3,027 research outputs found
Profile of author B.J. Morrison of Bar Harbor, plus a review of her most recent
No full textProfile of author B.J. Morrison of Bar Harbor, plus a review of her most recent novel, The Martini Effect
RRS Charles Darwin Cruise 123C3-4, 19 Jul - 15 Sep 2000. Atlantic Margin Environmental Surveys and North Sea Environmental Surveys
No full textThis cruise formed part of the continuing Atlantic Margin Environmental Survey (AMES).The objectives of the cruise were: 1) to continue the AMES process in the deep waters to thenorth and west of Scotland on behalf of the Department of Trade and Industry (DTI); 2) tocarry out a seabed sampling programme in the Fladen Ground area of the North Sea on behalfof the DTI; and 3) to conduct commercially funded seabed surveys in areas adjacent to thoseaddressed in objectives 1 and 2.The cruise encompassed a number of survey areas: Ymir Ridge, Wyville Thomson Ridge(including Darwin Mounds area), Faroe Bank Channel, Faroe-Shetland Channel (axialtransect), West Shetland Slope (bathymetric transect), West Shetland Slope (contourite body),Enterprise survey (northwest of Shetland), Texaco survey (deep Faroe-Shetland Channel),North of Shetland slope (Tranches 65-67), Statoil / BP survey (North of Shetland slope),Marathon survey (Brae oil field, central North Sea), and the Fladen Ground (central NorthSea). In each of these areas seabed samples were obtained (Day grab, box core, Megacore,gravity corer) to study various environmental parameters (hydrocarbons, heavy metals,particle size) and macrobenthos communities. In the deep-water survey areas photographicand video observations (SOC WASP system) of the seabed and its fauna were alsoundertaken
SV Kommandor Jack cruise Leg 2, 26 Jul-21 Aug 2002. DTI ‘Northern Triangle’ Environmental Survey: seabed survey of the deep waters to the north of Shetland
No full textThis cruise formed part of the continuing Atlantic Margin Environmental Survey (AMES). Thegeneral objective of this cruise was to carry out a seabed environmental survey of the deepwaters to the North of Shetland within the UKCS (United Kingdom Continental Shelf) area. Thecruise carried out seabed sampling and photography:(a) To describe and characterise the ‘iceberg ploughmark zone’ on the North Shetland Slope.(b) To assess alongslope variation in sediments and associated fauna on the North ShetlandSlope.(c) To examine the potential contourite deposit and its associated fauna at the foot of the NorthShetland Slope.(d) To investigate the seabed environment and fauna of the ‘Pilot Whale Diapirs’.(e) To describe and characterize ‘hard ground’ areas of the NE Faroe Plateau.(f) To investigate the Tampen Slide area in the extreme north of the UKCS.In each of these areas seabed samples were obtained (Day grab, box corer, Megacorer, gravitycorer) to study various environmental parameters (hydrocarbons, heavy metals, particle size)and macrobenthos communities. Photographic and video observations (SOC WASP system) ofthe seabed and its fauna were also undertaken
MV Ocean Endeavour cruise 13 Oct-06 Nov 2005. Seabed environmental survey of Angola Blocks 18 and 31
No full textThis cruise was carried out on behalf of BP Angola and comprised a seabed environmentalsurvey of Angola Blocks 18 and 31 (bathyal SE Atlantic). Seabed sampling was undertaken byMegacorer to provide samples for macrobenthos, hydrocarbon, heavy metal and particle sizeanalysis. Seabed photography (still and video) was undertaken with the NOC WASP vehicle.Baited, time-lapse camera deployments were undertaken using the BP ROBIO system(Oceanlab, Aberdeen). The survey spanned water depths of 1300-2050m over the AngolanMargin and included studies in and around seabed pockmarks and salt diapirs. Someindications of fluid flow and chemosynthetic communities were encountered.Should you wish to consult or cite this report please contact the author directly (Brian Bett,[email protected], +44 (0)23 80596355)
RRS "Discovery" Cruise 282, 30 Jun - 01 Aug 2003. The environment and ecology of Seine and Sedlo Seamounts, NE Atlantic
No full textThe general aim of the cruise is to undertake a range of physical, chemical and biological investigations on and around Seine and Sedlo Seamounts. Specific objectives for the cruise included: a) the recovery of two current meter moorings from Seine Seamount (originally deployed from FS Poseidon in March 2004); b) to make underway observations of upper water column currents and zooplankton migrations (using ADCPs and 10 kHz echosounder); c) to assess water column hydrography, primary production and biogeochemistry through deployments of a CTD and water bottle rosette; d) to assess the biochemistry and biogeochemistry of suspended particulate matter by the use of SAPS (stand alone pumping system); e) to investigate the taxonomy, ecology and biogeochemistry of zooplankton communities using a multiple opening and closing net system (MOCNESS); f) to make photographic (stills and video) observations of the seabed and its larger fauna (megabenthos) using the SOC SHRIMP system (Seabed High Resolution Imaging Platform); and g) to carry out a suite of seabed sampling (coring, dredging and trawling) to investigate the taxonomy, ecology and biogeochemistry of seabed communities. The latter objective was immediately precluded by the unavailability of either the coring or trawl winches for the duration of this cruise. Only limited SHRIMP operations and no MOCNESS operations were undertaken at Sedlo Seamount as a result of the failure of the electro-optical tow winch. All other cruise objectives were fully achieved
The Effect Of Error Correcting Coding On Indoor Wireless Communications Systems In The 20 - 60 GHz Region
