561 research outputs found
Plastik in der Offshore-Windbranche - Eintragspotenziale in der deutschen Nordsee
Die anhaltende Plastikverschmutzung der Nordsee ist ein alarmierendes Problem. Sie hat verschiedene Ursachen â einige konnten bereits durch die Forschung identifiziert werden, andere sind
noch unbekannt. Eine aktuelle explorative Studie zeigt, dass auch
Offshore-Windparks, deren Zahl stÀndig weiter zunimmt, eine der
möglichen Eintragsquellen von Plastik darstellen. Unklar war
bisher, in welchen Prozessen der Offshore-Windbranche derartige Eintragspotenziale entstehen. In diesem Beitrag werden sowohl die Bereiche, in welchen Plastik eine Rolle spielt, als auch
die sich daraus ergebenden Eintragspotenziale entlang der gesamten Wertschöpfungskette der Offshore-Windbranche in der
deutschen Nordsee identifiziert. HierfĂŒr wurden semistrukturierte Interviews mit verschiedenen Experten der Branche durchgefĂŒhrt und mithilfe einer Qualitativen Inhaltsanalyse ausgewertet.
Die Ergebnisse zeigen, dass Kunststoffe sowohl in der Fertigung
â insbesondere bei RotorblĂ€ttern â als auch bei den AblĂ€ufen auf
See, z.âB. in Form von Verpackungsmaterialien, vorkommen. Potenzielle Eintragsquellen, sowohl von Makro- als auch von Mikroplastik, liegen vor allem in der Errichtung von Offshore-Windparks und den damit verbundenen Transportprozessen. Eine
Einbringung von Mikroplastik findet speziell durch MaterialabtrĂ€ge der Bauteile von Windenergieanlagen statt. ZukĂŒnftig
könnte der RĂŒckbau von Anlagen zu einer weiteren Quelle werden; wie dieser vonstattengehen soll, ist bislang nicht im Detail
bekannt. Die vorliegende qualitative Untersuchung zeigt, dass
die Offshore-Windbranche Eintragspotenziale sowohl fĂŒr Makro- als auch fĂŒr Mikroplastik vorweist. Quantitative Untersuchungen könnten daran anknĂŒpfen, um das AusmaĂ der PlastikeintrĂ€ge abzuschĂ€tzen.The continuous plastic pollution of the North Sea is an alarming
problem and has various causes â some of them have already
been identified by research, others are still unknown. A recent explorative study shows that offshore wind farms, constantly growing in number, are one of the potential sources of plastic pollution.
However, so far it was unclear in which processes of the offshore
wind industry such potential for input may occur. In this paper,
areas in which plastics play a role as well as the resulting input
potentials along the whole value chain of the offshore wind industry in the German North Sea are identified. For this purpose,
guideline-oriented interviews with various experts in the industry were conducted and evaluated with the help of Qualitative
Content Analysis. Results show that plastics, both macro and micro plastics, can be found in production â especially for rotor
blades â and in processes at sea, e.g. in the form of packaging
materials. Potential sources of input mainly lie in the construction phase of offshore wind farms and associated transport processes. Particularly, microplastics are introduced by the abrasion
of material from the wind turbinesâ parts. In the future, decommissioning activities may become an additional source of pollution. How these will be carried out is not known in detail yet. The
present qualitative study shows that the offshore wind industry
has input potentials for both macro- and microplastics. Quantitative studies could pick up at this point to explore the extent of
these plastic inputs
Metamaterial near-field sensor for deep-subwavelength thickness measurements and sensitive refractometry in the terahertz frequency range
We present a metamaterial-based terahertz (THz) sensor for thickness
measurements of subwavelength-thin materials and refractometry of liquids and
liquid mixtures. The sensor operates in reflection geometry and exploits the
frequency shift of a sharp Fano resonance minimum in the presence of dielectric
materials. We obtained a minimum thickness resolution of 12.5 nm (1/16000 times
the wavelength of the THz radiation) and a refractive index sensitivity of 0.43
THz per refractive index unit. We support the experimental results by an
analytical model that describes the dependence of the resonance frequency on
the sample material thickness and the refractive index.Comment: 10 pages, 5 figure
Early Dynamics of Cerebrospinal CD14+ Monocytes and CD15+ Granulocytes in Patients after Severe Traumatic Brain Injury: A Cohort Study
In traumatic brain injury (TBI) the analysis of neuroinflammatory mechanisms gained increasing interest. In this context certain immunocompetent cells might play an important role. Interestingly, in the actual literature there exist only a few studies focusing on the role of monocytes and granulocytes in TBI patients. In this regard it has recently reported that the choroid plexus represents an early, selective barrier for leukocytes after brain injury. Therefore the aim of this study was to evaluate the very early dynamics of CD14+ monocytes and CD15+ granulocyte in CSF of patients following severe TBI with regard to the integrity of the BBB. Cytometric flow analysis was performed to analyze the CD14+ monocyte and CD15+ granulocyte population in CSF of TBI patients. The ratio of CSF and serum albumin as a measure for the BBB's integrity was assessed in parallel. CSF samples of patients receiving lumbar puncture for elective surgery were obtained as controls. Overall 15 patients following severe TBI were enrolled. 10 patients were examined as controls. In patients, the monocyte population as well as the granulocyte population was significantly increased within 72 hours after TBI. The BBB's integrity did not have a significant influence on the cell count in the CSF
Quantitative Histomorphometry of the Healthy Peritoneum
The peritoneum plays an essential role in preventing abdominal frictions and
adhesions and can be utilized as a dialysis membrane. Its physiological
ultrastructure, however, has not yet been studied systematically. 106
standardized peritoneal and 69 omental specimens were obtained from 107
patients (0.1â60 years) undergoing surgery for disease not affecting the
peritoneum for automated quantitative histomorphometry and
immunohistochemistry. The mesothelial cell layer morphology and protein
expression pattern is similar across all age groups. Infants below one year
have a thinner submesothelium; inflammation, profibrotic activity and
mesothelial cell translocation is largely absent in all age groups. Peritoneal
