Оценка надежности высоконадежных систем с учетом ЗИП

Предложены приближенные верхние и нижние оценки коэффициента готовности высоконадежной восстанавливаемой системы со структурной избыточностью. Полученные расчетные соотношения могут использоваться для оценки надежности высоконадежных систем с учетом различных стратегий пополнения ЗИП

Directive versus empowering leadership: A field experiment comparing impacts on task proficiency and proactivity

Using a field experiment in the United Arab Emirates, we compared the impacts of directive and empowering leadership on customer-rated core task proficiency and proactive behaviors. Results of tests for main effects demonstrated that both directive and empowering leadership increased work unit core task proficiency, but only empowering leadership increased proactive behaviors. Examination of boundary conditions revealed that directive leadership enhanced proactive behaviors for work units that were highly satisfied with their leaders, whereas empowering leadership had stronger effects on both core task proficiency and proactive behaviors for work units that were less satisfied with their leaders. We discuss implications for both theory and practice. © Academy of Management Journal

Active transsection faults in rift transfer zones: evidence for complex stress fields and implications for crustal fragmentation processes in the western branch of the East African Rift

New structural and seismologic evidence from the Rwenzori Mountains, Uganda, indicate that continental rifts can capture and rotate fragments of the lithosphere while rift segments interact, in a manner analogous to the interaction of small-scale fractures. The Rwenzori Mountains are a basement block within the western branch of the East African Rift System that is located at the intersection of two rift segments and is apparently rotating clockwise. Structural data and new seismological data from earthquake epicentres indicate a large-scale, 20-km-long transsection fault is currently detaching the Rwenzori micro-plate on its northern margin from the larger Victoria plate (Tanzania craton), whereas it is already fully detached in the south. We propose that this fault develops due to the rotation of the Rwenzori block. In a numerical model we show how rift segment interaction, block rotation and the development of transsection faults (faults that cut through the Rwenzori Mountains) evolve through time. The model suggests that uplift of the Rwenzori block can only take place after the rift has opened significantly, and rotation leads to the development of transsection faults that connect two rift segments, so that the block is captured within the rifts. Our numerical model suggests that the majority of the uplift has taken place within the last 8 Ma

Active Composites with Integrated Piezoceramics

The rapid development of industrial products in the fields of traffic technology, printing, textile machines, mechanical engineering, etc. requires higher efficiency of materials and structures. Thus, lightweight design has become very important, mainly for effects of accelerated mass. New materials like high-performance fiber composites not only find application in aerospace technology, but are also gaining importance areas. Carbon fibers, embedded in polymer matrix systems, offer much more possibilities than the usual materials like steel, titan, aluminium because of their excellent properties of weight, stability, stiffness, as well their designable material anisotropy. Nevertheless, lightweight design with fiber composites also has problems, for example vibrational sensitivity due to low mass, tendency to buckling, and susceptibility to damage. With adaptive techniques these lightweight structures can be optimized by integrating multifunctional materials such as piezoelectrics, SMA, etc. To handle multifunctional material in different applications statements regarding the compatibility, the degree of efficiency and the overall electromechanical behavior of material are important. In this paper the advantages of fiber composite technology and integration of adaptive elements shall by showing selected examples. Some basic design that were developed at the Institute of Structural Mechanics of the DLR Braunschweig are presented

Archeologia della morte in Daunia: nuovi dati dalle necropoli di Arpi tra topografi, tipologia e pratiche funerarie.

Dal 2014 il Centre Jean Bérard di Napoli e l’Università degli Studi di Salerno, in collaborazione con la Soprintendenza prima di Taranto e poi ABAP di Foggia, hanno ripreso lo studio dell’insediamento daunio di Arpi. Il lavoro ha come obiettivo di definire, attraverso l’analisi incrociata della documentazione d’archivio e l’apporto di nuovi studi sulle dinamiche di trasformazione dei paesaggi rurali e urbani, le fasi di frequentazione e di abbandono, nonché la destinazione d’uso degli spazi residenziali e i rapporti tra l’abitato, le aree di culto e le zone di necropoli. Lo studio congiunto delle strutture abitative, dei nuclei di necropoli, del sistema viario e del sistema di gestione delle acque, ha permesso poco alla volta di estendere la ricerca dal singolo contesto al quartiere e, infine, all’intera area dell’insediamento. Insieme ai quartieri abitativi, la topografia delle necropoli costituisce uno dei fenomeni più significativi della struttura di questo grande abitato. Il contributo vuole fornire, su questi ultimi aspetti, grazie all'analisi critica effettuata, nuovi spunti di riflessione

Windenergieanlagen im Verbundbetrieb. T. 1. Windenergieanlagen (WEAn) in elektrischen Energieversorgungssystemen kleiner Leistung Schlussbericht. Abschlussdatum: Dezember 1985

TIB: FR 213 (1)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman