The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Today non-destructive evaluation techniques become more and more important. Consequently, X-ray detectors are suitable tools to get information about specimens. In comparison to the already established scintillation principle, the direct converting method on the basis of semiconductor materials delivers several advantages. Hence, it is necessary to speed this measurement method and develop appropriate...
A novel algorithm for multienergy X-ray radiography systems that simultaneously estimate multiple measurements with energy diversity is presented. In contrast to conventional dual source X-ray radiography which utilizes simple weighted subtractions, the proposed algorithm aims for an accurate material decomposition of more than two materials. The numerical simulation as well as the real experiment...
Countries around the world are deploying radiation detection instrumentation to interdict the illegal shipment of radioactive material crossing international borders. These efforts include deployments in the U.S. and in a number of other countries by governments and international organizations. Most deployed radiation portal monitor systems are based on plastic scintillator for gamma-ray detection...
This paper described an infrared (IR) radiation sensor based on Film Bulk Acoustic-wave Resonator (FBAR). The resonant frequency of FBAR sensor downshifts linearly when there is IR (peak wavelength at 780nm) illumination on the device. This effect attributed to the temperature sensitivity of the FBAR. The noise equivalent temperature difference (NETD) and the detection limit for 780 nm IR of the sensor...
The purkinje fiber network (PFN) is a very important conduction system in the endocardial surface of the ventricle, whose structure is crucial in ventricular physiopathology. Traditional medical imaging methods, such as magnetic resonance imaging (MRI) or computed tomography (CT), however, fail to reveal the detailed PFN information. An alternative is to model PFN as idealized self-similar fractal...
It is introduced a novel imaging technique for medical diagnostic X-ray coherent scatter in this paper. A set of experimental equipment for X-ray coherent scatter imaging was set up with X-ray digital flat detector and medical diagnostic X-ray source. According to this equipment, the scatter images obtained are made of some circles with the same center. It is vital to calculate the energy template...
In this paper theoretical background of electromagnetic induction modeling is presented. Response function of the homogenous sphere shaped sample - for ferromagnetic and non-ferromagnetic material is introduced. Some experimental data measured on a metal detector excited by Polyharmonic signal are also presented.
High-efficiency multiple-junction detectors for thermophotovoltaic energy conversion are designed based on the series combination of different quantum cascade structures. Numerical simulations indicate that these devices can outperform existing interband solutions.
A simple nanobiosensor based on CdTe/CdS quantum dots (QDs) was designed for the direct determination of glucose with high sensitivity. Herein we demonstrated that the photoluminescence (PL) of CdTe/CdS QDs was sensitive to hydrogen peroxide (H2O2). With glucose as substrate and glucose oxidase (GOx) as catalyzer, the product, H2O2 could quench the fluorescence of QDs. Experimental results showed...
We present TubeTagger, a concept-based video retrieval system that exploits Web video as an information source. The system performs a visual learning on YouTube clips (i. e., it trains detectors for semantic concepts like "soccer" or "windmill"), and a semantic learning on the associated tags (i.e., relations between concepts like "swimming" and "water" are...
This paper gives an overview of the Medipix2 x-ray detector and its use in medical imaging, with the MARS-CT scanner (MARS, Medipix All Resolution System) as an example. The Medipix2 chip is a photon counting pixel detector with the ability of energy discrimination. It was developed at CERN and is composed of a sensor layer bump bonded to electronics layer. It has 256??256 pixels, each one covering...
An accurate analysis of radiation data is essential in many nuclear related applications. In the intelligent model assisted sensing system (iMASS) development, nuclear resonance fluorescence (NRF) spectra of radioactive isotopes are used for detection of nuclear material in cargo containers at US ports. The NRF spectrum of a particular radioactive isotope has a unique signature at unique energy levels...
X-ray imaging is of paramount importance for clinical and preclinical imaging but it is fundamentally restricted by the attenuation-based contrast mechanism, which has remained essentially the same since Roentgen's discovery a century ago. Different from the conventional method based on the attenuation contrast mechanism, X-ray phase-contrast imaging (XPCI) is proposed for the study of biological...
An ultrasonic detecting system based on LabVIEW has been devised by means of virtual technology. Its hardware has been devised by using TMS320C5402 DSP; its upper software has been developed by using LabVIEW. The communication software between ultrasonic detector and upper computer has been designed by using TCP/IP protocol. This system can realize acquisition, analysis, process and storage of ultrasonic...
The authors have demonstrated that the bias-tunability of quantum-dots-in-a-well photodetector (DWELL) FPA can be utilized for material classification. With the ongoing improvement and development of hardware and software for data acquisition and analysis, which allows for the increased bias-tunability and efficient data collection and processing, the DWELL FPA is expected to have a wide range of...
In this review paper the peculiarities of using the indium arsenide multielement CID photodetectors in multi-channel spectrometry and FPA-based infrared thermography are presented. It is shown that the short-wave narrow band infrared thermography and wide band spectrometry realized on the base of such detectors are able to solve in full measure the problems inherent to the above-mentioned scientific-technical...
One way of smuggling drugs into a country is via the postal and courier services. Automated systems are necessary to scan incoming parcels and make quick decisions on whether they contain drugs or not. Few false positive and negative results are an important requirement for the end users of such a system, as neither parcels containing drugs should be lost nor parcels without drugs should stop the...
A 1024-channel pixel array has been constructed utilizing the perforated diode neutron detector design currently produced at Kansas State University. In this design a single pixel consists of a pn-junction diode fabricated around a single trench 4 cm long, 30 microns wide and 100 microns deep. The trench is filled with 6LiF powder to provide conversion of neutrons to energetic charged particles which...
Cosima is the Geant4-based simulator of the medium-energy gamma-ray astronomy library MEGAlib. Within the MEGAlib framework, Cosima is designed to be a simple, fool-proof interface to Geant4 and to enable the simulation of most of the measurement scenarios encountered by X-ray and gamma-ray detectors in space and on Earth.
Photon counting x-ray detectors (PCXDs) with energy discrimination capabilities offer various advantages over the current intensity integrating detectors, such as improved accuracy in material decomposition, reduced image noise, reduced radiation dose, etc. The major problem of PCXDs, however, is the limited speed. The required count rate for clinical x-ray CT scanners may be 109 counts-per-second-per-square-millimeters...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.