bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the impact of the 204Tl neutron capture cross section on the s-process only isotope 204Pb
Authors: Casanovas-Hoste Adrià , Domingo-Pardo César , Guerrero Carlos , Tarifeño-Saldivia Ariel , Calviño Francisco , Lerendegui-Marco Jorge
Published: February 2022

In the study of the slow (s) process of nucleosynthesis branching nuclei become of particular interest. These nuclei have half-lives of the order of 1-100 years, and in the stellar environment their decay rate can compete with the neutron capture rate, which effectively leads to a split of the s-process path. Due to the dependence of the decay and the neutron capture rates on the the physical conditions -temperature and neutron density-of the nucleosynthesis environment, variations in these conditions lead to a change in the abundances of the immediately following nuclei. A very interesting branching point is the s-process only 204Tl, which decays to 204Pb. In this work we show how the capture cross section of 204Tl is a key nuclear input which, in addition to being crucial in fixing the ultimate 204Pb s-process abundance, makes the latter sensible to the temperature and neutron density of the stellar environment where the s-process takes place.
Axion-like Particles from Nearby Type Ia Supernovae
Authors: Mori Kanji
Published: February 2022

Axion-like particles (ALPs) are a class of hypothetical pseudo-scalar particles and can be created in hot astrophysical plasma through the interaction between photons. I calculate the production of ALPs in type Ia supernovae. It is found that many ALPs lighter than a few MeV can be produced in type Ia supernovae. Once produced, heavy ALPs decay into photons during propagation in the interstellar space. I calculate the flux of the decay photons and find that it may be detected by future MeV γ-ray telescopes if a type Ia supernova explodes near the Solar System.
Exploring the uncertainties of (α, xn) reactions for the weak r-process
Authors: Psaltis Athanasios , Arcones Almudena , Avila Melina L. , Jacobi Maximillian , Meisel Zach , Mohr Peter , Montes Fernando , Ong Wei Jia
Published: February 2022

“Light” heavy elements (Z = 38 − 47) can be synthesized in the neutrino–driven ejecta of core–collapse supernovae via the weak r–process. This nucleosynthesis scenario exhibits uncertainties from the absence of experimental data from (α, n) reactions on neutron–rich nuclei, and are mostly based on statistical model calculations. We present preliminary results from a recent sensitivity study, using the Atomki–V2 α-nucleus potential to identify the most important (α, n) reactions that can affect the production of “light” heavy elements between strontium and silver under different astrophysical conditions. We also discuss the planning of studies to experimentally determine (α, xn) reaction rates using the MUSIC detector at Argonne National Laboratory and the SECAR recoil separator at FRIB.
Measurement of the low energy 25Mg(p,γ)26Al resonances
Authors: Su Jun , Li Zhihong , Zhang Hao , Li Yunju , Li Ertao , Chen Chen , Shen Yangping , He Jianjun , Zhang Liyong , Li Xinyue , Lian Gang , Guo Bing , Wang Luohuan , Sheng Yaode , Chen Yinji , Zhang Long , Cao Fuqiang , Liu Weiping
Published: February 2022

The cosmic 1.809 MeV γ-ray emitted by the radioactive nucleus 26Al in the Galaxy is one of the key observation targets of the γ-ray astronomy. The 26Al is mainly produced by the 25Mg(p,γ)26Al reaction in the stellar Mg-Al reaction cycle. At the astrophysical relevant temperatures, the reaction rates of 25Mg(p,γ)26Al are dominated by several narrow resonances at low energy. This work reports a measurement of the low energy 25Mg(p,γ)26Al resonances at Jinping Underground Nuclear Astrophysics experimental facility (JUNA) in the China Jinping Underground Laboratory (CJPL).
Effect of the Nuclear Equation of State and Relativistic Turbulence on Core-Collapse Supernovae
Authors: Boccioli Luca , Mathews Grant , O’Connor Evan
Published: February 2022

The nuclear Equation of State (EoS) is an important component in the evolution and subsequent explosion of core collapse supernovae. We make a survey of various equations of state that can be found in the literature and analyze their effect on the explosion. To simulate the supernovae, we use the general relativistic spherically-symmetric code GR1D, modified to take into account the effects of three-dimensional turbulence through a new mixing length theory approach (STIR). We show that the viability of the explosion is quite EoS dependent and that the strength of explosions correlate best with the central entropy density right after bounce and the onset of turbulent mixing in the proto-neutron star.
Adaptation for Vigenère Cipher Method for Auto Binary Files Ciphering
Authors: AlTuhafi Ammar Waysi
Published: February 2022

Protecting the private information from third party became an important issue in computer science nowadays; cryptography is a science of encryption and decryption information. The first use of cryptography was in ciphering text messages, with the developing of computer usage; other type of files has been appeared such as: picture, audio, video, etc. These types of files can carry private information that needs to be saved from the third part. This paper based on design and implement system for auto encryption/decryption binary files by adapting well-knownVigenère encryption methods, by converting binary files to stream of bytes and encrypting each byte of this stream. The result shows the complete auto protection for the binary files.
Hurst analysis of dynamic networks
Authors: Nie Chun-Xiao
Published: February 2022

