CO2-assisted hydrolytic hydrogenation of cellulose and cellulose-based waste into sorbitol over commercial Ru/C

A single-step protocol was developed for the hydrolytic hydrogenation of microcrystalline cellulose into sorbitol over commercial carbon-supported Ru, in the presence of gaseous CO2 as an acid source and molecular hydrogen as a reductant. Under these conditions, cellulose was first hydrolysed to glucose by reversibly formed carbonic acid in water and then instantaneously hydrogenated on Ru/C. By tuning the reaction parameters, such as temperature, time and the relative pressure of CO2 and hydrogen gas, cellulose was fully converted at 220 & DEG;C in 18 h under 30 and 40 bar of H-2 and CO2, respectively, with a sorbitol yield of 81%. Blank experiments revealed that without a catalyst and hydrogen, the reaction exhibited <5% conversion and glucose was the only detected product when the reaction was performed under CO2 pressure. XRD measurements on CO2-treated cellulose surprisingly revealed no noticeable changes in the crystallinity index (<10% with respect to microcrystalline cellulose), suggesting that hydrolytic hydrogenation took place on crystalline, not amorphous, cellulose. Furthermore, not only several cellulosic feedstocks, including filter paper, cotton wool, and cotton fiber, but also typical cellulose-based wastes such as a cardboard pizza box were also tested and under the optimized conditions sorbitol was obtained with yields ranging from 56% up to 72% in all cases. No less significant was the Ru/C catalyst stability, which could be recycled at least six times without any noticeable activity loss

Advancing fertilizer technology in Brazil.

The main trend is a reduction of the importance of labour and land; Scientific developments; Brazil already has a series of sustainable systems that can be considered 'land-saving'; Impacting factors; Sustainable production; Fertilizers account for about 2.5% of total greenhouse gas emissions; Strategic studies

Patterns of Extinction Risk and Threat for Marine Vertebrates and Habitat-Forming Species in the Tropical Eastern Pacific

Marine conservation activities around the globe are largely undertaken in the absence of comprehensive species-specific information. To address this gap, complete regional species assemblages of major marine taxa are being progressively assessed against the Categories and Criteria of the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species. The present study is the first analysis of entire major components of the biota of a large marine biogeographic region conducted in the Tropical Eastern Pacific (TEP). It is based on recently completed IUCN Red List assessments for all known species of bony and cartilaginous shorefishes, corals, mangroves, and seagrasses in the TEP. Twelve percent of the \u3e1600 species assessed are in threatened categories, indicative of elevated extinction risk. Spatial analysis of all assessed taxonomic groups, including previous IUCN Red List assessments for seabirds, marine mammals, and marine turtles, highlights specific geographical areas of elevated threatenedspecies richness. The distribution of threatened species in the TEP is primarily linked to areas with high rates of overfishing, habitat loss, and increasing El Niño-Southern Oscillation (ENSO) event impacts, as well as oceanic islands with high stochastic risk factors for endemic species. Species assigned to the highest threat categories have life history traits that likely decrease their resilience to various regional and site-specific threats. Comprehensive information in the form of IUCN Red List assessments combined with spatial analysis will greatly help to refine both site- and species-specific marine conservation priorities in the TEP

A Revised Approach for One-Dimensional Time-Dependent Heat Conduction in a Slab

Classical Green's and Duhamel's integral formulas are enforced for the solution of one dimensional heat conduction in a slab, under general boundary conditions of the first kind. Two alternative numerical approximations are proposed, both characterized by fast convergent behavior. We first consider caloric functions with arbitrary piecewise continuous boundary conditions, and show that standard solutions based on Fourier series do not converge uniformly on the domain. Here, uniform convergence is achieved by integrations by parts. An alternative approach based on the Laplace transform is also presented, and this is shown to have an excellent convergence rate also when discontinuities are present at the boundaries. In both cases, numerical experiments illustrate the improvement of the convergence rate with respect to standard methods

Fertbrasil: an innovative network for the development of tropical soils fertilizers.

This paper aims to present the FertBrasil network, a network leaded by the Brazilian Agricultural Research Corporation ? Embrapa, that includes more than three hundreds of researchers in more than fifty institutions, among public agents, universities and private companies. First, we introduce the subject of network innovation and a little background on tropical fertilizers. Then, we present the FertBrasil network, since its creation, passing by its leadership, partners and the products the network intends to develop. After, a little is discussed about the innovative control mechanism of the network and the product development flow, as well as the interaction between FertBrasil and other governmental initiatives or public policies about the same subject. At least, we discuss about the results of the network until now, in terms of products, technologies and political impacts and mobilization in fertilizers research for tropical regions. Then, we conclude presenting some challenges for FertBrasil network as well as reinforcing the important role assumed by this network in contributing to Brazil keeps its high position in agricultural production and productivity

A geometric statement of the Harnack inequality for a degenerate Kolmogorov equation with rough coefficients

We consider weak solutions of second-order partial differential equations of Kolmogorov-Fokker-Planck-type with measurable coefficients in the form ∂tu + (v,∇xu) = div(A(v,x,t)∇vu) + (b(v,x,t),∇vu) + f, (v,x,t) ϵ2n+1, where A is a symmetric uniformly positive definite matrix with bounded measurable coefficients; f and the components of the vector b are bounded and measurable functions. We give a geometric statement of the Harnack inequality recently proved by Golse et al. As a corollary, we obtain a strong maximum principle

Solos, sustentabilidade e provisão de serviços ecossistêmicos.

O potencial de prestação de serviços ecossistêmicos do solo ainda é um assunto a ser mais explorado, apresentando uma grande diversidade e potencial graças às funções ecossistêmicas desempenhadas por esse recurso natural. Especificamente no Brasil, a falta de conhecimento dos solos em temas relacionados à sustentabilidade e à prestação de serviços ecossistêmicos pode ser um agravante e potencializar seus processos de degradação e perda