An easily installable groundwater lysimeter to determine waterbalance components and hydraulic properties of peat soils

International audienceA simple method for the installation of groundwater lysimeters in peat soils was developed which reduces both time and financial effort significantly. The method was applied on several sites in the Rhinluch, a fen peat land 60 km northwest of Berlin, Germany. Over a two-year period, upward capillary flow and evapotranspiration rates under grassland with different groundwater levels were measured. The installation of tensiometers and TDR probes additionally allowed the in situ determination of the soil hydraulic properties (water retention and unsaturated hydraulic conductivity). The results of the measurements of the unsaturated hydraulic conductivity demonstrate that more than one single method has to be applied if the whole range of the conductivity function from saturation to highly unsaturated is to be covered. Measuring the unsaturated conductivity can be done only in the lab for an adequately wide range of soil moisture conditions. Keywords: peat soils, soil hydraulic properties, evapotranspiration, capillary flow, root distribution, unsaturated zone</p

Policy Words and Policy Deeds: The ECB and the Euro

This paper examines the role of the ECB communication activities on daily Eurodollar exchange rate and interest rates. We estimate the relationship between monetary policy and the exchange rate using a technique that explicitly recognizes the joint determination of both the levels and volatilities of these variables. We also consider more traditional estimation strategies as a test of the robustness of our main results. We introduce a new indicator of ECB communications policies that focuses on what the ECB says about the future economic outlook for the euro area along five different economic dimensions. The impact of ECB communications policies is more apparent in the time series framework than in the heteroskedasticity estimator approach. Previous studies that conclude that news effects are significant at the daily frequency may have reached such a conclusion because the measurement of news was too highly aggregated. The endogeneity of the exchange rate – interest rate relationship is more apparent when the proxy for monetary policy is the euro area – US differential than when any other proxy for monetary policy is employed. Finally, interest rate changes generally have a much larger impact on exchange rate movements, and their volatility, than do ECB verbal pronouncements.Central bank communication; Eurodollar exchange rate

Commissioning of the I-LHC RF low level with beam

During the machine development session of 2007-10-03, the energy matching between PS and SPS was completed for the 208Pb82+ beam. The I-LHC RF low level, including the phase loop and the synchronisation loop, was commissioned to capture a single bunch of 208Pb82+. After commissioning, the beam was used for several non RF related machine developments

Scaffold searching: automated identification of similar ring systems for the design of combinatorial libraries

Rigid ring systems can be used to position receptor-binding functional groups in 3D space and they thus play an increasingly important role in the design of combinatorial libraries. This paper discusses the use of shape-similarity methods to identify ring systems that are structurally similar to, and aligned with, a user-defined target ring system. These systems can be used as alternative scaffolds for the construction of a combinatorial library

Converging Perturbative Solutions of the Schroedinger Equation for a Two-Level System with a Hamiltonian Depending Periodically on Time

We study the Schroedinger equation of a class of two-level systems under the action of a periodic time-dependent external field in the situation where the energy difference 2epsilon between the free energy levels is sufficiently small with respect to the strength of the external interaction. Under suitable conditions we show that this equation has a solution in terms of converging power series expansions in epsilon. In contrast to other expansion methods, like in the Dyson expansion, the method we present is not plagued by the presence of ``secular terms''. Due to this feature we were able to prove absolute and uniform convergence of the Fourier series involved in the computation of the wave functions and to prove absolute convergence of the epsilon-expansions leading to the ``secular frequency'' and to the coefficients of the Fourier expansion of the wave function

An easily installable groundwater lysimeter to determine waterbalance components and hydraulic properties of peat soils

A simple method for the installation of groundwater lysimeters in peat soils was developed which reduces both time and financial effort significantly. The method was applied on several sites in the Rhinluch, a fen peat land 60 km northwest of Berlin, Germany. Over a two-year period, upward capillary flow and evapotranspiration rates under grassland with different groundwater levels were measured. The installation of tensiometers and TDR probes additionally allowed the <i>in situ</i> determination of the soil hydraulic properties (water retention and unsaturated hydraulic conductivity). The results of the measurements of the unsaturated hydraulic conductivity demonstrate that more than one single method has to be applied if the whole range of the conductivity function from saturation to highly unsaturated is to be covered. Measuring the unsaturated conductivity can be done only in the lab for an adequately wide range of soil moisture conditions.</p> <p style='line-height: 20px;'><b>Keywords: </b>peat soils, soil hydraulic properties, evapotranspiration, capillary flow, root distribution, unsaturated zone</p

