bluuebunny/crossref_metadata_2025 huggingface dataset:
Double-strand breaks measured along a 160 MeV proton Bragg curve using a novel FIESTA-DNA probe in a cell-free environment
Authors: McConnell Kristen A , Chang Chang , Giebeler Annelise , Liu Lawrence , Zhu Qu Lingyan , Moiseenko Vitali
Published: January 2021

Proton radiotherapy treatment planning systems use a constant relative biological effectiveness (RBE) = 1.1 to convert proton absorbed dose into biologically equivalent high-energy photon dose. This method ignores linear energy transfer (LET) distributions, and RBE is known to change as a function of LET. Variable RBE approaches have been proposed for proton planning optimization. Experimental validation of models underlying these approaches is a pre-requisite for their clinical implementation. This validation has to probe every level in the evolution of radiation-induced biological damage leading to cell death, starting from DNA double-strand breaks (DSB). Using a novel FIESTA-DNA probe, we measured the probability of double-strand break (P
DSB) along a 160 MeV proton Bragg curve at two dose levels (30 and 60 Gy (RBE)) and compared it to measurements in a 6 MV photon beam. A machined setup that held an Advanced Markus parallel plate chamber for proton dose verification alongside the probes was fabricated. Each sample set consisted of five 10 μl probes suspended inside plastic microcapillary tubes. These were irradiated with protons to 30 Gy (RBE) at depths of 5–17.5 cm and 60 Gy (RBE) at depths of 10–17.2 cm with 1 mm resolution around Bragg peak. Sample sets were also irradiated using 6MV photons to 20, 40, 60, and 80 Gy. For the 30 Gy (RBE) measurements, increases in P
DSB/Gy were observed at 17.0 cm followed by decreases at larger depth. For the 60 Gy (RBE) measurements, no increase in P
DSB/Gy was observed, but there was a decrease after 17.0 cm. Dose-response for P
DSB between 30 and 60 Gy (RBE) showed less than doubling of P
DSB when dose was doubled. Proton RBE effect from DSB, RBEP,DSB, was <1 except at the Bragg peak. The experiment showed that the novel probe can be used to perform DNA DSB measurements in a proton beam. To establish relevance to clinical environment, further investigation of the probe’s chemical scavenging needs to be performed.
Fast neutron energy based modelling of biological effectiveness with implications for proton and ion beams
Authors: Jones Bleddyn
Published: January 2021

A practical neutron energy dependent RBE model has been developed, based on the relationship between a mono-energetic neutron energy and its likely recoil proton energy. Essentially, the linear energy transfer (LET) values of the most appropriate recoil proton energies are then used to modify the linear quadratic model radiosensitivities (α and β) from their reference LET radiation values to provide the RBE estimates. Experimental neutron studies published by Hall (including some mono-energetic beams ranging from 0.2 to 15 MeV), Broerse, Berry, and data from the Clatterbridge and Detroit clinical neutron beams, which all contain some data from a spectrum of neutron energies, are used to derive single effective neutron energies (NEeff) for each spectral beam. These energies yield a recoil proton spectrum, but with an effective mean proton energy (being around 50% of NEeff). The fractional increase in LET is given by the recoil proton LET divided by the proton (LETU) value which provides the highest RBE. This ratio is then used to determine the change in the linear-quadratic model α and β parameters, from those of the reference radiation, to estimate the RBE. The predicted proton recoil RBE is then reasonably close to the experimental neutron RBE values found when taking into account the variation inherent in biological experiments. The work has some important consequences. The data of Hall et al (1975 Radiat. Res.
64 245–55) shows that the highest RBE values are found with neutron energies around 0.3–0.4 MeV, but this energy cannot possibly generate recoil proton energies which are higher, as necessary for a 0.68 MeV proton with a 30.5 keV μm−1 LETU (the LET value which provides the maximum obtainable RBE for a specified ion). For 0.4 MeV neutrons with proton recoil energies of around 0.2 MeV, the latter have a LET of around 62.88 keV μm−1. This could have an impact on proton beam RBE modelling. However, this is compensated by finding that the maximum radiosensitivity for mono-energetic neutrons was around 1.7 times larger than previously suggested from experimental ion beam studies, probably due to the necessary spreading out of Bragg peaks for ion beam experimental purposes, sampling errors and particle range considerations. This semi-empirical model can be used with minimal computer support and could have applications in ionic beams and in radioprotection.
Silicon nanowires: the promoter of performance improvement of microplasma in a microcavity array device
Authors: Ma Xiaoqin , Wang Yaogong , Chen Lichi , Hu Long , Wang Wenjiang , Zhang Xiaoning , Liu Chunliang
Published: January 2021

