bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of the simultaneous calibration of multiple ring dosimeters on the individual absorbed dose
Authors: Calatayud-Jordán J , Candela-Juan C , Palma J D , Pujades-Claumarchirant M C , Soriano Á , Gracia-Ochoa M , Vilar-Palop J , Vijande J 
Published: March 2021

Abstract
Ring dosimeters for personal dosimetry are calibrated in accredited laboratories following ISO 4037-3 guidelines. The simultaneous irradiation of multiple dosimeters would save time, but has to be carefully studied, since the scattering conditions could change and influence the absorbed dose in nearby dosimeters. Monte Carlo simulations using PENELOPE-2014 were performed to explore the need to increase the uncertainty of

H

p

0

.07

in the simultaneous irradiation of three and five DXT-RAD 707H-2 (Thermo Scientific) ring dosimeters with beam qualities: N-30, N-80 and N-300. Results show that the absorbed dose in each dosimeter is compatible with each of the others and with the reference simulation (a single dosimeter), with a coverage probability of 95% (k = 2). Comparison with experimental data yielded consistent results with the same coverage probability. Therefore, five ring dosimeters can be simultaneously irradiated with beam qualities ranging, at least, between N-30 and N-300 with a negligible impact on the uncertainty of

H

p

0

.07

.
Development of compact electronic noses: a review
Authors: Cheng Lu , Meng Qing-Hao , Lilienthal Achim J , Qi Pei-Feng 
Published: March 2021

Abstract
An electronic nose (e-nose) is a measuring instrument that mimics human olfaction and outputs ‘fingerprint’ information of mixed gases or odors. Generally speaking, an e-nose is mainly composed of two parts: a gas sensing system (gas sensor arrays, gas transmission paths) and an information processing system (microprocessor and related hardware, pattern recognition algorithms). It has been more than 30 years since the e-nose concept was introduced in the 1980s. Since then, e-noses have evolved from being large in size, expensive, and power-hungry instruments to portable, low cost devices with low power consumption. This paper reviews the development of compact e-nose design and calculation over the last few decades, and discusses possible future trends. Regarding the compact e-nose design, which is related to its size and weight, this paper mainly summarizes the development of sensor array design, hardware circuit design, gas path (i.e. the path through which the mixed gases to be measured flow inside the e-nose system) and sampling design, as well as portable design. For the compact e-nose calculation, which is directly related to its rapidity of detection, this review focuses on the development of on-chip calculation and wireless computing. The future trends of compact e-noses include the integration with the internet of things, wearable e-noses, and mobile e-nose systems.
Scalable nanophotonic neural probes for multicolor and on-demand light delivery in brain tissue
Authors: Lanzio V , Lorenzon M , Dhuey S , Pirri C F , Lamberti A , Cabrini S 
Published: March 2021

Abstract
Neural probes are in vivo brain-invasive devices that record and manipulate neural circuits using electricity, light, or drugs. The capability to shine distinct wavelengths and control their respective output locations for activation or deactivation of specific groups of neurons is desirable but remains unachieved. Here, we discuss our probe’s capability to deliver two independently controllable wavelengths (450 and 655 nm) in the location(s) of interest using nanophotonic directional couplers and ring resonators. These nanophotonics are scalable to dozens of outputs without significantly increasing the device’s lateral dimensions. Furthermore, they are entirely passive and thus do not require electrical input that results in heat generation. Besides, we integrate a high number of electrodes for a simultaneous neural activity readout. Thus, we overcome the challenges associated with multicolor illumination for neural devices by exploiting the capability of miniaturizable, passive probes to deliver two different frequencies in several areas of interest. These devices open the path towards investigating the in vivo electrical signal propagation under the individual or simultaneous activation or inhibition of distinct brain regions.
Composite Si–Ni nanoparticles produced by plasma spraying physical vapor deposition for negative electrode in Li-ion batteries
Authors: Ohta R , Gerile N , Kaga M , Kambara M 
Published: March 2021

