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See detailChallenges for imaging and therapy of musculoskeletal tumours
COOK, GARY; HUSTINX, Roland ULg

in Clinical and Translational Imaging (2015)

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See detailChallenges for Scale-Up of Batch Phase Separation
Pfennig, Andreas ULg; Becker, Karsten; Bach, S. et al

Conference (2015, September 10)

Bi-phasic phase separations in batch processes often are operations which influence cycle times and production capacity. A realistic assessment of phase separation time for technical scale is important ... [more ▼]

Bi-phasic phase separations in batch processes often are operations which influence cycle times and production capacity. A realistic assessment of phase separation time for technical scale is important with respect to defining vessel sizes, process step-time planning and an optimized adaption to further process steps. This requires a rating of batch mixing & phase-separation at an early step of chemical-process development in laboratory and a robust scale-up to the technical scale. Currently available methods for design and optimization of such batch phaseseparations show gaps in knowledge and in transfer from laboratory to technical scale. Up to now it is not possible to trustfully predict mean drop diameter or dropsize distribution for technical relevant bi-phasic systems in technical scale based on laboratory tests. These are one of the key inputs to describe phase separation behavior, i.e. sedimentation and coalescence. The prediction of drop-size distribution after scale-up is important, since a remaining turbidity is significantly influenced by these. In addition systems with higher viscosity show wider drop-size distributions and tendency of turbidity will increase. The specific industrial demand for a safe and validated scale-up method will be discussed. Aspects are an integral general scale-up method for batch mixing and phase separation, starting with standardized characterization of mixing and phaseseparation behavior in lab and development of a scale-up method in order to evaluate relevant aspects as equipment and mixing device, energy input, mixing time, phase separation time, height of dispersion etc. For modelling the performance of a batch settling accounting for polydisperse dropsize spectra, the model of Henschke has been chosen as starting point, which accounts for different average drop sizes. The Henschke model has been extended as to include the sedimentation of drops with polydisperse drop-size distribution according to the ReDrop approach (representative drops) by modelling an ensemble of individual drops as they sediment and reach the close-packed layer. In principle coalescence of the sedimenting droplets could be accounted for in this approach, but this has been neglected in this first step. The Henschke model already accounts for the time- and height-dependent average drop sizes in the close-packed layer. This has been extended as to allow taking the different drop sizes into account of those drops that are arriving at the close-packed layer over time. The coalescence in the close-packed layer is described with the approach used already by Henschke, which has been validated in principle by Kopriwa. The results show that the polydispersity can well be described by this approach (see Fig. 1). Especially – as is to be expected – the major phase separation occurs relatively quickly leaving behind fine droplets in the continuous phase. Since this remaining turbidity has a relatively low holdup, the sedimentation of the fine dispersion occurs essentially with the sedimentation velocity of droplets in infinitely extended medium. As a consequence the remaining turbidity as function of settling time can be estimated with relatively good accuracy from the fraction of the fine droplets in the original dispersion and their individual sedimentation velocity. It can also be seen that the close-packed layer disappears after a certain settling time and after that the rate of the arriving droplets is smaller than the time for their coalescence. The open questions remaining will finally be addressed, namely the prediction of the drop-size distribution after the mixing step, the detailed drop behavior within the close packed layer as well as the influence of large-scale fluid dynamics within the settler. [less ▲]

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See detailChallenges for Scale-Up of Batch Separations
Pfennig, Andreas ULg; Becker, Karsten; Bach, S. et al

in Chemie Ingenieur Technik (2015), 87(8), 1051

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See detailChallenges for the development of bone forming agents in Europe: introduction
Kanis, JA; Rizzoli, R; Cooper, C et al

in Osteoporosis International (2014), 25(2), 66-67

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See detailChallenges for the Development of Bone-Forming Agents in Europe.
Kanis, John A.; Rizzoli, Rene; Cooper, Cyrus et al

in Calcified tissue international (2014), 94

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See detailChallenges for the restoration of dry calcareous grasslands in quarries: does nature need help?
Pitz, Carline ULg; Piqueray, Julien; Harzé, Mélanie ULg et al

Conference (2015, August 26)

In order to maximize the biodiversity potential of dry calcareous grasslands in former quarries two options are available to managers: (i) allow species to spontaneously recolonize the site, (ii ... [more ▼]

