Osovetsky Boris M is a Professor of Mineralogy and Petrography department, the Leader of Nano-mineralogy Sector of Perm State University (with 2010). He deals with the problems of gold, platinum and diamond prospecting, as well as sedimentology, geo-environment, mineralogy, etc. He is the author of many books on Nanomineralogy of gold (“Nanosculpture of gold surface”, 2012; “Natural Nanogold”, 2013; and “Fine diamonds and their prospecting role”, 2014).
Some of the processes occurring in the environment and associated with migration of nanoparticles of metals can be considered as the natural nanotechnologies. Their detailed study will contribute to the future development of the industrial technologies, which are especially important for scarce and precious metals. As a priority it should highlight the problems of development of objects with nano gold. The discovery in Russia of a number of major gold deposits with so-called refractory ores (Olimpiadinskoe, Maiskoe, and Nezhdaninskoe) requires significant improvement in the technology of their development. Presumably, some of the gold in them is represented by nanometer-sized forms of occurrence. One of directions of solving this problem is the study of natural processes of nano gold concentration. It turned out that it is directly connected with the problem of “new” gold origin. We have shown growths of the newly formed metal on placer gold surface represent aggregates of nanoparticles deposited from ionic or colloidal solutions. Conditions required for mass deposition of “new” gold are favorable geological environment (weathering rocks of sulfide ore bodies with an abundance of nano-gold minerals-concentrators: Aspyrite, arsenopyrite, etc., tailings of the excavation of alluvial deposits, buried placers, etc.), uneven gold surface with numerous micro- and nano-defects, etc. As another option we can consider the natural process of amalgamation, which leads to the formation of aggregate grains composed of nanoparticles of mercury-bearing gold and cementing their amalgams. Finally, the natural processes of nano gold concentration can be implemented in environments where gold-bearing solutions migrate in the rocks containing natural sorbents of metal (carbonaceous substance, chlorides, ferriferous compounds, etc.). Natural nanotechnologies can be the basis for the creation of industrial technologies of development of deposits with nanoscale gold or recycling their wastes. Besides, the experimental studies play an important role. They confirm the high sorption capacity of gold nanoparticles and their tendency to aggregate.
Noureddine Ouerfelli has a PhD and Habilitation Diploma in Chemistry; he is a head of research project in the Laboratory of Biophysics and Medical technologies. He has published more than 45 papers in reputed journals on modeling of physicochemical properties in solution.
Knowledge and estimation of transport properties of fluids are necessary for mass flow and heat transfer. Viscosity is one of the main properties which are sensitive to temperature and pressure variation. In the present work, based on the use of statistical techniques for regression analysis and correlation tests, we propose an original equation modeling the relationship between the two parameters of viscosity Arrhenius-type equation (ln = lnAs + Ea/RT). Empirical validation using 90 data set of fluids provided from the literature and studied at different temperature ranges gives excellent statistical results which allow us to redefine the Arrhenius-type equation using a single parameter instead of two ones (E_a=λ•R(-〖lnA_s)〗^(α_0 )). More, causal correlation between these parameters and the normal boiling temperature (Tb) of the corresponding fluids leads us to propose two predictive empirical equations one with the activation energy (T_b (E_a)= -E_a/(68 - 4.05×〖Ea〗^0.34 )) and one with the logarithm of pre-exponential factor (T_b (lnA_s)= ((-〖lnA_s)〗^2.933)/(8.2 + lnA_s )). We conclude that the boiling temperature is in causal correlation with the two Arrhenius parameters, but with other physical and chemical properties implicitly for which there are some ones are common for the two Arrhenius parameters while others are in relationship only for a single parameter (lnAs) or (Ea). To correct this observation, we will try to suggest in future works, an expression both explicit, the two viscosity Arrhenius parameters Tb(Ea,lnAs) alternatively in the numerator and in the denominator. Note that this equation is tested to some heavy oils with reliable agreement for which we can conclude that it can be useful for petroleum chemistry.\r\n\r\nWhere TA / (K) is the Arrhenius temperature for each pure solvents defined by the following equation:\r\nT_A=(-〖 E〗_a)/Rln(A_s ) \r\n