The objective of this research was to evaluate the air stripping technology for the removal of ammonia from landfill leachates. In this process, pH, temperature, airflow rate and operation time were investigated. Furthermore, the relationship between the leachate alkalinity and the ammonia removal efficiency during the process was studied. The leachate used in the tests was generated in the Gramacho Municipal Solid Waste Landfill (Rio de Janeiro State, Brazil). The best results were obtained with a temperature of 60(o)C, and they were independent of the pH value for 7 h of operation (the ammonia nitrogen removal was greater than 95%). A strong influence of the leachate alkalinity on the ammonia nitrogen removal was observed; as the alkalinity decreased, the ammonia concentration also decreased because of prior CO2 removal, which increased the pH and consequently favored the NH3 stripping. The air flow rate, in the values evaluated (73, 96 and 120 L air.h(-1).L(-1) of leachate), did not influence the results.

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The treatment of cellulose with cold plasma in the presence of two silanes is found to be efficient in the grafting of cellulose macromolecules. The occurrence of the grafting is proven by contact angle measurement, ESCA, and SEM. Thus, after plasma treatment the polar component of the surface energy of the treated samples decreases from 23 mJ · m−2 to practically zero. The ESCA spectra showed the appearance of two new peaks at 102 and 150 eV, relative to the presence of Si atoms and a substantial increase in Cl signal, attributed to the enrichment of the surface by CH moieties borne by the silanes. SEM confirms the presence of the silane, both in the bulk and at the surface of the treated samples.magnified image

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The compound of poly(lactic acid) (PLA) and cellulose was made by the emulsion-solvent evaporation technique in order to obtain spheres which are then compression molded to produce a biocomposite film. The effect of the dispersant (poly(vinyl alcohol)—PVA)/PLA ratio on the spheres yield was studied. Moreover, to evaluate the effect of cellulose particle size and surface chemistry on the process yield, unbleached eucalypt kraft pulp and microcrystalline cellulose (MCC), both unmodified and physically or chemically modified were used. PLA/cellulose spheres were characterized regarding its physical properties. It was found that the spheres yield is essentially determined by the PVA/PLA ratio and the percentage of cellulose incorporation is greatly affected by the surface chemistry of cellulose. Regarding the films, DSC runs showed a significant effect of the cellulose type incorporated into PLA matrix on the cold crystallization temperature and on the degree of crystallinity of the biocomposite films. The measurement of tensile properties of the biocomposite films revealed that the strength, elongation at break and toughness (tensile energy absorption at break) of the films incorporating unmodified and chemically modified MCC were substantially improved.

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New Findings What is the central question of this study?Does glucocorticoid excess disrupt brown adipose tissue (BAT) phenotype and function? What is the main finding and its importance?Glucocorticoid excess induced an extensive remodelling of interscapular BAT, resulting in a white‐like phenotype in association with metabolic disturbances. Glucocorticoids might be an important modulator of BAT physiology and BAT may have a role in pathophysiology of metabolic disturbances induced by glucocorticoid excess. Abstract In mammals, brown adipose tissue (BAT) is centrally involved in energy metabolism. To test the hypothesis that glucocorticoid excess disrupts BAT phenotype and function, male Wistar rats were treated with corticosterone in drinking water for 21 days. To confirm induction of glucocorticoid excess and metabolic disturbances, adrenal weight, corticotrophin releasing hormone mRNA levels and corticosterone serum levels were measured and a glucose tolerance test and serum triacylglycerol analyses were performed. Adipose tissue deposits were excised, weighed and evaluated by a set of biochemical, histological and molecular procedures, including thin‐layer chromatography, histochemistry, immunohistochemistry, quantitative real‐time polymerase chain reaction, high‐resolution oxygraphy, ATP synthesis and enzymatic activity measurements. The approach was successful in induction of glucocorticoid excess and metabolic disturbances. Lower body weight and increased adiposity were observed in corticosterone‐treated rats. Interscapular brown adipose tissue (iBAT) showed higher sensitivity to glucocorticoids than other fat deposits. The treatment induced lipid accumulation, unilocular rearrangement, increased collagen content and decreased innervation in iBAT. Furthermore, expression of Prdm16 (P < 0.05), Ucp1 (P <0.05) and Slc7a10 (P <0.05) mRNA decreased, while expression of Fasn (P <0.05) and Lep (P <0.05) mRNA increased in brown adipose tissue. Also, the levels of UCP1 diminished (P <0.001, 2.5‐fold). Finally, lower oxygen consumption (P <0.05), ATP synthesis (P <0.05) and mitochondrial content (P <0.05) were observed in iBAT of glucocorticoid‐treated rats. Glucocorticoid excess induced an extensive remodelling of interscapular brown adipose tissue, resulting in a white‐like phenotype in association with metabolic disturbances.

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