Spin transition zone in Earth's lower mantle

Mineral properties in Earth's lower mantle are affected by iron electronic states, but representative pressures and temperatures have not yet been probed. Spin states of iron in lower-mantle ferropericlase have been measured up to 95 gigapascals and 2000 kelvin with x-ray emission in a laser-heated diamond cell. A gradual spin transition of iron occurs over a pressure-temperature range extending from about 1000 kilometers in depth and 1900 kelvin to 2200 kilometers and 2300 kelvin in the lower mantle. Because low-spin ferropericlase exhibits higher density and faster sound velocities relative to the high-spin ferropericlase, the observed increase in low-spin (Mg,Fe)O at mid-lower mantle conditions would manifest seismically as a lower-mantle spin transition zone characterized by a steeper-than-normal density gradient.     

Energy and resource conservation in the grain corn cultivation on irrigated lands

The possibility of increasing the efficiency of grain maize (corn) cultivation is shown in the comparative study of two cultivation technologies of this culture: the traditional and the proposed one—based on chisel tillage.     

Soils оf Oligomesotrophic аnd Mesotrophic Bogs in the Boreal Zone of West Siberia: Possibilities of Botanical Diagnostics within the Framework of the Type of Mesotrophic Peat Soils

Eurasian Soil Science - Despite the widespread use of the taxon “mesotrophic (transitional) peat soils” in the present-day Russian and foreign pedology, including some fundamental...     

Growth Responses,Metal Accumulation and Phytoremoval Capability in Amaranthus Plants Exposed to Nickel Under Hydroponics

Surfactant-enhanced solubilization and subsequent biodegradation of phenanthrene and pyrene from aqueous solutions by Arthrobacter strain Sphe3 was investigated. The results show that growth of Arthrobacter strain Sphe3 was increased upon increase in concentration of Tween 20 and Tween 80. Inhibition of bacterial growth was observed with increasing Triton X-100 concentrations, whereas sodium dodecyl sulfate (SDS) totally inhibited this bacterial growth. Phenanthrene and pyrene solubilization was enhanced in the presence of surfactants and found to be linearly proportional to their concentrations, above the critical micelle concentration (CMC). In addition, Tween 20 and Tween 80 enhanced the biodegradation of phenanthrene and pyrene. The high correlation coefficient (R ²) values obtained at all the concentrations studied, suggest that biodegradation kinetics of both phenanthrene and pyrene in the presence of Tween 20 and Tween 80 follow first-order kinetic equation model. Experimental results suggest that Tween 20 and Tween 80 may have great potential for applications in bioremediation of these polycyclic aromatic hydrocarbon (PAH) compounds using Arthrobacter strain Sphe3.     

Ecological limits of gray forest soil erosion in central regions of the European part of Russia

This article describes a “humus“ linear modification of the Skidmore method, allowing us to calculate the tolerable limits of soil loss taking into account the current ecological requirements and economic opportunities. These limits were developed depending not only on the genetic types of soil, but also on the degree of its erodability, types of use, the structure of crop rotation, and crop capacity.