bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptive Gaussian process regression for efficient building of surrogate models in inverse problems
Authors: Semler Phillip , Weiser Martin 
Published: October 2023

Abstract
In a task where many similar inverse problems must be solved, evaluating costly simulations is impractical. Therefore, replacing the model y with a surrogate model ys
that can be evaluated quickly leads to a significant speedup. The approximation quality of the surrogate model depends strongly on the number, position, and accuracy of the sample points. With an additional finite computational budget, this leads to a problem of (computer) experimental design. In contrast to the selection of sample points, the trade-off between accuracy and effort has hardly been studied systematically. We therefore propose an adaptive algorithm to find an optimal design in terms of position and accuracy. Pursuing a sequential design by incrementally appending the computational budget leads to a convex and constrained optimization problem. As a surrogate, we construct a Gaussian process regression model. We measure the global approximation error in terms of its impact on the accuracy of the identified parameter and aim for a uniform absolute tolerance, assuming that ys
is computed by finite element calculations. A priori error estimates and a coarse estimate of computational effort relate the expected improvement of the surrogate model error to computational effort, resulting in the most efficient combination of sample point and evaluation tolerance. We also allow for improving the accuracy of already existing sample points by continuing previously truncated finite element solution procedures.
Adaptation of metrology-grade ac current source in velocity mode of Planck-Balance 2: direct referencing induced voltages with ac quantum voltage standard
Authors: Vasilyan Suren , Rogge Norbert , Preißler Hannes , Starkloff Michael , Schubert Marco , Fröhlich Thomas 
Published: October 2023

Abstract
The adaptation of developed metrology-grade ac current source (MCS) to the velocity mode of measurements of the Planck-Balance 2 as a means for generating ac mechanical oscillations is presented. The universality in operating with the MCS unit especially practical for the Planck-Balance setup for frequencies of 0.1 Hz–20 Hz (including but not limited to the negligence of a broader range of 0.01 Hz up to several hundred Hz) and for amplitudes of up to 10 mA with 16 (offset with 14)-bit effective resolution is demonstrated. MCS allows generating complex ac waveform signals as waveform synthesizers by adding to the original signal an extra five independent harmonic components, each of which with an adjustable resolution of 10 ns for phase and 16-bit for amplitude. Additionally, the MCS is supported by an external clock at 10 MHz frequency which serves also as a common reference time base for the comparison between the direct output signal of MCS, or of the induced voltage in the coil of the Planck-Balance resulting due to the applied current by MCS, with the ac quantum voltage standard at the required accuracy levels.
The effects of physical morphologies and strain rate on piezoelectric potential of boron nitride nanotubes: a molecular dynamics simulation
Authors: Ghashami Gholamreza , Moghimi Zand Mahdi , Mahnama Maryam , Allaei S Mehdi Vaez , López-Suárez Miquel 
Published: October 2023

Abstract
The growing demand for self-powered systems and the slow progress in energy storage devices have led to the emergence of piezoelectric materials as a promising solution for energy harvesting. This study aims to investigate the effects of chirality, length, and strain rate on the piezoelectric potential of boron nitride nanotubes (BNNTs) through molecular dynamics simulation. Accurate data and guidance are provided to explain the piezoelectricity of chiral nanotubes, as the piezoelectric potentials of these nanotubes have previously remained unclear. The present study focuses on calculating the effect of these parameters based on the atomic model. The observed results stem from the frequencies and internal deformations, as the axial frequencies and deformations exhibit more substantial modifications compared to transverse directions. The piezoelectricity was found to depend on chirality, with the order of BNNT piezoelectricity sufficiency being in the sequence of zigzag > chirality > armchair configurations. The length of the BNNTs was also found to influence piezoelectricity, while the strain rate had no effect. The results also indicate that BNNTs can generate power in the milliwatts range, which is adequate for low-power electronic devices and Internet of Things applications. This research provides valuable insights into the piezoelectricity of chiral nanotubes and offers guidance for designing efficient energy harvesting devices.
A self-balanced electron-emissive double Langmuir probe drawing no electron loss from its diagnosed plasma
Authors: Yip Chi-Shung , Jin Chenyao , Zhang Wei , Jiang Di , Xu Guo Sheng 
Published: October 2023

