15,629 research outputs found
Differential expression of pattern recognition receptors during the development of foetal sheep
Timber roof structure for outdoor auditorium in Parque Paraiso, San Blas (Madrid)
p. 468-475A timber shell structure is designed to provide covering for an outdoor auditorium in
Madrid (Spain). The covering comprises five independent overlapped marquees with
similar shape but diverse dimensions. The surface geometry of each marquee is defined by a hyperbolic paraboloid, with its boundaries delimited by elliptical curves in horizontal
projection. Structural section for the timber shell is a composite section with several
staggered layers of straight sawn timber planks, arranged in two orthogonal directions
following the straight skew lines of the hyperbolic paraboloid. Over them two continuous
top layers are arranged which provides bracing for the structure and support for the
waterproofing material. Each layer is laid over the previous one, bolted and glued with
polyurethane adhesive. Special characteristics of the design analysis and detailed erection process are described. The designed solution provides lightweight roofing with a powerful and original image, short construction time and reasonable budget.Anton, A.; Meijide, AG.; Corbal, JJ. (2009). Timber roof structure for outdoor auditorium in Parque Paraiso, San Blas (Madrid). Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/653
Odd viscosity in chiral active fluids
Chiral active fluids are materials composed of self-spinning rotors that
continuously inject energy and angular momentum at the microscale.
Out-of-equilibrium fluids with active-rotor constituents have been
experimentally realized using nanoscale biomolecular motors, microscale active
colloids, or macroscale driven chiral grains. Here, we show how such chiral
active fluids break both parity and time-reversal symmetries in their steady
states, giving rise to a dissipationless linear-response coefficient called odd
viscosity in their constitutive relations. Odd viscosity couples pressure and
vorticity leading, for example, to density modulations within a vortex profile.
Moreover, chiral active fluids flow in the direction transverse to applied
compression as in shock propagation experiments. We envision that this
collective transverse response may be exploited to design self-assembled
hydraulic cranks that convert between linear and rotational motion in
microscopic machines powered by active-rotors fluids
On the assessment of the nature of open star clusters and the determination of their basic parameters with limited data
Our knowledge of stellar evolution and of the structure and chemical
evolution of the Galactic disk largely builds on the study of open star
clusters. Because of their crucial role in these relevant topics, large
homogeneous catalogues of open cluster parameters are highly desirable.
Although efforts have been made to develop automatic tools to analyse large
numbers of clusters, the results obtained so far vary from study to study, and
sometimes are very contradictory when compared to dedicated studies of
individual clusters. In this work we highlight the common causes of these
discrepancies for some open clusters, and show that at present dedicated
studies yield a much better assessment of the nature of star clusters, even in
the absence of ideal data-sets. We make use of deep, wide-field, multi-colour
photometry to discuss the nature of six strategically selected open star
clusters: Trumpler~22, Lynga~6, Hogg~19, Hogg~21, Pismis~10 and Pismis~14. We
have precisely derived their basic parameters by means of a combination of star
counts and photometric diagrams. Trumpler~22 and Lynga~6 are included in our
study because they are widely known, and thus provided a check of our data and
methodology. The remaining four clusters are very poorly known, and their
available parameters have been obtained using automatic tools only. Our results
are in some cases in severe disagreement with those from automatic surveys.Comment: 22 pages, 16 figures, in pres
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