bluuebunny/crossref_metadata_2025 huggingface dataset:
Narrow-linewidth diamond single-photon sources prepared via femtosecond laser
Authors: Gao Si , Yin Si-Yu , Liu Zhao-Xin , Zhang Zong-Da , Tian Zhen-Nan , Chen Qi-Dai , Chen Nian-Ke , Sun Hong-Bo
Published: January 2022

Nitrogen-vacancy (NV) color centers in diamonds with narrow optical linewidths are commonly used as solid-state single-photon sources that emit indistinguishable photons. However, NV color centers prepared using ion implantation typically have large optical linewidths of over 100 MHz. Herein, we used the femtosecond laser direct writing (FsLDW) technique to prepare single NV color centers in diamond with a narrow optical linewidth of 13.05 ± 0.2 MHz and a long decoherence time of 445 ± 27.6 μs. In addition, the density functional theory was adopted to establish calculation models and illustrate why single NV color centers prepared by FsLDW have narrower linewidths compared to those of the ion implantation method. Thus, this study provides an effective reference for the preparation of narrow-linewidth single-color centers in diamonds and other wide-gap crystals.
Evaluation of thermal material properties based on SAW dispersion in the laser-induced dynamic subsurface temperature gradient
Authors: Liu Xiangen , Lomonosov Alexey M. , Shen Zhonghua
Published: January 2022

Dispersion of surface acoustic waves (SAWs) caused by a dynamic surface heating–cooling cycle has been applied for evaluation of thermal properties. A laser-generated broad-band SAW pulse is propagated through the material whose elastic properties and density were modified by the dynamic inhomogeneous temperature field produced by laser heating and subsequent cooling. A sample with depth-dependent material properties introduces a phase velocity dispersion in SAW propagation. Dispersion was measured by a differential technique, which helped to isolate the thermally induced dispersion and eliminate the contributions of other possible sources of dispersion. The dispersion curves were measured at several time instants, which allowed evaluation of the following parameters: thermal diffusivity, temperature dependence of the shear modulus, and the temperature magnitude. The inverse problem was solved by fitting the experimental dispersion curves into the theoretical ones by means of differential evolution techniques.
Lord Robert May of Oxford 1936–2020
Authors: Krebs Lord (John) , Hassell Michael , Godfray Sir Charles
Published: January 2022

Robert May was the leading theoretical ecologist of his generation. He started his career as a theoretical physicist and began the transition to ecology soon after completing a post-doctoral fellowship at Harvard. His mathematical analysis of the stability of ecological communities challenged orthodox views and spawned a new research agenda. He demonstrated that many different patterns of population fluctuations, including chaotic behaviour, could arise from simple mathematical models. Together with R. M. Anderson he transformed the mathematical modelling of infectious diseases. All of his work was characterised by his remarkable ability to reduce complex problems to their essential simplicities. His achievements were recognised by the award of numerous major international prizes. May also served as government chief scientific advisor (UK) between 1995 and 2000, and as president of the Royal Society between 2000 and 2005.
A guaranteed immediate payout reduces impatience of financially constrained individuals
Authors: van der Heijden Kimberley , Festjens Anouk , Goukens Caroline , Meyvis Tom
Published: January 2022

Significance

A wealth of existing findings show that financially constrained individuals are myopic decision-makers who are particularly concerned about the present. We propose that the use of existing intertemporal choice tasks may have skewed our understanding of the decision-making of financially constrained individuals. Specifically, we observe that—as long as an immediate payout is guaranteed—financially constrained individuals are no more myopic than their more affluent counterparts.
Vps13-like proteins provide phosphatidylethanolamine for GPI anchor synthesis in the ER
Authors: Toulmay Alexandre , Whittle Fawn B. , Yang Jerry , Bai Xiaofei , Diarra Jessica , Banerjee Subhrajit , Levine Tim P. , Golden Andy , Prinz William A.
Published: January 2022

Glycosylphosphatidylinositol (GPI) is a glycolipid membrane anchor found on surface proteins in all eukaryotes. It is synthesized in the ER membrane. Each GPI anchor requires three molecules of ethanolamine phosphate (P-Etn), which are derived from phosphatidylethanolamine (PE). We found that efficient GPI anchor synthesis in Saccharomyces cerevisiae requires Csf1; cells lacking Csf1 accumulate GPI precursors lacking P-Etn. Structure predictions suggest Csf1 is a tube-forming lipid transport protein like Vps13. Csf1 is found at contact sites between the ER and other organelles. It interacts with the ER protein Mcd4, an enzyme that adds P-Etn to nascent GPI anchors, suggesting Csf1 channels PE to Mcd4 in the ER at contact sites to support GPI anchor biosynthesis. CSF1 has orthologues in Caenorhabditis elegans (lpd-3) and humans (KIAA1109/TWEEK); mutations in KIAA1109 cause the autosomal recessive neurodevelopmental disorder Alkuraya-Kučinskas syndrome. Knockout of lpd-3 and knockdown of KIAA1109 reduced GPI-anchored proteins on the surface of cells, suggesting Csf1 orthologues in human cells support GPI anchor biosynthesis.
Theoretical study of generalized oscillator strengths for the low-lying electronic excitations of CH3Cl and CF3Cl
Authors: Watanabe Noboru , Takahashi Masahiko
Published: January 2022

