scholarly journals NMRexSeer: Metadata extraction and search for large scale Nuclear Magnetic Resonance (NMR) experimental data

2015 ◽  
Author(s):  
Suppawong Tuarob ◽  
Kevin A Glass ◽  
C. Lee Giles
Keyword(s):  
Experimental Data ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Large Scale ◽  
Metadata Extraction ◽  
Nuclear Magnetic

scholarly journals One-Pot Synthesis of 7, 7-Dimethyl-4-Phenyl-2-Thioxo-2,3,4,6,7, 8-Hexahydro-1H-Quinazoline-5-OnesUsing Zinc Ferrite Nanocatalyst and Its Bio Evaluation

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 431
Author(s):  
Tentu Nageswara Rao ◽  
Nalla Krishnarao ◽  
Faheem Ahmed ◽  
Suliman Yousef Alomar ◽  
Fadwa Albalawi ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Zinc Ferrite ◽  
Large Scale ◽  
Cyano Group ◽  
Proton Nuclear Magnetic Resonance ◽  
Scale Production ◽  
One Pot ◽  
Antibacterial And Antifungal ◽  
Nuclear Magnetic

A simple and highly efficient protocol for the synthesis of derivatives 7, 7-dimethyl-4-phenyl-2-thioxo-2, 3, 4, 6, 7, 8-hexahydro-1H-quinazoline-5-one from 5, 5-dimethyl cyclohexane-1, 3-dione (4a–4h) (dimedone) has been described. The aryl aldehydes were substituted with thiourea in the presence of synthesized zinc ferrite nanocatalyst, which increased the yield under reflux through condensation, followed by cyclization to give desired products. The other advantages are that it is eco-friendly and economically affordable for large-scale production. Structural validation and characterization of all the newly synthesized compounds were evaluated by spectral analysis (mass spectrometry, proton nuclear magnetic resonance (1HNMR), and Carbon-13 nuclear magnetic resonance(13CNMR)spectroscopies. The structure of antibacterial and antifungal assays was performed with the newly synthesized compounds. The antimicrobial activity of title compounds possessing electron-withdrawing groups such as (4e–4h) (Cl, Br, and cyano group) exhibited more active potential than the electron-donating groups, C6H5,4-C6H4, 3-OC2H5-4OH-C6H3, etc., (4a–4d) containing moiety.

scholarly journals A New Hybrid Inversion Method for 2D Nuclear Magnetic Resonance Combining TSVD and Tikhonov Regularization

2021 ◽  
Vol 7 (2) ◽  
pp. 18
Author(s):  
Germana Landi ◽  
Fabiana Zama ◽  
Villiam Bortolotti
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Tikhonov Regularization ◽  
Large Scale ◽  
Regularization Parameter ◽  
High Sensitivity ◽  
Inversion Method ◽  
Nmr Relaxometry ◽  
Value Decomposition ◽  
Nuclear Magnetic

This paper is concerned with the reconstruction of relaxation time distributions in Nuclear Magnetic Resonance (NMR) relaxometry. This is a large-scale and ill-posed inverse problem with many potential applications in biology, medicine, chemistry, and other disciplines. However, the large amount of data and the consequently long inversion times, together with the high sensitivity of the solution to the value of the regularization parameter, still represent a major issue in the applicability of the NMR relaxometry. We present a method for two-dimensional data inversion (2DNMR) which combines Truncated Singular Value Decomposition and Tikhonov regularization in order to accelerate the inversion time and to reduce the sensitivity to the value of the regularization parameter. The Discrete Picard condition is used to jointly select the SVD truncation and Tikhonov regularization parameters. We evaluate the performance of the proposed method on both simulated and real NMR measurements.

scholarly journals Improving the accuracy of model-based quantitative nuclear magnetic resonance