blood capillaries, lymphatics and nerve fibers locate in three distinct
submesothelial layers. Blood vessel density and endothelial surface area
follow a U-shaped curve with highest values in infants below one year and
lowest values in children aged 7â12 years. Lymphatic vessel density is much
lower, and again highest in infants. Omental blood capillary density
correlates with parietal peritoneal findings, whereas only few lymphatic
vessels are present. The healthy peritoneum exhibits major thus far unknown
particularities, pertaining to functionally relevant structures, and subject
to substantial changes with age. The reference ranges established here provide
a framework for future histomorphometric analyses and peritoneal transport
modeling approaches
Prediction of RECRUITment In randomized clinical Trials (RECRUIT-IT)â : ârationale and design for an international collaborative study
Funding: BK has received a project specific grant from the University of Basel to realize this project. In addition, this study is supported by the Swiss National Science Foundation (grant 320030_149496/1) and the Gottfried and Julia Bangerter-Rhyner Foundation. The provided work by BG, JHL, CW, and JY has been supported by the National Cancer Institute Cancer Centre Support Grant P30 CA168524 and used BISR core. The Health Services Research Unit, University of Aberdeen, receives core funding from the Chief Scientist Office of the Scottish Government Health Directorates. DC is supported by a Research Chair from the Canadian Institute for Health Research. The mentioned funding sources have no role in the design and conduct of the study; the collection, management, analysis, and interpretation of the data; the preparation, review, or approval of the manuscript; or the decision to submit the manuscript for publication.Peer reviewedPublisher PD
Development of LGAD sensors with a thin entrance window for soft X-ray detection
We show the developments carried out to improve the silicon sensor technology
for the detection of soft X-rays with hybrid X-ray detectors. An optimization
of the entrance window technology is required to improve the quantum
efficiency. The LGAD technology can be used to amplify the signal generated by
the X-rays and to increase the signal-to-noise ratio, making single photon
resolution in the soft X-ray energy range possible. In this paper, we report
first results obtained from an LGAD sensor production with an optimized thin
entrance window. Single photon detection of soft X-rays down to 452~eV has been
demonstrated from measurements, with a signal-to-noise ratio better than 20.Comment: 10 pages, 6 figure
Characterization of iLGADs using soft X-rays
Experiments at synchrotron radiation sources and X-ray Free-Electron Lasers
in the soft X-ray energy range (eV--keV) stand to benefit from the
adaptation of the hybrid silicon detector technology for low energy photons.
Inverse Low Gain Avalanche Diode (iLGAD) sensors provide an internal gain,
enhancing the signal-to-noise ratio and allowing single photon detection below
keV using hybrid detectors. In addition, an optimization of the entrance
window of these sensors enhances their quantum efficiency (QE). In this work,
the QE and the gain of a batch of different iLGAD diodes with optimized
entrance windows were characterized using soft X-rays at the
Surface/Interface:Microscopy beamline of the Swiss Light Source synchrotron.
Above eV, the QE is larger than for all sensor variations, while
the charge collection efficiency is close to . The average gain depends
on the gain layer design of the iLGADs and increases with photon energy. A
fitting procedure is introduced to extract the multiplication factor as a
function of the absorption depth of X-ray photons inside the sensors. In
particular, the multiplication factors for electron- and hole-triggered
avalanches are estimated, corresponding to photon absorption beyond or before
the gain layer, respectively.Comment: 16 pages, 8 figure
First operation of the JUNGFRAU detector in 16-memory cell mode at European XFEL
The JUNGFRAU detector is a well-established hybrid pixel detector developed at the Paul Scherrer Institut (PSI) designed for free-electron laser (FEL) applications. JUNGFRAU features a charge-integrating dynamic gain switching architecture, with three different gain stages and 75Â ÎŒm pixel pitch. It is widely used at the European X-ray Free-Electron Laser (EuXFEL), a facility which produces high brilliance X-ray pulses at MHz repetition rate in the form of bursts repeating at 10Â Hz. In nominal configuration, the detector utilizes only a single memory cell and supports data acquisition up to 2Â kHz. This constrains the operation of the detector to a 10Â Hz frame rate when combined with the pulsed train structure of the EuXFEL. When configured in so-called burst mode, the JUNGFRAU detector can acquire a series of images into sixteen memory cells at a maximum rate of around 150Â kHz. This acquisition scheme is better suited for the time structure of the X-rays as well as the pump laser pulses at the EuXFEL. To ensure confidence in the use of the burst mode at EuXFEL, a wide range of measurements have been performed to characterize the detector, especially to validate the detector alibration procedures. In particular, by analyzing the detector response to varying photon intensity (so called âintensity scanâ), special attention was given to the characterization of the transitions between gain stages. The detector was operated in both dynamic gain switching and fixed gain modes. Results of these measurements indicate difficulties in the characterization of the detector dynamic gain switching response while operated in burst mode, while no major issues have been found with fixed gain operation. Based on this outcome, fixed gain operation mode with all the memory cells was used during two experiments at EuXFEL, namely in serial femtosecond protein crystallography and Kossel lines measurements. The positive outcome of these two experiments validates the good results previously obtained, and opens the possibility for a wider usage of the detector in burst operation mode, although compromises are needed on the dynamic range
Differential cross section measurements for the production of a W boson in association with jets in protonâproton collisions at âs = 7 TeV
Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript â1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
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