No full textAs a follow-up of the literature study ’An Overview Of Indoor Wireless Communications Systems In Ilie 20 - 60 GHz Region’, published by B.J. Bout jand W.A. Schouten in December 1992, a further study has been performed to investigate the effect of Forward Error Correcting Coding on Indoor Wireless Communications Systems. This has been done by calculating the average fade- and non-fade duration as a function of the frequency and the Signal To Noise ratio. These results are conveyed to a Bit Error Probability. After that, the same calculations are done for the same channel, but with Forward Error Correcting Coding.Electrical Engineering, Mathematics and Computer ScienceTelecommunicatie- en Verkeersbegeleidingssysteme
Transient energy growth modulation by temperature dependent transport properties in a stratified plane Poiseuille flow
No full textWe investigate the effect of temperature dependent thermal conductivity λ and isobaric specific heat c_P on the transient amplification of perturbations in a thermally stratified laminar plane Poiseuille flow. It is shown that for decreasing thermal conductivity the maximum transient energy growth is amplified with respect to the λ=1 case, while the opposite occurs for increasing λ. A reversed mechanism is induced by a variable c_p. Substantial maximum growth enhancement/suppression is found in the range of Prandtl numbers Pr which encompasses most fluids of practical interest. The relative growth modulation shows an optimum Pr under spanwise perturbations. For energy amplifying property distributions a speed-up of the transient to reach the maximum energy growth is observed at low Pr, while a slow-down is found at large Pr. The opposite is true when the property variations suppress the growth of perturbations
Interim report on the seabed environmental survey of Angola Blocks 18 and 31 (MV Ocean Endeavour cruise 2005)
No full textThis report is based on initial (at sea) observations of the seabed environment and fauna of Angola Blocks 18 and 31 as assessed during the MV Ocean Endeavour environmental survey (13 Oct-06 Nov, 2005). The report draws on the appearance and other physical characteristics of core samples and on photographic observations of the seafloor from deployments of the NOCS WASP system and the BP ROBIO lander. The megabenthos and fish populations appear to be consistent with a quiescent, fine-sedimented, bathyal region. No living cold seep (or comparable) communities were encountered during the survey. However, site ME1 (Block 31, large pockmark) has cemented sediments, both within the sediment column and at the sediment surface, and the fragmented shell remains of what appear to be large cold seep mussels; an extant community may be present in this vicinity. Other bivalve molluscs (both living and dead) of possible chemosynthetic nature were recovered from other sites (Block 31, on the periphery of diapiric features).Should you wish to consult or cite this report please contact the author directly (Brian Bett, [email protected], +44 (0)23 80596355).<br/
Collected reports of commercial deep-water surveys carried out north and west of Shetland during RRS Charles Darwin cruise 123C3-4
No full textRRS Charles Darwin cruise 123C3-4 formed part of the Atlantic Margin Environmental Survey(AMES) and also carried out commercially funded deep-water seabed surveys. This contribution detailsthose activities and comprises four sections:Part A. Report of seagoing operations and seabed observations undertaken in Tranche 4 (West ofShetland) on behalf of Enterprise. This report addresses a survey of the deep (1030-1275m) Faroe-Shetland Channel (61°36´N 001°55´W) encompassing a range of habitats (open slope; lineated slope,contourite band; basin floor). These habitats are readily distinguished in terms of their megabenthiccommunities; example photographs of the seafloor and its associated fauna are provided.Part B. Report of seagoing operations and seabed observations undertaken in Tranches 65-67 (Northof Shetland) on behalf of Statoil and BP. This report addresses a survey of the deep (900-1000m) slopeNorth of Shetland (62°20´N 000°10´E) in a region of silty sand contourite deposit. The megabenthiccommunities are dominated by cerianthid anemones and stalked sponges and also notable for theoccurrence of ‘giant’ seapens (Umbellula sp.). An intriguing observation is made of two occurrences (atseparate sites some 7km apart) of fabric bags on the seafloor that appear to have attracted (scavenging)gastropods and prompted the deposition of numerous egg masses. Example photographs of the seafloorand its associated fauna are provided.Part C. Report of seabed observations made in the vicinity of Texaco site TX1: observation of a“tubeworm” patch. This report addresses a survey of the deep (1550m) Faroe-Shetland Channel floor(61°55´N 003°00´W). The survey is notable for recording what appeared to be small (c. 20m across)discrete patch of what appeared to be tubeworms (Siboglinidae). Example photographs of the seafloorand its associated fauna are provided.Part D. Assessment of Texaco site TX1 environmental data. This report addresses a survey of the deep(1550m) Faroe-Shetland Channel floor (61°55´N 003°00´W) and provides an analysis of physicochemical(hydrocarbons, heavy metals, sediments) and biological parameters (macrobenthos) at thesurvey site compared with 35 other sites in the deep Faroe-Shetland Channel obtained during theAtlantic Frontier Environmental Network surveys of 1996 and 1998.Should you wish to consult or cite this report or any of its constituent parts please contact the author directly(Brian Bett, [email protected], +44 (0)23 80596355)
Effect of viscosity and density gradients on turbulent channel flows
No full textWe perform Direct Numerical Simulations (DNS) of a turbulent channel flow with temperature dependent density and viscosity. The Navier-Stokes equations are solved using their low Mach number formulation. In the simulations performed, the fluid is internally heated and the temperature at the walls is fixed. The friction Reynolds number based on half channel height and wall friction velocity is Reτ = 395. The modulation of turbulence, which is caused by the density and viscosity gradients, is characterized using the semi-local scaling of Huang et al. [1995, JFM]
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