Local law-of-the-wall in complex topography: a confirmation from wind tunnel experiments

It is well known that in a neutrally-stratified turbulent flow in a deep constant-stress layer above a flat surface, the variation of the mean velocity with respect to the distance from the surface obeys the logarithmic law (the so-called ``law-of-the-wall''). More recently, the same logarithmic law has been found also in the presence of non flat surfaces. It governs the dynamics of the mean velocity (i.e. all the smaller scales are averaged out) and involves renormalized effective parameters. Recent numerical simulations analyzed by the authors of the present Letter show that a more intrinsic logarithmic shape actually takes place also at smaller scales. Such a generalized law-of-the-wall involves effective parameters smoothly depending on the position along the underlying topography. Here, we present wind tunnel experimental evidence confirming and corroborating this new-found property. New results and their physical interpretation are also presented and discussed.Comment: 9 pages, (Latex), 4 figure

Idee und Erfahrungen der "Science Centers"

Ein Feld von Experimentierstationen, an welchen ein breites Publikum selber Phänomene erzeugen und variieren kann: Diese Vision verwirklichte der amerikanische Physiker Frank Oppenheimer im Jahre 1969 mit seinem "Exploratorium" in San Francisco. Nach seinem Muster sind seither weltweit viele weitere sogenannte Science Centers entstanden. Deren Publikumserfolg sowie wissenschaftliche Evaluationen der Bildungswirksamkeit haben auch traditionelle naturwissenschaftlichtechnische Museen veranlasst, zumindest Abteilungen mit interaktiven Exponaten einzurichten. Das Technorama der Schweiz hat sich ab 1990 das Exploratorium zum Vorbild genommen und ist inzwischen das grösste Science Center Europas. Die Entwicklung guter interaktiver Exponate bleibt dabei eine faszinierende Herausforderung, die immer noch von wenigen angenommen wird

Bereichsbesprechung. zum Thema: Systemtheorie

Cristina Besio: Systemtheorie. Besprechung der Titel: PETER FUCHS, Konturen der Modernität. Systemtheoretische Essays II. Bielefeld: transcript 2005. PETER FUCHS, Die Psyche. Studien zur Innenwelt der Außenwelt der Innenwelt. Weilerswist: Velbrück 2005. FRANZ KASPER KRÖNIG, Die Ökonomisierung der Gesellschaft. Systemtheoretische Perspektiven. Bielefeld: transcript 2007. GUNTER RUNKEL / GÜNTER BURKART (Hrsg.), Funktionssysteme der Gesellschaft. Beiträge zur Systemtheorie von Niklas Luhmann. Wiesbaden: VS 2005. FRITZ B. SIMON, Einführung in Systemtheorie und Konstruktivismus. Heidelberg: Carl-Auer 2006. FRITZ B. SIMON, Einführung in die systemische Organisationstheorie. Heidelberg: Carl-Auer 200

Prospettive telematiche per la disabilit? : comunicazione interpersonale e accesso all\u27informazione

Abstract not availabl

The organization and administration of a program to interpret the first grade reading program to parents in the Modesto City Schools

It was the purpose of this study to: (1) survey the organization and administration of the program currently used in the Modesto City Schools in interpreting the first grade reading program to parents, (2) identify the characteristics of an effective program for interpreting first grade reading to parents as revealed by the literature, (3) determine the schools’ effectiveness in informing parents of first grade pupils in the area of reading, and (4) offer recommendations for the effective improvement of the Modesto program

Wave energy resource assessment in the Mediterranean Sea on the basis of a 35-year hindcast

A state-of-the-art, in terms of spatio-temporal resolution (about 10 km and on a hourly basis) and temporal span (35 years), wave hindcast is exploited to update existing assessments of wave energy potential in the Mediterranean Sea. The hindcast, covering the period 1979-2013, has been obtained using WavewatchIII with calibrated source-term parameters recently proposed by L. Mentaschi et al. (2015) [1]. The main advantage of such a calibration is that it takes into account the peculiarity of the Mediterranean basin with respect to other calibrations carried out in the oceans. The high resolution allowed to perform a detailed analysis of wave energy potential characteristics providing information on seasonal and longer term variability necessary for reliable and optimal design of wave energy conversion devices. As a result, the identification of areas where the mean wave power reaches values of the order of 10 kW/m clearly emerge. However, these regions are not necessarily optimal in relation to the efficiency of energy extraction, due to possible relevant time variation of the energy availability. The high temporal resolution allows to address issues related to the time variability of the available resource and thus to provide a complete set of statistical information to carry out optimal design of WEC (wave energy converter)

Inside organizations and out: methodological tenets for empirical research inspired by systems theory

