99 research outputs found

    Auswirkungen von Bewirtschaftungsmaßnahmen auf die Treibhausgasemissionen eines kleiüberdeckten Niedermoores

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    Für die klassische landwirtschaftliche Nutzung von Moorflächen ist die Entwässerung unerlässlich, verursacht aber Emissionen der Treibhausgase (THG) Kohlendioxid (CO2) und Lachgas (N2O). THG-Emissionen aus "echten" Torfböden sind hinsichtlich der Auswirkungen von Hydrologie und Bewirtschaftung gut untersucht, aber es gibt wenig Daten zu THG-Emissionen von überdeckten organischen Böden. Die Mineralbodenhorizonte können entweder anthropogen Ursprungs sein oder sind, z.B. durch die Ablagerung von fluviatilen oder marinen Sedimenten natürlich entstanden. Überdeckte Moorstandorte sind in Nordwestdeutschland und anderen Regionen mit intensiv genutzten Torfgebieten oder (ehemaliger) Überflutungsdynamik weit verbreitet. Hier wollen wir die Auswirkungen der Bewirtschaftung, des Wasserstandes und der Eigenschaften der Kleiauflage auf die Emissionen von CO2, N2O und Methan (CH4) quantifizieren. Das Untersuchungsgebiet wird als Intensivgrünland genutzt (4 bis 5 Schnitte pro Jahr, N-Düngung von 112 bis 157 kg/ha a) und künstlich entwässert. Der Niedermoortorf mit einer Mächtigkeit von 0,6 bis 1,50 m ist mit Klei überdeckt. Es wurden sechs Messstandorte ausgewählt, welche für das Gebiet typische Bedingungen repräsentieren. Die Standorte unterscheiden sich im Gehalt des organischen Bodenkohlenstoffes (SOC) der Kleiauflage (4 – 1 % SOC), im Auftreten eines Pflughorizontes sowie der Entwässerung und der Bewirtschaftung. Wir verwenden manuelle Hauben zur Messung von CO2-, CH4- und N2O-Flüssen. Ganztägige CO2-Messkampagnen mit transparenten und nicht-transparenten Hauben finden je nach Jahreszeit jede dritte oder vierte Woche statt. Gasproben für die Messung der CH4 und N2O-Flüsse werden alle zwei Wochen und zusätzlich am ersten, dritten und siebten Tag nach Düngeranwendung genommen und gaschromatographisch analysiert. Erste Ergebnisse zeigen aufgrund des niedrigen Grundwasserspiegels sehr geringe CH4-Flüsse. Kumulierte N2O-Emissionen spiegeln vor allem die unterschiedlichen Düngergaben wieder, obwohl es im bisherigen Messzeitraum selten N2O-Peaks direkt nach der Düngerapplikation gab. Dies ist wahrscheinlich durch die geringe Bodenfeuchte zu erklären. Hochgerechnet von den Daten der ersten sechs Monaten zeigte sich, dass die N2O-Emissionen des kleiüberdeckten Niedermoores gleiche Größenordnungen wie die Emissionen von „echten“ Torfböden mit vergleichbarer N-Düngung erreichen. Die Ergebnisse der CO2-Messungen des ersten Jahres werden ebenfalls präsentiert werden

    Pseuduscalar Heavy Quarkonium Decays With Both Relativistic and QCD Radiative Corrections

