Lanthanum cobaltite perovskite supported onto mesoporous zirconium dioxide: nature of active sites of VOC oxidation

Novel catalytic nano-sized materials based on LaCoO(x) perovskite nanoparticles incapsulated in the mesoporous matrix of zirconia were prepared, characterized by physicochemical methods and tested in complete methanol oxidation. LaCoO(x) nanoparticles were prepared inside the mesopores of ZrO(2) by decomposition of bimetallic La-Co glycine precursor complexes. The catalysts have been studied by diffuse-reflectance FTIR-spectroscopy using such probe molecules as CO, CD(3)CN and CDCl(3) to test low-coordinated metal ions. At low temperatures of decomposition of complexes (up to 400°C), low-coordinated Co(3+) ions predominate in the LaCoO(x) nanoparticles, whereas basically Co(2+) ions are found upon increasing the decomposition temperature to 600°C. The novel nano-sized perovskite catalysts exhibit a very high catalytic activity in the abatement of volatile organic compounds present in air, like methanol and light hydrocarbons.     

Estimation of Smog Effects in the Hydrocarbon-Nitric Oxide System

Hydrocarbon components (propylene, simulated auto exhaust, or authentic auto exhaust) were irradiated in the presence of nitric oxide in large chambers instrumented for measurements of numerous variables. Eye irritation was measured using a selected panel of human subjects. The various dependent variables are presented as functions of the reactant concentrations by means of contour diagrams derived by computer treatment. The effect of “hydrocarbon” and nitric oxide levels on smog effects are discussed; the observed relationships between end effects and reaction rates are considered. The study simulated the effects of varying degrees of vehicular emissions control over one or both reactants and has a bearing on the establishment of vehicle emission standards in California.     

Permafrost and infrastructure in the usa Basin (Northeast European Russia): possible impacts of global warming

The relationship between permafrost conditions and the distribution of infrastructure in the Usa Basin, Northeast European Russia, is analyzed. About 75% of the Basin is underlain by permafrost terrain with various degrees of continuity (isolated patches to continuous permafrost). The region has a high level of urban and industrial development (e.g., towns, coal mines, hydrocarbon extraction sites, railway, pipelines). GIS-analyses indicate that about 60% of all infrastructure is located in the 'high risk' permafrost area, here defined as the zones of isolated to discontinuous permafrost (3-90% coverage) with 'warm' ground temperatures (0 to -2 degrees C). Ground monitoring, aerial photo interpretation, and permafrost modeling suggest a differential response to future global warming. Most of the permafrost-affected terrain will likely start to thaw within a few decades to a century. This forecast poses serious challenges to permafrost engineering and calls for long-term investments in adequate infrastructure that will pay back overtime.     

乌萨盆地(俄罗斯欧洲部分东北部)的多年冻土和基础设施:全球变暖的可能影响

文章分析了位于俄罗斯欧洲部分东北部的乌萨盆地的多年冻土地区环境条件与基础设施分布的关系.规模不一的多年冻土带(从孤立碎片到连续的多年冻土)占了整个盆地的75%.这个地区的城市化和工业化发展水平很高(例如,城镇、煤矿、烃类提炼厂、铁路和管道等).GIS分析表明这个地区的60%的基础设施都位于"高危险"的多年冻土地带,这里的"高危险"的多年冻土地带是指地温达到0～-2℃且孤立的或者不连续的多年冻土区(3%～90%的覆盖度).地温监测、航空相片解译及多年冻土模拟都表明了它们对未来全球变暖响应的差异性.在未来的几十年到一百年内,大多数受多年冻土影响的地区将可能发生解冻.这将对多年冻土区的工程建设提出很大的挑战,同时要求对那些需要经过较长时间才能获得回报的基础设施方案进行远期投资.