bluuebunny/crossref_metadata_2025_split huggingface dataset:
Energy spread estimation of radioactive oxygen ion beams using optical imaging
Authors: Kang Han Gyu , Yamamoto Seiichi , Takyu Sodai , Nishikido Fumihiko , Mohammadi Akram , Akamatsua Go , Sato Shinji , Yamaya Taiga 
Published: October 2020

Abstract
Radioactive ion (RI) beams combined with in-beam positron emission tomography enable accurate in situ beam range verification in heavy ion therapy. However, the energy spread of the radioactive beams generated as secondary beams is wider than that of conventional stable heavy ion beams which causes Bragg peak region and distal falloff region broadening. Therefore, the energy spread of the RI beams should be measured carefully for their quality control. Here, we proposed an optical imaging technique for the energy spread estimation of radioactive oxygen ion beams. A polymethyl methacrylate phantom (10.0 × 10.0 × 9.9 cm3) was irradiated with an 15O beam (mean energy = 247.7 MeV u−1, standard deviation = 6.8 MeV u−1) in the Heavy Ion Medical Accelerator in Chiba. Three different momentum acceptances of 1%, 2% and 4% were used to get energy spreads of 1.9 MeV u−1, 3.4 MeV u−1 and 5.5 MeV u−1, respectively. The in-beam luminescence light and offline beam Cerenkov light images were acquired with an optical system consisting of a lens and a cooled charge-coupled device camera. To estimate the energy spread of the 15O ion beams, we proposed three optical parameters: (1) distal-50% falloff length of the prompt luminescence signals; (2) full-width at half maximum of the Cerenkov light signals in the beam direction; and (3) positional difference between the peaks of the Cerenkov light and the luminescence signals. These parameters estimated the energy spread with the respective mean squared errors of 2.52 × 10−3 MeV u−1, 5.91 × 10−3 MeV u−1, and 0.182 MeV u−1. The distal-50% falloff length of the luminescence signals provided the lowest mean squared error among the optical parameters. From the findings, we concluded optical imaging using luminescence and Cerenkov light signals offers an accurate energy spread estimation of 15O ion beams. In the future, the proposed optical parameters will be used for energy spread estimation of other RI beams as well as stable ion beams.
Cone beam CT multisource configurations: evaluating image quality, scatter, and dose using phantom imaging and Monte Carlo simulations
Authors: Becker Amy E , Hernandez Andrew M , Schwoebel Paul R , Boone John M 
Published: October 2020

Abstract
The purpose of this study was to compare various multisource configurations applied to cone beam CT (CBCT) using phantom imaging and Monte Carlo simulations. Image quality, scatter, and dose were evaluated in both overlapping (large cone angle) and collimated (small cone angle) configurations for CBCT. Four x-ray tube configurations were considered: traditional one source, three source overlapping, six source overlapping, and six source collimated. Image quality was evaluated on a prototype breast CT system using the following five phantoms: a Defrise phantom, a previously reported CBCT QA phantom (Corgi), a polyethylene cylinder, and two anthropomorphic phantoms (hand and knee). Scatter contamination and radiation dose were evaluated using Monte Carlo simulations of a voxelized polyethylene cylinder. The modulation of the Defrise phantom disks on average was 2.7X greater for the six source collimated configuration than the six source overlapping configuration. The data lost from cone beam artifact (spatial domain) and the null cone (frequency domain) in the overlapping configuration were completely recovered using the collimated configuration. The maximum scatter-to-primary ratio (SPR) for the overlapping configuration was 0.81 and the maximum SPR for the collimated configuration was 0.26. The average dose and maximum dose was 4X less in the collimated six source configuration when compared with the overlapping configurations. The maximum dose for the overlapping configurations (one, three & six) remained constant, but the average dose for the multisource (three & six source) overlapping configurations increased 25% when compared to the one source configuration. Use of a collimated multisource x-ray tube configuration was shown to provide significant improvements in image quality throughout the cone-beam geometry field-of-view, reduction in scatter contamination, and more efficient use of dose in comparison to both the traditional CBCT geometry with a single source and the overlapping multisource configurations.
In vivo neutron activation assembly design for quantification of trace elements using MCNP
Authors: Tabbassum Sana , Nie Linda H 
Published: October 2020