The sequence of network snapshots with time stamps is an effective tool for describing system dynamics. First, this article constructs a multifractal analysis of a snapshot network, in which the Hurst integral is used to describe the fractal structure hidden in structural dynamics. Second, we adjusted the network model and conducted comparative analysis to clarify the meaning of the Hurst exponent and found that the snapshot network usually includes multiple fractal structures, such as local and global fractal structures. Finally, we discussed the fractal structure of two real network datasets. We found that the real snapshot network also includes rich dynamics, which can be distinguished by the Hurst exponent. In particular, the dynamics of financial networks includes multifractal structures. This article provides a perspective to study the dynamic networks, thereby indirectly describing the fractal characteristics of complex system dynamics.
Broadband absorption enhancement of metal-dielectric structures in the optical range and their application in solar energy storage
Authors: Orlenson V. B. , Akhramovich L. N. , Volvach A. E.
Published: February 2022

In this work, scattering properties of a metal-dielectric structure are carried out in the optical range. In the proposed structure design, the absorption coefficient reaches more than 80% and has an almost constant character in the entire visible spectrum. Based on the obtained simulation results, such structures can be utilized in the field of solar energy storage applications. A review of works in the field of plasmonic solar cells is given, where the efficiency is usually increased due to the confinement of incident radiation in the active region of photoelectric conversion using localized modes, which are concentrated at the surface of conducting nanoparticles. That is, such batteries are operated in narrow wavelength intervals. However, in this article, the assumed solar cell efficiency enhancement can be achieved by incorporating the entire optical range due to the proposed metamaterial structure.
Effect of the mechanical properties of the cell membrane on the transition energy barrier of electroporation
Authors: Mi Yan , Wu Xiao , Xu Jin , Zheng Wei , Ma Chi , Chen Wenjuan , Zhang Qin
Published: February 2022

The mechanical properties of the cell membrane play an important role in electroporation. This paper studied the influence of the mechanical properties of the cell membrane on the transition energy of electroporation through both modeling and experiments. An electromechanical coupling model of a single pore on the cell membrane was established in COMSOL, and the effect of elastic strain energy on the formation of pores was analyzed. Additionally, to compare the transition energy barrier of pores for different elastic properties of the cell membrane, electroporation experiments were carried out at different temperatures. The simulation showed that the elastic strain energy of the cell membrane increased the transition energy barrier of the pores. The experiments also showed that the transition energy barrier was larger when the elasticity of the cell membrane is intact, which was in good agreement quantitatively with the simulation results. We demonstrated that the mechanical properties of the cell membrane hinder the pore formation, which may be due to the increase of the transition energy barrier. We analyzed the possible mechanism of the effect of cell membrane mechanical properties on electroporation and found the contribution of cell membrane mechanical properties to electroporation during the delivery of exogenous substances, which can provide guidance for improving therapies in electrochemotherapy.
Broadband Josephson parametric amplifier using lumped-element transmission line impedance matching architecture
Authors: Lu Yapeng , Xu Wenqu , Zuo Quan , Pan Jiazheng , Wei Xingyu , Jiang Junliang , Li Zishuo , Zhang Kaixuan , Guo Tingting , Wang Shuo , Cao Chunhai , Wang Huabing , Xu Weiwei , Sun Guozhu , Wu Peiheng
Published: February 2022

We present a fishbone-like lumped-element artificial transmission line to overcome impedance mismatch in a reflection-type Josephson parametric amplifier between a nonlinear resonator and an external transmission line. Using this easily prepared architecture, we design and fabricate a broadband Josephson parametric amplifier, which has gain in an excess of 20 dB with a bandwidth of hundreds of MHz. Furthermore, by varying the working point of the device, the operating frequency of amplification can be tuned in a wide frequency range of 1 GHz while the amplifier operates in the mode of either three-wave mixing or four-wave mixing. Such a parametric amplifier is suitable for engineering applications of superconducting circuit quantum electrodynamics.
Effect of post-annealing on thermally evaporated reduced-dimensional perovskite LEDs
Authors: Wang Liang , Li Jinghui , Du Peipei , Liu Zhengzheng , Guo Qinxun , Liu Nian , Gao Liang , Du Juan , Tang Jiang , Song Boxiang , Luo Jiajun
Published: February 2022

Reduced-dimensional perovskites (RDPs) with self-assembled multi-quantum well structures have emerged as promising candidates for light-emitting diodes (LEDs) due to their high color purity, high photoluminescence quantum yield, and decent stability. Compared to the traditional RDP film preparation methods reported in the previous literature, thermal evaporation is an appealing option for RDP film fabrication with uniform crystallization, high repeatability, and precise control. Here, based on the vacuum deposition method, we adopted a combined strategy, including annealing treatment and device structure optimization. Meanwhile, we investigated the effects of post-annealing on charge carrier recombination kinetics, exciton energy transfer, and phase distribution of vacuum-deposited RDP films. As a result, we achieved an external quantum efficiency of 6.5% for the device, which is one of the best performances among prevailing research on vacuum-processed RDP-based LEDs.
Corrigendum to: Growth, mortality, and reproduction of the oblique-banded snapper (Pristipomoides zonatus) in Guam
Authors: Schemmel Eva , Nichols Ryan , Cruz Eric , Boyer Jane F. F. , Camacho Frank A.
Published: February 2022

