bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast multi-fidelity Gaussian processes with derivatives for complex system modeling
Authors: Jia Jia-Xing , Lian Feng , Feng Wen-Hui , Liu Xia , Fan Zi-En 
Published: November 2024

Abstract
Accurately obtaining physics model information is essential for comprehending the mechanisms of physical dynamics. However, the inherent complexity of these models, especially in scenarios involving turbulence and irregular terrains, often requires significant computational resources to acquire high-fidelity (HF) data. While deep learning-based approaches have demonstrated considerable potential, they generally necessitate large volumes of training data and often face challenges in efficiently integrating physical information, such as derivatives. Leveraging the concept of multi-fidelity (MF) surrogate model and Gaussian processes (GPs), we introduce a novel approach, fast MF GPs with derivatives, in which the posterior mean of the low-fidelity (LF) model replaces the prior mean of the HF model, with the relationship between the two encapsulated by an unknown function. To speed up convergence during likelihood function optimization, we also initialize the kernel of the HF model using the best hyperparameters from the LF model. This model seamlessly integrates derivative information, facilitating accurate reconstruction of general physical models by synthesizing data from multiple fidelities, including derivatives. To address computational demands, we incorporate kernel approximation techniques based on structured kernel interpolation with derivatives. The effectiveness of our proposed method is validated through three case studies: (1) solving a partial differential equation describing fluid or scalar transport in a 1D domain, (2) reconstructing a high-resolution local turbulence velocity field using the Johns Hopkins forced isotropic turbulence dataset, and (3) predicting the surface of a rugged mountainous area while finding the peak via Bayesian optimization. Comparative analysis against four other algorithms underscores the superiority of our approach across multiple fields and highlights its significant potential for engineering applications.
Field emission from flipped and patterned vertically aligned carbon nanotube arrays
Authors: Olsen S C , Vandyke B , Vanfleet R R , Robinson V 
Published: November 2024

Abstract
Carbon nanotubes (CNTs) possess many unique properties that make them ideal for field emission. However, screening due to high density and poor substrate adhesion limits their application. We tested the field emission of various patterned vertically aligned carbon nanotube (VACNT) arrays adhered to copper substrates using carbon paste. After many fabrication steps to improve uniformity, we found that the field emission was dominated by individual CNTs that were taller than the bulk VACNT arrays. After testing a sample with silver epoxy as the binder, we found that the failure mechanism was adhesion to the substrate. Using energy dispersive x-ray spectroscopy, we found that the carbon paste migrated into the VACNT bulk volume while the silver epoxy did not. The migration of carbon paste into the volume may explain why the carbon paste had greater adhesion than the silver epoxy.
Optimization studies on output stabilization time and graphene oxide concentration in graphene-based flexible micro-supercapacitor
Authors: G S Sangeetha Gopan , Abraham Nelsa , R S Harikrishnan , S Rani , Xavier T S 
Published: November 2024

Abstract
Miniature energy storage devices are vital for developing flexible and wearable electronics. This paper discusses the fabrication of flexible laser-induced graphene-based micro-supercapacitors (MSCs) using graphene oxide (GO) coated polyimide film as the precursor for laser scribing. The areal capacitance of the MSCs was assessed daily after applying a H2SO4/polyvinyl alcohol (PVA) gel electrolyte. The capacitance displayed a substantial increase in the early days before stabilizing at a consistent value. The stabilization time was evaluated through systematic experimentation conducted over ten consecutive days. The experiments showed that the capacitance stabilized after six days. Various concentrations of GO were used to assemble the MSCs, and their performance was evaluated to determine the optimal concentration. The electrochemical impedance spectroscopy revealed that the supercapacitor fabricated with the optimum concentration of GO exhibited the lowest resistance. The optimized MSC displayed an areal capacitance of 10.07 mF cm−2 at a current density of 13 µA cm−2. The device could maintain a reliable output at different bending states and retain 87.9% of its original capacitance after 5000 charge-discharge cycles, highlighting its suitability for flexible and self-powered systems.
Optical effects in unmagnetized cold plasmas by a chiral axion factor
Authors: Ribeiro Filipe S , Silva Pedro D S , Ferreira Jr Manoel M 
Published: November 2024