A microcavity array device decorated by silicon nanowires (SiNWs) is fabricated and the discharge property improvement is investigated. The array device can be operated stably from several kPa to atmospheric pressure of argon, powered by a 20 kHz bipolar nanosecond pulse source. Profiting by electron emission from SiNWs, the microplasma discharge dynamics and emission properties are significantly enhanced. Experimental results manifest that the instantaneous total current of the device decorated by SiNWs is up to ∼20% higher than that of the device without SiNWs and the mean current is increased by ∼12.5% compared with the conventional device (without SiNWs), and the ignition voltage decreased by ∼24%. The setup time is less than 90 ns before the device is fully ignited, and emission intensity enhanced by over 60% compared with the conventional plain surface device. Moreover, calculated by Lissajous figures, the discharge power of proposed device is higher than that of the traditional device with increment of ∼26%, and the impact of SiNWs on microdischarge processes is analyzed. The mechanism of the microplasma property enhancement is discussed through introducing the electric field enhancement effect at SiNWs cap and initial seed electrons emitted from SiNWs. This work combines the characteristic advantages of SiNWs with microcavity gas discharge to achieve the performance improvement of microplasma, and the results reported here has profound impacts on improving microplasma discharge properties and implies potential significance in promoting the performance of plasma applications.
Axial–azimuthal, high-frequency modes from global linear-stability model of a Hall thruster
Authors: Bello-Benítez Enrique , Ahedo Eduardo
Published: January 2021

Axial–azimuthal instabilities of a Hall-thruster plasma discharge are investigated using fluid model and a linear global stability approach, appropriate to the large axial inhomogeneity of the equilibrium solution. Electron pressure and electron inertia are considered in both the equilibrium and perturbed solutions. Fourier transform in time and azimuth are taken and the dispersion relation, for the resultant Sturm–Liouville problem governing the axial behavior of the modes, is numerically obtained. The analysis, focused in mid-to-high frequencies and large wavenumbers identifies two main instability types. The dominant mode develops in the near plume at 1–5 MHz and azimuthal mode numbers ∼10–50, has a weak ion response and seems to be triggered by negative gradients of the magnetic field. The subdominant mode develops near the anode at 100–300 kHz and azimuthal mode numbers ∼1–10, and seems of the rotating-spoke type. Both instabilities are well characterized by investigating their oblique propagation, the influence of design and operation parameters, and the effects of anode–cathode electric connection, electron inertia, and temperature perturbations. The possible impact of these instabilities on electron cross-field transport is estimated through a quasilinear approach, which yields a spatially-rippled turbulent force.
GaN FinFETs and trigate devices for power and RF applications: review and perspective
Authors: Zhang Yuhao , Zubair Ahmad , Liu Zhihong , Xiao Ming , Perozek Joshua , Ma Yunwei , Palacios Tomás
Published: January 2021

Gallium nitride (GaN) is becoming a mainstream semiconductor for power and radio-frequency (RF) applications. While commercial GaN devices are increasingly being adopted in data centers, electric vehicles, consumer electronics, telecom and defense applications, their performance is still far from the intrinsic GaN limit. In the last few years, the fin field-effect transistor (FinFET) and trigate architectures have been leveraged to develop a new generation of GaN power and RF devices, which have continuously advanced the state-of-the-art in the area of microwave and power electronics. Very different from Si digital FinFET devices, GaN FinFETs have allowed for numerous structural innovations based on engineering the two-dimensional-electron gas or p–n junctions, in both lateral and vertical architectures. The superior gate controllability in these fin-based GaN devices has not only allowed higher current on/off ratio, steeper threshold swing, and suppression of short-channel effects, but also enhancement-mode operation, on-resistance reduction, current collapse alleviation, linearity improvement, higher operating frequency, and enhanced thermal management. Several GaN FinFET and trigate device technologies are close to commercialization. This review paper presents a global overview of the reported GaN FinFET and trigate device technologies for RF and power applications, as well as provides in-depth analyses correlating device design parameters to device performance space. The paper concludes with a summary of current challenges and exciting research opportunities in this very dynamic research field.
Two-membrane cavity optomechanics: non-linear dynamics
Authors: Piergentili Paolo , Li Wenlin , Natali Riccardo , Malossi Nicola , Vitali David , Di Giuseppe Giovanni
Published: January 2021

We study the non-linear dynamics of a multimode optomechanical system constituted of a driven high-finesse Fabry–Pérot cavity containing two vibrating dielectric membranes. The analytical study allows to derive a full and consistent description of the displacement detection by a probe beam in the non-linear regime, enabling the faithful detection of membrane displacements well above the usual sensing limit corresponding to the cavity linewidth. In the weak driving regime where the system is in a pre-synchronized situation, the unexcited oscillator has a small, synchronized component at the frequency of the excited one; both large and small amplitude resonator motions are transduced in a nontrivial way by the non-linear response of the optical probe beam. We find perfect agreement between the experimental results, the numerical simulations, and an analytical approach based on slowly-varying amplitude equations.
Numerical solution and characteristic study of time-fractional shocks collision
Authors: Shakeel Mehnaz , Parveen Shahida , Islam Siraj-ul , Hussain Iltaf
Published: January 2021

