instrumentation has existed for hundreds of years in one form or another. The oldest manometer invented by Evangelista Torricelli in 1643. The thermometer has been credited to many scientists of about the same period. Over that time, small and large scale industrial plants have always had use for measurements. For the most part, these were passive measuring devices. If a process needed a control, they'd hire someone at a low wage to control the process manually.
World War II brought about a revolution in the use of instrumentation[1]. Advanced processes requires tighter control than people could provide, and advanced instruments were required to provide measurements in modern processes. Also, the war left industry with a substantially reduced workforce. Industrial instrumentation solved both problems, leading to a rise in its use. Pipe fitters had to learn more about instrumentation and control theory, and a new trade was born.[2]
Today, instrument mechanics have more to do with electricians than pipe fitters. Almost all new instrumentation is electronic, using either 4-20mA control signals or digital signalling standards.
Fields of study
Instrument mechanics are required to study a large body of knowledge. This includes information on[4]:
* Process Control
* Measurement Instrumentation
* Final Control Elements
* Motors
* Electronics
* Industrial networks
* Signalling standards
* Chemistry
* Fluid Dynamics
nanotechnology
cables
Electrical wiring in general refers to insulated conductors used to carry electricity, and associated devices. This article describes general aspects of electrical wiring as used to provide power in buildings and structures, commonly referred to as building wiring. This article is intended to describe common features of electrical wiring that should apply worldwide.
A cable is two or more wires or ropes running side by side and bonded, twisted or braided together to form a single assembly. In mechanics, cables are used for lifting and hauling; in electricity they are used to carry electrical currents. An optical cable contains one or more optical fibers in a protective jacket that supports the fibers. Mechanical cable is more specifically called wire rope.
Electric cables discussed here are mainly meant for installation in buildings and industrial sites. For power transmission at distances from some km's to 600 km see high voltage cable, power cables and HVDC.
Electrical cables may be made more flexible by stranding the wires. In this process, smaller individual wires are twisted or braided together to produce larger wires that are more flexible than solid wires of similar size. Bunching small wires before concentric stranding adds the most flexibility. Copper wires in a cable may be bare, or they may be coated with a thin layer of another material: most often tin but sometimes gold, silver or some other material. Tin, gold, and silver are much less prone to oxidisation than copper, which may lengthen wire life, and makes soldering easier. Tight lays during stranding makes the cable extensible (CBA - as in telephone handset cords).
Cables can be securely fastened and organized, such as by using cable trees with the aid of cable ties or cable lacing. Continuous-flex or flexible cables used in moving applications within cable carriers can be secured using strain relief devices or cable ties. Copper corrodes easily and so should be layered with Lacquer.
At high frequencies, current tends to run along the surface of the conductor and avoid the core. This is known as the skin effect. It may change the relative desirability of solid versus stranded wires.
Electric trace heating, also known as electric heat tracing or surface heating, is a system used to maintain or raise the temperature of pipes and vessels. Trace heating takes the form of an electrical heating element run in physical contact along the length of a pipe. The pipe must then be covered with thermal insulation to retain heat losses from the pipe. Heat generated by the element then maintains the temperature of the pipe.
A cable is two or more wires or ropes running side by side and bonded, twisted or braided together to form a single assembly. In mechanics, cables are used for lifting and hauling; in electricity they are used to carry electrical currents. An optical cable contains one or more optical fibers in a protective jacket that supports the fibers. Mechanical cable is more specifically called wire rope.
Electric cables discussed here are mainly meant for installation in buildings and industrial sites. For power transmission at distances from some km's to 600 km see high voltage cable, power cables and HVDC.
Electrical cables may be made more flexible by stranding the wires. In this process, smaller individual wires are twisted or braided together to produce larger wires that are more flexible than solid wires of similar size. Bunching small wires before concentric stranding adds the most flexibility. Copper wires in a cable may be bare, or they may be coated with a thin layer of another material: most often tin but sometimes gold, silver or some other material. Tin, gold, and silver are much less prone to oxidisation than copper, which may lengthen wire life, and makes soldering easier. Tight lays during stranding makes the cable extensible (CBA - as in telephone handset cords).
Cables can be securely fastened and organized, such as by using cable trees with the aid of cable ties or cable lacing. Continuous-flex or flexible cables used in moving applications within cable carriers can be secured using strain relief devices or cable ties. Copper corrodes easily and so should be layered with Lacquer.
At high frequencies, current tends to run along the surface of the conductor and avoid the core. This is known as the skin effect. It may change the relative desirability of solid versus stranded wires.
Electric trace heating, also known as electric heat tracing or surface heating, is a system used to maintain or raise the temperature of pipes and vessels. Trace heating takes the form of an electrical heating element run in physical contact along the length of a pipe. The pipe must then be covered with thermal insulation to retain heat losses from the pipe. Heat generated by the element then maintains the temperature of the pipe.
Electrical wiring in general refers to insulated conductors used to carry electricity, and associated devices. This article describes general aspects of electrical wiring as used to provide power in buildings and structures, commonly referred to as building wiring. This article is intended to describe common features of electrical wiring that should apply worldwide.
A cable is two or more wires or ropes running side by side and bonded, twisted or braided together to form a single assembly. In mechanics, cables are used for lifting and hauling; in electricity they are used to carry electrical currents. An optical cable contains one or more optical fibers in a protective jacket that supports the fibers. Mechanical cable is more specifically called wire rope.
Electric cables discussed here are mainly meant for installation in buildings and industrial sites. For power transmission at distances from some km's to 600 km see high voltage cable, power cables and HVDC.
Electrical cables may be made more flexible by stranding the wires. In this process, smaller individual wires are twisted or braided together to produce larger wires that are more flexible than solid wires of similar size. Bunching small wires before concentric stranding adds the most flexibility. Copper wires in a cable may be bare, or they may be coated with a thin layer of another material: most often tin but sometimes gold, silver or some other material. Tin, gold, and silver are much less prone to oxidisation than copper, which may lengthen wire life, and makes soldering easier. Tight lays during stranding makes the cable extensible (CBA - as in telephone handset cords).
Cables can be securely fastened and organized, such as by using cable trees with the aid of cable ties or cable lacing. Continuous-flex or flexible cables used in moving applications within cable carriers can be secured using strain relief devices or cable ties. Copper corrodes easily and so should be layered with Lacquer.
At high frequencies, current tends to run along the surface of the conductor and avoid the core. This is known as the skin effect. It may change the relative desirability of solid versus stranded wires.
Electric trace heating, also known as electric heat tracing or surface heating, is a system used to maintain or raise the temperature of pipes and vessels. Trace heating takes the form of an electrical heating element run in physical contact along the length of a pipe. The pipe must then be covered with thermal insulation to retain heat losses from the pipe. Heat generated by the element then maintains the temperature of the pipe.
A cable is two or more wires or ropes running side by side and bonded, twisted or braided together to form a single assembly. In mechanics, cables are used for lifting and hauling; in electricity they are used to carry electrical currents. An optical cable contains one or more optical fibers in a protective jacket that supports the fibers. Mechanical cable is more specifically called wire rope.
Electric cables discussed here are mainly meant for installation in buildings and industrial sites. For power transmission at distances from some km's to 600 km see high voltage cable, power cables and HVDC.
Electrical cables may be made more flexible by stranding the wires. In this process, smaller individual wires are twisted or braided together to produce larger wires that are more flexible than solid wires of similar size. Bunching small wires before concentric stranding adds the most flexibility. Copper wires in a cable may be bare, or they may be coated with a thin layer of another material: most often tin but sometimes gold, silver or some other material. Tin, gold, and silver are much less prone to oxidisation than copper, which may lengthen wire life, and makes soldering easier. Tight lays during stranding makes the cable extensible (CBA - as in telephone handset cords).
Cables can be securely fastened and organized, such as by using cable trees with the aid of cable ties or cable lacing. Continuous-flex or flexible cables used in moving applications within cable carriers can be secured using strain relief devices or cable ties. Copper corrodes easily and so should be layered with Lacquer.
At high frequencies, current tends to run along the surface of the conductor and avoid the core. This is known as the skin effect. It may change the relative desirability of solid versus stranded wires.
