Catching the wave [gravity wave communication]

In 1873, when James Clerk Maxwell published his treatise unifying electromagnetic theory, he stated that light was electromagnetic in nature and he predicted that electromagnetic waves of greater length might exist. A dozen years later, Heinrich Hertz constructed apparatus with which he generated and received these longer waves, and he demonstrated that their behavior was identical to that of light. In the century following Hertz, these longer waves, which we now call radio waves, have been utilized to provide a vast worldwide communication system. In his theory of general relativity, published in 1915, Albert Einstein postulated the existence of gravity waves that propagate at the speed of light. If these waves could be used for communication purposes, they would open a whole new spectrum for exploitation, independent of the electromagnetic spectrum. Why is it that today, three quarters of a century later, we don't have gravity-wave transmitting and receiving stations? The article examines the reasons for this and then determines quantitatively how far we are from adding gravity waves to our communications repertoire     

Flame temperature, fuel structure, and fuel concentration effects on soot formation in inverse diffusion flames

Insights into soot formation processes are gained from chemical sampling and thermocouple probing of co-flowing inverse diffusion flames (IDFs), with the oxidizer in the center. The transition from near-to slightly sooting flames and the effects of flame temperature, fuel concentration, and fuel structure (using methane, ethene, propene and 1-butene) are investigated. The aromatic content of IDFS scales with the fuel's sooting tendency, and suggests that the formation of the aromatic ring is a controlling step in soot formation. In addition to the relatively well-established reactions involving C4 and C2 species, benzene may form directly from two C3 species for fuels that readily produce C3 species during pyrolysis and/or oxidative pyrolysis. The total concentration of growth species increases almost linearly with fuel concentration, but depends more weakly on flame temperature than would be expected if pure pyrolysis governed the intermediate hydrocarbon behavior.     

A magnetoelastic metallic glass low-frequency magnetometer

A complete theoretical analysis is presented of the operation of a magnetoelastic amorphous metal low-frequency magnetic field sensor. This directional magnetometer is a hybrid device consisting of a piezoelectric plate, a field-annealed amorphous metal ribbon, and a viscous fluid, and it exhibits a low-frequency magnetic field detection level of 8.0 pT/√Hz at 1.0 Hz. The sensor may also be configured as a first- and second-order gradiometer. The device analysis focuses on the influence of the constituent materials on the magnetometer performance, identifying potential noise sources and optimal design parameters. This analysis may be applied to a variety of magnetoelastic amorphous metal sensors, e.g. stress, strain, and torque sensors, and is also useful in research concerning fundamental aspects of magnetoelasticity. Experimental data are presented demonstrating the performance of magnetometers constructed with amorphous metal ribbons exhibiting striped and closure domain structures     

Asbestos replacement aspects: Modification of the fibre-matrix interphase in lonomer based composites

Asbestos fibres, of the chrysotile variety, and chopped carbon fibres were pretreated by an in-situ polycondensation technique eventually resulting in a polyamide coating on the fibre surface. Ionomer based composites containing either carbon or asbestos fibres in random in plane fibre orientation were prepared, and the influence of this coating process on the tensile properties was investigated. It was found that for the asbestos-filled composites the presence of the nylon 6,6 interlayer improves the tensile performance, especially at moderate polyamide depositions. This is not the case with the pretreated carbon-filled composites for which carbon fibres with higher polyamide contents are preferred. Combinations of the treated asbestos fibres with carbon and/or aramid fibres may be used to reduce the asbestos content in asbestos-only based engineering plastics.     

Deuterated liquid scintillator (NE230) as a fast neutron detectorfor cold-fusion and other research

Deuterated scintillators (NE230) can provide, without time-of-flight, usable neutron energy spectra for neutrons E _n⩾1 MeV. The authors have assembled and calibrated several of these detectors and used them in experiments searching for d+d fusion-neutron emission (E_n, 2.5 MeV) in Pd+D ₂O electrolysis and Ti+D₂ adsorption at LN temperatures. The detectors yielded direct fusion-neutron spectra and set limits in the Pd+D and Ti+D experiments of <7×10^-24 fusion n/s/dd pair and <3×10^-24 fusion n/s/dd pair respectively. In addition, these detectors have been used for in-beam accelerator experiments requiring coincidence between fast neutrons and scattered ions     

Use of liquid sealants to protect still-waste-containing tanks-settling basins from corrosion

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 10, pp. 29–31, October, 1992.     

Methylaluminoxane/haloalkane as initiator system for styrene polymerization

Summary Styrene polymerization was initiated by methylaluminoxane in the presence of haloalkane. The propagating species are shown by trapping experiments and electron paramagnetic resonance to be both radicals and cations.