The point of departure of a particle sliding on a curved surface

A particle is thrown tangentially on a surface. It is shown that for some surfaces and for special initial velocities the thrown particle leaves immediately the surface, and for special conditions it never leaves the surface. The conditions for leaving the surface is investigated. The problem is studied for a surface with the cross section $y=f(x)$. The surfaces with the equations $f(x)= -\alpha x^{k}\ (\alpha, k>0)$ is considered in more detail. At the end the effect of friction is also considered.Comment: 10 pages, 4 figure

A revisitation of the 1888 H.Hertz experiment

We propose a revisitation of the original experiment performed by H. Hertz in 1888. With a simple setup it is possible to produce electromagnetic waves with a frequency in the range of 3 MHz. By performing Fourier analysis of the signal captured by a resonant antenna it is possible to study the behaviour of the RLC series circuit, frequency splitting of coupled resonances and finally the characteristics of the near-field emitted by the loop antenna

Construyendo Una Frontera Comun O Desconstruyendo Una Identidad Nacional?: Un Analisis Del Esfuerzo De Centralizar Control De Inmigracion De Tercer Pais En La Union Europea

Lejos de los ataques espantosos sobre las torres gemelas y el Pentdgono, una pared al lado de una mezquita en Inglaterra del Norte lee, Vengue EE. UU - maten a un Musulmin ahora

Retransmission of water resources data using the ERTS-1 data collection system

There are no author-identified significant results in this report

Building A Common Frontier Or Deconstructing National Identity?: An Analysis Of The Effort To Centralize Control Of Third Country Immigration In The European Union

Faraway from the frightening attacks on the World Trade Center and the Pentagon, a wall next to a mosque in Northern England reads, Avenge USA - kill a Muslim now

Phasor analysis of atom diffraction from a rotated material grating

The strength of an atom-surface interaction is determined by studying atom diffraction from a rotated material grating. A phasor diagram is developed to interpret why diffraction orders are never completely suppressed when a complex transmission function due to the van der Waals interaction is present. We also show that atom-surface interactions can produce asymmetric diffraction patterns. Our conceptual discussion is supported by experimental observations with a sodium atom beam.Comment: 5 pages, 6 figures, submitted to PR

The Oriental Red Mite, Eutetranychus orientalis (Klein) (Acarina: Tetranychidae), in Australia

The oriental red mite, Eutetranychus orientalis, an important pest of citrus and other crops in many parts of the world, has been in Queensland for at least 30 years. We review Australian collections of oriental red mite, clarify confusion over its name and pest status, discuss its potential biological control agents, and provide a key to differentiate known Australian species of Eutetranychus and the African red mite, E. africanus (Tucker)