References of "Lambert, Stéphanie"
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See detailStructural and optoelectronic properties of SnO2 thin films doped by group-1A elements
Benhebal, Hadj; Benrabah, Bedhiaf; Ammari, Aek et al

in Surface Review and Letters (2018), 25

This paper presents the results of an experimental work devoted to the synthesis and the characterization of tin dioxide (SnO2 Þ thin layers doped with group-IA elements (Li, Na and K). The materials were ... [more ▼]

This paper presents the results of an experimental work devoted to the synthesis and the characterization of tin dioxide (SnO2 Þ thin layers doped with group-IA elements (Li, Na and K). The materials were synthesized by the sol–gel method and deposited by dip-coating, using tin (II) chloride dihydrate as a source of tin and absolute ethyl alcohol as solvent. Thin ¯lms prepared were characterized by several techniques including X-ray di®raction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (IR), visible and ultraviolet spectroscopy and complex impedance method. The results obtained show that the materials kept their tetragonal rutile structure with preferred orientation of (101), whereas doping leads to a reduction of their energy band gap. The complex impedance analysis suggests that the di®erent processes occurring at the electrode interface are modeled by an electrical circuit not a®ected by the doping. [less ▲]

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See detailCatalytic reforming of biomass gasification tars with bimetallic catalysts
Wolfs, Cédric ULg; Claude, Vincent; Lambert, Stéphanie ULg

Poster (2017, September 07)

The thermochemical method called “biomass gasification” is generating emphatic interest for the production of bio-Syngas (CO+H2) since this process presents the advantage of being renewable without ... [more ▼]

The thermochemical method called “biomass gasification” is generating emphatic interest for the production of bio-Syngas (CO+H2) since this process presents the advantage of being renewable without emitting CO2. However, in practical applications, there are still some technical problems due to high concentration of tars in the outlet gas, which can condensate and clog the pipes. Previous studies have highlighted the fact that the tar elimination via catalytic reforming seem to be the more practical and economical solution. Reforming catalysts present the following properties : a tailored mesoporous texture for the support and the high dispersion of active sites like metallic nanoparticles (Ni, Pd, Fe,…) [1]. In this work, Ni based alumina catalysts and doped with a second metal (Co, Cu, Fe, Mn, Mo) are synthesized by an aqueous sol-gel process. [less ▲]

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See detailOptimization of hydroxyapatite synthesis via sol-gel process for bone reconstruction application
Tilkin, Rémi ULg; Regibeau, Nicolas ULg; Grandfils, Christian ULg et al

Poster (2017, September 07)

During the past few years, tissue engineering has become one of the most promising techniques to maintain, improve, or reconstruct human tissue, even complete human organs. This solution is frequently ... [more ▼]

During the past few years, tissue engineering has become one of the most promising techniques to maintain, improve, or reconstruct human tissue, even complete human organs. This solution is frequently based on the realization of temporary porous matrices, also called "scaffolds". Scaffolds are highly porous matrices notably designed to structure the development of cells, but also to guarantee the function of the implant during the regeneration process. Several materials have been proposed for the conception of scaffold. These have to meet strict criteria regarding biocompatibility, degradability, mechanical and surface properties. As a result of their biomimetism, bioceramics, like hydroxyapatite (Ca5(PO4)3(OH)), have been widely developed during the past few years for bone reconstruction. The aim of this study is the optimization of the synthesis of hydroxyapatite by sol-gel process to be used in the conception of scaffold for bone reconstruction application. In this optic, powder obtained from two synthesis processes (wet precipitation and sol-gel process) were compared with commercial hydroxyapatite. For wet precipitation process, calcium nitrate and phosphoric acid were used as reagent. For sol-gel process, calcium acetate was used as the source of calcium and triethylphosphate as the source of phosphate. Reagents were mixed and the solution was aged. The powder was then dried and sintered. Finally, particles were washed in HCl to remove CaO and then dried. Those new materials were characterized, particularly in terms of chemical composition (XRD, FTIR), crystallinity (XRD), morphology (SEM, TEM), size (TEM, DLS) and Ca/P ratio (EDX). [less ▲]

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See detailHighly efficient doped nanocristalline TiO2 for water Treatment
Mahy, Julien ULg; Léonard, Géraldine ULg; Zubiaur, Anthony ULg et al

