Spectral Methods Application for the Electrocardiograms Analysis

2016 ◽  
Vol 5 (3) ◽  
pp. 70-77
Author(s):  
V. A. Rumyantseva ◽  
◽  
V. V. Stuchilin ◽  
I. S. Svirin ◽  
S. Z. Shkundin ◽  
...  
Keyword(s):  
Spectral Methods

Finite volume and spectral methods applied to Pb-30%TI alloy solidification

2001 ◽  
Vol 11 (PR6) ◽  
pp. Pr6-151-Pr6-159 ◽  
Author(s):  
R. Guérin ◽  
M. El Ganaoui ◽  
P. Haldenwang ◽  
P. Bontoux
Keyword(s):  
Finite Volume ◽  
Spectral Methods ◽  
Ti Alloy ◽  
Alloy Solidification

Synthesis and Characterization of Some New Esters Containing Heterocyclic and Derived From Azo Dyes

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Zena G. Alrecabi ◽  
Zainab Amer ◽  
Naeemah Al-Lami
Keyword(s):  
Schiff Base ◽  
13C Nmr ◽  
Azo Dyes ◽  
Spectral Methods ◽  
Anthranilic Acid ◽  
Heterocyclic Compounds ◽  
Synthesis And Characterization ◽  
Cooh Group ◽  
Molecular Weights

This study including prepared new colored esters containing heterocyclic with high molecular weights. In the first part of work we synthesized azo dyes [1,2] from the reaction p-toluidine with β-naphthol and o-nitro phenol, thin we synthesized Schiff bases [3,4] by the reaction anthranilic acid with benzaldehyde and dimethyl benzaldehyde. The reaction azo dyes (contain OH group) with Schiff base (contain COOH group) these led to produce the new colored esters [A1-A4]. The second part of work was modification the (C=N-) group in esters to heterocyclic compounds by reacting with phenyl iso cyanide to produce new β-lactam [B1-B4] and with anthranilic acid to get new hydroquinazoline [C1-C4]. All these compounds were characterized by physical properties and spectral methods FTIR, 1H-NMR and 13C-NMR.

Solvolytic reactions of empiric 3-methanesulfonyloxy-7-benzoyloxy-5β,6β-cyclopropanocholestanes

1986 ◽  
Vol 51 (2) ◽  
pp. 436-446 ◽  
Author(s):  
Ladislav Kohout ◽  
Vijay Kumar Sethi ◽  
Jaroslav Zajíček ◽  
Alexander Kasal
Keyword(s):  
Spectral Methods ◽  
Elimination Reactions

Acetolysis of 3-methanesulfonyloxy-7-benzoyloxy-5β,6β-cyclopropanocholestanes with various configurations in positions 3 and 7 is described and the products are assigned structure using spectral methods. The 7-substituted compounds show greater propensity to elimination reactions than the 7-unsubstituted ones.

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

Spectral Methods

2018 ◽  
Author(s):  
S. G. Rajeev
Keyword(s):  
Simple Model ◽  
Differential Equations ◽  
Boundary Conditions ◽  
Linear Algebra ◽  
Spectral Methods ◽  
Differential Operators ◽  
Higher Dimensions ◽  
Standard Linear ◽  
Sommerfeld Equation ◽  
Spectral Discretization

Thenumerical solution of ordinary differential equations (ODEs)with boundary conditions is studied here. Functions are approximated by polynomials in a Chebychev basis. Sections then cover spectral discretization, sampling, interpolation, differentiation, integration, and the basic ODE. Following Trefethen et al., differential operators are approximated as rectangular matrices. Boundary conditions add additional rows that turn them into square matrices. These can then be diagonalized using standard linear algebra methods. After studying various simple model problems, this method is applied to the Orr–Sommerfeld equation, deriving results originally due to Orszag. The difficulties of pushing spectral methods to higher dimensions are outlined.

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