Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:

Dictionary of Energy

31.12 Mб

respiratory loss



Rresource curse Common sense and simple economics suggest that countries

blessed with an abundance of natural resources should live long and prosper. Yet over many years, it has been observed that nations rich in oil, gas, or mineral resources have been disadvantaged in the drive for economic progress. This has been labeled “resource curse”. In the 1950s and 1960s, concern was based upon deteriorating terms of trade between industrial and developing countries. In the 1970s, it was driven by the impact of the oil price shocks on the oil exporters where windfall revenues seemed to introduce serious distortions to the economies. In the 1980s, the phenomenon of “Dutch Disease”—an overvaluation of the real exchange rate—attracted attention. In the 1990s, it was the impact on government behavior—rent seeking and corruption—that dominated discus-

respiratory loss Biological Energetics. the energy loss by an organism or system due to the process of respiration.

response time Climate Change. the time needed for a climate system or its components to reach a new state of balance following a forcing.

resting energy expenditure (REE) Biological Energetics. the total energy requirements of a person for daily sleep and rest, excluding energy expended in physical activity.

restoration Environment. a long-term process of reestablishing the original composition, structure, and function of a disturbed environmental site or an ecosystem, as by stabilizing contaminated soil, treating groundwater, removing wastes, planting native vegetation, and so on.

restructuring Electricity. a reconfiguration of a vertically-integrated electric utility; this usually refers to the separation of the various utility functions into entities that are individually operated and owned. RSee next page.

retail Economics. 1. describing transactions in which the end-use consumer of the good is also the purchaser; e.g., the sale of fuel at the pump to a vehicle owner is a retail purchase. Usually involves sale of items in small quantities and not for subsequent resale. 2. specifically, having to do with electricity or other utility services sold directly for residential,

sions. More recently a revival of interest follows the World Bank’s “Extractive Industry Review” and growing concern over corporate social responsibility. Existence of the “curse” is controversial in literature and there is growing evidence that its occurrence is far from inevitable. In many countries natural resource revenues can produce tangible benefit. Where a “curse” has occurred, the main explanation lies in the way large windfall resource revenues affect government behavior. Thus avoidance implies political reform to encourage good governance. Increasingly, analysis addresses how the various players in natural resource projects— international financial institutions, multinational corporations and NGOs—can assist governments at risk to create capacity to manage the problem.

Paul Stevens

Dundee University

commercial, or industrial end-use purposes. Thus, retail competition, customer, market, pricing, and so on. Compare WHOLESALE.

retort Materials. 1. a glass vessel, typically a bulb with a long, downward-pointing neck, used to distill or decompose solid or semisolid substances. 2. a cylindrical refractory chamber used to heat coal or ore.

retreat mining (retreating) Mining. a method of coal mining in which the service roadways are created to their predetermined length before any coal is removed from the working face, then mining takes place in a “retreating” direction, back to the original development. The workers mine as much coal as possible from the remaining pillars until the roof falls in; the mined area is then abandoned.

retrofit Consumption & Efficiency. to modify an existing structure or technology after it has been put in service, as opposed to creating something entirely new; e.g., an older building can be retrofitted with advanced windows to slow the flow of energy into or out of the house. Thus, retrofitting.

retrograde condensation Oil & Gas. the condensation of the vapor phase of a hydrocarbon in contact with its liquid phase, occurring either when the pressure decreases at constant temperature or the temperature increases at constant pressure.

reuse Renewable/Alternative. the use of material over again instead of disposing of it as



reverse osmosis

Rrestructuring Changes in the regulatory and corporate structure of the electric

power industry transforming it from fully regulated monopolies to one in which competition is allowed or required in certain portions of the industry. Traditionally, vertically-integrated monopolies provided generation, transmission, and distribution services to captive customers. Following restructuring, these services were separated, either functionally within one company, or physically with different companies offering different services. Several states that have “restructured” required jurisdictional electric utilities to sell off their generation assets to independent companies. Expectations that competitive forces would lead to more efficient prices than government regulation spurred restructuring. In the U.S., restructuring at the wholesale level began in the mid 1990s with FERC’s rule on open access to the transmission system. In response to

waste or recycling it; e.g., using cloth napkins instead of paper or a durable coffee mug instead of a paper cup.

revegetation Ecology. the restoration of plant life to an area that had previously been devoid of or deficient in vegetation; can be either a natural process or human-assisted.

