Genetically engineered products include bacteria designed to break down oil slicks and industrial waste products, drugs (human and bovine growth hormones, human insulin, interferon), and plants that are resistant to diseases, insects, and herbicides, that yield fruits or vegetables with desired qualities, or that produce toxins that act as pesticides. Genetic engineering techniques have also been used in the direct genetic alteration of livestock and laboratory animals (see pharming). Genetically engineered products usually require the approval of at least one U.S. government agency, such as the Dept. of Agriculture, the Food and Drug Administration, or the Environmental Protection Agency.

Because genetic engineering involves techniques used to obtain patents on human genes and to create patentable living organisms, it has raised many legal and ethical issues. The safety of releasing into the environment genetically altered organisms that might disrupt ecosystems has also been questioned. The discovery in 2001 of genetically engineered DNA in native Mexican corn varieties made concerns of genetic pollution actual, and led some scientists to worry that the spread of transgenes through cross-pollination could lead to a reduction in genetic diversity in important crops. Imports of genetically modified corn, soybeans, and other crops have been curtailed or limited in some countries, and the vast majority of such crops are grown in just a handful of nations. The Cartagena Protocol on Biosafety, which has been signed by more than 100 nations and took effect in Sept., 2003, requires detailed information on whether and how imported seeds, plants, animals, other organisms, and the like are genetically modified and permits a nation to bar those imports. The United States, however, is not party to the treaty.

Types of Engineering

The primary types of engineering are chemical, civil, electrical, industrial, and mechanical.

Chemical engineering deals with the design, construction, and operation of plants and machinery for making such products as acids, dyes, drugs, plastics, and synthetic rubber by adapting the chemical reactions discovered by the laboratory chemist to large-scale production. The chemical engineer must be familiar with both chemistry and mechanical engineering.

Civil engineering includes the planning, designing, construction, and maintenance of structures and altering geography to suit human needs. Some of the numerous subdivisions are transportation (e.g., railroad facilities and highways); hydraulics (e.g., river control, irrigation, swamp draining, water supply, and sewage disposal); and structures (e.g., buildings, bridges, and tunnels).

Electrical engineering encompasses all aspects of electricity from power engineering, the development of the devices for the generation and transmission of electrical power, to electronics. Electronics is a branch of electrical engineering that deals with devices that use electricity for control of processes. Subspecialties of electronics include computer engineering, microwave engineering, communications, and digital signal processing. It is the engineering specialty that has grown the most in recent decades.

Industrial engineering, or management engineering, is concerned with efficient production. The industrial engineer designs methods, not machinery. Jobs include plant layout, analysis and planning of workers' jobs, economical handling of raw materials, their flow through the production process, and the efficient control of the inventory of finished products.

Mechanical engineering is concerned with the design, construction, and operation of power plants, engines, and machines. It deals mostly with things that move. One common way of dividing mechanical engineering is into heat utilization and machine design. The generation, distribution, and use of heat is applied in boilers, heat engines, air conditioning, and refrigeration. Machine design is concerned with hardware, including that making use of heat processes.

Aeronautical engineering is applied in the designing of aircraft and missiles and in directing the technical phases of their manufacture and operation. Mineral engineering includes mining, metallurgical, and petroleum engineering, which are concerned with extracting minerals from the ground and converting them to pure forms. Other important branches of engineering are agricultural engineering, engineering physics, geological engineering, naval architecture and marine engineering, and nuclear engineering.

Another way of dividing engineering is by function. Among the top functional divisions are design, operation, management, development, and construction; development engineering is concerned with converting an idea into a practical product.

Development of Engineering

Until the Industrial Revolution there were only two kinds of engineers. The military engineer built such things as fortifications, catapults, and, later, cannons. The civil engineer built bridges, harbors, aqueducts, buildings, and other structures. During the early 19th cent. in England mechanical engineering developed as a separate field to provide manufacturing machines and the engines to power them. The first British professional society of civil engineers was formed in 1818; that for mechanical engineers followed in 1847. In the United States, the order of growth of the different branches of engineering, measured by the date a professional society was formed, is civil engineering (1852), mining and metallurgical engineering (1871), mechanical engineering (1880), electrical engineering (1884), and chemical engineering (1908). Aeronautical engineering, industrial engineering, and genetic engineering are more modern developments.

The first schools in the United States to offer an engineering education were the United States Military Academy (West Point) in 1817, an institution now known as Norwich Univ. in 1819, and Rensselaer Polytechnic Institute in 1825. An engineering education is based on a strong foundation in mathematics and science; this is followed by courses emphasizing the application of this knowledge to a specific field and studies in the social sciences and humanities to give the engineer a broader education.