Abstract
Unmagnetized cold plasma modes are investigated in the context of the chiral Maxwell-Carroll-Field-Jackiw (MCFJ) electrodynamics, where the axion chiral factor acts retrieving some typical properties of magnetized plasmas. The Maxwell equations are rewritten for a cold, uniform, and collisionless fluid plasma model, allowing us to determine the dispersion relation, new refractive indices, and propagating modes. We find four distinct refractive indices modified by the purely timelike CFJ background that plays the magnetic conductivity chiral parameter role associated with right-circularly polarized (RCP) and left-circularly polarized (LCP) waves. For each refractive index, the propagation and absorption zones are determined and illustrated for some specific parameter values. Modified RCP and LCP helicons are found in the low-frequency regime. The optical behavior is investigated, revealing that the chiral factor induces birefringence, measured in terms of the rotatory power (RP). The dichroism coefficient is carried out for the absorbing zones. The negative refraction zones may enhance the involved RP, yielding RP sign reversion, a feature of rotating plasmas and MCFJ chiral plasmas. Charge density oscillations and Langmuir waves are also discussed, revealing no modified dispersion relation due to the chiral axion factor.
Shallow donor states and interlevel transitions in gapped graphene bilayers
Authors: Djotyan A P , Moulopoulos K , Avetisyan A A 
Published: November 2024

Abstract
A variational calculation for the energies of the ground and first excited states of a shallow donor impurity in bilayer graphene (BLG) with an open energy gap is presented in this study. It is shown that the binding energies of the lowest states and the distance between them can be tuned in the region of few tens of meV by changing the gap and tight binding parameter

γ
1

, which is responsible for the nearest neighboring interlayer coupling. Based on the results obtained, the optical transition of an impurity electron from the ground to the first excited state in BLG is investigated. We find that the oscillator strength of the transition between the lowest energy states

1
S
→
2

P
x

of a shallow donor also depends on the gap and tight binding parameter

γ
1

, but is not sensitive to the value of the cutting parameter of the soft Coulomb potential that is proposed. The transitions between shallow impurity levels in BLG can serve as an alternative tunable source of terahertz radiation. The possibility to tune the energy levels of hydrogenic-like impurities can open new ways for either the creation of coherent superpositions of the energy states or the coherent population transfer between them by applying laser pulses.
Calibration of syndrome measurements in a single experiment
Authors: Wimmer Christian , Szangolies Jochen , Epping Michael 
Published: November 2024

Abstract
Quantum error correction can reduce the effects of noise in quantum systems, e.g. in metrology or most notably in quantum computing. Typically, this requires making measurements that provide information about the errors that have occurred in the system. However, these syndrome measurements themselves introduce noise into the system, for example by using noisy gates. A complete characterization of the measurements is very costly. Here we describe a calibration method to obtain the syndrome statistics taking into account the additional noise sources. All calibration data are extracted from a single experiment in which the syndrome measurement is performed twice in a row. Thus, our method allows an accurate evaluation of syndrome measurements with significantly less effort than existing methods. We give examples of the application of this method to noise estimation and error correction. Finally, we discuss the results of experiments performed on an IBM quantum computer.
Efficient adders for nano computing: an approach using QCA
Authors: Qureshi Vaseem Ahmed , Khan Angshuman , Arya Rajeev 
Published: November 2024

