Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
See detailApplication of molecular techniques to monitor the evolution of bacterial consortia composed of Clostridium sp. in a hydrogen producing bioreactor
Calusinska, Magdalena ULg; Savichtcheva, Olga; Joris, Bernard ULg et al

Poster (2009, December 11)

Our current dependence on fossil fuels as the primary energy source contributes to global climate change, environmental degradation and health problems. Hydrogen offers a tremendous potential as a clean ... [more ▼]

Our current dependence on fossil fuels as the primary energy source contributes to global climate change, environmental degradation and health problems. Hydrogen offers a tremendous potential as a clean, renewable energy currency and it is compatible with electrochemical and combustion processes for energy conversion without producing carbon – based emissions. Many microorganisms, especially photosynthetic as well as facultative and anaerobic bacteria have been reported to produce large amounts of hydrogen from soluble and insoluble biomass. Clostridia, being obligate anaerobes, are capable of biogas production during ‘dark fermentation’ of a wide range of carbohydrates. In this ARC project, entitled Micro – H2 we have focused on a new direction in bio – hydrogen production systems which is the use of mixed cultures of microorganisms (consortia). We expect that the combination of complementary metabolisms could significantly increase the efficiencies of mixed systems compared to monocultures. However, a few fundamental studies need to be carried out in order to investigate and improve the stability of microbial populations involved in the processes. It is now recognised that molecular microbial ecology tools provide the scientific basis to monitor the processes used in environmental biotechnology. To characterize the diversity of bacterial communities, quantitative techniques such as Real – Time Quantitative PCR and FISH (Fluorescence in situ hybridization) and semi – quantitative DGGE (Denaturing Gradient Gel Electrophoresis) have been optimized and applied on different bioreactor samples. This approach enabled for the temporal monitoring of the evolution of bacterial consortia, both in terms of species dominance and their metabolic activity. Molecular analysis of bacterial consortia allowed for careful examination of interactions between different bacterial species within a consortium, which is crucial in the stabilization of the hydrogen production process. [less ▲]

Detailed reference viewed: 40 (4 ULg)
Full Text
See detailApplication of molecular tools to study the hydrogen production by the bacteria of the genus Clostridium
Calusinska, Magdalena ULg

Doctoral thesis (2012)

L’hydrogène moléculaire a un potential énorme comme futur vecteur énergétique car sa combustion n’est pas polluante. Cependant, les processus industriels actuels de production contribuent ... [more ▼]

L’hydrogène moléculaire a un potential énorme comme futur vecteur énergétique car sa combustion n’est pas polluante. Cependant, les processus industriels actuels de production contribuent substantiellement à l’effet de serre. Au contraire, une production d’H2 qui est neutre en CO2 peut être obtenue par la fermentation anaérobique obscure. Les bactéries du genre Clostridium peuvent fermenter les sucres en H2 et CO2 avec production d’ acide acétique et butyrique qui servent d’accepteurs principaux d’électrons. Cependant, en fonction de la souche/co-culture utilisée et des conditions de culture, des composés plus réduits peuvent être obtenus, par ex. l’éthanol, le lactate, ce qui réduit substantiellement le rendement final en H2. De plus, les différentes voies métaboliques et les circuits de régulation conduisant à la production d’H2 dans les clostridies ne sont pas bien connus. Dans cette étude, nous avons étudié deux sujets principaux. D’une part, nous avons étudié différentes co-cultures de Clostridium spp. dans des bioréacteurs produisant de l’H2. En suivant les co-cultures de C. butyricum et C. pasteurianum par FISH (Fluorescence in situ hybridisation) et qPCR (quantitative real-time PCR), nous avons montré que les deux espèces co-existent de manière stable durant la fermentation de différents sucres dans deux bioréacteurs. D’autre part, en utilisant Clostridium butyricum CWBI1009 comme modèle, nous avons étudié le métabolisme complexe de l’H2 chez les clostridies. La découverte de gènes nouveaux codant pour des hydrogènases [FeFe] dans les génomes séquencés a changé notre vue de la façon dont ces microbes produisent l’ H2. En effet, en utilisant différents outils moléculaires (2D-DIGE, RT-qPCR et RNA-seq), nous avons montré que dans différents conditions de milieu, différentes hydrogénases contribuent à la production d’H2. De plus, sous atmosphère d’N2 pendant la fermentation du glucose dans des conditions de pH non régulées, nous observons que la nitrogénase contribue à la production globale d’H2. De manière surprenante, alors que les clostridies semblent bien équipées pour produire de l’H2, elles n’ont probablement développé cette capacité que pour s’adapter rapidement aux variations de conditions, cad la diminution du pH. Donc, pour maintenir un pH intracellulaire constant, elles rejettent les protons (sans doute sous forme de H2) dans le milieu. Ainsi, elles se débarrassent de l’excès d’équivalents réducteurs produits pendant la fermentation du glucose. En résumé, nos résultats contribuent à une meilleure connaissance du métabolisme complexe de l’H2 chez les clostridies. Cependant, un défi pour le futur consiste à caractériser les enzymes responsables de ce métabolisme et, par bioengineering métabolique, de développer des systèmes microbiens optimaux pour la conversion de la biomasse en H2. [less ▲]

