Dynamic cyclic performance of phenol-formaldehyde resin derived carbons for pre-combustion CO2 capture : An experimental study

Acknowledgments This work was carried out with financial support from the Spanish MINECO (Project ENE2011-23467), co-financed by the European Regional Development Fund (ERDF).Peer reviewedPublisher PD

Preparation of carbon dioxide adsorbents from the chemical activation of urea–formaldehyde and melamine–formaldehyde resins

10 pages, 4 figures, 3 tables.-- Available online Aug 14, 2006.Adsorption is considered to be one of the more promising technologies for the capture of CO2 from flue gases. In general, nitrogen enrichment is reported to be effective in enhancing the specific adsorbent–adsorbate interaction for CO2. Nitrogen enriched carbons were produced from urea–formaldehyde and melamine–formaldehyde resins polymerised in the presence of K2CO3 as a chemical activation agent, with activation undertaken over a range of temperatures. CO2 adsorption capacity was determined to be dependent upon both textural properties and more importantly nitrogen functionality. Adsorbents capable of capturing above 8 wt.% CO2 at 25°C were produced from the chemical activation of urea–formaldehyde resin at 500°C. Chemical activation seems to produce more effective adsorbents than CO2 activation.The authors are grateful for support for this work provided by the Research Fund for Coal and Steel (RFC-CR-03008) and for CP a grant from Plan I + D + I Gobierno del Principado de Asturias.Peer reviewe

High body adiposity drives glucose intolerance and increases cardiovascular risk in normoglycemic subjects

Objective: We aimed to assess the utility of the 2 - hour oral glucose tolerance test (OGTT) value to discriminate between different cardiometabolic profiles and examine the role of body composition to predict the associated increased risk for glucose impairment, beta cell dysfunction and cardiovascular disease. Methods: Subjects with normal fasting glucose (NFG) completed a 2 - h OGTT and were categorized to the carbohydrate metabolism alterations (CMA) or contro l group based upon a 2 - h glucose threshold of 7.8 mmol l - 1 . Body composition, visceral adipose tissue, OGTT - based parameters and cardiovascular risk factors (CVRF) such as hypertension, dyslipidemia, obstructive sleep apnea, non - alcoholic fatty liver disea se and smoking status, were measured. Results: Subjects with CMA exhibited a significantly higher 1 - h postload glucose, greater decline in beta cell function and CVRF profile. After multivariate adjustment, excess of total body and visceral fat was associ ated with an increased risk of CMA, - cell dysfunction, CVRF and a lower whole - body insulin sensitivity. Conclusions: These data support the ethiopathogenic role of body and visceral fat in the development of glucose derangements and CVRF early on in the metabolic dysregulation process. Thus, body composition analysis and OGTT assessment performed in individuals with NFG enables a better identification of patients at risk of developing type 2 diabetes and cardiovascular disease

The Aguablanca Ni–(Cu) sulfide deposit, SW Spain: geologic and geochemical controls and the relationship with a midcrustal layered mafic complex

