http://hdl.handle.net/2268/150 Chercher dans ce canal chercher http://orbi.ulg.ac.be/simple-search http://hdl.handle.net/2268/149150 Titre: Synthesis and catalytic application of palladium imidazol(in)ium-2- dithiocarboxylate complexes <br/> <br/>Auteur, co-auteur: Champion, Martin J. D.; Solanki, Riten; Delaude, Lionel; White, Andrew J. P.; Wilton-Ely, James D. E. T. <br/> <br/>Résumé: The palladium(ii) dimer, [Pd(C,N-C 6H 4CH 2NMe 2)Cl] 2 reacts with two equivalents of the NHC·CS 2 zwitterionic ligands [NHC = IPr (1,3- diisopropylimidazol-2-ylidene), ICy (1,3-dicyclohexylimidazol-2-ylidene), IMes (1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene), IDip (1,3-bis(2,6- diisopropylphenyl)imidazol-2-ylidene), SIMes (1,3-bis(2,4,6-trimethylphenyl) imidazolin-2-ylidene)] in the presence of NH 4PF 6, to yield the cationic products [Pd(C,N-C 6H 4CH 2NMe 2)(S 2C·NHC)] +. In a similar fashion, the compounds [Pd(C,N-bzq)(S 2C·NHC)] + (bzq = benzo[h]quinolinyl, NHC = ICy, IMes, IDip) are obtained from the corresponding dimer [Pd(C,N-bzq)Cl] 2. The bis(phosphine) compounds [Pd(S 2C·NHC)(PPh 3) 2] 2+ (NHC = ICy, IMes, IDip, SIMes) are obtained on treatment of [PdCl 2(PPh 3) 2] with NHC·CS 2 zwitterions in the presence of NH 4PF 6. The reaction of [PdCl 2(dppf)] with IMes·CS 2 and NH 4PF 6 provides the complex [Pd(S 2C·IMes)(dppf)] 2+. The complexes [Pd(S 2C·NHC)(PPh 3) 2](PF 6) 2 (NHC = IMes, IDip) were active pre-catalysts (1 mol% loading) for the conversion of benzo[h]quinoline to 10-methoxybenzo[h]quinoline in the presence of PhI(OAc) 2 and methanol. The intermediacy of [Pd(C,N-bzq)(S 2C·NHC)] + was supported by the high yield of 10-methoxybenzo[h]quinoline using [Pd(C,N-bzq)(S 2C·IDip)] + to promote the same reaction. Small amounts of 2,10-dimethoxybenzo[h]quinoline were also isolated from these reactions. Using [Pd(C,N-bzq)(S 2C·IDip)] + and N-chlorosuccinimide as the oxidant led to the formation of 10-chlorobenzo[h]quinoline in moderate yield from benzo[h]quinoline. The molecular structures of [Pd(S 2C·IMes)(PPh 3) 2](PF 6) 2 and [Pd(S 2C·IMes) (dppf)](PF 6) 2 were determined crystallographically. http://hdl.handle.net/2268/149149 Titre: Assessing the ligand properties of 1,3-dimesitylbenzimidazol-2-ylidene in ruthenium-catalyzed olefin metathesis <br/> <br/>Auteur, co-auteur: Borguet, Yannick; Zaragoza, Guillermo; Demonceau, Albert; Delaude, Lionel <br/> <br/>Résumé: The deprotonation of 1,3-dimesitylbenzimidazolium tetrafluoroborate with a strong base afforded 1,3-dimesitylbenzimidazol-2-ylidene (BMes), which was further reacted in situ with rhodium or ruthenium complexes to afford three new organometallic products. The compounds [RhCl(COD)(BMes)] (COD is 1,5-cyclooctadiene) and cis-[RhCl(CO)2(BMes)] were used to probe the steric and electronic parameters of BMes. Comparison of the percentage of buried volume (%VBur) and of the Tolman electronic parameter (TEP) of BMes with those determined previously for 1,3-dimesitylimidazol-2-ylidene (IMes) and 1,3-dimesitylimidazolin-2-ylidene (SIMes) revealed that the three N-heterocyclic carbenes (NHCs) had very similar profiles. Nonetheless, changes in the hydrocarbon backbone subtly affected the stereoelectronic properties of these ligands. Accordingly, the corresponding [RuCl2(PCy 3)(NHC)(CHPh)] complexes displayed different catalytic behaviors in the ring-closing metathesis (RCM) of α,ω-dienes. In the benchmark cyclization of diethyl 2,2-diallylmalonate, the new [RuCl2(PCy 3)(BMes)(CHPh)] compound (1d) performed slightly better than the Grubbs second-generation catalyst (1a), which was in turn significantly more active than the related [RuCl2(PCy3)(IMes)(CHPh)] initiator (1b). For the formation of a model trisubstituted cycloolefin, complex 1d ranked in-between catalyst precursors 1a and 1b, whereas in the RCM of tetrasubstituted cycloalkenes it lost its catalytic efficiency much more rapidly. http://hdl.handle.net/2268/149118 Titre: Integrated field assessment of contaminant fate and transport in the unsaturated and saturated zone <br/> <br/>Auteur, co-auteur: Fernandez de Vera, Natalia; Peña Hernandez, Juan Angel; Jamin, Pierre; Vanclooster, Marnik; Brouyère, Serge <br/> <br/>Résumé: In the poster, a multidisciplinary methodology is presented with the aim of characterizing fate and transport of pollutants in the vadose and the saturated zone of industrial sites. The methodology used for the vadose zone consist in the