bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanoscale mapping of surface strain in tapered nanorods using confocal photoluminescence spectroscopy
Authors: Hwang Hyeong-Yong , Baek Hyeonjun , Yi Gyu-Chul , Jho Young-Dahl 
Published: August 2022

Abstract
The strain occurs spontaneously at the heterogeneous interfaces of virtually all crystalline materials. Consequently, the analysis across multiple interfaces requires a complementary characterization scheme with a resolution that fits the deformation scale. By implementing two-photon confocal laser scanning nanoscopy with an axial resolution of 10 nm, we extract the surface strain from the photoluminescence (PL) spectra, epitomized by a 2-fold enhancement at the tapered tips in comparison to the substrate of ZnO nanorods. We firstly traced the well-established contribution from quantum confinement (QC) to PL shift in three geometrically classified regions: (I) a strongly tapered region where the diameter increases from 3 to 20 nm; (II) a weakly tapered region with a gradually increasing diameter from 20 to 58 nm; (III) round cylindrical region interfacing the sapphire substrate. The measured PL shift influenced by the deformation is significantly stronger than the attained QC effect. Particularly, surface strain at the strongly tapered region turned out to drastically increase the PL shift which matches well with the analysis based on the surface to volume ratio incorporating mechanical parameters such as the compliance tensor component, strain dislocation constant, and surface stress. The surface strain increased at a lower temperature, further disclosing its inherent dependence on the thermal expansion coefficients in clear contrast to the temperature-invariant characteristics of QC.
Optical determination of layered-materials InSe thickness via RGB contrast method and regression analysis
Authors: Lu Yi-Ying , Yu Hsiao-Ching , Wang You-Xin , Hung Chih-Keng , Chen You-Ren , Jhou Jie , Yen Peter Tsung-Wen , Hsu Jui-Hung , Sankar Raman 
Published: August 2022

Abstract
Indium selenide (InSe) features intriguing thickness-dependent optoelectronic properties, and a simple, and precise way to identify the thickness is essential for the rapid development of InSe research. Here, a red, green, and blue (RGB) color contrast method with regression analysis for quantitative correlation of three optical contrasts from RGB channels with the InSe thickness (1–35 nm), is demonstrated. The lower accuracy of the thickness identification obtained from the individual channels was discussed. Moreover, the effective refractive indices in the three RGB regions can be extracted from the Fresnel equation and numerical analysis by finding the best fit to the experimental optical contrast. After further consideration of the wavelength-dependent refractive indices, the slope of the regression line between the estimated thickness and that obtained from the atomic force microscope was improved from 1.59 ± 0.05 to 0.97 ± 0.02. The complex refractive index spectra of InSe (1–10 layers) generated from ab initio numerical calculation results were also adopted to identify the InSe thickness. Compared to dispersion, the evolution of the band structure had less effect on thickness identification. This work could be extended to other layered materials, facilitate the thickness-dependent study of layered materials, and expedite the realization of their practical applications.
Self-catalyzed InAs nanowires grown on Si: the key role of kinetics on their morphology
Authors: Dhungana Daya S , Mallet Nicolas , Fazzini Pier-Francesco , Larrieu Guilhem , Cristiano Fuccio , Plissard Sébastien R 
Published: August 2022

Abstract
Integrating self-catalyzed InAs nanowires on Si(111) is an important step toward building vertical gate-all-around transistors. The complementary metal oxide semiconductor (CMOS) compatibility and the nanowire aspect ratio are two crucial parameters to consider. In this work, we optimize the InAs nanowire morphology by changing the growth mode from Vapor–Solid to Vapor–Liquid–Solid in a CMOS compatible process. We study the key role of the Hydrogen surface preparation on nanowire growths and bound it to a change of the chemical potential and adatoms diffusion length on the substrate. We transfer the optimized process to patterned wafers and adapt both the surface preparation and the growth conditions. Once group III and V fluxes are balances, aspect ratio can be improved by increasing the system kinetics. Overall, we propose a method for large scale integration of CMOS compatible InAs nanowire on silicon and highlight the major role of kinetics on the growth mechanism.
Hot electron and x-ray generation by sub-ns kJ-class laser-produced tantalum plasma
Authors: Singh Sushil , Krupka Michal , Istokskaia Valeria , Krasa Josef , Giuffrida Lorenzo , Dudzak Roman , Dostal Jan , Burian Tomas , Versaci Roberto , Margarone Daniele , Pisarczyk Tadeusz , Krus Miroslav , Juha Libor 
Published: August 2022

