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Metropol Parasol

Metropol Parasol is a wooden structure located at La Encarnación square, in the old quarter of Seville, Spain. It was designed by the German architect Jürgen Mayer and completed in April 2011, it has dimensions of 150 by 70 metres and an approximate height of 26 metres and claims to be the largest wooden structure in the world. Its appearance, location and cost overruns in construction resulted in much public controversy; the building is popularly known as Las Setas de la Encarnación. The structure consists of six parasols in the form of giant mushrooms, whose design is inspired by the vaults of the Cathedral of Seville and the ficus trees in the nearby Plaza de Cristo de Burgos. Metropol Parasol is organized in four levels; the underground level houses the Antiquarium, where Roman and Moorish remains discovered on site are displayed in a museum. Level 1 is the Central Market; the roof of Level 1 is the surface of the open-air public plaza, shaded by the wooden parasols above and designed for public events.

Levels 2 and 3 are the two stages of the panoramic terraces, offering one of the best views of the city centre. From the 19th century a market was located in the plaza, housed in a dedicated building; the building was demolished in 1948 in accordance with plans for urban renewal. The market itself remained, until 1973, when the rest of the dilapidated building was demolished; the land remained dormant until 1990, when the city decided to construct underground parking with space for a market on top. However, in the midst of construction, ruins dating to the Roman and Al-Andalus eras were discovered, construction was frozen after an expenditure of 14 million euros. In 2004, the city decided to attempt to develop the area again, opened an international competition to solicit bids. Construction began on June 26, 2005, with an estimated cost of 50 million euros and a projected completion date in June 2007. However, unknown to the public, the project soon faced difficulties. By May 2007 engineering firm Arup informed the municipal authorities that the structure was technically unfeasible as designed, given that a number of structural assumptions had not been tested and the design appeared to violate the limitations of known materials.

The wood used was birch, imported from Finland, because of its straight qualities. Much time was spent developing feasible alternative plans to buttress the structure, which themselves proved impractical because of the added weight. A feasible design using glue as reinforcement was settled on only at the beginning of 2009. By some estimates, due to delays, the total cost of the structure approached 100 million euros

Pericyma

Pericyma is a genus of moths in the family Erebidae. The genus was erected by Gottlieb August Wilhelm Herrich-Schäffer in 1851. Pericyma albidens Pericyma albidentaria Pericyma andrefana Pericyma atrifusa Pericyma basalis Wileman & South, 1916 Pericyma caffraria Pericyma cruegeri Butler, 1886 Pericyma deducta Pericyma detersa Walker, 1865 Pericyma griveaudi Pericyma mendax Pericyma metaleuca Hampson, 1913 Pericyma polygramma Hampson, 1913 Pericyma scandulata Pericyma squalens Lederer, 1855 Pericyma subtusplaga Berio, 1984 Pericyma umbrina Guenée, 1852 Pericyma viettei Pericyma vietti Pericyma vinsonii De Prins, J. & De Prins, W.. "Pericyma Herrich-Schäffer, 1851". Afromoths. Retrieved December 14, 2019

Laser rangefinder

A laser rangefinder is a rangefinder that uses a laser beam to determine the distance to an object. The most common form of laser rangefinder operates on the time of flight principle by sending a laser pulse in a narrow beam towards the object and measuring the time taken by the pulse to be reflected off the target and returned to the sender. Due to the high speed of light, this technique is not appropriate for high precision sub-millimeter measurements, where triangulation and other techniques are used; the pulse may be coded to reduce the chance. It is possible to use Doppler effect techniques to judge whether the object is moving towards or away from the rangefinder, if so, how fast; the precision of the instrument is determined by the rise or fall time of the laser pulse and the speed of the receiver. One that uses sharp laser pulses and has a fast detector can range an object to within a few millimeters. Despite the beam being narrow, it will spread over long distances due to the divergence of the laser beam, as well as due to scintillation and beam wander effects, caused by the presence of air bubbles in the air acting as lenses ranging in size from microscopic to half the height of the laser beam's path above the earth.

These atmospheric distortions coupled with the divergence of the laser itself and with transverse winds that serve to push the atmospheric heat bubbles laterally may combine to make it difficult to get an accurate reading of the distance of an object, beneath some trees or behind bushes, or over long distances of more than 1 km in open and unobscured desert terrain. Some of the laser light might reflect off leaves or branches which are closer than the object, giving an early return and a reading, too low. Alternatively, over distances longer than 1200 ft, the target, if in proximity to the earth, may vanish into a mirage, caused by temperature gradients in the air in proximity to the heated surface bending the laser light. All these effects have to be taken into account; the distance between point A and B is given by D = c t 2 where c is the speed of light and t is the amount of time for the round-trip between A and B. T = ϕ ω where φ is the phase delay made by the light traveling and ω is the angular frequency of optical wave.