2020 ◽  
Vol 1 (2) ◽  
pp. 141-153
Author(s):  
Yevgen Matviychuk ◽  
Ellen Steimers ◽  
Erik von Harbou ◽  
Daniel J. Holland
Keyword(s):  
Experimental Data ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Model Fitting ◽  
Adjustment Procedure ◽  
Peak Integration ◽  
Model Based ◽  
Numerous Model ◽  
Functional Forms ◽  
Nuclear Magnetic

Abstract. Low spectral resolution and extensive peak overlap are the common challenges that preclude quantitative analysis of nuclear magnetic resonance (NMR) data with the established peak integration method. While numerous model-based approaches overcome these obstacles and enable quantification, they intrinsically rely on rigid assumptions about functional forms for peaks, which are often insufficient to account for all unforeseen imperfections in experimental data. Indeed, even in spectra with well-separated peaks whose integration is possible, model-based methods often achieve suboptimal results, which in turn raises the question of their validity for more challenging datasets. We address this problem with a simple model adjustment procedure, which draws its inspiration directly from the peak integration approach that is almost invariant to lineshape deviations. Specifically, we assume that the number of mixture components along with their ideal spectral responses are known; we then aim to recover all useful signals left in the residual after model fitting and use it to adjust the intensity estimates of modelled peaks. We propose an alternative objective function, which we found particularly effective for correcting imperfect phasing of the data – a critical step in the processing pipeline. Application of our method to the analysis of experimental data shows the accuracy improvement of 20 %–40 % compared to the simple least-squares model fitting.

scholarly journals Permeability Calculation of Sand Conglomerate Reservoirs Based on Nuclear Magnetic Resonance (NMR)

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
You Zhou ◽  
Songtao Wu ◽  
Zhiping Li ◽  
Rukai Zhu ◽  
Shuyun Xie ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Junggar Basin ◽  
Northwest China ◽  
Free Fluid ◽  
Iteration Parameters ◽  
Nuclear Magnetic

The concept of an intermingled fractal unit (IFU) model was first proposed by Atzeni and Pia in 2008, and their model has since been successfully applied to predict thermal conductivity, electrical conductivity, and the mechanical properties of porous media materials. This paper, based on the Pia IFU model, fits the pore size distribution spectrum to quantitatively characterize the Triassic Karamay Formation conglomerate reservoirs in the Mahu region, in the Junggar Basin of Northwest China, and makes permeability predictions using the free fluid T 2 spectrum according to the nuclear magnetic resonance (NMR) experimental data. The results show that the accuracy of the IFU model is significantly higher than that of the classic Coates and SDR models for conglomerate reservoirs with complex pore structures, indicating that this is an effective method to calculate permeability based on NMR. In addition, preliminary discussions are entered into regarding the intermingled fractal expression of the Kozeny-Carman equation and the relative permeability, in order to widen the application of the IFU model in reservoir physics. The derived expressions appear complicated in form but are straightforward to calculate and apply using computer programming since their iteration parameters are definite. The findings set out in this paper provide a valuable reference for further research of the IFU model in reservoir physics.

Guidelines for the representation of pulse sequences for solution-state nuclear magnetic resonance spectrometry (IUPAC Recommendations 2001)

2001 ◽  
Vol 73 (11) ◽  
pp. 1749-1764 ◽  
Author(s):  
Antony N. Davies ◽  
Jörg Lambert ◽  
Robert J. Lancashire ◽  
Peter Lampen ◽  
Woody Conover ◽  
...  
Keyword(s):  
Experimental Data ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pulse Sequence ◽  
Pulse Sequences ◽  
Resonance Spectroscopy ◽  
Data Content ◽  
Nuclear Magnetic Resonance Spectrometry ◽  
Magnetic Resonance Spectrometry ◽  
Nuclear Magnetic

