A current transformer (CT) is a measurement device designed to provide a current in its secondary coil proportional to the current flowing in its primary. Current transformers are commonly used in metering and protective relaying in the electrical power industry where they facilitate the safe measurement of large currents, often in the presence of high voltages. The current transformer safely isolates measurement and control circuitry from the high voltages typically present on the circuit being measured.
Current transformers are often constructed by passing a single primary turn (either an insulated cable or an uninsulated bus bar) through a well-insulated toroidal core wrapped with many turns of wire. The CT is typically described by its current ratio from primary to secondary. For example, a 4000:5 CT would provide an output current of 5 amperes when the primary was passing 4000 amperes. The secondary winding can be single ratio or have several tap points to provide a range of ratios. Care must be taken that the secondary winding is not disconnected from its load while current flows in the primary, as this will produce a dangerously high voltage across the open secondary and may permanently affect the accuracy of the transformer.
Voltage transformers (VTs) or potential transformers (PTs) are another type of instrument transformer, used for metering and protection in high-voltage circuits. They are designed to present negligible load to the supply being measured and to have a precise voltage ratio to accurately step down high voltages so that metering and protective relay equipment can be operated at a lower potential. Typically the secondary of a voltage transformer is rated for 69 or 120 Volts at rated primary voltage, to match the input ratings of protection relays.
The transformer winding high-voltage connection points are typically labelled as H1, H2 (sometimes H0 if it is internally grounded) and X1, X2, and sometimes an X3 tap may be present. Sometimes a second isolated winding (Y1, Y2, Y3) may also be available on the same voltage transformer. The high side (primary) may be connected phase to ground or phase to phase. The low side (secondary) is usually phase to ground.
Friday, March 13, 2009
WildLife animals
Wildlife includes all non-domesticated plants, animals, and other organisms. Domesticating wild plant and animal species for human benefit has occurred many times all over the planet, and has a major impact on the environment, both positive and negative.
Wildlife can be found in all ecosystems, Deserts, rain forests, plains, and other areas—including the most developed urban sites—all have distinct forms of wildlife. While the term in popular culture usually refers to animals that are untouched by human factors, most scientists agree that wildlife around the world is impacted by human activities.
Humans have historically tended to separate civilization from wildlife in a number of ways including the legal, social, and moral sense. This has been a reason for debate throughout recorded history. Religions have often declared certain animals to be sacred, and in modern times concern for the natural environment has provoked activists to protest the exploitation of wildlife for human benefit or entertainment. Literature has also made use of the traditional human separation from wildlife.
Wildlife can be found in all ecosystems, Deserts, rain forests, plains, and other areas—including the most developed urban sites—all have distinct forms of wildlife. While the term in popular culture usually refers to animals that are untouched by human factors, most scientists agree that wildlife around the world is impacted by human activities.
Humans have historically tended to separate civilization from wildlife in a number of ways including the legal, social, and moral sense. This has been a reason for debate throughout recorded history. Religions have often declared certain animals to be sacred, and in modern times concern for the natural environment has provoked activists to protest the exploitation of wildlife for human benefit or entertainment. Literature has also made use of the traditional human separation from wildlife.
Energy Meter
An electric meter or energy meter is a device that measures the amount of electrical energy supplied to or produced by a residence, business or machine. The most common type is more properly known as a kilowatt hour meter or a joule meter. When used in electricity retailing, the utilities record the values measured by these meters to generate an invoice for the electricity. They may also record other variables including the time when the electricity was used.
The most common unit of measurement on the electricity meter is the kilowatt hour, which is equal to the amount of energy used by a load of one kilowatt over a period of one hour, or 3,600,000 joules. Some electricity companies use the SI megajoule instead. Demand is normally measured in watts, but averaged over a period, most often a quarter or half hour. Reactive power is measured in "Volt-amperes reactive", (varh) in kilovar-hours.
A "lagging" or inductive load, such as a motor, will have negative reactive power. A "leading", or capacitive load, will have positive reactive power. Volt-amperes measures all power passed through a distribution network, including reactive and actual. This is equal to the product of root-mean-square volts and amperes. Distortion of the electric current by loads is measured in several ways. Power factor is the ratio of resistive (or real power) to volt-amperes. A capacitive load has a leading power factor, and an inductive load has a lagging power factor. A purely resistive load (such as a fillament lamp, heater or kettle) exhibits a power factor of 1.
Current harmonics are a measure of distortion of the wave form. For example, electronic loads such as computer power supplies draw their current at the voltage peak to fill their internal storage elements. This can lead to a significant voltage drop near the supply voltage peak which shows as a flattening of the voltage waveform. This flattening causes odd harmonics which are not permissible if they exceed specific limits, as they are not only wasteful, but may interfere with the operation of other equipment. Harmonic emissions are mandated by law in EU and other countries to fall within specified limits.