Abstract
This research paper presents a detailed evaluation of Quantum-dot Cellular Automata (QCA) digital adder designs utilizing advanced analytical tools, specifically QCADesigner, QCAPro, and QCADesigner-E. The study introduces novel adder designs that significantly enhance cell efficiency, reduce latency, and optimize cost. The study underscores the benefits of using coplanar crossovers to reduce fabrication complexity and avoid additional cell layers, which helps maintain high polarization levels and operational efficiency. The proposed full adder, built using a three-input XOR gate, shows a significant 88% reduction in QCA-specific cost (QSC) and a 0.5 clock cycle reduction in latency compared to the best-optimized existing designs. This improvement is achieved by integrating a single majority gate and MMV gate, removing the need for inverters and consuming 144.2 meV of energy. This design offers a major enhancement over previous designs, which lack such thorough evaluations. Additionally, the proposed ripple carry adder uses 40 fewer cells, achieves a 0.75 clock cycle reduction in latency over the best available design, provides an 81% improvement in QSC, and demonstrates a fully scalable and reliable circuit suitable for nanocomputing applications. Furthermore, the study introduces a single-bit carry look-ahead adder based on half-adder instantiation, with the proposed four-bit carry look-ahead adder achieving a 14% improvement in QCA-specific cost, highlighting its innovative features and practical advantages for advanced QCA circuits.
Random Forest Model Driven by CLT-Simulated Data for Predicting the Growth Rate of Internal Kink Mode in Tokamak
Authors: Ning Hongwei , Yang Jinhong , Wang Weihua , Ren Zhenzhen , Liu sheng , Zhang Peijie , Kai Zhong , Zhou Teng , Wu Jianguo 
Published: November 2024

Abstract
Real-time prediction of the growth rate of internal kink modes and the timely implementation of control measures are crucial for the stable operation of tokamak devices. In this study, machine learning techniques are combined with the three-dimensional toroidal nonlinear magnetohydrodynamic code CLT (Ci-Liu-Ti) to enable real-time prediction of the growth rate of internal kink modes. The CLT code is first utilized to generate a dataset of internal kink mode growth rates with 15 input features. Based on this dataset, four machine learning algorithms are applied to predict the growth rate of internal kink modes within a timescale of less than 25 microseconds. Experimental results indicate that Random Forest model achieves the highest coefficient of determination (R2) at 95.07%. Additionally, dataset size was progressively expanded, starting from 50 data points and increasing by 10 points at a time, resulting in a total of 16 datasets of varying sizes. Random Forest and other machine learning models are trained on each of these 16 datasets. The results suggest that the current dataset contains a sufficient volume of data, and the four machine learning models trained exhibit adequate generalization capabilities, making the predictions of the internal kink mode growth rate reliable.&#xD;
Simulation of novel CsSnBr3 perovskite solar cells achieving efficiency of 31.62 %
Authors: Kheswa B V , Majola SNT 
Published: November 2024

Abstract
In this study, we performed computational optimization on four designs of CsSnBr3 perovskite solar cells using the SCAPS-1D simulation tool. Our main objective was to enhance the efficiency of the FTO/AlZnO/CsSnBr3/WSe2/Se, FTO/ZnO/CsSnBr3/WSe2/Se, FTO/LiTiO2/CsSnBr3/WSe2/Se, and FTO/WS2/CsSnBr3/WSe2/Se configurations. We investigated how adjusting the thicknesses of the electron transport layer (ETL), hole transport layer (HTL), and perovskite layer, along with varying temperature, series and shunt resistances, and the acceptor doping density of the HTL, affected key performance metrics, such as the short-circuit current (Jsc), open-circuit voltage (Voc), fill factor (FF), and power conversion efficiency (PCE). The optimized PCEs for these configurations were 30.52%, 31.62%, 30.42%, and 30.51%, respectively, indicating that they all achieved similar levels of efficiency. The solar cells performed optimally at a temperature of 300 K, with zero series resistance and a shunt resistance of at least 1 × 105 Ω cm2. While zero series resistance is not practical in real-world applications, the findings suggest it should be minimized as much as possible for maximum efficiency. Furthermore, when comparing our results to prior studies, we found that the PCE values of all CsSnBr3-based solar cell designs developed in this research surpassed that of the previously reported ITO/WS2/CsSnBr3/Cu2O/Au cell, which had the highest recorded PCE for similar devices. Our best-performing structure showed a 9.19% improvement in efficiency over the previous record.
Non-autonomous exact solutions and dynamic behaviors for the variable coefficient nonlinear Schrödinger equation with external potential
Authors: Qin Qing , Li Li , Yu Fajun 
Published: November 2024

