bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predominant reaction products and dielectric breakdown properties of gas mixtures consisting of SF6 and ablation products of C2F4/BN in the temperature range of 300–3000 K
Authors: Yokomizu Y , Terada M , Kodama N , Ishii T , Kojima Y , Kuroda M , Urai H 
Published: January 2021

Abstract
For a high voltage SF6 circuit breaker equipped with a boron nitride (BN)-filled polytetrafluoroethylene ((C2F4)

n

) nozzle, the predominant reaction products in a high-temperature SF6 mixture with vapor decomposition of C2F4 and BN at temperatures of 300–3000 K are determined based on calculations of equilibrium composition. The calculation is performed by considering the molecular products obtained by chemical reactions with boron atoms (e.g. BN, BS, BC, BF, BF2 and BF3), nitrogen atoms (e.g. N2, N3, CN, NS, NF, NF2 and NF3) and carbon atoms (e.g. CS, CS2, C2F4, CF2, CF3 and CF4). The results obtained for the C2F4–BN molar fraction

X

C
F
B
N

of 20%–80% reveal that BF3, N2 and CF4, the molecules originating from the nozzle material, are produced at high molar fractions over a range of 300–3000 K. Such an evaluation of the gas composition allows the derivation of a reduced collision ionization coefficient α/N and a reduced electron attachment coefficient η/N of the gas, considering various electron impact processes such as BF3 + e

→

BF2 + F− and CF4 + e

→

CF3 + F−. The evaluation subsequently enables us to determine a critical reduced electric field strength

E

c
r

/

N

causing

(
α
−
η
)

/

N
=
0

. The results suggest that the decomposed C2F4–BN mixture at

X

C
F
B
N

of 80% causes the reduction of

E

c
r

/

N

to 110 Td in the range of 1000–2000 K at a gas pressure of 1.0 MPa. This strength

E

c
r

/

N

is 20 Td lower than that determined separately for the SF6 gas mixture with only 80% C2F4 vapor decomposition, because of the CF4 molar fraction reduction in the SF6/C2F4–BN mixture.
Controlling the macroscopic electrical properties of reduced graphene oxide by nanoscale writing of electronic channels
Authors: Kayal Arijit , G Harikrishnan , Bandopadhyay K , Kumar Amit , Silva S Ravi P , Mitra J 
Published: January 2021

Abstract
The allure of all-carbon electronics stems from the spread of its physical properties across all its allotropes. The scheme also harbours unique challenges, such as tunability of band gap, variability of doping and defect control. Here, we explore the technique of scanning probe tip-induced nanoscale reduction of graphene oxide (GO), which nucleates conducting,

sp

2

rich graphitic regions on the insulating GO background. The flexibility of direct writing is supplemented with control over the degree of reduction and tunability of band gap through macroscopic control parameters. The fabricated reduced GO channels and ensuing devices are investigated via spectroscopy and temperature and bias-dependent electrical transport and correlated with spatially resolved electronic properties, using surface potentiometry. The presence of carrier localization effects, induced by the phase-separated

sp

2

/

sp

3

domains, and large local electric field fluctuations are reflected in the non-linear transport across the channels. Together, the results indicate a complex transport phenomenon, which may be variously dominated by tunnelling or variable range hopping or activated depending on the electronic state of the material.
Selective area growth of AlGaN nanopyramids by conventional and pulsed MOVPE
Authors: Boughaleb Sofia , Martin Brigitte , Matei Constantin , Templier Roselyne , Borowik Łukasz , Rochat Nevine , Gil Bernard , Dussaigne Amélie 
Published: January 2021

