| Records |
| Author |
Mortier, S.T.F.C.; Van Hoey, S.; Cierkens, K.; Gernaey, K.V.; Seuntjens, P.; De Baets, B.; De Beer, T.; Nopens, I. |
| Title |
A GLUE uncertainty analysis of a drying model of pharmaceutical granules |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
European journal of pharmaceutics and biopharmaceutics |
Abbreviated Journal |
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| Volume |
85 |
Issue  |
3:b |
Pages |
984-995 |
| Keywords |
A1 Journal article; Pharmacology. Therapy; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
A shift from batch processing towards continuous processing is of interest in the pharmaceutical industry. However, this transition requires detailed knowledge and process understanding of all consecutive unit operations in a continuous manufacturing line to design adequate control strategies. This can be facilitated by developing mechanistic models of the multi-phase systems in the process. Since modelling efforts only started recently in this field, uncertainties about the model predictions are generally neglected. However, model predictions have an inherent uncertainty (i.e. prediction uncertainty) originating from uncertainty in input data, model parameters, model structure, boundary conditions and software. In this paper, the model prediction uncertainty is evaluated for a model describing the continuous drying of single pharmaceutical wet granules in a six-segmented fluidized bed drying unit, which is part of the full continuous from-powder-to-tablet manufacturing line (Consigma (TM), GEA Pharma Systems). A validated model describing the drying behaviour of a single pharmaceutical granule in two consecutive phases is used. First of all, the effect of the assumptions at the particle level on the prediction uncertainty is assessed. Secondly, the paper focuses on the influence of the most sensitive parameters in the model. Finally, a combined analysis (particle level plus most sensitive parameters) is performed and discussed. To propagate the uncertainty originating from the parameter uncertainty to the model output, the Generalized Likelihood Uncertainty Estimation (GLUE) method is used. This method enables a modeller to incorporate the information obtained from the experimental data in the assessment of the uncertain model predictions and to find a balance between model performance and data precision. A detailed evaluation of the obtained uncertainty analysis results is made with respect to the model structure, interactions between parameters and uncertainty boundaries. (C) 2013 Elsevier B.V. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000330200800019 |
Publication Date |
2013-03-29 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0939-6411 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:114876 |
Serial |
8005 |
| Permanent link to this record |
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| Author |
Van De Vijver, E.; Van Meirvenne, M.; Saey, T.; Delefortrie, S.; De Smedt, P.; De Pue, J.; Seuntjens, P. |
| Title |
Combining multi-receiver electromagnetic induction and stepped frequency ground penetrating radar for industrial site investigation |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
European journal of soil science |
Abbreviated Journal |
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| Volume |
66 |
Issue |
4 |
Pages |
688-698 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
The soil at industrial sites is frequently characterized by very heterogeneous properties, which are often related to physical disturbance and contamination. A conventional approach to characterize the soil, with only a limited number of invasive observations, fails to capture the full extent of soil heterogeneity. Proximal soil sensing provides efficient tools to record spatially dense soil information. Nevertheless, because the output of most sensors is affected by more than one soil property, the simultaneous characterization of different soil properties requires the use of multiple sensors. Here, we apply multi-receiver electromagnetic induction (EMI) and stepped frequency ground penetrating radar (GPR) to survey a former gasworks site in a seaport area of Belgium. We used the EMI and GPR sensors in a motorized system to obtain densely sampled measurements of apparent electrical conductivity, apparent magnetic susceptibility and contrasts in relative dielectric permittivity. Our study shows that the sensors give detailed information on the variation in these electromagnetic soil properties. Interpretation of the variation in terms of the stratification of the soil was hampered by localized anthropogenic disturbances. However, the sensors provided complementary information that enabled the identification, discrimination and accurate location of several of these localized disturbances, including underground utility services such as electric cables, buried structures such as the remains of foundations and contamination by salts. Because these represent typical targets in industrial site investigation, we conclude that multi-receiver EMI and stepped frequency GPR provide a useful set of tools to expedite the investigation of industrial sites. |
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| Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000357341900008 |
Publication Date |
2015-02-27 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1351-0754 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:127112 |
Serial |
7684 |
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| Author |
Van Hoey, S.; Nopens, I.; van der Kwast, J.; Seuntjens, P. |
| Title |
Dynamic identifiability analysis-based model structure evaluation considering rating curve uncertainty |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Journal of hydrologic engineering |
Abbreviated Journal |
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| Volume |
20 |
Issue |
5 |
Pages |
04014072 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
