An ancient compound rediscovered: perspectives of aphid control in organic hop growing by the use of quassia products

In the first three decades of the 20th century, quassia extract was widely used in hop growing as a chemical agent to control Phorodon humuli and other insect pests. In the first years of the 21st century this compound was rediscovered by German organic hop growers. In nine efficacy trials conducted in five field seasons, quassia products proved to be effective control agents for P. humuli in organically grown aroma cultivars. As the best method of application a systemic variant was developed by painting a suspension of quassia extract to the bines. This method proved not only to be very effective but was also best from an environmental point of view as sprayed quassia extracts had side effects on non-target organisms. As an optimal systemic application rate 24 g/ha of the active ingredient quassine was determined

Entwicklung von Pflanzenschutzstrategien im ökologischen Hopfenbau als Alternativen zur Anwendung kupfer- und schwefelhaltiger Pflanzenschutzmittel

Hopfen als Dauerkultur wird von vielen Schadorganismen befallen, die auch in Öko Betrieben regelmäßig bekämpft werden müssen. Brauereien, die Öko-Hopfen verwenden, stellen nämlich grundsätzlich die gleichen Qualitätsanforderungen an die Hopfendolden wie die Käufer konventionell erzeugter Ware. Bei den verfügbaren Hopfensorten gibt es große Unterschiede in der Anfälligkeit gegenüber Krankheiten. Grundsätzlich wird der Öko-Hopfenpflanzer widerstandsfähige oder tolerante Sorten auswählen. Es gibt aber auch den Fall, dass ein Brauer für seinen Biertyp eine spezielle Sorte benötigt, die anfällig gegenüber Krankheiten ist. Die wichtigsten Krankheiten, der Falsche Mehltau und der Echte Mehltau, werden in Öko Betrieben überwiegend mit kupfer- und schwefelhaltigen Produkten in Kombination mit Gesteinsmehl und effektiven Mikroorganismen bekämpft. Um Alternativen testen zu können, hat das Bundesamt für Landwirtschaft und Ernährung dazu Forschungen finanziell unterstützt. Es wurden rein biologische Mittel und Produkte mit geringerem Kupfergehalt geprüft. Nach dreijähriger Prüfung muss festgestellt werden, dass die rein biologischen Mittel keine Alternative zu den in der Praxis verwendeten kupferhaltigen Produkten sind; auch nicht im Umfeld der Produktionsbedingungen eines Biobetriebes. Ein wichtiger und alljährlich vorkommender Schädling ist die Hopfen-Blattlaus. Zur Bekämpfung wurden die rein pflanzlichen Produkte Spruzit Neu, NeemAzal T/S und Quassia in Versuchsreihen geprüft. Um umweltschonend arbeiten zu können, wurden die Mittel nicht nur gespritzt, sondern auch alternativ an die Reben gestrichen. Es wurde erstmals nachgewiesen, dass der Wirkstoff von Quassia in den Leitungsbahnen der Pflanze nach oben transportiert wird und diese Methode somit zur Blattlausbekämpfung im Hopfen gut geeignet ist

Local measures of fluctuations in inhomogeneous liquids: Statistical mechanics and illustrative applications

We show in detail how three one-body fluctuation profiles, namely the local compressibility, the local thermal susceptibility, and the reduced density, can be obtained from a statistical mechanical many-body description of classical particle-based systems. We present several different and equivalent routes to the definition of each fluctuation profile, facilitating their explicit numerical calculation in inhomogeneous equilibrium systems. This underlying framework is used for the derivation of further properties such as hard wall contact theorems and novel types of inhomogeneous one-body Ornstein-Zernike equations. The practical accessibility of all three fluctuation profiles is exemplified by grand canonical Monte Carlo simulations that we present for hard sphere, Gaussian core and Lennard-Jones fluids in confinement.Comment: 17 pages, 8 figure

DECISION SUPPORT FOR SELECTING AN APPLICATION LANDSCAPE INTEGRATION STRATEGY IN MERGERS AND ACQUISITIONS

Mergers and Acquisitions (M&A) represent a powerful strategic instrument increasingly applied in today\u27s business environment. Besides juridical, financial, and organizational challenges, it is crucial to rapidly integrate the existing application landscapes in order to capitalize the aspired synergies. Literature documents four commonly agreed strategies: \u27best-of-breed\u27, \u27absorption\u27, \u27co-existence\u27, and \u27new-build\u27. However, no consolidated set of criteria exists to ease the selection of an integration strategy most suitable for the merger or the acquisition. Based on the results of a literature study, this paper proposes four integration profiles enabling a structured decision support for selecting the appropriate application landscape strategy during M&A. Each profile comprises relevant driving factors and resulting consequences as selection criteria. The identified literature statements regarding the criteria are validated by means of 12 confirmatory interviews with M&A experts. Furthermore, collected findings from an additional exploratory interview part with the practitioners complement the devised strategy profiles