Conference (2017, July 13)

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See detailAdvanced oxidative treatment for waste water contaminated by pharmaceutical products
Wolfs, Cédric ULg; Vreuls, Christelle; Gillard, Nathalie et al

Conference (2017, July 12)

The objective of this study is to determine operational processes for advanced oxidative treatment of waste waters contaminated with pharmaceutical products. The aim is to validate a physico-chemical ... [more ▼]

The objective of this study is to determine operational processes for advanced oxidative treatment of waste waters contaminated with pharmaceutical products. The aim is to validate a physico-chemical process that has to be placed downstream a classical biological treatment in existing waste water treatment plants (domestic, industrial or hospital). [less ▲]

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See detailEffect of surface modification of polylactides on fibroblasts L-929 and osteoblasts MG-63
Tilkin, Rémi ULg; Regibeau, Nicolas ULg; Lambert, Stéphanie ULg et al

Conference (2017, July 12)

During the past few years, tissue engineering has become one of the most promising techniques to maintain, improve, or reconstruct human tissue, even complete human organs. This solution is frequently ... [more ▼]

During the past few years, tissue engineering has become one of the most promising techniques to maintain, improve, or reconstruct human tissue, even complete human organs. This solution is frequently based on the realization of temporary porous matrices, also called "scaffolds", design as model and structure for the development of cells. Surface properties of those biomaterials are some determinant criteria for cell adhesion and proliferation. The scope of this work is the study of adhesion and proliferation of fibroblasts L-929 and osteoblasts MG-63 on untreated, hydrolyzed or aminolyzed polylactides. First, these substrates are developed: poly-L,D-lactide (PDLLA) powder is pressed into disks. The surface of disks was chemically modified by hydrolysis and aminolysis surface treatments. Surface modifications were based on previous studies. [1,2] The hydrolysis process is carried out by immersing PDLLA disks in 2 M NaOH for 20 min at room temperature (24°C) under constant agitation. The aminolysis process is performed by placing PDLLA disks in 15 % ethylenediamine in isopropanol for 5 min at room temperature (24°C) under constant agitation. Substrates are characterized by optical microscopy, Scanning Electron Microscopy and water contact angle. Finally, cell adhesion, proliferation, and viability on these substrates are assessed by cell counting and MTT assay after 1, 4, and 8 days of cell culture. Results from surface characterization show an increase of roughness for hydrolyzed polylactide. Regarding water contact angle measurements, values are smaller on treated substrates even though the difference with untreated substrates appears smaller than expected in the literature. [1,2] Cell counting and MTT assay show an increase of cell proliferation and cell viability for treated polylactide substrates in the case of fibroblasts and a decrease of cell proliferation for aminolyzed polylactide substrates in the case of osteoblasts. In conclusions, this work highlights the different effects of surface modification on fibroblasts and osteoblasts viability. References : [1]. Wang YQ, Cai JY. Enhanced cell affinity of poly(L-lactic acid) modified by base hydrolysis: wettability and surface roughness at nanometer scale. Current Applied Physics 2007, 7(S1):e108–e111. [2]. Lin Y, Chrzanowski W, Knowles J, Bishop A, Bismarck A. Functionalized poly(D,L-lactide) for pulmonary epithelial cell culture. Advanced Engineering Materials 2010, 12(4): B101–B112. [less ▲]

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See detailAdvanced oxidative treatment for waste water contamined by pharmaceutical products
Belet, Artium ULg; Vreul, Christelle; Gillard, Nathalie et al

Conference (2017, July 07)

The objective of this study is to determine operational processes for advanced oxidative treatment of waste waters contaminated with Pharmaceutical Products (PPs). The aim is to validate a physico ... [more ▼]

The objective of this study is to determine operational processes for advanced oxidative treatment of waste waters contaminated with Pharmaceutical Products (PPs). The aim is to validate a physico-chemical process combining ozonation and photocatalysis and that has to be placed downstream a classical biological treatment in existing waste water treatment plants (WWTP - domestic, industrial or hospital). [less ▲]

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See detailCatalytic reforming of gasification tars with bi- and trimetallic catalysts optimized with organosilane precursors
Claude, Vincent ULg; Lambert, Stéphanie ULg