In this study, the interaction of counter-propagating ion acoustic shock waves in three-component unmagnetized plasmas with inertial warm ions, superthermal electrons and positrons are examined. By employing the extended Poincare-Lighthill-Kuo (PLK) method, two-sided Korteweg-deVries-Burgers (KdVB) equations and their corresponding phase shifts for the shock wave are also derived. The derived two-sided KdVB equations are converted to two-sided time-fractional KdVB (TFKdVB) equations by semi inverse method, which is then solved numerically by a local meshless method (LMM). The effects of the ratio of electron temperature to positron temperature, the spectral index

κ

e

,

κ

p

and fractional concentration of positron component p on the phase shift are also examined. Figures are given to judge the performance of the LMM. Comparison is made with the exact solution for the classical case (i.e. ρ = 1) and with Petrov-Galerkin method (PGM) in case of fractional derivative. The influence of the fractional parameter on the behaviour of ion acoustic shock wave in e-p-i plasma is investigated.
Two-dimensional MnN utilized as high-capacity anode for Li-ion batteries*
Authors: Hu Junping , Wang Zhangyin , Zhang Genrui , Liu Yu , Liu Ning , Li Wei , Li Jianwen , Ouyang Chuying , Yang Shengyuan A.
Published: January 2021

When developing high performance lithium-ion batteries, high capacity is one of the key indicators. In the last decade, the progress of two-dimensional (2D) materials has provided new opportunities for boosting the storage capacity. Here, based on first-principles calculation method, we predict that MnN monolayer, a recently proposed 2D nodal-loop half-metal containing the metallic element Mn, can be used as a super high-capacity lithium-ion batteries anode. Its theoretical capacity is above 1554 mA⋅h/g, more than four times that of graphite. Meanwhile, it also satisfies other requirements for a good anode material. Specifically, we demonstrate that MnN is mechanically, dynamically, and thermodynamically stable. The configurations before and after lithium adsorption exhibit good electrical conductivity. The study of Li diffusion on its surface reveals a very low diffusion barrier (∼ 0.12 eV), indicating excellent rate performance. The calculated average open-circuit voltage of the corresponding half-cell at full charge is also very low (∼ 0.22 V), which facilitates higher operating voltage. In addition, the lattice changes of the material during lithium intercalation are very small (∼ 1.2%–∼ 4.8%), which implies good cycling performance. These results suggest that 2D MnN can be a very promising anode material for lithium-ion batteries.
Floquet bands and photon-induced topological edge states of graphene nanoribbons*
Authors: Wang Weijie , Lüu Xiaolong , Xie Hang
Published: January 2021

Floquet theorem is widely used in the light-driven systems. But many 2D-materials models under the radiation are investigated with the high-frequency approximation, which may not be suitable for the practical experiment. In this work, we employ the non-perturbative Floquet method to strictly investigate the photo-induced topological phase transitions and edge states properties of graphene nanoribbons under the light irradiation of different frequencies (including both low and high frequencies). By analyzing the Floquet energy bands of ribbon and bulk graphene, we find the cause of the phase transitions and its relation with edge states. Besides, we also find the size effect of the graphene nanoribbon on the band gap and edge states in the presence of the light.
Effects of post-sinter annealing on microstructure and magnetic properties of Nd–Fe–B sintered magnets with Nd–Ga intergranular addition*
Authors: Zhu Jin-Hao , Jin Lei , Jin Zhe-Huan , Ding Guang-Fei , Zheng Bo , Guo Shuai , Chen Ren-Jie , Yan A-Ru
Published: January 2021

We investigate the effects of post-sinter annealing on the microstructure and magnetic properties in B-lean Nd–Fe–B sintered magnets with different quantities of Nd–Ga intergranular additions. The magnet with fewer Nd–Ga additions can enhance 0.2 T in coercivity, with its remanences nearly unchanged after annealing. With the further increase of the Nd–Ga addition, the annealing process leads coercivity to increase 0.4 T, accompanied by a slight decrease of remanence. With the Nd–Ga addition further increasing and after annealing, however, the increase of coercivity is basically constant and the change of remanence is reduced. Microstructure observation indicates that the matrix grains are covered by continuous thin grain boundary phase in the magnets with an appropriate Nd–Ga concentration after the annealing process. However, the exceeding Nd–Ga addition brings out notable segregation of grain boundary phase, and prior formation of part RE
6Fe13Ga phase in the sintered magnet. This prior formation results in a weaker change of remanence after the annealing process. Therefore, the diverse changes of magnetic properties with different Nd–Ga concentrations are based on the respective evolution of grain boundary after the annealing process.
The NUBASE2020 evaluation of nuclear physics properties *
Authors: Kondev F.G. , Wang M. , Huang W.J. , Naimi S. , Audi G.
Published: January 2021

The NUBASE2020 evaluation contains the recommended values of the main nuclear physics properties for all nuclei in their ground and excited, isomeric (T1/2