combination of the Vadose Monitoring System, cross-hole and surface geophysics at a local scale. For saturated zone studies, the approach consist in the chemical and isotopic analysis of the various contaminants present on site at regional scale. http://hdl.handle.net/2268/149098 Titre: Venus nitric oxide nightglow mapping from SPICAV nadir observations. <br/> <br/>Auteur, co-auteur: Stiepen, Arnaud; Gérard, Jean-Claude; Dumont, Maïté; Cox, Cédric; Bertaux, Jean-Loup <br/> <br/>Résumé: Nitric oxide δ (190-240 nm) and γ (255-270 nm) emissions on the Venus nightside have been observed with Venus Express SPICAV instrument operated in the nadir mode. These ultraviolet emissions arise from the desexcitation of excited NO molecules created by radiative recombination of O(3P) and N(4S) atoms. These atoms are produced on the dayside of the planet through photodissociation of CO2 and N2 molecules and are transported to the nightside by the global subsolar to antisolar circulation. We analyze a wide dataset of nadir observations obtained since 2006 to determine the statistical distribution of the NO nightglow and its variability. Individual observations show a great deal of variability and may exhibit multiple maxima along latitudinal cuts. We compare this global map with the results obtained during the Pioneer-Venus mission and with the recent O2(a1Δg) nightglow map. The NO airglow distribution shows a statistical bright region extending from 01:00 and 03:30 local time and 25°N to 10°S, very similar to the Pioneer result obtained 35 years earlier during maximum solar activity conditions. The shift from the antisolar point and the difference with the O2 airglow indicate that superrotating zonal winds are statistically weak near 97 km, but play an important role in the lower thermosphere. We compare these results with other evidence for superrotation in the thermosphere and point out possible sources of momentum transfer. http://hdl.handle.net/2268/149095 Titre: Cartographie du nightglow de Vénus <br/> <br/>Auteur, co-auteur: Stiepen, Arnaud http://hdl.handle.net/2268/149093 Titre: Etude des émission UV de Mars et Vénus <br/> <br/>Auteur, co-auteur: Stiepen, Arnaud http://hdl.handle.net/2268/149089 Titre: Macroporous poly(ionic liquid)s and poly(acrylamide)s monoliths from CO2-in-water emulsion templates stabilized by sugar-based surfactants <br/> <br/>Auteur, co-auteur: Boyère, Cédric; Favrelle, Audrey; Léonard, Alexandre; Boury, Frank; Jérôme, Christine; Debuigne, Antoine <br/> <br/>Résumé: Highly interconnected poly(acrylamide) (PAM) and poly(vinylimidazolium) (PVIm) porous monoliths were templated by carbon 10 dioxide-in-water (CO2/W) high internal phase emulsions (HIPEs), a toxic-solvent free process. A range of sugar-based fluorinated surfactants prepared by chemoenzymatic synthesis were used as emulsifiers. Both the concentration and the structure of the surfactants, especially the length of their CO2-philic part and of their spacer between the sugar head and the tail, were found to strongly affect the cellular structure and morphology of the PAM polyHIPEs, i.e. the size of pores and cells. A mannose derivative bearing a chain ranging from 6 to 10 perfluorinated carbons and a long spacer emerged as the best stabilizer, leading to a porous monolith with average pores and 15 cells sizes (about 2.6 1m and 5-10 1m, respectively) among the lowest reported for polyHIPEs produced from CO2/W emulsions. The same template then served for the preparation of the first macroporous poly(ionic liquid)s (PILs) polyHIPE by using 1-vinyl-3- ethylimidazolium bromide as monomer. Shrinkage of the final material was prevented by adjusting the divinylimidazolium crosslinker content. The resulting low density polyHIPE exhibits small spherical cells (~5 1m) connected by numerous small pores (~2 1m), confirming that the CO2/W HIPE templating methodology based on fluorinated glycosurfactants is a technique of choice for the 20 preparation of macroporous PILs. http://hdl.handle.net/2268/149082 Titre: Effect of head-to-head addition in vinyl acetate controlled radical polymerization: why is Co(acac)2-mediated polymerization so much better? <br/> <br/>Auteur, co-auteur: Morin, Aurélie N.; Detrembleur, Christophe; Jérôme, Christine; De Tullio, Pascal; Poli, Rinaldo; Debuigne, Antoine <br/> <br/>Résumé: The controlled polymerization of vinyl acetate has been recently achieved by several techniques, but