Substituting the values in the equation, D = 1 2 c t = 1 2 c ϕ ω = c 4 π f = λ 4 In this equation, λ is the wavelength c/f. Time of flight - this measures the time taken for a light pulse to travel to the target and back. With the speed of light known, an accurate measurement of the time taken, the distance can be calculated. Many pulses are fired sequentially and the average response is most used; this technique requires accurate sub-nanosecond timing circuitry. Multiple frequency phase-shift - this measures the phase shift of multiple frequencies on reflection solves some simultaneous equations to give a final measure. Interferometry - the most accurate and most useful technique for measuring changes in distance rather than absolute distances. Rangefinders provide an exact distance to targets located beyond the distance of point-blank shooting to snipers and artillery, they can be used for military reconnaissance and engineering. Handheld military rangefinders operate at ranges of 2 km up to 25 km and are combined with binoculars or monoculars.

When the rangefinder is equipped with a digital magnetic compass and inclinometer it is capable of providing magnetic azimuth and height of targets. Some rangefinders can measure a target's speed in relation to the observer; some rangefinders have cable or wireless interfaces to enable them to transfer their measurement data to other equipment like fire control computers. Some models offer the possibility to use add-on night vision modules. Most handheld rangefinders use rechargeable batteries; the more powerful models of rangefinders measure distance up to 25 km and are installed either on a tripod or directly on a vehicle or gun platform. In the latter case the rangefinder module is integrated with on-board thermal, night vision and daytime observation equipment; the most advanced military rangefinders can be integrated with computers. To make laser rangefinders and laser-guided weapons less useful against military targets, various military arms may have developed laser-absorbing paint for their vehicles.

Regardless, some objects don't reflect laser light well and using a laser rangefinder on them is difficult. Laser rangefinders are used extensively in 3-D object recognition, 3-D object modelling, a wide variety of computer vision-related fields; this technology constitutes the heart of the so-called time-of-flight 3D scanners. In contrast to the military instruments described above, laser rangefinders offer high-precision scanning abilities, with either single-face or 360-degree scanning modes. A number of algorithms have been dev

Louis Speyer

Louis-Marius Speyer was a French-born American oboist best known for playing solo English horn in the Boston Symphony Orchestra from 1918 to 1964. Speyer studied oboe at the Paris Conservatoire under Georges Gillet. At the annual Paris Conservatoire Concours he won a second Accessit in 1909, a first Accessit in 1910, followed by a Premier prix in 1911. Speyer became an extra oboist for the Orchestre Colonne, which accompanied the Ballets Russes in France, in that way participated in several premieres of works by Ravel and Stravinsky. In early 1913 he joined the newly formed Orchestre du Théâtre des Champs-Élysées, conducted by Pierre Monteux, which gave its first performance on 2 April 1913. Two months he played in this orchestra in one of the most famous concerts of all time: the program included Les Sylphides, Le Spectre de la Rose and the Polovtsian Dances, but is remembered for the raucous premiere of Stravinsky's Rite of Spring. Speyer came to America in the summer of 1918 with a French military band for a three-week good-will tour, but stayed, as he had been invited to join the Boston Symphony Orchestra, for which he was hired by Henri Rabaud.

During his exceptionally long career, he played under the conductors Pierre Monteux, Serge Koussevitzky, Charles Munch and Erich Leinsdorf. Munch was under pressure to ease the 72-year-old Speyer into retirement, but failed to do so and Speyer outlasted Munch by 2 years. Early in his career in the U. S. Speyer played in the Boston Symphony Ensemble, a summer concert chamber orchestra conducted by Daniel Kuntz. Speyer was awarded both the Reconnaissance Française medal and knighthood in the Legion of Honor by the French government. Speyer became a US citizen in October 1923, he married Camille Torno. Inspired by Speyer's playing, the art patron Elizabeth Sprague Coolidge convinced Arthur Honegger in 1947 to write a concerto for English horn. Though Honegger ended up writing a double concerto premiered in 1949 in Europe without Speyer, the Concerto da camera for flute, English horn and orchestra is dedicated to him. Numerous other English horn works have been dedicated to Speyer. Among the better known is Paul Hindemith's English horn sonata completed in 1941 at the end of a summer at Tanglewood

Softpedia

Softpedia is a software and tech-news website based in Romania. It indexes and hosts downloadable software, has dedicated sections for Windows, Linux, Drivers, Mobile and News, reports on technology and science topics from both external and in-house sources. Whenever possible, Softpedia includes one or more screenshots of each downloadable application showing its menus to help illustrate its features. Unlike most software sites that publish information provided by software developers, Softpedia's reviews are written by its staff reviewers; each review features the reviewer's 1–5 star rating, a public rating, to which any of the site's visitors may contribute. Products are arranged in categories and sub-categories, which visitors can sort according to most recent updates, number of downloads, or ratings. Free software and commercial software can be viewed separately. SP displays virtual awards for products free of adware and commercial tie-ins. Products that include unrelated and/or unanticipated components and offers are marked with links to complete details, so visitors can make educated choices about downloading and installing them.

Softpedia does not repack software for distribution. It provides direct downloads of software in its original provided form, links to developers's downloads, or both. Unlike most software sites, Softpedia hosts many products on their own servers, so they are available when their developers's sites are not. Besides being "a popular destination for software downloads", Softpedia features news and interviews on information technology and tech accessories, it is owned by a Romanian company. Internet in Romania Official website