Poster (2017, March 07)

Biomass gasification is interesting for the production of CO + H2 from wastes and catalysts are necessary for tars degradation. Catalysts were synthesized by the sol-gel process to develop γ-Al2O3 doped ... [more ▼]

Biomass gasification is interesting for the production of CO + H2 from wastes and catalysts are necessary for tars degradation. Catalysts were synthesized by the sol-gel process to develop γ-Al2O3 doped with 10%wt of nickel and 2 wt.% of a second dopant (Co, Cu, Fe, Mn, Mo). Before their adding in AlOOH sol, metallic dopants were complexed with (OCH3)3-Si-(CH2)3-NH-(CH2)2-NH2 (EDAS) to increase their dispersion by cogelation between EDAS and AlOOH clusters. These catalysts were tested at 650°C for toluene reforming. [less ▲]

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See detailCopper adsorption from wasterwater using bone charcoal
Ghrab, Sana; Benzina, Mourad; Lambert, Stéphanie ULg

in Advances in Materials Physics and Chemistry (2017), 7

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See detailAdsorption of terpenic compounds onto organo-palygorskite
Ghrab Sana; Eloussaief, Mabrouk; Lambert, Stéphanie ULg et al

in Environmental Science and Pollution Research (2017)

Essential oils of aromatic plants are currently mentioned as suitable tools for excellent protection of stored grains from insect pest attacks. The present work aimed to study the processes of the ... [more ▼]

Essential oils of aromatic plants are currently mentioned as suitable tools for excellent protection of stored grains from insect pest attacks. The present work aimed to study the processes of the synthesis insecticidal formulation. The active terpenic compounds of essential oil of eucalyptus globulus were fixed in the palygorskite by adsorption process. Two samples types of palygorskites were used; raw and organo-palygorskite. The palygorskite clays were characterized by different physicochemical techniques including X-RAY Diffraction (XRD), Fourier Transformed Infra Red (FTIR) analyses, Thermogravimetric analysis (TG) and differential thermal analysis (DTA), (BET) and Scanning Electron Microscope (SEM). Results reveal that the raw clay has a fibrous structure with impurities essential calcite. These structures and physicochemical properties of raw palygorskite and organo-palygorskite give it the potential of material adsorbent. Results show that the adsorption capacity strongly depends on affinity between terpenic compounds and organic cations rather than on interlayer distance of organo-palygorskite. The highest adsorption capacity of terpenic compounds is acquired with palygorskite interlaced by DDDMA. These results validated the potential utility of the Paly-DDDMA as adsorbents fibrous clay for the retention of terpenic compounds in application of environmental preservation. [less ▲]

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See detailEthylene polymerization and hydrodechlorination of 1,2-dichloroethane mediated by nickel(II) covalently anchored to silica xerogels
Mahy, Julien ULg; Claude, Vincent ULg; Sacco, Luigi et al

in Journal of Sol-Gel Science and Technology (2017), 81(1), 59-68

Ni/SiO2 cogelled xerogel catalysts have been prepared in ethanol containing nickel acetylacetonate, tetraethoxysilane (TEOS), an aqueous ammonia solution of 0.54 mol L-1 and either a commercial sylilated ... [more ▼]

Ni/SiO2 cogelled xerogel catalysts have been prepared in ethanol containing nickel acetylacetonate, tetraethoxysilane (TEOS), an aqueous ammonia solution of 0.54 mol L-1 and either a commercial sylilated ligand, 3-(2-aminoethyl)aminopropyltrimethoxysilane (EDAPMS), or a home-made new silylated pyrazolypyridine ligands, respectively 2-[4-[3-(trimethoxysilyl)propyl]-3,5-dimethyl-1H-pyrazol-1-yl]pyridine (MS-PzPy) and 2-[4-[3-(trimethoxysilyl)propyl]-3,5-dimethyl-1H-pyrazol-1-yl]-6-methylpyridine (MS-PzPyMe), able to form a chelate with a metal ion such as Ni2+. All samples form homogeneous and very highly dispersed Ni/SiO2 cogelled xerogel catalysts. The resulting catalysts are composed of nickel nanoparticles with a diameter of about 2.8 nm, located inside primary silica particles exhibiting a monodisperse microporous distribution. The silylated organic ligand has a strong influence on the textural properties of cogelled xerogel catalysts, both before and after calcination and reduction steps. Changing the nature of the silylated ligand permits tailoring textural properties such as pore volume, pore size and surface area. Homogenous nickel complexes synthesized from pyrazolylpyridine derivatives are inactive for ethylene polymerization. In opposite, heterogenous nickel-based catalysts onto silica xerogel synthesized from pyrazolylpyridine derivatives bearing a tethered trialkoxysilyl group allow increasing ethylene polymerization activity. Although nickel nanoparticles are located inside the silica crystallites, their complete accessibility, via the micropore network, has been shown. For 1,2-dichloroethane hydrodechlorination over Ni/SiO2 catalysts, the conversion of 1,2-dichloroethane is high at the temperature of 350°C and mainly ethane is produced. [less ▲]

