Science and technology
Biology and medicine
- Immediate-release, related to time release technology in pharmaceuticals
- Incidence Rate, in epidemiology
- Insulin receptor, a transmembrane receptor that is activated by insulin
- Insulin resistance, a pathological condition
- Interventional radiology and interventional radiologist, an independent medical specialty
- Inverted repeat, a sequence of nucleotides that is the reversed complement of another sequence further downstream
Computing
- .ir, the Internet country code top-level domain for Iran
- Adobe ImageReady, a bitmap graphics editor shipped with Adobe Photoshop by Adobe Systems
- Image retention, the LCD and plasma display equivalent of screen burn
- Information retrieval, the science of searching for information in or as documents or databases
- Information revolution, one of the theoretical frameworks within which trends in current society can be conceptualized
- Institutional repository, a digital collection for preserving the intellectual output of an institution
- Institutional research, the collection, analysis, and reporting of institutional data
- Instruction register, part of a CPU's control unit
- Intermediate representation, a computer data structure
- Internal router
Other uses in science and technology
- Imaginary numbers, in mathematics, denoted or iR
- Infrared, a portion of the electromagnetic radiation spectrum
- Impulse response, an output function of a dynamic system presented with a brief input signal
- Insulation resistance, a measure of insulation material performance
- Ionizing radiation
- Iridium, symbol Ir, a chemical element
