bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical properties of compacted carbon nanomaterials
Authors: Lapekin Nikita I. , Shestakov Artem A. , Brester Andrey E. , Ukhina Arina V. , Bannov Alexander G.
Published: July 2021

In this paper, the electrical properties of various compacted carbon nanomaterials were investigated. Compacted carbon nanomaterials (carbon nanofibers, multi-walled carbon nanotubes) were compacted into cylindrical samples and the electrical properties were measured in a frequency range from 50 Hz to 1MHz.
Mesoporous oxide films grown on Sn foil using various anodizing modes in alkaline electrolyte
Authors: Vasilyeva Tatyana , Uvarov Nikolai
Published: July 2021

The mesoporous structures of tin oxide were obtained by a simple method of one-stage electrochemical anodizing of Sn foil in 1M NaOH in various anodizing modes. Anodizing in the pulse potentiostatic mode allowed determination of actual value of the voltage drop on the anode. For the first time the possibility of obtaining mesoporous oxide films on the surface of tin using galvanostatic mode of anodizing was demonstrated. It was found that the surface morphology of the obtained tin oxide layers is strongly dependent on the anodizing mode. Based on the data obtained, a two-stage mechanism was proposed for the growth of porous structures on the surface of tin in the galvanostatic mode including initial formation of the layer of SnO·xH2O which is subsequently oxidized to SnO2·xH2O mesoporouslayer.
Study of the dependence of organic additives on the properties of 3D-structured catalysts properties for hydrocarbon hydrotreatment
Authors: Lazarenko N.S. , Kaplin N.D. , Vorobyeva E.Е. , Parkhomchuk E.V. , Lysikov A.I.
Published: July 2021

The dependence of porosity and durability of Al2O3 on various organic additives (ethylene glycol, diethylene glycol, glycerin, industrial oil and their combinations) was shown. Some of results were used to synthesize 3D-structured catalysts.
Synchrotron X-ray diffraction in situ study of Li4Ti5O12 synthesis from rutile and anatase
Authors: Kozlova Anna , Sharafutdinov Marat
Published: July 2021

The comparative study of solid state synthesis of Li4Ti5O12 from rutile and anatase as initial reagents was carried out using the method of in situ synchrotron radiation dynamic diffractometry. Initial samples were obtained by mechanical treatment of Li2CO3 and TiO2 (anatase or rutile modifications). It was found that on the first stage an intermediate β-Li2TiO3 phase forms in the reaction system. On further heating the process of formation of the Li4Ti5O12 phase from β-Li2TiO3 and TiO2 is limited by lithium cation diffusion through the β-Li2TiO3 phase. Reaction strongly accelerates at temperatures above 800 oC. Using nano-sized anatase precursor, well-crystallized LTO with smaller grain size may be obtained at lower temperatures.
Tools and methodologies for box-wing aircraft conceptual aerodynamic design and aeromechanic analysis
Authors: Abu Salem Karim , Giuseppe Palaia , Vittorio Cipolla , Vincenzo Binante , Davide Zanetti , Mario Chiarelli
Published: July 2021

A way to face the challenge of moving towards a new greener aviation is to exploit disruptive aircraft architectures; one of the most promising concept is the PrandtlPlane, a box-wing aircraft based on the Prandtl's studies on multiplane lifting systems. A box-wing designed accordingly the Prandtl “best wing system” minimizes the induced drag for given lift and span, and thus it has the potential to reduce fuel consumption and noxious emissions. For disruptive aerodynamic concepts, physic-based aerodynamic design is needed from the very early stages of the design process, because of the lack of available statistical data; this paper describes two different in-house developed aerodynamic design tools for the PrandtlPlane conceptual aerodynamic design: AEROSTATE, for the design of the box-wing lifting system in cruise condition, and THeLMA, aiming to define the layout of control surfaces and high lift devices. These two tools have been extensively used to explore the feasible space for the aerodynamic design of the box-wing architecture, aiming to define preliminary correlations between performance and design variables, and guidelines to properly initialize the design process. As a result, relevant correlations have been identified between the rear-front wing loading ratio and the performance in cruise condition, and for the rear-front flap deflections and the aeromechanic characteristics in low speed condition.
Toxoplasma gondii in domiciled dogs and cats in urban areas of Brazil: risk factors and spatial distribution
Authors: Arruda Igor Falco , Millar Patricia Riddell , Barbosa Alynne da Silva , Abboud Luiz Claudio de Souza , dos Reis Izabel Cristina , Moreira Alex Sander da Cruz , Guimarães Mariana Pedrosa de Paula , Amendoeira Maria Regina Reis
Published: July 2021

