Materials Literature
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The use of nitroxide-mediated ‘living’ free radical procedures as a synthetic tool for obtaining polymers with well defined and complex macromolecular architectures is discussed. The preparation of linear homo, block, and random co-polymers by ‘living’ free radical procedures have been demonstrated for a variety of sy…
Three bimetallic assemblies, PPh 4 [Ni(pn) 2 ][M(CN) 6 ]·H 2 O (M = Fe ( 1 ), Cr ( 2 ), Co ( 3 ); pn = rac- 1,2-diaminopropane), have been prepared and structurally and magnetically characterized. Assembly 2 crystallizes in the monoclinic system of the space group P 2/ c (No. 13) with a = 12.927(2) Å, b = 8.454(2) Å,…
Nanocomposites, consisting of a hard magnetic rare earth–transition metal phase exchange coupled to soft magnetic α-Fe or α-(Fe,Co), exhibit enhancement of the remanent magnetization due to exchange coupling across interfaces between grains. Modeling studies have shown that crystallite sizes of less than 20 nm are gen…
Abstract Fusion-bonded epoxy coating is extensively used to enhance the corrosion resistance of reinforcing steel. The bond strength between these bars and the concrete is expected to be less than that of the uncoated bars and it may be further impaired due to prolonged exposure to thermal variations. This investigati…
The die upset of hot pressed NdFeB magnets modifies the equiaxed grains to platelets, develops the c-axis texture parallel to press direction, and improves magnetic properties. The mechanism of c-axis alignment has been suggested to be a combination of grain-boundary sliding and anisotropic grain growth in a direction…
An analysis is given of recent electron paramagnetic resonance (EPR) experiments in manganite materials displaying colossal magnetoresistance behavior. These experiments have established that in highly homogeneous samples characterized by a single resonance line, the EPR linewidths above the critical region associated…
Oxomolybdenum phthalocyanine (MoOPc) and tin phthalocyanine (SnPc), which both have a pyramidal molecular shape, were deposited onto sapphire by organic molecular beam deposition. The crystalline phase of these films was determined to be triclinic by X-ray diffraction and absorption spectra with reference to previousl…
Electrical charging of insulating samples during XPS is of direct concern for referencing the binding energy scale. Results are presented on charging of composite insulating samples that consist of an organic overlayer of polystyrene (PS) or polydimethylsiloxane (PDMS) deposited on NaCl particles. The samples were ana…
A formulation consisting of 300ppm sodium salt of phenyl phosphonic acid (PPA) and 50ppm Zn 2+ is 95 per cent efficient in inhibiting the corrosion of mild steel in a neutral aqueous environment containing 60ppm chloride. A higher concentration of Zn 2+ lowered inhibition efficiency. This is due to the formation of an…
The temperature dependence of the magnetic moment measured by a superconducting quantum interference device magnetometer in ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Na}}_{x}{\mathrm{MnO}}_{3}$ $(x=0.1,\phantom{\rule{0ex}{0ex}}0.15,\phantom{\rule{0ex}{0ex}}0.2)$ ferromagnetic perovskites is compared with the temperatu…
The objective of this study was to provide a contribution to a database on the heavy metal status of tropical soils. We assessed the partitioning of Al, Cd, Cu, Fe, Mn, Pb, and Zn in A horizons of Costa Rican soils used for coffee cultivation. These soils are subject to heavy metal inputs as a result of the regular us…
Experiments of quasi static hydrostatic and uniaxial strain compression, and of shock wave propagation performed on 9% and 17% porous aluminum are presented, analyzed, and compared. Quasi static experiments show the influence of coupling between void collapse and plasticity induced in the matrix on the material macros…
After the logging and fires of the late nineteenth century, the upland stump prairies of Michigan's Upper Peninsula, which had previously supported dense forest, have remained deforested. Surrounding areas in similar geomorphologic settings have returned to forest. We investigated whether soil B horizon properties hav…
We measure the refractive index and the absorption of porous silicon layers in the millimetric and submillimetric wavelength range using the terahertz time-domain spectroscopy technique. For the studied range of porosity (55%–76%), the refractive index of porous silicon is rather well described by mixture theories, in…
Porous silicon is a unique example of a porous material exhibiting the properties of a nearly perfect single crystal. High resolution x-ray diffraction has been used to investigate thin p− and p+ type porous silicon layers in the 100–1000-nm-thickness range. Since several thickness fringes are observed, the comparison…
The finite-temperature magnetism of rare-earth transition-metal intermetallics is investigated by extending the n-component vector spin model to two-sublattice magnets. Mean-field analysis shows that the influence of the rare-earth anisotropy on the mean-field Curie temperature is much smaller than expected from the l…
In this paper, the deterministic prediction of damage via damage function analysis (DFA), which provides a robust technology for estimating the damage function at future times, is described. General analytical expressions for calculating the damage functions that can be used with arbitrary dependencies of pit nucleati…
An X-ray diffraction peak-decomposition procedure using a Pearson type VII function is described and implemented in a Microsoft Excel spreadsheet to aid a beginning student of X-ray diffraction.
All-polymer electrostrictive soft films were developed for the first time by depositing conductive polymer (polypyrrole) directly on both sides of solution-cast electrostrictive polyurethane elastomer films. The final composite films are flexible with strong adhesion between the polyurethane film and the conductive po…
Oxygen bubbles evolved in potassium hydroxide solution during electrolysis have been reported to be mutually attractive. A model based on thermocapillary flow and migration can explain the effect. A temperature gradient directed perpendicular to the electrode's surface into the liquid phase arises during electrolysis…