Activity of Exoenzymes in Treated Wastewater Irrigated Soils

The reuse of reclaimed wastewater for irrigation of agricultural fields greatly influences the activity of soil microorganisms through the input of organic compounds. Due to the production of exoenzymes by microorganisms for the decomposition of substrates it can be assumed that the irrigation with treated wastewater (TWW) has a strong influence on the soil enzyme pool. In this study the activity of ten exoenzymes, which catalyses processes in C, N and P nutrient cycles, were determined in 3 different soils in 0-10, 10-20, 20-30, 30-50, 50-70 and 70-100 cm soil depth. The soils were used for agriculture and irrigated with reclaimed wastewater reused after a secondary treatment step. Additionally a control after freshwater irrigation was studied. Due to the influence of TWW on the soil biology of these soils, also clear effects on soil exoenzymes in freshwater and TWW irrigated soils could be seen. According to Sinsabaugh et al. (2008) we calculated indices which describe the enzymatic resources for acquisition of organic P and organic N relative to C and therefore give insides into the functional convergence of extracellular enzyme activities in soils and the relative nutrient demand. The distribution pattern of these functional enzyme activities varied between freshwater and TWW irrigated soils and shows therefore a strong influence of the TWW irrigation on the activity of exoenzymes. (Sinsabaugh et al. (2008): Stoichiometry of soil enzyme activity at global scale. Ecology Letters 11 (11), 1252-1264.

Treated wastewater irrigation effects on soil hydraulic conductivity and aggregate stability of loamy soils in Israel

The use of treated wastewater (TWW) for agricultural irrigation becomes increasingly important in water stressed regions like the Middle East for substituting fresh water (FW) resources. Due to elevated salt concentrations and organic compounds in TWW this practice has potential adverse effects on soil quality, such as the reduction of hydraulic conductivity (HC) and soil aggregate stability (SAS). To assess the impact of TWW irrigation in comparison to FW irrigation on HC, in-situ infiltration measurements using mini disk infiltrometer were deployed in four different long-term experimental orchard test sites in Israel. Topsoil samples (0-10 cm) were collected for analyzing SAS and determination of selected soil chemical and physical characteristics. The mean HC values decreased at all TWW sites by 42.9% up to 50.8% compared to FW sites. The SAS was 11.3% to 32.4% lower at all TWW sites. Soil electrical conductivity (EC) and exchangeable sodium percentage (ESP) were generally higher at TWW sites. These results indicate the use of TWW for irrigation is a viable, but potentially deleterious option, as it influences soil physical and chemical properties

Microstructures to control elasticity in 3D printing

We propose a method for fabricating deformable objects with spatially varying elasticity using 3D printing. Using a single, relatively stiff printer material, our method designs an assembly of small-scale microstructures that have the effect of a softer material at the object scale, with properties depending on the microstructure used in each part of the object. We build on work in the area of metamaterials, using numerical optimization to design tiled microstructures with desired properties, but with the key difference that our method designs families of related structures that can be interpolated to smoothly vary the material properties over a wide range. To create an object with spatially varying elastic properties, we tile the object's interior with microstructures drawn from these families, generating a different microstructure for each cell using an efficient algorithm to select compatible structures for neighboring cells. We show results computed for both 2D and 3D objects, validating several 2D and 3D printed structures using standard material tests as well as demonstrating various example applications

GIS-gestützte Risikobewertung der Bodeneignung für die Bewässerung mit Abwässern in Israel und dem Westjordanland

Die Forschungsgruppe Abwassermanagement im BMBF-geförderten multilateralen Projektverbund GLOWA Jordan River untersucht unter Federführung der Ruhr-Universität Bochum mittels Geographischer Informationssysteme (GIS) und Vor-Ort-Untersuchungen die Bodenverhältnisse und Bodeneigenschaften im Einzugsgebiet des Jordans (Israel, Jordanien & Westjordanland). Erstmals wurden auf überregionaler Ebene digitale Bodenkarten mit Bodenparametern verschnitten. Verschiedene landwirtschaftlich bedeutende Risiken wurden definiert. Anhand der jeweiligen Standortparameter wurden weitergehend mittels der Anwendung von Standardmethoden sowie eigens entwickelter Ableitungen spezifische bodenbezogene Eignungs- und Risikograde einer Bewässerung mit Abwässern ermittelt und eine Gesamtbewertung der Bodeneignung für die Bewässerung mit Abwässern durchgeführt