Abstract

Background: Trace and essential elements both play a crucial role in maintaining normal cellular and organ functions in human, while abnormal exposure to some of them is also potentially related to diseases, e.g. manganism. To study the association between elemental intake and health outcomes, accurate assessment of elemental uptake and storage in the human body is essential. Objective: Technology based on neutron activation analysis can be used for in vivo measurement of the trace elements given that the measurement system guarantees a low detection limit with an acceptable dose. This study aims to design and optimize a customized and portable deuterium–deuterium neutron generator-based irradiation assembly for the NAA of trace elements in vivo, using Monte Carlo simulations. Approach: The irradiation assembly includes a moderator, a fast neutron filter, a reflector, and shielding. The human hand phantoms doped with manganese (Mn) and potassium (K) are used to determine the respective elements’ system sensitivity and detection limit. Main results: The calculated detection limit is 0.16 μg Mn per gram dry bone (ppm) for Mn and 17 ppm for K, with an equivalent dose of 36 mSv to the hand for 10 min irradiation. Significance: This more sensitive in vivo neutron activation analysis system will detect trace elements in vivo.
Design and verification of novel silicon-controlled-rectifier-memristor based on standard CMOS process
Authors: Wang Yang , Cao Shengguo , Jin Xiangliang , Peng Yan , Luo Jun 
Published: October 2020

Abstract
Due to the unique nonlinear theory of memristors, it has been a research hotspot in the application of bionic synapses and neuromorphic computing for a long time. However, the currently designed memristors are difficult to be compatible with standard microelectronic processes to achieve large-scale integration. In this paper, a prototype structure of a silicon-controlled-rectifier-memristor (SCRM) will be proposed to solve the above problems. Technology computer aided design is utilized to simulate the memristive behavior of SCRM. The device is manufactured by the 0.18 μm bipolar complementary-metal-oxide-semiconductor double-diffused-metal-oxide-semiconductor process. The test platform was established to verify the memristive characteristics of SCRM. When a preset pulse is applied to both terminals of the device, the voltage and current of the SCRM are clamped to a lower level due to the negative-resistance effect, and hysteresis occurs. The I–V hysteresis loop fitted by extracting parameters verifies the consistency of theory, simulation and experiment. SCRM can change continuously between low-resistance state and high-resistance state. The design idea of SCRM compatible with silicon-based processes will promote further research on large-scale on-chip integrated neuromorphic computing.
Effect of steam conversion on the cellular structure, Young’s modulus and negative Poisson’s ratio of closed-cell foam
Authors: Duncan Olly , Allen Tom , Birch Alana , Foster Leon , Hart John , Alderson Andrew 
Published: October 2020

AbstractOpen-cell auxetic foams have shown potential for use in sporting and other protective equipment. Previous conversion methods for auxetic closed-cell foam used a bespoke pressure vessel. This work expands upon a recent method, using steam absorption followed by cooling and condensation, to change the cell shape of closed-cell foam to impart a negative Poisson’s ratio. Aiming to present a simple, repeatable conversion method, foam samples (20 × 10 × 100 mm) floating in water-filled (∼20 °C), covered ceramic containers (300 × 200 × 100 mm) were heated in an oven at 105 °C for between 1 and 6.5 hrs. Based on the results for these smaller samples, a larger sample of foam (30 × 100 × 100 mm) was also converted, with a steaming time of 8 hrs. The final volume ratio (original/final volume) increased with heating time, up to a maximum of 4.6. The amount and angle of re-entrant (inward-folding) cell walls increased with the final volume ratio as cells contracted further, as evidenced by micro-computed tomography. Poisson’s ratios, measured using digital image correlation, were as low as −0.3 in tension and −1.1 in compression. The tensile Young’s modulus increased from ∼2 up to ∼6 MPa with the final volume ratio and the compressive Young’s modulus reduced from ∼1.5 MPa for low values of the final volume ratio between one and three and then remained close to 1.5 MPa.
Multi-party quantum fingerprinting with weak coherent pulses: circuit design and protocol analysis
Authors: Gómez-Sousa Hipólito 
Published: October 2020

