We report the advances in the principal structural and experimental factors that might influence the carbon dioxide (CO 2 ) adsorption on natural and synthetic zeolites. The CO 2 adsorption is principally govern by the inclusion of exchangeable cations (countercations) within the cavities of zeolites, which induce basicity and an electric field, two key parameters for CO 2 adsorption. More specifically, these two parameters vary with diverse factors including the nature, distribution and number of exchangeable cations. The structure of framework also determines CO 2 adsorption on zeolites by influencing the basicity and electric field in their cavities. In fact, the basicity and electric field usually vary inversely with the Si/Al ratio. Furthermore, the CO 2 adsorption might be limited by the size of pores within zeolites and by the carbonates formation during the CO 2 chemisorption. The polarity of molecules adsorbed on zeolites represents a very important factor that influences their interaction with the electric field. The adsorbates that have the most great quadrupole moment such as the CO 2 , might interact strongly with the electric field of zeolites and this favors their adsorption. The pressure, temperature and presence of water seem to be the most important experimental conditions that influence the adsorption of CO 2 . The CO 2 adsorption increases with the gas phase pressure and decreases with the rise of temperature. The presence of water significantly decreases adsorption capacity of cationic zeolites by decreasing strength and heterogeneity of the electric field and by favoring the formation of bicarbonates. The optimization of the zeolites structural characteristics and the experimental conditions might enhance substantially their CO 2 adsorption capacity and thereby might give rise to the excellent adsorbents that may be used to capturing the industrial emissions of CO 2 .

A study of carbon dioxide (CO 2 ) absorption/desorption has been carried out to estimate the influence of the structural features of distinct amines on their CO 2 absorption and regeneration. The absorption has been made at two different CO 2 flow rates with a series of aqueous 5 wt % ammonia, monoethanolamine (MEA), triethanolamine (TEA), triethylamine, pyridine, pyrrolidine, 2-(2-aminoethylamino)ethanol (AEE), and N-(2-aminoethyl)-1,3-propanediamine (AEP-DNH 2 ) solutions, while the CO 2 desorption has been performed by heating these solutions. The presence of two or three amino groups in AEE and AEPDNH 2 , the structure of tertiary amine and alkanolamine, and a nonaromatic ring of pyrrolidine might favor the CO 2 absorption, while the structural features of ammonia and pyridine seem to be unfavorable. The tertiary alkanolamine is the most easy to regenerate and looses less of its CO 2 loading after regeneration. It appears that AEE and AEPDNH 2 would represent interesting compounds which could be used as CO 2 absorbents in industrial technologies to prevent CO 2 release into the atmosphere.

A study of carbon dioxide sequestration has been performed in aqueous electric arc furnace (EAF) and ladle furnace (LF) slag suspensions, in leached hydrated-matrixes, and in leachates to estimate their intrinsic sequestration potential at ambient conditions (temperature of 20 ( 1°C and atmospheric pressure). The CO 2 sequestration was tested in aqueous suspensions of steel slags at a liquid-to-solid ratio of 10 kg/kg as well as in leached hydrated-matrixes and leachates isolated from these fresh slag suspensions after three consecutive leachings. The sequestration assays were performed at 20°C with a flow rate of 5 mL/min of a CO 2 concentration of 15.00 vol %. The results have revealed that the CO 2 sequestration capacity of the LF slag suspension (24.7 g of CO 2 /100 g of slag) is 14 times superior to that of the EAF slag suspension. This greater CO 2 sequestration capacity of the LF slag suspension may be associated in large part to its higher content of portlandite, which reacts with CO 2 relative to the EAF slag suspension. Moreover, the separation of hydratedmatrixes and leachates significantly enhanced the CO 2 sequestration capacity of EAF slag while a slight decrease was observed for the LF slags. This may be due to an obstruction of the CO 2 binding sites of LF slag hydrated-matrixes following the accumulation of calcium carbonate. Taken together, these results suggest that EAF and LF slags could be used for the CO 2 sequestration and given a good yield as well in aqueous suspension as in separated matrixes and leachates.

Recent advances in understanding of the biological functions of the epidermal growth factor and epidermal growth factor receptor (EGF-EGFR) system and ceramide production for the maintenance of skin integrity and barrier function are reported. In particular, the opposite roles of EGFR and ceramide cascades in epithelial keratinocyte proliferation, migration and terminal differentiation are described. Moreover, the functions of ceramides in the epidermal permeability barrier are reviewed. The alterations in EGFR signaling and ceramide metabolism, which might be involved in the etiopathogenesis of diverse skin disorders and cancers, are described. New progress in understanding of skin organization, which might provide the basis for the design of new transcutaneous drug delivery techniques as well as for the development of new therapies of skin disorders and cancers, are reported.