Electric trace heating, also known as electric heat tracing or surface heating, is a system used to maintain or raise the temperature of pipes and vessels. Trace heating takes the form of an electrical heating element run in physical contact along the length of a pipe. The pipe must then be covered with thermal insulation to retain heat losses from the pipe. Heat generated by the element then maintains the temperature of the pipe.
Power electronics
Standby power, also called vampire power, vampire draw, phantom load, or leaking electricity, refers to the electric power consumed by electronic appliances while they are switched off or in a standby mode. A very common "electricity vampire" is a power adapter which has no power-off switch. Some such devices offer remote controls and digital clock features to the user, while other devices, such as power adapters for laptop computers and other electronic devices, consume power without offering any features.
Power electronic converters can be found wherever there is a need to modify the form of electrical energy (i.e modify its voltage, current or frequency). The power range of these converters is from some milliwatts (as in a mobile phone) to hundreds of megawatts (e.g in a HVDC transmission system). With "classical" electronics, electrical currents and voltage are used to carry information, whereas with power electronics, they carry power. Thus, the main metric of power electronics becomes the efficiency.
The first very high power electronic devices were mercury arc valves. In modern systems the conversion is performed with semiconductor switching devices such as diodes, thyristors and transistors. In contrast to electronic systems concerned with transmission and processing of signals and data, in power electronics substantial amounts of electrical energy are processed. An AC/DC converter (rectifier) is the most typical power electronics device found in many consumer electronic devices, e.g., television sets, personal computers, battery chargers, etc. The power range is typically from tens of watts to several hundred watts. In industry the most common application is the variable speed drive (VSD) that is used to control an induction motor. The power range of VSDs start from a few hundred watts and end at tens of megawatts.
Power electronic converters can be found wherever there is a need to modify the form of electrical energy (i.e modify its voltage, current or frequency). The power range of these converters is from some milliwatts (as in a mobile phone) to hundreds of megawatts (e.g in a HVDC transmission system). With "classical" electronics, electrical currents and voltage are used to carry information, whereas with power electronics, they carry power. Thus, the main metric of power electronics becomes the efficiency.
The first very high power electronic devices were mercury arc valves. In modern systems the conversion is performed with semiconductor switching devices such as diodes, thyristors and transistors. In contrast to electronic systems concerned with transmission and processing of signals and data, in power electronics substantial amounts of electrical energy are processed. An AC/DC converter (rectifier) is the most typical power electronics device found in many consumer electronic devices, e.g., television sets, personal computers, battery chargers, etc. The power range is typically from tens of watts to several hundred watts. In industry the most common application is the variable speed drive (VSD) that is used to control an induction motor. The power range of VSDs start from a few hundred watts and end at tens of megawatts.
sports
Golf is a precision club-and-ball sport, in which competing players (golfers), using many types of clubs, attempt to hit balls into each hole on a golf course while employing the fewest number of strokes. Golf is one of the few ball games that does not require a standardized playing area. Instead, the game is played on golf "courses", each of which features a unique design, although courses typically consist of either nine or 18 holes. Golf is defined, in the rules of golf, as "playing a ball with a club from the teeing ground into the hole by a stroke or successive strokes in accordance with the Rules." Golf competition is generally played for the lowest number of strokes by an individual, known simply as stroke play, or the lowest score on the most individual holes during a complete round by an individual or team, known as match play.
The origin of golf is unclear and open to debate. Some historians[who?] trace the sport back to the Roman game of paganica, in which participants used a bent stick to hit a stuffed leather ball. One theory asserts that paganica spread throughout Britain and Europe as the Romans conquered much of the continent, during the first century B.C., and eventually evolved into the modern game.[2] Others cite chuiwan ("chui" means striking and "wan" means small ball) as the progenitor, a Chinese game played between the eighth and 14th centuries.[3] The game is thought to have been introduced into Europe during the Middle Ages. Another early game that resembled modern golf was known as cambuca in England and chambot in France.[4] This game was, in turn, exported to the Low Countries, Germany, and England (where it was called pall-mall, pronounced “pell mell”). Some observers, however, believe that golf descended from the Persian game, chaugán. In addition, kolven (a game involving a ball and curved bats) was played annually in Loenen, Netherlands, beginning in 1297, to commemorate the capture of the assassin of Floris V, a year earlier.
According to the most widely accepted account, however, the modern game originated in Scotland around the 12th century, with shepherds knocking stones into rabbit holes on the current site of the Royal and Ancient Golf Club of St. Andrews.
Cricket is a bat-and-ball team sport that is first documented as being played in southern England in the 16th century. By the end of the 18th century, cricket had developed to the point where it had become the national sport of England. The expansion of the British Empire led to cricket being played overseas and by the mid-19th century the first international matches were being held. Today, the game's governing body, the International Cricket Council (ICC), has 104 member countries.[1] With its greatest popularity in the Test playing countries, cricket is widely regarded as the world's second most popular sport
The origin of golf is unclear and open to debate. Some historians[who?] trace the sport back to the Roman game of paganica, in which participants used a bent stick to hit a stuffed leather ball. One theory asserts that paganica spread throughout Britain and Europe as the Romans conquered much of the continent, during the first century B.C., and eventually evolved into the modern game.[2] Others cite chuiwan ("chui" means striking and "wan" means small ball) as the progenitor, a Chinese game played between the eighth and 14th centuries.[3] The game is thought to have been introduced into Europe during the Middle Ages. Another early game that resembled modern golf was known as cambuca in England and chambot in France.[4] This game was, in turn, exported to the Low Countries, Germany, and England (where it was called pall-mall, pronounced “pell mell”). Some observers, however, believe that golf descended from the Persian game, chaugán. In addition, kolven (a game involving a ball and curved bats) was played annually in Loenen, Netherlands, beginning in 1297, to commemorate the capture of the assassin of Floris V, a year earlier.
According to the most widely accepted account, however, the modern game originated in Scotland around the 12th century, with shepherds knocking stones into rabbit holes on the current site of the Royal and Ancient Golf Club of St. Andrews.
Cricket is a bat-and-ball team sport that is first documented as being played in southern England in the 16th century. By the end of the 18th century, cricket had developed to the point where it had become the national sport of England. The expansion of the British Empire led to cricket being played overseas and by the mid-19th century the first international matches were being held. Today, the game's governing body, the International Cricket Council (ICC), has 104 member countries.[1] With its greatest popularity in the Test playing countries, cricket is widely regarded as the world's second most popular sport
integrated devices
An integrated device manufacturer (IDM) is a semiconductor company which designs, manufactures, and sells integrated circuit (IC) products. As a classification, IDM is often used to differentiate between a company which handles semiconductor manufacturing in-house, and a fabless semiconductor company, which outsources production to a third-party. Due to the dynamic nature of the semiconductor industry, the term IDM has become less accurate than when it was coined.
An Integrated Access Device (or IAD) is a customer premises device that provides access to wide area networks and the Internet. Specifically, it aggregates multiple channels of information including voice and data across a single shared access link to a carrier or service provider PoP (Point of Presence). The access link may be a T1 line, a DSL connection, a cable (CATV) network, a broadband wireless link, or a metro-Ethernet connection.
At the PoP, the customer's aggregated information is typically directed into an Add-drop multiplexer or an MSPP (multiservice provisioning platform), which are complex and expensive devices that sit between customers and the core network. They manage traffic streams coming from customers and forward those streams to the PSTN (voice) or appropriate wide area networks (ATM, frame relay, or the Internet).
An IAD is sometimes installed by the service provider to which a customer wishes to connect. This allows the service provider to control the features of the access link and manage its operation during use. Competitive service providers are now offering access services over a variety of access technologies, including wireless optical (i.e., Terabeam) and metro-Ethernet networks. Old telco protocols and transport methods (T1 lines and time division multiplexing) are replaced with access methods that are appropriate for the underlying transport. Because of this, the provider will usually specify an appropriate IAD, or install an IAD.
An Integrated Access Device (or IAD) is a customer premises device that provides access to wide area networks and the Internet. Specifically, it aggregates multiple channels of information including voice and data across a single shared access link to a carrier or service provider PoP (Point of Presence). The access link may be a T1 line, a DSL connection, a cable (CATV) network, a broadband wireless link, or a metro-Ethernet connection.