Abstract
Planar UV-C light emitting diodes still suffer from low efficiency, mainly due to substrate crystalline quality, p doped conductivity and extraction efficiency. One possible way to overcome partly these issues is to realize the whole UV structure on AlGaN pyramids by selective area growth in order to benefit from the advantages of such structures, i.e. the dislocation filtering and the semi polar planes. We present here a detailed study about the epitaxy of AlGaN nano-sized pyramids by metal organic vapor phase epitaxy on patterned templates presenting different holes apertures and pitches as 1.5 μm and 4 μm or 100 nm and 250 nm respectively. While increasing the Al content, their height decreases while the thickness of the deposition on the mask increases whatever the design of the mask. Those changes of the pyramid shapes and deposition are directly linked to the properties of Al adatoms, i.e. low Al diffusion length. Using the conventional growth mode for the epitaxy of those pyramids did not permit the incorporation of Al from the base of the pyramids to their truncated apex. Its presence was concentrated on the edges and top of the pyramids. On the contrary, a pulsed growth mode, coupled with a strongly reduced pitch, allowed an incorporation of Al since the base of the nanopyramid, and a decrease of the deposition height on the mask. These results can be explained by the desorption of Ga species, due to the presence of H2 in the reactor chamber during the step without the metal precursors, leading to a higher Al/Ga ratio. It is even enhanced inside the holes by the reduced pitch.
Comprehensive model toward optimization of SAG In-rich InGaN nanorods by hydride vapor phase epitaxy
Authors: Hijazi Hadi , Zeghouane Mohammed , Jridi Jihen , Gil Evelyne , Castelluci Dominique , Dubrovskii Vladimir G , Bougerol Catherine , André Yamina , Trassoudaine Agnès 
Published: January 2021

Abstract
Controlled growth of In-rich InGaN nanowires/nanorods (NRs) has long been considered as a very challenging task. Here, we present the first attempt to fabricate InGaN NRs by selective area growth using hydride vapor phase epitaxy. It is shown that InGaN NRs with different indium contents up to 90% can be grown by varying the In/Ga flow ratio. Furthermore, nanowires are observed on the surface of the grown NRs with a density that is proportional to the Ga content. The impact of varying the NH3 partial pressure is investigated to suppress the growth of these nanowires. It is shown that the nanowire density is considerably reduced by increasing the NH3 content in the vapor phase. We attribute the emergence of the nanowires to the final step of growth occurring after stopping the NH3 flow and cooling down the substrate. This is supported by a theoretical model based on the calculation of the supersaturation of the ternary InGaN alloy in interaction with the vapor phase as a function of different parameters assessed at the end of growth. It is shown that the decomposition of the InGaN solid alloy indeed becomes favorable below a critical value of the NH3 partial pressure. The time needed to reach this value increases with increasing the input flow of NH3, and therefore the alloy decomposition leading to the formation of nanowires becomes less effective. These results should be useful for fundamental understanding of the growth of InGaN nanostructures and may help to control their morphology and chemical composition required for device applications.
Modelling dust transport in DIII-D with DTOKS-Upgrade
Authors: Simons L , Cowley C , Fuller P , Bykov I , Rudakov D , Andrew Y , Coppins M 
Published: January 2021

Abstract
Comprehensive upgrades to the dust transport code Dust in TOKamaks (DTOKS) that extend the plasma-dust interaction model are presented and compared with recent measurements of dust transport in DIII-D. Simulations incorporating variation in physical properties of graphite dust with temperature and size in a stationary plasma background suggest a substantial decrease in lifetimes due principally to thermal expansion. The trajectories of 53 dust grains identified from analysis of visible camera data taken across two similar shots were used to measure the dust particle velocity distributions. Dust tracks terminated mostly at the outer divertor strike point having a mean observation time of 2.1 ± 0.4 ms. Stochastic modelling of 200 graphite dust particles in the DIII-D tokamak performed with DTOKS-U using plasma simulations generated by OEDGE found similar behaviour, with particles ablating rapidly after acquiring a positive charge in the region close to the outer strike point, creating an acute source of neutral carbon atoms. The simulated mean lifetime, 11 ± 2 ms, showed approximate agreement with experimental observation when corrected by accounting for dust visibility and ignoring the longest trajectories 1.5 ± 0.2 ms. Synthetic diagnostic data generated from coupling the results of DTOKS-U with the visualisation software Calcam offers a powerful new tool for validation of simulations and predictive calculations of dust dynamics.
Investigation of a helium tubular cold atmospheric pressure plasma source and polymer surface treatment application
Authors: Turicek J , Ratts N , Kaltchev M , Masoud N 
Published: January 2021

