New collaborative workflows - immersive co-design from sketching to 3d cad and production

Digital technologies have enabled design sketching to expand into new applications and domains. Inevitably, these new forms of visualisation require re-evaluating how we use drawing to see, visualise, understand, and fabricate products and services in design education and the profession. This paper presents a selection of discoveries after...

Accurate prediction of liquid-solid fluidized bed porosity in drinking water treatment processes using empirical data-driven genetic programming models

For an accurate prediction of the porosity of a liquid-solid homogenous fluidized bed, various empirical prediction models have been developed. Symbolic regression machine learning techniques are suitable for analyzing experimental fluidization data to produce empirical expressions for porosity as a function not only of fluid velocity and...

Change analysis of laser scans of laboratory rock slopes subject to wave attack testing

For better understanding how coastal structures with gentle slopes behave during high energy events, a wave attack experiment representing a storm of 3000 waves was performed in a flume facility. Two setups with different steepness of slope were compared under the same conditions. In order to quantify changes in the rock slopes after the wave...

Drinking water pellet softening: prediction the terminal settling velocity of natural particles

Natural particles are frequently applied in drinking water treatment in up-flow fluidisation processes. Additionally, sedimentation processes are applied to clarify water and to concentrate solids. To estimate the terminal settling velocity of single solid particles in a liquid system, a comprehensive collection of equations is available. For...

Prediction of the terminal settling velocity of drinking water pellet softening particles

The literature provides a comprehensive collection of equations to estimate the<br/>terminal settling velocity of single solid particles in a liquid system. The settling velocity for perfectly round spheres can accurately be calculated. In the contrary for natural imperfect particles the experimentally measured settling velocity deviates...

Deep sub-wavelength metrology for advanced defect classification

Particle defects are important contributors to yield loss in semi-conductor manufacturing. Particles need to be detected and characterized in order to determine and eliminate their root cause. We have conceived a process flow for advanced defect classification (ADC) that distinguishes three consecutive steps; detection, review and...

Cavitation for improved sludge conversion into biogas

In several studies the beneficial influence of pre-treatment of waste activated sludge with cavitation on the biogas production was demonstrated. It is however, still not fully certain whether this effect should be mainly contributed to an increase in conversion rate of organics into biogas by anaerobic bacteria, and how much cavitation...

Model-based prediction of fluid bed state in full-scale drinking water pellet softening reactors

Softening at drinking water treatment plants is often realised by fluidised bed pellet reactors. Generally, sand is used as seeding material and pellets are produced as a by-product. To improve to sustainability, research has been carried out to replace the seeding material by re-using grained and sieved calcite pellets as seeding material. An...

Plant wide chemical water stability modelling with PHREEQC for drinking water treatment

In practice, drinking water technologists use simplified calculation methods for aquatic chemistry calculations. Recently, the database stimela.dat is developed especially for aquatic chemistry for drinking water treatment processes. The database is used in PHREEQC, the standard in geohydrology for calculating chemical equilibria in groundwater....

Increased sustainability of softening by producing pure calcite pellets for reuse

About 50% of the drinking water in the Netherlands is centrally softened by the drinking water companies in a process known as pellet softening. In this process a base and seeding material are mixed in an upflow reactor, where subsequently CaCO3 precipitates on a seed core as pellets. The seeding material is usually sand, but recently CaCO3 was...

Modelling of Waves and Wave-Structure Interactions using Non-Linear Numerical Models

The aim of this study is to validate a fully non-linear finite-element model to simulate waves and wave-structure interactions. The Navier–Stokes equations are solved on an extended domain, which covers both fluid and structure. The latter is represented by a non-zero solid-concentration field, which is computed by conservatively mapping a mesh...

High-throughput parallel SPM for metrology, defect, and mask inspection

Scanning probe microscopy (SPM) is a promising candidate for accurate assessment of metrology and defects on wafers and masks, however it has traditionally been too slow for high-throughput applications, although recent developments have significantly pushed the speed of SPM [1,2]. In this paper we present new results obtained with our...

Parallel, Miniaturized Scanning Probe Microscope for Defect Inspection and Review

With the device dimensions moving towards the 1X node, the semiconductor industry is rapidly approaching the point where 10 nm defects become critical. Therefore, new methods for improving the yield are emerging, including inspection and review methods with sufficient resolution and throughput. Existing industrial tools cannot anymore fulfill...

Safety management within Task Force Uruzgan: A report of working with Unmanned Aerial Vehicles

In this paper we present a conceptualization of safety management that is based on the cybernetic concepts of “controllability” and “control capacity”. In particular, we explore what this conceptualization means for safety management of the Dutch Army’s UAV unit that was part of Task Force Uruzgan (TFU) in the years 2006–2007 and 2008–2009. In...

Numerical Investigation of the Impact of SES-Waterjet Interactions and Flow Non-uniformity on Pump Performance

De waarde van Koopgarant. Koopgarant en de waardeontwikkeling van wijken

Parallelsessie II. E. De waarde van Koopgarant

Innovative social sales programs: Valuation and risk issues

Papers workshops. In recent years, Dutch housing associations have introduced a number of innovative types of sale, having in common that a house is sold to the tenant at a discount. In this way, buying a house becomes affordable for lower-income households. On the other hand the housing association obtains cash, which can be used for (social)...