2,020 Works

A general algorithm for the development of control algorithms for RTC of sewer systems

M. Sch\303\274tze, J. Alex & M. Ogurek.
Despite the large number of publications on the topic of real time control (RTC) of urban drainage systems, there are, however, only few indications on how a control algorithm for a particular case study is actually determined. Often, this involves an time-consuming and costly heuristic procedure, based on the expertise and intuition of the person carrying out such study. This paper presents a generic procedure for the set up of RTC strategies. Essentially RTC control...

First year experience of CDIO adoption into an IT program

Tien Dinh, Bac Le, Thu Tran & Duc Duong
The paper describes an adoption process of CDIO into the IT program at the Faculty of Information Technology, University of Science, Vietnam National University of Ho Chi Minh city. It has been carried out on 4 related programs at the same time, including Computer Science, Software Engineering, Information System and Computer Networking and Telecommunication. We have built a detailed adoption process for customizing the CDIO syllabus for the school, which can be applied to other...

CO2 storage through mineral trapping in geothermal reservoirs

Michael Kuehn, Katrin Vosbeck, Martin Back, Christoph Clauser, Helge Stanjek, Stefan Peiffer & Michael Kuehn
Costs for carbon dioxide sequestration into deep saline aquifers can be transformed into a benefit when combined with ecologically desirable geothermal heat or power production. The produced energy can be used and marketed. Aim is a scientifically and technically feasible new technology to achieve a safe and economically attractive long-term storage of CO2 trapped in minerals. We develop, study, and evaluate a novel approach not only to sequester CO2 by physical trapping within a reservoir,...

Ensemble KF with Statistical Orthogonality

Dimitri Treebushny & Dimitri Treebushny
Correct propagation of uncertainty is of primary importance for a model when the assimilation of data is to be utilized. The most popular choice is a Monte Carlo approach within the Ensemble Kalman filter framework. In the filter independent realizations of the unofirm random noise should be generated each model time step. Additionally it has to be noted, that stochastic independency is one of the important assumptions in the classical Kalman filter derivation. The paper...

Wind Sensing Doppler LIDAR, Improving Wind Turbines

Anders Sig Olesen, Karsten Rottwitt & Anders Tegtmeier Pedersen
In recent years, the focus on alternative energy has grown and with that the interest in optimizing of known alternative energy sources. It has been shown by Catch The Wind inc. that wind sensing Doppler LIDAR mounted on a wind turbine can be used to optimize the performance of wind turbines up to 10%. This project investigates a novel technique of Doppler LIDAR and its pros and cons. In addition to this, other uses of...

Assessment of CSO loads \342\200\223 based on UV/VIS spectroscopy by means of different regression methods

M. Hochedlinger, H. Kainz & W. Rauch
The use of UV/VIS-spectroscopy for water quality measurements is based on the solution of the correlation between the surrogate parameter absorbance and the resulting equivalence parameters. The coherence of absorbance and equivalence parameters (CODtot, CODsol, TSS) will be solved in this paper with different regression methods. The correlation of absorbance and concentrations are analysed based on linear regression methods, model tree regressions, multivariate regression methods and support vector machines using sequential minimal optimisation algorithm. For...

The effect of climate change on urban drainage: An evaluation based on regional climate model simulations

M.Grum, A. T. J\303\270rgensen, R. M. Johansen & J. J. Linde
That we are in a period of extraordinary rates of climate change is today evident. These climate changes are likely to impact local weather conditions with direct impacts on precipitation patterns and urban drainage. In resent years several studies have focused on revealing the nature, extent and consequences of climate change on urban drainage and urban runoff pollution issues. This study uses predictions from a regional climate model to look at the effects of climate...

Filtration for metals removal from stormwater

S. Clark, P. Johnson, R. Pitt, S. Gill & M. Pratap
Filtration as a method of stormwater treatment was investigated in a 3-year study. Equilibrium and kinetic studies of metals\342\200\231 capture were performed initially on twelve media. The three best performing media: peat-sand mix, compost, and zeolite were then selected for in-depth study. Upflow filters did not clog as easily as downflow, and longer-term performance was better in the upflow column. Metals were retained on the filters during anaerobiosis. Metal retention by the filters was not...

