Line Contour Research Articles

High-order rational solutions and rogue wave for the (2 + 1)-dimensional nonlinear Schrödinger equation

In this paper, some exact explicit rational solutions of the (2 + 1)-dimensional nonlinear Schrödinger equation are presented in terms of the Gram determinants by using the bilinear method. The expressions of the fundamental line rogue wave, second-order parallel line rogue wave and third-order parallel line rogue wave all involve determinants whose matrix elements are simple polynomials. These line rogue waves, which all generate from a constant background with line contours and then disappear into the same background, are plotted in the (x, y)-plane. Moreover, we also consider different structures of higher-order rogue waves, and their dynamical behaviors are illustrated in the (x, t)-plane.

Digital Nullification of Visual Distortion to Quantify Metamorphopsia: A Pilot Study.

To evaluate a novel digital method of metamorphopsia quantification in patients with symptomatic visual distortion as determined by M-CHARTS. In this institutional review board-approved, prospective, cross-sectional observational study, subjects were presented with an objectively straight dotted line that bisects a central fixation point. The subjects digitally altered the line's contour until it appeared straight. Calculation of the area between the original objectively straight line presented to the subject and their newly manipulated line was performed to determine the manipulated area under the curve (M-AUC). Sixty-two percent of test targets were fully or significantly straightened by affected subjects. M-AUC was significantly correlated with M-CHARTS scores in both the horizontal (P < .001) and vertical (P = .05) orientations. The deformation of an objectively straight line by a subject with metamorphopsia may be a viable way of both quantifying and spatially characterizing visual distortions. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:11-20.].

Liberal and Illiberal Internationalism in the Making of the League of Nations Convention on Broadcasting in the Cause of Peace

The 1936 League of Nations Convention on the Use of Broadcasting in the Cause of Peace sought to shape a liberal international public sphere, through encouragement of empathetic and neighborly broadcasts to other nations and prohibitions on international broadcast of hostile speech and false claims. It expressed 1920s liberal hopes that adding protocols and rules to international communications would foster peace. How was it then that by the late 1930s these same hopes for an international public sphere of civil and peace-fostering international discourse appeared to many liberals in national contexts as not only fantastical, but illiberal, a clear threat to the emerging core liberal value of free speech? Analysis of the making and early implementation of the Convention facilitates understanding of the rapid change in the valency of these ideas and illuminates the historical contours of the always-contested line between liberal and illiberal policies in communications history. That line is difficult to discern clearly in this case for two main reasons: removing offensive criticism of other nations from international broadcasting was perceived as illiberal censorship by some and as laudable self-restraint and international good manners by others; positive liberal internationalist content was perceived as educational by liberal internationalists and as potentially illiberal propaganda by nationalists. Viewing the making of the Convention through the lens of the contest about what constituted liberal and illiberal internationalism helps us better understand both its high ambition and some of the reasons why it was so quickly labelled a failure. [End Page 165]

Study of the Working Area of a Ring Magnet Magnetic Levitation System Using a Thin Layer of Magnetic Fluid

We present an experimental system aimed at mapping the magnetic field created by a ring magnet in the working region of a single-magnet magnetic levitation system. The key idea is based on the photoregistration of a transparent air-filled cavity formed in a thin magnetic fluid layer due to balancing the gas pressure and the pressure emerging due to magnetic forces. As a result, the contour of the magnetic field lines in 3-D space is visible. It was shown that the theoretical analysis, numerical simulations, and experimental results are consistent.

Decrease in imprisonment of resonance radiation due to the broadening of the absorption line contour caused by the rotation of the plasma sphere

Imprisonment of resonance radiation in the spherical barium plasma rotating around its symmetry axis is numerically studied. Photoexcitation of barium ions at resonance transition with the wavelength λ0= 455.4 nm by laser radiation is modeled. A numerical algorithm allows one to calculate the emission spectrum and the Holstein's escape factor of resonant radiation using the afterglow intensity of rotating plasma. The full width at half maximum of the emission line is considerably wider than the one for the static medium, and the central frequency of emission is shifted to either red or blue wing of the spectrum. Location of the frequency of intensity maximum of the emission line unambiguously determines the projection of velocity of ions on the ray direction in the plasma. For rotational plasma, the imprisonment of resonant quanta decreases due to the broadening of the ion absorption line. The appearance of two qualitatively novel effects that distinguish rotating plasma from static one is predicted: 1) more facilitated diffusion of resonant photons to the medium surface and more facilitated escape of them out of it (effect strengthened escape); 2) presence of a velocity gradient along the sphere radius leads to “spreading” of the line over a wider frequency range, impeding free propagation of continual photons (effect of frequency band narrowing).

