In telecommunications, return loss is the loss of power in the signal returned/reflected by a discontinuity in a transmission line or optical fiber. This discontinuity can be a mismatch with the terminating load or with a device inserted in the line, it is expressed as a ratio in decibels. Return loss is related to both standing wave reflection coefficient. Increasing return loss corresponds to lower SWR. Return loss is a measure of how well lines are matched. A match is good. A high return loss results in a lower insertion loss. Return loss is used in modern practice in preference to SWR because it has better resolution for small values of reflected wave. Properly, loss quantities, when expressed in decibels, should be positive numbers. However, return loss has been expressed as a negative number, this convention is still found in the literature; the correct definition of return loss is the difference in dB between the incident power sent towards the Device Under Test and the power reflected, resulting in a positive sign: R L = 10 log 10 P i P r However taking the ratio of reflected to incident power results in a negative sign for return loss.
Return loss with a positive sign is identical to the magnitude of Γ when expressed in decibels but of opposite sign. That is, return loss with a negative sign is more properly called reflection coefficient; the S-parameter S11 from two-port network theory is also called return loss, but is equal to Γ. Caution is required when discussing increasing or decreasing return loss since these terms have the opposite meaning when return loss is defined as a negative quantity. In metallic conductor systems, reflections of a signal traveling down a conductor can occur at a discontinuity or impedance mismatch; the ratio of the amplitude of the reflected wave Vr to the amplitude of the incident wave Vi is known as the reflection coefficient Γ. Γ = V r V i When the source and load impedances are known values, the reflection coefficient is given by Γ = Z L − Z S Z L + Z S where ZS is the impedance toward the source and ZL is the impedance toward the load. Return loss is the negative of the magnitude of the reflection coefficient in dB.
Since power is proportional to the square of the voltage, return loss is given by, R L = − 20 log 10 | Γ | where the vertical bars indicate magnitude. Thus, a large positive return loss indicates the reflected power is small relative to the incident power, which indicates good impedance match from source to load; when the actual transmitted power and the reflected power are known the return loss in dB can be calculated as the difference between the incident power Pi and the reflected power Pr, R L = P i − P r In optics a loss that takes place at discontinuities of refractive index at an air-glass interface such as a fiber endface. At those interfaces, a fraction of the optical signal is reflected back toward the source; this reflection phenomenon is called "Fresnel reflection loss," or "Fresnel loss." Fiber optic transmission systems use lasers to transmit signals over optical fiber, a high optical return loss can cause the laser to stop transmitting correctly. The measurement of ORL is becoming more important in the characterization of optical networks as the use of wavelength-division multiplexing increases.
These systems use lasers that have a lower tolerance for ORL, introduce elements into the network that are located in close proximity to the laser. ORL = 10 log
Albania–China relations refer to the current and historical relations of Albania and China. The two countries established diplomatic relations on November 23, 1949. Albania has an embassy in Beijing and China has an embassy in Tirana. From the 1960s onwards, the People's Republic of Albania under Enver Hoxha, moved an annual resolution in the General Assembly to transfer China's seat at the UN from the Republic of China to the People's Republic of China. On October 25, 1971, Resolution 2758, sponsored by Albania, was passed by the General Assembly, withdrawing recognition of the ROC as the legitimate government of China, recognizing the PRC as the sole legitimate government of China. China considers Albania an important part of Road Initiative. In 2001, the two countries signed three agreements covering financial and technical aspects of constructing a new hydroelectric power facility —to be known as Hydro Central— in northern Albania. China pledged USD126 million in credit to the project. Albanian Prime Minister Sali Berisha visited Chinese Premier Wen Jiabao in April 2009.
Wen put forth a four-point proposal to further cooperation with Albania. It urged both countries to: increase exchanges at all levels to cement political relations by using the opportunity of the 60th anniversary of Sino-Albanian ties. Foreign relations of Albania Foreign relations of China Sino-Albanian split
555% is the fourth solo album by the English rock musician Ginger, released under the name Ginger Wildheart. The full album of thirty tracks was only available online for a limited time; the album was recorded over three sessions in England and Denmark during October 2011 and January 2012. Funding for the recording of the album was raised by Ginger's Triple Album Project managed through PledgeMusic; when the project raised more money than Ginger had estimated would be required to record the album, he announced that the album would be titled 555% when donations reached that percentage of the original goal. The success of the fundraising effort encouraged Ginger to make extra songs available online while offering special CD and vinyl packages to contributors. Via the PledgeMusic website, persons who pledged money to the project were allowed to download completed tracks before they were released in other forms; the first track to be made available for download by pledgers was the rough mix of "You're The One, You're The One, Yeah, I Know You're The One, You're The One."
