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Vertical control
Published in W. Schofield, M. Breach, Engineering Surveying, 2007
The vertical height of a point above or below a reference datum is referred to as the reduced level or simply the level of a point. Reduced levels are used in practically all aspects of construction: to produce ground contours on a plan; to enable the optimum design of road, railway or canal gradients; to facilitate ground modelling for accurate volumetric calculations. Indeed, there is scarcely any aspect of construction that is not dependent on the relative levels of ground points.
Validation of Unresolved Neutron Resonance Parameters Using a Thick-Sample Transmission Measurement
Published in Nuclear Science and Engineering, 2020
Jesse M. Brown, R. C. Block, A. Youmans, H. Choun, A. Ney, E. Blain, D. P. Barry, M. J. Rapp, Y. Danon
Here, it can be seen that the resulting calculation reduces the discrepancies found in the energy range 2 to 25 keV. This is partly due to the reduced level spacing used in the URR. The RPI modification reduced the level spacing to that found in Atlas of Neutron Resonances by Mughabhgab, resulting in less resonance fluctuation in the URR. This reduction in predicted resonance fluctuation results in a reduced transmission in the RPI modification compared to JEFF-3.3. The structured nature of the cross section, however, still remains unaccounted for. It should be noted that the McDermott et al. evaluated parameters come from fitting the experimental capture cross section and the theoretical JEFF-3.2 total cross section, biasing the evaluation to JEFF-3.2. This can be improved by making URR transmission measurements and including them in the fit; this is important for predicting an accurate cross section for 181Ta in the URR.
Machine learning of geological details from borehole logs for development of high-resolution subsurface geological cross-section and geotechnical analysis
Published in Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 2022
It is common in engineering practice to discard stratigraphic details and simplify the stratigraphy based on local comparable experience or expert knowledge (Beer et al. 2013; Bogusz and Godlewski 2019). In Hong Kong, a typical weathering profile in granite has a reduced level of degree of decomposition with a reduced elevation. Based on this principle, the alternated CDG, HDG and MDG in the middle part of borehole log B are often simplified as HDG, as shown in Figure 1(a). Similarly, the geology of borehole log A is simplified as stratigraphic successions of RS, CDG, HDG, MDG, SDG and fresh rock. Afterwards, a subsurface geological cross-section can be developed using straight lines to connect the stratigraphic boundaries that separate different soil types along the simplified log A and log B. Even with the simplification described above, difficulty might still exist and lead to significant stratigraphic uncertainty. As shown by the question marks in Figure 1(b), the stratum boundaries for HDG cannot be determined accurately as HDG is not available in the simplified log A. Note that a less reliable geological cross-section has a risk of error propagation to subsequent geotechnical analysis and design and can possibly lead to a false interpretation of engineering performance, such as slope stability. Therefore, it is of great importance to develop a method for automatic generation of high-resolution subsurface geological cross-sections with the proper incorporation of all the geological details, which have been observed from available borehole logs but often discarded in the current engineering practice of manually interpreting subsurface stratigraphy with a low spatial resolution.
Water shortage risk mapping: a GIS-MCDA approach for a medium-sized city in the Brazilian semi-arid region
Published in Urban Water Journal, 2020
Maria José de Sousa Cordão, Iana Alexandra Alves Rufino, Priscila Barros Ramalho Alves, Mauro Normando Macêdo Barros Filho
The results show that 36.4% of residential users located in areas with high and very high risk. Notably, a relevant number, as it suggests a reduced level of public water services and poor urban water security (Figure 10(b)). Industrial consumers are the ones with less susceptibility to WSR. Most of the industries in Campina Grande are in areas with favourable hydraulic criteria. Then it is a useful application of WSR mapping for residential areas. The criteria are slightly away from the industrial reality in the study case. Census data predominantly used households, population, and income variables.