Search results for "ionic"

Gallium preference for the occupation of tetrahedral sites in Lu3(Al5-xGax)O12multicomponent garnet scintillators according to solid-state nuclear ma…

2019

Abstract In this study, the distributions of aluminum and gallium atoms over the tetrahedral and octahedral sites in the garnet structure were investigated in mixed Lu3Al5-xGaxO12 crystals by using 27Al and 71Ga magic angle spinning nuclear magnetic resonance (NMR) and single crystal 71Ga NMR. The experimental study was supported by theoretical calculations based on density functional theory (DFT) in order to predict the trends in terms of the substitutions of Al by Ga in the mixed garnets. Both the experimental and theoretical results indicated the non-uniform distribution of Al and Ga over the tetrahedral and octahedral sites in the garnet structure, with a strong preference for Ga occupy…

A Theoretical and Experimental Investigation of the Spectroscopic Properties of a DNA-Intercalator Salphen-Type ZnIIComplex

2014

The photophysical and DNA-binding properties of the cationic zinc(II) complex of 5-triethylammonium methyl salicylidene ortho-phenylenediiminato (ZnL 2 + ) were investi- gated by a combination of experimental and theoretical methods. DFT calculations were performed on both the ground and the first excited states of ZnL 2 + and on its possi- ble mono- and dioxidation products, both in vacuo and in selected solvents mimicked by the polarizable continuum model. Comparison of the calculated absorption and fluores- cence transitions with the corresponding experimental data led to the conclusion that visible light induces a two-elec- tron photooxidation process located on the phenylenediimi- nato…

Crystal structure and Hirshfeld surface analysis of [N(CH3)4][2,2′-Fe(1,7-closo-C2B9H11)2]

2017

Abstract This work investigates the meta -ferrabis(dicarbollide) anion that was isolated as salt of tetramethylammonium. The structure of the obtained crystal consisted of discrete [2,2′-Fe(1,7- closo -C 2 B 9 H 11 ) 2 ] − anions and disordered [N(CH 3 ) 4 ] + cations. The anion had a considerable chemical stability ensured by ionic and Van der Waals interactions. Thus, Hirshfeld surfaces and fingerprint plot were used to visualize, explore, and quantify intermolecular interactions in the crystal lattice of the title compound. This investigation proved that close contacts were dominated by H⋯H interactions.

Reimagining humanity in Battlestar Galactica, Bionic Woman and V

2015

Hybrid ionogels: adsorbent for the removal of pharmaceutical active compounds from wastewater

Surfactant self-assembling in the gas phase: bis(2-ethylhexyl)- sulfosuccinate divalent metal ion anionic aggregates

2012

RATIONALE: Investigation of fundamental aspects driving surfactant self-assembling and of the capability of including guest molecules or ions in their micellar aggregates is an exciting research field for theoretical and technological reasons. In this light, assembling and chelating properties of sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) towards divalent metal ion chlorides have been investigated in the gas phase by electrospray ionization mass spectrometry in negative ion mode, tandem mass spectrometry and energy-resolved mass spectrometry. METHODS:Water/methanol solutions of AOTNa and chloride salts of nickel, magnesium, calcium and manganese, with different AOTNa/metal salt ratios, …

A route to simple nonionic surfactants

2016

AbstractA method for the synthesis of nonionic surfactants – N-alkyl-O-(2-hydroxyethyl) carbamates is proposed by acylation of fatty amines with ethylene carbonate without any solvent or catalyst. The surface tension of the prepared surfactants was measured, toxicity and biodegradability were determined for the surfactant with n-dodecyl as a hydrophobic group and N-monosubstituted amide and hydroxyl groups for their hydrophilic part.

Task-Specific Organic Salts and Ionic Liquids Binary Mixtures: A Combination to Obtain 5-Hydroxymethylfurfural From Carbohydrates

2019

The increase in energy demand and depletion of fossil fuels are among major issues of modern society. Valorization and transformation of raw materials in products of industrial value represents a challenge. This justifies the growing interest of scientific research towards the identification of suitable media and methodologies able to pursue above goals, paying attention to matter of sustainability. On this subject, we studied sulfonic-acid functionalized diimidazolium salts as catalysts for the conversion of fructose and sucrose to 5-hydroxymethylfurfural (5-HMF) in an ionic liquid mixture. In general, using these salts allowed us to obtain 5-HMF in good yields from both substrates in mild…

Clay/Non-Ionic Surfactant Hybrid Nanocomposites

2020

This chapter gives an overview of the structural and chemical physical properties of nanocomposites formed by clay minerals and surfactants, which represent a class of materials with promising features for applications in different industrial, biomedical, and environmental applications. Due to their non-toxicity and biocompatibility, a great deal of attention is nowadays devoted to the study of non-ionic surfactants. Among them, block copolymers represent a combination of the properties of common amphiphilic molecules and long polymer chains. These macromolecules can form a great variety of supra-molecular structures generated from self-organization phenomena in aqueous media. Nanostructure…

Cybersecurity Attacks on Software Logic and Error Handling Within ADS-B Implementations: Systematic Testing of Resilience and Countermeasures

2022

Automatic Dependent Surveillance-Broadcast (ADS-B) is a cornerstone of the next-generation digital sky and is now mandated in several countries. However, there have been many reports of serious security vulnerabilities in the ADS-B architecture. In this paper, we demonstrate and evaluate the impact of multiple cyberattacks on ADS-B via remote radio frequency links that affected various network, processing, and display subsystems used within the ADS-B ecosystem. Overall we implemented and tested 12 cyberattacks on ADS-B in a controlled environment, out of which 5 attacks were presented or implemented for the first time. For all these attacks, we developed a unique testbed that consisted of 1…