Relevant bibliographies by topics / Reactivity descriptor

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Reactivity descriptor'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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Journal articles on the topic "Reactivity descriptor"

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Morell, Christophe, André Grand, and Alejandro Toro-Labbé. "New Dual Descriptor for Chemical Reactivity." Journal of Physical Chemistry A 109, no. 1 (January 2005): 205–12. http://dx.doi.org/10.1021/jp046577a.

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Padmanabhan, J., R. Parthasarathi, M. Elango, V. Subramanian, B. S. Krishnamoorthy, S. Gutierrez-Oliva, A. Toro-Labbé, D. R. Roy, and P. K. Chattaraj. "Multiphilic Descriptor for Chemical Reactivity and Selectivity." Journal of Physical Chemistry A 111, no. 37 (September 2007): 9130–38. http://dx.doi.org/10.1021/jp0718909.

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Guo, Chunna, Xin He, Chunying Rong, Tian Lu, Shubin Liu, and Pratim Kumar Chattaraj. "Local Temperature as a Chemical Reactivity Descriptor." Journal of Physical Chemistry Letters 12, no. 23 (June 10, 2021): 5623–30. http://dx.doi.org/10.1021/acs.jpclett.1c01207.

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ZHAO, DongXia, ZhongZhi YANG, and ZhenZhen XU. "Prediction on molecular reactivity of enzymatic catalysis by the generalized reactivity descriptor." Chinese Science Bulletin 57, no. 30 (October 1, 2012): 2787–93. http://dx.doi.org/10.1360/972012-537.

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Cárdenas, Carlos, Nataly Rabi, Paul W. Ayers, Christophe Morell, Paula Jaramillo, and Patricio Fuentealba. "Chemical Reactivity Descriptors for Ambiphilic Reagents: Dual Descriptor, Local Hypersoftness, and Electrostatic Potential." Journal of Physical Chemistry A 113, no. 30 (July 30, 2009): 8660–67. http://dx.doi.org/10.1021/jp902792n.

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Martínez-Araya, Jorge Ignacio. "Why is the dual descriptor a more accurate local reactivity descriptor than Fukui functions?" Journal of Mathematical Chemistry 53, no. 2 (November 5, 2014): 451–65. http://dx.doi.org/10.1007/s10910-014-0437-7.

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Frau, Juan, and Daniel Glossman-Mitnik. "Local Molecular Reactivity of the Colored Dansylglycine in Water and Dioxane Studied through Conceptual DFT." Journal of Chemistry 2018 (July 15, 2018): 1–7. http://dx.doi.org/10.1155/2018/3172412.

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This study evaluated a fixed long-range corrected range-separated hybrid (RSH) density functional associated with the Def2TZVP basis set alongside the SMD solvation model for the computation of the structure, molecular properties, and chemical reactivity of the M8 intermediate melanoidin pigment in the presence of water and dioxane. The preference of the active sites pertinent to radical, nucleophilic, and electrophilic attacks is made through linking them with the electrophilic and nucleophilic Parr functions, Fukui function indices, and condensed dual descriptor which are chemical reactivity descriptors that arise from conceptual density functional theory. The study confirmed the results from previous works showing that the MN12SX density functional is the most appropriate in predicting the chemical reactivity of this molecule in both solvents.
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Primbs, Mathias, Yanyan Sun, Aaron Roy, Daniel Malko, Asad Mehmood, Moulay-Tahar Sougrati, Pierre-Yves Blanchard, et al. "Establishing reactivity descriptors for platinum group metal (PGM)-free Fe–N–C catalysts for PEM fuel cells." Energy & Environmental Science 13, no. 8 (2020): 2480–500. http://dx.doi.org/10.1039/d0ee01013h.

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Chattaraj, P. K., D. R. Roy, M. Elango, and V. Subramanian. "Chemical reactivity descriptor based aromaticity indices applied to and systems." Journal of Molecular Structure: THEOCHEM 759, no. 1-3 (February 2006): 109–10. http://dx.doi.org/10.1016/j.theochem.2005.10.041.

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Mucsi, Zoltan, Gregory A. Chass, and Imre G. Csizmadia. "Reply to the ‘Comment on “Penicillin's catalytic mechanism revealed by inelastic neutrons and quantum chemical theory”’ by S. A. Glover, Phys. Chem. Chem. Phys., 2019, 21, 18012." Physical Chemistry Chemical Physics 21, no. 45 (2019): 25513–17. http://dx.doi.org/10.1039/c9cp00152b.

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Dissertations / Theses on the topic "Reactivity descriptor"

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Wang, Siwen. "Orbital Level Understanding of Adsorbate-Surface Interactions in Metal Nanocatalysis." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/98923.