When applying hydrological models, different sources of uncertainty are present, and evaluations of model performances should take these into account to assess model outcomes correctly. Furthermore, uncertainty in the discharge observations complicates the model identification, both in terms of model structure and parameterization. In this paper, the authors compare two different lumped model structures (PDM and NAM) considering uncertainty coming from the rating curve. Limits of acceptability for the model simulations were determined based on derived uncertainty bounds of the discharge observations. The authors applied the DYNamic Identifiability Approach (DYNIA) to identify structural failure of both models and to evaluate the configuration of their structures. In general, similar model performances are observed. However, the model structures tend to behave differently in the course of time, as revealed by the DYNIA approach. Based on the analyses performed, the probability based soil storage representation of the PDM model outperforms the NAM structure. The incorporation of the observation error did not prevent the DYNIA analysis to identify potential model structural deficiencies that are limiting the representation of the seasonal variation, primarily indicated by shifting regions of parameter identifiability. As such, the proposed approach is able to indicate where deficiencies are found and model improvement is needed. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000353995400002 |
Publication Date |
2014-03-06 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1084-0699 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:126056 |
Serial |
7829 |
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| Author |
Baken, S.; Salaets, P.; Desmet, N.; Seuntjens, P.; Vanlierde, E.; Smolders, E. |
| Title |
Oxidation of iron causes removal of phosphorus and arsenic from streamwater in groundwater-fed lowland catchments |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Environmental science and technology |
Abbreviated Journal |
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| Volume |
49 |
Issue |
5 |
Pages |
2886-2894 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
The fate of iron (Fe) may affect that of phosphorus (P) and arsenic (As) in natural waters. This study addresses the removal of Fe, P, and As from streams in lowland catchments fed by reduced, Fe-rich groundwater (average: 20 mg Fe L-1). The concentrations of dissolved Fe (<0.45 mu m) in streams gradually decrease with increasing hydraulic residence time (travel time) of the water in the catchment. The removal of Fe from streamwater is governed by chemical reactions and hydrological processes: the oxidation of ferrous iron (Fe(II)) and the subsequent formation of particulate Fe oxyhydroxides proceeds as the water flows through the catchment into increasingly larger streams. The Fe removal exhibits first-order kinetics with a mean half-life of 12 h, a value in line with predictions by a kinetic model for Fe(II) oxidation. The Fe concentrations in streams vary seasonally: they are higher in winter than in summer, due to shorter hydraulic residence time and lower temperature in winter. The removal of P and As is much faster than that of Fe. The average concentrations of P and As in streams (42 mu g P L-1) and 1.4 mu g As L-1) are 1 order of magnitude below those in groundwater (393 mu g P L-1 and 17 mu g As L-1). This removal is attributed to fast sequestration by oxidizing Fe when the water enters oxic environments, possibly by adsorption on Fe oxyhydroxides or by formation of ferric phosphates. The average P and As concentrations in groundwater largely exceed local environmental limits for freshwater (140 mu g P L-1 and 3 mu g As L((-1)), but in streams, they are below these limits. Naturally occurring Fe in groundwater may alleviate the environmental risk associated with P and As in the receiving streams. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000350611100040 |
Publication Date |
2015-02-06 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0013-936x; 1520-5851 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:125409 |
Serial |
8354 |
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| Author |
Boënne, W.; Desmet, N.; Van Looy, S.; Seuntjens, P. |
| Title |
Use of online water quality monitoring for assessing the effects of WWTP overflows in rivers |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Environmental science : processes & impacts |
Abbreviated Journal |
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| Volume |
16 |
Issue |
6 |
Pages |
1510-1518 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
The effects on river water quality of sewer overflows are not well known. Since the duration of the overflow is in the order of magnitude of minutes to hours, continuous measurements of water quality are needed and traditional grab sampling is unable to quantify the pollution loads. The objective of this paper was to demonstrate the applicability of high frequency measurements for assessing the impacts of waste water treatment plants on the water quality of the receiving surface water. In our in situ water quality monitoring setup, two types of multiparameter sensors mounted on a floating fixed platform were used to determine the dynamics of dissolved oxygen, specific conductivity, ammonium-N, nitrate-N and dissolved organic carbon downstream of a waste water treatment plant (WWTP), in combination with data on rainfall, river discharge and WWTP overflow discharge. The monitoring data for water quantity and water quality were used to estimate the pollution load from waste water overflow events and to assess the impact of waste water overflows on the river water quality. The effect of sewer overflow on a small river in terms of N load was shown to be significant. The WWTP overflow events accounted for about 1/3 of the river discharge. The NH4-N loads during overflow events contributed 29% and 21% to the August 2010 and June 2011 load, respectively, in only 8% and 3% of the monthly time span. The results indicate that continuous monitoring is needed to accurately represent the effects of sewer overflows in river systems. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000336841600031 |
Publication Date |
2014-03-18 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2050-7887; 2050-7895 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:118390 |
Serial |
8722 |
| Permanent link to this record |
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| Author |
Van de Vijver, E.; Van Meirvenne, M.; Vandenhaute, L.; Delefortrie, S.; De Smedt, P.; Saey, T.; Seuntjens, P. |
| Title |
Urban soil exploration through multi-receiver electromagnetic induction and stepped-frequency ground penetrating radar |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Environmental science : processes & impacts |
Abbreviated Journal |
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| Volume |
17 |
Issue |
7 |
Pages |
1271-1281 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