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See detailTowards a large scale aqueous sol-gel synthesis of doped TiO2: Study of various metallic dopings for the photocatalytic degradation of p-nitrophenol
Mahy, Julien ULg; Lambert, Stéphanie ULg; Léonard, Géraldine ULg et al

in Journal of Photochemistry and Photobiology A : Chemistry (2016), 329

In this paper, an easy aqueous sol-gel synthesis developed previously by Mahy et al. [J. Sol-Gel Sci. Technol. (2016)] is adapted to produce highly active TiO2 catalysts doped with Fe3+, Ag+, Cu2+, Zn2 ... [more ▼]

In this paper, an easy aqueous sol-gel synthesis developed previously by Mahy et al. [J. Sol-Gel Sci. Technol. (2016)] is adapted to produce highly active TiO2 catalysts doped with Fe3+, Ag+, Cu2+, Zn2+, Cr3+, Al3+, Mn2+, and Co2+ ions and Pt metallic nanoparticles. Samples are characterized by inductively coupled plasma–atomic emission spectroscopy (ICP-AES), X-ray diffraction (XRD), Mössbauer spectroscopy, transmission electron microscopy (TEM), nitrogen adsorption–desorption measurements and diffuse reflectance spectroscopy measurements. Results show that the samples are composed of anatase-brookite TiO2 nanoparticles with a spherical shape and mean diameter of around 5-8 nm and a surface area of between about 150 - 250 m2 g-1. In each doped sample, the dopant is present in the form added during the synthesis, given that the sample has not undergone any particular treatment. Photoactivity tests show improvement in catalyst activity for Fe3+, Ag+, Cu2+, Zn2+, and Al3+ ion and Pt metallic nanoparticle dopants, while a decrease of activity is obtained for Cr3+, Mn2+ and Co2+ ion dopants. For some dopants, the activity of TiO2 doped with metallic ions and synthesized from the aqueous sol-gel process is equal or superior to the activity of the commercial photocatalyst Degussa P25. Some mechanisms are proposed to explain these modifications of activity with doping. Furthermore, cost comparison at laboratory scale showed that Zn and Cu nitrate salt dopings are clearly less expensive for a halogen light (UV/visible) or low energy light enhanced catalyst and may be considered for industrial applications. Using this method, a large scale Zn-doped TiO2 photocatalyst is synthesized with properties homologous to the lab-scale product. Results show that the aqueous sol-gel synthesis developed previously can be easily adapted for doping in order to produce an up-scalable synthesis. [less ▲]

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See detailIntegrated Project with Focus on Energy Transition and Circular Economy for Developing Engineering Students' Soft Skills
Léonard, Grégoire ULg; Pfennig, Andreas ULg; Toye, Dominique ULg et al

Poster (2016, September 05)

The present work reports the experience of an integrated project developed at the University of Liege for master students in chemical engineering. The goals are to promote the acquisition of soft skills ... [more ▼]