Abstract
Cold atmospheric plasma (CAP) is a simple and inexpensive method to produce plasma in ambient air. In this study, CAP was generated by flowing helium gas through a glass tube with a copper electrode rounded externally around it to provide an electric field for gas excitation. The plasma extended for up to a few centimeters from the opening of the tube forming a plume. Optical emission spectroscopy (OES) was used to identify the composition of the plasma along the length of the plume. Four positions along the plume were investigated at flow rates of 1, 1.5, and 2.5 L min−1. Results revealed that the plume consisted of a varying composition of excited state species dependent on the location in the plume and gas flow rate. Identified in the emission spectra were the nitrogen second positive and first negative system along with OH* emissions at 282 and 308 nm. The OH* emissions, found at the opening of the tube, had a higher intensity as the flow rate increased and were attributed to impurities from the ambient air in the source tubing, while the N2 and N2
+ emissions came from the nitrogen of the ambient air and dominated the rest of the measured spectra. Identifying the species and their intensities at different locations of the plume with different flow rates helped in determining the appropriate location and flow rate needed for a specific application of the surface treatment of ultra-high-molecular-weight-polyethylene (UHMWPE) to change its roughness. Additional spectra were taken in situ with an UHMWPE sample present to compare the reactive species of a free jet with those when a target was present. Finally, preliminary roughness tests showed increases of as low as three and as much as over ten times the pristine value depending on the position of the polymer in the plume and the source flow rate.
Study on the characteristics of helium plasma jet by pulsed micro-hollow cathode discharge
Authors: Duan Zhengchao , Li Peizhen , He Feng , Han Ruoyu , Ouyang Jiting 
Published: January 2021

Abstract
In this paper, the helium plasma jet generated by micro-hollow cathode discharge (MHCD) was studied. The MHCD was driven by a square-wave pulsed power source, and the characteristics of discharge and plasma jet were measured experimentally. The influences of the gas flow rate on the MHCD and the plasma jet were investigated. And the propagation mechanisms of the plasma jet were analyzed. The results show that within 100–1000 sccm of the gas flow rate, the breakdown delay time of the MHCD increases with the helium flow increasing. It is considered that the gas flow affects the density of seed electrons and thus the breakdown delay time. With the helium flow rate increasing, the whole plasma jet length increases firstly and then decreases. A detailed investigation shows that during one discharge pulse, two distinguishable propagation processes of the plasma jet are observed. It is found that the jet of the first stage is formed during the rising edge of the current pulse, while the other is generated after the discharge current becomes stable. The propagation velocity of jet in the first stage is on the order of several km s−1, which is similar to that of the discharge evolution obtained by simulation. And the propagation speed of the jet in the second stage is on the order of several hundred m s−1, which is close to the velocity of gas flow. The spatial–temporal distributions of light emission show that high-energy electrons can only be observed during the jet propagation in the first stage, and low-energy electrons can be detected in both the first and second stages. The results show that the electric field plays an important role on the jet propagation in the first stage, and the jet propagation during the second stage is mainly promoted by the thermal gas expansion.
Spatial resolution in photoacoustic computed tomography
Authors: Tian Chao , Zhang Chenxi , Zhang Haoran , Xie Dan , Jin Yi 
Published: January 2021

Abstract
Photoacoustic computed tomography (PACT) is a novel biomedical imaging modality and has experienced fast developments in the past two decades. Spatial resolution is an important criterion to measure the imaging performance of a PACT system. Here we survey state-of-the-art literature on the spatial resolution of PACT and analyze resolution degradation models from signal generation, propagation, reception, to image reconstruction. Particularly, the impacts of laser pulse duration, acoustic attenuation, acoustic heterogeneity, detector bandwidth, detector aperture, detector view angle, signal sampling, and image reconstruction algorithms are reviewed and discussed. Analytical expressions of point spread functions related to these impacting factors are summarized based on rigorous mathematical formulas. State-of-the-art approaches devoted to enhancing spatial resolution are also reviewed. This work is expected to elucidate the concept of spatial resolution in PACT and inspire novel image quality enhancement techniques.
Reservoir computing with solitons
Authors: Silva Nuno Azevedo , Ferreira Tiago D , Guerreiro Ariel 
Published: January 2021