Technique of using knowledge from various branches of engineering and science to introduce technological innovations into the planning and development stages of a system. Systems engineering was first applied to the organization of commercial telephone systems in the 1920s and '30s. Many systems-engineering techniques were developed during World War II in an effort to deploy military equipment more efficiently. Postwar growth in the field was spurred by advances in electronic systems and by the development of computers and information theory. Systems engineering usually involves incorporating new technology into complex, man-made systems, in which a change in one part affects many others. One tool used by systems engineers is the flowchart, which shows the system in graphic form, with geometric figures representing various subsystems and arrows representing their interactions. Other tools include mathematical models, probability theory, statistical analysis, and computer simulations.

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Art and practice of designing and building military works and of building and maintaining lines of military transport and communications. It includes both tactical support (see tactics) on the battlefield, including construction of fortifications and demolition of enemy installations, and strategic support (see strategy) away from the front lines, such as construction or maintenance of airfields, ports, roads, railroads, bridges, and hospitals. Its most notable feat in ancient times was the Great Wall of China. The preeminent military engineers of the ancient Western world were the Romans, who maintained their power by constructing not only forts and garrisons but roads, bridges, aqueducts, harbors, and lighthouses. Seealso civil engineering.

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Branch of engineering concerned with the design, manufacture, installation, and operation of engines, machines, and manufacturing processes. Mechanical engineering involves application of the principles of dynamics, control, thermodynamics and heat transfer, fluid mechanics, strength of materials, materials science, electronics, and mathematics. It is concerned with machine tools, motor vehicles, textile machinery, packaging machines, printing machinery, metalworking machines, welding, air conditioning, refrigerators, agricultural machinery, and many other machines and processes essential to an industrial economy.

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Application of engineering principles and techniques of scientific management to the maintenance of high levels of productivity at optimum cost in industrial enterprises. Frederick W. Taylor pioneered in the scientific measurement of work, and Frank (1868–1924) and Lillian (1878–1972) Gilbreth refined it with time-and-motion studies. As a result, production processes were simplified, enabling workers to increase production. The industrial engineer selects tools and materials for production that are most efficient and least costly to the company. The engineer may also determine the sequence of production and the design of plant facilities or factories. Seealso ergonomics.

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Profession of designing machines, tools, and work environments to best accommodate human performance and behaviour. It aims to improve the practicality, efficiency, and safety of a person working with a single machine or device (e.g., using a telephone, driving a car, or operating a computer terminal). Taking the user into consideration has probably always been a part of tool design; for example, the scythe, one of the oldest and most efficient human implements, shows a remarkable degree of ergonomic engineering. Examples of common devices that are poorly designed ergonomically include the snow shovel and the computer or typewriter keyboard.

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Scientific discipline concerned with the application of geologic knowledge to engineering problems such as reservoir design and location, determination of slope stability for construction purposes, and determination of earthquake, flood, or subsidence danger in areas considered for roads, pipelines, bridges, dams, or other engineering works.

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Artificial manipulation, modification, and recombination of DNA or other nucleic-acid molecules in order to modify an organism or population of organisms. The term initially meant any of a wide range of techniques for modifying or manipulating organisms through heredity and reproduction. Now the term denotes the narrower field of recombinant-DNA technology, or gene cloning, in which DNA molecules from two or more sources are combined, either within cells or in test tubes, and then inserted into host organisms in which they are able to reproduce. This technique is used to produce new genetic combinations that are of value to science, medicine, agriculture, or industry. Through recombinant-DNA techniques, bacteria have been created that are capable of synthesizing human insulin, human interferon, human growth hormone, a hepatitis-B vaccine, and other medically useful substances. Recombinant-DNA techniques, combined with the development of a technique for producing antibodies in great quantity, have made an impact on medical diagnosis and cancer research. Plants have been genetically adjusted to perform nitrogen fixation and to produce their own pesticides. Bacteria capable of biodegrading oil have been produced for use in oil-spill cleanups. Genetic engineering also introduces the fear of adverse genetic manipulations and their consequences (e.g., antibiotic-resistant bacteria or new strains of disease). Seealso biotechnology, molecular biology.

