Humusumsatz und Stickstoffeinträge in Gewässer: Dynamische Bilanzierung von Humushaushalt und Nährstoffaustrag im regionalen Maßstab im Kontext von Landnutzungs- und Klimawandel: Phase 2: Bilanzierung von Stickstoffeinträgen in sächsische Gewässer

Der Bericht knüpft an die Broschüre „Regionale Humus- und Nährstoffdynamik“ an und führt die dort vorgestellten Grundlagenarbeiten zur Kopplung der Teilmodelle CCB (Kohlenstoffhaushalt) und STOFFBILANZ (Nährstoffhaushalt) fort. Die sachsenweiten Modell-Ergebnisse zur Stickstoff-Bilanzierung zeigen, dass ein kontinuierlicher Humusaufbau auf Landwirtschaftsflächen die Stickstoff-Austräge aus dem Boden bzw. deren Einträge in die Gewässer verringern kann. Die Veröffentlichung richtet sich an Verwaltungen, Planungsbüros, Lehr- und Forschungsinstitutionen sowie Interessenverbände mit Bezug zu Landwirtschaft und Gewässerschutz. Redaktionsschluss: 11.07.201

Humusumsatz und Stickstoffeinträge in Gewässer: Dynamische Bilanzierung von Humushaushalt und Nährstoffaustrag im regionalen Maßstab im Kontext von Landnutzungs- und Klimawandel: Phase 2: Bilanzierung von Stickstoffeinträgen in sächsische Gewässer

Der Bericht knüpft an die Broschüre „Regionale Humus- und Nährstoffdynamik“ an und führt die dort vorgestellten Grundlagenarbeiten zur Kopplung der Teilmodelle CCB (Kohlenstoffhaushalt) und STOFFBILANZ (Nährstoffhaushalt) fort. Die sachsenweiten Modell-Ergebnisse zur Stickstoff-Bilanzierung zeigen, dass ein kontinuierlicher Humusaufbau auf Landwirtschaftsflächen die Stickstoff-Austräge aus dem Boden bzw. deren Einträge in die Gewässer verringern kann. Die Veröffentlichung richtet sich an Verwaltungen, Planungsbüros, Lehr- und Forschungsinstitutionen sowie Interessenverbände mit Bezug zu Landwirtschaft und Gewässerschutz. Redaktionsschluss: 11.07.201

Evaluation of critical source areas to reduce nutrient loading from agriculture in river basins in Saxony/Germany

vokMTT, Viestintä ja informaatiopalvelut, 31600 Jokioine

Humusumsatz und Stickstoffeinträge in Gewässer: Dynamische Bilanzierung von Humushaushalt und Nährstoffaustrag im regionalen Maßstab im Kontext von Landnutzungs- und Klimawandel: Phase 2: Bilanzierung von Stickstoffeinträgen in sächsische Gewässer

Der Bericht knüpft an die Broschüre „Regionale Humus- und Nährstoffdynamik“ an und führt die dort vorgestellten Grundlagenarbeiten zur Kopplung der Teilmodelle CCB (Kohlenstoffhaushalt) und STOFFBILANZ (Nährstoffhaushalt) fort. Die sachsenweiten Modell-Ergebnisse zur Stickstoff-Bilanzierung zeigen, dass ein kontinuierlicher Humusaufbau auf Landwirtschaftsflächen die Stickstoff-Austräge aus dem Boden bzw. deren Einträge in die Gewässer verringern kann. Die Veröffentlichung richtet sich an Verwaltungen, Planungsbüros, Lehr- und Forschungsinstitutionen sowie Interessenverbände mit Bezug zu Landwirtschaft und Gewässerschutz. Redaktionsschluss: 11.07.201

Simulation of land use impacts on sediment and nutrient transfer in coastal areas of Western Cape, South Africa

A major challenge for water resource management in Western Cape, South Africa, is the reduction of the growing sediment and nutrient loads in coastal areas, which belong to the areas most affected by land use change. We used the WebGIS based software STOFFBILANZ to simulate runoff, soil loss, sediment, phosphorus, and nitrogen input in the surface water and groundwater of study area (ca. 6,450 km²). The simulated runoff shows a large regional variability caused by the heterogeneous distribution of rainfall. For the reference catchment Klein River simulated total daily runoff fit the observed values of the reference year 2012. The calculation of potential input of sediment, phosphorus, and nitrogen into waters is based on aggregated or generalized information on climate data, land use types, crop and fruit types, yields, mineral fertilizers, farm manure, nitrogen fixing by leguminous plants, atmospheric nitrogen deposition, and soil denitrification. Critical source areas for potential sediment input, particulate P input and diffuse N input are mainly agricultural areas. Additionally, point sources of high relevance for N and P are found in urban areas. Based on the potential input of sediment and nutrients the impacts of current land use change on water resources were estimated. We used the web-based information system WebLand for the simulation aiming at the provision of stakeholders with information for decision making in water resource management

Heterogeneous Nanostructural Aging of Fuel Cell Ionomer Revealed by Operando SAXS

