The springtail cuticle as a blueprint for omniphobic surfaces

Omniphobic surfaces found in nature have great potential for enabling novel and emerging products and technologies to facilitate the daily life of human societies. One example is the water and even oil-repellent cuticle of springtails (Collembola). The wingless arthropods evolved a highly textured, hierarchically arranged surface pattern that affords mechanical robustness and wetting resistance even at elevated hydrostatic pressures. Springtail cuticle-derived surfaces therefore promise to overcome limitations of lotus-inspired surfaces (low durability, insufficient repellence of low surface tension liquids). In this review, we report on the liquid-repellent natural surfaces of arthropods living in aqueous or temporarily flooded habitats including water-walking insects or water spiders. In particular, we focus on springtails presenting an overview on the cuticular morphology and chemistry and their biological relevance. Based on the obtained liquid repellence of a variety of liquids with remarkable efficiency, the review provides general design criteria for robust omniphobic surfaces. In particular, the resistance against complete wetting and the mechanical stability strongly both depend on the topographical features of the nano- and micropatterned surface. The current understanding of the underlying principles and approaches to their technological implementation are summarized and discussed

In Situ Experiments To Reveal the Role of Surface Feature Sidewalls in the Cassie–Wenzel Transition

Waterproof and self-cleaning surfaces continue to attract much attention as they can be instrumental in various different technologies. Such surfaces are typically rough, allowing liquids to contact only the outermost tops of their asperities, with air being entrapped underneath. The formed solid–liquid–air interface is metastable and, hence, can be forced into a completely wetted solid surface. A detailed understanding of the wetting barrier and the dynamics of this transition is critically important for the practical use of the related surfaces. Toward this aim, wetting transitions were studied in situ at a set of patterned perfluoropolyether dimethacrylate (PFPEdma) polymer surfaces exhibiting surface features with different types of sidewall profiles. PFPEdma is intrinsically hydrophobic and exhibits a refractive index very similar to water. Upon immersion of the patterned surfaces into water, incident light was differently scattered at the solid–liquid–air and solid–liquid interface, which allows for distinguishing between both wetting states by dark-field microscopy. The wetting transition observed with this methodology was found to be determined by the sidewall profiles of the patterned structures. Partial recovery of the wetting was demonstrated to be induced by abrupt and continuous pressure reductions. A theoretical model based on Laplace’s law was developed and applied, allowing for the analytical calculation of the transition barrier and the potential to revert the wetting upon pressure reduction

Körnerleguminosen und Bodenfruchtbarkeit - Strategien für einen erfolgreichen Anbau

Der Boden ist eine der wichtigsten Grundlagen unseres Lebens, das erkannte bereits der Bodenkundler und Jurist Friedrich Albert Fallou. Um der großen Bedeutung des Bodens gerecht zu werden, schrieb das „Bundesprogramm Ökologischer Landbau und andere Formen nachhaltiger Landwirtschaft“ (BÖLN*) eine interdisziplinäre Bekanntmachung aus, um praxisnahe Anbaustrategien zu entwickeln, um die Bodenfruchtbarkeit und Pflanzenernährung im Körnerleguminosenanbau zu verbessern. So wurde das interdisziplinäre Bodenfruchtbarkeitsprojekt ins Leben gerufen, in dem Wissenschaft, Beratung und Praxis eng verzahnt waren. Im Laufe des fünfjährigen Projektes kristallisierten sich viele praxisrelevante Erkenntnisse heraus, die nun in der Praxisbroschüre "Körnerleguminosen und Bodenfruchtbarkeit - Strategien für einen erfolgreichen Anbau" nachgelesen werden können

Steigerung der Wertschöpfung ökologisch angebauter Marktfrüchte durch Optimierung des Managements der Bodenfruchtbarkeit

Das interdisziplinäre Bodenfruchtbarkeitsprojekt beschäftigte sich in vier Versuchs- und fünf Projektjahren mit den Zusammenhängen zwischen dem Anbau von Körnerleguminosen und Bodenfruchtbarkeit, insbesondere auf viehschwachen bzw. viehlosen Biobetrieben. In Erhebungen auf 32 Praxisbetrieben konnten bislang allenfalls vermutete Zusammenhänge wie z. B. die Zunahme des Unkrautdeckungsgrades mit zunehmendem Humusgehalt bestätigt werden. Die Ergebnisse deuten auch darauf hin, dass z. B. die Anbauabstände im Erbsenanbau im Vergleich zu praxisüblichen Empfehlungen vergrößert werden müssen, daneben ergaben sich auch interessante neue Anknüpfungspunkte. Hinsichtlich der Leguminosengesundheit ermöglicht die neu entwickelte Differenzialdiagnose, die Ursache für ggf. auftretende „Leguminosenmüdigkeit“ einzugrenzen bzw. Praxisschläge vor dem Anbau auf Krankheitsrisiken zu testen. Im Projekt konnte außerdem gezeigt werden, dass Grüngutkomposte die Wurzelgesundheit von Erbsen deutlich verbessern können. Es wurden darüber hinaus verschiedene Methoden zur Kompostapplikation zu Körnerleguminosen geprüft und für den Praxiseinsatz optimiert. Neben Grüngutkomposten spielt auch Grünguthäcksel eine wichtige Rolle bei der Nährstoffversorgung von Leguminosen. Oberflächlich leicht eingearbeiteter Grünguthäcksel ist in der Lage, das Wachstum der Kulturpflanzen sowohl durch eine unkrautunterdrückende Wirkung als auch durch Schutz vor Verschlämmung sowie erhöhte Wasserinfiltrationsraten zu verbessern. Die Ergebnisse zum Landtechnikeinsatz zeigen, dass schon geringe Belastungen zu Bodenverdichtungen und damit zu Ertragsrückgängen in Erbsen führen, weshalb Maßnahmen zu Reduzierung des Bodendrucks essenziell sind. Hinsichtlich der beikrautunterdrückenden Wirkung des Gemengeanbaus von Erbsen in Kombination mit Hafer konnte gezeigt werden, dass der Gemengeanbau das erhöhte Beikrautaufkommen bei flachwendender Bodenbearbeitung erfolgreich ausgleichen kann und hinsichtlich der Ertragssicherheit Vorteile mit sich bringt. Nicht zuletzt machte das Projekt auf die Vorteile und Potenziale des Wintererbsenanbaus aufmerksam. Über einen fortlaufenden Wissenstransfer war das Projekt von Beginn an in der landwirtschaftlichen Praxis präsent

Reallabor Asylsuchende in der Rhein-Neckar-Region: Vielfalt an Problemen - Vielfalt an Lösungen

Deutschland steht vor der Aufgabe, viele Geflüchtete unterzubringen und ihnen neue Lebensperspektiven zu eröffnen. Die Menschen, die in den vergangenen Jahren gekommen sind, um Schutz zu suchen, sind keine homogene Gruppe. Sie unterscheiden sich nach Geschlecht, Alter, Herkunft, kulturellem Hintergrund, Bildung, Arbeitserfahrung, Sprachkompetenz, Migrations- und Fluchterfahrung, Zukunftsentwürfen und vielerlei mehr. Standardmaßnahmen für alle laufen so oftmals ins Leere, Ressourcen werden schlecht genutzt und Chancen verschenkt

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector

Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results