Abstract
Quantum communication has been leading the way of many remarkable theoretical results and experimental tests in physics. In this context, quantum communication complexity (QCC) has recently drawn earnest research attention as a tool to optimize the amounts of transmitted qubits and energy that are required to implement distributed computational tasks. On this matter, we introduce a novel multi-user quantum fingerprinting (QF) protocol that is ready to be implemented with existing technology. Particularly, we extend to the multi-user framework a well-known two-user coherent-state fingerprinting scheme. This generalization is highly non-trivial for a twofold reason, as it requires not only to extend the set of protocol rules but also to specify a procedure for designing the optical devices intended for the generalized protocol. Much of the importance of our work arises from the fact that the obtained QCC figures of merit allow direct comparison with the best-known classical multi-user fingerprinting protocol, of significance in the field of computer technologies and networking. Furthermore, as one of the main contributions of the manuscript, we deduce innovative analytical upper bounds on the amount of transmitted quantum information that are even valid in the two-user protocol as a particular case. These original analytical bounds are of interest for estimating the realistic protocol performance prior to experimental realizations. Ultimately, comparative results are provided to contrast different protocol implementation strategies and, importantly, to show that, under realistic circumstances, the multi-user protocol can achieve tasks that are impossible by using classical communication alone. Our work provides relevant contributions towards understanding the nature and the limitations of QF and, on a broader scope, also the limitations and possibilities of quantum-communication networks embracing a node that is accessed by multiple users at the same time.
Manipulation of valley splitting for the WSe2/NiCl2 heterostructure by adjusting the interlayer spacing and constructing a NiCl2/WSe2/NiCl2 heterojunction
Authors: Teng Sukai , Mao Xiujuan , Liu Ze , Liu Yang , Xu Xiuting , Li Linyang , Xie Xinjian , Fan Shanshan , Zhou Guoxiang , Li Jun , Li Jia 
Published: October 2020

Abstract
The electronic band structure and valley splitting of the WSe2/NiCl2 heterostructure have been investigated by density functional theory and Berry curvature calculations. We demonstrate that the valley polarization of monolayer WSe2 is induced due to the magnetic proximity effect caused by the single layer of ferromagnetic NiCl2. The magnitude of valley splitting depends on the stacking configurations of WSe2/NiCl2, and the maximum value of valley splitting reaches −11.87 meV. Large valley splitting can be achieved by adjusting the layer spacing and constructing a NiCl2/WSe2/NiCl2 heterojunction with Ni spins arranged in parallel between two NiCl2 sheets. The valley-contrasting Berry curvature between the K and K′ valleys suggests that the WSe2/NiCl2-based heterostructure could potentially be used as a valleytronic device to realize the valley-polarized anomalous Hall effect as both spin and valley filter.
The secondary ionization wave and characteristic map of surface discharge plasma in a wide time scale
Authors: Zhu Yifei , Wu Yun 
Published: October 2020

Abstract
The surface discharge is the elementary process in a broad range of low temperature plasma applications. Variation of voltage profiles with different time scales leads to the redistribution of deposited energy as well as electro-hydrodynamic forces of surface discharges, while the mechanism and scaling law is still unknown. On the basis of theoretical and numerical analysis, we show that a secondary surface ionization wave forms during the voltage rising slope when electron density decreases to a critical level while the voltage is still rising. A characteristic map of energy and electro-hydrodynamics force in time scales between 1 ns and 0.1 s at atmospheric pressure is proposed, opening the door towards the target-directed design of surface discharges.
Some theory and applications of 2N-dimensional canonical systems: periodic and nonperiodic
Authors: Acharya Keshav Raj , Ludu Andrei 
Published: October 2020

Abstract
In this paper, we study the 2N-dimensional canonical systems and their physical applications. We first discuss some basic theory including proving the existence of solutions of any canonical system and establish some properties of its fundamental solution. Then we discuss the periodic canonical systems, establish Floquet theory, and observe the asymptotic behavior of their solutions. We also explore some important physical applications of the systems, namely linear stability of periodic Hamiltonian systems, position-dependent effective mass, and pseudo-periodic nonlinear water waves.
Millimeter-wave generation using hybrid silicon photonics
Authors: Degli-Eredi Iterio , An Pengli , Drasbæk Jacob , Mohammadhosseini Hakimeh , Nielsen Lars , Tønning Peter , Rommel Simon , Monroy Idelfonso Tafur , Heck Martijn J R 
Published: October 2020