We report a theoretical study of electronic excitation in CH3Cl and CF3Cl by electron impact. Momentum-transfer-dependent generalized oscillator strengths (GOSs) are calculated for transitions to low-lying excited singlet-states at the equation-of-motion coupled-cluster singles and doubles level. The influence of molecular vibration is taken into account in the calculation. The theoretical results show reasonable overall agreement with experimental data reported in the literature. The shapes of the GOS profiles reveal that the 1 1E state of CH3Cl has a valence-Rydberg mixed nature, while that of CF3Cl is of a predominant C–Cl antibonding character. A comparison with the experimental GOSs of CH3Cl provides unambiguous evidence that the 3pe state is lower in energy than the 3pa1 state. Optical oscillator strengths are also calculated and comparison is made with available experimental and other theoretical results.
Radiation tolerance of GaN: the balance between radiation-stimulated defect annealing and defect stabilization by implanted atoms
Authors: Titov A I , Karabeshkin K V , Struchkov A I , Karaseov P A , Azarov A
Published: January 2022

Realization of radiation-hard electronic devices that are able to work in harsh environments requires deep understanding of the processes of defect formation/evolution occurring in semiconductors bombarded by energetic particles. In the present work we address such intriguing radiation phenomenon as high radiation tolerance of GaN and analyze structural disorder, employing advanced co-irradiation schemes where low and high energy implants with different ions have been used. Channeling analysis revealed that the interplay between radiation-stimulated defect annealing and defect stabilization by implanted atoms dominates defect formation in the crystal bulk. Furthermore, the balance between these two processes depends on implanted species. In particular, strong damage enhancement leading to the complete GaN bulk amorphization was observed for the samples pre-implanted with fluorine ions, whereas the co-irradiation of the samples pre-implanted with such elements as neon, phosphorus and argon leads to a decrease of the bulk damage.
Trivalent ion overcharging on electrified graphene
Authors: Carr Amanda J , Lee Sang Soo , Uysal Ahmet
Published: January 2022

The structure of the electrical double layer (EDL) formed near graphene in aqueous environments strongly impacts its performance for a plethora of applications, including capacitive deionization. In particular, adsorption and organization of multivalent counterions near the graphene interface can promote nonclassical behaviors of EDL including overcharging followed by co-ion adsorption. In this paper, we characterize the EDL formed near an electrified graphene interface in dilute aqueous YCl3 solution using in situ high resolution x-ray reflectivity (also known as crystal truncation rod) and resonant anomalous x-ray reflectivity (RAXR). These interface-specific techniques reveal the electron density profiles with molecular-scale resolution. We find that yttrium ions (Y3+) readily adsorb to the negatively charged graphene surface to form an extended ion profile. This ion distribution resembles a classical diffuse layer but with a significantly high ion coverage, i.e., 1 Y3+ per 11.4 ± 1.6 Å2, compared to the value calculated from the capacitance measured by cyclic voltammetry (1 Y3+ per ∼240 Å2). Such overcharging can be explained by co-adsorption of chloride that effectively screens the excess positive charge. The adsorbed Y3+ profile also shows a molecular-scale gap (⩾5 Å) from the top graphene surfaces, which is attributed to the presence of intervening water molecules between the adsorbents and adsorbates as well as the lack of inner-sphere surface complexation on chemically inert graphene. We also demonstrate controlled adsorption by varying the applied potential and reveal consistent Y3+ ion position with respect to the surface and increasing cation coverage with increasing the magnitude of the negative potential. This is the first experimental description of a model graphene-aqueous system with controlled potential and provides important insights into the application of graphene-based systems for enhanced and selective ion separations.
A ReaxFF potential for Al–ZnO systems
Authors: Brown I , Smith R , Kenny S D
Published: January 2022

A reactive field force potential has been created in order to model the structural effects of low percentage dopant aluminium in a zinc oxide (ZnO) system. The potential’s parameters were fitted to configurations computed with density functional theory: binding energies were considered for surface structures and for Al in ZnO bulk crystals. Energies for Zn–Al alloys were also considered. Forces were fit to zero for all equilibrium structures and were also fitted for some non-equilibrium structures. As a first application of the model, the energetic deposition (0.1–40 eV) of an aluminium atom onto the polar surface of a ZnO

(

000

1

¯

)

is considered. For low energies the Al atom attaches to two preferred sites on the surface but as the energy increases above ≈15 eV subplantation is preferred at near normal incidence, with high diffusion barriers between stable sites. At these energies, reflection of the Al atom occurs at incident angles above

≈
55
°

.
A new method for high resolution curvature measurement applied to stress monitoring in thin ﬁlms
Authors: Grachev Sergey , Hérault Quentin , Wang Jun , Balestrieri Matteo , Montigaud Hervé , Lazzari Remi , Gozhyk Iryna
Published: January 2022