Abstract
The nonlinear Schrödinger(NLS) equation represents a nonlinear dynamical system, which is usually used to describe nonlinear waves in deep water, self-focusing of intense lasers contained in electrolytes, and so on. The exact solutions of the variable coefficient nonlinear Schrödinger equation with external potential are considered. The variable coefficient nonlinear Schrödinger equation is transformed into a constant coefficient nonlinear equation by using the similarity transformation method, the exact solutions of the constant coefficient nonlinear equation are generated by using the homogeneous balance method. We obtain one-soliton, two-soliton, kink type soliton, bright soliton, parabolic soliton and rogue wave solutions. A ‘stepped’ type soliton solution is obtained in this paper, which is a novel type solution and different from the solutions of most nonlinear Schrödinger equations. Some special dynamic behaviors of solitons of the variable coefficient nonlinear Schrödinger equation with external potential are obtained via selecting some free functions. We found that the numerical simulation result is consistent with the exact solution through illustrating the time evolution of bright soliton solution.
Non-uniform Al2O3 back reflector for performance enhancement of thin rear passivated silicon solar cells
Authors: Banerjee Pritam , Mukhopadhyay Sumita , Hossain Syed Minhaz 
Published: November 2024

Abstract
Low material usage, physical flexibility, portability, and lightweight applications are some of the major advantages that have claimed serious research attention towards ultrathin crystalline wafer-based solar cells. This work seeks to address a major challenge for such cells namely poor light absorption in thin absorbers. A novel inclined back reflector layer (BRL) of aluminium oxide for both planar and textured surfaced silicon devices with a thickness of 20 μm was investigated, combined with the passivation properties of the metal oxide film. A study of symmetric, asymmetric, and textured conformal BRL revealed an optical gain of ∼32% for the optimized BRL as compared to the structure without BRL. The combined effect of passivation and back reflection of the proposed BRL improved the power conversion efficiency by 60%. The optical and efficiency gain of 17% was observed for the structures with inclined BRL, as compared to that of a planar BRL. A remarkable omnidirectional response was also observed for textured BRL structures.
Observation of bi-directional global Alfvén eigenmodes in the MAST-U tokamak
Authors: Dreval M.B. , Oliver H.J.C. , Sharapov S.E. , Rivero-Rodriguez J.F. , Fitzgerald M. , Michael C. , Ochoukov R. , Velarde L. , Cecconello M. , Ryan D. ,   the MAST-U Team
Published: November 2024

Abstract
The first observations and classification of deuterium beam-driven sub-cyclotron frequency range Alfvén eigenmodes (AEs) are presented for the MAST-Upgrade tokamak. Sets of observed eigenmodes are separated in frequency by approximately 200 kHz. We observe a lower frequency separation of ∼10 kHz within each set, and the toroidal mode number n increases with frequency sequentially. The ∼200 kHz step between the sets coincides with the interval between successive curves of the Shear Alfvén continuum according to linear ideal MHD modeling. The sub-cyclotron frequency AEs can be identified as the global AEs (GAEs) localized at the continuum extrema regions. Each set contains the same range of n. These observations are consistent with our GAE modeling. In low plasma current (I
p) discharges, we observe only GAEs propagating counter to the plasma current and the beam direction. These GAEs are located near the magnetic axis. We observe counter and co-propagating GAEs simultaneously in higher I
p discharges. The co-propagating GAEs occur because of the formation of second continuum minima. Very flat safety factor profiles in higher I
p MAST-U discharges give rise to these minima. They are located at around half of the plasma radius. The GAEs have properties that are very different to those of compressional AEs previously reported for the MAST tokamak with low magnetic fields (Sharapov et al 2014 Phys. Plasmas
21 082501) before the upgrade.
Regionally optimized fire parameterizations using feed-forward neural networks
Authors: Ham Yoo-Geun , Nam Seung-Ho , Kang Geun-Hyeong , Kim Jin-Soo 
Published: November 2024