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We develop a theoretical framework for a priori estimation of catalytic activity of metal nanoparticles using geometry-based reactivity descriptors of surface atoms and kinetic analysis of reaction pathways at various types of active sites. We show that orbitalwise coordination numbers 𝐶𝑁α (α = 𝑠 or 𝑑) can be used to predict chemical reactivity of a metal site (e.g., adsorption energies of critical reaction intermediates) by being aware of the neighboring chemical environment, outperforming their regular (𝐶𝑁) and generalized (𝐶̅𝑁̅) counterparts with little added computational cost. Here we include two examples to illustrate this method: CO oxidation on Au (5𝑑¹⁰6𝑠¹) and O₂ reduction on Pt (5𝑑⁹6𝑠¹). We also employ Bayesian learning and the Newns-Anderson model to advance the fundamental understanding of adsorbate-surface interactions on metal nanocatalysts, paving the path toward adsorbate-specific tuning of catalysis.
Doctor of Philosophy
The interactions between reaction intermediates and catalysts should be neither too strong nor too weak for catalytic optimization. This Sabatiers principle arising from the scaling relations among the energetics of reacting species at geometrically similar sites, provides the conceptual basis for designing improved catalysts, but imposes volcano-type limitations on the attainable catalytic activity and selectivity. One of the greatest challenges faced by the catalysis community today is how to develop design strategies and ultimately predictive models of catalytic systems that could circumvent energy scaling relations. This work brings the quantum-chemical modeling and machine learning technique together and develops a novel stochastic modeling approach to rationally design the catalysts with desired properties and bridges our knowledge gap between the empirical kinetics and atomistic mechanisms of catalytic reactions.
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Matito, i. Gras Eduard. "Development, implementation and application of electronic structural descriptors to the analysis of the chemical bonding, aromaticity and chemical reactivity." Doctoral thesis, Universitat de Girona, 2006. http://hdl.handle.net/10803/7940.

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En la literatura sobre mecànica quàntica és freqüent trobar descriptors basats en la densitat de parells o la densitat electrònica, amb un èxit divers segons les aplicacions que atenyin. Per tal de que tingui sentit químic un descriptor ha de donar la definició d'un àtom en una molècula, o ésser capaç d'identificar regions de l'espai molecular associades amb algun concepte químic (com pot ser un parell solitari o zona d'enllaç, entre d'altres). En aquesta línia, s'han proposat diversos esquemes de partició: la teoria d'àtoms en molècules (AIM), la funció de localització electrònica (ELF), les cel·les de Voroni, els àtoms de Hirshfeld, els àtoms difusos, etc.
L'objectiu d'aquesta tesi és explorar descriptors de la densitat basats en particions de l'espai molecular del tipus AIM, ELF o àtoms difusos, analitzar els descriptors existents amb diferents nivells de teoria, proposar nous descriptors d'aromaticitat, així com estudiar l'habilitat de totes aquestes eines per discernir entre diferents mecanismes de reacció.
In the literature, several electronic descriptors based in the pair density or the density have been proposed with more or less success in their pratical applications. In order to be chemically meaningful the descriptor must give a definition of an "atom" in a molecule, or instead be able to identify some chemical interesting regions (such as lone pair, bonding region, among others). In this line, several molecular partition schemes have been put forward: atoms in molecules (AIM), electron localization function (ELF), Voronoi cells, Hirshfeld atoms, fuzzy atoms, etc.
The goal of this thesis is to explore the density descriptors based on the molecular partitions of AIM, ELF and fuzzy atom, analyze the existing decriptors at several levels of theory, propose new aromaticity descriptors, and study its ability to discern between different mechanisms of reaction.
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Hoffmann, Guillaume. "Mise au point de nouveaux descripteurs théoriques pour la réactivité chimique Can molecular and atomic descriptors predict the electrophilicity of Michael acceptors? On the influence of dynamical effects on reactivity descriptors Predicting experimental electrophilicities from quantum and topological descriptors : a machine learning approach Electrophilicity indices and halogen bonds : some new alternatives to the molecular electrostatic potential." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMR042.

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L’étude des descripteurs de réactivité globaux, locaux et non locaux d'un système réactif est d’une importance capitale afin de comprendre la réactivité de la totalité des processus chimiques lors d’une réaction. Le but de cette thèse a ainsi été de mettre au point de nouveaux descripteurs de réactivités, ainsi que des modèles de prédiction basés sur ces derniers, afin d’étudier la réactivité chimique. Les principale méthodes théoriques employées ont été la Théorie de la fonctionnelle de la densité conceptuelle (CDFT) et la théorie quantique « Atoms in Molecules » (QTAIM) qui sont toutes deux basées sur la densité électronique. Notre domaine d’étude se place principalement dans le cadre de l’échelle expérimentale de Mayr, qui permet par le biais de mesures cinétiques d’effectuer un classement des molécules par ordre de réactivité. Dans un premier temps, de grande avancées ont été réalisées durant cette thèse vis-à-vis de la prédiction théorique de l’électrophilie expérimentale des accepteurs de Michael. Puis dans un second temps, nous nous sommes intéressées à l’application des descripteurs de réactivité sur la liaison chimique, et particulièrement la liaison halogène. Enfin, une partie de synthèse réalisée au cours de cette thèse est présentée, en proposant une nouvelle voie de synthèse des cations iminium vinylogues
The study of global, local and non-local reactivity descriptors of a reactive system is of paramount importance in order to understand the reactivity of all chemical processes during a reaction. The goal of this thesis was then to develop new reactivity descriptors, as well as prediction models based on them, in order to study chemical reactivity. The main theoretical methods used were the Conceptual Density Functional Theory (CDFT) and Quantum Theory of “Atoms in Molecules” (QTAIM), which are both based on electron density. Our field of study is mainly within the framework of the Mayr experimental scale, which allows, through kinetic measurements a classification of molecules in order of reactivity. In the first part, great advances were made during this thesis with respect to the theoretical prediction of experimental electrophilicity of Michael acceptors. Then in a second step, we looked at the application of reactivity descriptors on the chemical bond, and in particular the halogen bond. Finally, a part of synthesis carried out during the course of this thesis is presented, by proposing a new way of synthesis of vinylogous iminium cations
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Rohde, Ulrich, and Ulrich Grundmann. "The Code DYN3D/M2 for the Calculation of Reactivity Initiated Transients in Light Water Reactors with Hexagonal Fuel Elements -Code Manual and Input Data Description-." Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-32789.

