The corrosion and preservation of iron antiques
The chemistry and prevention of the corrosion of iron.
Materials Literature
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CaO segregation in MnZn ferrite
The reaction between CaO and MnZn ferrite is investigated by in-situ heating in a scanning electron microscope. The existence of an intermediate phase and a eutectic liquid at about 1300°C is observed. The CaO segregation behavior of low loss MnZn ferrite is studied by in-situ heating in transmission electron microsco…
Enhancement in oscillator strength of color centers in electrochromic thin films deposited from WO2 powder
Color centers in amorphous films evaporated from WO2 powder and WO3 powder were investigated. It was found that the device using ‘‘WO2’’ film, which has a WO3-like structure, exhibits a high-speed response and a high optical density, which is attributed to the enhancement in oscillator strength of the color centers in…
Soft magnetic ferrites and applications in telecommunication and power converters
Ferrite cores are mainly used in filters and broad-band transformers for telecommunication and increasingly in power converters. The requirements for the material properties are different for different applications and accordingly different compositions of the ferrite materials are used. Commercially available ferrite…
An unusual fatigue crack‐tip plastic zone: The epsilon plastic zone of polycarbonate
Abstract Polycarbonate exhibits an extraordinary crack‐tip plastic zone under certain fatigue loading conditions. During discontinuous growth (multiple load cycles per crack jump), the plastic zone consists of a leading craze and a pair of sharply delineated shear bands, which together look like the Greek letter epsil…
Analysis of a hysteresis motor with overexcitation
The performance of a hysteresis motor can be improved greatly if it is overexcited for a short period when running at synchronous speed. The change in the magnetic state of the rotor hysteresis material when the stator voltage is raised and then reduced to the original value, is described in detail. Based on this, a m…
Near-zero magnetostrictive metallic glasses with very high saturation induction
The soft magnetic properties of a series of metallic glasses in the Co–Fe–Ni–Mn–B–Si system are described. These glasses have very low values for saturation magnetostriction (+5 to −1 ppm) and some of the highest values for saturation induction (1.1 to 1.3 T) reported for such glasses. Most importantly, the Curie temp…
Exchange interactions in heterodinuclear complexes with one ion possessing an orbitally degenerate ground state. Nickel(II)-cobalt(II) pairs in diaqua(1,4-dihydrazinophthalazine)nickel(II) chloride hydrate
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTExchange interactions in heterodinuclear complexes with one ion possessing an orbitally degenerate ground state. Nickel(II)-cobalt(II) pairs in diaqua(1,4-dihydrazinophthalazine)nickel(II) chloride hydrateLucia Banci, Alessandro Bencini, Cristiano Benelli, and Dante Gattesch…
Autohesion of Elastomers
Abstract Autohesion is a particular form of adhesion. It occurs when two surfaces of the same elastomer are pressed together. The increase of the autohesive strength, with the increase of contact time, is caused by interdiffusion of mobile macro-molecule chain ends across the boundary face. After a certain time of con…
Adsorption of β‐carotene: II. On cation exchanged bleaching clays
Abstract X‐ray diffraction patterns of a number of commercial bleaching earths indicate that they consist mainly of montmorillonite mixed with smaller amount of kaolinites as well as mica, quartz and cristobalite. The active sites in these earths for the adsorption of β‐carotene are identified through ion exchange and…
Brillouin Scattering Study of NaNO2 in the Vicinity of Its Phase Transition Temperatures
The ultrasonic dispersion in the incommensurate (antiferroelectric) phase of NaNO 2 has been examined by a Brillouin scattering experiment with a special emphasis on the temperature regulation near its phase transition temperatures. A slight anomaly of the frequency shift ( Δ ν) of the longitudinal mode was observed o…
Processable heat‐resistant polymers. VII. Synthesis and characterization of polyamideimide from N‐(p‐carboxyphenyl) trimellitimide and p,p′‐di(aminocyclohexyl) methane
Abstract Polyamideimides were prepared either directly from N‐(p ‐carboxyphenyl)trimellitimide and p , p ′‐di(aminocyclohexy)methane (PACM‐20) by low temperature (<5°C) polycondensation in presence of thionyl chloride or by reacting the diacid chloride of N ‐( p ‐carboxyphenyl)trimellitimide and PACM‐20 at 30–70°C.…
The Photoreduction of Viologen Dyes with Palladium meso-Tetraphenylporphyrintrisulfonate
Abstract Pd–TPPS3 was found to be an effective photosensitizer for the photoreduction of viologen dyes, such as methyl, ethyl, propyl, butyl, and heptyl viologens. The order of the reduction rate was as follows: Ethyl&gt;Butyl&gt;Methyl&gt;Propyl&gt;Heptyl. The respective complex formation was observed…
Mineralogy and Iron Characterization of Plinthitic Soils on Alluvial Landforms in Venezuela
Abstract The iron oxides and clay mineralogy were characterized for several soils of Venezuela which contain plinthite and pseudo‐plinthite. Molar ratios of SiO 2 /Al 2 O 3 (Ki ratios) of the plinthite and pseudo‐plinthite zones range from below 2 to above 4 suggesting a wide range in mineral composition. Cation excha…
Magnetic properties of Gd(FeyAl1-y)3and (GdxY1-x)Fe3compounds
Reports the results of magnetic measurements performed on Gd(Fe y Al 1-y ) 3 and (Gd x Y 1-x )Fe 3 compounds over the temperature range 4.2-1300K. For x and y>or=0.2 the compounds are ferrimagnetically ordered. In this case, the reciprocal susceptibility chi -1 follows a Neel-type hyperbolic law. The YFe 3 compound is…
Concerning the discommensurate character of NbSe3
Recent data have been used to develop the strongly discommensurate model for NbSe 3 that was introduced in 1978/9. The tightly defined q vectors found for both CDWS are accounted for by a plausible internal structure for the discommensurations. These, because of their relatively weak impurity pinning, seem to form a v…
Temperature dependence of the configurational entropy of undercooled melts and the nature of glass transition
The configurational entropy as well as other related thermodynamic properties of a (poly)disperse glass-forming polymer melt have been calculated exactly in terms of a lattice-hole model and within the framework of the mean field approximation (MFA). One of the main results of the calculation, in which the average “st…
Response curves for the thermoluminescence induced by alpha particles: interpretation using track structure theory
A three dimensional model is developed to describe the linear-sublinear behaviour of the thermoluminescence (TL) dose response curve induced by heavy charged particles specifically 'low energy' ( approximately 1 MeV u -1 ) alpha particles. Supralinearity induced by alpha particles is shown to be suppressed or non-exis…
Ground State of a Wigner Crystal in a Magnetic Field I. Cubic Structure
The ground-state energies in magnetic fields are calculated for the electron crystals with the bcc and fcc structures at low electronic densities. The energies are obtained as sums of the static energy and the zero-point vibration energy in the harmonic approximation. The zero-point energy of the fcc becomes lower tha…
Universal law for the rotational viscosity of nematic liquid crystals
The rotational viscosity ${\ensuremath{\gamma}}_{1}(T)$ of a nematic is of dominant importance for wide operating temperature display applications. In this paper we show that ${\ensuremath{\gamma}}_{1}(T)$ is, except for a small prefactor variation, a universal function of $T\ensuremath{-}{T}_{g}$ where ${T}_{g}$ is t…