bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ablated precursor plasma and evolution of magnetic field of exploding cylindrical thin liner
Authors: Zhang Daoyuan , Wu Jian , Chen Ziwen , Lu Yihan , Shi Huantong , Li Xingwen , Jia Shenli , Wang Guanqiong , Gan YunDan , Zhang Jiangbo 
Published: January 2021

Abstract
The formation of precursor plasma and ablation dynamics of Al thin liner explosion are investigated in this manuscript. The size of 12 mm in diameter, 10 μm in thickness Al liners are exploded on the Qin-1 facility (about 450 ns, 450 kA). An axial laser shadowgraphy and interferometry platform is set up to observe the plasma dynamics inside the liner. To solve the problem that the inside plasma density of the liner cannot be absolutely calibrated due to the lack of a zero plasma density area, we have established a CW laser interference system using a streak camera which can trace the interference lines over time. Low-density (10−7−10−6 g cm−3) precursor plasma is generated from the interior wall and flows towards the center with a velocity of about 150–200 km s−1, thus forming a column with high electron density by accumulation. Simultaneously, a high-density plasma layer flows toward the center at about 10 km s−1. The electron density of the central plasma column rises up rapidly after the precursor reaches the center and achieves 2.5 × 1018 cm−3 at 280 ns after the current starts. To fully understand the process, we have used the resistive magnetohydrodynamic code FLASH to realize a simulation to study interior precursor dynamics. We compared these simulation results with our experiments. Finally, we measured the voltage for the whole process and derived the inductance change and effective current radius. We compared the simulated current density distribution with the experimental result which proves that a considerable amount of current flows through the center plasma column, making the effective radius of current become smaller over time.
Single-shot 3D imaging of hydroxyl radicals in the vicinity of a gliding arc discharge
Authors: Bao Yupan , Dorozynska Karolina , Stamatoglou Panagiota , Kong Chengdong , Hurtig Tomas , Pfaff Sebastian , Zetterberg Johan , Richter Mattias , Kristensson Elias , Ehn Andreas 
Published: January 2021

Abstract
Plasma-related studies in gas phase are challenging to carry out due to plasma’s transient and unpredictable behavior, excessive luminosity emission, 3D complexity and aggressive chemistry and physiochemical interactions that are easily affected by external probing. Laser-induced fluorescence is a robust technique for non-intrusive investigations of plasma-produced species. In this letter, we present 3D distributions of ground state hydroxyl radicals (OH) radicals in the vicinity of a glow-type gliding arc plasma. Such radical distributions are captured instantaneously in one single camera acquisition by combining structured laser illumination and a lock-in based imaging analysis method called FRAME. The interference of plasma emission is automatically subtracted by the FRAME technique. In addition, the orientation of the plasma discharge can be reconstructed from the 3D data matrix, which can then be used to calculate 2D distributions of ground state OH radicals in a plane perpendicular to the orientation of the plasma channel. Our results indicate that OH distributions around a gliding arc are strongly affected by gas dynamics. We believe that the ability to instantaneously capture 3D transient molecular distributions in a plasma discharge, with minimal plasma emission interference, will have a strong impact on the plasma community for in situ investigations of plasma-induced chemistry and physics.
Two-dimensional oxygen functionalized honeycomb and zigzag dumbbell silicene with robust Dirac cones
Authors: Chen Xin , Li Linyang , Peeters François M , Sanyal Biplab 
Published: January 2021

Abstract
Dumbbell-like structures are recently found to be energetically favored in group IV two-dimensional (2D) materials, exhibiting rich physics and many interesting properties. In this paper, using first-principles calculations, we have investigated the oxidized form of the hexagonal honeycomb (ODB-h) and zigzag dumbbell silicene (ODB-z). We confirm that both oxidization processes are energetically favorable, and their phonon spectra further demonstrate the dynamic stability. Contrary to the pristine dumbbell silicene structures (PDB-h and PDB-z silicene), these oxidized products ODB-h and ODB-z silicene are both semimetals with Dirac cones at the Fermi level. The Dirac cones of ODB-h and ODB-z silicene are at the K point and between Y and Γ points respectively, possessing high Fermi velocities of 3.1 × 105 m s−1 (ODB-h) and 2.9–3.4 × 105 m s−1 (ODB-z). The origin of the Dirac cones is further explained by tight-binding models. The semimetallic properties of ODB-h and ODB-z are sensitive to compression due to the self-absorption effect, but quite robust against the tensile strain. These outstanding properties make oxidized dumbbell silicene a promising material for quantum computing and high-speed electronic devices.
Nonlinear localized modes in two-dimensional hexagonally-packed magnetic lattices
Authors: Chong Christopher , Wang Yifan , Maréchal Donovan , Charalampidis Efstathios G , Molerón Miguel , Martínez Alejandro J , Porter Mason A , Kevrekidis Panayotis G , Daraio Chiara 
Published: January 2021

