Quantitation of Eugenol,Cinnamaldehyde and Isoeugenol from Cinnamomum tamala Nees and Eberm. Leaf Powder and Cinnamomum zeylanicum Breyn Stem Bark Powder by LC

An LC method has been developed for the simultaneous quantitative determination of eugenol, cinnamaldehyde and isoeugenol from dried leaf powder of Cinnamomum tamala Nees & Eberm and stem bark powder of Cinnamomum zeylanicum Breyn. Linear responses for eugenol, cinnamaldehyde and isoeugenol were obtained over the concentration ranges of 0.20–2.50, 5.00–100.00 and 0.10–1.00 μg mL⁻¹, respectively.

     

Screening of silver nanoparticles containing carbonized yeast cells for adsorption of few long-lived active radionuclides

The present study involves the screening of silver nanoparticles containing carbonized yeast cells isolated from coconut cell sap for efficient adsorption of few long lived radionuclides like ¹³⁷Cs₅₅, ⁶⁰Co₂₇, ¹⁰⁶Ru₄₄, ²³⁹Pu₉₄ and ²⁴¹Am₉₅. Yeast cells containing silver nanoparticles produced through biological reduction were subjected to carbonization (400 °C for 1 h) at atmospheric conditions and their properties were analyzed using fourier transform infra-red spectroscopy, X-ray diffraction, scanning electron microscope attached with energy dispersive spectroscopy and transmission electron microscope. The average size of the silver nanoparticles present on the surface of the carbonized silver containing yeast cells (CSY) was 19 ± 9 nm. The carbonized control yeast cells without silver exposure (CCY) did not contain any particles on its surface. The efficiency of CSY and CCY towards the radionuclide adsorption was studied in batch mode at fixed contact time, concentration, and at its native pH. CSY was efficient in removal of ²³⁹Pu₉₄ (76.75%) and ¹⁰⁶Ru₄₄ (54.73%) whereas CCY showed efficient removal only for ²⁴¹Am₉₅ (62.89%). Both the adsorbents did not show any retention with respect to ⁶⁰Co₂₇ and ¹³⁷Cs₅₅. Based on the experimental data, decontamination factor and distribution coefficient (K _d) were calculated and, from the values, it was observed that these adsorbents have greater potential to adsorb radionuclides.     

Alkaloids and flavonoids of Argemone mexicana

A new protopine alkaloid, protomexicine and a new isoflavonoid, mexitin, together with 8-methoxydihydrosanguinarine, 13-oxoprotopine, rutin and quercetrin have been isolated from the aerial part of the methanolic extract of Argemone mexicana. The structures of these compounds have been established by various spectral data. The structure of protomexicine was further confirmed by heteronuclear multiple bond correlation experiment. Protomexicine and mexitin are new compounds, and other compounds are first reported from A. mexicana and genus Argemone.     

Measurement of circulation rates of coal particles in standpipe of a circulating fluidized bed system (CFBS) using radiotracer technique

Radiotracer technique was applied to measure the circulation rates of fine coal particles in standpipe of a pilot-scale bubbling circulating fluidized bed system (CFBS). ¹⁹⁸Au adsorbed on coal particles was used as a radiotracer. The radiotracer was injected into the standpipe and monitored at four different downstream locations. The circulation times and circulation rates were determined from the measured tracer concentration curves at different operating conditions. The measured parameters were intended to be used for optimizing the performance of existing CFBSs operating in industry and design of a new CFBS to be used as coal gasifier.     

Effect of salt on the hybridization of DNA by sequential immobilization of oligonucleotides at the air-water interface in the presence of ODA/DOTAP monolayers

The effect of low ionic strength on the binding of preformed DNA duplexes and the hybridization of single-stranded oligonucleotides at the air-water interface in the presence of cationic Langmuir monolayers of octadecylamine (ODA), as well as 1,2-dioleoyloxytrimethylammonium propane (DOTAP), is investigated. The complexation of the single-stranded DNA molecules and preformed duplexes with NaCl in solution with ODA/DOTAP Langmuir monolayers was followed in time by monitoring the pressure-area isotherms, wherein a very large and rapid expansion of the ODA/DOTAP monolayer was observed. In the case of sequential immobilization of complementary oligonucleotides, after addition of the complementary strand and intercalator, there was not much expansion, indicative of the fact that equilibrium had been rapidly achieved. Langmuir-Blodgett (LB) films of the ODA/DOTAP-DNA complex were formed on different substrates and characterized using quartz-crystal microgravimetry (QCM), fluorescence spectroscopy, and thermal melting studies. These measurements clearly showed that the preformed duplexes retained their native form as double helices and further, hybridization of the complementary single-stranded DNA molecules had occurred at the air-water interface, leading to the characteristic double-helical structure.     

