Physique Élementaire -- Condensé

E-print/Working paper (2009)

This document is a kind of Physics formula's form. It is majoritarly coming from a volonty of classifying these last so they are easily accessible. Firstly, this document was redacted in order to be ... [more ▼]

This document is a kind of Physics formula's form. It is majoritarly coming from a volonty of classifying these last so they are easily accessible. Firstly, this document was redacted in order to be prepared to the engineering studies (at ULg). For this reason, the text has not been very developped, so this document is as short (and quick) as possible, with no need to read unnecessary sentences which would slow the reading. Principal sentences have been written, to make links, because Physics is not only formula's: speaking is a very important way to communicate ideas and to link concepts, especially in Sciences. This document is the minimum minimorum that is given in first degree of Computer Sciences at the University of Liège; some notions also come from the Civil Engineers' course (of this same university). Only few proves will be made, to lighten the document; however, formula's will be admitted. Many different notations will be used for the same idea, in order to give the habit of the reader to use different notations (e.g. $U$ or $V$ in $V=RI$). This synthesis is not comprehensive, and does not pretend to be rigourous. Only the essential chapters and sections have been kept. When prerequisites are necessary, they are announced. Indeed, many points are supposed to be known: this document consists only in a set of reminds! It is clear that the reading of this document needs some basical math. knowledge. A summary of the most important notions is ML_SM2009, from the same author. [less ▲]

Phytochemical and pharmacological study of roots and leaves of Guiera senegalensis JF Gmel (Combretaceae)

in Journal of Ethnopharmacology (2006), 106(2), 173-178

The chemical composition of total alkaloids from leaves and roots of Guiera senegalensis was investigated. Three beta-carboline alkaloids were purified: in addition to harman and tetrahydroharman, known ... [more ▼]

The chemical composition of total alkaloids from leaves and roots of Guiera senegalensis was investigated. Three beta-carboline alkaloids were purified: in addition to harman and tetrahydroharman, known in roots and leaves. harmalan (dihydroharman) was isolated for the first time from roots of Guiera senegalensis. Guieranone A, a naphthyl butenone, was also purified from leaves and roots. The in vitro antiplasmodial activity and the cytotoxicity of extracts and pure compounds were evaluated. Each total alkaloid extract and beta-carboline alkaloids presented an interesting antiplasmodial activity associated with a low cytotoxicity. Harmalan was less active than harman and tetrahydroharman. Guieranone A showed a strong antiplasmodial activity associated with a high cytotoxicity toward human monocytes. Its cytotoxicity was performed against two cancer cell lines and normal skin fibroblasts in order to study its anticancer potential: guieranone A presented a strong cytotoxicity against each cell strains. Finally, we evaluated the potent synergistic antimalarial interaction between Guiera senegalensis and two plants commonly associated in traditional remedies: Mitragyna inermis and Pavetta crassipes. Three associations evaluated were additive. A synergistic effect was shown between total alkaloids extracted from leaves of Guiera senegalensis and those of Mitragyna inermis. This result justified the traditional use of the plants in combination to treat malaria. (c) 2006 Elsevier Ireland Ltd. All rights reserved. [less ▲]

Phytoplankton Biomass and Production in the River Meuse (Belgium)

in Water Research (1987), 21(12), 1557-1566

The biomass and production of the phytoplankton in a relatively unpolluted reach of the river Meuse (Belgium) were followed through two years (1983 and 1984).

The phytoplankton community of the river Meuse, Belgium: seasonal dynamics (year 1992) and the possible incidence of zooplankton grazing

in Hydrobiologia (1994), 289

Qualitative and quantitative aspects of the phytoplankton of the river Meuse were studied during 1992 at a point 537 km from the source. The phytoplankton was dominated by diatoms and green algae. The ... [more ▼]

Qualitative and quantitative aspects of the phytoplankton of the river Meuse were studied during 1992 at a point 537 km from the source. The phytoplankton was dominated by diatoms and green algae. The factors regulating the phytoplankton groxth were clearly physical variables : discharge, temperature and irradiance. [less ▲]

Phytoplankton ecology of Lake Kivu (Eastern Africa): biomass, production and elemental ratios

Conference (2007, August 16)

Phytoplankton ecology of Lake Kivu (eastern Africa): biomass, production and elemental ratios

in Verhandlungen der Internationalen Vereinigung für Theoretische und Angewandte Limnologie = Proceedings of the International Association of Theoretical and Applied Limnology (2009, January), 30(5), 709-713

Phytoplankton of the River Loire, France: a biodiversity and modelling study

in Journal of Plankton Research (2011)

