Polycyclic aromatic hydrocarbons in C8 isomer aromatic feed: analysis by GC, GC/MS, and GC/FTIR techniques

Polycyclic aromatic hydrocarbons (PAHs), apart from their carcinogenic and mutagenic nature, create many problems in the petrochemical industry due to their tendency toward carbonization. Compounds in C8 aromatic isomer feed are analyzed by means of sample concentration, followed by separation of individual compounds by gas chromatography on a stainless steel OV-101 phase capillary column and identification by gas chromatography/mass spectrometry and gas chromatography/Fourier transform infrared spectroscopy. Various compounds belonging to different classes (mainly monocyclic, dicyclic, and tricyclic aromatics), oxygenated aromatics, and aliphatic saturates are quantified in the concentrated hydrocarbon residue of C8 isomer feed. Both unsubstituted and alkyl substituted ring type compounds are present. Concentrations obtained for PAH compounds in the C8 isomer feed range from 0.2 to 0.42 micrograms/mL.     

Direct amplitude detection of Zernike modes by computer-generated holographic wavefront sensor: Modeling and simulation

A fast holographic wavefront sensor is proposed using a computer-generated hologram (CGH). This CGH is a multiplexed hologram of different Zernike mode–amplitude combinations, and is designed in such a manner as to get the corresponding spots on the detector according to the presence and strength of a particular aberration. Interference between the aberrated wavefront (with a single mode–amplitude combination) and the Fourier transform of an image with single bright pixel (defined as dot image) is numerically calculated for one hologram. Different mode–amplitude combination and corresponding different positions of bright pixels (dots) are taken to compute various holograms and then all the holograms are multiplexed to get the final hologram. When the aberrated wavefront with a particular mode–amplitude combination is incident onto the multiplexed hologram, the corresponding dot is generated in the Fourier plane. A lens performs the Fourier transform in optical domain and provides the instant detection of amplitude of the respective Zernike mode. The main advantage of the scheme is to avoid the need of any computations, which makes it really fast. The simulation results are presented with the cross-talk analysis for few Zernike terms.     

Application of possibility theory to investment decisions

Carlson and Fuller (2001, Fuzzy Sets and Systems, 122, 315–326) introduced the concept of possibilistic mean, variance and covariance of fuzzy numbers. In this paper, we extend some of these results to a nonlinear type of fuzzy numbers called adaptive fuzzy numbers (see Bodjanova (2005, Information Science, 172, 73–89) for detail). We then discuss the application of these results to decision making problems in which the parameters may involve uncertainty and vagueness. As an application, we develop expression for fuzzy net present value (FNPV) of future cash flows involving adaptive fuzzy numbers by using their possibilistic moments. An illustrative numerical example is given to illustrate the results.     

Population Genetic Structure and Marker Trait Associations Using Morphological,Phytochemical and Molecular Parameters in <Emphasis Type="Italic">Habenaria edgeworthii</Emphasis>—a Threatened Medicinal Orchid of West Himalaya,India

Habenaria edgeworthii Hook. f. ex Collett is an important terrestrial orchid used in different Ayurvedic formulations. In the present study, variations among morphological, phytochemical and molecular markers were assessed. A significant difference was observed among populations using morphological traits. Inter-simple sequence repeat (ISSR) data revealed lower genetic diversity at population level (He = 0.207) as compared to species level (He = 0.334). Analysis of molecular variance (AMOVA) indicates 74 % variation among populations and 26 % within population. Tuber extracts showed significantly (p < 0.05) higher total phenolics and flavonoids among the populations. Antioxidant activity determined by 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP) assays exhibited considerable antioxidant potential. Furthermore, the associations between molecular and morphological and phytochemical attributes were studied using multiple regression analysis (MRA). Several ISSR fragments were associated with some morphological and phytochemical traits. These ISSR fragments can be useful for breeding programme of the species when no other genetic information, such as linkage maps and quantitative trait loci, is available.     

