Cavitation in the context of Mantis shrimp

A blunt instrument is any solid object that can be used as a hand tool, weapon or thrown projectile for striking a target, exerts impact via direct transfer of force and momentum, and has no sharp point or edge on the contact surface with the target. A blunt weapon may be contrasted with edged weapons in that the former causes mostly closed trauma instead of open incisions or puncture wounds, and are also different to kinetic projectiles such as bullets or arrows, whose speed and kinetic energy are so significant that they cause penetrating trauma often with cavitations even if the projectile is of a blunt shape.

Blunt instruments typically inflict blunt force trauma, causing contusions, fractures and internal bleeding while leaving the skin intact, although they occasionally can produce irregular lacerations by shearing. Depending on the parts of the body struck, organs may be ruptured or otherwise damaged, and attacks with a blunt instrument may be fatal, especially when striking vital areas such as the head, neck and chest.

In fluid mechanics, multiphase flow is the simultaneous flow of materials with two or more thermodynamic phases. Virtually all processing technologies from cavitating pumps and turbines to paper-making and the construction of plastics involve some form of multiphase flow. It is also prevalent in many natural phenomena.

These phases may consist of one chemical component (e.g. flow of water and water vapour), or several different chemical components (e.g. flow of oil and water). A phase is classified as continuous if it occupies a continually connected region of space (as opposed to disperse if the phase occupies disconnected regions of space). The continuous phase may be either gaseous or a liquid. The disperse phase can consist of a solid, liquid or gas.

In fluid dynamics, the Reynolds number (Re) is a dimensionless quantity that helps predict fluid flow patterns in different situations by measuring the ratio between inertial and viscous forces. At low Reynolds numbers, flows tend to be dominated by laminar (sheet-like) flow, while at high Reynolds numbers, flows tend to be turbulent. The turbulence results from differences in the fluid's speed and direction, which may sometimes intersect or even move counter to the overall direction of the flow (eddy currents). These eddy currents begin to churn the flow, using up energy in the process, which for liquids increases the chances of cavitation.

The Reynolds number has wide applications, ranging from liquid flow in a pipe to the passage of air over an aircraft wing. It is used to predict the transition from laminar to turbulent flow and is used in the scaling of similar but different-sized flow situations, such as between an aircraft model in a wind tunnel and the full-size version. The predictions of the onset of turbulence and the ability to calculate scaling effects can be used to help predict fluid behavior on a larger scale, such as in local or global air or water movement, and thereby the associated meteorological and climatological effects.

An antifreeze is an additive which lowers the freezing point of a water-based liquid. An antifreeze mixture is used to achieve freezing-point depression for cold environments. Common antifreezes also increase the boiling point of the liquid, allowing higher coolant temperature. However, all common antifreeze additives also have lower heat capacities than water, and do reduce water's ability to act as a coolant when added to it.

Because water has good properties as a coolant, water plus antifreeze is used in internal combustion engines and other heat transfer applications, such as HVAC chillers and solar water heaters. The purpose of antifreeze is to prevent a rigid enclosure from bursting due to expansion when water freezes. Commercially, both the additive (pure concentrate) and the mixture (diluted solution) are called antifreeze, depending on the context. Careful selection of an antifreeze can enable a wide temperature range in which the mixture remains in the liquid phase, which is critical to efficient heat transfer and the proper functioning of heat exchangers. Most if not all commercial antifreeze formulations intended for use in heat transfer applications include anti-corrosion and anti-cavitation agents (that protect the hydraulic circuit from progressive wear).

Megasonic cleaning is a specialized cleaning method that utilizes high-frequency sound waves to remove contaminants from delicate surfaces. It is particularly effective in industries like semiconductor manufacturing, optics, and medical device production, where precision and gentle cleaning are crucial. It is a type of acoustic cleaning related to ultrasonic cleaning. Similar to ultrasonic cleaning, megasonic cleaning uses a transducer that sits on top of a piezoelectric substrate. The transducer creates acoustic waves at a higher frequency (typically 0.8–2 MHz) than ultrasonic cleaning (20-200 kHz). As a result, the cavitation that occurs is reduced and on a much smaller scale.