In environmental assessments, the characterization of urban soils relies heavily on invasive investigation, which is often insufficient to capture their full spatial heterogeneity. Non-invasive geophysical techniques enable rapid collection of high-resolution data and provide a cost-effective alternative to investigate soil in a spatially comprehensive way. This paper presents the results of combining multi-receiver electromagnetic induction and stepped-frequency ground penetrating radar to characterize a former garage site contaminated with petroleum hydrocarbons. The sensor combination showed the ability to identify and accurately locate building remains and a high-density soil layer, thus demonstrating the high potential to investigate anthropogenic disturbances of physical nature. In addition, a correspondence was found between an area of lower electrical conductivity and elevated concentrations of petroleum hydrocarbons, suggesting the potential to detect specific chemical disturbances. We conclude that the sensor combination provides valuable information for preliminary assessment of urban soils. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000357793300008 |
Publication Date |
2015-06-04 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2050-7887; 2050-7895 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:127130 |
Serial |
8715 |
| Permanent link to this record |
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| Author |
Schneidewind, U.; van Berkel, M.; Anibas, C.; Vandersteen, G.; Schmidt, C.; Joris, I.; Seuntjens, P.; Batelaan, O.; Zwart, H.J. |
| Title |
LPMLE3: A novel 1-D approach to study water flow in streambeds using heat as a tracer |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Water resources research |
Abbreviated Journal |
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| Volume |
52 |
Issue |
8 |
Pages |
6596-6610 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
We introduce LPMLE3, a new 1-D approach to quantify vertical water flow components at streambeds using temperature data collected in different depths. LPMLE3 solves the partial differential equation for coupled water flow and heat transport in the frequency domain. Unlike other 1-D approaches it does not assume a semi-infinite halfspace with the location of the lower boundary condition approaching infinity. Instead, it uses local upper and lower boundary conditions. As such, the streambed can be divided into finite subdomains bound at the top and bottom by a temperature-time series. Information from a third temperature sensor within each subdomain is then used for parameter estimation. LPMLE3 applies a low order local polynomial to separate periodic and transient parts (including the noise contributions) of a temperature-time series and calculates the frequency response of each subdomain to a known temperature input at the streambed top. A maximum-likelihood estimator is used to estimate the vertical component of water flow, thermal diffusivity, and their uncertainties for each streambed subdomain and provides information regarding model quality. We tested the method on synthetic temperature data generated with the numerical model STRIVE and demonstrate how the vertical flow component can be quantified for field data collected in a Belgian stream. We show that by using the results in additional analyses, nonvertical flow components could be identified and by making certain assumptions they could be quantified for each subdomain. LPMLE3 performed well on both simulated and field data and can be considered a valuable addition to the existing 1-D methods. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000383684400051 |
Publication Date |
2016-08-05 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0043-1397; 0043-137x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:144678 |
Serial |
8189 |
| Permanent link to this record |
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| Author |
Van Hoey, S.; Seuntjens, P.; van der Kwast, J.; Nopens, I. |
| Title |
A qualitative model structure sensitivity analysis method to support model selection |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Journal of hydrology |
Abbreviated Journal |
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| Volume |
519 |
Issue |
D |
Pages |
3426-3435 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
The selection and identification of a suitable hydrological model structure is a more challenging task than fitting parameters of a fixed model structure to reproduce a measured hydrograph. The suitable model structure is highly dependent on various criteria, i.e. the modeling objective, the characteristics and the scale of the system under investigation and the available data. Flexible environments for model building are available, but need to be assisted by proper diagnostic tools for model structure selection. This paper introduces a qualitative method for model component sensitivity analysis. Traditionally, model sensitivity is evaluated for model parameters. In this paper, the concept is translated into an evaluation of model structure sensitivity. Similarly to the one-factor-at-a-time (OAT) methods for parameter sensitivity, this method varies the model structure components one at a time and evaluates the change in sensitivity towards the output variables. As such, the effect of model component variations can be evaluated towards different objective functions or output variables. The methodology is presented for a simple lumped hydrological model environment, introducing different possible model building variations. By comparing the effect of changes in model structure for different model objectives, model selection can be better evaluated. Based on the presented component sensitivity analysis of a case study, some suggestions with regard to model selection are formulated for the system under study: (1) a non-linear storage component is recommended, since it ensures more sensitive (identifiable) parameters for this component and less parameter interaction; (2) interflow is mainly important for the low flow criteria; (3) excess infiltration process is most influencing when focussing on the lower flows; (4) a more simple routing component is advisable; and (5) baseflow parameters have in general low sensitivity values, except for the low flow criteria. (C) 2014 Elsevier B.V. All rights reserved. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000347589600057 |
Publication Date |
2014-10-08 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0022-1694 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:123809 |
Serial |
7395 |
| Permanent link to this record |
