M A Martin-Luengo has studied Chemistry in the Autonomous University of Madrid, Spain. At Consejo Superior de Investigaciones Cientifi cas (CSIC), Spain; she presented her Masters work on Oxidation Catalysts and her PhD on Hydrogenation Catalysts. As a Postdoctoral grant holder of the CSIC she has worked in Brunel University, UK and in the University of Louvain la Neuve, Belgium. She has worked as a Fellowship IA with the Scientifi c Engineering Research Council, UK, on Fischer-Tropsch and from 1992 she is permanent Scientifi c Staff of CSIC, Spain. She has participated in more than 25 research projects, 100 scientifi c papers and chapters of books, 120 congresses and several patents. She is a Chartered Chemist of RSC and Member of ACS and the Spanish Societies of Catalysis and Clays. Presently she carries out studies on sustainable issues, searching for the use of renewable materials, energies and chemical processes, especially giving priority to countries with deprived economies.
The use of agro-industrial wastes is a prime target of utmost importance nowadays, because solutions to environmental pollution problems are crucial to achieving sustainable development and this approach can have a significant contribution towards the so called Renewable Raw Materials (RRM). Th is topic is considered today as one of the main scientific goals at international level, given its social, economic and environmental interest. Using waste to obtain useful materials avoids the expense of others often non-renewable materials, among many other benefits. Research groups are working on the application of the philosophy called cradle to grave in which companies may be able to convert their wastes into useful materials for themselves or others, thus closing a cycle of obvious benefits. Furthermore, the developed processes are based also on avoiding the use of toxic substances to the environment and achieve maximum economy and reduction of energy expenditure, i.e., by using renewable vs. conventional energy demanding ways of activation. Given their origin, the materials derived can be considered Eco materials. Some of the processes that have been implemented in our research group are: (1) Immobilization of enzymes and their use in biocatalytic processes (biodiesel and nutraceuticals production). (2) Renewable biomaterials are being used as matrices for regenerative medicine, based on analysis of their toxicities and their ability as scaff olds for cell growth. (3) Conversion of liquid wastes to fine chemicals and biohydrogen, avoiding the need to use petroleum derivatives. (4) Catalysts for environmental protection and (5) Multivalorization of agri wastes.
Anna Kapranova is the Head of Department of Theoretical Mechanics and Strength of Materials at Yaroslavl State Technical University, Yaroslavl, Russia.
Statement of the Problem: The efficiency of the control equipment for the transportation of fluid flows depends on the degree of protection of the valve from the undesirable effects of cavitation phenomenon. Th e study of the formation of cavitation bubbles at the initial stage of hydrodynamic cavitation in a fl owing part of the control valve allows identify from a set of its constructive regime parameters to identify the main factors influencing the evolution of bubbles. Despite the existence of various deterministic and stochastic descriptions of this process, the modeling problem is relevant. Th e purpose of this study is to determine the integral characteristics of the process of formation of cavitation bubbles when operating the control valve. Methodology & Theoretical Orientation: On the basis of the stochastic approach, the model of formation of cavitation bubbles proposed by the authors is used. Th e application of the formalism of process Ornstein-Uhlenbeck with the description of stochastic energy of a spherical bubble depending on its radius and the velocity of the center of mass allows using the differential distribution function of the cavitation bubbles according to their sizes for the estimation of the integral characteristics of the process. Findings: Th e simulation results allow to evaluate average values for the radius of the cavitation bubble, surface area of bubble and to estimate the volume of a cavity in the initial stage of hydrodynamic cavitation, depending on constructive-regime parameters of fl ow area control valve. Conclusion & Signifi cance: Modeling the initial stage hydrodynamic cavitation can be performed from the positions of the stationary and homogeneous Markov process. The results obtained here can be used in the formation of methods of engineering calculations of control valves.