Search results for "Experiments"
showing 10 items of 435 documents
Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory
2011
The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies $E>E_{th}=5.5\times 10^{19}$ eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at $E>E_{th}$ are heavy nuclei with charge $Z$, the proton component of the sources should lead to excesses in the same regions at energies $E/Z$. We here report the lack of anisotropies in these directions at energies above $E_{th}/Z$ (for illustrative values of $Z=6,\ 13,\ 26$). If the anisotropies above $E_{th}$ are du…
Age affects myosin relaxation states in skeletal muscle fibers of female but not male mice
2018
The recent discovery that myosin has two distinct states in relaxed muscle–disordered relaxed (DRX) and super-relaxed (SRX)–provides another factor to consider in our fundamental understanding of the aging mechanism in skeletal muscle, since myosin is thought to be a potential contributor to dynapenia (age-associated loss of muscle strength independent of atrophy). The primary goal of this study was to determine the effects of age on DRX and SRX states and to examine their sex specificity. We have used quantitative fluorescence microscopy of the fluorescent nucleotide analog 2′/3′-O-(N-methylanthraniloyl) ATP (mantATP) to measure single-nucleotide turnover kinetics of myosin in skinned skel…
The Relevance of Mineral Mobilization and -Dissolution on the Reservoir Quality of Sandstones in CO2 Storage Sites
2014
Abstract Rotliegend siliciclastic formations are important reservoirs in central Europe. These sediments consist of pristine red coloured and bleached, high porous and permeable sandstones. To evaluate the relevance of distinct fluids and their fluid-rock alteration reactions on such bleaching processes laboratory static batch experiments under reservoir conditions were conducted. Thereby mineralogical, petrophysical and (hydro-, geo-) chemical rock features were investigated by different analytical methods before and after the experiments. The achieved results suggest that during such fluid-rock interactions a complex interplay between mineral detachment and mineral dissolution processes w…
Development of a new indole derivative dry powder for inhalation for the treatment of biofilm-associated lung infections
2022
The aim of this work was to produce an inhalable dry powder formulation of a new anti-biofilm compound (SC38). For this purpose, chitosan was used as a polymeric carrier and l-leucine as a dispersibility enhancer. SC38 was entrapped by spray-drying into previously optimized chitosan microparticles. The final formulation was fully characterized in vitro in terms of particle morphology, particle size and distribution, flowability, aerodynamic properties, anti-biofilm activity and effects on lung cell viability. The SC38-loaded chitosan microparticles exhibited favorable aerodynamic properties with emitted and respirable fractions higher than 80 % and 45 % respectively. The optimized formulati…
A versatile mechanized setup for controlled experiments in archeology
2020
Experimentation has always played an important role in archeology, in particular to create reference collections for use-wear studies. Different types of experiments can answer different questions; all types should therefore be combined to obtain a holistic view. In controlled experiments, some factors are tested, while the other factors are kept constant to improve the signal-to-noise ratio. Yet, controlled experiments have been conducted with variable degrees of control. Although they seem decoupled from archeological applications, mechanized experiments and the robust causal relationships they measure are critical to answer archeological questions like understanding the processes of use-…
Using mechanical experiments to study ground stone tool use: Exploring the formation of percussive and grinding wear traces on limestone tools
2021
Ground Stone Tools (GST) have been identified in several Levantine archaeological sites dating to the Middle Paleolithic. These tools, frequently made of limestone, are often interpreted based on their morphology and damage as having been used for knapping flint, and sometimes for breaking animal bones or processing vegetal materials as well. However, the lack of experimental referential collections on limestone is a major obstacle for the identification of diagnostic traces on these types of tools and raw material. In this sense, the understanding of the specific function of these GST and the association between tool types and activity often remains unknown or merely speculative. Recent di…
Reconstruction of inclined air showers detected with the Pierre Auger Observatory
2014
We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than $60^\circ$ detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an…
A first search for coincident gravitational waves and high energy neutrinos using LIGO, Virgo and ANTARES data from 2007
2013
A search for high-energy neutrinos coming from the direction of the Sun has been performed using the data recorded by the ANTARES neutrino telescope during 2007 and 2008. The neutrino selection criteria have been chosen to maximize the selection of possible signals produced by the self-annihilation of weakly interacting massive particles accumulated in the centre of the Sun with respect to the atmospheric background. After data unblinding, the number of neutrinos observed towards the Sun was found to be compatible with background expectations. The 90% CL upper limits in terms of spin-dependent and spin-independent WIMP-proton cross-sections are derived and compared to predictions of two sup…
First search for neutrinos in correlation with gamma-ray bursts with the ANTARES neutrino telescope
2013
A search for neutrino-induced muons in correlation with a selection of 40 gamma-ray bursts that occurred in 2007 has been performed with the ANTARES neutrino telescope. During that period, the detector consisted of 5 detection lines. The ANTARES neutrino telescope is sensitive to TeV-PeV neutrinos that are predicted from gamma-ray bursts. No events were found in correlation with the prompt photon emission of the gamma-ray bursts and upper limits have been placed on the flux and fluence of neutrinos for different models.
Ultrahigh energy neutrinos in the Mediterranean: Detecting ντ and νμ with a km3 telescope
2007
23 pages, 13 figures.-- PACS nrs.: 95.85.Ry, 95.55.Vj, 13.15.+g.-- ISI Article Identifier: 000245928000025.-- ArXiv pre-print available at: http://arxiv.org/abs/astro-ph/0609241