Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLiquid crystals. IV. Effects of terminal substituents on the nematic mesomorphism of p-phenylene dibenzoatesJ. P. Schroeder and D. W. BristolCite this: J. Org. Chem. 1973, 38, 18, 3160–3164Publication Date (Print):September 1, 1973Publication History Published online1 May 20…
Simple domain structures were observed in iron-silicon and cobalt-iron single crystals by three techniques using polarized neutrons. The first method involves scanning the specimen with a fine beam and measuring the depolarization suffered by the beam after transmission: it can only detect regions where the magnetizat…
Observation of the nucleation of surface disclination lines in nematics shows their correspondence to emergences of walls at the boundary of the sample; these lines have no core discontinuity and their width gives an estimate of the anchoring energy of the molecules to the surface.
Exposure trials in different water supplies have been carried out using copper tubes having various degrees of carbon contamination in the bore. On exposure to a water that supports pitting, the electrode potential of highly-contaminated tubes increases to a value greater than the critical potential for pitting. On th…
Abstract The infrared spectra of amorphous films of GaP, GaAs, GaSb, InAs, and Ge prepared by sputtering have been measured from 10 to 4000 cm −1 . The absorption spectra in the region of the “optical” phonon frequencies show similarities to the phonon density of states as deduced from Raman scattering but the absorpt…
An improved atmosphere sintering process was developed for fabricating large transparent PLZT plates for electrooptic applications. Cold‐pressed 9/85/35 PLZT slugs were sintered in O 2 in Pt crucibles for ∼45 min at 1180°C and were then heat‐treated in air for 60 h at 1200°C in Al 2 O 3 crucibles containing PbZrO 3 at…
Spectral transmission losses of unclad optical fibers drawn from various types of commercial vitreous silica and of soda-lime-silicate glasses were measured in the wavelength range between 0.5 and 1.12 µm. The automated technique employed was both convenient to use and sensitive enough to measure losses of 6 dB/km, i.…
The pressure (0-21 kbar) and temperature [(4-300)\ifmmode^\circ\else\textdegree\fi{}K] dependence of the static dielectric properties of rubidium dihydrogen phosphate were investigated. Among the important results of these measurements are the large decrease in the transition temperature with pressure leading to the e…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMetalloporphyrin redox chemistry. Effect of extraplanar ligands on the site of oxidation in ruthenium porphyrinsGilbert M. Brown, Frederick R. Hopf, John A. Ferguson, Thomas J. Meyer, and David G. WhittenCite this: J. Am. Chem. Soc. 1973, 95, 18, 5939–5942Publication Date (P…
The short-range-order diffuse scattering from disordered Cu-Pd and Cu-Pt alloys has been studied by electron diffraction using thin foils prepared from bulk specimens. Twofold and fourfold splittings of diffuse scattering are observed at 100, 110 and equivalent positions in the composition ranges from about 13 to 60 a…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon catalyzed racemization of 1,1'-binaphthylRichard E. Pincock, Wynona M. Johnson, Keith R. Wilson, and John. Haywood-FarmerCite this: J. Am. Chem. Soc. 1973, 95, 19, 6477–6478Publication Date (Print):September 1, 1973Publication History Published online1 May 2002Publish…
Some recent developments and problems in the field of microwave ferrites will be reviewed. Properties which are considered interesting will be presented and discussed for materials with new chemical formulas in the spinel and garnet diagrams. Then we shall give an example of the physico-chemical problems brought up by…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTVolume Changes of Mixing and Excess Coefficients of Thermal Expansion for Solutions of Polymethylene in n-DecaneRobert A. Orwoll and John A. SmallCite this: Macromolecules 1973, 6, 5, 755–757Publication Date (Print):September 1, 1973Publication History Published online1 May…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrical conductivity of nickel oxide-magnesium oxide single crystalsJae Shi Choi, Hoo Young Lee, and Keu Hong KimCite this: J. Phys. Chem. 1973, 77, 20, 2430–2433Publication Date (Print):September 1, 1973Publication History Published online1 May 2002Published inissue 1 Se…
Abstract The influence of carbon black type on the dynamic properties of natural rubber is examined for nine carbon blacks, encompassing a wide range of structure and surface area. The dynamic properties are measured at 23° C and 100° C, over a 2 decade range of log frequency, and over a range of 1 to 25 per cent dyna…
The electrffication of growing ice crystals during condensation and evaporation was studied in ionized air of various small-ion concentrations. It was found that ice crystals were electrified positively during condensation and negatively during evaporation. Because of the difficulty of controlling humidity during evap…
In isopentane at 25° a 0.1 M solution of nortropane N-oxyl (1) contains 0.0618 M of the free radical and a 0.1 M solution of 9-azabicyclo[3.3.1]nonane N-oxyl (4) contains 0.0854 M of radical. Measurements at lower temperatures show that the thermodynamic parameters for the dimerization of these two nitroxides are very…
Abstract Mineralogical analyses of clays from two Alotenango soil horizons were made by utilizing transmission and scanning electron microscopy, infrared, X‐ray diffraction, and chemical methods. This report of spheroidal halloysite demonstrates the presence of this mineral form in an area of important volcanic ash‐de…
Available data on the range of electrons with energies less than 600 keV in air and other light materials are reviewed critically. It is shown that the practical (extrapolated) range R p (in g cm -2 ) can be related to the energy E(in keV) by using the following expressions: x=lgE;y=lgR p y=-6.160+2.585x-0.220x 2 (E>1…
Three previously considered relations for the dependence of the activation energy $\ensuremath{\Delta}$ on magnetic order, in "activated" EuO samples, are tested. These relations are: (i) $\ensuremath{\Delta}={\ensuremath{\Delta}}_{0}\ensuremath{-}(1+\ensuremath{\alpha}){\ensuremath{\delta}}_{R}$, where ${\ensuremath{…