Toxoplasma gondii is a highly prevalent zoonotic parasite in Brazil capable of infecting mammals and birds. The increase in the urban populations of pets and the narrowing of the human–animal relationship can facilitate the transmission of important public health zoonoses, such as toxoplasmosis. This study aimed to evaluate the frequency and spatial distribution of T. gondii infection and its risk factors in domiciled dogs and cats attended at the Jorge Vaitsman Institute, Rio de Janeiro. Serum samples from 400 dogs and 272 cats were evaluated by an indirect fluorescent antibody test (IFAT) for IgG anti-T. gondii antibodies. Epidemiological questionnaires were used to interview the animals’ owners to identify risk factors for infection. Of the total, 34% (136/400) of dogs and 8.1% (22/272) of cats had anti-T. gondii antibodies. Breed (OR: 2.10–95%, CI 1.27–3.46) was a risk factor for dogs, while sex (OR: 3.40–95%, CI 1.10–10.52) and homemade food consumption (OR: 8.49–95%, CI 2.48–29.05) were risk factors for cats. Offal consumption was considered a risk factor for both species evaluated (OR: 2.74–95%, CI 1.38–5.43 for dogs; OR: 7.66–95%, CI 1.24–47.29 for cats). The spatial analysis showed that T. gondii seropositive animals were widely distributed in the metropolitan region of Rio de Janeiro state, with a concentration observed mainly in the west and north zones of Rio de Janeiro city. The results emphasize the importance of adopting prophylactic measures to control T. gondii transmission in domiciled dogs and cats in Rio de Janeiro, contributing positively to public health.
Bioinspired Total Synthesis of Marine Anticancer Meroterpenoids Dysideanone B and Dysiherbol A and Structure Revision of Dysiherbol A
Authors: Lu Zhaoyong , Chong Chuanke
Published: July 2021

Our recent progress on the total synthesis of marine anticancer sesquiterpene quinone/hydroquinone dysideanone B and dysiherbol A is briefly highlighted. This success relied on some key transformations. The union of the terpene and quinone/hydroquinone moieties was realized through a site and stereoselective α-position alkylation of Wieland–Miescher ketone derivative with a bulky benzyl bromide. The 6/6/6/6-tetracycle of dysideanone B was constructed using an intramolecular radical cyclization and the 6/6/5/6-fused core structure of dysiherbol A was forged by an intramolecular Heck reaction, respectively. The possible origin of ethoxy group in dysideanone B was revealed by mimicking the isolation conditions at a late stage. The structure of dysiherbol A was revised through the total synthesis of this natural product. Schmalz’s synthesis of dysiherbol A was also included.
Semantic Textual Similarity in Japanese Clinical Domain Texts Using BERT
Authors: Mutinda Faith Wavinya , Yada Shuntaro , Wakamiya Shoko , Aramaki Eiji
Published: July 2021

Background Semantic textual similarity (STS) captures the degree of semantic similarity between texts. It plays an important role in many natural language processing applications such as text summarization, question answering, machine translation, information retrieval, dialog systems, plagiarism detection, and query ranking. STS has been widely studied in the general English domain. However, there exists few resources for STS tasks in the clinical domain and in languages other than English, such as Japanese.

Objective The objective of this study is to capture semantic similarity between Japanese clinical texts (Japanese clinical STS) by creating a Japanese dataset that is publicly available.

Materials We created two datasets for Japanese clinical STS: (1) Japanese case reports (CR dataset) and (2) Japanese electronic medical records (EMR dataset). The CR dataset was created from publicly available case reports extracted from the CiNii database. The EMR dataset was created from Japanese electronic medical records.

Methods We used an approach based on bidirectional encoder representations from transformers (BERT) to capture the semantic similarity between the clinical domain texts. BERT is a popular approach for transfer learning and has been proven to be effective in achieving high accuracy for small datasets. We implemented two Japanese pretrained BERT models: a general Japanese BERT and a clinical Japanese BERT. The general Japanese BERT is pretrained on Japanese Wikipedia texts while the clinical Japanese BERT is pretrained on Japanese clinical texts.

Results The BERT models performed well in capturing semantic similarity in our datasets. The general Japanese BERT outperformed the clinical Japanese BERT and achieved a high correlation with human score (0.904 in the CR dataset and 0.875 in the EMR dataset). It was unexpected that the general Japanese BERT outperformed the clinical Japanese BERT on clinical domain dataset. This could be due to the fact that the general Japanese BERT is pretrained on a wide range of texts compared with the clinical Japanese BERT.
Business model and planning approach for hydrogen energy systems at three application scenarios
Authors: Zhang Hong , Yuan Tiejiang , Tan Jie
Published: July 2021

Green hydrogen is used as fuel or raw material in power systems, transportation, and industry, which is expected to curb carbon emissions at the root. First, a unified energy system consisting of clean power generation systems, hydrogen energy systems (HESs), and transmission systems was proposed, and the characteristics of hydrogen load in different fields are analyzed. Possible business models for HESs in industry and transportation are then presented, cost and benefit functions for stakeholders of HES were created, and a business model with multi-party participation was modeled as a multi-objective optimization model. In a power system, the business model of combining two operating modes for hydrogen storage was proposed at the power generation side as well. Finally, three HESs were designed for a chemical plant with a hydrogen demand of 1000 Nm3/h, a hydrogen refueling station with a daily hydrogen load of 600 kg, and a 100% clean power generation system, respectively. The results of the case study show that one or more feasible business models (i.e., all stakeholders are profitable) can be found in both industrial and transportation by the HES planning approach proposed, while the internal rate of return of HES installed on the generation side is less than 5% due to high investment cost at this stage and low utilization rate; nonetheless, the profitable strategies are shown by 3D graphics.
Theoretical analysis and experimental verification of electron beam transmission with low guiding magnetic field in V-band coaxial transit-time oscillator
Authors: Deng Bingfang , He Juntao , Ling Junpu , Wang Lei , Song Lili , Xu Weili
Published: July 2021

