bluuebunny/crossref_metadata_2025_split huggingface dataset:
Escherichia coli
Physiology in Luria-Bertani Broth
Authors: Sezonov Guennadi , Joseleau-Petit Danièle , D'Ari Richard 
Published: September 2007

ABSTRACT

Luria-Bertani broth supports
Escherichia coli
growth to an optical density at 600 nm (OD
600
) of 7. Surprisingly, however, steady-state growth ceases at an OD
600
of 0.3, when the growth rate slows down and cell mass decreases. Growth stops for lack of a utilizable carbon source. The carbon sources for
E. coli
in Luria-Bertani broth are catabolizable amino acids, not sugars.
A marine foundation problem in the Arabian Gulf
Authors: Broadhead A. 
Published: September 2007

Summary
The paper describes a foundation problem associated with a tanker berth at Das Island in the Arabian Gulf. The tanker berth, to accommodate 200 000 ton tankers, was constructed in 1967 using high tensile steel tubes drilled into the sea bed to form mooring and berthing dolphins. A jack-up platform was used for the installation of these cylinders and this platform subsequently became part of the permanent installation as the central island. Site investigation borings were sunk at the locations of each dolphin and calculations of the lateral resistance of the dolphin cylinders were made. The location where the lowest lateral resistance was indicated was chosen for a full scale site pulling test. The results of this test are described in the paper together with the methods used for the installation of the mooring and berthing dolphin cylinders.
Geotechnical aspects of shallow sewer tunnels in urban areas
Authors: Newbery John , Davenport Colin Anthony 
Published: September 2007

Summary
Geology is an important determinant affecting the construction of tunnels. This paper gives the principal characteristics of three shallow sewer tunnels constructed with segmental and flexible linings in Kent and Worcestershire, England, where their location in urban areas adds additional geotechnical constraints to those generally encountered.
Methods of construction and rates of progress are shown to be controlled by lithology, structure, ground-water, recent human activity such as mining, quarrying and waste disposal, and the response of residents to blasting techniques.
These experiences show that even such exotic problems as those arising when tunnelling at shallow depth beneath refuse tips should be anticipated by careful investigation and that conflicting interests of residents and tunnellers should be resolved by sympathetic negotiation.
A geophysical investigation of saline water in the chalk of the South Coast of England
Authors: Monkhouse R. A. , Fleet M. 
Published: September 2007

Summary
The Chalk on the South Coast of England between the rivers Adur and Ouse is in hydraulic continuity with the sea. Certain pumping stations up to 3.5 km from the shoreline have shown in the past abnormal chloride ion concentrations which have been considered to be due to seawater intrusion into the aquifer. Geophysical logging of boreholes especially drilled for the purpose close to the shoreline has confirmed the presence of saline water at various horizons, and has also shown diurnal variations in salinity due to the tide and seasonal variations related to infiltration and groundwater abstraction rates.
Case histories of some effects of solution/dissolution in the Keuper rocks of the Severn Estuary region
Authors: Hawkins A. B. 
Published: September 2007

Summary
The Keuper strata in the Severn Estuary region can be divided into two fades, a scree/rock fan deposit known as the Dolomitic Conglomerate and a basin facies referred to as the Keuper Marl. Both facies contain gypsum or evidence indicating that gypsum was once present. As a result of diagenetic changes, such as the release of strontium when aragonite changes to calcite, and also calcite to dolomite, in some areas the initial gypsum, anhydrite accumulation has been replaced by celestine.
Recent construction works have indicated that in parts of the area cavities occur in the Keuper rocks. Some of these cavities have caused engineering problems. Those near the top of the Keuper Marl in the Airport Road tunnel caused machine stress due to the Dosco boom attempting to deflect to the areas of nil resistance. In addition, there was some overbreak and increased grout take.
Data obtained on samples from Llandough Quarry, Cardiff are presented to support the hypothesis that where dolomitic strata combine with gypsum, dedolomitization may occur resulting in degraded, very weak mudstone. Pronounced dolomitised ‘veins’ occur in one area of the quarry; these are described and X-ray diffraction traces are presented to support dolomitization from a joint outwards.
Soil pipes and slope stability
Authors: Pierson T. C. 
Published: September 2007

Summary
Experimentation with a Hele-Shaw viscous-flow analogue apparatus has supported earlier suggestions, based on field evidence, that a causal link may exist between some soil pipes and slope failure. The analogue has shown that when a pipe is blocked or is a dead-end passageway (a closed pipe), the cavity can readily fill with water during rainstorms. Pipes partially filled with standing water will generate pore pressures in the surrounding soil matrix in proportion to the hydrostatic head achieved. Long pipes parallel to the fall line of the slope have the potential, when partially filled with water, of generating soil pore-water pressures much greater than those generated by total saturation of the soil. Such pore-pressure increases could trigger landslides at sites that would otherwise be stable.
Controls of size and shape of natural armourstone
Authors: Dibb T. E. , Hughes D. W. , Poole A. B. 
Published: September 2007

Summary

The sizes and shapes of armourstone blocks for rubble breakwaters are primarily determined at the quarryface, and later modification then occurs
in situ
in the breakwater environment. The principal controlling parameters in the quarry include: rock type, rock joint frequency and orientation, size and type of blasting charge and the orientation of the blast's fractionating power.

