Results 91 to 100 of about 42,233 (256)

A multivariate generalized independent factor GARCH model with an application to financial stock returns [PDF]

, 2008
We propose a new multivariate factor GARCH model, the GICA-GARCH model , where the data are assumed to be generated by a set of independent components (ICs).
García-Ferrer, Antonio, González-Prieto, Ester, Peña, Daniel   +2 more
core   +1 more source

Investigating the Electrochemical Double Layer with Quantum‐Chemical Simulations and Implicit Solvation Models

Chemistry – A European Journal, EarlyView.
ESM‐RISM is applied to model electrochemical interfaces and benchmarked against Poisson–Boltzmann and molecular dynamics results. Density profiles, differential capacitance, and adsorption energetics at the gold–electrolyte interface are analyzed, highlighting the capabilities of this implicit electrolyte framework.
Alessandro Mangiameli, Christopher J. Stein   +1 more
wiley   +1 more source

Reverse Engineering and Performance Evaluation of a Pump Impeller Fabricated With Additive Manufacturing

Chemie Ingenieur Technik, EarlyView.
This study explores the process chain for reverse engineering and additive manufacturing of a water pump impeller in a process plant. Key aspects include digital twin creation, CAD redesign, material certification, Hirtisation postprocessing, and performance testing. Insights highlight iterative design for improved precision and reliability.
Michael Stadler, Kati Schatz, Sebastian Rehfeldt, Harald Klein   +3 more
wiley   +1 more source

Impact of Trace Water on the Macroscopic Activity of Commercial Ammonia Cracking Catalysts Under Process‐Relevant Conditions

Chemie Ingenieur Technik, EarlyView.
This study evaluates how small water impurities—typical in ammonia cracking feedstock—affect catalyst performance at elevated pressures and temperatures. By decoupling permanent degradation from reversible inhibition, the findings highlight trace water as a significant factor for reliable catalyst screening and industrial ammonia cracking scale‐up ...
Bruno V. P. Lago, Sebastian Wodak, Marianne Ponceau, Axel Behrens, Jan‐Peter Bohn, Sebastian Rehfeldt, Harald Klein   +6 more
wiley   +1 more source

Extreme conditional quantile estimation for time series

Canadian Journal of Statistics, EarlyView.
Abstract We consider the estimation of an extreme conditional quantile QY(1−p|x0)$$ {Q}_Y\left(1-p|{x}_0\right) $$ for a heavy‐tailed distribution in the case of a strictly stationary time series (Xt,Yt)t∈ℤ$$ {\left({X}_t,{Y}_t\right)}_{t\in \mathbb{Z}} $$. Here, QY(·|x0)$$ {Q}_Y\left(\cdotp |{x}_0\right) $$ denotes the conditional quantile function of
Yuri Goegebeur, Armelle Guillou, Jing Qin   +2 more
wiley   +1 more source

A Fast and Highly Stable Aqueous Calcium‐Ion Battery for Sustainable Energy Storage

ChemSusChem, Volume 18, Issue 6, March 15, 2025.
Aqueous batteries provide a low‐cost, safer alternative to lithium‐ion batteries, but their viability is often limited by rapid electrode degradation. This study shows that replacing K+ with divalent Ca2+ ions in the electrolyte significantly boosts the stability of both copper hexacyanoferrate cathodes and polyimide anodes, enabling fast‐charging ...
Raphael L. Streng, Samuel Reiser, Sabrina Wager, Nykola Pommer, Aliaksandr S. Bandarenka   +4 more
wiley   +1 more source

Coupling Fluid Neutrals to Gyrokinetic Plasma Dynamics for Edge and SOL Turbulence Simulations

Contributions to Plasma Physics, EarlyView.
ABSTRACT Accurate modeling of turbulent transport in magnetic confinement fusion devices requires extending first‐principles gyrokinetic simulations from the core to the edge and scrape‐off layer (SOL), where additional physics—particularly plasma–neutrals interactions—must be included.
Sabine Ogier‐Collin, Philipp Ulbl, Wladimir Zholobenko, Frank Jenko   +3 more
wiley   +1 more source

Edge Fluid Turbulence Simulations of Stellarators With GRILLIX

Contributions to Plasma Physics, EarlyView.
ABSTRACT The edge fluid turbulence code GRILLIX has recently been extended from axisymmetric tokamak geometries to support 3D stellarator configurations. Following successful proof‐of‐principle simulations published in Stegmeir et al., we present here a comprehensive simulation of the Wendelstein 7‐AS stellarator.
Andreas Stegmeir, Christoph Pitzal, Barnabas Csillag, Miguel Madeira, Marion Finkbeiner   +4 more
wiley   +1 more source

Towards a Mean‐Field Braginskii Model for Stellarators

Contributions to Plasma Physics, EarlyView.
ABSTRACT Experiments in the stellarator Wendelstein 7‐X indicate that particle drifts have a significant impact on the plasma in the scrape‐off layer. However, drift effects have been absent in the mean‐field transport codes such as EMC3‐Eirene. For this reason, we present the first steps towards a mean‐field model that incorporates drifts. The code is
T. Tork, F. Reimold, D. Bold, B. Shanahan, B. Dudson, A. Stegmeir, P. Manz, The W7‐X Team   +7 more
wiley   +1 more source

Improved Conservative Scheme for Lenard‐Bernstein Collisions in Gyrokinetic Turbulence Simulations

Contributions to Plasma Physics, EarlyView.
ABSTRACT Turbulence in the edge and scrape‐off layer regions plays a critical role for the performance of future magnetic confinement fusion power plants. Gyrokinetic simulations allow studying this regime with high fidelity. A key aspect in these regions is the high concentration of impurities, which can radiate energy, leading to significant losses ...
Andrew Ivan Sulimro, Philipp Ulbl, Jordy Trilaksono, Frank Jenko   +3 more
wiley   +1 more source