Deep-water snapper fisheries in the Mariana Archipelago are important commercial, recreational and subsistence fisheries. Pristipomoides zonatus, one of the top four deep-water snapper species harvested in Guam, lacked life-history information. To fill this gap, a comprehensive life-history assessment for P. zonatus, which included age, growth, mortality and reproduction, was conducted in Guam. The size range of P. zonatus sampled for life history was from 11.5cm to 40.4cm (fork length), with ages ranging from 0.5 to 30 years. Von Bertalanffy growth model-combined sex parameters were L∞=36.91cm and K=0.29. Males obtained a larger average size and a larger asymptotic size (+3.03cm) than did females. Pristipomoides zonatus matures at a small size and age (L50 ≤ 24.0cm and A50 ≤ 2.1 years) relative to their maximum size (40.4cm) and age (30 years). Additionally, P. zonatus has a long spawning season and a short spawning interval, suggesting high reproductive output. Our results expand knowledge on Pristipomoides life history (fast early growth, moderately long-lived, high productivity), providing the necessary information for the management of P. zonatus in Guam.
The highly divergent spermatozoon of the Palawan spiny rat,
Authors: Breed W. G. , Leigh C. M. , Peirce E. J.
Published: February 2022

Context Sperm morphology varies greatly across mammalian species and this variability is especially evident in murid rodents with both sperm head shape and tail length being sexually selected traits. The Palawan spiny rat, Maxomys panglima has a longer sperm tail than that currently recorded for any other mammalian species. Aims The aim of the current study was to determine the sperm morphology of an individual Palawan spiny rat, M. panglima. Methods Light and transmission electron microscopy were carried out. Key results We found that the sperm tail of M. panglima has an average length of 380 μm with the midpiece being approximately 185 μm in length with comparatively small mitochondria but very large coarse fibres. Furthermore, the sperm head has a less acutely flexed apical hook than that of most other murid rodents including those of several other Maxomys species. Conclusions The Palawan spiny rat has a highly divergent sperm morphology with an extremely long tail. It may turn out to be an important species for testing various hypotheses of sperm form and function in mammals. Implications These findings suggest markedly different selective pressures may have resulted in this unique sperm morphology, the functional significance of which remains to be determined.
Nutrition for female athletes: What we know, what we don't know, and why
Authors: Areta José L. , Elliott‐Sale Kirsty J.
Published: February 2022

Men are often considered as the default sex for studies in sports nutrition. Indeed, most of the seminal work to date in sports nutrition has been exclusively conducted on male participants. The 2021 Olympic Games had 49% female participation, signalling [almost] parity between sportsmen and sportswomen at the most elite sporting level for the first time. The volume of sports nutrition research using women as participants has, however, not kept pace with this rise in participation and professionalism. Therefore, to highlight what we currently know and don't know about sports nutrition for female athletes we invited well‐known and emerging researchers to contribute to this special edition on Nutrition for Female Athletes. Contributions cover three main themes: dietary and hydration requirements; low energy availability and making weight; and dietary supplements and gut health. In addition, this special addition explores why our understanding on this topic is limited and how we can further progress and promote this research area.
Neuronal KCNQ2/3 channels are recruited to lipid raft microdomains by palmitoylation of BACE1
Authors: Dai Gucan
Published: February 2022

β-Secretase 1 (β-site amyloid precursor protein [APP]-cleaving enzyme 1, BACE1) plays a crucial role in the amyloidogenesis of Alzheimer’s disease (AD). BACE1 was also discovered to act like an auxiliary subunit to modulate neuronal KCNQ2/3 channels independently of its proteolytic function. BACE1 is palmitoylated at its carboxyl-terminal region, which brings BACE1 to ordered, cholesterol-rich membrane microdomains (lipid rafts). However, the physiological consequences of this specific localization of BACE1 remain elusive. Using spectral Förster resonance energy transfer (FRET), BACE1 and KCNQ2/3 channels were confirmed to form a signaling complex, a phenomenon that was relatively independent of the palmitoylation of BACE1. Nevertheless, palmitoylation of BACE1 was required for recruitment of KCNQ2/3 channels to lipid-raft domains. Two fluorescent probes, designated L10 and S15, were used to label lipid-raft and non-raft domains of the plasma membrane, respectively. Coexpressing BACE1 substantially elevated FRET between L10 and KCNQ2/3, whereas the BACE1-4C/A quadruple mutation failed to produce this effect. In contrast, BACE1 had no significant effect on FRET between S15 probes and KCNQ2/3 channels. A reduction of BACE1-dependent FRET between raft-targeting L10 probes and KCNQ2/3 channels by applying the cholesterol-extracting reagent methyl-β-cyclodextrin (MβCD), raft-disrupting general anesthetics, or pharmacological inhibitors of palmitoylation, all supported the hypothesis of the palmitoylation-dependent and raft-specific localization of KCNQ2/3 channels. Furthermore, mutating the four carboxyl-terminal cysteines (4C/A) of BACE1 abolished the BACE1-dependent increase of FRET between KCNQ2/3 and the lipid raft–specific protein caveolin 1. Taking these data collectively, we propose that the AD-related protein BACE1 underlies the localization of a neuronal potassium channel.
Equilibrium properties of inhomogeneous partially-magnetized plasma containing negative ions
Authors: Singh Pawandeep , Swati  , Karkari Shantanu Kumar
Published: February 2022

