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See detailComparison of FEM simulations for the incremental forming process
Henrard, Christophe ULg; Habraken, Anne ULg; Szekeres, A. et al

in Advanced Materials Research (2005), 6-8

Incremental forming is an innovative and highly flexible sheet metal forming technology for small batch production and prototyping that does not require any adapted dies or punches to form a complex shape ... [more ▼]

Incremental forming is an innovative and highly flexible sheet metal forming technology for small batch production and prototyping that does not require any adapted dies or punches to form a complex shape. The purpose of this article is to perform FEM simulations of the forming of a cone with a 50-degree wall angle by incremental forming and to investigate the influence of some crucial computational parameters on the simulation. The influence of several parameters will be discussed: the FEM code used (Abaqus or Lagamine, a code developed at the University of Liège), the mesh size, the potential simplification due to the symmetry of the part and the friction coefficient. The output is given in terms of final geometry (which depends on the springback), strain history and distribution during the deformation, as well as reaction forces. It will be shown that the deformation is localized around the tool and that the deformations constantly remain close to a plane strain state for this geometry. Moreover, the tool reaction clearly depends on the way the contact is taken into account. [less ▲]

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See detailComparison of fermentation industrial components such as corn steep and yeast extract for lactic bacteria production
Cornelius, C.; Erpicum, T.; Jacques, Philippe ULg et al

in Mededelingen van de Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen (Rijksuniversiteit te Gent) (1996), 61/4a

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See detailComparison of Field Transfer Methods between two meshes
Bussetta, Philippe ULg; Ponthot, Jean-Philippe ULg

in Proceedings of "IV European Conference on Computational Mechanics" (2010)

In many cases, the numerical computation of mechanical problem with Finite Element Method has to transfer some information between two different meshes. For example, if a remeshing is needed or if several ... [more ▼]

In many cases, the numerical computation of mechanical problem with Finite Element Method has to transfer some information between two different meshes. For example, if a remeshing is needed or if several meshes are used (e.g. one for a thermal problem and another one for a mechanical problem). In spite of the research on the Transfer Methods, none of them has been so far clearly established as the best. Each method has advantages and disadvantages. Many problems can happen during the field transfer, like the minimization of the numerical diffusion, the value of the field on the boundaries, etc. This paper compares on the one hand the performances of the Field Transfer Method by classical interpolation with on the other hand one using Mortar Elements. The comparison of the two methods is based on two indicators: the numerical diffusion and the evaluation of the field on the boundaries. In this paper, only the continuous fields are considered. [less ▲]

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See detailComparison of five radioimmunoassay systems for PAG measurement: Ability to detect early pregnancy in cows
Ayad, A.; Melo de Sousa, Noelita ULg; Sulon, Joseph ULg et al

in Reproduction in Domestic Animals (2007), 42(4), 433-440

This study was conducted to describe the minimum detection limit, reproducibility, accuracy, specificity and parallelism of different pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) systems ... [more ▼]

This study was conducted to describe the minimum detection limit, reproducibility, accuracy, specificity and parallelism of different pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) systems: RIA-497, RIA-706, RIA-780, RIA-809 and RIA-Pool. Their ability to distinguish between non-pregnant and pregnant females at day 30 after artificial insemination (Al) was investigated. The antisera were raised in rabbits against different PAG preparations. All RIA systems proved to be sensitive, repeatable and accurate for measuring PAG concentrations. The dilutions of plasma samples taken at an early stage of pregnancy were found to be parallel to the standard curves. No cross-reaction was observed with different carbohydrates, either with Pregnant Marc Serum Gonadotropin (PMSG) or human Chorionic Gonadotropin (hCG). The concentrations of PAG in pregnant females at day 30 after Al were shown to be higher with the use of antisera R#706, R#780, R#809 and Pool when compared with antiserum R#497. All the RIA systems gave 100% sensitivity and negative predictive values. On the other hand, the use of antisera R#780 and R#809 resulted in lower specificity and positive predictive values. The present study clearly shows that the ability of PAG-RIA systems to diagnose pregnancy specifically at day 30 after Al can be improved by using a combination of antisera raised against different forms of PAG. [less ▲]

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See detailComparison of food conversion by the Pirapatinga Piaractus brachypomus under different times of feeding
Baras, E.; Mélard, Charles ULg; Grignard, J. C. et al

in Progressive Fish-Culturist (1996), 58

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See detailComparison of four cartridge type automated blood gas analysers for arterial blood gas analysis in dogs
Roels, Elodie ULg; Delvaux, François ULg; Farnir, Frédéric ULg et al

in Proceedings of the 23th ECVIM Meeting (2013, September)