Abstract
We conduct an extensive study of nonlinear localized modes (NLMs), which are temporally periodic and spatially localized structures, in a two-dimensional array of repelling magnets. In our experiments, we arrange a lattice in a hexagonal configuration with a light-mass defect, and we harmonically drive the center of the chain with a tunable excitation frequency, amplitude, and angle. We use a damped, driven variant of a vector Fermi–Pasta–Ulam–Tsingou lattice to model our experimental setup. Despite the idealized nature of this model, we obtain good qualitative agreement between theory and experiments for a variety of dynamical behaviors. We find that the spatial decay is direction-dependent and that drive amplitudes along fundamental displacement axes lead to nonlinear resonant peaks in frequency continuations that are similar to those that occur in one-dimensional damped, driven lattices. However, we observe numerically that driving along other directions results in asymmetric NLMs that bifurcate from the main solution branch, which consists of symmetric NLMs. We also demonstrate both experimentally and numerically that solutions that appear to be time-quasiperiodic bifurcate from the branch of symmetric time-periodic NLMs.
Characterizing spatially varying optical emissions in a steady-state dipole plasma: inversion based experiments and modeling
Authors: Bhattacharjee Sayak , Baitha Anuj Ram , Mathew Jose V , Bhattacharjee Sudeep 
Published: January 2021

Abstract
This study characterizes spatially varying optical emissions in a compact dipole plasma device driven at steady-state by continuous mode microwaves. The study is motivated by visual observations, which indicate a distinct pattern of alternate bright and less bright regions (bearing structural resemblance to the two particle radiation belts found in the Earth's magnetosphere). The investigation is performed in two experimental systems of cylindrical and spherical geometries, and boundary effects in the optical emissivity are observed in the smaller cylindrical system. Two optical diagnostic techniques are employed, namely, a simplistic linear inversion method, and the standard Abel inversion method, to invert the measured intensities and determine the local (spatially varying) emissivities in the equatorial plane of the dipole plasma. The study involves the design and development of the two optical probes, specifically, a telescopic probe capable of motion along a radial line (for linear inversion), and a mechanical gear-operated probe capable of bidirectional motion to obtain chord integrated intensities (for Abel inversion). Finally, the transition specific photon emission rates are determined by the application of a modified corona model, and the emission rates are compared with the experimental results. The existence of two bright belts separated by a darker band in the dipole plasma is confirmed by both the experimental and modeling results.
Pencil-like periodic ridges under second Bragg incidence as dual-function beam separation
Authors: Lin Zefan , Wang Bo 
Published: January 2021

Abstract
A reflective dual-function pencil-like grating under second Bragg incidence is proposed in this paper. The finite element analysis method is chosen to be the research technique of this grating. Based on it, the influence of the incident angle, period, duty cycle, incident wavelength, and other parameters on the diffraction efficiency are analyzed in detail. At an incident laser wavelength of 1.55 μm, for TE polarization, the efficiency of −2nd order is 96.57% so that the proposed grating can be regarded as a single-port high-efficiency reflective grating. For TM polarization, the grating can function as a dual-port grating with the efficiency 46.03% for 0th order and 45.96% for −2nd order. What is more, the proposed grating has a broader angular bandwidth compared with other dual-function gratings, which ensures the diffraction performance of the grating while allowing some operational changes.
Investigation of quark distributions in a family of pentaquarks using the Thomas–Fermi quark model
Authors: Giri Mohan , Baral Suman , Kaphle Gopi Chandra , Dangi Nirmal , Shiwakoti Sudip , Bardomero Leonardo , Lashomb Paul , Wilcox Walter 
Published: January 2021

