Abstract: Novel, rechargeable magnesium/magnesium sulfide batteries are disclosed therein, having energy density competitive with lithium batteries, high cycle life, land lower cost. Production method of stabilized MgS is also described, as well as various cells' constructions.

Abstract: A wind turbine rotor blade and a wind turbine incorporating the rotor blade include a first and second composite skin. A first and a second spar pultrusion having a base and a plurality of integral ribs generally normal to base are attached to the inside surface of the first and second composite skins and extend the span of the rotor blade. At least one shear web connects a rib of the first spar pultrusion to a corresponding rib of the second spar pultrusion. The width of the spar pultrusions decreases in a step-wise fashion along the span of the rotor blade from the root to the tip. The leading or trailing edge of the rotor blade may be selectably opened for inspection and repair.

Abstract: A supplementary power drive system for providing additional power to the drive system of rotary wing aircraft that powers the aircraft main lifting rotor and tail mounted torque compensating rotor or propeller in a manner as avoids overloading the power capacity of the main rotor transmission. The supplementary power system, utilizing the power of a usually installed auxiliary power plant as a source of additional power, bypasses the main engine powered main rotor transmission in providing power to the tail mounted rotor or propeller and main rotor if the main transmission cannot absorb it.

Abstract: A structural joint and method of making the joint wherein an end portion of each of a plurality of tubes is partially flattened into an elongated, oval annular shape of a cross sectional contour that the flattened ends of the tubes can be telescopically nested within one another, the tubes are arranged to have their axes coplanar to intersect at the joint node with the tube flattened ends in a telescopically, mutually nesting relationship to each other, a splice plate extending into the interior of the nested array of flattened tube ends and having upper and lower surfaces in an underlying, closely adjoining relation to interior surfaces of each of the tube flattened end portions, and fastening means tightly clamping together the nesting, flattened tube ends and splice plate contained therewithin.