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The code DYN3D/M2 is used for investigations of reactivity transients in cores of thermal power reactors with hexagonal fuel elements. The 3-dimensional neutron kinetics model HEXDYN3D of the code is based on a nodal expansion method for solving the two-group neutron diffusion equation. The thermo-hydraulic part FLOCAL consists of a two-phase flow model describing coolant behaviour and a fuel rod model. The fuel elements are simulated by separate coolant channels. Additional, some hot channels with power peaking factors belonging to chosen fuel elements can be considered. Several safety parameters as temperatures, DNBR and fuel enthalpy are evaluated. Macroscopic cross sections depending from the thermo-hydraulic parameters and boron concentration are input data of the code. The stationary state and transient behaviour can be analyzed. The arrangement of input data are descibed for using the different option of the code.
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Rohde, Ulrich, and Ulrich Grundmann. "The Code DYN3D/M2 for the Calculation of Reactivity Initiated Transients in Light Water Reactors with Hexagonal Fuel Elements -Code Manual and Input Data Description-." Forschungszentrum Rossendorf, 1993. https://hzdr.qucosa.de/id/qucosa%3A22105.

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The code DYN3D/M2 is used for investigations of reactivity transients in cores of thermal power reactors with hexagonal fuel elements. The 3-dimensional neutron kinetics model HEXDYN3D of the code is based on a nodal expansion method for solving the two-group neutron diffusion equation. The thermo-hydraulic part FLOCAL consists of a two-phase flow model describing coolant behaviour and a fuel rod model. The fuel elements are simulated by separate coolant channels. Additional, some hot channels with power peaking factors belonging to chosen fuel elements can be considered. Several safety parameters as temperatures, DNBR and fuel enthalpy are evaluated. Macroscopic cross sections depending from the thermo-hydraulic parameters and boron concentration are input data of the code. The stationary state and transient behaviour can be analyzed. The arrangement of input data are descibed for using the different option of the code.
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Bornot, Sébastien. "De la composition de systèmes temporisés." Phd thesis, Université Joseph Fourier (Grenoble), 1998. http://tel.archives-ouvertes.fr/tel-00004871.

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La composition des systèmes temporisés est source de nombreux problèmes, notamment de blocage. Nous proposons un cadre de description compositionnelle des systèmes temporisés qui préserve la réactivité temprorelle, à savoir que si le système ne peut réagir, alors le temps peut avancer. Nous effectuons d'abord une étude préliminaire sur la spécification des évolutions temporelles dans les systèmes, débouchant sur la définition de mécanismes de description adéquats. Ceci nous permet de définir une classe de modèles temporisés temporellement réactifs, par construction. Nous définissons sur cette classe des opérateurs de choix et de composition parallèle qui préservent cette propriété. En outre, les opérateurs sont définis de sorte à préserver l'activité dans le sens où si à partir d'un état une action est possible dans un composant, alors une action est possible dans la composition. L'opérateur de composition parallèle respecte également la propriété de progrès maximal grâce à l'utilisation d'opérateurs de choix avec priorités qui favorise les synchronisations. Un cadre général est donné pour exprimer différents modes de synchronisation, parmi lesquels on retiendra AND (synchronisation classique), MAX (synchronisation avec attente) et MIN (interruption). Pour terminer, nous développons une approche algébrique pour une sous-classe des modèles considérés.
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Halldin, Stenlid Joakim. "Computational Studies of Chemical Interactions: Molecules, Surfaces and Copper Corrosion." Doctoral thesis, KTH, Tillämpad fysikalisk kemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-213028.