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See detailComparison of four different methods for Salmonella detection in fecal samples of porcine origin
Korsak Koulagenko, Nicolas ULg; Degeye, Jean-Noel; Etienne, Grégory et al

in Journal of Food Protection (2004), 67(10), 2158-2164

Performances of four detection methods were evaluated for recovery of Salmonella spp. in naturally contaminated fecal specimens of porcine origin. The NMKL 71 method consisted of enrichment in Rappaport ... [more ▼]

Performances of four detection methods were evaluated for recovery of Salmonella spp. in naturally contaminated fecal specimens of porcine origin. The NMKL 71 method consisted of enrichment in Rappaport-Vassiliadis broth and plating on xylose-lysine-desoxycholate medium, whereas the SP-VG-M002 method relied on a Diasalm enrichment followed by streaking on xylose-lysine-tergitol 4 agar (XLT-4). The VIDAS SLM method was composed of double enrichment in Muller-Kauffmann tetrathionate broth and in M broths before processing in a VIDAS device. lf the results were positive, the VIDAS ICS immunoenrichment was performed and the result transferred onto three different selective media. The VIDAS ICS protocol is an immunoconcentration step followed by plating on XLT-4. Seventy-eight samples were tested with all four methods simultaneously, leading to 34 positive samples with at least one method. For this assay, VIDAS SLM revealed 31 positive samples (91.2%), whereas the average positive percentage of the three other methods was 37.3% (P < 0.001). Two-paired comparisons with the VIDAS SLM method were also performed. McNemar values were systematically highly significant (P < 0.001). The proportion of agreement was significantly inferior (P < 0.05) for the comparison of VIDAS ICS and VIDAS SLM (68.7%) compared with the two other paired comparisons (average percentage, 81.5%). The conclusion reached by this trial is that VIDAS SLM significantly improves the recovery of Salmonella in naturally contaminated fecal specimens. For the paired-comparisons, NMKL 71 and SP-VG-M002 were comparable in terms of efficiency, whereas the VIDAS ICS protocol, as established by the manufacturer for food samples only, seemed less efficient than the other two. [less ▲]

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See detailComparison of four markers of bone resorption as diagnostic or monitoring tools in postmenopausal osteoporosis
Reginster, Jean-Yves ULg; Taquet, AN; Christiansen, C et al

in Arthritis and Rheumatism (1999), 42(S1), 291

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See detailComparison of Four Refractometers for the Investigation of the passive transfer in Beef Calves
Vandeputte, Sébastien ULg; Detilleux, Johann ULg; Rollin, Frédéric ULg

in Journal of Veterinary Internal Medicine (2011), 25

Background: Failure of passive transfer (FPT) in beef calves can be detected by refractometry. Nevertheless, different models of refractometers are available, and few studies compare them for the ... [more ▼]

Background: Failure of passive transfer (FPT) in beef calves can be detected by refractometry. Nevertheless, different models of refractometers are available, and few studies compare them for the detection of FPT. Objectives: To compare the accuracy of 4 different refractometers for measuring serum total protein concentrations in comparison with results obtained by the biuret method and, based on the serum IgG threshold of 1,600 mg/mL, to determine, for each refractometer, the optimal serum protein concentration’s lowest threshold for successful passive transfer. Animals: One hundred and eight healthy beef calves, 3–8 days of age. Methods: Observational study. The concentrations of serum total proteins were determined with 4 different models of refractometers and compared with the biuret method by a Bland–Altman statistical method. The optimal serum protein concentration’s lowest threshold for successful passive transfer was determined for each refractometer by receiver operating characteristic (ROC) analysis. In addition, the serum immunoglobulin G (IgG) concentration was compared with the serum gamma-glutamyl transferase (c-GT) activity and with the total immunoglobulin concentration. Results: The refractometric measurements were highly correlated with those obtained by the biuret method. Serum total protein concentration threshold values of 56, 58, 54, and 56 g/L were found respectively for the Atago, Atago ATC, Wolf ATC, and digital ATC refractometers. Immunoglobulins were highly correlated with IgG, whereas Gamma-GT only reflected colostrum uptake by the calf. Conclusions and Clinical Importance: All refractometers could be used for the assessment of passive transfer using their individual serum protein concentration threshold. [less ▲]

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See detailComparison of free-surface and rigid-lid finite element models of barotropic instabilities
White, Laurent; Beckers, Jean-Marie ULg; Deleersnijder, Eric et al

in Ocean Dynamics (2006), 56(2), 86-103

The main goal of this work is to appraise the finite element method in the way it represents barotropic instabilities. To that end, three different formulations are employed. The free-surface formulation ... [more ▼]

