394 research outputs found
A Light Calibration System for the ProtoDUNE-DP Detector
A LED-based fiber calibration system for the ProtoDUNE-Dual Phase (DP) photon
detection system (PDS) has been designed and validated. ProtoDUNE-DP is a 6x6x6
m3 liquid argon time-projection-chamber currently being installed at the
Neutrino Platform at CERN. The PDS is based on 36 8-inch photomultiplier tubes
(PMTs) and will allow triggering on cosmic rays. The system serves as prototype
for the PDS of the final DUNE DP far detector in which the PDS also has the
function to allow the 3D event reconstruction on non-beam physics. For this
purpose an equalized PMT response is desirable to allow using the same
threshold definition for all PMT groups, simplifying the determination of the
trigger efficiency. The light calibration system described in this paper is
developed to provide this and to monitor the PMT performance in-situ.Comment: 15 pages, 5 figure
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Is the patella apprehension test a valid diagnostic test for patellar instability? A systematic review
Introduction
Patellar instability can arise from a traumatic event with anatomical predisposing factors increasing the risk of dislocation. Accurate diagnosis is required to initiate appropriate treatment. We aimed to evaluate the patella apprehension test (PAT) as a method to diagnose patellar instability.
Methods
The PRISMA diagnostic test accuracy checklist was followed. The review protocol was registered on PROSPERO with registration number CRD42022357898. Electronic databases, currently registered studies, conference proceedings and the reference lists of included studies were searched. A narrative synthesis evaluated the validity of the PAT as a method of diagnosing patellar instability.
Results
A total of 4867 records were screened in the initial search. Of these, 34 articles satisfied the inclusion criteria, assessing 1139 knees of 1046 patients. The PAT was found to have a high sensitivity and specificity. Its intra and inter-rater reliability was highly variable among studies. Studies reporting patellar instability correction following surgery also found a decrease in the number of patients exhibiting a positive PAT.
Conclusion
Current evidence suggests that the PAT has a high sensitivity and specificity. The intra- and inter-rater validities of the PAT are widely variable due to its subjective nature. Thus, though the PAT can be used to provide a provisional clinical diagnosis of patellar instability, formal functional assessment and imaging should be performed to confirm the diagnosis. Further research should explore the association between a positive PAT and anatomical parameters. In addition, studies comparing the accuracy of the PAT and radiological investigations should be performed
Analysis of the electromagnetic radiation generated by a multipactor discharge occurring within a microwave passive component
International audienceMultipactoring is a non-linear phenomenon that appears in highpower microwave equipments operating under vacuum conditions and causes several undesirable effects. In this manuscript, a theoretical and experimental study of the RF spectrum radiated by a multipactor discharge, occurring within a realistic microwave component based on rectangular waveguides, is reported. The electromagnetic coupling of a multipactor current to the fundamental propagative mode of a uniform waveguide has been analyzed in the context of the microwave network theory. The discharge produced under a single-carrier RF voltage regime has been approached as a shunt current source exciting such a mode in a transmission-line gap-region. By means of a simple equivalent circuit, this model allows predicting the harmonics generated by the discharge occurring in a realistic passive waveguide component. Power spectrum radiated by a third order multipactor discharge has been measured in an E-plane silver-plated waveguide transformer, thus validating qualitatively the presented theory to simulate the noise generated by a single-carrier multipactor discharge
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Noise in operating theatres, is it safe?
Introduction
Noise-Induced Hearing Loss (NIHL) is a condition caused by repeated exposure to loud noise, with operating theatre personnel potentially at risk. The aims of this study were to establish the typical noise levels in orthopaedic theatres and to compare these to The Control of Noise at Work Regulations 2005.
Materials and methods
We measured the average noise levels in 40 trauma and orthopaedic surgeries in a single centre. We used the Decibel X app to take measurements, then performed corrections to ascertain noise levels at the surgeon’s ear (Leq). The daily noise exposure level for theatre staff for each procedure (LEP, d) and the LEP, d over an average 8-hour working day when performing different groups of procedures were calculated. Data were analysed using descriptive statistics, ANOVA, t-test and the Pearson coefficient of correlation.
Results
The LEP, d lower action value (80 dBA) as set by the Health and Safety Executive (HSE) was met by performing a single revision total knee replacement or a right open ankle debridement. Assuming three procedures are conducted per list, lists consisting of joint replacements (82 dBA) or medium elective procedures (81 dBA) exceed this lower limit. Additionally, lists comprising large and medium bone fractures would be within 1 dB of the limit (79 dBA and 79 dBA, respectively). Soft tissue (74 dBA), arthroscopic (73 dBA), and small bone fracture (71 dBA) procedures had the lowest LEP, d. The greatest contributors to noise levels were surgical instruments. The number of people in the room made a significant difference to noise levels (p = 0.032).
Conclusions
We have established the baseline noise levels in various orthopaedic procedures. Measures should be taken to meet UK regulations. Further research should determine suitable measures for protection from hearing damage for theatre staff and evaluate the risks high noise levels pose to patients
Uso de sensoriamento remoto na identificação de corredores ecológicos: estudo de caso da Bacia Hidrográfica do Rio Formoso, Bonito, MS.
Os corredores ecológicos são importantes estruturas ambientais com a finalidade de conservação e recuperação da biodiversidade em áreas degradadas, decorrentes do desenvolvimento humano desordenado, que favorece a fragmentação florestal e a perda da conectividade entre os diversos habitats naturais. Com a utilização do sensoriamento remoto e de sistemas de informações geográficas, esta pesquisa teve como objetivo identificar áreas com potencial para corredores ecológicos por meio de uma técnica automatizada, o que reduz o caráter pessoal na interpretação visual da imagem. Assim, realizou-se uma análise da conexão entre as Unidades de Conservação presentes na Bacia Hidrográfica do Rio Formoso, Mato Grosso do Sul, mediante a identificação das Unidades de Conservação, das Áreas de Preservação Permanente e dos fragmentos florestais remanescentes. Além disso, foi realizada uma análise da cobertura do solo
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