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1. ### List of HTTP status codes - Wikipedia

en.wikipedia.org › wiki › List_of_HTTP_status_codes

This is a list of Hypertext Transfer Protocol (HTTP) response status codes. Status codes are issued by a server in response to a client's request made to the server. It includes codes from IETF Request for Comments (RFCs), other ...

2. ### Harmonic damper - Wikipedia

en.wikipedia.org › wiki › Harmonic_damper
• Need
• Torsional Crankshaft Movement and Harmonics
• Countering Torsional Crank Motion and Harmonic Vibration
• Construction
• Engine Design, Materials & Other Factors
• Identification
• Maintenance
• Effects of Removal
• Original Invention
• See Also

The need for a damper will depend on the age of the engine design, its manufacture, strength of components, usable powerband, rev range and, most importantly,[citation needed] the quality of the engine's tune. The engine's tune especially in computer controlled applications can have a dramatic effect on durability,[citation needed] the aggressiveness of the tune puts the engine at risk of detonation which can be catastrophic to all rotating assembly components. Modern (roughly 1988+) DOHC, SOHC flat 4, flat 6, flat 8, and flat-plane V8 have no need for this device. With or without the presence of a damper, a crankshaft will act as a torsional spring to some extent. Impulses applied to the crankshaft by the connecting rods will "wind" this spring, which will respond (as a spring–mass system) by unwinding and re-winding in the opposite direction. This crankshaft winding will usually be damped out naturally. However, at certain crankshaft rotational speeds, such winding can overlap wit...

Each time a cylinder fires, the force of the combustion is imparted to the crankshaft rod journal. The rod journal deflects in a torsional motion to some degree under this force. Harmonic vibrations result from the torsional motion imparted on the crankshaft. These harmonics are a function of many factors including frequencies created by the actual combustion and the natural frequencies the metals make under the stresses of combustion and flexing. In some engines, the torsional motion of the crankshaft at certain speeds can synchronize with the harmonic vibrations, causing a resonance. In some cases the resonance may stress the crankshaft to the point of cracking or complete failure.

The harmonic balancer helps minimize torsional crankshaft harmonics and resonance. The damper is composed of two elements: an inertia massand an energy dissipating element. Most often made of rubber, this element may be composed of a synthetic elastomer, a clutch, a spring or fluid. The mass counteracts the torsional crank motions and in concert with the energy dissipating element absorbs the harmonics vibrations.

An OEM damper consists of an outer mass bonded/vulcanized to an inner hub. An aftermarket performance damper consists of a mass which is attached/mounted to a housing (steel, aluminum, titanium, etc.) based on the different types of damper and where the mass is controlled differently. The first three use older technology; First is the liquid type damper which surrounds the mass immersed in the housing which is then bonded or welded together. Second is the o-ring type which surrounds the mass with a number of o-rings as it sits in its housing. Third is the friction type which has clutches and spring acting on the mass inside the outer housing. Fourth is the newest type in which the mass sits over and is attached an elastomer ring which is then attached to the outer housing. The crankshaft and damper together become (in its torsional response) a spring–mass–dampersystem again which can only occur by the two being interference fit together.

Over time engine development has continually advanced in almost all areas from material, operation, and function. Many of the advances were led by the Japanese manufacturers as they have made quality and durability the cornerstone of their programs. The Japanese advanced the proliferation of forged crankshafts with rotating assemblies at 0 gram balance. Forged crankshafts are much stronger and are significantly less apt to exhibit detrimental torsional crankshaft movement which also mitigates harmonic frequencies. This progression has also seen the addition of forged rods and pistons initially in forced induction engines and more recently in normally aspirated engines. Adding these additional forged components ramps the engines rigidity reducing concern about crankshaft damage even further. With the advent of computer aided design and finite element analysis, manufacturers can now find and re-engineer weaker areas. Regardless of some of these improvements, certain engines, like the...

The damper will be fitted at the front of the engine (opposite the clutch or transmission) just beyond the cover of the timing chain, gears, or belt, and behind the accessory drive pulley (which may carry one or more V, serpentine, or cogged belts.) In older vehicles the pulley and damper were separate units that were bolted together. In late model vehicles the two have been combined into one unit. Timing marks are almost always engraved for purposes of setting the ignition timing.

