Materials Literature
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The substitution of [4]B for [4]Si in tourmaline has been the source of much discussion. A sample of olenite from Stoffhütte, Koralpe, Styria, Austria has been found to contain more than one [4]B per formula unit of 31 (O,OH,F), demonstrating that significant [4]B = [4]Si substitution does indeed occur in tourmaline.…
The ring-opening polymerization of ω-pentadecalactone (PDL), a 16-membered lactone, in the bulk and in solution using yttrium isopropoxide as an initiator was investigated. All isopropoxide groups of yttrium isopropoxide participated in the initiation and the polymerization took place via acyl-oxygen cleavage of the m…
Abstract Pyrochlore group minerals have the general formula A 16– x B 16 O 48 Z 8– y · n H 2 O, with A mainly Na, Ca, Sr, REE , Th, U; B mainly Nb, Ta, Ti and Z being O, F, OH. In this study, pyrochlore specimens were examined from carbonatites at Argor, Carillon Dam, Chilwa Island, Fen, Lueshe, Oka, Mbeya, Meech Lake…
The results of single-site and many-site measurements of cell dimensions from single crystals are compared for Bond and four-circle diffractometers using samples of corundum (essentially pure rhombohedral alpha-Al2O3, aluminum oxide) of high diffraction quality, where the effects of small changes in temperature and co…
In this research, PHA (polyhydroxyalkanoate) production system by activated sludge was studied. PHA behaves as carbon and energy storage material in bacteria. And PHA is a biodegradable plastic when extracted from bacteria. In this paper, the investigations from 3 aspects were reported; control of PHA composition, PHA…
Stabilized bismuth oxides undergo a decay in conductivity when subjected to annealing at temperatures of <600°C, because of the formation of an ordered superstructure, which is observed in transmission electron microscopy (TEM) diffraction patterns. Neutron‐diffraction studies of the aged samples indicate that ther…
The quadratic residue diffuser was originally designed for enhanced scattering. Subsequently, however, it has been found that these diffusers can also be designed to produce exceptional absorption. This paper looks into the absorption mechanism of the one-dimensional quadratic residue diffuser. A theory for enhanced a…
On-line studies of the structural development during continuous drawing of a polypropylene fiber were carried out using synchrotron wide-angle X-ray diffraction. A unique image analysis method was introduced to extract quantitative information on the crystal, amorphous and mesomorphic fractions. In addition, the unit-…
A short-ranged classical force-field for the modeling of silicon nitrides, boron nitrides, and borosilazanes (Si/B/N) has been derived on the basis of experimental and ab initio solid state and diatomic molecular data. The potential is a sum of pure two-body interaction terms with functional forms apt for fraction sim…
Ordered macroporous structures have been produced by templating echinoid (sea urchin) skeletal plates. Results are summarized that describe how the CaCO3 plates that form the test of the sea urchin provide excellent templates for producing porous structures. This extremely general method has been used in this case to…
This study of two new total hand simulating methods for knits uses fuzzy theory and neural networks. One method, a neural network system trained with a back-propaga tion algorithm, performs functional mapping between mechanical properties and the resulting total hand values of the fuzzy predicting method. The second m…
Anisotropic peak broadening in hydrogen-cycled hexagonal LaNi 5 and substitutional derivatives has been studied by means of synchrotron powder diffraction. The data have been analysed by a local lattice parameter variation method implemented in a Rietveld code and by an individual profile fitting using a dislocation p…
Surface photovoltage spectrum (SPS) and field-induced surface photovoltage spectrum (FISPS) are valuable techniques for the determination of pn conduction type of organic semiconductors. Here, conduction characters of azo pigment films composed of pure 4,4‘-2-[ N −(β-hydroxyl)naphthyl]azodiphenyl ( A ) and 4,4‘-2-{ N…
This work focuses on the development of a novel method for molecular level assembly and processing of multilayer azo polymer films. Poly(acrylic acid)-based precursor anilino-functional polymer was first synthesized and used as a polyanion. This polymer was assembled into mono- and multilayer thin films by an electros…
We present an analysis and results on the homogeneous nucleation of a dislocation loop under stress in a perfect crystal. By using a variational boundary integral method in the Peierls-Nabarro framework, we have determined the saddle-point configurations of embryonic dislocation loops and their associated activation e…
Palladium catalysts offer a rich and highly versatile chemistry for the synthesis of novel porphyrins and phthalocyanines. These mild and flexible reactions have been used extensively in the preparation of interesting porphyrins and phthalocyanines, either in the synthesis of substituted precursors or in the modificat…
UNLABELLED: Hydrogenated diamond-like carbon films (DLC, a-C:H), deposited using plasma-assisted or ion beam-assisted techniques, offer great potential as self-lubricating coatings in many tribological applications. Additionally, studies on biocompatibility have shown that DLC is an inert, impervious hydrocarbon with…
Five indole alkaloids, corynantheidine, corynantheine, dihydrocorynantheine, alpha-yohimbine and corynanthine were isolated from bark of Corynanthe pachyceras K. Schum. (Rubiaceae). The structures were established by spectroscopic methods, including previously unreported assignment of all 1H-NMR resonances by COSY and…
Resistance degradation in perovskites generally is assumed to be caused by stoichiometry variations that occur during high field stress. According to this assumption, distinct conductivity profiles should develop during degradation. In this study, microcontact impedance spectroscopy is used to determine the conductivi…
Electrical resistivity, magnetization, and specific-heat measurements on the Heusler-type alloy ${\mathrm{Fe}}_{2}\mathrm{TiSn}$ reveal the occurrence of weak ferromagnetism below 240 K and heavy fermion behavior with a quasiparticle effective mass of $\ensuremath{\sim}40$ times the free electron mass. Ab initio elect…