List of definitions of terms and concepts related to civil engineering
This glossary of civil engineering terms is a list of definitions of terms and concepts pertaining specifically to civil engineering, its sub-disciplines, and related fields. For a more general overview of concepts within engineering as a whole, see Glossary of engineering.
An instrument used in surveying which consists of a fixed sighting tube, a movable spirit level that is connected to a pointing arm, and a protractor scale. An internal mirror allows the user to see the bubble in the level while sighting a distant target. It can be used as a hand-held instrument or mounted on a Jacob's staff for more precise measurement.[1][2]
A law which states that the strength of a concrete mix is inversely related to the massratio of water to cement.[3][4][5][6] As the water content increases, the strength of the concrete decreases.
The process of scuffing, scratching, wearing down, marring, or rubbing away a substance or substrate. It can be intentionally imposed in a controlled process using an abrasive. Abrasion may also be an undesirable effect of exposure to normal use or exposure to the elements.
In electrochemistry, according to an IUPAC definition,[7] is the electrode potential of a metal measured with respect to a universal reference system (without any additional metal–solution interface).
In chemistry, the common logarithm of the ratio of incident to transmitted radiant power through a material. Spectral absorbance or spectral decadic absorbance is the common logarithm of the ratio of incident to transmitted spectral radiant power through a material.[11] Absorbance is a dimensionless quantity, and in particular is not a length, though it is a monotonically increasing function of path length, and approaches zero as the path length approaches zero.
A chemical reaction that occurs between an acid and a base, which can be used to determine pH. Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems; these are called the acid–base theories, for example, Brønsted–Lowry acid–base theory.
A special kind of board made of sound-absorbing materials, designed to provide sound insulation.[17][18] Between two outer walls sound-absorbing material is inserted and the wall is porous. Thus, when sound passes through an acoustic board, the intensity of the sound is decreased. The loss of sound energy is typically balanced by the production of heat energy.
A generic name for a group of mathematical methods to model activated sludge systems. The research in this area is coordinated by a task group of the International Water Association (IWA). Activated sludge models are used in scientific research to study biological processes in hypothetical systems. They can also be applied on full scale wastewater treatment plants for optimisation, when carefully calibrated with reference data for sludge production and nutrients in the effluent.
In cellular biology, the movement of molecules across a membrane from a region of their lower concentration to a region of their higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement. There are two types of active transport: primary active transport that uses ATP, and secondary active transport that uses an electrochemical gradient.
A mechanism by which a control system acts upon an environment. The control system can be simple (a fixed mechanical or electronic system), software-based (e.g. a printer driver, robot control system), a human, or any other input.[19]
The tendency of dissimilar particles or surfaces to cling to one another (cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another). The forces that cause adhesion and cohesion can be divided into several types. The intermolecular forces responsible for the function of various kinds of stickers and sticky tape fall into the categories of chemical adhesion, dispersive adhesion, and diffusive adhesion. In addition to the cumulative magnitudes of these intermolecular forces, there are also certain emergent mechanical effects.
In thermodynamics, an adiabatic process is one that occurs without transfer of heat or mass of substances between a thermodynamic system and its surroundings. In an adiabatic process, energy is transferred to the surroundings only as work.[20][21] The adiabatic process provides a rigorous conceptual basis for the theory used to expound the first law of thermodynamics, and as such it is a key concept in thermodynamics.
A process in sewage treatment designed to reduce the volume of sewage sludge and make it suitable[22] for subsequent use.[23] More recently, technology has been developed that allows the treatment and reduction of other[24] organic waste, such as food, cardboard and horticultural waste.
The study of the motion of air, particularly its interactions with solid objects such as airplane wings. Aerodynamics is a sub-field of fluid dynamics and gas dynamics, and many aspects of aerodynamics theory are common to these fields.
In optics, an optical system without focus, i.e. one that produces no net convergence or divergence of a beam of light, and which therefore has an infinite effective focal length.[25]
The engineering discipline that studies agricultural production and processing. Agricultural engineering combines the disciplines of mechanical, civil, electrical and chemical engineering principles with a knowledge of agricultural principles according to technological principles. A key goal of this discipline is to improve the efficacy and sustainability of agricultural practices.[5]
A broad area of mathematics, together with number theory, geometry and analysis. In its most general form, algebra is the study of mathematical symbols and the rules for manipulating these symbols;[26] it is a unifying thread of almost all of mathematics.[27] It includes everything from elementary equation solving to the study of abstractions such as groups, rings, and fields. The more basic parts of algebra are called elementary algebra; the more abstract parts are called abstract algebra or modern algebra. Elementary algebra is generally considered to be essential for any study of mathematics, science, or engineering, as well as such applications as medicine and economics. Abstract algebra is a major area in advanced mathematics, studied primarily by professional mathematicians.