100 ns) states. It encompasses all experimental data published in primary (journal articles) and secondary (mainly laboratory reports and conference proceedings) references, together with the corresponding bibliographical information. In cases where no experimental data were available for a particular nuclide, trends in the behavior of specific properties in neighboring nuclei were examined and estimated values are proposed. Evaluation procedures and policies that were used during the development of this evaluated nuclear data library are presented, together with a detailed table of recommended values and their uncertainties.
Isotope dependence of the type I ELMy H-mode pedestal in JET-ILW hydrogen and deuterium plasmas
Authors: Horvath L. , Maggi C.F. , Chankin A. , Saarelma S. , Field A.R. , Aleiferis S. , Belonohy E. , Boboc A. , Corrigan G. , Delabie E.G. , Flanagan J. , Frassinetti L. , Giroud C. , Harting D. , Keeling D. , King D. , Maslov M. , Matthews G.F. , Menmuir S. , Silburn S.A. , Simpson J. , Sips A.C.C. , Weisen H. , Gibson K.J. , JET Contributors
Published: January 2021

The pedestal structure, edge transport and linear MHD stability have been analyzed in a series of JET with the ITER-like wall hydrogen (H) and deuterium (D) type I ELMy H-mode plasmas. The pedestal pressure is typically higher in D than in H at the same input power and gas rate, with the difference mainly due to lower density in H than in D (Maggi et al (JET Contributors) 2018 Plasma Phys. Control. Fusion
60 014045). A power balance analysis of the pedestal has shown that higher inter-ELM separatrix loss power is required in H than in D to maintain a similar pedestal top pressure. This is qualitatively consistent with a set of interpretative EDGE2D-EIRENE simulations for H and D plasmas, showing that higher edge particle and heat transport coefficients are needed in H than in D to match the experimental profiles. It has also been concluded that the difference in neutral penetration between H and D leads only to minor changes in the upstream density profiles and with trends opposite to experimental observations. This implies that neutral penetration has a minor role in setting the difference between H and D pedestals, but higher ELM and/or inter-ELM transport are likely to be the main players. The interpretative EDGE2D-EIRENE simulations, with simultaneous upstream and outer divertor target profile constraints, have indicated higher separatrix electron temperature in H than in D for a pair of discharges at low fueling gas rate and similar stored energy (which required higher input power in H than in D at the same gas rate). The isotope dependence of linear MHD pedestal stability has been found to be small, but if a higher separatrix temperature is considered in H than in D, this could lead to destabilization of peeling-ballooning modes and shrinking of the stability boundary, qualitatively consistent with the reduced pedestal confinement in H.
Technologies for automation creation of an ontology of urbanonyms in the aspect of historical changes (on the example of Almaty)
Authors: Barakhnin Vladimir , Mansurova Madina , Dossanov Bekzhan , Kyrgyzbayeva Marzhan
Published: January 2021

When creating geoinformation systems of a city scale, relation this or that information from Internet, there comes the task of creation an ontology of urbanonyms taking into account their historical changes. The account of historical changes is necessary, for example, to process messages about urban event from blogs: since more and more representatives of the middle and older generations are becoming active Internet users, the massages often contain the former names of urbanonyms. Let us note that it is the accounting of historical changes that is required to solve this problem that determines the need to create not a thesaurus, which is sufficient, as shown in [1], to take into account geographical names commonly used (at least in natural science articles) in their actual from, but an ontology. Taking into account the specifics of the task of creating an ontology of Almaty, in should be bilingual: in the Kazakh and Russian languages.
Parallel news clustering and topic modeling approaches
Authors: Shomanov A S , Mansurova M E
Published: January 2021

At the current age there is an urgent need in developing massively scalable and efficient tools to Big Data processing. Even the smallest companies nowadays inevitably require more and more resources for data processing routines that could enhance decision making and reliably predict and simulate different scenarios. In the current paper we present our combined work on different massively scalable approaches for the task of clustering and topic modeling of the dataset, collected by crawling Kazakhstan news websites. In particular, we propose Apache Spark parallel solutions to news clustering and topic modeling problems and, additionally, we describe results of implementing document clustering using developed partitioned global address space Mapreduce system. In our work we describe our experience in solving these problems and investigate the efficiency and scalability of the proposed solutions.
Improvement of metrological measurements of bridge crossings at waterworks when studying non-destructive testing methods
Authors: Bandurin M A , Bandurina I P , Yurchenko I F
Published: January 2021

The article considers the main parameters of applying the modern methods of metrological measurements of bridge crossings on water channels during research with non-destructive testing methods. Instrumental surveys of water supply facilities in Russia showed that in some cases their effectiveness, operational quality and reliability are insufficient, which is associated with violations of normal water supply systems functioning. In modern conditions, with limited public resources allocated for the reconstruction of water facilities, problems of optimizing the requirements for metrological support of the developed non-destructive testing measuring instruments and the unification of observation technologies are of particular importance. The most common are defects of an internal nature, leading to the disruption of waterworks normal functioning. We can conclude that violations of the butt joints of prefabricated elements, breaking and breaching of walls in various zones, cracks, sliding and subsidence of elements relative to each other lead to disruption of the normal operation of bridge crossings. This raises problems such as the loss of scarce irrigation water, rising groundwater levels, waterlogging and salinization of irrigated lands. The solution to these problems should be based on the mandatory consideration of reliability requirements in design, construction and operation. The purpose of research with non-destructive testing instruments was to detect possible defects in concrete bridge crossings and determine the condition of reinforcing bars. These field studies were carried out using the OKO-2 GPR and the electronic concrete strength measurer IPS-MG4.01. Comparison of the vertical displacement profiles of bridge crossing bearing components through the waterworks horizontally along and across the bearing elements revealed insignificant internal changes. A metrological support system for research by non-destructive methods for monitoring bridge crossings at waterworks is necessary to achieve unity and the required accuracy, completeness, timeliness and efficiency of measurements.
Combined hydroacoustic research of Lake Baikal
Authors: Gubin N A , Grigorev K A , Poletaev A S , Chensky A G
Published: January 2021