Abstract
In this work, a new form of double Langmuir probe (DLP) system, an emissive double Langmuir probe (EDLP), which connects a collecting probe tip and an electron-emitting probe tip to form a DLP system, has been proposed as a replacement of the currently more common asymmetric double Langmuir probes (ADLPs). The EDLP was both computationally and experimentally investigated in this work. Using an emissive probe to provide an emission current I
E to balance the electron collection current I
C,e, the EDLP can obtain a full I–V trace when I
E,TL > I
C,es and be used in a similar manner to a single Langmuir probe with the exception that the EDLP, as with the ADLP, does not measure the local plasma potential. I
E,TL ≫ I
C,es can be realized on an EDLP without needing the much larger ion collection area required by the ADLP, and at I
E,TL ∼ 2I
C,es the relative error between the EDLP and a single Langmuir probe is ∼15% due to space-charge limited effects, which is better than that of the ADLP at ∼30% under similar conditions. The performance of an EDLP depends on whether its electron emission current sufficiently offsets its electron-collecting current, making it particularly fitting for scenarios where the plasma density is low but a large probe is difficult to employ due to the limited balancing ion current. This makes the EDLP potentially useful on satellites, which operate in very low temperature plasmas with a limited ion loss area to balance a Langmuir probe’s electron-collecting current. With the advances in highly emitting materials, EDLPs are expected to significantly remove the design barriers of Langmuir probes on satellites.
Transparent superhydrophilic metal oxide coating with mechanical and chemical robustness for photocatalytic self-cleaning applications
Authors: Hossain Muhammad Nobi , Lee Sung-Jun , Kim Chang-Lae 
Published: October 2023

Abstract
A photoactive TiO2-KH550 (3-aminopropyltriethoxysilane) - PEG (Polyethelyneglycol) coating film with excellent superhydrophilicity is deposited on a glass substrate by means of the dip coating method for self-cleaning applications. The effects of the number of coating layers, molecular weight of PEG (200–8000), surface roughness, and film thickness on the hydrophilicity of the film coated on the glass substrate are analyzed. In addition, the mechanical durability, and thermal and chemical stability of the coated film are studied. The tribological properties (friction coefficient and wear track) of the film coated on the glass substrate are investigated. The photo-catalyzed self-cleaning properties of the film are also evaluated. In addition, the effect of withdrawal speed on the optical properties (transmittance) of the film are investigated by obtaining and analyzing its UV spectra. The results indicated that the hydrophilicity of the TiO2 coating film decreased as its surface roughness and thickness increased. The TiO2-KH550-PEG coating fabricated using PEG with a low molecular weight of 400 exhibited a smooth and uniform morphology. The composite TiO2 coating film prepared herein exhibited excellent mechanical durability in a sandpaper abrasion test and retained its superhydrophilicity under harsh chemical conditions (strong acidic and basic media). The coated glass substrate presented superior wear resistance compared to that of the uncoated glass substrate. Moreover, the transparent TiO2 composite film coating exhibited excellent photocatalytic self-cleaning properties. Therefore, it is expected that the TiO2 composite film coated on glass has good potential for use in applications such as window glasses, architectural buildings, and photovoltaic modules.
Modelling and simulation of electrical analogous for permanent magnet materials
Authors: Fernandez Antonio Paulo Rodrigues , Perigo Elio Alberto , de Faria Junior Rubens Nunes 
Published: October 2023

Abstract
Expressions to simulate the intrinsic demagnetizing curve of permanent magnets are derived from the classical electrical analogy of a 2RLC circuit as an equivalent to a magnet under demagnetization in a closed magnetic circuit. Comparisons between experimental and theoretical intrinsic M x H curves were carried out for hard magnetic materials, and the possibility of using this analogous circuit with two components has also been investigated. The demagnetization curves of permanent sintered magnets have been simulated with time domain analytical expressions obtained using an electric equivalent circuit analogous to a closed magnetic circuit. This has been carried out for magnets measured at room temperature and at 373 K. Equivalent electric parameters influenced the various regions of the demagnetization curve. It has also been shown that it was possible to simulate the demagnetization curve of rare earth magnets and also other types of permanent magnets. The Stoner-Wohlfarth model theoretical curves have also been used as a comparison. At last, the electrical analogous parameters have been systematically varied in order to correlate them to the magnetic properties.
Constraints on cosmological model in Weyl-Cartan spacetime from astronomical measurements
Authors: Wang Jun , Qiang Ling-Xuan , Zhao Yi-Fei , Yin Qing-Yuan , Chen Xue-You 
Published: October 2023

