1.
Wind instrument
–
The pitch of the vibration is determined by the length of the tube and by manual modifications of the effective length of the vibrating column of air. In the case of wind instruments, sound is produced by blowing through a reed. Using different air columns for different tones, such as in the pan flute and this method is used on nearly all brass instruments. Changing the length of the air column by lengthening and/or shortening the tube using a sliding mechanism. This method is used on the trombone and the slide whistle, changing the frequency of vibration through opening or closing holes in the side of the tube. This can be done by covering the holes with fingers or pressing a key which then closes the hole and this method is used in nearly all woodwind instruments. Making the column of air vibrate at different harmonics without changing the length of the column of air, almost all wind instruments use the last method, often in combination with one of the others, to extend their register. A more accurate way to determine whether an instrument is brass or woodwind is to examine how the player produces sound, in brass instruments, the players lips vibrate, causing the air within the instrument to vibrate. For example, the saxophone is typically made of brass, but is classified as an instrument because it produces sound with a vibrating reed. In the Hornbostel-Sachs scheme of musical instrument classification, wind instruments are classed as aerophones, sound production in all wind instruments depends on the entry of air into a flow-control valve attached to a resonant chamber. The resonator is typically a long cylindrical or conical tube, open at the far end, a pulse of high pressure from the valve will travel down the tube at the speed of sound. It will be reflected from the end as a return pulse of low pressure. Under suitable conditions, the valve will reflect the pulse back, with increased energy, Reed instruments such as the clarinet or oboe have a flexible reed or reeds at the mouthpiece, forming a pressure-controlled valve. Standing waves inside the tube will be odd multiples of a quarter-wavelength, with a pressure anti-node at the mouthpiece, the reed vibrates at a rate determined by the resonator. For Lip Reed instruments, the controls the tension in their lips so that they vibrate under the influence of the air flow through them. They adjust the vibration so that the lips are most closed, and the air flow is lowest, standing waves inside the tube will be odd multiples of a quarter-wavelength, with a pressure anti-node at the mouthpiece, and a pressure node at the open end. For Air Reed instruments, the thin grazing air sheet flowing across an opening in the pipe interacts with an edge to generate sound. The jet is generated by the player, when blowing through a thin slit, for recorders and flue organ pipes this slit is manufactured by the instrument maker and has a fixed geometry
2.
Fipple
–
A fipple is a constricted mouthpiece common to many end-blown flutes, such as the tin whistle and the recorder. These instruments are known variously as fipple flutes, duct flutes, exiting from the windway, the breath is directed against a hard, bladed edge, called the labium lip or windcutter, producing a Bernoulli effect or siphon. The air flowing over the voicing mouth creates a flow-controlled valve, interaction between the air reed and the air column in the body of the instrument excites standing waves in the air column, which determines the pitch of the sound. This oscillation results in the sound in ducted flue instruments. See wind instrument and flue pipe, a distinct tone color, determined by the dimensions of the instrument and the voicing mouth, is then slightly modified by the players technique or embouchure. The space created between the ducted flue windway and the labium ramp edge is referred to as the mouth or voicing, the size of the mouth is usually in proportion to the instruments bore, depending on the model of instrument and specifically which original instrument is being copied. Many mass-produced factory instruments feature a voicing of a rectangular or flat lozenge cross section, such a flat and rectangular voicing however, produces a less-than-sweet tone and offers far less dynamic flexibility than a flute embouchure. The recorder voicing was designed to limit pitch bending for a more stable tone with variations in breath pressure, some modern recorder makers now produce curved labium lip voicings to add harmonic tone color. If the air stream strikes a curved D shaped lip, there will be slight turbulence created at the voicing mouth and this translates to extra sympathetic harmonics or tone color. The chamfer/rounding at the end of the windway that opens on the mouth/voicing is responsible for the quality of articulation of the ducted flue instrument and it consists of one or both of the windway exit lips being rounded. This can be seen by looking through the labium at the place where the windway opens out on the mouth/window and these rounded edges affect the responsiveness produced by the player. This enables the rhythmic and dynamic language of the instrument to be spoken, articulations such as Ta, Da, Ra, Ta-ka and Da-ga and Diddle will be very clearly differentiated in a good instrument played by a good player. An inferior instrument lacking these modified rounded edges on the exit will greatly limit the dynamics of tone or create dead spots in the music. The lack of this feature will degrade the performance of a ducted flue instrument, regardless of the effort made by the player to correct tone, or his or her level of skill. Because of the position of the windway with respect to the labium. However, it is not true that no embouchure is required to make a beautiful-sounding tone, embouchure on fipple flutes is centered on the idea of focusing the air inside the instruments windway and bore alike, following the shape of the bore. A bore which tapers down to a bell sounds best when the lips are used to focus the air to a tighter stream. The idea is to always resonate the full length and width of the bore with the airflow, at all times, closing the lips around the beak of the recorder or fipple flute will help to focus the air down the narrow windway
3.