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The chemical bond – a corner stone in science and a prerequisite for life – is the focus of this thesis. Fundamental and applied aspects of chemical bonding are covered including the development of new computational methods for the characterization and rationalization of chemical interactions. The thesis also covers the study of corrosion of copper-based materials. The latter is motivated by the proposed use of copper as encapsulating material for spent nuclear fuel in Sweden. In close collaboration with experimental groups, state-of-the-art computational methods were employed for the study of chemistry at the atomic scale. First, oxidation of nanoparticulate copper was examined in anoxic aqueous media in order to better understand the copper-water thermodynamics in relation to the corrosion of copper material under oxygen free conditions. With a similar ambition, the water-cuprite interface was investigated with regards to its chemical composition and reactivity. This was compared to the behavior of methanol and hydrogen sulfide at the cuprite surface. An overall ambition during the development of computational methods for the analysis of chemical bonding was to bridge the gap between molecular and materials chemistry. Theory and results are thus presented and applied in both a molecular and a solid-state framework. A new property, the local electron attachment energy, for the characterization of a compound’s local electrophilicity was introduced. Together with the surface electrostatic potential, the new property predicts and rationalizes regioselectivity and trends of molecular reactions, and interactions on metal and oxide nanoparticles and extended surfaces. Detailed atomistic understanding of chemical processes is a prerequisite for the efficient development of chemistry. We therefore envisage that the results of this thesis will find widespread use in areas such as heterogeneous catalysis, drug discovery, and nanotechnology.
Den kemiska bindningen – en hörnsten inom naturvetenskapen och oumbärlig för allt liv – är det centrala temat i den här avhandlingen. Både grundläggande och tillämpade aspekter behandlas. Detta inkluderar utvecklingen av nya beräkningsmetoder för förståelse och karaktärisering av kemiska interaktioner. Dessutom behandlas korrosion av kopparbaserade material. Det sistnämnda är motiverat av förslaget att använda koppar som inkapslingsmaterial för hanteringen av kärnavfall i Sverige. Kvantkemiska beräkningsmetoder enligt state-of-the-art har använts för att studera kemi på atomnivå, detta i nära sammabete med experimentella grupper. Initialt studerades oxidation av kopparnanopartiklar under syrgasfria och vattenrika förhållanden. Detta för att bättre kartlägga koppar-vattensystemets termodynamik. Av samma orsak detaljstuderades även gränsskiktet mellan vatten och kuprit med fokus på dess kemiska sammansättning och reaktivitet. Resultaten har jämförts med metanols och vätesulfids kemiska beteende på ytan av kuprit. En övergripande målsättningen under arbetet med att utveckla nya beräkningsbaserade analysverktyg för kemiska bindningar har varit att överbrygga gapet mellan molekylär- och materialkemi. Därför presenteras teoretiska aspekter samt tillämpningar från både ett molekylärt samt ett fast-fas perspektiv. En ny deskriptor för karaktärisering av föreningars lokala elektrofilicitet har introducerats – den lokala elektronadditionsenergin. Tillsammans med den elektrostatiska potentialen uppvisar den nya deskriptorn förmåga att förutsäga samt förklara regioselektivitet och trender för molekylära reaktioner, och för interaktioner på metal- och oxidbaserade nanopartiklar och ytor. En detaljerad förståelse av kemiska processer på atomnivå är en nödvändighet för ett effektivt utvecklande av kemivetenskapen. Vi förutspår därför att resultaten från den här avhandlingen kommer att få omfattande användning inom områden som heterogen katalys, läkemedelsdesign och nanoteknologi.

QC 20170829

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Khan, E., A. Shukla, K. Srivastava, D. Gangopadhyay, Khaled H. Assi, P. Tandon, and Venu R. Vangala. "Structural and reactivity analyses of nitrofurantoin 4 dimethylaminopyridine salt using spectroscopic and density functional theory calculations." 2019. http://hdl.handle.net/10454/17782.

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Yes
Pharmaceutical salt, nitrofurantoin–4-dimethylaminopyridine (NF-DMAP), along with its native components NF and DMAP are scrutinized by FT-IR and FT-Raman spectroscopy along with density functional theory so that an insight into the H-bond patterns in the respective crystalline lattices can be gained. Two different functionals, B3LYP and wB97X-D, have been used to compare the theoretical results. The FT-IR spectra obtained for NF-DMAP and NF clearly validate the presence of C33–H34⋅⋅⋅O4 and N23–H24⋅⋅⋅N9 hydrogen bonds by shifting in the stretching vibration of –NH and –CH group of DMAP+ towards the lower wavenumber side. To explore the significance of hydrogen bonding, quantum theory of atoms in molecules (QTAIM) has been employed, and the findings suggest that the N23–H24⋅⋅⋅N9 bond is a strong intermolecular hydrogen bond. The decrement in the HOMO-LUMO gap, which is calculated from NF → NF-DMAP, reveals that the active pharmaceutical ingredient is chemically less reactive compared to the salt. The electrophilicity index (ω) profiles for NF and DMAP confirms that NF is acting as electron acceptor while DMAP acts as electron donor. The reactive sites of the salt are plotted by molecular electrostatic potential (MEP) surface and calculated using local reactivity descriptors.
SERB, DST, India, for providing the National Post-doctoral Fellowship (Project File Number: PDF/2016/003162); Central Facility for Computational Research (CFCR), University of Lucknow; Newton-Bhabha Ph.D. placement award (2017); Royal Society seed corn research grant (2018-19)
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"Development, implementation and application of electronic structural descriptors to the analysis of the chemical bonding, aromaticity and chemical reactivity." Universitat de Girona, 2006. http://www.tesisenxarxa.net/TDX-1004106-130623/.

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Books on the topic "Reactivity descriptor"

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Martinho Simões, José A., and Manuel Minas da Piedade. Molecular Energetics. Oxford University Press, 2008. http://dx.doi.org/10.1093/oso/9780195133196.001.0001.

