Materials Literature
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A simple three-state lattice model that incorporates two states for locally ordered and disordered forms of liquid water in addition to empty cells is introduced. The model is isomorphic to the Blume-Emery-Griffith model. The locally ordered (O) and disordered (D) forms of water are treated as two components, and we a…
Abstract Natural cellulose molecules have a strong tendency of being aggregated into larger structures. Thus, the imaging of isolated individual cellulose molecules is hampered for a long time. In this work, we manage to observe, for the first time, the isolated individual natural cellulose chains on a sample surface…
Ceramic/metal interfaces were studied that fail by atomistic separation accompanied by plastic dissipation in the metal. The macroscopic toughness of the specific Ni alloy/Al2O3 interface considered is typically on the order of ten times the atomistic work of separation in mode I and even higher if combinations of mod…
Patterned ZnO deposition on substrates has received increasing attention because of its great potential in photocatalysis, energy conversion, and electro-optical techniques. Chemical solution growth is especially promising for organic substrates due to its very mild reaction conditions. Here this method is used on fun…
We propose an efficient numerical scheme, based on the method of lines, for solving the Landau-de Gennes equations describing the relaxational dynamics of nematic liquid crystals. Our method is computationally easy to implement, balancing requirements of efficiency and accuracy. We benchmark our method through the stu…
We use group theory to classify the superconducting states of systems with two orbitals on a tetragonal lattice. The orbital part of the superconducting gap function can be either symmetric or antisymmetric. For the orbital symmetric state, the parity is even for spin singlet and odd for spin triplet; for the orbital…
Y-TZP presents excellent properties at room temperature but these properties decrease as the temperature increases. This paper studies the behavior 20vol%Si3N4-SiC when added in YTZP matrix and heated under no pressure system. Al2O3 and Y2O3 were used to maintain the stability of the matrix and as sintering aids. The…
Polycrystalline SiC-diamond composites have been fabricated by high pressure and high temperature, HPHT, sintering using a Si infiltration method. However, infiltration of liquid silicon around the diamond particles results not only in SiC but also in free silicon, which causes deterioration of the composite propertie…
The 716-amino-acid guanidino kinase from the parasitic flatworm Schistosoma mansoni results from the fusion of two guanidino kinase subunits. Crystals of this 80 kDa protein have been obtained in the monoclinic space group P2(1), with unit-cell parameters a = 52.7, b = 122.1, c = 63.2 A, beta = 108.5 degrees . Synchro…
Polypropylene (PP) copolymer reinforced with talc, CaCO 3 , or multicomponent fillers (a combination of talc and CaCO 3 ) were compounded in a Brabender Plasti-Corder ® internal mixer. These compounds then experienced an extrusion process by means of a capillary rheometer. The rheological and morphological (SEM) prope…
The setting reaction of magnesium phosphate cements starts with water addition to a mixture of ammonium phosphate and magnesium oxide, is very fast and takes place at room temperature (cold setting). Literature shows that controversy is still going on about the reaction mechanism, hence, about the effect on the settin…
Abstract The missing member of the heteroadamantane series, 1‐oxoniaadamantane ( 4a ), was prepared by the ionization of suitable bicyclic precursors under strongly acidic conditions. The ion 4a was characterized by 1 H and 13 C NMR spectroscopy. The X‐ray crystal structure of ion 4a was also obtained with a CB 11 H 6…
The syntheses of new blue luminescent N(2)-modified guanosine derivatives with chromophores p-4,4'-biphenyl-NPh2 (1a), p-4,4'-biphenyl-N(2-py)2 (1b), and p-4,4'-biphenyl-2-(2'-pyridyl)benzimidazolyl (1c), respectively, have been achieved. These new N(2)-guanosines are moderate blue emitters with lambda(max) = 395 nm (…
The dielectric properties of TEA-CoCl2Br2 nanocrystals incorporated into the polymethylmethacrylate matrix within the frequency range of 3 × 105–2.6 × 109 Hz in the temperature region of 90–300 K were investigated. The considerable difference in the dielectric spectra of the nanocomposite compared to those of the bulk…
Transparent films of PMMA (poly methyl methacrylate) and PVAc (polyvinyl acetate), previously dissolved in chloroform, toluene and tetrahydrofuran (THF), were prepared by using solution-cast technique. FT-IR transmission spectra were obtained from the samples. Also, different concentrations of PMMA/PVAc blend, dissolv…
Powdered uranium silicide (U3Si2) 20% U235 enriched is an intermetallic compound used as nuclear fuel material dispersed in aluminum to be the meat of fuel elements. U3Si2 powder is the state-of-the-art as nuclear fuel material mostly used in modern research reactors. Its recent established fabrication in IPEN replace…
In an attempt to tailor the dehydrogenation temperature of lithium imides, we have investigated the ternary imide Li 2Ca(NH) 2, which crystallizes in a structure (space group P3 m1) different from that of Li 2Mg(NH) 2 (space group Iba2). First-principles density functional calculations yield the stable ground-state st…
Polymer-layered silicate nanocomposites have attracted strong interest in today's materials research, due to the possible impressive enhancements of material properties, comparatively with those of pure polymers. Several starch/poly(vinylalcohol)/montmorillonite nanocomposites have been subjected to surface modificati…
The structure of an ordered (2 × 1) overlayer of [HCOO] − on rutile TiO 2 (110)(1 × 1) has been elucidated using quantitative low energy electron diffraction. Both the location of adsorbate atoms, and substrate relaxation are determined. In agreement with previous work, it is concluded that the formate moiety binds to…
The mechanisms of magnetic exchange interactions in two heterobridged mu-hydroxyl-mu-X dicopper complexes A and B (X = azaindole for A and X = pyrazole for B) are investigated by the calculations based on density functional theory combined with the broken-symmetry approach (DFT-BS). It is found that although the coord…