Revelle, Roger 1909–1991, U.S. oceanographer best known for his pioneering work on carbon dioxide balance in the oceans and its effect on climate.

Revelle factor see BUFFER FACTOR.

reverberatory furnace Consumption & Efficiency. a historic type of furnace with a shallow hearth and a roof that deflects the flame and radiates heat toward the hearth or the surface of the charge.

reverse bias Electricity. a voltage applied to a semiconductor P–N junction to make the P side negative with respect to the N side.

reverse Brayton cycle Refrigeration. a refrigeration cycle consisting of four processes: a fluid is compressed at constant entropy and then cooled by reversible con- stant-pressure cooling; the high-pressure fluid expands reversibly in the engine and exhausts at low temperature; the cooled fluid passes through the cold storage chamber and picks up heat at constant pressure; the fluid returns to the suction side of com-

this rule, and under pressure from large industrial customers seeking lower rates, regulators in several U.S. states issued rules that moved to retail competition in the generation sector. Many municipalities own their own electric systems and were not required to make the same changes to their businesses. There are strongly divergent opinions on the success of restructuring. The term “privatization” refers to the change from government to private ownership as occurred in the electric industry in the U.K. in the early 1990s. The term “deregulation” is sometimes used interchangeably with “restructuring” but implies a greater reduction in regulation than has actually occurred in the U.S. electric industry.

Jeannie Ramey

Synapse Energy Economics, Inc.

Cambridge, Massachusetts

pressor. [Described by U.S. engineer George Brayton, 1830–1892.]

reverse Carnot cycle Thermodynamics. an ideal thermodynamic cycle consisting of four processes: an expansion at constant entropy; a constant-temperature expansion; a compression at constant entropy; and a constant-tem- perature compression. These processes occur in the reverse order in the standard CARNOT


reverse current Electricity. the direct current that flows when a reverse bias is applied to a semiconductor device.

reverse-cycle HVAC. 1. describing a yearround air-conditioning system in which heat is transferred from the outside of a building to the inside in the winter, by means of a heat pump that extracts heat from the exterior air and transfers it to the interior. In summer the system operates in the conventional manner, shifting heat from the inside to the outside to cool the building. Thus, reverse-cycle heat (pump); reverse-cycle system. 2. see REVERSE


reverse osmosis Chemistry. the application of external pressure to oppose the natural process of osmosis, which would normally cause movement from a region of higher concentration (such as pure fresh water) into one of lower concentration (such as a water-salt solution). By the use of a membrane to allow

reverse water gas shift



the passage of water molecules but block larger salt molecules, reverse osmosis will cause water to move out of the salt solution, providing a means to remove salt from seawater.

reverse water gas shift (RGWS) see WATER


reversible Thermodynamics. describing an ideal thermodynamic process that can be exactly repeated in the reverse direction by means of an infinitesimal change in the external conditions; the entropy change for the system and its environment is zero. Thus, reversible change, cycle, or process.

reversible fuel cell see REGENERATIVE FUEL


reversible turbine Conversion. a hydraulic turbine that can be used either as a pump or as an engine, turbine, water wheel, or other such apparatus to drive an electrical generator; used in pumped-storage plants,

revisions Oil & Gas. the total quantity of oil and gas added to proved reserves in a year that derive mainly from non-drilling factors, such as the installation of improved recovery techniques or equipment; changes in economic, geologic, technological, and political factors, and correction of prior reporting errors.

revolution Physics. the motion of a body around a closed path, relative to some point that is internal or external to the moving body.

See also ROTATION.

Reynolds number Measurement. a measure for the importance of viscous friction in a flow, related to the speed of the flow. A lower Reynolds numbers means the flow speed is low and/or the fluid is very viscous, and thus friction is important; a higher number means the speed is high, and friction is unimportant. [Named for British physicist Osborne Reynolds, 1842–1912.]