The transmission of an electron beam with a low magnetic field is theoretically and experimentally investigated. In a high frequency band, due to a narrow tunnel of the electron beam, the transmission of the electron beam highly depends on beam parameters. The transmission of the electron beam is analyzed through the beam envelope equation, and accordingly, the relationship between beam parameters and transversal diffusion of the electron beam is derived. By particle-in-cell simulation, the influence of the current density, loading position, and guiding magnetic field on the electron beam is discussed. An electron beam with a beam voltage of 400 kV and a beam current of 5.0 kA in the guiding magnetic field of 1.0 T is applied in the experiment. The experiment consists of the electron beam bombardment on the nylon target and measurements of the beam current. The experimental results show that the electron beam can be stably and uniformly transmitted at a low loss under the given conditions.
Dirac Hamiltonian in a supersymmetric framework
Authors: Bagchi Bijan , Ghosh Rahul
Published: July 2021

We investigate the most general form of the one-dimensional Dirac Hamiltonian HD in the presence of scalar and pseudoscalar potentials. To seek embedding of supersymmetry (SUSY) in it, as an alternative procedure to directly employing the intertwining relations, we construct a quasi-Hamiltonian K, defined as the square of HD, to explore the consequences. We show that the diagonal elements of K under a suitable approximation reflect the presence of a superpotential, thus proving a useful guide in unveiling the role of SUSY. For illustrative purposes, we apply our scheme to the transformed one-dimensional version of the planar electron Hamiltonian under the influence of a magnetic field. We generate spectral solutions for a class of isochronous potentials.
Effect of in-plane shear flow on the magnetic island coalescence instability
Authors: Mahapatra Jagannath , Bokshi Arkaprava , Ganesh Rajaraman , Sen Abhijit
Published: July 2021

Using a 2D Viscoresistive Reduced MagnetoHydroDynamic model, the magnetic island coalescence problem is studied in the presence of in-plane, parallel shear flows. Extending the analytical work of Waelbroeck et al. [Phys. Plasmas 14, 022302 (2007)] and Throumoulopoulos et al., [J. Phys. A 42, 335501 (2009)] in the sub-Alfvénic flow shear regime for Fadeev equilibrium, the super-Alfvénic regime is studied for the first time numerically. A wide range of values of shear flow amplitudes and shear scale lengths have been considered to understand the effect of sub-Alfvénic and super-Alfvénic flows on the coalescence instability and its nonlinear fate. We find that for flow shear length scales greater than the magnetic island size, the maximum reconnection rate decreases monotonically from sub-Alfvénic to super-Alfvénic flow speeds. For scale lengths smaller than the island size, the reconnection rate decreases up to a critical value v0c, beyond which the shear flow is found to destabilize the islands. The value of v0c decreases with a decrease in the value of shear flow length scale. Interestingly, for our range of parameters, we find suppression of the Kelvin–Helmholtz instability in super-Alfvénic flows even when the shear scale length is smaller than the island width. Observation of velocity streamlines shows that the plasma circulation inside the islands has a stabilizing influence in strong shear flow cases. Plasma circulation is also found to be responsible for the decrease in upstream velocity, causing less pileup of magnetic flux on both sides of the reconnection sheet.
Laser spot measurement using simple devices
Authors: Bonnett Del Alamo M. , Soncco C. , Helaconde R. , Bazo Alba J. L. , Gago A. M.
Published: July 2021

We have designed and tested an automated simple setup for measuring the profile and spot size of a Gaussian laser beam, which exhibits a similar performance to ready-made optical devices, using three light sensors. We use a light dependent resistor as a novel instrument in this approach with good accuracy. We provide the setup in detail in order to be reproduced with the current technology at a standard laboratory. Two profiling techniques were implemented: the imaging technique for the CMOS 2D array (webcam) and scanning knife-edge-like technique using a single photodiode and a light dependent resistor. We apply up-to-date devices, such as a Raspberry Pi, for automation. The methods and sensors were compared to determine their accuracy using lasers of two different wavelengths and technologies. We verify that it is possible to use a webcam to determine the profile of a laser with 1% uncertainty on the beam waist, 1.5% error on the waistline position, and less than 3% error in determining the minimum spot radius. We show that it is possible to use a light dependent resistor to estimate the laser spot size with an 11% error. The photodiode measurement is the most stable since it is not affected by the change in laser intensity.
Ab initio molecular dynamics modeling of single polyethylene chains: Scission kinetics and influence of radical under mechanical strain
Authors: Kedziora Gary S. , Moller James , Berry Rajiv , Nepal Dhriti
Published: July 2021

