10,164 research outputs found

    Biofilm monitoring coupon system and method of use

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    An apparatus and method is disclosed for biofilm monitoring of a water distribution system which includes the mounting of at least one fitting in a wall port of a manifold in the water distribution system with a passage through the fitting in communication. The insertion of a biofilm sampling member is through the fitting with planar sampling surfaces of different surface treatment provided on linearly arrayed sample coupons of the sampling member disposed in the flow stream in edge-on parallel relation to the direction of the flow stream of the manifold under fluid-tight sealed conditions. The sampling member is adapted to be aseptically removed from or inserted in the fitting and manifold under a positive pressure condition and the fitting passage sealed immediately thereafter by appropriate closure means so as to preclude contamination of the water distribution system through the fitting. The apparatus includes means for clamping the sampling member and for establishing electrical continuity between the sampling surfaces and the system for minimizing electropotential effects. The apparatus may also include a plurality of fittings and sampling members mounted on the manifold to permit extraction of the sampling members in a timed sequence throughout the monitoring period

    Where Is My Mama

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    https://digitalcommons.library.umaine.edu/mmb-vp/3431/thumbnail.jp

    Some n-p (Hg,Cd)Te photodiodes for 8-14 micrometer heterodyne applications

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    The results describing the dc and CO2 laser heterodyne characteristics of a three element photodiode array and single element and four element photodiode arrays are presented. The measured data shows that the n(+)-p configuration is capable of achieving bandwidths of 475 to 725 MHz and noise equivalent powers of 3.2 x 10 to the minus 20th power W/Hz at 77 K and 1.0 x 10 to the minus 19th power W/Hz at 145 K. The n(+)-n(-)-p photodiodes exhibited wide bandwidths (approximately 2.0 GHz) and fairly good effective heterodyne quantum efficiencies (approximately 13-30 percent at 2.0 GHz). Noise equivalent powers ranging from 1.44 x 10 to the minus 19th power W/Hz to 6.23 x 10 to the minus 20th power W/Hz were measured at 2.0 GHz

    Advanced underwater lift device

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    Flexible underwater lift devices ('lift bags') are used in underwater operations to provide buoyancy to submerged objects. Commercially available designs are heavy, bulky, and awkward to handle, and thus are limited in size and useful lifting capacity. An underwater lift device having less than 20 percent of the bulk and less than 10 percent of the weight of commercially available models was developed. The design features a dual membrane envelope, a nearly homogeneous envelope membrane stress distribution, and a minimum surface-to-volume ratio. A proof-of-concept model of 50 kg capacity was built and tested. Originally designed to provide buoyancy to mock-ups submerged in NASA's weightlessness simulators, the device may have application to water-landed spacecraft which must deploy flotation upon impact, and where launch weight and volume penalties are significant. The device may also be useful for the automated recovery of ocean floor probes or in marine salvage applications

    Physical Constraints to Aquatic Plant Growth in New Zealand Lakes

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    The nature of aquatic plant communities often defines benthic habitat within oligotrophic and mesotrophic lakes and lake management increasingly recognizes the importance of maintaining plant diversity in order to sustain biological diversity and capacity within lakes. We have developed simple statistical relationships between key physical and vegetation variables that define the habitat requirements, or “habitat-templates”, of key vegetation types to facilitate management of plant communities in New Zealand lakes. Statistical relationships were derived from two datasets. The first was a multi-lake dataset to determine the effects of water level fluctuation and water clarity. The second dataset was from a comprehensive shoreline survey of Lake Wanaka, which allowed us to examine within-lake variables such as beach slope and wave action. Sufficient statistical relationships were established to develop a habitat template for each of the major species or assemblages. The relationships suggested that the extent and diversity of shallow-growing species was related to a combination of the extent of water level fluctuation and wave exposure. (PDF contains 9 pages.

    Advanced collapsible tank for liquid containment

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    Tanks for bulk liquid containment will be required to support advanced planetary exploration programs. Potential applications include storage of potable, process, and waste water, and fuels and process chemicals. The launch mass and volume penalties inherent in rigid tanks suggest that collapsible tanks may be more efficient. Collapsible tanks are made of lightweight flexible material and can be folded compactly for storage and transport. Although collapsible tanks for terrestrial use are widely available, a new design was developed that has significantly less mass and bulk than existing models. Modelled after the shape of a sessible drop, this design features a dual membrane with a nearly uniform stress distribution and a low surface-to-volume ratio. It can be adapted to store a variety of liquids in nearly any environment with constant acceleration field. Three models of 10L, 50L, and 378L capacity have been constructed and tested. The 378L (100 gallon) model weighed less than 10 percent of a commercially available collapsible tank of equivalent capacity, and required less than 20 percent of the storage space when folded for transport

    A functional analysis of change propagation

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    A thorough understanding of change propagation is fundamental to effective change management during product redesign. A new model of change propagation, as a result of the interaction of form and function is presented and used to develop an analysis method that determines how change is likely to propagate. The analysis produces a Design Structure Matrix, which clearly illustrates change propagation paths and highlights connections that could otherwise be ignored. This provides the user with an in-depth knowledge of product connectivity, which has the potential to support the design process and reduce the product's susceptibility to future change

    Interview with David Flanagan by Mike Hastings

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    Biographical NoteDavid T. Flanagan was born in Bangor, Maine on June 39, 1947. He grew up in Bangor, Hampden, and then Portland, where he attended Deering High School. He was the eldest of eight children. His mother, Constance Flanagan, was a registered nurse, and his father, Thomas Flanagan, was an insurance claims adjustor for the USF&G Company. David attended Harvard University, where he studied history and government, and then went on to the University of London, Kings College, earned a master’s degree, and returned to Boston College Law School on a scholarship. He worked on the congressional campaign of Peter Kyros, Sr., and did some political work for Elmer Violette and Governor Ken Curtis. He ran as an Independent candidate for governor of Maine in 2002. For many years, he served as president and CEO of Central Maine Power. He has also been chairman of the American University in Bulgaria and general counsel to the U.S. Senate Homeland Security Committee’s investigation of Hurricane Katrina. At the time of this interview, he was a member of a task force to investigate restructuring of the University of Maine System. As of 2010, he is chairman of the Board of Visitors for the Muskie School of Public Service at the University of Southern Maine. SummaryInterview includes discussion of: interests while in high school; growing up in Portland; Harvard University and work-study jobs; King’s College School of Economics and traveling to Moscow and Leningrad; Boston College School of Law; working in the Maine legislature; working for Governor Brennan; working as the attorney for the Maine Bureau of Public Lands; securing the Maine public lands from the timber industry in a lawsuit; working as the attorney general for Maine Department of Conservation; Peter Kyros, Jr.; John O’Leary; Brennan’s working style; the Maine Indian Land Claims Settlement Act; Mitchell’s rise to leadership in the Senate; Central Maine Power’s role in Maine politics; the American University in Bulgaria; and the Senate investigation of Hurricane Katrina
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