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    We estimate the decay rates of ηc2γ\eta_c\rightarrow 2\gamma, ηc2γ\eta_c'\rightarrow 2\gamma, and J/ψe+eJ/\psi\rightarrow e^+ e^-, ψe+e\psi^\prime\rightarrow e^+e^-, by taking into account both relativistic and QCD radiative corrections. The decay amplitudes are derived in the Bethe-Salpeter formalism. The Bethe-Salpeter equation with a QCD-inspired interquark potential are used to calculate the wave functions and decay widths for these ccˉc\bar{c} states. We find that the relativistic correction to the ratio RΓ(ηc2γ)/Γ(J/ψe+e)R\equiv \Gamma (\eta_c \rightarrow 2\gamma)/ \Gamma (J/ \psi \rightarrow e^+ e^-) is negative and tends to compensate the positive contribution from the QCD radiative correction. Our estimate gives Γ(ηc2γ)=(67) keV\Gamma(\eta_c \rightarrow 2\gamma)=(6-7) ~keV and Γ(ηc2γ)=2 keV\Gamma(\eta_c^\prime \rightarrow 2\gamma)=2 ~keV, which are smaller than their nonrelativistic values. The hadronic widths Γ(ηc2g)=(1723) MeV\Gamma(\eta_c \rightarrow 2g)=(17-23) ~MeV and Γ(ηc2g)=(57) MeV\Gamma(\eta_c^\prime \rightarrow 2g)=(5-7)~MeV are then indicated accordingly to the first order QCD radiative correction, if αs(mc)=0.260.29\alpha_s(m_c)=0.26-0.29. The decay widths for bbˉb\bar b states are also estimated. We show that when making the assmption that the quarks are on their mass shells our expressions for the decay widths will become identical with that in the NRQCD theory to the next to leading order of v2v^2 and αs\alpha_s.Comment: 14 pages LaTex (2 figures included

    Analysis of Localization Phenomena in Weakly Interacting Disordered Lattice Gases

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    Disorder plays a crucial role in many systems particularly in solid state physics. However, the disorder in a particular system can usually not be chosen or controlled. We show that the unique control available for ultracold atomic gases may be used for the production and observation of disordered quantum degenerate gases. A detailed analysis of localization effects for two possible realizations of a disordered potential is presented. In a theoretical analysis clear localization effects are observed when a superlattice is used to provide a quasiperiodic disorder. The effects of localization are analyzed by investigating the superfluid fraction and the localization length within the system. The theoretical analysis in this paper paves a clear path for the future observation of Anderson-like localization in disordered quantum gases.Comment: 9 pages, 13 figure

    The minimum information required for a glycomics experiment (MIRAGE) project: improving the standards for reporting glycan microarray-based data

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    MIRAGE (Minimum Information Required for A Glycomics Experiment) is an initiative that was created by experts in the fields of glycobiology, glycoanalytics and glycoinformatics to produce guidelines for reporting results from the diverse types of experiments and analyses used in structural and functional studies of glycans in the scientific literature. As a sequel to the guidelines for sample preparation (Struwe et al. 2016, Glycobiology, 26:907–910) and mass spectrometry  data (Kolarich et al. 2013, Mol. Cell Proteomics, 12:991–995), here we present the first version of guidelines intended to improve the standards for reporting data from glycan microarray analyses. For each of eight areas in the workflow of a glycan microarray experiment, we provide guidelines for the minimal information that should be provided in reporting results. We hope that the MIRAGE glycan microarray guidelines proposed here will gain broad acceptance by the community, and will facilitate interpretation and reproducibility of the glycan microarray results with implications in comparison of data from different laboratories and eventual deposition of glycan microarray data in international databases

    PEAT-CLSM : A Specific Treatment of Peatland Hydrology in the NASA Catchment Land Surface Model

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    Peatlands are poorly represented in global Earth system modeling frameworks. Here we add a peatland-specific land surface hydrology module (PEAT-CLSM) to the Catchment Land Surface Model (CLSM) of the NASA Goddard Earth Observing System (GEOS) framework. The amended TOPMODEL approach of the original CLSM that uses topography characteristics to model catchment processes is discarded, and a peatland-specific model concept is realized in its place. To facilitate its utilization in operational GEOS efforts, PEAT-CLSM uses the basic structure of CLSM and the same global input data. Parameters used in PEAT-CLSM are based on literature data. A suite of CLSM and PEAT-CLSM simulations for peatland areas between 40 degrees N and 75 degrees N is presented and evaluated against a newly compiled data set of groundwater table depth and eddy covariance observations of latent and sensible heat fluxes in natural and seminatural peatlands. CLSM's simulated groundwater tables are too deep and variable, whereas PEAT-CLSM simulates a mean groundwater table depth of -0.20 m (snow-free unfrozen period) with moderate temporal fluctuations (standard deviation of 0.10 m), in significantly better agreement with in situ observations. Relative to an operational CLSM version that simply includes peat as a soil class, the temporal correlation coefficient is increased on average by 0.16 and reaches 0.64 for bogs and 0.66 for fens when driven with global atmospheric forcing data. In PEAT-CLSM, runoff is increased on average by 38% and evapotranspiration is reduced by 19%. The evapotranspiration reduction constitutes a significant improvement relative to eddy covariance measurements.Peer reviewe

