1,362 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
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)
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]
Angola Block 18WAD and Block 31 pre-operational environmental survey, October 2005: analysis of seabed images taken using WASP (Wide-Angle Seabed Photography)
No full textThis report details seabed observations carried out on behalf of BP Angola for an environmental survey of Angola Blocks 18 and 31 (bathyal SE Atlantic). Seabed photography (still and video) was undertaken with the NOC WASP vehicle. The WASP deployments spanned water depths of 1550-2050m over the Angolan Margin and included studies on the open continental slope and on and around seabed pockmarks and salt diapirs. The shallower sites (Block 18; 1550-1650m) were dominated by small elpidiid holothurians. At intermediate depths (Block 31; c. 1800m) the megabenthos was dominated by the holothurian Scotoplanes globosa. The deeper sites (Block 31 >1900m) were dominated by the spatangoid urchin Pourtalesia alcocki. Two ‘local variant’ faunas were recognized; one associated with the elevated topography of salt diapirs and dominated by ophiuroids. The other from a large seabed pockmark with a highly abundant population of Pourtalesia alcocki (mean abundance 39.56 10m-2; maximum 108.88 10m-2) and also notable for the presence of fragments of cemented sediment, large numbers of dead bivalve tests (including Vesicomyidae Calyptogena-type), squat lobsters (Munidopsis sp.), a bacterial mat and a possible tubeworm (? Siboglinidae). All the latter observations suggest the possibility of fluid flow / cold seep conditions in the vicinity of the pockmark.Should you wish to consult or cite this report please contact the author directly (Brian Bett, [email protected], +44 (0)23 80596355).<br/
Seabed environmental survey of Angola Blocks 18WAD and 31: analysis of seabed samples
No full textThis report details the analysis and interpretation of seabed sample data carried out on behalf of BPAngola for an environmental survey of Angola Blocks 18 and 31 (bathyal SE Atlantic). Seabedsampling was undertaken with the NOC Megacorer to produce material for the assessment ofhydrocarbons, heavy metals, particle size, total organic carbon and nitrogen and macrobenthos. Seabedsampling spanned water depths of 1300-2050m over the Angolan Margin and included sites on the opencontinental slope and on and around seabed pockmarks and salt diapirs. Analysis of the resultant dataindicates that many physical / chemical parameters vary systematically with water depth and withseabed type (background, diapir and pockmark habitats). Contrary to expectation, sediments coarsenand organic matter (total organic carbon and total nitrogen) increases with depth, this, however, may bea local rather then regional trend. A number of the sampled diapir and pockmark sites are notable forpossible indicators of fluid flow, elevated total hydrocarbon levels, unusual hydrocarbon compositionsand variant macrobenthos species composition, all potentially indicative of fluid escape from the seabed(? seep sites). The macrobenthos are highly diverse and likely include a majority of species new toscience. There is a strong trend of increasing biodiversity, particularly species richness, with depth andsome indication that biodiversity is enhanced at diapir sites and somewhat reduced at pockmark sites.Controls on the species composition of the macrobenthos are undoubtedly complex and include both asuite of depth varying factors together with local habitat variation, which likely includes the influence of fluid flow.Should you wish to consult or cite this report please contact the author directly (Brian Bett, [email protected], +44 (0)23 80596355)
Ansicht der staphylomatösen Metamorphosen des Auges, und der Künstlichen Pupillenbildung.
No full textAuthor mentioned in Garrison-Morton.Association: Alvin A. Hubbell.Errata page at end of text indicates that author statement should read "G.J. Beers" instead of "B.J. Beers"At head of title: B.J. Beers.Mode of access: Internet
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