In order to maximize the biodiversity potential of dry calcareous grasslands in former quarries two options are available to managers: (i) allow species to spontaneously recolonize the site, (ii) implement technical support for ecosystem restoration. This study aimed at characterizing the spontaneous communities established in dry area of unexploited quarries and at comparing communities encountered to the succession panel of dry grasslands. To evaluate the ecological succession in quarries, three successional stages where defined: (i) less than three years; (ii) three to 20 years; and (iii) more than 20 years after exploitation. For each successional stage, six parcels were selected and 20 1m2 plots were randomly marked in each parcel. All selected parcels presented dry grasslands abiotic conditions: filtering and stony soils and south orientation. During the 2014 vegetation period, percentage cover of higher plant species was recorded in each plot. Explaining environmental variables including coordinates, altitude, slope (degrees), soil depth, exposure, maximum vegetation height, bare ground cover, moss cover, and shrub cover (%) were measured. Our main results showed that, over decades of time, the ecological succession in dry area of unexploited quarries does not approach a typical formation of dry calcareous grassland. Most recolonizations tended to form meadows communities, except for three sites belonging to a specific landscape context. Potential implications for future quarries restoration will be discussed. [less ▲]

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See detailChallenges in identifying the beneficiaries of the poverty reduction strategy in Northern Mountains of Vietnam: the case of Xuan Phong and Tu Ly communes, Hoa Binh Province
Mai, Lan Phuong ULg; Lebailly, Philippe ULg

in International Journal of Research In Social Sciences (2013), 3(3), 38-51

In many developing countries, poverty alleviation programs have been implemented since the 1980’s and 1990’s, and will be continued into the next decades. The emerging question is why “poverty issues” ... [more ▼]

In many developing countries, poverty alleviation programs have been implemented since the 1980’s and 1990’s, and will be continued into the next decades. The emerging question is why “poverty issues” still exist for such a long time and do challenge not only the Vietnamese government but also many countries all over the world. One may ask if poverty reduction strategies, applied in Vietnam and other countries, are suited to the real poverty situation, and if they are sustainable. This paper is based on a research to investigate the nature of government’s interventions as a “poverty reduction strategy”, at Tu Ly and Xuan Phong communes in Hoa Binh province. Vietnam’s official poverty identification method and participatory poverty assessment of people are applied. This study does claim that the currently “inappropriate definition of poverty” is one of keys problems at the roots of the lack of obvious success of the ongoing strategy. [less ▲]

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See detailChallenges in stakeholders participation in research
Mairiaux, Philippe ULg

Scientific conference (2012, June 20)

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See detailChallenges in teaching architectural morphogenesis
Stals, Adeline ULg; Elsen, Catherine ULg; Jancart, Sylvie ULg et al

in Proceedings of the 3rd International Conference for Design Education Researchers (2015)

Reviewing the successive cognitive, operative and constructive models of architectural morphogenesis through time, the paper first recalls students and teachers in architecture how designers started ... [more ▼]

Reviewing the successive cognitive, operative and constructive models of architectural morphogenesis through time, the paper first recalls students and teachers in architecture how designers started experimenting digital design to reach self-generative, morphogenetic morphologies. Generally referred to as “non-standard architecture”, this innovative morphogenesis favours a new kind of spatial and architectural audacity but also generates three types of rupture: i) a rupture between form and structure; ii) a rupture in terms of process continuity and iii) a rupture in terms of multi-disciplinary collaboration. We consequently have to acknowledge the fact that, at a current state, non-standard architecture still struggles in terms of self-coherency and implementation, leaving a large amount of projects at their virtual, embryonic state especially in pedagogical contexts. We believe the challenge resides in overcoming the overly simplistic and reductionist appeal of purely formal and visual non-standard architecture: these morphologies should, on the contrary, be intrinsically defined by their form and structure relationship. We suggest such reconciliation should occur during the early stages of architectural education. Two experimental instruments, that perhaps constitute interesting renewed pedagogical models, are reported in this paper and we conclude by listing the remaining challenges when it comes to the teaching of architectural morphogenesis. [less ▲]

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See detailChallenges in the field of economic and financial crime in Europe and the US
Ligeti, Katalin; Franssen, Vanessa ULg

Book published by Hart (in press)

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See detailChallenges in the thermodynamic description of mixtures of complex molecules
Pfennig, Andreas ULg

Conference (2007, October 29)

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See detailChallenges in treatment of acromegaly patients
Beckers, Albert ULg

Scientific conference (2012, April 20)

Detailed reference viewed: 17 (1 ULg)
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See detailChallenges of Semantic 3D City Models: A Contribution of the COST Research Action TU0801
Billen, Roland ULg; Cutting-Decelle, Anne-Françoise; Métral, Claudine et al

in International Journal of 3-D Information Modeling (2015), 4(2), 68-76

This technical paper is a contribution to the identification of current challenges of semantic 3D city models. They are presented in four parts, namely 3D enriched city models and their connection with ... [more ▼]

This technical paper is a contribution to the identification of current challenges of semantic 3D city models. They are presented in four parts, namely 3D enriched city models and their connection with urban information models and smartcities, urban models integration, urban analyses and data. This work is an output of the COST Action TU0801 “Semantic Enrichment of 3D city models for sustainable urban development”. [less ▲]

Detailed reference viewed: 68 (3 ULg)