Detailed reference viewed: 186 (22 ULg)
Full Text
Peer Reviewed
See detailApplication of MRI for improved local control in complex radiotherapy of cervical cancer
Janaki, Hadjiev; Zsolt, Cselik; Péter Bogner et al

in Archive of Oncology (2006), 14(3-4), 95-100

Background: The aim of this study was to analyze the use of magnetic resonance imaging (MRI) as a modern medical imaging technique in radiotherapy with special emphasis on the integration of MRI and a ... [more ▼]

Background: The aim of this study was to analyze the use of magnetic resonance imaging (MRI) as a modern medical imaging technique in radiotherapy with special emphasis on the integration of MRI and a novel technique in brachytherapy to optimize treatment outcome in cervical cancer. Methods: In addition to the CT based shrinking volume conformal teletherapy in 31 patients with locally advanced cervical cancer, MRI examination with a special adjustable applicator at the treatment site was performed for the brachytherapy planning. To avoid excessive doses to the healthy structures during complex cervical radiotherapy isodose curves were calculated upon the information of the MR image and dose distribution was evaluated. Results: The consecutive application of CT and MRI limited the possibility for overdosage of the critical organs and undertreatment of the advanced tumor spread in all cases. The overall response rate for the complex treatment was 74.2% with complete regression in 25.8% of the cases. Based on the exact information of the three dimensional digital data radiation doses could be optimized without increasing the possibility of acute complications rate. Conclusion: The introduction of 3D treatment planning for teletherapy pelvic and boost irradiation of cervical carcinoma as well as for the brachytherapy part of the complex treatment is to be recommended. [less ▲]

Detailed reference viewed: 20 (0 ULg)
Full Text
Peer Reviewed
See detailApplication of multi-dimensional GC techniques to the analysis of cigarette smoke
Ticha, J; Bishop, L; Brokl, M et al

Conference (2014, September)

Detailed reference viewed: 7 (2 ULg)
Full Text
See detailApplication of multi-scale variography for inferring the spatial variability of the hydraulic conductivity of a sandy aquifer
Rogiers, Bart; Vienken, Thomas; Gedeon, M et al

Poster (2014, April 28)

In the framework of the disposal of short-lived low- and intermediate-level radioactive waste in a near-surface disposal facility in Dessel (Belgium), extensive characterization of the hydraulic ... [more ▼]

