In frozen soils

Dortz SH, Sparrman T, Nilsson MB, Schleucher J, Oquist MG. Both catabolic and anabolic heterotrophic microbial activity proceed in frozen soil. Proc. Natl. Acad. Sci. U.S.A. 2010 107 21046-21051. 

Panday, S. and Corapcioglu, M. Y., 1994, Theory of Phase-Separate Multi-Component Contamination in Frozen Soil Journal of Contaminant Hydrology, Vol. 16, pp. 235-269. 

Our approach for studies of gas hydrate formation and decomposition in sedimentary pore space consists of two steps. The first one is devoted to the hydrate accumulation kinetics in pore space of frozen soils to obtain frozen hydrate-saturated samples. The second one concentrates on the pore hydrate dissociation kinetics in frozen soils under non-equilibrium conditions. 

In order to study the kinetics of pore hydrate dissociation in frozen soils, the pressure in the pressure chamber was lowered to atmospheric values at the second stage of cooling after the complete freezing of the sample. Then the pressure chamber was opened in a cold-room at a temperature of -8°C... 

Pore ice plays a particular role for the self-preservation effect in frozen soils Initial hydrate preservation apparently is helped by frozen pore water (not transformed into hydrate). Additional ice formation in the form of a film on the surface of gas-hydrate forming due to hydrate surface dissociation is expected to take place upon gas pressure release. Thus in the sample with 7% of montmorillonite particles (Win=17%), pore hydrate showed a higher stability after pressure release as a consequence of the greater ice content due to the freezing of remaining pore water (Figure 4).Our results clearly indicate that the hydrate content decreases on the expense of an increases of ice (Figure 5). 

The mineral composition of the soil will also influence the kinetics of gas hydrates dissociation in frozen soils. Our results show, that gas hydrate formations in pore space of samples with montmorillonite particles dissociate less markedly as compared to the samples with kaolinite admixture. This influence may be explained by microstructural specificities of pore hydrate saturated samples but undoubtedly requires additional micro-morphological studies for a full understanding. 

Ice may occur in frozen soil as small disseminated crystals whose total mass exceeds that of the mineral grains. It also may occur as large tabular masses that range up to several metres... 

In general an increase of temperature on a soil-chemical system should cause an increase in the volatilization rate, through an increase of the equilibrium vapour density [30]. However, complicating factors may alter the expected result and an increase in temperature may not lead to an increase in volatilization rate. In addition, low temperature may not eliminate entirely the volatilization process since diffusion may continue even in frozen soil [35]. 

Elberling B, Brandt KH (2003) Uncoupling of microbial CO2 production and release in frozen soils and its implications for field studies of arctic C cycling. Soil Biol Biochem 35 263-272... 

Since the Wenner formula [Eq. (24-41)] was deduced for hemispherical electrodes, measuring errors appear for spike electrodes. To avoid errors in excess of 5%, the depth of penetration must be less than a 5. Soil resistivity increases greatly under frost conditions. While electrodes can be driven through thin layers of frost, soil resistivity measurements deeper than 20 cm in frozen ground are virtually impossible. 

Many hydrologic reservoirs can be further subdivided into smaller reservoirs, each with a characteristic turnover time. For example, water resides in the Pacific Ocean longer than in the Atlantic, and the oceans surface waters cycle much more quickly than the deep ocean. Similarly, groundwater near the surface is much more active than deep reservoirs, which may cycle over thousands or millions of years, and water frozen in the soil as permafrost. Typical range in turnover times for hydrospheric reservoirs on a hillslope scale (10-10 m) are shown in Table 6-4 (estimates from Falkenmark and Chapman, 1989). Depths are estimated as typical volume averaged over the watershed area. 

Azoxystrobin residues in crops, soil and water are stable (>80%) during 2 years of frozen storage. 

Thin sections can also be obtained from frozen soil. This type of thin section is best suited to soils that are naturally frozen at least part of the time. In these cases, the soil thin section must be kept frozen during the subsequent examination. Sectioning of frozen soil is generally more difficult than sectioning of resin-impregnated solids [10],... 

Two soil sampling tubes were removed from each tank 2, 5, 9, 15, 27, 30, 43, and 58, and 72 days after the start of the experiment, then frozen and stored for later analyses. For analyses, the frozen soil cores were removed from the glass tubes (by brief immersion in hot water), then sectioned into four 1-cm cylinders representing 0-1, 1-2, 2-3, and 3-4 cm soil depths. Samples from each depth were shake-extracted with 100 ml ethyl acetate hexane overnight, and again with 100 ml methanol overnight. Extracts were filtered, concentrated to 20 ml and analyzed by LS and TLC as described below. 

The Arctic Foundations, Inc. (AFl), frozen soil barrier technology is constructed by artificially freezing the soil pore water. As the pore water freezes, the soil permeability decreases, thereby forming an impermeable barrier that surrounds and contains the contaminants. When properly installed, the frozen soil barrier prevents the migration of contaminants within groundwater and soil. Contaminants are contained in situ, with the frozen native soils serving as the containment medium. The contaminants are isolated by the wall until appropriate remediation techniques can be applied. 

It was Razum s way of telling them all the certainties he had foreseen, the futures he could never relate in words that if the plan failed, then Mogushestvo would raze Sverdlovsk and plough their corpses into the frozen soil, with sufficient armour left in Omsk to grind Wargaard s proud divisions to a fine powder that if the Doctor failed, then Razum would allow that to happen and take command of the Alliance, division by division, to claim the Earth and all its territories as his own. And if the Doctor succeeded, then all of this would be irrelevant, and the Earth and all of his officers, his staff, support personnel and rank-and-file troopers and the rest of the human race would join him and Dusha in a new life. In an embrace of solar flame. 

Soil temperature influences chemical degradation, microbial decomposition, and volatilization. For example, no aldrin or heptachlor was lost from frozen soils, but at 6°C, 16-27% of the dose applied to soil was lost in 56 days at 26°C, 51-55% disappeared and at 46°C, 86-98% was lost. Diazinon was also degraded faster at higher temperatures than at low ones (Edwards, 1973b). Temperature also influences the adsorption of pesticide in soils because adsorption is a exothermic process, so that increased temperatures decrease adsorption and release pesticides. 

Many scientists theorize that Mars s atmosphere thinned, and, as the planet cooled, the water boiled array. Some of the water may still remain c i the planet, permanently frozen in the ice caps or in the soil. Much of it was probably lost when the Sun s ultraviolet radiatim dissociated the water molecules into their hydrogen and oxygen atoms. 

Regardless of moisture inputs, temperature and radiation flux both depend on season, so tree growth will be limited by lower values of the physical variables. Indeed, photosynthesis and respiration depend on temperature (Tranquillini, 1979), new plant tissue formation requires at least 5-TC to occur, and frozen soil causes high water stress that only highly specialized plants can compensate. PAR photon fluxes will vary not only with season but also with cloud cover and immersion, which has been suggested as a significant limitation in cloud enshrouded forests. 

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