By combining the well-known grid reﬂection method with a digital image correlation algorithm and a geometrical optics model, a new method is proposed for measuring the change of curvature of a smooth reﬂecting substrate, a common reporter of stress state of deposited layers. This tool, called Pattern Reﬂection for Mapping of Curvature (PReMC), can be easily implemented for the analysis of the residual stress during deposition processes and is suﬃciently accurate to follow the compressivetensile-compressive stress transition during the sputtering growth of a Ag ﬁlm on a Si substrate. Unprecedented resolution below 10-5m-1can be reached when measuring a homogeneous curvature. A comparison with the conventional laser-based tool is also provided in terms of dynamical range and resolution. In addition, the method is capable of mapping local variations in the case of a non-uniform curvature as illustrated by the case of a non-homogeneous Mo ﬁlm under high compressive stress. PReMC oﬀers interesting perspectives for in situ accurate stress monitoring in the ﬁeld of thin ﬁlm growth.
Fast magnetic resonance elastography with multiphase radial encoding and harmonic motion sparsity based reconstruction
Authors: Wang Runke , Chen Yu , Li Ruokun , Qiu Suhao , Zhang Zhiyong , Yan Fuhua , Feng Yuan
Published: January 2022

Objective. To achieve fast magnetic resonance elastography (MRE) at a low frequency for better shear modulus estimation of the brain. Approach. We proposed a multiphase radial DENSE MRE (MRD-MRE) sequence and an improved GRASP algorithm utilizing the sparsity of the harmonic motion (SH-GRASP) for fast MRE at 20 Hz. For the MRD-MRE sequence, the initial position encoded by spatial modulation of magnetization (SPAMM) was decoded by an arbitrary number of readout blocks without increasing the number of phase offsets. Based on the harmonic motion, a modified total variation and temporal Fourier transform were introduced to utilize the sparsity in the temporal domain. Both phantom and brain experiments were carried out and compared with that from multiphase Cartesian DENSE-MRE (MCD-MRE), and conventional gradient echo sequence (GRE-MRE). Reconstruction performance was also compared with GRASP and compressed sensing. Main results. Results showed the scanning time of a fully sampled image with four phase offsets for MRD-MRE was only 1/5 of that from GRE-MRE. The wave patterns and estimated stiffness maps were similar to those from MCD-MRE and GRE-MRE. With SH-GRASP, the total scan time could be shortened by additional 4 folds, achieving a total acceleration factor of 20. Better metric values were also obtained using SH-GRASP for reconstruction compared with other algorithms. Significance. The MRD-MRE sequence and SH-GRASP algorithm can be used either in combination or independently to accelerate MRE, showing the potentials for imaging the brain as well as other organs.
Ultrafast modulation of vibrational polaritons for controlling the quantum field statistics at mid-infrared frequencies
Authors: Triana Johan F. , Herrera Felipe
Published: January 2022

Controlling the quantum field statistics of confined light is a long-standing goal in integrated photonics. We show that by coupling molecular vibrations with a confined mid-infrared cavity vacuum, the photocount and quadrature field statistics of the cavity field can be reversibly manipulated over sub-picosecond timescales. The mechanism involves changing the cavity resonance frequency through a modulation of the dielectric response of the cavity materials using femtosecond UV pulses. For a single anharmonic molecular vibration in an infrared cavity under ultrastrong coupling conditions, the pulsed modulation of the cavity frequency can adiabatically produce mid- infrared light that is simultaneously sub-Poissonian and quadrature squeezed, depending on the dipolar behavior of the vibrational mode. For a vibration-cavity system in strong coupling, non-adiabatic polariton excitations can be produced after the frequency modulation pulse is over, when the system is initially prepared in the lower polariton state. We propose design principles for the generation of mid-infrared quantum light by analyzing the dependence of the cavity field statistics on the shape of the electric dipole function of the molecule, the cavity detuning at the modulation peak and the anharmonicity of the Morse potential. Feasible experimental implementations of the modulation scheme are suggested. This work paves the way for the development of molecule-based mid-infrared quantum optical devices at room temperature.
Enhanced transmission efficiency of magneto-inductive wave propagating in non-homogeneous 2-D magnetic metamaterial array
Authors: Hong Hiep Le Thi , Pham Thanh Son , Khuyen Bui Xuan , Tung Bui Son , Ngo Quang Minh , Thi Hien Nguyen , Minh Nguyen Thai , Lam Vu Dinh
Published: January 2022

In this work, we investigate the propagation of magneto-inductive waves (MIWs) in ordering magnetic metamaterial (MM) structures. The proposed non-homogeneous MM slab consists of 9 × 9 MM unit cells constructed from a five-turn spiral embedded on an FR-4 substrate. External capacitors with the value of 40 pF or 50 pF were added to control the resonant frequency of each unit cell in accordance with the waveguide configurations. The characteristics of metamaterial structures, such as negative permeability, current ratio, transmission response, and field distribution in the waveguide, have been thoroughly analyzed by simulation and experiment. A non-homogeneous metamaterial slab operating in the MHz frequency range with a low propagation loss is demonstrated. Because of the strong magnetic field confinement in the waveguide, the transmittance after nine elements of the non-homogeneous MM slab is 5.2 times greater than that of the homogeneous MM slab. This structure can be applied to the planar near-field wireless power transfer, position sensor, and low-frequency communication.
Constraining beyond ΛCDM models with 21cm intensity mapping forecasted observations combined with latest CMB data
Authors: Berti M. , Spinelli M. , Haridasu B.S. , Viel M. , Silvestri A.
Published: January 2022

