Water management in the Flemish steel industry: the Arcelor Gent case

Steel production is an energy- and water-intensive process: large quantities of water are used for cooling, process and environmental-technical applications. In the mid-1990s, Arcelor Gent, a large integrated carbon steel producing company in Flanders (Belgium), started a number of water-related projects: the existing water infrastructure was adapted: the water from the coke plant was biologically treated; canal water was demineralised using reverse osmosis; waste water from the blast furnaces was neutralised with alkaline water from the steel plant. As a result of these projects, the quantity of discharged waste water was reduced by a factor of 2 (water recycling doubled from a factor of 10 to a factor of 20), and the discharge of pollutants decreased. Also resource consumption decreased: lime used in the steel plant, could be recovered to precipitate Zn in the waste water of the blast furnaces. Arcelor Gent obtained for these projects several Environmental Awards.     

The effect of silane coupling agents on radiata pine fibre for use in thermoplastic matrix composites

Gamma-aminopropyltriethoxysilane (GS) and dichlorodiethylsilane (DCS) were employed for surface modification of radiata pine (Pinus radiata) wood fibre. Levels of fibre moisture were carefully controlled to optimise chemical and hydrogen bonding with these silane coupling agents. The effect of pre-treatment using 2% sodium hydroxide, shown to be effective in assisting silane coupling for other natural fibres [Composites, Part B: Engng 30 (1999) 321], was also investigated. X-ray photoelectron spectroscopy and nuclear magnetic resonance (NMR) were used to characterise modification of the wood fibre. Concentrations of up to 3.2 wt% Si were obtained on the fibre surface due to silane coupling, however, pre-treatment was found to dramatically reduce this value. NMR provided evidence that coupling had occurred between the fibre and DCS by reaction producing ether linkages between the hydroxyl groups on the wood fibre and silane. Pre-treatment and treatment were found to have an insignificant effect on fibre strength. Composite sheets were produced by blending fibre (5, 10 and 20 wt%) with polyethylene followed by extrusion. An increase in strength was obtained at fibre contents of 5 wt% for all treatments compared to composites with untreated fibre. This is believed to be mainly due to increased compatibility of the fibre surface to polyethylene. However, there was no such improvement obtained at higher fibre contents. Evidence suggests that the production of voids is limiting composite strength.     

Waste-to-energy is compatible and complementary with recycling in the circular economy

Clean Technologies and Environmental Policy - This paper reviews the role of conventional waste-to-energy, i.e. incineration of (mainly) municipal solid waste with energy recovery, in the circular...     

Arch effect in high isostatic pressure compacts

Arch effect arising under isostatic pressing of the cylindrical or spherical powder compacts is commonly known to cause a loosely packed interior region inside the pressings. Using the results of the shell stability theory it is shown that under definite compact's geometry and powder characteristics, arch effect can involve latent cracking of the pressing as well, with its final breakdown during green machining or sintering. Experiments using 0·6 GPa large alumina pressing revealed all the above phenomena including formation of an overpressed cylindrical layer with predicted 0·133R (R is the radius of the pressing) thickness and close packing density. It is concluded that each CIP route must be pre-calculated as for specified shape, powder and green machining in order to find CIP pressures lower than the critical shell breakdown pressure or higher than the powder's yield stress where the arch effect disappears. ©     

Study on the design and performance of a bi-directional cone flowmeter

The present study explores a novel design of cone flowmeter for bi-directional flow metering application. Two identical cone shapes are machined with their base circle surfaces joined together with a small step in between them and differential pressure measurement is done across the apex of the cones. The bi-directional cone flowmeter is tested under fully developed flow conditions and its performance under double 90° bend (out-of-plane) is also evaluated. The bi-directional cone flowmeter is tested in a circular pipe (inside diameter of 101 mm) with water as the working medium for the flow Reynolds number ranging from 1.18×10⁵ to 5.48×10⁵. Influence of the half cone angle (α) and the location of static pressure taps on the coefficient of discharge (C_d) of a cone flowmeter are studied. Two cones with half cone angles α=30° and α=45° with a constant constriction ratio (β) of 0.75 are studied. Static pressure taps are located on both sides of the bi-directional cone. Two sets of locations of static pressure taps are studied. First set includes two static pressure taps on the pipe wall in the planes of apexes of the bi-directional cone—called apex taps. Second set includes pressure taps on the pipe wall in the planes at a distance D/4 away from the apexes of the bi-directional cone—called D/4 taps. Double 90° bend (out-of-plane) is placed at 1.5D, 5.5D, 9.5D and 13.5D upstream to the bi-directional cone flowmeter. It is observed that the apex static pressure taps located in the plane of apexes of the bi-directional cone result in statistically consistent coefficient of discharge for all Reynolds numbers covered in this study. The results suggest that the bi-directional cone flowmeter is insensitive to the swirl created by double 90° bend (out-of-plane) placed at the upstream of cone flowmeter, if placed at a distance of 9.5D or more.     

