Diatom flora of Southern Africa
The diatoms flora of Southern Africa No.3. Shcoeman, FR and Archibal, REM. CSIR Special report WAT 50, September 1977
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Effects of para substituent and metal ion on rates of phenyl ring rotation in ruthenium, indium, and titanium complexes of para-substituted tetraphenylporphyrins
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffects of para substituent and metal ion on rates of phenyl ring rotation in ruthenium, indium, and titanium complexes of para-substituted tetraphenylporphyrinsS. S. Eaton and G. R. EatonCite this: J. Am. Chem. Soc. 1977, 99, 20, 6594–6599Publication Date (Print):September…
Alteration of the Bacillus subtilis glutamine synthetase results in overproduction of the enzyme
A mutational leading to glutamine auxotrophy was located near a 5-fluorouracil resistance marker in the citB-thyA region of the Bacillus subtilis chromosome. This mutation resulted in a glutamine synthetase with altered kinetic and feedback properties. The specific activity of manganese-stimulated glutamine synthetase…
Synthesis of new 14-, 15- and 16-membered crown compounds containing oxygen and nitrogen heteroatoms
Facile syntheses for new 14-, 15-, and 16-membered crown compounds derived from salicylaldehyde and 5-chlorosalicylaldehyde are reported. The new compounds contain both oxygen and nitrogen heteroatoms.
Reactions of Aluminosilicates, Aluminum Hydrous Oxides, and Aluminum Oxide with o‐Phosphate: The Formation of X‐ray Amorphous Analogs of Variscite and Montebrasite
Abstract The formation of X‐ray amorphous analogs of variscite and Namontebrasite was demonstrated to occur when Al 2 O 3 · n H 2 O, synthetic allophanes, and allophanic soils were reacted with sodium o ‐phosphates, Na 3‐ A H A PO 4 , of varying acidity A . The formation of the two amorphous Al‐phosphates, Al(OH) 2 H…
Effect of washing procedures on trace-element content of hair.
A pooled sample of hair was divided and portions prepared for analysis by three washing procedures, to evaluate the effect of washing procedure on the subsequent trace-element (Zn, Cu, Mg) content. The methods selected were a detergent wash, a hexane-ethanol wash, and an acetone-ether-detergent wash. For all elements,…
Estimation of the degree of crystallinity in digoxin by X-ray and infrared methods
The X-ray procedure for estimation of the degree of crystallinity in digoxin is based upon measurement of the total X-ray scattering and the scattering from crystalline regions of the drug. The infrared procedures are based upon measurement of the peak height ratios, 1775/1618 and 3095/1618 cm-1. Correlation between r…
Magnetic exchange interactions in transition metal dimers. 11. Structural and magnetic characterization of [Ni2(tren)2(C6O4Cl2)](BPh4)2 and [Cu2(Me5dien)2(C6O4Cl2)](BPh4)2. Magnetic exchange interactions propagated by the dianions of 2,5-dihydroxy-1,4-benzoquinones
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMagnetic exchange interactions in transition metal dimers. 11. Structural and magnetic characterization of [Ni2(tren)2(C6O4Cl2)](BPh4)2 and [Cu2(Me5dien)2(C6O4Cl2)](BPh4)2. Magnetic exchange interactions propagated by the dianions of 2,5-dihydroxy-1,4-benzoquinonesCortlandt…
Defect Structure of α‐Al 2 O 3 Doped with Titanium
Titanium‐doped α‐Al 2 O 3 exhibits a high‐temperature conductivity which is ionic at high oxygen pressures and electronic at low oxygen pressures. Both are isotropic. The temperature dependence of conductivity under conditions where equilibrium with the atmosphere is not maintained indicates both the position of the e…
Details of the structure of bound excitons and bound multiexciton complexes in Si
The high resolution photoluminescence spectra reported here reveal new details of the structure of both bound excitons and bound multiexciton complexes in donor and acceptor doped Si. The bound exciton and bound multiexciton complexes in Si containing P impurities are found to have excited states, as was postulated in…
