Preface     

Joanne E. Norris  Erik Cammeraat  Alexia Stokes  Ioannis Spanos 《Geotechnical and Geological Engineering》2006,24(3):427-428

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OBC signal fidelity     

Michael W. Norris  Marvin L. Johnson  Mat Walsh 《Geophysical Prospecting》2006,54(6):793-815

A suite of three tests was performed to characterize the signal fidelity of OBC 4C acquisition systems. The test methodology was to evaluate individual sensor stations by acquiring source lines that were parallel to the in‐line and cross‐line horizontal sensors and source lines that were at 45° to the in‐line and cross‐line sensors. This technique provides constant azimuth gathers with a uniform offset range and removes issues associated with source array directivity. Characterization of the test data identified the frequency content of the geophone signals and the correlation between the vertical and cross‐line geophones as the most sensitive indicators of signal infidelity. In the former case, stations with questionable signal fidelity exhibited a very reverberatory signal. This signal was most evident on the cross‐line sensor. In the latter case, when normalized cross‐correlation coefficients are computed in a moving window, the cross‐line sensor and the vertical sensor are highly correlated, beginning several hundred milliseconds after the first arrivals. These characteristics can be exploited to allow stations with questionable signal fidelity to be programmatically identified. One means of identifying questionable stations is to compute the histogram of the instantaneous frequency. The frequency distributions from questionable stations are unambiguously distinguishable from stations that exhibit better signal fidelity. It was noted that signal fidelity appeared as a range, between acceptable and poor. To characterize the signal fidelity of an acquisition system adequately, the number of test samples must be statistically significant.  相似文献   

Cainozoic history of southern New Zealand: An accord between geological observations and plate-tectonic predictions     

R.M. Carter  R.J. Norris 《Earth and Planetary Science Letters》1976,31(1):85-94

Sea-floor spreading data from the Southwest Pacific have recently been used to predict the Cainozoic geological history along the Indo-Australian/Pacific plate boundary. Geologic and sedimentologic data pertaining to this plate boundary where it crosses southern New Zealand, as the Alpine Fault, are summarised and discussed. It is concluded that there is a close accord between the plate-tectonic predictions and South Island Cainozoic geological history. In particular, (1) no Cainozoic plate boundary traversed the New Zealand region prior to 38 m.y. B.P. (late Eocene); (2) transcurrent movement on the Alpine Fault took place largely between ca. 30 m.y. B.P. (middle Oligocene) and ca. 10 m.y. B.P. (late Miocene); and (3) the period 10 m.y. B.P. to present corresponds to a phase of oblique compression, continental collision, and mountain building along the Alpine Fault sector of the plate boundary. There is a close correlation between the sites and histories of Cainozoic sedimentation and this tectonic timetable.  相似文献   

Expert Testimony for the Plaintiffs in the Case that Brought Ohio Ground-Water Law into the 20th Century     

E. Scott Bair  Stanley E. Norris 《Ground water》1990,28(5):767-774

Abstract. The 1984 Ohio Supreme Court ruling on Cline v. American Aggregates changed Ohio's ground-water law from an 1861 ruling based on the English Rule of absolute ownership to a doctrine of reasonable use which recognizes that landowners have the privilege to use the water beneath their land but can be held liable to others if their use of ground water causes others unreasonable harm. The Ohio Supreme Court did not define unreasonable harm in the Cline case. As a result, unreasonable harm is being established through case law, the first such case being the relitigation of Cline v. American Aggregates.
Depositions and expert testimony presented during the Cline cases, which represent a group of 56 landowners in a single lawsuit, showed the diverse ways in which the quantity and quality of ground water used for domestic-water supplies were affected by operation of a dewatering system at an aggregate mine. The testimony highlighted the complex interaction between regional hydrodynamics, variations in local hydrogeologic settings, well-construction methods, spatial variations in infiltration and recharge, and vertical leakage with the effects of the regional decline in water levels produced by the dewatering system.  相似文献   

Observations on the algal genus Basicladia and the red-bellied turtle,Chrysemys rubriventris     

Carl H. Ernst  James N. Norris 《Estuaries and Coasts》1978,1(1):54-57

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Kinetic model of ammonia synthesis in the solar nebula     

Thomas L. Norris 《Earth and Planetary Science Letters》1980,47(1):43-50

The synthesis of ammonia in the primitive solar nebula was probably catalyzed by metallic iron grains because the gas phase reaction is kinetically inhibited. A preliminary kinetic model predicts a maximum of 3% of the nitrogen in the form of ammonia at the time of planetary accretion. Rates of reaction were derived from industrial data on ammonia iron catalysts. Due to the low rates of reaction, molecular nitrogen remains the dominant species even at the low temperatures where chemical equilibrium favors ammonia formation. Thus planetary atmospheres formed from a reservoir composed largely of molecular nitrogen. The non-equilibrium volatile gases (CO and N₂) suggested to comprise most of the carbon and nitrogen in comets is consistent with the model.  相似文献   

