Technology glossary

Super-Eddington Accretion

The inflow of matter onto a compact object at a rate above the conventional Eddington limit, where outward radiation pressure would normally balance gravity. Thick gas can trap or redirect radiation, allowing faster growth for a time.

Superconducting Qubit

A quantum bit implemented with electrical circuits made from superconducting materials and interrupted by Josephson junctions. At very low temperatures, selected circuit energy states represent 0 and 1 and can be controlled with microwave pulses, though noise and material defects limit coherence.

Superjunction

A semiconductor structure that balances neighboring positive and negative charge regions to distribute electric field more evenly, enabling high breakdown voltage with lower resistance.

Supply Chain Risk Designation

A government determination that a supplier or component may threaten the integrity, security or continuity of systems used in a protected supply chain.

Suppressor tRNA(sup-tRNA)

An engineered transfer RNA that recognizes a premature stop codon, inserts an amino acid and allows a cell to continue building a full-length protein.

Surface Code

A quantum error-correction method that arranges qubits on a grid and repeatedly measures local parity checks.

Surface Passivation

A materials treatment that reduces electrically active defects at a surface or interface. In solar cells, passivation limits charge recombination and can also improve resistance to moisture or chemical degradation.

Surface Roughness

A measure of how strongly elevation varies across a surface at a specified spatial scale. In remote planetary mapping, roughness can reveal terrain history but can also affect whether small faults and ridges are preserved or detected.

Surgical Robotics

Robotic systems that assist clinicians in performing surgical procedures by translating their inputs into precise instrument movements or automating limited subtasks. They can improve dexterity and visualization but do not replace clinical judgment, training, or operating-room safeguards.

Surrogate Endpoint

A laboratory measurement, biomarker, imaging result, or intermediate outcome used in a clinical trial as a substitute for a direct patient-centered outcome such as survival or symptom improvement. It is useful only to the extent that evidence shows it reliably predicts clinical benefit or harm.

Symbiosis

A close, long-term biological relationship between two different organisms in which at least one benefits, sometimes with a smaller partner living inside or on the tissues of a larger one.

Symbiotic Algae

Microscopic algae that live inside coral tissues and exchange nutrients with their animal host. Through photosynthesis they provide much of the coral's energy, while the coral supplies shelter and compounds the algae need.

Synthetic Cell

A laboratory-built system that reproduces selected features of living cells, often inside a lipid membrane compartment. A synthetic cell may perform reactions, exchange molecules or respond to signals, but it is not necessarily alive and usually lacks the full machinery of a biological cell.

Synthetic Media

Images, audio, video or text created or substantially altered by computational systems, including generative AI. Synthetic media can support legitimate creative work, but its credibility depends on labeling, provenance and the context in which it is presented.

Systemic Risk

A risk whose effects could spread widely across society, markets, infrastructure or many downstream users rather than remaining confined to one person or application. In AI governance, highly capable or widely deployed models may require extra evaluation and mitigation because of this reach.

Techno-Economic Analysis(TEA)

A modelling method that combines process performance, equipment needs, energy use and costs to test whether a proposed technology could be technically and financially viable.

Technology Leakage

The unauthorised transfer of technical knowledge, designs, data or production methods outside the organisation or country that controls them. Leakage may be deliberate or accidental and can occur through people, networks, suppliers, research partnerships or poorly secured devices.

Teleoperated Surgery

Surgery in which a clinician controls robotic instruments from a separate console, potentially at a different location from the patient. Safe operation depends on reliable communication, low latency, trained local support, cybersecurity, and procedures for equipment or network failure.

Teleoperation

Controlling a robot from another location through a communication link.

Temperature Span

The steady temperature difference a cooling device can maintain between its cold and hot sides under stated operating conditions.

Thalamocortical Projection

A nerve-fiber pathway that grows from the thalamus toward the cerebral cortex. In mature brains it carries sensory and regulatory signals, while early projections can also influence development.

Therapeutic Apheresis

A medical procedure that draws blood from a patient, separates out the plasma, passes it through a filter or adsorption column to remove specific substances such as cholesterol-carrying lipoproteins, then returns the cleaned plasma to the body. It has been used for decades to treat severe, treatment-resistant lipid disorders.

Therapeutic Drug Monitoring(TDM)

The measurement and clinical interpretation of drug concentrations in a patient's blood or other biological samples to guide dosing. It is most useful for medicines with narrow therapeutic ranges, variable metabolism, or a clear relationship between concentration and response or toxicity.

Therapy-Related Mutation

A genetic change that arises after exposure to a cancer treatment and may affect later disease behavior.

Thermal Boundary Conductance(TBC)

A measure of how readily heat crosses the interface between two materials. A high value means the boundary transfers heat efficiently, while a low value indicates thermal resistance that can create or worsen hotspots in layered devices.

Thermal Management

The control, removal and distribution of heat in devices and systems.

Thermal Radiation

Electromagnetic radiation emitted by matter because of its temperature. Its intensity and spectrum depend on temperature and surface properties; at everyday temperatures much of it is infrared, while hotter objects emit more energy at shorter wavelengths.

Thermoelectric Generator

A solid-state device that produces electricity from a temperature difference between two sides. It has no moving parts, but its output depends on maintaining that temperature gradient and is usually limited by conversion efficiency.

Thin-Film Electronics

Electronic devices and circuits fabricated from very thin layers of conductive, semiconducting, or insulating materials deposited on a surface. They are used in products such as displays, sensors, solar cells, and flexible electronics.

Three-Dimensional Cell Culture

A method of growing cells in a three-dimensional scaffold that better resembles natural tissue than a flat dish.