Real-time control of the integrated urban drainage system in the city of Leipzig

R. Rohlfing, C. Nietzschmann & M. Wiemann
ABSTRACT The existing sewer network of the City of Leipzig (Germany) is characterized by old brick sewer pipes. The objective of the old part of the drainage system consists in the rapid discharge of stormwater to the numerous outlets of the network. In the given system, even small storm events cause combined sewer overflows (CSOs). About 80 % of all combined sewer overflows occur at the overflow structure at the inlet of the treatment plant...

Winter water quality profiles for a stormwater pond in southern Sweden

A. Semadeni-Davies
Profiles of conductivity, temperature, dissolved oxygen (DO) and pH were made for B\303\244ckasl\303\266v stormwater pond (ca. 1.8 ha, average depth 1.6 m) in V\303\244xj\303\266, south Sweden, over two winters (2001-2 and 2002-3). The first winter had mild and wet conditions while the second was cold and dry. The pond was at least partially ice covered over both winters. Readings were taken at 20 cm vertical intervals approximately every fortnight from December to April at three...

Statistical classification of frequent rainfall events as a basis for operational aspects of sewer systems

H.-R. Verworn, S. Kraemer & L. Shi
Statistical analysis of rainfall and runoff are generally carried out for design and rehabilitation purposes. All processes generated by smaller events are of no interest in this context. While these design events have no relevance for the everyday performance of the drainage systems, statistical analysis of the more frequent events has to cover more aspects than just the maxi-mum intensities of certain durations. Operational aspects for sewer systems include e.g. sedi-mentation and remobilisation of settleable...

Analysis of concentration under non-ergodic transport as sampled in natural aquifers

Virgilio Fiorotto, Elpidio Caroni, Matteo Nicolini & Matteo Nicolini
Groundwater is probably the major source of water supply in the world, and the predictive ability in describing the fate of chemical contaminants in soils is of great importance when performing risk assessment and designing effective and efficient techniques to mitigate such problems. Most of environmental regulations (e.g., U.S. EPA, 1988; European Union, Directive 80/778/EEC) define water quality standards and acceptability in terms of concentration thresholds, and thus the prediction in natural aquifers must be...

Magnetic Room Temperature Cooling Using Stacks of Gadolinium Plates

Kasper Wigh Lipsø, Luise Theil Kuhn, Christian Bahl & Nielsen
Magnetic refrigeration is an alternative to conventional refrigeration. Where conventional refrigeration uses vapor compression cycles, magnetic refrigeration is based on the magnetocaloric effect, i.e. the property of magnetic materials to change temperature when exposed to a changing magnetic field. The technology is currently used for low temperature cooling (<10K). By implementing stacks of magnetic plates instead of powder, it can be optimized to yield a more energy efficient room temperature cooling than conventional refrigeration. This...

Adsorption of fluoride by clays from the potential sites for acid waste storage

Noureddine HAMDI & Noureddine HAMDI
Noureddine HAMDI1*, Ezzeddine SRASRA1 1Unité de recherche sur les matériaux, Institut National de recherche scientifique et technique, Tunis, BP 95-2050 Hammam lif, Tunisia ; *Corresponding Author: email: hamdinoureddine@yahoo.fr The aim of this work, consists to evaluate the potential effectiveness of clays coming from three sites (MK, H and ZB) intended for the storage of acid industrial waste Charged by F-. The interaction between fluoride and clays is affected by some parameters: pH, contact time, type...

Effect of rainfall hyetograph on pollutant loads in an urban catchment area

K. Michiokui, N. Wada & Y. Tsuji
Field measurements and runoff analysis of stormwater in a small urban area were performed. The effects of rainfall hyetograph on the pollutant runoff process were examined. Excellent agreement between SWMM simulation and field data were found not only with the runoff discharge, but also with the concentration and washoff rate of nutrients. A response analysis of pollutant runoff was carried out for design storms of single-peaked triangular hyetographs with various durations and peak intensities. The...

A concept for a bachelor program in electrical engineering

Henrik Niemann
The main concept for the Bachelor of Science in Engineering (BScE) in electrical engineering at Technical University of Denmark (DTU) will be described in this paper. A new curriculum was introduced from the start of the autumn semester in 2010. The curriculum was the result of more than one year of work with first description of competences followed by a more detailed description of the single main areas. Finally, the new study plan was implemented...

Unfired clay – the green construction material

Emilie Kristiansen, Thea Gregersen & Kurt Kielsgaard Hansen
Unfired clay can be used as a green construction material alternative to ordinary concrete. The clay is mixed with sand, water and either crushed tiles or gravel. The method to process the clay in a wall construction is called pisé where the clay is stamped in layers inside the formwork. The clay has positive qualities regarding moisture and heat buffering of the inside air.