In the framework of the disposal of short-lived low- and intermediate-level radioactive waste in a near-surface disposal facility in Dessel (Belgium), extensive characterization of the hydraulic conductivity (K) in the shallow Neogene aquifer has been performed at a regional scale. In the last few years the small-scale heterogeneity has been additionally characterized by outcrop analogue, hydraulic direct push, and borehole core air permeameter studies. The gathered data now include a) more than 350 hydraulic conductivity measurements on samples from 8 cored boreholes, mostly reaching depths of 50 m and data at 2 m intervals, b) more than 5000 air permeability measurements on the same borehole cores, c) more than 250 cone penetration tests (CPTs) with depths down to 40 m and data at 2 cm intervals, d) over 100 dissipation tests performed during the CPT campaigns, e) 17 direct push injections loggings, 6 hydraulic profiling tool logs, and 6 direct push slug tests, f) several hundreds of air permeability measurements on outcrop analogues of the aquifer sediments, and g) numerous grain size analyses. The current study aims to quantify the heterogeneity of K from the centimetre- to the kilometre-scale and to check the compatibility of the spatial variability revealed by the different datasets. This is achieved through gathering all K values (either direct measurements, calibrated relative K values, or K estimates from secondary data), and the use of variography to quantify spatial variability in terms of two-points geostatistics. The results are discussed, and the main differences between the different data sources are explained. In a final step, different multi-scale variogram models are proposed for capturing the main characteristics of multi-scale variability within the shallow Neogene aquifer in Belgium. [less ▲]

Detailed reference viewed: 28 (3 ULg)
Full Text
See detailApplication of multiple-point geostatistics on groundwater flow and transport in media with complex geological heterogeneity: lessons learnt and remaining challenges
Huysmans, Marijke; Dassargues, Alain ULg

in Proceedings (2014, July 09)

Multiple-point geostatistics has been increasingly applied on groundwater problems in the last ten years. Several case studies have been published indicating simulating realistic geological heterogeneity ... [more ▼]

Multiple-point geostatistics has been increasingly applied on groundwater problems in the last ten years. Several case studies have been published indicating simulating realistic geological heterogeneity using multiple-point geostatistics can significantly improve groundwater flow and solute transport predictions. There are however several remaining challenges when applying multiple-point geostatistics to groundwater problems often suffering from data scarcity. These challenges might be the reason why multiple-point has been used to a much lesser extent by practitioners than by researchers. This paper gives an overview of the current challenges and discusses new advancements to overcome them. The following questions will be discussed: How to obtain 3D training images? Can the representativity of the used training image be validated ? How sensitive are groundwater calculations to the selection of the training image? Is it worth incorporating fine scale geological heterogeneity in groundwater problems or are other features (boundary conditions, data uncertainty/quality, …) more important for improving predictions? How can multiple-point geostatistics be used without suffering from very long computation times for the numerical models? Is overparametrization of groundwater models an issue ? What are the practical obstacles to apply multiple-point geostatistics by groundwater practitioners? [less ▲]

Detailed reference viewed: 44 (3 ULg)
Full Text
Peer Reviewed
See detailApplication of multiple-point geostatistics on modelling groundwater flow and transport in a cross-bedded aquifer
Huysmans, Marijke; Dassargues, Alain ULg

in Hydrogeology Journal (2009), 17(8), 1901-1911

Sedimentological processes often result in complex three-dimensional subsurface heterogeneity of hydrogeological parameter values. Variogram-based stochastic approaches are often not able to describe ... [more ▼]

Sedimentological processes often result in complex three-dimensional subsurface heterogeneity of hydrogeological parameter values. Variogram-based stochastic approaches are often not able to describe heterogeneity in such complex geological environments. This work shows how multiple-point geostatistics can be applied in a realistic hydrogeological application to determine the impact of complex geological heterogeneity on groundwater flow and transport. The approach is applied to a real aquifer in Belgium that exhibits a complex sedimentary heterogeneity and anisotropy. A training image is constructed based on geological and hydrogeological field data. Multiple-point statistics are borrowed from thistraining image to simulate hydrofacies occurrence, while intrafacies permeability variability is simulated using conventional variogram-based geostatistical methods. The simulated hydraulic conductivity realizations are used as input to a groundwater flow and transport model to investigate the effect of small-scale sedimentary heterogeneity on contaminant plume migration. Results show that small-scale sedimentary heterogeneity has a significant effect on contaminant transport in the studied aquifer. The uncertainty on the spatial facies distribution and intrafacies hydraulic conductivity distribution results in a significant uncertainty on the calculated concentration distribution. Comparison with standard variogram-based techniques shows that multiple-point geostatistics allow better reproduction of irregularly shaped low-permeability clay drapes that influence solute transport. [less ▲]

