Cu,Zn,Al layered double hydroxides as precursors for copper catalysts in methanol steam reforming – pH-controlled synthesis by microemulsion technique

By co-precipitation inside microemulsion droplets a Cu-based catalyst precursor was prepared with a Cu:Zn:Al ratio of 50:17:33. A pH-controlled synthesis was applied by simultaneous dosing of metal solution and precipitation agent. This technique allows for continuous operation of the synthesis and enables easy and feasible up-scaling. For comparison conventional co-precipitation was applied with the same composition. Both techniques resulted in phase pure layered double hydroxide precursors and finally (after calcination and reduction) in small Cu nanoparticles (8 nm) and ZnAl2O4. By applying the microemulsion technique smaller Cu/ZnAl2O4 aggregates with less embedded Cu particles were obtained. The microemulsion product exhibited a higher BET and specific Cu surface area and also a higher absolute catalytic activity in methanol steam reforming. However, the Cu surface area-normalized, intrinsic activity was lower. This observation was related to differences in interactions of Cu metal and oxide phase

Nanoparticles Supported on Sub-Nanometer Oxide Films : Scaling Model Systems to Bulk Materials

Ultrathin layers of oxides deposited on atomically flat metal surfaces have been shown to significantly influence the electronic structure of the underlying metal, which in turn alters the catalytic performance. Upscaling of the specifically designed architectures as required for technical utilization of the effect has yet not been achieved. Here, we apply liquid crystalline phases of fluorohectorite nanosheets to fabricate such architectures in bulk. Synthetic sodium fluorohectorite, a layered silicate, when immersed into water spontaneously and repulsively swells to produce nematic suspensions of individual negatively charged nanosheets separated to more than 60 nm, while retaining parallel orientation. Into these galleries oppositely charged palladium nanoparticles were intercalated whereupon the galleries collapse. Individual and separated Pd nanoparticles were thus captured and sandwiched between nanosheets. As suggested by the model systems, the resulting catalyst performed better in the oxidation of carbon monoxide than the same Pd nanoparticles supported on external surfaces of hectorite or on a conventional Al2O3 support. XPS confirmed a shift of Pd 3d electrons to higher energies upon coverage of Pd nanoparticles with nanosheets to which we attribute the improved catalytic performance. DFT calculations showed increasing positive charge on Pd weakened CO adsorption and this way damped CO poisoning

CORPORATIONS--SECTION 16 (b) OF SECURITIES EXCHANGE ACT-SHORT SWING PROFITS-STATUTE OF LIMITATIONS

Plaintiffs brought a shareholders\u27 class action under section 16 (b) of the Securities and Exchange Act of 1934 alleging that defendant, an officer, director, and substantial stockholder of the corporation, had realized profits from trading in the corporation\u27s securities within a six-month period and had fraudulently concealed such profits by failing to file the statement required by section 16 (a) of the act until after suit was instituted against him over four years later by the S.E.C., thereby delaying plaintiff\u27s discovery of the facts. Defendant moved for dismissal on the ground that suit was not brought within the two-year period as prescribed by section 16 (b), and also on the ground that plaintiffs commenced suit before the expiration of the sixty-day period after notice and demand upon the corporation as provided in section 16 (b). Held, motion denied. Fraudulent concealment by an insider of profits realized within a six-month period tolls the two-year limitation provision of the statute. Grossman v. Young, (D.C. N.Y. I 94 7) 72 F. Supp. 375

Comparison of fouling between aerobic and anaerobic MBR treating municipal wastewater

The key driver for anaerobic membrane bioreactors (AnMBR) for municipal wastewater treatment is enabling the transition to energy neutral wastewater treatment. However, municipal wastewater delivers a comparatively constrained methane yield, which means energy conservation must be prioritised to achieve the proposed energy neutral ambition. A critical focus on membrane fouling is therefore warranted, as membrane operation represents the primary energy demand in MBRs. This review seeks to quantify the characteristics of the prevailing AnMBR biological suspension and to ascertain whether knowledge transfer exists between fouling characteristics in aerobic and anaerobic MBRs for municipal applications. Analysis of literature data revealed that the level of extractable extracellular polymeric substrate is slightly higher in aerobic MBRs than in anaerobic MBRs. However, AnMBR comprises considerably higher soluble microbial product concentrations, which have been widely reported to increase fouling propensity in aerobic systems. More distinct is the difference in the colloidal and fine solids fraction (between 1 and 10–15 μm), which is likely to dominate fouling in anaerobic systems and limit knowledge transfer from aerobic MBRs. Literature data on energy production was compared to that employed for membrane operation, and evidences that despite the challenging character of the particle matrix, energy neutral operation is achievable for AnMBR applied to municipal wastewater treatment

Challenges in biogas production from anaerobic membrane bioreactors

© 2016 Spectacular applications of anaerobic membrane bioreactors (AnMBRs) are emerging due to the membrane enhanced biogas production in the form of renewable bioresources. They produce similar energy derived from the world's depleting natural fossil energy sources while minimizing greenhouse gas (GHG) emissions. During the last decade, many types of AnMBRs have been developed and applied so as to make biogas technology practical and economically viable. Referring to both conventional and advanced configurations, this review presents a comprehensive summary of AnMBRs for biogas production in recent years. The potential of biogas production from AnMBRs cannot be fully exploited, since certain constraints still remain and these cause low methane yield. This paper addresses a detailed assessment on the potential challenges that AnMBRs are encountering, with a major focus on many inhibitory substances and operational dilemmas. The aim is to provide a solid platform for advances in novel AnMBRs applications for optimized biogas production