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Precise graphical representation of a structure, machine, or its component parts that communicates the intent of a technical design to the fabricator (or the prospective buyer) of the product. Drawings may present the various aspects of an object's form, show the object projected in space, or explain how it is built. Drafting uses orthographic projection, in which the object is viewed along parallel lines that are perpendicular to the plane of the drawing. Orthographic drawings include top views (plans), flat front and side views (elevations), and cross-sectional views showing profile. Perspective drawing, which presents a realistic illusion of space, uses a horizon line and vanishing points to show how objects and spatial relationships might appear to the eye, including diminution of size and convergence of parallel lines. Drafting was done with precision instruments (T square or parallel rule, triangle, mechanical pens and pencils) until computerization revolutionized production methods in architectural and engineering offices.

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Professional art of applying science to the optimum conversion of the resources of nature to the uses of humankind. Engineering is based principally on physics, chemistry, and mathematics and their extensions into materials science, solid and fluid mechanics, thermodynamics, transfer and rate processes, and systems analysis. A great body of special knowledge is associated with engineering; preparation for professional practice involves extensive training in the application of that knowledge. Engineers employ two types of natural resources, materials and energy. Materials acquire uses that reflect their properties: their strength, ease of fabrication, lightness, or durability; their ability to insulate or conduct; and their chemical, electrical, or acoustical properties. Important sources of energy include fossil fuels (coal, petroleum, gas), wind, sunlight, falling water, and nuclear fission. Seealso aerospace engineering, civil engineering, chemical engineering. genetic engineering, mechanical engineering, military engineering.

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Branch of engineering concerned with the practical applications of electricity in all its forms, including those of electronics. Electrical engineering deals with electric light and power systems and apparatuses; electronics engineering deals with wire and radio communication, the stored-program electronic computer, radar, and automatic control systems. The first practical application of electricity was the telegraph, in 1837. Electrical engineering emerged as a discipline in 1864 when James Clerk Maxwell summarized the basic laws of electricity in mathematical form and predicted that radiation of electromagnetic energy would occur in a form that later became known as radio waves. The need for electrical engineers was not felt until the invention of the telephone (1876) and the incandescent lamp (1878).

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Integration of design and manufacturing into a system under direct control of digital computers. CAD systems use a computer with terminals featuring video monitors and interactive graphics-input devices to design such things as machine parts, patterns for clothing, or integrated circuits. CAM systems use numerically controlled (see numerical control) machine tools and high-performance programmable industrial robots. Drawings developed during the design process are converted directly into instructions for the production machines, thus optimizing consistency between design and finished product, and providing flexibility in altering machine operations. These two processes are sometimes grouped as CAE (computer-aided engineering).

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Profession of designing and executing structural works that serve the general public, including bridges, canals, dams, harbors, lighthouses, roads, tunnels, and environmental works (e.g., water-supply systems). The modern field includes power plants, aircraft and airports, chemical-processing plants, and water-treatment facilities. Civil engineering today involves site investigations and feasibility studies, structural design and analysis, construction, and facilities maintenance. The design of engineering works requires the application of design theory from many fields (e.g., hydraulics, thermodynamics, nuclear physics). Research in structural analysis and the technology of materials such as steel and concrete has opened the way for new concepts and greater economy of materials. The engineer's analysis of a building problem determines the structural system to be used. Structural designs are rigorously analyzed by computers to determine if they will withstand loads and natural forces.

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Academic discipline and industrial activity concerned with developing processes and designing and operating plants to change materials' physical or chemical states. With roots in the inorganic and coal-based chemical industries of western Europe and the oil-refining industry in North America, it was spurred by the need to supply chemicals and products during the two World Wars. The field includes research, design, construction, operation, sales, and management activities. Chemical engineers must master chemistry (including the nature of chemical reactions, the effects of temperature and pressure on equilibrium, and the effects of catalysts on reaction rates), physics, and mathematics. The engineering aspect, involving fluid flow (see deformation and flow) and heat and mass transfer, is broken down into “unit operations,” including vaporization, distillation, absorption, filtration, extraction, crystallization, agitation and mixing, drying, and size reduction; each is described mathematically, and its principles apply to any material. Chemical engineers work not only in the chemical and oil industries but also in such processing industries as foods, paper, textiles, plastics, nuclear, and biotechnology.

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Field concerned with the development, design, construction, testing, and operation of airplanes and spacecraft. The field has its roots in balloon flight, gliders, and airships, and in the 1960s it was broadened to include space vehicles. Principal technologies are those of aerodynamics, propulsion, structure and stability, and control. Aerospace engineers in academic, industrial, and government research centres cooperate in designing new products. Flight testing of prototypes follows, and finally quantity production and operation take place. Important developments in aerospace engineering include the metal monocoque fuselage, the cantilevered monoplane wing, the jet engine, supersonic flight, and spaceflight.

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