Abstract
Reservoir computing is a promising framework that facilitates the approach to physical neuromorphic hardware by enabling a given nonlinear physical system to act as a computing platform. In this work, we exploit this paradigm to propose a versatile and robust soliton-based computing system using a discrete soliton chain as a reservoir. By taking advantage of its tunable governing dynamics, we show that sufficiently strong nonlinear dynamics allows our soliton-based solution to perform accurate regression and classification tasks of non-linear separable datasets. At a conceptual level, the results presented pave a way for the physical realization of novel hardware solutions and have the potential to inspire future research on soliton-based computing using various physical platforms, leveraging its ubiquity across multiple fields of science, from nonlinear optical media to quantum systems.
Anomalous nonlinear optical effect and enhanced emission by magnetic excitons in CVD grown cobalt-doped ZnSe nanoribbon
Authors: Zou Bingsuo , Hou Lipeng , Tian Ye , Han Junbo , Peng Hui , Yang Xiongtao , Shi Lijie 
Published: January 2021

Abstract
The magnetic excitons in diluted magnetic semiconductor (DMS) have varied formats due to the inhomogeneous phases out of doping concentration and/or structural relaxations or defects. Here the high quality cobalt-doped zinc blende ZnSe nanoribbons (NRs) were synthesized, showing bright and color-variable emissions from blue, yellow to a little mixed white colors. Their power and temperature dependent micro-photoluminescence (PL) spectra have been obtained in which two emission bands, one magnetic exciton band near the band-edge and a Co2+ high-level d–d transition emission band at 550 nm out of their ferromagnetic (FM) coupled aggregates in ZnSe lattice, both bands could also be reflected by a nonlinear optical absorption enhancement. The easy formed stacking fault defects in a chemical vapor deposition (CVD) grown ZnSe zincblende NR took part in the above optical processes out of magnetic polaronic excitons (PXs). The femtosecond (fs) laser pulse pumping on single ZnSe:Co NR produces obvious lasing behavior but with profile of a complicated magnetic exciton interactions with indication of a crossover from collective exciton magnetic polarons (EMP) to bound magnetic polaron (BMP) scattering in Co doped ZnSe NR. These findings indicate the complication of the magnetic coupling natures in varied DMS structures, whose optical properties have been found to be highly nonlinear, due to the involvement of the spin–spin, spin–exciton and spin–phonon interactions, verified by the theoretic calculation in Yang X-T et al (2019 Interstitial Zn-modulated ferromagnetism in Co-doped ZnSe Mater. Res. Express
6 106121).
First mirror erosion–deposition studies in JET using an ITER-like mirror test assembly
Authors: Rubel M. , Moon Sunwoo , Petersson P. , Widdowson A. , Pitts R.A. , Aleiferis S. , Fortuna-Zaleśna E. , De Temmerman G. , Reichle R. 
Published: January 2021

Abstract
Mirror tests for ITER have been carried out in JET for over 15 years. During the third JET campaign with the ITER-like wall (2015–2016), comprising a total tokamak plasma exposure duration of 23.4 h and 1027 h of glow discharge cleaning, a new experiment was performed with a specially designed ITER-like test assembly housing six polycrystalline molybdenum mirror samples and featuring trapezoidal entrance apertures simulating the geometry of cut-outs in the diagnostic first wall of the ITER shielding blanket. The assembly was installed on the vacuum vessel wall at the outer midplane, set back radially behind the JET poloidal outer limiters such that the contact with thermal plasma should be largely avoided. The total and diffuse reflectivity of all mirrors was measured in the range 300–2500 nm before and after exposure. Post-exposure studies of mirror surface composition and of surfaces outside and inside the assembly were performed using microscopy, x-ray spectroscopy and ion beam analysis methods. The main results are: (i) no measured degradation of total reflectivity; (ii) diffuse reflectivity increased especially at short wavelengths (below 500 nm) from 1.1 to 2.7% and from 0.8%–1.3% above 1000 nm; (iii) mirrors were coated with a thin co-deposited layer (∼20–30 nm) containing carbon, oxygen and traces of nitrogen, beryllium and metals (Ni, Cr, Fe); (iv) no deuterium was detected; (v) surface composition of the mirror box inner walls was similar to that of the mirrors; (vi) ≲100 nm thick beryllium was the main component on external surfaces of the assembly. These results provide new input to ITER both for the modelling of FM erosion/deposition and for the consideration of requirements for mirror cleaning methods.
Web-based geographic information system for flood disaster using spatial autoregressive method
Authors: Nurrijal M A , Helen A , Abdullah A S 
Published: January 2021