Abstract
Si–Ni composite nanoparticles have been produced by a single and continuous plasma spray physical vapor deposition (PS-PVD) from Si and Ni powder feedstocks and their electrochemical performances as anode in lithium-ion batteries (LiB) are investigated. Si nanoparticles with 20–40 nm on which Ni is directly attached with Si/NiSi2 epitaxial interface are formed spontaneously through co-condensation of high temperature elemental gas mixtures during PS-PVD. When only a little amount of Ni is added to Si, the effect of the epitaxial Ni attachment on the Si nanoparticles becomes evident; the cycle capacity is appreciably improved to reach a 1.6 times higher capacity than that of the Si only cell after 50 cycles, due to reduced charge-transfer resistance and nanosized Si particle. In contrast, excessive Ni addition to Si feedstock leads to formation of various silicides as a result of the accelerated silicidation during PS-PVD, which results in a significant decrease in the cycle capacity due to reduction of the active Si phase amount despite reduced charge-transfer resistance.
Exploration of the form factors of turbulence kinetic energy transfer for shear exfoliation of graphene
Authors: Liu Kangwei , Chiang Sum-Wai , Liang Bin , Liang Caiwu , Sui Yiming , Dai Wanyu , Wang Min , Hu Shengyu , Kang Feiyu , Yang Cheng 
Published: March 2021

Abstract
Mass production of defect-free and large-lateral-size 2D materials via cost-effective methods is very important. Recently, shear exfoliation has shown great promise for large-scale production due to its simple operation, environmental-benignity and wide adaptability. However, a long-standing challenge is that with the production of more nanosheets, a ceiling yield and shattered products are encountered, which significantly limits their wider application. The method and efficiency of energy transfer in fluid is undoubtedly the key point in determining exfoliation efficiency, yet its in-depth mechanism has not yet been described. Thus, a thorough investigation of turbulence energy transfer is critically necessary. Herein, we identify two main factors that critically determine the exfoliation yield and provide a statistical analysis of the relationship between these factors and the exfoliation yield. In the initial shearing process, the coexistence of the 2D nanosheets and raw particles is the dominant factor; as time passes, the dimensional change of raw materials gradually has a greater influence on the energy transfer. These factors together lead to attenuated efficiency and a power function relationship between yield and exfoliation time. This investigation gives a statistical explanation of shear exfoliation technology for 2D material preparation and provides valuable insights for mechanical exfoliating high-quality 2D materials.
Influence of the gas pressure in a Torr regime capacitively coupled plasma deposition reactor
Authors: Kim Ho Jun 
Published: March 2021

Abstract
The adjustment of the gas pressure has been shown to improve the deposition rate and uniformity of a plasma process. This led us to investigate the effect of the gas pressure in a 300 mm wafer reactor. We numerically simulated SiH4/He capacitively coupled plasma discharges for the deposition of a hydrogenated amorphous silicon film. The results indicated that an increase in the gas pressure leads to uniform dissipation of the power coupled to the plasma and deposition profiles. By toggling the sidewall condition from grounded to dielectric while varying the gas pressure, we observed a modification of the plasma distributions and deposition profiles. Based thereupon, we concluded that the combination of high pressure with narrow electrode spacing can guarantee more efficient and uniform deposition. Additionally, this result was experimentally validated using the plasma deposition of hydrogenated amorphous carbon from the mixture C3H6/Ar/He. Even though the mixture differed from that we adopted in the simulation, the combination of high pressure with narrow electrode spacing still induced uniform deposition.
PISCES-RF: a liquid-cooled high-power steady-state helicon plasma device
Authors: Thakur Saikat Chakraborty , Simmonds Michael J , Caneses Juan F , Chang Fengjen , Hollmann Eric M , Doerner Russell P , Goulding Richard , Lumsdaine Arnold , Rapp Juergen , Tynan George R 
Published: March 2021

