<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Gómez-Tamayo, M Del Mar</style></author><author><style face="normal" font="default" size="100%">Macías-García, Antonio</style></author><author><style face="normal" font="default" size="100%">Díaz Díez, M Angeles</style></author><author><style face="normal" font="default" size="100%">Cuerda-Correa, Eduardo M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Adsorption of Zn(II) in aqueous solution by activated carbons prepared from evergreen oak (Quercus rotundifolia L.).</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of hazardous materials</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Adsorption</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon: chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydrogen-Ion Concentration</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Solutions</style></keyword><keyword><style  face="normal" font="default" size="100%">Water Pollutants, Chemical</style></keyword><keyword><style  face="normal" font="default" size="100%">Water Pollutants, Chemical: chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Water Purification</style></keyword><keyword><style  face="normal" font="default" size="100%">Water Purification: methods</style></keyword><keyword><style  face="normal" font="default" size="100%">Wood</style></keyword><keyword><style  face="normal" font="default" size="100%">Zinc</style></keyword><keyword><style  face="normal" font="default" size="100%">Zinc: chemistry</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><volume><style face="normal" font="default" size="100%">153</style></volume><pages><style face="normal" font="default" size="100%">28-36</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In the present work activated carbons have been prepared from evergreen oak wood. Different samples have been prepared varying the concentration of the activating agent (H(3)PO(4)) and the treatment temperature. The yield of the process decreases with increasing phosphoric acid concentrations. Furthermore, high concentrations of activating agent lead to mainly mesoporous activated carbons to the detriment of the microporous texture. Treatment temperatures up to 450 degrees C lead to a progressive increase of the micro- and mesopore volumes. Values of specific surface area (S(BET)) as high as 1723 m(2) g(-1)have been obtained using appropriate phosphoric acid concentrations and treatment temperatures. The samples prepared have been successfully used in the removal of Zn(II) from aqueous solutions. From the adsorption kinetic data it may be stated that the equilibrium time is, in all cases, below 170 h. The adsorption process as a rule becomes faster as the mesopore volume and specific surface area of the samples increase. The adsorption isotherms in liquid phase point out that the adsorption capacity (n(0)(s)) and the affinity towards the solute (K(ci)) are higher for the sample showing the most developed mesoporous texture and surface area as well.</style></abstract><accession-num><style face="normal" font="default" size="100%">17875366</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Criquet, Stéven</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Measurement and characterization of cellulase activity in sclerophyllous forest litter.</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of microbiological methods</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Buffers</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulase</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulase: analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulase: isolation &amp; purification</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulose</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulose: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Endoglucanase</style></keyword><keyword><style  face="normal" font="default" size="100%">Extraction</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydrogen-Ion Concentration</style></keyword><keyword><style  face="normal" font="default" size="100%">Isoenzyme</style></keyword><keyword><style  face="normal" font="default" size="100%">Isoenzymes</style></keyword><keyword><style  face="normal" font="default" size="100%">Isoenzymes: analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">litter</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves: enzymology</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: enzymology</style></keyword><keyword><style  face="normal" font="default" size="100%">Temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">Trees</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2002///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/11997167</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">50</style></volume><pages><style face="normal" font="default" size="100%">165 - 173</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Cellulases are enzymatic proteins which hydrolyze cellulose polymers to smaller oligosaccharides, cellobiose and glucose. They consist in three major types of enzymes: endoglucanases (EC 3.2.1.4), cellobiohydrolases (EC 3.2.1.91) and beta-glucosidases (EC 3.2.1.21) which play an essential role in carbon turnover of forest ecosystem. The aim of this study was firstly to determine the parameters (i.e. buffer type, pH, temperature, quantity of litter, incubation time and reagent type) which affect the measurement of cellulase activity in a sclerophyllous forest litter, and secondly to compare two methods for measuring cellulase activity: a direct method and an extraction method. In the direct method, the litter was directly incubated with a buffered solution containing the enzyme substrate, whereas in the extraction method, the cellulases were firstly extracted before measuring their activity. The results were compared with other studies about soil cellulase activity, and it appeared that several parameters (buffer type, pH, temperature and sample quantity) which influence the measurement of cellulase activity differ according to whether a soil or a litter is considered. Concerning the procedure used for the measurement of cellulase activity, results showed that the activity values were higher when using an extraction procedure than when using a direct procedure. The extraction procedure, combined with a concentration stage of the extract, also allowed electrophoretic analysis (PAGE) of the cellulases extracted from the litter. The electrophoretic pattern revealed two cellulase isoenzymes which may be related to the occurrence of two pH-activity peaks of these enzymes when citrate buffer was used for the measurement of cellulase activity in the litter.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;accession-num: 11997167</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Criquet, Stéven</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Measurement and characterization of cellulase activity in sclerophyllous forest litter.</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of microbiological methods</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Buffers</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulase</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulase: analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulase: isolation &amp; purification</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulose</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulose: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Endoglucanase</style></keyword><keyword><style  face="normal" font="default" size="100%">Extraction</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydrogen-Ion Concentration</style></keyword><keyword><style  face="normal" font="default" size="100%">Isoenzyme</style></keyword><keyword><style  face="normal" font="default" size="100%">Isoenzymes</style></keyword><keyword><style  face="normal" font="default" size="100%">Isoenzymes: analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">litter</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves: enzymology</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: enzymology</style></keyword><keyword><style  face="normal" font="default" size="100%">Temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">Trees</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year></dates><volume><style face="normal" font="default" size="100%">50</style></volume><pages><style face="normal" font="default" size="100%">165-173</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Cellulases are enzymatic proteins which hydrolyze cellulose polymers to smaller oligosaccharides, cellobiose and glucose. They consist in three major types of enzymes: endoglucanases (EC 3.2.1.4), cellobiohydrolases (EC 3.2.1.91) and beta-glucosidases (EC 3.2.1.21) which play an essential role in carbon turnover of forest ecosystem. The aim of this study was firstly to determine the parameters (i.e. buffer type, pH, temperature, quantity of litter, incubation time and reagent type) which affect the measurement of cellulase activity in a sclerophyllous forest litter, and secondly to compare two methods for measuring cellulase activity: a direct method and an extraction method. In the direct method, the litter was directly incubated with a buffered solution containing the enzyme substrate, whereas in the extraction method, the cellulases were firstly extracted before measuring their activity. The results were compared with other studies about soil cellulase activity, and it appeared that several parameters (buffer type, pH, temperature and sample quantity) which influence the measurement of cellulase activity differ according to whether a soil or a litter is considered. Concerning the procedure used for the measurement of cellulase activity, results showed that the activity values were higher when using an extraction procedure than when using a direct procedure. The extraction procedure, combined with a concentration stage of the extract, also allowed electrophoretic analysis (PAGE) of the cellulases extracted from the litter. The electrophoretic pattern revealed two cellulase isoenzymes which may be related to the occurrence of two pH-activity peaks of these enzymes when citrate buffer was used for the measurement of cellulase activity in the litter.</style></abstract><accession-num><style face="normal" font="default" size="100%">11997167</style></accession-num></record></records></xml>