Anion‐Aluminum Hydroxide Gel Interactions
Abstract The interaction of the nitrate, sulfate, and carbonate anion with aluminum hydroxide gel was studied by infrared spectroscopy. A lowering in the anion symmetry due to the interaction with the aluminum hydroxide surface was observed. Evidence suggests that the nitrate anion interaction is outside of the coordi…
The Role of Morphology and Structure of Carbon Blacks in the Electrical Conductance of Vulcanizates
Abstract The low electrical resistance of vulcanizates loaded with conductive carbon blacks in a given particle size range is cause by the low density of the particles, high structure, or both. In addition, the smaller the particle size of the black, the lower the resistivity. The same factors also cause high modulus…
Monomeric and polymeric azoinitiators
Abstract The reaction of ethylene glycol, 1,4‐butanediol, 1,6‐hexanediol, 3,6‐dioxaoctane‐1,8‐diol (triethylene glycol), poly(ethylene oxide)s with M̄ n = 300,1000 and 3000, or with poly(propylene oxide)s with M̄ n = 425 and 2000 in excess with AIBN leads to the corresponding bis(hydroxyalkyl) 2,2′‐azodiisobutyrates (…
Double Layer Capacitance and Charging Rate of Ultramicroporous Carbon Electrodes
Adsorption of ions from aqueous solutions into pores, as narrow as 3.7Å was observed, using linear sweep cyclic voltametry. The conductivity of the solution in pores of less than 7Å diameter is several orders of magnitude lower than that of a free solution in contact with the carbon electrode. It seems negligibly slow…
Neutron Scattering Studies on the Molecular Trajectory in Polyethylene Crystallized from Solution and Melt
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNeutron Scattering Studies on the Molecular Trajectory in Polyethylene Crystallized from Solution and MeltD. M. Sadler and A. KellerCite this: Macromolecules 1977, 10, 5, 1128–1140Publication Date (Print):September 1, 1977Publication History Published online1 May 2002Publish…
Strength Degradation of Glass Resulting from Impact with Spheres
The nature and extent of degradation incurred by glass surfaces impacted with spheres of steel and tungsten carbide were studied. The residual strength after impact depends on the velocity, radius, and density of the projectile; on the toughness and (indirectly) the hardness of the target; and, to a lesser degree, on…
Crystallinity, Supermolecular Structure, and Thermodynamic Properties of Linear Polyethylene Fractions
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystallinity, Supermolecular Structure, and Thermodynamic Properties of Linear Polyethylene FractionsJ. Maxfield and L. MandelkernCite this: Macromolecules 1977, 10, 5, 1141–1153Publication Date (Print):September 1, 1977Publication History Published online1 May 2002Publishe…
Molecular structure of the gaseous metal carbonyl hydrides of manganese, iron, and cobalt
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMolecular structure of the gaseous metal carbonyl hydrides of manganese, iron, and cobaltE. A. McNeill and F. R. ScholerCite this: J. Am. Chem. Soc. 1977, 99, 19, 6243–6249Publication Date (Print):September 1, 1977Publication History Published online1 May 2002Published iniss…
Configurational Thermodynamics of the Liquid and Glassy Polymeric States
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConfigurational Thermodynamics of the Liquid and Glassy Polymeric StatesRobert SimhaCite this: Macromolecules 1977, 10, 5, 1025–1030Publication Date (Print):September 1, 1977Publication History Published online1 May 2002Published inissue 1 September 1977https://pubs.acs.org/…
X-ray diffraction pattern and models of liquid benzene
X-ray diffraction data for liquid benzene at 25°C are analyzed using scattering factors for C–H groups rather than for C and H atoms. This new approach permits the unique extraction of structure and correlation functions for carbon–carbon interactions from a single experiment. The data are used to find parameters for…