R-factor another term for R-VALUE. RFC regenerative fuel cell.

RFG reformulated gasoline.

rhodium Chemistry. a metallic element having the symbol Rh, the atomic number 45, an atomic weight of 102.9, a melting point of 1970°C and a boiling point of 3730°C; a gray- ish-white, ductile metal that is obtained from platinum ores and gold gravels; used in high temperature alloys with platinum or palladium and in electrical components.

ribbon Materials. a thin sheet of crystalline or multicrystalline material produced in a continuous process by withdrawal from a molten bath of the parent material. Thus, ribbon silicon.

Ricardian Economics. having to do with or following the theories of David Ricardo (see below).

Ricardian rent Economics. rent accruing to owners of natural resources due to differing quality, and hence costs, of their holdings. For example, at a prevailing price for oil, the owner of a large, shallow oil field will have lower costs than the owner of a smaller, deeper field, and hence receive a greater Ricardian rent.

Ricardo, David 1772–1823, British economist who helped found the classical school of economics; noted especially for describing the principles of DIMINISHING RETURNS and


Ricardo, Harry 1885–1974, English engineer who established a measurement system that is the basis of today’s classification of fuels according to octane rating. He also made important improvements to diesel and airplane engines, most notably a patent for a two-stroke engine design.

rice coal see COAL SIZING.

rich mixture Oil & Gas. an air-fuel mixture that has a relatively high proportion of fuel and a relatively low proportion of air.

Richter scale Earth Science. a description of earthquake intensity, based on a logarithmic scale ranging from 1 to 9 that expresses the magnitude (Richter magnitude) of a given earthquake based on a measurement of the amount of energy dispersed during the event. [Developed by U.S. seismologist Charles F. Richter, 1900–1985.]

Rickover, Hyman 1900–1986, U.S. naval officer who led the effort to develop the world’s first nuclear-powered submarine, Nautilus, which was launched in 1954.

rider Coal. a term for a thinner seam of coal positioned above a thicker one.

riding carriage see REITWAGEN.

right-to-know Social Issues. 1. the principle that is in the public interest to disclose certain information, especially concerning the actions of the government or other large institutions.

Riker, Andrew Lawrence


Risk National Laboratory

2. specifically, the public release of information about the presence of hazardous or toxic chemicals in a community; e.g., from agricultural pesticides.

Riker, Andrew Lawrence 1868–1930, U.S. engineer who founded the Riker Electric Vehicle Company (1888), which became one of the country’s largest manufacturers of electric cars and trucks.

Ring of Fire Earth Science. a term for the Circum-Pacific belt, a zone of geothermal activity encircling the Pacific Ocean that is the site of frequent volcanic eruptions and earthquakes.

Ringelmann chart Environment. a scale traditionally used to make a subjective visual evaluation of the amount of solid matter emitted by a smokestack or other source; the observer compares the color of the smoke with a series of illustrations shaded in various levels of gray. A corresponding number (Ringelmann number) is assigned to the shade describing the best match; numbers range from 0 (white) to 5 (black). Named for French engineer Maximilian Ringelmann, 1861–1931.

Rio Declaration see EARTH SUMMIT.

riometer Measurement. relative ionospheric opacity meter; a specially designed radio receiver for the continuous monitoring of cosmic noise.

riparian Ecology. 1. having to do with or located on the bank of a river or stream. 2. describing an ecosystem that is transitional between terrestrial and aquatic ecosystems.

ripper Mining. a device used to break up solid material in a mine; e.g., earth, rock, or a coal seam, usually by means of a series of large teeth that tear away the surface.

ripple Electricity. the presence of an alternating current component in a direct-current signal; e.g., an undesirable AC component of a pulsating DC current produced by a rectifier or similar power conditioning device. Thus, ripple current.

riser Oil & Gas. 1. in an offshore drilling operation, the piping that extends from the platform to the hole, through which drilling is conducted. 2. piping through which gas or liquid may flow upward. 3. Electricity. the cable that connects buried or ground-level electrical cables to overhead power lines.