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This book offers a broad discussion of the concepts required to understand the thermodynamic stability of molecules and bonds and a description of the most important condensed-phase techniques that have been used to obtain that information. Above all, this book attempts to provide useful guidelines on how to choose the "best" data and how to use it to understand chemistry. Although the book assumes some basic knowledge on physical-chemistry, it has been written in a "textbook" style and most topics are addressed in a way that is accessible to advanced undergraduate students. Many examples are given throughout the text, involving a variety of molecules. This text will provide a good starting point for those who wish to initiate in the field or simply to understand how to assess, to estimate, and to use thermochemical data. It will therefore appeal to a broad range of practicing chemists and particularly to those interested in energetics-structure-reactivity relationships.
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Book chapters on the topic "Reactivity descriptor"

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Bywater, Robert P. "Quantitative Measurement of Molecular Similarity Using Shape Descriptors." In Molecular Similarity and Reactivity, 113–22. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-015-8488-3_6.

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Fries, P. H., and E. Belorizky. "A Simple Description of the Intermolecular Proton Transfer by Tunnelling in Solutions." In Chemical Reactivity in Liquids, 205–11. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4613-1023-5_17.

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Verhaar, Henk J. M., Arno Goffin, Emiel Rorije, and Joop L. M. Hermens. "Modelling the aquatic toxicity of reactive organic chemicals: Finding descriptors for SN2 reactivity." In Trends in QSAR and Molecular Modelling 92, 336–38. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1472-1_68.

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Geerlings, P., R. Vivas-Reyes, F. Proft, M. Biesemans, and R. Willem. "DFT Based Reactivity Descriptors and Their Application to the Study of Organotin Compounds." In Metal-Ligand Interactions, 461–95. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-010-0191-5_21.

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Labet, Vanessa, Christophe Morell, Vincent Tognetti, Olga A. Syzgantseva, Laurent Joubert, Nelly Jorge, André Grand, and Jean Cadet. "Characterization of the Chemical Reactivity and Selectivity of DNA Bases Through the Use of DFT-Based Descriptors." In Topics in Heterocyclic Chemistry, 35–70. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-45149-2_2.

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Klebe, Gerhard. "Correlation of Crystal Data and Charge Density with the Reactivity and Activity of Molecules: Towards a Description of Elementary Steps in Enzyme Reactions." In NATO ASI Series, 287–318. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4615-3700-7_12.

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Morell, Christophe, André Grand, Soledad Gutiérrez-Oliva,, and Alejandro Toro-Labbé. "Chapter 7 Using the reactivity-selectivity descriptor Δ f(r) in organic chemistry." In Theoretical and Computational Chemistry, 101–17. Elsevier, 2007. http://dx.doi.org/10.1016/s1380-7323(07)80008-2.

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Maiti, B., P. Chattaraj, and S. Nath. "Reactivity Descriptors." In Computational Medicinal Chemistry for Drug Discovery. CRC Press, 2003. http://dx.doi.org/10.1201/9780203913390.ch11.

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"Local Reactivity Descriptors." In Structure Property Correlations for Nanoporous Materials, 77–94. CRC Press, 2010. http://dx.doi.org/10.1201/9781420082753-c4.

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"4Chapter Local Reactivity Descriptors." In Structure Property Correlations for Nanoporous Materials, 95–112. CRC Press, 2010. http://dx.doi.org/10.1201/9781420082753-9.

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Conference papers on the topic "Reactivity descriptor"

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Nabbi, R. "Inverse point kinetics for the reactivity Determination: Description of the KINIK Code." In Proceedings of the Workshop. WORLD SCIENTIFIC, 1991. http://dx.doi.org/10.1142/9789814439398_0017.

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Chegrani, Yacine, Corinne d’Aletto, Jacques Di Salvo, and Evgeny Ivanov. "Validation of SIMMER-III Neutronics Module for the Simulation of Reactivity Injection Accident in Material Testing Reactors." In 18th International Conference on Nuclear Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/icone18-29188.

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The “Institut de Radioprotection et de Suˆrete´ Nucle´aire”, as the technical support of the French Safety Authority, carries out studies and research to analyze and assess the safety of all nuclear plants. In this frame IRSN studies the feasibility of modeling Material Testing Reactor core with SIMMER-III code, for simulation of reactivity initiated accidental transients. The SIMMER-III multi-physics code system was initially developed for mechanistic safety analyses of liquid metal cooled fast reactors while employing coupled spatial neutron kinetics and thermal hydraulics models. Neutronics and thermal-hydraulics SIMMER-III models have been extended to safety analyses for water cooled and moderated reactors. The use of a code like SIMMER-III requires approximations; it computes a simplified R-Z geometry and chemistry description of the core that must be validated. The methods applied consist here in developing models of the same reactor on several scales of detail. The first step is the validation of the cross section condensation for deterministic APOLLO2 calculation against Monte Carlo TRIPOLI4 2D model. Temperature effects, kinetic parameters and void coefficients on the whole core are then calculated on a 2D APOLLO2 model, using the Method of Characteristics. These parameters are also computed with a 3D combined transport and diffusion calculations by means of APOLLO2/CRONOS2 calculations, validated against a TRIPOLI4 3D precise reference model. The final step is the validation of the simmer-like R-Z geometry in APOLLO2 Sn and Pij. Finally, an R-Z geometry has been computed in SIMMER-III, for the calculation of the kinetic parameters and temperature coefficients. This validation method has been applied to Jules Horowitz Reactor, a French Material Testing Reactor currently in commissioning by the CEA. This leads to conclude that discrepancies due to simplifications are acceptable. Moreover SIMMER-III shows quite a good agreement with CEA ring calculation on the kinetic parameters. Concerning neutronics feedbacks coefficients, further analyses remain necessary.
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Fiorina, Carlo, Manuele Aufiero, Sandro Pelloni, and Konstantin Mikityuk. "A Time-Dependent Solver for Coupled Neutron-Transport Thermal-Mechanics Calculations and Simulation of a Godiva Prompt-Critical Burst." In 2014 22nd International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/icone22-30395.