At the PoP, the customer's aggregated information is typically directed into an Add-drop multiplexer or an MSPP (multiservice provisioning platform), which are complex and expensive devices that sit between customers and the core network. They manage traffic streams coming from customers and forward those streams to the PSTN (voice) or appropriate wide area networks (ATM, frame relay, or the Internet).
An IAD is sometimes installed by the service provider to which a customer wishes to connect. This allows the service provider to control the features of the access link and manage its operation during use. Competitive service providers are now offering access services over a variety of access technologies, including wireless optical (i.e., Terabeam) and metro-Ethernet networks. Old telco protocols and transport methods (T1 lines and time division multiplexing) are replaced with access methods that are appropriate for the underlying transport. Because of this, the provider will usually specify an appropriate IAD, or install an IAD.
Sensor
A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury-in-glass thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated glass tube. A thermocouple converts temperature to an output voltage which can be read by a voltmeter. For accuracy, all sensors need to be calibrated against known standards.
The resolution of a sensor is the smallest change it can detect in the quantity that it is measuring. Often in a digital display, the least significant digit will fluctuate, indicating that changes of that magnitude are only just resolved. The resolution is related to the precision with which the measurement is made. For example, a scanning tunneling probe (a fine tip near a surface collects an electron tunnelling current) can resolve atoms and molecules.
Automotive oxygen sensors, colloquially known as O2 sensors, make modern electronic fuel injection and emission control possible. They help determine, in real time, if the air fuel ratio of a combustion engine is rich or lean. Since oxygen sensors are located in the exhaust stream, they do not directly measure the air or the fuel entering the engine. But when information from oxygen sensors is coupled with information from other sources, it can be used to indirectly determine the air-to-fuel ratio. Closed-loop feedback-controlled fuel injection varies the fuel injector output according to real-time sensor data rather than operating with a predetermined (open-loop) fuel map. In addition to enabling electronic fuel injection to work efficiently, this emissions control technique can reduce the amounts of both unburnt fuel and oxides of nitrogen from entering the atmosphere. Unburnt fuel is pollution in the form of air-borne hydrocarbons, while oxides of nitrogen (NOx gases) are a result of combustion chamber tempuratures exceeding 1300 Kelvin due to excess air in the fuel mixture and contribute to smog and acid rain. Volvo was the first automobile manufacturer to employ this technology in the late 1970s, along with the 3-way catalyst used in the catalytic converter.
The resolution of a sensor is the smallest change it can detect in the quantity that it is measuring. Often in a digital display, the least significant digit will fluctuate, indicating that changes of that magnitude are only just resolved. The resolution is related to the precision with which the measurement is made. For example, a scanning tunneling probe (a fine tip near a surface collects an electron tunnelling current) can resolve atoms and molecules.
Automotive oxygen sensors, colloquially known as O2 sensors, make modern electronic fuel injection and emission control possible. They help determine, in real time, if the air fuel ratio of a combustion engine is rich or lean. Since oxygen sensors are located in the exhaust stream, they do not directly measure the air or the fuel entering the engine. But when information from oxygen sensors is coupled with information from other sources, it can be used to indirectly determine the air-to-fuel ratio. Closed-loop feedback-controlled fuel injection varies the fuel injector output according to real-time sensor data rather than operating with a predetermined (open-loop) fuel map. In addition to enabling electronic fuel injection to work efficiently, this emissions control technique can reduce the amounts of both unburnt fuel and oxides of nitrogen from entering the atmosphere. Unburnt fuel is pollution in the form of air-borne hydrocarbons, while oxides of nitrogen (NOx gases) are a result of combustion chamber tempuratures exceeding 1300 Kelvin due to excess air in the fuel mixture and contribute to smog and acid rain. Volvo was the first automobile manufacturer to employ this technology in the late 1970s, along with the 3-way catalyst used in the catalytic converter.
scada
SCADA stands for supervisory control and data acquisition. It generally refers to an industrial control system: a computer system monitoring and controlling a process. The process can be industrial, infrastructure or facility based as described below:
* Industrial processes include those of manufacturing, production, power generation, fabrication, and refining, and may run in continuous, batch, repetitive, or discrete modes.
* Infrastructure processes may be public or private, and include water treatment and distribution, wastewater collection and treatment, oil and gas pipelines, electrical power transmission and distribution, civil defense siren systems, and large communication systems.
* Facility processes occur both in public facilities and private ones, including buildings, airports, ships, and space stations. They monitor and control HVAC, access, and energy consumption.
There is, in several industries, considerable confusion over the differences between SCADA systems and Distributed control systems (DCS). Generally speaking, a SCADA system usually refers to a system that coordinates, but does not control processes in real time. The discussion on real-time control is muddied somewhat by newer telecommunications technology, enabling reliable, low latency, high speed communications over wide areas. Most differences between SCADA and DCS are culturally determined and can usually be ignored. As communication infrastructures with higher capacity become available, the difference between SCADA and DCS will fade.
* Industrial processes include those of manufacturing, production, power generation, fabrication, and refining, and may run in continuous, batch, repetitive, or discrete modes.
* Infrastructure processes may be public or private, and include water treatment and distribution, wastewater collection and treatment, oil and gas pipelines, electrical power transmission and distribution, civil defense siren systems, and large communication systems.
* Facility processes occur both in public facilities and private ones, including buildings, airports, ships, and space stations. They monitor and control HVAC, access, and energy consumption.
There is, in several industries, considerable confusion over the differences between SCADA systems and Distributed control systems (DCS). Generally speaking, a SCADA system usually refers to a system that coordinates, but does not control processes in real time. The discussion on real-time control is muddied somewhat by newer telecommunications technology, enabling reliable, low latency, high speed communications over wide areas. Most differences between SCADA and DCS are culturally determined and can usually be ignored. As communication infrastructures with higher capacity become available, the difference between SCADA and DCS will fade.
Control system
A control system is a device or set of devices to manage, command, direct or regulate the behavior of other devices or systems.
There are two common classes of control systems, with many variations and combinations: logic or sequential controls, and feedback or linear controls. There is also fuzzy logic, which attempts to combine some of the design simplicity of logic with the utility of linear control. Some devices or systems are inherently not controllable.
Modern day control engineering (also called control systems engineering) is a relatively new field of study that gained a significant attention during twentieth century with the advancement in technology. It can be broadly defined as practical application of control theory. Control engineering has an essential role in a wide range of control systems from a simple household washing machine to a complex high performance F-16 fighter aircraft. It allows one to understand a physical system in terms of its inputs, outputs and various components with different behaviors using mathematical modeling, control it in a desired manner with the controllers designed using control systems design tools, and implement the controller on the physical system employing available technology. A system can be mechanical, electrical, fluid, chemical, financial and even biological, and the mathematical modeling, analysis and controller design shall be done using control theory in one or many of the time, frequency and complex-s domains depending on the nature of the control system design problem.
intimate knowledge of the physical system being controlled is often desired.
Electrical circuits, digital signal processors and microcontrollers can all be used to implement Control systems. Control engineering has a wide range of applications from the flight and propulsion systems of commercial airliners to the cruise control present in many modern automobiles.
In most of the cases, control engineers utilize feedback when designing control systems. This is often accomplished using a PID controller system. For example, in an automobile with cruise control the vehicle's speed is continuously monitored and fed back to the system which adjusts the motor's torque accordingly. Where there is regular feedback, control theory can be used to determine how the system responds to such feedback. In practically all such systems stability is important and control theory can help ensure stability is achieved.
Although feedback is an important aspect of control engineering, control engineers may also work on the control of systems without feedback. This is known as open loop control. A classic example of open loop control is a washing machine that runs through a pre-determined cycle without the use of sensors.
There are two common classes of control systems, with many variations and combinations: logic or sequential controls, and feedback or linear controls. There is also fuzzy logic, which attempts to combine some of the design simplicity of logic with the utility of linear control. Some devices or systems are inherently not controllable.
Modern day control engineering (also called control systems engineering) is a relatively new field of study that gained a significant attention during twentieth century with the advancement in technology. It can be broadly defined as practical application of control theory. Control engineering has an essential role in a wide range of control systems from a simple household washing machine to a complex high performance F-16 fighter aircraft. It allows one to understand a physical system in terms of its inputs, outputs and various components with different behaviors using mathematical modeling, control it in a desired manner with the controllers designed using control systems design tools, and implement the controller on the physical system employing available technology. A system can be mechanical, electrical, fluid, chemical, financial and even biological, and the mathematical modeling, analysis and controller design shall be done using control theory in one or many of the time, frequency and complex-s domains depending on the nature of the control system design problem.
intimate knowledge of the physical system being controlled is often desired.
