Funnel control for a moving water tank

We study tracking control for a moving water tank system, which is modelled using the Saint-Venant equations. The output is given by the position of the tank and the control input is the force acting on it. For a given reference signal, the objective is to achieve that the tracking error evolves within a prespecified performance funnel. Exploiting recent results in funnel control we show that it suffices to show that the operator associated with the internal dynamics of the system is causal, locally Lipschitz continuous and maps bounded functions to bounded functions. To show these properties we consider the linearized Saint-Venant equations in an abstract framework and show that it corresponds to a regular well-posed linear system, where the inverse Laplace transform of the transfer function defines a measure with bounded total variation.Comment: 11 page

New bounds for the inhomogenous Burgers and the Kuramoto-Sivashinsky equations

We give a substantially simplified proof of near-optimal estimate on the Kuramoto-Sivashinsky equation from [F. Otto, "Optimal bounds on the Kuramoto-Sivashinsky equation", JFA 2009], at the same time slightly improving the result. The result in the above cited paper relied on two ingredients: a regularity estimate for capillary Burgers and an a novel priori estimate for the inhomogeneous inviscid Burgers equation, which works out that in many ways the conservative transport nonlinearity acts as a coercive term. It is the proof of the second ingredient that we substantially simplify by proving a modified K\'arm\'an-Howarth-Monin identity for solutions of the inhomogeneous inviscid Burgers equation. This gives a new interpretation of the results obtained in [F. Golse, B. Perthame "Optimal regularizing effect for scalar conservation laws", Rev. Mat. Iber., 2013]

Tackling post-harvest cereal losses in sub-Saharan Africa

Post-harvest loss reduction raises food availability without increasing the use of land, water and agricultural inputs. This article refers to the case of grain to show the hurdles that farmers have to clear in taking measures to reduce losses and suggests ways that post-harvest practitioners can target mitigating actions in sub-Saharan Africa

Exploring the INTEGRAL sources in search for new microquasars

Here we present a search for new microquasars among the sources detected with the INTEGRAL satellite (IGR sources). We focus on radio emitting IGR sources and report the discovery of two new probable extragalactic sources behind the galactic plane, as well as the detection at higher energies of the ASCA source AX J1639.0-4642, probably a new microquasar in the Galaxy and coincident with a high-energy gamma-ray emitting EGRET source.Fil: Ribó, Marc. CEA Saclay; FranciaFil: Combi, Jorge Ariel. Universidad de Jaén; España. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Mirabel Miquele, Igor Felix. CEA Saclay; Franci

Pro-Secretory Activity and Pharmacology in Rabbits of an Aminophenyl-1,3,5-Triazine CFTR Activator for Dry Eye Disorders.

PurposePharmacological activation of ocular surface cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels is a potential pro-secretory approach to treat dry eye disorders. We previously reported the discovery of aminophenyl-1,3,5-triazines, one of which, N-methyl-N-phenyl-6-(2,2,3,3-tetrafluoropropoxy)-1,3,5-triazine-2,4-diamine (herein called CFTRact-K267), fully activated human wildtype CFTR with EC50 ∼ 30 nM and increased tear volume for 8 hours in mice. Here, functional and pharmacological studies of CFTRact-K267 were done in adult New Zealand white rabbits.MethodsCFTR chloride conductance was measured in vivo by ocular surface potential differences and in ex vivo conjunctiva by short-circuit current. Tear volume was measured by the Schirmer tear test II and CFTRact-K267 pharmacokinetics and tissue distribution by liquid chromatography/mass spectrometry. Toxicity profile was studied for 28 days with twice-daily topical administration.ResultsElectrophysiological measurements in vivo and in ex vivo conjunctiva demonstrated CFTR activation by CFTRact-K267. A single topical dose of 3 nmol CFTRact-K267 increased tear production by >5 mm for 9 hours by the Schirmer tear test, with predicted therapeutic concentrations maintained in tear fluid. No tachyphylaxis was seen following 28-day twice-daily administration, and changes were not observed in corneal surface integrity or thickness, intraocular pressure, or ocular histology. At day 28, CFTRact-K267 was concentrated in the cornea and conjunctiva and was not detectable in blood or peripheral organs.ConclusionsThese studies support the development of CFTRact-K267 as a pro-secretory therapy for dry eye disorders

