Search results for "Nuclear chemistry"

FTIR Analysis of Electron Irradiated Single and Multilayer Si<sub>3</sub>N<sub>4</sub> Coatings

2018

Silicon nitride (Si3N4) due to its good mechanical and electrical properties is a promising material for wide range of applications, including exploitation under action of ionizing radiation. For estimating the changes of chemical bonds in silicon nitride nanolayers under action of ionizing radiation single and multi-layer silicon nitride nanolayered coatings on prepared Si subtrate were investigated by means of Fourier transform infrared spectrometry. Three main groups of signals were identified in both types of nanolayers, at 510 and 820 cm-1 and group of broad signals at 1000-1200 cm-1. Irradiation with accelerated electrons up to absorbed doses 36 MGy causes minor changes of signal inte…

Effect of Mn doping on the low-temperature synthesis of tricalcium phosphate (TCP) polymorphs

2019

Abstract Effect of Mn doping on the low-temperature synthesis of tricalcium phosphate (TCP) polymorphs was demonstrated in α- and β-TCP polymorphs prepared by wet precipitation method under identical conditions and annealed at 700 °C. Calcium phosphates with Mn doping level in the range from 1 to 5 mol% were studied and the formation of desired polymorph was controlled by varying Mn content in as-prepared precipitates. It was found that increasing Mn content resulted in the formation of β-TCP, while α-TCP was obtained with low Mn doping level, whereas a mixture of two polymorphs was obtained for intermediate Mn concentrations. Moreover, doping with Mn ions allowed the synthesis of β-TCP at …

Carbonyl compounds of Tc, Re, and Bh: Electronic structure, bonding, and volatility.

2018

Calculations of molecular properties of M(CO)5 and MH(CO)5, where M = Tc, Re, and Bh, and of the products of their decomposition, M(CO)4 and MH(CO)4, were performed using density functional theory and coupled-cluster methods implemented in the relativistic program suits such as ADF, DIRAC, and ReSpect. The calculated first M—CO bond dissociation energies (FBDEs) of Bh(CO)5 and BhH(CO)5 turned out to be significantly weaker than those of the corresponding Re homologs. The reason for that is the relativistic destabilization and expansion of the 6d AOs, responsible for weaker σ-forth and π-back donations in the Bh compounds. The relativistic FBDEs of M(CO)5 have, therefore, a Λ-shape behavior …

Determination of the chemical warfare agents Sarin, Soman and Tabun in natural waters employing fluorescent hybrid silica materials

2017

[EN] A novel mesoporous silica material containing boron-dipyrromethene (BODIPY) moieties (I) is employed for the detection of nerve agent simulants (NASs) and the organophosphate nerve or chemical warfare agents (CWAs) Sarin (GB), Soman (GD), and Tabun (GA) in aqueous environments. The reactive BODIPY dye with an optimum positioned hydroxyl group undergoes acylation reactions with phosph(on)ate substrates, yielding a bicyclic ring. Due to aggregation of the dyes in water, the sensitivity of the free dye in solution is very low. Only after immobilization of the BODIPY moieties into the silica substrates is aggregation inhibited and a sensitive determination of the NASs diethyl cyanophosphon…

2017

The title compound, C12H9BrN2O3, was prepared in two steps from 2-chloro-3-nitropyridine. The nitrobiaryl unit is twisted, with dihedral angles of 35.4 (5)° between the nitro substituent and the pyridine ring to which it is bound, and 51.0 (5)° between the nitro group and the benzene ring. In the crystal, the molecules are connectedviaC—H...O hydrogen bonds, forming strands along theb-axis direction.

Corrosion inhibition performance of a structurally well-defined 1,2,3-triazole derivative on mild steel-hydrochloric acid interface

2021

Abstract In the present work, a new 1,4-disubstituted-1,2,3-triazole product, named 4-[1-(4-methoxy-phenyl)-1H-[1,2,3]triazol-4-ylmethyl]-morpholine (MPTM) was successfully synthesized under click chemistry regime. The structure of the new compound that has a rigid triazole moiety and a flexible morpholine ligand has been characterized using 1H NMR, 13C NMR, HRMS, and FTIR spectroscopy. Its inhibition performance for mild steel in acidic medium 1 M HCl has been studied by utilizing a combination of experimental, spectroscopic and computational methods. The electrochemical characterization was carried out by a gravimetric study, electrochemical impedance spectroscopy (EIS), and potentiodynam…

2016

The title compound, C32H48O8P2S2, was prepared by the nickel-catalyzed reaction of bis(5-bromothienyl)dipropoxybenzene and triisopropyl phosphite. The thiophene rings are inclined to the benzene ring by 14.6 (2) and 25.3 (3)°. One propyloxy group is disordered. Four hydrogen bonds connect the molecules, which are arranged in ribbons parallel to thebcplane.

Determination and Toxicology Studies of Quaternary Ammonium Salts in Solution after Organoclay Processing

2018

Organoclays have potential to be used as additives in various facade paints and other finishing materials. Such new innovative materials must be rigorously tested for them to have no impact on environment. Focus of this study was to develop HPLC – TOF/MS method for determining quaternary ammonium salts in various material washing solutions and to determine organoclay toxicity by performing acute toxicity test on Daphnia magna. From the obtained results, it was possible to conclude that organoclays can be safely used as additives in various materials with low or no impact on environment. We determined that organoclays are significantly less toxic then some quaternary ammonium salts on its ow…

Imidazolium Based Ionic Liquids: A Promising Green Solvent for Water Hyacinth Biomass Deconstruction.

2018

Water hyacinth (WH) is a troublesome aquatic weed of natural and artificial water bodies of India and other tropical countries and causing severe ecological problems. The WH biomass is low in lignin content and contains high amount of cellulose and hemicellulose, making it suitable material for conversion into liquid fuels for energy production. This study highlighted that, how different imidazolium based ionic liquids (ILs) [1-alkyl-3-methylimidazolium bromide, [Cnmim]Br (n = 2, 4, 6, 8, and 10)] with tunable properties can be employed for the degradation of WH biomass. Different characterizations techniques, such as XRD, FT-IR, SEM, and DSC are used to unravel the interplay between ILs an…

Behaviour of alkyl oleates following foliar application in relation to their influence on the penetration of phenmedipham and quizalofop-P-ethyl

1997

Summary The foliar penetration of four alkyl oleates (methyl to butyl) and their influence on the penetration of phenmedipham and quizalofop-P-ethyl was studied in barley (Hordeum vulgare L.), cleavers (Galium aparine L.) and pea (Pisum sativum L.). Loss of alkyl oleates from glass and plant surfaces was inversely related to the length of the alkyl chains and was assumed to be due to volatilization. All four alkyl oleates after application alone, readily penetrated into pea and barley leaves but much less into G. aparine. Penetration of methyl oleate appeared to be faster than that of butyl oleate. Both alkyl oleates were completely metabolized in barley and pea in 27 h, but not in G. apari…