Abstract
This paper presents experimental investigation of temperature scaling and threshold of instability in hot electron and bremsstrahlung radiation from the interaction of sub-nanosecond and kilo-joule class laser pulses with a tantalum foil target at Prague Asterix Laser System. The laser intensity was varied between

4
×

10

15

and

3
×

10

16

W · cm−2 at the target focus. The energy distribution functions of electrons were measured by an angular array of magnetic spectrometers indicating the electron temperature in the range between 30 keV and 70 keV. The bremsstrahlung spectrum was characterized using a scintillator-based calorimeter. In particular, we show the laser-energy scaling of the total flux of hot electrons in the forward and backward directions with respect to the laser vector, the conversion efficiency of the laser energy to the energy carried by hot electrons, and the temperature of hot electrons as well as the unfolded bremsstrahlung temperature using a Monte Carlo code consistent with signals of the scintillator detector. The scaling shows that the electron flux increases discontinuously with increasing laser intensity from

∼

1
−
2
×

10

16

W · cm−2 with consequent instability in the production of hot electrons and bremsstrahlung radiation.
The effect of obstacles near a silo outlet on the discharge of soft spheres
Authors: Wang Jing , Harth Kirsten , Puzyrev Dmitry , Stannarius Ralf 
Published: August 2022

Abstract
Soft smooth particles in silo discharge show peculiar characteristics, including, for example, non-permanent clogging and intermittent flow. This paper describes a study of soft, low-frictional hydrogel spheres in a quasi-2D silo. We enforce a more competitive behavior of these spheres during their discharge by placing an obstacle in front of the outlet of the silo. High-speed optical imaging is used to capture the process of discharge. All particles in the field of view are identified and tracked by means of machine learning software using a mask region-based convolutional neural network algorithm. With particle tracking velocimetry, the fields of velocity, egress time, packing fraction, and kinetic stress are analyzed in this study. In pedestrian dynamics, it is known that the placement of an obstacle in front of a narrow gate may reduce the stress near the exit and enable a more efficient egress. The effect is opposite for our soft grains. Placing an obstacle above the orifice always led to a reduction of the flow rates, in some cases even to increased clogging probabilities.
Fate of the false vacuum in string-inspired nonlocal field theory
Authors: Ghoshal Anish , Nortier Florian 
Published: August 2022

AbstractIn this article, we study Coleman bounce in weakly nonlocal theories which are motivated from string field theory. The kinetic term is extended via an infinite series of high-order derivatives, which comes into play at an energy scale M, without introducing any new states or ghosts in the mass spectrum. We calculate the bubble nucleation in thin-wall approximation, treating the system in semi-classical manner. We find that the effect of nonlocal scale M in the theory is to suppress the vacuum tunneling rate from false to true vacuum compared to the standard local bouncing scenario. Likewise, we show that as we move further away from the bubble wall, the effects of nonlocality gets reduced and this suppression is significant only around the wall of the nucleated bubble. From our investigations, we conclude that the main effect is due to the fact that the nonlocality smears the solution of the local bubble profile. However, the energy of the bubble wall remains unaffected by the microscopic nonlocal behavior of the theory in the thin-wall approximation. We also discuss the cases for Lee-Wick theories and applications of our result to cosmology.
Non-Gaussianity in the squeezed three-point correlation from the relativistic effects
Authors: Yoo Jaiyul , Grimm Nastassia , Mitsou Ermis 
Published: August 2022

