2,220 research outputs found
A Smart Pixel Camera for future Cherenkov Telescopes
The Smart Pixel Camera is a new camera for imaging atmospheric Cherenkov
telescopes, suited for a next generation of large multi-telescope ground based
gamma-ray observatories. The design of the camera foresees all electronics
needed to process the images to be located inside the camera body at the focal
plane. The camera has a modular design and is scalable in the number of pixels.
The camera electronics provides the performance needed for the next generation
instruments, like short signal integration time, topological trigger and short
trigger gate, and at the same time the design is optimized to minimize the cost
per channel. In addition new features are implemented, like the measurement of
the arrival time of light pulses in the pixels on the few hundred psec
timescale. The buffered readout system of the camera allows to take images at
sustained rates of O(10 kHz) with a dead-time of only about 0.8 % per kHz.Comment: 8 pages, 5 figures; to appear in the proceedings of "Towards a
Network of Atmospheric Cherenkov Detectors VII", 2005, Palaiseau, Franc
Analysis of H.E.S.S. Data on the Supernova Remnants Kepler's SNR, Vela Junior and SN1006 and The Smart Pixel Camera: A Camera for Future Cherenkov Telescopes
One of the most violent events in our Universe is the death of a star in a supernova. The remnants of these supernovae are believed to be sources of the Galactic cosmic rays (CRs). However, it is still an open question which processes take place in the production of CRs. The CRs itself arrive isotropically on Earth, as they get deflected by interstellar magnetic fields. To study the acceleration regions of CRs, gamma rays which are produced in the vicinity of these regions are observed. In the very-high-energy waveband these gamma rays are detected with Imaging Atmospheric Cherenkov Telescopes making use of the atmosphere as a part of the detector. To date the H.E.S.S. experiment is the most sensitive telescope array in this field. In this work the analysis of H.E.S.S. data from three supernova remnants is presented and it is shown that two of them emit very-high-energy gamma rays. In the second part of this work a new type of camera for future arrays containing of multiple Imaging Atmospheric Cherenkov Telescopes is presented. It is shown that this camera is well-suited to be operated in such telescopes
Scoliosis correction with pedicle screws in Duchenne muscular dystrophy
This report describes the spinal fixation with pedicle-screw-alone constructs for the posterior correction of scoliosis in patients suffering from Duchene muscular dystrophy (DMD). Twenty consecutive patients were prospectively followed up for an average of 5.2years (min 2years). All patients were instrumented from T3/T4 to the pelvis. Pelvic fixation was done with iliac screws similar to Galveston technique. The combination of L5 pedicle screws and iliac screws provided a stable caudal foundation. An average of 16 pedicle screws was used per patient. The mean total blood loss was 3.7l, stay at the intensive care unit was 77h and hospital stay was 19days. Rigid stabilisation allowed immediate mobilisation of the patient in the wheel chair. Cobb angle improved 77% from 44° to 10°, pelvic tilt improved 65% from 14° to 3°. Lumbar lordosis improved significantly from 20° to 49°, thoracic kyphosis remained unchanged. No problems related to iliac fixation, no pseudarthrosis or implant failures were observed. The average percentage of predicted forced vital capacity (%FVC) of the patients was 55% (22-94%) preoperatively and decreased to 44% at the last follow-up. There were no pulmonary complications. One patient with a known cardiomyopathy died intraoperatively due to a sudden cardiac arrest. The rigid primary stability with pedicle screws allowed early mobilisation of the patients, which helped to avoid pulmonary complication
N-{4-[4-(4-FluoroÂphenÂyl)-1-methyl-2-[(R)-methylÂsulfinÂyl]-1H-imidazol-5-yl]-2-pyridyl}acetamide dihydrate
In the crystal structure of the title compound, C18H17FN4O2S¡2H2O, the organic molÂecules are linked by interÂmolecular OâHâŻO, OâHâŻN and NâHâŻO hydrogen bonds with the water molÂecules, generating a three-dimensional network. The imidazole ring system forms a dihedral angle of 24.9â
(2)° with the 4-fluoroÂphenyl ring. The pyridine ring is oriented approximately perpendicular [72.24â
(8)°] to the imidazole ring system
Probabilistic and semi-probabilistic analysis of slender columns frequently used in structural engineering
