Materials Literature
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Hydrogen bond strength depends on both temperature and pressure. The gradient for hydrogen bond strength with temperature, or pressure, depends upon the hydrogen bonded structure. These features create an intimate connection between quantum mechanics and thermodynamics in the structure of liquid water. The equilibrium…
This manuscript reports the demonstration of strong interparticle electromagnetic coupling in nanoparticle:molecule:nanoparticle sandwiches. These assemblies were prepared by adsorption of cytochrome c (Cc)-coated colloidal Au nanoparticles onto aggregated colloidal Ag. Surface enhanced Raman scattering (SERS) spectra…
The electronic structure of [Cr(tren)(3,6-DTBSQ)] 2+, where tren is tris(2-aminoethyl)amine and 3,6-DTBSQ is 3,6-di- tert -butylorthosemiquinone, has been studied by self-consistent-field non-local gradient-corrected density functional theory. The results are consistent with a Heisenberg exchange formulation where a C…
Galvanic corrosion of copper (UNS C11000), 1018 carbon steel (CS, UNS G10180), aluminum alloy 3003 (UNS A93003), and zinc (UNS Z32121) coupled to cathodes of UNS N08367 was tested with and without natural marine biofilms on the cathode surface. Weight losses were significantly higher, and corrosion currents were up to…
Complexes of discotic liquid crystals would ideally possess the conductive properties of semiconductors and metals as well as the highly anisotropic mechanical, optical and structural properties of liquid crystals. High-resolution X-ray diffraction is used by the authors to study the structure of a liquid-crystalline…
The degradation of poly(propylene fumarate-co-ethylene glycol) hydrogels was examined in vitro in phosphate-buffered saline at pH 7.4 and in vivo in a subcutaneous rat model. These hydrogels have potential application as biodegradable, injectable cardiovascular stents, and, as such, their mass loss, dimensional change…
Obtaining high resolution x-ray photoemission spectroscopy (XPS) spectra of insulating samples has long been a problem because of difficulty controlling sample surface potentials. A flood of low energy electrons has traditionally been used to control surface potential, but as monochromatized instruments with small, in…
Additions of Bi 2 O 3 were used to promote grain growth and to increase magnetic permeability during sintering of MnZn ferrites. The results showed that small additions of Bi 2 O 3 of <0.05 wt% remarkably increase the permeability of MnZn ferrites. On the other hand, addition of 0.05 wt% Bi 2 O 3 induced the format…
The oxidative durability of a SiC‐SiC composite with Hi‐Nicalon fiber and a BN interphase was investigated at 800°C (where pesting is known to occur in SiC‐SiC composites) for exposure durations of up to 500 h and in a variety of oxidant mixes and flow rates, ranging from quasi‐stagnant room air, through slow‐flowing…
The properties of convex gratings fabricated by electron-beam lithography are investigated. Three grating types are shown. The first is a single-panel, true blazed grating in which the blaze angle stays constant relative to the local surface normal. This grating provides high peak efficiencies of approximately 88% in…
ABSTRACT Tensile strength (TS), percent elongation (%E), oxygen permeability (OP), and water vapor permeability (WVP) of lactic acid and rennet precipitated casein‐based edible films were studied to determine the effect of protein to plasticizer ratio (0.6:1, 1:1, 1.4:1) and plasticizer type (sorbitol, glycerol) on th…
Abstract A method for predicting the shape of solution‐grown organic crystals is presented. The shapes depend on properties of their internal crystal structure, as well as on the processing environment. The model developed here can account for the effects of solvent and may be extended to account for the influence of…
The binary compounds Ca 3 Al 2 O 6 (C 3 A), Ca 12 Al 14 O 33 (C 12 A 7 ), CaAl 2 O 4 (CA), CaAl 4 O 7 (CA 2 ), and CaAl 12 O 19 (CA 6 ) in the CaO‐Al 2 O 3 system have been synthesized as high‐compound‐purity ceramic powders by using the self‐propagating combustion synthesis (SPCS) method. Materials characterization o…
A nuclei size measurement technique is developed, based on a dispersion relation for propagation of sound waves through a bubbly liquid. This is used to relate the attenuation and phase velocity of a sound wave to the bubble population, leading to two integral equations. These equations are ill posed, and require spec…
Crystallography at sub-atomic resolution permits the observation and measurement of the non-spherical character of the electron density (parameterized as multipoles) and of the atomic charges. This fine description of the electron density can be extended to structures of lower resolution by applying the notion of tran…
The electrochemistry of (OEC)M where M = Mn, Co, Ni, or Cu and OEC is the trianion of 2,3,7,8,12,13,17,18-octaethylcorrole was investigated in dichloromethane, benzonitrile, or pyridine, and the oxidized compounds were characterized by UV−visible and/or ESR spectroscopy. The first two oxidations of the Co, Ni, and Cu…
Optimized syntheses of 5,15-diphenylporphyrin (DPP, 1) and its dipyrrolic precursors are described. A novel procedure for the synthesis of dipyrromethane (2), prepared by hydrodesulfurization of the corresponding di-2-pyrrolylthione (8), is presented, as well as an improved method to isolate large quantities of 5-phen…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSynthesis and Properties of the Longest Oligothiophenes: The Icosamer and HeptacosamerHidetaka Nakanishi, Naoto Sumi, Yoshio Aso, and Tetsuo OtsuboView Author Information Department of Applied Chemistry, Faculty of Engineering, Hiroshima University, Higashi-Hiroshima 7…
Analysis of data on the chemical composition of primary fluid inclusions (brine inclusions) in primary‐bedded halite from many evaporite formations of northern Pangea shows that during the Phanerozoic the chemical composition of marine brines was oscillating significantly between the Na‐K‐Mg‐Ca‐Cl type and the Na‐K‐Mg…
Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy were used to monitor the chemical composition of both ladder and cage hydrogen silsesquioxane (HSQ) as a function of bake and cure temperature in the range 150–425°C. Three distinct chemical compositions evolve as the temperature of the HSQ f…