International audienceProton exchange membrane fuel cells (PEMFCs) represent one of the most interesting technologies for powering vehicles and small portable electronic devices in an eco-friendly way. Large scale implementation of PEMFCs requires to tailor novel resilient economically viable materials with prolongated lifetimes. One key issue is the durability of the ionomer membrane, which is responsible for the conduction of protons from anode to cathode. Here we report on the impact of aging on the membrane structure by means of operando SAXS. By analyzing the most prominent features of the in-situ aged and pristine spectra at different relevant positions in the fuel cell, we could establish that structural aging is highly heterogeneous and strongly dependent on the local conditions. The increase in current density produces a decrease in ionic nanodomain sizes in aged ionomer due to continuous membrane drying, as in pristine materials. However, long-term operation most dramatically affects the polymer organization into bundles, in particular at the air inlet and in the middle of the cell. Variations of the low-angle intensity of more than an order of magnitude are ascribed to significant increase in the area of interfacial regions, potentially impacting the diffusion within grain boundaries. With this study, we demonstrate that operando SAXS provides unique insights into ionomer structural aging in dependence of the local hydration and helps to identify the relevant scale for physical degradation. This information is needed for optimizing fuel cells operating strategies and improving the durability of membranes

Improved Approach for the Investigation of Submarine Groundwater Discharge by Means of Radon Mapping and Radon Mass Balancing

The paper presents an improved approach for investigating submarine groundwater discharge (SGD) based on radon mapping and radon mass balancing in the coastal sea. While the use of radon as an environmental tracer in SGD studies is well-established, we identified based on our longstanding experience six methodical shortcomings of the conventional approach and suggest corresponding developments. The shortcomings include: (1 and 2) inadequate consideration of both detection equipment response delay and influence of tidal stage; (3 and 4) incorrect quantification of radon losses, due to offshore mixing and degassing resulting in a potentially incorrect radon mass balance; (5) inaccurate determination of the terrestrial groundwater endmember, due to inhomogeneous radon distribution in the coastal aquifer; and (6) difficulties in distinguishing between discharged fresh groundwater and recirculated seawater. The improved approach is practically demonstrated in a step by step manner in a large-scale field study, which was carried out in False Bay (South Africa) and which consisted of two parts, namely (i) qualitative SGD localization along the entire False Bay coastline based on coastal radon distribution patterns and (ii) quantitative SGD investigation within a defined coastal area of interest (AOI) based on a radon mass balance (RMB). The plausibility of the AOI related results was evaluated by a hydrogeological model, used for qualitative SGD localization, and a hydrological model, applied for estimating groundwater recharge within the AOI catchment

Operando Raman Spectroscopy and Synchrotron X-ray Diffraction of Lithiation/Delithiation in Silicon Nanoparticle Anodes

International audienc

Effect of a Strategy of Comprehensive Vasodilation vs Usual Care on Mortality and Heart Failure Rehospitalization Among Patients With Acute Heart Failure: The GALACTIC Randomized Clinical Trial

Short-term infusions of single vasodilators, usually given in a fixed dose, have not improved outcomes in patients with acute heart failure (AHF).; To evaluate the effect of a strategy that emphasized early intensive and sustained vasodilation using individualized up-titrated doses of established vasodilators in patients with AHF.; Randomized, open-label blinded-end-point trial enrolling 788 patients hospitalized for AHF with dyspnea, increased plasma concentrations of natriuretic peptides, systolic blood pressure of at least 100 mm Hg, and plan for treatment in a general ward in 10 tertiary and secondary hospitals in Switzerland, Bulgaria, Germany, Brazil, and Spain. Enrollment began in December 2007 and follow-up was completed in February 2019.; Patients were randomized 1:1 to a strategy of early intensive and sustained vasodilation throughout the hospitalization (n = 386) or usual care (n = 402). Early intensive and sustained vasodilation was a comprehensive pragmatic approach of maximal and sustained vasodilation combining individualized doses of sublingual and transdermal nitrates, low-dose oral hydralazine for 48 hours, and rapid up-titration of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or sacubitril-valsartan.; The primary end point was a composite of all-cause mortality or rehospitalization for AHF at 180 days.; Among 788 patients randomized, 781 (99.1%; median age, 78 years; 36.9% women) completed the trial and were eligible for primary end point analysis. Follow-up at 180 days was completed for 779 patients (99.7%). The primary end point, a composite of all-cause mortality or rehospitalization for AHF at 180 days, occurred in 117 patients (30.6%) in the intervention group (including 55 deaths [14.4%]) and in 111 patients (27.8%) in the usual care group (including 61 deaths [15.3%]) (absolute difference for the primary end point, 2.8% [95% CI, -3.7% to 9.3%]; adjusted hazard ratio, 1.07 [95% CI, 0.83-1.39]; P = .59). The most common clinically significant adverse events with early intensive and sustained vasodilation vs usual care were hypokalemia (23% vs 25%), worsening renal function (21% vs 20%), headache (26% vs 10%), dizziness (15% vs 10%), and hypotension (8% vs 2%).; Among patients with AHF, a strategy of early intensive and sustained vasodilation, compared with usual care, did not significantly improve a composite outcome of all-cause mortality and AHF rehospitalization at 180 days.; ClinicalTrials.gov Identifier: NCT00512759