Most studies of phytoplankton dynamics in lowland rivers have been conducted in regulated rivers. This study deals the phytoplankton of the River Loire, a relatively unregulated river in Western Europe ... [more ▼]

Most studies of phytoplankton dynamics in lowland rivers have been conducted in regulated rivers. This study deals the phytoplankton of the River Loire, a relatively unregulated river in Western Europe, and aims at investigating the factors controlling phytoplankton composition and dynamics in this river. Phytoplankton biodiversity was assessed by pooling data from monthly sampling for 8 years at different sites. A correspondence analysis showed temporal and longitudinal gradients, with a dominance of small centric diatoms and green algae for most of the year, in the middle and lower river sectors. Phytoplankton dynamics were further explored using the POTAMON simulation model, run for the year 2005. The simulations, in agreement with the observations, confirmed the virtual absence of a Stephanodiscus spring peak, and reproduced well the development of small centric diatoms and green algae. Production and loss rates calculated by the model helped us to explain the dynamics of the three main phytoplankton categories, which attained high net production rates due to the low river depth (∼1 m at low discharge), but were subject to high sedimentation losses. Model calculations also showed that P limitation was likely, particularly for green algae, with a reduction of growth rate of up to 35%. In addition, the simulations showed a significant impact of the invasive Asian clam, Corbicula spp., on phytoplankton biomass. This study shows that the factors determining phytoplankton diversity and dynamics in this unregulated river are basically the same as those identified in other lowland rivers, but that key factors are habitat diversity and variation of water level in the river channel. [less ▲]

Phytoremediation of persistent organic pollutant in soils: study of the absorption mechanism in two cucurbitacean species and future applications

in Kaltsikes, P.J. (Ed.) Phytoremediation 2000 State of the art in Europe (2000, April 06)

La phytoremédiation par le saule

in Forêt Wallonne (2011), 112(mai/juin), 36-46

En Wallonie, les sites potentiellement contaminés se comptent par milliers. La région subit aujourd’hui les conséquences de son manque historique de législations environnementales. Parmi les contaminants ... [more ▼]

En Wallonie, les sites potentiellement contaminés se comptent par milliers. La région subit aujourd’hui les conséquences de son manque historique de législations environnementales. Parmi les contaminants présents sur ces sites, les plus préoccupants sont certainement les métaux lourds qui s’accumulent dans le sol et menacent l’environnement. Pour remédier à ce problème, certains chercheurs s’intéressent particulièrement à la phytoremédiation, une technologie nouvelle qui exploite le potentiel des végétaux et de leur microflore associée pour extraire, stabiliser ou volatiliser ces métaux lourds. Cette technique biologique s’avère prometteuse et son application à l’aide de ligneux, comme le saule, serait une solution favorable à la préservation de la biodiversité et au développement des matériaux et des énergies renouvelables. [less ▲]

PHYTOSTABILISATION OF COPPER-CONTAMINATED SOIL IN KATANGA: AN EXPERIMENT WITH THREE NATIVE GRASSES AND TWO AMENDMENTS

in International Journal of Phytoremediation (2010), 12(6), 616-632

This study evaluates the feasibility of using the grass species Rendlia altera, Monocymbium ceresiiforme, Cynodon dactylon and amendments (compost and lime) for the phytostabilisation of soils ... [more ▼]

This study evaluates the feasibility of using the grass species Rendlia altera, Monocymbium ceresiiforme, Cynodon dactylon and amendments (compost and lime) for the phytostabilisation of soils contaminated by Cu in the province of Katanga (Democratic Republic of Congo). Species were grown on control and Cu-contaminated plots (artificially contaminated with 2,500 mg kg-1 Cu) unamended (NA), amended with 4.5 kg compost m-2 or 0.2 kg lime m-2. R. altera was also grown on contaminated plots amended with 22.5 kg compost m-2 or 1 kg lime m-2. Plant survival, growth and reproduction were monitored for two years. Cu-concentration in leaves of R. altera and M. ceresiiforme were analysed. pH and extractable Cu (0.01 M CaCl2) in soil were analysed in April 2007 and 2008. Results showed that R. altera seems to be the best candidate because of its highest survival on NA, followed by M. ceresiiforme, while liming was necessary to ensure survival of C. dactylon. Lime increased plant reproduction and reduced Cu accumulation in leaves compared to compost. However, higher survival and number of spikes of R. altera obtained in experiment 2 with 22.5 kg compost m-2 suggest that lime x compost interactions should be investigated in further studies. [less ▲]