GIS-gestützte Risikobewertung der Bodeneignung für die Bewässerung mit Abwässern in Israel und dem Westjordanland

Die Forschungsgruppe Abwassermanagement im BMBF-geförderten multilateralen Projektverbund GLOWA Jordan River untersucht unter Federführung der Ruhr-Universität Bochum mittels Geographischer Informationssysteme (GIS) und Vor-Ort-Untersuchungen die Bodenverhältnisse und Bodeneigenschaften im Einzugsgebiet des Jordans (Israel, Jordanien & Westjordanland). Erstmals wurden auf überregionaler Ebene digitale Bodenkarten mit Bodenparametern verschnitten. Verschiedene landwirtschaftlich bedeutende Risiken wurden definiert. Anhand der jeweiligen Standortparameter wurden weitergehend mittels der Anwendung von Standardmethoden sowie eigens entwickelter Ableitungen spezifische bodenbezogene Eignungs- und Risikograde einer Bewässerung mit Abwässern ermittelt und eine Gesamtbewertung der Bodeneignung für die Bewässerung mit Abwässern durchgeführt

Modeling and estimation of internal friction in cloth

Force-deformation measurements of cloth exhibit significant hysteresis, and many researchers have identified internal friction as the source of this effect. However, it has not been incorporated into computer animation models of cloth. In this paper, we propose a model of internal friction based on an augmented reparameterization of Dahl's model, and we show that this model provides a good match to several important features of cloth hysteresis even with a minimal set of parameters. We also propose novel parameter estimation procedures that are based on simple and inexpensive setups and need only sparse data, as opposed to the complex hardware and dense data acquisition of previous methods. Finally, we provide an algorithm for the efficient simulation of internal friction, and we demonstrate it on simulation examples that show disparate behavior with and without internal friction

Microstructures to control elasticity in 3D printing

We propose a method for fabricating deformable objects with spatially varying elasticity using 3D printing. Using a single, relatively stiff printer material, our method designs an assembly of small-scale microstructures that have the effect of a softer material at the object scale, with properties depending on the microstructure used in each part of the object. We build on work in the area of metamaterials, using numerical optimization to design tiled microstructures with desired properties, but with the key difference that our method designs families of related structures that can be interpolated to smoothly vary the material properties over a wide range. To create an object with spatially varying elastic properties, we tile the object's interior with microstructures drawn from these families, generating a different microstructure for each cell using an efficient algorithm to select compatible structures for neighboring cells. We show results computed for both 2D and 3D objects, validating several 2D and 3D printed structures using standard material tests as well as demonstrating various example applications

Biogeochemical limitations of carbon stabilization in forest subsoils

Background: Soils are important carbon (C) sinks or sources and thus of utmost importance for global carbon cycling. Particularly, subsoils are considered to have a high potential for additional C storage due to mineral surfaces still available for sorptive stabilization. Aims: Little information exists about the extent to which additional litter-derived C is transferred to and stabilized in subsoils. This study aimed at evaluating the role of litter-derived dissolved organic matter (DOM) inputs for the formation of stable mineral-associated C in subsoils. Methods: We carried out a multiple-method approach including field labeling with 13C-enriched litter, exposure of 13C-loaded reactive minerals to top- and subsoils, and laboratory sorption experiments. Results: For temperate forest soils, we found that the laboratory-based C sink capacity of subsoils is unlikely to be reached under field conditions. Surface C inputs via litter leachates are little conducive to the subsoil C pool. Only 0.5% of litter-derived C entered the subsoil as DOM within nearly 2 years and most of the recently sorbed C is prone to fast microbial mineralization rather than long-term mineral retention. Desorption to the soil solution and an adapted microbial community re-mobilize organic matter in subsoils faster than considered so far. Conclusions: We conclude that the factors controlling the current mineral retention and stabilization of C within temperate forest subsoils will likewise limit additional C uptake. Thus, in contrast to their widely debated potential to accrue more C, the role of forest subsoils as future C sink is likely overestimated and needs further reconsideration