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The present paper describes a first step taken at the Paul Scherrer Institut in the development of a new multi-physics platform for reactor analysis. Such platform is based on the finite-volume software OpenFOAM and aims at a tightly coupled description of neutron transport, thermal mechanics and fluid dynamics. For this purpose, a steady-state 3-D discrete ordinates/thermal-mechanics solver was first developed in collaboration with the Politecnico di Milano. The present work briefly discusses such solver and its preliminary validation, which will be described in detail in parallel publications. It then focuses on its extension to time-dependent simulations. The solver is first tested by simulating different step-wise reactivity insertions in a critical configuration constituted by an infinite slab of highly enriched uranium. Subsequently, a super-prompt-critical power burst in the Godiva reactor has been simulated. Godiva was a spherical assembly of highly enriched uranium built and operated at the Los Alamos National Laboratory (US) during the Fifties. A prompt-critical transient in such system configures as a quick power excursion (up to ∼10 GW), which causes a temperature rise, and a subsequent reactivity reduction via expansion of the sphere. The overall transient lasts for few fractions of a millisecond. Results obtained with the newly developed model have been compared to experimental results, showing a relatively good agreement.
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Pfaendtner, Jim, Linda J. Broadbelt, and Q. Jane Wang. "Strategies for Constructing Reaction Networks of Lubricant Degradation." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-64008.

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Automated mechanism generation is an essential tool to be able to create mechanistic models of lubricant degradation chemistry. To date, modeling of lubricant degradation has been accomplished only through the use of lumped or pathways-style approaches. These methods have yielded important insights into major degradation pathways but lack predictive power and fail to produce some key trends in the product distribution, even qualitatively. Mechanistic models of lubricant degradation include reactivity of individual species as well as the role of secondary reactions. Such models have much to offer in terms of fundamental understanding of degradation chemistry. Furthermore, they may be exploited to directly study the effect of radical stabilizers and additives. Key results obtained include a quantitative description of the degradation of a model lubricant as well as detailed kinetic correlations for estimating rate constants. This poster presents our efforts to construct detailed reaction mechanisms of lubricant degradation. The underlying theories of automated network generation and preliminary results are presented.
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Ciriello, Antonio, and Man Liu. "General Overview of CVCS Design for the TSN Project." In 18th International Conference on Nuclear Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/icone18-29248.

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This paper resumes the results of the collaboration between AREVA and CNPDC during the past two years for performing and achieving the basic design of EPR™ reactor CVCS system for the TSN NPP. The CVCS (Chemical and Volume Control System) is an essential auxiliary system of the PWR technology based nuclear power plants all around the world. In the EPR™ reactor design, as it is also in similar nuclear power plants, this auxiliary system has well determined functions, which are: reactivity control, reactor coolant volume control, coolant chemistry control, primary system main pumps seal water injection as well as the pressurizer auxiliary spray regulation for the Reactor Coolant System. In the EPR™ reactor design, the CVCS is mainly an operational system and only some valves and instrumentations take part at some specific safety functions, (e.g. Reactivity Control, Containment of Radioactive Substances). In the first part of this paper a general introduction to the EPR™ reactor CVCS technology, including the related safety functions and detailed operational functions of CVCS, is presented. In the TSN EPR™ reactor CVCS design, the system is divided into eight sections, (defined from RCV1 to RCV8). The corresponding detailed description of these sections, including their functions, structure and main components, as they have been implemented in the EPR™ reactor CVCS design for the TSN NPP, is then presented in the second part of this paper. In addition some specific design features for EPR™ reactor CVCS system for the TSN NPP, such as the hydrogenation station technology, are also focused in this paper. The reference power plant, concerning the CVCS design, for the TSN NPP is the FA3 NPP, but different design concepts have been implemented in the TSN NPP with regards to the coolant purification section (RCV2), and the coolant filtering in the reactor coolant pumps seal injection and leak-off lines.
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Gokulakrishnan, P., R. Joklik, D. Viehe, A. Trettel, E. Gonzalez-Juez, and M. Klassen. "Optimization of Reduced Kinetic Models for Reactive Flow Simulations." In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-95215.