Ab initio molecular dynamics was used to estimate the response to constant imposed strain on a short polyethylene (PE) chain and a radical chain with a removed hydrogen atom. Two independent types of simulations were run. In the first case, the chains were strained by expanding a periodic cell, restraining the length but allowing the internal degrees of freedom to reach equilibrium. From these simulations, the average force on the chain was computed, and the resulting force was integrated to determine the Helmholtz free energy for chain stretching. In the second set of simulations, chains were constrained to various lengths, while a bond was restrained at various bond lengths using umbrella sampling. This provided free energy of bond scission for various chain strains. The sum of the two free energy functions results in an approximation of the free energy of chain scission under various strains and gives a realistic and new picture of the effect of chain strain on bond breaking. Unimolecular scission rates for each chain type were examined as a function of chain strain. The scission rate for the radical chain is several orders of magnitude larger than that of the pristine chain at smaller strains and at equilibrium. This highlights the importance of radical formation in PE rupture and is consistent with experiments. Constant strain results were used to derive a constant-force model for the radical chain that demonstrates a roll over in rate similar to the “catch-bond” behavior observed in protein membrane detachment experiments.
Influence of Rogowski coil structure for sub-ns current pulses
Authors: Nassisi V. , Serra A.
Published: July 2021

Short current pulses are very diffuse and have also been used in many electronic devices for biological stress recently. In order to measure these current pulses, Rogowski coils are applied. In this work, we focus our efforts on the structure of the Rogowski box, which has a narrow slit, needed to correctly lead the current to be diagnosed. The attenuation coefficient depends mainly on the inductance values, the load resistance, and the virtual capacitance between coil and ground. Until now, the influence of the slit length and its width was never considered. We have studied, either theoretically or experimentally, the influence of the slit dimensions on calibration factor variations. The attenuation factor ranged from 11.3 to 16.3 A/V for s ranging from 0.8 to 0.2 mm, respectively. The device we realized is able to perform precise measurements of sub-nanosecond rise time pulses (∼100 ps).
Young's modulus and corresponding orientation in β-Ga2O3 thin films resolved by nanomechanical resonators
Authors: Zheng Xu-Qian , Zhao Hongping , Jia Zhitai , Tao Xutang , Feng Philip X.-L.
Published: July 2021

We report on the nondestructive measurement of Young's modulus of thin-film single crystal beta gallium oxide (β-Ga2O3) out of its nanoscale mechanical structures by measuring their fundamental mode resonance frequencies. From the measurements, we extract the Young's modulus in the (100) plane, EY,(100) = 261.4 ± 20.6 GPa, for β-Ga2O3 nanoflakes synthesized by low-pressure chemical vapor deposition (LPCVD), and in the [010] direction, EY,[010] = 245.8 ± 9.2 GPa, for β-Ga2O3 nanobelts mechanically cleaved from bulk β-Ga2O3 crystal grown by the edge-defined film-fed growth (EFG) method. The Young's moduli extracted directly on nanomechanical resonant device platforms are comparable to theoretical values from first-principle calculations and experimentally extracted values from bulk crystal. This study yields important quantitative nanomechanical properties of β-Ga2O3 crystals and helps pave the way for further engineering of β-Ga2O3 micro/nanoelectromechanical systems (M/NEMS) and transducers.
Topological antennas: Aperture radiators, leaky-wave surfaces, and orbital angular momentum beam generation
Authors: Singh Shreya , Bisharat Dia’aaldin , Sievenpiper Dan
Published: July 2021

The emerging field of topological photonics has extended our capability to control and manipulate electromagnetic waves. Thus far, however, research has focused on realizing defect-immune waveguides for on-chip communication. Making similar advancement for antennas, which are an integral component and crucial to the performance of wireless devices, could lead to a parallel impact on wireless communication. In particular, the requirement for impedance matching that is fundamental to current antenna technology constitutes a major limitation to transmitting and receiving free-space signals in terms of bandwidth and power efficiency. Here, we show how reciprocal photonic topological insulator (PTI) metasurfaces can be designed to enable a unique radiation mechanism needless of impedance matching. This relies on the fact that counter-propagating spin states are decoupled from each other; hence, this self-matching characteristic spans the entire bandwidth of the PTI’s bandgap. Specifically, we present two strategies for out-coupling spin-polarized edge modes: (1) in the form of an end-fire antenna at the abrupt termination of the PTI with free space and (2) in the form of a leaky-wave antenna by engineering the dispersion of the edge mode to lie above the light line. In the first approach, we compare our results to conventional rectangular waveguide apertures and planar Vivaldi antennas, which either have a large profile or flared ends to obtain gradual impedance matching. In the second approach, we demonstrate how our structure can emit orbital angular momentum (OAM) beams with various orbital charge numbers by simply varying the length of the PTI interface when made into a circular loop. The reduced device area and complexity due to removing the need for any matching network and the ability to easily multiplex OAMs of any charge, in addition to the wideband and high efficiency performance, make the proposed topological antennas highly attractive for many applications.
Dynamics and energy coupling of gas puff Z-pinches on a fast linear transformer driver
Authors: Conti F. , Narkis J. , Williams A. , Fadeev V. , Beg F. N.
Published: July 2021

Gas puff Z-pinch experiments with annular Ar and Ne gas shells have been conducted on the Compact Experimental System for Z-pinch and Ablation Research (CESZAR) linear transformer driver (LTD) with 500 kA current and 160 ns rise time. Here, we present results from the first systematic gas puff Z-pinch experiments using a fast (≤200 ns) LTD as a driver, in which we show that 7% of the stored energy in the capacitors is coupled to plasma kinetic energy as estimated via self-emission and laser schlieren images. 0D and 1D simulations—which do not allow instability growth and thus reach greater maximum average velocities—using initial conditions inferred from experimental implosion trajectories predict coupling in excess of 10% of the stored energy. The Ar and Ne implosions were comparably massed and thus achieved similar maximum kinetic energies, though the Ne pinches were more stable and the x-ray pulses were longer and produced higher yield: 2–5 ns and 0.21–0.52 J (0.15–0.37 J/cm) of Ar K-shell and 12–25 ns and 2.2–3.9 J (1.6–2.6 J/cm) of Ne K-shell, respectively. The difference in stability is most likely attributed to variations in initial conditions such as density distribution and gas breakdown initiation.
Solution of disordered microphases in the Bethe approximation
Authors: Charbonneau Patrick , Tarzia Marco
Published: July 2021