Electrical circuits, digital signal processors and microcontrollers can all be used to implement Control systems. Control engineering has a wide range of applications from the flight and propulsion systems of commercial airliners to the cruise control present in many modern automobiles.
In most of the cases, control engineers utilize feedback when designing control systems. This is often accomplished using a PID controller system. For example, in an automobile with cruise control the vehicle's speed is continuously monitored and fed back to the system which adjusts the motor's torque accordingly. Where there is regular feedback, control theory can be used to determine how the system responds to such feedback. In practically all such systems stability is important and control theory can help ensure stability is achieved.
Although feedback is an important aspect of control engineering, control engineers may also work on the control of systems without feedback. This is known as open loop control. A classic example of open loop control is a washing machine that runs through a pre-determined cycle without the use of sensors.
Automation
Automation is the use of control systems (such as numerical control, programmable logic control, and other industrial control systems), in concert with other applications of information technology (such as computer-aided technologies [CAD, CAM, CAx]), to control industrial machinery and processes, reducing the need for human intervention.[1] In the scope of industrialization, automation is a step beyond mechanization. Whereas mechanization provided human operators with machinery to assist them with the muscular requirements of work, automation greatly reduces the need for human sensory and mental requirements as well. Processes and systems can also be automated.
Automation plays an increasingly important role in the global economy and in daily experience. Engineers strive to combine automated devices with mathematical and organizational tools to create complex systems for a rapidly expanding range of applications and human activities.
Many roles for humans in industrial processes presently lie beyond the scope of automation. Human-level pattern recognition, language recognition, and language production ability are well beyond the capabilities of modern mechanical and computer systems. Tasks requiring subjective assessment or synthesis of complex sensory data, such as scents and sounds, as well as high-level tasks such as strategic planning, currently require human expertise. In many cases, the use of humans is more cost-effective than mechanical approaches even where automation of industrial tasks is possible.
Specialised hardened computers, referred to as programmable logic controllers (PLCs), are frequently used to synchronize the flow of inputs from (physical) sensors and events with the flow of outputs to actuators and events. This leads to precisely controlled actions that permit a tight control of almost any industrial process.
Human-machine interfaces (HMI) or computer human interfaces (CHI), formerly known as man-machine interfaces, are usually employed to communicate with PLCs and other computers, such as entering and monitoring temperatures or pressures for further automated control or emergency response. Service personnel who monitor and control these interfaces are often referred to as stationary engineers.
Building automation describes the functionality provided by the control system of a building. A building automation system (BAS) is an example of a distributed control system. The control system is a computerized, intelligent network of electronic devices, designed to monitor and control the mechanical and lighting systems in a building.
BAS core functionality keeps the building climate within a specified range, provides lighting based on an occupancy schedule, and monitors system performance and device failures and provides email and/or text notifications to building engineering staff. The BAS functionality reduces building energy and maintenance costs when compared to a non-controlled building. A building controlled by a BAS is often referred to as an intelligent building system.
Home automation (also called domotics) may designate an emerging practice of increased automation of household appliances and features in residential dwellings, particularly through electronic means that allow for things impracticable, overly expensive or simply not possible in recent past decades. The term may be used in contrast to the more mainstream "building automation," which refers to industrial settings and the automatic or semi-automatic control of lighting, climate doors and windows, and security and surveillance systems. The techniques employed in home automation include those in building automation as well as the control of home entertainment systems, houseplant watering, pet feeding, "scenes" for different events (such as dinners or parties), and the use of domestic robots.
Automation plays an increasingly important role in the global economy and in daily experience. Engineers strive to combine automated devices with mathematical and organizational tools to create complex systems for a rapidly expanding range of applications and human activities.
Many roles for humans in industrial processes presently lie beyond the scope of automation. Human-level pattern recognition, language recognition, and language production ability are well beyond the capabilities of modern mechanical and computer systems. Tasks requiring subjective assessment or synthesis of complex sensory data, such as scents and sounds, as well as high-level tasks such as strategic planning, currently require human expertise. In many cases, the use of humans is more cost-effective than mechanical approaches even where automation of industrial tasks is possible.
Specialised hardened computers, referred to as programmable logic controllers (PLCs), are frequently used to synchronize the flow of inputs from (physical) sensors and events with the flow of outputs to actuators and events. This leads to precisely controlled actions that permit a tight control of almost any industrial process.
Human-machine interfaces (HMI) or computer human interfaces (CHI), formerly known as man-machine interfaces, are usually employed to communicate with PLCs and other computers, such as entering and monitoring temperatures or pressures for further automated control or emergency response. Service personnel who monitor and control these interfaces are often referred to as stationary engineers.
Building automation describes the functionality provided by the control system of a building. A building automation system (BAS) is an example of a distributed control system. The control system is a computerized, intelligent network of electronic devices, designed to monitor and control the mechanical and lighting systems in a building.
BAS core functionality keeps the building climate within a specified range, provides lighting based on an occupancy schedule, and monitors system performance and device failures and provides email and/or text notifications to building engineering staff. The BAS functionality reduces building energy and maintenance costs when compared to a non-controlled building. A building controlled by a BAS is often referred to as an intelligent building system.
Home automation (also called domotics) may designate an emerging practice of increased automation of household appliances and features in residential dwellings, particularly through electronic means that allow for things impracticable, overly expensive or simply not possible in recent past decades. The term may be used in contrast to the more mainstream "building automation," which refers to industrial settings and the automatic or semi-automatic control of lighting, climate doors and windows, and security and surveillance systems. The techniques employed in home automation include those in building automation as well as the control of home entertainment systems, houseplant watering, pet feeding, "scenes" for different events (such as dinners or parties), and the use of domestic robots.
Oil refinery
An oil refinery is an industrial process plant where crude oil is processed and refined into more useful petroleum products, such as gasoline, diesel fuel, asphalt base, heating oil, kerosene and liquefied petroleum gas.[1][2] Oil refineries are typically large sprawling industrial complexes with extensive piping running throughout, carrying streams of fluids between large chemical processing units.
Raw or unprocessed crude oil is not generally useful. Although "light, sweet" (low viscosity, low sulfur) crude oil has been used directly as a burner fuel for steam vessel propulsion, the lighter elements form explosive vapors in the fuel tanks and are therefore hazardous, especially in warships. Instead, the hundreds of different hydrocarbon molecules in crude oil are separated in a refinery into components which can be used as fuels, lubricants, and as feedstock in petrochemical processes that manufacture such products as plastics, detergents, solvents, elastomers and fibers such as nylon and polyesters.
Petroleum fossil fuels are burned in internal combustion engines to provide power for ships, automobiles, aircraft engines, lawn mowers, chainsaws, and other machines. Different boiling points allow the hydrocarbons to be separated by distillation. Since the lighter liquid products are in great demand for use in internal combustion engines, a modern refinery will convert heavy hydrocarbons and lighter gaseous elements into these higher value products.
The refining process releases numerous different chemicals into the atmosphere; consequently, there are substantial air pollution emissions[7] and a notable odor normally accompanies the presence of a refinery. Aside from air pollution impacts there are also wastewater concerns,[3] risks of industrial accidents such as fire and explosion, and noise health effects due to industrial noise.
Raw or unprocessed crude oil is not generally useful. Although "light, sweet" (low viscosity, low sulfur) crude oil has been used directly as a burner fuel for steam vessel propulsion, the lighter elements form explosive vapors in the fuel tanks and are therefore hazardous, especially in warships. Instead, the hundreds of different hydrocarbon molecules in crude oil are separated in a refinery into components which can be used as fuels, lubricants, and as feedstock in petrochemical processes that manufacture such products as plastics, detergents, solvents, elastomers and fibers such as nylon and polyesters.
Petroleum fossil fuels are burned in internal combustion engines to provide power for ships, automobiles, aircraft engines, lawn mowers, chainsaws, and other machines. Different boiling points allow the hydrocarbons to be separated by distillation. Since the lighter liquid products are in great demand for use in internal combustion engines, a modern refinery will convert heavy hydrocarbons and lighter gaseous elements into these higher value products.