The article outlines the main approaches to studying the bottom topography of Lake Baikal and interpretation of bathymetric data. Measurement equipment and experimental data processing algorithms are described. A measuring complex is based on using the Kongsberg EM710S multibeam echosounder which allows one to take a detailed digital elevation model of the bottom. The paper demonstrates experimental results obtained during a series of expeditions to the Baikal in 2015 – 2019. Currently an area of about 12117 km2 (∼38%) of Lake Baikal bottom has been explored. Examples of a digital model of the Baikal bottom are also presented. The paper demonstrates 3D models of detected water columns showing intense of a gas bubbles emanation near the mouth of Selenga river, acoustic images of the Baikal Gigaton Volume Detector (Baikal-GVD), and a bathymetric map of Academician Ridge that was previously examined with the Mir 1 and Mir 2 in July 2009.
Thermophysical properties control during transportation of the liquefied hydrocarbon mixtures by means of REFPROP software package
Authors: Zakirova G S , Krapivsky E I
Published: January 2021

The authors have presented an argument for the possibility of REFPROP software package application for thermophysical properties control of the liquefied hydrocarbon mixtures depending on the composition including design and measured data of phase states of the hydrocarbon mixtures. The studies were carried out by the example of the Chayandinskiy oil and gas condensate field. The presented results of the phase state of mixtures of an oil and gas condensate field using the example of the Chayandinskiy field allow us to predict the behavior of liquefied hydrocarbons at low temperatures, as well as determine the parameters for further transportation in a single-phase liquid state through low-temperature pipelines. Also the task of thermophysical properties control during transportation of the liquefied hydrocarbon mixtures has been analysed. The composition changing of methane and light hydrocarbon mixture allows one to enlarge the mixture density greatly and to change its other properties at acceptable temperatures and pressures. In the article it is shown that the mixture usage is energetically more efficient than the liquefied gas.
Research of influence of failures on the productivity of the technological module in the structure of mechanical-assembly production
Authors: Zamoryonov M V , Kopp V Ya , Rapatskiy Yu L , Zamoryonova D V , Lypka V M
Published: January 2021

The effect of various failures on the real productivity of the process module in the structure of mechanical-assembly production is investigated. A semi-Markov mathematical model is proposed, which allowsone to investigate the productivity of a hierarchically organized technological system taking into account its stochasticity and various failures. The model also allows you to explore the processes of testing and operation of finished products. This is proposed as an example of how to simulate an exploitation process of the item of machine-building. The proposed model allows one to take into account the influence of technological inheritance. Initial data for simulation are obtained by processing the results of production experiments.
The determination of requirements for metrological parameters of geotechnical monitoring systems based on the bifurcation approach
Authors: Dorofeev N V , Grecheneva A V , Pankina E S
Published: January 2021

The article is devoted to substantiating the possibility of applying the bifurcation approach to determine the requirements for the metrological characteristics of the measuring part of geotechnical monitoring systems. It is noted that during the operation of the constructions, the change of physicomechanical properties is in the “soil base-foundation-structure” system. It is caused by seasonal, climatic factors and the change in the industrial environment. Prospects of using the bifurcation approach to assessing the stability of constructions under the influence of exogenous factors are noted. The nonlinear model of the deformation of the construction is described using an example of the rod with one degree of freedom, and the bifurcation diagram of its stability is constructed. It is noted that at the development stage of the construction the application of the bifurcation approach allows one to carry out the modelling and to determine bifurcation points, requirements for the sensitivity and accuracy of measuring instruments. It is proved that the probability of occurrence of errors of the 1st and 2nd kind is much lower on the basis of the proposed approach to assessing stability. The possibility of estimating the permissible error of measuring instruments is proved based on data from bifurcation diagrams.
Method of accelerated industrial testing of hydroabrasive wear of polymer coatings of steel pipes
Authors: Kuskildin R B , Vatlina A M
Published: January 2021

