Analysis of high load dampers

High load damping requirements for modern jet engines are discussed. The design of damping systems which could satisfy these requirements is also discusseed. In order to evaluate high load damping requirements, engines in three major classes were studied; large transport engines, small general aviation engines, and military engines. Four damper concepts applicable to these engines were evaluated; multi-ring, cartridge, curved beam, and viscous/friction. The most promising damper concept was selected for each engine and performance was assessed relative to conventional dampers and in light of projected damping requirements for advanced jet engines

Social distancing strategies against disease spreading

The recurrent infectious diseases and their increasing impact on the society has promoted the study of strategies to slow down the epidemic spreading. In this review we outline the applications of percolation theory to describe strategies against epidemic spreading on complex networks. We give a general outlook of the relation between link percolation and the susceptible-infected-recovered model, and introduce the node void percolation process to describe the dilution of the network composed by healthy individual, $i.e$, the network that sustain the functionality of a society. Then, we survey two strategies: the quenched disorder strategy where an heterogeneous distribution of contact intensities is induced in society, and the intermittent social distancing strategy where health individuals are persuaded to avoid contact with their neighbors for intermittent periods of time. Using percolation tools, we show that both strategies may halt the epidemic spreading. Finally, we discuss the role of the transmissibility, $i.e$, the effective probability to transmit a disease, on the performance of the strategies to slow down the epidemic spreading.Comment: to be published in "Perspectives and Challenges in Statistical Physics and Complex Systems for the Next Decade", Word Scientific Pres

Outlier Detection, Seasonal Adjustment and Cycle Extraction in New Member States of European Union

An econometric exercise is run to identify outliers, seasonal adjust and extract the cycle from New Member States GDPs series. Obtained results are showed with full statistics. For the NMS aggregate direct vs. indirect approach is compared.Seasonal adjustment, outlier detection and Demetra

Transient dynamics of a flexible rotor with squeeze film dampers

A series of simulated blade loss tests are reported on a test rotor designed to operate above its second bending critical speed. A series of analyses were performed which predicted the transient behavior of the test rig for each of the blade loss tests. The scope of the program included the investigation of transient rotor dynamics of a flexible rotor system, similar to modern flexible jet engine rotors, both with and without squeeze film dampers. The results substantiate the effectiveness of squeeze film dampers and document the ability of available analytical methods to predict their effectiveness and behavior

The Business of Empire: American Capitalists, the Nicaraguan Canal, and the Monroe Doctrine, 1849-1858

In the mid-nineteenth century, U.S. policymakers designed foreign policy to enhance the reach of American commerce and create a commercial empire in and through Latin America. To create this empire U.S policymakers wanted to construct a canal through Central America, which they envisioned as a joint enterprise between American businesses and the federal government. In 1849, Cornelius Vanderbilt and his associates reserved a charter from the Nicaraguan government to build and operate a canal and transit route through their county. Yet competition between varied business interests prompted the U.S. destruction of the Nicaraguan port city of San Juan del Norte and the rise of filibuster William Walker. This thesis argues that the 1854 bombardment of San Juan and the 1857 and 1858 arrests of Walker defined the Monroe Doctrine and constituted a vital turning point in the United States’ position in Central America. To grow the reach of U.S. merchants, Monroe had proclaimed the Western Hemisphere under the protection of the United States. But the doctrine left unclear how the U.S. would impose its control over the region. The events in Nicaragua set the course for how the United States would achieve a commercial empire in the following decades. Critical to these developments was the changing role of American businessmen in foreign policy and commercial growth. Before these events, policymakers had encouraged businessmen to take the lead, but the problems in Nicaragua caused policymakers to place military force at the forefront of expansion

Experimental pre-assessing entanglement in Gaussian states mixing

We suggest and demonstrate a method to assess entanglement generation schemes based on mixing of Gaussian states at a beam splitter (BS). Our method is based on the fidelity criterion and represents a tool to analyze the effect of losses and noise before the BS in both symmetric and asymmetric channels with and without thermal effects. More generally, our scheme allows one to pre-assess entanglement resources and to optimize the design of BS-based schemes for the generation of continuous variable entanglement.Comment: 10 pages, 15 figure