Friction friction and wear in so-called self-lubricating materials. Fluid friction occurs between fluid layers that are moving relative to each other. This internal resistance to flow is named "viscosity". In everyday terms, the viscosity of a fluid is described as its "thickness". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity. The less viscous the fluid, the greater its ease of deformation or movement. All real fluids (except superfluids) offer some resistance to shearing and therefore are viscous. For teaching and explanatory purposes it is helpful to use the concept of an inviscid fluid
Resistance to interrogation Abu Ghraib resembled the techniques used in RTI training. Resistance to interrogation Resistance to interrogation, RTI or R2I is a type of military training to British and other NATO soldiers to prepare them, after capture by the enemy, to resist interrogation techniques such as humiliation and torture. The trainees undergo practices such as hooding, sleep deprivation, time disorientation, prolonged nakedness, sexual humiliation and deprivation of warmth, water and food. Many of these techniques are against international law if used in interrogations. In such interrogation sessions, the subjects must maintain dead silence regardless of the practice being inflicted on them. Only