    Endotracheal tube mucus as a source of airway mucus for rheological study

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    Muco-obstructive lung diseases (MOLDs), like cystic fibrosis and chronic obstructive pulmonary disease, affect a spectrum of subjects globally. In MOLDs, the airway mucus becomes hyperconcentrated, increasing osmotic and viscoelastic moduli and impairing mucus clearance. MOLD research requires relevant sources of healthy airway mucus for experimental manipulation and analysis. Mucus collected from endotracheal tubes (ETT) may represent such a source with benefits, e.g., in vivo production, over canonical sample types such as sputum or human bronchial epithelial (HBE) mucus. Ionic and biochemical compositions of ETT mucus from healthy human subjects were characterized and a stock of pooled ETT samples generated. Pooled ETT mucus exhibited concentration-dependent rheologic properties that agreed across spatial scales with reported individual ETT samples and HBE mucus. We suggest that the practical benefits compared with other sample types make ETT mucus potentially useful for MOLD research

    Estimation of physician supply by specialty and the distribution impact of increasing female physicians in Japan

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    <p>Abstract</p> <p>Background</p> <p>Japan has experienced two large changes which affect the supply and distribution of physicians. They are increases in medical school enrollment capacity and in the proportion of female physicians. The purpose of this study is to estimate the future supply of physicians by specialty and to predict the associated impact of increased female physicians, as well as to discuss the possible policy implications.</p> <p>Methods</p> <p>Based on data from the 2004 and 2006 National Survey of Physicians, Dentists and Pharmacists, we estimated the future supply of physicians by specialty, using multistate life tables. Based on possible scenarios of the future increase in female physicians, we also estimated the supply of physicians by specialty.</p> <p>Results</p> <p>Even if Japan's current medical school enrollment capacity is maintained in subsequent years, the number of physicians per 1000 population is expected to increase from 2.2 in 2006 to 3.2 in 2036, which is a 46% increase from the current level. The numbers of obstetrician/gynecologists (OB/GYNs) and surgeons are expected to temporarily decline from their current level, whereas the number of OB/GYNs per 1000 births will still increase because of the declining number of births. The number of surgeons per 1000 population, even with the decreasing population, will decline temporarily over the next few years. If the percentage of female physicians continues to increase, the overall number of physicians will not be significantly affected, but in specialties with current very low female physician participation rates, such as surgery, the total number of physicians is expected to decline significantly.</p> <p>Conclusion</p> <p>At the current medical school enrollment capacity, the number of physicians per population is expected to continue to increase because of the skewed age distribution of physicians and the declining population in Japan. However, with changes in young physicians' choices of medical specialties and as the percentage of female physicians increases, patterns of physician supply will vary between specialties. Specialties less often chosen by young physicians and where males have dominated will face a decline in physician supply. These results highlight the necessity for developing a work environment that attracts female physicians to these types of specialties. This will also lead to improved gender equality in the workforce and more effective use of human resources.</p

    Mineralogical and geochemical analysis of Fe-phases in drill-cores from the Triassic Stuttgart Formation at Ketzin CO₂ storage site before CO₂ arrival