The refining process releases numerous different chemicals into the atmosphere; consequently, there are substantial air pollution emissions[7] and a notable odor normally accompanies the presence of a refinery. Aside from air pollution impacts there are also wastewater concerns,[3] risks of industrial accidents such as fire and explosion, and noise health effects due to industrial noise.
cosmetic
Cosmetics are substances used to enhance the appearance or odor of the human body. Cosmetics include skin-care creams, lotions, powders, perfumes, lipsticks, fingernail and toe nail polish, eye and facial makeup, permanent waves, colored contact lenses, hair colors, [hair sprays] [3]and gels, deodorants, baby products, bath oils, bubble baths, bath salts, butters and many other types of products. Their use is widespread, especially among women in Western countries. A subset of cosmetics is called "make-up," which refers primarily to colored products intended to alter the user’s appearance. Many manufacturers distinguish between decorative cosmetics and care cosmetics.
The manufacture of cosmetics is currently dominated by a small number of multinational corporations that originated in the early 20th century, but the distribution and sale of cosmetics is spread among a wide range of different businesses. The U.S. Food and Drug Administration (FDA) which regulates cosmetics in the United States[1] defines cosmetics as: "intended to be applied to the human body for cleansing, beautifying, promoting attractiveness, or altering the appearance without affecting the body's structure or functions." This broad definition includes, as well, any material intended for use as a component of a cosmetic product. The FDA specifically excludes soap from this category.
Plastic surgery is a medical specialty concerned with the correction or restoration of form and function. While famous for aesthetic surgery, plastic surgery also includes two main fields: body modification and reconstructive surgery. The word "plastic" derives from the Greek plastikos meaning to mold or to shape; its use here is not connected with the synthetic polymer material known as plastic.
The manufacture of cosmetics is currently dominated by a small number of multinational corporations that originated in the early 20th century, but the distribution and sale of cosmetics is spread among a wide range of different businesses. The U.S. Food and Drug Administration (FDA) which regulates cosmetics in the United States[1] defines cosmetics as: "intended to be applied to the human body for cleansing, beautifying, promoting attractiveness, or altering the appearance without affecting the body's structure or functions." This broad definition includes, as well, any material intended for use as a component of a cosmetic product. The FDA specifically excludes soap from this category.
Plastic surgery is a medical specialty concerned with the correction or restoration of form and function. While famous for aesthetic surgery, plastic surgery also includes two main fields: body modification and reconstructive surgery. The word "plastic" derives from the Greek plastikos meaning to mold or to shape; its use here is not connected with the synthetic polymer material known as plastic.
perfume
Perfume is a mixture of fragrant essential oils and aroma compounds, fixatives, and solvents used to give the human body, animals, objects, and living spaces a "pleasant" smell..Prince Matchabelli is a perfume line. It was first designed by Prince Georges V. Matchabelli who was an amateur chemist. Georges Matchabelli was a Georgian prince and Georgian ambassador to Italy, but fled the Soviet Union and immigrated to the United States after the Russian Revolution. In New York City he and his wife, Princess Norina Matchabelli (an actress whose stage name was Maria Carmi), opened a small antiques shop Le Rouge et le Noir at 545 Madison Avenue. The name came from Stendhal's novel, red for aristocracy (Matchabelli's origins) and black for clergy (The Miracle, a famous religious play in which Norina had starred). They later established the Prince Matchabelli Perfume Company in 1926. Perfumes were personally blended for clients by Prince Matchabelli. The first three perfumes were Princess Norina, Queen of Georgia and Ave Maria. The company became known for the many color-coded, crown-shaped bottles designed by Norina after the Matchabelli crown and introduced in 1928 with labels on the underside.
Houbigant was a perfume manufacturer founded in Paris, France in 1775 by Jean-François Houbigant of Grasse (1752-1807), originally selling gloves, perfumes, and bridal bouquets. The original shop, called "A la Corbeille de Fleurs", was in the rue du Faubourg Saint-Honoré. Clients included Queen Marie-Antoinette of France; two French emperors; Princess Adélaïde d'Orléans (1829); Princess Dagmar of Denmark, wife of emperor Alexander III of Russia (1890); Madame Du Barry, mistress of King Louis XV of France; and Queen Victoria of England.
Houbigant was a perfume manufacturer founded in Paris, France in 1775 by Jean-François Houbigant of Grasse (1752-1807), originally selling gloves, perfumes, and bridal bouquets. The original shop, called "A la Corbeille de Fleurs", was in the rue du Faubourg Saint-Honoré. Clients included Queen Marie-Antoinette of France; two French emperors; Princess Adélaïde d'Orléans (1829); Princess Dagmar of Denmark, wife of emperor Alexander III of Russia (1890); Madame Du Barry, mistress of King Louis XV of France; and Queen Victoria of England.
Sunglasses
Sunglasses or sun glasses are a form of protective eyewear that usually enclose or protect the eye pupil in order to prevent strong light, ultraviolet (UV) rays, and increasingly, blue light ("blue blocking") from penetrating. They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist which feature lenses that are colored, polarized or darkened. In the early 20th century they were also known as sun cheaters (cheaters being an American slang term for glasses).[1]
Many people find direct sunlight too bright for comfort. During outdoor activities, the human eye can receive more light than usual. Healthcare professionals recommend eye protection whenever outside to protect the eyes from ultraviolet radiation and blue light, which can cause several serious eye problems. Sunglasses have long been associated with celebrities and film actors primarily from a desire to hide or mask their identity. Since the 1940s sunglasses have been popular as a fashion accessory, especially on the beach.
Peoria (named after the Peoria tribe) is the largest city on the Illinois River and the county seat of Peoria County,[1] Illinois, in the United States. As of the 2000 census, the city was the fifth-largest in Illinois, with a population of 112,936; by 2007 it was the sixth-largest city and had population of 113,546.[2] The Peoria Metropolitan Statistical Area had a population of 372,487 in 2008, making it the third largest metropolitan area in the state after Chicagoland and the Metro-East portion of the St. Louis metropolitan area.
Photochromic lenses are lenses that darken on exposure to ultraviolet (UV) radiation. Once the UV is removed (for example by walking indoors), the lenses will gradually return to their clear state. Photochromic lenses may be made of glass, polycarbonate, or another plastic. The glass version of this type of lenses was first developed by Corning in the 1960s. More recently, plastic versions of these lenses have been commercialized. The first of these was the Photolite lens sold in the early 1980s by American Optical Corporation. But the first commercially successful plastic photochromic lens was introduced by Transitions Optical in 1991.[1]
The glass version of these lenses achieve their photochromic properties through the embedding of microcrystalline silver halides (usually silver chloride), or molecules in a glass substrate. Plastic photochromic lenses rely on organic photochromic molecules (for example oxazines and naphthopyrans) to achieve the reversible darkening effect. The reason these lenses darken in sunlight but not indoors under artificial light, is that room light does not contain the UV (short wavelength light) found in sunlight. Automobile windows also block UV so these lenses would darken less in a car. Lenses that darken in response to visible (rather than UV) light would avoid these issues, but they are not feasible for most applications. In order to respond to light, it is necessary to absorb it, thus the glass could not be made to be clear in its low-light state. This correctly implies photochromic lenses are not entirely transparent, specifically they filter out UV light. This does not represent a problem, because the human eye does not see in the UV spectrum.
Many people find direct sunlight too bright for comfort. During outdoor activities, the human eye can receive more light than usual. Healthcare professionals recommend eye protection whenever outside to protect the eyes from ultraviolet radiation and blue light, which can cause several serious eye problems. Sunglasses have long been associated with celebrities and film actors primarily from a desire to hide or mask their identity. Since the 1940s sunglasses have been popular as a fashion accessory, especially on the beach.
Peoria (named after the Peoria tribe) is the largest city on the Illinois River and the county seat of Peoria County,[1] Illinois, in the United States. As of the 2000 census, the city was the fifth-largest in Illinois, with a population of 112,936; by 2007 it was the sixth-largest city and had population of 113,546.[2] The Peoria Metropolitan Statistical Area had a population of 372,487 in 2008, making it the third largest metropolitan area in the state after Chicagoland and the Metro-East portion of the St. Louis metropolitan area.