We explore constraints on dark energy and modified gravity with forecasted 21cm intensity mapping measurements using the Effective Field Theory approach. We construct a realistic mock data set forecasting a low redshift 21cm signal power spectrum P
21(z,k) measurement from the MeerKAT radio-telescope. We compute constraints on cosmological and model parameters through Monte-Carlo Markov-Chain techniques, testing both the constraining power of P
21(k) alone and its effect when combined with the latest Planck 2018 CMB data.
We complement our analysis by testing the effects of tomography from an ideal mock data set of observations in multiple redshift bins. We conduct our analysis numerically with the codes EFTCAMB/EFTCosmoMC, which we extend by implementing a likelihood module fully integrated with the original codes. We find that adding P
21(k) to CMB data provides significantly tighter constraints on Ωc
h
2 and H
0, with a reduction of the error with respect to Planck results at the level of more than 60%.
For the parameters describing beyond ΛCDM theories, we observe a reduction in the error with respect to the Planck constraints at the level of ≲ 10%. The improvement increases up to ∼ 35% when we constrain the parameters using ideal, tomographic mock observations. We conclude that the power spectrum of the 21cm signal is sensitive to variations of the parameters describing the examined beyond ΛCDM models and, thus, P
21(k) observations could help to constrain dark energy. The constraining power on such theories is improved significantly by tomography.
Hadronuclear interpretation of the possible neutrino emission from PKS B1424-418, GB6 J1040+0617 and PKS 1502+106
Authors: Wang Ze-Rui , Xue Rui
Published: January 2022

In addition to neutrino event IceCube-170922A which is observed to be associated with a γ-ray flare from blazar TXS 0506+056, there are also several neutrino events that may be associated with blazars. Among them, PKS B1424-418, GB6 J1040+0617 and PKS 1502+106 are low synchrotron peaked sources, which are usually believed to have the broad line region in the vicinity of the central black hole. They are considered as counterparts of IceCube event 35, IceCube-141209A and IceCube-190730A, respectively. By considering the proton-proton (pp) interactions between the dense gas clouds in the broad line region and the relativistic protons in the jet, we show that the pp model that is applied in this work can not only reproduce the multi-waveband spectral energy distribution but also suggest a considerable annual neutrino detection rate. We also discuss the emission from the photopion production and Bethe-Heitler pair production with a sub-Eddington jet power that is suggested in our model and find that it has little effect on the spectrum of total emission for all of three sources.
Investigation of two coronal mass ejections from circular ribbon source region:Origin, Sun-Earth propagation and Geoeffectiveness
Authors: Ibrahim M. Syed , Uddin Wahab , Joshi Bhuwan , Chandra Ramesh , Awasthi Arun Kumar
Published: January 2022

In this article, we compare the properties of two coronal mass ejections (CMEs) that show similar source region characteristics but different evolutionary behaviors in the later phases. We discuss the two events in terms of their near-Sun characteristics, interplanetary evolution and geoeffectiveness. We carefully analyzed the initiation and propagation parameters of these events to establish the precise CME-interplanetary CME (ICME) connection and their near-Earth consequences. The first event is associated with poor geomagnetic storm disturbance index (Dst ≈-20 nT) while the second event is associated with an intense geomagnetic storm of DST ≈-119 nT. The configuration of the sunspots in the active regions and their evolution are observed by Helioseismic and Magnetic Imager (HMI). For source region imaging, we rely on data obtained from Atmospheric Imaging Assembly (AIA) on board Solar Dynamics Observatory (SDO) and Hα filtergrams from the Solar Tower Telescope at Aryabhatta Research Institute of Observational Sciences (ARIES). For both the CMEs, flux rope eruptions from the source region triggered flares of similar intensities (≈M1). At the solar source region of the eruptions,we observed a circular ribbon flare (CRF) for both cases, suggesting fan-spine magnetic configuration in the active region corona. The multi-channel SDO observations confirm that the eruptive flares and subsequent CMEs were intimately related to the filament eruption. Within the Large Angle and Spectrometric Coronograph (LASCO) field of view (FOV) thetwo CMEs propagated with linear speeds of 671 and 631 km s−1, respectively. These CMEs were tracked up to the Earth by Solar Terrestrial Relations Observatory (STEREO) instruments. We find that the source region evolution of CMEs, guided by the large-scale coronal magnetic field configuration, along with near-Sun propagation characteristics, such as CME-CME interactions, played important roles in deciding the evolution of CMEs in the interplanetary medium and subsequently their geoeffectiveness.
JAX, M.D. A framework for differentiable physics*
Authors: Schoenholz Samuel S , Cubuk Ekin D
Published: January 2022

We introduce JAX MD, a software package for performing differentiable physics simulations with a focus on molecular dynamics. JAX MD includes a number of physics simulation environments, as well as interaction potentials and neural networks that can be integrated into these environments without writing any additional code. Since the simulations themselves are differentiable functions, entire trajectories can be differentiated to perform meta-optimization. These features are built on primitive operations, such as spatial partitioning, that allow simulations to scale to hundreds-of-thousands of particles on a single GPU. These primitives are flexible enough that they can be used to scale up workloads outside of molecular dynamics. We present several examples that highlight the features of JAX MD including: integration of graph neural networks into traditional simulations, meta-optimization through minimization of particle packings, and a multi-agent flocking simulation. JAX MD is available at https://www.github.com/google/jax-md.
Integrated development of low-temperature thermal waters
Authors: Alkhasova D A , Alkhasov B A
Published: January 2022