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    Reactive iron (Fe) oxides and sheet silicate-bound Fe in reservoir rocks may affect the subsurface storage of CO2 through several processes by changing the capacity to buffer the acidification by CO2 and the permeability of the reservoir rock: (1) the reduction of three-valent Fe in anoxic environments can lead to an increase in pH, (2) under sulphidic conditions, Fe may drive sulphur cycling and lead to the formation of pyrite, and (3) the leaching of Fe from sheet silicates may affect silicate diagenesis. In order to evaluate the importance of Fe-reduction on the CO2 reservoir, we analysed the Fe geochemistry in drill-cores from the Triassic Stuttgart Formation (Schilfsandstein) recovered from the monitoring well at the CO2 test injection site near Ketzin, Germany. The reservoir rock is a porous, poorly to moderately cohesive fluvial sandstone containing up to 2–4 wt% reactive Fe. Based on a sequential extraction, most Fe falls into the dithionite-extractable Fe-fraction and Fe bound to sheet silicates, whereby some Fe in the dithionite-extractable Fe-fraction may have been leached from illite and smectite. Illite and smectite were detected in core samples by X-ray diffraction and confirmed as the main Fe-containing mineral phases by X-ray absorption spectroscopy. Chlorite is also present, but likely does not contribute much to the high amount of Fe in the silicate-bound fraction. The organic carbon content of the reservoir rock is extremely low (<0.3 wt%), thus likely limiting microbial Fe-reduction or sulphate reduction despite relatively high concentrations of reactive Fe-mineral phases in the reservoir rock and sulphate in the reservoir fluid. Both processes could, however, be fuelled by organic matter that is mobilized by the flow of supercritical CO2 or introduced with the drilling fluid. Over long time periods, a potential way of liberating additional reactive Fe could occur through weathering of silicates due to acidification by CO2

    Treibhausgasemissionen aus organischen Böden im deutschen Treibhausgasinventar: Methodenentwicklung und Ergebnisse

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    Entwässerte organische Böden sind in vielen Ländern, darunter auch in Deutschland, eine starke Quelle anthropogener Treibhausgase (THG). Daher müssen sie bei der Berichterstattung gemäß UNFCCC und Kyoto-Protokoll angemessen berücksichtigt werden. Hier beschreiben wir die Methodik, Daten und Ergebnisse der deutschen detaillierten Tier-3-Methodik zur Berichterstattung anthropogener Treibhausgasemissionen aus entwässerten organischen Böden, die für das deutsche Treibhausgasinventar entwickelt und angewandt wurden. Der Ansatz basiert auf nationalen Daten und bietet das Potenzial, Änderungen der Landnutzung und des Wassermanagements zu verfolgen, falls Zeitreihen zu relevanten Aktivitätsdaten vorliegen. Die Aktivitätsdaten umfassen hochauflösende Karten zu Klima, Landnutzung, organischen Böden und vom mittleren jährlichen Grundwasserflurabstand. Die Grundwasserkarte wurde durch ein statistisches Modell aus Daten von &gt; 1000 Standorten abgeleitet. Die THG-Emissionen beruhen auf einem einzigartigen Datensatz mit mehr als 200 THG-Bilanzen für fast alle Kombinationen von Landnutzungskategorien und Typen organischer Böden. Die Messungen wurden mit vollständig harmonisierten Protokollen durchgeführt. Nicht-lineare Funktionen beschreiben die Abhängigkeit der Kohlendioxid- und Methan-Flüsse vom mittleren jährlichen Grundwasserstand und, wenn erforderlich, von der Landnutzung. Die daraus resultierenden "angewandten Emissionsfaktoren" für jede Landnutzungskategorie berücksichtigen sowohl die Unsicherheit der nicht-linearen Funktionen als auch die Verteilung der Grundwasserstände in jeder Landnutzungskategorie. Da keine einfachen funktionellen Zusammenhänge für die Lachgasemissionen gefunden wurden, wurden die entsprechenden Emissionsfaktoren daher als Mittelwerte der Messwerte jeder Landnutzungskategorie berechnet. Für kleinere THG-Quellen wie Methanemissionen aus Gräben und Austräge von gelöstem organischem Kohlenstoff wurden IPCC-Standard-Emissionsfaktoren verwendet
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