Abstract
In order to give some lights on the issue of Hubble tension, alternative to Riemannian spacetime, we investigate a cosmological model in Weyl-Cartan spacetime by astronomical measurements, where a new density parameter Ω
ϕ
is introduced to denote the non-Riemannian spacetime structure, which scales as ∼(1 + z)6. Based on Markov Chain Monte Carlo estimation and taking astronomical measurements of cosmic microwave background (Planck 2018), baryon acoustic oscillations and Type Ia supernova (Pantheon), model parameters of our considering case are constrained. Our results show that Hubble tension cannot be alleviated in Weyl-Cartan cosmology. However, constraints on the parameter Ω
ϕ
can not be distinguished from ΛCDM model in 1σ confidence region. Moreover, the space of the Universe is infinite and unbounded, and an upper limit of the model parameter Ω
ϕ
is also obtained. Additionally, it is worth noting that results obtained in this work are valid for models that the scaling behavior of density parameters is same to our considering case.
Tunable double-layer dual-band metamaterial with negative mass density
Authors: Yang Xiao , Hao Limei , Yan Xiaole , Liu Dong-an , Guo Jifeng , Cheng Hong , Pang Shaofang , Xie You , Chen Zhi 
Published: October 2023

Abstract
Due to the huge structure and low efficiency of acoustic metamaterial (AM) with local resonance, a tunable dual-band AM with nested double layer hollow tube (NDLHT) is presented here, which is achieved by adjusting the inner or outer layer tube’s lengths or diameters to modulate the frequency band with the negative mass density. In addition, an accurate resonant frequency formula for OE-CE (Open End-Close End) NDLHT was derived based on the principle of standing wave resonance. The theoretical calculated resonant frequencies exhibit in good agreement with the simulated frequencies. Thus, the structural unit can then be actively constructed in the desired response frequency range using the geometric parameters that were obtained from this theoretical formula. This type of the nested AM with negative mass density has the advantages of high space utilization, active design, programmed modelling, customized production, 3D quantitative printing and is easily combined with other structure units with negative modulus to prepare AM with double negative in the desired frequency band.
Nonlinear optical response of silver trimer adsorbed para-aminobenzoic acid: A DFT study
Authors: Lakhera Shradha , Devlal Kamal , Rana Meenakshi 
Published: October 2023

Abstract
The reported study is motivated by our previously done experimental demonstration of the optical limiting behavior of para-aminobenzoic acid and enhanced nonlinear optical responses of compounds with Ag3 nanoparticle complex. The present study is a theoretical insight into the nonlinear optical responses of para-aminobenzoic acid adsorbed with Ag3 trimer. The enhancement in the optical nonlinearity of the para-aminobenzoic acid after the adsorption of the silver trimer (Ag3) was accounted in the present study. The density functional theory was used to establish the occurrence of the intra and intermolecular charge transfer between the donor and acceptor moieties of the para-aminobenzoic acid and Ag3 trimer. The molecular electrostatic potential surface and inter-fragment charge transfer analysis were used to establish the donor nature of the Ag3 trimer, amino group, and acceptor of the carboxyl group. The absorption spectra and Fourier-transform infrared spectra were used to account for the electronic and vibrational modes. The value of first-order hyperpolarizability of para-aminobenzoic acid and Ag3 complex was observed to increase by six times that of para-aminobenzoic acid. The high value of first-order hyperpolarizability shows the potential nonlinear optical activity of para-aminobenzoic acid adsorbed with Ag3 trimer. The presented study forms a strong base for experimental demonstration of the nonlinear optical activity of the PABA and the silver nanoparticles and the experimental work will be done in the near future for the NLO responses and optical limiting activity of PABA combined with silver nanoparticles.
Investigation on the impact of cobalt doping on optical, structural and magnetic properties of zinc oxide nanoparticles
Authors: Roy Shradha , Mukherjee Samrat 
Published: October 2023