Detailed reference viewed: 91 (16 ULg)
Full Text
Peer Reviewed
See detailApplication of multiple-point geostatistics on modelling groundwater flow and transport in a cross-bedded aquifer
Huysmans, Marijke; Dassargues, Alain ULg

in Atkinson, P. M. M.; Lloyd, C. D. D. (Eds.) GeoENV VII – Geostatistics for Environmental Applications, Quantitative Geology and Geostatistics (2010)

In this work, the problem of modelling groundwater flow and transport in a heterogeneous environment with complex geological structures is addressed. This study demonstrates how a training image can be ... [more ▼]

In this work, the problem of modelling groundwater flow and transport in a heterogeneous environment with complex geological structures is addressed. This study demonstrates how a training image can be constructed based on geological and hydrogeological field data and how multiple-point geostatistics can be applied to determine the impact of complex geological heterogeneity on groundwater flow and transport in a real aquifer. [less ▲]

Detailed reference viewed: 60 (12 ULg)
Full Text
See detailApplication of multiple-point geostatistics on modelling pumping tests and tracer tests in heterogeneous environments with complex geological structures
Huysmans, Marijke; Dassargues, Alain ULg

in Geophysical Research Abstracts (2014, April 28)

In heterogeneous environments with complex geological structures, analysis of pumping and tracer tests is often problematic. Standard interpretation methods do not account for heterogeneity or simulate ... [more ▼]

In heterogeneous environments with complex geological structures, analysis of pumping and tracer tests is often problematic. Standard interpretation methods do not account for heterogeneity or simulate this heterogeneity introducing empirical zonation of the calibrated parameters or using variogram-based geostatistical techniques that are often not able to describe realistic heterogeneity in complex geological environments where e.g. sedimentary structures, multi-facies deposits, structures with large connectivity or curvi-linear structures can be present. Multiple-point geostatistics aims to overcome the limitations of the variogram and can be applied in different research domains to simulate heterogeneity in complex environments. In this project, multiple-point geostatistics is applied to the interpretation of pumping tests and a tracer test in an actual case of a sandy heterogeneous aquifer. This study allows to deduce the main advantages and disadvantages of this technique compared to variogram-based techniques for interpretation of pumping tests and tracer tests. A pumping test and a tracer test were performed in the same sandbar deposit consisting of cross-bedded units composed of materials with different grain sizes and hydraulic conductivities. The pumping test and the tracer test are analyzed with a local 3D groundwater model in which fine-scale sedimentary heterogeneity is modelled using multiple-point geostatistics. To reduce CPU and RAM requirements of the multiple-point geostatistical simulation steps, edge properties indicating the presence of irregularly-shaped surfaces are directly simulated. Results show that for the pumping test as well as for the tracer test, incorporating heterogeneity results in a better fit between observed and calculated drawdowns/concentrations. The improvement of the fit is however not as large as expected. In this paper, the reasons for these somewhat unsatisfactory results are explored and recommendations for future applications of multiple-point geostatistics on pumping tests and tracer tests are formulated. [less ▲]

Detailed reference viewed: 19 (0 ULg)
Peer Reviewed
See detailApplication of near infrared reflectance spectroscopy (NIRS) for predicting chemical composition, cellulase digestiblity of organic matter and energy values of compound feedstuffs for ruminants.
Verheggen, S.; Dardenne, Pierre; Thewis, André ULg et al

in Biston, Robert; Barthiaux-Thill, Nicole (Eds.) Proceedings of the Third International Conference on Near Infrared Spectroscopy, vol.1 (1990)

