Developing the dairy business in New Reality

Verslag van een studiedag voor melkveehouders, waarin wordt uitgelegd hoe ze goed op de toekomst kunnen anticipere

On the parameterization of all admissible pairs in a class of CCF-ILC algorithms

This paper extends some recent results on the parameterization of all admissible pairs in a class of 2-parameter current-cycle-feedback ILC algorithms. In addition, a necessary and sufficient condition is given under which the associated set of equivalent controllers coincides with the set of all stabilizing controller

Degradation of BTEX by anaerobic bacteria: physiology and application

Pollution of the environment with aromatic hydrocarbons, such as benzene, toluene, ethylbenzene and xylene (so-called BTEX) is often observed. The cleanup of these toxic compounds has gained much attention in the last decades. In situ bioremediation of aromatic hydrocarbons contaminated soils and groundwater by naturally occurring microorganisms or microorganisms that are introduced is possible. Anaerobic bioremediation is an attractive technology as these compounds are often present in the anoxic zones of the environment. The bottleneck in the application of anaerobic techniques is the lack of knowledge about the anaerobic biodegradation of benzene and the bacteria involved in anaerobic benzene degradation. Here, we review the existing knowledge on the degradation of benzene and other aromatic hydrocarbons by anaerobic bacteria, in particular the physiology and application, including results on the (per)chlorate stimulated degradation of these compounds, which is an interesting new alternative option for bioremediatio

Prediction of mechanical fatigue caused by multiple random excitations

A simulation method is presented for the fatigue analysis of automotive and other products that are subjected to multiple random excitations. The method is denoted as frequency domain stress-life fatigue analysis and was implemented in the automotive industry at DAF Trucks N.V. in Eindhoven, The Netherlands. As an example case, a chassis part is analysed. The results of the analysis are consistent with fatigue cracks encountered during testing, which illustrates the effectiveness of the adopted method in the automotive industry

Modelling, screening, and solving of optimisation problems: Application to industrial metal forming processes

Coupling Finite Element (FEM) simulations to mathematical optimisation techniques provides a high potential to improve industrial metal forming processes. In order to optimise these processes, all kind of optimisation problems need to be mathematically modelled and subsequently solved using an appropriate optimisation algorithm. Although the modelling part greatly determines the final outcome of optimisation, the main focus in most publications until now was on the solving part of mathematical optimisation, i.e. algorithm development. Modelling is generally performed in an arbitrary way. In this paper, we propose an optimisation strategy for metal forming processes using FEM. It consists of three stages: a structured methodology for modelling optimisation problems, screening for design variable reduction, and a generally applicable optimisation algorithm. The strategy is applied to solve manufacturing problems for an industrial deep drawing process

Planten en luchtkwaliteit

Planten hebben een grote waarde voor het milieu en de levenskwaliteit van mensen. Dit wordt steeds meer erkend. Mensen houden van groen en het is aangetoond dat een groene leefomgeving mensen tot rust brengt en bijdraagt aan een goede gezondheid. Voor een deel hebben deze effecten een psychologische oorzaak. Maar er zijn ook meer tastbare oorzaken. Planten produceren zuurstof en halen kooldioxide (CO2) uit de atmosfeer. Verder kan groen schadelijke deeltjes uit de lucht wegvangen, zoals fijnstof, stikstofoxiden en ozon. Het is wel zaak om planten gericht in te zetten. De effectiviteit verschilt per plantensoort. Verder kan te dichte vegetatie langs de weg de concentratie van luchtverontreinigende stoffen juist verhogen. En sommige plantensoorten kunnen een verhoging van de ozonconcentratie veroorzaken. Voor een optimaal effect is kennis van zaken dus essentieel. Planten zijn geen wondermiddel voor het zuiveren van de lucht, maar kunnen zeker een goede bijdrage leveren. Dit artikel geeft handvaten om als kweker en groenvoorziener optimaal te profiteren van de luchtzuiverende werking van groen

Deterministic and robust optimisation strategies for metal forming proceesses

Product improvement and cost reduction have always been important goals in the metal forming industry. The rise of\ud Finite Element simulations for metal forming processes has contributed to these goals in a major way. More recently, coupling\ud FEM simulations to mathematical optimisation techniques has shown the potential to make a further contribution to product\ud improvement and cost reduction.\ud Mathematical optimisation consists of the modelling and solving of optimisation problems. Although both the\ud modelling and the solving are essential for successfully optimising metal forming problems, much of the research published until\ud now has focussed on the solving part, i.e. the development of a specific optimisation algorithm and its application to a specific\ud optimisation problem for a specific metal forming process.\ud In this paper, we propose a generally applicable optimisation strategy which makes use of FEM simulations of metal\ud forming processes. It consists of a structured methodology for modelling optimisation problems related to metal forming.\ud Subsequently, screening is applied to reduce the size of the optimisation problem by selecting only the most important design\ud variables. Screening is also utilised to select the best level of discrete variables, which are in such a way removed from the\ud optimisation problem. Finally, the reduced optimisation problem is solved by an efficient optimisation algorithm. The strategy is\ud generally applicable in a sense that it is not constrained to a certain type of metal forming problems, products or processes. Also\ud any FEM code may be included in the strategy.\ud However, the above strategy is deterministic, which implies that the robustness of the optimum solution is not taken\ud into account. Robustness is a major item in the metal forming industry, hence we extended the deterministic optimisation\ud strategy in order to be able to include noise variables (e.g. material variation) during optimisation. This yielded a robust\ud optimisation strategy that enables to optimise to a robust solution of the problem, which contributes significantly to the industrial\ud demand to design robust metal forming processes. Just as the deterministic optimisation strategy, it consists of a modelling,\ud screening and solving stage.\ud The deterministic and robust optimisation strategies are compared to each other by application to an analytical test\ud function. This application emphasises the need to take robustness into account during optimisation, especially in case of\ud constrained optimisation. Finally, both the deterministic and the robust optimisation strategies are demonstrated by application to\ud an industrial hydroforming example

Numerical product design: Springback prediction, compensation and optimization

Numerical simulations are being deployed widely for product design. However, the accuracy of the numerical tools is not yet always sufficiently accurate and reliable. This article focuses on the current state and recent developments in different stages of product design: springback prediction, springback compensation and optimization by finite element (FE) analysis. To improve the springback prediction by FE analysis, guidelines regarding the mesh discretization are provided and a new through-thickness integration scheme for shell elements is launched. In the next stage of virtual product design the product is compensated for springback. Currently, deformations due to springback are manually compensated in the industry. Here, a procedure to automatically compensate the tool geometry, including the CAD description, is presented and it is successfully applied to an industrial automotive part. The last stage in virtual product design comprises optimization. This article presents an optimization scheme which is capable of designing optimal and robust metal forming processes efficiently

Cercis: een lust voor het oog

Het is een breed vertakte struik of een kleine boom, die rijk bloeit en typisch blad heeft. Een nadere kennismaking met de bijzondere Cercis

Inheemse en uitheemse plantensoorten in stad en landschap

Het doel van deze brochure is om het groenvak achtergrond informatie te geven wat betreft de toepassing en de waarde van inheemse en uitheemse soorten op basis van actuele wetenschappelijke inzichten