Abstract
Using the Thomas–Fermi quark model, a collective, spherically symmetric density of states is created to represent a gas of interacting fermions with various degeneracies at zero temperature. Over a family of pentaquarks,

uudc

c

¯

, color interaction probabilities were obtained after averaging over all the possible configurations. Three different functions are developed for light, charm, and anti-charm quarks and are assumed to be linearly related by some proportionality constants. Interesting patterns of quark distributions are observed while analyzing the quark function consistency conditions for such constants.
Magnetohydrodynamic flow and heat transfer of a hybrid nanofluid over a rotating disk by considering Arrhenius energy
Authors: Reddy M Gnaneswara , R Naveen Kumar , Prasannakumara B C , Rudraswamy N G , Ganesh Kumar K 
Published: January 2021

Abstract
This research work explores the effect of hybrid nanoparticles on the flow over a rotating disk by using an activation energy model. Here, we considered molybdenum disulfide and ferro sulfate as nanoparticles suspended in base fluid water. The magnetic field is pragmatic normal to the hybrid nanofluid flow direction. The derived nonlinear ordinary differential equations are non-dimensionalized and worked out numerically with the help of Maple software by the RKF-45 method. The scientific results for a non-dimensionalized equation are presented for both nanoparticle and hybrid nanoparticle case. Accoutrements of various predominant restrictions on flow and thermal fields are scanned. Computation estimation for friction factor, local Nusselt number and Sherwood number are also executed. Results reveal that the reduction of the heat transfer rate is greater in hybrid nanoparticles when compared to nanoparticles for increasing values of Eckert Number and the thermal field enhances for the enhanced values of volume fraction.
Exploring the latest Pantheon SN Ia dataset by using three kinds of statistics techniques
Authors: Wang Shuang , Luo Xiaolin 
Published: January 2021

Abstract
In this work, we explore the cosmological consequences of the latest Type Ia supernova (SN Ia) dataset, Pantheon, by adopting the wCDM model. The Pantheon dataset currently contains the largest number of SN Ia samples, which contains 1048 supernovae on the redshift range 0 < z < 2.3. Here we take into account three kinds of SN Ia statistics techniques, including: (1) magnitude statistics (MS), which is the traditional SN Ia statistics technique; (2) flux statistics (FS), which is based on the flux-averaging (FA) method; and (3) improved flux statistics (IFS), which combines the advantages of MS and FS. It should be mentioned that the IFS technique needs to scan the (z
cut, Δz) parameters plane, where z
cut and Δz are redshift cut-off and redshift interval of FA, respectively. The results are as follows. (1) Using the SN dataset only, the best FA recipe for IFS is (z
cut, Δz) = (0.1, 0.08); (2) comparing to the old SN dataset, JLA, adopting the Pantheon dataset can reduce the 2σ error bars of equation of state w by 38%, 47% and 53% for MS, FS and IFS, respectively; (3) FS gives closer results to other observations, such as Baryon acoustic oscillations and cosmic microwave background; (4) compared with FS and IFS, MS more favors a Universe that will end in a ‘big rip’.
A new calibration setup for lock-in amplifiers in the low frequency range and its validation in a bilateral comparison
Authors: Cultrera Alessandro , Corminboeuf David , D’Elia Vincenzo , Tran Ngoc Thanh Mai , Callegaro Luca , Ortolano Massimo 
Published: January 2021

Abstract
This paper addresses the calibration of lock-in amplifiers in the low frequency range. A simple but effective calibration setup implemented at INRIM is described. This includes a stable low-voltage source, composed of a digital sine wave generator and a cascade of two voltage dividers, one inductive and one resistive. The magnitude error is the lock-in magnitude error, which can be determined with an uncertainty of the order of 10−4 or better, that is, two orders of magnitude lower than the typical lock-in accuracy specification. The system can operate with an input voltage from 0.1 µV to 10 µV and a frequency from a few hertz to about 1 kHz. The performances of the calibration setup were evaluated at 1 µV and 10 μV at 20 Hz and 103 Hz and compared with those of another existing setup, implemented at METAS, through a direct comparison in the framework of an EURAMET research project.
Quasilinear critical gradient model for Alfven eigenmode driven energetic particle transport with intermittency
Authors: Waltz R.E. , Bass E.M. , Collins C.S. , Gage K. 
Published: January 2021