AbstractAssuming a ΛCDM universe in a single-field inflationary scenario, we compute the three-point correlation function of the observed matter density fluctuation in the squeezed triangular configuration, accounting for all the relativistic effects at the second order in perturbations. This squeezed three-point correlation function characterizes the local-type primordial non-Gaussianity, and it has been extensively debated in literature whether there exists a prominent feature in galaxy clustering on large scales in a single-field inflationary scenario either from the primordial origin or the intrinsic nonlinearity in general relativity. First, we show that theoretical descriptions of galaxy bias are incomplete in general relativity due to ambiguities in spatial gauge choice, while those of cosmological observables are independent of spatial gauge choice. Hence a proper relativistic description of galaxy bias is needed to reach a definitive conclusion in galaxy clustering. Second, we demonstrate that the gauge-invariant calculations of the cosmological observables remain unaffected by extra coordinate transformations like CFC or large diffeomorphism like dilatation. Finally, we show that the relativistic effects associated with light propagation in observations cancel each other, and hence there existsnonon-Gaussian contribution from the so-called projection effects in the squeezed three-point correlation function.
Examining the in vivo functionality of the magnetically aligned regenerative tissue-engineered electronic nerve interface (MARTEENI)
Authors: Atkinson Eric W , Kuliasha Cary A , Kasper Mary , Furniturewalla Abbas , Lim Alexander S , Jiracek-Sapieha Ladan , Brake Alexis , Gormaley Anne , Rivera-Llabres Victor , Singh Ishita , Spearman Benjamin , Rinaldi-Ramos Carlos M , Schmidt Christine E , Judy Jack W , Otto Kevin J 
Published: August 2022

Abstract

Objective. Although neural-enabled prostheses have been used to restore some lost functionality in clinical trials, they have faced difficulty in achieving high degree of freedom, natural use compared to healthy limbs. This study investigated the in vivo functionality of a flexible and scalable regenerative peripheral-nerve interface suspended within a microchannel-embedded, tissue-engineered hydrogel (the magnetically aligned regenerative tissue-engineered electronic nerve interface (MARTEENI)) as a potential approach to improving current issues in peripheral nerve interfaces. Approach. Assembled MARTEENI devices were implanted in the gaps of severed sciatic nerves in Lewis rats. Both acute and chronic electrophysiology were recorded, and channel-isolated activity was examined. In terminal experiments, evoked activity during paw compression and stimulus response curves generated from proximal nerve stimulation were examined. Electrochemical impedance spectroscopy was performed to assess the complex impedance of recording sites during chronic data collection. Features of the foreign-body response (FBR) in non-functional implants were examined using immunohistological methods. Main results. Channel-isolated activity was observed in acute, chronic, and terminal experiments and showed a typically biphasic morphology with peak-to-peak amplitudes varying between 50 and 500 µV. For chronic experiments, electrophysiology was observed for 77 days post-implant. Within the templated hydrogel, regenerating axons formed minifascicles that varied in both size and axon count and were also found to surround device threads. No axons were found to penetrate the FBR. Together these results suggest the MARTEENI is a promising approach for interfacing with peripheral nerves. Significance. Findings demonstrate a high likelihood that observed electrophysiological activity recorded from implanted MARTEENIs originated from neural tissue. The variation in minifascicle size seen histologically suggests that amplitude distributions observed in functional MARTEENIs may be due to a combination of individual axon and mini-compound action potentials. This study provided an assessment of a functional MARTEENI in an in vivo animal model for the first time.
Graphene bandgap opening by constructing superlattices with BN or MoO2 under pressure
Authors: Wang Bohan , Song Chaoyang 
Published: August 2022