This paper presents an analytical model for inhomogeneous, partially-magnetized electronegative plasma. It is shown that the radial potential of the plasma can be related to the electronegativity parameter

α
=

n

v

/

n

e

, the positive ion density, and the electron temperature distribution inside the plasma system. Using this expression, the electronegativity parameter has been determined in an oxygen plasma produced by a 13.56 MHz capacitive coupled radio-frequency discharge, and it is shown that the negative ion parameter obtained using this model is in good qualitative agreement with the saturation current ratio technique based on the cylindrical Langmuir probe.
A self-verification temperature sensor based on surface plasmon resonance in a hollow core negative curvature fiber
Authors: Chen Qiang , Chen Hailiang , Liu Yundong , Wang Yujun , Fan Xiaoya , Bai Ge , Zhang Mengwei , Du Huijing
Published: February 2022

We proposed and simulated a surface plasmon resonance (SPR) temperature sensor with two loss peaks in a hollow core negative curvature fiber (HC-NCF). Inner walls of the anti-resonant tubes in HC-NCF were plated with gold films to stimulate SPR, while the thermo-optic mixture of toluene and chloroform was filled in the air holes in HC-NCF to modulate the coupling between core modes and surface plasmon polaron modes (SPPMs). Simulation results showed that two SPPMs with opposite thermo-optic respond effects were excited at two separate wavelength bands due to their different dispersion characteristics. Temperature measurement sensitivities of −3.976 nm °C−1 and 1.071 nm °C−1 were obtained for the two SPPMs, while the sensitivity reached −5.047 nm °C−1 when detected the wavelength interval between the two SPPMs loss peaks. The two separate loss peaks could also be utilized in self-verification. The designed temperature sensor based on HC-NCF and SPR depicts high sensitivity and self-verification, which could be utilized for high precision and stable temperature monitoring.
Uncovering the physical properties, structural characteristics, and electronic application of superlattice-like Ti/Sb phase-change thin films
Authors: Huang Yufeng , Wu Weihua , Xu Shengqing , Zhu Xiaoqin , Shen Bo , Zhai Jiwei , Yue Zhenxing , Song Sannian , Song Zhitang
Published: February 2022

Superlattice-like (SLL) Ti/Sb thin films were proposed and investigated from the viewpoint of physical properties, structural characteristics, and electronic application. Magnetron sputtering was employed to deposit the SLL Ti/Sb thin films with different thickness ratios. In-situ resistance–temperature measurement indicates that the crystallization temperature, crystallization-activation energy, and data-retention capacity increase significantly and the resistance drift index reduces with an increment in thickness ratio of the Ti to Sb layer, meaning higher amorphous thermal stability and reliability of SLL Ti/Sb thin films. X-ray diffraction and Raman spectra reveal that the inserted Ti layer can inhibit grain growth and refine the grain size, causing remarkable improvement of thermal stability and crystalline resistance. Analyses of x-ray reflectivity and atomic force microscopy demonstrate that the thickness fluctuation of SLL Ti/Sb thin films becomes smaller and the surface topography becomes smoother, respectively. The Avrami exponent of the SLL (Ti3Sb7)5 thin film reflects the growth-dominated crystallization mechanism, implying a rapid phase transition speed. Phase-change memory cells based on the SLL (Ti3Sb7)5 thin film can realize a reversible SET/RESET operation under an electrical pulse with a width of 100 ns. The RESET power consumption was estimated to be much lower than that of traditional Ge2Sb2Te5 material. The above results strongly prove that the suitable SLL structure of Ti/Sb thin films have tremendous potential in the area of high-temperature and low-power electronic storage.
Emergence of Floquet edge states in the coupled Su–Schrieffer–Heeger model
Authors: Borja Carla , Gutiérrez Esther , López Alexander
Published: February 2022

The emergence of non equilibrium topological phases in low dimensional systems offers an interesting route for material properties engineering. We analyze the dynamical modulation of two coupled one-dimensional chains, described by the Su–Schrieffer–Heeger model. We find that the interplay of driving interactions and interchain coupling leads to the emergence of non-equilibrium edge states with nontrivial topological properties. Using an effective Hamiltonian approach, we quantify the emergent topological phases via the winding number and show that oscillations in the mean pseudospin polarization arise as a consequence of the periodic modulation. The patterns of these pseudospin oscillations are different for the static trivial and topological phases offering a dynamical means to distinguish both physical configurations. The system also exhibits non integer values of the winding number, which have been recently reported experimentally in connection to spin textures.
From spherical to periodic symmetry: the analog of orbital angular momentum for semiconductor crystals
Authors: Combescot Monique , Shiau Shiue-Yuan
Published: February 2022

The angular momentum formalism provides a powerful way to classify atomic states. Yet, requiring a spherical symmetry from the very first line, this formalism cannot be used for periodic systems, even though cubic semiconductor states are commonly classified according to atomic notations. Although never noted, it is possible to define the analog of the orbital angular momentum, by only using the potential felt by the electrons. The spin–orbit interaction for crystals then takes the

L
^

⋅

S
^

form, with

L
^

reducing to

L
^

=

r
^

×

p
^

for spherical symmetry. This provides the long-missed support for using the eigenvalues of

