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matt50025002
matt50025002, M.B.A.
Category: Engineering
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Experience:  Through my many years of life and learning, I have become wise beyond my years.
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I need to harness a pulse of high pressure gas, to drive a

Customer Question

I need to harness a pulse of high pressure gas, to drive a small piston, to compress air and send a pressure pulse through a short pipe or tube to do mechanical work (move an object). The motive gas pressure can be quite high (1600psi for a fraction of time) and the piston is small (1/4"). I think that compressibility of the air will act as a shock absorber to soak up energy.
Is there a formula for compression losses?
Submitted: 2 months ago.
Category: Engineering
Expert:  matt50025002 replied 2 months ago.

Data compression ratio is defined as the ratio between the uncompressed size and compressed size:[1][2][3][4][5]

{\displaystyle {\rm {Compression\;Ratio}}={\frac {\rm {Uncompressed\;Size}}{\rm {Compressed\;Size}}}}

Thus a representation that compresses a 10 MB file to 2 MB has a compression ratio of 10/2 = 5, often notated as an explicit ratio, 5:1 (read "five" to "one"), or as an implicit ratio, 5/1. Note that this formulation applies equally for compression, where the uncompressed size is that of the original; and for decompression, where the uncompressed size is that of the reproduction.

Sometimes the space savings is given instead, which is defined as the reduction in size relative to the uncompressed size:

{\displaystyle {\rm {Space\;Savings}}=1-{\frac {\rm {Compressed\;Size}}{\rm {Uncompressed\;Size}}}}

Thus a representation that compresses a 10MB file to 2MB would yield a space savings of 1 - 2/10 = 0.8, often notated as a percentage, 80%.

For signals of indefinite size, such as streaming audio and video, the compression ratio is defined in terms of uncompressed and compressed data rates instead of data sizes:

{\displaystyle {\rm {Compression\;Ratio}}={\frac {\rm {Uncompressed\;Data\;Rate}}{\rm {Compressed\;Data\;Rate}}}}

and instead of space savings, one speaks of data-rate savings, which is defined as the data-rate reduction relative to the uncompressed data rate:

{\displaystyle {\rm {Data\;Rate\;Savings}}=1-{\frac {\rm {Compressed\;Data\;Rate}}{\rm {Uncompressed\;Data\;Rate}}}}

For example, uncompressed songs in CD format have a data rate of 16 bits/channel x 2 channels x 44.1 kHz ≅ 1.4 Mbit/s, whereas AAC files on an iPod are typically compressed to 128 kbit/s, yielding a compression ratio of 10.9, for a data-rate savings of 0.91, or 91%.

When the uncompressed data rate is known, the compression ratio can be inferred from the compressed data rate.

Customer: replied 2 months ago.
Absolutely worthless answer. Off topic, and nonsensical! Did Matt 50025002 even read the question????? I want a full refund!