7,346 research outputs found
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 . The surfaces with the
equations 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
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
Radiation induced zero-resistance states: a dressed electronic structure effect
Recent results on magnetoresistance in a two dimensional electron gas under
crossed magnetic and microwave fields show a new class of oscillations,
suggesting a new kind of zero-resistance states. A complete understanding of
the effect is still lacking. We consider the problem from the point of view of
the electronic structure dressed by photons due to a in plane linearly
polarized ac field. The dramatic changes in the dressed electronic structure
lead to a interpretation of the new magnetoresistance oscillations as a
persistent-current like effect, induced by the radiation field.Comment: 5 pages, 5 figures, revtex4, changes in introduction and added
reference
When Peace is Not Enough: The Flag Protests and The Politics of Identity and Belonging in East Belfast
The flag protests that occurred during the tail of 2012 and early 2013 gained international media attention. Much of the media attention focused on the involvement of young people and sought to seek answers to how young people who had grown up in more peaceful times could be involved in violence that belonged in Northern Ireland’s past. Research being conducted by the authors during the course of the flag protests on young people’s experiences of living in post conflict Belfast enabled the researchers to gain insight and clarity on the flag protests, why they had occurred and underlying factors that fuelled the riots and violence that followed, giving a snap shot of the strength of feeling and overall mood of the Protestant community at that time. Using an interpretative phenomenological analysis (IPA) approach, 2 focus groups with 14 young people aged between 15-24 (M=17 years), were conducted followed by more in-depth semi structured interviews with 6 young people from the focus groups and a further 6 interviews with youth and community workers from the East Belfast area
Continuous Casting Development for Steel
Continuous casting processes for steel have all had
their origin in some form of pilot Plant development and experience, the importance of gaining "know-how" being a Predominant feature.
The first pilot plant to cast metal continuously was built by Henry Bessemer just over one hundred years ago. Whilst machines were developed for non-ferrous metals, progress with liquid steel was more difficult, mainly due to the high handling temperatures and to its low thermal
conductivity when solidified
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