Materials Literature
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The microscale syntheses of Tetraphenylporphyrin, H 2 (TPP), and the corresponding metalloporphyrins Zn II (TPP) and Ni II (TPP) are reported. H 2 (TPP) is synthesized by the condensation of benzaldehyde and pyrrole, and the subsequent metallation of H 2 (TPP) is achieved with anhydrous Zn II Cl 2 or Ni II Cl 2 in DMF…
Using a pin‐on‐plate tribometer with the reciprocating motion of SiC against yttria‐doped tetragonal zirconia polycrystal (Y‐TZP) plates, the friction and wear of Y‐TZP ceramics were investigated as a function of grain size in dry N 2 at room temperature. The results showed that the overall wear resistance increased a…
It has been shown that the temperature behavior of dielectric permittivity ($\ensuremath{\varepsilon}$) in the isotropic phase of nematogens can be described in the same way as in critical binary solutions. Hence, using a relation with the critical exponent $\ensuremath{\varphi}=1\ensuremath{-}\ensuremath{\alpha}=0.5\…
Synergistic effects between erosion and corrosion processes on mild steel (MS) in an aqueous carbonate-bicarbonate solution were studied using electrochemical measurements from a rotating cylinder electrode (RCE) system. A rigorous basis for definition and measurement of the “pure” erosion rate and corrosion rate was…
RATIONALE AND OBJECTIVES: The authors compare in vivo transmetallation of three magnetic resonance contrast agents in humans in terms of their kinetic stability. METHODS: Blood and urine samples were taken before and after the intravenous injection of gadolinium (Gd)-HP-DO3A, Gd-DTPA, or Gd-DTPA-BMA at 0.1 mmol/kg to…
A new assessment of the thermodynamic properties of the stable phases of the Ni-Ti system is presented, based on the experimental thermochemical and phase diagram data from the literature. Suitable sublattice models are used to describe the non-stoichiometries of NiTi and Ni 3 Ti. The calculated phase diagram and the…
Using electron paramagnetic resonance two types of ${\mathrm{Ti}}^{3+}$-related centers are identified in BaTi${\mathrm{O}}_{3}$, which are attributed to ${\mathrm{Ti}}^{3+}$-${V}_{\mathrm{O}}$ and to ${\mathrm{Ti}}^{3+}$-${V}_{\mathrm{O}}$ associated with Na or K, respectively. This assignment is based on the chemica…
Abstract Calculations of electron inelastic mean free paths and stopping powers for several alkali halides (KF, KCl, KBr, and KI) and metal oxides (BeO, MgO, SiO 2 , and Al 2 O 3 ) have been performed in the 50 eV to 10 keV energy range. The complex dielectric formalism, improved to include the energy gap, was used fo…
In enteric bacteria, the hexitol galactitol (Gat) (formerly dulcitol) is taken up through enzyme II (II(Gat)) of the phosphoenolpyruvate-dependent phosphotransferase system (PTS), and accumulated as galactitol 1-phosphate (Gat1P). The gat genes involved in galactitol metabolism have been isolated from the wild-type is…
Abstract A well-characterized kaolinite has been hydrated in order to test the hypothesis that platey kaolinite will roll upon hydration. Kaolinite hydrates are prepared by repeated intercalation of kaolinite with potassium acetate and subsequent washing with water. On hydration, kaolinite plates roll along the major…
We have investigated the activation barriers and the intermediate paths of the transformation to cubic diamond and that to hexagonal diamond from graphite under pressure, allowing both atomic geometry and unit-cell shape to vary, in order to clarify the difference of the microscopic mechanisms between them. For this i…
Cuboid silsesquioxanes with appropriate side chains (see below; n = 4, 6, 11) provide a means of structuring soft matter with inorganic cores. These compounds combine material characteristics of polymer and low molecular mass liquid crystals.
The purpose of this work was to evaluate the effect of compositional modifications on the electrical properties of lead lanthanum zirconate stannate titanate (PLZST) ceramics, as well as to examine their electrically induced phasechange behavior. Variations in the Ti:Sn ratio were evaluated. Increased Ti 4+ content pr…
We present a neutron-scattering study of depletion interactions in a mixture of a hard-sphere-like colloid and a nonadsorbing polymer. By matching the scattering length density of the solvent with that of the polymer, we measured the partial structure factor ${S}_{c}(Q)$ for the colloidal particles. It is found that t…
An extensive experimental study has been conducted to examine the influence of ultraflne SiC particles on grain growth in A1 2 O 3 . Grain growth has been studied as a function of annealing time, particle volume fraction, and annealing temperature. The SiC particles reduce the grain‐growth rate of A1 2 O 3 by >3 order…
Porous silicon is emerging in micromachining technology as an excellent material for use as a sacrificial layer. This is largely due to the ease of fabrication and freedom of design it allows. The rate of pore formation is heavily dependent upon the doping type and concentration of the silicon, allowing patterned poro…
Structural aspects of the Bechgaard salts (TMTSF)2X and related 2:1 salts, mostly based on the sulfur donors TMTTF and BCPTTF as well as on the hybrid TMDTDSF donor, are considered in relationship with their physical properties. The basic structure of these salts is reviewed with a special emphasize on the dimerizatio…
Nutritional characteristics of the hyperthermophilic archaeon Thermococcus litoralis have been investigated with emphasis on the development of a sulfur-free, defined growth medium, analysis of an exocellular polysaccharide, and formation of a biofilm. An artificial-seawater-based medium, containing 16 amino acids, ad…
The size distribution of liposomes is often determined using freeze fracture, cryoelectron microscopy or dynamic light scattering. However, the resulting size distributions do not directly coincide owing to the different weighting of the techniques. We present several methods which correct for these effects and allow…
It has been reported that the silicate phase as well as the cross-linking of the polycarboxylic acid by aluminum and calcium ions played an important role in the hardening of glass-ionomer cement. The objective of this study was to investigate the structural change during hardening of the cements by means of infrared…