An isentropic process is an idealized thermodynamic process that is both adiabatic and reversible.

In thermodynamics, a change in the thermodynamic state of a system and all of its surroundings cannot be precisely restored to its initial state by infinitesimal changes in some property of the system without expenditure of energy.

Irradiation is the process by which an object is exposed to radiation.

Iron is a chemical element with symbol Fe and atomic number 26.

The International Renewable Energy Agency (IRENA) is an intergovernmental organisation supporting countries in their transition to a sustainable energy future .

A private company in the business of generating and supplying electrical power to end users.

Ionizing radiation (ionising radiation) consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them.

Ionisation energy is the minimum amount of energy required to remove the most loosely bound electron of an isolated neutral gaseous atom or molecule

The Ion is a subatomic particle whose electric charge is negative one elementary charge.

The iodine pit, also called the iodine hole or xenon pit, is a temporary disabling of a nuclear reactor due to buildup of short-lived nuclear poisons in the reactor core.

An inverter, is a power electronic device or circuitry that changes direct current to alternating current.

Power conversion from DC to AC.

Maximum expected operating pressure (MEOP) is the highest expected operating pressure.

Maximum allowable working pressure is defined as the maximum pressure based on the design codes that the weakest component of a pressure vessel can handle.

Maximum Allowable Operating Pressure is a pressure limit set, usually by a government body, which applies to compressed gas pressure vessels, pipelines, and storage tanks.

Matter is any substance that has mass and takes up space by having volume.

A mathematical model is a description of a system using mathematical concepts and language.

A materials property is an intensive property of some material, i.e., a physical property that does not depend on the amount of the material.

The interdisciplinary field of materials science, also commonly termed materials science and engineering, covers the design and discovery of new materials, particularly solids.

In physics, mass–energy equivalence is the relationship between mass and energy in a system's rest frame, where the two values differ only by a constant and the units of measurement.