"Dieser Aufsatz stellt die Frage, wie eine durch Niklas Luhmanns Systemtheorie inspirierte Organisationsforschung epistemologisch und methodologisch gestaltet werden kann. Besprochen werden methodologisch zentrale Aspekte wie die strukturelle und semantische Analyse, die Beobachtung von Kontingenzen, die Erklärung von 'Trivialitäten', die funktionale Methode und die Erforschung von Koppelungsmechanismen. Aufbauend auf einigen schon verfügbaren Studien zeigen wir, dass die Systemtheorie ein sehr wirkungsvoller Rahmen für die Untersuchung moderner Organisationen ist, da sie eine ungewöhnliche Beobachtungsperspektive ermöglicht, die erlaubt, das infrage zu stellen, was häufig als nicht erklärungsbedürftig angesehen wird. Schließlich versuchen die Autoren zu zeigen, wie das Management von der systemtheoretischen Forschung von Organisationen profitieren kann." (Autorenreferat)"This paper focuses on how organizational research inspired by Niklas Luhmann's systems theory can be epistemologically framed and methodologically designed. Central methodological pillars such as structural and semantic analyses, observing contingencies, explaining trivialities, functional analysis and exploring coupling mechanisms are discussed. Drawing from several empirical studies, the authors demonstrate that systems theory is a highly efficacious framework for the study of modern organizations, as it permits an uncommon observational perspective that is able to question what is often taken for granted. Finally, they highlight how management can profit from systems theoretical research on organizations." (author's abstract

Inside Organizations and Out. Methodological Tenets for Empirical Research Inspired by Systems Theory

Este trabajo se centra en cómo la investigación organizacional inspirada en la teoría de sistemas de Niklas LUHMANN puede enmarcarse epistemológicamente y diseñarse metodológicamente. Se discuten los principales pilares metodológicos, tales como: los análisis estructurales y semánticos, la observación de las contingencias, la explicación de trivialidades, el análisis funcional y el estudio de los mecanismos de acoplamiento. A partir de varios estudios empíricos, demostramos que la teoría de sistemas es un marco muy eficaz para el estudio de las organizaciones modernas, ya que permite una perspectiva de observación poco común que es capaz de cuestionar lo que se suele dar por sentado. Por último, destacamos cómo la gestión puede obtener beneficios de la investigación teórica de sistemas en las organizaciones. URN: urn:nbn:de:0114-fqs1003165Dieser Aufsatz stellt die Frage, wie eine durch Niklas LUHMANNs Systemtheorie inspirierte Organisationsforschung epistemologisch und methodologisch gestaltet werden kann. Besprochen werden methodologisch zentrale Aspekte wie die strukturelle und semantische Analyse, die Beobachtung von Kontingenzen, die Erklärung von "Trivialitäten", die funktionale Methode und die Erforschung von Koppelungsmechanismen. Aufbauend auf einigen schon verfügbaren Studien zeigen wir, dass die Systemtheorie ein sehr wirkungsvoller Rahmen für die Untersuchung moderner Organisationen ist, da sie eine ungewöhnliche Beobachtungsperspektive ermöglicht, die erlaubt, das infrage zu stellen, was häufig als nicht erklärungsbedürftig angesehen wird. Schliesslich versuchen wir zu zeigen, wie das Management von der systemtheoretischen Forschung von Organisationen profitieren kann. URN: urn:nbn:de:0114-fqs1003165This paper focuses on how organizational research inspired by Niklas LUHMANN's systems theory can be epistemologically framed and methodologically designed. Central methodological pillars such as structural and semantic analyses, observing contingencies, explaining trivialities, functional analysis and exploring coupling mechanisms are discussed. Drawing from several empirical studies, we demonstrate that systems theory is a highly efficacious framework for the study of modern organizations, as it permits an uncommon observational perspective that is able to question what is often taken for granted. Finally, we highlight how management can profit from systems theoretical research on organizations. URN: urn:nbn:de:0114-fqs100316

Future changes and seasonal variability of the directional wave spectra in the Mediterranean Sea for the 21st century

A state-of-the-art regional assessment of future directional wave spectra in the Mediterranean Sea and the projected changes with respect to hindcast is presented. A multi-model EURO-CORDEX regional ensemble of bias-adjusted wave climate projections in eleven locations of the Mediterranean are used for the assessment of future seasonal changes in the directional wave spectra under the high-emission scenario RCP8.5. This analysis allows us to identify climate change effects on the spectral energy of the swell and wind-sea systems and their seasonal variability which cannot be captured with the standard integrated wave parameters, such as significant wave height and mean wave direction. The results show an overall robust decrease in the predominant wave systems, resulting in a likely decrease in the significant wave height that is in agreement with previous studies. However, the results depict a robust increase in other less energetic frequencies and directions leading to a projected behavioral change from unimodal to bimodal/multimodal wave climate in many locations which has strong repercussions on the vulnerability of coastal assets and ports operability

Local log-law of the wall: numerical evidences and reasons

Numerical studies performed with a primitive equation model on two-dimensional sinusoidal hills show that the local velocity profiles behave logarithmically to a very good approximation, from a distance from the surface of the order of the maximum hill height almost up to the top of the boundary layer. This behavior is well known for flows above homogeneous and flat topographies (``law-of-the-wall'') and, more recently, investigated with respect to the large-scale (``asymptotic'') averaged flows above complex topography. Furthermore, this new-found local generalized law-of-the-wall involves effective parameters showing a smooth dependence on the position along the underlying topography. This dependence is similar to the topography itself, while this property does not absolutely hold for the underlying flow, nearest to the hill surface.Comment: 9 pages, Latex, 2 figure