risk Health & Safety. the possibility of loss or injury; a finite measure of the severity and likelihood of an occurrence of damage, disease, or any other negative consequence.

risk analysis (assessment) Measurement. a detailed analysis of the nature and magnitude of unwanted, negative consequences to life, health, property, resources, or the natural environment.

risk aversion Economics. 1. the theory or principle that when facing alternate choices with apparently comparable returns, people and organizations will tend to choose the alternative that seems to offer less risk. 2. Ecology. a similar principle applied to animal behavior.

risk communication Health & Safety. the fact or process of providing the public with information about the risks associated with particular substances, products, activities, or technologies; e.g., prescription drugs, household cleaning products, toxic wastes.

risk factor Health & Safety. any condition, event, activity, or environmental characteristic that increases the likelihood of a given individual developing a certain disease or experiencing a negative change in his/her health status; e.g., cigarette smoking is identified as the leading risk factor for lung cancer; obesity is regarded as a risk factor for adultonset diabetes.

risk loving see RISK SEEKING.

risk phrases (R-phrases) Health & Safety. a set of warnings required by the European Union to appear on labels and safety data sheets for hazardous chemicals. These consist of the letter R followed by a number and a phrase describing the type of risk (explosive, flammable, toxic, and so on); e.g., R1: explosive when dry; R11: highly flammable; R25: toxic if swallowed.

risk proclivity see RISK SEEKING.

risk seeking Economics. the converse of the usual principle of RISK AVERSION; the theory that when facing alternate choices with apparently comparable returns, someone will tend to choose the alternative that seems to offer more risk; e.g., investing in speculative rather than blue-chip stocks.

Risk National Laboratory a Danish government research institution that is a world leader in wind energy research.

Rittenhouse, William


Rockefeller, John D.

Rittenhouse, William 1644–1708, builder of the first American paper mill (1690), near Philadelphia. He also developed an early recycling system in which much of the mill’s fiber for hand papermaking was obtained from discarded rags and cotton.

Rivaz, Francois Isaac de 1752–1828, Swiss engineer, believed to be the first person to equip a stationary gas engine with electric ignition. In 1813 he fitted an engine of this type to a vehicle and conducted test runs near Lake Geneva.

R lamp short for REFLECTOR LAMP.

road carriage History. a name for early steampowered passenger vehicles, such as a type developed by engineer Richard Trevithick in the early 1800s.

road engine History. a name for one of the earliest vehicles powered by an internal-com- bustion engine, patented by attorney George


road octane Oil & Gas. the measured antiknock rating of a motor fuel, determined under normal driving conditions.

road oil Oil & Gas. any heavy petroleum oil, including residual asphaltic oil, used as a dust palliative and surface treatment on roads and highways. It is generally produced in six grades from 0, the most liquid, to 5, the most viscous.

robbed-out Coal. describing an area of a coal mine from which the supporting pillars have been removed.

robbing Coal. the process of extracting pillars of coal that had previously been left in place for support

Robinson, Enders born 1930, U.S. geophysicist who developed the theory and method of DECONVOLUTION, which would revolutionize the interpretation of seismic data in petroleum exploration.

robot Consumption & Efficiency. 1. any industrial device that can be programmed to perform a variety of tasks involving manipulation and movement under automatic control. 2. specifically, such a device that has somewhat of a humanlike appearance or that operates with humanlike capacities.

robotics Consumption & Efficiency. the technology of robots; the design, manufacture, and use of mechanical devices that can be

programmed to perform various industrial tasks.

rock bed storage Storage. a type of thermal storage medium used in passive solar heating or cooling, consisting of an underground accumulation of rocks serving as a heat exchanger.

rock drill Mining. a drill, generally having bits detachable from the drill stem, that is designed to bore relatively short holes through rock for blasting purposes; powered either by electricity, compressed air, or steam. Used to excavate large amounts of earth and rock in tunneling, mining, and quarrying.

rock dusting Mining. the process of removing a layer of dust, typically composed of powdered limestone, from wall areas in order to contain or minimize explosions, aid in the lighting of the mine, and reduce health hazards