Abstract
A simplified quasilinear critical gradient model (QLCGM) for Alfven eigenmode (AE) driven energetic particle (EP) transport is used to treat the intermittency (burstiness) of the transport. Here intermittency is defined as the ratio of the root mean square deviation from mean flow to the mean flow. The model posits that the intermittency results from the micro-turbulent noise induced in the thermal plasma damping rate for the AE. The model is embedded in a time-dependent EP density transport code to generate the transport-flow time traces from typical critical gradient and slowing down density profiles. The QLCGM appears to be in reasonable agreement with the level and characteristics of the intermittency observed in the DIII-D fast particle loss detector flow time traces: high kurtosis [O(40)] of the burstiness with the intermittency O(1–2) increasing with the level of mean flow.
The updated ITPA global H-mode confinement database: description and analysis
Authors: Verdoolaege G. , Kaye S.M. , Angioni C. , Kardaun O.J.W.F. , Maslov M. , Romanelli M. , Ryter F. , Thomsen K. , ASDEX Upgrade Team the , EUROfusion MST1 Team the , Contributors JET 
Published: January 2021

Abstract
The multi-machine International Tokamak Physics Activity (ITPA) Global H-mode Confinement Database has been upgraded with new data from JET with the ITER-like wall and ASDEX Upgrade with the full tungsten wall. This paper describes the new database and presents results of regression analysis to estimate the global energy confinement scaling in H-mode plasmas using a standard power law. Various subsets of the database are considered, focusing on type of wall and divertor materials, confinement regime (all H-modes, ELMy H or ELM-free) and ITER-like constraints. Apart from ordinary least squares (OLS), two other, robust regression techniques are applied, which take into account uncertainty on all variables. Regression on data from individual devices shows that, generally, the confinement dependence on density and the power degradation are weakest in the fully metallic devices. Using the multi-machine scalings, predictions are made of the confinement time in a standard ELMy H-mode scenario in ITER. The uncertainty on the scaling parameters is discussed with a view to practically useful error bars on the parameters and predictions. One of the derived scalings for ELMy H-modes on an ITER-like subset is studied in particular and compared to the IPB98(y, 2) confinement scaling in engineering and dimensionless form. Transformation of this new scaling from engineering variables to dimensionless quantities is shown to result in large error bars on the dimensionless scaling. Regression analysis in the space of dimensionless variables is therefore proposed as an alternative, yielding acceptable estimates for the dimensionless scaling. The new scaling, which is dimensionally correct within the uncertainties, suggests that some dependencies of confinement in the multi-machine database can be reconciled with parameter scans in individual devices. This includes vanishingly small dependence of confinement on line-averaged density and normalized plasma pressure (β), as well as a noticeable, positive dependence on effective atomic mass and plasma triangularity. Extrapolation of this scaling to ITER yields a somewhat lower confinement time compared to the IPB98(y, 2) prediction, possibly related to the considerably weaker dependence on major radius in the new scaling (slightly above linear). Further studies are needed to compare more flexible regression models with the power law used here. In addition, data from more devices concerning possible ‘hidden variables’ could help to determine their influence on confinement, while adding data in sparsely populated areas of the parameter space may contribute to further disentangling some of the global confinement dependencies in tokamak plasmas.
Statistical and neural net model in predicting the strength of pozzolan admixed concrete
Authors: Mandal Rishav , Shanmugasundaram M , Karthiyaini S 
Published: January 2021