Photochromic lenses are lenses that darken on exposure to ultraviolet (UV) radiation. Once the UV is removed (for example by walking indoors), the lenses will gradually return to their clear state. Photochromic lenses may be made of glass, polycarbonate, or another plastic. The glass version of this type of lenses was first developed by Corning in the 1960s. More recently, plastic versions of these lenses have been commercialized. The first of these was the Photolite lens sold in the early 1980s by American Optical Corporation. But the first commercially successful plastic photochromic lens was introduced by Transitions Optical in 1991.[1]
The glass version of these lenses achieve their photochromic properties through the embedding of microcrystalline silver halides (usually silver chloride), or molecules in a glass substrate. Plastic photochromic lenses rely on organic photochromic molecules (for example oxazines and naphthopyrans) to achieve the reversible darkening effect. The reason these lenses darken in sunlight but not indoors under artificial light, is that room light does not contain the UV (short wavelength light) found in sunlight. Automobile windows also block UV so these lenses would darken less in a car. Lenses that darken in response to visible (rather than UV) light would avoid these issues, but they are not feasible for most applications. In order to respond to light, it is necessary to absorb it, thus the glass could not be made to be clear in its low-light state. This correctly implies photochromic lenses are not entirely transparent, specifically they filter out UV light. This does not represent a problem, because the human eye does not see in the UV spectrum.
Power line communication
Power line communication or power line carrier (PLC), also known as Power line Digital Subscriber Line (PDSL), mains communication, power line telecom (PLT), or power line networking (PLN), is a system for carrying data on a conductor also used for electric power transmission. Broadband over Power Lines (BPL) uses PLC by sending and receiving information bearing signals over power lines to provide access to the Internet.
Electrical power is transmitted over high voltage transmission lines, distributed over medium voltage, and used inside buildings at lower voltages. Powerline communications can be applied at each stage. Most PLC technologies limit themselves to one set of wires (for example, premises wiring), but some can cross between two levels (for example, both the distribution network and premises wiring).
All power line communications systems operate by impressing a modulated carrier signal on the wiring system. Different types of powerline communications use different frequency bands, depending on the signal transmission characteristics of the power wiring used. Since the power wiring system was originally intended for transmission of AC power, in conventional use, the power wire circuits have only a limited ability to carry higher frequencies. The propagation problem is a limiting factor for each type of power line communications. A new discovery called E-Line that allows a single power conductor on an overhead power line to operate as a waveguide to provide low attenuation propagation of RF through microwave energy lines while providing information rate of multiple Gbps is an exception to this limitation.
Data rates over a power line communication system vary widely. Low-frequency (about 100-200 kHz) carriers impressed on high-voltage transmission lines may carry one or two analog voice circuits, or telemetry and control circuits with an equivalent data rate of a few hundred bits per second; however, these circuits may be many miles long. Higher data rates generally imply shorter ranges; a local area network operating at millions of bits per second may only cover one floor of an office building, but eliminates installation of dedicated network cabling.
Broadband over power lines (BPL), also known as power-line Internet or powerband, is the use of PLC technology to provide broadband Internet access through ordinary power lines. A computer (or any other device) would need only to plug a BPL "modem" into any outlet in an equipped building to have high-speed Internet access. International Broadband Electric Communications or IBEC and other companies currently offer BPL service to several electric cooperatives.
BPL may offer benefits over regular cable or DSL connections: the extensive infrastructure already available appears to allow people in remote locations to access the Internet with relatively little equipment investment by the utility. Also, such ubiquitous availability would make it much easier for other electronics, such as televisions or sound systems, to hook up.
But variations in the physical characteristics of the electricity network and the current lack of IEEE standards mean that provisioning of the service is far from being a standard, repeatable process. And, the amount of bandwidth a BPL system can provide compared to cable and wireless is in question. The prospect of BPL could motivate DSL and cable operators to more quickly serve rural communities. [5]
PLC modems transmit in medium and high frequency (1.6 to 80 MHz electric carrier). The asymmetric speed in the modem is generally from 256 kbit/s to 2.7 Mbit/s. In the repeater situated in the meter room the speed is up to 45 Mbit/s and can be connected to 256 PLC modems. In the medium voltage stations, the speed from the head ends to the Internet is up to 135 Mbit/s. To connect to the Internet, utilities can use optical fiber backbone or wireless link.
The system has a number of issues. The primary one is that power lines are inherently a very noisy environment. Every time a device turns on or off, it introduces a pop or click into the line. Energy-saving devices often introduce noisy harmonics into the line. The system must be designed to deal with these natural signaling disruptions and work around them.
Broadband over power lines has developed faster in Europe than in the United States due to a historical difference in power system design philosophies. Power distribution uses step-down transformers to reduce the voltage for use by customers. But BPL signals cannot readily pass through transformers, as their high inductance makes them act as low-pass filters, blocking high-frequency signals. So, repeaters must be attached to the transformers. In the U.S., it is common for a small transformer hung from a utility pole to service a single house or a small number of houses. In Europe, it is more common for a somewhat larger transformer to service 10 or 100 houses. For delivering power to customers, this difference in design makes little difference for power distribution. But for delivering BPL over the power grid in a typical U.S. city requires an order of magnitude more repeaters than in a comparable European city. On the other hand, since bandwidth to the transformer is limited, this can increase the speed at which each household can connect, due to fewer people sharing the same line. One possible solution is to use BPL as the backhaul for wireless communications, for instance by hanging Wi-Fi access points or cellphone base stations on utility poles, thus allowing end-users within a certain range to connect with equipment they already have.
Electrical power is transmitted over high voltage transmission lines, distributed over medium voltage, and used inside buildings at lower voltages. Powerline communications can be applied at each stage. Most PLC technologies limit themselves to one set of wires (for example, premises wiring), but some can cross between two levels (for example, both the distribution network and premises wiring).
All power line communications systems operate by impressing a modulated carrier signal on the wiring system. Different types of powerline communications use different frequency bands, depending on the signal transmission characteristics of the power wiring used. Since the power wiring system was originally intended for transmission of AC power, in conventional use, the power wire circuits have only a limited ability to carry higher frequencies. The propagation problem is a limiting factor for each type of power line communications. A new discovery called E-Line that allows a single power conductor on an overhead power line to operate as a waveguide to provide low attenuation propagation of RF through microwave energy lines while providing information rate of multiple Gbps is an exception to this limitation.
Data rates over a power line communication system vary widely. Low-frequency (about 100-200 kHz) carriers impressed on high-voltage transmission lines may carry one or two analog voice circuits, or telemetry and control circuits with an equivalent data rate of a few hundred bits per second; however, these circuits may be many miles long. Higher data rates generally imply shorter ranges; a local area network operating at millions of bits per second may only cover one floor of an office building, but eliminates installation of dedicated network cabling.
Broadband over power lines (BPL), also known as power-line Internet or powerband, is the use of PLC technology to provide broadband Internet access through ordinary power lines. A computer (or any other device) would need only to plug a BPL "modem" into any outlet in an equipped building to have high-speed Internet access. International Broadband Electric Communications or IBEC and other companies currently offer BPL service to several electric cooperatives.
BPL may offer benefits over regular cable or DSL connections: the extensive infrastructure already available appears to allow people in remote locations to access the Internet with relatively little equipment investment by the utility. Also, such ubiquitous availability would make it much easier for other electronics, such as televisions or sound systems, to hook up.
But variations in the physical characteristics of the electricity network and the current lack of IEEE standards mean that provisioning of the service is far from being a standard, repeatable process. And, the amount of bandwidth a BPL system can provide compared to cable and wireless is in question. The prospect of BPL could motivate DSL and cable operators to more quickly serve rural communities. [5]
PLC modems transmit in medium and high frequency (1.6 to 80 MHz electric carrier). The asymmetric speed in the modem is generally from 256 kbit/s to 2.7 Mbit/s. In the repeater situated in the meter room the speed is up to 45 Mbit/s and can be connected to 256 PLC modems. In the medium voltage stations, the speed from the head ends to the Internet is up to 135 Mbit/s. To connect to the Internet, utilities can use optical fiber backbone or wireless link.