PVAc with targeted Mn and low dispersity up to very high monomer conversions and high degrees of polymerization was only obtained with Co(acac)2 as controlling agent in the so-called CMRP, a type of organometallic mediated radical polymerization (OMRP). Other techniques (including ATRP, ITP, TERP, and RAFT/MADIX) have shown a more or less pronounced slowdown in the polymerization kinetics, which was attributed to the higher strength of the C−X bond between the radical PVAc chain and the trapping agent (X) in the dormant species and to a consequent slower reactivation after a less frequent head-to-head monomer addition. The reason for the CMRP exception is clarified by the present contribution. First, a detailed investigation by 1H, 13C and multiplicity-edited HSQC and DEPT-135 NMR of the PVAc obtained by CMRP, in comparison with a regular polymer made by free radical polymerization under the same conditions, has revealed that Co(acac)2 does not significantly alter the fraction of head-to-head sequences in the polymer backbone and that there is no accumulation of Co(acac)2-capped chains with a head-to-head ω end. Hence, both dormant chains (following the head-to-head and the head-to-tail monomer additions) must be reactivated at similar rates. A DFT study shows that this is possible because the dormant chains are stabilized not only by the C−Co σ bond but also by formation of a chelate ring through coordination of the ω monomer carbonyl group. The head-to-head dormant chain contains an inherently stronger C−Co bond but forms a weaker 6-membered chelate ring, whereas the weaker C−Co bond in the head-to-tail dormant chain is compensated by a stronger 5-membered chelate ring. Combination of the two effects leads to similar activation enthalpies, as verified by DFT calculations using a variety of local, gradient-corrected, hybrid and “ad hoc” functionals (BPW91, B3PW91, BPW91*, M06 and M06L). While the BDE(C−X) of model H-VAc−X molecules [X = Cl, I, MeTe, EtOC(S)S and Co(acac)2] are functional dependent, the BDE difference between head-to-head and head-to-tail dormant chain models is almost functional insensitive, with values of 5−9 kcal/mol for the ATRP, ITP and TERP models, 3−6 for the RAFT/MADIX model, and around zero for CMRP. http://hdl.handle.net/2268/149065 Titre: Study of a solar concentrator for space based on a diffractive/refractive optical combination <br/> <br/>Auteur, co-auteur: Michel, Céline; Loicq, Jerôme; Mazzoli, Alexandra; Languy, Fabian; Habraken, Serge <br/> <br/>Résumé: This paper presents a new design of a planar solar concentrator for space applications focusing on two spatially separated PV cells, allowing independent control of output power of each cell. It has the advantages of both spectral splitting and solar concentration by the combination of a blaze transmission diffraction grating and a flat cylindrical Fresnel lens. An optical optimization has been realized and two variations of configuration have been developed to improve tracking tolerance: first, a design completed by secondary reflective concentrators and second, a symmetrical configuration composed of two lenses. First numerical results are presented, highlighting the possibility to design a concentrator at about 10×, with an electrical output power about 290W/m² lens and less than 10% losses for tracking errors lower than ±0.9°. http://hdl.handle.net/2268/149049 Titre: Minéralogie et propriétés physico-chimiques des smectites de Bana et Sabga (Cameroun). Utilisation dans la décoloration d'une huile végétale alimentaire <br/> <br/>Auteur, co-auteur: Mache, Jacques Richard <br/> <br/>Résumé: In this study, clay samples were collected in the localities of Bana and Sabga, in the regions of the west and north-west Cameroon, respectively. The purpose of this study was to determine their mineralogical composition, their physico-chemical properties and to assess their potential use in the bleaching process of palm oil, which is the main edible vegetable oil produced and refined in Cameroon. <br /> The results obtained from the analyses (XRD, FTIR, DTA / TGA and SEM) revealed that montmorillonite is the main clay mineral in these materials. It is associated with kaolinite and mica. Non-clay minerals such as quartz, anatase, cristobalite, K-feldspar and heulandite are also identified in variable quantities. Chemical analyses of the major elements show that the clays from Bana and Sabga consist