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This article belongs to the Section Polymer Physics and Theory. ; We present fully atomistic molecular dynamics simulations on polyisobutylene (PIB) in a wide temperature range above the glass transition. The cell is validated by direct comparison of magnitudes computed from the simulation and measured by neutron scattering on protonated samples reported in previous works. Once the reliability of the simulation is assured, we exploit the information in the atomic trajectories to characterize the dynamics of the different kinds of atoms in PIB. All of them, including main-chain carbons, show a crossover from Gaussian to non-Gaussian behavior in the intermediate scattering function that can be described in terms of the anomalous jump diffusion model. The full characterization of the methyl-group hydrogen motions requires accounting for rotational motions. We show that the usually assumed statistically independence of rotational and segmental motions fails in this case. We apply the rotational rate distribution model to correlation functions calculated for the relative positions of methyl-group hydrogens with respect to the carbon atom at which they are linked. The contributions to the vibrational density of states are also discussed. We conclude that methyl-group rotations are coupled with the main-chain dynamics. Finally, we revise in the light of the simulations the hypothesis and conclusions made in previously reported neutron scattering investigations on protonated samples trying to address the origin of the dielectric β-process. ; This research was funded by the Basque Government, code: IT-1175-19 and the Ministerio de Economía y Competitividad code: PGC2018-094548-B-I00 (MCIU/AEI/FEDER, UE). ; Peer reviewed

We present molecular dynamics simulations with empirical potentials to study the type of defects produced when irradiating graphene with low energy carbon ions (100 eV and 200 eV) and different dose rates. Simulations show the formation of very stable structures such as dimers, single chains of carbons and double chains of carbons. These structures are similar to those described in the literature, observed experimentally when irradiating graphene. For high doses or dose rates, the formation of nanopores is observed, similar to previous results by other authors for higher energies of the implanted ions. These simulations show how tunning the different parameters of irradiation conditions can be used to selectively create defects in graphene. ; This work is supported by the Generalitat Valenciana through grant reference PROMETEO2012/011 and the Spanish government through grant FIS2010-21883.

Cover -- Half Title -- Title -- Copyright -- Contents -- About the Authors -- Preface -- Acknowledgments -- Chapter 1 Deep Eutectic Solvents -- 1.1 Introduction -- 1.2 Hydrophobic and Hydrophilic DESs -- 1.3 An Overview of Eutectics -- 1.4 Eutectic Behavior of DESs -- 1.5 Entropy Change -- 1.6 ILs versus DESs -- 1.7 DES Preparation -- 1.8 Properties of DESs -- 1.8.1 Density -- 1.8.2 Viscosity -- 1.8.3 Solubility of DESs in Water -- 1.8.4 Thermal Stability -- 1.9 Environmental Aspects of DESs -- 1.10 Summary -- References -- Chapter 2 Thermodynamic Insights and Phase Equilibria Measurements on Aromatic Systems -- 2.1 Aromatic and Polyaromatic Hydrocarbons -- 2.2 Formulation of Eutectic Solvents -- 2.2.1 Preparation -- 2.2.2 Extraction Studies -- 2.2.3 Measurement of Extract and Raffinate Phase -- 2.3 Extraction of Aromatics and Polyaromatic Hydrocarbon from Fuel -- 2.3.1 Ternary Systems of DES-Aromatic-Aliphatic -- 2.3.2 Quaternary Mixtures Involving DES-Aromatic (1)-Aromatic (2)-Aliphatic -- 2.4 Thermodynamics Modeling -- 2.5 Continuum Solvation Models for Solutes in Phases -- 2.6 Summary -- References -- Chapter 3 Molecular Dynamics Simulations for the Extraction of Aromatics and Pesticide -- 3.1 Introduction -- 3.2 MD Simulation Details -- 3.3 Extraction of Quinoline and Benzene from the Aliphatic Phase -- 3.3.1 Noncovalent Interaction Energy -- 3.3.2 Structural Information -- 3.3.3 SDFs -- 3.3.4 Hydrogen Bond Properties -- 3.3.5 Transport and Diffusive Properties -- 3.3.6 2D NMR Analysis -- 3.4 Extraction of Nitenpyram from an Aqueous Environment -- 3.4.1 Nonbonded Energies -- 3.4.2 Local Structural Ordering -- 3.4.3 Density Distribution -- 3.4.4 Hydrogen Bonding Associated with Nitenpyram -- 3.4.5 Diffusive Property Analysis of Nitenpyram -- 3.5 Summary -- References.

Die Einsatzmöglichkeiten der additiven Technologie wachsen und verändern die Art und Weise wie wir produzieren. Gleichzeitig steigen die Anforderungen an die Qualität und Reproduzierbarkeit der noch jungen Technologie. Eine Möglichkeit zur Optimierung der Qualität durch Prozessmodellierung stellen Simulationen dar. Dieser Beitrag zeigt einen Ansatz zur Modellierung des additiven Prozesses mit metallischen Werkstoffen auf der Ebene eines einzelnen Pulverpartikels mittels der Molekulardynamik.

Additive applications are rising and are changing the way we will manufacture in the future. At the same time demands for quality and reproducibility are growing. A possibility for improving quality lies in the simulation of the process. This article presents an approach for modelling the additive process on the scale of a single powder particle using molecular dynamics.

Derivatives from biomass have attracted increasing interest in academic, social and political areas because of environmental problems caused by fossils fuel. Among these derivatives, stand out the polyalcohols, whose electrooxidation leads to value-added chemicals besides generating energy from fuel cells. In this work, the adsorption-desorption process of 4 solutions of polyalcohols on platinum (100), (110) and (111) surfaces will be investigated to compare the polyalcohol distributions and conformation on the different surfaces.