The periodic microphases that self-assemble in systems with competing short-range attractive and long-range repulsive (SALR) interactions are structurally both rich and elegant. Significant theoretical and computational efforts have thus been dedicated to untangling their properties. By contrast, disordered microphases, which are structurally just as rich but nowhere near as elegant, have not been as carefully considered. Part of the difficulty is that simple mean-field descriptions make a homogeneity assumption that washes away all of their structural features. Here, we study disordered microphases by exactly solving a SALR model on the Bethe lattice. By sidestepping the homogenization assumption, this treatment recapitulates many of the key structural regimes of disordered microphases, including particle and void cluster fluids as well as gelation. This analysis also provides physical insight into the relationship between various structural and thermal observables, between criticality and physical percolation, and between glassiness and microphase ordering.
β-Ga2O3 epitaxial growth on Fe-GaN template by non-vacuum mist CVD and its application in Schottky barrier diodes
Authors: Xu Yu , Zhang Chunfu , Yan Pengru , Li Zhe , Zhang Yachao , Chen Dazheng , Zhu Weidong , Feng Qian , Xu Shengrui , Zhang Jincheng , Hao Yue
Published: July 2021

In this work, we report on demonstrating lateral β-Ga2O3 Schottky barrier diodes (SBDs) fabricated on Fe-GaN/sapphire (0001) substrates by using the non-vacuum, low-cost mist chemical vapor deposition (mist CVD) method for the first time. The x-ray diffraction scanning pattern identifies that β-Ga2O3 layers are grown with (−201) planes parallel to the (0001) plane of the GaN template, and the transmission electron microscopy shows that the β-Ga2O3 lattice is regularly and neatly arranged, indicating good crystal quality. β-Ga2O3 based SBDs with 4 and 20 µm anode–cathode lengths (LAC) exhibit the specific on-resistance (Ron,sp) of 1.58 and 39.8 Ω cm2 and breakdown voltage (Vbr) of 580 and 2400 V, respectively. The present results show the great potential of the non-vacuum and cost-effective mist CVD method as the epitaxial growth technique employed in β-Ga2O3 devices.
Treatment of unphysical numerical oscillations via local grid refinement
Authors: Xu Haosen H. A. , Yang Xiang I. A.
Published: July 2021

Unphysical numerical oscillations (UNOs) arise when a non-dissipative scheme is employed to discretize fluid equations on a coarse grid. Treating UNOs often relies on upwind schemes, digital filtration, artificial viscosity, or adaptive mesh refinement, which are either too dissipative or too costly. We propose an alternative solution by refining one grid in regions where the flow velocity changes drastically. The effectiveness of our single-point grid refinement strategy is tested in various two-dimensional and three-dimensional flows at both laminar and turbulent flow conditions, and the results are highly favorable.
Doping of organic semiconductors: Insights from EPR spectroscopy
Authors: Biskup Till
Published: July 2021

Doping, here understood as purposefully introducing charge carriers, is a standard procedure, which is regularly employed with semiconductors to enhance conductivity and, hence, improve efficiency. Organic semiconductors are no different here, only the ratio of a dopant to a host is dramatically different compared to their inorganic counterparts. Therefore, doping of organic semiconductors will often affect the morphology and the conductivity of the host material. As the charge carriers created upon doping are usually paramagnetic, electron paramagnetic resonance (EPR) spectroscopy is perfectly suited to investigate the doping process, providing unique insights due to its exclusive sensitivity to paramagnetic states and high resolution on a molecular scale. To make an impact, EPR spectroscopy needs to be applied routinely to a large series of different systems, and the data obtained need to be analyzed in a reliable and robust way. This strongly advocates for using conventional X-band cw-EPR spectroscopy at room temperature wherever possible. Questions that can be addressed by EPR spectroscopy are discussed, and this Perspective presents how the method can gain greater importance for addressing the urgent research questions in the field, mainly by automating both data acquisition and analysis and developing robust and reliable analysis tools.
Dependency of a localized phonon mode intensity on compositional cluster size in SiGe alloys
Authors: Chung Sylvia Yuk Yee , Tomita Motohiro , Takizawa Junya , Yokogawa Ryo , Ogura Atsushi , Wang Haidong , Watanabe Takanobu
Published: July 2021

