List of definitions of terms and concepts related to civil engineering
Thisglossary of civil engineering terms is a list of definitions of terms and concepts pertaining specifically tocivil engineering, its sub-disciplines, and related fields. For a more general overview of concepts withinengineering as a whole, seeGlossary of engineering.
An instrument used insurveying 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 aJacob's staff for more precise measurement.[1][2]
A law which states that the strength of aconcrete mix is inversely related to themassratio ofwater tocement.[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 anabrasive. Abrasion may also be an undesirable effect of exposure to normal use or exposure to the elements.
Inelectrochemistry, according to anIUPAC definition,[7] is theelectrode potential of ametal measured with respect to a universal reference system (without any additional metal–solution interface).
In chemistry, thecommon logarithm of the ratio of incident to transmittedradiant power through a material.Spectral absorbance orspectral decadic absorbance is the common logarithm of the ratio of incident to transmittedspectral radiant power through a material.[11] Absorbance is adimensionless 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.
Achemical reaction that occurs between anacid and abase, which can be used to determinepH. Severaltheoretical 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 isporous. 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 modelactivated sludge systems. The research in this area is coordinated by a task group of theInternational 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 usesATP, andsecondary 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 orsurfaces 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, anadiabatic process is one that occurs without transfer ofheat ormass of substances between athermodynamic system and its surroundings. In an adiabatic process, energy is transferred to the surroundings only aswork.[20][21] The adiabatic process provides a rigorous conceptual basis for the theory used to expound thefirst law of thermodynamics, and as such it is a key concept inthermodynamics.
A process insewage 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 ofair, particularly its interactions with solid objects such asairplane wings. Aerodynamics is a sub-field offluid dynamics andgas dynamics, and many aspects of aerodynamics theory are common to these fields.
Inoptics, 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 infiniteeffective focal length.[25]
Theengineering discipline that studiesagricultural production and processing. Agricultural engineering combines the disciplines ofmechanical,civil,electrical andchemical 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]
Abroad area ofmathematics, together withnumber theory,geometry andanalysis. In its most general form, algebra is the study ofmathematical 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 asgroups,rings, andfields. The more basic parts of algebra are calledelementary algebra; the more abstract parts are calledabstract 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 ofelectric current which periodically reverses direction, in contrast todirect current (DC) which flows only in one direction. Alternating current is the form in whichelectric power is delivered to businesses and residences, and it is the form ofelectrical energy that consumers typically use when they plugkitchen appliances, televisions, fans and electric lamps into awall socket. A common source of DC power is abattery cell in aflashlight. The abbreviationsAC andDC are often used to mean simplyalternating anddirect, as when they modifycurrent orvoltage.[32][33]
In chemistry, anamphoteric compound is a molecule or ion that can react both as anacid and as abase.[40] Many metals (such ascopper,zinc,tin,lead,aluminium, andberyllium) form amphoteric oxides or hydroxides. Amphoterism depends on theoxidation states of the oxide.Al2O3 is an example of an amphoteric oxide.
An electronic device that can increase thepower of asignal (a time-varyingvoltage orcurrent). It is atwo-port electronic circuit that uses electric power from apower supply to increase theamplitude 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 itsgain: the ratio of output voltage, current, or power to input. An amplifier is a circuit that has apower 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 upwardbuoyant force that is exerted on a body immersed in afluid, whether fully or partially submerged, is equal to theweight of the fluid that the bodydisplaces and acts in the upward direction at the center of mass of the displaced fluid.[46] Archimedes' principle is alaw of physics fundamental to fluid mechanics. It was formulated byArchimedes of Syracuse.[47]
The process and the product ofplanning,designing, andconstructingbuildings or any otherstructures.[48] Architectural works, in the material form ofbuildings, are often perceived as cultural symbols and asworks 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 variouscontrol 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-operatingmachine, 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 moreelectrochemical cells with external connections provided to power electrical devices such asflashlights,mobile phones, andelectric cars.[53] When a battery is supplyingelectric power, its positive terminal is thecathode and its negative terminal is theanode.[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, aredox reaction converts high-energy reactants to lower-energy products, and thefree-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]
Astructural element that primarily resistsloads applied laterally to its axis. Its mode of deflection is primarily bybending. The loads applied to the beam result inreaction forces at the beam's support points. The total effect of all the forces acting on the beam is to produceshear forces andbending 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 tostress, it breaks without significantplastic deformation. Brittle materials absorb relatively little energy prior to fracture, even those of highstrength.
A measure of how resistant tocompression 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 tostress, along with theshear modulus andYoung's modulus.
The professionalengineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, includingpublic 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 totalpressure exerted is equal to the sum of thepartial pressures of the individual gases.[60] This empirical law was first observed byJohn Dalton in 1801 and published in 1802,[61] and is closely related to theidealgas laws.
An engineer whose profession focuses on theengineering 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 ofelectrical elements (e.g. voltage sources, current sources, resistances, inductances, and capacitances).
The study of the combined disciplines ofphysics,mathematics andengineering, particularly computer, nuclear, electrical, electronic, materials or mechanical engineering. By focusing on thescientific 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 ofangular momentum to storerotational energy. Flywheels are therefore a type ofaccumulator, analogous toelectrical 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.
Asynthetic material used to insulate and protect buildings. Housewrap functions as aweather-resistant barrier, preventing rain from getting into the wall assembly while allowingwater vapor to pass to the exterior. If moisture from either direction is allowed to build up within stud or cavity walls,mold androt can set in andfiberglass orcellulose insulation will lose itsR-value due to heat-conducting moisture. House wrap may also serve as anair 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 asbeams, connected atnodes, where the members are organized such that the assemblage as a whole behaves as a single, rigid object.[71]
Alsoultimate strength or simplytensile strength (TS).
The maximumstress that a material undertension can withstand while being stretched or pulled before breaking. Ultimate tensile strength is usually found by performing atensile test and recording the stress versusstrain; the highest point of thestress–strain curve is the ultimate tensile strength. Tensile strengths are often important in the design ofbrittle members. Contrastcompressive strength.
The nominalfrequency of the oscillations ofalternating current (AC) in awide area synchronous grid transmitted from apower station to an end-user. In much of the world the utility frequency is standardized at 50Hz, 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 expertPhilip 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 withinsupply chains wherever large volumes of components are being purchased (common items such as nuts and bolts are good examples).
States that if twothermodynamic systems are each inthermal equilibrium with a third one, then they are in thermal equilibrium with each other. Accordingly, thermal equilibrium between systems is atransitive 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 fromthe original on 7 October 2014. Retrieved20 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.
^SeeHerstein, I. N. (1964).Topics in Algebra. Ginn and Company.ISBN0-471-02371-X.{{cite book}}:ISBN / Date incompatibility (help), 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.
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^"amino acid".Cambridge Dictionaries Online. Cambridge University Press. 2015. Retrieved3 July 2015.
^"amino".FreeDictionary.com. Farlex. 2015. Retrieved3 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. Retrieved21 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.
