Results 51 to 60 of about 1,718 (186)

Advanced control of non‐isothermal axial dispersion tubular reactors with recycle‐induced state delay

The Canadian Journal of Chemical Engineering, EarlyView.
Abstract We develop a delay‐aware estimation and control framework for a non‐isothermal axial dispersion tubular reactor modelled as a coupled parabolic‐hyperbolic PDE system with recycle‐induced state delay. The infinite‐dimensional dynamics are preserved without spatial discretization by representing the delay as a transport PDE and adopting a late ...
Behrad Moadeli, Stevan Dubljevic
wiley   +1 more source

Optimal model‐based design of experiments for parameter precision: Supercritical extraction case

The Canadian Journal of Chemical Engineering, EarlyView.
Abstract This study investigates the process of chamomile oil extraction from flowers. A parameter‐distributed model consisting of a set of partial differential equations is used to describe the governing mass transfer phenomena in a cylindrical packed bed with solid chamomile particles under supercritical conditions using carbon dioxide as a solvent ...
Oliwer Sliczniuk, Pekka Oinas
wiley   +1 more source

Self‐Similar Blowup for the Cubic Schrödinger Equation

Communications on Pure and Applied Mathematics, EarlyView.
ABSTRACT We give a rigorous proof for the existence of a finite‐energy, self‐similar solution to the focusing cubic Schrödinger equation in three spatial dimensions. The proof is computer‐assisted and relies on a fixed point argument that shows the existence of a solution in the vicinity of a numerically constructed approximation.
Roland Donninger, Birgit Schörkhuber
wiley   +1 more source

Stability Bounds for the Generalized Kadanoff‐Baym Ansatz in the Holstein Dimer

Contributions to Plasma Physics, EarlyView.
ABSTRACT Predicting real‐time dynamics in correlated systems is demanding: exact two‐time Green's function methods are accurate but often too costly, while the Generalized Kadanoff‐Baym Ansatz (GKBA) offers time‐linear propagation at the risk of uncontrolled behavior. We examine when and why GKBA fails in a minimal yet informative setting, the Holstein
Oscar Moreno Segura, Yaroslav Pavlyukh, Riku Tuovinen   +2 more
wiley   +1 more source

Nonlinear Response‐History Analyses of Masonry and Mixed Structures With HybriDFEM

Earthquake Engineering &Structural Dynamics, EarlyView.
ABSTRACT The hybrid discrete‐finite element (HybriDFEM) method, previously developed to perform static and modal analysis in discrete and coupled discrete‐finite element models, is extended to nonlinear response‐history analyses. The equations of motion for the HybriDFEM model are solved through various numerical time‐integration schemes, both explicit
Igor Bouckaert, Michele Godio, João Pacheco de Almeida   +2 more
wiley   +1 more source

Analytical Floor Response Spectra for Performance‐Based Seismic Design of Non‐structural Elements in Reinforced Concrete Frame Buildings

Earthquake Engineering &Structural Dynamics, EarlyView.
ABSTRACT Damage to non‐structural elements significantly impacts the seismic performance of buildings in terms of economic and functionality losses. Consequently, performance‐based seismic design of non‐structural elements has become a key pillar of a comprehensive building‐seismic resilience strategy, for instance, through loss‐targeted earthquake ...
Roberto J. Merino, Roberto Gentile, Carmine Galasso   +2 more
wiley   +1 more source

Mechanism and Control Analysis of Synchronous Frequency Resonance in Distributed Power Generation System Connected to Grid

Energy Science &Engineering, EarlyView.
Small‐signal modeling reveals that insufficient system damping positions conjugate poles near the imaginary axis, fundamentally explaining the SFR mechanism. A virtual resistance control is consequently proposed to damp the resonance and effectively suppress SFR, which is validated through Hardware‐in‐the‐Loop experiments.
Yujie Gu, Jianbo Yi, Haoran Rui, Qi Huang   +3 more
wiley   +1 more source

Local Polynomial Regression and Filtering for a Versatile Mesh‐Free PDE Solver

International Journal for Numerical Methods in Fluids, EarlyView.
A high‐order, mesh‐free finite difference method for solving differential equations is presented. Both derivative approximation and scheme stabilisation is carried out by parametric or non‐parametric local polynomial regression, making the resulting numerical method accurate, simple and versatile. Numerous numerical benchmark tests are investigated for
Alberto M. Gambaruto
wiley   +1 more source

Aggregating distributed energy resources for grid flexibility services: A distributed game theoretic approach

International Journal of Robust and Nonlinear Control, EarlyView., 2023
Abstract We propose a hierarchical energy management scheme for aggregating Distributed Energy Resources (DERs) for grid flexibility services. To prevent a direct participation of numerous prosumers in the wholesale electricity market, aggregators, as self‐interest agents in our scheme, incentivize prosumers to provide flexibility. We firstly model the
Xiupeng Chen, Mehran Shakarami, Jacquelien M. A. Scherpen, Nima Monshizadeh   +3 more
wiley   +1 more source

A posteriori error estimation for non-linear eigenvalue problems for differential operators of second order with focus on 3D vertex singularities

, 2006
This thesis is concerned with the finite element analysis and the a posteriori error estimation for eigenvalue problems for general operator pencils on two-dimensional manifolds. A specific application of the presented theory is the computation of corner singularities.
openaire   +1 more source