The majority of existing data on this subject has been obtained from detailed studies of quarries principally concerned with aggregate production in Britain, but extensive studies have recently been carried out on a variety of rock types in quarries that are currently producing primary armourstone for breakwater structures in the United Arab Emirates and the United Kingdom. These studies combine to permit the relative importance of the various controlling factors which operate during quarrying, transport, placement and subsequently in service to be evaluated and are reported here.

The quarry-orientated study is supplemented by detailed studies of block modification and deterioration in the several different environmental zones of breakwater structures. The principal factors controlling this shape modification are micro-fracture pattern, mineralogy and fabric, grade of weathering of the original rock, grain interlock and intergranular cement type. Changes in shape will modify the stability factors of
in situ
armour blocks and alter void ratios and slope angles, which together are perhaps the most important factors controlling the dissipation of wave energies on rubble mound breakwaters.

The importance of long-term abrasion effects should not be underestimated; to monitor these effects, damage assessments have been used to relate the shape modification to slope.
A55 Pwll Melyn Slip and remedial works: a case history
Authors: Siva Subramaniam A. , Carr R. W. 
Published: September 2007

Summary
In October 1976 a 7-year old road embankment, constructed on side-long ground across a stream valley to eliminate a bend, failed after a period of exceptionally heavy rainfall. Site investigation identified slip surfaces at the weathered and softened top of the mudstone bedrock. Fluvioglacial deposits encountered beneath and up-slope of the embankment were considered the main source of the high pore-water pressures responsible for failure. The remedial measures adopted included drainage provision to prevent the future build-up of pore-water pressures beneath the reconstructed embankment. The original road, carrying the diverted traffic since the time of the slip, was supported by a temporary, rock-anchored, sheet-pile retaining wall during the excavation of slip debris and weathered bedrock.
The events leading up to the slip, the subsequent site investigations and resulting design are described, together with the construction of the remedial measures.
Microprocessors and microcomputers: a review and implications for engineering geologists
Authors: Hill John J. , Young R. Paul 
Published: September 2007

Summary
The low cost of microprocessor and microcomputer technology is such that microcomputers are finding wide application in many of the geological sciences and engineering. This paper, therefore, is aimed at providing an introduction to, and brief review of, the microcomputer field. The basic terms in use are explained and the main microprocessor chips and microcomputer systems surveyed. The distinction is made between systems which use embedded microprocessors and systems which provide enhanced capabilities by software development and interfacing to a personal microcomputer. A number of applications of microcomputers in engineering geology and engineering geophysics are used to illustrate the impact and scope of the new technology.
An example of tomographic and Fourier microcomputer processing of seismic records
Authors: New B. M. 
Published: September 2007

Summary
A technique for processing seismic data has been developed that provides a ‘representative velocity’ tomogram which may be interpreted in terms of the engineering properties of the subject rock mass. This transmission system is intended for use in cross-borehole surveys and has been successfully tested between sub-parallel mine roadways in a massive granite body.
The velocities of compressional waves between numerous source and transducer locations are analysed, and the interactive character of the observations is used to build a two-dimensional array of computed ‘representative velocities’ appropriate to specific areas within the intervening rock mass. Evaluation of the processed data is undertaken using site-specific and more general rock mass classification systems. The processing is carried out on a CBM Pet microcomputer and the program is readily adaptable to most field configurations. The program also allows various mapping and influence parameters to be varied and optimized to obtain the best resolution of rock mass inhomogeneities.
Fast Fourier transform routines for the calculation of the energy spectral density (and other frequency domain functions) of ground vibrations are also briefly discussed.
Microcomputer based seismic instrumentation systems
Authors: Young R. P. , Hill J. J. , Green A. D. , Haigh R. N. , Middleton R. 
Published: September 2007