Interaction of bathocuproine with metals (Ca, Mg, Al, Ag, and Au) studied by density functional theory

Electronic structure of the interface between a bathocuproine (BCP) molecule and metal surface was studied by density functional theory. The bond energy of BCP with metal surface increased with decreasing work function of metals, that is, Au, Ag, Al, Mg, and Ca in this order. The charge transfer also increased with decreasing metal work function. It was analyzed that the Fermi level and the lowest unoccupied molecular orbital of BCP are composed of both BCP and metal orbital component, and electron transport properties across the BCP and metal is discussed based on these analyses.     

Synthesis and thermal properties of mesomorphic 1,1'-bis[ω-(4'-cyano-4-biphenyloxy)alkyl] ferrocenes

A new series of 1,1'-disubstituted ferrocene compounds of the type [(η⁵-C₅H₄(CH₂)_nOC₆H₄C₆H₄CN]₂Fe (3a-d, n = 5, 6, 8, 11) incorporating a variable length alkyloxy cyanobiphenyl unit has been prepared and their mesomorphic properties have been investigated. Compounds 3b, c and d exhibit a thermotropic smectic C phase and 3c also exhibits a monotropic smectic A phase over a fairly wide range near ambient temperature.     

Determination of penciclovir in human plasma by liquid chromatography-electrospray ionization tandem mass spectrometry: application to a clinical pharmacokinetic study

A rapid, specific and sensitive liquid chromatography tandem mass spectrometry (LC–MS/MS) method was developed for the determination of penciclovir in human plasma. The method involved simple, one‐step SPE procedure coupled with a C₁₈, 75 × 4.mm, 3µm column with a flow‐rate of 0.5 mL/min, and acyclovir was used as the internal standard. The Quattro Micro mass spectrometry was operated under the multiple reaction‐monitoring mode using the electrospray ionization technique. Using 250 µL plasma, the methods were validated over the concentration range 52.555–6626.181 ng/mL, with a lower limit of quantification of 52.55 ng/mL. The intra‐ and inter‐day precision and accuracy values were found to be within the assay variability limits as per the FDA guidelines. The developed assay method was applied to a clinical pharmacokinetic study in human volunteers. Copyright © 2010 John Wiley & Sons, Ltd.     

Antimicrobial activities of essential oil and methanol extract of Coriaria nepalensis

Plant extracts and products have been used for centuries in traditional medicine; for most of them, in addition to the scant scientific credibility, the chemical composition and spectrum of activity are yet to be explored. To put forward this effort and to identify novel antimicrobial agents, the inhibitory activities of methanolic extract and essential oil from Coriaria nepalensis against various microorganisms including pathogenic yeast, and Gram-positive and negative bacteria were evaluated. Chemical compositions of C. nepalensis methanolic extract and essential oil were analysed by gas chromatography-mass spectrometry. In vitro susceptibility tests against all the tested isolates were performed in terms of minimum inhibitory concentration (MIC), and well diffusion assay using standard protocols. All microorganisms tested were profoundly found susceptible to both the C. nepalensis extract and oil with MIC values of 1.3-2.1?mg?mL?1 (Gram-positive bacteria), 1.4-2.2?mg?mL?1 (Gram-negative bacteria) and 0.9-1.6?mg?mL?1 (yeasts). The extent of inhibition was shown more by methanolic extract than by essential oil. This study is the first to report the antimicrobial activity of extracts obtained from the C. nepalensis. It can be concluded that the observed antimicrobial characteristics of C. nepalensis indicate that it might be a promising antimicrobial agent.     

Accessing C-1 phosphonylated 2-acylamino uronic acids via 2-nitro-glycals

Two approaches are described for the synthesis of 2-acylamino uronic acid glycosyl phosphonates from readily accessible D-glucal. The first approach that entailed oxidation of the C-6 hydroxyl group followed by phosphonylation of the uronate 2-nitro-glycal, resulted in the formation of the β-L-gulo-configured phosphonate. Reversing the reaction order resulted in the exclusive formation of the β-D-gluco-configured phosphonate. In both cases the thermodynamic 1,2-trans-di-equatorial phosphonylation product is obtained.