The conversion of CO2 into CO is an important step in CO2 utilization to achieve clean fuels and value‐added chemicals. Herein, we explored the pyrolysis of zeolitic imidazolate framework‐8 (ZIF‐8) ...loaded with different amounts of Ni2+ to obtain Ni−Zn carbide (Ni3ZnC) embedded in N‐doped carbon. Ni is present in the intermetallic compound, while Zn excess remains on the N‐doped carbon. The Ni3ZnC phase catalyzes the selective hydrogenation of CO2 into CO via the reverse water gas shift reaction, reaching 100 % CO selectivity at ∼30 % CO2 conversion at 450 °C and atmosphere pressure (CO2 : H2=1 : 4, GHSV=30000 mL gcat−1 h−1). The methanation reaction of CO2/CO, which is usually favored over Ni catalysts, is suppressed. The selectivity to CO at the expense of CH4 is related to the stability of chemisorbed CO in the Ni3ZnC surface, which is lower compared to Ni surfaces. The Ni3ZnC@NC catalyst is selective towards CO over a wide range of conditions, including high pressure, that is usually required for the conversion of CO to hydrocarbons and alcohols via the Fisher‐Tropsch synthesis (FTS) process. Contrarily, a classical Ni/SiO2 catalyst prepared by impregnation produces CH4 under high pressure.
The Ni3ZnC phase catalyzes the selective hydrogenation of CO2 into CO via the reverse water gas shift (RWGS) reaction, while the methanation reaction of CO2/CO, which is usually favored over Ni catalysts, was completely suppressed, even at high pressures. This finding opens the door for the integration of RWGS/Fisher‐Tropsch synthesis (FTS) tandem process to achieve the conversion of CO2‐to‐liquids.
Heat-processed diets contain high amounts of advanced glycation end products (AGEs). Here we explore the impact of an AGE-enriched diet on markers of metabolic and inflammatory disorders as well as ...on gut microbiota composition and plasma proteins glycosylation pattern. C57BL/6 mice were allocated into control diet (CD,
= 15) and AGE-enriched diet (AGE-D,
= 15) for 22 weeks. AGE-D was prepared replacing casein by methylglyoxal hydroimidazolone-modified casein. AGE-D evoked increased insulin and a significant reduction of GIP/GLP-1 incretins and ghrelin plasma levels, altered glucose tolerance, and impaired insulin signaling transduction in the skeletal muscle. Moreover, AGE-D modified the systemic glycosylation profile, as analyzed by lectin microarray, and increased Nε-carboxymethyllysine immunoreactivity and AGEs receptor levels in ileum and submandibular glands. These effects were associated to increased systemic levels of cytokines and impaired gut microbial composition and homeostasis. Significant correlations were recorded between changes in bacterial population and in incretins and inflammatory markers levels. Overall, our data indicates that chronic exposure to dietary AGEs lead to a significant unbalance in incretins axis, markers of metabolic inflammation, and a reshape of both the intestinal microbiota and plasma protein glycosylation profile, suggesting intriguing pathological mechanisms underlying AGEs-induced metabolic derangements.
We investigated whether isotopic niche partitioning could mediate the coexistence between native (Hoplias sp. B) and non‐native (Hoplias mbigua) trahira in a Neotropical floodplain. We hypothesised ...that during the dry season both species inhabit isolated sites (i.e. lakes) and thus rely on distinct food resources to sustain their coexistence. We found evidence of trophic segregation among native and non‐native freshwater fish in the Upper Paraná River, Brazil. Even though both species rely on the same primary littoral carbon sources and present similar trophic diversity, trophic segregation was attained through larger niche amplitude and smaller isotopic niche width for the non‐native fish. Three decades after initial invasion, non‐native Hoplias have distinct foraging behaviour and do not compete for trophic resources with native trahira; this is likely due to morpho‐anatomical differences. Limited morphological similarity between these congeneric species might be the strongest factor contributing to their coexistence in the Paraná River floodplain during the dry season.
Sugarcane, one of the world’s major crops, is used to produce sucrose and biofuel. Before harvesting, sugarcane is burned to facilitate manual cutting, generating ashes that may reach water bodies ...and cause the death of aquatic organisms. While studies have addressed the lethal effects of sugarcane ashes (SCA) on different fishes, little is known about the effects of sublethal SCA concentration on aquatic organisms. In this study, we evaluated the behaviour of a piscivorous (
Hoplerythrinus unitaeniatus
) and an invertivorous (
Moenkhausia forestii
) fish species, after a short-term (24 h) exposure to a sublethal concentration of SCA (0.8 g L
−1
). We hypothesized that the outcomes of predator–prey interaction would change when the players are subjected to sublethal SCA concentration. Our findings revealed that neither the behaviours of predator and prey fish species nor the outcome of their interactions was changed by the exposure to sublethal SCA concentrations, suggesting that their behavioural traits were not particularly sensitive to SCA. However, we emphasize that (i) other predatory and anti-predator behavioural traits could be affected by SCA even at under 0.8 g L
−1
concentration and (ii) higher concentrations of SCA and/or long-term exposure may trigger profound changes in the behaviour of predator and prey fish species. Our findings are worrisome because there are new public policies to expand sugarcane production in Brazil, with the possibility of continuing burning sugarcane crops across the country. This will increase the input of SCA into aquatic systems, generating more prominent and pervasive negative impacts than those evaluated in this study.
Balancing energy demand and supply will become an even greater challenge considering the ongoing transition from traditional fuel to electric vehicles (EV). The management of this task will heavily ...depend on the pace of the adoption of light-duty EVs. Electric vehicles have seen their market share increase worldwide; the same is happening in Portugal, partly because the government has kept incentives for consumers to purchase EVs, despite the COVID-19 pandemic. The consequent shift to EVs entails various challenges for the distribution network, including coping with the expected growing demand for power. This article addresses this concern by presenting a case study of an area comprising 20 municipalities in Northern Portugal, for which battery electric vehicles (BEV) sales and their impact on distribution networks are estimated within the 2030 horizon. The power required from the grid is estimated under three BEV sales growth deterministic scenarios based on a daily consumption rate resulting from the combination of long- and short-distance routes. A Monte Carlo computational simulation is run to account for uncertainty under severe EV sales growth. The analysis is carried out considering three popular BEV models in Portugal, namely the Nissan Leaf, Tesla Model 3, and Renault Zoe. Their impacts on the available power of the distribution network are calculated for peak and off-peak hours. The results suggest that the current power grid capacity will not cope with demand increases as early as 2026. The modeling approach could be replicated in other regions with adjusted parameters.
Brazil's vegetation ravage may be encouraged by law Alves, Gustavo H. Zaia; Tófoli, Raffael M.; Rodrigues-Filho, Jorge L. ...
Biodiversity and conservation,
03/2020, Letnik:
29, Številka:
3
Journal Article
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