In this study, long-lived nuclear singlet order methods are combined with diffusion tensor imaging the purpose of characterizing full molecules diffusing freely in large pores up to a millimeter size. Such sizes out reach conventional because limitations imposed by relaxation decay constant longitudinal magnetization. A singlet-assisted methodology able circumvent such is discussed, and new pos...

permeability is a property of porous medium that quantifies rock capacity to transmit fluids. frequently, core based permeability data are not available either because of the borehole conditions or due to the high cost of coring. for these reasons, over the years attempts have been made to estimate permeability by alternative ways. permeability is an elusive parameter in hydrocarbon reservoirs ...

Abstractl Density functional theory (DFT) was used to investigate the effects of intra-moecular interactions and implicit water molecules on the relative stability and the NMR shielding tensors of hallucinogenic harmine in the monomeric and dimeric states. Results represented that the relative stability and the NMR shielding tensors are dependent on the resonance interactions and chemical envir...

In this article we consider nuclear magnetic resonance (NMR) as an example of a quantum technology; we consider in particular detail the implementation of quantum computers using NMR. We begin by outlining the physical principles underlying NMR, and give an introduction to the quantum mechanics involved. We next discuss the general characteristics of quantum technologies and the ways and extent...

A green chemistry approach has been adopted for the synthesis of thirty-four new picolinium-based ionic liquids using microwave (MW) and ultrasound (US) irradiation as well as conventional thermal heating. Their structures were confirmed by FT-IR, 1H NMR, 13C NMR, 11B NMR, 19F NMR, 31P NMR, mass spectra and elemental analyses. The antimicrobial profile of the novel ionic liquids was evaluated a...

isolated five known iridoids glycosides (scrophuloside a, harpagoside b, 5-hydroxyloganin, 8-o-acetylharpagide and 6-o-methyl,1-glucopyranosyl catalpol ),one phenyl ethanoid glycoside (verbascoside) and a phenyl ethanol amine (2-(4-chlorobenzyl amino) ethanol ) compound from the methanolic extract of aerial parts of scrophularia oxysepala using by high performance liquid chromatography based on...

nowadays nmr spectroscopy becomes a powerful tool in chemistry because of the nmr chemical shifts. hartree–fock theory and the gauge-including atomic orbital (giao) methods are used in the calculation of 29si nmr chemical shifts of various silicate species in the silicate solution as initial components for zeolite synthesis both in gas and solution phase. calculations have been performed at geo...

a green and convenient protocol is described for the preparation of 1-(alkylamino)-3-(1,3-dioxoisoindolin-2-yl)-2-methyl-1-oxopropan-2-yl benzoates via one-pot three-component reaction between 2-(2-oxopropyl)isoindoline-1,3-dione, an alkyl isocyanide and an aromatic carboxylic acid in water at room temperature. the methods used to follow the reactions are tlc and nmr, which indicated that there...

A general overview of the advancements and applications of nuclear magnetic resonance (NMR) hyphenated with other analytical techniques is given from a practical point of view. Details on the advantages and disadvantages of the hyphenation of NMR with liquid chromatography as LC–NMR and also with mass spectrometry as LC–MS–NMR are demonstrated with two examples. Current developments of NMR with...

Nuclear magnetic resonance (NMR) has been recognized for well over 40 years. Although the first successful in vivo NMR experiments date back to 1946-1948, it was not until the 1970s that the first experiments involving NMR spectroscopyand imagingof living systems were reported in the literature. Since that time the clinical application of NMR has experienced exponential growth. Because of this ...