To gain insight into the nitrogen-related gas-surface reaction dynamics on carbon-based thermal protection systems of hypersonic vehicles, we have investigated adsorption, diffusion, and reactions atomic nitrogen, N(4S), (0001) face graphite using periodic density functional theory with a dispersion corrected functional. The nitrogen is found to bind pristine at bridge site, barrier 0.88 eV for...

This paper is concerned with the multiple container loading problem with rectangular boxes of different sizes and one or more containers, which means that the boxes should be loaded into the containers so that the waste space in the containers are minimized or the total value of the boxes loaded into the containers is maximized. Several approaches have been taken to solve this problem (Ivancic ...

Formaldehyde has been widely observed in the icy mantle of interstellar grains. H 2 CO may be formed from successive hydrogenations and further contribute to chemical complexity Interstellar medium (ISM) participating heterogeneous reactions with colliding gas phase atoms. Within this context, Eley-Rideal Langmuir-Hinshelwood rate constants formation on a formaldehyde doped amorphous water ice ...

SO2 poisoning is a great challenge for the practical application of Mn-based catalysts in low-temperature selective catalytic reduction (SCR) reactions NOx with NH3. A series Gadolinium (Gd)-modified MnOx/ZSM-5 were synthesized via citric acid–ethanol dispersion method and evaluated by NH3-SCR. Among them, GdMn/Z-0.3 catalyst molar ratio Gd/Mn 0.3 presented highest activity, which 100% NO conve...

Utilizing ammonia as a storage medium for hydrogen is currently receiving increased attention. A possible method to retrieve the by plasma-catalytic decomposition. In this work, we combined an experimental study, using dielectric barrier discharge plasma reactor, with kinetic model, get insights into decomposition mechanism. The results revealed similar effect on conversion when changing flow r...

Zeolite X was synthesized from fly ash under optimized conditions, which supported with Mn, Ce, and Mn-Ce respectively. Fly ash-derived zeolite catalysts exhibited similar catalytic performance as compared the commercial catalyst. XRD, N2 adsorption, SEM, XPS, H2-TPR were used to investigate relationship among structure, physicochemical properties, activities of catalysts. Finally, mechanism NH...

The oxidation of CO has attracted great interest in recent years because of its important role in enhancing the catalyst durability in fuel cells and in solving the growing environmental problems caused by CO emission. The usually used noble metal nanocatalysts are costly and require high reaction temperature for efficient operation. We report here a density functional theory (DFT) study of low...

—A new subspecies. Siplornis srriaticollis nortoni. is described from the eastern slope of the Andes in Ecuador and northwestern Peru. The nominate form, .V. 5. striaticoliis, is restricted to the Magdalen a Valley of Colombia. Until recently, the Spectacled Pricklctail {Siptornisstriaticoliis) was known only from "Bogota" trade skins without specific locality data, a few specimens collected in...