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Phosphorus (P) is one of the major limiting nutrient in many freshwater ecosystems. During the last decade, attention has been focused on the fluxes of suspended sediment and particulate P through freshwater drainage systems because of severe eutrophication effects in aquatic ecosystems. Hence, the analysis and prediction of phosphorus and sediment dynamics constitute an important element for ecological conservation and restoration of freshwater ecosystems. In that sense, the development of a suitable prediction model is justified, and the present work is devoted to the validation and application of a predictive soluble reactive phosphorus (SRP) uptake and sedimentation models, to a real riparian system of the middle Ebro river floodplain. Both models are coupled to a fully distributed two-dimensional shallow-water flow numerical model. The SRP uptake model is validated using data from three field experiments. The model predictions show a good accuracy for SRP concentration, where the linear regressions between measured and calculated values of the three experiments were significant ( r2 ≥ 0.62; p ≤ 0.05), and a Nash-Sutcliffe coefficient ( E) that ranged from 0.54 to 0.62. The sedimentation model is validated using field data collected during two real flooding events within the same river reach. The comparison between calculated and measured sediment depositions showed a significant linear regression ( p ≤ 0.05; r2 = 0.97) and an E that ranged from 0.63 to 0.78. Subsequently, the complete model that includes flow dynamics, solute transport, SRP uptake and sedimentation is used to simulate and analyse floodplain sediment deposition, river nutrient contribution and SRP uptake. According to this analysis, the main SRP uptake process appears to be the sediment sorption. The analysis also reveals the presence of a lateral gradient of hydrological connectivity that decreases with distance from the river and controls the river matter contribution to the floodplain. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The natural rubber specific heat capacity dependence on pressure was estimated on thermodynamic grounds on the basis of the values empirically determined from differential scanning calorimetry data, (in the temperature range of −70 to 50°C), and by means of the Tait equation of state (in the pressure range of 0.1-240 MPa). It was found that the specific heat capacity decreases with pressure, being the dependency more pronounced at low pressures. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013 [ABSTRACT FROM AUTHOR]

The dielectric relaxation spectra of poly(2-ethoxyethylmethacrylate) in the frequency domain exhibits above Tgand at high frequencies a well-developed secondary γrelaxation. This process is followed in decreasing order of frequencyfor a relatively weak β relaxation and an ostensible glass–rubberrelaxation which at high temperatures and low frequencies is dominatedby electrode–polymer interfacial processes. By slightly cross-linkingthe polymer using 2.5% (mol) of 2-ethoxyethyldimethacrylate as cross-linkingagent, the β relaxation disappears, the γ relaxation remaining.The activation energy of the γ relaxation for the cross-linkedand un-cross-linked polymers is ca. 30 kJ·mol–1, about 10 kJ·mol–1below that of the βrelaxation. Cross-linking shifts the location of the glass–rubberrelaxation nearly 10 °C to higher temperatures, without wideningthe distribution of relaxation times. The X-rays pattern of the cross-linkedpolymer presents two peaks at q= 5.6 nm–1and 12.76 nm–1, resembling the X-ray patternsof poly(n-alkyl methacrylate)s. The peaks in poly(n-alkyl methacrylate)s were attributed to the formationof nanodomains integrated by side chains flanked by the backbone.However, whereas this heterogeneity produces an αPEpeak in poly(n-alkyl methacrylate)s with n≥ 2, this microheterogeneity gives rise to a Maxwell–Wagner–Sillars(MWS) relaxation in the cross-linked polymer located at lower frequenciesthan the glass rubber relaxation. Finally the interfacial-electrodeconductive processes of the cross-linked and un-cross-linked polymericsystems are studied in the light of current theories. [ABSTRACT FROM AUTHOR]

The possibility of instability of cylindrical tubes of elastomers is analyzed taking into account Mooney-Rivlin (M. Mooney, J. Appl. Phys. 11, 582 (1940)) and Ogden (R.W. Ogden, Proc. R. Soc. London, Ser. A 326, 565 (1972)) models. In some aspects this paper is the elasto-electric counterpart of a previous paper by Bustamante, Dorfmann and Ogden (R. Bustamante, A. Dorfmann, R.W. Ogden, J. Engn. Math. 59, 139 (2007)). However in the present case the appearance of instability is checked. The results indicate that models more complex than the Mooney-Rivlin model are necessary to predict instability zones showing minimum critical points. [ABSTRACT FROM AUTHOR]

The article examines the relationship between channel width (W) and channel discharge(Q) using rill and gully channel junction data. It was found that the WQ exponent increases with increasing channel width in a continuous fashion. The WQ relation is a scaling formula providing an estimate of the channel width compatible with a given flow discharge. The relation can predict channel width at a short distance downstream of channel junctions using tributary widths.

The article discusses the effects of weather condition on soil erodibility. The paper aims to consider whether climate affects the condition of soils to water erosion. The study collected soil erodibility data using measured soil loss from standard run-off plots. It illustrates the strong climate effect on soil by calculating seasonal variation of mean monthly soil erodibility. Soil erodibilities are divided into two large groups, one corresponding to soils in cool climate and another to soils located in warm climates.

Flavor-changing effective vertices q q V, where V represents a neutral gauge boson (γ, Z, g), involving a heavy external quark, are discussed within the standard model at one-loop level and second-order approximation in external momenta and masses: the logarithmic singular terms in the form factors at vanishing mass of the internal quark in the loop have to be replaced by pieces coming from next order in external momenta. Implications in the b→d+X penguin transitions are commented. [ABSTRACT FROM AUTHOR]

We study rare Kaon and B mesons decays within the Gelmini-Roncadelli model. Expressions are obtained and a numerical analysis is done for the modification of rates and the energy spectrum of the emitted pion in the decay K→π+ (unobserved neutrals), when a majoron particle θ and its light scalar partner ρ contribute as new channels to the final state. Rates for inclusive rare B meson decays are analyzed too. [ABSTRACT FROM AUTHOR]