Abstract
Radio-frequency (RF) driven helicon plasma sources can produce relatively high-density plasmas (n > 1019 m−3) at relatively moderate powers (<2 kW) in argon. However, to produce similar high-density plasmas for fusion relevant gases such as hydrogen (H), deuterium (D) and helium (He), much higher RF powers are needed. For very high RF powers, thermal issues of the RF-transparent dielectric window, used in the RF source design, limit the plasma operation timescales. To mitigate this constraint, we have designed, built and tested a novel helicon plasma source assembly with a fully liquid-cooled RF-transparent window which allows steady state operations at high power (up to 20 kW) and successfully produces high-density plasma with both argon and H. Deionized (DI) water, flowing between two concentric dielectric RF windows, is used as the coolant. We show that a full azimuthal blanket of DI water does not prevent high-density plasma production. From calorimetry on the DI water, we measure the net heat removed by the coolant at steady state conditions. Using infra-red imaging, we calculate the constant plasma heat deposition and measure the final steady state temperature distribution patterns on the inner surface of the ceramic layer. The heat deposition pattern follows the helical shape of the antenna. We also show the consistency between the heat absorbed by the DI water, as measured by calorimetry, and the total heat due to the combined effect of the plasma heating and the absorbed RF. These results are being used to answer critical engineering questions for the 200 kW RF device materials plasma exposure experiment being designed at the Oak Ridge National Laboratory as a next generation plasma material interaction device.
The shape memory properties of multi-layer graphene reinforced poly(L-lactide-co-ϵ-caprolactone) by an atomistic investigation
Authors: Zhang Xue-Jiao , Yang Qing-Sheng , Shang Jun-Jun , Liu Xia , Leng Jin-song 
Published: March 2021

Abstract
In this paper, an atomistic investigation was performed to reveal the dependence of the graphene content on the shape memory effect of the multilayer graphene reinforced poly (L-lactide-co-ε-caprolactone). Uniaxial compression deformation was carried out to show the shape memory effect of the graphene composites. The temperature response of the composites was obtained during shape recovery. It is observed that the composites with higher graphene content exhibit larger recovery ratio and are more sensitive to temperature during a gradual warming recovery. The graphene composites show good reusable properties and the shape of composites is able to fully recover by constant temperature recovery tests. Especially, the graphene of the composite was subjected to a separate heating test to check the role of the graphene in shape recovery of the composite, where electro-induced indirect heating was qualitatively simulated. It is shown that the recovery first appeared in composites with the most content of graphene. The polymer will have a temperature hysteresis compared with graphene in composites. The shape recovery trajectory of graphene and the evolution of the interaction between graphene and polymers during the process of shape memory were clearly presented to reveal the mechanism how graphene promotes the performance of shape memory. This research can provide a guidance for obtaining composite materials with ideal shape memory effect.
Electronic transport properties and hydrostatic pressure effect of FeSe0.67Te0.33 single crystals free of phase separation
Authors: Xing Xiangzhuo , Sun Yue , Yi Xiaolei , Li Meng , Feng Jiajia , Meng Yan , Zhang Yufeng , Li Wenchong , Zhou Nan , He Xiude , Ge Jun-Yi , Zhou Wei , Tamegai Tsuyoshi , Shi Zhixiang 
Published: March 2021

Abstract
FeSe1−x
Te
x
superconductors manifest some intriguing electronic properties depending on the value of x. In FeSe single crystal, the nematic phase and Dirac band structure have been observed, while topological surface superconductivity (SC) with the Majorana bound state was found in the crystal of x∼ 0.55. Therefore, the electronic properties of single crystals with 0 < x ⩽ 0.5 are crucial for probing the evolution of those intriguing properties as well as their relations. However, this study is still left blank due to the lack of single crystals because of phase separation. Here, we report the synthesis, magnetization, electronic transport properties, and hydrostatic pressure effect of FeSe0.67Te0.33 single crystals free of phase separation. A structural (nematic) transition is visible at T
s = 39 K, below which the resistivity exhibits a Fermi-liquid behavior. Analysis of the upper critical fields suggests that spin-paramagnetic effect should be taken into account for both H || c axis and H || ab plane. A crossover from the low-H quadratic to the high-H quasi-linear behavior is observed in the magnetoresistance, signifying the possible existence of Dirac-cone state. Besides, the strong temperature dependence of Hall coefficient, violation of (modified) Kohler’s rule, and two-band model analysis indicate the multiband effects in FeSe0.67Te0.33 single crystals. Hydrostatic pressure measurements reveal that T
s is quickly suppressed with pressure while T
c is monotonically increased up to 2.31 GPa, indicating the competition between nematicity and SC. No signature of magnetic order that has been detected in FeSe1−x
S
x
is observed. Our findings fill up the blank of the knowledge on the basic properties of FeSe1−x
Te
x
system with low-Te concentrations.
Astrophysics with heavy-ion beams
Authors: Senger P 
Published: March 2021