L
^

and

J
^

=

L
^

+

S
^

, as quantum indices to label cubic semiconductor states. Importantly, these quantum indices also control the phase factor that relates valence electron to hole operators, in the same way as particle to antiparticle, in spite of the fact that the hole is definitely not the valence-electron antiparticle. Being associated with a broader definition, the

(

L
^

,

J
^

)

analogs of the

(

L

^

,

J

^

)

angular momenta, must be distinguished by names: we suggest ‘spatial momentum’ for

L
^

that acts in the real space, and ‘hybrid momentum’ for

J
^

that also acts on spin, the potential symmetry being specified as ‘cubic spatial momentum’. This would cast

J

^

as a ‘spherical hybrid momentum’, a bit awkward for the concept is novel.
Short-time consistent domain adaptation for rolling bearing fault diagnosis under varying working conditions
Authors: Zhang Qiyang , Zhao Zhibin , Zhang Xingwu , Liu Yilong , Yu Xiaolei , Chen Xuefeng
Published: February 2022

Although traditional deep learning improves the accuracy of intelligent fault diagnosis, it suffers from a problem, which is that a change in working conditions may reduce the diagnostic accuracy. The reason for this phenomenon is that a change of working conditions influences the probability distributions. To solve this problem, domain adaptation is adopted to perform intelligent fault diagnosis. However, the design of regularization methods, such as maximum mean discrepancy (MMD), neglects the phenomenon of fault extension. Considering the property of fault extension, the paper sums up a concept named short-time consistency which means that ‘during stable operation, a failure does not expand over a short time period.’ Moreover, short-time consistent regularization is proposed to ensure that the output of the model meets the requirement for short-time consistency, and closed-set regularization is proposed to further solve the problem of ‘types of label drop’ when short-time consistent regularization is used. When the problem occurs, the number of predicted label types in the target domain is smaller than that in the source domain in the closed-set domain adaptation. Two types of regularization, namely entropy-based regularization and regularization based on the

L
2

norm, are easily adopted in the final loss function. The proposed method is verified by experiments.
The irradiance instrument subsystem (IRIS) on the airborne-lunar spectral irradiance (air-LUSI) instrument
Authors: Grantham Steven E , Turpie Kevin R , Stone Thomas C , Gadsden S Andrew , Larason Thomas C , Zarobila Clarence J , Maxwell Stephen E , Woodward John T , Brown Steven W
Published: February 2022

The objective of the airborne lunar spectral irradiance (air-LUSI) project is to make low uncertainty, SI-traceable measurements of the LUSI in the visible to near-infrared region from an aircraft above most of the optically absorbing components of the atmosphere. The measurements are made from a NASA ER-2 aircraft, which can fly at altitudes of approximately 20 km above sea level. Air-LUSI measurements, corrected for residual atmospheric attenuation, are designed to provide a matrix of low uncertainty top-of-the-atmosphere lunar irradiances at known lunar phase and libration angles to be compared and combined with other lunar irradiance data sets to constrain the uncertainties in models of lunar irradiance and reflectance. The measurements are also expected to provide insight into the differences between models and satellite sensor measurements of lunar irradiance. This paper describes the development and characterization of the air-LUSI subsystem for acquiring lunar measurements, called the irradiance instrument subsystem, prior to flight.
1D NiO–3D Fe2O3 mixed dimensional heterostructure for fast response flexible broadband photodetector
Authors: Reddy B Kumaar Swamy , Veeralingam Sushmitha , Borse Pramod H , Badhulika Sushmee
Published: February 2022

Conventional heterojunction photodetectors rely on planar junction architecture which suffer from low interfacial contact area, inferior light absorption characteristics and complex fabrication schemes. Heterojunctions based on mixed dimensional nanostructures such as 0D-1D, 1D-2D, 1D-3D etc have recently garnered exceptional research interest owing to their atomically sharp interfaces, tunable junction properties such as enhanced light absorption cross-section. In this work, a flexible broadband UV–vis photodetector employing mixed dimensional heterostructure of 1D NiO nanofibers and 3D Fe2O3 nanoparticles is fabricated. NiO nanofibers were synthesized via economical and scalable electro-spinning technique and made composite with Fe2O3 nanoclusters for hetero-structure fabrication. The optical absorption spectra of NiO nanofibers and Fe2O3 nanoparticles exhibit peak absorption in UV and visible spectra, respectively. The as-fabricated photodetector displays quick response times of 0.09 s and 0.18 s and responsivities of 5.7 mA W−1 (0.03 mW cm−2) and 5.2 mA W−1 (0.01 mW cm−2) for UV and visible spectra, respectively. The fabricated NiO–Fe2O3 device also exhibits excellent detectivity in the order of 1012 jones. The superior performance of the device is ascribed to the type-II heterojunction between NiO–Fe2O3 nanostructures, which results in the localized built-in potential at their interface, that aids in the effective carrier separation and transportation. Further, the flexible photodetector displays excellent robustness when bent over ∼1000 cycles thereby proving its potential towards developing reliable, diverse functional opto-electronic devices.
On the nonlinear dynamics of a cardiac electrical conduction system model: theoretical and experimental study
Authors: Kuate Guy Chance Gildas , Fotsin Hilaire Bertrand
Published: February 2022

