Carbones pobres. Problemas de los anillos. Conferencia pronunciada en el Instituto Técnico de la Construcción y del Cemento el día 30 de Abril de 1959
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Study of Ferroelectric Transitions of Solid-Solution Single Crystals of KNbO3-KTaO3
Methods of preparation and results of measurements of the dielectric constant of solid-solution single crystals of KNb${\mathrm{O}}_{3}$ and KTa${\mathrm{O}}_{3}$ are presented. Data are given for the composition range 0-80 mole percent KTa${\mathrm{O}}_{3}$ in the temperature interval -180\ifmmode^\circ\else\textdegr…
Thermally activated glide in face-centred cubic metals and its application to the theory of strain hardening
The influence of temperature and strain rate on the flow stress of polycrystalline aluminium, and single crystals of aluminium, copper and silver was studied. Tensile tests were carried out at various temperatures down to 1.7°K. The results indicate that the reversible change of flow stress (after correction for varia…
Structure and Adsorption Characteristics of Clean Surfaces of Germanium and Silicon
Diffraction patterns obtained from atomically clean germanium surfaces contained half-integral order beams in (110) azimuths for both (100) and (110) surfaces and in all azimuths for the (111) surface. These results are considered to be due to displacements of surface atoms from their normal bulk lattice positions in…
The atomization of hydrogen on tungsten
Abstract The dissociation of hydrogen at a tungsten filament has been studied in the temperature range 1200 to 1800°K and at pressures between 10-2 and 10-6 mm. The results obtained differ from those found in the literature and it is shown that this is because the surfaces employed by previous workers were contaminate…
Konstitution und Eigenschaften grenzflächenaktiver Stoffe I. Messungen an p‐n‐Alkyl‐Benzolsulfonaten
Abstract Es werden die textilchemischen Eigenschaften (Oberflächenspannung, Grenzflächenspannung, Netzvermögen, Emulgiervermögen, Schaumvermögen, Schaumbeständigkeit, Schmutztragevermögen, Waschvermögen) von p‐n‐Alkylbenzolsulfonaten in Abhängigkeit von der Länge ihrer Alkylkette untersucht. Grenzflächenaktivität im t…
Magnetic Oscillations of Ultrasonic Attenuation in a Copper Crystal at Low Temperatures
Received 24 February 1959DOI:https://doi.org/10.1103/PhysRevLett.2.250©1959 American Physical Society
Magnetic Form Factor of Cobalt
Received 26 February 1959DOI:https://doi.org/10.1103/PhysRevLett.2.254©1959 American Physical Society
On the crystal structure of kernite, Na2B4O7.4H2O
As part of a program to correlate X-ray and nuclear magnetic resonance data on the structures of oxy-anions, it was found necessary to re-investigate the crystal structure of kernite. The results of this study indicate that the originally proposed space group and structure
The Role of Oxidation-Reduction Systems in Vulcanization with Sulfur
Abstract 1. The reaction between trichlorothiophenol or dienols and SO2 brings about vulcanization of rubber without separation of elemental sulfur. The mechanism of the Peachey process of rubber vulcanization is examined on the basis of concepts of the role of intermediate products of the reaction—free radicals. 2. S…
The Vulcanization of Elastomers. 20. Sulfur Vulcanization Accelerated with Thiuram Compounds. I
Abstract The present paper deals with the results of an orientating, quantitative investigation of sulfur vulcanization accelerated by thiuram disulfide, with tetramethylthiuram disulfide as the representative example. It was found: In the sulfur cure of natural rubber with tetramethylthiuram disulfide at different TM…
On the Limiting Band Width of Interference Filters
The effects of variations of the thickness of the individual layers of an interference filter made with dielectric multilayers are examined, with respect both to the displacement of the pass band and to its width as affected by random fluctuations in these thicknesses. It is shown that the use of special multilayer st…
A hydrated barium-strontium pyrochlore in a biotite rock from Panda Hill, Tanganyika
Summary A hydrated barium-strontium pyrochlore with only subordinate amounts of Ca and Na has been found in a weathered biotite rock (contact-rock of a carbonatite) from Panda Hill, Tanganyika, as small euhedral yellowish-grey cubic crystals (showing the combination of the octahedron and the cube) in a rock containing…
Interferometrically Controlled Ruling of Ten-Inch Diffraction Gratings*
Seven plane gratings of high quality having ruled widths of more than 10 in. have now been produced on the M.I.T. servo controlled ruling engine, monitored with interference fringes. Resolving powers closely approaching the theoretical 900 000 in the 12th order green, and above 1 200 000 in the 26th order of 2537 A, h…
Refinement of the crystal structure of triclinic magnesium pyroborate
The t riclinic m odification of M gzBz0 5 wa s classifi ed as a m ember of a n isostr uct ural seri es which also includes MnzBz0 5, F ezBz0 5, and C02Bz0 5 Th e cr ystal st ru cture was re fi ned by the use of successive Fourier projectio ns and a least-squares refi nement program on a n electroni c compu ter. The st…
The effect of solvents on high molecular weight, stable acetal resins
Abstract High molecular weight polyoxymethylenes are not soluble at room temperature in any of the hundreds of solvents or solvent systems tested. However, solutions can be obtained at elevated temperatures with a wide variety of solvents. Phenolic compounds are the most effective at temperatures of 50–100°C. At the o…
Preparation and Properties of the Systems LanFexCr1−xO3 and LaFexCo1−xO3
ADVERTISEMENT RETURN TO ISSUEPREVArticlePreparation and Properties of the Systems LanFexCr1−xO3 and LaFexCo1−xO3Aaron Wold and William CroftCite this: J. Phys. Chem. 1959, 63, 3, 447–448Publication Date (Print):March 1, 1959Publication History Published online1 May 2002Published inissue 1 March 1959https://pubs.acs.or…
Die Reaktion Natriumborhydrid und Wasser
Abstract Die Geschwindigkeit der Wasserstoffentwicklung bei der Umsetzung von NaBH 4 mit H 2 O zeigt, daß das erste Wasserstoffatom des BH rascher reagiert als die übrigen drei. Der Schluß, daß sich ein primäres Reaktionsprodukt Na[H 3 BOH] bildet, konnte infrarotspektroskopisch bestätigt werden. Die weitere Hydrolyse…
Ceramic Properties of Europium Oxide
Europium oxide of 99.7% purity was compacted into small bars and pellets which were fired at temperatures from 1050° to 1700°C. for 2 to 120 hours in atmospheres that were oxidizing, mildly reducing (open furnace), or strongly reducing. It was found that (1) europium oxide compacts fired in oxygen for 2 hours at 1500°…