Materials Literature
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Scanning Electron Microscope (SEM) is a powerful research tool, but since it requires high vacuum conditions, the wet materials and biological samples must undergo a complex preparation that limits the application of SEM on this kind of specimen and often causes the introduction of artifacts. The introduction of Envir…
We generalize the Bergman-Milton spectral representation, originally derived for a two-component composite, to extract the spectral density function for the effective dielectric constant of a graded composite. This work has been motivated by a recent study of the optical absorption spectrum of a graded metallic film […
The structure of bundles of single-walled carbon nanotubes (SWNT) has been refined by Rietveld analysis using neutron and X-ray powder diffraction data. Based on previous simulation studies of powder diffraction data of SWNT and standard Rietveld analyses, we have developed a pattern fit technique for SWNT which provi…
Granular flows and vibro-fluidised granular gases have been extensively studied recently; most of the theoretical analyses and the experimental descriptions use temperature and other thermodynamics concepts. However, taking the very simple case of a vibro-fluidised gas made of identical particles, we show the lack of…
Classical soil mechanics results are used to propose the equation of the jamming transition surface in the (stress, specific volume) space. Taking axis-ymmetric conditions, labelling q the deviatoric stress and p' the mean pressure applied on the granular skeleton, and considering normal range of pressure (10 kPa-10MP…
A theory of spin-polarized electron transport in ferromagnet-semiconductor heterostructures, based on a unified semiclassical description of ballistic and diffusive transport in semiconductors, is outlined. The aim is to provide a framework for studying the interplay of spin relaxation and transport mechanism in spint…
An alternative method for computing dipole-dipole interaction energy in systems of 1D and 2D periodicity like nanowires, nanotubes and thin films is presented. The approach is based on the use of periodic Green's functions that satisfy Laplace's equation and are analytically determined. The method, when combined with…
Recently Francoual et al. claimed to have observed the dynamics of long-wavelength phason fluctuations in i-AlPdMn quasicrystals. We will show that the data reported call for a more detailed development of the elasticity theory of Jaric and Nelsson in order to determine the nature of small phonon-like atomic displacem…
A general approach for the synthesis of manganese-doped II-VI and III-V nanowires based on metal nanocluster-catalyzed chemical vapor deposition has been developed. High-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy studies of Mn-doped CdS, ZnS, and GaN nanowires demonstrate that…
We present the first calculations of finite length carbon nanotube thermal conductivity that extend from the ballistic to the diffusive regime, throughout a very wide range of lengths and temperatures. The long standing problem of vanishing scattering of the "long wavelength phonf dramatically here, making the thermal…
Laser Brillouin scattering is applied to measure the sound velocity and the sound anisotropic velocity in high-quality single-domain tetragonal Ce:BaTiO 3 single crystals at room temperature. The elastic and piezoelectric constants are thus determined. Based on the sound propagation equations and these results, the di…
Abstract The Raman spectra of GaS x Se 1− x layered mixed crystals were studied for a wide range of composition (0 ≤ x ≤ 1) at 300 and 10 K. The effect of crystal disorder on the linewidth broadening of shear and compressional modes is discussed. The asymmetry in the Raman lineshape was analyzed for intralayer modes e…
Abstract The light depolarization and the Raman scattering spectrum were measured in a KTa 1− x Nb x O 3 crystal with a dilute Nb concentration (1.2%). Measurements were performed on cooling to 10 K without and then with an electric field. The unexpected Raman lines detected well above T C are attributed to one‐phonon…
Large high-quality type-II a diamond crystals in size of about 4.0 mm have been grown under the condition of 5.5 GPa and 1200–1300 degrees C by using the temperature gradient method in a domestic cubic anvil high-pressure apparatus. The Fe 55 Co 16 Ni 25 alloy (KOV) is used as the solvent metal, and Ti with the conten…
A phenomenological model is developed to describe the isotropic-chiral-smectic-C phase transition. The anomalous part of the heat capacity of the chiral-smectic-C liquid crystals above the isotropic-chiral-smectic-C phase transition is calculated using Landau's fluctuation theory. The temperature dependence of the hea…
The influence of succinylation on lysozyme is studied using circular dichroism, fluorescence spectroscopy, and differential scanning calorimetry. The spectroscopic data reveal that at room temperature the structures of succinylated lysozyme and native lysozyme are similar. However, the calorimetric results show that t…
Complexes of Mn(II) with 1,10-phenanthroline (phen) and 2,2'-bipyridine (bipy) are investigated by means of electrospray ionization (ESI) mass spectrometry. Under the conditions used, [MnL(n)]2+ with n = 2 and 3, [MnL(n)Cl]+ with n = 0-2, and [Mn2L(n)Cl3]+ with n = 2 and 3 are produced (where L = phen or bipy). The co…
Abstract Electrochemical deposition of polybithiophene (PbT) films on suitably roughened silver and copper electrodes enabled us to record surface‐enhanced Raman scattering (SERS) spectra of oxidized and reduced species showing the important changes in the spectral features of the different oxidation states of the pol…
We report a theoretical study of the multiple oxidation states (1+, 0, 1-, and 2-) of a meso,meso-linked diporphyrin, namely bis[10,15,20-triphenylporphyrinatozinc(II)-5-yl]butadiyne (4), using Time-Dependent Density Functional Theory (TDDFT). The origin of electronic transitions of singlet excited states is discussed…
As a candidate scaffold material for cardiac tissue engineering, Type I collagen material shows different mechanical properties due to the differences in the structural features such as orientation of fibril alignment and the environmental factors such as ultraviolet (UV) irradiation. In this article one-dimensional t…