Abstract
The ‘Facility for Antiproton and Ion Research’ (FAIR), an international accelerator centre, is under construction in Darmstadt, Germany. FAIR will provide high-intensity primary beams of protons and heavy-ions, and intense secondary beams of antiprotons and of rare short-lived isotopes. These beams, together with a variety of modern experimental setups, will allow to perform a unique research program on nuclear astrophysics, including the exploration of the nucleosynthesis in the universe, and the exploration of QCD matter at high baryon densities, in order to shed light on the properties of neutron stars, and the dynamics of neutron star mergers. The Compressed Baryonic Matter (CBM) experiment at FAIR will investigate collisions between heavy nuclei, and measure various diagnostic probes, which are sensitive to the high-density equation-of-state (EOS), and to the microscopic degrees-of-freedom of high-density matter. The CBM physics program will be discussed.
Modified MIT Bag Models—part II: QCD phase diagram and hot quark stars
Authors: Lopes Luiz L , Biesdorf Carline , Marquez K D , Menezes Débora P 
Published: March 2021

Abstract
In the present work we use the modified versions of the MIT bag model, on which both a vector field and a self-interacting term are introduced, to obtain hot quark matter and to investigate the QCD phase diagram. We first analyze two-flavored quark matter constrained to both the freeze-out and the liquid-gas phase transition at the hadronic phase. Later, three-flavored quark matter subject to β equilibrium and charge neutrality is used to compute quark star macroscopic properties, which are confronted with recent observational massive and canonical star radius results. Finally, a comparison with QCD phase diagrams obtained from the Nambu-Jona-Lasinio model is performed.
Ricci flow in general relativity: dynamics of gluon fields on an arbitrary curved background from unified spinor fields
Authors: Bellini Mauricio 
Published: March 2021

Abstract
We describe the gluon field dynamics from Unified Spinor Fields, taking into account the quantum self-interactions which come from a Ricci flow in a varied Einstein-Hilbert action. A new action to describe the Yang-Mills fields is introduced and it is obtained the nonlinear equation of motion on a curved background Riemann manifold, with self-interactions included, for the gluon field components.
Neutrino mass bounds from confronting an effective model with BOSS Lyman-α data
Authors: Garny Mathias , Konstandin Thomas , Sagunski Laura , Viel Matteo 
Published: March 2021

Abstract
We present an effective model for the one-dimensional
Lyman-α flux power spectrum far above the baryonic Jeans
scale. The main new ingredient is constituted by a set of two
parameters that encode the impact of small, highly non-linear scales
on the one-dimensional power spectrum on large scales, where it is
measured by BOSS. We show that, by marginalizing over the model
parameters that capture the impact of the intergalactic medium, the
flux power spectrum from both simulations and observations can be
described with high precision. The model displays a degeneracy
between the neutrino masses and the (unknown, in our formalism)
normalization of the flux power spectrum. This degeneracy can be
lifted by calibrating one of the model parameters with simulation
data, and using input from Planck CMB data. We demonstrate that this
approach can be used to extract bounds on the sum of neutrino masses
with comparably low numerical effort, while allowing for a
conservative treatment of uncertainties from the dynamics of the
intergalactic medium. An explorative analysis yields an upper bound
of 0.16eV at 95% C.L. when applied to BOSS data at
3 ≤ z ≤ 4.2. We also forecast that if the systematic and
statistical errors will be reduced by a factor two the upper bound
will become 0.1eV at 95% C.L, and 0.056eV when assuming a
1% error.
On the energy of the protons producing the very high-energy astrophysical neutrinos
Authors: Roulet Esteban , Vissani Francesco 
Published: March 2021

