Search results for "Civil Engineering"
showing 10 items of 1216 documents
Uncertainty assessment of sewer sediment erosion modelling
2008
Urban stormwater quality modelling has become a fundamental issue in the evaluation of the receiving water bodies' quality state. Laboratory study as well as field campaigns have widely demonstrated that combined sewer sediments present cohesive-like properties which increase their resistance to erosion. However, only few models take sewer sediments into account considering their rheological properties. In the present paper different sewer sediment erosion models have been tested and their uncertainties have been assessed. The main goal was to discriminate the algorithms with respect to their robustness and the reduction of uncertainty. In order to accomplish such objective the GLUE methodo…
Uncertainty assessment of an integrated urban drainage model
2009
Over the last few years, the use of mathematical models has gained importance in urban drainage system management; indeed, such models enable the combined analysis of different components that constitute a drainage system; the sewer system, wastewater treatment plant and the receiving water body. The effectiveness of an integrated approach has been widely demonstrated in the past and is presented in the EU Water Framework Directive, which also introduces a new point of view regarding the water quality management of the whole system, requiring a global analysis at the river basin scale for pollutant sources. However, integrated urban drainage models introduce several uncertain factors that a…
Assessing the performance of thermal inertia and Hydrus models to estimate surface soil water content
2017
The knowledge of soil water content (SWC) dynamics in the upper soil layer is important for several hydrological processes. Due to the difficulty of assessing the spatial and temporal SWC dynamics in the field, some model-based approaches have been proposed during the last decade. The main objective of this work was to assess the performance of two approaches to estimate SWC in the upper soil layer under field conditions: the physically-based thermal inertia and the Hydrus model. Their validity was firstly assessed under controlled laboratory conditions. Thermal inertia was firstly validated in laboratory conditions using the transient line heat source (TLHS) method. Then, it was applied in…
Carbon Nanotubes Dispersion Assessment in Nanocomposites by Means of a Pulsed Thermographic Approach
2020
The extensive production of polymer composites reinforced by carbon nanotube is limited by the absence of non-destructive evaluation (NDE) methods capable of assessing product quality to guarantee compliance with specifications. It is well known that the level of dispersion of carbon nanotubes (CNTs) in the polymer matrix is the parameter that, much more than others, can influence their enhancement capabilities. Here an active Infrared Thermography Non Destructive Testing(IR-NDT) inspection, joined with pulsed phase thermography (PPT), were applied for the first time to epoxy-CNT composites to evaluate the level of dispersion of the nanoparticles. The PPT approach was tested on three groups…
Modelling of a hydro-pneumatic system for heave compensation
2018
This paper presents a mathematical model of the dynamic behaviour of a passive heave compensation system. The main purpose is to develop a model that enables cost-efficient prototyping and testing of the control system in an active heave compensator. The physics are described by first principles, and result in 21 ordinary differential equations. Temperature calculations are included as an option during simulation in order to investigate its effect on the results. Similarly is a non-ideal gas law (Redlich-Kwong equation) implemented and compared to the ideal gas law. Verification against field data shows that the model is in good accordance with real-life drilling operations. It is further s…
Contactless power transfer application for devices identification
2019
This paper deals with the problem of non-contact power transfer systems to identify components based on infrared signatures reading. This approach enables the distinction of a larger number of different devices situated in a relatively small area, compared to RFID technology. Moreover, the presented infrared contactless identification is resilient to natural environmental infrared perturbations. The advantages of this approach are demonstrated in a simple use-case: continuously identifying low consumption chess pieces on a custom chessboard. This approach can be further instantiated for high consumption devices such as electrically charging small autonomous guided vehicles.
Experimental calibration of flat jacks for in-situ testing of masonry
2018
Flat-jack testing method is one of the most commonly used techniques for the structural assessment of existing masonry structures. Single and double flat jacks are usually adopted to evaluate the acting normal stress, or the compressive behaviour of masonry material. Test procedures are codified by international standards (e.g., A.S.T.M D4729-87; C1196-04; C1197-04, R.I.L.E.M TC 177–MDT D.4; R.I.L.E.M. TC 177–MDT D.5), which provide the preliminary calibration of an experimental coefficient (km) and of the effective area (Aeff), which determination influences significantly the reliability of the test. This article presents the result of an experimental study on the calibration of flat jacks…
Features of selected benchmark soils along an elevational transect of the northeastern part of the Moldavian Plateau (Romania)
2018
Soil morphological, physical and chemical properties are described at four locations along an elevational transect in the northeastern part of the Moldavian Plateau (Romania). These data contribute to the knowledge of the soils of this area and to their classification according to the USDA-Soil Taxonomy, FAO-WRB and the SRTS-Romanian System. The soils were classified as Inceptisols, Alfisols and Mollisols, according to the USDA-Soil Taxonomy; Gleysol, Chernozem and Luvisol, according to the FAO-WRB and Gleiosol, Cernoziom, Preluvosol, Luvosol, according to the SRTS-Romanian System. The selected soils have a range of properties that represent the soilscape of the Moldavian subcarpathian plat…
Space syntax analysis applied to urban street lighting: Relations between spatial properties and lighting levels
2019
According to the international technical standards, higher lighting levels (luminance and illuminance levels) are expected in trafficked and central roads (where restrictive minimum lighting requirements are necessary) and lower lighting levels are expected in peripheral and less trafficked roads. Starting from this assumption, in this paper, the authors analyse the correlations between spatial properties (expressed by spatial indicators, for example, the integration index and the choice index) and lighting levels (expressed by lighting parameters, for example luminance and illuminance) upon roads of an urban context. The analysis has been applied to the case study of the medium sized town …
Empirical Equations for the Direct Definition of Stress–Strain Laws for Fiber-Section-Based Macromodeling of Infilled Frames
2018
Equivalent strut macromodels are largely used to model the influence of infill walls in frame structures due to their simplicity and effectiveness from a computational point of view. Despite these advantages, which are fundamental to carrying out seismic simulation of complex structures, equivalent struts are phenomenological models and therefore have to conventionally account for the influence of really large amounts of geometrical and mechanical variables with a relatively simple inelastic response. Mechanical approaches, generally used to evaluate the force-displacement curve of a strut, are based on hypothesizing the damage mechanism that will occur for an infill-frame system subject to…