mainly of the follow oxides such as SiO2, Al2O3 and Fe2O3. Bana clays have a cation exchange capacity (CEC) between 50 and 60 meq/100 g and a specific surface area between 50 and 60 m2/ g. Sabga clays have a lower capacity cation exchange (38- 46 meq/100 g) and a wider range of specific surface area (33-90 m2 / g). The characterization of the natural clays allowed to select of one sample by locality for sulfuric acid treatment. <br />The acid treatment of these materials led to structural, morphological and textural changes. Analysis by X-ray diffraction showed a progressive decrease in the intensity of the (001) reflection of montmorillonite and a shift of its basal d001-value. Treatment with more acid concentration causes an increase in the surface area of the obtained products and a decrease in cation exchange capacity. <br />The assessment of the bleaching power of natural and acid-activated Bana clay in palm oil decolorization shows that the activated clay has a high bleaching capacity (~ 87%) compared to the natural clay (~ 55%). palm oil Bleaching by these clay materials does not deteriorate the bleached oil. These materials can thus be used as bleaching earths in the refining oil process. http://hdl.handle.net/2268/149012 Titre: Light-induced Hetero-Diels Alder cycloaddition as a new coupling method to biomolecule radiolabeling <br/> <br/>Auteur, co-auteur: Dammicco, Sylvestre; Luxen, André; Thonon, David; Flagothier, Jessica; Warnier, Corentin <br/> <br/>Résumé: The formation of a C-18F bond requires hard conditions which is problematic for the biomolecule radiolabelling. The alternative method which has been developed since a few decades consists in incorporating the 18F on a prosthetic group and coupling it to the biomolecule. The copper (I)-catalysed 1,2,3-triazole formation involving azides and terminal alkynes is a powerful and rapid method of coupling but present the inconvenient of the employment of cytotoxic reagents. The photoclick conjugation is a promising alternative with no need of catalyst[1]. Recently, a light-induced hetero-Diels Alder cycloaddition involving a 3-(hydroxymethyl)-2-naphthol derivative and an electron-rich olefin has been developed[2]. This reaction seems well adapted for the fast conjugation of radionuclides to biomolecules. Herein we report the synthesis of a [18F]fluoronaphtoquinone derivative as prosthetic group and its reaction with vinyl ethers. http://hdl.handle.net/2268/149010 Titre: Fluorine-18 labeling of biocompatible nanoparticles for PET imaging <br/> <br/>Auteur, co-auteur: Kaisin, Geoffroy; Warnier, Corentin; Luxen, André http://hdl.handle.net/2268/149006 Titre: Synthesis of [18F]4-(4-fluorophenyl)-1,2,4-triazole-3,5-dione: an agent for specific radiolabelling of tyrosine. <br/> <br/>Auteur, co-auteur: Flagothier, Jessica; Warnier, Corentin; Lemaire, Christian; Luxen, André <br/> <br/>Résumé: Objectives: Metal-free and mild tyrosine modification reactions are an attractive alternative to the commonly used lysine and cysteine modification protocols for peptide and proteins labelling. Recently, Ban and co-workers have reported a tyrosine bioconjugation through ene-type reactions. Cyclic diazodicarboxamides, which are electrophilic compounds, react selectively in o-position on the phenol side chain of tyrosine in mild aqueous conditions and the 1,2,4-triazolidine-3,5-dione linkage is hydrolytically and thermally stable. We herein present the synthesis of [18F]4-(4-fluorophenyl)-1,2,4-triazole-3,5-dione and the coupling with N-acyl tyrosine methylamide. Methods: The N,N,N-trimethyl-4-nitrobenzeneammonium trifluoromethanesulfonate 1 was prepared following a procedure previously reported [2]. The [18F]prosthetic group 6, [18F]4-(4-fluorophenyl)-1,2,4-triazole-3,5-dione, was synthesized in five steps. Results: The synthesis of the [18F]prosthetic group has been realized with a decay-corrected radiochemical yield of 20% in 90 minutes. The radiochemical yield of the coupling with N-acyl tyrosine methylamide is 40% (DC). This presented synthetic pathway should be easily automated: particulary because the purifications between the different steps are exclusively done on SPE cartridges. Conclusions: We successfully developed an efficient bioconjugation method for fluorine-18 labelling of tyrosine without prior modifications of the peptide in very mild conditions. http://hdl.handle.net/2268/148982 Titre: Influence of