Synthesis of novel highly functionalized biologically active polycyclic caged amides

The synthesis of novel polycyclic amides has been achieved through the reaction of bishalomethyl pentacyclo[5.4.0.0^2,6.0^3,10.0^5,9]undecane diones with acyclic and cyclic secondary amines in the presence of an ionic liquid. Three of the compounds prepared have been found to possess antituberculosis activity.     

Preparation,crystal structure,and magnetic properties of β-Li3TiF6 = LiLi(TiF6)(TiF6)2 – a double fluoride?

Purple colored single crystals of the β-modification of Li₃TiF₆ have been prepared by heating an appropriate mixture of LiF and TiF₃ at 820°C under an argon atmosphere. β-Li₃TiF₆ crystallizes in C2/c with a = 14.452(2) Å, b = 8.798(1) Å, c = 10.113(1) Å and β = 96.30(1)º. The structure is isotypic to β-Li₃VF₆ and contains isolated compressed TiF₆ octahedra (d_Ti–F = 1.91–2.01 Å). Magnetic properties of β-Li₃TiF₆ were studied and discussed. Band structure calculations and calculations of the Madelung part of the lattice energy, MAPLE, were performed to discuss the chemical bonding.     

Analysis of PPMMA films from oxygen plasma using X-ray photoelectron spectroscopy

Plasma polymerized methyl methacrylate (PPMMA) films have been synthesised on silicon substrates in RF glow discharge using oxygen plasma. The electron beam delineation sensitivity of the PPMMA films has been studied systematically by varying oxygen and monomer flow rates. X-ray photoelectron spectroscopy (XPS) analysis clearly illustrates how C/O ratio in the films determines the properties of PPMMA films as electron beam resist. © 1994 John Wiley & Sons, Inc.     

Molecular dynamic simulations of self-assembled alkylthiolate monolayers on an Au(III) surface

Molecular dynamics simulations incorporating explicit gold atoms in the simulations have been carried out for alkanethiol self-assembled monolayers chemisorbed on the Au(III) surface. The structural properties of the monolayer are evaluated for two force fields: one in which the Au--S--C bond is fixed (FF I), and the other in which it is flexible (FF II). The influence of these force fields on the structural properties of HS(CH2)14CH3 on the structured Au surface is compared at different temperatures. FF I yields greater tilt angles and a smaller film thickness when compared with FF II. Both of the force fields predict that the tilt angles do not follow a monotonic decrease with temperature but show minima around 200 K. Simulations carried out at different chain lengths at 300 K reveal that FF II predicts a greater film thickness than FF I; however, the difference is within 1 A.     

Preparation, Structure, and Properties of V2GeO4F2—Chains of VO4F2 Octahedra in the First V(III) Metallate Fluoride

Powder samples of the new oxide fluoride V₂GeO₄F₂ have been obtained by the reaction of appropriate amounts V₂O₃, VF₃, and GeO₂ at 700°C for 18 h in an argon-filled sealed platinum tube. V₂GeO₄F₂ crystallizes in the space group Pnma with a=9.336(1), b=8.898 (1), and c=4.912 (1) Å. The structure has been refined from X-ray powder diffraction data using the Rietveld method (R_int=5.5% and R_p=9.8%). The structure of V₂GeO₄F₂ exhibits close packed layers of the anions with an ordering of O and F. The characteristic building units are discrete GeO₄ tetrahedra with Ge-O distances of 1.75-1.80 Å. The V are coordinated by four O and two F to form VO₄F₂ octahedra connected via two common edges to give zigzag chains. These chains are linked via corners to form a three-dimensional network. The temperature dependence of the magnetic susceptibility of V₂GeO₄F₂ indicates antiferromagnetic correlations.     

A nonlinear Picone’s identity and its applications

The purpose of this note is to show a generalization to Picone’s identity in a nonlinear framework. The classical Picone’s identity turns out to be a particular case of our result. We show, as an application of our results, that the Morse index of the zero solution to a semilinear elliptic boundary value problem is 0 and also establish a linear relationship between the components of the solution of a nonlinear elliptic system.     

Neutron diffraction studies on Ca1−x Ba x Zr4P6O24 solid solutions

Herein we report the results of detailed crystallographic studies of Ca_1−x Ba _x Zr₄P₆O₂₄ compositions from combined Rietveld refinements of powder X-ray and neutron diffraction data. All the studied compositions crystallize in rhombohedral lattice (space group R-3 No. 148). A continuous solid solution is concluded from the systematic variation of unit cell parameters. The variation of unit cell parameters with the composition indicates decreasing trend in a parameter with increasing Ba2+ concentration contrast to an increasing trend in c parameter.      

Exergy and thermoeconomic analysis of cream pasteurisation plant

Journal of Thermal Analysis and Calorimetry - Cream is a milk derivative comparatively rich in fat, present in the form of emulsion of fat in skimmed milk, and acquired by physical extraction from...