Materials Literature
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We report the results of Monte Carlo simulations of the Lebwohl-Lasher model of nematic liquid crystals confined to cylindrical cavities with homeotropic anchoring. We show that the ratio of the bulk to surface couplings is not in general equal to the corresponding parameter K/W used in elastic theory (where K is the…
The forthcoming European legislation on cars and environment protection has an impact on the materials used for the production of cars. Weight reduction to limit the emission of green house effect gases is possible using new designs with recently developed high strength steels. Examples are described for the body in w…
The nucleation of grains by subgrain growth has been investigated using a two-dimensional vertex model. The initial geometry has an on average flat grain boundary, separating two populations of subgrains. The phenomenon has been studied using (i) a constant ratio between the subgrain and the grain boundary mobility or…
Six series of liquid crystal materials containing a 2,5-disubstituted thiophene unit were synthesized. The liquid crystal compounds obtained were characterized by NMR, differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction techniques. The properties of liquid crystalline phases were inv…
Abstract Morphology of natural rubber (NR) thin films crystallized under molecular orientation was examined by transmission electron microscopy (TEM). A thin film of NR (RSS#1) was made by casting its n -hexane (or benzene) solution onto the water surface, and prestretched up to a desired amount of strain (%). Each of…
A significant fraction of radionuclides released by nuclear events, for instance nuclear weapons tests, nuclear reactor accidents, and fires involving nuclear installations is associated with particles. Furthermore, effluents from nuclear reactors and reprocessing plants under normal operating conditions contain radio…
Michael-type additions of functionalized amines to CH2=CH−P=N−P=S linkages located at the core of phosphorus-containing dendrons allowed for the grafting of functions suitable to join these dendrons together or to various dendritic molecules. This reactivity led to original multidendritic systems incorporating differe…
Sol–gel‐derived LaCoO 3 thin films were deposited on yttria‐stabilized zirconia (YSZ) substrates from a lanthanum isopropoxide–cobalt acetate (with 2‐methoxyethanol) precursor solution. A chelating agent (2‐ethylacetoacetate) and polyethylene glycol (PEG) were used to modify the above‐mentioned precursor solution. The…
We present a general formulation based on the Jones-matrix theory for reciprocal nonabsorbing polarization devices, including polarization interference filters and liquid-crystal displays. The development of this formulation is based on general symmetry conditions that relate the Jones matrix when the device is illumi…
Impedance spectroscopy has been used to characterize Sr 0.97 Ti 1− x Fe x O 3−δ materials. This technique was suitable to evaluate the grain and grain‐boundary conductivities of samples with ≤5% iron. The role of grain boundaries was changed by sintering in different conditions, and this was interpreted by accounting…
Several 4-(oligodimethylsiloxyl)alkoxybenzoic acids and their hydrogen-bonded complexes with 4,4-dipyridyl or 1,2-bis(4-pyridyl)ethane were prepared and their phase behaviour studied by DSC and polarized optical microscopy. The neat acids showed no liquid crystalline phases. The 4,4-dipyridyl complex of 4-(n-heptameth…
It is well known that uncompensated in-plane switching (IPS) liquid crystal displays (LCDs) have much better viewing angle than conventional twisted-nematic (TN) LCDs. However, to achieve optimal viewing angle performance in these devices, they must be compensated by one or more films. In this paper, we will study the…
A novel fabrication process of AlN ceramics via aqueous colloidal processing and pressureless sintering has been presented. The chemical stability of AlN powder in water was improved by the surface chemical modification with sebacic acid, while maintaining a hydrophilic surface. The treatment of the sebacic acid‐modif…
The ${e}_{g}$-orbital states with complex coefficients of the linear combination of ${x}^{2}\ensuremath{-}{y}^{2}$ and ${3z}^{2}\ensuremath{-}{r}^{2}$ are studied for the ferromagnetic state in doped manganites. Especially the focus is put on the competition among uniform complex, staggered complex, and real orbital s…
Hexagonal and tetragonal CuIn 5 Se 8 thin films have been successfully prepared by physical vapor deposition. A hexagonal CuIn 5 Se 8 thin film was obtained via the reaction of (Cu+Se) and (In+Se) layers. This hexagonal film had a layered structure with a lattice spacing of approximately 16 Å, corresponding to fivefol…
Monocomponent ferroelectric liquid crystals based on L-tyrosine (see Figure) are investigated here. It is shown that the series synthesized exhibits a wide ferroelectric thermal range between –20 °C and 65 °C as well as a high magnitude of spontaneous polarization. Hence these materials are a promising alternative to…
Synthetic heme−oligopeptide complexes of coproporphyrin-I-atoiron(III) have been prepared in aqueous solution, and their equilibrium formation constants have been determined by spectrophotometric titration. The presence of hydrophobic residues flanking the coordinated histidine dramatically increase peptide binding to…
This investigation aimed to characterise conditioning layers formed on AISI 316 stainless steel by different types of extracellular polymeric substances (EPS), i.e. biofilm, planktonic and capsular exopolymers, isolated from continuous cultures of marine Pseudomonas received from the National Collection of Industrial…
It is well known that the dislocation luminescence (DL) in silicon consists of four main bands, conventionally labelled D1 to D4, where E1 = 0.807 eV, E2 = 0.874 eV, E3 = 0.95 eV and E4 = 0.99 eV, of which the D1 is considered of interest for optoelectronic devices working in the third window of optical communications…
The nonlinear dielectric relaxation spectra of ferroelectric liquid crystals (FLCs) have been studied in the chiral smectic-C phase. The linear and third-order nonlinear dielectric spectra show the relaxation corresponding to the fluctuation in the azimuthal angle of directors called the Goldstone mode. We calculated…