The research concerns the efficient development of low-potential thermal waters in the East-Ciscaucasian artesian basin. A technology is proposed for the integrated development of low-temperature thermal water, using its heat potential for district heating and hot water supply, as well the water itself for various water management purposes, with its quality previously brought to the standards of drinking water. Various chemical water treatment units are suggested for this purpose, with their design and technological features being formed depending on the quality of the source water. The system will enable the maximization of the resource potential of the geothermal well and its all-year-round operation. The paper shows the efficiency of using the potential of geothermal energy resources in energy- biological complexes. The geothermal-biogas technology with the integrated application of thermal waters for various needs is presented. Such thermal water utilization provides for the most efficient use of its thermal potential with a decrease in temperature to a value close to the ambient temperature.
Study on Using High Temperature Steam Preparation of Ultra Light Foam TPU Pellets Based Supercritical CO2
Authors: Li Zhou , Liu Qin
Published: January 2022

This paper mainly introduces the technology of supercritical CO2 pretreatment and high temperature steam preparation of super mild foaming TPU pellets. Mainly discusses the supercritical CO2 pretreatment preparation ultra mild foaming TPU pellets process in high temperature steam condition change of TPU micro foaming granule structure and properties of impact. Experimental results show that the high temperature steam temperature, processing time will influence TPU granules of microporous quantity, structure, resulting in pellets of different physical properties.
Test of Membrane Aerated Biofilm Reactors for Nitrogen Removal in Wastewater Treatment
Authors: Chen Cheng
Published: January 2022

Membrane aerated biofilm reactor, as a biological wastewater treatment technology, has been nearly mature on a commercial scale. It uses bubble-free aeration to provide oxygen for biological nitrification and wastewater degradation. A novel oxygen-permeable hollow fiber membrane (Zeelung cord) specifically designed for use in a membrane aerated biofilm reactors (MABR). These fibers are organized into bundles, which are wrapped around the reinforcing core to increase strength. This permeable membrane allows oxygen to diffuse into the attached biofilm, which directly leads to the biological oxidation of pollutants in the wastewater. This study aimed to determine the nitrification and oxygen transfer capacity of Zeelung fibers used in the MABR system. The effects of various C/N ratios (in the range of 1.0 to 3.0) on the membrane modules were studied using three laboratory-scale reactors over the course of 165 days. In this test, the average removal efficiency of COD can reach 74% under selected conditions, up to 90%. Meanwhile, the average nitrification rate is 3.9 g/d/m2, the average ammonia removal rate is 90%, and the maximum value can reach 99%. In addition, the oxygen transfer rate of the fiber in the liquid phase was 19.65 g/d/m2. The experiment also indicated that the nitrification rate is directly proportional to the transfer flux of oxygen and is related to the content of dissolved oxygen in the water. The nitrification rate can be controlled by controlling the concentration of dissolved oxygen in water, thus affecting the removal rate of ammonia nitrogen.
Stability Analysis of Mechanical Sludge Dewatering Machine Frame Based on Numerical Simulation
Authors: Chen Li
Published: January 2022

Sludge is the inevitable product of sewage treatment plant and sewage treatment. Before sludge treatment, dewatering is generally required. Mechanical sludge dewatering machine is a common sludge dewatering equipment. Due to the complex operation conditions, the stability of sludge dewatering machine frame directly affects its reliability. In this paper, a mechanical sludge dewatering machine frame as the research object, based on ANSYS Workbench finite element analysis platform, static analysis and modal analysis. The analysis results show that: under normal working conditions, the maximum variable of the frame is 0.07mm, which can effectively ensure the normal operation of the sludge dewatering machine; the equivalent stress is 4.22Mpa, which is far less than the Xu Yong stress of the material; the vibration of the first two modes of the frame is relatively concentrated, and the corresponding motor speed under the interference frequency is 1241.4-1595.4r/min, which should be avoided in the use process.
On-line Monitoring and Data Analysis of Environmental Vibration of High Concrete Dam
Authors: Lv Shengmei
Published: January 2022

As we all know, our country has actually gradually developed into a country with frequent occurrence of global earthquakes. The global earthquakes in the southwest region are the most serious. The most severe earthquake occurred in parts of the southwest. In short, the seismic performance design of a high dam is reflected under the action of the high dam for a given amount of seismic motion and input load. At present, one of the main technical methods for studying high dam seismic engineering is to use model calculations and experiments on its structural dynamics. Moreover, the earliest dam prototype dynamic experiments in my country only occurred in the 1970s and 1980s, and few people in China conducted experiments on these dams. Although there were already a certain degree of practical results at that time, a batch of valuable materials was obtained. However, no matter from the perspective of safety or the actual effect on vibration, as well as the prototype dynamic measurement and test method of the above-mentioned main dam, it has not been well applied to the current expressway. Therefore, it is necessary to consider finding an alternative original kinetic test method. The purpose of this article is to in-depth study the data analysis and application of the online monitoring system of environmental vibration of reinforced concrete high dams in my country. A new online monitoring system for dam environmental vibration is carried out for simulation experiments. Experimental research shows that the noise frequency of the three detection points of environmental noise and vibration monitoring is basically controlled between 1.5~2.0 hz, while the noise frequency of the detection point of the symmetrical location is relatively close.
Investigation in double layer graphene superlattice and its electronic properties
Authors: Song Xingjian
Published: January 2022

