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Zhou B.,Potsdam Institute for Climate Impact Research | Lauwaet D.,Vlaamse Instelling voor Technologisch Onderzoek | Hooyberghs H.,Vlaamse Instelling voor Technologisch Onderzoek | De Ridder K.,Vlaamse Instelling voor Technologisch Onderzoek | And 3 more authors.
Journal of Applied Meteorology and Climatology | Year: 2016

This paper assesses the seasonality of the urban heat island (UHI) effect in the Greater London area (United Kingdom). Combining satellite-based observations and urban boundary layer climate modeling with the UrbClim model, the authors are able to address the seasonality of UHI intensity, on the basis of both land surface temperature (LST) and 2-m air temperature, for four individual times of the day (0130, 1030, 1330, and 2230 local time) and the daily means derived from them. An objective of this paper is to investigate whether the UHI intensities that are based on both quantities exhibit a similar hysteresis-like trajectory that is observed for LST when plotting the UHI intensity against the background temperature. The results show that the UrbClim model can satisfactorily reproduce both the observed urban-rural LSTs and 2-m air temperatures as well as their differences and the hysteresis in the surface UHI. The hysteresis-like seasonality is largely absent in both the observed and modeled 2-m air temperatures, however. A sensitivity simulation of the UHI intensity to incoming solar radiation suggests that the hysteresis of the LST can mainly be attributed to the seasonal variation in incoming solar radiation. © 2016 American Meteorological Society.


Mulder G.,Vlaamse Instelling voor Technologisch Onderzoek | Mulder G.,Vrije Universiteit Brussel | Omar N.,Vrije Universiteit Brussel | Omar N.,Erasmus University College Brussels | And 8 more authors.
Electrochimica Acta | Year: 2013

This article evaluates the behaviour of lithium-ion cells of several chemistries and one nickel-metal hydride cell for automotive applications like (plug-in) hybrid vehicles and battery electric vehicles. The evaluation is based on an enhanced test methodology that enables the comparison of cell behaviour. Tests for high power and high energy application have been integrated. The characterisation tests exist of four test methods. The tests make large differences visible between the cell species. The 5 C efficiency for example is between 75 and 90% while the cell temperature varies from 29 to 52 °C. The power density is 80 W/kg for the NiMH cell and lies between 330 and 3100 W/kg for the lithium-ion cells. The cell results have been brought into relation to the material properties, the shape, referring to existing literature. The test plan made it possible to make an initial division in the cells. It appears that the manufacturer's knowhow is more important than the general electrode classification to produce outstanding cells. © 2012 Elsevier Ltd.


Mulder G.,Vlaamse Instelling voor Technologisch Onderzoek | Omar N.,Vrije Universiteit Brussel | Omar N.,Erasmus University College Brussels | Pauwels S.,Flanders DRIVE | And 6 more authors.
Journal of Power Sources | Year: 2011

This article evaluates the methods to characterise the behaviour of lithium ion cells of several chemistries and a nickel metal hydride cell for automotive applications like (plug-in) hybrid vehicles and battery electric vehicles. Although existing characterisation test methods are used, it was also indicated to combine test methods in order to speed up the test time and to create an improved comparability of the test results. Also, the existing capacity tests ignore that cells can be charged at several current rates. However, this is of interest for, e.g. fast charging and regenerative braking. Tests for high power and high energy application have been integrated in the enhanced method. The article explains the rationale to ameliorate the test methods. The test plan should make it possible to make an initial division in a group of cells purchased from several suppliers. © 2011 Elsevier B.V. All rights reserved.


Patent
Ejlskov A S and Vlaamse Instelling Voor Technologisch Onderzoek | Date: 2012-03-14

Soil treatment device for treating a contaminated soil and/or groundwater contained therein, comprising measuring means for measuring contamination of the soil, injecting means for injecting soil decontamination agents in the soil and a longitudinal soil penetration rod provided with a rod tip at an end of the soil penetration rod for moving the soil penetration rod into the soil, the outer surface of the soil penetration rod comprising a measuring section comprising at least one sensor of the measuring means for measuring contamination of the soil adjacent to the measuring section when moved into the soil and an injection section comprising at least one injection nozzle of the injecting means for injecting decontamination agent in the soil adjacent to the injection section, wherein the measuring section and the injection section are provided at longitudinally distinct locations of the soil penetration rod and in that the measuring section is closer to the rod tip than the injection section, characterized in that the distance between the injection section and the measuring section is at least 0.5 m.


