1,129 research outputs found
Description of concept and first feasibility test results of a life support subsystem of the Botany Facility based on water reclamation
The Botany Facility allows the growth of higher plants and fungi over a period of 6 months maximum. It is a payload planned for the second flight of the Eureca platform around 1990. Major tasks of the Life Support Subsystem (LSS) of the Botany Facility include the control of the pressure and composition of the atmosphere within the plant/fungi growth chambers, control of the temperature and humidity of the air and the regulation of the soil water content within specified limits. Previous studies have shown that various LSS concepts are feasible ranging from heavy, simple and cheap to light, complex and expensive solutions. A summary of those concepts is given. A new approach to accomplish control of the temperature and humidity of the air within the growth chambers based on water reclamation is discussed. This reclamation is achieved by condensation with a heat pump and capillary transport of the condensate back into the soil of the individual growth chamber. Some analytical estimates are given in order to obtain guidelines for circulation flow rates and to determine the specific power consumption
Non-archimedean Yomdin-Gromov parametrizations and points of bounded height
We prove an analogue of the Yomdin-Gromov Lemma for -adic definable sets
and more broadly in a non-archimedean, definable context. This analogue keeps
track of piecewise approximation by Taylor polynomials, a nontrivial aspect in
the totally disconnected case. We apply this result to bound the number of
rational points of bounded height on the transcendental part of -adic
subanalytic sets, and to bound the dimension of the set of complex polynomials
of bounded degree lying on an algebraic variety defined over , in analogy to results by Pila and Wilkie, resp. by Bombieri and Pila.
Along the way we prove, for definable functions in a general context of
non-archimedean geometry, that local Lipschitz continuity implies piecewise
global Lipschitz continuity.Comment: 54 pages; revised, section 5.6 adde
Fonctions constructibles exponentielles, transformation de Fourier motivique et principe de transfert
We introduce spaces of exponential constructible functions in the motivic
setting for which we construct direct image functors in the absolute and
relative cases. This allows us to define a motivic Fourier transformation for
which we get various inversion statements. We define also motivic
Schwartz-Bruhat spaces on which motivic Fourier transformation induces an
isomorphism. Our motivic integrals specialize to non archimedian integrals. We
give a general transfer principle comparing identities between functions
defined by integrals over local fields of characteristic zero, resp. positive,
having the same residue field. Details of constructions and proofs will be
given elsewhere.Comment: 10 page
Motivic integration in all residue field characteristics for Henselian discretely valued fields of characteristic zero
We extend the formalism and results on motivic integration from
["Constructible motivic functions and motivic integration", Invent. Math.,
Volume 173, (2008) 23-121] to mixed characteristic discretely valued Henselian
fields with bounded ramification. We also generalize the equicharacteristic
zero case of loc. cit. by giving, in all residue characteristics, an axiomatic
approach (instead of only using Denef-Pas languages) and by using richer
angular component maps. In this setting we prove a general change of variables
formula and a general Fubini Theorem. Our set-up can be specialized to
previously known versions of motivic integration by e.g. the second author and
J. Sebag and to classical p-adic integrals.Comment: 33 pages. Final versio
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