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A robust optimization scheme, known as rkmGen, for reaction rate parameter estimation has been developed for the generation of reduced kinetics models of practical interest for reactive flow simulations. It employs a stochastic optimization algorithm known as Simulated Annealing, and is implemented in C++ and coupled with Cantera, a chemical kinetics software package, to automate the reduced kinetic mechanism generation process. Reaction rate parameters in reduced order models can be estimated by optimizing against target data generated from a detailed model or by experiment. Target data may be of several different kinds: ignition delay time, blow-out time, laminar flame speed, species time-history profiles and species reactivity profiles. The software allows for simultaneous optimization against multiple target data sets over a wide range of temperatures, pressures and equivalence ratios. In this paper, a detailed description of the optimization strategy used for the reaction parameter estimation is provided. To illustrate the performance of the software for reduced kinetic development, a number of test cases for various fuels were used: one-step, three-step and four-step global reduced kinetic models for ethylene, Jet-A and methane, respectively, and a fifty-step semi-global reduced kinetic model for methane. The fifty-step semi-global reduced kinetic model was implemented in the Star*CCM+ commercial CFD code to simulate Sandia Flame D using laminar flamelet libraries and compared with the experimental data. Simulations were also performed with the GRI3.0 mechanism for comparisons.
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Doucet, M., P. Faye, Ch Faignet, R. Babut, M. Landrieu, F. Marvaud, and G. Romanet. "FCC-NG: The AREVA Safe Fresh Fuel Shipping Cask to Deliver the Future EPR™ Reactors." In 18th International Conference on Nuclear Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/icone18-29436.

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AREVA as a worldwide PWR fuel provider has to have a fleet of fresh UO2 shipping casks being agreed within a lot of countries and to accommodate foreseen EPR™ Nuclear Power Plants fuel buildings. To reach this target the AREVA NP Fuel Sector together with TN International (a subsidiary of AREVA NC) decided to develop an up to date shipping cask gathering experience feedback of the today fleet and an improved safety allowing the design to comply with international regulations (NRC and IAEA) and other local foreign Safety Authorities requirements. Based on pre design features a safety case was set up to highlight safety margins. Criticality hypothetical accidental assumptions were defined: • Preferential flooding, • Fuel rod array expansion (so called “bird caging” effect), • Fuel sliding, • Neutron absorber penalty, • …. The French criticality code package CRISTAL is used to check several configurations reactivity and derived safety margins. The CRISTAL code package relies on a wide validation process helping defining uncertainties as required by regulations in force. The shipping cask, containing two fuel assemblies, is designed to maximize fuel isolation inside the cask and with neighboring ones even for large array configuration cases. Few and proven industrial products are used: • Stainless steel for the structural frame, • Balsa wood for impact limiters, • BORA® resin as neutron absorber. The cask is designed to handle mainly the EPR™ fuel assembly type and may be extended to other contents such as APWR fuel assembly type. After a brief presentation of the computer codes and the description of the shipping cask, the CRISTAL calculation results as well as the applied uncertainties will be discussed.
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Cheatham, Jesse, Bao Truong, Nicholas Touran, Ryan Latta, Mark Reed, and Robert Petroski. "Fast Reactor Design Using the Advanced Reactor Modeling Interface." In 2013 21st International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icone21-16815.

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The Advanced Reactor Modeling Interface (ARMI) code system has been developed at TerraPower to enable rapid and robust core design. ARMI is a modular modeling framework that loosely couples nuclear reactor simulations to provide high-fidelity system analysis in a highly automated fashion. Using a unified description of the reactor as input, a wide variety of independent modules run sequentially within ARMI. Some directly calculate results, while others write inputs for external simulation tools, execute them, and then process the results and update the state of the ARMI model. By using a standardized framework, a single design change, such as the modification of the fuel pin diameter, is seamlessly translated to every module involved in the full analysis; bypassing error-prone multi-analyst, multi-code approaches. Incorporating global flux and depletion solvers, subchannel thermal-hydraulics codes, pin-level power and flux reconstruction methods, detailed fuel cycle and history tracking systems, finite element-based fuel performance coupling, reactivity coefficient generation, SASSYS-1/SAS4A transient modeling, control rod worth routines, and multi-objective optimization engines, ARMI allows “one click” steady-state and transient assessments throughout the reactor lifetime by a single user. This capability allows a user to work on the full-system design iterations required for reactor performance optimizations that has traditionally required the close attention of a multi-disciplinary team. Through the ARMI framework, a single user can quickly explore a design concept and then consult the multi-disciplinary team for model validation and design improvements. This system is in full production use for reactor design at TerraPower, and some of its capabilities are demonstrated in this paper by looking at how design perturbations in fast reactor core assemblies affect steady-state performance at equilibrium as well as transient performance. Additionally, the pin-power profile is examined in the high flux gradient portion of the core to show the impact of the perturbations on pin peaking factors.
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Calabrese, R., and F. Vettraino. "Testing of TRANSURANUS Code for RIA Analysis: The FK-1 NSRR Case." In 18th International Conference on Nuclear Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/icone18-29098.