Abstract
After the isolation of the single layer graphene in 2004, which has overthrown the prediction of the two-dimensional material field, various aspects of its unique properties have been observed, including extremely high strength, carrier mobility and heat conductivity. Being the minority of nonmetallic materials with a conductive property as metals, its possible applications is much widened. Noteworthily, graphene has a zero bandgap. Although making it an excellent conductor, zero bandgap has also constrained its performance as a semiconductor. Fortunately, there are several possible ways to open its bandgap and make it behave like a semiconductor. In this study, we propose that constructing superlattices and controlling hydrostatic pressure to open the bandgap of graphene. Based on first-principles calculations, BN and MoO2 are used to form the superlattice with graphene and 1-30 GPa pressures in the vertical direction of two-dimensional plane are applied. The results show that the pressure can affect the structures and interlayer distances of the superlattice, which further lead to a bandgap of the superlattices containing graphene. Our research shows a method that adjusting the bandgap of graphene through pressure, which is of great significance for the application of graphene in the electronic field.
Surface roughness by selective-dissolving on PVA/PVP nanofibers with mobility driven concentration polarization
Authors: Zhang Zheng , Wang Feipeng 
Published: August 2022

Abstract
Surface roughened polyvinyl alcohol (PVA) nanofibers are produced by electrospinning and selective dissolution in ethanol. By electrospinning of PVA (Mw 74885) and polyvinylpyrrolidone(PVP) (Mw 44000-54000) blend solution, PVA/PVP blend nanofibers with smooth, homogenous surface are prepared. Then the surface roughened nanofibers are achieved via selective dissolution in ethanol. Fourier Transform Infrared Spectra (FTIR) and Energy Dispersive Spectrometer (EDS) result shows a complete removal of PVP from blend nanofibers. In this work, PVA/PVP is the first water-soluble polymer combination adopted to create surface roughened nanofibers by selective dissolution. Moreover, opposite to other selective dissolution schemes which removes polymers of higher Mw, this is the first time creating surface roughened nanofibers by selectively removing polymer of lower Mw successively. Through selective dissolution, rough structures appear on the ultra-fine PVA-PVP nanofibers surface. The successive preparation of surface roughened PVA nanofiber can be attributed to the mobility of PVP molecule. The method claimed in this paper is helpful for developing more types of surface roughened nanofibers in the future.
Preparation and investigation indium tin oxide for transparent electrode of MS Schottky photodiode
Authors: Sangwaranatee N , Srithanachai I 
Published: August 2022

Abstract
In this paper investigation photocurrent of MS Schottky photodiode by using transparent electrode. The transparent material use in this investigation is indium tin oxide (ITO). Transparent electrode can help to get more photocurrent under contact due to light can penetrate though into depletion region then generate photocurrent. ITO will prepare by RF sputtering technique and investigate material characteristics such as electrical and optical properties. Optimize ITO properties after various thickness by growth sputter time show high transparent around 91.2% with low resistance 3.4x10-3 ohm-cm. Build in voltage of device show 0.3V by same with metal contact and current under light exposure show around 1.5mA at 25,000 lux with bias -5V.
Performance of phosphor embedded plastic scintillators through thin film coating
Authors: Rajakrishna K. , Dhanasekaran A. , Yuvaraj N. , Ajoy K.C. , Venkatraman B. , Jose M.T. 
Published: August 2022

Abstract
A novel method of loading phosphor materials in a plastic scintillator (here on PS) is developed to improve light output. In the present work, phosphor materials ZnS(Ag) and ZnO are loaded into the PS medium through the thin-film coating, and the effect of these phosphors on radiation detection is investigated. PS are prepared using polystyrene as the base, xylene as the solvent, PPO and POPOP as primary and secondary flours. ZnS(Ag) and ZnO phosphors are added to the PS in powder form to investigate their effect on luminescence and scintillation output. The thickness of the prepared scintillators is ∼250 ± 30 µm. Photoluminescence, radioluminescence, luminescence lifetime and their detection efficiencies for the typical alpha, beta, gamma and neutron sources are selected as the tools for investigation, and the synthesized scintillators’ performance is studied. The results obtained showed a notable increase in the performance and the outcomes are compared with commercially available PS.
Instrumentation challenges of the strong-field QED experiment LUXE at the European XFEL*
Authors: Fleck K. 
Published: August 2022