Abstract
We study the distribution of the energy of the protons that can produce an astrophysical neutrino with a given observed energy, in the TeV–PeV range, both through pp or pγ interactions. Due to the increasing multiplicity of the pion production at high center of mass energies, the resulting average proton energies can be much larger than the often used approximate value Ep
≃ 20Eν
. Also the threshold of the pγ process can lead to a pronounced increase in the values of 〈Ep
〉/Eν
for decreasing neutrino energies. The results depend sensitively on the assumed proton spectrum, since steeper spectra give less weight to the lower energy neutrino tail resulting from the decays of the abundant low-energy pions. In the pγ scenarios they also depend sensitively on the spectrum of the target photons. The results are in particular relevant to relate possible characteristics of the neutrino spectrum to those of the corresponding cosmic rays that generated them. We also discuss the associated production of gamma rays at the sources.
Measurement of miscut angles in the determination of Si lattice parameters
Authors: Sasso C P , Mana G , Massa E 
Published: March 2021

Abstract
The measurement of the angle between an interferometer’s front mirror and the diffracting planes is a critical aspect of the measurement of Si lattice parameters by combined x-ray and optical interferometry. In addition to being measured offline by x-ray diffraction, it was checked online by moving the analyser crystal transversely and observing the phase shift of the interference fringe. We describe the measurement procedure and give the miscut angle of the 28Si crystal, whose lattice parameter was an essential input datum for the determination of the Avogadro constant in the past and which is now used in the definition of the kilogram, based on counting atoms. These data will benefit others that might wish to repeat the measurement of the lattice parameters of this unique crystal.
A Novel Design of Blowfish Algorithm for Image Security
Authors: Hashim Ashwaq T. , Jassem Ammar H. , Ali Suhad A. 
Published: March 2021

Abstract
In order to improve the security and efficiency of image encryption systems comprehensively an image encryption based on enhanced design of Blowfish scheme is proposed. The proposed system is employed block based image encryption technique combined with chaotic map properties. Firstly the digital image is scrambled and decomposed into several key based blocks randomly to decorrelated the relationship between original and processed image then each block is passed through an enhanced blowfish algorithm. The enhancement in design is to gain advantage of the strong facility, which is maintained by blowfish algorithm by overcoming its flaws, which leads to a significant improvement in security/performance. As a result the proposed system offers good performance for image encryption. The proposed algorithm is 320-bit Blowfish-like block cipher, where cascaded looking composition of F-functions is used instead of rounds. The key is accepted a variable length up to 400 bytes. The pragmatic aim of the proposed system is to decrease memory requirements and execution time while keeping the cipher simple and highly adaptable to future demands. To ensure improved encryption algorithm, the implementation of both techniques has been carried out for experimental purposes which is showed that the original image has a flat histogram after encrypted, a decreasing correlation between adjacent pixels in all color components and increasing entropy for the cases studied. The proposed algorithm has a sufficiently large key space and a very high sensitivity to the key. A comparative study with previous Blowfish algorithm shows the superiority of the modified algorithm.
Circuit simulation of two-degree-of-freedom unilateral impact dynamics system with gap
Authors: Chang Fengliang , Wang Zheng , Tao Yiming 
Published: March 2021

Abstract
In a two-degree-of-freedom unilateral collision system with a gap, the two oscillators will produce nonlinear motion. A dynamic model of the two-degree-of-freedom collision system is established, and the two oscillators are analyzed separately by numerical simulation. On this basis, an electronic circuit composed of TL074CN operational amplifier, capacitance and resistance is designed, which is equivalent to the mathematical model. The electronic circuit is simulated by multisim12.0, and the result is consistent with that of numerical simulation. The equivalent electronic circuit model not only has dramatically shortened the calculation time, but also has the advantage of adjustable dynamic parameters, which makes up for the lack of numerical simulation and provides a reference tool for the simulation analysis of multi-degree-of-freedom nonlinear mechanical vibration systems.