The stability of slender columns is a topic that has been dealt with in research and practice for many years. The importance of this topic also increases with the possibility of using non-linear modeling approaches to determine the stability and with the increasingly complex safety formats. In order to show the complexity and the variability associated with the non-linear models, two previous contributions discussed and compared (a) the results of the Round Robin Non-Linear Modeling, and (b) the existing international associated standard specifications and safety concepts with respect to experimental results. The aim herein is to determine the reliability level (safety index) on the basis of these investigations and findings and to examine the existing safety formats of classical and extended probabilistic analyses and to derive any necessary adjustments. In addition, the method of the safety format Estimation of Coefficient of Variance of resistance (ECOV) is used for the determination of the global safety resistance factors based on the non-linear analysesâ findings of the Round Robin modeling partners.This paper describes work mainly carried out during IABSE activities. The authors would like to acknowledge IABSE Commission 1 for supporting this project, the authors acknowledge the financial support provided by the Interreg project ATCZ190 SAFEBRIDGE. The authors also gratefully acknowledge Scientific Grant Agency of the Ministry of Education. This work was supported by the Slovak Research and Development Agency under the contract No. APVV-150658. The authors also would like to express their thanks for the support provided from the Czech Science Foundation project MUFRAS No. 19-09491S. In addition, this work was partly financed by: (1) national funds through the Foundation for Science and Technology (FCT) under Grant No. PD/BD/143003/2018 attributed to the seventh author; and (2) FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under Reference UIDB/04029/2020
SIGLEC1 (CD169): a marker of active neuroinflammation in the brain but not in the blood of multiple sclerosis patients
We aimed to evaluate SIGLEC1 (CD169) as a biomarker in multiple sclerosis (MS) and Neuromyelitis optica spectrum disorder (NMOSD) and to evaluate the presence of SIGLEC1(+) myeloid cells in demyelinating diseases. We performed flow cytometry-based measurements of SIGLEC1 expression on monocytes in 86 MS patients, 41 NMOSD patients and 31 healthy controls. Additionally, we histologically evaluated the presence of SIGLEC1(+) myeloid cells in acute and chronic MS brain lesions as well as other neurological diseases. We found elevated SIGLEC1 expression in 16/86 (18.6%) MS patients and 4/41 (9.8%) NMOSD patients. Almost all MS patients with high SIGLEC1 levels received exogenous interferon beta as an immunomodulatory treatment and only a small fraction of MS patients without interferon treatment had increased SIGLEC1 expression. In our cohort, SIGLEC1 expression on monocytes was-apart from those patients receiving interferon treatment-not significantly increased in patients with MS and NMOSD, nor were levels associated with more severe disease. SIGLEC1(+) myeloid cells were abundantly present in active MS lesions as well as in a range of acute infectious and malignant diseases of the central nervous system, but not chronic MS lesions. The presence of SIGLEC1(+) myeloid cells in brain lesions could be used to investigate the activity in an inflammatory CNS lesion
Round-Robin modelling of the load-bearing capacity of slender columns by using classical and advanced non-linear numerical and analytical prediction tools
Non-linear finite element analyses have intrinsic model and user factors that influence the results of the analyses. However, non-linear finite element analysis can provide a tool to assess safety using realistic descriptions of material behaviour with actual material properties. A realistic estimation of the existing safety and capacity of slender column elements can be achieved by means of "true" material properties. Nevertheless, it seems that for some structural components, such as slender columns, non-linear finite element analyses can, due to its complexity and its various setting parameters, cause the risk of overestimating the real performance of analysed components or systems. Hence, an invited expert group has carried out an investigation into the experimental testing and the prediction of the bearing capacity of slender columns by performing independent non-linear finite element analyses in order to determine the practical applicability, and its inconsistencies, with respect to the stability failure of slender columns. This work aims the characterization of modelling uncertainties, concerning the prediction of slender columns stability when forecasted by non-linear finite element analysis.This paper was partly carried out during research exchanges at TU Brno (BUT), Lehigh University (LU). The authors acknowledge also the financial support provided by the SAFEBRIDGE ATCZ190 EU Interreg project, the Scientific Grant Agency of the Ministry of Education of Slovak Republic, the Slovak Academy of Sciences VEGA No. 1/0696/14, and Slovak Research and Development Agency under the contract No. APVV-150658. The computational results presented have been achieved [in part] using the Vienna Scientific Cluster (VSC)