Detailed reference viewed: 41 (6 ULg)
Peer Reviewed
See detailApplication of neural networks in quality control of 'Jonagold' apples
Leemans, Vincent ULg; Bieuvelet, Frédéric; Destain, Marie-France ULg

in Bellon-Maurel, Véronique (Ed.) Sensoral 98 - International workshop on sensing quality of agricultural products (1998, February)

This paper studies the possibilities to grade the 'Jonagold', a bicolour apple, using neural networks and Fisher"s linear discriminant analysis. In a first step the pixels are sorted into three areas, the ... [more ▼]

This paper studies the possibilities to grade the 'Jonagold', a bicolour apple, using neural networks and Fisher"s linear discriminant analysis. In a first step the pixels are sorted into three areas, the blush colour area, the intermediate colour area and the ground colour area; the accuracy reached 95% with the neural networks. Int the second step the fruit are graded into four categories on their ground colour basis; the accuracy reached 68%whatever the method used. It si also shown that there is no need to separate the ground colour and the intermediate colour to compute the ground colour classification parameters. [less ▲]

Detailed reference viewed: 45 (3 ULg)
Full Text
Peer Reviewed
See detailApplication of new Eurocode 3 formulae for beam-columns to class 3 hollow section members
Boissonnade, Nicolas; Weynand, K.; Jaspart, Jean-Pierre ULg

in Proceedings of the 12th International Symposium on Tubular Structures (2008)

Detailed reference viewed: 42 (6 ULg)
Full Text
Peer Reviewed
See detailApplication of new methodologies based on design of experiments, independent component analysis and design space for robust optimization in liquid chromatography
Debrus, Benjamin ULg; Lebrun, Pierre ULg; Ceccato, Attilio ULg et al

in Analytica Chimica Acta (2011), 691

HPLC separations of an unknown sample mixture and a pharmaceutical formulation have been optimized using a recently developed chemometric methodology proposed by W. Dewé et al. in 2004 and improved by P ... [more ▼]

HPLC separations of an unknown sample mixture and a pharmaceutical formulation have been optimized using a recently developed chemometric methodology proposed by W. Dewé et al. in 2004 and improved by P. Lebrun et al. in 2008. This methodology is based on experimental designs which are used to model retention times of compounds of interest. Then, the prediction accuracy and the optimal separation robustness, including the uncertainty study, were evaluated. Finally, the design space (ICH Q8(R2) guideline) was computed as the probability for a criterion to lie in a selected range of acceptance. Furthermore, the chromatograms were automatically read. Peak detection and peak matching were carried out with a previously developed methodology using independent component analysis published by B. Debrus et al. in 2009. The present successful applications strengthen the high potential of these methodologies for the automated development of chromatographic methods. [less ▲]

Detailed reference viewed: 160 (43 ULg)
Full Text
See detailApplication of next generation sequencing for study and diagnosis of plant viral diseases in agriculture
van der Vlugt, René; Minafra, Angelanotio; Olmos, Antonio et al

Poster (2015, August)

Detailed reference viewed: 30 (1 ULg)
Full Text
See detailApplication of NIR hyperspectral imaging combined to chemometrics to assess the impact of tillage on the root system development of a winter wheat crop
Fraipont, Guillaume ULg; Eylenbosch, Damien ULg; Baeten, Vincent et al

Poster (2016, July)

This poster presents de results of a study of the influence of tillage on the root development of a winter wheat crop. The originality of this research lies in the application of an innovative root ... [more ▼]

This poster presents de results of a study of the influence of tillage on the root development of a winter wheat crop. The originality of this research lies in the application of an innovative root quantification method based on the near infrared hyperspectral imaging. [less ▲]

Detailed reference viewed: 16 (4 ULg)
See detailApplication of NMR to Identification of Metabolites
Frederich, Michel ULg

Scientific conference (2006, April 07)

