Falmouth Scientific (United States)

Rockfall has plagued infrastructure for centuries, whether generated by natural weathering of unaltered rock slopes or due to jointing and weaknesses in constructed rock slopes. Rockfall in the U.S. has been formally studied since the early 1960s, when Arthur Ritchie, chief geologist with the Washington State Department of Highways, assessed inadequacies with the state of practice relative to catchment ditch design. Since that time, rockfall analysis has become more sophisticated with the use of 3D simulation and rockfall runout models. Several international manufacturers have developed flexible rockfall barrier (fence-like) systems, the designs of which are continuously updated and improved based on testing and field performance. Most flexible rockfall barrier manufacturers also offer debris flow and avalanche barriers using similar elements.

Tethered buoys have long served as a common gateway for communications between underwater, terrestrial, and air assets. Although common, tethered buoys lack the versatility envisioned with an anchorless buoy that can closely maintain a station or waypoint as long as needed and be remotely commanded to move to another waypoint. Indeed, an untethered gateway buoy would have multiple uses in the defense, commercial and scientific sectors. The predominant challenge to develop an untethered buoy is generating enough energy for the buoy to maintain a station for months in open ocean currents. Falmouth Scientific, Inc. and its partners have developed an untethered, station-keeping, gateway buoy, named Gatekeeper, under an SBIR contract with the U.S. Navy. A spar-shape buoy, Gatekeeper inherently offers superior stability to meet the requirement for a persistent radio and satellite link A bail winch system for dropping and raising an acoustic transducer provides a robust underwater acoustic link. The primary energy and power source for the Gatekeeper is a 35 kilowatt-hour patent-pending Salt Water Activated Power System (SWAPS?), which provides at least 200 Watts of power. The Gatekeeper's SWAPS? uses 55 pounds of an environmentally friendly metal alloy that reacts with saltwater to produce hydrogen for a fuel cell generator. SWAPS? is an order of magnitude better than any battery technology in terms of mass, volume and cost for the same amount of energy. A solar panel array serves as a renewable energy source for the Gatekeeper system in order to preserve the SWAPS? fuel, which is not renewable during deployment. A 2 kilowatt-hour battery is also used to store energy from the SWAPS? and solar panels when the Gatekeeper is idling. Gatekeeper demonstrated excellent navigational and station-keeping capability at speeds up to 2 knots during a SBIR Phase ? sea trial in the Fall of 2008 and operated solely from the SWAPS? and a solar array at speeds up to about 1.5 knots. Gatekeeper is projected to endure deployments that last several weeks with its configuration from the fall of 2008, which is a significant milestone. Improvements to Gatekeeper's endurance will be made in preparation for an at-sea endurance test that is planned for the early spring of 2010.

The solar powered AUV is a new system that provides very long endurance sampling capability. The SAUV II is the latest version of the solar powered AUV and has been evaluated in a series of tests during 2004. A number of in water tests were undertaken investigating communication and cooperation among multiple heterogeneous AUVs; these tests included experiments related to low-level underwater networking and high-level language protocols, and user interface issues inherent in multiple AUV mission planning, monitoring and control. These tests have shown that communications protocols can be designed and used successfully in the underwater acoustic environment with both gateway buoys and multiple AUVs. While more testing has to be accomplished to assess efficiency, timing, and to refine software, the tests were very positive. The testing verified that a network infrastructure can be put in place in the underwater environment and that the network will allow communication pathways to be broken and then reconfigured autonomously. Three different in water tests were completed. This paper will describe the results of the 2004 testing with the SAUV II system.

Nontoxic, low surface free energy silicone coatings having reduced biofouling adhesion strength have been developed as an alternative to antifouling paints. Silicone coatings permit macrofouling to adhere; however, fouling can be removed easily by water pressure or light scrubbing. One of the current methods used to evaluate the performance of non‐toxic silicone fouling‐release coatings relies heavily on fouling coverage. The organismal community structure as well as total coverage can affect the ease of fouling removal from these coatings. This paper explores fouling coverage and organismal adhesion over time. Long‐term fouling coverage data were collected at four sites (in Massachusetts, Hawaii and Florida) using static immersion panels coated with silicone and oil‐amended silicone systems. Inter‐site differences in fouling coverage and community structure were observed for each coating. Intra‐site variation and temporal change in coverage of fouling was minimal, regardless of coating formulation. The extent of coverage was affected by the duration of immersion and the local environmental conditions; these factors may also have an impact on the foul‐release capability of the silicone coatings. Organismal adhesion data was collected in Hawaii and Florida. These adhesion measurements were used as a tool to discriminate and rank fouling release coatings.

An instrument for high accuracy measurement of wave directional spectra was designed and implemented. The instrument, called the 3D-ACM WAVE, combines an acoustic current meter and a high accuracy micromachined pressure sensor into a single instrument. The instrument measures two orthogonal horizontal components of current velocity and the pressure at the deployment depth. Data is collected, and sequences of these three measurements are used to determine wave spectra, based on readily available spectral analysis techniques. The sampling rate of the 3D-ACM WAVE is 5.36 Hz, allowing a wide spectral range for wave characterization. Field results from ocean deployments show that the data collected by the instrument can be successfully used to calculate wave directional spectra. The field results, which are presented in this paper, compare favorably with results acquired using other proven techniques.

(Uploaded by Plazi from the Biodiversity Heritage Library) No abstract provided.