A type of electric current which periodically reverses direction, in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, fans and electric lamps into a wall socket. A common source of DC power is a battery cell in a flashlight. The abbreviations AC and DC are often used to mean simply alternating and direct, as when they modify current or voltage.[32][33]
In chemistry, an amphoteric compound is a molecule or ion that can react both as an acid and as a base.[40] Many metals (such as copper, zinc, tin, lead, aluminium, and beryllium) form amphoteric oxides or hydroxides. Amphoterism depends on the oxidation states of the oxide. Al2O3 is an example of an amphoteric oxide.
An electronic device that can increase the power of a signal (a time-varying voltage or current). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude of a signal applied to its input terminals, producing a proportionally greater amplitude signal at its output. The amount of amplification provided by an amplifier is measured by its gain: the ratio of output voltage, current, or power to input. An amplifier is a circuit that has a power gain greater than one.[41][42][43]
is an ion with more electrons than protons, giving it a net negative charge (since electrons are negatively charged and protons are positively charged).[45]
states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces and acts in the upward direction at the center of mass of the displaced fluid.[46] Archimedes' principle is a law of physics fundamental to fluid mechanics. It was formulated by Archimedes of Syracuse.[47]
The process and the product of planning, designing, and constructingbuildings or any other structures.[48] Architectural works, in the material form of buildings, are often perceived as cultural symbols and as works of art. Historical civilizations are often identified with their surviving architectural achievements.
The technology by which a process or procedure is performed with minimal human assistance.[49] Automation [50] or automatic control is the use of various control systems for operating equipment such as machinery, processes in factories, boilers and heat treating ovens, switching on telephone networks, steering and stabilization of ships, aircraft and other applications and vehicles with minimal or reduced human intervention.
Any self-operating machine, or a machine or control mechanism designed to automatically follow a predetermined sequence of operations, or respond to predetermined instructions.[51]
A device consisting of one or more electrochemical cells with external connections provided to power electrical devices such as flashlights, mobile phones, and electric cars.[53] When a battery is supplying electric power, its positive terminal is the cathode and its negative terminal is the anode.[54] The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy.[citation needed] Historically the term "battery" specifically referred to a device composed of multiple cells, however the usage has evolved to include devices composed of a single cell.[55]
A structural element that primarily resists loads applied laterally to its axis. Its mode of deflection is primarily by bending. The loads applied to the beam result in reaction forces at the beam's support points. The total effect of all the forces acting on the beam is to produce shear forces and bending moments within the beam, which in turn induce internal stresses, strains and deflections of the beam. Beams are characterized by their manner of support, profile (shape of cross-section), length, and material.
A physical property of a material such that, when subjected to stress, it breaks without significant plastic deformation. Brittle materials absorb relatively little energy prior to fracture, even those of high strength.
A measure of how resistant to compression a substance is, defined as the ratio of the infinitesimal pressure increase to the resulting relative decrease in volume. It is one of three standard moduli used to describe a material's response to stress, along with the shear modulus and Young's modulus.
The professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, railways, canals, dams, airports, sewage systems, pipelines, structural components of buildings, and infrastructure for civic utilities.
In chemistry and physics, a law which states that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases.[60] This empirical law was first observed by John Dalton in 1801 and published in 1802,[61] and is closely related to the idealgas laws.
An engineer whose profession focuses on the engineering design process in any of the various disciplines of engineering, e.g. civil engineering. Design engineers tend to work on products and systems that involve adapting and using complex scientific and mathematical techniques in order to develop solutions for human society.
Any interconnection of electrical components (e.g. batteries, resistors, inductors, capacitors, switches, etc.), or a model of such an interconnection consisting of electrical elements (e.g. voltage sources, current sources, resistances, inductances, and capacitances).
The study of the combined disciplines of physics, mathematics and engineering, particularly computer, nuclear, electrical, electronic, materials or mechanical engineering. By focusing on the scientific method as a rigorous basis, it seeks ways to apply, design, and develop new solutions in engineering.[62][63][64][65]
A mechanical device which uses the conservation of angular momentum to store rotational energy. Flywheels are therefore a type of accumulator, analogous to electrical inductors, in that they store energy for later use. They are commonly used to smooth deviations in the power output of an energy source, to deliver stored energy at rates that exceed the ability of the energy source, and to control the orientation of mechanical systems.