Using molecular dynamics, we found that the localized phonon-mode spectrum in SiGe alloys, which was recently discovered by an inelastic x-ray scattering experiment, changes according to the size distribution of compositional clusters in alloys. By varying the spatial distributions of Si and Ge, alloy models with differing compositions of Si and Ge clusters were able to be produced. For a range of alloys comprising 20%–80% Ge, a mixture of small and intermediate sized clusters will give the highest intensities of the local mode. The Si–Ge optical mode intensity increases with the local mode intensity, but the Si–Ge bond alone is not sufficient to produce the local mode. Si rich alloys with small Ge clusters produce the highest local mode intensities, suggesting that this mode is caused by small Ge clusters surrounded by Si pairs.
Bi-stable asymmetry on a pointed-nosed slender body at a high angle of attack
Authors: Qi Zhongyang , Zong Siyu , Wang Yankui
Published: July 2021

The repeatable and determinate pattern of asymmetric vortices at a regular state can be obtained by manually setting an artificial micro-perturbation (AMP) on the nose tip of a pointed-nosed slender body at a high angle of attack (AoA). Wind tunnel experiments and numerical simulations were conducted to investigate the predominant role of AMP in an asymmetric flow at α = 50°. The bi-stable asymmetric flow structures are presented when AMP rotates around the body axis. Thus, the corresponding side force acting on the slender body is shown as a square wave with two periods. The shear layer separation is presented as the separation lines to investigate the bi-stable asymmetry induced by the AMP. Results show that the AMP restricts the flow separation on the same side of the model with itself when it is located at windward. The separation location on the same side of the AMP moves to the leeward of the model (or the separation angle on the same side of the AMP increases); hence, the vortex rolls up from this side later than the other side. When the AMP is located at leeward of the slender body, it promotes the separation of flow on the same side of the model with itself. Thus, the separation location on the same side of the AMP moves to the windward of the model (or the separation angle on the same side of the AMP decreases) and the vortex rolls up from this side earlier the other side.
Tunable carbon nanotube diode with varying asymmetric geometry
Authors: Funayama Keita , Hirotani Jun , Miura Atsushi , Tanaka Hiroya , Ohno Yutaka , Tadokoro Yukihiro
Published: July 2021

We propose and demonstrate a carbon nanotube (CNT)-based field emission nanoscale diode to realize a fully integrated nanoscale system, namely, a true nanosystem. To the best of our knowledge, this is the first time a nanodiode simultaneously achieves ease of fabrication and individual tunability of multiple CNT diodes on the nanoscale on the same substrate in a one-time process. A nanodiode comprises a single-wall CNT cathode placed on a substrate, layered insulator, and metal anode. The proposed nanodiode allows us to adjust the turn-on voltage from 1 to 2.4 V by varying the surface area of the anode. Furthermore, as an example of a basic nano-electronic system, nanodiode-based fundamental logic gates (OR and NAND) are demonstrated on a CNT. We propose a theoretical model that derives the theoretical I–V characteristics based on the image-charge method to design the nanodiode quickly. The results in this study contribute to the development of carbon-based nanoelectronic systems.
Magnetic nanohelices swimming in an optical bowl
Authors: Patil Gouri , Vashist Eklavy , Kakoty Hreedish , Behera Jyotiprakash , Ghosh Ambarish
Published: July 2021

Magnetically driven helical nanoswimmers can impact many problems related to biology and medicine, such as intracellular manipulation, microsurgery, and drug delivery, and provide a promising platform for simulating and studying the physics of active matter. Crucial aspects of studying this powerful system pertain to their motion and dynamics under different physical conditions. In this paper, we demonstrate the confinement and controlled manipulation of magnetic nanohelices within an optical bowl formed by a defocused optical tweezer. The interaction of helical swimmers with the optical confinement was modeled and further confirmed by experiments. The results suggest that the combination of optical and magnetic forces can offer interesting avenues in the study of magnetic nanoswimmers, especially those related to micro-rheology and hydrodynamics.
Optical characterization and photo-electrical measurement of luminescent solar concentrators based on perovskite quantum dots integrated into the thiol-ene polymer
Authors: Gu Gangwei , Zhang Xin , Guo Yanqing , Zheng Zida , Cao Xiudong , Zhang Yi , Huang Rui , Zhang Xiaowei
Published: July 2021

The luminescent solar concentrator (LSC) has attracted worldwide attention as a sunlight manager for harvesting solar energy in building integrated photovoltaic structures. However, until now the relatively low optical efficiency (ηopt) still severely hinders the advancement of the LSCs. In this work, we report the perovskite quantum dots (QDs) integrated into the thiol-ene polymer for LSC applications. After encapsulated by the thiol-ene polymer, the CsPbBr3 QDs exhibit a slight blue-shift of the PL peak position and increasing FWHM because of the dielectric screen effect. With the different QDs' concentrations from 8.3 × 10−3  to 2.5 × 10−2 mg/ml, the LSC performance is evaluated by the direct optical characterization and the indirect photo-electrical measurement in detail. After coupling the PV cells, the as-fabricated LSC shows the optimal optical efficiency of 2.11% and the power conversion efficiency of 1.06%.
Application of UV-C radiation light in fruit juice processing
Authors: Fundo Joana F. , Miller Fátima A. , Brandão Teresa R.S. , Silva Cristina L.M.
Published: July 2021

