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Geel, Belgium

The Katholieke Hogeschool Kempen is a university college where students can obtain a professional bachelor's degree in several domains. There is also the opportunity to study for a master's degree in engineering in agriculture or an engineering degree in electronics. Wikipedia.

Cao Y.,Catholic University of Leuven | Cao Y.,Belgian Nuclear Research Center | De Cock W.,Belgian Nuclear Research Center | Steyaert M.,Catholic University of Leuven | And 2 more authors.
IEEE Journal of Solid-State Circuits | Year: 2012

Two 1-1-1 MASH ΔΣ time-to-digital converters (TDCs) are presented in this paper. Third-order time domain noise-shaping has been adopted by the TDCs to achieve better than 6 ps resolution. Following a detailed analysis of the noise generation and propagation in the MASH ΔΣ structure, the first prototyping TDC has been realized in 0.13μm CMOS technology. It achieves an ENOB of 11 bits and consumes 1.7 mW from a 1.2 V supply. In the second MASH TDC, a delay-line assisted calibration technique is introduced to mitigate the phase skew caused by the large comparator delay, which is the main limiting factor of the MASH TDC's resolution. The demonstrated TDC achieves an ENOB of 13 bits and a wide input range of 100 ns. This TDC shows a temperature coefficient of 176 ppm° C within a temperature range of -20 to 120° C. It consumes only 0.7 mW and occupies 0.08 mm 2 area (core). © 2012 IEEE. Source

Luis P.,Catholic University of Leuven | Amelio A.,University of Calabria | Vreysen S.,KH Kempen | Calabro V.,University of Calabria | Van Der Bruggen B.,Catholic University of Leuven
International Journal of Life Cycle Assessment | Year: 2013

Purpose: The goal and scope of this research is focused on the application of life cycle assessment (LCA) to evaluate two alternatives (batch and continuous distillation and incineration with energy recovery) for the treatment of four waste-solvent mixtures typically produced in the chemical industry: acetonitrile-toluene, acetonitrile-toluene-tetrahydrofuran (THF), ethyl acetate-water and methanol-THF, with several compositions in order to determine the most appropriate technology depending on the characteristics of the mixture. Materials and methods: Ecosolvent® v.1.0.1 software is used to perform the LCA, considering two scenarios and the following methods of impact assessment: Eco-indicator 99, cumulative energy demand, method of ecological scarcity (UBP'97), global warming potential and CO2 balances. Results and discussion: Results show that distillation gives more environmental credits for the recovery of the most concentrated compound in acetonitrile-toluene mixtures. However, when THF is present in the waste solvent even in small quantities, it has to be recovered due to the high impact associated to its manufacture. Regarding the mixture ethyl acetate-water, distillation takes advantage at concentrations of ethyl acetate higher than 50 wt%, and for the mixture methanol-THF, recovery of methanol is not advantageous from an environmental point of view, but the recovery of THF is clearly necessary to decrease the total impact. Conclusions: From this study, it can be concluded that those compounds that yield a great environmental burden during the production step should be always recovered in order to minimize the total impact, even if they represent the minor concentration in the mixture. In case that similar impact is produced during the solvent production, the major compound in the mixture should be the target for recovery. © 2012 Springer-Verlag Berlin Heidelberg. Source

Vandenhove H.,Belgian Nuclear Research Center | Vanhoudt N.,Belgian Nuclear Research Center | Duquene L.,Belgian Nuclear Research Center | Antunes K.,KH Kempen | Wannijn J.,Belgian Nuclear Research Center
Journal of Environmental Radioactivity | Year: 2014

Two sequential extraction procedures were carried out on six soils with different chemical properties and contamination history to estimate the partitioning of uranium (U) between different soil fractions. The first standard method (method of Schultz) was specifically developed for actinides, while the second one (method of Rauret) was initially created for heavy metals. Reproducibility of both methods was compared by means of the coefficient of variation (CV). A soil-to-plant transfer experiment was also carried out with ryegrass to verify if one of the extracted fractions efficiently predicted plant uptake. In artificially contaminated soils, most of the U was retrieved from the exchangeable and the carbonates fractions. In soils with high natural levels of U or contaminated by industrial activity, most of the U was found in the less available fractions. Different U concentrations were found in the fractions which were supposed to be comparable in the two methods. Extracted fractions following Schultz differentiated more strongly between the tested soils but no relationships with soil parameters could be established. As expected, the highest U transfer factors (TF) were observed for ryegrass grown on artificially contaminated soils and the lowest on soils with high natural concentrations or industrial contamination, in agreement with the extraction procedures. No good relation was found between the soil-to-shoot TF and the extracted U concentrations. On the other hand, the U concentration in the roots, the U concentration in the shoots and the soil-to-root TF are well correlated to the U concentration determined in the first extracted fractions (so called exchangeable fractions) from the method of Schultz. We conclude that the extraction method according to Schultz should be preferably used for U, and that the exchangeable fraction can be proposed as a potential indicator to evaluate plant uptake in soils. © 2014 Elsevier Ltd. Source

Mercuri M.,Catholic University of Leuven | Schreurs D.,Catholic University of Leuven | Leroux P.,Catholic University of Leuven | Leroux P.,KH Kempen
RWW 2012 - Proceedings: 2012 IEEE Topical Conference on Biomedical Wireless Technologies, Networks, and Sensing Systems, BioWireleSS 2012 | Year: 2012

The use of a Stepped-Frequency Continuous Wave (SFCW) radar is proposed for non-invasive fall and vital signs detection. A fall in principle involves changes both in position and in speed. Measurements have been performed with the radar fixed both on the wall and on the ceiling. In both situations, position and speed of a target have been measured with good accuracy. By combining this information a fall can be properly detected, distinguishing the fall from both walking and sitting movements. The results show the feasibility of this approach. Moreover, the results demonstrate that vital signs can be monitored also. © 2012 IEEE. Source

Cao Y.,Catholic University of Leuven | Cao Y.,Belgian Nuclear Research Center | Leroux P.,Catholic University of Leuven | Leroux P.,KH Kempen | And 2 more authors.
Digest of Technical Papers - IEEE International Solid-State Circuits Conference | Year: 2011

Recently, high-resolution TDCs have gained more and more popularity due to their increasing implementation in digital PLLs, ADCs, jitter measurement and time-of-flight measurement units. Similar to ADCs, existing architectures of TDCs can be divided into several categories: flash TDCs [1, 3], pipeline TDCs [2], and SAR TDCs [4]. The highest achievable time resolution of a TDC is mainly limited by the CMOS gate delay. In order to achieve sub-gate-delay resolution, the Vernier method is commonly used. However, the mismatch problem caused by process variation limits its effectiveness, and the same holds for the time amplification method. The gated-ring-oscillator (GRO) method [5] is introduced to achieve sub-ps time resolution, but it still requires an equivalent CMOS gate delay as low as 6ps. Upcoming applications in 4 th-generation nuclear reactors, space, and high-energy physics such as the large Hadron collider (LHC), require the TDC to achieve a high time resolution in harsh environments with high temperature and radiation, where the threshold voltage, transconductance, and delay of a transistor undergo dramatic changes. In these cases, the high accuracy and robustness of the TDC need to be inherent to the design rather than by employing a fast CMOS technology. © 2011 IEEE. Source

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