From single-objective to multiple-objective multiple-rainfall events automatic calibration of urban storm water runoff models using genetic algorithms

F. Di Pierro, S.-T. Khu & D. Savic
The calibration of storm water runoff models is a complex task. Early attempts focused on the choice of a performance criterion function that could capture all the facets of the problem into a Single-Objective framework. Subsequently, the awareness that a good calibration must necessarily take into account conflicting objectives led to the adoption of more sophisticated Multi-Objective approaches. Only recently, the focus has shifted towards effective ways of exploiting the mounting information provided by the...

Pollution based real time control of a combined sewer overflow structure

K. Klepiszewski
Real time control processes in combined sewer systems are normally based on measurements of the hydraulic load conditions in the system. Dependent on the conditions, the flow in the system is adjusted to optimise the utilisation of available storage volume, to reduce discharged volume and pollutant loads into receiving water courses, and to support the operation of waste water treatment plants. Moreover, if the focal point of interest is the reduction of emitted pollutant loads...

A multiscale finite-volume method for three-phase flow influenced by gravity

Ivan Lunati, Patrick Jenny & Ivan Lunati
A multi-scale finite-volume (MSFV) method for solving multiphase flow problem in highly heterogeneous media was recently developed. In contrast with classical upscaling techniques, the goal of multiscale methods is not simply to capture the large-scale effects of the fine-scale heterogeneity, but to provide an efficient tool for solving large flow problems with fine-scale resolution. The MSFV is based on a fractional flow formulation of the problem: first an equation for the total velocity is solved,...

Pore-network modeling to calculate transport properties from small-scale data

Paper description: Modeling of two or three-phase flow in porous media is of prime importance in estimating the contamination of soils by liquid organic pollutants and in designing remediation solutions. For an accurate prediction of the transport properties of a porous medium, small-scale data on the pore space geometry and topology are needed. Although the small-scale structure is closely related to the capillary properties of the porous medium, it has been shown (Laroche and Vizika,...

Hydrological and hydraulic studies to analyse the main drainage system of the valley of Mexico

H. L. Cisneros-Iturbe & R. Dom\303\255nguez-Mora
ABSTRACT The present work deals with the mathematical simulations of the main drainage system of Mexico City, which serves an urban area of 20 million people on a surface of about 2500 km2. This system is composed by retention dams, surface channels, deep and semi-deep tunnels, pumping stations and retention lakes. Due to the aquifer\342\200\231s overexploitation and, its consequents, soil sink problems, the surface drainage channels have significantly diminished their conducting capacity. This has result...

Evaluation of thermal bridges by means of numerical simulation

Charlotte Gudum & Charlotte Gudum
Some themal bridges will always exist, where parts of the building envelopes have reduced insulation thickness. A thermal bridge will cause a local area with lower inside surface temperature, where the condensation of indoor moisture risk to cause local high relative humidity, and further mould growth. In practice it is significant that the cold bridge is detected in the design phase, before the building is build, so the design can be changed, and the damage...

Efficient and Accurate Simulation of Large General Reactive Multicomponent Transport Processes in Porous Media by Model-Preserving a priori and a posteriori Decoupling Techniques of Large General Reactive Multicomponent Transport Processes in Porous Media by Model-Preserving a priori and a posteriori Decoupling Techniques

Peter Knabner, Serge Kraeutle, Alexander Prechtel & Peter Knabner
Detailed modelling of reactive transport processes in the underground often requires the consideration of a wide range of reactive species. A prominent example is natural attenuation, that is the assessment and monitoring of microbially catalysed degradation processes of organic contaminants in the subsoil or aquifer with full geochemistry. Often the reactions exhibit a wide range of relaxation times, which advises to model those reactions being much faster than the time scale of the transport processes...

Scheduling home applications to reduce energy consumption

Ana Rossello-Busquet & Villy Bæk Iversen
In order to optimize the energy production, users should avoid consuming energy at the same time to avoid energy demand peaks. This can be achieved by setting a maximum energy consumption per user’s house. In other words, the overall consumption of the user’s appliances cannot exceed the maximum kwh. This project will study how home appliances tasks can be scheduled to not exceed this maximum consumption by using priorities.

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