Amperometric determination of opium and strychnos alkaloids with potassium iodotri-iodothallate(I)

The reagent potassium iodotri-iodothallate(I) is used for amperometric titration of alkaloids, at -0.7 V vs. SCE.     

Extraction of zinc thiocyanate complex by tributyl phosphate in benzene

The species extracted is shown to be Zn(SCN)X.2TBP, where X is a common anion. Good separation factors are obtained for extraction of zinc from solutions containing silver(I), manganese(II), cobalt(II), cadmium(II), mercury(II) and thallium(III).     

Response Surface Methodology-Based Optimisation of Agarose Gel Electrophoresis for Screening and Electropherotyping of Rotavirus

Management of rotavirus diarrhoea cases and prevention of nosocomial infection require rapid diagnostic method at the patient care level. Diagnostic tests currently available are not routinely used due to economic or sensitivity/specificity constraints. Agarose-based sieving media and running conditions were modulated by using central composite design and response surface methodology for screening and electropherotyping of rotaviruses. The electrophoretic resolution of rotavirus genome was calculated from input parameters characterising the gel matrix structure and running conditions. Resolution of rotavirus genome was calculated by densitometric analysis of the gel. The parameters at critical values were able to resolve 11 segmented rotavirus genome. Better resolution and electropherotypic variation in 11 segmented double-stranded RNA genome of rotavirus was detected at 1.96% (w/v) agarose concentration, 0.073 mol l⁻¹ ionic strength of Tris base–boric acid–ethylenediamine tetraacetic acid buffer (1.4×) and 4.31 h of electrophoresis at 4.6 V cm⁻¹ electric field strength. Modified agarose gel electrophoresis can replace other methods as a simplified alternative for routine detection of rotavirus where it is not in practice.     

Etching of Silicon Nitride in CCl2F2, CHF3, SiF4, and SF6 Reactive Plasma: A Comparative Study

Silicon nitride is an important material layer in various types of microelectronic devices. Because of continuous integration of devices, patterning of this layer requires a highly selective and anisotropic etching process. Reactive ion etching is one of the most simple and popular plasma processes. The present work is an experimental analysis of primary etch characteristics in reactive ion etching of silicon nitride using chlorine- and/or fluorine-based organic and inorganic chemistries (CCl ₂ F ₂+O ₂ , CHF ₃+O ₂ , SiF ₄ +O₂, SF₆+O ₂ , and SF ₆+He) in order to obtain a simultaneous etch selectivity against polysilicon and silicon dioxide. A recipe, in CCl ₂ F ₂ /O ₂ plasma chemistry, which provides acceptable etch characteristics, along with a reasonable simultaneous selectivity against polysilicon and silicon dioxide, has been formulated.     

Bonding Inferred from Study of Nephelauxetic Effect in Praseodymium Complexes

The comparative study of the bonding in complexes of praseodymium has not been reported so far. However, nephelauxetic effect in some of these complexes has been investigated.^1,2 Consequently it was thought worthwhile to carry out the present investigations.     

Vibrational dynamics and heat capacity in poly(L‐lactic acid)

Poly(L ‐lactic acid) (PLLA) (? CH(CH₃) ? COO? )_n is a biodegradable polymer, which exhibits many applications in the biomedical field and where thermoplastics are employed. A comprehensive study of the normal modes and their dispersion in PLLA using Wilson′s GF matrix method as modified by Higgs is being reported. Assignments of calculated normal modes have been made and characteristic features of dispersion curves are discussed. Heat capacity has been calculated via density‐of‐states using Debye relation in the temperature range 10–250 K, which is in fairly good agreement with the experimental data. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 175–182, 2010     

New Oenotheralanosterol A and B Constituents from the Oenothera biennis Roots

Two new compounds oenotheralanosterol A and B along with four known compounds have been isolated from the roots of Oenothera biennis. Their structures have been elucidated with the help of 300 MHz NMR using 1D and 2D spectral methods viz: ¹H and ¹³C NMR, ¹H‐¹H COSY, ¹H‐¹³C HETCOR and DEPT aided by EIMS, ESI Mass and IR spectroscopy.     

Protonation and solvent extraction of N-p-tolylbenzohydroxamic acid in hydrochloric acid medium

the protonation of N-p-tolylbenzohydroxamic acid (p-TBHA) in aqueous hydrochloric acid has been investigated by determination of its distribution between cyclohexane and hydrochloric acid. The pK(a) value found was - 2.30 +/- 0.02 at 30 degrees . The solubility of p-TBHA as a function of hydrochloric acid concentration has also been determined. At lower acid concentrations the solubility decreases owing to a salting-out effect, whereas at higher concentrations it increases because of formation of the more hydrophilic protonated species and a salting-in effect. Intramolecular hydrogen-bonding observed in p-TBHA provides evidence for protonation of the nitrogen atom.