Abstract
In the current article, we investigated the impact of transition metal Co2+ doping in ZnO nanoparticles and its effect on their optical, structural, and magnetic properties. The synthesized nanoparticles have the generic formula Zn1-xCoxO (x = 0.00, 0.03, 0.06, and 0.09). Single-phase hexagonal crystal structure of the synthesized nanopowder was confirmed by x-ray diffractograms. Tauc plots were used to calculate the band gap of all the samples. Multiple emission peaks were observed from the photoluminescence studies. HRTEM was employed to study the particle morphology and the size distribution. X-ray photoelectron (XPS) spectroscopy was performed to investigate the chemical composition of samples. Magnetic measurements were carried out to study the magnetic behaviour of pure and doped ZnO samples. Ferromagnetic behaviour became more prominent with the addition of Co doping, as observed by room temperature M-H plots.
Initial study on thermal stability of cold spray tantalum coating irradiated with deuterium for fusion applications
Authors: Ialovega Mykola , Dabney Tyler , Navarro Gonzalez Marcos , Yeom Hwasung , Velez Danah , Willing Evan , Anderson Jay K , Angot Thierry , Bisson Régis , Forest Cary , Kreter Arkadi , Schmitz Oliver , Sridharan Kumar 
Published: October 2023

Abstract
Removal of neutral hydrogen atoms in the plasma edge reduces the number of charge exchange events and thus, the net energy losses in the plasma, significantly improving performance of fusion devices. Effective control of the residual pressure of hydrogen isotopes (HIs) in the plasma edge may be achieved by utilizing a hydrogen absorbing first wall interface capable of withstanding the harsh fusion environment. In this study, we have investigated tantalum (Ta) coating deposited by cold spray technology on 316L stainless steel substrate as a potential plasma-facing material surface. High fluence low energy deuterium plasma irradiation experiments and subsequent thermal annealing cycles associated with thermal desorption spectrometry (TDS) demonstrated superior structural stability of the Ta coating. TDS experiments revealed the outgassing of deuterium (as measure of its retention) for cold spray Ta coatings to be three times higher than bulk Ta and two orders of magnitude greater than bulk polycrystalline W. X-ray photoelectron spectroscopy revealed evolution of oxidation states upon deuterium irradiation and a partial recovery of the metallic signature of Ta after the thermal treatment at 1100 K.
Quantum image encryption based on Baker map and DNA circular shift operation
Authors: Liu Xingbin 
Published: October 2023

Abstract
Quantum computation can improve the efficiency of image processing by utilizing parallelism and superposition characteristics. In this paper, a quantum cryptosystem based on Baker map and deoxyribonucleic acid (DNA) circular shift operation is designed. Firstly, the digital image to be encrypted is firstly represented with a novel enhanced quantum representation model. Then quantum Baker map is used to permutate the position information of the prepared quantum image. Next, the designed DNA circular shift operation is performed to preliminarily change the color information of the scrambled image. Finally, the ciphertext image is obtained by implementing the exclusive OR (XOR) operation between the pseudo-random sequence generated by a four-dimensional (4D) hyper-chaotic system and the DNA shift operated image. Numerical experimental results and security analysis verify that the proposed scheme has good performance at securing information storage and transmission as the histograms of ciphertexts are uniform, the correlation coefficient values of three directions are very close to 0, the average information entropy is 7.9972, the key space is more than 1015×4 to resist brute-force attack. Furthermore, it has lower computational complexity compared with classical algorithms.
Primarily investigation with multiple methods on permafrost state around a rapid change lake in the interior of the Tibet Plateau
Authors: Ding Zekun , Niu Fujun , Mu Yanhu , He Peifeng , Gao Zeyong , Fan Xingwen 
Published: October 2023

