Results 41 to 50 of about 129,913 (284)

The Helmholtz Equation

, 1992
Studying an inverse problem always requires a solid knowledge of the theory for the corresponding direct problem. Therefore, the following two chapters of our book are devoted to presenting the foundations of obstacle scattering problems for time-harmonic acoustic waves, that is, to exterior boundary value problems for the scalar Helmholtz equation ...
Colton, David, Kress, Rainer, Colton, David, Kress, Rainer   +3 more
openaire   +2 more sources

A methionine‐lined active site governs carbocation stabilization and product specificity in a bacterial terpene synthase

FEBS Letters, EarlyView.
This study reveals a unique active site enriched in methionine residues and demonstrates that these residues play a critical role by stabilizing carbocation intermediates through novel sulfur–cation interactions. Structure‐guided mutagenesis further revealed variants with significantly altered product profiles, enhancing pseudopterosin formation. These
Marion Ringel, Carl P. O. Helmer, Shani Zev, Ronja Driller, Emily Buhr, Markus Reinbold, Renana Schwartz, Gabriel Foley, Mikael Boden, Daniel Garbe, Gerhard Schenk, Dan Thomas Major, Bernhard Loll, Thomas Brück   +13 more
wiley   +1 more source

Application of DRBEM for 2D sine-Gordon equation

Journal of Taibah University for Science, 2021
This research paper introduces an application of dual reciprocity boundary element method (DRBEM) for the solution of sine-Gordon equation (SGE) in two-space dimension. Initially, the time derivatives are expanded using central difference schemes.
Nagehan Alsoy-Akgün
doaj   +1 more source

Exact Fourier expansion in cylindrical coordinates for the three-dimensional Helmholtz Green function

, 2009
A new method is presented for Fourier decomposition of the Helmholtz Green Function in cylindrical coordinates, which is equivalent to obtaining the solution of the Helmholtz equation for a general ring source.
A. Erdélyi, A.P. Prudnikov, D.H. Werner, G. Matviyenko, G.N. Watson, H.M. Srivastava, H.S. Cohl, H.S. Cohl, Howard S. Cohl, I.S. Gradshteyn, J. Mathews, J.T. Conway, J.T. Conway, John T. Conway, M. Abramowitz, P.L. Overfelt, P.M. Morse, P.R. Prentice, S. Wolfram   +18 more
core   +1 more source

Bistable Helmholtz bright solitons in saturable materials [PDF]

, 2009
We present, to the best of our knowledge, the first exact analytical solitons of a nonlinear Helmholtz equation with a saturable refractive-index model.
Aceves, Aceves, Anastassiou, Baruch, Bian, Bian, Blair, Catunda, Chamorro-Posada, Chamorro-Posada, Chamorro-Posada, Chamorro-Posada, Chi, Christian, Christian, Christian, Christian, Christodoulides, Ciattoni, Cohen, Coutaz, Crosignani, Demenicis, Feit, G. S. McDonald, Gatz, Gatz, Gordon, Herrmann, J. M. Christian, Kang, Kaplan, Kaplan, Kartashov, Kivshar, Kivshar, Krolikowski, Laine, Lax, Mihalache, Mihalache, Mihalache, Mihalache, Mihalache, P. Chamorro-Posada, Roussignol, Scheuer, Sheppard, Stegeman, Sánchez-Curto, Vakhitov, Wang Song, Wood, Wu, Wu   +54 more
core   +4 more sources

C2α‐carbanion‐protonating glutamate discloses tradeoffs between substrate accommodation and reaction rate in actinobacterial 2‐hydroxyacyl‐CoA lyase

FEBS Open Bio, EarlyView.
Enzymes of the 2‐hydroxyacyl‐CoA lyase group catalyze the condensation of formyl‐CoA with aldehydes or ketones. Thus, by structural adaptation of active sites, practically any pharmaceutically and industrially important 2‐hydroxyacid could be biotechnologically synthesized. Combining crystal structure analysis, active site mutations and kinetic assays,
Michael Zahn, Barbara Seroka, Ryszard Lazny, Zenon Lotowski, Thore Rohwerder   +4 more
wiley   +1 more source

Application of the Banach Fixed-Point Theorem to the Scattering Problem at a Nonlinear Three-Layer Structure with Absorption

Fixed Point Theory and Applications, 2010
A method based on the Banach fixed-point theorem is proposed for obtaining certain solutions (TE-polarized electromagnetic waves) of the Helmholtz equation describing the reflection and transmission of a plane monochromatic wave at a nonlinear lossy ...
V. S. Serov, H. W. Schüermann, E. Svetogorova   +2 more
doaj   +2 more sources

Transmission problems for the Helmholtz equation for a rectilinear-circular lune [PDF]

Opuscula Mathematica, 2007
The question related to the construction of the solution of plane transmission problem for the Helmholtz equation in a rectilinear-circular lune is considered. An approach is proposed based on the method of partial domains and the principle of reflection
Volodymyr Denysenko
doaj  

Propagating parabolic rotational beams, new family of accelerated beams [PDF]

EPJ Web of Conferences
A novel class of structured propagating waves with parabolic rotational symmetry is introduced for the first time. These are described by exact solutions of the non-paraxial Helmholtz equation.
Espíndola-Ramos Ernesto, Gómez-Correa Jesús Emmanuel, Hernández-Nolasco José Adán, Chávez-Cerda Sabino   +3 more
doaj   +1 more source

Solving ill-posed Helmholtz problems with physics-informed neural networks

Journal of Numerical Analysis and Approximation Theory, 2023
We consider the unique continuation (data assimilation) problem for the Helmholtz equation and study its numerical approximation based on physics-informed neural networks (PINNs).
Mihai Nechita
doaj   +1 more source