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Reactivity Initiated Accident (RIA) leads to an unwanted increase in fission rate and power in a region of the reactor core confined around the position of occurrence. The power excursion due to such events may cause fuel rods failures and a subsequent release of radioactive material into the primary coolant of reactor, in severe cases, this release could damage nearby fuel assemblies. In nuclear power plants, RIAs are due to control system faults, e. g. control elements ejection/insertion, or rapid changes in temperature or pressure of moderator. In Boiling Water Reactors (BWRs), the control rod drop accidents (RDAs) at cold zero power have been deeply investigated, in fact, notwithstanding they are less frequent in comparison with the control rod ejection event in PWRs, in this kind of plant these conditions are the most severe in case of a RIA occurrence. RDA transient, comprised in the design basis events considered in safety analysis, may cause rod failures especially at high burnup. To simulate a RIA, a peaked power pulse is applied to a pre-irradiated and re-instrumented rodlet aiming at investigating the most important phenomena that could lead to the rupture of cladding tubes. This paper is focused on the investigation of the TRANSURANUS fuel performance code capability to predict the thermomechanical state of rodlets subjected to RIA tests. To this purpose the FK-1 test, carried out at the Nuclear Safety Research Reactor (NSRR) of Japan Atomic Energy Research Institute (JAERI), was simulated. This experiment is part of a set of 12 tests performed at the NSRR facility to study the performance under a reactivity initiated accident of BWR rodlets with burnup between 41 and 61 MWd/kgHM. In the FK-1 test, a STEP I BWR rodlet, previously irradiated in the Fukushima Daiichi Nuclear Power Station (Unit 3) operated by the Tokyo Electric Power COmpany (TEPCO) up to 45 MWd/kgHM, was subjected to a peak enthalpy insertion of 544 J/g. In this paper the code findings for the FK-1 test are discussed on the basis of the experimental data and the predictions of other stand-alone codes for transient analysis. The FK-1 predictions of FRAPTRAN (2001), FALCON (2003) and SCANAIR (ver. 3–2) are reported. The choice of fuel relocation model and important cladding properties (swelling, thermal expansion, thermal conductivity) was made relying on preliminary calculations whose results are also presented. Notwithstanding a satisfactory agreement between predictions and experimental data and a good agreement in the presented code-to-code comparison were envisaged, these results also emphasized the need to improve the models for FGR, heat transfer to plenum. Investigations are also required to ascertain possible contribution from fission gas to pelles thermal expansion. Ongoing modeling activity, performed at the ITU Joint Research Centre, is focused on a new model for FGR, ENEA (Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile) is expected, in the near term, to give a contribution to refine the model for plenum gas temperature. These activities should improve the description of RIA transient and further investigations on NSRR tests will be performed with newly developed models. The work presented in this paper will be part of ENEA contribution in FUMEX III project leaded by the International Atomic Energy Agency (IAEA) and aimed at the improvement of fuel codes predictions at high burnup.
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Engblom, Markus, Pia Kilpinen, Fredrik Klingstedt, Kari Era¨nen, and Ranjit Katam Kumar. "NOx and N2O Emission Formation Tendency From Multifuel CFB-Boilers: A Further Development of the Predictor." In 18th International Conference on Fluidized Bed Combustion. ASMEDC, 2005. http://dx.doi.org/10.1115/fbc2005-78116.

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Present paper is a part of our on-going model development activities with aim to predict formation tendency of gaseous emissions from CFB combustion of different fuels, and especially, fuel-mixtures in real furnaces of various scale. The model is based on detailed description of homogeneous, catalytic, and heterogeneous chemical kinetics, and a sound but simple 1.5D representation of fluid dynamics. Temperature distribution is assumed known. With the tool, different fuels and fuel mixtures can be compared in respect to their tendency to form nitrogen oxides (NOx, N2O). In this paper the model was tested to predict nitrogen oxide emissions from mono- or co-combustion of coal, wood, and sludge. The plants simulated were the 12MWth CFB combustor located at Chalmers Technical University (A = 2.25m2, h = 13.6m) and the pilot scale CFB unit at the Technical University Hamburg-Harburg (d = 0.1m, h = 15m). The results gave reasonable representation of the measured emission data, and reflected correctly to the changes in the fuel characteristics and in the furnace operating conditions in most cases. An extensive laboratory fixed-bed reactor study was also performed in order to obtain input values for the kinetic constants of the catalytic reactions for the reduction and decomposition of nitrogen oxides. In literature, there is a limited data available regarding the catalytic activity of CFB solids during combustion of wood- and waste-derived fuels, especially at co-firing conditions. The kinetics for the NO reduction by CO in the temperature range of 780–910°C was determined to be of the following form (NO = 300ppm, CO = 5000ppm): −rNO=k·[NO]0.48·[CO]0.55mol/g-s with k=8.15·exp(−8869/T)m3/kg-s(emptyreactoreffectincluded)ork=830·exp(−14930/T)(emptyreactoreffectexcluded), when using a bed sample (250–355 μm) taken from the transport zone in the CTH boiler while burning a mixture of wood pellets and a pre-dried municipal sewage sludge. The role of char particle size and shape as well as the incorporation of energy balance on the char reactivity and the formation of nitrogen oxides is further illustrated by single char particle oxidation simulations.
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Reports on the topic "Reactivity descriptor"

1

Jeffries, H. E., K. G. Sexton, R. M. Kamens, and M. S. Holleman. Outdoor smog chamber experiments: reactivity of methanol exhaust. Part 2. Quality assurance and data processing system description. Office of Scientific and Technical Information (OSTI), September 1985. http://dx.doi.org/10.2172/5813696.

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