1,331 research outputs found
Investigation of a 2-Colour Undulator FEL Using Puffin
Initial studies of a 2-colour FEL amplifier using one monoenergetic electron
beam are presented. The interaction is modelled using the unaveraged, broadband
FEL code Puffin. A series of undulator modules are tuned to generate two
resonant frequencies along the FEL interaction and a self-consistent 2-colour
FEL interaction at widely spaced non-harmonic wavelengths at 1nm and 2.4nm is
demonstrated.Comment: Submitted to The 35th International Free-Electron Laser Conference,
Manhattan, New York (2013
Development of Prototype Pixellated PIN CdZnTe Detectors
We report initial results from the design and evaluation of two pixellated
PIN Cadmium Zinc Telluride detectors and an ASIC-based readout system. The
prototype imaging PIN detectors consist of 4X4 1.5 mm square indium anode
contacts with 0.2 mm spacing and a solid cathode plane on 10X10 mm CdZnTe
substrates of thickness 2 mm and 5 mm. The detector readout system, based on
low noise preamplifier ASICs, allows for parallel readout of all channels upon
cathode trigger. This prototype is under development for use in future
astrophysical hard X-ray imagers with 10-600 keV energy response. Measurements
of the detector uniformity, spatial resolution, and spectral resolution will be
discussed and compared with a similar pixellated MSM detector. Finally, a
prototype design for a large imaging array is outlined.Comment: 10 pages Latex, 9 figures, to appear in Proc. of SPIE Vol. 3446 "Hard
X-ray and Gamma-Ray Detector Physics and Applications
Big Data Analytics on combining RADAR and optical remote sensing imagery
Remote sensing data is big, which makes it inherently not FAIR, due to the great burden put on the users, for the data to be truly Accessible. In turn, this makes it unfeasible to process data to an Interoperable form. The ESA’s Copernicus program raised the bar for quality data in earth observation satellite sensors ..
The declining share of primary data and the neglect of the individual level in international business research
Complementing Nielsen and colleagues’ (2020) analysis of methodological trends in the Journal of International Business Studies over the past 50 years, we examine similar data on methods published in a wider range of leading international business (IB) journals. Our analysis shows a clear decline of studies based on primary data relative to secondary data, and a persistently low level of individual-level studies among the growing body of research using secondary data across all IB journals considered. We discuss the main mechanisms driving these trends and identify the problems of IB’s increasing exposure to the risks inherent in secondary data. We also discuss the implications related to neglecting individual-level data for theory advancement in IB, such as a disregard for novel secondary data opportunities at the individual level and the risk of reduced theoretical pluralism. In doing so, we substantially extend the debate initiated by Nielsen and colleagues (2020)
Tenacity of Animal Disease Viruses on Wood Surfaces Relevant to Animal Husbandry
The aim of this study was to analyse the hygienic suitability of wood often used in animal husbandry. To this end, the inactivation of viruses (Enterovirus E as a surrogate for non-enveloped viruses and Newcastle disease virus as a surrogate for enveloped viruses) on germ carriers consisting of various types of wood was studied over an extended period to assess the biosafety of wood as an agricultural building material. The study was designed to assess the intrinsic biocidal activity of the wood itself, without the use of a disinfectant. The laboratory tests were based on German test guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (Picea abies), pine (Pinus sylvestris), poplar (Populus sp.), beech (Fagus sylvatica) and Douglas fir (Pseudotsuga menziesii), as well as stainless-steel carriers, were inoculated with enveloped and non-enveloped viruses and stored for up to four months, and the remaining infectivity of the viruses was continuously assessed. The results showed that intact, finely sawn timber with a low depth of roughness had an inactivating effect on the viruses up to 7.5 decadal logarithmic levels. For the non-enveloped virus, inactivation was fastest on Douglas fir wood, with the target reduction for effective inactivation (reduction by factor 4.0 log10) being achieved after two weeks, and for the enveloped virus on pine wood, it was already achieved from the day of drying. The hygienic effects of the wood carriers may be due to their hygroscopic properties and wood constituents. These effects offer potential for further investigation, including tests with other wood species rich in extractives
Efficiency of Virucidal Disinfectants on Wood Surfaces in Animal Husbandry
The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood as a building material in animal husbandry. The laboratory disinfectant efficacy tests were based on German testing guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (Picea abies), pine (Pinus sylvestris), poplar (Populus sp.), beech (Fagus sylvatica) and Douglas fir (Pseudotsuga menziesii), were inoculated with enveloped or non-enveloped viruses and then treated with one of three different disinfectants. The results revealed that intact, fine-sawn timber with a low roughness depth can be effectively inactivated. Peracetic acid proved to be the most effective disinfectant across all tests. Regardless of the pathogen and the type of wood, a concentration of 0.1% of the pure substance at a temperature of 10 °C and an exposure time of one hour can be recommended. At a temperature of −10 °C, a concentration of 0.75% is recommended. The basic chemicals formic acid and glutaraldehyde demonstrated only limited effectiveness overall. The synergistic effects of various wood components on the inactivation of viruses offer potential for further investigation. Disinfectant tests should also be conclusively verified in field trials to ensure that the results from standardised laboratory tests can be transferred to real stable conditions
Transportable setup for amplifier phase fidelity measurements
One possible laser source for the Laser Interferometer Space Antenna (LISA) consists of an Ytterbium-doped fiber amplifier originally developed for inter-satellite communication, seeded by the laser used for the technology demonstrator mission LISA Pathfinder. LISA needs to transmit clock information between its three spacecraft to correct for phase noise between the clocks on the individual spacecraft. For this purpose phase modulation sidebands at GHz frequencies will be imprinted on the laser beams between spacecraft. Differential phase noise between the carrier and a sideband introduced within the optical chain must be very low. We report on a transportable setup to measure the phase fidelity of optical amplifiers.DFG/EXC/QUESTDLR/50OQ1301DLR/50OQ060
Concepts and processing techniques for a global Sentinel 1-3 Land Cover Dynamics and Change (LCDC) product
The present study proposes a concept and a joint processing chain for integrating the ESA’s upcoming Sentinel 1-3 satellites to address the needs from a series of users. The framework considers the advantages of the single Sentinel systems in terms of the spatial, temporal and thematic detail for the generation of a global land cover dynamics and change (LCDC) product. In addition, a calibration and validation plan is discussed and open science issues to fully implement the product have been identified. In order to (i) address key user requirements and (ii) develop concepts and processing techniques for a global LCDC product that go beyond the current state-of-the-art, user requirements and available global state-of-the-art land cover efforts and retrieval approaches of similar nature and their shortcomings were considered
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