Particulate number and NOx trade-off comparisons between HVO and mineral diesel in HD applications

The increase in worldwide greenhouse gas emissions and costs for fossil fuels are forcing fuel suppliers and engine manufacturers to consider more sustainable alternatives for powering internal combustion engines. One very promising equivalent to mineral diesel fuel is hydrotreated vegetable oil (HVO) as it is highly paraffinic and offers similar combustion characteristics. This fuel offer the potential of not requiring further engine hardware modification together with correspondingly lower exhaust gas emissions and better fuel consumption than mineral diesel. In this paper the spray and combustion characteristics of HVO and its blends are investigated and compared with mineral diesel (European standard). Evidence of the reported reductions in NOx emissions has proven contradictory with some researchers reporting large reductions, whilst others measured no differences. This paper reports the results from comparison of three different experimental tests methods using diesel/HVO binary fuel blends. The macroscopic spray characteristics have been investigated and quantified using a constant volume spray vessel. Engine performance and exhaust emissions have also been characterised using a HD diesel engine in its original configuration (mineral diesel fuel-ready) and then in a recalibrated configuration optimised for HVO fuel. The results show that the engine injection control and also the fuel quality can influence the formation of NOx and particulate matter significantly. In-particular a potential pilot injection proved highly influential upon whether NOx emissions were reduced or not. When optimising the fuel injection, a reduction in NOx emissions of up to 18% or reductions of PN of up to 42–66% were achieved with simultaneous savings in fuel consumption of 4.3%

Identification of target-specific bioisosteric fragments from ligand-protein crystallographic data

Bioisosteres are functional groups or atoms that are structurally different but that can form similar intermolecular interactions. Potential bioisosteres were identified here from analysing the X-ray crystallographic structures for sets of different ligands complexed with a fixed protein. The protein was used to align the ligands with each other, and then pairs of ligands compared to identify substructural features with high volume overlap that occurred in approximately the same region of geometric space. The resulting pairs of substructural features can suggest potential bioisosteric replacements for use in lead-optimisation studies. Experiments with 12 sets of ligand-protein complexes from the Protein Data Bank demonstrate the effectiveness of the procedure

Proton acceleration by irradiation of isolated spheres with an intense laser pulse

We report on experiments irradiating isolated plastic spheres with a peak laser intensity of 2-3 x 10(20) W cm(-2). With a laser focal spot size of 10 mu m full width half maximum (FWHM) the sphere diameter was varied between 520 nm and 19.3 mu m. Maximum proton energies of similar to 25 MeV are achieved for targets matching the focal spot size of 10 mu m in diameter or being slightly smaller. For smaller spheres the kinetic energy distributions of protons become nonmonotonic, indicating a change in the accelerating mechanism from ambipolar expansion towards a regime dominated by effects caused by Coulomb repulsion of ions. The energy conversion efficiency from laser energy to proton kinetic energy is optimized when the target diameter matches the laser focal spot size with efficiencies reaching the percent level. The change of proton acceleration efficiency with target size can be attributed to the reduced cross-sectional overlap of subfocus targets with the laser. Reported experimental observations are in line with 3D3V particle in cell simulations. They make use of well-defined targets and point out pathways for future applications and experiments.DFG via the Cluster of Excellence Munich-Centre for Advanced Photonics (MAP) Transregio SFB TR18NNSA DE-NA0002008Super-MUC pr48meIvo CermakCGC Instruments in design and realization of the Paul trap systemIMPRS-APSLMUexcellent Junior Research FundDAAD|ToIFEEuropean Union's Horizon research and innovation programme 633053Physic

Status of the LHC proton beam in the CERN SPS

During the 2000-2001 shutdown the SPS has undergone a major hardware upgrade to cope with its role of LHC injector. An impedance reduction campaign, improvements to the RF beam-control systems, and modifications to the injection kicker magnets and transverse feedback were the main items of this upgrade. By the end of the 2001 run, after a series of machine development sessions, a single LHC batch with half the nominal intensity could be accelerated from 26 to 450 GeV/c, the LHC injection energy, with nominal longitudinal and transverse parameters. At present the major known obstacle to the achievement of the nominal LHC beam with four batches is the beam-induced electron cloud. This generates both dramatic vacuum pressure increases and fast single and coupled bunch transverse instabilities. The problems encountered with this high brilliance beam and solutions developed so far are presented. Possible cures for the existing limitations are outlined