This paper mainly discussed the graphene and other 2D materials, as well as their electronic properties. The history and theory prediction of graphene, and production of graphene (mechanical exfoliation and CVD method) are discussed. Graphene hBN superlattice and bi-layer graphene superlattice are presented, with following discussion of the superconductivity of the magic angle. Finally, characterization methods such as AFM and SEM are presented.
Mechanical properties of metal and polymeric viscoelastic materials and their applications
Authors: Kang Kai
Published: January 2022

Nowadays, With the wide application of metals and polymeric materials, how to describe the property of Viscoelastic material and how to apply them in engineering has become more and more critical. Due to the lack of insight into the mechanical properties of viscoelastic materials, many scholars have done a lot of experiments in studying the behavior of viscoelastic materials. Axial tensile tests were conducted on specimens to derive different mechanical behaviors of metals, polymers, and other materials at different temperatures and loading rates. Metal can generally be divided into elastic and plastic parts, while polymeric materials have the phases of the linear elastic region, drawing region, and oriented molecular strength region. This paper also shows a test conducted by Argon, Ali S., and M. I. Bessonov of four different kinds of polymers at different circumstances of temperature. After that, the paper shows the application of viscoelastic materials as CLD in damping and some engineering problems caused by the mechanical properties of viscoelastic materials. Currently, research on viscoelasticity should mainly focus on the application of Finite Element Methods and the acquisition of more experimental data to establish a complete theoretical system.
Electron Delocalization on the Silicon Nanoparticles Surface
Authors: Mukhtarov A P , Mukhtarova S K , Usmanova SA
Published: January 2022

The specific properties of tubular and fullerenlike silicon nanoparticles depend on theirs electronic structure, which is directly related to the surface geometry. Using density functional approach, a novel dual nature of the surface structure of silicon nanotubes which depends on the type of nanotube have been revevaled. The rippled form of the surface has shown to be a favorable one for (n, n) type structure and the most stable form for (n, 0) Si NT is the nanotube with a smooth-walled graphene-like surface. The phenomenon is explained by the relative position of the non-hybridized p orbitals on the surface.
Helium accumulation in Cr18Ni10Ti austenitic steel under different saturation methods
Authors: Akayev S O , Ganeev G Z , Dikov A S , Kislitsin S B , Khromushin I V , Partyka Ya
Published: January 2022

Investigation results of changes in the surface structure and helium accumulation in steel Cr18Ni10Ti at various saturation methods are presented. It is shown that different methods of helium introduction can lead to both different and identical changes in the structure and to forms of helium accumulation.
Localization of Plastic Deformation in the Copper and Stainless Steels Samples, Irradiated with Neutrons
Authors: Merezhko Mikhail , Merezhko Diana
Published: January 2022

The reduction of ductility of austenitic stainless steels as a result of long-term operation in the nuclear reactor core is an important problem of modern radiation materials science. Understanding the mechanisms of the effect of neutron irradiation on the mechanical properties of austenitic steels is impossible without research of localization processes occurring during the deformation. In this paper, it was found that the value of the true local deformation corresponding to the onset of neck formation in face-centered cubic structured metals decreases with an increase in the radiation dose, while the true stress remains almost constant. Additional hardening of AISI 304 steel due to the intensive formation of the martensitic α’-phase increases not only the stress at which a neck is formed in this alloy, but also the true local deformation. As a result, the uniform elongation increases and remains high after neutron irradiation to 0.05 dpa. The forehanded formation of the martensitic α’-phase in sufficient quantity before the necking onset can be considered as an additional deformation mechanism that will increase the ability of the material to deform uniformly.
Tests of lithium CPS on basis of carboxylic fabric, reinforced with carbon nanotubes under high thermal and radiation loads
Authors: Tulubayev Ye Yu , Ponkratov Yu V , Baklanov V V , Bochkov V S , Karambayeva I S
Published: January 2022

This work is devoted to testing a lithium CPS based on carbon fabric reinforced with carbon nanotubes under conditions of thermal and radiation loads. The paper considers and analyzes: the properties of carbon nanotubes and methods of their synthesis, the nature of the interaction of carbon materials with liquid lithium at different temperatures. A description of all the main stages in the manufacture of lithium CPS based on carbon fabric reinforced with carbon nanotubes is given. Microstructural studies of a manufactured lithium CPS sample based on carbon fabric reinforced with carbon nanotubes are presented. Studies have shown that a carbon fabric with a fiber surface reinforced with carbon nanotubes is completely wetted by liquid lithium. The developed technology is fully suitable for the manufacture of lithium CPS samples for further research. The results of experiments on the interaction of lithium CPS based on graphite fabric reinforced with carbon nanotubes with hydrogen isotopes under thermal and radiation loads are presented.
Determination of the content of impurity elements in a sample of high purity India by the method of radiochemical neutron activation analysis
Authors: Sadikov I.I. , Kh. Yarmatov B. , Usmanov T.M. , Sadikova Z.O.
Published: January 2022

The present article is devoted to the development of a method for neutron activation analysis of a microimpurity composition of high-purity indium with the radiochemical separation of indium radionuclides from radionuclides of the determined elements by extraction chromatography in the system tributyl phosphate (TBP) - solutions of hydrobromic acid (HBr).