The most common unit of measurement on the electricity meter is the kilowatt hour, which is equal to the amount of energy used by a load of one kilowatt over a period of one hour, or 3,600,000 joules. Some electricity companies use the SI megajoule instead. Demand is normally measured in watts, but averaged over a period, most often a quarter or half hour. Reactive power is measured in "Volt-amperes reactive", (varh) in kilovar-hours.
A "lagging" or inductive load, such as a motor, will have negative reactive power. A "leading", or capacitive load, will have positive reactive power. Volt-amperes measures all power passed through a distribution network, including reactive and actual. This is equal to the product of root-mean-square volts and amperes. Distortion of the electric current by loads is measured in several ways. Power factor is the ratio of resistive (or real power) to volt-amperes. A capacitive load has a leading power factor, and an inductive load has a lagging power factor. A purely resistive load (such as a fillament lamp, heater or kettle) exhibits a power factor of 1.
Current harmonics are a measure of distortion of the wave form. For example, electronic loads such as computer power supplies draw their current at the voltage peak to fill their internal storage elements. This can lead to a significant voltage drop near the supply voltage peak which shows as a flattening of the voltage waveform. This flattening causes odd harmonics which are not permissible if they exceed specific limits, as they are not only wasteful, but may interfere with the operation of other equipment. Harmonic emissions are mandated by law in EU and other countries to fall within specified limits.
Blue Tooth Technology
Bluetooth is a wireless protocol for exchanging data over short distances from fixed and mobile devices, creating personal area networks (PANs). It was originally conceived as a wireless alternative to RS232 data cables. It can connect several devices, overcoming problems of synchronization.
The word "Bluetooth" is an Anglicized version of the name of a tenth-century king, Harald Blaatand, king of Denmark and Norway, who united dissonant Scandinavian tribes into a single kingdom. The implication is that Bluetooth does the same with communications protocols, uniting them into one universal standard.
It is possible that the name may have been inspired less by the historical Harald, than by the loose interpretation of him in The Long Ships by Frans Gunnar Bengtsson, a Swedish Viking-inspired novel.
Bluetooth uses a radio technology called frequency-hopping spread spectrum, which chops up the data being sent and transmits chunks of it on up to 79 frequencies. In its basic mode, the modulation is Gaussian frequency-shift keying (GFSK). It can achieve a gross data rate of 1 Mb/s. Bluetooth provides a way to connect and exchange information between devices such as mobile phones, telephones, laptops, personal computers, printers, Global Positioning System (GPS) receivers, digital cameras, and video game consoles through a secure, globally unlicensed Industrial, Scientific, and Medical (ISM) 2.4 GHz short-range radio frequency bandwidth. The Bluetooth specifications are developed and licensed by the Bluetooth Special Interest Group (SIG). The Bluetooth SIG consists of companies in the areas of telecommunication, computing, networking, and consumer electronics.
The word "Bluetooth" is an Anglicized version of the name of a tenth-century king, Harald Blaatand, king of Denmark and Norway, who united dissonant Scandinavian tribes into a single kingdom. The implication is that Bluetooth does the same with communications protocols, uniting them into one universal standard.
It is possible that the name may have been inspired less by the historical Harald, than by the loose interpretation of him in The Long Ships by Frans Gunnar Bengtsson, a Swedish Viking-inspired novel.
Bluetooth uses a radio technology called frequency-hopping spread spectrum, which chops up the data being sent and transmits chunks of it on up to 79 frequencies. In its basic mode, the modulation is Gaussian frequency-shift keying (GFSK). It can achieve a gross data rate of 1 Mb/s. Bluetooth provides a way to connect and exchange information between devices such as mobile phones, telephones, laptops, personal computers, printers, Global Positioning System (GPS) receivers, digital cameras, and video game consoles through a secure, globally unlicensed Industrial, Scientific, and Medical (ISM) 2.4 GHz short-range radio frequency bandwidth. The Bluetooth specifications are developed and licensed by the Bluetooth Special Interest Group (SIG). The Bluetooth SIG consists of companies in the areas of telecommunication, computing, networking, and consumer electronics.
Mumbai Share Marketing
The Stock Exchange, Mumbai; popularly called The Bombay Stock Exchange, or BSE has the greatest number of listed companies in the world, with 4700 listed as of August 2007. It is located at Dalal Street, Mumbai, India. On 31 December 2007, the equity market capitalization of the companies listed on the BSE was US$ 1.79 trillion, making it the largest stock exchange in South Asia and the tenth largest in the world.
