Statistics for Spatial Data.

The Social Psychology of Organizations.

Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

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Climate Change 2007: The Physical Science Basis.

Social Psychology of Organizations

The boundary layer equations for plane, incompressible, and steady flow are 

$$\matrix{ {u{{\partial u} \over {\partial x}} + v{{\partial u} \over {\partial y}} = - {1 \over \varrho }{{\partial p} \over {\partial x}} + v{{{\partial ^2}u} \over {\partial {y^2}}},} \cr {0 = {{\partial p} \over {\partial y}},} \cr {{{\partial u} \over {\partial x}} + {{\partial v} \over {\partial y}} = 0.} \cr }$$

Boundary Layer Theory

Sewer systems are costly to construct and even more costly to replace, requiring proper asset management Sewer asset management relies to a large extent on available information. In sewer systems where pipe corrosion is the dominant failure mechanism, visual inspection (CCTV) and core sampling are amongst the methods applied mostly to assess sewer pipe condition. This paper compares visual inspection and drill core analysis in order to enhance further understanding of the limitations and potentials of both methods. Both methods have been applied on a selected sewer reach in the city of the Hague, which was reportedly subject to pipe corrosion. Results show that both methods, visual inspection and core sampling, are associated with large uncertainties and that there is no obvious correlation between results of visual inspection and results of drill core analysis.

/pdf/comparison-of-core-sampling-and-visual-inspection-for-4qnj14821m.pdf

Comparison of core sampling and visual inspection for assessment of sewer pipe condition

This research deals with the design and implementation of an integrated control for the WWTP of Eindhoven. The control influences the operation of the primary settling tanks and influent pumping station to reduce reduce ammonia peaks in the WWTP effluent. The control takes into account the treatment capacity of the biological tanks, the influent flows and the available storage capacity in the individual catchments. It was implemented in winter 2016 and has been operational since April 2016. Model results and preliminary measurements show that the WWTP can be operated with a reduced number of PCs for over 90% of the time

/pdf/integrated-real-time-control-of-influent-pumping-station-and-1kjx44u35q.pdf

Integrated real time control of influent pumping station and primary settling tanks at WWTP Eindhoven

The objective of this paper is to demonstrate the applicability of, and need for, surrogate sensors as robust sensors for water quality based RTC. For this purpose 1.5 years of level, conductivity (EC) and turbidity (TU) measurements at 9 combined sewer overflow (CSO) locations have been performed and analysed to determine the most polluted CSO locations. The analysis is based on surrogate event mean concentrations (sEMC, defined as EC multiplied by TU) and surrogate pollution loads (sPL, defined as the sEMC multiplied by the overflow volume). It is shown that EC and TU measurements can serve as surrogate measurements to determine the relative pollution of a CSO location. Analysis of the EC and TU values with respect to the distance between the CSO location and the WWTP gave no indication that this is of importance. Comparison of the sEMC and sPL for the CSO locations, shows that water quality measurements will have a great impact on the application of RTC, leading to quality based RTC.

/pdf/cso-pollution-analysis-based-on-conductivity-and-turbidity-1ig5aeol28.pdf

CSO pollution analysis based on conductivity and turbidity measurements and implications for application of RTC

Sumps of wastewater pumping station can experience problems due the formation of (solid) floating layers of fat and scum as a result of insufficient current guidelines for sump design with respect to transport of floating debris. To complimentary the guidelines, the use of free-surface vortices is defined as a potential transport mechanism for floating debris. The transport ability and capacity of vortices is investigated in an experimental set-up and experimental data will be used to design and validate a theoretical vortex transport model describing the transport ability and capacity of a free-surface vortex. Two theoretical vortex models describing the vortex flow field are used as a base for the transport model. Experimental results show that both models needs adaptation to match experimental results. Furthermore, the experiments show that the ability to transport buoyant material is highly sensitive on the flow field in the vortex (core) and on the particle density. Particles can either get stuck in the vortex core with no or less transport or either translated around the core with efficient transport. Before designing and validating the vortex transport model, extensive future research is needed to capture the observed phenomena’s.

Experimental research on free-surface vortices as transport mechanism in wastewater sumps

There is still a long way to go in understanding the behaviour of solids in sewers due to the difficulties in obtaining sufficient monitoring data to be able to understand the dominant processes. Laser profilers have shown to be capable of measuring the pipe interior, with a high accuracy, which is sufficient to be able to detect and quantify wall losses. This paper describes the potential of laser scanning for measuring sediment volumes in sewers. In addition, the propagation of uncertainties from laser measurements to sediment volumes are discussed, with special attention to conditions that could affect the measurements. The Laser profiler has shown to be capable of measuring the pipe interior, which is sufficient to be able to detect and quantify sediment volume. Overall, this research is a first step in defining a new inspection concept that will be able to give reliable information on relevant failure mechanisms.

https://repository.tudelft.nl/islandora/object/uuid%3Ad4670724-342b-4ab1-84c4-0ac24e9af10a/datastream/OBJ/download

Francois Clemens

Papers

Comparison of core sampling and visual inspection for assessment of sewer pipe condition

Integrated real time control of influent pumping station and primary settling tanks at WWTP Eindhoven

CSO pollution analysis based on conductivity and turbidity measurements and implications for application of RTC

Experimental research on free-surface vortices as transport mechanism in wastewater sumps

Potential of Laser Scanning for Quantification of Sediment Deposits in Sewer