Snapthrough instability of a stochastic a von Mises truss

A von Mises truss with stochastically varying material properties is investigated for snapthrough instability. The variability of the snap-through load is calculated analytically as a function of the material property variability represented as a stochastic process. The bounds are established which are independent of the knowledge of the complete description of correlation structure which is seldom possible using the experimental data. Two processes are considered to represent the material property variability and the results are presented graphically. Ein von Mises Fachwerk mit stochastisch verteilten Materialeigenschaften wird bezüglich der Durchschlagsinstabilität untersucht. Die Spannbreite der Durchschlagslast wird analytisch als Funktion der Spannbreite der Materialeigenschaften berechnet, die stochastisch verteilt angenommen werden. Eine explizite Gesamtbeschreibung der Struktur ist bei Benutzung experimenteller Daten selten möglich. Deshalb werden Grenzen für die Durchschlagskraft entwickelt, die von der Kenntnis dieser Gesamtbeschreibung unabhängig sind. Zwei Grenzfälle werden betrachtet, um die Spannbreite der Materialeigenschaften darzustellen. Die Ergebnisse werden grafisch dargestellt.

A discrete state perspective of manipulator workspaces Vorstellungen von diskreten zuständen von manipulator-arbeitsräumen

The finite resolution of joint drives or sensors imparts a discrete nature to the joints of a manipulator. Because of this an arbitrary point in the workspace cannot be reached without error even in ideal mechanical environment. This paper investigates the effect of this discrete nature of the joints on the accuracy of performance of a manipulator and develops a method to select the joint states to reach a point with least error. It is shown that the configuration leading to least error cannot, in general, be found from configuration space, especially when there is large variation in the link lengths or joint resolutions or both. The anomaly becomes severe when the gross motion of the end-effector approaches the local resolution of the workspace. The paper also shows how to distinguish two workspaces which may be identical so far as the boundary points are concerned, taking the joint resolutions into account. Finally, the concepts have been extended to define continuous space global and local performance indices for general multi degree of freedom manipulators.

Structure-function hierarchies and von Karman-Howarth relations for turbulence in magnetohydrodynamical equations

We generalize the method of A. M. Polyakov, Phys. Rev. E 52, 6183 (1995)] for obtaining structure-function relations in turbulence in the stochastically forced Burgers equation, to develop structure-function hierarchies for turbulence in three models for magnetohydrodynamics (MHD). These are the Burgers analogs of MHD in one dimension Eur. Phys. J.B 9, 725 (1999)], and in three dimensions (3DMHD and 3D Hall MHD). Our study provides a convenient and unified scheme for the development of structure-function hierarchies for turbulence in a variety of coupled hydrodynamical equations. For turbulence in the three sets of MHD equations mentioned above, we obtain exact relations for third-order structure functions and their derivatives; these expressions are the analogs of the von Karman-Howarth relations for fluid turbulence. We compare our work with earlier studies of such relations in 3DMHD and 3D Hall MHD.

A Lagrangian for von Karman Equations of Large Deflection Problem of Thin Circular Plate

By the semi-inverse method proposed by He, a Lagrangian is established for the large deflection problem of thin circular plate. Ritz method is used to obtain an approximate analytical solution of the problem. First order approximate solution is obtained, which is similar to those in open literature. By Mathematica a more accurate solution can be deduced.

La leyenda artúrica en la literatura alemana : el Parzival de Wolfram von Eschenbach

Integran este número de la revista ponencias presentadas en Studia Hispanica Medievalia VIII: Actas de las IX Jornadas Internacionales de Literatura Española Medieval, 2008, y de Homenaje al Quinto Centenario de Amadis de Gaula.

La vigencia de las ideas de Ludwig von Mises, para la interpretación de los problemas de Latinoamérica, en la actualidad

Resumen: En los últimos 20 años, los problemas de las economías emergentes de Latinoamérica se han ido, en muchos casos acentuando, y en todos los casos, polarizando. Una serie de países han adoptado enfoques de políticas públicas que muchos identifican con lo que se conoce como “El Foro de Sao Paulo”. El estatismo, el desequilibrio del sector externo, el incremento del gasto fiscal y la pérdida de libertades se han visto asociados a toda esta problemática. Importa particularmente a los cultores de la “Escuela Austriaca de Economía” rescatar lo que podían decir al respecto, algunos de sus pensadores fundamentales.

La aportación de W. von Humboldt a la gramática vasca

[EN] The aim of this paper is to introduce the main contributions of Humboldt to the study of the Basque grammar. His methodological innovations and the influence he had on european linguists are pointed out, the grammatical sources available to him are mentioned and his woks on Basque grammar are enumerated. Some of Humboldt's most interesting analysis are mentioned and are placed in the former and later tradition of the Basque grammar.

Materiales vascos del legado de Wilhelm von Humboldt: la relevancia de Astarloa y el Plan de Lenguas

Este artículo es traducción del original alemán «Zum Stellenwert Astarloas und des Plan de Lenguas», publicado en B. Hurch (ed.), Die baskischen Materialien aus dem Nachlaß Wilhelm von Humboldts. Astarloa, Charpentier, Fréret, Aizpitarte und anderes. Paderborn: Schöningh, pp. 21-42. La traducción al español es obra de Oroitz Jauregi y ha sido revisada por Ricardo Gómez y Bernhard Hurch.

