Materials Literature
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Treatment of [Fe(OEP)]2O with trichloroacetic acid (2.5-fold excess) results in the formation of (octaethylporphinato)(trichloroacetato)iron(III). Various crystalline solvates can be isolated, depending on the crystallization solvent. Initial crystallization with CHCl3/hexanes resulted in the isolation of a monoclinic…
Five new polyamideimides (PAI) were synthesized from five diacid chlorides with preformed imide rings and a telechelic α,ω-diamino-polyoxyethylene (Jeffamine JFA ED600). The diacid chloride monomers could be obtained in high yields (77–92%) from chlorinating the corresponding diacids which were obtained from the react…
The synthesis and properties of a new mesogenic/nonmesogenic copolymer system, namely the poly[6-(4′-methoxyazobenzene-4′-oxy)hexyl methacrylate]-co-poly[methyl methacrylate]s, are described. Copolymers containing 0.59 or greater mol fraction of the mesogenic side-groups exhibit nematic behaviour while those containin…
Nowadays, a modern physical theory becomes of a principle importance in understanding the complexities of the living world: the physics of lyotropic states of matter. We demonstrate here what kind of specification is necessary in the molecular description of lyomesogens, in the theory of elastic and flexoelectric phen…
High‐temperature (1200–1550 K) mechanical‐loss and shear‐modulus measurements were performed on fine‐grained magnesia‐ and magnesia/ytrria‐doped alumina at low frequency (10 −4 −10 1 Hz), using a forced‐vibration torsion pendulum. Anelastic and viscoplastic relaxation phenomena were observed, which may be associated w…
A new, high sensitive, thermoluminescent material SrSO4:Mo, Tb is reported. TL sensitivity is three times that of widely used CaSO4:Dy. Emission of the phosphor is in the near UV-blue region of the spectrum which falls in the most sensitive region of the common photomultiplier tubes. In addition to this, good linearit…
A new calorimeter is constructed to precisely measure the heat of wetting of cotton, regular viscose rayon, high wet strength viscose rayon, and Tencel®. Our purpose is to investigate the relationship between the heat of wetting and structural characteristics of fibers such as crystal and fiber structure, degree of cr…
An ellipsometric method is used to study the dispersion of the real ɛ 1 ( ω ) and imaginary ɛ 2 ( ω ) parts of the complex dielectric permittivity of single-crystal La 1− x Sr x MnO 3 ( x =0.1, 0.2, and 0.3) for energies from 100 meV to 5 eV at room temperature. It is found that, when lanthanum is replaced by strontiu…
Characterization of the structure and chemical composition of nickel oxide films formed on AISI 316L stainless steel by electrochemical anodic treatment in an aqueous electrolyte containing 560 g l−1 NaOH was made by electron microscopy and x-ray photoelectron spectroscopy (XPS). The depth chemical composition, thickn…
The theory of the torque balance method for azimuthal anchoring energy measurements is investigated in detail under a general case of anchoring strength relationships between two substrates and a generalized relationship equation is deduced. As an example, azimuthal anchoring energies of several polyimide (PI) materia…
Abstract Complexes of vinylene-bridged bis- and tris(octaethylporphyrin)s (bis(OEP)–M and tris(OEP)–M) with d8 transition-metal ions (M = Ni(II), Pd(II), and Pt(II)) were synthesized. Metalation of (E)-bis(OEP)–H2 was carried out under the same conditions as for the corresponding octaethylporphyrin complex (OEP–M), to…
Photovoltaic devices remain an important aim for thin films of conjugated polymers. Here is reported the construction of devices with improved photovoltaic performance, which is achieved by blending elongated CdSe nanocrystals (see Figure) with regioregular poly(3-hexylthiophene). Improved transport arising from dense…
A finite two-dimensional (2D) foam sample bounded by walls contains inner bubbles (I-bubbles) and peripheric or edge bubbles (E-bubbles). We derive equations for the rate of area change of both types of bubbles, which depend linearly on the number of neighbours of a bubble but are. in general, not scale independent. F…
Control over surface texture in thin film production is necessary for preparing smooth films (e.g., for optical surfaces), but also where some roughening of the surface is required (e.g., patterning for liquid-crystalline display devices). These authors have found a way to control nanoscale roughening by adsorbing neg…
The prooxidant/antioxidant imbalance in familial adenomatous polyposis (FAP) is suggested by (i) the intimate connection between APC and prostaglandin H synthase-2 genes, (ii) the increase of the free radical-generating enzyme xanthine oxidase, and (iii) the decrease of antioxidant defences. In this research work we e…
A study of variations in IR absorption characteristics of fabrics with moisture regain and fiber type is discussed. Infrared spectral absorptivities of fabrics are measured over the range of wavelengths from 0.7 to 25 microns. These values are used with the normalized emission characteristics of blackbody emitters to…
Spectroscopic investigations of Cr3+ doped ZAPH are carried out. From the nature of optical absorption bands and their splittings at the liquid nitrogen temperature, the site symmetry of the Cr3+ in ZAPH is attributed to orthorhombic distortion.
Two linepipe steels with carbon mass contents of 0.09 and 0.15% were subjected to steady state unidirectional solidification in a special apparatus. The specimens were positioned in alumina tubes of 15 mm internal diameter, and were pulled downwards at a constant rate, R , from the high temperature furnace. The temper…
Glyceraldehyde-3-phosphate dehydrogenase was purified from Clostridium acetobutylicum by sequential ammonium sulfate precipitation, gel filtration and anion-exchange chromatography (to a specific activity of 27 U mg-1). The enzyme had a molecular mass of 40 kDa as determined by SDS-PAGE and a native molecular mass of…
One series of two-ring and two series of three-ring liquid crystal compounds, all containing omega, alpha, alpha-trihydroperfluoroalkoxy terminal tails, were prepared and characterized by IR, NMR, MS and elemental analysis. Their phase transition behaviour was investigated by DSC and polarizing optical microscopy. Bip…