Computational Modeling of Silicate Glasses: A Quantitative Structure-Property Relationship Perspective

This article reviews the present state of Quantitative Structure-Property Relationships (QSPR) in glass design and gives an outlook into future developments. First an overview is given of the statistical methodology, with particular emphasis to the integration of QSPR with molecular dynamics simulations to derive informative structural descriptors. Then, the potentiality of this approach as a tool for interpretative and predictive purposes is highlighted by a number of recent inspiring applications

in keeping with the spirit of the albertine statute constitutionalisation of the national unification

This chapter deals with the difficult process of constitutionalisation which characterised Italian Unification. Constitutionalisation is a long-term phenomenon which had the purpose of giving constitutional forms to the Nation. The promulgation of the Albertine Statute is more the start than the arrival of this phenomenon. The focus of this investigation is, therefore, to study the Constitution through its evolution paying particular attention to the process of legal integration within the structures of the Albertine Statute and to the amendment mechanisms of the constitutional text. The preamble of the Albertine Statute speaks of «perpetual and irrevocable fundamental law». The word «perpetual» meant the prohibition of revoking constitutional concession, while the word «irrevocable» was intended as a pact between the Sovereign and the Nation. Over the years, very few were the changes to the letter of the Albertine Statute. The interpretation and the practice represented the most important mechanisms of constitutional change (implicit constitutional changes). A primary role was acknowledged to non-written norms. In this perspective, it may well be said that the Italian Constitution consisted in something more than the written text and dwelt in the spirit and not in the letter of the Albertine Statute

Anti-refugee and Immigrant Representation in Three German Online Illustrations

Social criticism is often showed in various forms, one of it is through an illustration. Thus, many people ultimately poured their aspirations, criticism and even innuendo into a drawing. The easy access to the internet today also makes the illustrators take part in doing literary works that are published online. Through the semiotic theory of Ferdinand de Saussure, this paper analyses three online illustrations made by German cartoonists and illustrators; Schwarwel, Harm Bengen, and Freimut Woessner. These three corpuses are published online through their website. The result of this research indicates that the illustrations by Schwarwel, Harm Bengen, and Freimut Woessner represent a rejection of German refugees and immigrant in the political, educational and social sphere

Electrochemically controlled assembling/disassembling processes with a bis-imino bis-quinoline ligand and the CuII/CuI couple

The bis-iminoquinoline quadridentate ligand L is capable of forming air- and moisture-stable complexes both with Cu-II and Cu-I; thus the L/Cu-II/I set is a bistable system. Owing to its quite rigid preorganized structure, L forms the 1:1 complex [(CuL)-L-II](2+) when binding the d(9) cation Cu2+, while with the d(10) cation Cu+, dimeric complexes of the [(Cu2L2)-L-I](2+) type are formed in which each copper cation is coordinated by two iminoquinoline fragments belonging to two different ligands. Crystal and molecular structure determinations showed that, in [(CuL)-L-II](CF3SO3)(2), L binds to the metal center in a square-planar fashion, while in [(Cu2L2)-L-I](CF3SO3)(2) the Cu+ cations are coordinated with a tetrahedral geometry, with the two ligands L intertwined in a double helix. On the other hand, in the case of [(Cu2L2)-L-I](ClO4)(2) both a helical species and a dimeric nonhelical one were found to coexist in the same crystal cell. However, spectrophotometric and H-1 NMR studies demonstrated that, in acetonitrile solution, only two helical forms exist, one of which is more prevalent (87%, at 20 degrees C). The interconversion equilibrium between the two helical forms has been studied in acetonitrile by temperature variable H-1 NMR and the pertinent Delta H-circle minus and Delta S-circle minus values have been determined; these account for the small difference in energy between the two species. Finally, cyclic voltammetry and spectroelectrochemical experiments demonstrated that in acetonitrile solution it is possible to rapidly transform [(CuL)-L-II](2+) into the helical [(Cu2L2)-L-I](2+) dimer (or vice versa) by changing the potential applied to the working electrode, that is, it is possible to electrochemically control the self-assembly/disassembly process through the Cu-II/Cu-I redox couple. Moreover, it has been shown that self-assembly (reduction)/disassembly (oxidation) cycles can be repeated at will, without any degradation of the system

Synthesis, Characterization and Stereoselective Catalytic Oxidations of Chelated Deuterohaemin-Glycyl-L-Histidine Complexes

The manuscript reports on the synthesis and characterization of a series of chelated deuterohaemin-glycyl-L-histidine Complexes. They are able to perform stereoselective catalytic oxidations of phenols in the presence of hydrogen peroxide.

Reaction Mechanism in Alumina/Chromia (Al2O3/Cr2O3) Solid Solutions Obtained by Co-Precipitation

The aim of this work is to study the structural characteristics and properties of the solid solution (Al,Cr)(2)O-3. XRD analysis, Al-27 MAS-NMR measurements, and microstructural characterization were used to determine the relationship between color and crystallochemical properties of the compounds formed, In particular, to determine more accurately the mechanism of solid solution formation above the miscibility gap of the system, the marker technique was used. In order to define the behavior of the system for temperatures below the miscibility gap at 1 bar pressure, the composition Al2O3:Cr2O3 1:1 was studied with high-temperature XRD

Metal-Induced Assembling/Disassembling of Fluorescent Naphthalenediimide Dericatives Signalled by Excimer Emission

The new quadridentate bis-chelating ligands 2 and 3 display in solution the typical absorption and emission properties expected for naphthalenediimide derivatives. Spectrophotometric studies show that systems 2 and 3 interact with ZnII, CdII and CuI in CHCl3 or MeCN solution according to an apparent 1:1 stoichiometry. Molecular modelling, ESI-MS and 1H-NMR experiments point out that the complex species formed in the presence of stoichiometric amounts of metal ion are non-helical [2+2] adducts. The metal induced self-assembling process is signalled by an intense excimer-type emission due to the intramolecular interaction of two naphthalenediimide subunits which face each other in the [2+2] adduct, as shown by molecular modelling studies. In the presence of excess metal ion, a disassembling process takes place, leading to a dinuclear complex with a 2:1 metal:ligand stoichiometry, in which the intramolecular excimer is no longer allowed to form, since the interaction between the naphthalenediimide subunits has been lost. Thus, the overall metal-induced assembling/disassembling process is signalled by the appearance and disappearance of the excimer band in the emission spectrum