Results 41 to 50 of about 34,271 (206)

Commissioning an Inexpensive Off‐The‐Shelf Spectrograph for Radial‐Velocity Studies

Astronomische Nachrichten, EarlyView.
ABSTRACT We present a way to set up an inexpensive out of the shelf spectrograph at a local observatory. Stability and resolution of the spectrograph are high enough for radial velocity determination of binary stars or determination of stellar characteristics. Even some exoplanets might be detectable via the radial velocity method.
Lukas Stock, Andreas Schrimpf
wiley   +1 more source

Cosmographic analysis with Chebyshev polynomials

, 2017
The limits of standard cosmography are here revised addressing the problem of error propagation during statistical analyses. To do so, we propose the use of Chebyshev polynomials to parameterize cosmic distances.
Capozziello, Salvatore, D'Agostino, Rocco, Luongo, Orlando   +2 more
core   +1 more source

Study on fracture parameter calibration and failure characteristics of rock with hole and crack

Deep Underground Science and Engineering, EarlyView.
The SIF and plastic zone equations for a single hole and crack have been derived. The model's failure state leads to the identification of four types of cracks. The plastic zone increases with increased brittleness and decreased crack length. Abstract Cracks within the surrounding rock of roadways significantly affect their stability and failure ...
Shaochi Peng, Wensong Wang
wiley   +1 more source

Solving Non-Linear Fractional Variational Problems Using Jacobi Polynomials

Mathematics, 2019
The aim of this paper is to solve a class of non-linear fractional variational problems (NLFVPs) using the Ritz method and to perform a comparative study on the choice of different polynomials in the method.
Harendra Singh, Rajesh K. Pandey, Hari Mohan Srivastava   +2 more
doaj   +1 more source

Numerical estimation of the fractional advection–dispersion equation under the modified Atangana–Baleanu–Caputo derivative

Results in Physics, 2023
The transport of contaminants is a crucial environmental issue, and accurate modeling of this phenomenon is vital for developing effective strategies for its management.
Mohammad Partohaghighi, Marzieh Mortezaee, Ali Akgül, Sayed M. Eldin   +3 more
doaj   +1 more source

Total X‐Ray Illumination for Absolute Quantification of Crystalline Phases and Amorphous Content in PVDF and P(VDF‐TrFE)

Macromolecular Materials and Engineering, EarlyView.
A rigorous method, Total Illumination by X‐rays (TIX), is presented to quantify crystalline and amorphous phases in organic materials. Mitigating challenges such as low microabsorption and high amorphous content, an improved, general framework is established, applicable to polymers, MOFs, biological materials, etc.
Shaashwat Saraff, Giulio Isacco Lampronti, Sohini Kar‐Narayan   +2 more
wiley   +1 more source

Clenshaw algorithm in the interpolation problem by the Chebyshev collocation method

Discrete and Continuous Models and Applied Computational Science
The article describes a method for calculating interpolation coefficients of expansion using Chebyshev polynomials. The method is valid when the desired function is bounded and has a finite number of maxima and minima in a finite domain of interpolation.
P. Lovetskiy Konstantin, A. Tiutiunnik Anastasiia, Felix Jose do Nascimento Vicente, Celmilton Teixeira Boa Morte   +3 more
doaj   +1 more source

The Characteristics of the First Kind of Chebyshev Polynomials and its Relationship to the Ordinary Polynomials

JTAM (Jurnal Teori dan Aplikasi Matematika), 2021
In this article, we discuss the Chebyshev Polynomial and its characteristics. The second order difference equation and the process obtaining the explicit solution of the Chebyshev polynomial have been given for each real number.
Ikhsan Maulidi, Bonno Andri Wibowo, Vina Apriliani, Rofiqul Umam   +3 more
doaj   +1 more source

A New Template Family For The Detection Of Gravitational Waves From Comparable Mass Black Hole Binaries

, 2007
In order to improve the phasing of the comparable-mass waveform as we approach the last stable orbit for a system, various re-summation methods have been used to improve the standard post-Newtonian waveforms.
C. W. Helstrom, Edward K. Porter, F. S. Acton, J. C. Mason, K. Belczynski, K. Kuroda, M. A. Snyder   +6 more
core   +1 more source

A highly accurate numerical method for solving boundary value problem of generalized Bagley‐Torvik equation

Mathematical Methods in the Applied Sciences, EarlyView.
A highly accurate numerical method is given for the solution of boundary value problem of generalized Bagley‐Torvik (BgT) equation with Caputo derivative of order 0<β<2$$ 0<\beta <2 $$ by using the collocation‐shooting method (C‐SM). The collocation solution is constructed in the space Sm+1(1)$$ {S}_{m+1}^{(1)} $$ as piecewise polynomials of degree at ...
Suzan Cival Buranay, Mtema James Chin, Nazim I. Mahmudov   +2 more
wiley   +1 more source