Rockefeller, John D. 1839–1937, U.S. industrialist and philanthropist, generally regarded as the founder of the modern oil and gas industry. At its peak, his Standard Oil company controlled about 90% of oil refining in the U.S. This and other business activities made him reputedly the world’s richest man,

robot The term “robot” became known in the title of a play by Czech author Karel Capek, in which human-like machines rebel against their living masters.

rocker arm



and the name “Rockefeller” became a symbol for wealth.

rocker arm Transportation. a center-pivoted lever in an internal combustion engine that transmits motion from a cam or a push rod to a valve stem.

rocket Transportation. 1. a reaction engine that contains within itself everything necessary for the combustion of its fuel, and that therefore does not require an external medium of air for combustion (thus it can operate in outer space). The simplest rocket engine consists of a combustion chamber and a nozzle; a more complex type may have more than one combustion chamber. 2. a vehicle or projectile propelled by such an engine. Technically, a rocket engine is one that employs a liquid propellant, and a rocket motor employs a solid propellant.

rocket The launch of a U.S. Delta II rocket, carrying a GPS (global positioning system) satellite that provides strategic military information.

Rocket Transportation. an advanced type of locomotive designed by Robert Stephenson and Company (1829); its basic design principles were utilized from that time until the end of British steam locomotive building in the mid-20th century.

rocket fuel Transportation. any of various liquid or solid substances used as fuel in rockets, such as liquid hydrogen or gasoline; characterized by the potential for extremely

rapid, controlled combustion and subsequent production of large volumes of gas at high pressure and temperature.

rocketry Transportation. the science and technology of rocket design and operation.

rocketsonde Measurement. a rocket-borne instrument for measurement and transmission of upper-air meteorological data in the lower 76,000 m of the atmosphere, especially the portion that is inaccessible to radiosonde techniques.

rockfill dam Hydropower. an embankment formed largely of dumped rock for stability and fitted with an impervious water-face membrane and core-wall.

rock oil History. an early term for petroleum, based on its presence in rock formations.

rockwool Materials. a type of insulating material so called because it resembles old grayish wool with dark flecks; spun like fiberglass from the slag from refining metals.

Rocky Mountain Institute (est. 1982), a research and advocacy group founded by Amory Lovins in Snowmass, Colorado, aimed at transforming various sectors of the economy to more efficient use of natural resources, especially reduced dependence on fossil fuels.

Roentgen, Wilhelm 1845–1923, German physicist famous for his discovery of X-rays (1895). This discovery was the key to a new era of modern physics and it would revolutionize diagnostic medicine.

roentgen Nuclear. a unit of ionizing-radiation dosage of X-rays or gamma rays, equivalent to the amount that produces one electrostatic unit of electrical charge from secondary ionization in one cubic centimeter of dry air under standard conditions.

roentgen equivalent man see REM.

rolling blackout Electricity. a purposeful series of temporary, controlled power outages carried out by a utility company, with the intent of preventing heavy demand from crashing the electrical grid and causing a fullscale unplanned blackout.

rolling mill Materials. a sequential arrangement of milling devices used to crush and grind material.

roof Mining. 1. the rock, commonly shale and usually carbonaceous, found immediately

roof bolt



above a coal seam, ore body, or other tabular deposit. 2. the overhead surface of a coal working place.

roof bolt Mining. a long steel bolt driven into the roof of an underground excavations to prevent or limit the extent of roof falls. Thus, roof bolter.

roof fall Mining. a cave-in; a collapse of the roof of a coal mine, especially in a permanent area such as an entry.

roof pond Solar. 1. a solar energy collection device consisting of containers of water located on a roof that absorb solar energy during the day so that the heat can be used at night. 2. a similar system that cools a building by evaporation at night.

roof rock another term for SEAL ROCK.

roof sag Mining. a sinking of the roof of a coal mine, especially in the middle; the equivalent of heave which is a similar dislocation of a mine floor.

room Mining. 1. an area abutting an entry or airway in which coal is mined. 2. any wide working space within a flat mine.

room-and-pillar mining Mining. a common method of coal mining in which rooms (large open spaces) are cut into the coalbed leaving in place a series of pillars (columns of coal) to help support the mine roof and control the flow of air. As the mining advances, a gridlike pattern of rooms and pillars is formed. Also, room-and-pillar system.

root Wind. a term for the section of a wind turbine blade nearest to the hub; usually the thickest and widest part of the blade.

rose see WIND ROSE.