Recorder (musical instrument)
–
The recorder is a woodwind musical instrument in the group known as internal duct flutes—flutes with a whistle mouthpiece. It is distinguished from other duct flutes by having a thumb-hole for the hand and seven finger-holes. It is the most prominent duct flute in the classical tradition. Recorders are made in different sizes with compasses corresponding to different vocal ranges, the sizes most commonly in use today are the soprano, alto, tenor and bass. Recorders are traditionally constructed from wood and ivory, although the use of plastics is now common, other characteristics of their construction, such as bore profile and fingering systems, have varied over time and between instruments. The recorder is first documented in the Middle Ages, and continued to enjoy popularity in the renaissance and baroque periods. It was revived in the 20th century as part of the historically informed performance movement, today, there are many professional recorder players who demonstrate the instruments full solo range and a large community of amateurs. The sound of the recorder is described as clear and sweet. It is notable for its response and its corresponding ability to produce a wide variety of articulations. This ability, coupled with its open finger holes, allow it to produce a variety of tone colors. Acoustically, its tone is relatively pure and odd harmonics predominate in its sound, the instrument has been known by its modern English name at least since the 14th century. David Lasocki reports the earliest use of recorder in the accounts of the Earl of Derby in 1388. By the 15th century, the name had appeared in English literature, the instrument name recorder derives from the Latin recordārī, by way of Middle French recorder and MFr recordeur, itself derived from MFr recorder. Thus, the recorder cannot have been named after the sound of birds, the name of the instrument is also uniquely English, in Middle French there is no equivalent noun sense of recorder referring to a musical instrument. Partridge indicates that the use of the instrument by jongleurs led to its association with the verb, recorder the minstrels action, the reason we know this instrument as the recorder and not one of the other instruments played by the jongleurs is uncertain. Until about 1695, the recorder and flute overlapped, but from 1673 to the late 1720s in England. Until at least 1765, some still used flute to mean recorder. Until the mid 18th century, musical scores written in Italian refer to the instrument as flauto and this distinction, like the English switch from recorder to flute, has caused confusion among modern editors, writers and performers
4.
Piston
–
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder, in some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder wall. An internal combustion engine is acted upon by the pressure of the combustion gases in the combustion chamber space at the top of the cylinder. This force then acts downwards through the rod and onto the crankshaft. The connecting rod is attached to the piston by a swivelling gudgeon pin and this pin is mounted within the piston, unlike the steam engine, there is no piston rod or crosshead. The pin itself is of hardened steel and is fixed in the piston, a few designs use a fully floating design that is loose in both components. All pins must be prevented from moving sideways and the ends of the pin digging into the cylinder wall, gas sealing is achieved by the use of piston rings. These are a number of iron rings, fitted loosely into grooves in the piston. The rings are split at a point in the rim, allowing them to press against the cylinder with a light spring pressure. Two types of ring are used, the rings have solid faces and provide gas sealing, lower rings have narrow edges. There are many proprietary and detail design features associated with piston rings, pistons are cast from aluminium alloys. For better strength and fatigue life, some racing pistons may be forged instead, early pistons were of cast iron, but there were obvious benefits for engine balancing if a lighter alloy could be used. To produce pistons that could survive engine combustion temperatures, it was necessary to develop new alloys such as Y alloy and Hiduminium, a few early gas engines had double-acting cylinders, but otherwise effectively all internal combustion engine pistons are single-acting. During World War II, the US submarine Pompano was fitted with a prototype of the infamously unreliable H. O. R, although compact, for use in a cramped submarine, this design of engine was not repeated. Media related to Internal combustion engine pistons at Wikimedia Commons Trunk pistons are long relative to their diameter and they act both as a piston and cylindrical crosshead. As the connecting rod is angled for much of its rotation, a longer piston helps to support this
5.
Woodwind instrument
–
Woodwind instruments are a family of musical instruments within the more general category of wind instruments. There are two types of woodwind instruments, flutes and reed instruments. What differentiates these instruments from other instruments is the way in which they produce their sound. Examples are a saxophone, a bassoon and a piccolo, flutes produce sound by directing a focused stream of air below the edge of a hole in a cylindrical tube. The flute family can be divided into two sub-families, open flutes and closed flutes, to produce a sound with an open flute, the player is required to blow a stream of air across a sharp edge that then splits the airstream. This split airstream then acts upon the air contained within the flutes hollow causing it to vibrate. Examples of open flutes are the flute, panpipes and shakuhachi. Ancient flutes of this variety were often made from sections of plants such as grasses, reeds. Later, flutes were made of such as tin, copper. Modern concert flutes are made of high-grade metal alloys, usually containing nickel, silver, copper. To produce a sound with a flute, the player is required to blow air into a duct. This duct acts as a channel bringing the air to a sharp edge, as with the open flutes, the air is then split, this causes the column of air within the closed flute to vibrate and produce sound. Examples of this type of include the recorder, ocarina. Reed instruments produce sound by focusing air into a mouthpiece which then causes a reed, or reeds, similar to flutes, Reed pipes are also further divided into two types, single reed and double reed. Single-reed woodwinds produce sound by placing a reed onto the opening of a mouthpiece, when air is forced between the reed and the mouthpiece, the reed causes the air column in the instrument to vibrate and produce its unique sound. Single reed instruments include the clarinet, saxophone, and others such as the chalumeau, double-reed instruments use two precisely cut, small pieces of cane bound together at the base. This form of production has been estimated to have originated in the middle to late Neolithic period. The finished, bound reed is inserted into the instrument and vibrates as air is forced between the two pieces and this family of reed pipes is subdivided further into another two sub-families, exposed double reed, and capped double reed instruments
6.