Chemical reaction and Dufour effects on nonlinear free convection heat and mass transfer flow near a vertical moving porous plate

AbstractA theoretical analysis is made for steady fully developed free convection and mass transfer flow near an infinite vertical moving porous plate by taking into consideration the first‐order chemical reaction and Dufour effects. The mathematical model responsible for the present physical situation is based on the nonlinear density variation with temperature as well as nonlinear density variation with concentration. Exact solutions are derived for heat mass and momentum equations under relevant boundary conditions. The dimensionless velocity, temperature, and concentration are presented in terms of exponential functions. The impact of controlling parameters such as Dufour number (diffusion thermo effect), chemical reaction parameter, Prandlt number, Schmidt number, on velocity, temperature, Nusselt number, and skin friction are discussed with the aid of line graphs, contours, and tables. The analysis of the result shows that Nusselt number, skin friction, and velocity increases with increase in Dufour number. Furthermore, velocity and skin friction are higher in case of nonlinear convection in comparison to linear convection.

An experimental and analytical investigation of canyon fire spread

This work investigates the fire line evolution in canyon fire spread by analytical and experimental means. The purpose is to understand the mechanism of fire spread acceleration associated with eruptive fire in canyon terrain. A symmetrical model canyon is used for experiments, and in each test the fire is initiated by a point ignition using dead pine needles as the fuels. By experimental observations and data, three distinct types of fire line contour are identified under different central slope angles (the angle between the canyon centerline and the horizontal ground), resulting in different variation modes of rate of spread along the canyon centerline. It is found that the trace of fire head deviates from the line of maximum slope for non-zero central slope angles, and such a deviation increases with increasing central slope angle. The fire spread acceleration associated with eruptive fire occurs when the central slope angle reaches a certain critical value. Experimental data confirm that under higher slope conditions, the significant interaction between the two lateral flame fronts induces marked convective heating ahead of the flame front, which is inferred to be the potential mechanisms of eruptive fire in canyon topography. A model analysis further elucidates how the deflection of the trace of fire head, induced by the fire interaction effect, influences the acceleration of fire spread under higher slope conditions.

Grammars of Approach: Landscape, Narrative, and the Linguistic Picturesque. Cynthia Wall. Chicago: University of Chicago Press, 2019. Pp. xi+331.

<i>Grammars of Approach: Landscape, Narrative, and the Linguistic Picturesque</i>. Cynthia Wall. Chicago: University of Chicago Press, 2019. Pp. xi+331.

Obtaining low water line contour value for enclave claim regime 12 nautical miles on Hatohobei Island Republic of Palau against the Republic of Indonesia in according with UNCLOS 1982 using satellite-derived bathymetry

UNCLOS (United Nations Convention on the Law of The Sea) 1982 gives the authority to coastal state to make claims on their sea regime. An island that is more than 125 nautical miles from the mainland where the baseline to draw a territorial line is drawn is given the right to claim the maritime regime by enclave method 12 nautical miles maximum. In determining enclave claims, Low water line contour points are needed through satellite-derived bathymetry using the Lyzenga bathymetry algorithm. The data used in this study is a multispectral planet scope imagery with 3 meters resolution, where the imagery was acquired at the 07th April 2019 and depth sample from NGA nautical chart of the Hatohobei Island and Hellen reef region. To normalize the depth value, tidal correction is done by extrapolating from BIG tides data during 29 days of tides data prediction. The Lyzenga bathymetry is applied using intercept (24.422094) and the coefficient for each band result by Ordinary Least Square regression, where the R2 value obtained is 0.194075. That variable is applied in Lyzenga Bathymetry Formula. The results of the Lyzenga bathymetry algorithm are converted into contour lines to obtain low water line contour, and buffer 12 nautical miles is carried out. The result of this study shows the areas which can be claimed by Hatohobei Island (Republic of Palau). The claim of the maritime space that can be given to Tobi Island is 1634.39 km2.