Violation of the minimum h-h separation "Rule" for metal hydrides

Using gradient-corrected, full-potential, density-functional calculations, including structural relaxations, it is found that the metal hydrides RTInH1.333 (R=La, Ce, Pr, or Nd; T= Ni, Pd, or Pt) possess unusually short H-H separations. The most extreme value (1.454 A) ever obtained for metal hydrides occurs for LaPtInH1.333. This finding violates the empirical rule for metal hydrides, which states that the minimum H-H separation is 2 A. The paired, localized, and bosonic nature of the electron distribution at the H site are polarized towards La and In which reduces the repulsive interaction between negatively charged H atoms. Also, R-R interactions contribute to shielding of the repulsive interactions between the H atoms.     

Oxa bowls: synthesis and C-H...O mediated solid state structure of pentaoxa-[5]-peristylane

We have conceptualized [n]-oxa-[n]-peristylanes as a new family of "oxa bowls" having a crownlike shape and potential C(nv)() symmetry. Recognizing their equivalence to the corresponding [n]-formyl-[n]-cycloalkanes, we have conceived of a general synthetic strategy in which "intramolecular cascade acetalizations" constitute the pivotal step. As our first synthetic effort, we describe the synthesis of pentaoxa-[5]-peristylane 3b from the readily available Diels-Alder adduct 10 of 5,5-dimethoxy-tetrachlorocyclopentadiene and maleic anhydride. The norbornyl framework of 10 serves as the rigid structural matrix to build the stereochemical features and latent aldehyde functionalities as in 9 through a series of functional group adjustments. Ozonation of 9 furnished 3b in a one-step transformation in which five tetrahydrofuran rings were generated. While 3b exhibited C(5v) symmetry in solution, its symmetry in the solid state was observed to be C(s) by X-ray crystallography. In the solid state, 3b is endowed with a multicolumnar architecture, whose distinctive features include C-H...O interactions involving the less acidic cyclopentane hydrogens. Indeed, all the 10 CH moieties and 5 oxygen atoms (through both the lone pairs) of 3b (C(10)H(10)O(5)) are involved in short C-H...O contacts (strong and soft) and its crystal structure indicates marked proclivity toward maximal hydrogen bonding.     

Trivalent chromium,manganese, iron and cobalt chelates of a tetradentate N6 macrocyclie ligand

Summary Trivalent chromium, manganese, iron and cobalt salts reactin situ with 2,6-diaminopyridine and acetylacetone to form complexes of the 16-membered N₆ tetradentate macrocyclic ligand. The chelates are characterised as distorted square-pyramidal of [M(TML)X] type, where M = chromium(III), manganese(III), iron(III) and cobalt(III); X=Cl, Br, NO₃ or NCS for chromium(III) and iron(III) and X=(OAc) for manganese(III) and (OH) for cobalt(III). The ligand coordinates through all the nitrogen atoms through deprotonation of two of them, however, the pyridine nitrogens do not take part in coordination. The chelates incorporate one anion or hydroxyl group in the coordination sphere. The magnetic, electronic and i.r. spectral studies indicate lower symmetries for these chelates. The amount of distortion is calculated in terms of DT/DQ by applying NSH theory. X-ray measurements on powder form of the complexes show their isomorphic nature and also support the proposed structures.     

Signature Characters of Highest-Weight Representations of $U_{q}(\mathfrak {gl}_{n})$

We consider \(U_{q}(\mathfrak {gl}_{n})\), the quantum group of type A for |q| = 1, q generic. We provide formulas for signature characters of irreducible finite-dimensional highest weight modules and Verma modules. In both cases, the technique involves combinatorics of the Gelfand-Tsetlin bases. As an application, we obtain information about unitarity of finite-dimensional irreducible representations for arbitrary q: we classify the continuous spectrum of the unitarity locus. We also recover some known results in the classical limit \(q \rightarrow 1\) that were obtained by different means. Finally, we provide several explicit examples of signature characters.     

Preparation and characterization of γ-In2Se3 thin-film photoanodes for photoelectrochemical water splitting

Journal of Solid State Electrochemistry - Indium selenide (γ-In2Se3) films were prepared using RF magnetron sputtering. Influence of deposition time on structural, optical, morphological, and...