Abstract
The LUXE experiment aims at studying strong-field QED in electron-laser and photon-laser interactions, with the 16.5 GeV electron beam of the European XFEL and a laser beam with power of up to 350 TW. The strong-field QED processes are expected to have production rates ranging from 10−3 to 109 per 10 Hz bunch crossing. Additionally, these measurements must be performed in a low-energy, high-radiation background. The LUXE experiment will utilise various detector technologies to overcome these challenges.
Comparative characterization study of LYSO:Ce crystals for timing applications
Authors: Addesa F.M. , Barria P. , Bianco R. , Campana M. , Cavallari F. , Cemmi A. , Cipriani M. , Dafinei I. , D'Orsi B. , del Re D. , Diemoz M. , D'Imperio G. , Di Marco E. , Di Sarcina I. , Enculescu M. , Longo E. , Lucchini M.T. , Marchegiani F. , Meridiani P. , Nisi S. , Organtini G. , Pandolfi F. , Paramatti R. , Pettinacci V. , Quaranta C. , Rahatlou S. , Rovelli C. , Santanastasio F. , Soffi L. , Tramontano R. , Tully C.G. 
Published: August 2022

Abstract
Cerium-doped Lutetium-Yttrium Oxyorthosilicate (LYSO:Ce) is
one of the most widely used Cerium-doped Lutetium based
scintillation crystals. Initially developed for medical detectors it
rapidly became attractive for High Energy Particle Physics (HEP)
applications, especially in the frame of high luminosity particle
colliders.

In this paper, a comprehensive and systematic study of LYSO:Ce
([Lu(1-x)Y
x
]2SiO5:Ce) crystals
is presented. It involves for the first time a large number of
crystal samples (180) of the same size from a dozen of producers.
The study consists of a comparative characterization of LYSO:Ce
crystal products available on the market by mechanical, optical and
scintillation measurements and aims specifically, to investigate key
parameters of timing applications for HEP.
Effect of powders on microstructure and performance of inconel 718 alloy prepared by SPS
Authors: Qinggong Jia , Qingxiang Wang , Shuhua Liang 
Published: August 2022

Abstract
In this paper, 15–53 μm spherical powders obtained by plasma rotating electrode (PREP) and argon atomization (VIGA) were used to prepare the Inconel 718 alloy through spark plasma sintering(SPS), and then the sintered alloy was treated by solid solution and aging heat treatment. The effect of different powders on the microstructure and properties of Inconel 718 alloy as sintered and heat treated was studied. The results show that high density Inconel 718 alloy can be obtained by SPS technology, and the original particle boundary of powder can be reduced, and the original particle boundary of PREP is less. According to the densification process of spherical powder during SPS process, the change law of powder microstructure in rapid sintering is established.
Associations Between Childhood Obesity and Pubertal Timing Stratified by Sex and Race/Ethnicity
Authors: Aghaee Sara , Deardorff Julianna , Quesenberry Charles P , Greenspan Louise C , Kushi Lawrence H , Kubo Ai 
Published: August 2022

AbstractEarlier puberty has been associated with numerous adverse mental, emotional, and physical health outcomes. Obesity is a known risk factor for earlier puberty in girls, but research with boys has yielded inconsistent findings. We examined sex- and race/ethnicity-specific associations between childhood obesity and puberty in a multiethnic cohort of 129,824 adolescents born at a Kaiser Permanente Northern California medical facility between 2003 and 2011. We used Weibull regression models to explore associations between childhood obesity and breast development onset (thelarche) in girls, testicular enlargement onset (gonadarche) in boys, and pubic hair development onset (pubarche) in both sexes, adjusting for important confounders. Clear dose-response relationships were observed. Boys with severe obesity had the greatest risk for earlier gonadarche (hazard ratio = 1.23, 95% confidence limit: 1.15, 1.32) and pubarche (hazard ratio = 1.44, 95% confidence limit: 1.34, 1.55), while underweight boys had delayed puberty compared with peers with normal body mass index. A similar dose-response relationship was observed in girls. There were significant interactions between childhood body mass index and race/ethnicity. Childhood obesity is associated with earlier puberty in both boys and girls, and the magnitude of the associations may vary by race/ethnicity. Prevention of childhood obesity may delay pubertal timing and mitigate health risks associated with both conditions.