in this research, the tacticity and microstructure of polyvinyl chloride (pvc) were studied through back bone methylene and methine carbons and protons splitting by carbon (13c nmr), proton (1h nmr) and two-dimensional (2dnmr) nulear magnetic resonance spectroscopy in deuterated etrahydrofuran.polyvinyl chloride was synthesized by emulsion polymerization of vinyl chloride (vcm) under pressure t...

in this paper, the hydrogen bonding (hb) effects on the nmr chemical shifts of selected atoms in serineand serine-nh2o complexes (from one to ten water molecules) have been investigated with quantummechanical calculations of the 15n and 13c tensors. interaction with water molecules causes importantchanges in geometry and electronic structure of serine.for the compound studied, the most importan...

Aprotic diazotization of anthranilic acid with isoamylnitrite or amylnitrite gave benzenediazonium-2- carboxylate. Subsequent thermal decomposition of this diazonium salt (in situ) in 1,2-dichloroethane as a solvent at 85OC and in the presence of 2,5-diethyl-3,4-diphenylcyclopentadienonaes a trapping agent gave 1,4-diethyl-2, 3-diphenylnaphthalene in high yield, after loss of carbon monoxid...

This article addresses the problem of the computation of instantaneous firing speed in Invariant Behavior state (IB-state) of Constant speed Continuous Petri Net (CCPN) with presence of actual conflicts. The adopted approach is based on polyhedral computations applied to specify an area of possible instantaneous firing speed. If the actual conflicts are resolved by global priorities, the instan...

Even though there were actually a number of established scientists in attendance, the meeting seemed to be geared toward graduate students and postdocs. Many of the presentations focused on giving advice about and descriptions of the process of structural determination. There was little actual discussion of either algorithms or biology, but many of the opinions were quite thought provoking and ...

Phytochemical examination of corncob extracts led to the isolation of a new lignan identified as 7,7'-dihydroxy-3'-O-demethyl-4-methoxymatairesinol, together with seven known compounds, identified as β-sitosterol, β-sitosteryl-β-D-glucoside, 6β-hydroxy-campest-4-en-3-one, 5α,8α-epidioxyergosta-6,22-dien-3β-ol, tricin, kaempferol and p-coumaric acid. The isolated compounds were identified by one...

the dopamine has been studied theoretically at the b3lyp/6-31g* level were performed in gasphase. we calculated physical parameters like atomic charges, energy (=>), asymmetry parameter(?), chemical shift @iso, dipole moment and isotropic nmr determinant and in this work we usedgaussian 03 at nmr and calculation by using b3lyp methods with 6-31g* basis set.