Rosenfeld, Arthur U.S. physicist noted for his leadership in the development of energyefficient technologies, including electronic ballasts for fluorescent lamps, low-emissivity windows, and computer programs for the energy analysis and design of buildings.

rotary compressor Consumption & Efficiency. a machine having a rotating part that directly compresses fluid in an enclosed housing; the fluid pressure rises as the volume of the closed space decreases.

rotary drill Oil & Gas. a drilling machine having a rigid, rotating, tubular string of rods connected to a rock-cutting bit; a historic advance (mid 19th century) in drilling deep holes in

search of petroleum or gas, as compared to the previous technology of cable tool rigs that relied on pulverizing rock formations.

rotary engine Transportation. an engine having a thermodynamic cycle mechanism that is powered and designed to move on a circular path; used for steam engines and in some internal-combustion (automotive) engines.


rotation Physics. 1. the motion of a body about an internal axis of symmetry; the axis may be fixed or moving, and actual or theoretical. Rotation is the movement of a body in relation to an internal point, and revolution is its movement in reference to an external point. Thus the earth revolves around the sun, and rotates on its own axis. 2. a description of such rotating motion, expressed as the change in a body’s angular orientation over time, with respect to some relevant (usually inertial) frame of reference. 3. one complete turn of a celestial body about its axis. Thus, rotational.

rotational energy Physics. 1. the kinetic energy of a body as measured in a nonrotating frame of reference in which its center of mass is stationary. 2. the minimum work needed to cause an object to rotate at a certain velocity, starting from rest. 3. the difference between the energy in a molecule with more than one atom, and the energy in a theoretical molecule constructed by stopping the rotation of the atomic nuclei without hindering their vibrational electron movement.

roundwood Biomass. a term for logs, bolts, or other round sections cut from trees.

Rover History. the earliest commercially successful version of the modern bicycle, developed by John Kemp Starley of England and marketed by him and fellow bicycle innovator William Sutton through their Rover Company. In full, Rover Safety Bicycle.

Royal Dutch/Shell (est. 1907), the world’s third largest integrated oil company (after BP and Exxon Mobil). Its structure dates back to 1907 from the merger of Royal Dutch, formed in the Netherlands to develop oil fields in Asia, and SHELL.

royalty Economics. 1. a payment made for the use of property rights, especially intellectual property. 2. a payment made in money or kind for a stated share of production from mineral or fuel deposits, paid by the lessee to

r-per cent rule



the lessor; often calculated as a percentage of the gross income from a lease.

r-per cent rule another term for the HOTELLING


R-phrases see RISK PHRASES.

RPM revolutions per minute. RPS renewable portfolio standard.

RTG radioisotope thermoelectric generator. RTO regenerative thermal oxidizer.

rubber Materials. 1. a raw gum material characterized by its elasticity, obtained from a certain tree Hevea brasiliensis, that is native to tropical America, or from various other tropical trees, such as F. elastica, or other trees of the genus Ficus. 2. any of various synthetic polymers having similar properties to natural rubber.

rubber The para rubber tree, Hevea brasiliensis; the source of the largest amount and highest quality of natural rubber.

rubblization Nuclear. a decommissioning technique involving demolition and burial of formerly operating nuclear facilities; so called because above-grade structures are demolished into rubble and buried in the structure’s foundation below ground. The site surface is then covered for unrestricted use.

Rubisco Biological Energetics. short for ribu- lose-1,5-bisphosphate carboxylase, a ubiquitous enzyme that represents the crucial starting point

of any food chain, because of its ability to fix inorganic carbon dioxide from the atmosphere. rule of law Global Issues. the concept or practice of equal protection under the law for human rights as well as property and other economic rights, and punishment for the vio-

lation of such rights.

