1,223 research outputs found
Air recovery assessment on high-pressure pneumatic systems
A computational simulation and experimental work of the fluid flow through the pneumatic circuit used in a stretch blow moulding machine is presented in this paper. The computer code is built around a zero-dimensional thermodynamic model for the air blowing and recycling containers together with a non-linear time-variant deterministic model for the pneumatic three stations single acting valve manifold, which, in turn, is linked to a quasi-one-dimensional unsteady flow model for the interconnecting pipes. The flow through the pipes accounts for viscous friction, heat transfer, cross-sectional area variation, and entropy variation. Two different solving methods are applied: the method of characteristics and the Harten-Lax-Van Leer (HLL) Riemann first-order scheme. The numerical model allows prediction of the air blowing process and, more significantly, permits determination of the recycling rate at each operating cycle. A simplified experimental set-up of the industrial process was designed, and the pressure and temperature were adequately monitored. Predictions of the blowing process for various configurations proved to be in good agreement with the measured results. In addition, a novel design of a valve manifold intended for the polyethylene terephthalate (PET) plastic bottle manufacturing industry is also presented.Peer ReviewedPostprint (author's final draft
Bounded and unbounded polynomials and multilinear forms: Characterizing continuity
In this paper we prove a characterization of continuity for polynomials on a
normed space. Namely, we prove that a polynomial is continuous if and only if
it maps compact sets into compact sets. We also provide a partial answer to the
question as to whether a polynomial is continuous if and only if it transforms
connected sets into connected sets. These results motivate the natural question
as to how many non-continuous polynomials there are on an infinite dimensional
normed space. A problem on the \emph{lineability} of the sets of non-continuous
polynomials and multilinear mappings on infinite dimensional normed spaces is
answered.Comment: 8 page
Uniqueness of the optimal control for a Lotka-Volterra control problem with a large crowding effect
Stress analysis of finite anisotropic plates with cutouts under displacement boundary conditions
XI CONGRESO NACIONAL DE MATERIALES COMPUESTOS. Celebrado en MĂłstoles los dĂas 6, 7 y 8 de julio de 2015The aim of this article is to provide an analytical tool to estĂmate the stress
concentration in anisotropic plates weakened by a circular or elliptical hole; it is
achieved by developing Lekhnitskii formalism in order to allow fĂnite boundary effects
to be added (original formulation considers infinite plates). Only membrane problem is
herein considered, particularly when prescribed displacements are applied at externa!
boundaries, which could simulate boundary conditions of a manhole structure between
wing spars. A boundary collocation method in conjunction with a least squares
approach is used to solve the problem.Ministerio de EconomĂa y Competitividad de España DPT2012-3718
MiniAnDE: a reduced AnDE ensemble to deal with microarray data
This article focuses on the supervised classification of datasets with a
large number of variables and a small number of instances. This is the case,
for example, for microarray data sets commonly used in bioinformatics. Complex
classifiers that require estimating statistics over many variables are not
suitable for this type of data. Probabilistic classifiers with low-order
probability tables, e.g. NB and AODE, are good alternatives for dealing with
this type of data. AODE usually improves NB in accuracy, but suffers from high
spatial complexity since models, each with variables, are included in
the AODE ensemble. In this paper, we propose MiniAnDE, an algorithm that
includes only a small number of heterogeneous base classifiers in the ensemble,
i.e., each model only includes a different subset of the predictive
variables. Experimental evaluation shows that using MiniAnDE classifiers on
microarray data is feasible and outperforms NB and other ensembles such as
bagging and random forest
OPEN- AND CLOSED-LOOP EQUILIBRIUM CONTROL OF TROPHIC CHAINS
If a nearly natural population system is deviated from its equilibrium, an important task of conservation ecology may be to control it back into equilibrium. In the paper a trophic chain is considered, and control systems are obtained by changing certain model parameters into control variables. For the equilibrium control two approaches are proposed. First, for a fixed time interval, local controllability into equilibrium is proved, and applying tools of optimal control, it is also shown how an appropriate open-loop control can be determined that actually controls the system into the equilibrium in given time. Another considered problem is to control the system to a new desired equilibrium. The problem is solved by the construction of a closed-loop control which asymptotically steers the trophic chain into this new equilibrium. In this way, actually, a controlled regime shift is realized
Plain cigarette packs do not exert Pavlovian to instrumental transfer of control over tobacco-seeking
Journal ArticleResearch Support, Non-U.S. Gov'tCopyright © 2014 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of AddictionAIMS: To gain insight into the potential impact of plain tobacco packaging policy, two experiments were undertaken to test whether 'prototype' plain compared with branded UK cigarette pack stimuli would differentially elicit instrumental tobacco-seeking in a nominal Pavlovian to instrumental transfer (PIT) procedure. DESIGN, SETTING AND PARTICIPANTS: Two experiments were undertaken at the University of Bristol UK, with a convenience sample of adult smokers (experiment 1, n = 23, experiment 2, n = 121). MEASUREMENT: In both experiments, smokers were trained on a concurrent choice procedure in which two responses earned points for cigarettes and chocolate, respectively, before images of branded and plain packs were tested for capacity to elicit the tobacco-seeking response in extinction. The primary outcome was percentage choice of the tobacco- over the chocolate-seeking response in plain pack, branded pack and no-stimulus conditions. FINDINGS: Both experiments found that branded packs primed a greater percentage of tobacco-seeking (overall mean = 62%) than plain packs (overall mean = 53%) and the no-stimulus condition (overall mean = 52%; Ps ≤ 0.01, ŋp (2) s ≥ 0.16), and that there was no difference in percentage tobacco-seeking between plain packs and the no-stimulus condition (Ps ≥ 0.17, ŋp (2) s ≤ 0.04). Plain tobacco packs showed an overall 9% reduction in the priming of a tobacco choice response compared to branded tobacco packs. CONCLUSIONS: Plain packaging may reduce smoking in current smokers by degrading cue-elicited tobacco-seeking.British Heart FoundationCancer Research UKNIHRMRCESR
Physical Conditions in the Dwarf Local Group Irregular Galaxy IC10. I- Diffuse Ionized Gas
A detailed analysis on the physical conditions of the Interstellar Medium in
the main body of the Local Group dwarf irregular galaxy IC 10 is carried out
using long-slit spectroscopy. Maps of the excitation, the H flux,
[NII]/H and [SII]/H are presented. The Diffuse Ionized Gas
inside the galaxy is studied. We found that the spectral characteristics are
not similar to those for spiral galaxies: the values of the ratios
[NII]/H and [SII]/H are not as large as in spiral galaxies but
the excitation is much larger. These values, especially the large excitation,
can be explained by proposing an extra source of ionization. Different sources
are studied but any of the models at hand could be really fitted except a
combination of photons leaking from the HII regions in addition to the
ionization provided by the WR stars present in this galaxy. Shocks are not
needed for explaining the line intensity ratios except in a small part in the
west side of the galaxy.Comment: 12 pages, 12 figures, accepted for publication in A&
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