The main goal of this work is to appraise the finite element method in the way it represents barotropic instabilities. To that end, three different formulations are employed. The free-surface formulation solves the primitive shallow-water equations and is of predominant use for ocean modeling. The vorticity-stream function and velocity-pressure formulations resort to the rigid-lid approximation and are presented because theoretical results are based on the same approximation. The growth rates for all three formulations are compared for hyperbolic tangent and piecewise linear shear flows. Structured and unstructured meshes are utilized. The investigation is also extended to time scales that allow for instability meanders to unfold, permitting the formation of eddies. We find that all three finite element formulations accurately represent barotropic instablities. In particular, convergence of growth rates toward theoretical ones is observed in all cases. It is also shown that the use of unstructured meshes allows for decreasing the computational cost while achieving greater accuracy. Overall, we find that the finite element method for free-surface models is effective at representing barotropic instabilities when it is combined with an appropriate advection scheme and, most importantly, adapted meshes. [less ▲]

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See detailComparison of FT-NIR transmission and UV-vis spectrophotometry to follow the mixing kinetics and to assay low-dose tablets containing riboflavin
Bodson, Cédric; Dewé, Walthère ULg; Hubert, Philippe ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2006), 41(3), 783-790

For several years, near-infrared spectroscopy (NIRS) has become an analytical technique of great interest for the pharmaceutical industry, particularly for the non-destructive analysis of dosage forms ... [more ▼]

For several years, near-infrared spectroscopy (NIRS) has become an analytical technique of great interest for the pharmaceutical industry, particularly for the non-destructive analysis of dosage forms. The goal of this study is to show the capacity of this new technique to assay the active ingredient in low-dosage tablets. NIR spectroscopy is a rapid, non-destructive technique and does not need any sample preparation. As an example, a binary mixture of microcrystalline cellulose and riboflavin was used to prepare tablets of different weights by direct compression. A prediction model was built by using a partial least square regression fit method. The NIR assay was performed by transmission. The results obtained by NIR spectroscopy were compared with a conventional UV-vis spectrophotometry method. The study showed that tablets can be individually analysed by NIR with high accuracy. It was shown that the variability of this new technique is less important than that of the conventional method which is the UV-vis spectrophotometry. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailComparison of functional residual capacity and static compliance of the respiratory system during a positive end-expiratory pressure (PEEP) ramp procedure in an experimental model of acute respiratory distress syndrome.
Lambermont, Bernard ULg; Ghuysen, Alexandre ULg; Janssen, Nathalie ULg et al

in Critical Care (2008), 12(4), 91

INTRODUCTION: Functional residual capacity (FRC) measurement is now available on new ventilators as an automated procedure. We compared FRC, static thoracopulmonary compliance (Crs) and PaO2 evolution in ... [more ▼]

INTRODUCTION: Functional residual capacity (FRC) measurement is now available on new ventilators as an automated procedure. We compared FRC, static thoracopulmonary compliance (Crs) and PaO2 evolution in an experimental model of acute respiratory distress syndrome (ARDS) during a reversed, sequential ramp procedure of positive end-expiratory pressure (PEEP) changes to investigate the potential interest of combined FRC and Crs measurement in such a pathologic state. METHODS: ARDS was induced by oleic acid injection in six anesthetised pigs. FRC and Crs were measured, and arterial blood samples were taken after induction of ARDS during a sequential ramp change of PEEP from 20 cm H2O to 0 cm H2O by steps of 5 cm H2O. RESULTS: ARDS was responsible for significant decreases in FRC, Crs and PaO2 values. During ARDS, 20 cm H2O of PEEP was associated with FRC values that increased from 6.2 +/- 1.3 to 19.7 +/- 2.9 ml/kg and a significant improvement in PaO2. The maximal value of Crs was reached at a PEEP of 15 cm H2O, and the maximal value of FRC at a PEEP of 20 cm H2O. From a PEEP value of 15 to 0 cm H2O, FRC and Crs decreased progressively. CONCLUSION: Our results indicate that combined FRC and Crs measurements may help to identify the optimal level of PEEP. Indeed, by taking into account the value of both parameters during a sequential ramp change of PEEP from 20 cm H2O to 0 cm H2O by steps of 5 cm H2O, the end of overdistension may be identified by an increase in Crs and the start of derecruitment by an abrupt decrease in FRC. [less ▲]

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See detailComparison of functionalized carbon nanofibers and multi-walled carbon nanotubes as supports for Fe-Co nanoparticles
Vidick, Deborah; Herlitschke, Marcus; Poleunis, Claude et al

in Journal of Materials Chemistry A (2013), 1(6), 2050-2063

Multi-walled carbon nanotubes (MWCNT) and nanofibers (CNF) have been functionalized at their surfaces with chelating phosphine (PPh2) and ammonium (NMe3+) groups, as anchoring sites for metal complexes ... [more ▼]