Rumford, Count Benjamin Thompson 1753– 1814, British–American scientist noted for his contributions to the modern theory of heat. From his work boring cannon barrels, he noted that the cannon would stay hot as long as the friction of boring continued. This could not be explained by the prevailing CALORIC THEORY of heat as a fluid state of matter, and he concluded that heat is a form of mechanical energy produced by the motion of particles.

Rumford stove History. an improved stove invented by Count Rumford (1795), an innovative version providing greater heat with less smoke.

runner Conversion. the rotating part of a turbine that converts the energy of the working fluid (water, steam, or gas) into mechanical energy. runoff Earth Science. 1. the portion of precipitation that flows over the land surface and ultimately reaches streams to complete the water cycle; sources include melting snow and any surface water that moves to streams or rivers through a drainage basin. 2. wastewater (or other liquids) entering the environment as a

result of some industrial activity. run-of-mine coal Coal. a heterogeneous

material consisting of particles of various sizes, often wet and contaminated with impurities such as rock and/or clay and unsuitable for commercial use without treatment.

run-of-river Hydropower. describing a hydroelectric project that uses the power of moving water as it occurs, with little or no reservoir capacity for storage; typically employed at a site with a large water flow where major dam construction is not feasible.

run of the wind Wind. the indicated distance that the wind travels in a certain time, measured by the miles of wind blowing past an anemometer.

run-or-lose Consumption & Efficiency. a term for energy production that will be lost if not used at the time it is produced; usually refers to solar power and hydroelectric energy that cannot be stored after production.

rural electric cooperative


Rydberg formula

rural electric cooperative (REC) Electricity. an independent, locally owned business enterprise in which consumers who receive electrical service are member-owners of the cooperative and share responsibility for its success or failure along with the benefits they receive. Similarly, rural utilities cooperative.

rural electrification Social Issues. the fact or process of utilities providing electrical service to rural communities previously lacking or deficient in this service.

Rural Electrification Act (REA) History. a measure signed into law by President Franklin D. Roosevelt in 1936, to address the fact that the rural U.S. was still largely without electricity. Within 2 years REA projects provided electricity to 1.5 million farms, and by the mid-1950s virtually all American farms were electrified.

rural energy Social Issues. energy use by rural households, especially traditional forms such as the burning of wood or crop wastes; usually refers to domestic uses such as heating and cooking, as opposed to the energy used for crop and livestock production.

ruthenium Chemistry. a rare metallic element of the platinum group having the symbol Ru, the atomic number 44, and an atomic weight of 101.07, with 7 stable isotopes, a melting point of 2310°C, and a boiling point of about 4000°C; it is a grayish-white brittle metal used as a hardener for platinum and palladium, as a catalyst, and in alloys.

Rutherford, Ernest 1871–1937, New Zealand born British physicist noted for his studies of radioactivity and his discovery of the atomic nucleus. He coined the terms “alpha”, “beta”, and “gamma” to classify various forms of rays that were poorly understood before his time. He also devised the “half-life” concept to describe the fact that the intensity of radioactivity declines over time.

runtime or run time Storage. battery life; the total amount of time that a battery will provide power before it must be recharged.

Ruud heater History. the first device to store and automatically heat water (1889), developed by Norwegian–American engineer Edwin Ruud.

R-value HVAC. a unit of thermal resistance used for comparing the insulating values of

different material, indicating a given material’s effectiveness in retarding heat flow; higher R-value numbers indicate greater insulating properties. It is expressed in units of temperature (°F) × hours × square feet per Btu. RSee below.

Rydberg constant Nuclear. a fundamental physical constant used in studies of the spectrum of a substance; its value for hydrogen is 109,737.3 cm1. It is regarded as one of the most important physical constants since it has the potential to be determined with high precision and can be regarded as a natural unit of both length and time. [Described by Swedish physicist Johannes Rydberg 1854–1919.]

Rydberg formula Nuclear. a formula used in atomic physics to determine the full spectrum of light emission from hydrogen, later extended to be useful with any element.