Electricity, Heat, and Gas Sector Data for Modeling the German System
Diese Dokumentation beschreibt Daten zum deutschen Strom- Wärme- und Gassektor und ermĂśglicht eine modellgestĂźtzte Abbildung dieser Energiesysteme. Die Aufbereitung der Daten erfolgte im Rahmen des vom BMWi gefĂśrderten Forschungsprojekts LKD-EU (Langfristige Planung und kurzfristige Optimierung des Elektrizitätssystems in Deutschland im europäischen Kontext, FKZ 03ET4028C). In Zusammenarbeit mit dem Deutschen Institut fĂźr Wirtschaftsforschung (DIW), der Arbeitsgruppe Wirtschafts- und Infrastrukturpolitik (WIP) der Technischen Universität Berlin (TUB), dem Lehrstuhl fĂźr Energiewirtschaft (EE2), der Technischen Universität Dresden (TUD) und dem House of Energy Markets & Finance der Universität Duisburg-Essen (UDE). Ziel des Dokumentes ist es, Referenzdaten zur VerfĂźgung zu stellen, die den aktuellen Zustand des deutschen Energiesystems repräsentieren. Das Bezugsjahr ist 2015. Diese Dokumentation trägt dazu bei, die Transparenz in der VerfĂźgbarkeit von Daten zum deutschen Energiesystem zu erhĂśhen.This data documentation describes a data set of the German electricity, heat, and natural gas sectors compiled within the research project âLKD-EUâ (Long-term planning and short-term optimization of the German electricity system within the European framework: Further development of methods and models to analyze the electricity system including the heat and gas sector). The project is a joined effort by the German Institute for Economic Research (DIW Berlin), the Workgroup for Infrastructure Policy (WIP) at Technische Universität Berlin (TUB), the Chair of Energy Economics (EE2) at Technische Universität Dresden (TUD), and the House of Energy Markets & Finance at University of Duisburg-Essen. The project was funded by the German Federal Ministry for Economic Affairs and Energy through the grant âLKD-EUâ, FKZ 03ET4028A. The objective of this paper is to document a reference data set representing the status quo of the German energy sector. We also update and extend parts of the previous DIW Data Documentation 75 (Egerer et al. 2014). While the focus is on the electricity sector, the heat and natural gas sectors are covered as well. With this reference data set, we aim to increase the transparency of energy infrastructure data in Germany. On the one hand, this documentation presents sources of original data and information used for the data set. On the other hand, it elaborates on the methodologies which have been applied to derive the data from respective sources in order to make it useful for modeling purposes and to promote a discussion about the underlying assumptions. Furthermore, we briefly discuss the underlying regulations with regard to data transparency in the energy sector. Where not otherwise stated, the data included in this report is given with reference to the year 2015 for Germany
Detecting the human fingerprint in the summer 2022 western-central European soil drought
In the 2022 summer, western-central Europe and several other regions in the northern extratropics experienced substantial soil moisture deficits in the wake of precipitation shortages and elevated temperatures. Much of Europe has not witnessed a more severe soil drought since at least the mid-20th century, raising the question whether this is a manifestation of our warming climate. Here, we employ a well-established statistical approach to attribute the low 2022 summer soil moisture to human-induced climate change using observation-driven soil moisture estimates and climate models. We find that in western-central Europe, a June-August root zone soil moisture drought such as in 2022 is expected to occur once in 20 years in the present climate but would have occurred only about once per century during preindustrial times. The entire northern extratropics show an even stronger global warming imprint with a 20-fold soil drought probability increase or higher, but we note that the underlying uncertainty is large. Reasons are manifold but include the lack of direct soil moisture observations at the required spatiotemporal scales, the limitations of remotely sensed estimates, and the resulting need to simulate soil moisture with land surface models driven by meteorological data. Nevertheless, observation-based products indicate long-term declining summer soil moisture for both regions, and this tendency is likely fueled by regional warming, while no clear trends emerge for precipitation. Finally, our climate model analysis suggests that under 2C global warming, 2022-like soil drought conditions would become twice as likely for western-central Europe compared to today and would take place nearly every year across the northern extratropics.</p
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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