Search results for "Dynamics"
showing 10 items of 9782 documents
Grid-Following and Grid-Forming MODELS in ATP-EMTP for Power Systems Simulation
2022
The paper presents the models of grid-following and grid-forming converters in the software ATP-EMTP for power systems simulation. The models are developed using the MODELS language, they are described in details discussing all issues and aspects related to the implementation, and they are also shared as open source models. The models are validated with a simulation-based approach, comparing the results with the models developed in MATLAB/Simulink and in NEPLAN, considering both the phasor RMS and EMT time domains, and thus performing a comprehensive cross-platform and cross-domain validation. In line with the spirit of the ATP software and community, the models of grid-following and grid-f…
Quasiconformal Jordan Domains
2020
We extend the classical Carath\'eodory extension theorem to quasiconformal Jordan domains $( Y, d_{Y} )$. We say that a metric space $( Y, d_{Y} )$ is a quasiconformal Jordan domain if the completion $\overline{Y}$ of $( Y, d_{Y} )$ has finite Hausdorff $2$-measure, the boundary $\partial Y = \overline{Y} \setminus Y$ is homeomorphic to $\mathbb{S}^{1}$, and there exists a homeomorphism $\phi \colon \mathbb{D} \rightarrow ( Y, d_{Y} )$ that is quasiconformal in the geometric sense. We show that $\phi$ has a continuous, monotone, and surjective extension $\Phi \colon \overline{ \mathbb{D} } \rightarrow \overline{ Y }$. This result is best possible in this generality. In addition, we find a n…
Public vs private universities in Nigeria: Market dynamics perspective
2020
Due to the scarcity of literature on developing countries of Africa, there is a need for a conceptual paper on the market dynamics perspective of the Nigerian public and private universities. The price signal influences the two-tier universities’ growth. This signal has a different impact on its stakeholders. This study intends to examine the market dynamics of public and private universities in Nigeria. It aims to ascertain how price signal affects the Nigerian public and private universities market and the distinct factors that differentiate the public from private universities in the Nigerian context. The study conducted a literature review to identify the external and internal influence…
PROPAGATING INTERFACES IN A TWO-LAYER BISTABLE NEURAL NETWORK
2006
The dynamics of propagating interfaces in a bistable neural network is investigated. We consider the network composed of two coupled 1D lattices and assume that they interact in a local spatial point (pin contact). The network unit is modeled by the FitzHugh–Nagumo-like system in a bistable oscillator mode. The interfaces describe the transition of the network units from the rest (unexcited) state to the excited state where each unit exhibits periodic sequences of excitation pulses or action potentials. We show how the localized inter-layer interaction provides an "excitatory" or "inhibitory" action to the oscillatory activity. In particular, we describe the interface propagation failure a…
Pinning of a kink in a nonlinear diffusive medium with a geometrical bifurcation: Theory and experiments
2004
International audience; We study the dynamics of a kink propagating in a Nagumo chain presenting a geometrical bifurcation. In the case of weak couplings, we define analytically and numerically the coupling conditions leading to the pinning of the kink at the bifurcation site. Moreover, real experiments using a nonlinear electrical lattice confirm the theoretical and numerical predictions.
Immobilization of proteins in silica gel: Biochemical and biophysical properties
2015
The development of silica-based sol-gel techniques compatible with the retention of protein structure and function started more than 20 years ago, mainly for the design of biotechnological devices or biomedical applications. Silica gels are optically transparent, exhibit good mechanical stability, are manufactured with different geometries, and are easily separated from the reaction media. Biomolecules encapsulated in silica gel normally retain their structural and functional properties, are stabilized with respect to chemical and physical insults, and can sometimes exhibit enhanced activity in comparison to the soluble form. This review briefly describes the chemistry of protein encapsulat…
Investigating protein structure and dynamics through wide-angle X-ray solution scattering
2016
Wide-angle X-ray scattering (WAXS) is a powerful tool that can be used to gain information on the structure and dynamics of proteins and other biomolecules in solution. Improved methods for the calculation of WAXS patterns from available or putative protein models allow to better exploit the structural information contained in the experimental data. These methods, together with recent applications of static and time-resolved WAXS, are briefly reviewed.
Explicit proton transfer in classical molecular dynamics simulations.
2014
We present Hydrogen Dynamics (HYDYN), a method that allows explicit proton transfer in classical force field molecular dynamics simulations at thermodynamic equilibrium. HYDYN reproduces the characteristic properties of the excess proton in water, from the special pair dance, to the continuous fluctuation between the limiting Eigen and Zundel complexes, and the water reorientation beyond the first solvation layer. Advantages of HYDYN with respect to existing methods are computational efficiency, microscopic reversibility, and easy parameterization for any force field peerReviewed
Review of proton and nuclear shape fluctuations at high energy
2020
Determining the inner structure of protons and nuclei in terms of their fundamental constituents has been one of the main tasks of high energy nuclear and particle physics experiments. This quest started as a mapping of the (average) parton densities as a function of longitudinal momentum fraction and resolution scale. Recently, the field has progressed to more differential imaging, where one important development is the description of the event-by-event quantum fluctuations in the wave function of the colliding hadron. In this Review, recent developments on the extraction of proton and nuclear transverse geometry with event-by-event fluctuations from collider experiments at high energy is …
Exploring fast proton transfer events associated with lateral proton diffusion on the surface of membranes
2019
Proton diffusion (PD) across biological membranes is a fundamental process in many biological systems, and much experimental and theoretical effort has been employed for deciphering it. Here, we report on a spectroscopic probe, which can be tightly tethered to the membrane, for following fast (nanosecond) proton transfer events on the surface of membranes. Our probe is composed of a photoacid that serves as our light-induced proton source for the initiation of the PD process. We use our probe to follow PD, and its pH dependence, on the surface of lipid vesicles composed of a zwitterionic headgroup, a negative headgroup, a headgroup that is composed only from the negative phosphate group, or…