dipole-dipole interactions on the superradiant pulse <br/> <br/>Auteur, co-auteur: Damanet, François; Martin, John <br/> <br/>Résumé: Superradiance, known as the cooperative spontaneous emission of a directional light pulse by excited atoms placed in vacuum, has recently regained attention in the context of photon localization [1] and single photon cooperative emission [2]. The dissipative dynamics of the atoms is known to depend dramatically on the ratio between the typical inter-atomic distance and the atomic transition wavelength, notably because of dipole-dipole interactions [3]. In this work, we study the effects of these interactions on superradiance as in [4] by solving numerically the corresponding master equation. In particular, by averaging over many realizations of the randomly distributed atomic positions, we show that the decay of the radiated energy pulse height with the intensity of the dipolar coupling follows a power law. [1] E. Ackermans, A. Gero & R. Kaiser, Phys. Rev. Lett. 101, 103602 (2008). [2] R. Friedberg & J. T. Manassah, J. Phys. B 43, 035501 (2010). [3] M. Gross & S. Haroche, Physics reports 93, 301-396 (1982). [4] B. Coffey & R. Friedberg, Phys. Rev. A 17, 1033 (1978). http://hdl.handle.net/2268/148972 Titre: Spectral modelling of massive binary systems <br/> <br/>Auteur, co-auteur: Palate, Matthieu; Rauw, Grégor; Koenigsberger, Gloria; Moreno, Edmundo <br/> <br/>Résumé: Context. The spectra of massive binaries may be affected by interactions between the stars in the system. These are believed to produce observational phenomena such as the Struve-Sahade effect. Aims: We simulate the spectra of massive binaries at different phases of the orbital cycle, accounting for the gravitational influence of the companion star on the shape and physical properties of the stellar surface. Methods: We used the Roche potential modified to account for radiation pressure to compute the stellar surface of close circular systems. We furthermore used the tidal interactions with dissipation of energy through shear code for surface computations of eccentric systems. In both cases, we accounted for gravity darkening and mutual heating generated by irradiation to compute the surface temperature. We then interpolated non-local thermodynamic equilibrium (NLTE) plane-parallel atmosphere model spectra in a grid to obtain the local spectrum at each surface point. We finally summed all contributions, accounting for the Doppler shift, limb-darkening, and visibility to obtain the total synthetic spectrum. We computed different orbital phases and different sets of physical and orbital parameters. Results: Our models predict line strength variations through the orbital cycle, but fail to completely reproduce the Struve-Sahade effect. Including radiation pressure allows us to reproduce a surface temperature distribution that is consistent with observations of semi-detached binary systems. Conclusions: Radiation pressure effects on the stellar surface are weak in (over)contact binaries and well-detached systems but can become very significant in semi-detached systems. The classical von Zeipel theorem is sufficient for the spectral computation. Broad-band light curves derived from the spectral computation are different from those computed with a model in which the stellar surfaces are equipotentials of the Roche potential scaled by the instantaneous orbital separation. In many cases, the fit of two Gaussian/Lorentzian profiles fails to properly measure the equivalent width of the lines and leads to apparent variations that could explain some of the effects reported in the literature. http://hdl.handle.net/2268/148958 Titre: Prévision des rendements agricoles. Guide d'utilisation. <br/> <br/>Auteur, co-auteur: Bronne, Charles-Emmanuel; Wellens, Joost; Midekor, Akoly Agblévi; Diakité, Mamadou; Denis, Antoine; Tychon, Bernard <br/> <br/>Résumé: Manuel présentant une méthode, développée par l'Université de Liège, de prévision de la production agricole. Cette méthode se base sur l'utilisation de différents programmes informatiques, et a pour but de prévoir le rendement agricole à partir de données météorologiques, agrométéorologiques, et NDVI (télédétecté). Elle est appliquée dans ce manuel sur les cultures du coton et du maïs au Burki Faso. http://hdl.handle.net/2268/148938 Titre: Modeling soil respiration in wheat fields <br/> <br/>Auteur, co-auteur: Delogu, Emilie; Le