The heart has a leading and vital role in the human body, scientific researches dealing with this theme are sources of growing interest. In recent years, several mathematical models of the heart electrical conduction system have appeared in the scientific literature. In the present paper, the nonlinear dynamics of a heart’s electrical conduction system model is investigated. The model consists of three coupled nonlinear oscillators with time delay coupling as earlier proposed by Gois et al [S R F S M Gois and M A Savi, 2009 ‘An analysis of heart rhythm dynamics using a three-coupled oscillator model,’ Chaos, Solitons Fractals, 41, 2553-2565]. Our study here is both theoretical and experimental; theoretical study includes fixed points analysis, bifurcations analysis where the effect of some parameters on the system dynamics is investigated, coexisting bifurcations and hysteresis phenomenon are found for some range of the system parameters, Lyapunov exponents and basin of attraction calculation. The experimental study includes sizing an analog implementation of the mathematical model using OrCAD/Pspice software, as well as the practical realisation of the model. Experimental and practical results are then presented in order to confirm theoretical predictions.
Comparison of Mainardi, cos-Mainardi and cosh-Mainardi beams with and without optical vortex in FT and FrFT systems
Authors: Habibi Forouzan , Moradi Mohammad
Published: February 2022

In this paper, we investigated the propagation of the Mainardi, cos-Mainardi and cosh-Mainardi beams under the Fractional Fourier transforms (FrFT) and Fourier transforms (FT). The results show that with the change of b, q, p, and z, which are the hyperbolic parameter, the fractional order of Mittag-Leffler function, the fractional Fourier transform order, and the distance propagation, respectively, the properties of the Mainardi beam with and without optical vortex can be controlled. The results show that with changing b and q parameters, the beam size, number, width and direction of the beam changes. These results can be useful in signal processing and beam manipulation. Mainardi beam similar to AiB holds promise for wide applications because of its unique features of being diffraction-free, self-accelerating, and self-healing.
Jupiter Observing Velocity Experiment (JOVE): Introduction to Wind Rider Solar Electric Propulsion Demonstrator and Science Objectives
Authors: Freeze Brent , Greason Jeff , Nader Ronnie , Febres Jaime Jaramillo , Chaves-Jiminez Adolfo , Lamontagne Michel , Thomas Stephanie , Cassibry Jason , Fuller John , Davis Eric , Conway Darrel
Published: February 2022

The Jupiter Observing Velocity Experiment (JOVE) is a solar-powered technology demonstration of rapid flight to outer solar system targets, performing a flyby of Jupiter 30 days after launch. This is achieved using a magnetic drag device to accelerate with the solar wind plasma. This “Wind Rider” propulsion system can potentially also decelerate against the Jovian magnetosphere dawn eddy, to enable Jupiter orbital insertion in future missions. The 16U cubesat bus contains scientific instruments to record the plasma parameters from the vicinity of the spacecraft, with principal measurements coming from a SPAN-I ion velocity sensor. This paper includes a description of the propulsive mechanisms and supporting subsystems and trajectory simulation results derived from solar wind measurements over the past two solar cycles. The objectives of the JOVE technology demonstrator design include: (1) verify Wind Rider stability and control; (2) characterize loss mechanisms in the solar wind, such as resistive losses in the plasma, as well as the magnetic field transient interaction time; (3) operate onboard instruments to measure the velocity and direction of the solar wind (SPAN-Ai) and speed of the spacecraft relative to the Earth (radio Doppler shift), to enable precision navigation on future science missions; and (4) characterize the Lift-to-Drag ratio of the plasma magnetic field. (The lift force enables lateral course control and maneuvering within the solar wind.) Applying existing scientific data from Voyagers and other deep space probes into new engineering models was important for enabling new insights about Wind Rider propulsion. It enables more science to be performed in a shorter amount of time, across the Jovian system.
Research on Autofocus Recognition of the LAMOST Fiber View Camera System Under Front and Back Illumination
Authors: Zhou Zengxiang , Liang Jiadong , Duan Shipeng , Cai Zeyu , Hu Hongzhuan , Wang Jianping , Liu Zhigang , Cui Xiangqun , Zhang Yong , Zhang Haotong
Published: February 2022

In the closed-loop detection system of the LAMOST, the lens of the fiber view camera system must focus the end of the optical fiber to accurately acquire the fiber position. It is difficult to evaluate the fibers image with a very small proportion of the image with the traditional autofocus algorithm, whether it is recognition of the front illuminated by the fiber ceramic ferrules, or the light-emitting spot of the fibers in the black background, that is, the recognition of the back illumination of the fibers. In this paper, we propose an autofocus determination method for the LAMOST closed-loop control under front and back illumination conditions. Under the condition of front illumination, to greatly reduce the calculation time, the system first pre-recognizes the focusing target through the Faster R-CNN and then uses an optimized contrast algorithm to evaluate the image definition of the corrected focusing target ROI. Then, the algorithm is compared with Tenengrad gradient and Laplacian gradient calculations using the Sobel operator and Laplacian operator in OpenCV. The results show that this method takes only one-ninth of the time required by the other methods to obtain the same accuracy. Under the condition of back illumination, we use the average number and average brightness of spot pixels as the evaluation basis of image sharpness. This method can complete the evaluation of image sharpness in the process of spot recognition and provide initial data for the subsequent detection for closed-loop control. The focus accuracy of the camera is of great significance for thousand-fiber metrology, which will have an important influence on the accuracy of astronomical observations. These focusing methods not only play an important role in the closed-loop control of the LAMOST but also apply to the focusing of closed-loop detection systems of other multi-target optical fiber spectral astronomical telescopes.
Direct and 2f-wavelength modulation spectroscopy of NO and OCS using an astigmatic multipass cell coupled with a mid-IR 5.2 µm cw-QCL
Authors: Panda Biswajit , Pal Ardhendu , Pradhan Manik
Published: February 2022