In drawing up the specifications for a standard for multidimensional nuclear magnetic resonance spectroscopy (NMR) it became clear that the spectroscopic data content needed to be qualified by experimental condition information especially pertaining to the pulse sequences used to obtain the free induced decays or spectra. Failure to include this information not only severely inhibits the ability of subsequent data handling packages to work with the experimental data, but also makes interpretation of the final results virtually impossible.This paper has been produced in collaboration with the NMR spectrometer manufacturers in an attempt to get agreement on a definitive list of the most frequently used pulse sequence programs. The list includes entries where common agreement has been reached as to the acronym to name the experiment and the key instrument independent parameters needed to report concisely. It is not intended to restrict in any way the freedom of manufacturers or users to develop new and novel experimental pulse sequences, but should aid reporting of experimental data where the more common sequences are in use.

scholarly journals Predicting oil saturation of tight conglomerate reservoirs via well logs based on reconstructing nuclear magnetic resonance T2 spectrum under completely watered conditions

2019 ◽  
Vol 17 (2) ◽  
pp. 328-338
Author(s):  
Xiaojun Wang ◽  
Zhenlin Wang ◽  
Cheng Feng ◽  
Tao Zhu ◽  
Ni Zhang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Quantitative Prediction ◽  
Quantitative Relation ◽  
Oil Saturation ◽  
Comparison Results ◽  
Porosity And Permeability ◽  
Nmr T2 Spectrum ◽  
Nuclear Magnetic

Abstract Due to complex lithology, strong heterogeneity, low porosity and permeability; resistivity logging faces great challenges in oil saturation prediction of tight conglomerate reservoirs. First, 10 typical core samples were selected to measure and analyse the porosity, permeability, nuclear magnetic resonance (NMR) T2 spectrum and mercury injection capillary pressure (MICP) curve. Second, an empirical method was proposed for reconstructing the NMR T2 spectrum under completely watered conditions using MICP curve based on the ‘three-piece’ power function. The parameters of different models were calibrated via experimental data analysis, respectively. The 180 core experimental data from an MICP curve were used as the input database. Porosity and permeability were regarded as the MICP data selection criteria to apply this model in formation evaluation. The comparison results show good application effects. Finally, to reflect oil saturation, the ratio of T2 geometric means of NMR T2 spectra under oil-bearing and completely watered conditions was proposed. Then, the quantitative relation between oil saturation and the proposed ratio was established via experimental data from the sealed cores, which established a quantitative prediction on oil saturation of tight conglomerate reservoirs. This showed a good application effect. The average relative error and the root mean square error (RMSE) of the predicted oil saturation and sealed coring measurement were around 10 and 3%, respectively. As the proposed method is only influenced by the wettability of reservoir and viscosity of oil, it is not only appropriate for the studied area, but also for other water-wet reservoirs containing light oil. It is important for identifying oil layers, calculating oil saturation and improving log interpretation accuracy in tight conglomerate reservoirs.

The 19F and 1H Nuclear Magnetic Resonance Spectra of 2-Thienylcarbonyl Fluoride and 2-Thiazolylcarbonyl Fluoride

1971 ◽  
Vol 49 (7) ◽  
pp. 1146-1148 ◽  
Author(s):  
Kjeld Schaumburg
Keyword(s):  
Experimental Data ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Carboxylic Acids ◽  
Coupling Constants ◽  
Spectroscopic Parameters ◽  
Nuclear Magnetic Resonance Spectra ◽  
1H Nuclear Magnetic Resonance ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The preparation of 2-thienylcarbonyl and 2-thiazolylcarbonyl fluorides from the corresponding carboxylic acids is described. The n.m.r. spectroscopic parameters are determined and compared with experimental data for similar systems. Theoretical values for the coupling constants have been obtained in the CNDO/2 approximation and they are compared with the experimental data.

Large-Scale Computation of Nuclear Magnetic Resonance Shifts for Paramagnetic Solids Using CP2K

2017 ◽  
Vol 14 (1) ◽  
pp. 377-394 ◽  
Author(s):  
Arobendo Mondal ◽  
Michael W. Gaultois ◽  
Andrew J. Pell ◽  
Marcella Iannuzzi ◽  
Clare P. Grey ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Large Scale ◽  
Nuclear Magnetic
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