Neutron activation analysis (NAA) has a special place among the physical methods for determining the trace composition of high-purity substances. Low detection limits, the possibility of simultaneous determination of a large number of impurity elements from one sample, no correction for the control experiment, the possibility of using inactive carriers in separating traces of radionuclides of impurity elements from matrix elements ensured the widespread use of NAA in the analysis of highly pure substances.

The developed technique allows separating matrix radionuclides from radionuclides of impurity elements with high efficiency and determination of 28 impurity elements in high-purity indium with detection limits of 0.7 ppm to 0.05 ppb.
Classification of Cardiac Arrhythmia using improved Feature Selection methods and Ensemble Classifiers
Authors: Jain Rajat , Betrabet Pranam R , Ashwath Rao B , Subba Reddy N V
Published: January 2022

Arrhythmia is one of the life-threatening heart diseases which is diagnosed and analyzed using electrocardiogram (ECG) recordings and other symptoms namely rapid heartbeat or chest-pounding, shortness of breath, near fainting spells, insufficient pumping of blood from the heart, etc along with sudden cardiac arrest. Arrhythmia records a hasty and aberrant ECG. In this implementation, the arrhythmia dataset is collected from the UCI machine learning repository and then classified the records into sixteen stated classes using multiclass classification. The large feature set of the dataset is reduced using improved feature selection techniques such as t-Distributed Stochastic Neighbor Embedding (TSNE), Principal Component Analysis (PCA), Uniform Manifold Approximation, and Projection (UMAP) and then an Ensemble Classifier is built to analyse the classification accuracy on arrhythmia dataset to conclude when and which approach gives optimal results.
Study of distance metrics on k - nearest neighbor algorithm for star categorization
Authors: Nayak Swathi , Bhat Manisha , Subba Reddy N V , Ashwath Rao B
Published: January 2022

Classification of stars is essential to investigate the characteristics and behavior of stars. Performing classifications manually is error-prone and time-consuming. Machine learning provides a computerized solution to handle huge volumes of data with minimal human input. k-Nearest Neighbor (kNN) is one of the simplest supervised learning approaches in machine learning. This paper aims at studying and analyzing the performance of the kNN algorithm on the star dataset. In this paper, we have analyzed the accuracy of the kNN algorithm by considering various distance metrics and the range of k values. Minkowski, Euclidean, Manhattan, Chebyshev, Cosine, Jaccard, and Hamming distance were applied on kNN classifiers for different k values. It is observed that Cosine distance works better than the other distance metrics on star categorization.
Emerging Military Applications of Free Space Optical Communication Technology: A Detailed Review
Authors: Kumar Suresh , Sharma Nishant
Published: January 2022

Free Space Optical Communication (FSOC) technology, designed to operate through free space as medium is rapidly emerging as reliable, fast & secure alternative for broadband communication. It is being researched & investigated for applications and technical utilities in both civil & military domain systems owing to its immense benefits including high security, better data rates & fast installations, no requirement of licensed spectrum, best costs & simplicity of design as compared to contemporary Radio Frequency (RF) systems. FSOC networks once established are difficult to detect & intercept in view of small divergence of the laser beams. This paper reviews the FSOC technology and presents features based merits as well as unmatched advantages & associated major applications in various fields collating them into a single reference point for future research. Efforts have also been invested to present a review of FSOC’s limitations & innovative emerging mitigation techniques which can prove to be a one stop feeder & a launch pad for future research in FSOC domain. A literature survey has been undertaken of available FSOC related military applications to review & gather relevant inputs to throw light on emerging trends in military applications including recent experiments & researched areas pertaining to laser systems & weapons, Unmanned Aerial Vehicles (UAVs), under sea usages, terrestrial applications, aerial, naval ships/shore based applications & RF/hybrid systems. It has been endeavored to shed light on findings & developments in these classified military domains to generate inputs for future work in this domain. Finally, a future technical roadmap and a way ahead & suggestions have been coined up pointing towards required impetus & focus areas in FSOC research domain.
Cardiac Disease Prediction using Supervised Machine Learning Techniques.
Authors: Gupta Chiradeep , Saha Athina , Subba Reddy N V , Dinesh Acharya U
Published: January 2022

