Abstract: An optical fibre system comprises an optical fibre cable comprising at least one microstructured optical fibre within a jacket; and a barrier mechanism responsive to a breach of the optical fibre cable through which water from a surrounding environment of the optical fibre cable may enter voids of the microstructured optical fibre; wherein the barrier mechanism is responsive to the breach by operating to introduce a barrier across the voids of the microstructured optical fibre, the barrier configured to inhibit movement of water along the voids.

Abstract: A muscle-powered continuously variable drive system, and apparatus having same, is disclosed. The system employs dual actuator levers pivoted at one end. The free pedal ends of the levers reciprocate through an arcuate range of motion via application of muscle power by the user, rather than cycling through complete revolutions of a small-radius circle, such as is common for conventional bicycles. The reciprocating motion of the levers initiated by the user generates a force that is translated into rotational motion of a drive wheel via a drive tether. The drive tether is attached to the actuator levers and runs around three idler pulleys mounted to the apparatus' frame. Two chain segments of the tether engage respective dual sprockets at the hub of the drive wheel. The geometry of the transmission enables a light, simple, system of continuously-variable torque multiplication, which eliminates the need for conventional derailleurs and multiple sprockets, or internal gear hubs.

Abstract: Gear oils and gear oil additive concentrates of enhanced positraction performance are described. They comprise: (i) at least one oil-soluble sulfur-containing extreme pressure or antiwear agent; (ii) at least one oil-soluble amine salt of a partial ester of an acid of phosphorus; and (iii) at least one oil-soluble succinimide of the formula ##STR1## where R.sub.1 is an alkyl or alkenyl group having an average of 8 to 50 carbon atoms, and each of R.sub.2, R.sub.3 and R.sub.4 is a hydrogen atom or an alkyl or alkenyl group having an average of up to about 4 carbon atoms. These compositions preferably contain one, more preferably two, and most preferably all three of the following additional components: (iv) at least one amine salt of a carboxylic acid; (v) at least one nitrogen-containing ashless dispersant; and (vi) at least one trihydrocarbyl ester of a pentavalent acid of phosphorus.

Abstract: Gear oil additive concentrates and lubricant compositions containing a combination of additives which minimize noise and vibration that occasionally develop in limited slip axles. The additive combinations include (i) an oil-soluble succinimide of the formula ##STR1## wherein R.sub.1 is alkyl or alkenyl having 8 to 50 carbon atoms, and R.sub.2, R.sub.3 and R.sub.4 are hydrogen atoms or alkyl or alkenyl groups having up to about 4 carbon atoms; and (ii) a boronated or non-boronated carboxylic derivative composition produced by reacting a substituted succinic acylating agent with (a) amine having at least one primary or secondary amino group in the molecule, or (b) at least one alcohol, or (c) a combination of (a) and (b). The substituent of the succinic acylating agent is derived from polyalkene having a number average molecular weight of about 500 to about 100,000. The additive concentrates and lubricant compositions are devoid of any metal-containing component.

Abstract: Gear oil additive concentrates and lubricant compositions containing a combination of additives which minimize noise and vibration that occasionally develop in limited slip axles. The additive combinations include (i) an oil-soluble succinimide of the formula ##STR1## wherein R.sub.1 is alkyl or alkenyl having 8 to 50 carbon atoms, and R.sub.2, R.sub.3 and R.sub.4 are hydrogen atoms or alkyl or alkenyl groups having up to about 4 carbon atoms; and (ii) a boronated or non-boronated carboxylic derivative composition produced by reacting a substituted succinic acylating agent with (a) amine having at least one primary or secondary amino group in the molecule, or (b) at least one alcohol, or (c) a combination of (a) and (b). The substituent of the succinic acylating agent is derived from polyalkene having a number average molecular weight of about 500 to about 100,000. The additive concentrates and lubricant compositions are devoidd of any metal-containing component.

Abstract: Polyesters suitable for use as lubricant additives are prepared by reacting a di-carboxylic acid or anhydride having a branched chain alkyl or alkenyl substituent containing at least 30 carbon atoms with a compound having the formula: ##STR1## wherein R and R.sup.1 are specified substituents which between them possess from 2 to 6 free hydroxyl groups. Lubricating compositions containing these polyester additives are also described.

Abstract: Polyesters suitable for use as lubricant additives are prepared by reacting a di-carboxylic acid or anhydride having a branched chain alkyl or alkenyl substituent containing at least 30 carbon atoms with a compound having the formula: ##STR1## wherein R and R.sup.1 are specified substituents which between them possess from 2 to 6 free hydroxyl groups. Lubricating compositions containing these polyester additives are also described.