Variational free energy based macroscopical modeling of ferroelectroelasticity

In this paper, a thermodynamically consistent minimum-type variational model for ferroelectric materials in a macroscopical continuum approach is presented. The motivation for this results from the lack of models in the literature that have on the one hand a Helmholtz free energy based variational structure and on the other hand are able to represent all important characteristic phenomena of ferroelectrics under quasi-static conditions. First of all, a unified variational theory for the material response of dissipative electro-mechanical solids in line with the framework of the generalized standard materials (GSM) is outlined. A macroscopic ferroelectric model with microscopically motivated internal state variables representing the switching processes taking place at the material microscale is adapted to the above mentioned variational structure. Additionally, a mixed variational principle for the global electro-mechanical boundary value problem is introduced in order to embed the Helmholtz free energy based local theory in a suitable finite element formulation. The solution processes for the resulting local and global variational problems is described in detail to enable easy implementation. The capability of the presented methods to reproduce the real behavior of ferroelectric systems is demonstrated by numerical examples. Here, a comparison to experimental results from the literature is a particular focus

Trisecting a 4-dimensional book into three chapters

We describe an algorithm that takes as input an open book decomposition of a closed oriented 4-manifold and outputs an explicit trisection diagram of that 4-manifold. Moreover, a slight variation of this algorithm also works for open books on manifolds with non-empty boundary and for 3-manifold bundles over the circle. We apply this algorithm to several simple open books, demonstrate that it is compatible with various topological constructions, and argue that it generalizes and unifies several previously known constructions.Comment: 29 pages, 15 figure

APHLIS - Postharvest cereal losses in Sub-Saharan Africa, their estimation, assessment and reduction

APHLIS provides estimates of the postharvest weight losses (PHLs) of cereal grains for Sub-Saharan Africa. These loss estimates support agricultural policy formulation, identification of opportunities to improve value chains, improvement in food security (by improving the accuracy of cereal supply estimates), andmonitoring of loss reduction activities. APHLIS is based on a network of local experts (see Annex 1). Each country supplies and quality controls its own data that are stored in an exclusive area of a shared database. The APHLIS website displays the loss estimates as maps and tables. The APHLIS Network members also have the opportunity to post a ‘Country Narrative’ that gives a commentary on these postharvest losses in the context of the postharvest systems and projects of their countries. The loss estimates are generated by an algorithm (the PHL Calculator) that works on two data sets, the postharvest loss (PHL) profiles and the seasonal data. Each PHL profile is itself a set of figures, one for each link in the postharvest chain. These figures are derived from a very detailed search of the scientific literature followed by screening for suitability. They remain more or less constant between years. The seasonal data are contributed by the APHLIS Network and address several factors that are taken into account in the loss calculation. They may vary significantly from season to season and year to year. APHLIS estimates are not intended to be ‘statistics’ although they are computed using the best available evidence; they give an understanding of the scale of postharvest losses using a ‘transparent’ method of calculation. The estimates are assigned by primary administative unit (province) and may be aggregated to country or to region. Provinces are usually large geographical units and may include several agro-climatic zones, consequently the loss figures are generalisations, i.e. may be at variance from those experienced in particular situations. APHLIS recognises this limitation and offers a downloadable PHL Calculator that enables practitioners to change the default values to those that are specific to the situation of interest and to obtain loss estimates at a chosen geographical scale. The PHL Calculator can also be used with hypothetical data inorder to model ‘what if’ scenarios. APHLIS offers a robust system for the estimation of PHLs, is transparent in operation and can capture improvements in loss estimation over time by the accumulation of new and more accurate data. It encourages the collection of new data and offers advice on modern approaches to loss asssessment. For the future, APHLIS is envisaged as a much broader communcition hub that informs, motivates and coordinates efforts to optimise postharvest mangement