The article is devoted to the discussion of the problem of choosing a protective coating for the inner walls of the slurry pipeline of mining enterprises. For the correct choice among the many polymer coatings, it is necessary to test various coatings for water-jet wear. Standardized test methods are not entirely suitable for assessing the durability of coatings in a specific production environment, they do not take into account the nature of the slurry flow, temperature, etc. Solid inclusions of a different particle size and chemical composition are often used in ready-made and published studies, which makes them irrelevant for mining specialists. Often, for a comparative assessment of the wear resistance of various coatings, enterprises conduct their own industrial tests for hydroabrasive wear, in which they recreate the same granulometric composition of the pulp and its concentration. However, they come with a significant investment of time and energy. The article proposes to use a method of accelerated wear testing based on a comparison of the wear of a straight section of a pipeline and a shaped one in the form of a rotary insert at an angle of 90°.
STUDY ON DAMAGE CONSTITUTIVE MODEL OF RECYCLED AGGREGATE CONCRETE IN CODE FOR DESIGN OF CONCRETE STRUCTURES AND DEVELOPMENT IN ABAQUS
Authors: Wei Huang , Tao Yang , Yan Chen , Pei Ge , Lang Zhou
Published: January 2021

Based on the damage constitutive of ordinary concrete in code for Design of Concrete Structures and considering the similarity of mechanical properties between recycled aggregate concrete and ordinary concrete, a uniaxial damage constitutive of recycled concrete was proposed. At the same time, the above model was programmed as a subroutine by FORTRAN language, and the subroutine was embedded into finite element analysis software ABAQUS to simulate and analyze the uniaxial compression mechanical properties of recycled concrete. The results of finite element simulation and test are compared from the aspects of stress-strain curve and damage evolution curve. The results show that the proposed elastic-plastic damage constitutive model can effectively represent the mechanical properties of recycled aggregate concrete under uniaxial compression at different substitution rates.
Facile fabrication of a red AIE luminogen with simple structure and bright emissions for cell imaging
Authors: Ding Guanyu , Wen Lili , Su Zhongmin , Shan Guogang
Published: January 2021

Fluorescence imaging in red region is of great interest in both practical applicantion and fundamental research. However, the complicated synthetic approaches and low emission efficiency of the fluorescence materials are still implement their bilolgical applications. Herein, a facile synthesis method for a red luminogen with aggregation-induced emission (AIE) is reported. The AIE probe possesses simple structure and high red brightness, favoring its applications toward in vitro and vivo imaging. This study offers an ideal architecture for the construction of red AIEgens with a simple structure.
First-principles calculation on thermodynamic properties of ZnO1-x
S
x
alloys with concidering lattice vibrations
Authors: Luo Minghai
Published: January 2021

Thermodynamic properties of zinc-blende (ZB) and wurtzite (WZ) ZnO1-x
S
x
has been studied with the first-principles methods. The critical temperature for separation is 1981 K for the ZB structures and 1563 K for the WZ structures with the inclusion of lattice vibrations which leads to a large reduction with 20.7 % and 16.7 % for the ZB and WZ structures, respectively. And with the analysis of the phase diagram, The lower critical temperature and the more symmetric phase diagram of WZ structure indicate it has better thermodynamic stability, which is in agreement with experiments.
Fault diagnosis method for power system of civil aircraft Assembly site
Authors: Ying Wu
Published: January 2021

During the process of producing civil aircraft(On the Aircraft Test Procedure), Whether the electric power system fault can be quickly, accurately and properly diagnosed and closed will directly affect the production schedule and even delay delivery of the aircraft. This paper introduces the diagnosis requirements and methods of power system failure in production field, based on the practical experience, a troubleshooting model is proposed, and has certain guiding function for engineering management staff and liaison engineers.
Nucleic acid-based rapid methods for the detection of foodborne pathogens
Authors: Wang Puyao
Published: January 2021

Food safety is critical to people’s health and even life. However, food safety incidents always emerge unexpectedly. This paper is divided into two parts. First, we introduced the common foodborne pathogens causing food pollution. After that, we reviewed nucleic acid-based rapid methods such as conventional PCR, NASBA, LAMP, RPA, and Microarray. Finally, existed problems and future improvement measures are proposed in order to make food detection more convenient and efficient in the future.
Affinity materials for Phosphorylated and Glycosylated Proteins/Peptides enrichment
Authors: Li Xinquan
Published: January 2021

Two typical types of protein post-translational modifications (PTM), protein/peptides phosphorylation and glycosylation play important roles in numerous biochemical processes including signal transduction, cell division, protein secretion and phagocytic vesicles trafficking. Mass spectrometry (MS) is one of the most widely used tools for PTM analysis. Although mass spectrometry is one of the most powerful analysis tool, it is always interfered by impurities and almost impossible to analyze phosphorylated and glycosylated proteins/peptides directly from complicated bio-sample because of low abundance of target proteins/peptides and interference of non-target substances. Thus, enrichment of phosphorylated and glycosylated proteins/peptides is an essential procedure before MS analysis to ensure the effectiveness of MS detection. In this review, recent progress in phosphorylated and glycosylated proteins/peptides enrichment strategies is summarized.
Novel polyrotaxane cross-linkers as a versatile platform for slide-ring silicone
Authors: Tran Jakob-Anhtu , Madsen Jeppe , Skov Anne Ladegaard
Published: January 2021

