Planning: principles, processes, and practical applications Planning An accessible overview of planning: what it is, core components, historical development, common methods, uses in organisations and government, and distinctions from self-organizati…
Plans (drawings): definition, types, and uses Plans (drawings) Plans are two-dimensional technical drawings that convey form, arrangement, dimensions and construction or fabrication instructions for buildings, machines and sites, following sta…
Plastic explosives: composition, uses, history and safety Plastic explosives Malleable high explosives formed by combining a detonable compound with binders and plasticizers. Covers characteristics, common types (C‑4, Semtex, gelignite), uses, history and s…
Plating: metal surface coatings — methods, history, and applications Plating Plating is the application of a metal layer onto a substrate for decoration, protection or performance. This article explains common methods, history, properties, uses and importan…
Plotter: large-format vector printers and cutting devices Plotter A plotter is a device that produces precise, large-format line drawings from vector instructions. Used for maps, CAD drawings, signage and vinyl cutting, plotters trace continuous…
Plumbing: systems, materials, history and modern practice Plumbing A concise yet comprehensive overview of plumbing: what it is, main parts and materials, historical origins, how plumbers work, uses for health and sanitation, maintenance and regul…
Plywood: manufactured wood panels made from cross‑layered veneers Plywood Overview of plywood: how it is made, its structure and grades, common types (marine, structural, decorative), main uses, advantages and limitations, and environmental consideration…
Pneumatics: Principles, Components, History and Common Uses Pneumatics Survey of pneumatics—the use of compressed air for mechanical work—covering basic components, historical development, typical applications, advantages and limitations.
Polyethylene (PE): Properties, Types, Uses, and Environmental Aspects Polyethylene Polyethylene (PE) is a common thermoplastic polymer used in packaging, pipes, films and many molded products. Overview, major grades, production history, applications, recycling an…
Potter's wheel: history, design, and throwing techniques Potter's wheel A concise encyclopedia entry on the potter's wheel — its history, parts and types, the throwing process (centering, pulling, trimming), and how it differs from turning lathes.
Power consumption: meaning, measurement, and practical considerations Power consumption Power consumption is the rate at which electrical energy is supplied to a device. This article explains units, measurement, losses, examples, efficiency and distinctions between po…
Power cut (power outage): causes, effects and preparedness Power cut A power cut (outage) is a temporary loss of electric supply. This article explains causes, types, impacts, protective devices, safety steps and how communities and equipment cope.
Power line: transmission and distribution of electrical energy Power line Overview of power lines: components, overhead vs underground types, transmission and distribution roles, typical voltages, safety, environmental impacts, maintenance, and modern gr…
Power system harmonics: causes, effects and mitigation Power system harmonics An overview of electrical power harmonics: what they are, typical sources, effects on equipment and networks, measurement and standards, and common mitigation methods including fil…
Power transmission Overview of power transmission: how energy is carried from source to use, common methods (mechanical, electrical, fluid), history, applications, and key distinctions.
Pressurized Heavy-Water Reactor (PHWR) Pressurized heavy-water reactor A nuclear reactor design that uses heavy water as moderator and coolant under pressure, allowing efficient use of natural uranium and distinctive operational features such as onlin…
Pressurized Water Reactor (PWR) Pressurized water reactor A pressurized water reactor (PWR) uses high-pressure water to remove heat from a nuclear core and transfer it to a secondary steam system that drives turbines for electricity or pr…
Prime mover (locomotive) A prime mover in a locomotive is the onboard engine that converts fuel or energy into mechanical or electrical power for traction. Common types include diesel engines, gas turbines…
Process: definition, types, characteristics and examples Process Overview of processes: what they are, planned vs natural types, components and stages, cycles and feedback, historical perspective, and common examples across disciplines.
Program specification Program specification: definition, types (informal and formal), components, history, role in development and safety‑critical systems, and relation to verification and interfaces.
Programming language A programming language is a formal written system used to express instructions for computers; it includes syntax, semantics, paradigms and execution models and is central to softwa…
Programming paradigm A programming paradigm is a coherent style or approach to writing software, classifying languages by concepts such as state, control flow, modularity, and abstraction.
Project management: principles, lifecycle, methods, and roles Project management Overview of project management: definition, core components, lifecycle stages, common methods, typical skills of project managers, industries, and notable distinctions between proj…
Propeller A propeller is a rotating assembly of blades that converts engine power into thrust by accelerating fluid (air or water), used on aircraft, ships and submarines.
