INFLUENCE OF ALLOYING Ti, Mo AND W ON THE KINETIC AND STRENGTH CHARACTERISTICS OF MEMBRANE ALLOYS BASED ON Nb AND V

Проведен анализ влияния Ti, Mo и W на характер аморфной нано- и кристаллической структуры на прочностные и кинетические характеристики - диффузии D и проницаемости Ф водорода в мембранных сплавах, созданных на основе бинарных Ni - Nb и V - Ni. Легирование сплавов Ni - V титаном, молибденом и вольфрамом ведет к постепенному замещению ими ниобия и ванадия и способствует образованию нескольких второстепенных фаз хотя и действующих как барьеры для диффузии водорода, но способствующих снижению процессов гидридообразования. Выявлена строгая зависимость кинетики водорода не только от термодинамических параметров -температуры и давления, но и от наличия свободного объема в формируемых аморфных, нано-кристаллических и кристаллических сплавов. Установлено, что процессы селективности, динамика водорода - его поток J, определяемый произведением диффузии и проницаемости (J = D×Ф), зависят от базового состава, выбора легирующих элементов (Ti,Mo и W ), а также формируемых структур - аморфной, нанокристаллической и полифазной дуплексной кристаллической микроструктурой. Установлено, что тщательно подобранный состав определяет производительность селективного процесса и способствует выделению высокочистого водорода с последующими его приложениями для зеленой энергетики. An analysis was carried out of influence of Ti, Mo and W on the nature of the amorphous nano- and crystalline structures on the strength and kinetic characteristics - diffusion D and permeability Ф of hydrogen in membrane alloys based on binary Nb - Ni, V - Ni. Doping with Nb - V alloys, titanium, molybdenum and tungsten leads to the gradual replacement of niobium and vanadium, and promotes the formation of several minor phases while acting as barriers for hydrogen diffusion, but contributing hydride reduction processes. A close dependence of the hydrogen kinetics was revealed not only on thermodynamic parameters - temperature and pressure, but also on the presence of free volume in the formed amorphous, nanocrystalline and crystalline alloys. So, the processes of selectivity, the dynamics of hydrogen - its flux J determined by the product of diffusion D and permeability Ф, J = D×Ф depend on the basic composition and the choice of alloying elements (Ti,Mo and W ), as well as the formed structures - amorphous, nanocrystalline and duplex, represented by multiphase crystalline microstructures. It was found that a carefully selected composition determines the productivity of the selective process and promotes the release of high-purity hydrogen with its subsequent applications for green energy.

Investigating and modelling the effect of light intensity on Rhodopseudomonas palustris growth

Photosynthetic bacteria can be useful biotechnological tools – they produce a variety of valuable products, including high purity hydrogen, and can simultaneously treat recalcitrant wastewaters. However, while photobioreactors have been designed and modelled for photosynthetic algae and cyanobacteria, there has been less work on understanding the effect of light in photosynthetic bacterial fermentations. In order to design photobioreactors, and processes using these organisms, robust models of light penetration, utilisation and conversion are needed. This article uses experimental data from a tubular photobioreactor designed to focus in on light intensity effects, to model the effect of light intensity on the growth of Rhodopseudomonas palustris, a model photosynthetic bacterium. The work demonstrates that growth is controlled by light intensity, and that this organism does experience photoinhibition above 600 W/m2, which has implications for outdoor applications. Further, the work presents a model for light penetration in circular photobioreactors, which tends to be the most common geometry. The work extends the modelling tools for these organisms, and will allow for better photobioreactor design, and the integration of modelling tools in designing processes which use photosynthetic bacteria.