Materials Literature
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Abstract The crystal packing effects upon the static and dynamic first hyperpolarizability of 2‐methyl‐4‐nitroaniline (MNA) clusters have been addressed at the TDHF/AM1 level. Due to electrostatic interactions, in 1‐D arrays of MNA unit cells extending along the a crystallographic axis, the effective hyperpolarizabili…
Abstract An optically active spiropyran 1 with a binaphthol moiety as a chiral source was synthesized. The colored merocyanine form of ( R )‐ 1 obtained by the UV irradiation remained in the presence of D ‐amino acids longer than with L ‐amino acids. Chirality 14:713–715, 2002. © 2002 Wiley‐Liss, Inc.
Relaxor ferroelectrics are widely used in various applications because of their high dielectric and piezoelectric response over a wide range of temperature. The microscopic mechanism of the relaxor behavior, however, is highly complex and still inadequately understood. We discuss the atomistic mechanisms that create t…
The effect of boron, in the amounts of 0.26, 0.39, and 0.59 wt.%, on the volume fraction and structure of carbides in Cr white irons was examined. It was demonstrated that the addition of boron can change the microstructural characteristics of white iron containing about 13 wt.% Cr. With increasing boron content, the…
The passivity of titanium, binary Ti-15Mo and ternary Ti-15Mo-5Al alloys in hydrochloric acid solutions was studied by potentiostatic, potentiodynamic, linear polarization and electrochemical impedance spectroscopy (EIS) techniques. The anodic passivity of binary Ti-15Mo and ternary Ti-15Mo-5Al titanium alloys differs…
Cross-linked enzyme crystals (CLECs) are a novel form of immobilized biocatalyst designed for application in industrial biotransformation processes. In this work we have investigated the mechanical stability of agitated CLEC suspensions in relation to the design and scale-up of bioconversions carried out in stirred-ta…
In an attempt to synthesize new synthetic metals which couple magnetic properties to conductivity, we prepared the novel salt (BEDT-TTF)2[Fe(tdas)2] [BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene, hereafter referred to as ET; tdas = 1,2,5-thiadiazole-3,4-dithiolate] by the electrocrystallization technique. The crys…
The objective of the study reported in this paper was to generate new models of the mechanical behaviour of knitted fabrics in quasi-static deformation from an initially relaxed state to the extended state. The problem of extension of a knitted structure is complicated by the combination of non-linear properties deriv…
Below the critical potential, selective dissolution of Cu from Cu-18 atom % Au proceeds via Cu transport through an essentially planar Au-rich product layer, which over time increases to hundreds of atom layers in thickness. Transmission electron micrographs (TEM) taken after the selective dissolution (at and subseque…
Hysteresis scans have been measured for Pd–H starting from both plateaux. Return point memory has been verified, i.e., a scan can always return to its starting point upon reversal. The symmetry of hysteresis scans with respect to a 180° rotation about the midpoint is pointed out for scans originating along a horizonta…
Chitosan microspheres were employed as adsorbent in aqueous medium for the reactive orange 16 containing the vinylsulfone group. Adsorption isotherms were obtained varying pH, contact time, and initial concentration of the dye in the solution. The results from the adsorption experiments were analyzed using Langmuir's…
The blue tetranuclear CuII complexes {[Cu(bpy)(OH)]4Cl2}Cl2 · 6 H2O (1) and {[Cu(phen)(OH)]4(H2O)2}Cl4 · 4 H2O (2) were synthesized and characterized by single crystal X-ray diffraction. (1): P 1 (no. 2), a = 9.240(1) Å, b = 10.366(2) Å, c = 12.973(2) Å, α = 85.76(1)°, β = 75.94(1)°, γ = 72.94(1)°, V = 1152.2(4) Å3, Z…
The immobilization of [Rh(cod)OCH3]2 (cod = cycloocta-1,5-diene) on mesoporous molecular sieves MCM-41 provides the first inorganic-type hybrid catalyst, which affords heterogeneous polymerization of phenylacetylene and its ring-substituted derivatives, – 2-fluorophenylacetylene, 4-fluorophenylacetylene, and 4-pentylp…
The diversity of eucaryotic picoalgae in three Swiss lakes was characterized by light microscopy and these observations were compared with analyses of SSU rDNA sequences. The phylogenetic analyses suggested that seven of the eight investigated strains were either related to Choricystis (Trebouxiophyceae) or Mychonaste…
The growth of an anodic oxide film on a specimen consisting of a layer of aluminum deposited upon a layer of tungsten was examined by transmission electron microscopy. The findings reveal initial growth of anodic alumina, followed by penetration of the alumina by fingers of tungsten oxide once the metal/film interface…
Abstract The processability of single bubble polyamide 11 and polyamide 12 films was investigated. The development of crystalline structure and chain orientation of polyamide 11 and polyamide 12 films in single bubble film blowing was studied by differential scanning calorimetry (DSC), wide angle X‐ray diffraction (WA…
A new concept of Ceramic Matrix Composite (CMC), mainly based on the use of a self–sealing technology for matrix and the use of a multilayer woven reinforcement, has been developed by Snecma for achieving high performance levels targeted by future jet engines. The driving force for this development has been to increas…
Magnesium (Mg 2+ ) alloys attract the focus of industries such as the telecom and computer industries and medical and household appliances due to their strength and weightlessness. However, magnesium is one of the major cell components of bacteria, which implicates it in microbial attachment and growth. To understand…
Segmented polyurethanes (PSEU) were synthesized from polydimethylsiloxane diol (PSi) mixed with poly(ethylene glycol) (PEG) in different ratios as soft segment, 4,4′-diphenylmethane diisocyanate as hard segment, and ethylene glycol as chain extender. FT-IR, NMR, and thermal analysis were used to characterize the struc…
Magnesium fluoride thin films were deposited on silica glass and single crystal silicon substrates by argon ion-beam assisted deposition (IBAD). The effects of argon ions impinging on the growing film on the optical and chemical properties of the single layers were investigated. Compared to MgF2 films produced by dire…