: September 2024

The decoherence process has a tendency to yield the evolution of a pure state into a mixed one and to cause the quantum-to-classical transition by the coupling of a system of interest to the reservoir with infinitely many degrees of freedom. This is the major obstacle to the implementation of quantum computation and hence the realization of quantum computers. We propose a scheme to create unconditionally sub-Poissonian entangled and steerable states of the collective cavity field modes by use of the dissipation process. Based on the suitable choice of combination modes, the scheme uses the inherent, efficient and controllable two-mode squeezed vacuum reservoir coupled to the combination modes of concern rather than the original cavity modes in the two-level quantum beat laser. The decoherence is shown to pull the collective modes into the sub-Poissonian entangled and steerable states in the stationary regime, while the job of the dissipation of the individual cavity fields is to give rise to the degradation of the bipartite entanglement of the two individual modes and to inhibit the occurrence of the quantum steering from one cavity mode to the other. In particular for the case that the external driving field is close to the exact resonance with the atom, the collective fields are eventually prepared asymptotically in the stationary Einstein–Podolsky–Rosen state, while the two individual cavity modes are pulled into the vacuum states and reach steady state. The disappearance of the decoherence disables the nonclassical states of the collective modes, while the ignorance of the dissipation process of the cavity field modes guarantees the generation of the entanglement between the pair of individual modes. The decoherence-induced formation of a nonclassical source is ascribed to the four-wave mixing process together with the intrinsic amplitude and phase locking.
Influence of Nb2O5 additives on SiO2–Pb3O4–ZnO glasses: a physical, structural, elastic, optical, and radiation shielding properties
Authors: El-Maaref A A , E A Abdel Wahab , Shaaban Kh S
Published: September 2024

A series of zinc lead silicate glass having compositions: 60SiO2—35Pb3O4—(5-x) ZnO-xNb2O5 where (

0
≤
x
≥
5

) mol% were successfully fabricated, by applying the melt-quenching technique. The density of these glasses increased from 5.91, gcm−3 for ZSPNb-0 to 6.782, gcm−3 for ZSPNb-5. Using ultrasonic velocity (

V

L

) and (

V

T

) data from the ultrasonic technique, elastic moduli and microhardness were computed. Both (

V

L

) and (

V

T

) increased, going from 4935 to 5215 m s−1 and 2520 to 2845 m s−1, respectively. Because of these results, the glass’s elastic moduli increase, and its structure becomes more rigid. The optical description Eg, n, α
o, ε
r, χ(3), n2, M, T and further were researched. Totally, the optical considerations are persuaded by alter niobium contents in the present specimens. As the concentration of Nb2O5 in the glass increases, (LAC) is also increased, while (HVL), and (MFP) decreased. This means that ZSPNb glass with higher Nb2O5 content becomes more effective at attenuating or reducing the intensity of gamma radiation. Such enhanced radiation-shielding properties make ZSPNb glass a promising material for potential applications in radiation shielding.
Impacts of slip and activation energy on MHD hybrid nanofluid flow past a stretching radiated surface with heat generation/absorption
Authors: Dey Sudip , Mukhopadhyay Swati
Published: September 2024

The influences of slip and activation energy on the magnetohydrodynamic (MHD) flow of hybrid nanofluid over a permeable stretching radiated surface in attendance of heat source/sink have been studied.

Al

2

O

3

and Cu nanoparticles are mixed up in water to produce a hybrid nanofluid which is very important in various industrial sectors as hybrid nanofluid has wider applications in enhancing thermal efficiency to provide efficient and reliable cooling. As no one has yet searched for the collective impacts of radiative heat flux, ‘heat generation/absorption’ and ‘Arrhenius activation energy’ on MHD flow of ‘hybrid nanofluid’ in presence of slip that we are exploring in this article, this identifies the novelty of our work. Using ‘similarity transformations’, the main equations which are partial in nature are transformed to ODEs (ordinary differential equations) which are numerically solved with the assistance of ‘shooting technique and Runge–Kutta method’ using MATHEMATICA software. The outcomes of this investigation have a noteworthy impact on the physical outlook for flow field, transfer of heat and mass. Fluid velocity diminishes due to the rise of magnetic parameter but increasing nature of concentration and temperature are observed. For the rising volume fraction of

