Inversion of potential field data by genetic algorithms     

Fabio Boschetti  Mike Dentith  Ron List 《Geophysical Prospecting》1997,45(3):461-478

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Treatment of Malting Wastewater in a Granular Sludge Sequencing Batch Reactor (SBR)     

Norbert Schwarzenbeck  Ron Erley  Belinda S. Mc Swain  Peter A. Wilderer  Robert L. Irvine 《洁净——土壤、空气、水》2004,32(1):16-24

Aerobic granular sludge was successfully cultivated in a sequencing batch reactor (SBR) treating wastewater from the malting process with a high content of particulate organic matter. At an organic loading rate of 3.2 kg/(m³ d) COD_total and an influent particle concentration of 0.95 g/L MLSS an average removal of 50% in COD_total and 80% in COD_dissolved could be achieved. A comparison of granular and flocculent sludge grown under the same operating conditions showed no significant difference in removal efficiency although granules exhibited a higher metabolic activity in terms of specific oxygen uptake rate (r_{O2, X}). Two distinct mechanisms of particle removal were observed for granular sludge: during initial granule formation, particles were incorporated into the biofilm matrix. For mature granules, a high level of protozoa growth on the granule surface accounted for the ability to remove particulate COD. Combined evaluation of the development in MLSS content and sludge bed settling rate (i.e., mean derivative of the normalized sludge volume) was found to be an adequate method for monitoring the characteristic settling properties of a granulizing sludge bed. By means of this method, a distinct substrate gradient out of several operating conditions was concluded to have the biggest impact on the formation of aerobic granular sludge.  相似文献   

On journal publication and professional responsibilities     

Ron Johnston  Charles Pattie 《Area》2004,36(1):84-85

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Anomalous lithospheric structure of Northern Juan de Fuca plate — a consequence of oceanic rift propagation?     

Alastair F. McClymont  Ron M. Clowes 《Tectonophysics》2005,406(3-4):213-231

Anomalous crustal and upper mantle structure of northern Juan de Fuca plate is revealed from wide-angle seismic and gravity modelling. A 2-D velocity model is produced for refraction line II of the 1980 Vancouver Island Seismic Project (VISP80). The refraction data were recorded on three ocean bottom seismometers (OBSs) deployed at the ends and middle of a 110 km line oriented parallel to the North American continental margin. The velocity model is constructed via ray tracing and conforms to first-arrival amplitude observations and travel time picks of direct, converted and reflected phases. Between sub-sediment depths of 3 to 11 km, depths normally associated with the lower crust and upper oceanic mantle, the final model shows that compressional-wave velocities decrease significantly from southeast to northwest along the profile. At sub-sediment depths of 11 km at the northwestern end of the profile, P-wave velocities are as low as 7.2 km/s. A complementary 2-D gravity model using the geometry of the velocity model and velocity–density relationships characteristic of oceanic crust is produced. The high densities required to match the gravity field indicate the presence of peridotites containing 25–30% serpentine by volume, rather than excess gabbroic crust, within the deep low velocity zone. Anomalous travel time delays and unusual reflection characteristics observed from proximal seismic refraction and reflection experiments suggest a broader zone of partially serpentinized peridotites coincident with the trace of a pseudofault. We propose that partial serpentinization of the upper mantle is a consequence of slow spreading at the tip of a propagating rift.  相似文献   

Estimating irrigation inputs for distributed hydrological modelling: a case study from an irrigated catchment in southeast Australia          下载免费PDF全文

Faith Githui  Thabo Thayalakumaran  Benny Selle 《水文研究》2016,30(12):1824-1835

Adequate irrigation inputs are essential for the application of hydrological models in irrigated catchments, but reliable data on both the amount and the frequency of irrigation applications are often missing at an appropriate spatial scale. In this paper, we demonstrate and test approaches to estimate irrigation inputs for distributed hydrological modelling. In this context, the Soil and Water Assessment Tool was applied to simulate water balances for an irrigated catchment in southeast Australia during the period 2008–2010. Two methods for estimating irrigation inputs were tested. One method was based on a fixed irrigation application rate, whereas the other one had variable irrigation rates depending on season and the irrigated crop. These two approaches were also compared with the ‘auto‐irrigation’ method within the Soil and Water Assessment Tool model. The method with variable irrigation rates resulted in the most reasonable interpretation of the readily available irrigation data, consistent estimates of irrigation runoff coefficients throughout the year and the best fit to observed data on both drain flows at the catchment outlet and spatial evapotranspiration patterns. We also found that the different irrigation inputs significantly affected simulated water balances, in particular deep percolation under relatively dry climatic conditions. All these results suggest that it is possible to infer irrigation inputs from readily available data and local knowledge, adequate for hydrological modelling in irrigated catchments. Our study also demonstrates that, in order to predict reliable water balances in irrigated catchments, an accurate knowledge of irrigation scheduling and irrigation runoff is required. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

The Upper Pliocene Bowden shell beds,southeast Jamaica     

Stephen K. Donovan  Ron K. Pickerill  David G. Keighley 《Geology Today》2014,30(6):232-238

The Neogene fossil record of the Antilles is particularly rich and can satisfy the interests of most collectors, from foraminifers to vertebrates. The molluscs are among the commonest and most diverse groups, being found in both terrestrial and marine deposits. The Pliocene Bowden shell beds of southeast Jamaica, best known for its hundreds of species of molluscs, also yields diverse members of other groups, the total exceeding 800 species from a mere 5 m of stratigraphical section.  相似文献   

North American Earth Science Megaproject Continuum, Part 1: LITHOPROBE (1984-2005)     

Ron M. Clowes 《《地质学报》英文版》2018,92(Z1):27-28

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Coupled finite‐element simulation of injection well testing in unconsolidated oil sands reservoir     

Bin Xu  Ron C.K. Wong 《国际地质力学数值与分析法杂志》2013,37(18):3131-3149

This paper presents a finite‐element (FE) model for simulating injection well testing in unconsolidated oil sands reservoir. In injection well testing, the bottom‐hole pressure (BHP) is monitored during the injection and shut‐in period. The flow characteristics of a reservoir can be determined from transient BHP data using conventional reservoir or well‐testing analysis. However, conventional reservoir or well‐testing analysis does not consider geomechanics coupling effects. This simplified assumption has limitations when applied to unconsolidated (uncemented) oil sands reservoirs because oil sands deform and dilate subjected to pressure variation. In addition, hydraulic fracturing may occur in unconsolidated oil sands when high water injection rate is used. This research is motivated in numerical modeling of injection well testing in unconsolidated oil sands reservoir considering the geomechanics coupling effects including hydraulic fracturing. To simulate the strong anisotropy in mechanical and hydraulic behaviour of unconsolidated oil sands induced by fluid injection in injection well testing, a nonlinear stress‐dependent poro‐elasto‐plastic constitutive model together with a strain‐induced anisotropic permeability model are formulated and implemented into a 3D FE simulator. The 3D FE model is used to history match the BHP response measured from an injection well in an oil sands reservoir. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Borehole Siting in Crystalline Basement Areas of Nigeria with a Microprocessor-Controlled Resistivity Traversing System   总被引：1，自引：0，他引：1  

Abel Olayinka  Ron Barker 《Ground water》1990,28(2):178-183

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Modelling nearshore oil slick trajectories     

Tom Beer  R.B. Humphries  Ron Bouwhuis 《Marine pollution bulletin》1983,14(4):141-144

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