2,998 research outputs found
Contamination of the coastal waters of Bermuda by organotins and the triazine herbicide Irgarol 1051
No full textA study of the distribution of the 'booster' biocide 2-methylthio-4-tert-butylamino-6-cyclopropyl amino-s-triazine (Irgarol 1051) was carried out in the coastal waters of Bermuda. Irgarol 1051 concentrations (as determined by GC/MS) up to 590 ngl-1 have been measured within Hamilton Harbour. The data presented herein unequivocally demonstrate contamination of the coastal system of Bermuda by Irgarol 1051. Concurrently, TBT concentrations were measured and results indicate that levels are falling through legislated changes in antifouling treatments, from 220 ngl-1 in 1990 to <20 ngl-1 (as Sn) by 1995, in the open water area of Hamilton Harbour. Concentrations of TBT immediately offshore from a boatyard were found to be >600 ngl-1 (Sn), indicating continuing release due to painting operations and sediments in the area
Flow cytometry and pigment analyses as tools to investigate the toxicity of herbicides to natural phytoplankton communities
No full textCharacterisation of natural phytoplanktonic communities is currently being advanced
through flow cytometry and high resolution pigment analyses. To date, toxicological
methods to assess impacts of herbicides on natural phytoplankton populations are lacking. Here, we report the novel use of these techniques in combination to study changes in phytoplankton populations exposed to 2-methylthio-4-tertiary-butylamino-6-cyclopropylaminos-triazine (Irgarol 1051), a herbicide used in antifouling paints. Flow cytometry results revealed that following a 72-h exposure to approximately 100 ng L -1, eukaryote abundance was less than half that in the controls. High performance liquid chromatographic analyses of pigments demonstrated that 190-hexanoyloxyfucoxanthin was selectively lost relative to the
control. This carotenoid is specific to the prymnesiophytes which are key constituents of phytoplanktonic communities within temperate marine waters. Values of EC50 (72 h) as low as 70 ng L -1 were calculated from the selective reduction in this compound. Concentrations substantially exceeding this level have been reported in UK and other European coastal waters
Development of an Atomic Force Microscope
No full textThis abstract presents the development of an Atomic Force Microscope (AFM) vertical scanner for surface topography measurements, which is composed of a single axis positioning stage with an integrated metrology system and AFM probe. The scanner is meant to track and measure a maximum topography step of 10 ?m with a measurement resolution of less then 0.1 nm and an uncertainty of less than 10 nm (1←) at a controllable bandwidth of at least 2 kHz.Precision and Microsystems EngineeringMechanical, Maritime and Materials Engineerin
Concrete Flow in Diaphragm Wall Panels: A Full-Scale In-Situ Test
No full textFlow processes, taking place during the concreting of diaphragm wall panels (D-wall panels), are of great importance for the quality of the wall. During this phase, the bentonite, present in the excavated trench, should be completely replaced by concrete in a controlled way. In literature several cases are described in which this process resulted in bentonite inclusions in the panel. These inclusions often lead to severe problems, like leakages, for the building pit to be excavated within the diaphragm wall panels. Beside the risks for the building pit, leakages caused by bentonite inclusions can also have large consequences for nearby constructions. In this article, set up and results of a full-scale diaphragm wall test are described. Conclusions are drawn with regard to the influence of several parameters on the flow process and subsequently on the quality of the wall and the risk on bentonite inclusions
Letter from J.W. Cook to Thomas Lamb Eliot
No full texthttps://rdc.reed.edu/v1/resources/5e17b7c9-4bca-4fcf-8784-0915783532dd/thumb/128.jpgIt is possible that the author is James W. Cook, who was an important figure in the establishment of the Portland Unitarian Church
Letter from J.W. Cook to Thomas Lamb Eliot
No full texthttps://rdc.reed.edu/v1/resources/c9f13811-9c93-449b-8b79-31dd26e7a981/thumb/128.jpgIt is probable that the author is James W. Cook, who was an important figure in the establishment of the Portland Unitarian Church
Letter from J.W. Cook to Thomas Lamb Eliot
No full texthttps://rdc.reed.edu/v1/resources/413865c0-390a-449d-9d4e-f69f66754b8e/thumb/128.jpgIt is possible that the author is James W. Cook, who was an important figure in the establishment of the Portland Unitarian Church
Verification of BREAKWAT for berm breakwaters and low-crested structures
No full textThis report describes the verification of the model on dynamic stability for berm breakwaters. The model runs on a pc and is called BREAKWAT. The data received from various people allover the world contained not only berm breakwaters, but also dynamically stable low-crested structures. The title of the report was therefore changed to "Verification of BREAKWAT for berm breakwaters and low-crested structures". The calculations were performed and the report was written by Dr. J.W. van der Meer of Delft Hydraulics
Letter from J.W. Cook to Thomas Lamb Eliot
No full texthttps://rdc.reed.edu/v1/resources/48a1abe6-3896-473b-bc17-0796ead5e587/thumb/128.jpgIt is probable that the author is James W. Cook, who was an important figure in the establishment of the Portland Unitarian Church
J.W. Waterhouse 1849-1917: The Modern Pre-Raphaelite
No full textThis is the catalogue for the exhibition J.W. Waterhouse: The Modern Pre-Raphaelite, held at the Groninger Museum, Groningen, the Netherlands (14 December 2008 - 3 May 2009), Royal Academy of Arts, London (27 June - 13 September 2009), and Montreal Museum of Fine Arts (1 October 2009 - 7 February 2010). The catalogue is co-authored and co-edited by the curators of the exhibition: Elizabeth Prettejohn (author of pp. 23-35 and 48 of the 100 catalogue entries), Peter Trippi, Robert Upstone, and Patty Wageman. The book won the Historians of British Art Prize for best multi-authored book 2010 (affiliated society to the College Art Association, USA).This is the catalogue for the exhibition J.W. Waterhouse: The Modern Pre-Raphaelite, held at the Groninger Museum, Groningen, the Netherlands (14 December 2008 - 3 May 2009), Royal Academy of Arts, London (27 June - 13 September 2009), and Montreal Museum of Fine Arts (1 October 2009 - 7 February 2010). The catalogue is co-authored and co-edited by the curators of the exhibition: Elizabeth Prettejohn (author of pp. 23-35 and 48 of the 100 catalogue entries), Peter Trippi, Robert Upstone, and Patty Wageman. The book won the Historians of British Art Prize for best multi-authored book 2010 (affiliated society to the College Art Association, USA)
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