Toward the low-scatter selection of X-ray clusters : Galaxy cluster detection with eROSITA through cluster outskirts

Context. One key ingredient in using galaxy clusters as a precision cosmological probe in large X-ray surveys is understanding selection effects. The dependence of the X-ray emission on the square of the gas density leads to a predominant role of cool cores in the detection of galaxy clusters. The contribution of cool cores to the X-ray luminosity does not scale with cluster mass and cosmology and therefore affects the use of X-ray clusters in producing cosmological constraints.Aims. One of the main science goals of the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) mission is to constrain cosmology with a wide X-ray survey. We propose an eROSITA galaxy cluster detection scheme that avoids the use of X-ray cluster centers in detection. We calculate theoretical expectations and characterize the performance of this scheme by simulations.Methods. We performed Monte Carlo simulations of the upcoming eROSITA mission, including known foreground and background components. By performing realistic simulations of point sources in survey mode, we searched for spatial scales where the extended signal is not contaminated by the point-source flux. We derive a combination of scales and thresholds, which result in a clean extended source catalog. We designed the output of the cluster detection, which enables calibrating the core-excised luminosity using external mass measurements. We provide a way to incorporate the results of this calibration in producing the final core-excised luminosity.Results. Similarly to other galaxy cluster detection pipelines, we sample the detection space of the flux - cluster core radius of our method and find many similarities with the pipeline used in the 400d survey. Both detection methods require large statistics on compact clusters in order to reduce the contamination from point sources. The benefit of our pipeline consists of the sensitivity to the outer cluster shapes, which are characterized by large core sizes with little cluster to cluster variation at a fixed total mass of the cluster.Conclusions. Galaxy cluster detection through cluster outskirts improves the cluster characterization using eROSITA survey data and is expected to yield well-characterized cluster catalogs with simple selection functions.Peer reviewe

The XXL Survey:XLII. Scatters and correlations of X-ray proxies in the bright XXL cluster sample

http://irfu.cea.fr/xxl/International audienceContext. Scaling relations between cluster properties embody the formation and evolution of cosmic structure. Intrinsic scatters and correlations between X-ray properties are determined from merger history, baryonic processes, and dynamical state.Aims. We look for an unbiased measurement of the scatter covariance matrix among the three main X-ray observable quantities attainable in large X-ray surveys: temperature, luminosity, and gas mass. This also gives us the cluster property with the lowest conditional intrinsic scatter at fixed mass.Methods. Intrinsic scatters and correlations can be measured under the assumption that the observable properties of the intra-cluster medium hosted in clusters are log-normally distributed around power-law scaling relations. The proposed method is self-consistent, based on minimal assumptions, and requires neither external calibration by weak lensing, or dynamical or hydrostatic masses, nor the knowledge of the mass completeness.Results. We analysed the 100 brightest clusters detected in the XXL Survey and their X-ray properties measured within a fixed radius of 300 kpc. The gas mass is the less scattered proxy (∼8%). The temperature (∼20%) is intrinsically less scattered than the luminosity (∼30%), but it is measured with a larger observational uncertainty. We found some evidence that gas mass, temperature, and luminosity are positively correlated. Time evolutions are in agreement with the self-similar scenario, but the luminosity–temperature and the gas mass–temperature relations are steeper.Conclusion. Positive correlations between X-ray properties can be determined by the dynamical state and the merger history of the halos. The slopes of the scaling relations are affected by radiative processes

Processing of Al–12Si–TNM composites by selective laser melting and evaluation of compressive and wear properties

Al-12Si (80 vol%)-Ti52.4Al42.2Nb4.4Mo0.9B0.06 (at.%) (TNM) composites were successfully produced by the selective laser melting (SLM). Detailed structural and microstructural analysis shows the formation of the Al6MoTi intermetallic phase due to the reaction of the TNM reinforcement with the Al-12Si matrix during SLM. Compression tests reveal that the composites exhibit significantly improved properties (∼140 and ∼160 MPa higher yield and ultimate compressive strengths, respectively) compared with the Al-12Si matrix. However, the samples break at ∼6% total strain under compression, thus showing a reduced plasticity of the composites. Sliding wear tests were carried out for both the Al-12Si matrix and the Al-12Si-TNM composites. The composites perform better under sliding wear conditions and the wear rate increases with increasing loads. At high loads, the wear takes place at three different rates and the wear rate decreases with increasing experiment duration