Nowadays, consumers demand high-quality and fresh-like food products. In the fruit juices industry, the applied processes to guarantee safety and increase shelf life often negatively impact final product quality. Although thermal treatments are the most frequently applied processes to preserve fruit juices, heating may induce undesirable changes in sensory and nutritional characteristics. These facts prompted research on alternative and mild-non-thermal processes that assure the quality and safety of this type of liquid food. In this context, UV-C light has emerged, presenting several characteristics that make it a promising alternative to traditional processing and appropriate for liquid foods. UV-C light attributes and their application in the food industry are described in this work. Due to the recognized potential of this non-thermal technology on fruit juices, numerous researchers have been focusing on this subject. A compilation of those works is presented and discussed, emphasizing the UV-C light impact on quality/nutritional aspects and microbial inactivation in fruit juices. This critical review paper aims to be a valuable tool for finding characteristics/conditions of UV-C treatments and determine the corresponding impact on quality and safety parameters of fruit juices, opening topics for further research.
Opioid Stewardship Training during the Transition to Residency to Prepare Medical Students to Recognize and Treat Opioid use Disorder
Authors: Estave Paige M. , Jacobs Marie L. , Rukstalis Margaret , Goforth Jon , Stone Shane N. , Choi Jungbin A. , Barrett Jessica , Douglas Heather E. , Oliver Jennifer B. , Keating Michelle K , Freischlag Julie A. , O'Brien Mary Claire , McEwen Sara , Strowd Roy E.
Published: July 2021

Background

With a drastic shortage of addiction medicine specialists—and an ever-growing number of patients with opioid use disorder (OUD)—there is a dire need for more clinicians to feel confident in prevention and management of OUD and obtain a DEA-X waiver to prescribe medications to treat OUD. Here we determine if it is feasible to certify 4th year medical students with DEA-X waiver training as a component of the PROUD (Prevent and Reduce Opioid Use Disorder) curriculum, and if PROUD enhanced preparedness for medical students to manage OUD as interns.

Methods

We implemented a sequential mixed-methods IRB approved study to assess feasibility (completing all required components of DEA-X waiver training) and impact of PROUD (measured by knowledge growth, enhancement for residency, and utilization of training during internship). Students completed 11 hours of required OUD training. Quantitative data included pre-/post- knowledge and curriculum satisfaction assessments as well as long-term impact with follow up survey as interns. Qualitative data was collected by survey and semi-structured focus groups.

Results

All 120 graduating medical students completed the required components of the curriculum. Knowledge improved on the Provider Clinical Support Services (12.9–17.3, p < 0.0001) and Brief Opioid Overdose Knowledge assessments (10.15–10.81, p < 0.0001). Course satisfaction was high: 90% recommended online modules; 85% recommended training overall. Six qualitative themes emerged: (1) curriculum content was practical, (2) online modules allowed flexibility, (3) in-person seminars ensured authenticity, (4) timing at the transition to residency was optimal, (5) curriculum enhanced awareness and confidence, and (6) training was applicable to future careers. At 3 months, 60% reported using their training during internship; 64% felt more prepared to treat OUD than peers.

Conclusions

PROUD trained 4th year medical students in opioid stewardship. As interns, students felt ready to serve as change agents to prevent, diagnose, and treat OUD.
Luminescence imaging of non-uniform phantoms during irradiation of protons
Authors: Yamamoto S. , Yabe T. , Akagi T.
Published: July 2021

Although luminescence imaging during irradiation of protons is a useful method for range and dose estimations, it has only been attempted for uniform phantoms. Since luminescence imaging inherently has high resolution, we will be able to measure the images with non-uniform phantoms. Therefore, we measured the luminescence images for a non-uniform structured acrylic block during irradiation of protons. Imaging was conducted using a cooled charge-coupled device (CCD) camera during the irradiation of 129-MeV protons to an acrylic block with a 10-mm diameter hole in which an acrylic rod, air, or a titanium rod was inserted. Under these three different conditions, we could obtain different luminescence images for protons. The luminescence images with the acrylic rod showed uniform Bragg peaks in the lateral direction. In the luminescence images with air, a part of the Bragg peak under the hole was elongated. In the luminescence images with the titanium rod, the part of the Bragg peak under the hole was shortened. The ranges estimated from the depth profiles of the measured images matched the simulated results within a 1-mm difference. We confirmed that the luminescence imaging of non-uniform phantoms was possible and that ranges could be estimated from the images. We conclude that luminescence imaging is promising not only for uniform phantoms but also non-uniform phantoms.
Modeling tree radial growth in a warming climate: where, when, and how much do potential evapotranspiration models matter?
Authors: Dannenberg Matthew P
Published: July 2021

Process-based models of tree-ring width are used both for reconstructing past climates and for projecting changes in growth due to climate change. Since soil moisture observations are unavailable at appropriate spatial and temporal scales, these models generally rely on simple water budgets driven in part by temperature-based potential evapotranspiration (PET) estimates, but the choice of PET model could have large effects on simulated soil moisture, moisture stress, and radial growth. Here, I use four different PET models to drive the VS-Lite model and evaluate the extent to which they differ in both their ability to replicate observed growth variability and their simulated responses to projected 21st century warming. Across more than 1200 tree-ring width chronologies in the conterminous United States, there were no significant differences among the four PET models in their ability to replicate observed radial growth, but the models differed in their responses to 21st century warming. The temperature-driven empirical PET models (Thornthwaite and Hargreaves) simulated much larger warming-induced increases in PET and decreases in soil moisture than the more physically realistic PET models (Priestley–Taylor and Penman–Monteith). In cooler and more mesic regions with relatively minimal moisture constraints to growth, the models simulated similarly small reductions in growth with increased warming. However, in dry regions, the Thornthwaite- and Hargreaves-driven VS-Lite models simulated an increase in moisture stress roughly double that of the Priestley–Taylor and Penman–Monteith models, which also translated to larger simulated declines in radial growth under warming. While the lack of difference in the models’ ability to replicate observed radial growth variability is an encouraging sign for some applications (e.g. attributing changes in growth to specific climatic drivers), the large differences in model responses to warming suggest that caution is needed when applying the temperature-driven PET models to climatic conditions with large trends in temperature.
Mathematical models of the new remote transformer current transducers
Authors: Amirov Sultan Faizullaevich , Kamilovna Babanazarova Nargisa
Published: July 2021

