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Malpezzi L.,Materials and Chemical Engineering G. Natta | MacCaroni E.,Materials and Chemical Engineering G. Natta | Carcano G.,CNR Institute for Energetics and Interphases | Ventimiglia G.,SRL Group
Journal of Thermal Analysis and Calorimetry | Year: 2012

Sodium Ibandronate (NaIb) belongs to the nitrogen-containing bisphosphonates drugs, used as anti-resorptive medications for the treatment of osteoporosis. The crystalline form of NaIb monohydrate was observed to undergo reversible thermal dehydration and rehydration, according to its hygroscopic nature and to the arrangement of the water molecules in the crystal lattice. Dehydration and rehydration were observed and confirmed by variable temperature X-ray diffraction on the basis of the DSC pattern and TG analysis that shows, by heating the sample from 40 to 200 °C, a loss of 5% weight corresponding to a water molecule loss. The water loss causes a phase transition to a more dense phase that can be rehydrated if it is left in a humid environment. The solid state characterization of NaIb monohydrate has been performed by X-ray single crystal diffraction analysis. The NaIb crystallizes as monohydrate salt in the triclinic system, space group P-1, with Z = 2, a = 5.973(1) Å, b = 9.193(1) Å, c = 14.830(2) Å, α = 98.22(1)°, β = 98.97(1)°, γ = 93.74(1)°, V = 792.9(2) Å 3. Each anionic group exist as zwitterionic entity with a total charge of -1. In the crystal packing, the octahedral coordination around the Na cations determines a centrosymmetric double chains structure elongated into the [100] direction. The water molecules are located inside the inter-chains cavities. © 2011 Akadémiai Kiadó, Budapest, Hungary. Source

Moioli S.,Materials and Chemical Engineering G. Natta | Pellegrini L.A.,Materials and Chemical Engineering G. Natta | Gamba S.,Materials and Chemical Engineering G. Natta | Li B.,University of Science and Technology of China
Frontiers of Chemical Science and Engineering | Year: 2014

This paper focuses on modeling and simulation of a post-combustion carbon dioxide capture in a coal-fired power plant by chemical absorption using monoethanolamine. The aim is to obtain a reliable tool for process simulation: a customized rate-based model has been developed and implemented in the ASPEN Plus® software, along with regressed parameters for the Electrolyte-NRTL model worked out in a previous research. The model is validated by comparison with experimental data of a pilot plant and can provide simulation results very close to experimental data. © 2014 Higher Education Press and Springer-Verlag Berlin Heidelberg. Source

Cuoci A.,Materials and Chemical Engineering G. Natta | Frassoldati A.,Materials and Chemical Engineering G. Natta | Faravelli T.,Materials and Chemical Engineering G. Natta | Ranzi E.,Materials and Chemical Engineering G. Natta
Computer Physics Communications | Year: 2015

OpenSMOKE++ is a general framework for numerical simulations of reacting systems with detailed kinetic mechanisms, including thousands of chemical species and reactions. The framework is entirely written in object-oriented C++ and can be easily extended and customized by the user for specific systems, without having to modify the core functionality of the program. The OpenSMOKE++ framework can handle simulations of ideal chemical reactors (plug-flow, batch, and jet stirred reactors), shock-tubes, rapid compression machines, and can be easily incorporated into multi-dimensional CFD codes for the modeling of reacting flows. OpenSMOKE++ provides useful numerical tools such as the sensitivity and rate of production analyses, needed to recognize the main chemical paths and to interpret the numerical results from a kinetic point of view. Since simulations involving large kinetic mechanisms are very time consuming, OpenSMOKE++ adopts advanced numerical techniques able to reduce the computational cost, without sacrificing the accuracy and the robustness of the calculations. In the present paper we give a detailed description of the framework features, the numerical models available, and the implementation of the code. The possibility of coupling the OpenSMOKE++ functionality with existing numerical codes is discussed. The computational performances of the framework are presented, and the capabilities of OpenSMOKE++ in terms of integration of stiff ODE systems are discussed and analyzed with special emphasis. Some examples demonstrating the ability of the OpenSMOKE++ framework to successfully manage large kinetic mechanisms are eventually presented. Program summary Program title: OpenSMOKE++ Catalogue identifier: AEVY-v1-0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEVY-v1-0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License, version 3 No. of lines in distributed program, including test data, etc.: 146353 No. of bytes in distributed program, including test data, etc.: 4890534 Distribution format: tar.gz Programming language: C++. Computer: Any computer that can run a C++ Compiler. Operating system: Tested on Microsoft Windows 7, Ubuntu 14.4. RAM: From a few Mb to several Gb depending on the size of the system being simulated. Classification: 22. External routines: Eigen, Boost C++ Libraries, RapidXML Nature of problem: Evolution of reacting gas mixtures with detailed description of thermodynamic, kinetic and transport data. Solution method: Stiff systems of Ordinary differential Equations, whose solution is obtained using methods based on the Backward Differentiation Formulas (BDF) (LU factorization of dense matrices is required). Additional comments: The code was specifically conceived for managing homogeneous, reacting mixtures including thousands of species and reactions. Running time: Problem-dependent, from seconds (small kinetics) to hours © 2015 Elsevier B.V. All rights reserved. Source

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