Abstract
The fire weather index (FWI) is a widely used metric for fire danger based on meteorological observations. However, even though it simulates the nonlinear relationship between the meteorological observations and fire intensity, the ability of the FWI to accurately represent global satellite-derived fire intensity observations is limited due to its empirical formulation based on a specific region. In this study, we propose a regionally-fitted fire parameterization method using feed-forward neural networks (FFNNs) to understand the nonlinear relationship between the meteorological variables and the fire intensity, which eventually improves the parameterization accuracy. These FFNNs for each grid point utilize daily-averaged meteorological variables (2 m relative humidity (RH2m), precipitation (PRCP), 2 m temperature, and wind speed) as inputs to estimate the satellite-derived fire radiative power (FRP) values. Applying the proposed FFNNs for fire parameterization during the 2001–2020 period revealed a marked enhancement in cross-validated skill compared to fire intensity estimation based on the FWI. This improvement was particularly notable across East Asia, Russia, the eastern US, southern South America, and central Africa. The sensitivity experiments demonstrated that the RH2m is the most critical variable in estimating the FRP. Conversely, the FWI-based estimations were primarily influenced by PRCP. The FFNNs accurately captured the observed nonlinear RH2m-FRP and PRCP-FRP relationship compared to that of the FWI-based estimations.
The Black Reveler in Christmas Villancicos
Authors: Davies Drew Edward 
Published: November 2024

Abstract
A unique genre of the Hispanic Baroque with roots in the theater, the villancico uses popularizing elements to communicate complex doctrinal ideas. One tradition of Christmas villancicos presents caricatures of Black revelers traveling to Bethlehem to celebrate Christ’s birth in a way that expresses the social inversion of the Christmas story through concepts derived from scenes of the adoration of the kings and shepherds as well as contemporaneous theatrical clichés. This chapter proposes topic theory as an interpretive framework for such villancicos and argues that the exaggerated simplicity of their musical gestures, as exemplified in three villancicos by Juan Gutiérrez de Padilla from the mid-seventeenth century, contribute to the inherent racism of their stereotyped content as directly as the poetry does. The topic theory approach warns against presuming verisimilitude between these works and actual historical communities in New Spain, although traces of sympathetic and humanistic representation of the characters occasionally emerge from the stereotyped language.
Imagining Latin America through Performance
Authors: Davies Drew Edward 
Published: November 2024

Abstract
The revival of New Spanish music has roots in a collaboration between Robert Stevenson and the Roger Wagner Chorale in 1960s Los Angeles. This final chapter critically chronicles how early music ensembles since then, and especially around 1992, have combined themes of exoticism, travel, discovery, and encounter to create a contemporary Latin Baroque performance tradition that foregrounds rhythm, improvised percussion, conviviality, and a Caribbean-themed imagination of Latin America. This new Latin Baroque tradition differs from historically plausible scenarios and celebrates Latinx identities in the present, sometimes problematically. Meanwhile, choral ensembles have taken historically informed approaches, but some repertories and timbral elements still await exploration and revival through performance.
Consent under Duress
Authors: Dougherty Tom 
Published: November 2024

Abstract
Consent can make actions morally permissible. But consent can lose its moral force when it is given under duress. Understanding how this happens requires answering the question of which types of duress undermine consent. Uncontroversially, severe coercion, like threats of violence, can prevent consent from creating moral permissions. But what about minor duress? Duress from natural causes? Duress from social norms? Duress that is merely apparent to the consent-giver with no objective basis in reality? To answer these questions, Consent under Duress defends an account that follows two key approaches. First, it adopts an expansive approach that broadens the class of misconduct that is constituted by acting on someone’s consent that is given under duress. Second, it adopts a scalar approach that allows that consent can be invalidated to varying degrees, which in turn can track the degrees of the severity of the duress to which the consent-giver is subject. The expansive and scalar approaches work in tandem. Once there is an expansion of the aforementioned class of misconduct, additional theoretical resources are needed to draw moral distinctions within this heterogeneous class. By providing these resources, the scalar approach supplements the expansive approach. Meanwhile, once it is recognized that consent can be partially invalidated by minor duress, it is necessary to expand the class of what constitutes misconduct that is constituted by acting on someone’s consent that is given under duress. By arguing independently for these mutually reinforcing approaches, Consent Under Duress offers a robust defense of their combination.