Abstract
The territory of Indonesia is classified as one of the countries prone to disasters, both natural disasters and disasters caused by human activities. Flood disaster is one example of a disaster that often occurs, especially in the DKI Jakarta area. The common cause of the flooding is usually caused by high rainfall exceeding the average in general so that water sources such as rivers, reservoirs, and lakes cannot accommodate the amount of rainwater. This is also supported because the water absorption system is minimal so that it is unable to absorb excess water, causing flooding. The method used to define the relationship between various factors and the relationship between regions is to use the Spatial Autoregressive (SAR) method. In order to get a better relationship between regions, the existing spatial data will be visualized with the Geographical Information System. This research focuses on creating a web-based Geographic Information System application. Applications created using the programming language PHP and Javascript with the Codeigniter framework. The results obtained by the SAR equation to predict the height of flooding in the DKI Jakarta Province and the test results using the Mean Absolute Deviation (MAD) were 1.354656% while using the Mean Absolute Percentage Error (MAPE) was 2.157288%. Testing applications using the black box testing method was obtained by 93.35%. This shows that the SAR Model is suitable for predicting flood heights in the DKI Jakarta Province. This flood prediction can be used one year from the prediction model made.
Naïve bayes and maximum entropy comparison for translated novel’s genre classification
Authors: Aditya M A , Helen A , Suryana I 
Published: January 2021

Abstract
In the last two decades, novel translation had become one of the popular products among the literature community. People had favorited some genre based on their ages. The reader needs to finish reading until the end first before they could determine what genre a novel should have. There were some cases where the genre written in the description differs from the real novel’s content, which made readers felt upset and had not pleasant reading experience. This research is going to do classification for the novel’s genre automatically. Naïve Bayes is the method chosen for classification, later the result of Naïve Bayes classification is going to be compared with another algorithm, which is Maximum Entropy algorithm. Each method would apply algorithms to label the data based on an existing class. The data origin was taken from 12 translated novel that has 3746 lines. Data was portioned into three genre classes, “Action-Fantasy” for about 1293 lines, “Modern-Slice-of-Life” for 1203 lines, and 1250 for “Other”. Evaluation of the two models, Naïve Bayes and MaxEnt, would be using confusion matrix that generated the highest number precision, recall, and F-score which values were 77,52%; 75,59%; and 77,55% for the Naïve Bayes method, and 78,11%; 83,82%; and 75,81% for MaxEnt method. The value of accuracy were 72,72% for Naïve Bayes, and 71,86% for MaxEnt. Both methods showed that the genre “Action-Fantasy” was the correct genre for almost every novel among 12 novels listed.
Application of text mining employing k-means algorithms for clustering tweets of Tokopedia
Authors: Rejito J. , Atthariq A , Abdullah A S 
Published: January 2021

Abstract
In this current digital era, people tend to shop online. Because of that, there are currently many e-commerce companies that can satisfy the various needs of society in shopping. Each company certainly has a strategy to attract consumers to shop at their shopping place. One of the media commonly used to attract consumers is social media. Tokopedia is one of the biggest marketplaces in Indonesia and is also active in utilizing Twitter as their social media mean. Therefore, it is essential for Tokopedia to pay attention to tweet contents interesting enough to be publicized. By applying text mining using K-Means Clustering algorithm, it can be seen which types of tweet contents that are attractive for Tokopedia consumers. Out of 885 Tokopedia tweets that have been collected, a clustering is then done using K-means algorithm, resulting 48 cluster tweets. Then, from the 48 clusters, they are further grouped into 5 major groups. Based on the results of the grouping, it can be seen that the most interesting content deals with quiz prizes and the least attractive content is on lifestyle.