The thirty tracks recorded for the project were made available to pledgers in three batches of ten, on 23 March, 30 March, 6 April 2012 respectively. On each date, the tracks were made available at 5:55 pm England time. All tracks are written except where noted. Persons who downloaded tracks from the PledgeMusic site were encouraged to vote for their four favorite songs out of each batch of ten; the twelve most popular songs were selected for the commercial version of the album, titled 100% and released in May 2012. The other eighteen tracks are now unavailable on CD but can be purchased as downloads via Ginger's official Bandcamp page.100% reached #9 on the UK midweek album chart on 27 June 2012. According to updates on the PledgeMusic website, the following personnel took part in the sessions: Ginger - vocals, guitar "Random" Jon Poole - bass, vocals Chris Catalyst - Guitar, vocals Denzel - drums Fyfe Ewing - drums Ritch Battersby - drums Willie Dowling - keyboards CD1 track 3, 4, 5, & 9 CD2 track 2, 3, 5, 6 7 & 9 CD3 track 1, 3, 4, 6 8 & 9, vocals C. J. - guitar, vocals Victoria Liedtke - vocals Laila K - vocals Jase Edwards - Guitar Kim Olesen - Keyboards on CD1 track 1, 2, 6, 7, 8 & 10.
CD2 track 1, 4, 8 & 10 CD3 track 2, 5, 7 & 10. Production teamWillie Dowling - producer, mixing Jacob Hansen - producer, mixing Jase Edwards - mixing Jon Astley - mastering The Wildhearts • View topic - Triple album, what we know so far.. - Transcribed album lyrics
A crankcase is the housing for the crankshaft in a reciprocating internal combustion engine. In most modern engines, the crankcase is integrated into the engine block. Two-stroke engines use a crankcase-compression design, resulting in the fuel/air mixture passing through the crankcase before entering the cylinder; this design of engine does not include an oil sump in the crankcase. Four-stroke engines have an oil sump at the bottom of the crankcase and the majority of the engine's oil is held within the crankcase; the fuel/air mixture does not pass through the crankcase in a four-stroke engine, however a small amount of exhaust gasses enter as "blow-by" from the combustion chamber. The crankcase forms the lower half of the main bearing journals, although in some engines the crankcase surrounds the main bearing journals. An "open-crank" engine has no crankcase; this design was used in early engines and remains in use in some large diesel engines, such as used in ships. Many two-stroke engines use a crankcase-compression design, where a partial vacuum draws the fuel/air mixture into the engine as the piston moves upwards.
As the piston travels downward, the inlet port is uncovered and the compressed fuel/air mixture is pushed from the crankcase into the combustion chamber. Crankcase-compression designs are used in small petrol engines for motorcycles, generator sets and garden equipment; this design has been used in some small diesel engines, however it is less common. Both sides of the piston are used as working surfaces: the upper side is the power piston, the lower side acts as a pump; therefore an inlet valve is not required. Unlike other types of engines, there is no supply of oil to the crankcase, because it handles the fuel/air mixture. Instead, two-stroke oil is mixed with the fuel used by the engine and burned in the combustion chamber. Large two-stroke engines do not use crankcase compression, but instead a separate scavenge blower or supercharger to draw the fuel/air mixture into the compression chamber; therefore the crankcases are similar to a four-stroke engine in that they are used for lubrication purposes.
Most four-stroke engines use a crankcase that contains the engine's lubricating oil, as either a wet sump system or the less common dry sump system. Unlike a two-stroke engine, the crankcase in a four-stroke engine is not used for the fuel/air mixture. Engine oil is recirculated around a four-stroke engine and much of this occurs within the crankcase. Oil is stored either in a separate reservoir. From here the oil is pressurized by an oil pump before it is squirted into the crankshaft and connecting rod bearings and onto the cylinder walls, drips off into the bottom of the crankcase. In a wet sump system, the crankshaft has minimal contact with the sump oil. Otherwise, the high-speed rotation of the crankshaft would cause the oil to froth, making it difficult for the oil pump to move the oil, which can starve the engine of lubrication. Oil from the sump may splash onto the crankshaft due to g-forces or bumpy roads, referred to as windage. Although the piston rings are intended to seal the combustion chamber from the crankcase, it is normal for some combustion gasses to escape around the piston rings and enter the crankcase.
