Materials Literature
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Properties of one-dimensional quasiperiodic discrete Schr\"odinger equations are analyzed by means of a finite-size scaling of the spectrum and the wave function. The incommensurate Harper model, which has only one Fourier component in the potential, is analyzed as an example, and some quantitative results, which are…
The band structures of cubic ${\mathrm{Cu}}_{2}$O and monoclinic CuO crystals have been calculated by means of the first-principles orthogonalized linear combination of atomic orbitals method. Using the wave functions obtained, the frequency-dependent interband optical conductivities are also evaluated. The results sh…
Polycrystalline barium titanate that has been doped to give a positive temperature coefficient of resistance (PTCR) effect is an inhomogeneous material electrically. Analysis of ac impedance data using the complex impedance plane representation gives the dc resistance of PTCR ceramics. By additional use of the complex…
The dielectric relaxation of 1,2,4-butanetriol in its supercooled liquid state has been studied at pressures up to 1 GPa. The frequency of the applied field is varied within the range from 1 mHz to 10 MHz. The automated and computer controlled dielectric spectroscopy measuring system is presented in detail. It is foun…
Low resistance ohmic contacts were manufactured on a natural semiconducting diamond (type IIb), by implanting boron ions at a temperature of 200 degrees C. This was followed by annealing at 1200 degrees C and removal of the top ion-damaged layer by etching in a hot acids solution. The thin, highly doped surface which…
Li 2 B 4 O 7 activated with a Cu impurity exhibits the 'unique' characteristics of linear thermoluminescence (TL) effects, a rare feature very similar to that of LiF:Mg, Cu, P, another phosphor of this category. Its thermoluminescence is investigated for its trap distribution characteristics. The analysis, based on a…
The nature and production of x-rays diffraction effects structures, composition, properties and occurences of clay minerals sample preparation techniques for clay minerals sample preparation techniques for clay minerals identification of individual clay minerals and associated minerals identification of mixed layered…
Cross-sectional and plan-view transmission electron micrograph analysis of the structure of porous silicon reveals that the pore walls are also porous, yielding a large distribution of pore sizes for a given porous silicon sample. This infrastructure appears to be a universal morphological feature of porous silicon, i…
ABSTRACT Stress corrosion cracking (SCC) in nonmagnetic drill string components made of austenitic stainless steel alloys has been a long-standing industry-wide problem. Three currently available technologies, each capable of producing a zero frequency of SCC, are presented in this paper. The application of compressiv…
Abstract When applied as conformance treatments, foams are required to effectively reduce gas injectivities over prolonged periods of time. Frequently, this ability must be manifested in the presence of a residual oil saturation which often exerts a destabilizing effect on foam and the capacity to generate foam. In th…
The ability of algae and bacteria to accumulate heavy metals from the surrounding environment is a widely recognized phenomenon that has a number of important implications. This work reports on the development of a quantitative model that addresses the basic mechanisms inherent in many uptake processes. The model post…
We have previously reported on liposome formulations with reduced uptake by the reticuloendothelial system, prolonged circulation time, and enhanced accumulation in transplanted tumors. One of these formulations, consisting of hydrogenated phosphatidylinositol (HPI), hydrogenated phosphatidylcholine (HPC), and cholest…
Uncooked foods commonly possess only weak aromas and desirable aromas are generated upon cooking. For example, unroasted coffee beans possess a weak green, bean character while raw beef possesses a weak, slightly sweet, and bloody character. Numerous chemical reactions occur upon roasting and the typical, highly desir…
Temperature-dependent Mossbauer spectroscopy and variable temperature Fourier transform infrared techniques were employed to follow the spin conversion of Fe(BPTN)(NCS) 2 and Fe(TPA)(NCS) 2 complexes. The hyperfine interaction parameters and Debye-Waller factors were determined using the Mossbauer effect. The complexe…
The authors have studied the behaviour of an optical hole in the 3 A to 3 E zero-phonon absorption of the nitrogen-vacancy centre in type 1b diamond under the influence of an externally applied magnetic field. Spin cross relaxation and level anti-crossing phenomena in the 3 A ground state are displayed as sudden reduc…
The phase transition in the relaxor ferroelectric lead scandium tantalate, Pb(Sc0.5Ta0.5)O3, is investigated in both ordered and partly disordered (Sc, Ta disorder) modifications through the technique of hard-mode Raman spectroscopy. The vibrational modes for ordered para phase, ordered ferroelectric phase, disordered…
The structural slowing down in a binary alloy of soft spheres near the fluid-glass transition has been investigated by extensive molecular dynamics simulations. An attempt is made to characterise the transition on the basis of r- and k-space representations of the incoherent and coherent parts of the density autocorre…
The x-ray-photoelectron core-level linewidths show pronounced differences between atomic C, N, and O adsorbed on Ni(100). Furthermore, the widths are temperature dependent. The observed effects are reproduced within a model based on the creation of vibrational excitations in the core-ionization process. This explains…
The mode-coupling theory of the liquid-glass transition is applied to the hard-sphere system. The critical exponents and amplitudes characterising the slow relaxation of density fluctuations in the vicinity of the transition are calculated. Particular attention is devoted to the description of the frozen correlations…
The existence of classical phase diffusion in hysteretic junctions is demonstrated by quantitative agreement between experimental and simulated I-V curves. The simulations are based on a circuit that accurately models both the junction and its external shunting impedance at microwave frequencies. We show that the bias…