Abstract
Technological innovation with millimeter waves (mm waves), signals having carrier frequencies between 30 and 300 GHz, has become an increasingly important research field. While it is challenging to generate and distribute these high frequency signals using all-electronic means, photonic techniques that transfer the signals to the optical domain for processing can alleviate several of the issues that plague electronic components. By realizing optical signal processing in a photonic integrated circuit (PIC), one can considerably improve the performance, footprint, cost, weight, and energy efficiency of photonics-based mm-wave technologies. In this article, we detail the applications that rely on mm-wave generation and review the requirements for photonics-based technologies to achieve this functionality. We give an overview of the different PIC platforms, with a particular focus on hybrid silicon photonics, and detail how the performance of two key components in the generation of mm waves, photodetectors and modulators, can be optimized in these platforms. Finally, we discuss the potential of hybrid silicon photonics for extending mm-wave generation towards the THz domain and provide an outlook on whether these mm-wave applications will be a new milestone in the evolution of hybrid silicon photonics.
X-ray multi-modal intrinsic-speckle-tracking
Authors: Pavlov Konstantin M , Paganin David M , (Thomas) Li Heyang , Berujon Sebastien , Rougé-Labriet Hélène , Brun Emmanuel 
Published: October 2020

Abstract
We develop x-ray multi-modal intrinsic-speckle-tracking (MIST), a form of x-ray speckle-tracking that is able to recover both the position-dependent phase shift and the position-dependent small-angle x-ray scattering (SAXS) signal of a phase object. MIST is based on combining a Fokker–Planck description of paraxial x-ray optics, with an optical-flow formalism for x-ray speckle-tracking. Only two images need to be taken in the presence of the sample, corresponding to two different transverse positions of the speckle-generating membrane, in order to recover both the refractive and local-SAXS properties of the sample. Like the optical-flow x-ray phase-retrieval method which it generalises, the MIST method implicitly rather than explicitly tracks both the transverse motion and the diffusion of speckles that is induced by the presence of a sample. Application to x-ray synchrotron data shows the method to be efficient, rapid and stable.
Automated extended depth of focus digital holographic microscopy using electrically tunable lens
Authors: Barak Neelam , Kumari Vineeta , Sheoran Gyanendra 
Published: October 2020

Abstract
A combination of electrically tunable lens with a microscope objective lens (MO) for multifocal plane imaging capability is proposed. The method aims at extending the depth of focus of the MO by changing its axial range and field of view. The combination is implemented in a common path off-axis digital holographic microscopy configuration experimentally and it achieves an axial scanning range of 363.5 μm. It utilizes image plane holography to obtain in-focus images throughout the axial range. The proposed method demonstrates its application in quantitative phase imaging of the USAF 1951 test chart and flowing red blood cells at different axial depths. An axial depth variation of 0.76 μm–0.81 μm is obtained between two consecutive focused planes. The results validate and postulate the advantage of the proposed method over traditional extended depth-of-focus algorithms. The quantitative and qualitative results exploit the possibility of using the proposed method further for localization and tracking of flowing microscopic samples.
Non-invasive tracking of polarization rotation from speckle contrast using uncorrelated speckle patterns
Authors: Roy Abhijit , Singh Rakesh Kumar , Brundavanam Maruthi M 
Published: October 2020