RR-value The term R-value stands for thermal resistance and is a measure of the

level of resistance to heat flow a given material or an assembly can offer as a result of suppressing conduction, convection, and radiation. The thermal resistance for a homogeneous material is mainly associated with the conduction of heat and is a function of material thermal conductivity and thickness (the length of heat flow path) and is expressed in F-ft2-h/Btu (K-m2/W). R-value is directly proportional to the material thickness and inversely proportional to its thermal conductivity.

Thermal resistance may also be associated with the heat transfer by convection and radiation at a surface. The thermal resistance follows the same analogy as the electrical resistance associated with the conduction of electricity. Therefore, the formulation of heat flows in terms of thermal resistance allows the heat flow through any assembly to be presented as a thermal circuit. Composite components that are characterized by multiple layers with resistances in series and parallel arrangements can be presented by an equivalent thermal circuit. Resistances in series are additive and the overall R-value of an assembly is obtained by summing up the equivalent resistances of all layers comprising that assembly.

Mohammad Al-Homoud

King Fahd University of Petroleum and Minerals Saudi Arabia


sabkha Earth Science. plural, sabkhat. a flat, low area covered by clay, silt, and sand, and often encrusted with salt, found in arid and semiarid environments; e.g., oil-producing regions such as the Arabian peninsula and the Permian Basin of West Texas. [From an Arabic term meaning “salt flat”.]

saccharification Chemistry. the process of converting starch or dextrin into sugar.

Sachs, Julius Von 1832–1897, German botanist who was a founder of experimental plant physiology. He discovered that, in the presence of light, chlorophyll catalyzes photosynthetic reactions (1865).

sacrificial protection Materials. the purposeful corrosion of a less desirable metal so that an adjacent preferred metal can be protected from corrosion. Thus, sacrificial anode, sacrificial metal.

SAE Society of Automotive Engineers.

SAE horsepower Transportation. a standard measure of a vehicle’s horsepower; the horsepower generated by the engine at the flywheel with all energy-drawing accessories attached, such as an alternator and power steering and air conditioning units. Also called SAE net horsepower in contrast with the earlier standard it replaced, SAE gross horsepower, which is horsepower measured with no load from a chassis or accessories and with ideal fuel and ignition conditions.

SAE number Transportation. a system for classifying crankcase, transmission, and differential lubricant according to their viscosities.

safety injection Nuclear. the rapid insertion of a chemically soluble neutron poison (such as boric acid) into a reactor coolant system to ensure reactor shutdown.

safety lamp Mining. a coal miner’s lamp that is deemed relatively safe for use even in atmospheres that may contain flammable gas.

safety rod Nuclear. a control rod used in a nuclear reactor to decrease the reactor reactivity in the case of emergencies.

SAFSTOR Nuclear. safe storage; a method of decommissioning for a nuclear facility in which it is placed and maintained in a condition that permits materials to be safely stored and the facility subsequently decontaminated to levels that permit release for unrestricted use.

Sagebrush Rebellion Policy. a term for organized resistance in the Western U.S. to government land management policies; applied to various populist movements and protests but generally referring to objections by ranchers and farmers to government restrictions on the private use of Federal land.

Sahara Blend Oil & Gas. an oil type of Algeria, one of an array or basket of seven crude oil types used by OPEC as reference points for pricing.

sail Transportation. 1. a large piece of fabric or similar flexible material that is used to catch or deflect the wind, providing propulsive power for a vessel to move forward. 2. Wind. the extended surface of the arm of a windmill.

sail wing Wind. a propeller on a wind turbine that is similar to the sail of a boat, with cloth stretched over a metal wire frame to form an airfoil section.

Saint Elmo’s fire Earth Science. a glow accompanying discharges of atmospheric lightning, historically seen at the tops of church steeples or the tall masts of sailing ships, now also seen on the wing tips of aircraft. [From Saint Elmo, (Erasmus), patron saint of early Mediterranean sailors.]

salable ton Coal. the total weight of coal mined and sold, with impurities removed by surface coal processing methods applied at the mine.

salinization Earth Science. the fact of becoming saline (salty); the process by which salts accumulate in water or soil.

salinometer Measurement. a device or instrument used to measure the salt content of a solution (e.g., brine), especially one based on electrical conductivity methods.