Torpidity of freshwater ostracodes
The freshwater ostracode Candona rawsoni Tressler can survive in a torpid state. The time required for rejuvenation of the torpid ostracode depends upon the temperature of the water and the soil-moisture content.
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The crystal structure of potassium tungstate, K2WO4
K2WO4 crystallizes in space group C2/m with the axes a 12.39, b 6.105, c 7.560 A., and b 115.96 Deg. The 4 formula units per unit cell form layers parallel to (001), in which each WO4 tetrahedron is surrounded by an almost regular hexagon of K ions. The W-O bond length is 1.79 A., and the K-O and O-O distances are in…
Optical activity in a non-enantiomorphous crystal of class \overline{4}: CdGa2S4
Optical activity has been observed for the first time in a crystal of the non-enantiomorphous class \bar 4 CdGa2S4 is optically isotropic at 4872 Å (20°C) and this allows observation of optical rotation for propagation in directions away from the c axis. The magnitude of the optical rotatory power is 17.3 deg.mm−1 alo…
Herstellung von Formaldehyd aus Methanol in der BASF
Abstract In der BASF wird Formaldehyd durch oxidative Dehydrierung von Methanol an einem Silberkristall‐Katalysator bei 600 bis 700°C erzeugt. Die Temperatur wird durch Regelung der Luftzufuhr eingestellt und ist für den maximalen Umsatz ebenso wichtig wie die Korngröße des Katalysators. Es wird über die optimale Kata…
Some properties of strontium-doped lanthanum chromite
The properties of strontium-doped lanthanum chromite (La 0·84 Sr 0·16 CrO 3 ) are discussed, with particular attention to its application as an electrode material for MHD power generation. The influence of firing temperature on the ceramic properties and the behaviour of strontium carbonate as a sintering agent are de…
Refinement of the crystal structure of hardystonite, Ca2ZnSi2O7
The structure of hardystonite, Ca2ZnSi207, was refined to R = 5.30/0 from three-dimensional diffractometer data. The Zn-O and Si-O bonds are predominantly covalent, and the adjacent covalent sheets of [ZnSi207 ]4- are linked by Ca2+ ions, with the interlayer bonding being predominantly ionic in character.
Entwicklung neuer Zellen für elektro‐organische Synthesen
Abstract Organische Reaktionssysteme mit sehr kleiner elektrolytischer Leitfähigkeit können in neuartigen Elektrolysezellen, die nach dem „Prinzip des kleinsten Elektrodenabstands”︁ konstruiert worden sind, unter technisch interessanten Strom/Spannungs‐Bedingungen umgesetzt werden. Für diaphragmenlose Elektrolysen wer…
THE FEEDING OF CALANUS HELGOLANDICUS ON SYNCHRONOUSLY GROWING POPULATIONS OF THE MARINE DIATOM DITYLUM BRIGHTWELLII1
The filtering rates of Calanus helgolandicus were measured on synchronously growing populations of the diatom Ditylum brightwellii, by following changes in cell numbers and also by measuring the ingestion of 14 C labeled cells at selected intervals during 2‐day periods. The growth of the diatoms was adjusted to be one…
Organometallic pnicogen complexes. III. Preparation and structural characterization of the triarsenic-cobalt atom cluster system As3Co(CO)3. The first known X3-transition metal analog of group VA tetrahedral X4 molecules
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOrganometallic pnicogen complexes. III. Preparation and structural characterization of the triarsenic-cobalt atom cluster system As3Co(CO)3. The first known X3-transition metal analog of group VA tetrahedral X4 moleculesAlan S. Foust, Michael S. Foster, and Lawrence F. DahlC…
The crystal structure of fresnoite, Ba2(TiO)Si2O7
Auszug Die KristaIIstruktur von Fresnoit, Ba2(TiO)Si207, wurde aus der PattersonProjektion P(uv) bestimmt und nach der Methode der kleinsten Quadrate aus hkl-Interferenzen verfeinert. Eigentfunlich fur die Struktur ist die tetragonalpyramidale Umgebung des Titans. Schichten aus heterozyklischen Hinfgliedrigen Ringen,…
A MODIFIED RADIOGRAPHIC METHOD FOR MEASURING SKIN THICKNESS*
SUMMARY.— A modified radiographic method for measuring skin thickness has been described; it has given consistent results. Normal values have been ascertained for adult males and females. It is suggested that this method will be of value in studying conditions in which changes in skin thickness are to be expected.
Vaporization reactions of vanadium iodides and evidence for gaseous vanadium(IV) iodide
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTVaporization reactions of vanadium iodides and evidence for gaseous vanadium(IV) iodideK. O. Berry, R. R. Smardzewski, and R. E. McCarleyCite this: Inorg. Chem. 1969, 8, 9, 1994–1997Publication Date (Print):September 1, 1969Publication History Published online1 May 2002Publi…
Meaning and measurement of crystallinity in polymers: A Review
Abstract A useful concept in polymer science is the degree of crystallinity—the fraction of the polymer that exists in a relatively ordered state. Methods of determination of the degree of crystallinity using density, infrared, thermal, N.M.R. and X‐ray measurements are examined in light of modern notions of the struc…
Carbon Black Morphology: I. Particle Microstructure. II. Automated EM Analysis of Aggregate Size and Shape
Abstract Carbon black particle and aggregate microstructure were studied in detail by means of high resolution electron microscopy. Improved instrumental and environmental conditions have enabled more detailed studies on the size, orientation, and spacing of graphite layers in carbon black particles than heretofore po…
Early Hydration of Tricalcium Silicate: A Solid Reaction with Induction and Acceleration Periods
The hydration of tricalcium silicate was studied using a sample with a limited particle size distribution. The hydration reaction was analyzed as an example of general solid reactions having induction and acceleration periods. The first product, which may have a structure similar to the reactant, forms on the surfaces…
Yield criteria for plastic deformation on glassy high polymers in general stress fields
Yield criteria for plastic deformation on glassy high polymers induced by stress field, noting crazing and shear yielding dependence on first stress invariant
Phase Equilibria in the 1375°C Isotherm of the System Sr‐Ti‐O
The phase relations in a portion of the 1375° isotherm of the system Sr‐Ti‐O were determined. The following ternary phases were identified: Sr 2 TiO 4 , Sr 3 Ti 2 O 7 , Sr 4 Ti 3 O 10 , SrTiO 3 (ss), and what is believed to be SrTi 12 O 19 . The experimental techniques used in the determination of tha phase diagram ar…
Preparation of SmCo5 Permanent Magnets
The technology of making SmCo5 magnets with energy products of 20 × 106 GOe is described. This technology consists of the preparation of a powder by grinding, aligning the powder particles in a magnetic field, and cold pressing by applying a uniaxial deformation at 20 kbar. The permanent magnetic properties of the SmC…
Noise of ferromagnetic materials
The main types of noise in ferromagnetic materials are thermal or Nyquist noise, excess noise, and Barkhausen noise. They differ in magnitude as well as in the frequency dependence of their associated power spectra. The comparatively weak Nyquist noise is generated by the thermal energy of the conduction electrons and…
A Texture Profile of Foodstuffs Based upon Well‐defined Rheological Properties
SUMMARY: Many attributes contribute to texture, and panel tests should be so arranged that all these attributes are analyzed. The texture profile concept used by Szczesniak and her co‐workers is critically examined, and several modifications are proposed. The new scheme consists of primary, secondary and tertiary cate…