We developed a mid-IR 2f-wavelength modulation spectroscopy (WMS) detection system combining a continuous wave external-cavity quantum cascade laser (QCL) at 5.2 μm and an astigmatic multipass cell. The high-sensitivity performance of the 2f-WMS system was validated by simultaneously probing the strongest interference-free absorption lines of Λ-doublet components of R (6.5) rotational line in 2Π1/2 magnetic electronic sub-state of nitric oxide (NO) centred at 1900.0706 cm−1 and the R (18) rotational line of carbonyl sulphide (OCS) in the (ν
1 + 2ν
2) combination band centred at 1899.9756 cm−1. We compared the results with the direct absorption spectroscopy and have shown that a detection limit of 300 ppb for NO and 3 ppm for OCS could easily be achieved by the 2f-WMS method with an optical pathlength of 76 m. Hence, we believe that in the future the present QCL based 2f-WMS detection method with high sensitivity and specificity could be deployed for real-time monitoring of NO and OCS in a harsh environment.
Exact solutions of the 2D Schrödinger equation with the inverse square root potential
Authors: Sun Guo-Hua , Chen Chang-Yuan , Dong Shi-Hai
Published: February 2022

The exact solutions of the 2D Schrödinger equation with the inverse square root potential

V
(
r
)
=
−
a

/

r

(a > 0) are found as the Biconfluent Heun function

H

B

(
α
,
β
,
γ
,
δ
;
z
)

. The wave functions with the variation of the potential parameter a and angular momentum quantum number m are illustrated graphically.
On the CFT describing the spin clusters in 2d Potts model
Authors: Picco Marco , Santachiara Raoul
Published: February 2022

We have considered clusters of like spins in the Q-Potts model, the spin Potts clusters (S clusters). Using Monte Carlo simulations, we studied these clusters on a square lattice with periodic boundary conditions for values of Q ∈ [1, 4]. We continue the work initiated by Delfino et al (2013 J. Stat. Mech. P11011) by measuring the universal finite size corrections of the two-point connectivity. The numerical data are perfectly compatible with the conformal field theory (CFT) prediction, thus supporting the existence of a consistent CFT, still unknown, describing the connectivity Potts spin clusters. We provided in particular new insights on the energy field of such theory. For Q = 2, we found a good agreement with the prediction that the Ising spin clusters behave as the Fortuin–Kasteleyn ones at the tri-critical point of the dilute one-Potts model. We show that the structure constants are likely to be given by the imaginary Liouville structure constants, consistently with the results by Delfino et al (2013 J. Stat. Mech. P11011); Ang and Sun (2021 arXiv:2107.01788). For Q ≠ 2 instead, the structure constants we measure do not correspond to any known bootstrap solutions. The validity of our analysis is backed up by the measures of the spin Potts cluster wrapping probability for Q = 3. We evaluate the main critical exponents and the correction to the scaling. A new exact and compact expression for the torus one-point of the Q-Potts energy field is also given.
Statistical aspects of interface adhesion and detachment of hierarchically patterned structures
Authors: Esfandiary Nosaibeh , Zaiser Michael , Moretti Paolo
Published: February 2022

We introduce a three dimensional model for interface failure of hierarchical materials adhering to heterogeneous substrates. We find that the hierarchical structure induces scale invariant detachment patterns, which in the limit of low interface disorder prevent interface failure by crack propagation (‘detachment fronts’). In the opposite limit of high interface disorder, hierarchical patterns ensure enhanced work of failure as compared to reference non-hierarchical structures. While the study of hierarchical adhesion is motivated by examples of fibrous materials of biological interest, our results indicate that hierarchical patterns can be useful in engineering scenarios in view of tuning and optimizing adhesion properties.
A note on matrix algebra for cryptography settings and applications
Authors: Ayo-Aderele A. O. , Edeki S. O. , Udjor V. O. , Ugbenu O.
Published: February 2022

Cryptography is an interdisciplinary topic that adopts concepts from several disciplines. In today’s environment, cryptography makes important use of computer science and mathematics, especially discrete mathematics. This study aims to discuss the daily use of matrices in cryptography. Globally, secure text communication is critical while various cryptosystems exist to accomplish this security. Hence, with regard to the cryptosystem, the key matrix from the plane’s equation is considered by determining the orthogonal matrix that implements reflection. This method boosts encryption security by making it more arduous to locate a secret key matrix. In order to produce encryptions, the approach uses the orthogonal matrix transform characteristics. The suggested encryption method’s simplicity enables it to be adapted to other circumstances requiring secret communication transmission
Geometric progression and relative strength index applied to FX hedging
Authors: Ebong D. J. , Ogunniyi P. O. , Edeki S. O.
Published: February 2022

