scholarly journals Role of translational entropy in spatially inhomogeneous, coarse-grained models

2018 ◽  
Vol 148 (9) ◽  
pp. 094112 ◽  
Author(s):  
Marcel Langenberg ◽  
Nicholas E. Jackson ◽  
Juan J. de Pablo ◽  
Marcus Müller
Keyword(s):  
Coarse Grained ◽  
Spatially Inhomogeneous ◽  
Translational Entropy

The Normalisation of Natural Philosophy: Occasional Causality and Coarse-Grained Reality

2020 ◽  
pp. 201-236
Keyword(s):  
Immanuel Kant ◽  
Early Modern ◽  
Natural Philosophy ◽  
Coarse Grained ◽  
Mutual Adaptation ◽  
Modern Natural ◽  
Conceptual Changes ◽  
Preliminary Application ◽  
The Way

This article investigates whether it possible to derive a new narrative about the transformation of early modern natural philosophy from the way in which natural philosophy was systematized in academic writings. It introduces the notion of ‘normalisation’—the mutual adaptation of certain ideas and existing traditions—as a way of studying and explaining conceptual changes during relatively long periods of time. The article provides the methodological underpinnings of this account of normalisation and offers a preliminary application of it by focusing on the role of ‘occasional causality’ in natural philosophy through the writings of four authors: Pierre Sylvain Régis (1632-1707), Johann Christoph Sturm (1635-1703), Petrus van Musschenbroek (1692-1761), and Immanuel Kant (1724-1804), who progressively normalise an account of ‘occasional causality’.

scholarly journals Piezoelectric characterization of lead-free ferroelectric ceramics

2010 ◽  
Vol 4 (3) ◽  
pp. 199-207 ◽  
Author(s):  
Lorena Pardo ◽  
Alvaro García ◽  
Klaus Brebøl ◽  
Lavinia Curecheriu ◽  
Liliana Mitoseriu ◽  
...  
Keyword(s):  
Sol Gel ◽  
Complex Impedance ◽  
Experimental Spectrum ◽  
Lead Free ◽  
Ferroelectric Ceramics ◽  
Coarse Grained ◽  
Shear Mode ◽  
Fine Grained ◽  
Accuracy Test

The challenge to develop high piezoelectric sensitivity and lead-free composition ferro-piezoelectric ceramics has recently dragged new attention to some classic ferroelectrics. Here, Ba(CexTi1-x)O3 (Ce-BT) and 0.94(Bi1/2Na1/2)TiO3-0.06BaTiO3 (BNBT6) ceramics were piezoelectrically characterized from measurements of complex impedance at electromechanical resonances and their analysis by Alemany et al. software. The reconstruction of the spectra for each resonance is used as an accuracy test of the set of calculated coefficients, quantitatively characterized by the regression factor (R2) of such reconstruction to the experimental spectrum. Piezoelectric activity at room temperature (RT) was observed for Ce-BT with x=0.06 and 0.1, ferroelectrics with T(?'max)>RT, but also for x=0.2 with T(?'max)<RT, which confirms its relaxor character (Ps?0 for T?T(?'max)). BNBT6 fine grained ceramics (~1 ?m) were prepared from nanopowder obtained by sol-gel autocombustion. Results obtained for the fine grained ceramic hot-pressed at 800?C for 2 h and recrystallized at 1050?C for 1 h are d33=148 pCN-1 and kp=26.8%. Despite of its lower grain size, the properties of this material are comparable with those reported for coarse grained ceramics obtained by sintering at T>1100?C. Some measurement issues, as the role of the mode coupling on the characterization results, illustrated for the shear mode of a thickness poled plate, are discussed.

scholarly journals Towards the realistic computer model of precipitation polymerization microgels

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Vladimir Yu. Rudyak ◽  
Elena Yu. Kozhunova ◽  
Alexander V. Chertovich
Keyword(s):  
Computer Simulations ◽  
Precipitation Polymerization ◽  
Coarse Grained ◽  
Polymerization Process ◽  
New Horizons ◽  
Experimental Systems ◽  
Structure Factors ◽  
The Subject ◽  
First Time

Abstract In this paper we propose a new method of coarse-grained computer simulations of the microgel formation in course of free radical precipitation polymerization. For the first time, we simulate the precipitation polymerization process from a dilute solution of initial components to a final microgel particle with coarse grained molecular dynamics, and compare it to the experimental data. We expect that our simulation studies of PNIPA-like microgels will be able to elucidate the subject of nucleation and growth kinetics and to describe in detail the network topology and structure. Performed computer simulations help to determine the characteristic phases of the growth process and show the necessity of prolongated synthesis for the formation of stable microgel particles. We demonstrate the important role of dangling ends in microgels, which occupy as much as 50% of its molecular mass and have previously unattended influence on the swelling behavior. The verification of the model is made by the comparison of collapse curves and structure factors between simulated and experimental systems, and high quality matching is achieved. This work could help to open new horizons in studies that require the knowledge of detailed and realistic structures of the microgel networks.

scholarly journals Modelling lipid systems in fluid with Lattice Boltzmann Molecular Dynamics simulations and hydrodynamics

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Astrid F. Brandner ◽  
Stepan Timr ◽  
Simone Melchionna ◽  
Philippe Derreumaux ◽  
Marc Baaden ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Lattice Boltzmann ◽  
Coarse Grained ◽  
Implicit Solvent ◽  
Mesoscopic Scale ◽  
Coarse Grained Model ◽  
Dynamics Simulations ◽  
Cellular Compartments ◽  
Biological Entities

Abstract In this work we present the coupling between Dry Martini, an efficient implicit solvent coarse-grained model for lipids, and the Lattice Boltzmann Molecular Dynamics (LBMD) simulation technique in order to include naturally hydrodynamic interactions in implicit solvent simulations of lipid systems. After validating the implementation of the model, we explored several systems where the action of a perturbing fluid plays an important role. Namely, we investigated the role of an external shear flow on the dynamics of a vesicle, the dynamics of substrate release under shear, and inquired the dynamics of proteins and substrates confined inside the core of a vesicle. Our methodology enables future exploration of a large variety of biological entities and processes involving lipid systems at the mesoscopic scale where hydrodynamics plays an essential role, e.g. by modulating the migration of proteins in the proximity of membranes, the dynamics of vesicle-based drug delivery systems, or, more generally, the behaviour of proteins in cellular compartments.

scholarly journals Kink dynamics in spatially inhomogeneous media: The role of internal modes

2007 ◽  
Vol 75 (3) ◽  
Author(s):  
Jorge A. González ◽  
Sara Cuenda ◽  
Angel Sánchez
Keyword(s):  
Inhomogeneous Media ◽  
Spatially Inhomogeneous
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