Diagnosis of cardiac disease requires being more accurate, precise, and reliable. The number of death cases due to cardiac attacks is increasing exponentially day by day. Thus, practical approaches for earlier diagnosis of cardiac or heart disease are done to achieve prompt management of the disease. Various supervised machine learning techniques like K-Nearest Neighbour, Decision Tree, Logistic Regression, Naïve Bayes, and Support Vector Machine (SVM) model are used for predicting cardiac disease using a dataset that was collected from the repository of the University of California, Irvine (UCI). The results depict that Logistic Regression was better than all other supervised classifiers in terms of the performance metrics. The model is also less risky since the number of false negatives is low as compared to other models as per the confusion matrix of all the models. In addition, ensemble techniques can be approached for the accuracy improvement of the classifier. Jupyter notebook is the best tool, for the implementation of Python Programming having many types of libraries, header files, for accurate and precise work.
Enhancement of Security of Diffie-Hellman Key Exchange Protocol using RSA Cryptography.
Authors: Gupta Chiradeep , Subba Reddy N V
Published: January 2022

Cryptography is related and referred to as the secured transmission of messages amongst the sender and the intended receiver by ensuring confidentiality, integrity, and authentication. Diffie – Hellman (DH) key exchange protocol is a well-known algorithm that would generate a shared secret key among the sender and the intended receiver, and the basis of cryptosystems for using public and private key for encryption and decryption process. But it is severely affected by the Man in the Middle (MITM) attack that would intercept and manipulate thus eavesdropping the shared secret key. This paper proposes a model of integrating the public-key RSA cryptography system with the DH key exchange to prevent the MITM attack. The performance of the proposed work has been compared to the DH Key Exchange algorithm as well as RSA Cryptosystem to conclude for effectiveness of the proposed model.
Accelerating Smith-Waterman Algorithm for Faster Sequence Alignment using Graphical Processing Unit
Authors: Kaur Karamjeet , Chakraborty Sudeshna , Kumar Gupta Manoj
Published: January 2022

In bioinformatics, sequence alignment is very important task to compare and find similarity between biological sequences. Smith Waterman algorithm is most widely used for alignment process but it has quadratic time complexity. This algorithm is using sequential approach so if the no. of biological sequences is increasing then it takes too much time to align sequences. In this paper, parallel approach of Smith Waterman algorithm is proposed and implemented according to the architecture of graphic processing unit using CUDA in which features of GPU is combined with CPU in such a way that alignment process is three times faster than sequential implementation of Smith Waterman algorithm and helps in accelerating the performance of sequence alignment using GPU. This paper describes the parallel implementation of sequence alignment using GPU and this intra-task parallelization strategy reduces the execution time. The results show significant runtime savings on GPU.
Hamiltonian Laceability in Book Graphs
Authors: Sumitra Devi M.R. , Girisha A
Published: January 2022

A connected graph network G is a Hamilton-t-laceable (Hamilton- t*-laceable) if Ǝ in G a Hamilton path connecting each pair (at least one pair) of vertices at distance ‘t’ in G such that 1 ≤ t ≤ diameter (G). In this paper, we discuss the f-edge-Hamilton-t-laceability of Book and stacked Book graphs, where 1 ≤ t ≤ diameter (G).
Grow-IoT (smart analytics app for comprehensive plant health analysis and remote farm monitoring using smart sensors)
Authors: Nigam Rohan , Rao Meghana , Rian Dias Nihal , Hariharan Arjun , Choraria Amit , Tendolkar Atharv , Manohara Pai M M
Published: January 2022

Agriculture is the primary source of livelihood for a large section of the society in India, and the ever-increasing demand for high quality and high quantity yield calls for highly efficient and effective farming methods. Grow-IoT is a smart analytics app for comprehensive plant health analysis and remote farm monitoring platform to ensure that the farmer is aware of all the critical factors affecting the farm status. The cameras installed on the field facilitate capturing images of the plants to determine plant health based on phenotypic characteristics. Visual feedback is provided by the computer vision algorithm using image segmentation to classify plant health into three distinct categories. The sensors installed on the field relay crucial information to the Cloud for real-time optimized farm status management. All the data relayed can then be viewed using the user-friendly Grow-IoT app to remotely monitor integral aspects of the farm and take the required actions in case of critical conditions. Thus, the mobile platform combined with computer vision for plant health analysis and smart sensor modules gives the farmer a technical perspective. The simplistic design of the application makes sure that the user has the least cognitive load while using it. Overall, the smart module is a significant technical step to facilitate efficient produce across all seasons in a year.
InRFNet: Involution Receptive Field Network for COVID-19 Diagnosis
Authors: Dhruv M , Sai Chandra Teja R , Sri Devi R , Nagesh Kumar S
Published: January 2022

COVID-19 is an emerging infectious disease that has been rampant worldwide since its onset causing Lung irregularity and severe respiratory failure due to pneumonia. The Community-Acquired Pneumonia (CAP), Normal, and COVID-19 Computed Tomography (CT) scan images are classified using Involution Receptive Field Network from Large COVID-19 CT scan slice dataset. The proposed lightweight Involution Receptive Field Network (InRFNet) is spatial specific and channel-agnostic with Receptive Field structure to enhance the feature map extraction. The InRFNet model evaluation results show high training (99%) and validation (96%) accuracy. The performance metrics of the InRFNet model are Sensitivity (94.48%), Specificity (97.87%), Recall (96.34%), F1-score (96.33%), kappa score (94.10%), ROC-AUC (99.41%), mean square error (0.04), and the total number of parameters (33100).