CACTUS is a hydrokinetic turbine performance code under development at Sandia National Laboratories (SNL). Details on it capabilities are given in [1]. CACTUS simulates arbitrary geometries, including crossflow and axial flow rotors. SNL added new capabilities to CACTUS and an outreach effort was begun to solicit interest among MHK researchers and developers who want to consider CACTUS for hydr...

This study aims to characterise the rainfall exceptionality and the meteorological context of the 20 February 2010 flash-floods in Madeira (Portugal). Daily and hourly precipitation records from the available rain-gauge station networks are evaluated in order to reconstitute the temporal evolution of the rainstorm, as its geographic incidence, contributing to understand the flash-flood dynamics...

We investigate the impact of large floods on civil conflict in a sample of 125 countries between 1985 and 2009, employing GDP growth as a potential transmission channel. We instrument for floods and control for potential spatial and temporal dependency of civil conflict. We find that floods increase the probability of conflict incidence through their effect on GDP growth.

An understanding of rates and mechanisms of incision and knickpoint retreat in bedrock rivers is fundamental to perceptions of landscape response to external drivers, yet only sparse field data are available. Here we present eye witness accounts and quantitative surveys of rapid, amphitheatre-headed gorge formation in unweathered granite from the overtopping of a rock-cut dam spillway by small-...

This paper documents tree-ring responses to a historic tornado and re-evaluates prehistoric tree-ring changes seen in archaeological wood of Wupatki Ruin used to date the 11 century eruption of Sunset Crater. The historic tornado occurred at Sunset Crater, northern Arizona, on 24 October 1992, and trees within areas damaged by the tornado survived the event and continue living today. The object...

[1] The Zagros mountains of southern Iran are marked by a zone of high seismicity and accommodate a significant portion of the convergence between Arabia and Eurasia. Due to the lack of dense local seismic or geodetic networks, the inferred kinematics of the collision in Iran is mainly based on catalogs of teleseismically determined earthquake locations. We surveyed all Mw > 4.5 earthquakes in ...

This paper develops a novel data-driven fuzzy modeling strategy and predictive controller for boiler-turbine unit using fuzzy clustering and subspace identification (SID) methods. To deal with the nonlinear behavior of boiler-turbine unit, fuzzy clustering is used to provide an appropriate division of the operation region and develop the structure of the fuzzy model. Then by combining the input...

A simple two-by-two model for a boiler-turbine unit is demonstrated in this paper. The model can capture the essential dynamics of a unit. The design of a coordinated controller is discussed based on this model. A PID control structure is derived, and a tuning procedure is proposed. The examples show that the method is easy to apply and can achieve acceptable performance.

A molecular epidemiological study of rotavirus (RV) and norovirus (NoV) infections was carried out in Nha Trang city in Vietnam between December 2005 and June 2006. RV and NoV were detected in 87 (47.5%) and 12 (6.6%) of the 183 fecal specimens from children hospitalized with acute gastroenteritis, respectively. The majority of patients with RV and NoV were children younger than 2 years of age....

Why does a single fire ant Solenopsis invicta struggle in water, whereas a group can float effortlessly for days? We use time-lapse photography to investigate how fire ants S. invicta link their bodies together to build waterproof rafts. Although water repellency in nature has been previously viewed as a static material property of plant leaves and insect cuticles, we here demonstrate a self-as...