OE dampers are predominantly made using rubber as the bonding agent between the inner hub and the outer mass. Rubber is susceptible to operational and environmental factors. Rubber only has a finite ability to withstand operating temperatures plus any fluids that may find their way onto the damper. They are also susceptible to low temperatures which can make the rubber brittle. Any cracking of the elastomer(rubber) would be an immediate indicator of the need to replace the unit. OE dampers must be balanced, unless acting as an external balancer (Harmonic Balancer), as the quality of materials (usually cast or sintered iron) do not lend themselves to acceptable/perfect balance specifications straight from manufacturing. Most aftermarket dampers are rebuildable, excluding the fluid type. When used in racing (drag, circle track, road race, etc.) they require regular inspection to ensure their proper function. When used on street driven vehicles, the damper manufacturer can provide insp...

This will depend on a number of factors from quality of engine materials used to engine balance to the type of crankshaft design the quality of engine tune and more. Engines have continually improved in nearly all aspects but most importantly in quality of materials used and their manufacture (also discussed in Engine design, materials & other factors above). These improvements range from forged crankshafts, pistons and rods to other rotational components. Engine balance has also improved significantly through more advanced balancing techniques and the higher quality engine components which make the balancing process easier. Many OE manufacturers have been achieving 0 gram balance across their production since the 1980's. Crankshaft design is also a factor as cross plane crankshafts can be the most susceptible to internal harmonic damage. Flat plane crankshafts, I format and H format engines do not exhibit these issues but can reach extremely output and RPM levels where a harmonic d...

Both Frederick Henry Royce and Frederick W. Lanchester have strong claims to the invention of the vibration damper, with the latest research showing Rolls-Royce using a crankshaft slipper (friction) vibration damper on their 1906 30HP models; however, Royce had not submitted it for patent. Lanchester had developed a theoretical multi-plate viscous design in 1910 (patent 21,139, 12 September 1910). Royce developed a viscous damper in 1912 that was then further developed and carried through to the B60 engine of the 1950s.

3. ### Tuned mass damper - Wikipedia

en.wikipedia.org › wiki › Tuned_mass_damper
• Principle
• Mass Dampers in Automobiles
• Mass Dampers in Spacecraft
• Dampers in Power Transmission Lines
• Dampers in Wind Turbines
• Dampers in Buildings and Related Structures

Tuned mass dampers stabilize against violent motion caused by harmonic vibration. They use a comparatively lightweight component to reduce the vibration of a system so that its worst-case vibrations are less intense. Roughly speaking, practical systems are tuned to either move the main mode away from a troubling excitation frequency, or to add damping to a resonance that is difficult or expensive to damp directly. An example of the latter is a crankshaft torsional damper. Mass dampers are frequently implemented with a frictional or hydraulic component that turns mechanical kinetic energy into heat, like an automotive shock absorber. Given a motor with mass m1 attached via motor mounts to the ground, the motor vibrates as it operates and the soft motor mounts act as a parallel spring and damper, k1 and c1. The force on the motor mounts is F0. In order to reduce the maximum force on the motor mounts as the motor operates over a range of speeds, a smaller mass, m2, is connected to m1 b...

Motorsport

The tuned mass damper was introduced as part of the suspension system by Renault, on its 2005 F1 car (the Renault R25), at the 2005 Brazilian Grand Prix. The system was invented by Dr. Robin Tuluie, and it reportedly reduced lap times by 0.3 seconds: a phenomenal gain for a relatively simple device.The Stewards of the meeting deemed it legal, but the FIA appealed against that decision. Two weeks later, the FIA International Court of Appeal deemed the mass damper illegal. It was deemed to be i...

Production cars

Tuned mass dampers are widely used in production cars, typically on the crankshaft pulley to control torsional vibrationand, more rarely, the bending modes of the crankshaft. They are also used on the driveline for gearwhine, and elsewhere for other noises or vibrations on the exhaust, body, suspension or anywhere else. Almost all modern cars will have one mass damper, and some may have ten or more. The usual design of damper on the crankshaft consists of a thin band of rubber between the hub...

One proposal to reduce vibration on NASA's Ares solid fuel booster was to use 16 tuned mass dampers as part of a design strategy to reduce peak loads from 6g to 0.25g, the TMDs being responsible for the reduction from 1g to 0.25g, the rest being done by conventional vibration isolatorsbetween the upper stages and the booster. Spin stabilized satellites have nutation development at specific frequencies. Eddy currentnutation dampers have flown on spin stabilized satellites to reduce and stabilize nutation.

High-tension lines often have small barbell-shaped Stockbridge dampers hanging from the wires to reduce the high-frequency, low-amplitude oscillation termed flutter.