This research aims at profit maximization and loss minimization in any FX market trading. A geometric progression (geometric sequence), is said to be a non-zero number progression or sequence in which each term following the first is obtained via multiplying the prior by the common ratio, which is a predetermined non-zero value. This method seeks to open an opposite position to an existing initial position in order to hedge that initial position in the event that the market moves against our trade. There are a number of mathematical models to develop new hedging strategies for Forex trading. Due to the apparent high level of unpredictability in price movement, forecasting the future of a stock price is a challenging endeavor. The research would like to study one with geometric progression in particular. In other words, every number can be entered as multiple integer of a different number. Thus, 1, 2, 4, 8,..., 2n is a step forward. Smart traders never take more risks than their capital, however, the otherwise is viewed and considered here.
Elzaki Adomian decomposition method applied to Logistic differential model
Authors: Dosunmu D.A. , Edeki S.O. , Achudume C. , Udjor V.O.
Published: February 2022

This study applies Elzaki Adomian Decomposition Method (EADM) to solve the Logistic Differential Model (LDM) of different forms and coefficients. Illustrative examples are considered, and the obtained results are in good agreement compared to those already in the literature. This study, therefore, recommends the proposed method (EADM) for application in other aspects of applied mathematics for real-life problems.
Threshold recovery policy for the machine interference repair problem with server vacations
Authors: Ojobor S A , Ogini N O
Published: February 2022

In this paper, we consider the threshold recovery policy for the machine interference problem (MIP) with server vacations, having a non-dependable server which operates a threshold recovery policy, i.e., service starts after a fixed threshold level q ≥ 1. In the threshold recovery policy, M machines of similar nature are subject to fail or break down with a single server responsible for maintaining or repairing the failed machines. When the server is working, it is subject to breakdown with exponential distribution rate α; it is not possible to repair any server until the number of failed computers exceeds a predetermined threshold, q where 1 ≤ q ≤ M. The repaired rate is exponentially distributed with rate β. The server breaks down with a constant failure rate. The repair and vacation time of server is exponentially distributed. We developed the difference differential equations for the transient state probabilities for the system. We calculate the threshold recovery strategy for the MIP with server vacation using the ODE45 (Runge-Kutta method for solving ordinary differential equations) in the MATLAB computer language. We develop a variety of operational quality metrics for the system.
A proposed Method for the Solution of One-Dimensional Gas Dynamic Equation with Legendre and Chebyshev polynomials
Authors: Ojobor S A , Inonoje S O E , Mamadu E J
Published: February 2022

We have considered a proposed method to efficiently handle the piecewise formulation in the generation of approximate solutions for gas dynamic equation via the Legendre and Chebychev basis functions. Two cases of the gas dynamic equation were considered for numerical illustrations aided by MAPLE 18 software. We did obtained some fascinating results. To be precise, applying the proposed method to the homogeneous gas dynamic via the Legendre polynomial, we attained a maximum error of order 10−4 as against that of VIM with a maximum error of order 10−3 at t = 0.0001. Also, the proposed method via Chebyshev polynomials at t = 0.0001 attained a maximum error of order 10−4 as against the VIM which has a maximum error of order 10−2. In like manner, applying the proposed method to the nonhomogeneous gas dynamic via the Legendre polynomials we attained a maximum error of order 10−4 at t = 0.0001 as against that of VIM, which does not show convergent. Also, proposed method via Chebyshev polynomials at t = 0.0001 attained a maximum error of order 10−4 as against the VIM which does converge at every grid points. Thus, it is obvious that the proposed method is a better convergent iterative scheme than the in as much as t decreases.
IRNet: A Real-time Intersection Recognition Network Based on Graph Classification and 3D LiDAR Point Cloud for UGVs
Authors: Tang Hanbo , Wu Tao , Dai Bin , Cai Ying , Cao Kai , Li Shi
Published: February 2022

The intersections are junctions of roads. Recognizing intersections based on LiDAR accurately and quickly is a key task for UGVs. In this paper, we propose an end-to-end real-time intersections recognition network (IRNet) with graph attention convolution based on graph classification and 3D LiDAR point cloud. Multiple evaluations on KITTI and Tunnel dataset demonstrate that our model performs better than other competitive models and meets the real-time recognition. We research the performance of our model under different number of input points, and certify that neither of two spatial transformation networks is effective for our model. Ablation experiments certify effectiveness of the proposed features skip connection.
Simulation and Implementation of Robot Obstacle Avoidance Algorithm on ROS
Authors: Zhang Jiaonan , Zhang Tengyu , Niu Yi , Guo Yuxuan , Xia Jiahao , Qiu Yang , Yuan Zhengyi , Yang Yingze
Published: February 2022

Robots often collide in the process of simulation soccer match. The collision will block the robot’s own motion trajectory, which is not conducive to the robot’s ball grasping and defense. Considering that the obstacles have the characteristics of dynamics, antagonism and uncertainty, the robot’s motion trajectory, path selection and obstacle avoidance are very important. Taking ROS as the research platform, the study focuses on the path planning of simulated soccer robot. Meanwhile, we have applied some obstacle avoidance algorithms to the Middle Size Simulation League of soccer.