Omar N.,Vrije Universiteit Brussel | Omar N.,Erasmus University College Brussels | Monem M.A.,Vrije Universiteit Brussel | Firouz Y.,Vrije Universiteit Brussel | And 8 more authors.
Applied Energy | Year: 2014

From these analyses, one can derive the impact of the working temperature on the battery performances over its lifetime. At elevated temperature (40. °C), the performances are less compared to at 25. °C. The obtained mathematical expression of the cycle life as function of the operating temperature reveals that the well-known Arrhenius law cannot be applied to derive the battery lifetime from one temperature to another.Moreover, a number of cycle life tests have been performed to illustrate the long-term capabilities of the proposed battery cells at different discharge constant current rates. The results reveal the harmful impact of high current rates on battery characteristics.On the other hand, the cycle life test at different depth of discharge levels indicates that the battery is able to perform 3221 cycles (till 80% DoD) compared to 34,957 shallow cycles (till 20% DoD). To investigate the cycle life capabilities of lithium iron phosphate based battery cells during fast charging, cycle life tests have been carried out at different constant charge current rates. The experimental analysis indicates that the cycle life of the battery degrades the more the charge current rate increases. From this analysis, one can conclude that the studied lithium iron based battery cells are not recommended to be charged at high current rates. This phenomenon affects the viability of ultra-fast charging systems.Finally, a cycle life model has been developed, which is able to predict the battery cycleability accurately. © 2013 Elsevier Ltd.


Mulder G.,Vlaamse Instelling voor Technologisch Onderzoek | Mulder G.,Vrije Universiteit Brussel | Six D.,Vlaamse Instelling voor Technologisch Onderzoek | Claessens B.,Vlaamse Instelling voor Technologisch Onderzoek | And 3 more authors.
Applied Energy | Year: 2013

Electric energy storage is probably the first viable for households since they pay the highest electricity tariffs, being a factor four higher than bulk electricity prices. The attractiveness depends on the subsidy systems (if existing), the electricity price and the purchase cost of a PV installation and a battery system. Since the electricity price may not remain constant during the lifetime of the storage system, a financial cash flow calculation is needed including discount rate and inflation. In this research the optimal PV-battery system is determined as a function of the remuneration (discerning a subsidised region, a "market" price region and no fees at all), the investment year (2012, 2017 and 2021) and the electricity price increase rate (0%, 4%, 6%) (including the general inflation rate). The analysis is based on available battery energy storage systems on the market and on real household measurement data. All these degrees of freedom secure the accuracy of the analysis. The article shows also the battery throughput cost with a direct comparison to the electricity cost. It becomes clear that batteries can already be cost-effective today without subsidies and irrespective of the electricity price increase, but without a return on investment if the electricity price does not increase more than the inflation. An investor cannot recommend batteries today. However, if the electricity price increases with 4% than batteries become quickly attractive and do not need subsidies. © 2013 Elsevier Ltd.


Welkenhuysen K.,Royal Belgian Institute Of Natural Sciences | Piessens K.,Royal Belgian Institute Of Natural Sciences | Baele J.-M.,University of Mons | Laenen B.,Vlaamse Instelling voor Technologisch Onderzoek | Dusar M.,Royal Belgian Institute Of Natural Sciences
Energy Procedia | Year: 2011

Potential CO2 reservoirs in Belgium are poorly explored. Consequently, the estimated storage capacities are theoretical capacities. The total theoretical storage capacity for Belgium is conservatively estimated at about 1Gt, additional exploration and research are needed to make better capacity assessments. An onset towards prioritising such actions is given here. Deep saline aquifers and coal sequences have created the geological storage options for CO2 in Belgium. The main criteria for reservoir selection and evaluation are reservoir properties, sealing, depth and the occurrence of trapping structures. Aquifer storage opportunities are the Houthem and Maastricht Formations, the Buntsandstein Formation, the Neeroeteren Formation, the Carboniferous Limestone Group (Dinantian) and the Devonian, the latter two in both the north and the south of the country. Of these, the Buntsandstein and the Dinantian reservoirs appear the most promising. Unmined coal sequences have a relatively large capacity, but the low permeability will pose technical difficulties. Storage in abandoned coal mines is likely feasible but pressure and sealing issues will have to be solved. © 2010 Elsevier Ltd. © 2011 Published by Elsevier Ltd.


