Materials Literature
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Corrosion products initially formed in a wet H2S environment with varying oxygen concentrations were consistently found to be FeS (Mackinawite). After exposure to the atmosphere, these products oxidized to FeO(OH) (Lepidocrocite) and elemental sulfur. Upon further exposure, the FeO(OH) transformed to Fe3O4 (magnetite)…
Abstract The mechanical degradation of pulp cellulose fiber was studied at ambient temperature and at 77°K. ESR findings reveal that mechanical degradation occurs via free‐radical routes. Three types of mechanoradicals contributing singlet, doublet, and triplet ESR signals are identified. The singlet signals are deriv…
A new method for separation and quantitative determination of arbutin, methylarbutin, hydroquinone and hydroquinonemonomethylether in Arctostaphylos alpina, Arctostaphylos Uva-ursi, Bergenia crassifolia, Calluna vulgaris, and Vaccinium Vitis-idaea with HPLC was elaborated. A reversed–phase system with a μ– Bondapak C…
The crevice corrosion of iron in neutral solutions is promoted by chloride ions and inhibited by chromate. For any given concentration of chloride in the range investigated , the crevice corrosion of iron can be inhibited by using a sufficient amount of chromate, with the concentration of chromate required decreasing…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReaction of molecular oxygen with copper(I). Structural characterization of dimeric .mu.-carbonato and tetrameric .mu.-hydroxo complexes resulting from the autoxidation of a copper(I) carbonyl complexRobert R. Gagne, Robert S. Gall, George C. Lisensky, Richard E. Marsh, and…
The hyperfine fields and Curie temperatures of the Heusler alloys (X2MnZ) are analyzed and show that: (1) The s-conduction electron polarization (sCEP) is essentially independent of the X or Z element. It is also independent of the difference in the number of valence electrons between a Cd impurity, at a Z site and th…
Magnetostriction λs has been measured at room temperature and 80 K in Fe100−xBx (14?x?23 at.%) glasses using metal foil strain gauges. Several compositions were also studied as a function of temperature from 80 K to T ? TC. The single-ion uniaxial temperature dependence confirmed previously for Fe80B20 glass is also o…
The effect of a sinusoidal axisymmetric shape imperfection on the plastic buckling of a long cylindrical shell under axial compression is studied. The load at which nonaxisymmetric bifurcation from the axisymmetric state occurs is determined as a function of the imperfection amplitude for relatively thin shells. Imper…
Grain-oriented samples of highly magnetostrictive rare earth–iron compounds have been prepared. These samples possess lower inhomogeneous strains than found in the random polycrystalline RFe2 compounds, resulting in much higher values of relative permeability (μr) and magnetomechanical coupling (k33). A partially orie…
This paper reviews the theory of unwinding from yarn packages and discusses the effect of air drag and gravity on the balloon parameters.
The effects of scratching perpendicular to the [001] direction on losses were studied as a function of the tilt angle of the [001] out of the crystal surface β both with and without tensile stress in 3-percent Si-Fe single crystals. The reduction of the total losses by scratching becomes larger with decreasing β. The…
Polarized neutron experiments on a single crystal of Y6Mn23 give evidence for a ferrimagnetic arrangement of Mn atoms. The value of the Mn moment depends on the crystallographic site. Magnetization measurements at low temperature suggest non-collinear magnetic structures for single crystals of Gd6Mn23, Dy6Mn23, and Er…
A new lignan, (+)-nortrachelogenin (I), and a known compound, daphnoretin were isolated from Wikstroemia indica C.A. Meyer (Thymelaeaceae). The structure of (+)-nortrachelogenin was established as 8(R)8'-4,4',8'-trihydroxy-3,3'-dimethoxylignan-olid, (9,9') on the basis of spectroscopic evidence and comparison with its…
A model is presented to explain the strength‐grain size behavior of ceramics exhibiting duplex microstructures and of ceramics with uniform coarse‐grained microstructures. Using an energy balance analysis, the model shows that in most ceramics an hitiipl flaw contained within a single large grain will initially propag…
The influence of microstructure on the intergranular corrosion and pitting corrosion resistance of 308 stainless steel was studied as a function of the volume percent of ferrite which was varied from 0 to 15%. The all‐austenitic matrix was highly susceptible to intergranular corrosion resulting from the formation of n…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and reactions of (4,5-dicarbomethoxy-1,3-dithiolyl)tributylphosphonium tetrafluoroborateMasaru Sato, Nina C. Gonnella, and Michael P. CavaCite this: J. Org. Chem. 1979, 44, 6, 930–934Publication Date (Print):March 1, 1979Publication History Published online1 May 20…
The defect structure of Li3N (space group P6/mmm, a ≃ 3.65, c ≃ 3.88 Å) has been investigated with data sets measured at seven temperatures in the range 153 to 678 K. The data have been used for normal and high-order refinements and for the calculation of the corresponding difference electron densities. The final Rw r…
Results of polarized neutron experiments on SmCo5 at 4.2 K and 300 K are reported. To overcome the problem of the huge Sm absorption the measurements were made at short wavelengths, but on a single crystal containing natural samarium. The Co moments are close to those found in YCo5. The Sm form factor is very differen…
We present an ultrahigh vacuum study of the carbon monoxide–silver system using Raman scattering. Silver films deposited in UHV on a room-temperature substrate cooled close to 78 K and exposed to saturation doses of CO show Raman lines at 1995 and 2070 cm−1. These disappear upon warming to room temperture. Films fresh…
The G-200 glass of the glass-ionomer cement has two phases: a continuous calcium aluminosilicate matrix and partly crystalline calcium fluoride-rich droplets, the nature of which depend on the thermal history of the glass. The setting process of the cement takes place when the glass is mixed with poly(acrylic acid). I…