Search results for "ddc:540"
showing 10 items of 212 documents
The next-generation liquid-scintillator neutrino observatory LENA
2012
We propose the liquid-scintillator detector LENA (Low Energy Neutrino Astronomy) as a next-generation neutrino observatory on the scale of 50 kt. The outstanding successes of the Borexino and KamLAND experiments demonstrate the large potential of liquid-scintillator detectors in low-energy neutrino physics. LENA's physics objectives comprise the observation of astrophysical and terrestrial neutrino sources as well as the investigation of neutrino oscillations. In the GeV energy range, the search for proton decay and long-baseline neutrino oscillation experiments complement the low-energy program. Based on the considerable expertise present in European and international research groups, the …
Neutron tomography of ancient lead artefacts
2014
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich. This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. The investigations presented here show the results of an epigraphic analysis on ancient Roman lead ingots rescued from shipwrecks along the coast of Sicily (Italy) by means of Neutron Tomography (NT). The artefacts, including a lead horn, can be dated back to a period between the 3rd and 1st century BC. The three dimensional NT reconstructions helped the decipherment of hidden s…
Nucleation and crystal growth in a suspension of charged colloidal silica spheres with bi-modal size distribution studied by time-resolved ultra-smal…
2014
A suspension of charged colloidal silica spheres exhibiting a bi-modal size distribution of particles, thereby mimicking a binary mixture, was studied using time-resolved ultra-small-angle synchrotron X-ray scattering (USAXS). The sample, consisting of particles of diameters d(A) = (104.7 ± 9.0) nm and d(B) = (88.1 ± 7.8) nm (d(A)/d(B) ≈ 1.2), and with an estimated composition A(0.6(1))B(0.4(1)), was studied with respect to its phase behaviour in dependance of particle number density and interaction, of which the latter was modulated by varying amounts of added base (NaOH). Moreover, its short-range order in the fluid state and its eventual solidification into a long-range ordered colloidal…
A fast algorithm for muon track reconstruction and its application to the ANTARES neutrino telescope.
2011
An algorithm is presented, that provides a fast and robust reconstruction of neutrino induced upward-going muons and a discrimination of these events from downward-going atmospheric muon background in data collected by the ANTARES neutrino telescope. The algorithm consists of a hit merging and hit selection procedure followed by fitting steps for a track hypothesis and a point-like light source. It is particularly well-suited for real time applications such as online monitoring and fast triggering of optical follow-up observations for multi-messenger studies. The performance of the algorithm is evaluated with Monte Carlo simulations and various distributions are compared with that obtained …
Few-layer Black Phosphorous Catalyzes Radical Additions to Alkenes Faster than Low-valence Metals
2020
Abstract The substitution of catalytic metals by p‐block main elements has a tremendous impact not only in the fundamentals but also in the economic and ecological fingerprint of organic reactions. Here we show that few‐layer black phosphorous (FL‐BP), a recently discovered and now readily available 2D material, catalyzes different radical additions to alkenes with an initial turnover frequency (TOF0) up to two orders of magnitude higher than representative state‐of‐the‐art metal complex catalysts at room temperature. The corresponding electron‐rich BP intercalation compound (BPIC) KP6 shows a nearly twice TOF0 increase with respect to FL‐BP. This increase in catalytic activity respect to t…
The energy spectrum of atmospheric neutrinos between 2 and 200 TeV with the AMANDA-II detector
2010
The muon and anti-muon neutrino energy spectrum is determined from 2000-2003 AMANDA telescope data using regularised unfolding. This is the first measurement of atmospheric neutrinos in the energy range 2 - 200 TeV. The result is compared to different atmospheric neutrino models and it is compatible with the atmospheric neutrinos from pion and kaon decays. No significant contribution from charm hadron decays or extraterrestrial neutrinos is detected. The capabilities to improve the measurement of the neutrino spectrum with the successor experiment IceCube are discussed.
Identification of binding peptides on calcium silicate hydrate: a novel view on cement additives.
2014
Cement is the most used industrial product in the world. Although the chemical composition of the material has stayed more or less the same since its discovery by the Romans around 2000 years ago, [ 1 ] the performance has been increased by chemical additives. Spectacular buildings like the Willis Tower in Chicago, Taipei 101 or lately the over 800 m high Burj Khalifa in Dubai were realizable thanks to the development of high performance building materials. [ 2 ] Not only for such prestige objects but also in daily building processes, the trend goes towards always higher buildings because of the continued urbanization which was identifi ed already in 1982 as one of the so-called “megatrends…
Phase Stability of Lanthanum Orthovanadate at High Pressure
2016
The journal of physical chemistry / C 120(25), 13749 - 13762(2016). doi:10.1021/acs.jpcc.6b04782
Cooperative phenomena and light-induced bistability in iron(II) spin-crossover compounds
1999
In iron(II) spin-crossover compounds, the transition from the 1A1 low-spin state at low temperatures to the 5T2 high-spin state at elevated temperatures is accompanied by a large increase in metal-ligand bond lengths. The resulting elastic interactions may be pictured as an internal pressure which is proportional to the concentration of the low-spin species. Because pressure stabilises the low-spin state relative to the high-spin state this results in a positive feedback. Thermal transition curves in neat iron(II) spin-crossover compounds are thus invariable much steeper than in diluted mixed crystals, and the high-spin→low-spin relaxation following the light-induced population of the high-…
NMR enantiodifferentiation of triphenylphosphonium salts by chiral hexacoordinated phosphate anions
2003
BINPHAT anion—rather than TRISPHAT—is an efficient NMR chiral shift reagent for triphenylphosphonium salts containing stereogenic centers on the aliphatic side-chain. BINPHAT—rather than TRISPHAT—anion is an efficient NMR (1H and 31P) chiral shift reagent for chiral triphenylphosphonium salts.