The system has a number of issues. The primary one is that power lines are inherently a very noisy environment. Every time a device turns on or off, it introduces a pop or click into the line. Energy-saving devices often introduce noisy harmonics into the line. The system must be designed to deal with these natural signaling disruptions and work around them.
Broadband over power lines has developed faster in Europe than in the United States due to a historical difference in power system design philosophies. Power distribution uses step-down transformers to reduce the voltage for use by customers. But BPL signals cannot readily pass through transformers, as their high inductance makes them act as low-pass filters, blocking high-frequency signals. So, repeaters must be attached to the transformers. In the U.S., it is common for a small transformer hung from a utility pole to service a single house or a small number of houses. In Europe, it is more common for a somewhat larger transformer to service 10 or 100 houses. For delivering power to customers, this difference in design makes little difference for power distribution. But for delivering BPL over the power grid in a typical U.S. city requires an order of magnitude more repeaters than in a comparable European city. On the other hand, since bandwidth to the transformer is limited, this can increase the speed at which each household can connect, due to fewer people sharing the same line. One possible solution is to use BPL as the backhaul for wireless communications, for instance by hanging Wi-Fi access points or cellphone base stations on utility poles, thus allowing end-users within a certain range to connect with equipment they already have.
safety
Industrial safety systems are crucial in any hazardous plants such as oil and gas plants and nuclear plants. They are used to protect human, plant, and environment in case the process went beyond the control margins. As the name suggests, these systems are not intended for controlling the process itself but rather protection. Process control is performed by means of process control systems (PCS) and is interlocked by the safety systems so that immediate actions are taken should the process control systems fail.
Process control and safety systems are usually merged under one system, called integrated control and safety system, (ICSS). Industrial safety systems typically use dedicated systems that are SIL 2 certified at minimum; whereas control systems can start with SIL 1. SIL applies to both hardware and software requirements such as cards, processors redundancy and voting functions.
Process control and safety systems are usually merged under one system, called integrated control and safety system, (ICSS). Industrial safety systems typically use dedicated systems that are SIL 2 certified at minimum; whereas control systems can start with SIL 1. SIL applies to both hardware and software requirements such as cards, processors redundancy and voting functions.
plc
A programmable logic controller (PLC) or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or lighting fixtures. PLCs are used in many industries and machines. Unlike general-purpose computers, the PLC is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed or non-volatile memory. A PLC is an example of a real time system since output results must be produced in response to input conditions within a bounded time, otherwise unintended operation will result.
he PLC was invented in response to the needs of the American automotive manufacturing industry. Programmable controllers were initially adopted by the automotive industry where software revision replaced the re-wiring of hard-wired control panels when production models changed.
Before the PLC, control, sequencing, and safety interlock logic for manufacturing automobiles was accomplished using hundreds or thousands of relays, cam timers, and drum sequencers and dedicated closed-loop controllers. The process for updating such facilities for the yearly model change-over was very time consuming and expensive, as electricians needed to individually rewire each and every relay.
In 1968 GM Hydramatic (the automatic transmission division of General Motors) issued a request for proposal for an electronic replacement for hard-wired relay systems.
The winning proposal came from Bedford Associates of Bedford, Massachusetts. The first PLC, designated the 084 because it was Bedford Associates' eighty-fourth project, was the result. Bedford Associates started a new company dedicated to developing, manufacturing, selling, and servicing this new product: Modicon, which stood for MOdular DIgital CONtroller. One of the people who worked on that project was Dick Morley, who is considered to be the "father" of the PLC. The Modicon brand was sold in 1977 to Gould Electronics, and later acquired by German Company AEG and then by French Schneider Electric, the current owner.
One of the very first 084 models built is now on display at Modicon's headquarters in North Andover, Massachusetts. It was presented to Modicon by GM, when the unit was retired after nearly twenty years of uninterrupted service. Modicon used the 84 moniker at the end of its product range until the 984 made its appearance.
The automotive industry is still one of the largest users of PLCs.
he PLC was invented in response to the needs of the American automotive manufacturing industry. Programmable controllers were initially adopted by the automotive industry where software revision replaced the re-wiring of hard-wired control panels when production models changed.
Before the PLC, control, sequencing, and safety interlock logic for manufacturing automobiles was accomplished using hundreds or thousands of relays, cam timers, and drum sequencers and dedicated closed-loop controllers. The process for updating such facilities for the yearly model change-over was very time consuming and expensive, as electricians needed to individually rewire each and every relay.
In 1968 GM Hydramatic (the automatic transmission division of General Motors) issued a request for proposal for an electronic replacement for hard-wired relay systems.
The winning proposal came from Bedford Associates of Bedford, Massachusetts. The first PLC, designated the 084 because it was Bedford Associates' eighty-fourth project, was the result. Bedford Associates started a new company dedicated to developing, manufacturing, selling, and servicing this new product: Modicon, which stood for MOdular DIgital CONtroller. One of the people who worked on that project was Dick Morley, who is considered to be the "father" of the PLC. The Modicon brand was sold in 1977 to Gould Electronics, and later acquired by German Company AEG and then by French Schneider Electric, the current owner.
One of the very first 084 models built is now on display at Modicon's headquarters in North Andover, Massachusetts. It was presented to Modicon by GM, when the unit was retired after nearly twenty years of uninterrupted service. Modicon used the 84 moniker at the end of its product range until the 984 made its appearance.
The automotive industry is still one of the largest users of PLCs.
control valves
Control valves are valves used to control conditions such as flow, pressure, temperature, and liquid level by fully or partially opening or closing in response to signals received from controllers that compare a "setpoint" to a "process variable" whose value is provided by sensors that monitor changes in such conditions.[1]
The opening or closing of control valves is done by means of electrical, hydraulic or pneumatic systems. Positoners are used to control the opening or closing of the actuator based on Electric, or Pnuematic Signals. These control signals, traditionally based on 3-15psi (0.2-1.0bar), more common now are 4-20mA signals for industry, 0-10V for HVAC systems, & the introduction of "Smart" systems, HART, Fieldbus Foundation, & Profibus being the more common protocols.
A valve is a device that regulates the flow of a fluid (gases, fluidized solids, slurries, or liquids) by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category.
Valves are also found in the human body. For example, there are several which control the flow of blood in the chambers of the heart and maintain the correct pumping action (see heart valve article).
Valves are used in a variety of contexts, including industrial, military, commercial, residential, and transportation.
Oil and gas, power generation, mining, water reticulation, sewerage and chemical manufacturing are the industries in which the majority of valves are used.
Plumbing valves, such as taps for hot and cold water are the most noticeable types of valves. Other valves encountered on a daily basis include gas control valves on cookers and barbecues, small valves fitted to washing machines and dishwashers, and safety devices fitted to hot water systems.
Valves may be operated manually, either by a hand wheel, lever or pedal. Valves may also be automatic, driven by changes in pressure, temperature or flow. These changes may act upon a diaphram or a piston which in turn activates the valve, examples of this type of valve found commonly are safety valves fitted to hot water systems or steam boilers.
More complex control systems using valves requiring automatic control based on an external input (i.e., regulating flow through a pipe to a changing set point) require an actuator. An actuator will stroke the valve depending on its input and set-up, allowing the valve to be positioned accurately, and allowing control over a variety of requirements.
Valves are also found in the Otto cycle (internal combustion) engines driven by a camshaft, lifters and or push rods where they play a major role in engine cycle control.
Contents
The opening or closing of control valves is done by means of electrical, hydraulic or pneumatic systems. Positoners are used to control the opening or closing of the actuator based on Electric, or Pnuematic Signals. These control signals, traditionally based on 3-15psi (0.2-1.0bar), more common now are 4-20mA signals for industry, 0-10V for HVAC systems, & the introduction of "Smart" systems, HART, Fieldbus Foundation, & Profibus being the more common protocols.
A valve is a device that regulates the flow of a fluid (gases, fluidized solids, slurries, or liquids) by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category.
Valves are also found in the human body. For example, there are several which control the flow of blood in the chambers of the heart and maintain the correct pumping action (see heart valve article).
Valves are used in a variety of contexts, including industrial, military, commercial, residential, and transportation.
Oil and gas, power generation, mining, water reticulation, sewerage and chemical manufacturing are the industries in which the majority of valves are used.
