Imaging the dome of Santa Maria del Fiore using cosmic rays Guardincerri, E; Bacon, J D; Barros, N ...
Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences,
12/2018, Letnik:
377, Številka:
2137
Journal Article
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The dome of Santa Maria del Fiore, Florence Cathedral, was built between 1420 and 1436 by architect Filippo Brunelleschi and it is now cracking under its own weight. Engineering efforts are under way ...to model the dome's structure and reinforce it against further deterioration. According to some scholars, Brunelleschi might have built reinforcement structures into the dome itself; however, the only known reinforcement is a wood chain 7.75 m above the springing of the Cupola. Multiple scattering muon radiography is a non-destructive imaging method that can be used to image the interior of the dome's wall and therefore ascertain the layout and status of any iron substructure in it. A demonstration measurement was performed at the Los Alamos National Laboratory on a mock-up wall to show the feasibility of the work proposed, and a lightweight and modular imaging system is currently under construction. We will discuss here the results of the demonstration measurement and the potential of the proposed technique, describe the imaging system under construction and outline the plans for the measurement.This article is part of the Theo Murphy meeting issue 'Cosmic-ray muography'.
This paper describes the design and performance of a high spatial resolution positron emission tomography (PET) detector with time-of-flight capabilities. With an emphasis on high spatial resolution ...and sensitivity, we initially evaluated the performance of several 1.5 ×1.5 and 2.0 ×2.0 mm 2 and 12-15 mm long LYSO crystals read out by several appropriately sized PMTs. Experiments to evaluate the impact of reflector on detector performance were performed and the final detector consisted of a 32 ×32 array of 1.5 ×1.5 ×15 mm 3 LYSO crystals packed with a diffuse reflector and read out by a single Hamamatsu 64 channel multi-anode PMT. Such a design made it compact, modular and offered a cost-effective solution to obtaining excellent energy and timing resolution. To minimize the number of readout signals, a compact front-end readout electronics that summed anode signals along each of the orthogonal directions was also developed. Experimental evaluation of detector performance demonstrates clear discrimination of the crystals within the detector. An average energy resolution (FWHM) of 12.7 ±2.6% and average coincidence timing resolution (FWHM) of 348 ps was measured, demonstrating suitability for use in the development of a high spatial resolution time-of-flight scanner for dedicated breast PET imaging.
A new comprehensive method for assessing Enhanced Low Dose Rate Sensitivity (ELDRS) in bipolar transistors to be used for very high total doses is applied to an advanced SiGe HBT technology for its ...use in the ATLAS Upgrade at CERN. Conventional ELDRS assessment methods are combined with switched experiments (high/low dose rate), providing a way to verify the presence of ELDRS at very high doses in reasonable irradiation time. Additionally, an anomalous damage recovery has been found in transistors with saturated damage after further low dose rate irradiations.
•It has been demonstrated that the bipolar technology under study does not show ELDRS in the whole range of total doses studied.•The previous radiation hardness tests of a SiGe HBT technology have been validated.•A new ELDRS test strategy is presented for ELDRS in very high total dose applications.•An anomalous damage recovery has been observed in switched dose rate experiments in the saturation region.
Summary Background Treatment-resistant major depression is common and potentially life-threatening in elderly people, in whom little is known about the benefits and risks of augmentation ...pharmacotherapy. We aimed to assess whether aripiprazole is associated with a higher probability of remission than is placebo. Methods We did a randomised, double-blind, placebo-controlled trial at three centres in the USA and Canada to test the efficacy and safety of aripiprazole augmentation for adults aged older than 60 years with treatment-resistant depression (Montgomery Asberg Depression Rating Scale MADRS score of ≥15). Patients who did not achieve remission during a pre-trial with venlafaxine extended-release (150–300 mg/day) were randomly assigned (1:1) to the addition of aripiprazole (target dose 10 mg maximum 15 mg daily) daily or placebo for 12 weeks. The computer-generated randomisation was done in blocks and stratified by site. Only the database administrator and research pharmacists had knowledge of treatment assignment. The primary endpoint was remission, defined as an MADRS score of 10 or less (and at least 2 points below the score at the start of the randomised phase) at both of the final two consecutive visits, analysed by intention to treat. This trial is registered with ClinicalTrials.gov , number NCT00892047. Findings From July 20, 2009, to Dec 30, 2013, we recruited 468 eligible participants, 181 (39%) of whom did not remit and were randomly assigned to aripiprazole (n=91) or placebo (n=90). A greater proportion of participants in the aripiprazole group achieved remission than did those in the placebo group (40 44% vs 26 29% participants; odds ratio OR 2·0 95% CI 1·1–3·7, p=0·03; number needed to treat NNT 6·6 95% CI 3·5–81·8). Akathisia was the most common adverse effect of aripiprazole (reported in 24 26% of 91 participants on aripiprazole vs 11 12% of 90 on placebo). Compared with placebo, aripiprazole was also associated with more Parkinsonism (15 17% of 86 vs two 2% of 81 participants), but not with treatment-emergent suicidal ideation (13 21% of 61 vs 19 29% of 65 participants) or other measured safety variables. Interpretation In adults aged 60 years or older who do not achieve remission from depression with a first-line antidepressant, the addition of aripiprazole is effective in achieving and sustaining remission. Tolerability concerns include the potential for akathisia and Parkinsonism. Funding National Institute of Mental Health, UPMC Endowment in Geriatric Psychiatry, Taylor Family Institute for Innovative Psychiatric Research, National Center for Advancing Translational Sciences, and the Campbell Family Mental Health Research Institute.
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