Summary
Developments in microprocessor technology are having considerable influence on the way engineering seismic data is collected, processed and analysed. Case studies of two seismic instrumentation systems and their applications are described.
A microcomputer enhanced engineering seismograph, Geoseis-Merlin, has been developed as a portable repackaged Apple unit with a 5 inch monitor, internal printer, bubble memory and disk drive to give on-site processing and results. The unit includes a multi-channel, 12 bit analogue to digital converter card with programmable gain amplifiers, and the system is designed to operate in the field as a self-contained, six channel, seismic processing system. Menu-driven software operations include: data capture incorporating a pre-trigger memory facility for blast monitoring, concatenation and editing of files, display of seismic time data, seismic refraction analysis of up to 24 channels, power spectral computation, display of power and attenuation spectra, spectral smoothing, and digital filtering of waveforms. The system can also be used as an interface to existing seismographs or to the radio telemetric seismic monitoring system.
A 24 channel, radio telemetric, seismic monitoring system has been developed, consisting of six portable outstations which can be positioned up to 2 km from a base station located in a Land Rover or site office. Each microcomputer controlled outstation has one air overpressure and three ground vibration channels for recording up to 16 sec of pre-and post-trigger data. Communication between each outstation recorder and base is via a UHF duplex telemetry link which is used to activate and program each outstation, to maintain synchronization and to transfer data from each recorder to the microcomputer controlled base station. Here the captured seismic event can be stored on cassette, displayed on a 5 inch monitor, or transferred to an Apple II microcomputer (Geoseis-Merlin) for processing.
The case studies outline the application of these systems in engineering geology to bedrock depth determination, rock mass characterization, and the monitoring of quarry blasting.
Magmatism during and after continental break-up
Authors: White R. S. 
Published: September 2007

Abstract
Magmatism accompanying continental break-up is caused primarily by decompression melting of the underlying mantle as it wells up beneath the rift. The amount of melt produced depends mainly on the temperature of the asthenospheric mantle and on the rate of rifting. Break-up above normal mantle generates only small amounts of melt, reaching a maximum of 7 km in fully oceanic crust. If extension lasts for 10 Ma or more, as on many such ‘non-volcanic’ continental margins, then still less melt is generated because the slowly upwelling mantle cools by conductive heat loss.
Break-up above abnormally hot mantle surrounding mantle plumes generates much larger melt volumes and ‘volcanic’ continental margins. The largest melt volumes occur when rifting is above a newly initiated mantle plume, with its transient high excess temperatures and flow rates. This creates flood basalt provinces. The resultant basalt may flow distances of over 1000 km, both as surface flows and as dykes and sills intruded laterally in the crust. Only about one-quarter of the melt reaches the surface, the remainder underplating or intruding the lower crust. The excess gravitational potential provided by mantle plumes assists rifting, though plumes do not always cause continental break-up.
The lower lithosphere as a major source for continental flood basalts: a re-appraisal
Authors: Menzies Martin A. 
Published: September 2007

Abstract

Continental flood basalt provinces (cfb) have isotopic ratios different from midocean ridge basalts, characteristics that may be due to (a) interaction of asthenospheric melts with old crust, (b) melting of enriched continental lower lithosphere, (c) upwelling of deep mantle plumes containing recycled components, (d) mixing of enriched and depleted mantle sources, or (e) combinations of these processes. It is apparent that several aspects of the chemistry of cfb are subcrustal in origin and therefore crustal contamination cannot be invoked as a generally applicable hypothesis. In addition wholesale extraction of cfb from the lower lithosphere is unlikely because the lithospheric mantle is believed to be a rather thin (< 150 km) reservoir of cold, anhydrous, granular peridotite. Dry melting of such peridotites would not produce a normal ‘basalt’ because they have already experienced a melting event. Metasomatism or enrichment processes can enhance the chemical budget of the lower lithosphere thus providing an adequate reservoir for small volume alkaline and potassic melts. However no conclusive evidence exists that such modification of the lower lithosphere is widespread enough to generate a laterally continuous, wet, enriched reservoir. It would appear that cfb require a dominant sub-lithospheric component (plume) to account for the large volumes of magma, in some cases produced over a short time period (e.g. Deccan). If so, the heterogeneity observed in mantle-derived magmas within flood basalt provinces reflects inhomogeneities within plumes rather than relatively shallow inhomogeneities in the lithosphere. The apparent concentration of depleted (
87
Sr/
86
Sr ≪ 0.7045) cfb in the northern hemisphere and enriched cfb (
87
Sr/
86
Sr ≫ 0.7045) in the southern hemisphere may be linked to the preponderance of enriched plumes in the Southern Oceans.
Consequences of plume-lithosphere interactions
Authors: Saunders A. D. , Storey M. , Kent R. W. , Norry M. J. 
Published: September 2007