A synthetic material used to insulate and protect buildings. Housewrap functions as a weather-resistant barrier, preventing rain from getting into the wall assembly while allowing water vapor to pass to the exterior. If moisture from either direction is allowed to build up within stud or cavity walls, mold and rot can set in and fiberglass or cellulose insulation will lose its R-value due to heat-conducting moisture. House wrap may also serve as an air barrier if it is sealed carefully at seams.[66]
An established norm or requirement for a repeatable technical task, especially when written in a formal document that establishes uniform criteria, methods, processes, and practices. A technical standard may be developed privately or unilaterally by edict, or by groups such as trade associations, industry standards organizations, or governments, often according to the formal consensus of experts in the discipline.
An assembly of two-force structural members such as beams, connected at nodes, where the members are organized such that the assemblage as a whole behaves as a single, rigid object.[71]
Also ultimate strength or simply tensile strength (TS).
The maximum stress that a material under tension can withstand while being stretched or pulled before breaking. Ultimate tensile strength is usually found by performing a tensile test and recording the stress versus strain; the highest point of the stress–strain curve is the ultimate tensile strength. Tensile strengths are often important in the design of brittle members. Contrast compressive strength.
The nominal frequency of the oscillations of alternating current (AC) in a wide area synchronous grid transmitted from a power station to an end-user. In much of the world the utility frequency is standardized at 50 Hz, although in the Americas and parts of Asia it is typically 60 Hz.
A management-led program to eliminate defects in industrial production that enjoyed brief popularity in American industry from 1964[72] to the early 1970s. Quality expert Philip Crosby later incorporated it into his "Absolutes of Quality Management" and it enjoyed a renaissance in the American automobile industry—as a performance goal more than as a program—in the 1990s. Although applicable to any type of enterprise, it has been primarily adopted within supply chains wherever large volumes of components are being purchased (common items such as nuts and bolts are good examples).
States that if two thermodynamic systems are each in thermal equilibrium with a third one, then they are in thermal equilibrium with each other. Accordingly, thermal equilibrium between systems is a transitive relation. Two systems are said to be in the relation of thermal equilibrium if they are linked by a wall permeable only to heat and they do not change over time.[73] As a convenience of language, systems are sometimes also said to be in a relation of thermal equilibrium if they are not linked so as to be able to transfer heat to each other, but would still not do so (even) if they were connected by a wall permeable only to heat.
^"Unit of thermodynamic temperature (kelvin)". SI Brochure, 8th edition. Bureau International des Poids et Mesures. 13 March 2010 [1967]. Section 2.1.1.5. Archived from the original on 7 October 2014. Retrieved 20 June 2017. Note: The triple point of water is 0.01 °C, not 0 °C; thus 0 K is −273.15 °C, not −273.16 °C.
^See Herstein, I. N. (1964). Topics in Algebra. Ginn and Company. ISBN0-471-02371-X., page 1: "An algebraic system can be described as a set of objects together with some operations for combining them".
^See (Herstein 1964) , page 1: "...it also serves as the unifying thread which interlaces almost all of mathematics".
^Callister, W. D. "Materials Science and Engineering: An Introduction" 2007, 7th edition, John Wiley and Sons, Inc. New York, Section 4.3 and Chapter 9.
^"Amino". Dictionary.com. 2015. Retrieved 3 July 2015.
^"amino acid". Cambridge Dictionaries Online. Cambridge University Press. 2015. Retrieved 3 July 2015.
^"amino". FreeDictionary.com. Farlex. 2015. Retrieved 3 July 2015.
^SI supports only the use of symbols and deprecates the use of abbreviations for units."Bureau International des Poids et Mesures"(PDF). 2006. p. 130. Archived(PDF) from the original on 21 June 2007. Retrieved 21 November 2011.
^Groover, Mikell (2014). Fundamentals of Modern Manufacturing: Materials, Processes, and Systems.
^Rifkin, Jeremy (1995). The End of Work: The Decline of the Global Labor Force and the Dawn of the Post-Market Era. Putnam Publishing Group. pp. 66, 75. ISBN978-0-87477-779-6.
^Williams, Jan R.; Susan F. Haka; Mark S. Bettner; Joseph V. Carcello (2008). Financial & Managerial Accounting. McGraw-Hill Irwin. p. 40. ISBN978-0-07-299650-0.
^The American Heritage Dictionary, Second College Edition (1985). Boston: Houghton Mifflin Co., p. 691.
^McGraw-Hill Dictionary of Physics, Fifth Edition (1997). McGraw-Hill, Inc., p. 224.
^Plesha, Michael E.; Gray, Gary L.; Costanzo, Francesco (2013). Engineering Mechanics: Statics (2nd ed.). New York: McGraw-Hill Companies Inc. pp. 364–407. ISBN978-0-07-338029-2.
