Work & Self Reliance

“In our friendly neighbor city of St. Augustine, great flocks of sea gulls are starving amid plenty. Fishing is still good, but the gulls don’t know how to fish. For generations they have depended on the shrimp fleet to toss them scraps from the nets.… Read more

Lord God, Mercy & Justice

These are the generations of the heavens and of the earth when they were created, in the day that the Lord God made the earth and the heavens. Genesis 2:4 * * * In rabbinic conception, Adonai “Lord” represents the attribute of mercy, while Elohim… Read more

Cuba Sonic Attack Analysis

A sound file from the attack on the U.S. Embassy in Cuba has now been made available on the Internet.  I did a spectral analysis of this file using my Matlab GUI scripts.  The sound source is still unknown.  The attacks have caused hearing, cognitive,… Read more

NASA SP-8072 Launch Vehicle Liftoff Acoustics

NASA SP-8072  Acoustics Loads Generate by the Propulsion System (Alternate SP-8072 link) The liftoff analysis has been added to the GUI package at:  Vibrationdata Matlab GUI The function can be accessed via: >> vibrationdata > Miscellaneous Functions I > Acoustics Vibroacoustics & SEA > acoustics >… Read more

Compression after Impact Testing of Composite Laminates Specimens

Figure 1.  Boeing 787 Aircraft Carbon fiber/epoxy laminates are widely used in aeronautic and aerospace structural components mainly because of their excellent specific mechanical properties.  These laminates show mechanical properties similar or higher than the conventional metallic materials in terms of strength-to-weight and stiffness-to-weight ratios.  The… Read more

Turbine Engine Blade-off Test

Rolls Royce Engine Blade-off Test     Video Link 1     Video Link 2 The engine blade-off test is performed to make sure that the engine can survive a fan. compressor or turbine blade breaking off within the engine, without fragments being ejected through the outside… Read more

Lomb-Scargle Periodogram

The Lomb-Scargle Periodogram is a least-square method which is useful for calculating the Fourier transform of a time history with gaps or an uneven sampling rate. Reference Paper This function has been added to the vibrationdata GUI package Python script & Utility: lomb_scargle.py tompy.py -… Read more