The applicability of the Electro-Ultra-Filtration (EUF) method in soil analyses was studied. The reproducibilities of the amounts of soil extracts, of ion concentrations in the extracts and of the ...distribution of cations and anions over the cathode and anode extracts by use of fully automatic EUF equipment were tested. The degree of variability among replicates was expressed as coefficient of variation (CV) and as the highest percentual divergence of an individual analytical measurement from the mean (L). The extraction volumes of five replicates of six different soils were found to vary between 1.1-7.1% with an average of 3.8%, as CV and between 1.5-11.3% as L. The reproducibility of desorbed P in the anode extract varied between 2.7-31.7% with an average of 8.7%, as CV and between 3.2-37.9% as L.Corresponding values for CV and L of K desorbed varied between 1.3-13.9% and 1.6-23.8%, respectively. Variations among replicates of desorbed P were especially high in the first 1-2 sub-fractions of a total of seven fractions in a single extraction run. Low K concentrations in the extract had a slightly negative influence on the reproducibility of K desorption. Furthermore, it was found that a portion of the cations is collected in the anode extract and a portion of the anions in the cathode extract, especially at the beginning of an extraction run. Pooling of anode and cathode extracts before analysis is therefore recommended.
The Patton site (33AT990), located within the Hocking Valley of southeastern Ohio, yielded evidence of a sedentary Middle Woodland community. During the summers of 2006 and 2008, excavations ...uncovered three episodes of construction, burning, and rebuilding of a houselot, which included a daub structure with an internal hearth and small internal posts used for storage shelves or benches, a food preparation and cooking activity area, a storage area, and a refuse disposal area. Overlapping and continuously used features indicated a reuse of the same distinct spatial layout throughout all three rebuilding episodes. Two large deep storage pits, a large refuse pit, and durable rectilinear structures were evidence of year-round long-term site occupation. Sedentism was further supported by the artifact assemblage, consisting of a large collection of ground stone tools and a chipped stone tool assemblage that contained a majority of unifacial/utilized flakes and heavily reworked bifacial tools.
The actual distribution of three nitrophilous therophytes, Chenopodium rubrum, Ch. glaucum and Atriplex prostrata, that are extending on the lower course of Loire and Allier, is presented. It is ...supplemented by an arrangement of floristical and ecological data taken from floras and herbarium specimen. The study reveals a connection between their multiplication and some soil parameters. At twenty ecologically similar study sites, distributed all along the two rivers, populations of the three species were investigated quantitatively and seven physicochemical parameters were mesured. Three soil parameters, pH, electric conductivity and carbonate show some correlations with the biomass of the three plants, both increasing from the upper to the lower parts. High values for electric conductivity in the lower part of the Loire river are interpreted as a strong sign for hypertrophication. The spread of these plants, reputed as indicators of eutrophication and water pollution, thus ecological degradation, is taken as a signal of alarm, which needs further supervision.
Abstract The Hardening Soil-Brick model for soils is designed to carry out complex numerical analyses of soil-structure interaction problems taking into account strong stiffness variation in the ...range of small strains. However, to calibrate its parameters advanced triaxial and oedometric tests are required. In case of uncemented sands laboratory testing is usually difficult. Therefore, to facilitate calibration procedures, a CPTU based method, enhanced by an experimental evidence derived from advanced triaxial drained and oedometric tests, has been proposed and verified. It is shown in the paper that using exclusively the CPTU test results one can calibrate most important model parameters for sands with accuracy that is sufficient for solving real life problems. The major goal of this paper is to identify correlations between all reference stiffness moduli, then verify them, and finally link with the CPTU based identification procedures. It is shown in the paper that such correlations exist and they exhibit very high coefficients of determination. Moreover, as the seismic version of the CPTU test is not often available in the practice, an enhanced procedure for identification of very small strain shear stiffness modulus has been proposed and then verified, using set of the SCPTU tests conducted in Gdańsk sands (Poland).
On‐site soil analysis in the framework of precision agriculture is gaining significant importance to achieve improved crop productivity, increased soil health and reduced fertilizer application. In ...situ sensing techniques can provide the information required for decision support systems immediately on the field, for example, to control fertilization and liming. Shifted excitation Raman difference spectroscopy (SERDS) pilot investigations for on‐site soil analysis are presented using a portable SERDS sensor system specifically developed for in‐field studies. The SERDS sensor includes a dual‐wavelength diode laser at 785 nm integrated in an in‐house realized turnkey laser system and an optical power of 36 mW at the sample was chosen for our experiments. Outdoor pre‐investigations with the device and polystyrene as test sample show the capability of SERDS for qualitative and quantitative analysis under changing daylight conditions. On‐site soil analysis is carried out and SERDS extracts Raman signals from disturbing background interference with a 15‐fold improvement of the signal‐to‐background‐noise ratio. Beside others, closely neighboured Raman signals of calcite and dolomite are identified and even mixtures of both soil carbonates are discriminated using SERDS. The number of accumulations for generating an averaged SERDS spectrum of soil with a sufficient signal stability and signal‐to‐background‐noise ratio is evaluated to optimize the overall exposure time for such in situ experiments. The presented results demonstrate the large capability of the developed portable SERDS sensor system for on‐site soil investigations as promising tool for precision agriculture.
Shifted excitation Raman difference spectroscopy (SERDS) pilot investigations for on‐site soil analysis are presented using a portable SERDS sensor system specifically developed for in‐field studies. SERDS extracts Raman signals from disturbing background interference with a 15‐fold improvement of the signal‐to‐background‐noise ratio enabling identification of soil minerals, even those with closely neighboured Raman signals, for example, calcite and dolomite. The presented results demonstrate the large capability of the portable SERDS sensor system for on‐site soil investigations as promising tool for precision agriculture.