Dantec, Valérie; Mordelet, Patrick; Buysse, Pauline; Aubinet, Marc; Pattey, E.; Ceschia, Eric; Tallec, Tiphaine http://hdl.handle.net/2268/148937 Titre: Soil respiration partitioning and its components in the total agro-ecosystem respiration <br/> <br/>Auteur, co-auteur: Delogu, Emilie; Le Dantec, Valérie; Mordelet, Patrick; Buysse, Pauline; Aubinet, Marc; Pattey, E.; Mary, B.; Ceschia, Eric; Tallec, Tiphaine http://hdl.handle.net/2268/148930 Titre: What asteroseismology can teach us about stellar evolution: the case of subdwarf B stars <br/> <br/>Auteur, co-auteur: Van Grootel, Valérie; Fontaine, Gilles; Charpinet, Stephane; Brassard, Pierre; Green, Elizabeth M.; Randall, Suzanna K. <br/> <br/>Résumé: Subdwarfs B (sdB) stars are hot (Teff=20,000-40,000 K) and compact (log g= 5.0-6.2) evolved objects that form the very hot end of the horizontal branch, the so-called Extreme Horizontal Branch (EHB). Understanding the formation of sdB stars is one of the remaining challenges of stellar evolution theory. Competing scenarios have been proposed to account for the existence of such evolved objects, and give quite different mass distributions for resulting sdB stars. Detailed asteroseismic analyses, including mass estimates, of 15 pulsating hot B subdwarfs have been published since a decade. The masses have also been reliably determined by light curve modeling and spectroscopy for 7 sdB components of eclipsing or reflection binaries. I will present in the talk the empirical mass distributions of sdB stars on the basis of these samples. I will discuss how these empirical mass distributions, although still based on small-number statistics, compare with the expectations of stellar evolution theory. In particular, the two He-white dwarfs merger scenario does not seem to be the dominant channel to form isolated sdB stars, while the post-red giant branch scenario is reinforced. This opens new questions on the extreme mass loss of red giants to form extreme horizontal branch stars, possibly in connection with the recently discovered close planets orbiting sdB stars. http://hdl.handle.net/2268/148923 Titre: Climate-carbon cycle feedback during glacial cycles <br/> <br/>Auteur, co-auteur: Ganopolski, A; Brovkin, V; Calov, R; Archer, D; Munhoven, Guy <br/> <br/>Résumé: Paleoclimate records reveal a close link between global ice volume and atmospheric CO2 concentration, at least, through the last 800,000 years. Despite many efforts over the last two decades, mechanisms of glacial-interglacial CO2 variability and its role for the glacial cycles remain elusive. Here using the Earth system model of intermediate complexity CLIMBER-2 which includes all major components of the Earth system – atmosphere, ocean, land surface, ice sheets, terrestrial biota, eolian dust and marine biogeochemistry – we performed simulations of the last glacial cycles employing variations in the Earth’s orbital parameters as the only prescribed climatic forcing. In the experiments with constant CO2 concentration, temporal dynamics of the simulated glacial cycles strongly depend on the CO2 level. For CO2 concentrations about and above preindustrial one, the model simulates only short glacial cycles with precessional and obliquity frequencies. However, for lower CO2 concentrations the model simulates long glacial cycles with dominant 100 kyr periodicity. Simulated glacial cycles agreed favorably with paleoclimate reconstructions, but their amplitude is underestimated compared to those of the simulations with time-dependent CO2 concentration. These results confirm that the positive climate-carbon cycle feedback plays an important role in amplification of long glacial cycles. Experiments with fully interactive CO2 shed some light on the mechanism of climate-carbon cycle feedback during glacial cycles. Forced by orbital variations only, the model is able to reproduce the main features of CO2 changes: the 40 ppmv CO2 drop during glacial inception, the minimum concentration at the last glacial maximum being 80 ppmv lower than the Holocene value, and the relatively abrupt CO2 rise during the deglaciation. The main drivers of atmospheric CO2 evolve with time: changes in sea surface temperature and volume of bottom water of southern origin exert CO2 control during glacial inception and deglaciation, while changes in carbonate chemistry and marine biology are dominant during the first and second parts of the glacial cycles, respectively.