Development of slaty cleavage in a mudstone unit from the Cantabrian Mountains, northern Spain     

R.J. Norris  N.A. Rupke 《Journal of Structural Geology》1986,8(8)

A 200 m thick mudstone unit in the Carboniferous of the Cantabrian Mountains, northern Spain, exhibits an increase in intensity of the slaty cleavage from top to bottom which appears to be correlated with a decrease in the mean grain size, average bed thickness and quartz: mica ratio. Anastomosing cleavage domains, formed by pressure solution and by kinking and rotation of the detrital micas, become closer spaced, wider and more continuous towards the finer-grained base of the unit. Growth of strongly oriented new micas within the cleavage domains also appears to be correlated with the intensity of the domain development and hence with the initial lithology. Clay minerals have been completely replaced throughout the mudstone by muscovite, paragonite and pyrophyllite during low-grade metamorphism. The growth of an oriented mica fabric, however, is restricted to samples with well-developed cleavage domains.  相似文献   

Non-destructive damage evaluation of a structure from limited modal parameters     

Klaus Gregor Topole  Norris Stubbs 《地震工程与结构动力学》1995,24(11):1427-1436

A method to predict structural damage in its location and severity from modal characteristics of the damaged structure is proposed. No a priori knowledge of the modal characteristics of a corresponding baseline structure is required in the proposed formulation. Instead, information on the geometry of the structure which is reflected in its mass and stiffness distribution is needed. From matrix structural analysis, a system of equations is generated which relates the relative change of stiffness of structural members to a load vector generated from modal parameters of the damaged structure. Different solution techniques are suggested to determine the damage from the generated equations. The feasibility of the proposed formulation is demonstrated via a numerical example of a 10-storey building. Further, an error investigation on the error in the damage predictions due to uncertainties in the input data is carried out.  相似文献   

Compact radio emission in 60-μm peaker galaxies     

Charlene A. Heisler  Ray P. Norris  David L. Jauncey  John E. Reynolds  & Edward A. King 《Monthly notices of the Royal Astronomical Society》1998,300(4):1111-1118

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Fate and transport of volatile organic compounds in glacial till and groundwater at an industrial site in Northern Ireland     

D.?H.?PhillipsEmail author  A.?O.?Thomas  K.?Forde  K.?Dickson  S.?Plant  G.?Norris  B.?Bone  R.?M.?Kalin 《Environmental Geology》2007,52(6):1117-1131

Volatile organic compound (VOC) contamination of subsurface geological material and groundwater was discovered on the Nortel Monkstown industrial site, Belfast, Northern Ireland. The objectives of this study were to (1) investigate the characteristics of the geological material and its influences on contaminated groundwater flow across the site using borehole logs and hydrological evaluations, and (2) identify the contaminants and examine their distribution in the subsurface geological material and groundwater using chemical analysis. This report focuses on the eastern car park (ECP) which was a former storage area associated with trichloroethene (TCE) degreasing operations. This is where the greatest amount of volatile organic compounds (VOCs), particularly TCE, were detected. The study site is on a complex deposit of clayey glacial till with discontinuous coarser grained lenses, mainly silts, sands and gravel, which occur at 0.45–7.82 m below ground level (bgl). The lenses overall form an elongated formation that acts as a small unconfined shallow aquifer. There is a continuous low permeable stiff clayey till layer beneath the lenses that performs as an aquitard to the groundwater. Highest concentrations of VOCs, mainly TCE, in the geological material and groundwater are in these coarser lenses at ∼4.5–7 m bgl. Highest TCE measurements at 390,000 μg L⁻¹ for groundwater and at 39,000 μg kg⁻¹ at 5.7 m for geological material were in borehole GA19 in the coarse lens zone. It is assumed that TCE gained entrance to the subsurface near this borehole where the clayey till was thin to absent above coarse lenses which provided little retardation to the vertical migration of this dense non-aqueous phase liquid (DNAPL) into the groundwater. However, TCE is present in low concentrations in the geological material overlying the coarse lens zone. Additionally, VOCs appear to be associated with poorly drained layers and in peat <3.0 m bgl in the ECP. Some indication of natural attenuation as VOCs degradation products vinyl chloride (VC) and dichloromethane (DCM) also occur on the site.  相似文献