Rolltop desk
A rolltop desk is a 19th-century reworking of the pedestal desk with, in addition, a series of stacked compartments, shelves, drawers and nooks in front of the user, much like the bureau à gradin or the Carlton House desk. In contrast to these the compartments and the desktop surface of a rolltop desk can be covered by means of a tambour consisting of linked wooden slats that roll or slide through slots in the raised sides of the desk. In that, it is a descendant in function, and partly in form, of the cylinder desk of the 18th century. It is a relative of the tambour desk whose slats retract horizontally rather than vertically.
Production
Unlike the cylinder desk, the rolltop desk could be mass-produced rather easily since the simple wooden slats could be turned out very fast in a uniform way. In contrast, the wooden section of a cylinder had to be treated with great pains to keep its form perfectly over time, lest it warp or bend, and make it impossible to retract or extend. The wooden slats of the rolltop's tambour were usually joined together by being all attached to a cloth or leather foundation, and were thus less influenced by the problems which plagued the cylinder desk.
Top
A top is a toy designed to be spun rapidly on the ground, the motion of which causes it to remain precisely balanced on its tip because of inertia. Such toys have existed since antiquity. Traditionally tops were constructed of wood, sometimes with an iron tip, and would be set in motion by aid of a string or rope coiled around its axis which, when pulled quickly, caused a rapid unwinding that would set the top in motion. Today they are often built of plastic, and modern materials and manufacturing processes allow tops to be constructed with such precise balance that they can be set in motion by a simple twist of the fingers and twirl of the wrist without need for string or rope.
Characteristics
The motion of a top is produced in the most simple forms by twirling the stem using the fingers. More sophisticated tops are spun by holding the axis firmly while pulling a string or twisting a stick or pushing an auger. In the kinds with an auger, an internal weight rotates, producing an overall circular motion. Some tops can be thrown, while firmly grasping a string that had been tightly wound around the stem, and the centrifugal force generated by the unwinding motion of the string will set them spinning upon touching ground.
Top (mathematics)
In the context of a module M over a ring R, the top of M is the largest semisimple quotient module of M if it exists.
For finite-dimensional k-algebras (k a field), if rad(M) denotes the intersection of all proper maximal submodules of M (the radical of the module), then the top of M is M/rad(M). In the case of local rings with maximal ideal P, the top of M is M/PM. In general if R is a semilocal ring (=semi-artinian ring), that is, if R/Rad(R) is an Artinian ring, where Rad(R) is the Jacobson radical of R, then M/rad(M) is a semisimple module and is the top of M. This includes the cases of local rings and finite dimensional algebras over fields.
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Top (clothing)
A top is clothing that covers at least the chest, but which usually covers most of the upper human body between the neck and the waistline. The bottom of tops can be as short as mid-torso, or as long as mid-thigh. Men's tops are generally paired with pants, and women's with pants or skirts. Common types of tops are t-shirts, blouses and shirts.
Design
The neckline is the highest line of the top, and may be as high as a head-covering hood, or as low as the waistline or bottom hem of the top. A top may be worn loose or tight around the bust or waist, and may have sleeves or shoulder straps, spaghetti straps (noodle straps), or may be strapless. The back may be covered or bare. Tops may have straps around the waist or neck, or over the shoulders.
Types
Neck styles
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References
External links
Flight dynamics
Flight dynamics is the study of the performance, stability, and control of vehicles flying through the air or in outer space. It is concerned with how forces acting on the vehicle influence its speed and attitude with respect to time.
In fixed-wing aircraft, the changing orientation of the vehicle with respect to the local air flow is represented by two critical parameters, angle of attack ("alpha") and angle of sideslip ("beta"). These angles describe the vector direction of airspeed, important because it is the principal source of modulations in the aerodynamic forces and moments applied to the aircraft.
Spacecraft flight dynamics involve three forces: propulsive (rocket engine), gravitational, and lift and drag (when traveling through the earths or any other celestial atmosphere). Because aerodynamic forces involved with spacecraft flight are very small, this leaves gravity as the dominant force.
Aircraft and spacecraft share a critical interest in their orientation with respect to the earth horizon and heading, and this is represented by another set of angles, "yaw," "pitch" and "roll" which angles match their colloquial meaning, but also have formal definition as an Euler sequence. These angles are the product of the rotational equations of motion, where orientation responds to torque, just as the velocity of a vehicle responds to forces. For all flight vehicles, these two sets of dynamics, rotational and translational, operate simultaneously and in a coupled fashion to evolve the vehicle's state (orientation and velocity) trajectory.
Mail on Sunday (album)
Mail on Sunday is the debut studio album by American hip hop artist Flo Rida, and was released on March 18, 2008 via Atlantic, and Poe Boy Entertainment. It spawned three singles; the first, "Low" was number-one on the U.S. Billboard Hot 100 for ten weeks. The second, and third singles, "Elevator", and "In the Ayer", were successful as well, being top twenty hits. "Roll" featuring Sean Kingston was not an official single, but it managed to peak at number fifty-nine on the US Billboard Hot 100, and number forty-three on the Canadian Hot 100 due to digital sales in both countries.
Music
T-Pain, who laced the first single, is only one of the many featured guests throughout the album. Timbaland, who produced the second single "Elevator", is also featured on the track. Rick Ross, and Trey Songz made appearances as well.Lil Wayne has also been added to the list with assistance by young Memphian, Jamil Smith- while Sean Kingston appears on the J. R. Rotem-produced "Roll" the concept was created, and co-written by Compton rapper Spitfiya, from The Bullets Production Team, Various other guests include Birdman, Brisco. The third single is "In the Ayer" featuring will.i.am. The fourth single was scheduled to be "Money Right" featuring Brisco, and Rick Ross, but was canceled due to the release of his upcoming second studio album R.O.O.T.S. His second collaboration with T-Pain, "I Bet", as well as his collaboration with Trina, named "Bout It", both didn't make the final tracklist, but were recorded. As for production, J. R. Rotem, DJ Montay, and Timbaland all provided tracks for Mail on Sunday, among others.
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