Da Ponte G.,Vlaamse Instelling voor Technologisch Onderzoek | Ghosh A.K.,SIM Researcher | Kakaroglou A.,Vrije Universiteit Brussel | Van Hemelrijck D.,Vrije Universiteit Brussel | And 2 more authors.
Plasma Processes and Polymers | Year: 2015

3-Aminopropyltriethoxysilane coatings have been deposited on stainless steel (SS) samples by means of an atmospheric pressure dielectric barrier discharge as an adhesive promotion layer in epoxy resin/SS composites. A multi-diagnostic analytical approach (FTIR, XPS) was used for the chemical characterization of the deposited coating with regard to improvement of adhesively bonded joint strength. The effect of a plasma post-treatment after the plasma coating deposition was compared to a thermal post-treatment. Both enhanced the siloxane networking resulting in a significant adhesion improvement. Fracture strength between SS and epoxy was increased with more than 20MPa. Atmospheric plasma deposited siloxane coatings including a plasma post treatment improve the adhesion strength in stainless steel/epoxy hybrids with 20MPa compared to untreated steel samples. Therefore these plasma coatings can be seen as worthy alternatives to more conventional wet chemical coatings with a thermal post treatment. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Mulder G.,Vlaamse Instelling voor Technologisch Onderzoek | Ridder F.D.,Vrije Universiteit Brussel | Six D.,Vlaamse Instelling voor Technologisch Onderzoek
Solar Energy | Year: 2010

Classically electricity storage for PV panels is mostly designed for stand-alone applications. In contrast, we focus in this article on houses connected to the grid with a small-scale storage to store a part of the solar power for postponed consumption within the day or the next days. In this way the house owner becomes less dependent on the grid and does only pay for the net shortage of his energy production. Local storage solutions pave the way for many new applications like omitting over-voltage of the line and bridging periods of power-line black-out. Since 2009 using self-consumption of PV energy is publicly encouraged in Germany, which can be realised by electric storage. This paper develops methods to determine the optimal storage size for grid-connected dwellings with PV panels. From measurements in houses we were able to establish calculation rules for sizing the storage. Two situations for electricity storage are covered: - the storage system is an optimum to cover most of the electricity needs; - it is an optimum for covering the peak power need of a dwelling. After these calculation rules a second step is needed to determine the size of the real battery. The article treats the aspects that should be taken into consideration before buying a specific battery like lead-acid and lithium-ion batteries. © 2010 Elsevier Ltd. All rights reserved.


Khan M.R.,Vrije Universiteit Brussel | Mulder G.,Vlaamse Instelling voor Technologisch Onderzoek | Van Mierlo J.,Vrije Universiteit Brussel
Journal of Power Sources | Year: 2014

In this article, an online state of charge (SoC) estimation framework is proposed, designed and implemented using the system identification approaches. The techniques are composed of cross combination between two modified nonlinear optimisation algorithms (modified Genetic Algorithm and modified Levenberg Marquardt) adapted for battery cell parameter estimation. Subsequently a linear recursive Kalman filter is employed to estimate the state parameters of the battery cell. Moreover, a newly statistical approach is developed to encounter hysteresis phenomena within the cell. The prerequisite for the SoC determination in the electrical vehicle (EV) is challenging as the battery can be composed of hundreds of cells while the load current changes dramatically inside the cells and the required elapsed time for SoC determination should be as short as possible to extend the expected lifetime of the battery pack. Thus, the accurate estimation of the SoC of the cells in a battery pack is one of the key factors for using them effectively. The framework is found to be robust, optimal and implementable in time constrained environment with acceptable accuracy. © 2013 Elsevier Ltd. All rights reserved.

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