Plumbing valves, such as taps for hot and cold water are the most noticeable types of valves. Other valves encountered on a daily basis include gas control valves on cookers and barbecues, small valves fitted to washing machines and dishwashers, and safety devices fitted to hot water systems.
Valves may be operated manually, either by a hand wheel, lever or pedal. Valves may also be automatic, driven by changes in pressure, temperature or flow. These changes may act upon a diaphram or a piston which in turn activates the valve, examples of this type of valve found commonly are safety valves fitted to hot water systems or steam boilers.
More complex control systems using valves requiring automatic control based on an external input (i.e., regulating flow through a pipe to a changing set point) require an actuator. An actuator will stroke the valve depending on its input and set-up, allowing the valve to be positioned accurately, and allowing control over a variety of requirements.
Valves are also found in the Otto cycle (internal combustion) engines driven by a camshaft, lifters and or push rods where they play a major role in engine cycle control.
Contents
textiles
A textile is a flexible material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw wool fibres, linen, cotton, or other material on a spinning wheel to produce long strands.[1] Textiles are formed by weaving, knitting, crocheting, knotting, or pressing fibres together (felt).
The words fabric and cloth are used in textile assembly trades (such as tailoring and dressmaking) as synonyms for textile. However, there are subtle differences in these terms in specialized usage. Textile refers to any material made of interlacing fibres. Fabric refers to any material made through weaving, knitting, crocheting, or bonding. Cloth refers to a finished piece of fabric that can be used for a purpose such as covering a bed.
Textiles have an assortment of uses, the most common of which are for clothing and containers such as bags and baskets. In the household, they are used in carpeting, upholstered furnishings, window shades, towels, covering for tables, beds, and other flat surfaces, and in art. In the workplace, they are used in industrial and scientific processes such as filtering. Miscellaneous uses include flags, backpacks, tents, nets, cleaning devices such as handkerchiefs and rags, transportation devices such as balloons, kites, sails, and parachutes; and strengthening in composite materials such as fibreglass and industrial geotextiles. Children can learn using textiles to make collages, sew, quilt, and make toys.
Textiles used for industrial purposes, and chosen for characteristics other than their appearance, are commonly referred to as technical textiles. Technical textiles include textile structures for automotive applications, medical textiles (e.g. implants), geotextiles (reinforcement of embankments), agrotextiles (textiles for crop protection), protective clothing (e.g. against heat and radiation for fire fighter clothing, against molten metals for welders, stab protection, and bullet proof vests). In all these applications stringent performance requirements must be met. Woven of threads coated with zinc oxide nanowires, laboratory fabric has been shown capable of "self-powering nanosystems" using vibrations created by everyday actions like wind or body movements
Plant textiles
Grass, rush, hemp, and sisal are all used in making rope. In the first two, the entire plant is used for this purpose, while in the last two, only fibres from the plant are utilized. Coir (coconut fibre) is used in making twine, and also in floormats, doormats, brushes, mattresses, floor tiles, and sacking.
Straw and bamboo are both used to make hats. Straw, a dried form of grass, is also used for stuffing, as is kapok.
Fibres from pulpwood trees, cotton, rice, hemp, and nettle are used in making paper.
Cotton, flax, jute, hemp, modal and even bamboo fibre are all used in clothing. Piña (pineapple fibre) and ramie are also fibres used in clothing, generally with a blend of other fibres such as cotton.
Acetate is used to increase the shininess of certain fabrics such as silks, velvets, and taffetas.
Seaweed is used in the production of textiles. A water-soluble fibre known as alginate is produced and is used as a holding fibre; when the cloth is finished, the alginate is dissolved, leaving an open area
Lyocell is a man-made fabric derived from wood pulp. It is often described as a man-made silk equivalent and is a tough fabric which is often blended with other fabrics - cotton for example.
[edit] Mineral textiles
The words fabric and cloth are used in textile assembly trades (such as tailoring and dressmaking) as synonyms for textile. However, there are subtle differences in these terms in specialized usage. Textile refers to any material made of interlacing fibres. Fabric refers to any material made through weaving, knitting, crocheting, or bonding. Cloth refers to a finished piece of fabric that can be used for a purpose such as covering a bed.
Textiles have an assortment of uses, the most common of which are for clothing and containers such as bags and baskets. In the household, they are used in carpeting, upholstered furnishings, window shades, towels, covering for tables, beds, and other flat surfaces, and in art. In the workplace, they are used in industrial and scientific processes such as filtering. Miscellaneous uses include flags, backpacks, tents, nets, cleaning devices such as handkerchiefs and rags, transportation devices such as balloons, kites, sails, and parachutes; and strengthening in composite materials such as fibreglass and industrial geotextiles. Children can learn using textiles to make collages, sew, quilt, and make toys.
Textiles used for industrial purposes, and chosen for characteristics other than their appearance, are commonly referred to as technical textiles. Technical textiles include textile structures for automotive applications, medical textiles (e.g. implants), geotextiles (reinforcement of embankments), agrotextiles (textiles for crop protection), protective clothing (e.g. against heat and radiation for fire fighter clothing, against molten metals for welders, stab protection, and bullet proof vests). In all these applications stringent performance requirements must be met. Woven of threads coated with zinc oxide nanowires, laboratory fabric has been shown capable of "self-powering nanosystems" using vibrations created by everyday actions like wind or body movements
Plant textiles
Grass, rush, hemp, and sisal are all used in making rope. In the first two, the entire plant is used for this purpose, while in the last two, only fibres from the plant are utilized. Coir (coconut fibre) is used in making twine, and also in floormats, doormats, brushes, mattresses, floor tiles, and sacking.
Straw and bamboo are both used to make hats. Straw, a dried form of grass, is also used for stuffing, as is kapok.
Fibres from pulpwood trees, cotton, rice, hemp, and nettle are used in making paper.
Cotton, flax, jute, hemp, modal and even bamboo fibre are all used in clothing. Piña (pineapple fibre) and ramie are also fibres used in clothing, generally with a blend of other fibres such as cotton.
Acetate is used to increase the shininess of certain fabrics such as silks, velvets, and taffetas.
Seaweed is used in the production of textiles. A water-soluble fibre known as alginate is produced and is used as a holding fibre; when the cloth is finished, the alginate is dissolved, leaving an open area
Lyocell is a man-made fabric derived from wood pulp. It is often described as a man-made silk equivalent and is a tough fabric which is often blended with other fabrics - cotton for example.
[edit] Mineral textiles
nano processors
Early CPUs were custom-designed as a part of a larger, sometimes one-of-a-kind, computer. However, this costly method of designing custom CPUs for a particular application has largely given way to the development of mass-produced processors that are made for one or many purposes. This standardization trend generally began in the era of discrete transistor mainframes and minicomputers and has rapidly accelerated with the popularization of the integrated circuit (IC). The IC has allowed increasingly complex CPUs to be designed and manufactured to tolerances on the order of nanometers. Both the miniaturization and standardization of CPUs have increased the presence of these digital devices in modern life far beyond the limited application of dedicated computing machines. Modern microprocessors appear in everything from automobiles to cell phones and children's toys.
While the complexity, size, construction, and general form of CPUs have changed drastically over the past sixty years, it is notable that the basic design and function has not changed much at all. Almost all common CPUs today can be very accurately described as von Neumann stored-program machines. As the aforementioned Moore's law continues to hold true, concerns have arisen about the limits of integrated circuit transistor technology. Extreme miniaturization of electronic gates is causing the effects of phenomena like electromigration and subthreshold leakage to become much more significant. These newer concerns are among the many factors causing researchers to investigate new methods of computing such as the quantum computer, as well as to expand the usage of parallelism and other methods that extend the usefulness of the classical von Neumann model.
While the complexity, size, construction, and general form of CPUs have changed drastically over the past sixty years, it is notable that the basic design and function has not changed much at all. Almost all common CPUs today can be very accurately described as von Neumann stored-program machines. As the aforementioned Moore's law continues to hold true, concerns have arisen about the limits of integrated circuit transistor technology. Extreme miniaturization of electronic gates is causing the effects of phenomena like electromigration and subthreshold leakage to become much more significant. These newer concerns are among the many factors causing researchers to investigate new methods of computing such as the quantum computer, as well as to expand the usage of parallelism and other methods that extend the usefulness of the classical von Neumann model.
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