Search results for "B1"
showing 10 items of 1109 documents
Insights Into the Inside – A Quantitative Histological Study of the Explosively Moving Style in Marantaceae
2018
This study aims to identify the histological basis for the extraordinary, fast movement of the style in Marantaceae. Although this explosive pollination mechanism was subject of many studies, quantitative measurements to document volumetric changes have never been conducted. Based on physical parameters and limitations (poroelastic time), the movement itself is by far too fast to be explained by turgor changes solely. Therefore, we address the hypothesis that the style contains elastic structures to store energy allowing the fast movement. We provide an experimental approach in Goeppertia bachemiana to identify histological differences of styles in various states, i.e., steady, unreleased, …
Synthesis and characterization of ZnO/ZnS/MoS2 core-shell nanowires
2017
The present research was supported by the Latvian National Research Program IMIS2 . Authors are grateful for Dr. Robert Kalendarev and Martins Zubkins for assistance in magnetron sputtering, Dr. Krisjanis Smits for TEM measurements, Dr. Roberts Zabels for AFM measurements and Reinis Ignatans for XRD measurements.
Efecto Bullwhip y restricciones de capacidad productiva en las cadenas colaborativas
2008
El objetivo del presente artículo es profundizar en el análisis de Evans y Naim (1) sobre la relación entre la capacidad de limitada producción y el efecto bullwhip, y actualizarlo en función de las recientes configuraciones de cadenas de suministro colaborativas. Se analizan tres cadenas de suministro con capacidad de producción limitada: la misma cadena de suministro tradicional estudiada por Evans y Naim (1), una cadena EPOS (Exchange Point of Sales) y una cadena sincronizada. Se adopta un sistema de métricas para evaluar los beneficios de los nodos de la cadena medidos en términos de estabilidad de la orden de pedido, estabilidad de los inventarios, y robustez del sistema, y en términos…
Dependence of the layer heat potentials upon support perturbations
2023
We prove that the integral operators associated with the layer heat potentials depend smoothly upon a parametrization of the support of integration. The analysis is carried out in the optimal H\"older setting.
Fixed angle inverse scattering in the presence of a Riemannian metric
2020
We consider a fixed angle inverse scattering problem in the presence of a known Riemannian metric. First, assuming a no caustics condition, we study the direct problem by utilizing the progressing wave expansion. Under a symmetry assumption on the metric, we obtain uniqueness and stability results in the inverse scattering problem for a potential with data generated by two incident waves from opposite directions. Further, similar results are given using one measurement provided the potential also satisfies a symmetry assumption. This work extends the results of [23,24] from the Euclidean case to certain Riemannian metrics.
Le cône diamant symplectique
2009
Resume Si n + est le facteur nilpotent d'une algebre semi-simple g , le cone diamant de g est la description combinatoire d'une base d'un n + module indecomposable naturel. Cette notion a ete introduite par N.J. Wildberger pour sl ( 3 ) , le cone diamant de sl ( n ) est decrit dans Arnal (2006) [2] , celui des algebres semi-simples de rang 2 dans Agrebaoui (2008) [1] . Dans cet article, nous generalisons ces constructions au cas des algebres de Lie sp ( 2 n ) . Les tableaux de Young semi-standards symplectiques ont ete definis par C. De Concini (1979) [4] , ils forment une base de l'algebre de forme de sp ( 2 n ) . Nous introduisons ici la notion de tableaux de Young quasi standards symplec…
Normal forms and embeddings for power-log transseries
2016
First return maps in the neighborhood of hyperbolic polycycles have their asymptotic expansion as Dulac series, which are series with power-logarithm monomials. We extend the class of Dulac series to an algebra of power-logarithm transseries. Inside this new algebra, we provide formal normal forms of power-log transseries and a formal embedding theorem. The questions of classifications and of embeddings of germs into flows of vector fields are common problems in dynamical systems. Aside from that, our motivation for this work comes from fractal analysis of orbits of first return maps around hyperbolic polycycles. This is a joint work with Pavao Mardešić, Jean-Philippe Rolin and Vesna Župano…
P-spaces and the Whyburn property
2009
We investigate the Whyburn and weakly Whyburn property in the class of $P$-spaces, that is spaces where every countable intersection of open sets is open. We construct examples of non-weakly Whyburn $P$-spaces of size continuum, thus giving a negative answer under CH to a question of Pelant, Tkachenko, Tkachuk and Wilson. In addition, we show that the weak Kurepa Hypothesis (a set-theoretic assumption weaker than CH) implies the existence of a non-weakly Whyburn $P$-space of size $\aleph_2$. Finally, we consider the behavior of the above-mentioned properties under products; we show in particular that the product of a Lindel\"of weakly Whyburn P-space and a Lindel\"of Whyburn $P$-space is we…
Existence results for parametric boundary value problems involving the mean curvature operator
2014
In this note we propose a variational approach to a parametric differential problem where a prescribed mean curvature equation is considered. In particular, without asymptotic assumptions at zero and at infinity on the potential, we obtain an explicit positive interval of parameters for which the problem under examination has at least one nontrivial and nonnegative solution.
Wittgenstein a la luz de Aristóteles
2008
This paper compares the way Aristotle explains how one body gets alive or the way one mind manages to understand, with the way Wittgenstein discusses some questions as how is it possible to get meaning from the sign, or to follow a rule. The paper’s goal is not to establish a real influence of Aristotle on Wittgenstein, but to explore some logical aspects of their explanation patterns, with the aim of clarifying several notions of Wittgenstein’s later philosophy. El artículo compara el modo como Aristóteles explica que un cuerpo llegue a vivir o que una mente llegue a entender, con el esquema explicativo que emplea Wittgenstein para dar cuenta de problemas como éstos: ¿qué hace posible que …