High population differentiation in the rock-dwelling land snail ( Trochulus caelatus ) endemic to the Swiss Jura Mountains

Understanding patterns of genetic structure is fundamental for developing successful management programmes for isolated populations of threatened species. Trochulus caelatus is a small terrestrial snail endemic to calcareous rock cliffs in the Northwestern Swiss Jura Mountains. Eight microsatellite loci were used to assess the effect of habitat isolation on genetic population structure and gene flow among nine populations occurring on distinct cliffs. We found a high genetic differentiation among populations (mean F ST=0.254) indicating that the populations are strongly isolated. Both allelic richness and effective population size were positively correlated with the size of the cliffs. Our findings support the hypothesis that T. caelatus survived on ice-free cliffs during the Pleistocene glacier advancements from the Alps. Due to the establishment of beech and pine forest under recent, temperate climate conditions, dispersal between cliffs is no longer possible for rock-dwelling snails such as T. caelatus. Our results provide basic data for developing a conservation action plan for this endangered gastropod specie

O gênero Dalechampia L. (Euphorbiaceae - Acalyphoidea) na região sul do Brasil

Dalechampia é um gênero de Euphorbiaceae amplamente distribuído no Velho e Novo Mundo, totalizando cerca de 120 espécies. Sua maior riqueza é encontrada nos neotrópicos, estando concentrada principalmente no Brasil com 72 espécies, as quais estão distribuídas em quase todos os estados. Devido à escassez de trabalhos taxonômicos na Região Sul do Brasil, os objetivos desse estudo foram: revisar a taxonomia e investigar as espécies da Região Sul. Através de coletas, revisão bibliográfica e de herbários e análises morfológicas se obteve: a) identificação e caracterização de 15 espécies de Dalechampia, para a área de estudo: D. clausseniana Baill., D. ficifolia Lam.; D. glechomifolia Baill., D. guaranitica Chodat & Hassl., D. leandrii Baill., D. micromeria Baill., D. pentaphylla Lam., D. reitzkleinii L.B. Sm & Downs, D. riparia L.B. Sm. & Downs, D. scandens L., D. schenckiana Pax & K. Hoffm., D. stenosepala Müll. Arg., D. stipulacea Müll. Arg., D. triphylla Lam., D. weddelliana Baill.; b) quatro novas ocorrências para os estados do Paraná e Santa Catarina; c) redescoberta de uma espécie endêmica considerada provavelmente extinta no estado de Santa Catarina; d) dados citogenéticos referentes à morfologia do pólen e tamanho de genoma de algumas espécies. Para essas espécies são apresentadas descrições, fotos, ilustrações, mapas, comentários e chave de identificação. Além disso, foram designados dois lectótipos. Dentre os 15 táxons, oito são endêmicos do Brasil e dois táxons são exclusivos da Região Sul. Os dados obtidos neste estudo permitiram ampliar os conhecimentos sobre o gênero e, ao mesmo tempo, apontar desafios taxonômicos ainda existentes, os quais poderão ser alvo de investigação de futuros estudos que integrem diferentes enfoques.Dalechampia is a genus of Euphorbiaceae that is widely spread in both the Old and the New World, numbering around 120 species. Its richness peaks in the Neotropics. The genus is mainly found in Brazil, with 72 species that are distributed throughout nearly every state. Due to the lack of taxonomic research in the South of Brazil, this study aimed to revise the taxonomy and to investigate the southern species. Through data collections, morphological analysis, literature review and herbaria review, we obtained: a) identification and characterization of 15 Dalechampia species for the study area (D. clausseniana Baill., D. ficifolia Lam.; D. glechomifolia Baill., D. guaranitica Chodat & Hassl., D. leandrii Baill., D. micromeria Baill., D. pentaphylla Lam., D. reitzkleinii L.B. Sm & Downs, D. riparia L.B. Sm. & Downs, D. scandens L., D. schenckiana Pax & K. Hoffm., D. stenosepala Müll. Arg., D. stipulacea Müll. Arg., D. triphylla Lam., D. weddelliana Baill); b) four new species occurrences for Paraná and Santa Catarina; c) rediscovery of an endemic species that had been considered extinct in Santa Catarina; d) cytogenetic data regarding pollen morphology and genome size of some species. For these species, we present descriptions, photos, illustrations, maps, comments and identification keys. We also designated two lectotypes. Among the 15 taxa, eigth are endemic and two are exclusive to the southern region. The data obtained in this study allowed us to broaden the knowledge on the genus and, at the same time, point the taxonomic challenges that still exist and might be approached by future research that adopts different perspectives

The Onomastics of Shakespeare\u27s Works with Classical Settings

The present invention discloses a set of dental arches comprising: an upper arch (1) formed by upper anterior (2) and posterior (3) artificial teeth and another lower arch (5) formed by lower anterior (6) and posterior (7) artificial teeth mounted in an orderly fashion on flexible bases (4) and (8) constructed of elastomeric resin in the form of an arch, having a three-dimensional movement capacity to enable adaptation to the anatomy and physiology of edentulous patients; the base material also allows the adjustment of each tooth individually, through changes of position, inclination or alignment, in a simple manner, thus producing custom prosthodontics; its use in the confection processes of removable complete and partial dentures saves time, labor and cost compared to traditional methods.US2009233255 (A1)A61C9/00A61C13/34US20070227690A61C9/00A61C13/3