Abstract
A technique based on the superposition of two uncorrelated speckle patterns and speckle contrast measurement is proposed and demonstrated to track the polarization rotation of an optical beam behind a scattering layer. One of the superposed speckle patterns is considered as reference, and it is shown that with the help of the reference speckle pattern of a known linear polarization, it is possible to track the polarization rotation behind a scattering layer in a non-invasive manner by measuring the contrast of the resultant speckle pattern. The working principle and the experimental demonstration of the proposed technique are presented, and the experimental results are compared with the theoretically predicted values. The performance of the proposed technique is quantitatively evaluated by determining the rotation of the polarization vector behind the scattering layer for two different cases, namely, polarization rotation by a half-wave plate and sugar solution of different concentrations, and good matches are found between the experimental results and the theoretical prediction. Issues like resolution of tracking the polarization vector rotation and determination of sugar solution concentration are also discussed in the context of the experimental results. The proposed technique can have potential applications in non-invasive sensing and biomedical studies.
Biaxial strain engineering of CVD and exfoliated single- and bi-layer MoS2 crystals
Authors: Michail Antonios , Anestopoulos Dimitris , Delikoukos Nikos , Parthenios John , Grammatikopoulos Spyridon , Tsirkas Sotirios A , Lathiotakis Nektarios N , Frank Otakar , Filintoglou Kyriakos , Papagelis Konstantinos 
Published: October 2020

Abstract
Single- and bi-layer MoS2 are two-dimensional semiconductors able to withstand very large deformations before failure, standing out as suitable templates for strain engineering applications and flexible electronics. It is imperative, for the proper integration of this material in practical applications, that the relationship between material property and strain is well understood. Two dimensional MoS2 crystals fabricated by chemical vapor deposition or micromechanical exfoliation are transferred onto flexible substrates and subjected to biaxial tension on a carefully designed and assessed loading stage with high accuracy and control. The successful stress transfer from substrate to the overlying 2D crystal is identified by in-situ monitoring of the strain-induced phonon frequency and photoluminescence peak shifts. Reliable values for the mode Grüneisen parameters and exciton deformation potentials were obtained by studying a significant number of crystals. The experimental results are backed by density functional theory calculations and are in good agreement with the experiments. This work highlights the potential of these materials in strain engineering applications and gives accurate values for single- and bi-layer MoS2 thermomechanical parameters.
Surface residual stress, micro-hardness and geometry of TC6 titanium alloy thin-wall parts processed by multiple oblique laser shock peening
Authors: Zhu Ran , Zhang Yongkang , Zhang Chi 
Published: October 2020

Abstract
The titanium alloy thin-walled part with light in weight and high specific strength is widely used in the aviation engine fan, turbine and compressor. The fatigue damage of the thin-walled part often happens under the action of the cyclic loads and high temperatures. Laser shock peening(LSP) is an innovative surface treatment process, which has been used to improve the fatigue life of metallic materials. Considering the shape and size of the thin-walled parts, the TC6 titanium alloy thin-wall parts were treated by the oblique incident laser beam in this work. The purpose of this study is to investigate the effects of multiple oblique LSP on TC6 titanium alloy thin-wall parts. Nd: YLF laser with a wavelength of 1053 nm was applied. The laser incidence angle was determined first by experiment. The effects of laser energies, impact times, pulse durations and pulse frequencies on the surface residual stress, micro-hardness and geometry of TC6 titanium alloy thin-wall parts were investigated. The results showed that by the use of oblique LSP, the higher surface residual stress and surface micro-hardness could be induced on the surface of treated specimens. However, surface deformation and surface roughness of treated specimens can also increase.
Boron nitride-palladium nanostructured catalyst: efficient reduction of nitrobenzene derivatives in water
Authors: Nayebi Behnam , Rabiee Navid , Nayebi Behzad , Shahedi Asl Mehdi , Ramakrishna Seeram , Jang Ho Won , Varma Rajender S , Shokouhimehr Mohammadreza 
Published: October 2020

Abstract
Boron nitride (BN) supported palladium (Pd) nanostructured catalyst, as an alternative support for heterogeneous reduction of nitrobenzene derivatives, was prepared by a mild reduction of a Pd precursor in water. The structural characteristics and distribution of the synthesized Pd nanoparticles (NPs) on BN support were investigated by transmission electron microscopy, scanning transmission electron microscopy, energy-dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy methods. The potential and efficiency of the BN supported Pd NPs as an active and stable nanostructured catalyst were verified in the reduction of nitroaromatics. Excellent yields of the corresponding aryl amines in water were obtained and due discussion were included about the catalytic activity of the synthesized catalyst. It was also indicated that the nanostructured catalyst can be recycled at least for six consecutive cycles in the reduction of nitrobenzene, without losing significant activity.