Multi-walled carbon nanotubes (MWCNT) and nanofibers (CNF) have been functionalized at their surfaces with chelating phosphine (PPh2) and ammonium (NMe3+) groups, as anchoring sites for metal complexes. The surface functionalization has been monitored by XPS, elemental analyses, N-2 physisorption and/or SEM surface morphology analysis at each step. Bimetallic Fe-Co nanoparticles from two different starting cluster complexes, [HFeCo3(CO)(12)] (1) and (NEt4)[FeCo3(CO)(12)] (2), have been deposited onto the surfaces of the functionalized MWCNT and CNF as well as their pristine forms for comparison. The samples have been fully characterized before and after thermal treatment. The obtained nanoparticles were shown by TEM to be better dispersed and of smaller size on functionalized than on pristine supports. Magnetic characterization revealed blocked superparamagnetic Fe-Co nanoparticles together with paramagnetic ions on CNF as well as MWCNT. [less ▲]

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See detailA Comparison of FUV Auroral Emissions During the April 2002 Events as seen by the IMAGE/FUV and TIMED/GUVI Instruments
Gladstone, G.; Retherford, K.; Solomon, S. et al

Conference (2002, December 01)

The auroral emissions that resulted from the series of solar particle events and magnetic storms during 14-24 April 2002 provide an excellent data set for the cross-comparison of the IMAGE/FUV and TIMED ... [more ▼]

The auroral emissions that resulted from the series of solar particle events and magnetic storms during 14-24 April 2002 provide an excellent data set for the cross-comparison of the IMAGE/FUV and TIMED/GUVI auroral imagers. The IMAGE/FUV instrument comprises the SI spectral imager (121.8 nm and 135.6 nm) and the WIC imaging photometer (LBH) and observes the entire Earth from high Earth orbit. The TIMED/GUVI spectral imager (121.6 nm, 130.4 nm, 135.6 nm, LBH short, and LBH long) scans a nadir-to-limb swath from low Earth orbit. Although there is a large difference in spatial resolution, preliminary comparison of simultaneously-observed diffuse auroral emissions indicates fairly good agreement between the calibrated brightnesses determined for common spectral features. We will present a detailed simulation of one or more of the April 2002 events as seen by each imager to determine if a single description of the auroral precipitation can self-consistently account for the proton- and electron-generated FUV emissions observed from the two spacecraft. [less ▲]

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See detailComparison of G1.2/G2.2 and Sydney IVF cleavage/blastocyst sequential media for the culture of human embryos: a prospective, randomized, comparative study.
Van Langendonckt, Anne; Demylle, Dominique; Wyns, Christine et al

in Fertility and Sterility (2001), 76(5), 1023-31

Objective: To compare two commercially available sequential media, G1.2/G2.2 and Sydney IVF cleavage/blastocyst media, as supports for human embryo culture. Design: Prospective randomized study. Setting ... [more ▼]

Objective: To compare two commercially available sequential media, G1.2/G2.2 and Sydney IVF cleavage/blastocyst media, as supports for human embryo culture. Design: Prospective randomized study. Setting: University-based IVF clinic. Patient(s): Two hundred forty-nine patients undergoing IVF treatment for the first or second time, randomly allocated at the time of oocyte retrieval, to either culture in G1.2/G2.2 or Sydney IVF media. Intervention(s): Oocyte recovery, IVF or intracytoplasmic sperm injection, embryo culture, transfer on day 3 or day 5/6. Main Outcome Measure(s): Developmental stage on day 3, blastocyst rate, pregnancy outcome as assessed by βhCG positive test, implantation rates, and ongoing pregnancies. Result(s): Embryos cultured in G1.2/G2.2 media displayed a faster kinetics of cleavage, compaction, blastulation, and hatching, but a lower day 3 embryo quality than those grown in Sydney IVF media. For patients with at least five embryos, G1.2/G2.2 media yielded higher implantation rates (26.2%) in our day 3 embryo transfer program when compared to Sydney IVF medium (15.5%), whereas similar implantation rates were obtained for day 5/6 embryo transfer for both media (43.1% and 36.1%, respectively). Conclusion(s): In our day 3 embryo transfer program, G1.2/G2.2 media were superior to Sydney IVF media, whereas both media yielded similar outcomes in our blastocyst transfer program. [less ▲]

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See detailComparison of gaseous cryotherapy with more traditional forms of cryotherapy following total knee arthroplasty
Demoulin, Christophe ULg; Brouwers, M.; Darot, S. et al

in Annals of Physical and Rehabilitation Medicine (2012), 55

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See detailComparison of gene expression in canine sino-nasal aspergillosis and idiopathic lymphoplasmacytic rhinitis: a microarray study
Vanherberghen, Morgane ULg; Bureau, Fabrice ULg; Peters, IR et al

in Proceedings of the 19th Annual ECVIM-CA Congress (2009)

Detailed reference viewed: 50 (15 ULg)