680 research outputs found
Moving dunes on the Google Earth
Several methods exist for surveying the dunes and estimate their migration
rate. Among methods suitable for the macroscopic scale, the use of the
satellite images available on Google Earth is a convenient resource, in
particular because of its time series. Some examples of the use of this feature
of Google Earth are here proposed.Comment: Keywords: Dunes, Dune Migration, Satellite Imagery, Google Earth,
Image Processin
Faience: the ceramic technology of ancient Egypt
Faiences are ancient Egyptian ceramic materials, considered as "high-tech" products. The paper discussed the method by which the faiences were produced and the application of SEM and Raman spectroscopy to their analysi
Discussion of the De Generatione Sonorum, a treatise on sound and phonetics by Robert Grosseteste
Here I am proposing a translation and discussion of the De Generatione Sonorum, one of the short scientific treatises written by Robert Grosseteste. The subject is the sound and the phonetics. In this treatise we find a discussion of oscillations and elasticity of materials and the description of some motions and their combinations to
Jerk and Hyperjerk in a Rotating Frame of Reference
Jerk is the derivative of acceleration with respect to time and then it is
the third order derivative of the position vector. Hyperjerks are the n-th
order derivatives with n>3. This paper describes the relations, for jerks and
hyperjerks, between the quantities measured in an inertial frame of reference
and those observed in a rotating frame. These relations can be interesting for
teaching purposes.Comment: Rotating frames, Physics education researc
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