Abstract
This paper predicts the compressive strength of reinforced cement concrete with different pozzolan having different biproducts such as flyash, GGBS, silica fumes and rice husk on 28 days with multiple regression analysis (MRA) and artificial neural network (ANN) and compares them. The model prepared uses the data from the previously published papers; the data collected from the papers are cement content, coarse aggregate, fine aggregate, water/cement ratio, replacement of cement with pozzolan materials like GGBS, flyash, silica fumes, rice husks, SiO2, Al2O3, Fe2O3, CaO, MgO, SO3 quantities are taken in the form of input for the models and the respective compressive strength obtained from the literature is taken as the target strength or parameter. The result shows that this the model made with these parameters produces a valid model through MRA and ANN.
Anomaly detection of fundus images
Authors: Jagtap Shalaka , Sahaya Rani Alex John 
Published: January 2021

Abstract
Research states that at least 2.2 billion people have a vision impairment or blindness all over the world. There are many reasons for blindness and few of them are leading causes such as cataract, macular degeneration due to age factor, glaucoma, diabetic retinopathy, corneal opacity, trachoma. In all of them, glaucoma is one of the main causes of blindness. Glaucoma is asymptomatic and non-reversible vision loss disease. This paper presents a method of early detection of glaucoma using deep Neural Network (NN) from the retinal images. In different retinal imaging modalities, fundus images are widely accepted. In deep learning, Convolution Neural Network (CNN) is used for feature extraction from the fundus image, and fully connected feed forward NN (FFNN) is used to find out the level of glaucoma. Typical image processing algorithms are used for feature extraction from fundus images and classified with FFNN. The accuracy is compared among different architectures. The TensorFlow software tool and python language are used for this research.
Hydrocracking process of coconut oil using Ni-Zn/HZSM-5 catalyst for hydrocarbon biofuel production
Authors: Muttaqii M Al , Kurniawansyah F , Prajitno D H , Roesyadi A 
Published: January 2021

Abstract
Renewable hydrocarbon biofuel was produced by hydrocracking of coconut oil using a bifunctional catalyst. Hydrocarbon biofuel is promising for production of future fuels from vegetable oil. The advantage of the hydrocracking is the formation of hydrocarbon biofuel products at the conventional fuel range. The purpose of this work is to produce hydrocarbon biofuel by hydrocracking of coconut oil using the catalyst of Ni-Zn/HZSM-5. The processes of hydrocracking processes were performed in a vessel reactor by stirring with magnetically at 350 °C and the reaction pressure of 15 bar for 2 h under flowing H2 with Ni-Zn/HZSM-5 catalyst. The effect of Ni-Zn/HZSM-5 catalyst was evaluated by determining the composition of products (hydrocarbon biofuel). The hydrocarbon biofuel was determined by Gas Chromatography-Mass Spectrometry (GC-MS). The GC-MS results of hydrocarbon biofuel show the aliphatic compounds in the range C12-C22. The presence of C17-C18 in the hydrocarbon biofuel was relatively low. Hydrocarbon biofuel composition consists of 0.11 cycloparaffins, 5.33 normal paraffins, 7.85 olefin, and 0.08 aromatics based on area%. The total amount of detected oxygenated compounds was 86.63 area% carboxylic acid. These compounds are responsible for the low quality of the hydrocarbon biofuel. However, the reaction must be carried out at above 350 °C to eliminate the oxygenated compounds in the hydrocarbon biofuel, as an important step to replace non-renewable fossil fuels.
Utilizing ordinal alpha reliability on modification of Mark H. Davis’s empathy rate instrument (case study in Department of Mathematics FMIPA UI)
Authors: Doko F A , Setiadi R , Soemartojo S M 
Published: January 2021

Abstract
Most psychology research requires the existence of an instrument to obtain the required information. An instrument using Likert scale needs to know its reliability and validity. However, the use of an instrument is not necessarily suitable for particular population. This can be seen from the fulfilment of reliability, construct validity, item validity, and content validity of the instrument. Unreliable and invalid instruments due to cultural differences in the population. Therefore, a modification of the instrument is needed such that better information can be obtained to the relevant population. Because in this study using ordinal scale data, then the reliability will be measured by the coefficient ordinal alpha with polychoric correlation. In this study, modifications will be made to Mark H. Davis’ rate empathy instrument consisting of 45 indicators into an instrument consisting of only 15 indicators. Modified measuring tools proved reliable, have valid content, valid constructs, and valid items. The methods to be used are factor analysis, Spearman correlation, polychoric correlation, and ordinal alpha reliability.