Strength Analysis of Polymer Conical Gear Wheel Made with 3D Printing Technique

Abstract The article deals with the problem of designing conical gears with a curved line contour. The contour of the tooth flank is described by means of a helix and involutions. In the work, a conical gear designed to drive of the lower limb rehabilitation exoskeleton has analysed. Parameters of the conical gearbox have been adapted to design requirements of the exoskeleton. Gear wheels were made with ABS material using 3D printing technique. The article presents the results of strength calculations obtained using the method classical design of the gear wheals described in the norm ISO 6336-1996. In the strength calculations, bending and contact stresses were taken into account. Creating the contour of gears was aided through the gearbox wizard available in Inventor program. The work contains the results of a static tensile test of the material from which the gear wheels were made. In experimental and numerical studies, the orthotropy of the material used was taken into account. The orthogonal values of the Young’s modulus, the Poisson’s ratio and the Kirchhoff’s modulus were determined. The publication also includes partial results of fatigue tests in the area of normal stresses. In the research used to finite element method (FEM), determine of internal loads in the gear. A structure of the FEM model is described in detail. Maximum values of contact pressures determined by use to FEM models have been compared with the results obtained on the basis of Hertz’s formulas. The article presents basic geometrical and strength parameters of the designed gear. The work demonstrates the validity of the material models used. Limitations in the application of the classic method of calculating conical gears made of orthotropic materials have been indicated. The results of analytical and numerical calculations are presented in tabular and graphical form.

On magnetized liquid stream statistics in grooved channel: A finite element visualization

The magnetized flow field statistics of hydrodynamic forces subject to the grooved channel is debated in the present pagination. To be more specific, the grooved channel as a computational domain is considered. The fluid flow is initiated with the parabolic velocity profile at an inlet of the grooved channel. The right wall of the channel is entertained with notable Neumann condition. The velocity of the rest of the walls is taken zero. Both square and circular shaped cylinders are placed fixed in between the grooved channel. The whole design is mathematically controlled in terms of coupled non-linear differential equations. The numerical solution is proposed by utilizing the finite element method commercially. The LBB-stable finite pair is used for the approximation of primitive variables namely, the velocity and pressure. The obtained outcomes are offered through both the line graphs and contour plots. The drag and lift forces are evaluated by carrying line integration around the outer surface of square and circular shaped obstacles. It is noticed that in the grooved channel the obstacles experience an extreme maximum drag force. Further, the drag force is found to be an increasing function of the Hartmann number.

Inversion of the Contribution of an Isotope of Small Relative Concentration to Total Absorption Coefficient of a Mixture of Neon Isotopes Associated with the 3s2–2p4 Transition

Absorption of probe laser radiation by a mixture of even isotopes of neon in a gas discharge plasma is investigated by the method of magnetic scanning of 3s2–2p4 transition. The contours of absorption lines of isotopes are resolved by means of numerical modeling. It is discovered that, upon decrease in relative concentration of one of the isotopes, its contribution to absorption is replaced by gain. The effect is found to be caused by radiative transfer of excitation energy between atoms of different kinds in the absence of a difference in level energies (the process known as optical pumping). The effect of this mechanism turned out to be substantial for the upper level transitions from which to the ground state are allowed while being absent for the lower level of the transition from which such transitions are forbidden although other decay channels are available.

Diode laser spectrometer for high-precision measurements

The issues of the development, calibration and putting into operation of a diode laser spectrometer for high-precision measurements are considered. The tests rely on the use of an isolated P20 line of the 00031 – 00001 band of the 12C16O2 molecule. The spectrometer error budget is analysed. A software programme for the approximation of a spectral line contour is designed and the procedure is analysed. It is shown that, for a baseline with a relative level of 2.3 × 10−5, it is optimal to use no more than six fitting parameters in the line contour approximation. The measured integral intensity of the analytical line constitutes 5.3865(85) × 10−23 cm per molecule.

Adaptive method of 5-axis milling of sculptured surfaces elements with a curved line contour

In this paper, an attempt to develop a new adaptive method of controlling the axis orientation of a toroidal milling cutter (leading angle α) depending on the radius of curvature (radius ρ1 in the feed direction, i.e. on a curved contour) of the treated surface profile in a 5-axis milling process was made. An application of this method required the development, based on the results of simulation and experimental tests (own tests), of a special procedure for selection of the lead angle α of the milling cutter depending on the continuously changing radius of curvature ρ1 in the direction of the milling cutter. This procedure was implemented in a commercial CAM system, thus modifying the classical strategy of controlling the movement of the tool into an adaptive strategy. The proposed method after entering the criterion of the permissible value of the deviation of shape Δk and limiting the permissible parameter Ra of the surface roughness, allows adapting the lead angle α of the toroidal axis to the current value of the radius of curvature ρ1 of the processed composite surface profile. By conducting experimental research on the example of the blade machining of the turbine blade, it was shown that the concept of a new method of controlling the axis of the toroidal milling axis allows the parameters of the lead angle and radius of curvature (α, ρ1) to increase the accuracy of the 5-axis surface treatment of complex elements with contours curvilinear by about 25 %.

