Abstract To rapidly evaluate and characterize the porosity permeability of shale reservoirs, this study uses Nuclear Magnetic Resonance (NMR) technology to classify T2 spectrums different analyzes correlation between cut-off values main peaks establishes a rapid identification evaluation method for fluid signals reservoirs. Also, area in signal intervals is explored, finally, pore structure cha...

Abstract. In this paper, we present a custom-designed nuclear magnetic resonance (NMR) platform based on broadband complementary metal–oxide–semiconductor (CMOS) NMR-on-a-chip transceiver and synchronous reference signal generator, which features arbitrary phase control of the excitation pulse in combination with phase-coherent detection at non-zero intermediate frequency (IF). Moreover, presen...

Prerequisites for the quantification of cerebral metabolite concentrations by NMR are a proper assignment of pertinent resonances and the identification of components with overlapping signals. The purpose of this study is to more closely examine the nature of the strong N-acetyl methyl signal that is observed in 'H NMR spectra of mammalian brain and commonly ascribed to N-acetylaspartate (NAA)....

Metabolites of new chemical entities can influence safety and efficacy of a molecule and often times need to be quantified in preclinical studies. However, synthetic standards of metabolites are very rarely available in early discovery. Alternate approaches such as biosynthesis need to be explored to generate these metabolites. Assessing the quantity and purity of these small amounts of metabol...

Heparin and low molecular weight heparins are polydisperse polysaccharides with a degree of polymerization ranging from 4 to approximately 40. The determination of their average molecular weights has traditionally relied on size exclusion chromatography involving the use of oligosaccharides of known size and molecular weight as standards. 13C NMR spectroscopy is applied for the first time to ob...

In this study, the change at rubbing surfaces has been investigated experimentally using an acoustic emission signal monitoring system. A steel ring is slipped on the surface of  a metallic sheet to simulate frictional conditions. The mechanical disturbances caused by the movement of the ring produce stress waves propagating along the sheet surface. The out of plane displacement of the sheet su...

On the basis of in situ MAS NMR technique under flow conditions,1-4 the combined in situ MAS NMR-UV/Vis spectroscopy5 has recently been developed to obtain complimentary information on solid catalysts and, therefore, to better elucidate the mechanism involved in heterogeneous catalysis. While NMR spectroscopy allows the identification of species on the working catalyst in more detail, UV/Vis sp...

We developed several novel two-dimensional (2D) NMR core analysis techniques, which not only enhance the analysis of fluid-saturated rock samples, but also open up an unexplored area for petrophysical research. This is different from the conventional one-dimensional (1D) NMR core analysis, in which only the proton population versus relaxation times, i.e., T1,2 distribution, is displayed to char...

A surface coil is any radiofrequency (RF) coil placed directly on the surface of the subject. Surface coils represent some of the simplest coil designs used in magnetic resonance, but are commonly used in experiments requiring the highest possible sensitivity. In contrast to volume coils, which are designed to provide homogeneous sensitivity over the whole field-of-view, surface coils sacrifice...

In the structural analysis of lignins by 13C-NMR, signal overlap limits definitive assignment and accurate inten­ sity measurement. Selective labeling by 13C-enrichment of a specific carbon in lignin enhances its signal intensity in the spectrum. Further enhancement of the specifically labeled carbons can be realized via difference spectra created from the enriched and unenriched samples. Diffe...