Biological significance of essential oil of Zataria multiflora boiss

The absolute from Zataria multiflora was explored for enzyme inhibition, insect repellent, and insecticidal activities. GC-MS of the absolute of fresh plant showed that thymol is the major constituent while carvacrol is the major constituent in the absolute of dried plant.     

Alpha-glucosidase inhibitory constituents from Duranta repens

Three C-alkylated flavonoids 7-O-alpha-D-glucopyranosyl-3,5-dihydroxy-3'-(4"-acetoxyl-3"-methylbutyl)-6,4'-dimethoxyflavone (1), 7-O-alpha-D-glucopyranosyl-3,4'-dihydroxy-3'-(4"-acetoxyl-3"-methylbutyl)-5,6-dimethoxyflavone (2), 3,7,4'-trihydroxy-3'-(8"-acetoxy-7"-methyloctyl)-5,6-dimethoxyflavone (3) and a trans-clerodane type diterpenoid (-)-6beta-hydroxy-5beta,8beta,9beta,10alpha-cleroda-3,13-dien-16,15-olid-18-oic acid (4) are reported from Duranta repens along with (+)-hardwickiic acid (5) and (+)-3,13-clerodadien-16,15-olid-18-oic acid (6), isolated for the first time from this species. Their structures were established on the basis of the spectral methods, especially two dimensional (2D) NMR spectroscopy.     

Gnapholide: a new guaiac-dimer from Pulicaria gnaphalodes (Asteraceae)

The ethyl acetate soluble part of the chloroform extract of Pulicaria gnaphalodes belonging to the family Asteraceae afforded a new sesquiterpene-dimer of guaiane class named as gnapholide and anabsinthin of the same skeleton. The structures of both the compounds were elucidated with the aid of spectroscopic techniques including 2D NMR.     

Alysinol--a new triterpene from Alysicarpus monolifer

A new triterpene named as alysinol 3alpha, 22beta-dihydroxyolean-12-ene [structure: see text] along with known compounds usnic acid, methyl 2,4-dihydroxy-3,6-dimethyl benzoate, 3-hydroxy benzoic acid, stigmasterol, poriferasterol and ursolic acid have been isolated from Alysicarpus monolifer. The structure of [structure: see text] has been established through spectroscopic techniques.     

Upscaling and Simulation of Waterflooding in Heterogeneous Reservoirs Using Wavelet Transformations: Application to the SPE-10 Model

We have developed an accurate and highly efficient method for upscaling and simulation of immiscible displacements in three-dimensional (3D) heterogeneous reservoirs, which is an extension of the technique that we developed previously for 2D systems. The method utilizes wavelet transformations (WTs) to upscale the geological model of a reservoir, based on the spatial distribution of the single-phase permeabilities and the locations of the wells in the reservoir. It generates a non-uniform grid in which the resolved structure of the fine grid around the wells, as well as in the high-permeability sectors, are preserved, but the rest of the grid is upscaled. A robust uplayering procedure is used to reduce the number of the layers, and the WTs are used to upscale each layer areally. To demonstrate the method’s accuracy and efficiency, we have applied it to the geological model of a highly heterogeneous reservoir put forward in the tenth Society of Petroleum Engineers comparative solution project (the SPE-10 model), and carried out simulation of waterflooding in the upscaled model. Various upscaling scenarios were examined, and although some of them resulted in efficient simulations and accurate predictions, the results when non-uniform upscaling is used based on the WT technique are in excellent agreement with the solution of the same problem in the fine grid of the SPE-10 model. Most importantly, the speed-up factors that we obtain are several orders of magnitude. Hence, the method renders it unnecessary to use massively parallel computations for such problems.     

The Rayleigh Stokes problem for rectangular pipe in Maxwell and second grade fluid

The Stokes and Rayleigh Stokes problems for a flat plate in a viscoelastic fluid has recently been generalized to an edge and an exact analytical solution is obtained. In this paper, the edge problem has further been extended to the case of a rectangular pipe and exact solutions are obtained for Maxwell and second grade fluids. Also, the flow due to an oscillating edge problem is extended to generalized Maxwell fluid.