The present work reports the experience of an integrated project developed at the University of Liege for master students in chemical engineering. The goals are to promote the acquisition of soft skills and to consolidate technical knowledge by integrating and linking chemical engineering disciplines usually taught separately. A case study was selected to address some of the challenges related to energy transition: students had to design the energy system of a remote island and make it as energy independent and CO2-neutral as possible by 2030. The course of action during the academic year, the assessment of soft skills, and the tools offered to ease the mentoring and encourage the acquisition of soft skills are described. Not all implemented techniques performed equally well, and this project finally appeared to be a challenge for the teaching team as well. 1 Introduction and background Over the last few years, University authorities, industrial partners as well as national and international experts that evaluated the education quality of our Department (AEQES, CTI) strongly suggested that opportunities should be offered to students to increase their soft skills as part of their curriculum. Moreover, many developments in chemical engineering are related to energy transition and circular economy, which are both transdisciplinary to conventional lectures. In this paper, we present methods and mentoring tools developed to teach students technical and soft skills for multi-disciplinary topics. 2 Description of the integrated project Objectives and constraints were defined at the onset of the project for both technical and soft skills. The technical objective was to propose an energy system that would make Reunion Island as energy independent and CO2-neutral as possible by 2030. This idea originated in the challenge set by the Eurecha 2015 student contest[1], for which students had to design facilities for a sheikhdom: electricity, water recycling, production of fertilizers… In our case, Reunion Island (~850 000 inhabitants) was considered as a case study as it is remote, has large biomass resources and high potential for renewable energies. Besides the objectives mentioned above and in order to force students to look at chemical engineering processes, the treatment of wastewater was imposed as well as the use of a synthetic liquid fuel as energy carrier. The targeted soft skills included working in large groups of minimum 4 students, efficient communication of results in English - both written and oral -, ability to integrate knowledge from various disciplines, development of critical mind and demonstration of independent and creative thinking. 3 Course of actions A team of 8 professors and senior scientists mentored the project and contributed to its assessment. The 10-ECTS project was divided in two parts. In the fall semester, students made global energy balances to design the energy system that would fulfill the objectives. As a result, a Sankey diagram of the energy flows on Reunion Island by 2030 was produced to allow for an overview of the available Island’s resources and needs, as well as of processes that can make the link between resources and needs. In the spring semester, two processes identified in the first part, namely the synthesis of bio-ethanol and bio-methanol, were modelled in more details using commercial software. Different tools were used to encourage student initiatives and work: • The use of a shared on-line portfolio for students to gather their documents improved their internal communication, but this remained a marginal channel for communication with teachers • In the fall semester, students orally presented progress reports every two weeks. After a feedback to students, the teaching team met to discuss the achievements and set the objectives for the next two weeks. This was very positive for the communication inside the teaching team. However, presentations every fortnight implied a work overload for students that had to constantly focus on preparing the presentations. • From the beginning, students were strongly encouraged to reach out to field experts whose contacts were provided. However, they preferred to rely mostly on Internet as their main source of information and reached out only rarely for help and usually very late. • In the fall semester, students had to designate new team leaders in turn every fortnight. This was abandoned as it prevented the establishment of clear structures in the group, reducing its efficiency. • In the spring semester, work tables allowed students to work directly with the teacher specialized in their task. This was appreciated by students and teachers, and it needs to be further encouraged. • Help in the group organization and interactions was provided by the PSGO (psychology of groups and organizations). This also included videoscopy, i.e. filming the students during their presentations and analyzing the records with them. This help was appreciated by students. The assessment was based on technical results for 60%, and soft skills for 40%. The evaluation of technical skills was done partly by all teachers equally and partly by teachers whose expertise was the closest to the technical sub-tasks. For soft skills, efficient communication, creativity in the work and results and links with conventional lectures were assessed. Critical thinking was evaluated through the relevance of qualitative and quantitative results and discussions. Group work was assessed by the teachers as well as by students through mutual evaluation. 4 Conclusions and perspectives The integrated project gave students a first opportunity to improve their soft skills along with their technical knowledge. It also improved their communication skills and their fluency in English. The teaching team proposed different mentoring techniques to encourage efficient work, with varying results. Finally, as the assessment ignored soft skills improvements, it may be modified by evaluating soft skills all year long so both the final result and the observed improvements contribute to the grade. Reference Eurecha, The European Committee for the Use of Computers in Chemical Engineering Education, 2015. Announcement for student contest problem competition 2015. http://bari.upc.es/eurecha/. [less ▲]

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See detailCogelled xerogel catalysts for applications in gazeous phase
Lambert, Stéphanie ULg

Conference (2016, June 15)

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