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An analysis of carbonation was carried out with the aqueous fresh red mud suspension at a liquid-to-solid ratio of 10 kg/kg, as well as in the leached-hydrated matrixes and leachates isolated from this red mud suspension after three successive leachings, to evaluate their intrinsic carbonation potential at ambient conditions (temperature of 20 ± 1 °C and atmospheric pressure). The carbonation assays were performed at 20 °C using a CO2 concentration of 15.00 vol% at a flow rate of 5 mL/min. The red mud matrix has a great leaching capacity of Na−(hydr)oxide, which is the principal hydroxide that seems to be implicated in the carbonation of leachates that have half-carbonation capacity of red mud. Moreover, the carbonation of the red mud suspension also involves a portlandite-containing matrix. The carbonation of the red mud suspension and leachates implicates a complete neutralization of their content in Ca− and Na−(hydr)oxides. Although the leached hydrated-matrixes seem to be partially carbonated, it preserves a carbonation capacity near to that of leachate after three successive leachings. Moreover, three leached hydrated-matrixes and leachates have a carbonation capacity (7.09 g of CO2/100 g of red mud) higher than the carbonation capacity obtained for the red mud suspension, which is evaluated to 4.15 g of CO2/100 g of red mud. Taken together, these results suggest that the carbonation of the red mud may be enhanced by the use of leached hydrated-matrixes and leachates obtained from multiple leaching.

A study of carbon dioxide (CO2) and sulfur dioxide (SO2)/CO2 mixtures absorption has been carried out in aqueous 2-(2-aminoethylamino)ethanol (AEE) solution and its blends with N-methyldiethanolamine (MDEA) and triethanolamine (TEA) to estimate the influence of SO2, MDEA, and TEA on the CO2 absorption capacity of the AEE. The CO2 absorption loading has been estimated in 15 wt % AEE alone and in the presence of either 5 and 10 wt % MDEA or 5 and 10 wt % TEA solutions with 100 vol % CO2 and 5.03 and 15.02 vol % SO2/CO2 mixtures at a starting temperature of 296 K and flow rates of 3.067, 3.229, and 3.605 L/min, respectively. The results revealed that the presence of SO2 in the gas decreases the CO2 absorption rate and loading in the AEE solution as a function of the concentration of SO2. The additions of 5 and 10 wt % of MDEA and TEA do not seem to influence the CO2 absorption rate in the AEE solution. Moreover, the addition of MDEA increases slightly the CO2 absorption capacity of AEE, while TEA decreases the absorption capacity of AEE in the absence and presence of SO2. These effects were enhanced with increases of MDEA and TEA. Altogether, the results indicated that the blend of 15 wt % AEE + 10 wt % MDEA represents an interesting solvent which could be used as absorbent for the removal of CO2 from emission into the atmosphere by industries.

A study of carbon dioxide (CO 2 ) absorption/desorption has been carried out in diverse aqueous amine solutions consisting of 2-(2-aminoethylamino)ethanol (AEE), monoethanolamine (MEA), and the blends of AEE and N-methyldiethanolamine (MDEA) at different concentrations to compare the CO 2 loading and recuperation properties of these amines. The CO 2 absorption loading has been estimated in 0.476, 0.951, 1.427, and 2.378 M AEE solutions, a 2.378 M MEA solution, and two blends of 1.427 M AEE + 0.418 M MDEA and 1.427 M AEE + 0.836 M MDEA with two CO 2 concentrations of 5.01 and 100 vol % at 23 °C and a flow rate of 3.067 L/min. The CO 2 desorption was performed by heating these solutions at 100-102 °C. The results revealed that the AEE diamine possesses a greater CO 2 absorption capacity than MEA while its CO 2 desorption capacity was inferior to that observed for MEA. Moreover, the CO 2 recuperation capacity obtained for AEE was greater than that of MEA at the same concentration. Interestingly, the CO 2 absorption in an aqueous AEE solution was also slightly increased in the presence of MDEA while its desorption was highly enhanced, resulting in an increase of about 15% of its CO 2 recuperation capacity. Taken together, these results suggest that the structural properties of AEE, including the presence of two amino groups, as compared to MEA could favor its CO 2 absorption and recuperation capacities. Therefore, AEE and the blends of AEE + MDEA could represent interesting absorbents for the development of new methods to eliminate the CO 2 emanation into the atmosphere by industrial combustion processing.