Abstract: A cylindrical strand with a thermoplastic outer shell (e.g., plastic insulated wire) is bonded along its length to a similar or different cylindrical strand by laser heating. The strands are brought into contact with one another at a contact point. A laser beam of selected power and wavelength is directed at the contact point in a direction approximately parallel to the axis of the strands as the strands are carried past this point. Absorption of the light by the plastic causes melting sufficient to produce bonding. The depth of penetration of the thermal energy into the plastic is controlled by selection of the wavelength of the laser radiation relative to the absorption spectrum of the thermoplastic material. The laser power level is adjusted to control the total energy input in accordance with the strand feed rate.

Abstract: A heavily germanium doped gallium arsenide layer is epitaxially deposited from solution on a Group III-V compound semiconductor device in order to provide contact between the device and external metallic circuitry. If the net p-type carrier concentration in the layer is greater than 3.5 .times. 10.sup.19 per cubic centimeter, the blocking voltage between the device and common contacting metals, such as chromium and titanium is less than 50 millivolts. Deposition takes place at temperatures from 850.degree.C to 700.degree.C with germanium included in the solution in a concentration from 20 to 50 atom percent.

Abstract: High silica content optical glasses, containing more volatile oxides such as GeO.sub.2 and B.sub.2 O.sub.3, are produced by plasma fusion of powders without inordinately high loss of the more volatile constituents. The powders are produced by a process including the heat treatment of intimately mixed materials, which include the glass forming constituents. Small quantities of GeO.sub.2 are included in borosilicate glass to suppress bubble formation. Pairs of glass compositions have been found, with sufficient index of refraction difference to produce guidance in optical transmission lines, while possessing sufficient thermal expansion match to reduce stresses in the line.

Abstract: Carbonyl iron powder core (dust core) materials whose rate of change of magnetic permeability with temperature are preselected, are produced by a process which includes the mixing together of powders from two source batches. These source batches produce core materials whose temperature coefficients, Y and Z, lie on either side of the desired temperature coefficient, X. The fraction, A, of the Y powder is selected in accordance with the formula:A = 0.7 [(X-Y)/(Z-Y)] + 0.15; 0.15 .ltoreq. A .ltoreq. 0.85.exemplary core materials incorporate a phosphate insulator and a phenolic binder.

Abstract: Group III-V compound semiconductor devices with attached gold conductor areas are etched using a basic ferricyanide etchant. The etchant is an aqueous solution containing ferricyanide ions in a concentration from 0.8 molar to 1.2 molar and sodium or potassium hydroxide in a concentration from 0.3 molar to 1.5 molar. This etchant rapidly removes the semiconductor material leaving smooth surfaces, while leaving the gold conductors and areas protected by oxide layers essentially intact. The use of titanium layers as etching masks, deposited for example by evaporating or sputtering through a removable mask, is also disclosed.