Pulley (simple machine) Pulley A pulley is a wheel and rope mechanism that changes the direction or magnitude of a force. Used for lifting, transmitting power, and redirecting motion, pulleys range from single s…
Pulse jet engine: simple pulsed combustion propulsion Pulse jet engine A pulse jet is a lightweight, low‑complexity jet engine in which combustion occurs cyclically. It powered early cruise missiles, is used in experimental craft and model engines, an…
Pyrotechnics: Principles, History, and Applications Pyrotechnics Pyrotechnics is the science and craft of controlled exothermic reactions used for fireworks, signaling, propulsion and safety devices in civilian, industrial and military contexts.
Quickdraw (climbing gear) Quickdraw A quickdraw is a short sling with two carabiners used in rock climbing to connect the rope to protection. This article explains parts, use in lead climbing, orientation, variations…
Race condition (computing and electronic systems) Race condition A race condition is a defect that makes a system's behavior depend on the relative timing of events. It occurs in hardware and software, especially in concurrent, multi-threaded, o…
Radiation hardening of electronic systems Radiation hardening Radiation hardening: methods to make electronic parts and systems tolerant of ionizing radiation in space, high-altitude flight, nuclear environments and other harsh radiation sett…
Ramjet: a simple high‑speed airbreathing jet propulsion system Ramjet Ramjet — an airbreathing jet engine with no moving compressors that uses forward speed and shock compression to produce thrust; efficient at high supersonic speeds and common in mi…
Rayon: a semi-synthetic cellulose fiber — production, types, properties Rayon Rayon is a semi-synthetic textile fiber made by chemically processing natural cellulose. This article outlines how it’s produced, major types (viscose, modal, lyocell), properties,…
Refinery — Industrial Facilities for Converting Raw Materials into Usable Products Refinery A refinery is an industrial plant that processes raw materials—most commonly crude oil—into finished products like fuels, lubricants and petrochemical feedstocks, with distinct pro…
Refractory (heat‑resistant materials) Refractory Materials designed to withstand very high temperatures and harsh chemical environments; used to line furnaces, kilns, incinerators and reactors in industry.
Register renaming (computer architecture technique) Register renaming Hardware method that removes false dependencies on CPU registers to enable out-of-order execution and higher instruction-level parallelism.
Reinforced concrete Concrete strengthened with embedded reinforcement (usually steel) to resist tension. Covers materials, behavior, history, common variants (prestressed, precast), uses, durability i…
Reinforcement learning: concepts, history, and applications Reinforcement learning Reinforcement learning (RL) teaches agents to make decisions from trial-and-error feedback. This article covers core ideas, historical development, common algorithms, uses, and pra…
Resistance welding: principles, types, uses, and practical considerations Resistance welding Resistance welding joins metals by heat from electrical resistance. This article explains how it works, common types, equipment, applications (notably automotive), advantages, limi…
Resistor A resistor is an electrical component that limits current, creates voltage drops, and converts electrical energy into heat. It is used in nearly all electronic circuits.
Respirators: Types, Applications, and Safety Requirements Respirator Overview of respirators: types, uses, and safety rules. Learn how filtering facepieces, elastomeric masks, PAPRs and supplied-air systems work, plus guidance on selection, fit, mai…
Reverse osmosis: principles, components, uses, and limitations Reverse osmosis Reverse osmosis (RO) is a pressure-driven membrane process that separates water from dissolved solids. It is used for desalination, water treatment, industrial purification and pro…
Rheology: the science of flow and deformation Rheology Rheology studies how materials deform and flow under applied forces, covering liquids, soft solids and complex fluids. It explains viscosity, viscoelasticity, measurement methods,…
Rhine–Main–Danube Canal Rhine-Main-Danube Canal A 171 km inland waterway completed in 1992 that links the Rhine and Danube river systems across Bavaria, creating a navigable route from the North Sea to the Black Sea and reshapin…
Rifling: purpose, types, history, and effects Rifling Rifling is the spiral grooves cut inside a firearm barrel to spin a projectile for gyroscopic stabilization. This article outlines terminology, twist rate, manufacturing methods, h…
Rivet: a permanent mechanical fastener and its roles in metalwork Rivet Rivets are permanent mechanical fasteners used to join metal parts. This article explains types, components, installation methods, historical development, testing and why riveting…
Road surface (pavement): materials, construction, history and uses Road surface Comprehensive overview of road surfaces (pavements): definition, layer structure, common materials, historical development, design considerations, maintenance, and sustainable alte…
Robotics: Principles, History, and Applications Robotics Overview of robotics — the multidisciplinary engineering and science of designing robots, their parts, history, common uses, and practical distinctions in industry and research.
Rocket engine A rocket engine accelerates reaction mass to generate thrust. This article explains principles, main components, engine types, performance measures, history, and common application…