The Aguablanca Ni–(Cu) sulfide deposit is hosted by a breccia pipe within a gabbro–diorite pluton. The deposit probably formed due to the disruption of a partially crystallized layered mafic complex at about 12– 19 km depth and the subsequent emplacement of melts and breccias at shallow levels (<2 km). The ore-hosting breccias are interpreted as fragments of an ultramafic cumulate, which were transported to the near surface along with a molten sulfide melt. Phlogopite Ar–Ar ages are 341– 332 Ma in the breccia pipe, and 338–334 Ma in the layered mafic complex, and are similar to recently reported U–Pb ages of the host Aguablanca Stock and other nearby calcalkaline metaluminous intrusions (ca. 350–330 Ma). Ore deposition resulted from the combination of two critical factors, the emplacement of a layered mafic complex deep in the continental crust and the development of small dilational structures along transcrustal strike-slip faults that triggered the forceful intrusion of magmas to shallow levels. The emplacement of basaltic magmas in the lower middle crust was accompanied by major interaction with the host rocks, immiscibility of a sulfide melt, and the formation of a magma chamber with ultramafic cumulates and sulfide melt at the bottom and a vertically zoned mafic to intermediate magmas above. Dismembered bodies of mafic/ultramafic rocks thought to be parts of the complex crop out about 50 km southwest of the deposit in a tectonically uplifted block (Cortegana Igneous Complex, Aracena Massif). Reactivation of Variscan structures that merged at the depth of the mafic complex led to sequential extraction of melts, cumulates, and sulfide magma. Lithogeochemistry and Sr and Nd isotope data of the Aguablanca Stock reflect the mixing from two distinct reservoirs, i.e., an evolved siliciclastic middle-upper continental crust and a primitive tholeiitic melt. Crustal contamination in the deep magma chamber was so intense that orthopyroxene replaced olivine as the main mineral phase controlling the early fractional crystallization of the melt. Geochemical evidence includes enrichment in SiO2 and incompatible elements, and Sr and Nd isotope compositions (87Sr/86Sri 0.708–0.710; 143Nd/144Ndi 0.512–0.513). However, rocks of the Cortegana Igneous Complex have low initial 87Sr/86Sr and high initial 143Nd/144Nd values suggesting contamination by lower crustal rocks. Comparison of the geochemical and geological features of igneous rocks in the Aguablanca deposit and the Cortegana Igneous Complex indicates that, although probably part of the same magmatic system, they are rather different and the rocks of the Cortegana Igneous Complex were not the direct source of the Aguablanca deposit. Crust–magma interaction was a complex process, and the generation of orebodies was controlled by local but highly variable factors. The model for the formation of the Aguablanca deposit presented in this study implies that dense sulfide melts can effectively travel long distances through the continental crust and that dilational zones within compressional belts can effectively focus such melt transport into shallow environments

Final Pre-40S Maturation Depends on the Functional Integrity of the 60S Subunit Ribosomal Protein L3

Ribosomal protein L3 is an evolutionarily conserved protein that participates in the assembly of early pre-60S particles. We report that the rpl3[W255C] allele, which affects the affinity and function of translation elongation factors, impairs cytoplasmic maturation of 20S pre-rRNA. This was not seen for other mutations in or depletion of L3 or other 60S ribosomal proteins. Surprisingly, pre-40S particles containing 20S pre-rRNA form translation-competent 80S ribosomes, and translation inhibition partially suppresses 20S pre-rRNA accumulation. The GTP-dependent translation initiation factor Fun12 (yeast eIF5B) shows similar in vivo binding to ribosomal particles from wild-type and rpl3[W255C] cells. However, the GTPase activity of eIF5B failed to stimulate processing of 20S pre-rRNA when assayed with ribosomal particles purified from rpl3[W255C] cells. We conclude that L3 plays an important role in the function of eIF5B in stimulating 3′ end processing of 18S rRNA in the context of 80S ribosomes that have not yet engaged in translation. These findings indicate that the correct conformation of the GTPase activation region is assessed in a quality control step during maturation of cytoplasmic pre-ribosomal particles

Templated polymeric materials as adsorbents for the postcombustion

Increasing awareness of the influence of greenhouse gases on global climate change has led to recent efforts to develop strategies for the reduction of carbon dioxide (CO2) emissions. The strategy that is receiving the most attention involves the capture of CO2 from large point sources (such as fossil fuelfired power plants) and long-term storage underground or in the ocean. Aqueous solutions of amines have long been used by industry as absorbents for acid gas (CO2, H2S) removal. However, they have a number of shortcomings for treating flue gases. As an alternative, adsorption is considered to be a promising technologies for capturing CO2 from flue gases, with the potential to overcome the problems associated with liquid amines.The EPSRC Advanced Research Fellowship EP/C543203/1Peer reviewe

The iron oxide –(Cu–Au) Deposits of SW Iberia Fregenal–Burguillos–Cala District: Lat. 38°18’ N, Long. 6°40’ W

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu