A large scale model study of placed stone breakwaters

The results of three hydraulic model tests to evaluate the stability of a placed stone breakwater are presented and discussed. The prototype breakwater was designed to protect offshore power and port facilities in 60 feet of water and was tested at scale ratios of 1:10, 1:20, and 1:100. The armor layer tested is formed from quarried stones of irregular parallelepiped shapes, individually placed long axis perpendicular to the plane of the surface. The resultant breakwater is relatively smooth, densely packed and very stable. Stability, runup, rundown, and reflection are evaluated for a variety of water depth, wave height, and periods. Analysis of the damage induced in the models shows that the placed stone armor is approximately as stable as Bolos. Runup, rundown, and reflection response is similar to rough impermeable slopes. Comparison of large and small scale results demonstrate that relative increases in drag forces at lower Reynolds numbers decrease stability and runup in small scale models

Breaking Out of the Local: International dimensions of science shops

In this article we want to give an overview of the international dimension and the interest of the European Union (EU) in the concept of Science Shops. The European Commission (EC) manages the day-to-day business by initiating and implementing EU policies and spending EU funds. The EC support for Science Shops has been an important factor for the international interest and progress of the Science Shop movement. This article will not give detailed information about daily routines of a Science Shop. Detailed information about the Science Shop concept can be found at the Living Knowledge website (www.livingknowledge.org). Living Knowledge represents the international Science Shop Network. In this article international developments of the Science Shop Network, like the project TRAMS, and Science Shop backgrounds will be linked with past and new EU policies like the EU 7th Framework Programme for Research. It shows how community-based research does not only have a local dimension. The international Science Shop activities show the strengths of international cooperation to break out of the local and to bring local issues on the international agenda. Detailed information about the Science Shop concept and daily routines of a Science Shop can be found at the Living Knowledge website (www.livingknowledge.org), e.g. at the FAQ section and in the toolbox

Psychrophilic methanogenic community development during long-term cultivation of anaerobic granular biofilms

Granular biomass was temporally sampled from a cold (4–15 °C) anaerobic bioreactor, which was inoculated with mesophilic biomass and used to treat industrial wastewater in a long-term (3.4 year) study. Data from 16S rRNA gene clone libraries, quantitative PCR and terminal restriction fragment length polymorphism analyses indicated that microbial community structure was dynamic, with shifts in the archaeal and bacterial communities' structures observed following start-up and during temperature decreases from 15 to 9.5 °C (phase 1). Specifically, the relative abundance of architecturally important Methanosaeta-like (acetoclastic) methanogens decreased, which was concomitant with granule disintegration and the development of a putatively psychrophilic hydrogenotrophic methanogenic community. Genetic fingerprinting suggested the development of a psychroactive methanogenic community between 4 and 10 °C (phase 2), which was dominated by acetogenic bacteria and Methanocorpusculum-like (hydrogenotrophic) methanogens. High levels of Methanosaeta-like acetoclastic methanogens and granular biofilm integrity were maintained during phase 2. Overall, decreasing temperature resulted in distinctly altered microbial community structure during phase 1, and the development of a less dynamic psychroactive methanogenic consortium during phase 2. Moreover, psychrophilic H2-oxidizing methanogens emerged as important members of the psychroactive consortia after >1200 days of low-temperature cultivation. The data suggest that prolonged psychrophilic cultivation of mesophilic biomass can establish a well-functioning psychroactive methanogenic consortium, thus highlighting the potential of low-temperature anaerobic digestion technology