This phenomenon is known as blow-by. If these gases accumulated within the crankcase, it would cause unwanted pressurisation of the crankcase, contamination of the oil and rust from condensation. To prevent this, modern engines use a crankcase ventilation system to expel the combustion gasses from the crankcase. In most cases, the gasses are passed through to the intake manifold. Early engines were of the "open-crank" style; the crankshaft and associated parts were open to the environment. This made for a messy environment. Another disadvantage was that dirt and dust could get on moving engine parts, causing excessive wear and possible malfunction of the engine. Frequent cleaning of the engine was required to keep it in normal working order; some two-stroke diesel engines, such as the large slow-speed engines used in ships, have the crankcase as a separate space from the cylinders, or as an open crank. The spaces between the crosshead piston and the crankshaft, may be open for maintenance access.
Saharsa College of Engineering is a government engineering college managed by the Department of Science and Technology, Bihar. It is affiliated with Aryabhatta Knowledge University and approved by All India Council for Technical Education. College was established in the year 2017, it is situated in Saharsa district of Bihar. Admission in the college for four years B. Tech. Course is made through UGEAC conducted by Bihar Combined Entrance Competitive Examination Board. To apply for UGEAC, appearing in JEE Main of that admission year is required. Civil Engineering Mechanical Engineering Electrical Engineering Electronics & Communication Engineering Official website BCECE Board website Aryabhatta Knowledge University website DST, Bihar website
The Brahman is an American breed of zebuine beef cattle. It was bred in the United States from 1885 from cattle originating in India, imported at various times from the United Kingdom, from India and from Brazil; the Brahman has a high tolerance of heat and humidity, good resistance to parasites. It has been exported to many countries in the tropics, it has been used in the creation of numerous taurine-indicine hybrids, some of which – such as the Brahmousin – are established as separate breeds.:137 The Indian-origin Brahman cattle breed is named after the Brahmins, who themselves are named after the Hindu deity Brahma. Many Hindu Brahmins consider cows holy and bulls sacred, eating neither; the American Brahman was first bred in the early 1900s as a cross of four different Indian cattle breeds: Gujarat, Ongole and Krishna Valley. The original American Brahman cattle originated from a nucleus of 266 bulls and 22 females of several Bos indicus varieties imported into the United States between 1854 and 1926.
The Brahman is used for the meat industry. It has been crossbred extensively, it has been used to develop numerous other U. S. beef breeds including Brangus, Beefmaster and Santa Gertrudis. The breed is used as a riding steer, it is favoured for its docility and intelligence. Brahman cattle are widespread in tropical regions, they are resistant to insects due to their thick skin. Brahman cattle live longer than many other breeds producing calves at ages 15 and older. In Oman and Fujairah, Brahman bulls are used in the traditional sport of bull-butting, it involves two of these bulls engaging in a ferocious round of headbutts. The first one to collapse or concede its ground is deemed the loser. Brahman bulls being readied for this sport are kept on a special diet of milk and honey for gaining superior strength; the American Brahman Breeders Association was formed in 1924 as the official herd registry to track and verify cattle bloodlines. This organization is now headquartered in Houston; the name "Brahman" was created by the American Brahman Breeder's Association first secretary, Mr. J. W. Sartwelle.
The Brahman Breed has made a major impact on the Australian beef cattle market in the northern parts of Australia. Since the introduction of the breed to Australia, over 50% of Australia's cattle population are either Brahman or Brahman cross cattle; the breed does well not only in hot temperatures but in the colder climate. There are breeders of the Brahman breed in Victoria right through to North Queensland, it is a common misconception. In Australia, the Brahman Breeders Association of Australia is the body in which members register their cattle and can become members if they wish to have registered cattle. However, there are a number of people which breed "commercial" cattle in which they are not registered breeders, these breeders supply cattle for the beef market use stud bulls to improve the quality of their stock. American Brahman Breeders Association Australian Brahman Breeders Association Brahman Cattle - Cattle.com Brahman Cattle Video - A Video on the American Brahman "Weird Cow Breeds: The American Brahman - The cow with the big long ears".
August 27, 2017