Abstract
Splitting or thinning of lithosphere above a mantle plume can result in voluminous melt generation, leading to the formation of large igneous provinces, or LIPs. Examples of LIPs include continental flood basalt provinces and oceanic plateaus. Basaltic samples from the Ontong Java Plateau, Nauru Basin and Manihiki Plateau, which are among the largest of the LIPs, have isotopic compositions within the range of ocean island basalts. The majority of continental basalts, however, record a trace element and isotopic contribution from the lithosphere through which they have erupted. We are thus unable to reconcile the available compositional data with models which derive the isotopic and large-ion lithophile element-enriched character of continental flood basalts solely from sub-lithospheric mantle plume sources. A combination of mantle sources is indicated, with the thermal energy being supplied by voluminous melts from a plume, and the lithospheric components in continental flood basalts being inherited by contamination of plume-derived melts by low melting point hydrous and carbonated fractions in the lithosphere. Successive injection of plume-derived melts serves to heat the lithosphere, reducing its viscosity and making it susceptible to rupture if allowed by regional plate forces. Furthermore, the lithosphere, including the mechanical boundary layer, may be thinned by thermal stripping from below, allowing the plume mantle to ascend and decompress further. Such a system has the potential for positive feedback leading to rapid melt generation. While we do not exclude recent models of LIP formation which require the sudden impact of a new mantle plume, we favour a model whereby the thermal anomaly builds gradually, incubating beneath a steady-state lithospheric cap.
Asthenosphere-derived magmatism in the Rio Grande rift, western USA: implications for continental break-up
Authors: Gibson S. A. , Thompson R. N. , Leat P. T. , Dickin A. P. , Morrison M. A. , Hendry G. L. , Mitchell J. G. 
Published: September 2007

Abstract
Magmas that are generated at continental rift zones provide an insight into the processes operating during the early stages of continental break-up. Our detailed study of mafic volcanism along the axis of the Rio Grande rift shows that, throughout both phases (30–17 and < 13 Ma) of its evolution, magmas with compositions interpreted as melts from the asthenospheric mantle have reached the surface. This recognition of early phase (26 Ma) magmas with incompatible trace element concentrations and radiogenic isotope ratios resembling those normally associated with ocean-island basalts and small seamounts (OIB) is significant because: (1) magmas dominated by the composition of asthenosphere-derived melts are not usually thought to be characteristic of early-phase continental rifting; (2) Tertiary mafic magmatism of an age greater than late Miocene in Colorado and New Mexico was hitherto regarded as subduction-related.
Previous studies have shown that the final erupted composition of asthenosphere-derived melts is determined by the potential temperature of the convecting mantle, the amount and rate of lithosphere extension, fractional crystallization and crustal contamination. However, in the Rio Grande rift and elsewhere, such as the Basin and Range province, Eifel, NW Sardinia and the Cameroon Line, the final composition of these melts is also significantly influenced by earlier magmatic episodes. During the initial stages of asthenosphere melt generation the magma batches that first penetrate may heat a previously undisturbed segment of lithosphere and mix with strongly potassic, low temperature melt fractions. When these segments have been subsequently temporarily purged of such fusible potassic fractions the asthenosphere-derived melts can rise unimpeded through the sub-continental lithosphere.
Role of subduction-plate boundary forces during the initial stages of Gondwana break-up: evidence from the proto-Pacific margin of Antarctica
Authors: Storey B. C. , Alabaster T. , Hole M. J. , Pankhurst R. J. , Wever H. E. 
Published: September 2007

Abstract

In the West Antarctic sector of Gondwana, early stages of break-up are associated with the large Antarctic-Karoo-Tasman basalt province. Formation of this
within-plate
province was synchronous with active margin tectonics and development of both a proto-Pacific margin magmatic suite along the Antarctic Peninsula and the extensive Tobífera volcanic suite associated with the Rocas Verdes marginal basin system of southern South America and South Georgia.

Extension, concurrent with subduction and oceanward migration of the magmatic focus, resulted in a broad extensional province in a back-arc and intra-arc-setting. High geothermal gradients and basalt underplating caused crustal melting on the east coast of the Antarctic Peninsula and formation of bimodal basalt-rhyolite suites. Large-ion lithophile element enriched initial rifting magmas were succeeded, at least in part of the Rocas Verdes basin, by early drift magmas of transitional chemistry and then by entirely asthenospheric MORB magmas representing lithospheric rupture and sea-floor spreading.
A plate interaction model is proposed for the initial stages of Gondwana break-up relating the broad zone of mantle melting to a reduction in subduction-plate boundary forces. The change from Gondwanide compression to lithospheric extension in the Jurassic may be linked to a change from shallow to steeply dipping subduction, and to a slowing of subduction rates caused by a change in plate boundary zone parameters. A possible reduction of compressive boundary stresses may have enabled unconfined, overthickened Permo-Triassic crust to extend because of gravitational instability, thus facilitating break-up. We suggest that break-up was not plume-related, but was due to variations in the regional stress field associated with changing plate-boundary forces. The continental crust was placed under tension with substantial lithospheric thinning and decompression melting of an enriched mantle source forming the broad linear zone of within-plate magmatism. The presence of a plume beneath the Karoo province may have thermally weakened the lithosphere and induced local rifting, contributing to, but not causing the eventual separation of East and West Gondwana.