Al

2

O

3

nanoparticles as well as for rising volume fraction of Cu nanoparticles, the heat transfer coefficient rises. Momentum ‘boundary layer thickness’ diminishes for rising velocity slip. 19.694% decrease in rate of surface heat transfer is observed when volume fraction of

Al

2

O

3

nanoparticles changes from 0.01 to 0.12 whereas 24.394% decrease is noted when volume fraction of Cu nanoparticles changes from 0.2 to 0.14. The consequences of this study can be applied to many thermal systems used in engineering and industrial developments that utilize hybrid nanofluid for heating and cooling purposes.
Polymer concentration adjustment for homogeneous carbon nanofibers precursors
Authors: Yahya Fatima M , Najim Manar A , Hamza Mohammed S
Published: September 2024

Introduction. Carbon nanofibers CNFs have emerged as an important material in many advanced applications, especially those related to high electrical conductivity. Objectives. The primary objective of this study was to prepare a homogeneous CNFs’ precursor (Polyacrylonitrile PAN nanofibers) with improved graphitization through controlling one of the solution parameters, that is, polymer concentration. Methods. Precursors of PAN nanofibers with the addition of multi-walled carbon nanotubes MWCNTs were prepared with two concentrations of 8% and 10% w/v PAN/MWCNTs to adjust the insertion and uniform distribution of MWCNTs within the PAN nanofibers. Field emission scanning electron microscopy FESEM was used to evaluate the morphology of the electro spun nanofibers and uniformity of the MWCNTs distribution within the PAN nanofibers. Fourier transform infrared spectroscopy FTIR was also conducted to notice the interaction between MWCNTs and PAN to yield precursor with better graphitization characteristics. Results. FESEM results revealed more uniformity and homogeneity in the precursor structure with increasing PAN/MWCNTs concentration from 8% to 10% w/v. FTIR results showed increased intensity of the characteristic peaks of PAN and a new peak emerged at approximately 659 cm−1(C=C) which is potentially formed by interactions with MWCNTs and might be associated with cross-linking. Conclusion. Increased PAN/MWCNTs concentration from 8% to 10% w/v improved the insertion of MWCNTs inside PAN nanofibers and FTIR indicated the interactions between the added MWCNTs and PAN in the precursor with better graphitization characteristics.
The optimisation of the STEP electron cyclotron current drive concept
Authors: Freethy Simon , Figini Lorenzo , Craig Steven , Henderson Mark , Sharma Ridhima , Wilson Thomas ,   the STEP team
Published: September 2024

A fusion reactor based on the spherical tokamak is very likely to be completely non-inductive for the majority of the plasma ramp-up and steady-state phases, due to the limitations imposed on the central coil assemblies by the compact design. Efficiency gains from solenoid-driven current cannot be relied upon. It is also critical that an electricity-producing plant maximises the wall-plug efficiency of its heating and current drive (HCD) system, this being one of the largest consumers of recirculating power. It is therefore essential that the HCD system is well-optimised for current drive efficiency in order to meet the goal of net electricity production. The UK’s Spherical Tokamak for Energy Production (STEP) reactor design program has recently taken the decision to use exclusively microwave-based heating and current drive actuators for its reactor concepts. We present the optimisation of an electron cyclotron current drive scheme for a spherical tokamak reactor, based around the STEP concept, arriving at a solution which overcomes the limitations imposed by the spherical tokamak geometry in terms of microwave access and high trapped particle fraction. The solution uses high-field side absorption and a mix of fundamental and 2nd harmonic O mode, with overall power requirements reducing with increasing number of frequencies used. An additional fundamental frequency is also added to further boost the efficiency during non-inductive plasma ramp.
Validation of prediction capability of operating space for plasma initiation in MAST-U
Authors: Kim Hyun-Tae , Jaulmes Fabien , El-Haroun Hana , Cunningham Geof , Vincent Charles , Kogan Lucy , Scannell Rory , Elmore Sarah , Casson Francis , Henderson Stuart , Thornton Andrew , Harrison James , Litaudon Xavier , Falchetto Gloria , Lovell Jack , Lee Jeongwon , Yun Hong-Sik , Lee Yeongsun , Chen Runze ,   MAST-U team
Published: September 2024