Scattering of Sunlight by Ion Cloud Under the Condition of Pulsating Mass Dynamics

Absorption and scattering of sunlight in a calcium plasma cloud at λ0 = 397 nm under the conditions of pulsating mass dynamics is analyzed. The problem is described by a set of integrodifferential equations and is solved numerically for the case of 3D spherical geometry of emitting plasma and harmonic variation of the expansion velocity of the plasma sphere. The causes of the frequency asymmetry of the spectral line contour for the emission scattered by the cloud along different ray directions ate analyzed.

Инверсия вклада изотопа малой относительной концентрации в суммарный коэффициент поглощения смеси изотопов неона на переходе 3s-=SUB=-2-=/SUB=--2p-=SUB=-4-=/SUB=-

AbstractAbsorption of probe laser radiation by a mixture of even isotopes of neon in a gas discharge plasma is investigated by the method of magnetic scanning of 3 s _2–2 p _4 transition. The contours of absorption lines of isotopes are resolved by means of numerical modeling. It is discovered that, upon decrease in relative concentration of one of the isotopes, its contribution to absorption is replaced by gain. The effect is found to be caused by radiative transfer of excitation energy between atoms of different kinds in the absence of a difference in level energies (the process known as optical pumping). The effect of this mechanism turned out to be substantial for the upper level transitions from which to the ground state are allowed while being absent for the lower level of the transition from which such transitions are forbidden although other decay channels are available.

模式向量法提取点云数据线轮廓点

模式向量法提取点云数据线轮廓点

Software system for numerical simulation of broadband laser gas analysis of the atmosphere

Introduction: Successful monitoring of environmental parameters requires the development of flexible software complexes with evolvable calculation functionality. Purpose: Developing a modular system for numerical simulation of atmospheric laser gas analysis. Results: Based on differential absorption method, a software system has been developed which provides the calculation of molecular absorption cross-sections, molecular absorption coefficients, atmospheric transmission spectra, and lidar signals. Absorption line contours are calculated using the Voigt profile. The prior information sources are HITRAN spectroscopic databases and statistical models of the distribution of temperature, pressure and gas components in the atmosphere. For modeling lidar signals, software blocks of calculating the molecular scattering coefficient and aerosol absorption/scattering coefficients were developed. For testing the applicability of various laser sources in the problems of environmental monitoring of the atmosphere, a concentration reconstruction error calculation block was developed for the atmospheric gas components, ignoring the interfering absorption of laser radiation by foreign gases. To verify the correct functioning of the software, a program block was developed for comparing the results of the modeling of atmospheric absorption and transmission spectra by using the standard SPECTRA information system. The discrepancy between the calculation of the atmospheric transmission spectra obtained using the developed system as compared to the SPECTRA results is less than 1%. Thus, a set of the presented program blocks allows you to carry out complex modeling of remote atmospheric gas analysis. Practical relevance: The software complex allows you to rapidly assess the possibilities of using a wide range of laser radiation sources for the problems of remote gas analysis.

The combined effects of anisotropic porous medium and stably stratified fluid on free convective flow through an annulus

ABSTRACTThis paper documents the semi-analytical results for transient natural convection fluid flow between two concentric vertical cylinders of infinite lengths in the presence of anisotropic porous medium and stratified fluid. The solutions for the time-dependent coupled second order partial differential equations modelling the flow formation are obtained by using trio-methods: Laplace transform techniques, a numerical procedure based on the Riemann Sum Approximation method and D’Alembert method. Line graphs and contour maps for the fluid velocity and temperature profiles are presented for different physical parameters of interest featuring in the solutions. The inclusion of the stratification and anisotropic parameters in the model has been found to aid the regulation of the fluid flow. Furthermore, from the numerical simulation conducted, it is found that for some saturated stratified fluids, the steady and transient state velocities (as well as the temperatures of the fluid) coincide at large time.

Nanofluid unsteady heat transfer in a porous energy storage enclosure in existence of Lorentz forces

In current article, nanofluid time dependent heat transfer under the influence of Lorentz forces during discharging process is simulated by means of FEM. In order to overcome the limitation of PCM, NEPCM has been utilized. CuO and water are employed as nanoparticles and PCM. Brownian motion role is taken into consideration to estimate nanofluid characteristics. Graphs are illustrated as isotherm, solid fraction and stream line contours. Results reveal that discharging rate improves with augment of Lorentz forces. As Hartmann number augments, solid fraction profile will be converged in lower time. Dispersing nanoparticles has significant impact on phase change front.