Löslichkeiten in homologen und isomeren Reihen

Solubilities of Homologous and Isomeric Series Solubilities in water and organic solvents of homologous series of symmetrical dialkyl ketones (having no melting point alternations) and of β-phenyl,β-hydroxyl,β-alkyl-propionic acids (all with alternating melting points) were determined. In the case of medium chained dialkyl ketones the solubilities decrease in linear logarithmic proportion with increasing alkyl chain, according to the relationship of Erichsen. In isomeric series having systematically displaced substituents on n-paraffin C₂₂H₄₆, the maximum solubilities correspond to lowest melting points. In this case a quantitative relationship can not be formulated.     

The earth location of geostationary satellite imagery

Spin scan cloud pictures from NASA's Applications Technology Satellites are being computer processed as an operational experiment. Details of this near-real-time image manipulating activity are described. Processing involves the treatment of horizon and landmark features in support of the photogrammetric aspects and the subsequent transformation of images onto standard map projections.     

Thermal diffusivity of polymers by the flash method

We have adopted the flash method to the measurement of thermal diffusivity α of polymers in the temperature range 100–400K. The pulsed radiant energy from a flash tube is applied to the ‘front’ side of a suspended sample disc, and α is deduced from the exponential decay time constant of the subsequent transient temperature difference between the ‘front’ and the ‘back’ side, while correction against radiation loss is made by measuring the much longer decay time of the back-side temperature. Calibration runs on polycarbonate (PC) samples of several thicknesses show that the method is quick, precise and fairly accurate, and the results obtained are in reasonable agreement with previous determinations. We have also carried out measurements on polyoxymethylene (POM), poly (vinylidene fluoride) (PVF₂) and poly (ethylene terephthalate) (PET) and computed their thermal conductivities. Results on POM and PVF₂, which are semicrystalline, are analysed in the framework of several two-phase models, and the effect of crystallization (produced by annealing) on the glass transition behaviour of PET has also been studied.     

Phosphate-bonded refractory coatings

Conclusions A study of the adhesion and cohesion strength of refractory coatings based on oxides of titanium, zirconium, hafnium, silicon; nitrides of hafnium, boron, silicon; mullite, magnesia spinel, zirconates of calcium, barium, strontium; disulfide and disilicide of molybdenum, and calcium titanate, using phosphate bonds, established the optimum compositions for the coatings for the following alloys: 1Kh18N9T, Él-703, ÉP-99, VT-9, OT-4, ÉI-961, Br.Kh08 bronzes, molybdenum and graphite.Results are given for the working temperatures, shear strengths, and thermal-shock resistance of the coatings and also the electric conductivity and temperature conductivity of some compositions. The refractory coatings with phosphate bonds that were developed are recommended for use in high-temperature installations in the temperature range 1000–1800°C.Translated from Ogneupory, No. 4, pp. 50–54, April, 1973.     

Properties of bioriented nylon 6 films related to film production technology

Four production steps, extrusion, blowing, stabilization, and finishing, are involved in the manufacture of biorented nylon 6 films. The films obtained after each step were studied by wide‐angle diffraction X‐rays, IR analysis, and density measurements. Orientation in the amorphous phase was evaluated by thermal retraction. Free volume was investigated by positron annihilation spectroscopy. Mechanical properties were tested by tensile tests, and permeability was tested with isopiestic permeameters. Quenching, after extrusion, generated an unstable γ crystalline phase and an amorphous phase. Blowing transformed the unstable γ phase into the thermodynamically stable α phase and increased the chain orientation; stabilization increased α phase crystals, favored hydrogen bond formation and, therefore, the mechanical properties, leaving unchanged the chain orientation; the final treatment increased the mechanical properties. The film permeabilities to O₂, N₂, and CO₂ were practically unchanged after each production step; this result may be explained by considering that the nanoholes, present in the films and responsible for the diffusion inside the polymer, maintained practically constant their radius, whereas their number concentration decreased slowly after thermomechanical treatments. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 559–571, 2002