DYON is a plasma initiation modelling code that solves the differential equation system of the full circuit equations (plasma current, active coil currents and eddy currents in full passive structures) and 0D global energy and particle balance equations (Kim 2022 Nucl. Fusion
62 126012). In order to test the capability of the full electromagnetic plasma initiation model to predict individual discharges in experiments and thus the operating space in the device, a dedicated experimental database was built in MAST-U by scanning the prefilled gas pressure p
0 and the induced loop voltage

V

loop

. In the experimental operating space of p
0 and

V

loop

the lower and the upper limits of p
0 are determined by the plasma breakdown failure and the plasma burn-through failure, respectively. The lower limit of

V

loop

is determined by the plasma burn-through failure. By directly reading the control room data used in each discharge (i.e. currents in the solenoid, poloidal field coils, and toroidal field coils, p
0, and gas puffing rate), the full electromagnetic DYON consistently predicted the failed breakdown, failed burn-through, and successful plasma initiation discharges in the experimental database, demonstrating its capability to predict the operating space for inductive plasma initiation. The Paschen curve calculated with the effective connection length in MAST-U indicates a much higher p
0 required for plasma breakdown than the experimental data, indicating that individual field line evaluation is necessary to calculate the quantitative requirements for Townsend breakdown. The demonstration in this paper shows that the full electromagnetic DYON could be a useful simulation tool to assess the feasibility of inductive plasma initiation and to optimise operating scenarios in future devices.
Analysis of the seismic performance of a 500 kV lightning arrester
Authors: Liu Chao , Liu Jinlong , Liu Yangyang , Gao Ge , Li Cong , Li Biao , Wang Yong
Published: September 2024

To evaluate the seismic safety of critical electrical equipment in substations and assess the porcelain equipment’s resilience against seismic hazards, a numerical simulation study was conducted on a 500 kV porcelain lightning arrester. Utilizing the seismic acceleration response spectrum within finite element analysis software, the arrester underwent modal and structural seismic response analyses to ascertain its seismic robustness. Results indicated that, when subjected to a 0.4 g seismic wave, the arrester exhibited a maximum displacement of 44.05 mm, a maximum stress of 31.70 MPa, and a minimum safety factor of 1.58, confirming compliance with standard design requirements.
An information/power fusion coordinated control framework for bipolar DC microgrids
Authors: Jiang Haiyang , Wang Zhichao , Zuo Feng , Yao Yao , Wang Panbao
Published: September 2024

In this paper, an information/power fusion coordinated secondary control strategy based on power line communication is proposed to realize the full-domain current balancing and bus voltage regulation of bipolar DC microgrid. Firstly, the information/power coordinated control strategy with AC signals is designed to realize the secondary control objective by using the AC signal frequency information superimposed on the DC voltage to transmit the unified voltage feedback signal. On this basis, to address the drawbacks of insufficient system stability margin and poor dynamic characteristics when the common voltage estimate is directly used as the feedback signal, an improved feedback structure combining the estimated voltage information and the local voltage information is proposed to enhance the robustness of the system toward the communication delay. In addition, the effects of controller parameters and control strategies on the system dynamics are investigated by establishing a small-signal model of the system. Finally, a bipolar DC microgrid experimental platform is established for validation, and the results show that the proposed control strategy can realize the control objectives under complex operating conditions.