Materials Literature
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The reactions of the tertiary phosphine oxides Ph3PO, Ph2MePO or Me3PO with hydrated yttrium(III) nitrate in ethanol gave the complexes [Y(R3PO)2(EtOH)(NO3)3] (R3PO = Ph3PO or Ph2MePO), [Y(Me3PO)2(H2O)(NO3)3], [Y(R3PO)3(NO3)3] (R3PO = Ph3PO, Ph2MePO or Me3PO), and [Y(Ph3PO)4(NO3)2]NO3. The species [Y(R3PO)4(NO3)2]NO3…
The thermal degradation of poly(ether imide) (PEI) was studied through a combination of thermogravimetric analysis and stepwise pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) techniques with consecutive heating of the samples at fixed temperature intervals to achieve narrow temperature pyrolysis conditions.…
In order to evaluate the influence of partial discharges on the lifetime of power electronic circuits models of different defects are developed. These defects cause PD within the silicon gel used to embed the circuit because of electrical and mechanical reasons. The first model is a spherical void in the middle betwee…
Adsorption and reaction of N2H4 and NH3 on powdered TiO2 have been studied by Fourier-transformed infrared spectroscopy. N2H4 decomposes on the surface to form NH3 and surface hydroxy groups at temperatures higher than ∽150°C. Based on these findings, a N2H4 reaction pathway on TiO2 is established to be N2H4→2NH2→NH+N…
The aim of the present work was to investigate the initial stages of NH3 interaction with nickel oxide layers formed on well-defined Ni(111) surfaces. The selected technique was x-ray photoelectron spectroscopy. Ammonia adsorption was performed at 10−7 mbar and room temperature in a preparation chamber attached to the…
After polyhydroxyalkanoate (PHA) fermentation for 42 - 48 h by the Azotobacter chroococcum G-3, the PHA content reached more than 75% of the dry weight. Biomass was isolated from culture by centrifugation and pretreated with freezing to release PHA pellet, then was treated with 10 g/L sodium dodecyl sulfate (SDS) for…
The behaviour of a model glass forming liquid is analyzed for a range of densities, with a focus on the temperature interval where the liquid begins to display non-Arrhenius temperature dependence on relaxation γ. Through analyzing the dynamics along with the properties of local potential energy minima sampled by the…
The use of a C3 complex bearing three imidazolate groups as a ‘building block’ allowed us to synthesize an infinite corrugated two-dimensional (2D) low-spin Fe(III)–high-spin Mn(II) polymer exhibiting weak ferromagnetic intralayer interaction through imidazolate bridge.
The microstructure, crystal structure, and morphology of oxide films growing on zirconium alloys have been studied to better understand the effect of tin on the corrosion of Zircaloy. Zr-Sn-Fe-Cr sheets whose tin content varied from 0.09 to 1.41% were prepared and corroded in 400°C static steam for 300 days. The weigh…
This thesis concerns the development of a systematic design procedure and predictive models for solution crystallisation processes, with a focus on both product and process performance.The introductory chapter starts with a discussion of the application, advantages and problems of crystallisation in the chemical proce…
The effects of biaxial stress on the magnetic properties of pure iron discs are reported. Isostress changes in the coercivity are well described by an effective stress /spl sigma//sub EFF/=/spl sigma//sub x/-/spl sigma//sub y/. Irreversible, stress-induced magnetization changes are presented in the form of contours in…
The spectroscopic properties of lanthanide(III) complexes with Schiff base ligands (substituted salicylaldimines) are described. Optical absorption spectra of Nd(III), Ho(III) and Er(III) complexes dissolved in chloroform were recorded. The dipole strengths of the transitions were determined experimentally and paramet…
The second part of this series of papers reviews well-known factors characterising cloth structure and analyses their advantages and shortcomings. An opinion is expressed that their main shortcoming is due to an inexact estimation of the influence of the weave. An integrated structure factor of woven fabric is propose…
Polyaniline was chemically synthesized in aqueous acidic medium (HCl) with ammonium peroxydisulfate [(NH4)2S2O8] as the oxidizing agent, using a procedure described in the literature. Because the synthesis of polyaniline was carried out in aqueous acidic media, the obtained product consisted of emeraldine hydrochlorid…
Barium titanate thin films have been prepared by chemical spray pyrolysis. Aqueous spray solutions of titanium isopropoxide and barium acetate, equimolar with respect to titanium and barium, were used as precursors. Deposition was carried out at a substrate temperature of 250 °C. As-deposited films are amorphous. Film…
Azospirillum brasilense Sp7 and its ntrA (rpoN), ntrBC, and ntrC mutants have been evaluated for their capabilities of poly-3-hydroxybutyrate (PHB) accumulation in media with high and low ammonia concentrations. It was observed that the ntrBC and ntrC mutants can produce PHB in both low- and high-C/N-ratio media, whil…
Two phenylphosphinic acid derivatives of tetraaza macrocycles, (1,4,7,10-tetraazacyclododecanetetrayl)tetrakis(methylene)tetrakis(phenylphosphinic acid) [(H4L1) and (1,4,8,11-tetraazacyclotetradecanetetrayl)tetrakis(methylene)tetrakis(phenylphosphinic acid)] (H4L2), were synthesised and the crystal structures of H4L2…
Abstract. Presence of coherent interfaces within crystallites, referred to as «annealing twins, » has many effects on the properties of several fcc metals and alloys. The mechanism of the formation of these twins have been subject of numerous studies over fifty years. Although much progress has been made in recent yea…
Tuning thermodynamic driving force and electronic coupling through structural modifications of a carotene (C) porphyrin (P) fullerene (C60) molecular triad has permitted control of five electron and energy transfer rate constants and two excited state lifetimes in order to prepare a high-energy charge-separated state…
Polycrystalline copper is investigated by a new surface sensitive in situ X-ray absorption spectroscopy method at the oxygen K-edge and copper L2,3-edges under, for the first time, dynamic steady-state methanol-oxidation reaction conditions close to those used in practice. It is found that the selective oxidation of m…