Materials Literature
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I describe new phases of a chiral liquid crystal with nematic and hexatic order. I find a conical phase, similar to that of a cholesteric in an applied magnetic field for Frank elastic constants $K_2>K_3$. I discuss the role of fluctuations in the context of this phase and the possibility of satisfying the inequality…
The effect of externally added molybdate (MoO42–) on the repassivation and SCC behavior of type 304 (UNS S30400) stainless steel (SS) was investigated in 1 M hydrochloric acid (HCl) at open-circuit potential (OCP). With the addition of MoO42–, the time to failure initially decreased but then gradually increased. From…
Abstract The bonding in the recently reported Cs 3 Te 22 phase, which contains both Te 8 rings and remarkable Te 6 sheets, is studied by approximate molecular orbital theory. Our focus is on the geometric and electronic features of the unique 2,3‐connected Te net found as a substructure in this phase. The calculations…
The fluorescence lifetime of a triphenylmethane dye, malachite green, doped in three glass-forming associated solvents, 1-propanol, propylene glycol, and glycerol, was measured in a wide temperature range. For each sample three temperature regimes were found in the temperature dependence of the nonradiative relaxation…
Abstract 1 H and 127 I NMR, differential thermal analysis (DTA), differential scanning calorimetry (DSC), electrical conductivity, and powder and single crystal X‐ray diffractions were studied for trimethylethylammonium iodide. Three solid phases, named I, II, and III, were obtained above 410 K, between 336 and 410 K,…
The photoinduced radical crosslinking of α,ω-ene-terminated silicones (vinyl, vinyloxy, allyl, norbornenyl, etc.) with siloxanes containing pendant mercapto groups has been investigated by means of calorimetry, Raman and swelling measurements. The reaction enthalpy depends on the type of olefin. The values vary from 9…
S-Adenosylmethionine synthetase (MAT, ATP:L-methionine S-adenosyltransferase, E.C.2.5.1.6.) plays a central metabolic role in all organisms. MAT catalyzes the two-step reaction which synthesizes S-adenosylmethionine (AdoMet), pyrophosphate (PPi) and orthophosphate (Pi) from ATP and L-methionine. AdoMet is the primary…
Reaction of β-enaminoketones with lanthanide salts leads to mesomorphic complexes displaying an SA mesophase. The mesophase was characterized using X-ray scattering, EPR and magnetic susceptibility. A very high magnetic anisotropy was deduced for a complex containing dysprosium.
The water vapor permeability of a given material plays an important part in evaluating the physiological wearing comfort of clothing systems or deter mining the performance characteristics of textile materials used in technical applica tions. Many methods are used for measuring the parameters of water vapor transfer t…
Abstract A model that makes it possible to evaluate the secondary nucleation rate in a pilot‐scale industrial crystallizer is presented. It relates the secondary nucleation rate directly to the volume rate of attrition of large parent crystals. Two other terms are included in the equality, one that expresses the distr…
Good damping materials should exhibit a high loss factor value over a broad temperature range. Polyurethane and polystyrene are highly immiscible polymers with glass transition regions far apart. The interpenetrating polymer network topology can restrict phase separation and result in materials with a broad transition…
A model is presented to interpret in situ laser reflectance interferometry (LRI) measurements of film growth. The model uses no adjustable parameters and measures film thickness, growth rate, attenuation, and root-mean-square (rms) surface roughness in situ and in real time. For the particular case of diamond film gro…
Abstract Highly filled lignin/polyethylene composites, with enhanced mechanical properties, were studied. Composites are prepared using the catalytic grafting technique of polyethylene on lignin particles. This technique improves wetting and dispersion of additives in the matrix as well as interactions between these t…
Abstract Three isomeric bis(ether carboxylic acid)s, 4,4′‐[1,2(1,3 or 1,4)‐phenylenedioxy]dibenzoic acid ( o ‐, m ‐, or p ‐ 3 ) were prepared by nucleophilic substitution reaction of the potassium phenolate of catechol, resorcinol, and hydroquinone, respectively, with p ‐fluorobenzonitrile, giving the corresponding bi…
In this paper, an attempt of the whole discharge model is proposed. This model is based on an equivalent electrical network, the parameters of which are determined from electromagnetic field and gas discharge theories. It uses the fact that the discharge channel may be likened to a long conductor and employs a typical…
Three-dimensional structures of trypsin with the reversible inhibitor leupeptin have been determined in two different crystal forms. The first structure was determined at 1.7 A resolution with R-factor = 17.7% in the trigonal crystal space group P3(1)21, with unit cell dimensions of a = b = 55.62 A, c = 110.51 A. The…
The absorption coefficients and the Faraday rotation spectra of nanocrystalline cobalt ferrite thin films were determined in the visible–near infrared range. The films prepared by rf sputtering in an Ar–O2 atmosphere display magnetic and structural properties which differ from those of the bulk material. Optical and m…
An extension of the theory of elastic material with voids to the case where the material undergoes an irreversible void growth is presented. The particularity of this theory is that the continuum is described by two kinematic variables: the displacements and the variation of the volume fraction of material in the poro…
Polylactides with various degrees of chain regularity-crystalline poly(L-lactide); amorphous poly(L/D-lactide), and amorphous poly(L/DL-lactide)-were processed into high-strength, high-modulus resorable rods using solid-state extrusion through a conical die. The rods with a highly fibrillated structure had flexural st…
The effects of chemical change during sample preparation and low molecular weight chains of low density polyethylene (LDPE) have been investigated in order to clarify the origins for heterocharge in LDPE which does not contain antioxidants. The carbonyls formed at the surface of polyethylene (PE) sheet prepared at 180…