A standard tuned mass damper for wind turbines consists of an auxiliary mass which is attached to the main structure by means of springs and dashpot elements. The natural frequency of the tuned mass damper is basically defined by its spring constant and the damping ratio determined by the dashpot. The tuned parameter of the tuned mass damper enables the auxiliary mass to oscillate with a phase shift with respect to the motion of the structure. In a typical configuration an auxiliary mass hung below the nacelle of a wind turbine supported by dampers or friction plates.

Typically, the dampers are huge concrete blocks or steel bodies mounted in skyscrapers or other structures, and moved in opposition to the resonance frequency oscillations of the structure by means of springs, fluid or pendulums.

4. ### Facebook - Wikipedia

en.wikipedia.org › wiki › Facebook

8. ### Central processing unit - Wikipedia

en.wikipedia.org › wiki › Central_processing_unit
• History
• Operation
• Structure and Implementation
• Virtual CPUs
• Performance
• External Links

Early computers such as the ENIAC had to be physically rewired to perform different tasks, which caused these machines to be called "fixed-program computers". The "central processing unit" term has been in use since as early as 1955. Since the term "CPU" is generally defined as a device for software (computer program) execution, the earliest devices that could rightly be called CPUs came with the advent of the stored-program computer. The idea of a stored-program computer had been already present in the design of J. Presper Eckert and John William Mauchly's ENIAC, but was initially omitted so that it could be finished sooner. On June 30, 1945, before ENIAC was made, mathematician John von Neumann distributed the paper entitled First Draft of a Report on the EDVAC. It was the outline of a stored-program computer that would eventually be completed in August 1949. EDVAC was designed to perform a certain number of instructions (or operations) of various types. Significantly, the program...

The fundamental operation of most CPUs, regardless of the physical form they take, is to execute a sequence of stored instructions that is called a program. The instructions to be executed are kept in some kind of computer memory. Nearly all CPUs follow the fetch, decode and execute steps in their operation, which are collectively known as the instruction cycle. After the execution of an instruction, the entire process repeats, with the next instruction cycle normally fetching the next-in-sequence instruction because of the incremented value in the program counter. If a jump instruction was executed, the program counter will be modified to contain the address of the instruction that was jumped to and program execution continues normally. In more complex CPUs, multiple instructions can be fetched, decoded and executed simultaneously. This section describes what is generally referred to as the "classic RISC pipeline", which is quite common among the simple CPUs used in many electronic...

Hardwired into a CPU's circuitry is a set of basic operations it can perform, called an instruction set. Such operations may involve, for example, adding or subtracting two numbers, comparing two numbers, or jumping to a different part of a program. Each basic operation is represented by a particular combination of bits, known as the machine language opcode; while executing instructions in a machine language program, the CPU decides which operation to perform by "decoding" the opcode. A complete machine language instruction consists of an opcode and, in many cases, additional bits that specify arguments for the operation (for example, the numbers to be summed in the case of an addition operation). Going up the complexity scale, a machine language program is a collection of machine language instructions that the CPU executes. The actual mathematical operation for each instruction is performed by a combinational logic circuit within the CPU's processor known as the arithmetic logic un...

Cloud computing can involve subdividing CPU operation into virtual central processing units (vCPUs). A host is the virtual equivalent of a physical machine, on which a virtual system is operating. When there are several physical machines operating in tandem and managed as a whole, the grouped computing and memory resources form a cluster. In some systems, it is possible to dynamically add and remove from a cluster. Resources available at a host and cluster level can be partitioned out into resources pools with fine granularity.

The performance or speed of a processor depends on, among many other factors, the clock rate (generally given in multiples of hertz) and the instructions per clock (IPC), which together are the factors for the instructions per second (IPS) that the CPU can perform.Many reported IPS values have represented "peak" execution rates on artificial instruction sequences with few branches, whereas realistic workloads consist of a mix of instructions and applications, some of which take longer to execute than others. The performance of the memory hierarchy also greatly affects processor performance, an issue barely considered in MIPS calculations. Because of these problems, various standardized tests, often called "benchmarks" for this purpose‍—‌such as SPECint‍—‌have been developed to attempt to measure the real effective performance in commonly used applications. Processing performance of computers is increased by using multi-core processors, which essentially is plugging two or more indiv...

 How Microprocessors Work at HowStuffWorks. 25 Microchips that shook the world – an article by the Institute of Electrical and Electronics Engineers.
9. ### The S.O.U.L. S.Y.S.T.E.M. - Wikipedia

en.wikipedia.org › wiki › The_S

The S.O.U.L. S.Y.S.T.E.M. was an American R&B and dance music group, assembled by Robert Clivillés and David Cole of C&C Music Factory, that was active in 1992. The group featured lead vocals by Michelle Visage, who was formerly a member ...

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