Bicycle pump
–
A bicycle pump is a type of positive-displacement air pump specifically designed for inflating bicycle tires. It has a connection or adapter for use with one or both of the two most common types of valves used on bicycles, Schrader or Presta, a third type of valve called the Dunlop valve exists, but tubes with these valves can be filled using a Presta pump. Several basic types are available, Floor pumps Frame mounted Compact or mini Foot operated Double action In its most basic form, during the up-stroke, this piston draws air through a one-way valve into the pump from the outside. During the down-stroke, the piston displaces the air from the pump into the bicycle tire. Most floor pumps, also commonly called track pumps, have a built in pressure gauge to indicate tire pressure, electrically-operated pumps intended to inflate car tires can in principle be used to inflate a bicycle tire if the right type of connection is available. Some such pumps are designed to cut off before a suitable pressure, others may not cut off, but deliver a high rate of flow to fill the larger car tire, with a risk of overinflating and bursting a bicycle tire unless it is stopped with split-second timing. The first bicycle pump consisted of a cylinder that had a metal rod running down the middle of it. This would have forced the air out of the cylinder and then sucked in new air when the rod was pulled up again. Many modern pumps use a similar method, while some, such as the electric pumps. When the cylinder is compressed, air is pushed down the tube of the pump and then into the tire via the valve, which is forced open by the pressure of the air. When the handle is pulled up again, the valve shuts off automatically so that the air cannot escape from the tire, some pumps have a gauge that shows the pressure of air that is forced into the tire. Once the tire is at the pressure, the pump valve can be removed from the tire. There are two types of tire valves to which the bicycle tire pump attaches. These are the Presta valve and the Schrader valve, some pumps fit both types of valves, whereas others do not, but adapters are available that enable the pump to fit any type of valve. The AVACS feature is available on pump models and can also be bought as a separate valve attachment. There are three types of bicycle pumps Stand pump Hand pump Foot pump Also known as a floor or track pump. To operate, the user rests the base of the pump on the floor, resting feet at the base, an additional tube must connect the pump to the fill valve, which may create dead volume. There are two types, tubed and integral
7.
Harmonic
–
A harmonic is any member of the harmonic series, the divergent infinite series. Every term of the series after the first is the mean of the neighboring terms. The phrase harmonic mean likewise derives from music, the term is employed in various disciplines, including music, physics, acoustics, electronic power transmission, radio technology, and other fields. It is typically applied to repeating signals, such as sinusoidal waves, a harmonic of such a wave is a wave with a frequency that is a positive integer multiple of the frequency of the original wave, known as the fundamental frequency. The original wave is called the 1st harmonic, the following harmonics are known as higher harmonics. As all harmonics are periodic at the frequency, the sum of harmonics is also periodic at that frequency. On strings, harmonics that are bowed have a glassy, pure tone, harmonics may also be called overtones, partials or upper partials. In some music contexts, the harmonic, overtone and partial are used fairly interchangeably. Most acoustic instruments emit complex tones containing many individual partials, rather, a musical note is perceived as one sound, the quality or timbre of that sound being a result of the relative strengths of the individual partials. Oscillators that produce harmonic partials behave somewhat like one-dimensional resonators, and are long and thin. Wind instruments whose air column is open at one end, such as trumpets and clarinets. However they only produce partials matching the odd harmonics, at least in theory, the reality of acoustic instruments is such that none of them behaves as perfectly as the somewhat simplified theoretical models would predict. Partials whose frequencies are not integer multiples of the fundamental are referred to as inharmonic partials, antique singing bowls are known for producing multiple harmonic partials or multiphonics. An overtone is any partial higher than the lowest partial in a compound tone, the relative strengths and frequency relationships of the component partials determine the timbre of an instrument. This chart demonstrates how the three types of names are counted, In many musical instruments, it is possible to play the upper harmonics without the note being present. In a simple case this has the effect of making the note go up in pitch by an octave, in some cases it also changes the timbre of the note. This is part of the method of obtaining higher notes in wind instruments. The extended technique of playing multiphonics also produces harmonics, on string instruments it is possible to produce very pure sounding notes, called harmonics or flageolets by string players, which have an eerie quality, as well as being high in pitch