Towards methods for evaluating and communicating participatory design: A multimodal approach

Participatory Design (PD) has been proposed as a useful strategy to address pitfalls in the design of serious games for children with special needs. Nonetheless, methodological weaknesses in the analysis of the results of PD workshops may hinder its effectiveness in providing useful and robust design contributions and facilitating communication in multidisciplinary teams. To address this issue we propose the use of multimodal analysis to evaluate participants’ contributions during PD workshops. We present an analysis that was applied in an informant workshop with autistic children, aimed at refining the design of a serious game based on Full-Body Interaction. Results show that multimodal analysis constitutes an effective and coherent method to capture and analyze users’ contributions across a wide range of semiotic resources, thus extending the richness of insights that can be derived from a PD workshop and communicated to the rest of the team. Furthermore, the analysis allowed the identification of fundamental design questions, thus offering a robust empirical ground for supporting dialogue and reflection between multiple stakeholders.     

Molten storage and carbonization characteristics of premium grade coal-tar pitch: Influence of crude tar type and distillation conditions

A growing trend towards the transport and use of molten rather than solidified pitch has caused tar distillers to examine the relative stability of pitches while held in storage tanks. The scope of laboratory storage-stability tests can be extended to higher temperatures as a method of studying the earliest stages of pitch polymerization/carbonization. Some indications of the ultimate performance of the pitch in the end-use process can be gained. Crude tar has a strong influence on the ultimate properties and performance of a pitch. Seven tars have been made into 120 °C Mettler softening-point pitches by two distillation methods to study their subsequent storage and carbonization behaviour. The behaviour exhibited by each pitch allows a judgement on overall ‘reactivity’ and on the sensitivity to thermal conditions in the distillation of each tar. Two distillation schemes were adopted: batch distillation followed by heat treatment; and batch distillation at a pressure which was progressively reduced. The results show that time at elevated temperature has a major effect on the properties and performance of the resulting pitch. Vacuum distillation allows lower processing temperatures. Larger amounts of secondary quinoline-insolubles were formed under the ‘distillation with heat treatment’ scheme. Complete wetting of coke by pitch took place at lower temperatures for the vacuum-distilled pitches. Heat-treated pitches increased more rapidly in softening point and lost more mass when thermally soaked. Distillation under vacuum conditions resulted in significantly modified pitch carbonization characteristics.     

Motivation profiles of online Poker players and the role of interface preferences: A laddering study among amateur and (semi-) professionals

Online Poker has become an increasingly popular form of gambling. In this study, the qualitative method of laddering interviews based on means-end chain theory was used to offer new insights in online Poker players’ psychological motives, and the way in which Poker website characteristics shape gambling preferences. A total of 18 Belgian young adults, experienced in Poker playing, were recruited via snowball sampling, of which 6 professionals (relying on online Poker as the sole source of income), 6 semi-professionals (playing for money, but not relying on it as a sole source of income) and 6 amateurs (not relying on Poker money for income). We focused on 2 Poker websites, PokerStars and Facebook Zynga Poker. Results revealed that an increase in the dependency on Poker profits shifted motives from learning towards monetary incentives. Yet, playing for real money could not be considered as a purely extrinsic motivation as it greatly determined the game play dynamics and experiences, and this both in the (semi-) professionals and amateur players. Finally, our study indicates that responsible gaming features should reconcile monetary worth with values of control, trust, entertainment and game play action.     

How to achieve the huggable behavior of the social robot Probo? A reflection on the actuators

Most robots have a mechanical look or are covered with plastic or metallic shells. Their actuators are stiff which gives them not only an unnatural look, but also an unnatural touch. The goal of the huggable robot Probo is to serve as robotic research platform for human-robot interaction (HRI) studies with a special focus on children. Since not only cognitive interaction, but also physical interaction is targeted a new mechatronic design must be developed. To give Probo a huggable and safe behavior a new set of actuators is developed together with a triple layered protection cover which is presented in this paper. Probo’s soft touch is introduced, on the one side by use of novel passive compliant actuators, Compliant Bowden Cable Driven Actuators (CBCDAs), and on the other side by combining custom made servo motors, Non Back Drivable Servos (NBDSs), with flexible components and materials such as springs, silicon and foam. The working principle of the novel CBCDA is extensively described, together with experiments in order to determine its level of compliance and its bandwidth.