El viajero Wilhelm von Humboldt y sus sucesores: caracterización cultural del País Vasco en las descripciones de viaje del siglo XIX

Berta Raposo Fernández e Ingrid García Wistädt (editoras)

The von Neumann-Morgenstern stable sets for 2x2 games

We analyze the von Neumann and Morgenstern stable sets for the mixed extension of 2 2 games when only single profitable deviations are allowed. We show that the games without a strict Nash equilibrium have a unique vN&M stable set and otherwise they have infinite sets.

Reise im innern von brasilien : auf allerhochsten befehl selner majestat des kaisers von osterreich, Franz des Esten, in den jahren 1817-1821 unternonmen und herausgegeben

O primeiro volume foi editado em 1832 e o segundo em 1837, após a morte do autor, fato que contribuiu para a pouco acurada nomenclatura em português verificada no segundo volume, conforme afirma Borba de Moraes. A grande importância do trabalho de Pohl residiu na descrição de Goiás, à época, uma parte do Brasil quase desconhecida para os cientistas estrangeiros. Seu texto contém descrições sobre a arquitetura colonial e do século XIX. Pohl também produziu um atlas que complementou, por meio de belas ilustrações, o trabalho contido nesses dois volumes. Estes, especialmente se acompanhados do atlas, são um trabalho mais raro do que os relativos às viagens de Martins

La traducción vista desde la perspectiva del concepto de "literatura universal" de Johann Wolfgang von Goethe (1749-1832)

Eguíluz, Federico; Merino, Raquel; Olsen, Vickie; Pajares, Eterio; Santamaría, José Miguel (eds.)

Abbildungen zur naturgeschichte brasiliens : herausgegeben Von Maximilian, Prinzen Von Wied-Neuwied = Recueil de Planches coloriées d'animaux Du Brésil / publie par S.A.S. le Prince Maximilien de Wied-Neuwied

Abbildungen zur naturgeschichte brasiliens é uma magnífica obra publicada em fascículos, cada um deles contendo seis lâminas e seis folhas de texto. As estampas, coloridas, foram gravadas em metal e o texto explicativo apresenta-se em alemão e francês. As gravuras representam espécies da fauna brasileira identificadas pelo autor durante a expedição científica que, juntamente com os naturalistas Georg Freyreiss e Friedrich Sellow, empreendeu ao brasil entre 1815 e 1817. Segundo Borba de Moraes trata-se de edição "muito rara nos dias de hoje".

Herstellung und Zusammensetzung von asiatischen Fischsaucen

Abstract Fish sauce belongs to the most important condiments in Southeast Asian cuisine. It is a clear, amber to reddish liquid with an intensive smell. Fish sauce is used instead of salt for nearly each meal. Asian fish sauce is made from anchovies and other small fish. For the traditional process whole fresh fish are mixed with salt in the ratio 1:1 to 6:1 in wooden, clay or concrete tanks at tropical temperatures for 6 to 18 months. The liquefaction of the fish tissue is due to the action of endogenous enzymes in fish and exogenous enzymes from bacteria. During the fermentation amino acids, peptides and a lot of other substances are built, which are responsible for the characteristic aroma and flavour of these sauces. You can buy pure fish sauce, diluted fish sauce and fish sauce made from other types of animals like mussels, prawns and squids. In single Asian countries there are different national standards for the quality of fish sauces. In order to get a general idea of these products we have bought 16 fish and two oyster sauces from the retail trade in Hamburg and analyzed them with physical, chemical, sensory and microbiological methods. Kurzfassung Fischsauce gehört zu den wichtigsten Würzsaucen in der südostasiatischen Küche. Es ist eine klare, bernsteinfarbene bis rötlichbraune, sehr intensiv riechende Flüssigkeit. Sie wird anstelle von Salz verwendet und daher fast zu jedem Essen gereicht. Zur Herstellung von Fischsaucen werden hauptsächlich Anchovis und ähnliche kleine Fische verwendet. Bei der traditionellen Herstellung werden die ganzen Fische mit Meersalz in einem Holzfass, Tongefäß oder Betontank im Verhältnis 1:1 bis 6:1 gemischt. Während der anschließenden 6 – 18 Monate dauernden Lagerung bei tropischen Temperaturen bauen sich die Gewebeproteine durch fischeigene Enzyme und Mikroorganismen ab. Bei diesem mehrmonatigen Fermentationsprozess entstehen die für den Geschmack wichtigen Aminosäuren, Peptide und Aromastoffe. Es gibt neben reiner Fischsauce, auch verdünnte Fischsauce und Fischsaucen aus anderen Tieren wie Muscheln, Garnelen und Tintenfische. In den einzelnen asiatischen Ländern gibt es unterschiedliche nationale Qualitätsstandards. Um diese Produktgruppe näher kennen zu lernen, haben wir 16 Fisch- und 2 Austernsaucen aus dem Einzelhandel (Hamburg) mit physikalischen, chemischen, sensorischen und mikrobiologischen Verfahren untersucht.