Search results for " Io"

Spatially ordered surfactant assemblies in the gas phase: negatively charged bis(2-ethylhexyl)sulfosuccinate- alkaline metal ion aggregates

2009

The formation and structural features of negatively charged aggregates of sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) surfactant molecules in the gas phase have been investigated by electrospray ionization mass spectrometry (ESI-MS) and density functional theory calculations. Mainly driven by the interactions of alkali metal ions both with the oxygen atoms of the sulfonate group and with the succinate moiety of the AOT(-) anion, spatially ordered supramolecular assemblies, characterized by an internal core composed of surfactant counterions and hydrophilic head groups surrounded by the surfactant alkyl chains pointing outwards, are formed. Calculations have shown that surfactant self-org…

Metalotioneiny i motywy policysteinylowe : oddziaływanie z jonami metali

2018

Many of biochemical paths and processes require some metal ions to occur. There are also known the negative effects of the presence of metal ions in the organism. The both sides of metal ions interactions on the living organism require specific regulations and cannot be left without supervision and control of the organism itself. One of the strategy to keep the control on metal ions are cystein-rich proteins that play crucial role in detoxication of metal ions that are dangerous for human organism as well as they help to maintain homeostasis of essential metal ions. Matallothioneins are one of the well known, but still not fully understood, cysteine- rich proteins. They are small proteins b…

Interaction of methyltin(IV) compounds with carboxylate ligands. Part 1: formation and stability of methyltin(IV)–carboxylate complexes and their rel…

2006

Quantitative data on the stability of mono-, di- and trimethyltin(IV)-carboxylate complexes (acetate, malonate, succinate, malate, oxydiacetate, diethylenetrioxydiacetate, tricarballylate, citrate, butanetetracarboxylate and mellitate) are reported at t=25°C and I → 0 mol l - 1 . Several mononuclear, mixed proton, mixed hydroxo and polynuclear species are formed in these systems. As expected, the stability trend is mono- > di- > trimethyltin(IV) and mono < di < tri < tetra < hexa for the organotin moieties and carboxylate ligands investigated, respectively. Moreover, ligands containing, in addition to carboxylic,-O-and-OH groups show a significantly higher stability with respect to analogou…

Development of economic MeV-ion microbeam technology at Chiang Mai University

2017

Developing high technologies but in economic manners is necessary and also feasible for developing countries. At Chiang Mai University, Thailand, we have developed MeV-ion microbeam technology based on a 1.7-MV Tandetron tandem accelerator with our limited resources in a cost-effective manner. Instead of using expensive and technically complex electrostatic or magnetic quadrupole focusing lens systems, we have developed cheap MeV-ion microbeams using programmed L-shaped blade aperture and capillary techniques for MeV ion beam lithography or writing and mapping. The programmed L-shaped blade micro-aperture system consists of a pair of L-shaped movable aperture pieces which are controlled by …

Green conditions for the Suzuki reaction using microwave irradiation and a new HNT- supported ionic liquid-like phase (HNT-SILLP) catalyst

2014

A new catalytic system based on modified halloysite nanotubes was employed in the Suzuki reaction under microwave irradi- ation. A set of solvents, times and bases was screened and the best experimental conditions were obtained when the reactions were carried out for 10 min in water–ethanol at 120 °C in presence of K2CO3 as base. Good recyclability was observed. The new catalytic system was employed using either 1 mol% or 0.1 mol%. The palladium catalyst displayed good activity, allowing the synthesis of several biphenyl compounds in high yield working with only 0.1 mol% palladium loading. The application of mi- crowave irradiation decreased the reaction time and also improved conversion wi…

Single Event Transients and Pulse Quenching Effects in Bandgap Reference Topologies for Space Applications

2016

An architectural performance comparison of bandgap voltage reference variants, designed in a $0.18~\mu \text {m}$ CMOS process, is performed with respect to single event transients. These are commonly induced in microelectronics in the space radiation environment. Heavy ion tests (Silicon, Krypton, Xenon) are used to explore the analog single-event transients and have revealed pulse quenching mechanisms in analogue circuits. The different topologies are compared, in terms of cross-section, pulse duration and pulse amplitude. The measured results, and the explanations behind the findings, reveal important guidelines for designing analog integrated circuits, which are intended for space appli…

STABILITY AND ORGANOCATALYTIC EFFICIENCY OF N-HETEROCYCLIC CARBENES ELECTROGENERATED IN ORGANIC SOLVENTS FROM IMIDAZOLIUM IONIC LIQUIDS

2015

The kinetic of degradation of 1-butyl-3-methylimidazole-2-ylidene (selected as model N-heterocyclic carbene - NHC), generated in organic solvents by cathodic reduction of the parent 1-butyl-3- methylimidazolium salts BMIm-X, was studied by a simple voltammetric analysis. The effect of NHC degradation rate on the efficiency of an organocatalyzed reaction (the synthesis of g-butyrolactone from cinnamaldehyde and trifluoromethylacetophenone) was investigated. The nature of the solvent and of the anion X have a remarkable effect on the stability of the NHC, the bis(trifluoromethylsulfonyl) imide anion being the best for a long lasting carbene (while acetonitrile seems to be the worst solvent). …

Strong field phenomena: Atoms, Molecules, Nanostructures.

Three-Dimensional Superconducting Nanohelices Grown by He

2019

Novel schemes based on the design of complex three-dimensional (3D) nanoscale architectures are required for the development of the next generation of advanced electronic components. He+ focused-ion-beam (FIB) microscopy in combination with a precursor gas allows one to fabricate 3D nanostructures with an extreme resolution and a considerably higher aspect ratio than FIB-based methods, such as Ga+ FIB-induced deposition, or other additive manufacturing technologies. In this work, we report the fabrication of 3D tungsten carbide nanohelices with on-demand geometries via controlling key deposition parameters. Our results show the smallest and highest-densely packed nanohelix ever fabricated s…

Notes on Shore Flies (Diptera: Ephydridae) from Finland and north-western Russia

2015

The recent checklist of the Ephydridae of Finland by Zatwarnicki and Kahanpää (2014) mentioned 13 ephydrid species as new for Finland without further details. This paper presents detailed records for those species and a few other species of interest. Four species are recorded for the first time from Russia. Trimerina indistincta Krivosheina, 2004 is herein considered as a new junior synonym of Trimerina microchaeta Hendel, 1932, syn. nov.