SOME NEW DIATOMS FROM THE JOG‐FALLS (MYSORE STATE)
SYNOPSIS Some new and interesting Diatoms from the Jog‐Falls are described and illustrated. One species of Achnanthes is re‐interpreted and five varieties are described as new to science.
Materials Literature
文献浏览
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
The Adsorption of Normal Olefins on Silica-Alumina Catalysts
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Adsorption of Normal Olefins on Silica-Alumina CatalystsD. S. MacIver, R. C. Zabor, and P. H. EmmettCite this: J. Phys. Chem. 1959, 63, 4, 484–489Publication Date (Print):April 1, 1959Publication History Published online1 May 2002Published inissue 1 April 1959https://pub…
Stress relaxation studies of scission in rubber vulcanizates
Abstract The method of stress relaxation has been used to study oxidative scission in crosslinked rubbers of five different chain structures. Each chain structure was crosslinked by sulfur and by a nonsulfur‐containing agent. Among the sulfur‐cured vuleanizates the rate of scission varied very significantly with chain…
High Power Effects in Ferrite Slabs at X Band
Measurements are reported of the attenuation at 9360 mc of full height ferrite slabs in wave guide as a function of ferrite length up to input powers of 120 kw. The ferrites were transversely magnetized to the field for subsidiary resonance. Above the critical power level for the subsidiary resonance the output power…
Structural and Magnetic Properties of Mn-Co-C Alloys
Mn X Co (80− X ) C 20 alloys were studied for magnetic properties, crystal structure, and metallographic appearance. A superlattice having the stoichiometric composition Mn2Co2C was found to be markedly magnetic. The structure of this alloy is pseudo-f.c.c. with the C atom in the central 121212 position, the Mn atoms…
cis‐trans Isomerization in polyisoprenes. Part I. Improvement of the low temperature properties of natural rubber by reaction with thiol acids in solution and in latex
Abstract Natural rubber is converted by reaction with a small amount of a thiol acid into a modified rubber which crystallizes at low temperatures much more slowly than the original rubber. This change in rate of crystallization is probably due to the conversion of some of the cis double bonds in natural rubber into t…
Swelling and elasticity of irradiated polydimethylsiloxanes
Abstract The G value for crosslinking of polydimethylsiloxanes by high energy electrons has been redetermined using cryoscopc methods and checked by quantitative determinations of the amounts of gases evolved. The value found, G = 2.5 ± 0.4, is significantly different from that reported previously. The swelling of hig…
Properties of Permalloy Films Having a Magnetoelastic Easy Axis Normal to the Film
Internal isotropic strain in Permalloy films having a negative magnetoelastic constant creates a magnetoelastic easy axis normal to the film. Below a critical thickness tc such films are single domain in the film plane and have a square B-H loop; above this thickness new configurations are established, characterized b…
On the Magnetic Anisotropy in Manganese-Iron Spinels
The magnetic anisotropy energy is measured as a function of temperature in eleven single crystal compositions corresponding to MnxFe3−xO4, where x is varied from 0.00 to 1.90. The interesting features observed are as follows. (1) Small manganese concentrations in magnetite (x=0) are shown to decrease the temperature o…
α-Ferric Oxide: Low Temperature Heat Capacity and Thermodynamic Functions
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTα-Ferric Oxide: Low Temperature Heat Capacity and Thermodynamic FunctionsFredrik Grønvold and Edgar F. WestrumCite this: J. Am. Chem. Soc. 1959, 81, 8, 1780–1783Publication Date (Print):April 1, 1959Publication History Published online1 May 2002Published inissue 1 April 1959…
Comments on intrinsic viscosity–weight‐average molecular weight relationships for polyethylene
Abstract Relationships, as reported in the literature, between intrinsic viscosity and weight‐average molecular weight for high‐density polyethylene are in poor agreement. Experimental work in this laboratory, aimed at resolving similarly conflicting data, suggests that likely causes for these discrepancies are: polyd…
Saturation Magnetization and Curie Points in Dilute Alloys of Iron
A report of the initial stages of an investigation of the intrinsic properties of dilute alloys of iron is given. Methods of determining spontaneous magnetization and Curie temperatures with precision of one part in 30 000 are discussed. The results for Fe-Ti alloys are singled out for attention. The decrease of spont…
Ferromagnetic Resonance of Iron Whisker Crystals
The ferromagnetic resonance absorption characteristics of iron single crystals (grown by K. W. DeBlois of this laboratory) have been examined between −196°C and 850°C. The crystals are of filamentary growth habit and are commonly known as whiskers. The selected crystals have 〈100〉 growth directions, and their square c…
THE SURFACE ENERGY OF TOBERMORITE
The total surface energy (or surface enthalpy) of a calcium silicate hydrate, tobermorite, having the composition of Ca 3 Si 2 O 7 •2H 2 O, was determined at 23.5 °C. The tobermorite was obtained from the room-temperature hydration of tricalcium silicate, Ca 3 SiO 5 , or β-dicalcium silicate, β-Ca 2 SiO 4 , two of the…
Promotion of Attack on Glass and Silica by Citrate and Other Anions in Neutral Solution
The observation that essentially neutral solutions of sodium citrate attacked sulfur‐treated soda‐lime glass bottles of generally high chemical resistance much more than was anticipated led to a general investigation. It has been found that neutral solutions of sodium citrate attack silicate glasses and silica with a…
Elastic Moduli of Single-Crystal Gallium Arsenide
Velocities of propagation of high-frequency ultrasonic waves and the adiabatic elastic moduli for single-crystal gallium arsenide are reported. Data at 25°C were obtained in the range of 20–180 mc/sec. The elastic moduli based on a density of 5.307 g/cm3 in units of 1012 dynes/cm2 are c11 = 1.188±0.14%; c12 = 0.538±0.…
THE THERMAL EXPANSION OF CUBIC BARIUM TITANATE (BaTiO3) FROM 350 °C TO 1050 °C
The lattice spacing of cubic barium titanate (BaTiO 3 ) has been measured as a function of temperature by means of a Unicam X-ray camera. The relation between a 0 (in Å) and t between 350 °C and 1050 °C is:[Formula: see text]The maximum systematic error in a 0 is 0.0005 Å. The linear expansion coefficient varies in an…
Saturation Magnetizations of Iron Carbides1
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSaturation Magnetizations of Iron Carbides1L. J. E. Hofer and Ernst M. CohnCite this: J. Am. Chem. Soc. 1959, 81, 7, 1576–1582Publication Date (Print):April 1, 1959Publication History Published online1 May 2002Published inissue 1 April 1959https://pubs.acs.org/doi/10.1021/ja…
Helical dislocations in quenched aluminium-4% copper alloys
Experiments by transmission electron microscopy on thin foils of polycrystalline A1-4 % Cu alloys, quenched from various temperatures have revealed helical dislocation lines which are thought to be produced by condensation of vacancies on dislocations of predominantly screw character. The axes of the helices are paral…
Thermal degradation of polyethylene oxide and polypropylene oxide
Abstract Polyethylene oxide and atactic and isotactic polypropylene oxides were pyrolyzed in a vacuum in the temperature range 265 to 363°C. One phase of the investigation consisted in fractionating the products of degradation and analyzing the fractions qualitatively and quantitatively. Another phase consisted in mea…