Biosorption of Rare-Earth Elements and Yttrium by Heterotrophic Bacteria in an Aqueous Environment

This paper reports the results of the experimental determination of the coefficient of sorption of rare-earth elements and yttrium (REY) under conditions of acidic pH using several strains of heterotrophic bacteria (Microbacterium sp., Curtobacterium sp., Bacillus subtilis, Pseudomonas putida, and Bacillus pumilis) that are widespread in natural and technogenic waters of the Far East (Russia). Insignificant fractionation between heavy and light rare-earth elements, negative cerium and dysprosium anomalies, and a positive europium anomaly were revealed. The selectivity of REY biosorption by gram-positive and gram-negative bacteria, as well as inertia of the biosorption process under more acidic conditions of the medium, were shown.     

Determination of the optimum period for ciliated protozoa colonizing of an artificial substrate in a tropical aquatic ecosystem

The optimum period for ciliated protozoa colonizing of an artificial substrate, the polyurethane foams have been assessed in a tropical aquatic ecosystem, the Ekozoa stream of the Mfoundi River Basin in Yaounde (Cameroon). 5?days were calculated as the highest period for the biological indicators of pollution to optimally colonize the artificial substrate. This time interval is the same for all the sampling stations assessed from upstream to downstream and the various microhabitats along the water course. The statistical method applied is that of the completely randomized blocks. The colonization of the substrate increases from the first day to the fifth day, before decreasing to the tenth day. The statistical analysis of variance between the maximum day and the other sampling period was significant at 5?% while the calculation of the value between different points of the same station was not significant. The average number of ciliated protozoan ranges from 20 to 23, from upstream to downstream.     

The formation of small cones in Isidis Planitia,Mars through mobilization of pyroclastic surge deposits

We investigate the distinctive distribution and pattern of subkilometer-sized cones in Isidis Planitia, and their relationship to the material that fills the basin. We observe that: (1) the cones show uniform size, spacing, and morphology across the entire basin; (2) they have large central depressions (relative to cone basal diameters) that are generally filled in and commonly show layering; (3) cone chains form highly organized spatial patterns; cones are also found in isolation and in dense fields; (4) many adjacent chains are parallel, and evenly spaced, creating a pattern that mimics lava flows that have experienced compressional folding; (5) no flows are associated with the cones, even where summit crater rims are breached; (6) the cones are at least temporally related to basin fill; (7) the basin fill material is largely fine-grained, but with locally indurated layers at shallow depth; blocks ejected by small craters from these locally indurated layers are commonly dark in color; and (8) relationships between cones along a chain show no systematic temporal formation sequence along the chain. We conclude that the basin was likely inundated by one or more hot, partially welded pyroclastic flows; devolatilization of these flows remobilized volcaniclastic material to form the cones without associated lava flows. The volume of gas required to account for the observed number of cones is low and does not require the presence of ground water or ice.     

Formalization of assessing radioactive waste burial site seismic regime parameters from seismological and geological data

A model is proposed that shows the relation of the block structure of the crust and earthquake sources (Sadovskii, 1979; Rodionov, 1979, 1984, 1994; Bugaev, 1999, 2011, 2014, 2015). The model can formalize how to assess the prediction of seismic regime parameters depending on the elastic limit and conditions and rate of deformation of the Earth’s crust. The spent nuclear fuel repository site in Olkiluoto (Finland) and a site in the area of the Krasnoyarsk Mining and Chemical Combine are considered as examples. It is demonstrated that the parameters of the prediction graphs limit the location of the points of magnitude repeatability graphs calculated for a site based on samples of earthquakes in the area according to different authors. This makes it possible to recommend predictive assessment of seismic regime parameters for stability monitoring of the seismic regime and safety analysis of a geological environment’s insulation properties for waste sites from the results of seismological monitoring and high-precision observations of modern movements of the Earth’s crust.     

Soil bentonite wall protects foundation from thrust faulting: analyses and experiment

When seismic thrust faults emerge on the ground surface,they are particularly damaging to buildings,bridges and lifelines that lie on the rupture path.To protect a structure founded on a rigid raft,a thick diaphragm-type soil bentonite wall(SBW) is installed in front of and near the foundation,at sufficient depth to intercept the propagating fault rupture.Extensive numerical analyses,verified against reduced–scale(1 g) split box physical model tests,reveal that such a wall,thanks to its high deformability and low shear resistance,"absorbs" the compressive thrust of the fault and forces the rupture to deviate upwards along its length.As a consequence,the foundation is left essentially intact.The effectiveness of SBW is demonstrated to depend on the exact location of the emerging fault and the magnitude of the fault offset.When the latter is large,the unprotected foundation experiences intolerable rigid-body rotation even if the foundation structural distress is not substantial.     

Behavior of the cosmic ray density during the initial phase of the Forbush effect

Variations in the cosmic ray density during the initial phase of the Forbush effect during the first hours after the arrival of the interplanetary shock wave have been studied with the use of data on variations in the cosmic ray density with a rigidity of 10 GV obtained by the global survey method by the world network of neutron monitors in 1957?2012. It is found that behavior of this parameter after the arrival of the shock wave demonstrates high variability. A small (~1/5 of total number), though distinct, group of Forbush effects, in which the density of the cosmic ray increases (not decreases) after the arrival of the shock wave, is defined. As a whole, the initial variation in cosmic ray density is correlated with the Forbush effect magnitude and the strength of the associated geomagnetic disturbance.     

Proton flux and radiation dose from galactic cosmic rays in the lunar regolith and implications for organic synthesis at the poles of the Moon and Mercury

Galactic cosmic rays are a potential energy source to stimulate organic synthesis from simple ices. The recent detection of organic molecules at the polar regions of the Moon by LCROSS (Colaprete, A. et al. [2010]. Science 330, 463–468, http://dx.doi.org/10.1126/science.1186986), and possibly at the poles of Mercury (Paige, D.A. et al. [2013]. Science 339, 300–303, http://dx.doi.org/10.1126/science.1231106), introduces the question of whether the organics were delivered by impact or formed in situ. Laboratory experiments show that high energy particles can cause organic production from simple ices. We use a Monte Carlo particle scattering code (MCNPX) to model and report the flux of GCR protons at the surface of the Moon and report radiation dose rates and absorbed doses at the Moon’s surface and with depth as a result of GCR protons and secondary particles, and apply scaling factors to account for contributions to dose from heavier ions. We compare our results with dose rate measurements by the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) experiment on Lunar Reconnaissance Orbiter (Schwadron, N.A. et al. [2012]. J. Geophys. Res. 117, E00H13, http://dx.doi.org/10.1029/2011JE003978) and find them in good agreement, indicating that MCNPX can be confidently applied to studies of radiation dose at and within the surface of the Moon. We use our dose rate calculations to conclude that organic synthesis is plausible well within the age of the lunar polar cold traps, and that organics detected at the poles of the Moon may have been produced in situ. Our dose rate calculations also indicate that galactic cosmic rays can induce organic synthesis within the estimated age of the dark deposits at the pole of Mercury that may contain organics.