Detailed reference viewed: 9 (4 ULg)
Full Text
Peer Reviewed
See detailApplication of non-stationary iterative methods to an exact Newton-Raphson solution process for power flow equations
Bacher, Rainer; Bullinger, Eric ULg

in 12th Power Systems Computation Conference (1996)

AC power flow problems are usually solved by the Newton-Raphson solution method. The main step is the linearization of the nonlinear power flow equations and the subsequent solution of this linear system ... [more ▼]

AC power flow problems are usually solved by the Newton-Raphson solution method. The main step is the linearization of the nonlinear power flow equations and the subsequent solution of this linear system. The characteristics of this linear system of equations vary for different power flow implementations; symmetric/unsymmetric, positive definite/indefinite system matrices can result. Based on these characteristics, different direct and iterative linear system solvers can be used to maximize performance and solution robustness. In this paper, results are given of nonstationary iterative methods for unsymmetric, indefinite linear systems derived from power flow equations [less ▲]

Detailed reference viewed: 65 (0 ULg)
Full Text
See detailApplication of nuclear scintigraphy to evaluation of pulmonary function
Votion, Dominique ULg

in In Proceedings: 17th Comparative Respiratory Society Meeting (1999, October)

Nuclear imaging techniques have a long history in pulmonary medicine and the clinical and experimental uses of lung scintigraphy have largely expanded these last years. Currently, the pulmonary ... [more ▼]

Nuclear imaging techniques have a long history in pulmonary medicine and the clinical and experimental uses of lung scintigraphy have largely expanded these last years. Currently, the pulmonary applications of nuclear scintigraphy are essentially: (I), the study of regional lung function; (II), the imaging of pulmonary infection and/or inflammation; (III), the determination of inflammatory cells involvement in lung diseases; (IV), the assessment of the alveolar-capillary barrier integrity; (V), the imaging of lung cancers and (VI), the study of aerosol deposition within the lung. Many faculty of veterinary medicine have acquired nuclear imaging facilities. The primary application of scintigraphy is in the investigation of equine orthopaedic conditions and, with the exception of rodents, only a few publications report the use of lung scintigraphy in any animal species. Nevertheless, lung scintigraphy using animals would be of great interest to better understand the lung physiology in general as well as animals’ peculiarities in particular. Following a brief introduction to the technique, this paper will review the main applications of pulmonary scintigraphy and will survey some new nuclear imaging techniques that should be available in the next future. [less ▲]

Detailed reference viewed: 18 (5 ULg)
Full Text
Peer Reviewed
See detailApplication of PIXE and PIGE under variable ion beam incident angle to several fields of archaeometry
Weber, Georges ULg; Martinot, L.; Strivay, David ULg et al

in X-Ray Spectrometry [=XRS] (2005), 34(4, JUL-AUG), 297-300

For several years, the specific features of PIXE and PIGE have made them very attractive in the field of archaeometry. Among them, non-destructivity is one of the most important. The possibility of ... [more ▼]

For several years, the specific features of PIXE and PIGE have made them very attractive in the field of archaeometry. Among them, non-destructivity is one of the most important. The possibility of working under atmospheric pressure is also important because of the very different shapes and sizes of the artefacts concerned. However, these ion beam techniques suffer from the same disadvantage: the information coming from x-rays or),brays produced at different places along the charged particle path is integrated. That prevents one from taking into account the possible element concentration gradients due to multilayered systems or diffusion processes. This paper presents several applications of PIXE and PIGE applied under variable ion beam incident angle. PIGE has been mainly used for studying ancient glass items or glass windows in order to detect or evaluate the glass corrosion process. The examples given for PIGE deal with Roman and Merovingian glass objects and cathedral glass windows and PIXE applications concern studies for resolving the multilayered structure of easel paintings. The set-up allowing one to perform the measurements should be very stable, the rotation axis should pass through the beam axis and the detector should follow the sample movement. Copyright (c) 2005 John Wiley [less ▲]

Detailed reference viewed: 35 (4 ULg)