Search results for "CCD"
showing 10 items of 24 documents
Gamma-ray irradiation tests on CCD and CMOS sensors used in imaging techniques
2012
Technologically-enhanced electronic devices are used in various fields as space imaging or diagnostic techniques in medicine. The devices can be exposed to intense radiation fluxes over time which may impair the functioning of the same apparatus, in particular in space applications. In this paper we report the results of a gamma irradiation tests on imaging sensors simulating the space radiation over a long time period. Two types of sensors are taken into consideration: CCD (Charge-Coupled Device) sensors and CMOS based on technology MOS (Metal Oxide semiconductor) used for the realization of transistors widely used in consumer electronics. The devices are supplied by Techno System (Italy),…
Radiometric and geometric evaluation of the capabilities of the new airborne digital photogrammetric sensors
2008
In this paper the theoretic and practical points of view about the applications of the modern digital airborne sensors in the photogrammetry and remote sensing fields are described. The first part of the paper describes the theoretic matter, the second one shows the first results regarding the carried out elaborations on an image of Palermo acquired by digital airborne sensor LH System ADS40. Besides the research has examined most of sides regarding the trilinear sensor and it has highlighted the capabilities and limitations respect to the traditional analogical system and the matricial CCD sensor.
Design, upgrade and characterization of the silicon photomultiplier front-end for the AMIGA detector at the Pierre Auger Observatory
2021
The successful installation, commissioning, and operation of the Pierre Auger Observatory would not have been possible without the strong commitment and effort from the technical and administrative staff in Malargue. We are very grateful to the following agencies and organizations for financial support: Argentina -Comision Nacional de Energia Atomica; Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET); Gobierno de la Provincia de Mendoza; Municipalidad de Malargue; NDM Holdings and Valle Las Lenas; in gratitude for their continuing cooperation over land access; Australia -the Australian Research Council; Braz…
Study of drilling and welding laser : dynamics of keyhole
2011
The aim of the present work is to study experimentally the formation of the capillary during the drilling and welding by laser beam and to develop the numerical simulation which allows following the dynamics and the evolution of the keyhole. The zinc was chosen as a test material because its thermodynamical properties are well known. To simplify the problem, in the first place the drilling mechanism was studied. Two experimental methods were used to characterize the evolution of the keyhole: the Direct Observation of Drilled Hole method, which allows the visualization of the keyhole after the application of laser pulses of different durations, and Zn-Quartz method, which allows the direct o…
Parameters for automated star identification
2014
The determination of parameters for identifying stars sensed by charge-coupled device (CCD) is discussed. Numerical experiments are summarized which support the parameter space bound estimation practicality of the proposed star pattern recognition and identification by matching with coordinate list in star catalogue. The parameter analysis performed to apply them for proper identification algorithm which is developed and used at the Institute of Geodesy and Geoinformatics. This algorithm is applied for identification of large volume star sets.
Update of the statements on biology and clinical impact of occult hepatitis B virus infection
2019
In October 2018 a large number of international experts with complementary expertise came together in Taormina to participate in a workshop on occult hepatitis B virus infection (OBI). The objectives of the workshop were to review the existing knowledge on OBI, to identify issues that require further investigation, to highlight both existing controversies and newly emerging perspectives, and ultimately to update the statements previously agreed in 2008. This paper represents the output from the workshop.
Hepatitis B virus maintains its pro-oncogenic properties in the case of occult HBV infection.
2003
Background & Aims: Occult hepatitis B virus (HBV) infection is characterized by persistence of HBV DNA into the tissue of hepatitis B surface antigen-negative individuals. The clinical relevance of this peculiar infection is still under debate. In particular, the impact of occult HBV infection in cases of hepatocellular carcinoma (HCC) is uncertain. We investigated the prevalence and molecular status of occult HBV in patients with HCC. Methods: We tested tumor tissues from 107 patients with HCC and the corresponding nontumor liver tissue from 72 of these patients for HBV DNA. We also examined liver specimens from 192 patients with chronic hepatitis. All cases were hepatitis B surface antige…
The FRAM robotic telescope for atmospheric monitoring at the Pierre Auger Observatory
2021
FRAM (F/Photometric Robotic Atmospheric Monitor) is a robotic telescope operated at the Pierre Auger Observatory in Argentina for the purposes of atmospheric monitoring using stellar photometry. As a passive system which does not produce any light that could interfere with the observations of the fluorescence telescopes of the observatory, it complements the active monitoring systems that use lasers. We discuss the applications of stellar photometry for atmospheric monitoring at optical observatories in general and the particular modes of operation employed by the Auger FRAM. We describe in detail the technical aspects of FRAM, the hardware and software requirements for a successful operati…
Impact of Pressurized Liquid Extraction and pH on Protein Yield, Changes in Molecular Size Distribution and Antioxidant Compounds Recovery from Spiru…
2021
The research aims to extract nutrients and bioactive compounds from spirulina using a non-toxic, environmentally friendly and efficient method—Pressurized Liquid Extraction (PLE). In this work, Response Surface Methodology (RSM)–Central Composite Design (CCD) was used to evaluate and optimize the extraction time (5–15 min), temperature (20–60 °C) and pH (4–10) during PLE extraction (103.4 bars). The multi-factor optimization results of the RSM-CCD showed that under the pressure of 103.4 bars, the optimal conditions to recover the highest content of bioactive compounds were 10 min, 40 °C and pH 4. Furthermore, the compounds and antioxidant capacity of PLE and non-pressurized extraction extra…
Noise estimation from digital step-model signal
2013
International audience; This paper addresses the noise estimation in the digital domain and proposes a noise estimator based on the step signal model. It is efficient for any distribution of noise because it does not rely only on the smallest amplitudes in the signal or image. The proposed approach uses polarized/directional derivatives and a nonlinear combination of these derivatives to estimate the noise distribution (e.g., Gaussian, Poisson, speckle, etc.). The moments of this measured distribution can be computed and are also calculated theoretically on the basis of noise distribution models. The 1D performances are detailed, and as our work is mostly dedicated to image processing, a 2D…