<unk>  is an important factor in many engineering disciplines. Transportation *Automobile brakes inherently rely on<unk> , slowing a vehicle by converting its kinetic energy into heat. Incidentally, dispersing this large amount of heat safely is one technical challenge in designing brake systems. Disk brakes rely on<unk>  between a disc and brake pads that are squeezed transversely against the rotating disc. In drum brakes, brake shoes or pads are pressed outwards against a rotating cylinder (brake drum) to create<unk> . Since braking discs can be more efficiently cooled than drums, disc brakes have better stopping performance. *Rail adhesion refers to the grip wheels of a train have on the rails, see<unk> al contact mechanics. *Road slipperiness is an important design and safety factor for automobiles *Split<unk>  is a particularly dangerous condition arising due to varying<unk>  on either side of a car. *Road texture affects the interaction of tires and the driving surface. Measurement *A tribometer is an instrument that measures<unk>  on a surface. *A profilograph is a device used to measure pavement surface roughness. Household usage<unk>  is used to heat and ignite matchsticks<unk>  between the head of a matchstick and the rubbing surface of the match box). *Sticky pads are used to prevent object from slipping off smooth surfaces by effectively increasing the<unk>  coefficient between the surface and the object.
Friction
Overpressure
Solvent drag
Adhesion 
Fixation 
Subluxation
Effacement 
Disarticulation