New designs of remote transformer current converters (RTCC) have been developed in this article. It is shown that an increase in sensitivity is achieved due to the implementation of the magnetic circuit in the form of a multiturn core with a common measuring winding, and the use of three identical RTCC installed to measure currents of all three phases with connected measuring windings according to open triangle circuit expands the functionality of device due to the simultaneous measurement of currents in three phases and unbalanced currents in a three-phase circuit. Generalized mathematical models of new RCTT have been developed taking into account the influence of magnetic fields of currents of neighboring buses for the most general case of their location in space in relation to the buses of a three-phase line. It is shown that for RTCC type TVM-P, in which the parallel rods are made in the form of a multi-turn core with a corresponding measuring winding, in order to reduce the effect on the readings of the current transducer installed to measure the current in phases A, the number of turns of the measuring winding located at a distance from of buses B and C, the multiturn core of the U-shaped magnetic circuit should be selected large in relation to the measuring winding placed on the multiturn core closest to the buses B and C.
ATWS Analysis for Innovative Lead-Cooled High-Power Fast Reactor with Accident Tolerant Materials of Core
Authors: Okunev V S
Published: July 2021

The main purpose of the article is to substantiate the safety of a lead-cooled fast reactor of high power. Thermal power of the reactor is about 5600 MW, electric power is about 2400 MW. The design is similar to the BREST-OD-300 project developed at NIKIET JSC. The safety of a high-power reactor is ensured only with the use of innovative core materials (previously the author proposed to use fuel based on micrograins of UN-PuN mononitride and uranium metal nanopowder, a coolant based on lead of thorium ores, fuel element cladding based on EP823 steel with nanopowder of titanium oxide and yttrium, tungsten-coated cladding are used). Research methods are mathematical modeling of the reactor and reactor emergency modes. The most dangerous emergency modes (ATWS – anticipated transients without scram and their combinations, taking into account the non-simultaneous start) are considered. The studies used the codes developed by the author (Dragon-M, FRISS-2D) and the well-known code for precision neutron-physical calculations (MCU). A safe reactor corresponds to the fulfillment of restrictions for a number of functionals characterizing emergency modes. Studies have shown that when using innovative core materials, any combination of emergency modes does not lead to unacceptable releases of radioactive substances outside the Nuclear Power Plant. The results of the study show the possibility of developing reliable, safe, environmentally acceptable nuclear power based on reactors of this type.
Green technologies in rural electric powerindustry
Authors: Naumov Igor V , Podyachikh Sergey V
Published: July 2021

The article examines the indicators of the quality of electric energy and additional power losses due to the asymmetry of the three-phase voltage system in rural distribution electric networks 0.38 kV. Violation the symmetrical mode operation of the electrical network causes a deterioration the power quality and can lead to fire-hazardous situations. The proposed method of using the means of balancing the modes of operation electric networks is considered as a scenario for the introduction of “green” technologies to improve the efficiency of electricity supply in rural areas. The connection of balancing devices (BD) and various types of three-phase symmetric and unbalanced loads, as well as their combinations are considered on the model of the electric network at various points of power consumption. The parameters of the electrical network and BD are modeled and calculated by the computer complex “Asymmetry-2”. The programs for the Matlab graphic editor are compiled and diagrams of changes the indicators characterizing the quality and additional losses of electricity from the changing unbalanced load are constructed. A numerical analysis is carried out on the basis of the performed calculation and recommendations are given for determining the most appropriate place for connecting the BD in the electrical network.
Prospects for the use of aluminum-air batteries in solar energy in Greece
Authors: Korolev I V , Bakirtzis A I , Burdyukov D A , Kravchenko M V
Published: July 2021

The topic of aluminum use in the production of air-aluminum batteries, for the future development of solar energy in Greece, is being considered in this work. The article analyses different systems of vehicles in order to propose the use of air-aluminum batteries instead of lithium-ion ones.
Analysis of power supply options for a stable from a solar power plant
Authors: Leshtaev O V , Rtishcheva N E , Rtishchev K P
Published: July 2021

The article describes the types of photovoltaic systems, options for their installation in agricultural land. The reasons for the slow development of alternative energy in our country today and the main advantages and disadvantages of this type of energy are considered.
The main directions of development of active-adaptive electrical networks for agricultural purposes
Authors: Shatrov A F , Stushkina N A , Gaitova T B
Published: July 2021

The article discusses the possibility of building intelligent (active-adaptive) electrical networks for rural purposes using a SCADA system in automated control systems for energy facilities.