Search results for " counting"
showing 10 items of 98 documents
Electronics for Application of Ion Beams in Nanoscience
2009
The breadth of ion-beam nanoscience methods discussed in the proceeding chapters implies that the control and readout systems also span a wide range of techniques. For many nanoscience and technology applications the need to process or characterise a batches of samples has lead to a convergence of data acquisition systems and control systems. This coupled with the development of high-performance lowcost computing over the past decades has lead to a progressive evolution in data acquisition technology. Historically, much of the electronics used in nanoscience and technology using ion beams is based on nuclear analogue pulse counting and spectrometry where NIM (Nuclear Instrumentation Modules…
Digital techniques for high-rate high-resolution radiation measurements
2014
Digital pulse processing (DPP) techniques are increasingly used in the development of modern spectroscopic systems. DPP systems, based on direct digitizing and processing of detector signals (preamplifier output signals), ensure higher flexibility, stability, lower dead time, higher throughput and better energy resolution than traditional pulse processing systems. In this work, we present our progress in the development of DPP systems for high-rate high-resolution radiation measurements. An innovative digital system, able to perform multi-parameter analysis (input counting rate, pulse height, pulse shape, event arrival time, etc.) even at high photon counting rates is presented. Experimenta…
Robust Conditional Independence maps of single-voxel Magnetic Resonance Spectra to elucidate associations between brain tumours and metabolites.
2020
The aim of the paper is two-fold. First, we show that structure finding with the PC algorithm can be inherently unstable and requires further operational constraints in order to consistently obtain models that are faithful to the data. We propose a methodology to stabilise the structure finding process, minimising both false positive and false negative error rates. This is demonstrated with synthetic data. Second, to apply the proposed structure finding methodology to a data set comprising single-voxel Magnetic Resonance Spectra of normal brain and three classes of brain tumours, to elucidate the associations between brain tumour types and a range of observed metabolites that are known to b…
The 15-Country Collaborative Study of Cancer Risk Among Radiation Workers in the Nuclear Industry: design, epidemiological methods and descriptive re…
2007
International audience; Radiation protection standards are based mainly on risk estimates from studies of atomic bomb survivors in Japan. The validity of extrapolations from the relatively high-dose acute exposures in this population to the low-dose, protracted or fractionated environmental and occupational exposures of primary public health concern has long been the subject of controversy. A collaborative retrospective cohort study was conducted to provide direct estimates of cancer risk after low-dose protracted exposures. The study included nearly 600,000 workers employed in 154 facilities in 15 countries. This paper describes the design, methods and results of descriptive analyses of th…
A multidisciplinary approach to the study of cultural heritage environments: Experience at the Palatina Library in Parma
2015
The aim of this paper is to describe a multidisciplinary approach including biological and particle monitoring, and microclimate analysis associated with the application of the Computational Fluid Dynamic (CFD). This approach was applied at the Palatina historical library in Parma. Monitoring was performed both in July and in December, in the absence of visitors and operators. Air microbial monitoring was performed with active and passive methods. Airborne particles with a diameter of ≥0.3, ≥0.5, ≥1 and ≥5 μm/m3, were counted by a laser particle counter. The surface contamination of shelves and manuscripts was assessed with nitrocellulose membranes. A spore trap sampler was used to identify…
Exploring the atomic structure of 1.8 nm monolayer-protected gold clusters with aberration-corrected STEM
2017
Abstract Monolayer-protected (MP) Au clusters present attractive quantum systems with a range of potential applications e.g. in catalysis. Knowledge of the atomic structure is needed to obtain a full understanding of their intriguing physical and chemical properties. Here we employed aberration-corrected scanning transmission electron microscopy (ac-STEM), combined with multislice simulations, to make a round-robin investigation of the atomic structure of chemically synthesised clusters with nominal composition Au 144 (SCH 2 CH 2 Ph) 60 provided by two different research groups. The MP Au clusters were “weighed” by the atom counting method, based on their integrated intensities in the high …
Multidimensional Integral Imaging for Sensing, Visualization, and Recognition in Degraded Environments
2019
An overview of multidimensional integral imaging for sensing, visualization, and recognition in degraded environments is presented. Applications include 3D visualization, photon starved imaging, material inspection, IR imaging, passive depth estimation, automated human gesture recognition, and long-range imaging.
Multidimensional Integral Imaging and Recognition in Degraded Environments
2018
We present an overview of our work on multidimensional integral imaging systems. Integral-imaging-based multidimensional optical sensing and imaging will be described for 3-D visualization, seeing through obscurations, material inspection, augmented reality, biomedical applications, and object recognition from microscales to long-range imaging.
The 15-Country Collaborative Study of Cancer Risk among Radiation Workers in the Nuclear Industry: Estimates of Radiation-Related Cancer Risks
2007
International audience; A 15-Country collaborative cohort study was conducted to provide direct estimates of cancer risk following protracted low doses of ionizing radiation. Analyses included 407,391 nuclear industry workers monitored individually for external radiation and 5.2 million person-years of follow-up. A significant association was seen between radiation dose and all-cause mortality [excess relative risk (ERR) 0.42 per Sv, 90% CI 0.07, 0.79; 18,993 deaths]. This was mainly attributable to a dose-related increase in all cancer mortality (ERR/Sv 0.97, 90% CI 0.28, 1.77; 5233 deaths). Among 31 specific types of malignancies studied, a significant association was found for lung cance…
False-positive I-131 whole-body imaging after I-131 therapy for a follicular carcinoma.
1997
A 57-year-old man was treated with ablative radioiodine therapy for follicular thyroid carcinoma. The post-therapeutic whole body scans detected radionuclide accumulation in the area of the right occiput at the site of a cranial defect. The defect was caused by trauma in 1964. Bone scintigraphy did not show increased uptake in this area. Magnetic resonance imaging showed porencephaly, but it did not show a metasasis.