Large-scale Basement Structures of the Outer Hebrides in the Light of Geophysical Evidence

1973 ◽  
Vol 245 (140) ◽  
pp. 1-3 ◽  
Author(s):  
R. McQUILLIN ◽  
JANET WATSON
Keyword(s):  
Large Scale ◽  
Outer Hebrides ◽  
Basement Structures

Large-scale Laxfordian structures of the outer hebrides in relation to those of the Scottish mainland

1970 ◽  
Vol 10 (4) ◽  
pp. 425-435 ◽  
Author(s):  
M.P. Coward ◽  
P.W. Francis ◽  
R.H. Graham ◽  
J. Watson
Keyword(s):  
Large Scale ◽  
Outer Hebrides

scholarly journals The Outer Hebrides: where genes and geography meet

1979 ◽  
Vol 77 ◽  
pp. 21-43
Author(s):  
R. J. Berry
Keyword(s):  
Island Biogeography ◽  
Large Scale ◽  
Random Pattern ◽  
Traditional Theory ◽  
Stochastic Sampling ◽  
Terrestrial Vertebrates ◽  
Local Selection ◽  
Outer Hebrides ◽  
Field Mice ◽  
Pygmy Shrew

SynopsisThe Outer Hebridean fauna is almost entirely the result of the chance characteristics of opportunist colonizers modified by subsequent adaptation and sometimes later immigrants. A few primitive relicts may persist (e.g. possibly, the moth Nyssia zonarid), but the fauna is certainly not largely composed of early post-glacial invaders. These, traditional theory argues, are likely to have been eliminated on the mainland by later arrivals but to have been able to persist on the islands by the timely breaking of hypothetical land-bridges.The influence of the original island colonizers is discernible through the persistence of similar traits in both ancestral and descendant populations despite massive genetical differences produced by stochastic sampling, and often by an apparently random pattern of differentiation between islands (e.g. field mice, cats, men, wrens). Adaptation is difficult to detect in the presence of unmeasurable founder effects, but is shown by large-scale clines (such as bridling in guillemots or colour phase frequencies in arctic skuas), by the existence of similar local races in different species (notably by melanism in Lepidoptera, especially Triphaena comes; but also possibly in bumble-bees and dragonflies), and by evidence of local selection (e.g. Cochlicella acuta).In the light of these many pressures, simple equilibrium theories of island biogeography are woefully inadequate; every species has to be considered on its merits. This can be done for terrestrial vertebrates, and virtually all but the Pygmy Shrew prove to have been introduced by man.

Geology of the Hebridean margin of the Rockall Trough

1986 ◽  
Vol 88 ◽  
pp. 27-51 ◽  
Author(s):  
E. J. W. Jones ◽  
R. G. Perry ◽  
J. L. Wild
Keyword(s):  
Large Scale ◽  
Sediment Accumulation ◽  
Geological Structure ◽  
Volcanic Material ◽  
Surface Ship ◽  
Rockall Trough ◽  
Outer Hebrides ◽  
Basic Volcanic ◽  
Cenozoic Sediments ◽  
Early Cenozoic

SynopsisThe geological structure and history of the Rockall Trough margin to the west of the Outer Hebrides (57°N-59°N) has been inferred from the analysis of bottom samples, seismic, sonar, magnetic, satellite altimeter and surface-ship gravity observations. Much of the continental shelf consists of a shallow platform of Precambrian Lewisian basement, covered by a thin (<300m) blanket of Cenozoic sediments. Apart from areas near the shelf break and immediately west of Lewis, the basement has not undergone the large-scale subsidence typical of many regions adjacent to the Rockall Trough. Beneath the outer shelf, the Lewisian dips steeply towards the deeper water and is covered by a westwardthickening succession (>3km) of Mesozoic and Cenozoic sediments.The eastern margin of the Rockall Trough appears to have been well established as a site of deposition by the end of the Triassic. Further subsidence occurred during the late Jurassic and continued into the Cretaceous when the axial province of the Rockall Trough off the Hebrides was invaded by basic volcanic material. Subsequently, the region was profoundly affected by early Cenozoic igneous activity. The long-term buoyancy of the Lewisian basement under the Outer Hebridean platform and early-formed structural discontinuities within it have influenced the overall pattern of sediment accumulation and the distribution of volcanic activity along the margin. During the later stages of deposition, sedimentation was closely controlled by the presence of early Cenozoic volcanics, by bottom currents and by glacial processes.