Slide-ring elastomers have garnered a lot of interest for their potential use in dielectric elastomer actuators due to their intrinsically soft nature and high elasticity. However, the use of sliding cross-linkers has been constrained by their low miscibility with commonly used elastomer precursors and the specialized curing chemistries that are necessary for incorporating them into networks. Here, we have presented a method to produce vinyl functional polyrotaxane cross-linkers that are compatible with polysiloxanes and can be processed by industrially scalable methods. The sliding silicone films that were fabricated with these novel cross-linkers were highly extensible (>350%) and did not exhibit strain hardening even at high elongation. The composite films also retained the favorable dielectric properties of silicone elastomers such as the characteristic low dielectric loss. The modified polyrotaxanes present a robust platform for producing a new class of sliding silicone elastomers with well-defined networks structures.
Polydopamine–Ag composite surface guides HBMSCs adhesion and proliferation
Authors: Bian Yifeng , Wang HaoRan , Xu Jiamin , Wang Zhuo , Du Xin , Wang Yuli , Du Yifei
Published: January 2021

Human bone marrow mesenchymal stem cells (HBMSCs) are regarded as an important resource in the field of maxillofacial bone regeneration because of their favorable properties when compared with other stem cells. Hence, finding suitable materials that could extend the application of HBMSCs has become an emerging medical topic and socioeconomic problem. In this work, polydopamine (PDA)–Ag surface was fabricated by PDA assisted photoreduction method, and the obtained PDA–Ag composite surface significantly promoted HBMSCs adhesion and proliferation. This effect is highly related to the amount of Ag nanoparticles (Ag NPs) present on the PDA surface. The behavior of HBMSCs on PDA–Ag surface could be spatially manipulated by controlling the distribution of Ag NPs on PDA surface (by controlling UV light). The general adhesion property allows the PDA–Ag surface to be fabricated on various substrates, making it a simple, general and controllable method for the fabrication of bioactive surface for HBMSCs.
Is wetter better? Exploring agriculturally-relevant rainfall characteristics over four decades in the Sahel
Authors: Porkka Miina , Wang-Erlandsson Lan , Destouni Georgia , Ekman Annica M L , Rockström Johan , Gordon Line J
Published: January 2021

The semi-arid Sahel is a global hotspot for poverty and malnutrition. Rainfed agriculture is the main source of food and income, making the well-being of rural population highly sensitive to rainfall variability. Studies have reported an upward trend in annual precipitation in the Sahel since the drought of the 1970s and early ‘80s, yet farmers have questioned improvements in conditions for agriculture, suggesting that intraseasonal dynamics play a crucial role. Using high-resolution daily precipitation data spanning 1981–2017 and focusing on agriculturally-relevant areas of the Sahel, we re-examined the extent of rainfall increase and investigated whether the increases have been accompanied by changes in two aspects of intraseasonal variability that have relevance for agriculture: rainy season duration and occurrence of prolonged dry spells during vulnerable crop growth stages. We found that annual rainfall increased across 56% of the region, but remained largely the same elsewhere. Rainy season duration increased almost exclusively in areas with upward trends in annual precipitation (23% of them). Association between annual rain and dry spell occurrence was less clear: increasing and decreasing frequencies of false starts (dry spells after first rains) and post-floral dry spells (towards the end of the season) were found to almost equal extent both in areas with positive and those with no significant trend in annual precipitation. Overall, improvements in at least two of the three intraseasonal variables (and no declines in any) were found in 10% of the region, while over a half of the area experienced declines in at least one intraseasonal variable, or no improvement in any. We conclude that rainfall conditions for agriculture have improved overall only in scattered areas across the Sahel since the 1980s, and increased annual rainfall is only weakly, if at all, associated with changes in the agriculturally-relevant intraseasonal rainfall characteristics.
The driving forces behind the change in energy consumption in developing countries
Authors: Li Shuping , Meng Jing , Zheng Heran , Zhang Ning , Huo Jingwen , Li Yuan , Guan Dabo
Published: January 2021

Economic growth is principally powered by energy fuels. While the potential energy transition pathways in developed countries are clear, they have not been well explored for developing countries. Here, we study the average annual growth rate of energy consumption in 12 aggregated regions during 2001–2017 and the driving factors behind that growth. The countries with high energy consumption growth rates were concentrated in Asia and North Africa and four of the top five regions were in Asia, while the energy consumption in developed countries was stable or even declined in that period. Therefore, based on a comprehensive consideration of factors such as population and economic development, to quantify the role of renewable energy, we analyze the long time series of energy consumption for China, India, Indonesia, Myanmar and Bangladesh since the 1970s. Despite economic development and population growth accelerating energy consumption substantially upward, energy intensity made energy consumption decrease. Coal and oil dominated the energy transition pathway in China and India, while biomass and natural gas dominated in Indonesia, Myanmar and Bangladesh. The amount of CO2 emissions in different countries was closely related to the amount and type of the energy they used. Our research results emphasize the importance of improving energy efficiency and adjusting energy structure to reduce energy consumption and achieve sustainable development.
Integrable hierarchies associated to infinite families of Frobenius manifolds
Authors: Basalaev Alexey , Dunin-Barkowski Petr , Natanzon Sergey
Published: January 2021