Abstract
Changes of the lakes on high-altitude regions of the Tibet Plateau influence the state of the surrounding permafrost. Due to the climate warming and wetting trend, extreme events including lake outburst has occurred more frequent. In 2011, an outburst event occurred on the Zonag Lake and this event changed the water distribution in the basin, leading a rapid expansion of the Tailwater lake, named as the Salt Lake. However, the construction of the drainage channel in the Salt Lake ended the expansion process and the shrinkage of the lake started since 2020. To investigate the permafrost state around the Salt Lake, multiple methods, including drilling boreholes, the unmanned aerial vehicle survey and the ground penetrating radar detection have been applied. By integrating these multi-source data, the thermal regime, topography and the spatial distribution of the permafrost around the Salt Lake were analyzed. The result showed that the permafrost state around the Salt Lake was related to the distance from the lake water. The permafrost table appears at 90 m away from the Salt Lake and interrupted by a nearby thermokarst lake at 220 m. The ground temperature in the natural field is 0.2 °C lower than the temperature in the lake at a depth of −5 m.
PM2.5 data inputs alter identification of disadvantaged communities
Authors: Carter Therese S , Kerr Gaige Hunter , Amini Heresh , Martin Randall V , Ovienmhada Ufuoma , Schwartz Joel , van Donkelaar Aaron , Anenberg Susan 
Published: October 2023

Abstract
Communities of color and lower income are often found to experience disproportionate levels of fine particulate matter (PM2.5) air pollution in the US (Pope and Dockery 2006 J. Air Waste Manage. Assoc.
56 709–42; Brook et al 2010 Circulation
121 2331–78; Tessum et al 2021 Sci. Adv. 7 eabf4491). The federal and several state governments use relatively coarsely resolved (12 km) PM2.5 concentration estimates to identify overburdened communities. Newly available PM2.5 datasets estimate concentrations at increasingly high spatial resolutions (50 m–1 km), with different magnitudes and spatial patterns, potentially affecting assessments of racial, ethnic, and socioeconomic exposure disparities. We show that two recently available high-resolution datasets from the scientific community and the 12 km dataset are consistent for national and regional average, but not intraurban, PM2.5 concentration disparities in 2019. The datasets consistently indicate that regional average PM2.5 concentrations are higher in the least White (by 3%–65%) and most Hispanic census tracts (2%–47%), compared with in the most Non-Hispanic White tracts. However, in nine of the ten most populous cities, the three datasets differ on the order of least-to-most exposed population subgroups. We identified 1029 tracts (representing ∼4.5 million people) as disadvantaged (⩾65th percentile for poverty and ⩾90th percentile PM2.5 as defined by the Climate and Economic Justice Screening Tool) in all three datasets, 335 tracts (∼1.5 million people) as disadvantaged using both high-resolution datasets but not the 12 km dataset, and 695 tracts (∼2.7 million people) as disadvantaged in the 12 km dataset but not the high-resolution datasets. The 12 km dataset does not capture intraurban disparities and may mischaracterize disproportionately exposed neighborhoods. The high-resolution PM2.5 datasets can be further improved by ground-truthing with observations from rapidly expanding ground and mobile monitoring and by integrating across available datasets.
GC-MS method for identification of organic chemical compounds nutmeg flesh of North Minahasa local varieties
Authors: Paat F J , Wantasen S , Toding M M , Pakasi S E , Tumbelaka S , Kaligis J B , Turang D A S , Porong J V , Linggi R J 
Published: October 2023

Abstract
The organic chemical compound Myristica fragrans has been identified in North Minahasa Regency. This study succeeded in identifying Neoisolongifolane, hydroxy-, 1HCyclopropa [a]naphthalene, 1a, 2, 3, 5, 6, 7, 7a, 7b-octahydro-1, 1, 7, 7a-tetramethyl, [1aR(1aα,7a,7aα,7bα)]-; 4,7-Methanoazulene, 1, 2, 3, 4, 5, 6, 7, 8-octahydro-1, 4, 9, 9-tetramethyl-, [1S-(1a,4a,7a)]-; Patchouli alcohol, 1(2H)- Naphthalenone, octahydro-4a, 8a-dimethyl-7-(1-ethylethyl)- [4aR-(4aα,7ß,8aα)]-, and Isoleden.