The vegetation of the Outer Hebrides

1979 ◽  
Vol 77 ◽  
pp. 219-265 ◽  
Author(s):  
Andrew Currie
Keyword(s):  
Large Scale ◽  
Oil Industry ◽  
Published Data ◽  
Agricultural Practice ◽  
Critical Factors ◽  
Outer Hebrides ◽  
Geographical Elements ◽  
Sand And Gravel ◽  
Southern Species ◽  
Phytosociological Study

SynopsisThe paper reviews four topics in relation to the vegetation of the Outer Hebrides: (a)history and flora, (b) environment and habitat, (c) geographical relationship, and (d) conservation. The preliminary flora edited by J. W. Heslop Harrison in 1941 remains the best published list, and there is need for a modern flora. A provisional checklist is presented, based upon recently published data, especially the Atlas of the Bristish Flora (Perring and Walters 1962) and the Critical Supplement (Perring 1968) Miss M. S. Campbell has been responsible for a great deal of recent recording. Geology and climate are critical factors, and soils are mainly peat, except in the extensive machair areas. Significant habitals are coastland, wetland, peatland, moorland and upland. woodland is scarce, though there are good amenity woodlands. Each habitat is reviewed in relation to the floristic lists in the Nature Conservation Review (Ratcliffe 1977b). There has been no phytosociological study of the vegetation overall, though particular localities such as St Kilda have been described. The geographical elements are listed, and related to those of Skye, Shetland and Faeroe. The flora is more restricted than that of the mainland. Important categories recognized are (a) species of localized distribution, (b) southern species reaching their northern limits and (c) ‘Atlantic’ species. The origin of the flora is discussed, and it is concluded that the facts have not yet been clearly demonstrated. Eight potential threats are identified as fire, changing agricultural practice including drainage, large-scale peat, sand and gravel extraction, the oil industry, wave-energy generation and tourism.

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

Some applications of electron beam microanalysis techniques in VLSI process evaluation

1983 ◽  
Vol 41 ◽  
pp. 160-161
Author(s):  
Simon Thomas
Keyword(s):  
Integrated Circuits ◽  
Process Evaluation ◽  
Large Scale ◽  
Technology Development ◽  
Analytical Techniques ◽  
Successful Implementation ◽  
Analysis Of Failures ◽  
Characterization Of Materials ◽  
Circuits Vlsi

Trends in the technology development of very large scale integrated circuits (VLSI) have been in the direction of higher density of components with smaller dimensions. The scaling down of device dimensions has been not only laterally but also in depth. Such efforts in miniaturization bring with them new developments in materials and processing. Successful implementation of these efforts is, to a large extent, dependent on the proper understanding of the material properties, process technologies and reliability issues, through adequate analytical studies. The analytical instrumentation technology has, fortunately, kept pace with the basic requirements of devices with lateral dimensions in the micron/ submicron range and depths of the order of nonometers. Often, newer analytical techniques have emerged or the more conventional techniques have been adapted to meet the more stringent requirements. As such, a variety of analytical techniques are available today to aid an analyst in the efforts of VLSI process evaluation. Generally such analytical efforts are divided into the characterization of materials, evaluation of processing steps and the analysis of failures.

Electron microscopy study of reactively sputter-deposited Ti/N films on silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1362-1363
Author(s):  
V. C. Kannan ◽  
A. K. Singh ◽  
R. B. Irwin ◽  
S. Chittipeddi ◽  
F. D. Nkansah ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Large Scale ◽  
Hexagonal Phase ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Process Conditions ◽  
Tin Films ◽  
Wide Range ◽  
Fcc Phase ◽  
Circuits Vlsi

Titanium nitride (TiN) films have historically been used as diffusion barrier between silicon and aluminum, as an adhesion layer for tungsten deposition and as an interconnect material etc. Recently, the role of TiN films as contact barriers in very large scale silicon integrated circuits (VLSI) has been extensively studied. TiN films have resistivities on the order of 20μ Ω-cm which is much lower than that of titanium (nearly 66μ Ω-cm). Deposited TiN films show resistivities which vary from 20 to 100μ Ω-cm depending upon the type of deposition and process conditions. TiNx is known to have a NaCl type crystal structure for a wide range of compositions. Change in color from metallic luster to gold reflects the stabilization of the TiNx (FCC) phase over the close packed Ti(N) hexagonal phase. It was found that TiN (1:1) ideal composition with the FCC (NaCl-type) structure gives the best electrical property.

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