We propose a new construction of an integrable hierarchy associated to any infinite series of Frobenius manifolds satisfying a certain stabilization condition. We study these hierarchies for Frobenius manifolds associated to A

N
, D

N
and B

N
singularities. In the case of A

N
Frobenius manifolds our hierarchy turns out to coincide with the dispersionless KP hierarchy; for B

N
Frobenius manifolds it coincides with the dispersionless BKP hierarchy; and for D

N
hierarchy it is a certain reduction of the dispersionless 2-component BKP hierarchy. As a side product to these results we illustrate the enumerative meaning of certain coefficients of A

N
, D

N
and B

N
Frobenius potentials.
Huygens’ principle for the generalized Dirac operator in curved spacetime
Authors: Yagdjian Karen
Published: January 2021

In this article we give sufficient conditions for the generalized Dirac operator to obey the incomplete Huygens principle, as well as necessary and sufficient conditions to obey the Huygens principle by the Dirac operator in the curved spacetime of the Friedmann–Lemaître–Robertson–Walker (FLRW) models of cosmology.
Effects analysis of vertical track irregularities on bogie vibration - method based on bogie modelling and wheelsets accelerations measurement
Authors: Dumitriu M , Fologea D , Cruceanu I C
Published: January 2021

The paper analyzes the effect of the vertical track irregularities upon the vibrations in a two-axle bogie. The method in use implies the bogie modelling and the measurement of the vibrations in wheelsets generated by the track vertical irregularities. The behaviour of vibrations in the bogie is evaluated via the results derived from applications of numerical simulation developed on the basis of the bogie model, where the inputs are the accelerations measured in the two wheelsets. The vibration features in the bogie are pointed out at according to the spectra of accelerations in the bogie frame, to the standard deviation values of accelerations and to the maximum values of the accelerations calculated against the two wheelsets.
Intelligent control of wheel rail contact noise phenomenon in rail transportation
Authors: Chiba E , Abdelkrim M , Belloufi A , Rezgui I
Published: January 2021

Railway transport systems play a very important role in the future of transport. They offer sustainable solutions that reduce carbon emissions (environmental requirements) and allow more mobility with better energy efficiency, and they generate advantageous economic benefits in the long term. But the interaction between the wheel and the rail is always very difficult to approach. There are a large number of studies in the literature on this problem. However, there is still no comprehensive approach. On this work we propose to study numerical modelling of contact between wheel-rail systems by using fuzzy logic. For this purpose, the experimental collection data reported in literature are used to predict the resonance noise during wheel-rail contact in rail transport. We found a good agreement between the elaborated model and the results of the literature.
Numerical modeling of pipe parts of agricultural machinery expansion by stepped punches
Authors: Puzyr R H , Shchetynin V T , Arhat R H , Sira Yu B , Muravlov V V , Kravchenko S I
Published: January 2021

The paper presents the research of plastic expansion of a pipe workpiece by punches of various configurations. It is shown that interest in this process is caused by the development of oil production, where there is a need to increase the diameter of well pipes, the automobile industry, where the protection of the driver and passengers in case of accidents comes first. Here, stable plastic deformation plays an important role as a good absorber of kinetic energy, etc. Data on the problems of expanding pipe ends are given, where special attention is paid to the destruction of the end in the form of localization of deformations and appearance of a longitudinal crack. To eliminate this phenomen onvarious technological methods are used. Here the influence of the design and shape of the punch on the localization of deformations along the thickness of the workpiece is researched. Several spatial outlines of the tool are proposed to create an effective reloading of the pipe workpiece in the deformation zone. Based on numerical modeling, the distribution of stresses according to Mises, the displacement of the end of the semi-finished product and logarithmic deformations in the radial direction is shown for each standard size of the punch. Comparative results reveal an increase in the thickness of the workpiece in the dangerous section for all presented punches. The comparison was carried out with a reference tool that has a straight generatrix of a tapered surface. The best results are shown by a punch with an enlarged generatrix at the end of the working stroke. Attention is focused on conducting further research in order to study the possibility of overcritical deformation by the proposed tool.
Automatic positioning methodology and algorithm for modular jigs and fixtures components
Authors: Savu T , Nanu S , Ene I C
Published: January 2021

One of the steps in designing a modular jig or fixture assembly is that of selecting the appropriate components. Among these components, those forming the jig’s body must be chosen for closing the dimensional chains between the other locating, clamping, or indexing components. The methodology starts by defining the components’ virtual connectors, specifying the rules for establishing their coordinates systems, and then is defining the rules to be followed for aligning and assembling two adjacent components. Different cases are described and only some of them are detailed, for clarity reasons. The algorithm is looking to determine a series of components from which the first is in a fixed position, related to other locating or clamping jig’s component. A hierarchical tree is generated, using available components, having in each node a component which is assembled with a previous one using the above-mentioned connectors. Interference criteria is checked for selecting possible solutions only. A stop criterion related to the number of components in a branch is used, Solutions from the different branches are compared using the distances to an end component.