The Bombay Stock Exchange was established in 1875. Around 6,000 Indian companies list on the stock exchange, and it has a significant trading volume. The BSE SENSEX (SENSitive indEX), also called the "BSE 30", is a widely used market index in India and Asia. Though many other exchanges exist, BSE and the National Stock Exchange of India account for most of the trading in shares in India.
Singapore Exchange (SGX) made a strategic investment in Bombay Stock Exchange, acquiring 5% of its shares for US$42.7 million. It is consistent with the strategy of building an Asian Gateway for securities and derivatives. BSE is also considering taking part of the capitalisation of the rising ascension of its partner, Singapore Exchange, which is becoming a leading financial hub in Asia-Pacific.
The Bombay Stock Exchange was established in 1875. Around 6,000 Indian companies list on the stock exchange, and it has a significant trading volume. The BSE SENSEX (SENSitive indEX), also called the "BSE 30", is a widely used market index in India and Asia. Though many other exchanges exist, BSE and the National Stock Exchange of India account for most of the trading in shares in India.
Singapore Exchange (SGX) made a strategic investment in Bombay Stock Exchange, acquiring 5% of its shares for US$42.7 million. It is consistent with the strategy of building an Asian Gateway for securities and derivatives. BSE is also considering taking part of the capitalisation of the rising ascension of its partner, Singapore Exchange, which is becoming a leading financial hub in Asia-Pacific.
Communication Transmission
Communication can be defined as "the transfer of meanings between persons and groups." The purpose of communication may range from completing a task or mission to creating and maintaining satisfying relationships. "Transfer of meanings" implies more than the simple process of "packaging" an idea as conceived by a sender and transporting it to the mind of a receiver, where it is "unpackaged." It implies the creation of meaning in the mind of a sender followed by a re-creation of the same meaning in the mind of a receiver. If something occurs along the way to change the sender's original meaning, the communication has failed in its intent.
The survival of an organization depends on individuals and groups who are able to maintain among themselves effective and continuing relationships. Practicing ethical leadership will benefit relationships between organizational members. One component of practicing effective communication is fairness. In order to maintain fairness an organization must avoid discrimination based on gender, race, religion etc... One theory related to discrimination and prevention of workers advancing in their organization is called the Glass ceiling. Communications training will assist in developing and maintaining relations in an organization.
Communication may be considered a functional part of an organizational system, and it may be considered in an interpersonal context. The structure of an organization is determined in part by the network of channels or paths along which information must flow between members or sub-units.
The survival of an organization depends on individuals and groups who are able to maintain among themselves effective and continuing relationships. Practicing ethical leadership will benefit relationships between organizational members. One component of practicing effective communication is fairness. In order to maintain fairness an organization must avoid discrimination based on gender, race, religion etc... One theory related to discrimination and prevention of workers advancing in their organization is called the Glass ceiling. Communications training will assist in developing and maintaining relations in an organization.
Communication may be considered a functional part of an organizational system, and it may be considered in an interpersonal context. The structure of an organization is determined in part by the network of channels or paths along which information must flow between members or sub-units.
W3C Web Services
The W3C Web service definition encompasses many different systems, but in common usage the term refers to clients and servers that communicate over the HTTP protocol used on the Web. Such services tend to fall into one of two camps: Big Web Services and RESTful Web Services.
"Big Web Services" use XML messages that follow the SOAP standard and have been popular with traditional enterprise. In such systems, there is often a machine-readable description of the operations offered by the service written in the Web Services Description Language (WSDL). The latter is not a requirement of a SOAP endpoint, but it is a prerequisite for automated client-side code generation in many Java and .NET SOAP frameworks (frameworks such as Spring, Apache Axis2 and Apache CXF being notable exceptions).
Some industry organizations, such as the WS-I, mandate both SOAP and WSDL in their definition of a Web service. More recently, RESTful Web services have been regaining popularity, particularly with Internet companies. These also meet the W3C definition, and are often better integrated with HTTP than SOAP-based services. They do not require XML messages or WSDL service-API definitions
"Big Web Services" use XML messages that follow the SOAP standard and have been popular with traditional enterprise. In such systems, there is often a machine-readable description of the operations offered by the service written in the Web Services Description Language (WSDL). The latter is not a requirement of a SOAP endpoint, but it is a prerequisite for automated client-side code generation in many Java and .NET SOAP frameworks (frameworks such as Spring, Apache Axis2 and Apache CXF being notable exceptions).
Some industry organizations, such as the WS-I, mandate both SOAP and WSDL in their definition of a Web service. More recently, RESTful Web services have been regaining popularity, particularly with Internet companies. These also meet the W3C definition, and are often better integrated with HTTP than SOAP-based services. They do not require XML messages or WSDL service-API definitions
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